KR20010090853A - Fuel injection valve for internal combustion engines and a method for producing same - Google Patents

Abstract

The present invention relates to a fuel injection valve for an internal combustion engine and a manufacturing method thereof. The valve of the invention comprises a valve base body 2. A piston-shaped and axially movable valve member 12 is disposed in the base body and the bore 21 against the force of at least one blocking spring 27, 28. The valve member controls the opening of the at least one injection channel 19 at the end facing the combustion chamber, and when the opening pressure is reached, the valve member is driven by the fuel pressure applied to the pressure shoulder 10 formed on the valve member 12. Can be moved in a direction. At least one blocking spring 27, 28 is placed in the spring chamber with the initial stress. The spring chamber is formed in the valve retainer (1). At least one of the blocking springs 27 and 28 is in contact with the adjusting pins 31 and 32 and thereby faces away from the combustion chamber. The opening pressure measured by the initial stress suitable for the at least one blocking spring 27, 28 is applied to the adjusting pins 31, 32 in the axial direction using an adjusting tool 49 which can be inserted through the adjusting tool 52. It can be adjusted by moving. The position of the adjusting pins 31 and 32 in the spring chamber 30 is subsequently fixed by caulking.

Description

FUEL INJECTION VALVE FOR INTERNAL COMBUSTION ENGINES AND A METHOD FOR PRODUCING SAME

This type of fuel injection valve, as disclosed in the patent specification DE 41 01 235 C, is arranged in a spring chamber formed in the valve body and has two shut-off springs acting against the force of the fuel pressure exerted on the valve member. . The first blocking spring is fixed between the spring plate coupled with the valve member through the ram bar and the end spaced apart from the combustion chamber of the spring chamber. The second shut-off spring is supported by a stop sleeve that can be coupled with the valve member on the combustion chamber side and the end spaced apart from the combustion chamber is in contact with the adjustment pin. In the adjustment pin section there is a thin wall caulking inward for fixing the adjustment pin to the wall of the spring chamber.

The assembly of the fuel injection valve proceeds in the following way. The first blocking spring is inserted into the spring chamber and the blocking spring is supported by the spring plate on the combustion chamber side. The opening pressure of the first blocking spring is adjusted according to the length of the ram bar, and the opening pressure of the second blocking spring is adjusted according to the thickness of the compensation washer. The adjusting pin is then inserted and caulked in the planned position. In the next step, the ram bar is inserted into the spring plate through the adjustment pin and the second blocking spring, the calibration washer and the stop sleeve are arranged. Finally, the valve base body is fixed to the valve fixture through the tension nut, wherein the valve member is in contact with the ram bar. For functional checks, the opening pressure of both shut-off springs is measured in a fully assembled fuel injection valve. If the opening pressure does not match the specified value, the valve base body is again removed from the valve holder and replaced with a calibration washer and ram bar corresponding to the measurement result. The fuel injection valve must then be reassembled and the open pressure measured again. This process is repeated until the open pressure reaches the specified value.

The method of assembling the fuel injection valves used up to now takes a long time and is expensive. In addition, disassembly and assembly of the fuel injection valve several times may cause contamination of the valve limit stop section and the spring chamber section, which may interfere with the normal operation of the fuel injection valve. In order to be able to supply a sufficient amount of parts for replacement, different lengths of ram bars or calibration washers of various thicknesses are manufactured in large quantities. This large amount of spare parts is required to store additional costs.

The present invention relates to a fuel injection valve for an internal combustion engine according to the type of claim 1.

1 is a cross-sectional view of a fuel injection valve including two blocking springs.

2 is an enlarged partial cross-sectional view of the middle plate section of FIG.

3 is an enlarged partial cross-sectional view of the adjustment pin section of the first blocking spring of FIG.

4 is a partial cross-sectional view of the same section as in FIG. 3, in which an adjustment tool and an alternative form of the adjustment tool are shown;

The fuel injection valve for an internal combustion engine according to the present invention having the features specified in claim 1 has the following advantages over the conventional fuel injection valve. On the side away from the combustion chamber, both shut-off springs are supported by respective adjusting pins which can be fixed by deformation of the wall surrounding the adjusting pins and axially moved in the spring chamber through the adjusting tool before being fixed in the final position. In this way, the opening pressure can be adjusted without replacing the parts of the fuel injection valve.

In the case of the first preferred embodiment, at least two caulking bores are formed, each facing inward, at the height of the adjusting pin. By doing so, the adjusting pin can be secured in a specific position in the spring chamber.

In another preferred embodiment, at least one annular rib is formed around the outer circumference of the adjusting pin that can be pressed through the residual wall between the base of the caulking bore and the spring chamber to improve the fixation of the adjusting pin.

In another preferred embodiment, the adjusting tool into which the adjusting tool is inserted into the spring chamber is formed perpendicular to the axis of the valve member, thereby reducing costs and facilitating assembly. In this case, the end of the adjusting tool inserted into the adjusting tool is formed in the form of an inclined surface, so that when the adjusting tool is inserted into the adjusting tool, the adjusting tool slides on the inclined surface formed in an advantageous shape corresponding to the surface spaced apart from the combustion chamber of the adjusting pin. Can be. Therefore, an axial force is applied on the adjusting pin.

In another preferred embodiment, the adjuster is arranged inclined at an angle of preferably 45 degrees with respect to the axis of the valve member, whereby a strong axial force can be applied to the adjusting pin. In this case, the end of the adjusting tool is preferably formed in a rounded shape, so that the adjusting tool can easily slide on the adjusting pin when the adjusting pin is inserted into the spring chamber.

In another preferred embodiment, the front face of the adjusting pin spaced apart from the combustion chamber is convexly raised outward. In this way, an inclined surface stably contacting the adjusting tool is formed on the adjusting pin when the adjusting pin is pushed in the axial direction.

It is also preferable to manufacture a fuel injection valve in which the adjusting pin is inserted into the spring chamber and the other parts of the fuel injection valve are finally assembled. The adjustment pin can be simply inserted into the spring chamber without replacing the parts of the fuel injection valve or reassembling and disassembling the fuel injection valve and the already adjusted opening pressure is maintained.

Other preferred embodiments and advantages of the invention are set forth in the drawings, detailed description and claims.

An embodiment of a fuel injection valve for an internal combustion engine according to the present invention is shown in the drawings and described in detail by the following description.

1 is a longitudinal sectional view of a fuel injection valve for an internal combustion engine according to the present invention. The fuel injection valve has a valve fixing body 1 in which the valve base body 2 is fixed by the tension nut 3 in the state in which the intermediate plate 5 is inserted. The valve base body 2 is formed with a bore 21, which is arranged with a valve member 12 which is guided to the section of the bore 21 spaced from the combustion chamber and is movable in the axial direction in the form of a piston. . Since the valve member 12 is narrowed toward the combustion chamber, a pressure shoulder 10 is formed in the valve member 12, which is arranged in the pressure chamber 7 surrounding itself. The pressure chamber 7 may be connected to a fuel high pressure pump not shown in the drawing through an inlet channel 4 formed in the valve base body 2, the intermediate plate 5, and the valve fixture 1.

The combustion chamber side end portion of the valve member 12 is formed as a valve sealing surface 14 which cooperates with a valve seat 17 formed in the valve base body 2. In a state in which the valve member 12 is blocked, the ring channel 16 formed between the valve member 12 and the bore 21 is closed by the valve sealing surface 14 and the valve member 12 is opened. At least one injection channel 19, which can be connected to the pressure chamber 7 via the valve seat 17, is formed. Ram bars arranged substantially coaxially with respect to the longitudinal axis 13 of the valve member 12 and projecting up to the spring chamber 30 formed in the valve fixing body 1 and pressed by the first blocking spring 27. (37) abuts the end spaced from the combustion chamber of the valve member (12).

FIG. 2 is an enlarged partial cross-sectional view of the section of the intermediate plate 5 of FIG. 1. Since the diameter of the ram bar 37 is smaller than the diameter of the valve member 12, a ring shoulder 11 is formed at the switch portion from the valve member 12 to the ram bar 37. In the opening operation, the circular shoulder 11 of the valve member 12 is in contact with a stop sleeve 8 which surrounds the ram bar 37 and is guided by the intermediate plate 5. The stop sleeve 8, which may be manufactured in a multi-piece type, may protrude up to the spring chamber 30, in which case the end of the stop sleeve spaced from the combustion chamber is formed as a spring plate and blocks the valve member 12. An end of the second blocking spring 28 which can be switched to the state abuts the spring plate. A stop shoulder 25 is formed on the outer surface of the stop sleeve 8 due to the reduction of the cross section, through which the stop sleeve 8 is in contact with the stop surface 26 formed on the intermediate plate 5 during the stroke movement. . Therefore, the maximum opening stroke of the valve member 12 is limited. On the combustion chamber side, the front face 22 of the stop sleeve 8 is in contact with the front face 23 of the valve base body 2 by the action of the blocking spring 28.

The first adjustment pin 31 in the form of a piston is arranged near the end spaced from the combustion chamber of the spring chamber 30, or the second adjustment pin in the form of a piston is formed at an intermediate portion between both ends of the spring chamber 30. (32) is arranged. The second adjusting pin 32 has a central hole that functions to guide the ram bar 37. The adjustment pins 31 and 32 are fixed in the spring chamber 30 through caulking. Between the spring plate 24 and the first adjusting pin 31 arranged at the end spaced apart from the combustion chamber of the ram bar 37, the first blocking spring 27, which is preferably formed as a coil spring, is applied with an initial stress. Are arranged. Correspondingly, between the spring plate formed on the stop sleeve 8 and the second adjusting pin 32, a second blocking spring 28, preferably formed in the form of a coil spring, is arranged in a state where the initial stress is applied. The spring chamber 30 is connected to the discharge pipe not shown in the drawing through the leak oil channel 36 formed in the valve fixing body 1.

At least one caulking bore 43 is formed in the wall of the spring chamber 30 in the form of a blind hole at the height of the first adjusting pin 31 and the height of the second adjusting pin 32. Through the caulking bore, a thin and easily deformable residual wall 46 of the spring chamber wall is formed. One or several annular ring lands are formed on the outer wall of the adjusting pins 31 and 32, and the remaining wall 46 remaining between the bottom of the caulking bore 43 and the spring chamber 30 is formed. ) Is pressed into the ringland. At the height of the end spaced apart from the combustion chambers of the adjusting pins 31 and 32, one adjusting hole 52 is formed.

3 is a partial cross-sectional view of the section of the first adjustment pin 31 of FIG. The surface spaced apart from the combustion chamber of the adjustment pin 31 is formed in a conical shape, the inclined surface 33 is formed. At the center of the shaft of the adjusting pin 31, a hole 55 through which the leak oil can flow from the spring chamber 30 to the discharge pipe 36 is formed. The adjusting port 52 is formed in a radial direction toward the center of the valve fixing body 1 and is formed at substantially right angles with the axis of the adjusting pin 31. The adjusting tool 49 can be inserted through the adjusting tool 52. The adjusting tool 49, which is inserted into the adjusting tool 52, is formed almost in the shape of a rod and has a slope formed at the end thereof. When the adjusting tool 49 is inserted into the spring chamber, the adjusting tool contacts the inclined surface 33 of the adjusting pin 31. When the adjusting tool 49 is continuously inserted, the inclined surface of the adjusting tool 49 pushes the inclined surface 33, which causes an axial force on the adjusting pin 31 and the adjusting pin 31 is Pushed into the combustion chamber.

4 shows an alternative form of the adjuster 52, where the adjuster has an angle of 30 degrees to 60 degrees, preferably 45 degrees, with respect to the axis of the adjusting pin 31. The part of the adjusting tool 49 inserted into the adjusting tool 52 is rounded at the end and is in contact with the inclined surface 33. When the adjusting tool 49 is inserted in the adjusting pin 31 direction, the adjusting pin 31 is pushed in the combustion chamber direction. At this time, the adjusting tool 49 slides on the inclined surface 33. Correspondingly, the second adjusting pin 32 is adjusted through the adjusting tool or the adjusting tools 52.

As an alternative to the adjusting pin 31 shown in FIGS. 3 and 4, the surface spaced apart from the combustion chamber of the adjusting pin 31 may be raised convexly in a different form than conical. Correspondingly, the inclined surface may slide on the inclined surface 33 of the adjusting pin 31 by realizing another inclined surface rather than manufacturing the end of the adjusting tool 49 as shown in FIG. You can do that. In order to make the bearing force on the adjusting pins 31 and 32 uniform, a plurality of adjusting tools 52 can be arranged symmetrically about the axis of the spring chamber 30 and used simultaneously for adjustment.

The operation of the fuel injection valve is as follows. At the start of the injection cycle, fuel is injected into the pressure chamber 7 through the inlet channel 4 at high pressure. The force thus formed is exerted on the pressure shoulder 10 in the axial direction away from the combustion chamber. Since the valve member 12 is urged to the valve seat 17 together with the valve sealing surface 14 through the first shut-off spring 27 and the ram bar 37, the fuel pressure in the pressure chamber 7 is reduced to the opening pressure. The fuel injection valve is opened only when the force reached and the force applied to the pressure shoulder 10 is greater than the force of the first shut-off spring 27. The valve sealing surface 14 is separated from the valve seat 17 so that the injection channel 19 is connected to the pressure chamber 7 through the ring channel 16 and fuel is injected into the combustion chamber. In the state in which the fuel injection valve is blocked, an axial gap is formed between the circular shoulder 11 and the stop sleeve 8 so that the force formed at the initial stage of the opening stroke movement of the valve member 12 is determined by the first blocking spring ( It works only against the power of 27). When the circular shoulder 11 is in contact with the stop sleeve 8, the stop sleeve 8 is moved together by the valve member 12 when the opening stroke is continuously performed. This requires a larger force because the force of the second shut-off spring 28 acts in a direction against the open stroke of the valve member 12. After the valve member 12 is moved together with the circular shoulder 11 to the limit stop position of the stop sleeve 8, both side blocking springs 27, by the force formed by the circular shoulder 11 at that position, The valve member 12 is held in this limit stop position until a corresponding higher fuel pressure, which can act in a direction against the force of 28, is generated in the pressure chamber 7 by the next supplied fuel. . In the next open stroke, the stop shoulder 25 of the stop sleeve 8 is in contact with the stop face 26, thereby ending the open stroke. The fuel injection, particularly in self-ignition internal combustion engines, is due to an open-stroke movement in which a force is initially applied in the direction against the blocking force of one blocking spring and then in the direction against the blocking force of the two blocking springs 27, 28. When a valve is used, the desired pattern of separation lines appears. If the fuel pressure in the pressure chamber 7 decreases until the force applied to the pressure shoulder 10 is not large enough to counter the forces of the shutoff springs 27 and 28, the fuel injection valve is shut off. The valve member 12 passes through the stop sleeve 8 and the ram bar 37 until the valve member 12 contacts the valve seat 17 again with the valve sealing surface 14 and blocks the injection channel 19. Accelerated in the valve seat 17 direction.

The following describes the method for manufacturing the fuel injection valve described above. The spring chamber 30 is arranged with two adjustment pins 31 and 32 which can be moved axially in the spring chamber 30. The other parts are arranged in the spring chamber 30 to the position already described above, and the valve base body 2 is connected to the valve body 1 through the tension nut 3 with the intermediate plate 5 inserted therein. Fixed against). One adjusting tool 49 is inserted through the adjusting tool 52 of the first adjusting pin 31 and the first adjusting pin 31 is inserted against the force of the first blocking spring 27 at a predetermined position. . The opening pressure exerted by the first shut-off spring 27 is then measured and taking into account this measured value, the first adjusting pin 31 is adjusted to its axial position corresponding to the measurement result via the adjusting tool 49. By inserting into the position of the adjustment pin 31 or the adjusted opening pressure can be modified.

If the measured opening pressure of the fuel injection valve is too large, the adjusting pin 31 should move in a direction away from the combustion chamber, and if too small, it should move correspondingly to the combustion chamber. Repeat this process until the desired opening pressure is adjusted at the fuel injection valve.

As an alternative to this, the opening pressure may be continuously measured using a suitable device when inserting the adjusting pin 31. In order to fix the first adjustment pin 31 to the optimum position where it is found, in the next step, the adjustment pin 31 presses the remaining wall 46 of the caulking bore 43 in the manner described above. Caulk 30). After caulking, the adjusting tool 49 is removed from the adjusting tool 52 and the adjusting tool 52 is closed. The adjuster can be closed, for example, by pressing one steel ball with the adjuster 52. In the same manner it is possible to fix the position of the second adjustment pin (32).

Instead of applying regulating power to the adjusting pins 31 and 32 through the inclined surface of the adjusting tool 49, the end of the adjusting tool inserted into the spring chamber may be manufactured in the form of a cam. In this case, the force applied to the adjusting pin is generated by rotating the adjusting tool.

In addition, the above method may be applied to a fuel injection valve in which only one blocking spring is arranged in the spring chamber 30. Likewise, two or more blocking springs can be arranged in the spring chamber 30 in which the opening pressure can be adjusted via the insertion of the adjusting pin in a manner as described above.

As described above, the present invention can be used to adjust the opening pressure without replacing the parts of the fuel injection valve.

Claims (16)

A portion of the entire length is guided in the bore 21 and at the end of the combustion chamber at least one shut-off spring is an axially movable piston-like valve member 12 that controls the opening of at least one injection channel 19. At least one formed in the valve retainer 1 arranged therein against the forces of (27, 28) and in the insertion section of the valve retainer 1 spaced apart from the combustion chamber of the valve member 12; Spring chamber 30 for receiving two blocking springs 27 and 28, wherein each piston-shaped adjustment pin 31 is fixed by caulking through deformation of the remaining wall 46 of spring chamber 30; The valve member 12, which can be supplied with high pressure fuel through the at least one shut-off spring 27, 28 supported by the end spaced apart from the combustion chamber 32. As the pressure shoulder (10) formed in the, through the pressure shoulder A fuel injection valve for an internal combustion engine, comprising a pressure shoulder 10, wherein a force greater than the force of at least one blocking spring 27, 28 at an open pressure is applied to the valve member 12 in the axial direction. At least one adjusting tool 52 capable of inserting the adjusting tool 49 for determining the axial position of the adjusting pins 31 and 32 is provided with the height of the adjusting pins 31 and 32 almost at the valve retainer 1. A fuel injection valve, characterized in that formed in the wall of the spring chamber 30 as a through hole in the. The valve wall (1) according to claim 1, wherein the remaining wall (46) of the valve retainer (1) faces at least one caulking bore (43) formed inwardly at a height of the adjusting pins (31, 32) and formed as a blind hole. It is formed through the residual wall 46 is characterized in that the fuel injection valve, which is pressed inwards when caulking the adjustment pin (31,32). According to claim 1, characterized in that at least one annular rib is formed on the outer surface of the adjustment pin (31, 32) pressed by the residual wall 46 pressed inwards when caulking the adjustment pin (31, 32). Fuel injection valve. 4. A fuel injection valve according to claim 3, characterized in that the caulking bore (43) is substantially perpendicular to the longitudinal axis (13) of the valve member (12). The fuel injection valve according to claim 1, characterized in that the adjustment port (52) extends radially from the outer circumference of the valve retainer (1) to the spring chamber (30). 6. A fuel injection valve according to claim 5, characterized in that the adjustment mechanism (52) is formed substantially perpendicular to the longitudinal axis (13) of the valve member (12). 6. The fuel injection valve according to claim 5, characterized in that the adjuster (52) is formed at an angle of 30 degrees to 60 degrees, preferably approximately 45 degrees with respect to the longitudinal axis (13) of the valve member (12). A fuel injection valve (1) according to claim 5, characterized in that a number of adjustment mechanisms, preferably arranged symmetrically about the longitudinal axis of the spring chamber (30), are arranged in the valve fixture (1). The fuel injection valve according to claim 1, characterized in that the adjustment pin (31,32) has the form of a hollow cylinder. The fuel injection valve according to claim 1, wherein a surface spaced apart from the combustion chamber of the adjustment pin (31,32) has a convexly raised shape. The fuel injection valve according to claim 1, characterized in that the surface of the adjusting pin (31, 32) spaced apart from the combustion chamber is conical and the tip of the cone points in the opposite direction to the combustion chamber. The fuel injection valve according to claim 1, characterized in that the portion of the adjustment tool (49) inserted into the adjustment tool (52) is almost in the form of a rod and the inserted end is formed in an inclined surface. The fuel injection valve according to claim 1, characterized in that the part of the adjusting tool (49) inserted into the adjusting tool (52) is almost in the form of a rod and the inserted end is rounded. A portion of the entire length is guided in the bore 21 and at the end of the combustion chamber at least one shut-off spring is an axially movable piston-like valve member 12 that controls the opening of at least one injection channel 19. At least one formed in the valve retainer 1 arranged therein against the forces of (27, 28) and in the insertion section of the valve retainer 1 spaced apart from the combustion chamber of the valve member 12; Spring chamber 30 for receiving two blocking springs 27 and 28, wherein each piston-shaped adjustment pin 31 is fixed by caulking through deformation of the remaining wall 46 of spring chamber 30; The valve member 12 is supplied to the valve member 12 through at least one blocking spring 27 and 28 supported at an end spaced from the combustion chamber 32, and can be supplied through a high-pressure fuel. As the pressure shoulder 10, a specific opening through the pressure shoulder A method of producing at least one of the blocking spring (27,28) for an internal combustion engine fuel injector, comprising a the pressure shoulder (10) acting on the valve member 12 in an axial force greater than the force on, Through the initial stress formed by the insertion of the adjustment pins 31 and 32, the adjustment pins 31 and 32 are fixed until the corresponding blocking springs 27 and 28 reach the required opening pressure of the valve member 12. Characterized in that it is adjusted via a stationary tool (49) before being applied. 15. The adjusting tool (49) according to claim 14, wherein the adjusting pins (31, 32) act on the adjusting pins (31, 32) in the axial direction and that can be inserted through the wall of the spring chamber (30). Characterized in that it is pushed in a direction against the opening force acting on the valve member (12) through displacement of the contact surface. The method of claim 14, A process step of inserting the adjusting tool 49 through the adjusting tool 52 formed in the wall of the spring chamber 30 so that the adjusting tool 49 can act on the adjusting pins 31 and 32; A process step of pushing the adjusting pins 31 and 32 through the adjusting tool 49 in the axial direction until the opening pressure of the fuel injection valve reaches the prescribed opening pressure of the fuel injection valve, wherein the opening of the fuel injection valve Pressure is measured, A process step of deforming the residual wall 46 of the spring chamber 30 at the height of the adjusting pins 31 and 32 so that the adjusting pins 31 and 32 can be fixed at their positions, A process step of removing the adjusting tool 49 from the adjusting tool 52; Characterized in that it comprises a method.