SK7362001A3 - Fuel injection valve for internal combustion engines and a method for producing same - Google Patents

Abstract

The invention relates to a fuel injection valve for internal combustion engines and a method for producing the same. The inventive valve comprises a valve base body (2). A piston-shaped and axially moveable valve element (12) is arranged in said base body and in a bore (21), against the force of at least one closing spring (27, 28). The valve element controls the opening of at least one injection channel (19) at the end facing the combustion chamber and can be moved in the axial direction by means of the fuel pressure onto a pressure shoulder (10) when an opening pressure is reached, whereby said shoulder is configured on the valve element (12). The at least one closing spring (27, 28) is arranged in spring chamber (30) against an initial tension. Said spring chamber is embodied in a valve holding body (1). The at least one closing spring (27, 28) rests on an adjustment pin (31, 31) and thereby faces away from the combustion chamber. The opening pressure which is detected by means of the initial tension pertaining to the at least one closing spring (27, 28) can be adjusted by displacing the adjustment pin (31, 32) in the axial direction using an adjustment tool (49) which can be introduced through an adjustment bore (52). The position of the adjustment pin (31, 32) in the spring chamber (30) is subsequently fixed by caulking (Fig.1).

Description

Technique • ······ · ··· ··· ·· ·· ··· 7?

valve valve, spring movable piston-shaped valve member, fuel on which it is arranged, which at its end controls opening

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine having a holding body against a force of at least one closing axially in a section of its length guided in a bore and facing the combustion chamber of the at least one injection channel and comprising at least one formed in the combustion chamber holding body. by shading the closing which is always supported by the residual positioning member of the valve, by the pressure resulting in the resultant being produced at a high pressure, thereby generating at a certain valve member a resulting force which is greater than the force of at least one spring space the side facing away from the guided section of the valve member, loaded with at least one closing end facing away from the combustion o adjusting element, which is secured by the walls of the spring space therein and by a pressure shoulder on which the opening fuel can act pressure in the axial direction of the closing spring.

The invention further relates to a method for producing this fuel injector.

BACKGROUND OF THE INVENTION

A fuel injector of this type known from the specification

DE 41 01 235 C, has two closing springs which are arranged in the spring space formed in the valve retaining body and counteract the force of the fuel pressure on the valve member. In this case, the first closing spring is clamped between the end of the spring space facing away from the combustion space and the spring plate connected to the valve member via a push rod. On the side facing the combustion chamber, the second closing spring rests on the stop sleeve with the valve member, while the combustion end facing the combustion chamber abuts against the adjusting element. At the location of the adjusting elements, shadings are formed in the wall of the spring space, which are darkened inwardly to secure the adjusting elements.

The assembly of the injection fuel is as follows: the first closing spring is inserted into the spring space and the spring plate on which the closing spring is supported on the side facing the combustion chamber. The opening pressure of the first closing spring can be adjusted by the length of the push rod and the opening pressure of the second closing spring by the thickness of the alignment disk. In the next step, the push rod is moved by the adjusting elements to the spring plate and a second closing spring, an alignment disc and a stop collar are provided. Finally, the valve body is clamped by a clamping nut to the valve retaining body, the valve member abutting on the push rod. To test the function, the opening pressure of both closing springs is measured on a fully assembled fuel injector. If the opening pressure is not in accordance with the specifications, the base valve body is released again from the valve holding body and the alignment disc and pressure rod are replaced according to the measurement result. The fuel injector is then reassembled and the opening pressures are measured again. This procedure is repeated until the opening pressures match the specifications.

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The fuel injection valve assembly methods used so far are time-consuming and expensive. Further, the multiple deployment and folding of the fuel injector carries the risk that dirt may enter the spring space and the valve stop, which may damage the correct operation of the fuel injector. A large number of different staggered push rods, or thickness of staggered alignment disks, must be made in order to have the correct stock size when replacing. Such stockholding entails additional costs.

SUMMARY OF THE INVENTION

The above-mentioned drawbacks are eliminated by the fuel injection valve for internal combustion engines with a valve retaining body, in which an axially movable piston-shaped valve member, which is guided in a borehole over a length of its length and which controls its end facing the combustion chamber, opening at least one injection channel and a spring space comprising at least one closing spring formed in the valve retaining body on the side facing away from the combustion chamber relative to the guided section of the valve member, the valve member being loaded with at least one closing spring which faces of the space from the combustion space always rests on an adjusting element which is positively secured by the deformation of the residual wall of the space of the springs in it by dimming and with a pressure shoulder formed on the valve member on which can exert a high pressure fuel, thereby generating at a certain opening pressure on the valve member a resultant force in the axial direction that is greater than the force of the at least one closing spring according to the invention, which is essentially about adjusting elements in the wall of the spring space

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at least one adjusting bore provided as a through bore, by means of which an adjusting tool can be inserted by means of which the axial position of the adjusting elements can be adjusted.

The fuel injector for internal combustion engines according to the invention has the advantage that the two closing springs are always supported on the side facing away from the combustion chamber by an adjusting element which is secured by deforming the wall surrounding it and which is possible in the space of the springs before final locking The adjustment of the opening lacquer is possible without changing the fuel injection valve component.

In a first preferred embodiment, at least two inwardly directed bore holes are provided at the height of the adjusting elements. In this way, the adjustment elements can be safely obscured in a certain position in the spring space.

In a further preferred embodiment, at least one circumferential rib is formed on the outer surface of the adjusting elements, which can be pressed into the rest of the wall between the bottom of the bore hole and the space of the springs, therefore better locking of the adjusting elements can be achieved.

In a further preferred embodiment, the adjusting bore, by which the adjusting tool is introduced into the spring space, is formed perpendicular to the axis of the valve member, which can be realized technically simply and inexpensively. In this case, the adjusting tool has a chamfered shape at the end which is fed into the adjusting bore, whereby the adjusting tool slips on a preferably corresponding bevel on the side of the adjusting tool facing away from the combustion tool when moving into the adjusting bore.

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space. As a result, an axial force is exerted on the adjusting element.

In a further preferred embodiment, the adjustment bore is inclined at an angle of in particular 45 ° to the axis of the valve member, which makes it possible to create a high axial force on the adjustment element. The end of the adjusting tool is preferably rounded, which allows the adjusting tool to slip on the adjusting element when the adjusting element is moved in the spring space.

In a further preferred embodiment, the front wall of the adjusting element is convexly convex on the side facing away from the combustion chamber. As a result, a chamfer is formed on the adjusting element, on which the adjusting tool can act advantageously in the axial displacement of the adjusting element.

A method of making an injection valve for internal combustion engines is still advantageous, in which the adjusting element is inserted into the spring space and the other parts of the fuel injector are assembled complete. The adjusting elements can be easily adjusted in the spring space and adjusted to a permanent opening pressure, without the need for replacing the fuel injector parts or re-assembling the injector fuel parts.

Further advantages and advantageous embodiments of the subject matter of the invention are apparent from the drawings, description and claims.

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BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of a fuel injector for internal combustion engines according to the invention is shown in the drawings and explained in more detail in the following description. In the drawings

Fig. 1 shows a cross-section of a fuel injector with two closing springs,

Fig. 2 is an enlarged detail of FIG. 1 at the intermediate disc,

Fig. 3 shows an enlarged detail of FIG. 1 in the position of the adjusting element of the first closing spring,

Fig. 4 shows the same detail as in FIG. 3 with an alternative embodiment of an adjustment bore and an adjustment tool.

DETAILED DESCRIPTION OF THE INVENTION

In FIG.

The combustion fuel injection fuel injection valve of the present invention has a retaining body with a longitudinal section nut, a valve body 7, a valve connected through a base body 2 shown by engines according to a fuel valve against which a base disc 5 is clamped. the axially movable piston valve member 12 is guided through the space. space setting in the section

A pressure shoulder 10 is provided by a constriction of the bore 21 facing away from the valve member 12 towards the member 12.

he is on

10, which can be coupled through a supply duct 6, arranged in a shape that the combustion combustion valve formed in the pressure chamber. The pressure chamber 4 is formed in the holding chamber.

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a valve body 7, a base body 25 and an intermediate disc 5, with a source of pressurized fuel, not shown in the drawing.

The end of the valve member 12 facing the combustion chamber is formed as a valve sealing surface 14 which cooperates with a valve seat 17 formed on the valve body 2. At least one injection channel 19 is provided in the valve seat 17, which is closed by the valve sealing surface 14 in the closing position of the valve member and is connectable in the opening position of the valve member by an annular channel 16 formed between the valve member 12 and the bore 21 with the pressure space. On the side of the valve member facing away from the combustion chamber, a pressure bar 37 is loaded by a closing spring 27, which is arranged substantially coaxially to the longitudinal axis 13 of the valve member 12 and extends up to the spring space 30 formed in the valve holding body.

In FIG. 2 is an enlarged detail of FIG. 1 in place of the intermediate disc 5. The push rod 37 has a smaller diameter than the guide section of the valve member 12, therefore, at the passage of the valve member 12 to the push rod 37, an annular shoulder 11 of the valve member 12 is formed on the stop sleeve 8 which surrounds the push rod 37 and is guided in the intermediate disc 5. A stop sleeve 8, which may be formed of several parts, protrudes up into the spring space 30, being formed at the end facing away from the combustion space as a spring plate against which the end of the second closing spring 28, which moves the valve member 12 into the closing position. On the outer surface of the stop sleeve 8, a stop shoulder 25 is formed by reducing the cross-section through which the stop sleeve 8 abuts the stop surface 26 formed in the intermediate disc 5 during its stroke movement. This limits the maximum opening stroke of the valve member 12. On the combustion chamber side, the stop sleeve 8 abuts with its end wall 23 by the action of the closing spring 28 on the end wall 22 of the base body 21.

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A first piston-shaped adjustment element 31 is provided near the end of the spring space 30 and away from the combustion space, and a second piston-shaped adjustment element 32 is arranged approximately in the middle between the two ends of the spring space 30. The second adjusting element 32 here has a central bore which serves as a guide for the push rod 37. The adjusting elements 31, 32 are secured in the spring space 30 by blanking. A spring formed is arranged between the first adjusting element 31 and the plate biased away from the first helical adjusting element of the push rod. Similarly, a closing spring 27 is connected to the spring body arranged on the combustion chamber by means of a spring plate and a spring formed by the spring plate. Similarly, the compression sleeve of the stop closure compression spring. The space formed in the holding guide, which is not adjusted for the bore hole 43, forms a thin space 30 of the elements 31, the annular blanks ¹ below, preferably between the second biased valve preferably a spiral valve through the ducts 36 with the outlet shown.

at least at the height of the first one there is at least a bore, one of which easily springs.

is a rib, a moldable wall 46 of the wall of the element 32 formed as a blind residual

On the outer surfaces of the adjusting elements, one which remains or more circumferential between the pressed bottom and the end space of the adjusting elements 31, of the spring bores. At a height away from

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One adjusting bore 52 is formed in the combustion chamber in the form of a through bore.

In FIG.

is a detail of FIG. 1 in the first place

adjustment element 31. Side of the adjusting element 31 turned away from the combustion chamber is formed conical, co forms a chamfer 32 · Concentric to the axis adjustment of element 31, a bore 55y is provided by which

The adjusting bore 52 is formed in a radial direction to the center of the valve holding body 7 and forms approximately a right angle with the axis of the adjusting element 31. An adjustment tool 49 can be guided through the adjustment bore 52, the portion of the adjustment tool 49 that is introduced into the adjustment bore 52 is approximately tubular and tapered at the end. By moving the adjusting tool 4 9 into the spring space 30, the adjusting tool 4 9 engages the chamfer 3 3 of the adjusting element 31. Further moving the adjusting tool 4 9 skips the adjusting tool 49 after the chamfer 3 3, from which an axial force flows to the adjusting element 31 an adjusting element 31 towards the combustion chamber.

In FIG. 4 is an alternative adjustment of the adjustment bore 52, which is inclined at an angle of between 30 and 60 °, preferably 45 °, relative to the axis of the adjustment element 31. The part of the adjusting tool 49y that is introduced into the adjusting bore 52 is rounded at its end and abuts the chamfer 32. By sliding the adjusting tool in the direction of the adjusting element 31, the adjusting element 31 is moved in the axial direction towards the combustion chamber. In this case, the adjusting tool 49 slides down after the chamfer 33. Similarly, the adjustment of the second

An adjusting element 32 adjusting one or more adjusting bores 52.

tool 52 ·· via

Alternatively to the adjusting element shown in FIG. 3 and 4, the side of the adjusting element 31 may be in a convex, arched shape. Similarly, it is also possible to provide the adjusting tool 49 in contrast to the simple tapered shape shown in FIG. 3, in another embodiment, therefore, it is possible to slide it on the chamfer 31 of the adjusting element 31. To equalize the supporting force on the adjusting element 31 or 32, it is possible to arrange a plurality of adjusting bores 52 symmetrically about the axis of the spring space 30 and use them simultaneously for adjustment.

The operation of the fuel injector is as follows. At the start of the injection cycle, the high pressure fuel is led through the supply duct 4 to the pressure space T. This implies a force on the pressure shoulder 10 in the axial direction away from the injection chamber, while the valve member 12 is pushed by the first closing spring 27 through the pressure rod 37 by the valve sealing surface 14 to the valve seat 17 and only open the fuel injector. the pressure chamber 7 has a greater force for the pressure shoulder 10 than the force of the first closing spring

27. By raising the valve sealing surface 14 above the valve seat 17, the injection channel 19 is connected via the annular channel 16 to the pressure space 7 and the fuel is injected into the combustion space. Since, in the closed state of the fuel injector, the axial distance between the annular shoulder 11 and the stop sleeve 8, the first part of the stroke movement of the valve member 12 is performed only against the force of the first closing spring 27. If the annular shoulder 11 engages the stop sleeve 8, the stop sleeve 8 is carried by the valve member 12 during the next opening movement. To do this, more power is needed, because now

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the force of the second closing spring 28 also counteracts the opening stroke volume of the movement of the valve member 12. After the valve member 12 arrives at the stop sleeve 8 by the annular shoulder 11, the valve member 12 remains in this position until the fuel tank has a correspondingly higher pressure in the pressure chamber 7 which acts through the pressure shoulder 10 against the force of the two closing springs 27, 28. In the further course of the opening stroke movement, the stop sleeve 8, with its stop shoulder 25, engages the stop surface 26 and the opening stroke movement is complete. The opening stroke movement, initially against the closing force of one and after a partial stroke against the force of the two closing springs 27, 28, results in a favorable injection molding process, especially when using a fuel injection valve in self-ignition internal combustion engines. Closing of the fuel injector starts when the fuel pressure in the pressure chamber 7 decreases until the force on the pressure shoulder 10 is no longer sufficient to exert an applied force of the closing springs 27, 28. The valve closure member 12 is accelerated in the direction of the valve seat 17 via the stop sleeve 8 and the push rod 37 until the valve member 12 engages the valve seat 17 again on the valve seat 17 and closes the injection channel 19.

In the following, a method of making the above fuel injector is described. Both adjusting elements 31 and 32 are disposed in the spring space 30 and are displaceable axially in the spring space 30. In addition, in the positions described above, the other parts are arranged in the space of the springs 30 and the valve body 2 is clamped by the clamping nut 3 to the valve holding body 1 via an intermediate disc 5. The adjusting bore 52 of the first adjusting element 31 introduces the adjusting tool 49 and the first adjusting element 31 is moved into position against the force of the first closing spring 27. Following this, the opening pressure is measured by the first closing spring 27, whereupon the position of the adjusting element 31 or the adjusting opening pressure can be corrected in that the first adjusting element 31 is axially displaced by the adjusting tool 39, depending on the measurement result. If the measured opening pressure of the fuel injector is too high, the adjusting element 31 must move away from the combustion chamber if it is too small, correspondingly to the combustion chamber. This process is repeated until the desired opening pressure is set on the fuel injector.

As an alternative to this, it can also be provided that the opening pressure can be measured continuously in a suitable manner when the adjusting element 31 is moved. In order to secure the first adjusting element 31 in the optimum position found, the adjusting element 31 is subsequently obscured from above by pressing the remainder wall 46 of the thrust bore 43 into the spring space 30. After blanking, the adjusting tool 49 is removed from the adjusting bore 52 and the adjusting bore 52 is closed. Closing is possible, for example, by pressing a steel ball into the adjustment bore 52. The same procedure is followed for locating the position of the second adjusting element 32.

Instead of exerting an adjusting force on the adjusting elements 31, 32 via the chamfer of the adjusting tool 49, it can also be provided that the adjusting tool 49 has a camming at its spring-loaded end 30. The force on the adjusting elements 31 and 32 is then exerted by turning the adjusting tool 49.

It may also be provided that the described method can be applied to a fuel injector having only one closing spring in the space 30. Likewise, it is possible to: · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · That more than two springs are arranged in the space of the springs 30, the opening pressure of which can be adjusted as described by moving the adjusting element.

Claims (14)

PATENT An injector on a retaining force of at least a piston guided in an inverted at least and with a closing spring space (30) in which the fuel valve has a valve body (1), one closing axially movable member having a bore (21) to the combustion one; wherein the injection spring space comprising (27, 28), which motors against the 28) of the section spring (12) controls their opening of the combustion is (27, the valve length of the end of the channel (19) at least one being formed in the valve holding body (1) a side facing away from the combustion chamber relative to the guided section of the valve member (12), wherein the valve member (12) is loaded with at least one closing spring (27, 28) which always rests on the adjusting element (31, 32) in the form of a piston which is positively locked in position by means of reshaping the residual wall (46) of the spring space (30) by means of blackout and with a pressure shoulder (10) ) formed on the valve member (12), which may be subjected to high pressure fuel, thereby generating at a certain opening pressure on the valve member (12) a resultant force greater than the force of at least the mark (27, 28), that in the retaining adjusters in the axial direction, one of the closing bodies (1) of the elements about in the spring, by the height of the spring space (30) a through bore (52), (49) by which the adjustable axial valve can be inserted (31, 32) at least one of the adjusting adjusters in the wall of the drilling tool position the adjusting elements (31, 32). · · · · · · · · · • · • · • · • · • · ·· ··· ·· ·· ··· Fuel injector according to claim 1, characterized in that the residual wall (46) of the valve holding body (1) is formed at least at the height of the adjusting element (31, 32) by at least one outwardly directed thrust bore (43) formed. as blind drilling, with the residual wall (31, 32) printed inwards. 3. The fuel injector according to claim 1 1, characterized in that, on the outer surface of the adjusting elements (31, at least one circumferential rib), a blanking of the adjusting element 32) which is (31, 32) an inwardly printed residual wall (46). The fuel injector according to claim 3, (43) (12) being substantially a valve. 5. The injection valve formed therein is impressed in that the caliper perpendicular to the longitudinal axis of the bore (13) of the fuel cell bore (52) is radially of the surface of the spring retaining body (30). The fuel injector receiving bore (52) according to claim 1, wherein the adjustment is to the longitudinal axis (13). An injector valve extending the elongated (1) valve according to the formed fuel cell (12) according to up to claim 5, wherein the outer to the space is known to be substantially adjusting the valve. perpendicular to claim 5, characterized in that the adjusting bore (52) is formed at an angle 30 to 60 °, preferably about 45 °, to the longitudinal axis (13) of the valve member (12). Fuel injection valve according to claim 5, characterized in that a plurality of adjustment bores are arranged in the valve retaining body (1) and are preferably arranged symmetrically about the longitudinal axis of the spring space (30). 9. The fuel injector as recited in claim 1, wherein the adjusting element (31, 32) has a hollow cylinder shape. Fuel injection valve according to claim 1, characterized in that the side of the adjusting element (31, 32) facing away from the combustion chamber has a convex, arched shape. Fuel injection valve according to claim 1, characterized in that the side of the adjusting element (31, 32) facing away from the combustion chamber has a conical shape, the cone cone point facing away from the combustion chamber. The fuel injector of claim 1, wherein the portion of the adjusting tool (49) introduced into the adjusting bore (52) is substantially tubular in shape and bevelled at the insertion end. 13. The fuel injector as recited in claim 1, wherein a portion of the adjusting tool (49) is introduced into the fuel injector (49). The adjusting bore (52) is substantially tubular in shape and rounded at the insertion end. Method for producing a fuel injection valve for internal combustion engines with a valve retaining body (1), in which an axially movable piston-shaped valve member (12) which is guided over a length of its length is arranged against the force of at least one closing spring (27, 28) in the bore (21) and which, by its end facing the combustion chamber, controls the opening of at least one injection channel (19) and a spring space (30) comprising at least one closing spring (27, 28) formed in the valve holding body (1) the valve member (12) is loaded with at least one closing spring (27, 28) which, at the end facing away from the combustion chamber, always bears against the adjusting element (31, 32) in the form of a piston, which is positively locked in position by deforming the residual wall (46) of the spring space (30), by a shoulder (10) formed on the valve member (12) which can be subjected to high pressure fuel, thereby generating at a certain opening pressure on the valve member (12) a resultant force in the axial direction that is greater than the force of the at least one closing springs (27, 28), characterized in that the adjusting elements (31, 32) are adjusted before being locked by the adjusting tool (49), as long as the bias of the abutting closing springs (27, 28) achieved by moving the adjusting elements (31, 32) ) does not reach the desired opening pressure of the valve member (12). ·· ·· · · · · · · · · · · · · · · · · · Method according to claim 14, characterized in that the movement of the adjusting elements (31, 32) is arranged axially on the adjusting elements (31, 32) of the space (30) opposite the opening valve. acting contact surface through the wall of the springs with a force insertable tool acting on the cell (49) (12) 16th The method according to claim 1, characterized in that the adjusting bore (52) is designed such that the adjusting adjusting movement of the adjusting element (31, the adjusting tool the opening tool and the wall of the tool (49) 32) (49) acts by the adjusting spring (30). on the element (31, (49)) the pressure in the axial direction is measured by the fuel until the fuel corresponds to the input, deformation of the residual wall of the springs at the height of the adjusting element (31, injection) 32) wherein the valve opening pressure of the injection valve (46) of the space (30) 32), by is adjusting element (32, 32) secured in his position, removal adjustment tool (49) from setup drilling (52).