DE102022209616A1 - Gas injector with armature damper - Google Patents

Abstract

The present invention relates to a gas injector for blowing in a gaseous medium, comprising a closing element (2), which opens and closes a through opening (4) on a sealing seat (3), and a restoring element (6), which closes the closing element (2). resets the starting position, a magnetic actuator (5) with an armature, which has a maximum armature stroke (S0), the magnetic actuator (5) actuating the closing element (2), and an armature damper (7), which is set up during an opening process of the gas injector to reduce a speed of the anchor (51) before the anchor (51) hits an anchor stop (53).

Description

State of the art

The present invention relates to a gas injector for blowing a gaseous medium, for example hydrogen or natural gas or the like, directly into a combustion chamber of an internal combustion engine with an armature damper.

Gas injectors are known from the prior art in different designs. Due to the gaseous medium that gas injectors blow in, gas injectors must perform a very large stroke compared to injectors for liquid media, for example fuel injectors. However, in gas injectors this can lead to significant wear on components, particularly on a sealing seat and a stroke limiter. The large switching forces required for gas injectors increase the wear on the components during operation.

Disclosure of the invention

The gas injector according to the invention for blowing in a gaseous medium, in particular for blowing in hydrogen or natural gas, with the features of claim 1 has the advantage that component wear can be significantly reduced. In particular, wear on an anchor can be significantly reduced. Furthermore, the gas injector according to the invention has significantly improved noise behavior. This is achieved according to the invention in that the gas injector has a closing element which opens and closes a through opening on a sealing seat. Furthermore, the gas injector includes a restoring element which returns the closing element to a closed starting position. Furthermore, the gas injector comprises a magnetic actuator with an armature, the magnetic actuator actuating the closing element and the armature having a maximum armature stroke S0. Furthermore, an armature damper is provided, which is set up to reduce a speed of the armature before the armature hits an armature stop, in particular an inner pole of the magnetic actuator, during an opening process of the gas injector. This means that significantly reduced wear on the armature and the armature stop can be achieved and excessive wear on the contact points between the armature and the armature stop during the opening stroke of the gas injector can be prevented.

The subclaims show preferred developments of the invention.

The anchor damper is preferably arranged on a side of the anchor facing away from the sealing seat. This means that the functionality and performance of the magnetic actuator is not restricted and the armature can carry out the maximum planned armature stroke S0 up to the armature stop without any interference from an armature damper in this area.

The anchor damper preferably comprises a spring element which is arranged on the side of the anchor facing away from the sealing seat. In other words, the spring element is arranged on a rear side of the anchor. This results in many degrees of freedom with regard to the design of the spring element. A very compact design of the gas injector can also be made possible.

Further preferably, the closing element comprises a valve needle and an anchor bolt, the anchor being fixed to the anchor bolt. The two-part structure of the closing element also increases the degrees of freedom with regard to the design of the components of the gas injector.

According to a further preferred embodiment of the invention, the armature damper comprises a, preferably cup-shaped, support element which is fixed to an inner housing of the gas injector. The support element serves to support the spring element. With a cup-shaped design of the support element, a radial positioning of the spring element is also ensured when a cylinder spring is used as the spring element.

More preferably, the armature damper further comprises a pressure washer and a first adjusting washer. The spring element of the anchor damper is arranged between the pressure washer and the support element of the anchor damper. Furthermore, a position of the pressure washer in the axial direction is defined by means of the first adjusting disk. This results in an easy-to-use adjustment option for a desired preload of the spring element of the anchor damper.

According to a further preferred embodiment of the invention, the armature damper further comprises a second adjusting disk which is fixed on the closing element, the second adjusting disk defining an axial gap S1 between the pressure disk and the second adjusting disk when the gas injector is closed. The axial gap S1 is smaller than the maximum armature stroke S0. The second adjusting disk is preferably fixed to the anchor bolt.

More preferably, the support element has a guide area on an inner circumference the closing element, in particular for the anchor bolt.

The spring element of the armature damper is further preferably a cylindrical coil spring or a spring washer. The spring washer can be, for example, a wave spring or a plate spring or the like.

The gas injector further preferably comprises a hydraulic damper, which is arranged on a side of the closing element facing away from the sealing seat. The hydraulic damper is preferably set up to support the closing element during the opening process as well as the closing process. In conjunction with the anchor damper, the anchor is particularly well dampened during the opening process, so that signs of wear on the anchor and anchor bolts can be avoided. The hydraulic damper also enables compensation for temperature-related changes in length of the components of the gas injector.

Further preferably, the armature damper is set up to be activated with a time delay after the start of an opening process of the gas injector, the axial gap between the pressure disk and the second adjusting disk defining the time delay.

The gas injector is preferably a gas injector that opens to the outside. Further preferably, the gas injector is designed to directly inject a gaseous fuel into a combustion chamber of an internal combustion engine.

The present invention further relates to an internal combustion engine with a gas injector according to the invention. The gas injector preferably blows hydrogen or natural gas or another fuel gas directly into a combustion chamber of the internal combustion engine.

Brief description of the drawings

• 1 eine schematische Schnittansicht eines Gasinjektors gemäß einem ersten bevorzugten Ausführungsbeispiel der Erfindung,
• 2 eine schematische, vergrößerte Teilschnittansicht des Gasinjektors von 1 im geschlossenen Zustand,
• 3 eine schematische, vergrößerte Teilschnittansicht des Gasinjektors von 1 im teilweise geöffneten Zustand,
• 4 eine schematische Schnittansicht eines Gasinjektors gemäß einem zweiten bevorzugten Ausführungsbeispiel der Erfindung, und
• 5 eine schematische Darstellung eines Einzelteils des Ankerdämpfers des zweiten Ausführungsbeispiels des Gasinjektors von 4.

Preferred exemplary embodiments of the invention are described in detail below with reference to the accompanying drawing. In the drawing is:

• 1 a schematic sectional view of a gas injector according to a first preferred embodiment of the invention,
• 2 a schematic, enlarged partial sectional view of the gas injector from 1 in the closed state,
• 3 a schematic, enlarged partial sectional view of the gas injector from 1 in the partially opened state,
• 4 a schematic sectional view of a gas injector according to a second preferred embodiment of the invention, and
• 5 a schematic representation of an individual part of the armature damper of the second exemplary embodiment of the gas injector 4 .

Preferred embodiments of the invention

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

How out 1 As can be seen, the gas injector 1 for injecting a gaseous medium into a combustion chamber 30 of an internal combustion engine comprises a closing element 2 and a magnetic actuator 5, which actuates the closing element 2. The closing element 2 is designed in two parts and includes a valve needle 20 and an anchor bolt 21.

The magnetic actuator 5 includes an inner pole 50, an armature 51 and a coil 52. An armature stop 53 is formed on the inner pole 50. The anchor stop 53 limits an opening stroke of the closing element 2.

The closing element 2 has a valve plate 20a on the valve needle 20 on the side facing the combustion chamber 30, which seals against a sealing seat 3. During the opening process, the closing element 2 releases an annular through opening 4 on the sealing seat 3 and closes it. The gas injector is therefore an injector that opens outwards, with the closing element 2 in the direction of arrow A (see 1 ) is moved outwards into the combustion chamber 30.

The gaseous fuel is injected into the combustion chamber 30 1 indicated by the arrows C, whereby it should be noted that 1 shows the closed state of the gas injector.

A gas inlet 31 is provided at the opposite end of the sealing seat 3. How out 1 As can be seen, the gas inlet 31 is arranged in line with the closing element 2 on a central axis which defines an axial direction XX of the gas injector 1.

In 1 The arrows B indicate the gas flow through the gas injector 1 starting from the gas inlet 31 to the sealing seat 3.

A reset element 6 places the gas injector 1 back into position after an opening process 1 closed state shown. The restoring element is in this embodiment play a cylindrical coil spring, which is supported on a spring plate 60 and a housing component 10a.

The gas injector 1 further comprises an armature damper 7, which is set up to brake and dampen a speed of the armature 51 before it hits the armature stop 53 during an opening process of the gas injector 1.

The armature damper 7 includes a cup-shaped support element 70, a spring element 75 and an inner housing 71. The inner housing 71 is sleeve-shaped and fixed to the inner pole 50.

The armature damper 7 further comprises a pressure washer 72, a first adjusting washer 73 and a second adjusting washer 74. As shown 2 As can be seen, the spring element 75 is arranged between the pressure washer 72 and the cup-shaped support element 70. Due to the cup-shaped design of the support element 70, the spring element 75, which in this exemplary embodiment is a cylindrical helical spring, is stabilized in the radial direction. The spring element 75 points in the closed state, which is in the 1 and 2 is shown, a spring force F with which the pressure disk 72 is pressed against the first adjusting disk 73.

The first adjusting disk 73 is fixed to an inner circumference of the inner housing 71.

A guide 70a for the anchor bolt 21 is provided on the inner circumference of the support element 70.

The second adjusting disk 74 is fixed on the closing element 2, more precisely on the anchor bolt 21. When the gas injector is closed ( 2 ) there is an axial gap S1 between the second adjusting disk 74 and the pressure disk 72. A preload force of the spring element 75 can thus be adjusted by positioning the first adjusting disk 73 in the axial direction XX, which defines an axial position of the pressure disk 72.

The pressure washer 72 is arranged to be axially movable inside the inner housing 71.

The anchor bolt 21 is as in the 1 and 2 shown, guided through the inner pole 50 in a freely movable manner, with a guide 50a preferably being provided for the anchor bolt 21. The anchor 51 is firmly connected to the anchor bolt 21 by means of a welded connection 51a.

When the gas injector 1 is closed, a maximum opening stroke of the closing element 2 is defined by an armature stroke S0. The armature stroke S0 is formed between the armature 51 and the inner pole 50. The armature stroke S0 is larger than the axial gap S1 between the second adjusting disk 74 and the pressure disk 72.

By providing the axial gap S1, the armature damper 7 is activated with a time delay when the gas injector is opened. For an opening process of the gas injector, the coil 52 is energized, whereby the armature 51 moves in the direction of arrow D (cf. 2 ) is pulled towards the inner pole 50. Due to the movement of the armature 51, the anchor bolt 21 and thereby also the valve needle 20 are moved in the axial direction XX, so that the gas injector 1 opens at the sealing seat 3 and releases the through opening 4.

This allows the gaseous fuel to be injected into the combustion chamber 30 (arrows C). Since the second adjusting disk 74 is firmly connected to the anchor bolt 21, the second adjusting disk 74 is also moved in the axial direction XX during the opening process. After the axial gap S1 has been covered, the second adjusting disk 74 lies against the pressure disk 72. This condition is in 3 shown. Until the axial gap S1 is overcome, the armature damper 7 is not yet in action, which enables delayed actuation of the armature damper 7.

If the anchor 51 comes out of the in 2 shown position is pulled further in the direction of arrow D onto the inner pole 50, the second adjusting disk 74 also moves further in the direction of the sealing seat 3 and takes the pressure disk 72 with it, which is arranged to be freely movable in the inner housing 71. As a result, the spring element 75 is compressed, whereby the armature 51 is slowed down in its speed of movement. At the in 3 In the state shown, the armature 51 still has to overcome the remaining partial axial gap S2 between the armature 51 and the inner pole 50 until the gas injector is completely opened. The complete opening occurs when the anchor 51 rests on the anchor stop 53 on the inner pole 50.

When the remaining axial gap S2 is covered, the armature damper 7 is activated, so that the impact speed of the armature 51 on the inner pole 50 is significantly reduced, thereby reducing wear on these components. Furthermore, impact noise of the armature 51 on the inner pole 50 can also be reduced, whereby the noise behavior of the gas injector 1 is significantly improved.

As soon as the injection has ended, the current supply to the coil 52 is stopped so that the restoring element 6 pushes the closing element 2 back into the in 1 and 2 starting position shown resets. The anchor 51 is returned to the starting position away from the anchor stop 53. The pressure washer 72 is also inserted into the in. by means of the spring element 75 2 shown closed position on the first adjusting disk 73 is reset.

The gas injector 1 further comprises a hydraulic damper 8, which is operatively connected to the closing element 2. The hydraulic damper 8 is designed to brake and dampen the closing element, particularly when returning from the open state to the closed state. This keeps wear on the sealing seat 3 of the gas injector to a minimum. By providing the anchor damper 7, the hydraulic damper 8 can be constructed very simply and in particular can only be set up to dampen the closing element 2 during the resetting process.

Thus, the armature damper 7 can be optimally designed for the armature and damping during the opening process and the hydraulic damper 8 can be optimally designed for damping when the gas injector is closing.

The 4 and 5 show a gas injector 1 according to a second exemplary embodiment of the invention, with identical or functionally identical parts being designated by the same reference numerals.

Like in particular 5 As can be seen, the armature damper 7 of the second exemplary embodiment includes a wave spring as a spring element 75. As in the first exemplary embodiment, the wave spring is arranged between the support element 70 and the pressure washer 72. The support element 70 can be designed as a simple disk.

Otherwise, this exemplary embodiment corresponds to the previous exemplary embodiment, so that reference can be made to the description given there.

Claims (11)

Gas injector for blowing in a gaseous medium, comprising - a closing element (2), which releases and closes a through opening (4) on a sealing seat (3), - a restoring element (6), which returns the closing element (2) to a closed starting position, - a magnetic actuator (5) with an armature (51), which has a maximum armature stroke (S0), the magnetic actuator (5) actuating the closing element (2), and - an armature damper (7), which is set up to reduce a speed of the armature (51) before the armature (51) hits an armature stop (53) when the gas injector is opened. Gas injector after Claim 1 , wherein the armature damper (7) is arranged on a side of the armature (51) facing away from the sealing seat (3). Gas injector after Claim 2 , wherein the armature damper (7) has a spring element (75) which is arranged on a side of the armature (51) facing away from the sealing seat (3). Gas injector according to one of the preceding claims, wherein the closing element (2) comprises a valve needle (20) and an anchor bolt (21), the anchor (51) being fixed on the anchor bolt (21). Gas injector after one of the Claims 3 or 4 , wherein the armature damper (7) comprises a support element (70) for the spring element (75) and an inner housing (71), the support element (70) being fixed to the inner housing (71). Gas injector after Claim 5 , wherein the armature damper (7) further comprises a thrust washer (72) and a first adjusting washer (73), wherein the spring element (75) is arranged between the thrust washer (72) and the support element (70) and wherein a position of the thrust washer (72 ) is defined in the axial direction (XX) by means of the first adjusting disk (73). Gas injector after Claim 6 , further comprising a second adjusting disk (74) which is fixed on the closing element (2), wherein the second adjusting disk (74) defines an axial gap (S1) between the pressure disk (72) and the second adjusting disk (74) when the gas injector is closed and where the axial gap (S1) is smaller than the maximum armature stroke (S0). Gas injector according to one of the preceding claims, wherein the support element (70) has a guide region (70a) for the closing element (2) on an inner circumference. Gas injector after one of the Claims 3 until 8th , wherein the spring element (75) is a coil spring or a spring washer or a wave spring or a disc spring. Gas injector after one of the Claims 7 until 9 , wherein the armature damper (7) is set up to be activated with a time delay after the start of an opening process of the gas injector, the axial gap (S1) between the pressure disk (72) and the second adjusting disk (74) defining the time delay. Gas injector according to one of the preceding claims, further comprising a hydraulic damper (8), which is arranged at an end of the closing element (2) facing away from the sealing seat and is set up to carry out damping at least during an opening process of the gas injector.

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