KR20180002533A - Injector with relief groove - Google Patents

Abstract

The present invention relates to an injector for injecting fluids, particularly, fuel, wherein the injector includes: a valve seat (3) having a sealing region (50); a closing member (5) for opening and closing at least one through-hole (30) in the valve seat (3); and a relief groove (9) provided on the valve seat (3), wherein the relief groove (9) is arranged on an outer surface (3a) of the valve seat (3), wherein the relief groove (9) is disposed closer to a central axis (X-X) of the injector in a radial direction than the through-hole (30).

Description

INJECTOR WITH RELIEF GROUVE {INJECTOR WITH RELIEF GROOVE}

The present invention relates to a fluid, particularly an injector for injecting fuel, comprising a relief groove for reducing stress in the injection hole of the injector.

Various embodiments of injectors for injecting fuel are disclosed in the prior art. In order to open the injection hole, a so-called inwardly opening injector, in which the closing member is pulled back from the sealing area on the valve seat into the injector, generates a high load particularly at the inlet of the injection hole. In this case, a very high component stress may appear in the region of the inflow portion of the injection hole. In particular, very high stresses occur in the closing process when the closure member reaches the sealing region. In addition, durability of the valve seat must also be provided, particularly in the region of the injection hole. Therefore, the intended wall thickness in the valve seat can not be exceeded. The corresponding thickness of the valve seat in the region of the injection hole must be larger in order to provide a certain degree of safety against pressure peaks. However, this also increases the weight and size of the associated valve seat.

An object of the present invention is to provide an injector including a relief groove for reducing stress in the injection hole of the injector.

The above problem is solved by an injector comprising the features of claim 1.

The injector according to the invention for injecting fluids, particularly fuel, comprising the features of claim 1 can reduce the stress on the valve seat, and thus the thickness of the valve seat in particular in the region of one or more through openings can be reduced Provides advantages. In particular, in the inflow region of the through-hole for fluid, the stress can be reduced by about 15% compared to conventional through-holes of the same construction. This is achieved according to the invention by providing a relief groove in the valve seat. In this case, the relief grooves are arranged on the discharge side of the fluid in the valve seat, that is, on the outer surface of the valve seat in which the fluid to be injected is injected from the through-holes into the branching chamber or the intake manifold. The relief grooves are arranged closer to the central axis of the injector in the radial direction of the injector than the through-hole opening. Whereby a relief groove is provided in the region of the valve seat, said region comprising a through opening and located inside a circle concentric with the central axis of the injector.

The dependent claims present preferred improvements of the present invention.

The relief grooves are preferably formed closed in the circumferential direction. Thereby, one or more through apertures can be arranged at any position in the radial direction outside the relief grooves.

The relief grooves preferably have a first diameter that is concentric with respect to the central axis of the injector.

Also preferably, the injector has a plurality of through openings, all of which are arranged radially outside the relief grooves.

The central axes of the plurality of through openings at the discharge side preferably lie in a second diameter which is concentric with the central axis of the injector.

Also preferably, the ratio of the first diameter D1 in which the relief grooves are located to the second diameter D2 in which the central axes of the through openings in the discharge side of the valve seat are located is 0.4 to 0.6, in particular 0.5. The spacing between the through openings and the relief grooves is selected from 0.4 to 0.6 in accordance with this specification, thereby reliably reducing the stress.

Also preferably, the cross-section of the relief grooves has a geometric shape of an arc having a first radius. As a result, the stress can be reduced in the region of the through openings as intended.

Also preferably, the transition from the relief grooves to adjacent areas on the valve seat is implemented in a tangential direction. The areas adjacent to the relief grooves having the third radius are particularly preferably implemented as arcs. Particularly preferably, the second arc with the second radius and the third arc with the third radius in the adjacent region of the relief grooves are arcuately embodied in a direction opposite to the first arc of the relief grooves. Particularly preferably, the radii of the second and third arcs are the same.

Also preferably, the first radius of the first arc of the relief grooves is smaller than the second radius of the second arc, and is smaller than the third radius of the third arc.

Also preferably, the minimum wall thickness of the valve seat in the relief grooves is at least 0.2 mm, in particular exactly 0.2 mm. So that a sufficient load bearing capacity of the valve seat can always be achieved.

The injector is particularly preferably a fuel injector for gasoline. Particularly preferably, the injector is a direct injection injector that directly injects fuel into the combustion chamber of the internal combustion engine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

1 is a cross-sectional view schematically illustrating an injector according to a preferred embodiment of the present invention.
Fig. 2 is an enlarged sectional view of the valve seat of the injector of Fig. 1; Fig.
Figure 3 is a partial cross-sectional view of the valve seat of Figure 2 without the closure member;

1, an injector 1 for injecting fuel according to a preferred embodiment of the present invention includes a valve housing 2 and a valve seat 3. As shown in Fig. The valve seat (3) is fixed to the valve housing (2) by means of a weld joint (4). The weld joint 4 is completely provided in the circumferential direction in this case.

The injector 1 also includes a closing member 5 having a valve needle 5a and a closing ball 5b and a return member 6 for supporting the closing member 5 in the closed position shown in Figure 1 do.

The closing member 5 is operated using the actuator 7 which is a magnetic actuator in this embodiment. Reference numeral 8 denotes an electrical connecting portion.

The fuel is guided from the inside of the injector to the end of the closing member 5, and the ball 5b is disposed at the end.

2, the valve seat 3 has a plurality of injection holes as the through-holes 30. The through holes 30 are opened and closed by lifting the ball 5b from the sealing area 50 in the valve seat 3. [ 2 shows the closed state of the injector.

The sealing region 50 is a ring-shaped linear sealing sheet in this embodiment, and the ball 5b in the sealing sheet contacts the valve seat 3.

When the injector is in the open state, the fuel passes through the ball 5b through the longitudinal groove 31 parallel to the center axis X-X of the injector.

2 and 3, the through openings 30 have an inlet 30a and an outlet 30b, respectively. The outlet 30b is provided on the outer surface 3a of the valve seat 3 in this case.

2 and 3, relief grooves 9 are provided on the outer surface 3a of the valve seat. The relief grooves 9 are formed in a circumferential direction on the outer surface of the valve seat 3.

The relief grooves 9 are closed in the circumferential direction and have a circular geometric shape with a first diameter D1. Further, the relief grooves 9 are arranged concentrically with respect to the central axis X-X of the injector 1.

As can be seen in Figure 3, the relief grooves 9 have a first arcuate cross-section with a radius R1.

The outer sides of the valve housing 3 are adjacent to the two sides of the relief grooves 9. More precisely, the first adjacent region 91 is adjacent to the radially inner side of the relief grooves 9 and the second adjacent region 92 is adjacent to the radially outer side of the relief grooves 9. The first adjacent region 91 has the shape of a second arc having a second radius R2 as viewed in cross section and the second adjacent region 92 has a third arc having a third radius R3 as viewed in cross section, And has a circular arc shape. The second and third arcs are formed in a direction opposite to the first arc of the relief grooves 9. In this case, tangential transition portions are respectively provided between the first arc and the second and third arcs.

As can be seen in Figure 2, a plurality of through openings 30 are provided. The through openings 30 are all disposed radially outside the relief grooves 9. Each through-hole 30 has a central axis Y-Y. The central axes Y-Y in this case lie in the second diameter D2 at the outlet 30b of each through-hole 30 and the second diameter is concentric with the central axis X-X of the injector. The relief grooves 9 lie in the first diameter D1.

The ratio of the first diameter D1 of the relief grooves to the second diameter D2 of the through openings 30 in the outer surface 3a is 0.4 to 0.6 and especially 0.5. The first diameter D1 and the second diameter D2 are arranged concentrically with respect to the central axis X-X of the injector 1, respectively.

The first radius R1 of the first arc of the relief grooves 9 is equal to the second radius R2 of the second arc of the two adjacent areas 91 and 92 and the third radius R3 of the third arc, Lt; / RTI >

The second radius R2 and the third radius R3 are particularly preferably the same size.

A relieving of the stress at the through openings 30 can be achieved by providing the relief grooves 9 on the outer surface of the valve seat 3 in the radially inner area of the injection hole circle.

As shown in the experiment, the provision of the relief grooves 9 allows a reduction in stress in the through openings 30 of about 15%. Unlike the valve seat 3 having a constant wall thickness S1 of 0.35 mm, the inlet 30a of the through opening 30 has a maximum stress value of 559 N / mm < 2 >. Alternatively, the stress value is 489 N / mm < 2 > due to the provision of the relief grooves 9 which causes the wall thickness of the valve seat 3 to decrease to a value S2 of 0.2 mm (see FIG. This results in a stress reduction of approximately 13% in the region of the inlet 30a of the through-hole 30.

Whereby a reduced stress can be achieved in the region of the through openings 30 by the force of the closure member 5 and the fuel pressure upon reaching the valve seat 3. When the ball 5b is pressed against the inner surface of the valve seat 3 in the sealing area 50, the relief grooves 9 are provided so that the elastic deformation of the sealing sheet 3 in the area of the relief grooves appears . This reduces the stress in the region of the inlet 30a of the through openings 30. [

Thereby a definite reduction of the stress in the region of the through openings 30 in the inner region of the valve seat 3 is achieved by the provision of the relief grooves 9 on the outer surface of the valve seat 3, .

3 valve seat
9 Relief Groove
30 through opening
50 sealing area

Claims (11)

An injector for injecting fluids, particularly fuel,
A valve seat 3 having a sealing region 50,
- a closing member (5) for opening and closing at least one through opening (30) in said valve seat (3)
- a relief groove (9) provided on the valve seat (3)
The relief grooves 9 are arranged on the outer surface 3a of the valve seat 3,
- the relief grooves (9) are arranged closer to the central axis (XX) of the injector in a radial direction than the through openings (30). 2. An injector according to claim 1, wherein said relief grooves (9) are circumferentially closed grooves. 3. The injector according to claim 1 or 2, wherein the relief grooves (9) are located at a first diameter (D1) which is concentric with the central axis (X-X) of the injector. 4. An injector according to any one of claims 1 to 3, characterized in that a plurality of through-openings (30) are provided, all of which are arranged radially outside the relief grooves (9) . 5. The injector according to claim 4, characterized in that the central axes of the plurality of through-openings (30) at the discharge side lie in a second diameter (D2) which is concentric with the central axis (X-X) of the injector. 6. A valve according to any one of the preceding claims, wherein the relief grooves (9) are located at the first diameter (D1) and the central axes (YY) of the through openings (30) Is placed in a second diameter (D2) at the outer surface of the seat (3), and the ratio of the first diameter (D1) to the second diameter (D2) is 0.4 to 0.6, in particular 0.5. 7. An injector according to any one of the preceding claims, wherein the relief grooves (9) have a geometrical shape of a first arc with a first radius (R1) in cross-section. 8. The injector of claim 7, wherein the transition from the relief grooves (9) to adjacent areas is implemented in a tangential direction. 9. A method as claimed in claim 8, characterized in that adjacent areas of the relief grooves (9) have a second arc and a third radius (R3) having a second radius (R2) opposite to the first arc of the relief grooves And a third arc having a second arc. 10. The method of claim 9, wherein the first radius (R1) of the first arc is smaller than the second radius (R2) of the second arc and less than the third radius (R3) . A valve according to any one of the preceding claims, characterized in that the minimum wall thickness (S2) of the valve seat (3) in the relief grooves (9) is at least 0.2 mm, Injector.

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