DE10152268A1 - Injector - Google Patents

Abstract

An injection valve is described with a valve control module (2) and a nozzle module (3) which adjoins the valve control module and which has a nozzle needle (14) which is axially displaceable in a nozzle body. The valve control module (2) borders the nozzle module (3) with a throttle plate (16). A spring plate (22) and a spring (19) arranged between the spring plate (22) and the nozzle needle (14) are provided in the region of an end of the nozzle needle (14) facing the throttle plate (16). The nozzle needle (14) is acted upon by an axial force from the spring (19) in the closing direction, a stop being provided for a stroke of an opening movement of the nozzle needle (14). Depending on a positive deviation of a real stroke value from a defined stroke value of the nozzle needle (14), means (27) are provided for reducing the real stroke value in the direction of the defined stroke value of the nozzle needle (14) (FIG. 3).

Description

State of the art

The invention relates to an injection valve with a Valve control module and a nozzle module according to the im The preamble of claim 1 defined in more detail.

Such an injection valve is known from practice and can be used in conjunction with Common rail injection systems used for diesel internal combustion engines become.

An injector known from practice which introduces mentioned type comprises a nozzle body of a nozzle module, in which a nozzle needle is axially displaceable and which at its one combustion chamber of the internal combustion engine facing end is provided with a plurality of injection openings.

These injection openings are made axially sliding nozzle needle controlled.

The injector further includes Valve control module, which has a module housing and an arranged thereon Piezoelectric actuator module. To the piezoelectric actuator module joins a valve member Arrangement over which a travel path of transfer piezoelectric actuator modules to a valve closing member becomes.

The valve member arrangement has a first piston, one so-called control piston, and a second piston, one so-called actuating piston, between which one hydraulic translation device or a hydraulic Coupler is arranged. The hydraulic coupler serves at the same time the compensation of axial differences in length caused by temperature differences.

The nozzle needle is moved using the valve control module Pressure changes in a so-called valve control room controlled, the pressure changes in the valve control chamber lead to an axial displacement of the nozzle needle, which in turn leads to the combustion chamber of the internal combustion engine leading injection openings of the nozzle body released or be closed.

For perfect functioning of the injection valve is an exact lifting or returning and closing of the injection ports required. For this reason the opening stroke of the nozzle module is exactly in practice set. The setting is made by a Nozzle needle face, which is a throttle plate of the Valve control module is facing, is processed by grinding. By targeted removal on the face of the nozzle needle becomes the desired stroke of the nozzle module or nozzle needle manufactured.

However, it is disadvantageous that the for a proper functioning of the injector required Tolerance ranges only through a very complex test, which is a great technical or equipment expense requires can be achieved.

Advantages of the invention

The injection valve according to the invention with the features according to the preamble of claim 1, in which a length of the nozzle needle is set such that a real stroke value greater than one for an optimal one Function of the valve required defined stroke value is dependent on a positive deviation from a real one Stroke value from a defined stroke value of Nozzle needle Means to reduce the real stroke in the direction the defined stroke of the nozzle needle are provided, has the advantage that an adjustment of the stroke the nozzle needle without time-consuming editing Nozzle needle face is feasible.

There is, for example, the possibility of their Dimensions standardized body in the area of the stroke the nozzle needle and thus the real stroke value limit in the direction of the defined stroke value.

This advantageously results in a reduction of manufacturing costs and also a separate and very precise adjustment of the stroke of the nozzle needle and the Spring force and the leadership game.

It is also an advantage that with the reduction of the real stroke distance value provided a simple and inexpensive assembly is made possible and the stroke of the Nozzle needle if necessary at any time during the Final assembly can be changed again.

Further advantages and advantageous developments of the Object according to the invention result from the Description, the drawing and the claims.

drawing

In the drawing, eight embodiments of the Injector according to the invention schematically shown in simplified form, which in the following description are explained in more detail. Show it:

Fig. 1 is a highly schematic longitudinal section through an injection valve,

Fig. 2, a nozzle module of the injection valve of FIG. 1 in isolation,

Fig. 3 shows the region of a valve control chamber of an injection valve, wherein a stroke adjusting disk is secured to an end side of a nozzle needle,

Fig. 4 shows the region of a valve control chamber of an injection valve, wherein a throttle plate to a stroke adjusting disk is fixed,

Fig. 5 shows the region of a valve control chamber of an injection valve, wherein a stroke adjusting disk is pressed by a further spring against the throttle plate,

Fig. 6 shows a portion of a valve control chamber of an injection valve, wherein a stroke adjusting disk is pressed by a further spring against a nozzle needle,

Fig. 7 shows a portion of a valve control chamber of an injection valve, wherein a stroke adjusting element is pressed with a bore for receiving a clamping spring of the clamping spring against a nozzle needle,

Fig. 8 shows the region of a valve control chamber of an injection valve, which is provided for limiting a real Hubwegwertes a nozzle needle, a stepped or graded throttle plate,

Fig. 9 shows a portion of a spring plate of an injection valve, wherein a stroke adjusting disk is provided between the spring plate and the nozzle needle for limiting a real Hubwegwertes of the nozzle needle, and

Fig. 10 shows the portion of a spring plate of an injection valve, wherein a sleeve-like portion of the spring plate is surrounded by a spring.

Description of the embodiments

In Fig. 1, an injection valve 1 with a valve control module 2 and a nozzle module 3 is shown. The valve control module 2 is designed with an actuator module 4 , the actuator module being a piezoelectric actuator unit. To the actuator module 4, a valve member arrangement includes at 5, which has an adjusting piston 6 and an actuating piston 7, wherein 7 operating as a hydraulic coupler and hydraulic transmission, and the balance of temperature-induced fluctuations in length of the injection valve 1 hydraulic chamber between the two pistons 6, 8 is provided.

Further, the injection valve 1 is provided with a high pressure port 9, a running in a housing 10 of the valve control module 2 channel 11 is fed by under common-rail high-pressure fuel via, which is supplied to the nozzle module 3, wherein the common rail pressure can assume up to 1.5 kbar.

Furthermore, the injection valve 1 is provided with a pressure limiting valve 12 , via which a system pressure of a low-pressure area of the injection valve 1 is set. The system pressure of the injection valve 1 can assume values between 2 bar and 50 bar, a system pressure of 30 bar preferably being set in the present case via the pressure limiting valve 12 . Another channel 13 of the injection valve 1 represents a return area which generally has a pressure of about 1 bar.

FIG. 2 shows the nozzle module 3 in a more detailed and enlarged representation, a nozzle needle 14 being arranged axially displaceably in a nozzle body 15 . The nozzle body 15 shown in more detail in Fig. 2 is, as shown in Fig. 1 to a throttle plate 16 of the valve control module 2 and is fixedly connected via a nozzle clamping nut 17 to the housing 10 of the valve control module 2.

The nozzle needle 14 cooperates at its end facing away from the valve control module 2 with a valve seat 18 of the nozzle body 15 such that when the nozzle needle 14 is lifted off the valve seat 18, injection openings 26 of the nozzle body 15 are released and fuel is injected into a combustion chamber of an internal combustion engine ,

During the injection process, the nozzle needle 14 is moved in the nozzle body 15 against a spring force of a spring 19 acting on the nozzle needle 14 in the closing direction of the nozzle needle 14 by the valve seat 18 in the direction of the valve control module 2 or the throttle plate 16 .

The spring 19 is supported with its end facing away from the valve control module 2 via a disk 20 on a shoulder 21 of the nozzle needle 14 . At its end facing the valve control module 2 , the spring 19 rests on a so-called spring plate 22 , which in turn is supported in a manner not shown on the throttle plate 16 from FIG. 1.

The nozzle needle 14 , the spring plate 22 and the throttle plate 16 delimit a control chamber 23 , in each of which an inlet throttle 24 and an outlet throttle 25 , as shown in FIG. 3, open.

In Fig. 3, the region of the spring plate is of the injection valve 1 shown in enlarged view 22, wherein the nozzle needle 16 facing end side is provided with an as stroke adjusting disk 27 formed means for reducing a real Hubwegwertes of the nozzle needle 14 on its throttle plate 14. The stroke adjusting disc 27 has a central bore 28 , via which a welding point can be attached for firmly connecting the stroke adjusting disc 27 to the nozzle needle 14 without having to carry out post-processing of the nozzle needle 14 or the stroke adjusting disc 27 after the welding process.

The stroke adjusting disk 27 according to the embodiment of FIG. 3 is carried out 16 facing the end having such a diameter at its the throttle plate so that the inlet throttle 24 and the outlet throttle 25 are in concern of the nozzle needle 14 on the throttle plate 16 of stroke adjusting disk 27 does not completely cover and a desired flow is guaranteed.

The stroke adjusting disk 27 according to the embodiment according to FIG. 3 is a prefabricated classified disk for adjusting the stroke distance value of the nozzle needle 14 , which has a required disk thickness determined in a measuring method for setting a defined stroke distance values required for the fuel valve 1 to function properly. The stroke adjusting disk 27 is welded onto the end face of the nozzle needle 14 , so that the stroke distance of the nozzle needle 14 , which in the present case is limited by the throttle plate 16 , is reduced by the height of the stroke adjusting disk 27 .

Fig. 4 represents an alternative to the embodiment of the stroke travel limitation shown in Fig. 3 in that the stroke adjusting disc is welded to the throttle plate and is formed with through bores 29 which are at least approximately congruent with the inlet throttle 24 and the outlet throttle 25 . This ensures the flow of the inlet throttle 24 and the outlet throttle 25 and is not impaired by the stroke adjusting disk 27 . The throttle plate 16 is removed during assembly depending on the required flow rates of the outlet throttle 25 and the inlet throttle 24 from an associated classification.

The required disk thickness of the stroke adjusting disk 27 is determined during a measuring method provided for determining the real stroke distance value. A correspondingly classified stroke adjusting disk 27 is then used and welded onto the throttle plate 16 , the stroke adjusting disk 27 being aligned with respect to the throttles 24 , 25 during welding.

The stroke adjusting disk 27 according to FIG. 3 and FIG. 4 are each a stamped part, the flat sides of which are ground. This means that it has a high surface quality. Of course, the stroke adjuster can also be made in another suitable way and z. B. represent a turned part.

An injection valve, which is provided with the stroke adjusting disk 27 according to FIG. 3 and FIG. 4, can be designed with a valve control chamber 23 which has a small control chamber volume. This has the advantage that in the area of the spring plate 22 there is only a minimal fuel reservoir in the injection valve 1 . In addition, in particular in the case of the exemplary embodiment according to FIG. 4, there is the possibility of adjusting the flow through the throttle plate 16 and the stroke of the nozzle needle 14 separately from one another, the adjustment of the flow resulting from the positioning of the stroke adjusting disk 27 in relation to the throttle plate 16 ,

The Fig. 5, 6 and 7 show an alternative to the solid in FIGS. 3 and 4, connection between the stroke adjustment washer 27 and the throttle plate 16 and the nozzle needle 14 is another structural configuration for limiting the Hubwegwertes of the nozzle needle 14. The stroke adjusting disc 27 is pressed against the throttle plate 16 or the nozzle needle 14 via a further spring 30 , the further spring 30 being arranged between the throttle plate 16 and the stroke adjusting disc 27 or the stroke adjusting disc 27 and the nozzle needle 14 in the pretensioned installation position.

In FIG. 5, the additional spring 30 between the nozzle needle 14 and the stroke adjusting disk 27 is arranged, wherein the nozzle needle 14 and the stroke adjusting disk are each formed 27 with a cylindrical extension 31, 32 for guiding the further spring 30. The spring force of the further spring 30 is provided in such a way that the stroke adjusting disk 27 is in permanent contact with the throttle plate 16 regardless of an axial position of the nozzle needle 14 and the closing behavior or the damping properties of the injection valve 1 , which are also characterized by the spring 19 , are one Corresponding injection valve, which is formed without the further spring 30 . This means that the spring force of the further spring 30 is very small or that the spring force of the further spring 30 and the spring force of the spring 19 must be coordinated accordingly.

The diameter of the stroke adjusting disk 27 is provided such that a flow through the inlet throttle 24 and the outlet throttle 25 is influenced in an undesirable manner. The receiving space of the further spring 30 is formed by the stroke adjusting disk 27 and the nozzle needle 14 in the region of the two cylindrical extensions 31 , 32 , whereas in the exemplary embodiment according to FIG. 6 the receiving space of the further spring 30 is formed by a recess 33 provided in the throttle plate 16 is trained. Here, the stroke adjusting disc is pressed against the end face of the nozzle needle 14 by means of the further spring 30 .

In Fig. 7 the further spring is provided of a 30 a blind hole 34 as a stroke adjusting member 35 formed agent for reducing a real stroke travel of the nozzle needle 14 as a receiving space. This embodiment is characterized by easy assembly, since the spring is positioned exactly in the blind hole 34 of the stroke adjustment element 35 .

In order to ensure the flow through the two throttles 24 , 25 , the stroke adjustment part 35 is formed at its end facing the throttle plate 16 in the region of the throttle openings with a slope 36 extending to the outside thereof, so that the stroke adjustment part 35 when in contact with the throttle plate 16 Throttles 24 , 25 are not blocked and flow through them is not reduced in an undesirable manner.

In the present case, the further spring 30 is designed as a helical spring, it naturally being within the discretion of the person skilled in the art to design the further spring 30 as a corrugated spring or a plate spring. In addition, of course, any other type of spring suitable for the application in question can be used.

Fig. 8 shows the throttle plate 16, which is designed as a stepped, graded throttle plate. Here, the throttle plate 16 is formed in the area of the valve control chamber 22 with a throttle plate shoulder 37 , which is provided to reduce the stroke value of the nozzle needle 14 . The throttle plate 16 with the throttle plate shoulder 37 is selected from a specific class, the throttling plates being classified as a function of the height of the throttle plate heels. Which class the throttle plate 16 is taken from is determined as a function of the measuring method in which a positive deviation of the real stroke value of the nozzle needle 14 from the defined stroke value is determined.

It is conceivable that the end face of the throttle plate shoulder 37 is precisely adjusted during a so-called final grinding with the rest of the contact surface 38 of the throttle plate 16 in one manufacturing process. The final grinding of the surface of the throttle plate 16 facing the valve control chamber 23 or the spring plate 22 is carried out in two operations. The high-precision grading of the throttle plate 16 is then achieved by a so-called in-process measurement control, ie during the verification of the stroke value, and a subsequent classification of the grading.

FIGS. 9 and 10 show a further embodiment of a stroke adjusting disk 27 formed as means for reducing the real Hubwegwertes the nozzle needle 14. The stroke adjusting disk 27 is designed as an annular disk guided over the nozzle needle 14 , which rests on the shoulder 21 of the nozzle needle 14 . The stroke of the nozzle needle is limited by the stroke adjusting disc 27 and the spring plate 22 arranged above it. Between the spring plate 22 and the stroke adjusting disk 27, the spring 19 is arranged, whereby the spring force is set over a defined between the spring plate 22 and the spring 19 arranged Federkrafteinstellscheibe. 39 The spring force adjusting disk 39 can also be provided in the previously described exemplary embodiments according to FIGS. 1 to 7 for adjusting the spring force of the spring 19 .

The difference between the two embodiments according to FIGS. 9 and 10 is given in the configuration of the spring plate 22 . The spring plate 22 has a sleeve-like area, which in FIG. 9 surrounds the spring force adjusting disk 39 and the spring 19 , and which, as shown in FIG. 10, is surrounded by the spring 19 and the spring force adjusting disk 39 .

The stroke stop for the nozzle needle 14 is thus provided on the spring plate 22 , the gap between the stroke adjusting disk 27 and the spring plate 22 representing the real stroke distance value or the stroke of the nozzle needle 14 . After the stroke adjustment, the spring force of the spring 19 can be adjusted to the target force by means of the separate spring force adjusting disk 39 .

With only one additional stroke adjusting disc 27 and the modified spring plate 22 , a separate adjustability of stroke, spring force and guide play is achieved, whereby the small wall thickness of the spring plate 22 in the area of the stroke stop allows a small spring chamber diameter for the spring 19 to be achieved, which additionally results in a Space saving is achieved.

Claims (14)

1.Injection valve ( 1 ) with a valve control module ( 2 ) and an adjoining nozzle module ( 3 ), which has a nozzle needle ( 14 ) axially displaceably arranged in a nozzle body ( 15 ), the valve control module ( 2 ) being connected to the nozzle module ( 3 ) with a throttle plate ( 16 ) and a spring plate ( 22 ) and a spring ( 19 ) arranged between the spring plate ( 22 ) and the nozzle needle ( 14 ) are provided in the region of an end of the nozzle needle ( 14 ) facing the throttle plate ( 16 ) , which acts on the nozzle needle ( 14 ) in the closing direction with an axial force, and wherein a stop is provided for a stroke of an opening movement of the nozzle needle ( 14 ), characterized in that, depending on a positive deviation of a real stroke value from a defined stroke value, means ( 27 , 35 ) to reduce the real stroke value in the direction of the defined stroke value of the nozzle needle ( 14 ). 2. Injection valve according to claim 1, characterized in that the means are designed as at least one stroke adjusting disc ( 27 ). 3. Injection valve according to claim 2, characterized in that the stroke adjusting disc ( 27 ) on the throttle plate ( 16 ) facing the end of the nozzle needle ( 14 ) is arranged. 4. Injection valve according to claim 2, characterized in that the stroke adjusting disk (27) is designed as a nozzle needle (14) surrounding the annular disc which is arranged on a shoulder (21) of the nozzle needle (14), wherein an end face of the shoulder (21 ) facing the throttle plate ( 16 ). 5. Injection valve according to one of claims 2 to 4, characterized in that the stroke adjusting disc ( 27 ) is fixedly connected to the nozzle needle ( 14 ). 6. Injection valve according to claim 4, characterized in that the stroke adjusting disc ( 27 ) via the spring ( 19 ) is pressed against the shoulder ( 21 ) of the nozzle needle ( 14 ). 7. Injection valve according to one of claims 1 to 4, characterized in that the stroke adjusting disc ( 27 ) is pressed against the nozzle needle ( 14 ) by a further spring ( 30 ). 8. Injection valve according to claim 1 or 3, characterized in that the stroke adjusting disc ( 27 ) is arranged on the throttle plate ( 16 ). 9. Injection valve according to claim 8, characterized in that the stroke adjusting disc ( 27 ) with the throttle plate ( 16 ) is fixedly connected or is integrally formed therewith. 10. Injection valve according to claim 8, characterized in that the stroke adjusting disc ( 27 ) is pressed against the throttle plate ( 16 ) via a further spring ( 30 ). 11. Injection valve according to one of claims 2 to 10, characterized in that the stroke adjusting disc ( 27 ) is designed as a stamped part, the flat surfaces of which are ground. 12. Injection valve according to claim 1, characterized in that the means are designed as at least one stroke adjusting element ( 35 ) which is formed with a bore ( 34 ) for partially receiving a further spring ( 30 ). 13. Injection valve according to claim 11, characterized in that the stroke adjusting element ( 35 ) is pressed via a further spring ( 30 ) against the nozzle needle ( 14 ) or the throttle plate ( 16 ). 14. Injection valve according to one of claims 1 to 12, characterized in that a spring force adjusting disc ( 39 ) is provided between the spring ( 19 ) and the spring plate ( 22 ).