JP2024514431A - 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 - Google Patents

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); withdrawing 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) arranged on the cylindrical sealing seat (7) from slipping off the sealing seat (7).
[Selected Figure] Figure 1

Description

The present invention relates to a method for manufacturing a deep-drawn part for an ejector, in particular a magnetic cup for an injector, a deep-drawn part, as well as an injector having a deep-drawn part of this type.

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. In some cases, it has been found 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 or is completely lost at the customer's site. 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 to be tapered only minimally 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 when transporting the injector.

In contrast, the method of the present invention for producing a deep-drawn injector part having the features of claim 1 has the advantage that a deep-drawn part having a first cylindrical region can be produced in which the elastic sealing element stretched over the outer circumference cannot slip or get lost. This deep-drawing method can furthermore be carried out at very low cost 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, particularly within the range of the inner diameter tolerance 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 having a first cylindrical region.

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

The dependent claims indicate preferred developments of the invention.

The first outer diameter of the first cylindrical region is enlarged to a dimension equal to or minimally greater than a second outer diameter in the cylindrical seal seat for the resilient seal member. is preferable. This reliably prevents the stretched elastic sealing element from slipping out of the first cylindrical region of the deep-drawn part.

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. In this case, for example, in a step following 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.

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 on the outside of the first axial end. , such that the first axial end is non-circular or slightly oval. At this time, the semi-major axis of the ellipse created in this way is equal to the second outer diameter of the seal sheet in the first cylindrical area, or is larger than this by the minimum amount.

More preferably, 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. . Then, the outer dimension of the first cylindrical region at the first end is 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.

The deep drawn part is particularly preferably a magnetic cup for a magnetic actuator of an injector.

In a further deep drawing step, preferably, an outwardly facing step and a second cylindrical region are produced, 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, so that an overmolded plug for the injector can be securely fixed in the second cylindrical region.

The invention further provides an injector comprising a first cylindrical region having a first axial end having a first outer diameter and a second axial end having a second outer diameter. Regarding deep drawing parts. The second axial end is then set up as a sealing seat for the elastic sealing element. Additionally, the first outer diameter is greater than or equal to the second outer diameter. More preferably, an outwardly facing step is formed adjacent to the second axial end of the first cylindrical region.

The present invention further relates to an injector having a deep-drawn part with a first cylindrical region and an elastomeric sealing member, 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 is then 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 member stretched across the first cylindrical region is prevented from slipping off. In this way, the elastic sealing member can be reliably retained on the sealing seat at the second axial end of the first cylindrical region.

More preferably, the first axial end of the first cylindrical region is configured cylindrically, with the first outer diameter of the first axial end being 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, with the major semi-axis of the ellipse at the first axial end being greater than or equal to the second outer diameter of the second axial end of the first cylindrical region. This ensures that the elastic seal member does not slip off.

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. This step is preferably arranged perpendicular to the long axis of the deep drawn part. Preferably, the sealing sheet for the resilient sealing member is arranged in the first cylindrical region directly adjacent to the step. Thereby, sealing can be effected both in the first cylindrical region and in the axial step.

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

The elastic sealing member is preferably an O-ring, or a grommet, or a sealing member having an inner cylindrical surface in the first cylindrical region and a second end that rests on a sealing seat.

Preferably, the injector is an injector for injecting fuel or water. The injector for injecting fuel can then be a gas injector or a power fuel injector for liquid power fuel.

Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings. The drawing shows the following:

1 is a schematic side view of an injector having a deep drawn part according to a preferred embodiment of the present invention; FIG. 2 is a perspective view of the deep drawn part of FIG. 1 . FIG. 2 is a schematic cross-sectional view showing the deep drawn part of FIG. 1. FIG. FIG. 2 is a schematic perspective view showing an elastic sealing member of the injector of FIG. 1 .

In the following, an injector 1 according to a first preferred embodiment of the invention will be described in detail with reference to FIGS. 1 to 4. FIG.

As is clear from FIG. 1, the injector 1 includes a magnetic actuator, of which only the magnetic cup 2 is shown in FIG. The magnetic cup 2 together with the cylindrical valve housing 3 forms part of the outer surface of the injector 1 .

The injector 1 further comprises a fuel inlet 4, through which fuel (arrow A) is supplied to the inner region of the injector. The fuel is then discharged on the opposite side of the injector in the axial direction X-X into an intake manifold 100, which is not shown in detail in FIG. 1.

Furthermore, on its outer circumference, the magnetic cup 5 is further fitted with an overmolded plug 6 made of plastic, through which it is possible to supply power to the injector 1 by means of a laterally mounted arm.

The injector 1 further includes an elastic sealing member 5, which is also arranged on the outer surface of the injector 1 in a cylindrical region of the magnetic cup 2. Here, the elastic sealing member 5 seals the injector at its outer circumference with the cylindrical bore of the intake pipe to prevent gas from the intake manifold 100 in the axial direction X-X from being able to reach the surroundings via the bore of the intake pipe.

Figures 2 and 3 show the magnetic cup 2 in detail. The magnetic cup 2 includes 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 X-X. The second cylindrical region 22 further includes a number of grooves 23 into which the material of the overmolded plug 6 penetrates and prevents the overmolded plug 6 from sliding axially.

As is further evident from FIGS. 2 and 3, the diameters of the first and second cylindrical regions 21, 22 are different. Here, the diameter of the first cylindrical region 21 is smaller than the diameter of the second cylindrical region 22.

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

As can be seen in particular from FIG. 3, the first cylindrical region 21 has a first axial end forming an end of the first cylindrical region 21 located in the direction of the suction manifold. 21a. Furthermore, the first cylindrical region 21 includes a second axial end 21 b 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.

FIG. 4 shows in detail the elastic sealing member 5 with a cylindrical inner surface 50. FIG. Here, the elastic sealing element 5 seals with the sealing sheet 7 by means of a cylindrical inner surface 50 . At this time, in the axial direction XX, the elastic sealing member 5 seals at the stepped portion 20.

In order to enable the magnetic cup 2 to accommodate the valve housing 3, a punching out 24 is further provided at the end of the magnetic cup 2 facing the combustion chamber.

The first outer diameter D1 at the first axial end 21a is then equal to or alternatively minimally greater 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 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 allowing a short design form of the first cylindrical region 21.

To ensure this, during the manufacture 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, the first cylindrical region 21 A further step is contemplated in which the outer diameter D1 at the first axial end 21a of is enlarged. At this time, the first outer diameter D1 is enlarged to a size that prevents the elastic seal member 5 from slipping off or being lost. Preferably, the first outer diameter D1 is enlarged to an outer diameter D2 equal to the second axial end 21b.

This expansion can be done in two different steps. Firstly, by expanding the first axial end 21a from the inner surface of the first cylindrical region 21, the first outer diameter D1 can be produced. Alternatively, by upsetting the first axial end 21a of the first cylindrical region 21, an enlargement of the first outer diameter from the outer surface of the first axial end 21a can be effected. , so that the first axial end 21a is minimally oval. Accordingly, the first axial end 21a has a semi-major axis equal to the second outer diameter D2 at the second axial end 21b of the first cylindrical region 21, or Form a larger oval.

The invention thus makes it possible to provide a magnetic cup configured as a deep-drawn part for an injector, in which slipping off and loss of the elastic sealing element 5 in the first cylindrical region 21 is prevented. Make it. In this way, the state of delivery to the customer of the injector 1 shown in FIG. It can be guaranteed that it will not slip or get lost.

Therefore, 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 the first outer diameter D1 is expanded to a dimension greater than the second outer diameter D2 according to the present invention, the initial stress that fixes the elastomeric member as it moves in the direction from the second axial end 21b toward the first axial end 21a can be made higher.

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 member to be attached thereto could slip off and/or become lost, for example due to vibrations or other handling steps.

In this way, the elastic sealing element 5 can be protected against slipping or loss in the deep-drawn, preferably precisely cylindrical area.

1 Injector 2 Magnetic cup 5 Elastic sealing member 7 Seal sheet 20 Step portion 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 (14)

A method of manufacturing an injector deep-drawn part, in particular a magnetic cup, comprising the steps of:
A first axial end (21a), a second axial end (21b), and a cylindrical sealing sheet (7) on the outer circumference of the second axial end (21b). deep drawing the blank by a punch so as to form a first cylindrical region having a
the punch from the deep drawn blank is withdrawn from the first cylindrical region (21) at the second axial end (21b);
A first outer diameter (D1) at the first axial end (21a) of the first cylindrical region (21) is elastic, which is arranged on the cylindrical sealing sheet (7). the sealing member (5) being enlarged to a size that prevents it from slipping off the sealing sheet (7). The first outer diameter (D1) is the second outer diameter of the cylindrical seal seat (7) located at the second axial end (21b) of the first cylindrical region (21). 2. The method according to claim 1, wherein the method is enlarged to a dimension greater than or equal to the diameter (D2). The method according to claim 1 or 2, wherein the enlargement of the first outer diameter (D1) at the first axial end (21a) is performed by expanding the first axial end (21a) from inside the first cylindrical region (21). The method according to claim 1 or 2, wherein the enlargement of the first outer diameter (D1) at the first axial end (21a) is performed by upsetting the first axial end (21a) of the first cylindrical region (21) outside the first axial end (21a) so that the first axial end (21a) becomes elliptical. The method according to any one of claims 1 to 4, wherein after the deep drawing step, the 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. The method according to any one of claims 1 to 5, wherein the injector deep-drawn part is a magnetic cup (2) of a magnetic actuator of the injector. The method according to any one of claims 1 to 6, further comprising producing an outwardly facing step (20) and a second cylindrical region (22) during the deep drawing step, the step (20) connecting the first cylindrical region (21) with the second cylindrical region (22). In deep drawn parts of injectors,
A first cylindrical shape having a first axial end (21a) having a first outer diameter (D1) and a second axial end (21b) having a second outer diameter (D2). including the area (21),
Said second axial end (21b) is set up as a sealing seat (7) for an elastic sealing member, said first outer diameter (D1) being smaller than said second outer diameter (D2). Larger or equal, deep-drawn parts. Adjacent to said second axial end (21b) an outwardly facing step (20) is arranged, in particular a second cylindrical region (22) is arranged on said step (20). , deep drawn part according to claim 8. 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. The first axial end (21a) has a cylindrical shape, and the first outer diameter (D1) of the first axial end (21a) corresponds to the first cylindrical region (21a). ) is greater than or equal to the second outer diameter (D2) at the second axial end (21b), or
The first axial end (21a) is configured non-circularly or elliptically with a semi-major axis, the semi-major axis of the second axial end (21b) Injector according to claim 10, which is greater than or equal to the diameter (D2). 12. Injector according to claim 10 or 11, wherein the deep drawn part has a second cylindrical region (22) connected to the first cylindrical region (21) by a step (20). The injector according to any one of claims 10 to 12, further comprising a magnetic actuator and a magnetic cup, the magnetic cup being the deep-drawn part (2). Any of claims 10 to 13, wherein the resilient sealing member (5) has an inner cylindrical surface (50) that rests on the sealing seat (7) at the second axial end (21b). The injector according to item 1.

Images