KR102122709B1 - High pressure fuel pump comprising an outlet valve arranged between a conveyor chamber and an outlet - Google Patents

Abstract

The present invention is a high pressure comprising a discharge valve (32) disposed between the delivery chamber (42) and the discharge section (30), and a pressure limiting valve (54) disposed between the discharge section (30) and the delivery chamber (42). It relates to a fuel pump (10). According to the invention, the discharge valve 32 and the pressure limiting valve 54 include a common valve seat body 58.

Description

High pressure fuel pump with a discharge valve disposed between the delivery chamber and the discharge section{HIGH PRESSURE FUEL PUMP COMPRISING AN OUTLET VALVE ARRANGED BETWEEN A CONVEYOR CHAMBER AND AN OUTLET}

The present invention relates to a high pressure fuel pump according to the preamble of claim 1.

In the market, a fuel system for an internal combustion engine is known which includes a high pressure fuel pump capable of delivering the required amount of fuel into a fuel accumulator or fuel distributor at a predetermined pressure. High pressure fuel pumps generally include multiple valves. For example, this high pressure fuel pump is implemented as a piston insertion pump.

An object of the present invention is to combine a discharge valve and a pressure limiting valve of a high pressure fuel pump and place them in a common housing.

This problem is solved by the high pressure fuel pump according to claim 1. Preferred embodiments are presented in the dependent claims. Features that are important to the invention are shown in the following description and drawings, which may be important to the invention alone and in various combinations.

The present invention has the advantage that the discharge valve and the pressure limiting valve of the high pressure fuel pump are combined and arranged in a common housing. In this case, since the required number of members is reduced, the cost can be reduced. For example, the discharge valve and the pressure limiting valve can be embodied in only six members in some cases. In particular, the sealing seat of the combined discharge valve and pressure limiting valve ("valve device") according to the invention can be arranged on a common valve seat body. The valve elements or valve body of the valve device can be guided radially in a common housing in a simple manner.

In addition, the members of the combined discharge valve and pressure limiting valve according to the present invention can be realized by relatively simple stamping and deep drawing parts. Due to this, the valve members (“closed members”) and the remaining parts of the valve device can be realized with a relatively small mass. Since the valve device according to the present invention requires a relatively small installation space, improved flexibility can be given in the construction of the high pressure fuel pump. In particular, a valve arrangement with a short axial length (“installation length”) can be implemented.

Further, with the valve arrangement at least partially assembled, the limit of the maximum allowable fuel pressure for the pressure limiting valve can be adjusted during assembly "outside", ie before the final assembly of the pressure limiting valve in the fuel pump. For this reason, since the addition of the value when an error occurs is relatively small, the assembly error cost can be reduced. This is especially the case when the discharge valve and pressure limiting valve are combined and placed in the outlet connection (which can be manufactured as a separate part) of the high pressure fuel pump.

In addition, since the valve device according to the present invention has a relatively small dead space, the transmission power (“volume efficiency”) of the high-pressure fuel pump can be increased. The assembly or final assembly of the combined discharge valve and pressure limiting valve can be made relatively simple and inexpensive. In particular, the valve device according to the present invention can be implemented without the use of a material bonding method.

The present invention relates to a high-pressure fuel pump including a discharge valve disposed between the delivery chamber and the discharge portion, and a pressure limiting valve disposed between the discharge portion and the delivery chamber. According to the invention, the discharge valve and the pressure limiting valve comprise a common valve seat body. Due to this, the high-pressure fuel pump according to the present invention can be produced relatively small, simple and economically. In particular, fewer and simple members are required due to the common valve seat body. Preferably, the valve seat body is disposed centrally between the discharge valve and the pressure limiting valve, and includes sealing seats required for the discharge valve or the pressure limiting valve, respectively, in the two end sections or opposite end faces arranged oppositely. The hydraulic perfusion of the discharge valve can be achieved, for example, through a through hole disposed in the center, and the hydraulic perfusion of the pressure-limiting valve can be through, for example, one or more through holes disposed in a radially outer region of the valve seat body. It can be done.

If the discharge valve and the pressure limiting valve are arranged substantially coaxial with each other, a place saving arrangement is made in particular. Preferably, at least some members of the discharge valve and the pressure limiting valve and the housing comprising the discharge valve and the pressure limiting valve are implemented substantially rotationally symmetrically or radially symmetrically. Due to this, the discharge valve and the pressure limiting valve together can be manufactured very small, simple and economically.

The function of the pressure limiting valve can be improved when the pressure limiting valve comprises a ring-shaped valve member. Due to this, the pressure limiting valve can be implemented particularly efficiently and simply.

Additionally, the pressure limiting valve can include a leaf spring as a valve spring. The leaf spring-for example as a sheet spring-can be manufactured relatively simply and has a small installation space. Nevertheless, a relatively large force can be created for the prestress of the pressure limiting valve.

In one embodiment of the high pressure fuel pump, the pressure limiting valve includes a valve member integrally formed with the leaf spring. For example, a leaf spring ("spring") is formed as a bent or corrugated ring spring. The circumferential section of the leaf spring can act as a valve body and cooperate with the valve seat in a common valve seat body. Due to this, the pressure-limiting valve can be manufactured particularly simply and economically, and especially contains fewer individual parts.

In addition, in the housing including the discharge valve and the pressure limiting valve, a first spring support portion in which the spring of the discharge valve is supported is disposed, and a second spring support in which the spring of the pressure limiting valve is supported is disposed in the housing. The first and second spring supports are substantially ring-shaped. Preferably, the radially outer region of the first or second spring support is pressed in the corresponding radially inner region of the housing. In this embodiment, the first and second spring supports are members separated from the housing, respectively, and can be embodied in particular simply, for example, as a ring-shaped, disk with a hole. In addition, the first and second spring supports can each be press-fit in a defined axial size, for example, each spring force can be adjusted during assembly.

Additionally, the spring of the discharge valve can be a helical spring. Spiral springs have a larger number of springs compared to leaf springs and can be designed with corresponding durability.

In another embodiment of the high pressure fuel pump, the valve body of the discharge valve is embodied in a port shape, and the spring of the discharge valve provides pressure to the bottom of the valve body in the radial direction of the valve body. This results in a particularly simple and reliable embodiment of the discharge valve, with the valve body and the spring constantly being positioned in a defined position relative to each other.

In another embodiment of the high pressure fuel pump, a radially outer section of the valve body is guided radially within a portion of the valve seat body. This results in a coaxial arrangement of the members of the discharge valve in a particularly simple manner, providing a secure sealing seating of the valve body to the valve seat.

In an alternative embodiment to this, in the high-pressure fuel pump, the radially outer section of the valve body is guided radially in a guide member disposed separately from the valve seat body. Due to this, a valve seat body having a simpler shape can be realized, and cost can be reduced. The separately arranged guide member expands the structural possibilities in the formation of the discharge valve.

The high pressure fuel pump according to the present invention is constructed particularly simply when the combined discharge valve and pressure limiting valve are integrated in the outlet connection of the high pressure fuel pump. Due to this, the discharge valve and the pressure limiting valve are arranged in a particularly space-saving manner. From a functional point of view, the arrangement of the discharge valve and the pressure limiting valve near the outlet of the high pressure pump is particularly preferred. Finally, the discharge valve and the pressure limiting valve must be assembled at the end of assembly when assembling the outlet connection.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.

1 is a schematic cross-sectional view of a high pressure fuel pump implemented in accordance with the prior art substantially for a fuel system of an internal combustion engine.
Figure 2 is an axial cross-sectional view of the outlet connection of the high-pressure fuel pump according to the present invention comprising a combination discharge valve and a pressure limiting valve.
3 is an enlarged cross-sectional view of a combination discharge valve and a pressure limiting valve similar to FIG. 2;
4 is a cross-sectional view of an alternative embodiment to FIG. 3 of a combination discharge valve and a pressure limiting valve.
5 is a perspective view of a valve member integrally formed with a leaf spring of a pressure limiting valve with a portion of the valve seat body.

In all figures, functionally equivalent members and sizes are denoted by the same reference numerals in different embodiments.

1 shows a high-pressure fuel pump 10 of a fuel system for an internal combustion engine (not shown) in a schematic sectional view. The high pressure fuel pump 10 of FIG. 1 substantially corresponds to the prior art, but some members related to the present invention are shown at least symbolically in FIG. 1. 2 to 5 show the present invention in detail.

The high pressure fuel pump 10 includes a pump housing 12, and in the drawing of the pump housing, an electromagnet 14 including a coil 16, an armature 18, and an armature spring 20 is provided in the left part. Is placed. In addition, the high-pressure fuel pump 10 is connected to the low-pressure line 22 and the inlet 24 with an inlet valve 26, and the outlet with a discharge valve 32 connected to the high-pressure line 28 30. The discharge valve 32 includes a valve body 33 and a spring 35 here implemented as a helical spring. The discharge part connection part 34 is disposed in the discharge part 30.

In addition, the high pressure fuel pump 10 includes a pressure limiting valve 54 indicated by a circuit symbol in the upper right area of FIG. 1. The pressure limiting valve will be described in detail in FIGS. 2 to 5. The pressure limiting valve 54 can be opened toward the delivery chamber 42 as opposed to the delivery direction of the high pressure fuel pump 10 determined by the discharge valve 32.

The inlet valve 26 includes a valve spring 36 and a valve body 38. The valve body 38 is horizontally movable in the drawing and can be moved by a valve needle 40 connected to the armature 18. When current is supplied to the electromagnet 14, the inlet valve 26 may be closed by the force of the valve spring 36. If no current is supplied to the electromagnet 14, the inlet valve 26 may be forced open by the force of the armature spring 20, or it may be forced to remain open.

In the delivery chamber 42, the piston 44 is arranged to be vertically movable as seen in the drawing. The piston 44 can be moved here within the cylinder 50 through the roller 46 by an elliptical cam 48. The cylinder 50 is formed in a part of the pump housing 12. The inlet valve 26 is hydraulically connected to the delivery chamber 42 through the opening 52.

In the operating state of the high-pressure fuel pump 10, the pump delivers the fuel from the inlet 24 to the outlet 30. The discharge valve 32 is opened and closed according to the difference in hydraulic pressure between the delivery chamber 42 and the discharge portion 30 and the force of the spring 35. The inlet valve 26 is operated by the pressure difference between the inlet 24 and the outlet chamber 42 when fully delivered, but is also operated by the valve needle 40 or the electromagnet 14.

In the case of certain partial delivery, the current is supplied to the electromagnet 14 from a certain point during the delivery stroke, so that the inlet valve 26 can be closed and the fuel still present in the delivery chamber 42 is fed back into the low pressure line 22. It is not sent out but into the high pressure accumulator (not shown) (not shown) through the discharge section 30. The volume of the high-pressure fuel pump 10 disposed inside the pump housing 12 is substantially filled with fuel.

2 shows an axial sectional view of the outlet connection 34 of the high pressure fuel pump 10. The discharge valve 32 and the pressure limiting valve 54 are integrated in the discharge connection 34 and are arranged in combination with each other. The discharge valve 32 and the pressure limiting valve 54 are arranged substantially coaxial with each other. The outlet connection 34 is also referred to as the housing 56 hereinafter.

Here, the members shown in FIG. 2 are implemented substantially rotationally symmetrically or radially symmetrical about the longitudinal axis 55. Members important to the function of the combined discharge valve 32 and the pressure limiting valve 54 are arranged in the left part of FIG. 2. During normal operation (closing the pressure limiting valve), the delivery of fuel is substantially from left to right in FIG. 2.

The discharge valve 32 and the pressure limiting valve 54 include a common valve seat body 58, the valve seat body being in the drawing approximately axially pressure limiting valve 54 (left) and discharge valve 32; Right). The valve seat body 58 has a substantially cylindrical basic shape and is preferably disposed within the housing 56 in a pressure-fitting manner. Alternatively, the valve seat body 58 may be disposed within the housing 56 in a material-fitting manner or in a shape-fitting manner.

A cylindrical hole 59 is disposed in the valve seat body 58 at the center in the axial direction, and the hole 59 includes a portion having a diameter that is rapidly increased in the right portion as viewed in the drawing, so that a step hole is formed. The ported valve body 33 of the discharge valve 32 is disposed in a portion having a rapidly enlarged diameter, and the radially outer section of the valve body 33 is of a portion having a rapidly enlarged diameter of the valve seat body 58. It is guided in the radial direction by the radial inner wall.

The spring 35 of the discharge valve 32 formed as a helical spring inside the radial direction of the port-type valve body 33 is arranged concentrically with respect to the remaining members. As the axial end section of the spring 35, as seen in the drawing, is supported on the bottom 64 of the ported valve body 33, the spring 35 sees the pressure on the bottom 64 in the drawing. When serving towards the left.

In addition, the valve seat body 58 includes a sealing seat 66 embodied as a ring-shaped web, in which the bottom 64 of the port-type valve body 33 with respect to the sealing seat 66 is axially spring 35 ). 2, the right end section of the spring 35 is supported by the first spring support 68.

In the axial end section on the left side as seen in FIG. 2 of the valve seat body 58, in the operating state shown here, the ring-shaped valve member 70 of the pressure limiting valve 54 contacts the sealing seat 78. The ring-shaped valve member 70 is embodied as a substantially cylindrical disk with a hole in the center. The outer diameter of the ring-shaped valve member 70 corresponds approximately to the radial inner diameter of the housing 56. There is at least a small radial gap between the ring-shaped valve member 70 and the housing 56 so that the ring-shaped valve member 70 is axially movable within the housing 56 according to the function of the pressure limiting valve 54. .

In FIG. 2, the valve spring of the pressure limiting valve 54 is disposed on the left side of the ring-shaped valve member 70 in the form of a leaf spring 72. Here the leaf spring 72 is embodied as a substantially curved cylindrical and disc with a hole in the center. In the drawing, a second spring support 74 is disposed on the left side of the leaf spring 72. Thus, the leaf spring 72 creates a pressure between the second spring support 74 and the ring-shaped valve member 70, and the valve member 70 is pressed against the sealing seat 78 by the pressure.

In the cross-sectional view of FIG. 2, two axial fluid channels 80 are shown in the valve seat body 58, which are disposed in a substantially central area in the radial direction of the valve seat body 58. In the state of the device shown in Figure 2, the axial fluid channels 80 are closed by a ring-shaped valve member 70 in one side.

The spring supports 68 and 74 are implemented in a substantially “ring-like” shape as a cylindrical disk with holes, and the radially outer sections of the spring supports 68 and 74 correspond to the corresponding radial direction of the housing 56 It is placed in the inner section, where it is pressed. The central hole allows fuel perfusion.

In the normal operation of the high pressure fuel pump 10, the discharge valve 32 according to FIG. 2 operates in a similar manner to FIG. 1. In the delivery stroke of the high pressure fuel pump 10, if the fuel pressure in the delivery chamber 42 is greater than the fuel pressure in the high pressure line 28 (plus the force of the spring 35), the ported valve body 33 is a valve From the sealing seat 66 on the seat body 58 it can be separated towards the right as seen in the drawing, so that the discharge valve 32 is opened.

In this case, the hydraulic connection between the delivery chamber 42 and the high-pressure line 28 and the resulting delivery of fuel takes place as follows: through the central opening of the second spring support 74, then the leaf spring 72 ) Through the central opening, then through the central opening in the ring-shaped valve member 70, then through the central opening in the valve seat body 58, and then outside the ported valve body 33 The first spring support (axially and through a radial gap formed radially inside the valve seat body 58, then into the radially inner portion of the spring 35, and then in the axial direction Through the central opening in 68, then in the form of a substantially nozzle of the outlet connection 34, i.e. through a hollow chamber inside the radially formed cylindrically and cylindrically and finally into the high pressure line 28.

If the pressure in the delivery chamber 42 is less than the pressure in the high pressure line 28 plus the force of the spring 35, the discharge valve 32 can be closed. The bottom 64 of the pot-shaped valve body 33 strikes the valve seat body 58 against the ring-shaped sealing seat 66. In this state, both the discharge valve 32 and the pressure limiting valve 54 are closed.

In the case of an operation different from the normal operation of the high pressure fuel pump 10, the fuel pressure in the high pressure line 28 is the pressure in the delivery chamber 42 and the force exerted on the ring-shaped valve member 70 by the leaf spring 72. If is greater than the value added, the ring-type valve member 70 can be opened from the sealing seat 78, thereby opening the pressure limiting valve 54.

The flow of fuel in this case is as follows: from the right in the figure through the central inner opening of the first spring support 68, then radially outward through the spring 35, then axially the valve seat Through the fluid channel 80 of the body 58, then past the separated ring-shaped valve member 70, radially inward, and then through the central opening in the ring-shaped valve member 70, then the plate It flows through the central opening in the spring 72, then through the central opening in the second spring support 74 and finally into the delivery chamber 42.

Briefly, the pressure limiting valve 54 is opened when the fuel pressure in the region of the discharge section 30 exceeds a predetermined allowable maximum value, and then the pressure limiting valve 54 is opened if the fuel pressure does not exceed the maximum value. Is closed. Since the valve body 33 is formed in a port shape and the ring-shaped valve member 70 is disc-shaped, the two members have a relatively small mass, so the discharge valve 32 and the pressure limiting valve 54 are relatively quickly. It can be open or closed.

FIG. 3 shows an embodiment of a combination outlet valve 32 and a pressure limiting valve 54, similar to the embodiment according to FIG. 2. Unlike the embodiment according to FIG. 2 in which the members are assembled from the left in the drawing, in the embodiment according to FIG. 3 the members of the combined discharge valve 32 and the pressure limiting valve 54 are assembled from the right in the drawing. This is made possible by the housing 56 here having a axial opening in the left end section in the drawing according to FIG. 3 and having a partially reduced diameter. In this case, the leaf spring 72 is supported on the inner end surface of the housing 56 unlike FIG. 2.

The housing 56 includes radial inner diameter ends in the area on the right in the figure. Due to this, the members of the combined discharge valve 32 and the pressure limiting valve 54 are limited in the axial direction and can be assembled from the right in the drawing. The rest of the arrangement and configuration of the members of FIG. 3 substantially correspond to those of FIG. 2.

4 shows another embodiment of the combination discharge valve 32 and the pressure limiting valve 54 based on FIG. 3. In particular, the valve body 58 in the embodiment according to FIG. 4 has a simplified shape with respect to FIGS. 2 and 3. In this case, there is no radial bore jump of the central hole 59 in the valve seat body 58. Even in the embodiment according to FIG. 4, the sealing seat 66 of the discharge valve 32, which is implemented as a ring-shaped web, is arranged on the right end face of the valve seat body 58, as seen in the figure.

Unlike FIGS. 2 and 3, in FIG. 4 there is a guide member 76 disposed separately from the valve seat body 58, the radially outer section of the valve body 33 radiates within the guide member 76 Guided in the direction. Here, the guide member 76 is only schematically shown. In particular, fixing of the guide member 76 to the housing 56 is not shown for convenience.

The remaining members of the combined discharge valve 32 and pressure limiting valve 54 correspond to those of FIGS. 2 and 3. The functions of the combined discharge valve 32 and pressure limiting valve 54 according to FIG. 4 are similar to those of FIGS. 2 and 3.

FIG. 5 shows a perspective view of a valve member 70 integrally formed with a leaf spring 72 of a pressure limiting valve 54 with a briefly illustrated axial section of the valve seat body 58. Unlike in the embodiment according to FIGS. 2 to 4, the leaf spring 72 in this case additionally functions as a ring-shaped valve member 70 and thus “directly acts” with respect to the valve function. To this end, the leaf spring 72 comprises two sealing sections embodied in a substantially cylindrical shape (indicated by the reference numeral "70" in FIG. 5), wherein the sealing sections are two axial fluids in the valve seat body 59 The channel 80 can be closed.

In the closed state of the pressure limiting valve 54, the leaf spring 72 strikes the sealing seat 78 of the valve seat body 58 only with a substantially cylindrical sealing section. If the fuel pressure in the high pressure line 28 is greater than the fuel pressure in the delivery chamber 42 plus the axial force provided by the leaf spring 72, the two cylindrical sealing sections of the leaf spring 72 are sealed sheets. By being separated from 78, force flow from high pressure line 28 to delivery chamber 42 is enabled.

10 high pressure fuel pump
30 outlet
32 drain valve
33 valve body
34 Outlet connection
35 spring
42 delivery chamber
54 pressure limiting valve
58 pressure seat body
64 floor
68, 74 spring support
70 valve member
72 leaf spring
76 Guide absence

Claims (11)

High pressure fuel comprising a discharge valve (32) disposed between the delivery chamber (42) and a discharge section (30), and a pressure limiting valve (54) disposed between the discharge section (30) and the delivery chamber (42). In the pump 10,
The discharge valve 32 and the pressure limiting valve 54 include a common valve seat body 58,
The pressure limiting valve 54 includes a valve member 70 formed integrally with the leaf spring 72,
The valve body 33 of the discharge valve 32 is embodied in a port shape, and the spring 35 of the discharge valve 32 is a bottom of the valve body 33 in the radial direction of the valve body 33 High pressure fuel pump characterized in that it provides pressure to the (64). The high pressure fuel pump according to claim 1, wherein the discharge valve (32) and the pressure limiting valve (54) are disposed substantially coaxial with each other. The high pressure fuel pump according to claim 1 or 2, characterized in that the pressure limiting valve (54) comprises a ring-shaped valve member (70). delete delete The first spring according to claim 1 or 2, wherein a spring (35) of the discharge valve (32) is supported in a housing (56) including the discharge valve (32) and the pressure limiting valve (54). A support portion 68 is disposed, a second spring support portion 74 in which the spring 72 of the pressure limiting valve 54 is supported is disposed in the housing 56, and the first and second spring support portions 68 are disposed. , 74) is a high-pressure fuel pump, characterized in that substantially implemented in a ring shape. The high pressure fuel pump according to claim 6, wherein the spring (35) of the discharge valve (32) is a helical spring. delete The high pressure fuel pump according to claim 1, characterized in that a radially outer section of the valve body (33) is guided radially within a portion of the valve seat body (58). The high-pressure fuel pump according to claim 1, characterized in that the radially outer section of the valve body (33) is guided radially within a guide member (76) disposed separately from the valve seat body (58). The high pressure fuel pump according to claim 1 or 2, characterized in that the combined discharge valve (32) and the pressure limiting valve (54) are integrated in the outlet connection (34) of the high pressure fuel pump (10).

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