Method for manufacturing a deep-drawn part for an injector, as well as an injector having a deep-drawn part of this type - Patents.com

Abstract

The present invention relates to a method for manufacturing an injector deep-drawn part, in particular a magnetic cup, comprising the steps of: deep-drawing a blank with a punch to form a first cylindrical region having a first axial end (21a), a second axial end (21b) and a cylindrical sealing seat (7) on the outer circumference of the second axial end (21b); retracting the punch from the deep-drawn blank at the second axial end (21b) from the first cylindrical region (21); and expanding a first outer diameter (D1) at the first axial end (21a) of the first cylindrical region (21) to a dimension that prevents an elastic sealing member (5) placed on the cylindrical sealing seat (7) from slipping off the sealing seat (7).

Description

[Technical field]

[0001] The present invention relates to a method for producing a deep-drawn part for an ejector, in particular a magnetic cup for an injector, to the deep-drawn part as well as to an injector comprising a deep-drawn part of such kind. [Background technology]

[0002] Injectors are known from the prior art in various embodiments. In injectors with a magnetic actuator, the magnetic cup is usually configured as a deep-drawn part for reasons of the lowest possible manufacturing cost. Such deep-drawn parts have a cylindrical area, on the outer circumference of which is provided a cylindrical sealing seat for a sealing element, for example an O-ring or a grommet. Such a sealing element seals radially against the wall of the cylindrical bore of the intake pipe, for example after installation of the injector in the bore, and thus seals the intake manifold of the internal combustion engine against the surroundings. It has been found in some cases that the sealing element, which is stretched over the cylindrical area of ​​the deep-drawn part after the injector is assembled, is subsequently not positioned at the intended sealing point at the customer's site or is completely lost. The reason for this is that the deep-drawn part is produced with a punch, which has to be further pulled out of the deep-drawn part after the deep-drawing step, and which is configured with only a minimal tapering at its free end. For this reason, the deep-drawn part also tends to have a slight conicity or a slightly reduced outer diameter at the free end of the cylindrical area. This creates a risk that the seal may slip or get lost during transportation of the injector. Summary of the Invention

[0003] In contrast, the method according to the invention for producing a deep-drawn injector part according to the features of claim 1 has the advantage that a deep-drawn part with a first cylindrical region can be produced in which the elastic sealing element stretched over the outer circumference cannot slip off and cannot be lost. This deep-drawing method can furthermore be carried out very cost-effectively and in a manner suitable for mass production. In this case, the invention provides for an additional step of enlarging the first outer diameter at the first axial end of the first cylindrical region after the blank has been deep-drawn to produce the first cylindrical region and the punch has been withdrawn from the first cylindrical region, to a dimension in which the elastic sealing element stretched over the outer circumference cannot slip off, in particular within the tolerance of the inner diameter of the elastic sealing element. In this way, it is possible to counteract the tendency of the free end of the first cylindrical region to have a minimally reduced outer diameter due to the slightly tapered configuration of the punch during deep-drawing of such types of parts with a first cylindrical region.

[0004] Preferably, within the framework of the cylindrical tolerances, the larger outer diameter is located in the region of the elastic sealing element, which allows for a particularly short design of the first cylindrical region.

[0005] The dependent claims indicate preferred developments of the invention.

[0006] The first outer diameter of the first cylindrical region is preferably enlarged to a dimension equal to or minimally greater than the second outer diameter of the cylindrical sealing seat for the elastic sealing element, thereby reliably preventing the stretched elastic sealing element from slipping out of the first cylindrical region of the deep-drawn part.

[0007] The expansion of the first outer diameter at the first axial end of the first cylindrical region is preferably performed by expanding the first cylindrical region from the inside, whereby, for example in a step subsequent to the deep drawing, a correspondingly configured additional tool can be inserted into the inner region of the first cylindrical region to realize the expansion process and thus the expansion of the first outer diameter of the first cylindrical region.

[0008] Alternatively, the enlargement of the first outer diameter at the first axial end of the first cylindrical region is performed by upsetting the first axial end outside the first axial end such that the first axial end is non-circular or slightly elliptical, with the major semi-axis of the ellipse thus created being equal to or minimally greater than the second outer diameter at the sealing seat of the first cylindrical region.

[0009] It is further preferred that after the deep drawing step, the bottom surface remaining at the first end of the first cylindrical region or the inwardly facing flange region is removed in a subsequent step, for example by punching, and the outer dimension of the first end of the first cylindrical region is then subsequently enlarged. The deep drawing process can then be carried out, for example, on a plate-shaped part, so that after the deep drawing step, a bottom surface remains at the first end of the first cylindrical region.

[0010] The deep-drawn part is particularly preferably a magnetic cup of a magnetic actuator of an injector.

[0011] More preferably, an outwardly facing step and a second cylindrical region are produced in a further deep drawing step, the step connecting the first and second cylindrical regions to each other. More preferably, the second cylindrical region is provided with an additional geometric shape, such as, for example, a recess or a circumferential groove, by which an overmolded plug for the injector can be securely fixed in the second cylindrical region.

[0012] The invention further relates to a deep-drawn part for an injector, comprising a first cylindrical region having a first axial end with a first outer diameter and a second axial end with a second outer diameter, the second axial end being set up as a sealing seat for an elastic sealing member. Furthermore, the first outer diameter is greater than or equal to the second outer diameter. It is further preferred that adjacent to the second axial end of the first cylindrical region an outwardly facing step is formed.

[0013] The invention further relates to an injector having a deep-drawn part with a first cylindrical region and an elastomeric sealing element, in particular an O-ring or grommet, arranged in the first cylindrical region. The first cylindrical region of the deep-drawn part has a first and a second axial end and a cylindrical sealing seat on the outer circumference of the first cylindrical region, the sealing seat being arranged at the second axial end of the first cylindrical region. The first outer diameter of the first axial end of the first cylindrical region is configured such that the elastic sealing element stretched across the first cylindrical region is prevented from slipping off. In this way, the elastic sealing element can be reliably retained on the sealing seat at the second axial end of the first cylindrical region.

[0014] More preferably, the first axial end of the first cylindrical region is configured cylindrically and the first outer diameter of the first axial end is greater than or equal to the second outer diameter of the second axial end of the first cylindrical region. Alternatively, the first axial end is configured non-circular or elliptical and the major semi-axis of the ellipse of the first axial end is greater than or equal to the second outer diameter of the second axial end of the first cylindrical region, thereby ensuring that the elastic sealing member does not slip off.

[0015] In another preferred embodiment of the invention, the deep-drawn part has a second cylindrical region, and a step connects the first cylindrical region with the second cylindrical region. The step is preferably arranged perpendicular to the longitudinal axis of the deep-drawn part. A sealing seat for the elastic sealing element is preferably arranged in the first cylindrical region directly adjacent to the step, so that sealing can be performed both in the first cylindrical region and in the axial direction at the step.

[0016] More preferably, the injector includes a magnetic actuator, and the deep drawn part is a magnetic cup of the magnetic actuator.

[0017] The resilient sealing member is preferably an O-ring or grommet or sealing member having an inner cylindrical surface at a first cylindrical region and a second end which rests against a sealing seat.

[0018] The injector is preferably an injector for injecting fuel or water, where the injector for injecting fuel may be a gas injector or a motive fuel injector for liquid motive fuel.

[0019] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0020] [Figure 1] 1 is a schematic side view of an injector having a deep drawn part according to a preferred embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view of the deep-drawn part of FIG. 1. [Diagram 3] FIG. 2 is a schematic cross-sectional view showing the deep-drawn part of FIG. 1. [Figure 4] FIG. 2 is a schematic perspective view showing an elastic sealing member of the injector of FIG. 1; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] In the following, an injector 1 according to a first preferred embodiment of the present invention will be described in detail with reference to FIGS.

[0022] As can be seen from Figure 1, the injector 1 includes a magnetic actuator, of which only a magnetic cup 2 is shown in Figure 1. The magnetic cup 2 together with a cylindrical valve housing 3 forms part of the outer surface of the injector 1.

[0023] Furthermore, the injector 1 comprises a fuel inlet 4, via which fuel (arrow A) is fed into the inner region of the injector, and is discharged at the oppositely situated side in the axial direction XX of the injector into an intake manifold 100, which is not shown in detail in FIG.

[0024] The magnetic cup 5 further comprises, on its outer circumference, an overmolded plug 6 made of plastic, through which the injector 1 can be supplied with power by means of a laterally mounted arm.

[0025] Furthermore, the injector 1 includes an elastic sealing element 5, which is also arranged on the outer surface of the injector 1 in the cylindrical region of the magnetic cup 2. Here, the elastic sealing element 5 seals the injector at its outer circumference with the cylindrical bore of the intake pipe in order to prevent gas from the intake manifold 100 being able to reach the surroundings via the bore of the intake pipe in the axial direction XX.

[0026] 2 and 3 show the magnetic cup 2 in detail. The magnetic cup 2 comprises a first cylindrical region 21 and a second cylindrical region 22. Both cylindrical regions 21, 22 are connected to each other via a step 20. The step 20 is a step arranged perpendicular to the axial direction XX. The second cylindrical region 22 further comprises a number of grooves 23 into which the material of the overmolded plug 6 penetrates and which prevent the overmolded plug 6 from axially sliding.

[0027] As can be further seen from Figures 2 and 3, the diameters of the first and second cylindrical regions 21, 22 are different, where the diameter of the first cylindrical region 21 is smaller than the diameter of the second cylindrical region 22.

[0028] The magnetic cup 2 here is a deep-drawn part, which can be produced either in one deep-drawing step or in two deep-drawing steps for one of the cylindrical regions 21, 22, respectively.

[0029] As can be seen in particular from Figure 3, the first cylindrical region 21 has a first axial end 21a which forms the end of the first cylindrical region 21 which is located in the direction of the intake manifold. The first cylindrical region 21 further comprises a second axial end 21b which is arranged directly adjacent to the step 20. Here, at the second axial end 21b, a sealing seat 7 for the elastic sealing element 5 is arranged on the outer circumference.

[0030] 4 shows in detail the elastic sealing element 5 with a cylindrical inner surface 50. Here, the elastic sealing element 5 seals with the sealing seat 7 by means of the cylindrical inner surface 50. In the axial direction XX, the elastic sealing element 5 then seals with the step 20.

[0031] In order to enable the magnetic cup 2 to receive the valve housing 3, a stamped out portion 24 is further provided at the end of the magnetic cup 2 facing towards the combustion chamber.

[0032] The first outer diameter D1 at the first axial end 21a is then equal to or alternatively minimally larger than the second outer diameter D2 at the second axial end 21b at the sealing seat 7. This makes it possible to prevent the elastic sealing element 5, which is stretched across the first cylindrical region 21 in the delivery state of the injector 1 to the customer, from being displaced at the sealing seat 7 or being completely lost. The outer diameter D1 can be located in the sealing region of the elastic sealing element 5, thereby enabling a short design form of the first cylindrical region 21.

[0033] In order to ensure this, during the production of the deep-drawn part, after one or more deep-drawing steps and the withdrawal of the punch from the deep-drawn magnetic cup 2, a further step is provided in which the outer diameter D1 of the first cylindrical region 21 at the first axial end 21a is enlarged to a dimension that prevents the elastic sealing element 5 from slipping off or being lost. The first outer diameter D1 is preferably enlarged to an outer diameter D2 equal to the second axial end 21b.

[0034] This expansion can be performed in two different steps. First, the first outer diameter D1 can be produced by expanding the first axial end 21a from the inner surface of the first cylindrical region 21. Alternatively, the expansion of the first outer diameter can be performed from the outer surface of the first axial end 21a of the first cylindrical region 21 by upsetting the first axial end 21a of the first cylindrical region 21, so that the first axial end 21a is minimally elliptical. The first axial end 21a thus forms an ellipse whose major semi-axis is equal to or greater than the second outer diameter D2 at the second axial end 21b of the first cylindrical region 21.

[0035] The invention thus makes it possible to provide a magnetic cup configured as a deep-drawn part for an injector, in which the elastic sealing element 5 in the first cylindrical region 21 is prevented from slipping off or becoming lost. In this way it can be ensured that the injector 1 shown in Figure 1 as delivered to the customer will remain in its final assembled state even after transportation and possible further handling, and that the elastic sealing element 5 will not slip off or become lost.

[0036] Thereby, the method of the present invention and the deep-drawn part of the present invention allow the circular critical cylindrical region to be adjusted during deep drawing within the permitted tolerances with a slightly tapered configuration of the original cylindrical region. If, according to the present invention, the first outer diameter D1 is expanded to a dimension larger than the second outer diameter D2, a higher prestress can be provided to fix the elastomeric member as it moves in the direction from the second axial end 21b towards the first axial end 21a.

[0037] In this way, it is possible to prevent the deep-drawn part from tapering towards the deep-drawn end after completion of the deep-drawing step, such that the elastic sealing members to be attached thereto can slip off and / or become lost, e.g. due to vibrations or other handling steps.

[0038] In this way, the elastic sealing element 5 can be protected in the deep-drawn, preferably precisely cylindrical, area against slipping off or being lost. [Explanation of symbols]

[0039] 1 Injector 2 Magnetic Cups 5 Elastic sealing member 7 Seal Sheet 20 steps 21 First cylindrical region 21a First axial end 21b Second axial end 22 Second cylindrical region 50 Inner cylindrical surface D1 First outer diameter D2 Second outer diameter

Claims

1. A method for manufacturing an injector deep-drawn part, in particular a magnetic cup, comprising the steps of: a punch is used to deep draw the blank to form a first cylindrical region having a first axial end (21a), a second axial end (21b) and a cylindrical sealing seat (7) on the outer circumference of said second axial end (21b); the punch is withdrawn from the first cylindrical region (21) at the second axial end (21b) from the deep drawn blank, The method of claim 1, wherein a first outer diameter (D1) at the first axial end (21a) of the first cylindrical region (21) is expanded to a dimension that prevents an elastic sealing member (5) disposed on the cylindrical sealing seat (7) from slipping off the sealing seat (7).

2. 2. The method according to claim 1, wherein the first outer diameter (D1) is expanded to a dimension greater than or equal to a second outer diameter (D2) of the cylindrical sealing seat (7) at the second axial end (21b) of the first cylindrical region (21).

3. 3. The method according to claim 1 or 2, wherein the enlargement of the first outer diameter (D1) at the first axial end (21a) is achieved by expanding the first axial end (21a) from inside the first cylindrical region (21).

4. 3. The method according to claim 1 or 2, wherein the enlargement of the first outer diameter (D1) at the first axial end (21 a) is performed by upsetting the first axial end (21 a) of the first cylindrical region (21) outside the first axial end (21 a) so that the first axial end (21 a) becomes elliptical.

5. 5. The method according to claim 1, wherein after the deep drawing step, a bottom or flange area remaining at the first axial end (21a) of the first cylindrical region (21) is removed, in particular punched out, in a next step, if present.

6. 6. The method according to claim 1, wherein the injector deep-drawn part is a magnetic cup (2) of a magnetic actuator of the injector.

7. 7. The method according to claim 1, further comprising producing an outwardly facing step (20) and a second cylindrical region (22) during the deep drawing step, said step (20) connecting said first cylindrical region (21) with said second cylindrical region (22).

8. In injector deep drawing parts, a first cylindrical region (21) having a first axial end (21a) with a first outer diameter (D1) and a second axial end (21b) with a second outer diameter (D2); The deep drawn part, wherein the second axial end (21b) is set up as a sealing seat (7) for an elastic sealing member, and wherein the first outer diameter (D1) is greater than or equal to the second outer diameter (D2).

9. 9. The deep-drawn component according to claim 8, wherein an outwardly facing step (20) is arranged adjacent to the second axial end (21b), in particular a second cylindrical region (22) being arranged on the step (20).

10. In an injector, the injector comprises a deep-drawn part (20) having at least one first cylindrical region (21) having a first axial end (21a) and a second axial end (21b), a cylindrical sealing seat (7) on the outer circumference of the first cylindrical region (21), and an elastic sealing member (5) arranged on the first cylindrical region (21), the dimension of the first outer diameter (D1) at the first axial end (21a) of the first cylindrical region (21) is configured to prevent the elastic sealing member (7) disposed on the first cylindrical region (21) from slipping off.

11. the first axial end (21a) is configured cylindrically and the first outer diameter (D1) of the first axial end (21a) is greater than or equal to the second outer diameter (D2) of the first cylindrical region (21) at the second axial end (21b), or 11. The injector of claim 10, wherein the first axial end (21 a) is configured non-circular or elliptical with a major semi-axis, the major semi-axis being greater than or equal to the second outer diameter (D2) of the second axial end (21 b).

12. 12. Injector according to claim 10 or 11, wherein the deep-drawn part has a second cylindrical region (22) joined to the first cylindrical region (21) by a step (20).

13. 13. The injector according to any one of claims 10 to 12, further comprising a magnetic actuator and a magnetic cup, said magnetic cup being said deep-drawn part (2).

14. 14. The injector according to claim 10, wherein the elastic sealing member (5) has an inner cylindrical surface (50) which rests on the sealing seat (7) at the second axial end (21b).

Images