EP3019736A1

EP3019736A1 - Tappet tip geometry for a pressure control valve

Info

Publication number: EP3019736A1
Application number: EP14736826.0A
Authority: EP
Inventors: Elmar Vier
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2013-07-09
Filing date: 2014-07-08
Publication date: 2016-05-18
Also published as: DE102013213419A1; JP2016520766A; CN105358820A; WO2015004140A1; US20160153319A1

Abstract

The invention relates to a tappet element (2), in particular for a pressure control valve (4), comprising a tappet body (2a), in particular an elongated tappet body. The tappet body has a first side (2b), a second side (2c), and a centre axis (2d). A tappet tip (14) is formed on the first side (2a), which tappet tip is designed to contact a valve ball (6). A driving device (10) for the tappet element (2) can be provided on the second side (2c). The tappet tip (14) has a recess (12) for contacting a valve ball (6). The tappet element is characterised in that the recess (12) has a first region (16a) and a second region (16b), the two regions (16a, b) being arranged concentrically with respect to the centre axis (2d); and a valve ball (6) being movable (18a) on the surface (22a) of the recess (12) substantially in a radial direction (20a) perpendicular to the centre axis (2d) in the first region (16a); and a valve ball (6) being movable (18b) on the surface (22b) of the recess (12) substantially in a combined motion both in the radial direction (20a) and in an axial direction (20b) in the second region (16b).

Description

PUNCH GEOMETRY FOR A PRESSURE CONTROL VALVE

The present invention relates to engine technology for vehicles. In particular, the present invention relates to pressure control valves for diesel injection systems. More particularly, the present invention relates to a novel

Plunger element or a novel plunger tip geometry for a

Pressure control valve.

State of the art

Pressure control valves are used, inter alia, in engine technology in the context of diesel engines for the direct injection of fuel. In particular, a pressure regulating valve is used in the context of common rail diesel systems. In this case, a high pressure pump ensures the maintenance of a fuel pressure in a manifold. A pressure control valve is now provided to adjust and maintain the pressure in the rail depending on the setpoint pressure in the control unit. In this case, a valve ball is usually pressed by means of magnetic force in a valve seat to close the valve.

Pressure control valves in diesel injection systems based on a common rail, also known as pressure control valve (PCV), are used to set and limit the rail pressure. The basic construction contains a valve seat or a valve body, which by a spherical

Closing element, the valve ball, can be opened or closed. The valve ball is actuated by a valve stem guided in the valve stem, which is part of a magnetic circuit, through the energization of which

Actuating force of the valve stem is generated.

Figures la, b show the schematic structure of a conventional pressure control valve. Pressure control valve 4 has a plunger element 2, which has a plunger tip 14 on a first side 2b, which presses a valve ball 6 into a valve seat 24 and thereby closes the pressure control valve 4. The plunger element 2 itself has an elongate plunger body 2a with a central axis 2d. On a second side 2c, a drive device 10 is arranged. Such

Drive device 10 may for example be a magnetic drive, which in the active state, starting from the representation in Figures la, b the

Moves plunger element 2 in the direction of the valve ball 6 and thereby presses them into the valve seat 24. In a pressure regulating valve conventionally produced valve body 8a is introduced into the valve housing 8b and fixed there, for example, pressed or, as shown in Figure lb, flanged.

With continued reference to FIGS. 2a, b, exemplary embodiments of a plunger tip 14 of a conventional pressure control valve will be described.

FIG. 2 a shows a tappet tip 14 with a substantially planar outer surface or end region 22. FIG. 2 b shows a recess 12, which conventionally has a circular depression with a defined radius

is trained on. The plunger tip 14 according to FIG. 2a is thus

plane ground, while the plunger tip 14 of Figure 2b has a recess 12 in the form of a ball stamping.

Referring still to Figures 3a, b, the arrangement of a valve ball 6 on a conventional plunger tip 14 is indicated.

FIG. 3a shows the original geometry of a flat-ground plunger tip with the valve ball, which permits a radial tolerance compensation, but is not noise-optimized. In this case, the valve ball 6 lies substantially at a contact point on the outer surface 22 of the plunger tip 14. 3 b shows a "ball-in-ball" constellation which offers noise advantages, but causes a change in the axial position due to the ball surface of the recess when the radial play of the components is compensated. wherein regularly the radius of the recess 12, at least slightly, is formed larger than the radius of the valve ball 6. This also provides a substantially point-shaped support of the valve ball 6 on or in the recess 12. In the flat ground plunger tip 3a, valve ball 6 can deflect radially, thus to the left or to the right in FIG. 3a, without a length difference in the axial direction occurring and without substantially influencing the transmission of an axial force, in FIG. 3a, a downward force. In FIG. 3b, in turn, the valve ball 6 can also move slightly to the left or to the left.

on the right, thus dodge radially with respect to the central axis 2d, but due to the spherical shape of the recess 12 can be pulled back to the central axis 2d under axial load or changed in radial displacement, the axial position of the plunger tip and thus detunes. a magnetic circuit of the drive unit.

Disclosure of the invention

One aspect of the present invention can thus be seen to provide a plunger element for a pressure regulating valve that is adapted to compensate for inaccuracies in the radial direction to a certain extent without changing the axial position.

Accordingly, a tappet member for a pressure regulating valve, a pressure regulating valve for a vehicle, especially an automobile, a motor element for a vehicle and a vehicle, in particular automobile, according to the independent

Claims are displayed. Preferred embodiments will be apparent from the dependent claims.

For the correct functioning of a pressure control valve, the setting of a defined operating point in the magnetic force map is of great importance. In the course of assembly, inaccuracies of the actual dimensions of the installed individual parts in the axial direction are compensated by suitable measures. All permanent influences on the axial lengths occurring during operation, for example setting, leveling, burying of contours, etc., detune the magnetic operating point from the target state produced during assembly. One aspect is therefore to minimize this detuning. A finite guiding accuracy of the components in the radial direction, in particular that of the plunger element of a pressure regulating valve, should as far as possible also have no influence on the axial tuning. Therefore have valve body, disc and the recess in the valve housing, which receives these parts, regularly flat bearing surfaces, which are perpendicular to the main axis of the valve. In the original realization of a plunger tip (see Figure 2a), this is also ground flat and thus perpendicular to the main axis, so that a radial play of the plunger element produces no effect on the axial lengths. In order to anticipate a real impression of a valve ball in the plane surface or outer surface of the plunger tip, thus avoiding detuning during operation, the plunger tip can be impressed prior to assembly (see FIG. This embossing has a slightly larger diameter than the valve ball and also improves the noise behavior of a pressure control valve. However, in this case, the radial clearance of the plunger due to the circular surface of the recess in the plunger tip also affects in the axial direction, which can undesirably change the balance of power in the magnetic circuit.

According to the invention, a plunger element is now provided which is designed to compensate for radial play and for optimized noise behavior

provide equally without significant additional costs in the

To cause component manufacturing and / or assembly. In this case, when using a plunger element according to the invention, a fit between

Valve body and valve body should be designed so that a radial clearance between the components is minimized in the context of cost-neutral measures. According to the invention, the tappet tip is now not spherical, but pre-embossed with a combined geometry, so that no axial effects are effective within an existing radial clearance. As a result, in particular the previously counteracting functions radial play compensation and noise behavior can be combined and optimized.

Thus, the recess in the plunger tip on a first and a second region. Both areas may be arranged concentrically with each other and in particular with respect to the center axis of the plunger element. In the first area this is essentially as a flat surface perpendicular to

Center axis or formed to the longitudinal extension direction of the plunger body.

Thus, the first region has a possibility of the valve ball a radial To provide compensation or a radial movement possibility, without this on the axial position of the plunger element or the plunger tip influence. The valve ball can thus deviate on the flat surface of the first area substantially free laterally, without affecting the axial position of the plunger element. A second, at first

Area adjacent area essentially forms a suitable transition region between the first area and the actual

Outer surface or frontal area of the plunger tip. This second region forms a suitable transition between the first region and the outer surface. Such a surface configuration of the second region may be e.g. as an inclined plane, a truncated cone portion, a suitably curved surface, for example the surface of a spherical shape, be formed. In this case, the surface of the second region preferably has a radius, comparable to the valve ball, possibly also slightly larger. However, the spherical surface may also have a radius greater than that

Radius of the valve ball is, in particular significantly larger, have.

To first a clearance-free design between the valve body and

To provide valve housing, the nominal size, not the tolerance, of the outer diameter of the valve body can be selected such that the maximum positive fit is 0 mm. The minimum fit is slightly negative, whereby the valve body is essentially to be pressed into the valve housing and thus is always arranged centrally in the recess of the valve housing. Furthermore, it can be checked whether a production of the recess in

Valve housing in one clamping with the central guide bore of the

Tappet is possible, thus can be generated in the same step, which may account for more radial tolerances on the valve body. A possibly remaining radial clearance can now be determined constructively and used as the basis for the geometry of a stamping tool for the plunger tip of the plunger element. The first region thus preferably has a dimension which is sufficient to compensate for an existing radial play such that an axial position of the tappet element is not influenced or changed in the radial play.

The recess of the plunger tip can now be preferred as a combination of a central, circular, flat flattening (first area) with a Ball (similar) form (second area) may be formed as a stamping geometry. Such a combination of a substantially flat, in particular formed perpendicular to the central axis of the plunger element level and a ball-like configuration of the second region is hereinafter referred to as a flat round embossing.

Embodiments of the invention are illustrated in the figures and explained in more detail in the following description.

Show it

Figures la, b the schematic structure of a conventional

Pressure control valve according to the present invention;

Figures 2a, b show exemplary embodiments of a plunger tip 14 of a conventional pressure control valve according to the present invention;

3a, b, the arrangement of a valve ball 6 to a conventional

Plunger tip 14 according to the present invention; and

Figure 4 shows an exemplary embodiment of the shape of the recess of a plunger tip according to the invention.

With further reference to FIG. 4, an exemplary embodiment of the shape of the depression of a tappet tip according to the invention is shown.

Tappet tip 14 shows in detail a stamping geometry with a flat-round embossing, which is formed in diameter such that the contact between the valve ball and plunger tip 14 in the recess 12 over the remaining

Radial tolerances always in the region of the flattening, thus remains in the first region 16a. As a result, a radial movement 20a, essentially a movement 18a that does not influence the axial position of the plunger element 2, is possible along the plane of the region 16a. Outside this first region 16a, a second region 16b is arranged, by way of example the geometry is continued in a manner comparable to that of a ball embossing. These

Connection geometry of the second region 16b can be performed, for example spherical or progressive, depending on which boundary conditions of the ball stamping to be maintained. In the second area 16b takes place Thus, depending on the specific geometric configuration of the surface of the second region 16b of the recess 12 dependent movement 18b, which in Figure 4 by way of example has a circular course and thus a movement about a center with radius R of the recess 12 in the second region 16b. During a movement in the second region 16b, therefore, not only a radial movement 20a but also combined with a further movement in the axial direction 20b is carried out, whereby the axial position of the tappet element and thus the design of the drive device 10, in particular a magnetic circuit, changes. When moving in the area 16a, however, the axial position does not change. Now, if all tolerances are designed such that only a movement of the valve ball 6 in the first region 16a is necessary to compensate for these tolerances, these tolerances can be substantially complete without changing the axial position of the plunger element 2 and thus without movement in the axial direction 20b ,

The flat circular embossing is exaggerated in FIG. 4, in particular based on the fact that a radius of the second region 16b is substantially only slightly different from the radius of the valve ball 6. Macroscopically, a situation similar to that of the ball embossing (see Figure 3b) results in the second region 16b, whereby the noise-inhibiting effect and also the anticipated setting of the tappet element are retained. In the area of the radial clearance of the arrangement, however, there is no axial effect due to the flattening in the region 16a.

Claims

Tappet element (2), in particular for a pressure control valve (4), with a, in particular elongated, plunger body (2a) comprising a first side (2b), a second side (2c) and a central axis (2d);

wherein on the first side (2a) a plunger tip (14) is formed and adapted for contacting with a valve ball (6);

wherein on the second side (2c) a drive device (10) for the plunger element (2) is providable; and

wherein the plunger tip (14) has a recess (12) for contacting with a valve ball (6);

characterized in that

the depression (12) has a first region (16a) and a second region (16b), the two regions (16a, b) being arranged concentrically with respect to the central axis (2d); and

wherein in the first region (16a) a valve ball (6) on the surface (22a) of the recess (12) substantially exclusively in the radial direction (20a) perpendicular to the central axis (2d) is movable (18a); and

wherein in the second region (16b) a valve ball (6) on the surface (22b) of the recess (12) substantially in a combined movement in both the radial direction (20a) and in the axial direction (20b) is movable (18b).

Tappet element according to claim 1,

wherein a play of the plunger body (2a) in the radial direction (20a) can be compensated by the recess (12), in particular by the first region (16a).

Tappet element according to claim 2,

wherein the play in the radial direction (20a) is compensated without im

Essentially to change the axial position of a valve ball (6),

in particular so that the play in the radial direction (20a) a position a valve ball (6) in a valve seat (24) substantially not affected.

4. plunger element according to one of claims 1 to 3,

wherein the first region (16a) of the depression (12) is formed as a surface (22a) perpendicular to the central axis (2d); and

wherein the second region (16b) provides a transition region (22b) from the first region (16a) to the outer surface and to the end region (22c) of the plunger tip (14), respectively.

5. tappet element according to one of claims 1 to 4,

wherein the second region (16b) is formed as an area of the group consisting of linear region not perpendicular to the central axis, part-circular region, partial oval region, bent region, curved region and region formed as a flat circular imprint.

6. Pressure control valve (4) for a vehicle, in particular automobile, comprising a plunger element (2) according to one of claims 1 to 5.

7. Motor element for a vehicle, in particular automobile, comprising a plunger element (2) according to one of claims 1 to 5 and / or a pressure regulating valve (4) according to claim 6.

8. Vehicle, in particular automobile, comprising a plunger element (2) according to one of claims 1 to 5, a pressure regulating valve (4) according to claim 6 and / or a motor element according to claim 7.