KR102477719B1 - Fuel injection valve - Google Patents

Abstract

A fuel injection valve (1) used in particular as an injector for a fuel injection system of a motor vehicle comprises an actuator module (6) with an armature (8). In addition, a valve needle 4 actuable via the armature 8 is provided, and a stop member 12 is arranged on the valve needle 4, the stop member being formed by welding seams 28, 29. It is coupled to the valve needle (4). The armature 8 of the actuator module 6 hits the stop member 12 upon actuation of the valve needle 4 along the longitudinal axis 5 . In this case, the weld seams 28 , 29 extend coaxially with respect to the longitudinal axis 5 .

Description

Fuel injection valve {FUEL INJECTION VALVE}

The present invention relates to fuel injection valves, in particular to injectors for fuel injection systems of internal combustion engines. In particular, the invention relates to the field of injectors for fuel injection systems of motor vehicles. A particularly suitable application appears in the field of internal combustion engines, where gasoline is injected directly by means of a fuel injection valve into the combustion chamber of a mixture compression type, externally fired internal combustion engine.

In the case of a fuel injection valve for gasoline direct injection having a valve needle moved against a closing spring by an actuator so that a predetermined amount of fuel is introduced into the combustion chamber as intended, the actuator may be implemented electromagnetically or piezoelectrically. Especially in electromagnetic actuators, the magnetic armature can be separated from the valve needle. When opening the valve, the magnetic armature must be separated from the lower stopper on the valve needle, that is, the stopper formed by the stop sleeve, as quickly as possible, overcome the free path of the armature quickly, and open the valve quickly when hitting the upper stopper formed by the stop ring. do. When the current supply to the actuator is terminated, the valve needle closes the valve seat again. After the valve needle closes the valve seat again, the magnetic armature continues its movement until it hits the stop sleeve. In this embodiment, it is possible for the stop ring to be coupled to the valve needle by a radial weld seam.

A number of problems are presented in fuel injection valve embodiments in which the stop sleeve is joined to the valve needle by a radial weld seam. A radial weld seam between the stop ring and valve needle results in a metallurgical notch at the bottom and top of the weld seam. The impact load of the magnetic armature on the stop ring can destroy the valve needle and render the fuel injection valve no longer functional. Also, for the functioning of the fuel injection valve, it is important how small the axial runout deviation of the lower face of the stop ring relative to the valve needle is. However, the radial weld seam associated with a loose fit results in large axial runout variations as the stop ring is welded at an angle on the needle.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel injection valve in which the axial runout deviation of the contact surfaces is reduced and thus the valve function is improved.

This problem is solved by a fuel injection valve comprising the features of claim 1 .

A fuel injection valve according to the invention comprising the features of claim 1 has the advantage that an improved design and function are possible. In particular, the load capacity in relation to the cooperation of the actuator module and the valve needle can be improved, and the one or more working connections between the actuator module and the valve needle in relation to the geometry of the actuator module and the valve needle can be improved. In particular in this case, the axial runout deviation of the contact surfaces can be reduced, so that the valve function can be improved.

The advantageous improvement of the fuel injection valve according to claim 1 is possible by means of the measures specified in the dependent claims.

Two stop members can be arranged on the valve needle, one stop member or two stop members of said stop members are each coupled to the valve needle by at least one welding seam, said valve needles about a longitudinal axis. extends at least approximately coaxially with respect to In particular, the stop element formed in this way can be designed as a stop ring. Additionally or alternatively, the stop member formed in this way can be designed as a stop sleeve. In particular with regard to the stop ring and the stop sleeve, a preferred coupling with the valve needle can be achieved by means of at least one welding seam extending at least approximately coaxially with respect to the longitudinal axis.

It is also preferred that the stop member surrounds the valve needle in a closed state in the circumferential direction, and a crimp connection between the stop member and the valve needle is formed due to welding deformation caused by the formation of at least one weld seam. Thus, metallurgical notches in the valve needle, which occur during welding, are reduced, and also a crimp connection is formed between the stop member, in particular the stop ring or stop sleeve, and the valve needle by welding deformation, which join adds to the weld seam to stop the force. It can transfer from the member to the valve needle, thereby reducing the load on the weld seam, thereby increasing the strength of the assembly at the valve needle.

Further, the stop member comprises a ring-shaped recess on an end face remote from the armature, and at least one weld seam is provided at least partially in the region of the ring-shaped recess, so as to couple the stop member to the valve needle in the region of the ring-shaped recess. It is desirable to do Due to this, the space required for the coaxial extension of the weld seam is advantageously ensured. In this case also it is preferred that the stop member is coupled to the valve needle by a plurality of weld seams, the plurality of weld seams extending at least approximately coaxially with respect to the longitudinal axis. In particular, in this case exactly two welding seams can be provided, which are arranged offset from each other by 180° in the circumferential direction relative to the longitudinal axis. With this arrangement of the two weld seams, a uniform distribution in the circumferential direction can be achieved. However, more than two weld seams may be provided, which weld seams extend at least approximately coaxially with respect to the longitudinal axis and are equally distributed and disposed circumferentially with respect to the longitudinal axis.

In a variant embodiment, it is also possible that a plurality of weld seams are provided, the weld seams extending at least approximately coaxially with respect to the longitudinal axis and distributing non-uniformly in the circumferential direction with respect to the longitudinal axis.

Further, guide ridges are provided for axial guiding of the stationary member, the guide ridges being uniformly distributed in the circumferential direction with respect to the longitudinal axis and disposed on the stationary member, each of the welding seams, viewed in the circumferential direction, respectively It is preferably provided between two adjacent guide ridges. Further, it is preferable that at least two pairs of adjacent guide ridges are provided, each with a free area between them, and no welding seam is provided on the stationary member within the free area. For example, four guide ridges may be provided, and each one cavity is provided between each adjacent guide ridge. The guide ridges are formed such that the cavity is deep enough that two axial weld seams can be implemented on the two opposite sides of the valve needle with a sufficiently large joint length. The remaining two cavities are used for the alignment of the stop element, in particular the stop sleeve, and form a free area. By reducing component weight, the dynamics of the fuel injection valve (injection valve) can be increased. Also, component length and unit cost can be minimized. If a larger joint length is required, the formation of two additional weld seams in the two remaining, opposite cavities can be achieved in a corresponding manner by rotation of the stop element, in particular the stop ring, by 90° relative to the longitudinal axis. In this embodiment, a weld seam may always be provided between adjacent guide ridges. The four recesses ensure the flow of medium in the finished injection valve.

It is also preferred that the stop member comprises a flat circular stop face facing the armature, said circular stop face being oriented perpendicular to the longitudinal axis. By virtue of the axial orientation of the weld seams, engagement with the valve needle can be effected such that the stop member is aligned and welded to the valve needle. This avoids axial runout deviations. Thus, the runout deviation in the axial direction of the contact surfaces of the stop member is reduced. Due to this, the valve function is improved. Thus, the strength and valve function of the needle assembly can be improved.

Functional improvements can in particular improve the formation of qdyn-characteristic curves. Thus, an improved formation with respect to the injection amount qdyn is achieved. Also, manufacturing tolerances and CVO signals used to control valve actuation may be improved.

Preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Corresponding parts in the drawings are denoted by like reference numerals.

1 is a schematic cross-sectional view of a fuel injection valve according to an embodiment of the present invention.
Fig. 2 is a schematic cross-sectional view of the fuel injection valve shown in Fig. 1 according to the embodiment of the present invention;
Fig. 3 is a schematic view of the fuel injection valve shown in Fig. 2 viewed from the direction indicated by III;

1 shows a schematic excerpt in cross section of a fuel injection valve 1 according to an embodiment. The fuel injection valve 1 can in particular be used as an injector for a fuel injection system of a motor vehicle. Of course, the fuel injection valve 1 can also be used for other fuel injection systems of internal combustion engines. In particular, the fuel injection valve 1 can be formed as a high-pressure injection valve for injecting fuel, in particular gasoline, into a combustion chamber of an internal combustion engine under high pressure.

The fuel injection valve 1 comprises a housing with a valve seat 2 and a valve closing body 3 denoted by a ball 3 . The valve closing body 3 is actuated via a valve needle 4 movable along a longitudinal axis 5 . An actuator 6 is used to actuate the valve needle 4 . Also provided is a valve spring 7 configured as a return spring 7 in this embodiment.

The actuator 6 is formed as an electromagnetic actuator 6 in this embodiment. Of course, other designs of actuator 6 are possible.

The actuator 6 includes an armature 8 formed as a magnetic armature 8, and through holes 9 and 10 distributed around the circumference of the armature 8 are provided in suitable numbers. An amateur free path (11) is established for the armature (8). The armature free path 11 is in this case via a gap between one stop element 12 and a further stop element 13 arranged and fixed on the valve needle 4 spaced apart from each other along the longitudinal axis 5. given The stop members 12 and 13 are in this case arranged on mutually distant end faces 14 and 15 of the armature 8 .

The stop member 12 is formed as a stop ring 12 in this embodiment. A further stop member 13 is formed as a stop sleeve 13 . When the valve needle 8 is actuated, the end face 14 of the armature 8 hits the stop ring 12 . Upon further movement of the armature 8 in the opening direction 16, the sealing seat formed between the valve closing body 3 and the valve seat 2 opens. Due to this, the fuel injection valve 1 can be operated to inject fuel directly into a corresponding combustion chamber of, for example, an internal combustion engine.

After operation, the armature 8 is moved back to its starting position to close the sealing seat between the valve closing body 3 and the valve seat 2. In this case, the stop member 12 is subjected to a restoring force opposite to the opening direction 16 by the valve spring 7 , which returns the valve needle 4 to the starting position shown in FIG. 1 .

The actuator module (actuator) 6 also comprises a spring port 20 and a further valve spring 21 disposed within said spring port 20, said valve spring 21 having the starting point shown in FIG. It is used as a return spring to ensure the armature free path (11) in the state.

FIG. 2 shows a schematic excerpted sectional view of the fuel injection valve 1 shown in FIG. 1 according to the embodiment. The stop ring 12 surrounds the valve needle 4 in a circumferentially closed state. The stop ring 12 has an end face 25 facing the end face 14 of the armature 8 . The stop ring 12 also includes an end face 26 remote from the end face 25 . The end face 26 of the stop ring 12, away from the armature 8, includes a ring-shaped recess 27. The stop ring 12 is coupled to the valve needle 4 by means of at least one welded seam 28,29. In this embodiment, a weld seam 28 and a weld seam 29 (FIG. 3) are provided. The weld seams 28 and 29 each extend coaxially with respect to the longitudinal axis 5 . Due to this, the weld seams 28 and 29 are formed as axial weld seams 28 and 29 . In this case, the weld seam 28 partially extends into the region of the annular recess 27 . In this embodiment the weld seam 28 is provided in the region of the ring-shaped recess 27 of the collar 30 of the stop ring 12 and in the central region 31 of the stop ring 12 . The stop ring 12 also includes an additional collar 32 on which an end face 25 is formed. In this embodiment the weld seam 28 does not extend into the area of the collar 32 . Because of this, the formation of the weld seam 38 does not affect the shape of the end face 25 .

The weld seam 29 is formed correspondingly to the weld seam 28 .

Welding deformation is caused by the formation of the weld seams 28, 29. Due to the welding deformation, a crimp connection is formed between the stop ring 12 and the valve needle 4 . The joining of the stop ring 12 and the valve needle 14 results from a welded joint via weld seams 28, 29 and a further crimped joint. The welding seams 28 , 29 in this case connect the stop ring 12 to the valve needle 4 , in particular in the region of the annular recess 27 .

Due to this, the stop ring 12 is aligned with respect to the longitudinal axis 5 . The end face 25 is oriented perpendicular to the longitudinal axis 5 and is formed as a plane. Due to this, the stopper 25 is formed by the end face 25 of the stop ring 12 for the armature 8. The stopper 25 is here formed by the stop face 25 .

The fixing of the stop sleeve 13 on the valve needle 4 can be implemented correspondingly to the fixing of the stop ring 12 on the valve needle 4 . In an alternative embodiment, the stop ring 12 and the stop sleeve 13 may be formed over suitable weld seams 28 , 29 extending coaxially with respect to the longitudinal axis 5 . In another possible variant, it is also possible that only the stop sleeve 13 and not the stop ring 12 are connected to the valve needle 4 by means of these axial welding seams 28 , 29 .

FIG. 3 shows an excerpted schematic view of the fuel injection valve 1 shown in FIG. 2 viewed from the direction indicated by III. This embodiment is provided with guide ridges 35 , 36 , 37 , 38 , which can be formed on a common guide sleeve 39 , for example. Guide ridges are used for axial guidance of the stop ring 12 . For this purpose, guide ridges 35 to 38 are arranged on the stop ring 12 uniformly distributed in the circumferential direction about the longitudinal axis 5 . Welding seams 28 and 29 are provided between two adjacent guide ridges 35 to 38, respectively, as viewed in the circumferential direction. A weld seam 28 is formed over the region 40 between the guide ridges 37 and 38 . Correspondingly, a weld seam 29 is formed above the region 41 between the guide ridges 35 and 36 . A free area 42 is given between the guide ridges 35 and 38, within which no weld seam is provided on the stop ring 12. Corresponding to the free area 42, a further free area 43 is given between the guide ridges 36, 37, within which the weld seam on the stop ring 12 is not provided

The free regions 42 , 43 form cavities 42 , 43 in this embodiment, which cavities 42 , 43 are used for alignment of the stop ring 12 . Welding seams 28 and 29 are implemented on two opposite sides in areas 40 and 41 . Due to this, the component weight can be reduced and the dynamics of the fuel injection valve increased. Also, component length and unit cost can be minimized. If more joint length is required in relation to the overall length of the weld seams 28, 29, rotation of the stop ring 12 by 90° allows two additional weld seams into the two remaining cavities 42, 43. can be formed. In this case, weld seams 28 and 29 are always provided between adjacent guide ridges 35 to 38 .

In an alternative embodiment, a different number of weld seams 28, 29 and possibly only one weld seam may be provided.

The present invention is not limited to the foregoing embodiments and modifications.

1 fuel injection valve
4 valve needle
5 longitudinal axis
6 actuator module
8 amateur
12, 13 stop member
25 stop face
26 end face
27 recess
28, 29 weld seam
35-38 guide ridge
42, 43 free area

Claims (10)

Fuel injection valve (1) comprising an actuator module (6) with an armature (8) and a valve needle (4) actuable via said armature (8), said valve needle (4) having at least one stop A member (12, 13) is arranged, the stop member being joined to the valve needle (4) by at least one weld seam (28, 29), the armature (8) of the actuator module (6) being connected to the valve When the needle (4) runs along the longitudinal axis (5) it strikes the stop member (12, 13) and the at least one weld seam (28, 29) is at least relative to the longitudinal axis (5). elongated approximately coaxially,
The stop member 12, 13 surrounds the valve needle 4 in a closed state in the circumferential direction, and due to the welding deformation caused by the formation of the at least one weld seam 28, 29, the stop member ( A fuel injection valve characterized in that a crimp connection is formed between 12, 13) and the valve needle (4). Fuel injection valve (1) comprising an actuator module (6) with an armature (8) and a valve needle (4) actuable via said armature (8), said valve needle (4) having at least one stop A member (12, 13) is arranged, the stop member being joined to the valve needle (4) by at least one weld seam (28, 29), the armature (8) of the actuator module (6) being connected to the valve When the needle (4) runs along the longitudinal axis (5) it strikes the stop member (12, 13) and the at least one weld seam (28, 29) is at least relative to the longitudinal axis (5). elongated approximately coaxially,
The stop member (12, 13) comprises a ring-shaped recess (27) on an end face (26) remote from the armature (8), wherein the at least one weld seam (28, 29) is at least partially ring-shaped. A fuel injection valve, characterized in that it is provided in the region of a recess (27) to engage the stop member (12, 13) with the valve needle (4) in the region of the annular recess (27). Fuel injection valve (1) comprising an actuator module (6) with an armature (8) and a valve needle (4) actuable via said armature (8), said valve needle (4) having at least one stop A member (12, 13) is arranged, the stop member being coupled to the valve needle (4) by at least one weld seam (28, 29), the armature (8) of the actuator module (6) being connected to the valve When the needle (4) runs along the longitudinal axis (5) it strikes the stop member (12, 13) and the at least one weld seam (28, 29) is at least relative to the longitudinal axis (5). elongated approximately coaxially,
Guide ridges 35 - 38 are provided for axial guidance of the stop members 12 , 13 , the guide ridges 35 - 38 being uniform in the circumferential direction about the longitudinal axis 5 . Distributed and arranged around the stop member (12, 13), characterized in that each of the welding seams (28, 29) is provided between two adjacent guide ridges (35-38) when viewed in the circumferential direction. fuel injection valve. According to any one of claims 1 to 3,
Fuel injection valve, characterized in that the stop member (12) is designed as a stop ring (12) and/or the stop member (13) is designed as a stop sleeve (13). According to any one of claims 1 to 3,
The stop member (12, 13) is coupled to the valve needle (4) by means of a plurality of weld seams (28, 29), the plurality of weld seams (28, 29) about the longitudinal axis (5). A fuel injection valve characterized in that it extends at least approximately coaxially. According to claim 5,
The fuel injection valve, characterized in that the weld seams (28, 29) are arranged uniformly distributed in the circumferential direction with respect to the longitudinal axis (5). According to claim 3,
At least two pairs (35-38) of adjacent guide ridges (35-38) are provided, between which free regions (42, 43) are provided, in which free regions (42, 43) the stop member (12) is provided. , 13) is not provided with a weld seam, or one weld seam (28, 29) is always provided between adjacent guide ridges (35-38). According to any one of claims 1 to 3,
The stop member (12, 13) comprises a flat, circular stop surface (25) facing the armature (8), the circular stop surface (25) oriented perpendicular to the longitudinal axis (5). Characterized in that the fuel injection valve. According to any one of claims 1 to 3,
The armature 8 is guided on the valve needle 4 movably along the longitudinal axis 5 and/or the actuator module 6 has an armature 8 formed as a magnetic armature 8. Fuel injection valve, characterized in that it is formed as an electromagnetic actuator module (6). delete

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