DE102015211971A1 - Gas injector with improved tightness - Google Patents

Abstract

The present invention relates to a gas injector for injecting a gaseous medium, comprising a sealing element (5) which is arranged on an outer surface of an outer member (4, 10) of the gas injector, wherein the sealing element (5) is arranged between the outer surface and a Sealing member (6) of an internal combustion engine, wherein the sealing element (5) has an outer sealing geometry (50) for sealing on the receiving element (6) and an inner sealing geometry (51) for sealing on the outer surface of the gas injector, and wherein the sealing element (5) a support region (56) which is arranged on the outer circumference of the sealing element (5) with respect to the inner sealing geometry (51) and is spaced from the outer sealing geometry in the axial direction (XX).

Description

State of the art

The present invention relates to a gas injector for injecting a gaseous medium with improved tightness, in particular with respect to an injector-internal tightness and a tightness with respect to an engine compartment in the installed state, and a gas engine, in particular with a turbocharger.

Gas injectors are known from the prior art in different configurations. Such a gas injector is for example from the DE 10 2013 202 631 A1 known. A sealing of this gas injector with respect to an internal combustion engine component, for example a cylinder head, takes place by means of O-rings. Such an injector is for example in 4 shown. The well-known gas injector 1 includes a closing element 3 , which is attached to a sealing seat 2 seals. An O-ring 15 seals the gas injector 1 opposite a cylinder head 6 from. The use of turbochargers increases the pressure in the area 7 in front of the gas injector 1 , which causes leakage problems. On the one hand, in this case, as indicated by the arrow A, a leak between the cylinder head 6 and the O-ring 15 occur so that gas or air-gas mixtures can penetrate into the engine compartment. On the other hand, as indicated by the arrow B, an injector-internal leakage between a valve housing 10 and a metal sleeve 4 result. This allows gas to enter injector-internal areas. Since the gaseous medium is flammable, this can lead to undesirable problems in the gas injector and / or in the engine compartment.

Disclosure of the invention

The gas injector according to the invention for injecting a gaseous medium with the features of claim 1, in contrast, has the advantage that an improved tightness against high pressures can be obtained. The tightness can easily seal pressures, which can be caused by using a turbocharger. Nevertheless, the gas injector according to the invention nevertheless has a simple and inexpensive construction. The risk of leakage of a combustible medium in the region of the gas injector on the one hand on a mounting side and on the other hand through injector-internal leakage paths can be prevented according to the invention. This is inventively achieved in that the gas injector has exactly one sealing element which seals both a leakage path in the direction of the engine compartment and an injector-internal leakage path. The gas injector in this case comprises a sealing element, which is arranged on an outer surface of an outer injector component of the gas injector, in particular a valve housing. The sealing element is arranged to seal between the outer surface of the injector component and a receiving element of an internal combustion engine, in particular a cylinder head or a suction tube or the like. The sealing element has an outer sealing geometry for sealing on the receiving element and an inner sealing geometry for sealing on the outer surface of the gas injector. The sealing element further comprises a support region, which is arranged on the outer circumference of the sealing element with respect to the inner sealing geometry and is spaced from the outer sealing geometry in the axial direction. As a result, an improved seal on the inner sealing geometry can be achieved so that valve-internal leakage in the region of the inner sealing geometry can be prevented.

The dependent claims show preferred developments of the invention. In order to achieve a sufficient sealing length, the sealing element is preferably designed sleeve-shaped. The sealing element is preferably made of an elastomeric material.

More preferably, the inner sealing geometry has a first sealing region and a second sealing region. As a result, a double sealing of the injector-internal leakage path can be achieved.

In order to achieve the highest possible sealing forces on the inner sealing geometry, a tapered outer region is provided at least partially in the axial direction relative to the inner sealing geometry on the outer circumference of the sealing element.

More preferably, the gas injector comprises a cylinder sleeve, in particular of metal, on which the inner sealing region seals. In this way, in particular, a hitherto provided design of the gas injector can essentially be retained and only the sealing element has to be adapted.

According to a further preferred embodiment of the present invention, the first and the second sealing region are spaced apart in the axial direction of the gas injector by a predetermined distance. In this case, a first distance in the axial direction between the support region and the first sealing region is greater than a second distance between the support region and the second sealing region. As a result, different forces are exerted on the first and second sealing area over the support area. In the arrangement of the support region as described above, different sealing forces on the first and second sealing regions can thus be achieved in a simple manner.

A ratio of the first distance to the second distance is preferably in a range of 1: 1 to 4: 1, and more preferably in a range of 3.5: 1. When the ratio is 1, a sealing force across the support area at the first and second sealing areas is equal.

For mounting the sealing element on the gas injector, the sealing elements are usually present in containers in the form of bulk materials. In order to prevent the sealing elements from sticking to one another during transport and handling of the sealing elements, the sealing element according to the invention preferably has a projecting bead region at at least one end lying in the axial direction. The bead region is preferably formed completely encircling and prevents sticking together of sealing elements.

In order to allow a particularly simple installation, the sealing element further preferably in the axial direction on a lying between the outer and inner sealing region, slimmer central region.

The invention further relates to a gas internal combustion engine comprising a gas injector according to the invention. More preferably, the gas engine further comprises a turbocharger. The gas injector is particularly preferably arranged in a suction pipe of the gas internal combustion engine.

drawing

Hereinafter, a preferred embodiment of the invention will be described in detail with reference to the accompanying drawings. In the drawing is:

1 a schematic sectional view of a gas injector according to an embodiment of the invention,

2 an enlarged partial sectional view of the gas injector of 1 .

3 a schematic partial sectional view of a bead of a sealing element of the gas injector of 1 , and

4 a gas injector according to the prior art,

Preferred embodiments of the invention

The following is with reference to the 1 to 3 a gas injector 1 according to a preferred embodiment of the invention described in detail.

The gas injector 1 of the embodiment is on a suction pipe 7 arranged and used for injecting gaseous fuel into the suction pipe. Alternatively, the gas injector could also blow directly into a combustion chamber.

The gas injector 1 includes a valve housing 10 , a magnet armature 12 , a magnetic coil 13 and a closing spring 14 , An adjusting bolt 16 is provided to a restoring force of the closing spring 14 adjust. The gas is supplied in the axial direction XX of the gas injector (arrow H) and through a filter 11 guided. The magnetic coil 13 is on the valve body 10 fixed. An electrical plug connection 18 is provided on the side of the gas injector.

At one axial end of the armature 12 is a closing element 3 attached to which an elastomeric sealing element 9 is arranged. The closing element 3 closes through openings, which in a valve seat carrier 2 are formed (see. 2 ).

In 1 is the closed state of the gas injector 1 shown. The arrows G indicate a flow direction of the gaseous fuel when the gas injector is open.

The gas injector 1 further comprises a cylindrical metal sleeve 4 which an entrance hall 40 forms for the gaseous fuel from which this then via openings 15 in the suction pipe 7 can get.

The gas injector 1 is in a receptacle 6 arranged, which in this embodiment, a wall portion of the suction pipe 7 is. The receiving element 6 but may for example be a cylinder head or the like.

A sealing element 5 seals between the receiving element 6 and the gas injector 1 from.

The sealing element 5 is in detail 2 seen. The sealing element 5 is a sleeve-shaped sealing element and includes an outer sealing geometry 50 and an inner sealing geometry 51 , The outer sealing geometry 50 seals against the receiving element 6 from. The inner sealing geometry 51 seals against the gas injector 1 from.

How out 2 it can be seen, the inner sealing geometry is a double-seal geometry comprising a first sealing area 52 and a second sealing area 53 , educated. The inner sealing geometry 51 seals on an outer surface of the gas injector, in this embodiment, on the cylinder sleeve 4 of the gas injector.

The sealing element 5 also includes a tapered outside area 54 , which in the axial direction XX at the level of the first sealing area 52 the inner sealing geometry 51 is arranged. The rejuvenating outdoor area 54 thus partially overlaps in the radial direction of the inner sealing geometry 51 ,

The sealing element 5 further comprises a support area 56 , The support area 56 is at an outer periphery of the sealing element 5 is formed and is located in the axial direction XX of the gas injector at the level of the inner sealing geometry 51 , The support area 56 is in the axial direction XX of the outer sealing geometry 50 spaced.

How out 2 it can be seen, are the first sealing area 52 and the second sealing area 53 the inner sealing geometry 51 in the axial direction XX spaced from each other by a distance c. Further, in the axial direction XX is a distance between the support region 56 and the first sealing area 52 denoted by a and a distance between the support area 56 and the second sealing area 53 denoted by b. A ratio of the first distance a to the second distance b in this embodiment is 4: 1, ie, a / b = 4/1. As a result, a different sealing force on the first and second sealing area over the support area 56 exercised. Depending on the distance between the first and second sealing region, the sealing force acting on the respective sealing regions can be varied easily.

Furthermore, due to the tapered outdoor area 54 of the sealing element 5 even at greater pressure, which on the tapered outdoor area 54 , For example, by turbocharging, acts, increase a sealing force.

According to the invention thus a compressive force, which in the region of the tapered outer area 54 on the sealing element 5 acts, used, a higher sealing force at the first and second sealing area 52 . 53 exercise. The force generated by the support area 56 is introduced, then distributed to two sealing areas, depending on the ratio in which the distance between the support area 56 and the first and second sealing areas 52 . 53 in the axial direction XX. Thus, the sealing element according to the invention 5 easy to be designed for a wide variety of requirements.

Thus, according to the invention, both a leakage path between the gas injector 1 and the receiving element 6 as well as a leakage path between the valve housing 10 and the sleeve 4 be securely sealed.

The sealing element 5 also has a slim middle section 55 on, which in the axial direction XX between the outer sealing geometry 50 and the inner sealing geometry 51 lies. As a result, in particular a mounting can be facilitated. Furthermore, also a simple adaptation of the sealing element 5 to a shape of the valve housing 10 , which at his to the suction pipe 7 directed end a radially outwardly projecting projection 10a has to be adjusted.

Furthermore, as in particular from the 2 and 3 it can be seen has the sealing element 5 an annular bead area 8th on. The bead area 8th is at an axial end, which from the suction pipe 7 is directed away, arranged. The bead area 8th has the function, a sticking together of sealing elements 5 to prevent. The sealing elements 5 are usually provided as bulk material during transport. Without the bead area 8th This may lead to an adhesion of sealing elements to each other. By integrating the bead area 8th in the sealing element 5 can thus also faster assembly and damage-free handling and damage-free transport of the sealing elements 5 be ensured. By providing the bead area 8th is a possible area of adherence between the sealing elements 5 reduced to a radius, so that the sealing elements 5 can not stick together anymore.

Since according to the invention now a single sealing element 5 is provided to two leakage paths, namely a leakage path on the outer circumference of the gas injector 1 and a leakage path between the valve housing 10 and cylinder sleeve 4 seals, may be on a previously necessary in the prior art further sealing element, which is arranged in the interior of the gas injector, be dispensed with. According to the invention, a seal can be sealed even at high pressures generated by 5 turbochargers, in particular in the range of 1.5 to 2 × 10 Pascals. Thus, according to the invention, a safe and durable operation of the gas injector 1 be ensured.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102013202631 A1 [0002]

Claims (11)

Gas injector for injecting a gaseous medium, comprising - a sealing element ( 5 ), which on an outer surface of an outer member ( 4 . 10 ) of the gas injector is arranged, - wherein the sealing element ( 5 ) is arranged between the outer surface and a receiving element ( 6 ) of an internal combustion engine, - wherein the sealing element ( 5 ) an outer sealing geometry ( 50 ) for sealing on the receiving element ( 6 ) and an inner sealing geometry ( 51 ) for sealing on the outer surface of the gas injector, and - wherein the sealing element ( 5 ) a support area ( 56 ), which on the outer circumference of the sealing element ( 5 ) compared to the inner sealing geometry ( 51 ) and is spaced from the outer sealing geometry in the axial direction (XX). Gas injector according to claim 1, characterized in that the sealing element ( 5 ) is sleeve-shaped. Gas injector according to one of the preceding claims, characterized in that the inner sealing geometry ( 51 ) a first sealing area ( 52 ) and a second sealing area ( 53 ) having. Gas injector according to one of the preceding claims, characterized in that the sealing element ( 5 ) a rejuvenating outdoor area ( 54 ), which in the axial direction (XX) at least partially opposite the inner sealing geometry. Gas injector according to one of the preceding claims, further comprising a cylinder sleeve ( 4 ), at which the inner sealing geometry ( 51 ) seals. Gas injector according to one of claims 3 to 5, characterized in that the first sealing region ( 52 ) and the second sealing area ( 53 ) in the axial direction (XX) of the gas injector by an overall distance (c) are spaced from each other and a first distance (a) in the axial direction (XX) between the support region ( 56 ) and the first sealing area ( 52 ) is greater than a second distance (b) between the support area ( 56 ) and the second sealing area ( 53 ): Gas injector according to claim 6, characterized in that a ratio of the first distance (a) to the second distance (b) in a range of 1: 1 to 4: 1. Gas injector according to one of the preceding claims, characterized in that the sealing element ( 5 ) at a end lying in the axial direction (XX) has a protruding bead area (US Pat. 8th ) having. Gas injector according to one of the preceding claims, characterized in that the sealing element ( 5 ) in the axial direction (XX) between the outer sealing geometry ( 50 ) and the inner sealing geometry ( 51 ) a streamlined middle region ( 55 ) having. A gas internal combustion engine comprising a gas injector according to any one of the preceding claims. A gas engine according to claim 10, further comprising a turbocharger.

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