CZ314995A3 - Fuel injection valve for internal combustion engines - Google Patents

Abstract

An inwardly facing ring flange (30) engages the combustion chamber-side faces surface (27) of the valve body, and in it is a central through passage aperture (33) in the area of the axial covering of a plain area of the combustion chamber-side face surface of the valve body surrounding a fuel outlet position. The valve body (1) at its combustion chamber-side end has at least one conical transition to the even face side incorporating the fuel outlet position, with which a conically formed part (31) of the ring flange locates, closing a space between the valve body and the tension nut.

Description

Fuel injector for internal combustion engines

Technical field

The invention relates to a fuel injector for spalo fuel. ya_c í _m_o tor y under 1 e _ preactio n th e pa t e n t o n e o n e l. 1 .____

BACKGROUND OF THE INVENTION. .

In the fuel injector known from DECbm, 32 04 053, a valve body having an axially displaceable valve member is clamped by a clamping nut against the valve holder, wherein the clamping nut has an injection orifice formed by a guide orifice. which is guided through the outlet opening of the valve member, on the side facing the combustion chamber, a through opening in the front face of the valve body. To. in this case, the heating of the front surface, i.e. the bottom of the valve body on the side of the combustion chamber, was prevented, and as a result the clamping of the valve member or plugging of the injection port has a known fuel injector. the surface of the valve body n ₍ j side of the combustion chamber and between the clamping nut) in order to reduce the end face of the valve body over which the combustion gases flow directly and thus prevent the ingress of these gases into the interior of the clamping nut.

A disadvantage of this known fuel injector is that the space which is formed between the end face of the valve body on the combustion chamber side and the end face of the clamping nut on the combustion side &

- the space is relatively large in the area of the through hole. However, this large, dead space in the region of the injection orifices has a negative effect on the preparation of the mixture and on the combustion processes in the combustion chamber of the internal combustion engine, which lead to a deterioration in the emission values of the entire internal combustion engine.

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The fuel injector according to the invention with the features of claim 1, in contrast, has the advantage that, by substantially reducing the dead space in the region of the through hole in the clamping nut associated with the injection hole, the processes in the combustion chamber of the internal combustion engine are affected. by improving emission values. ⁱⁿ AVICEL advantageously achieves a further reduction in the front surface of the valve body, and after that the combustion gases, so that the valve body as a whole is not so strongly heated longer, which increases the reliability and lifetime of the fuel injector.

This reduction of the dead volume within the through-hole of the clamping nut is achieved by conical shaping of the transition between the face and the stem of the valve body and between the conically formed bearing surface on the clamping nut, the inclination angle of the conical sealing surface on the valve member being less clamping nuts. By this embodiment, it is advantageously ensured that the sealing edge of the sealing surface and the contact surface is always as close as possible to the through hole of the clamping nut, thereby passing through it. keeps the created space as small as possible.

In this case, the sealing edge can be formed according to the arrangement by a valve body and / or a bearing surface.

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A further reduction in the dead volume is achieved by engaging the sealing surface of the valve body in the region of the through hole, whereby the conical sealing surface can still be divided into another conical surface formed with a different pitch. By advantageously providing an intersection between the stem of the valve body and the opposite wall of the clamping nut, especially in the transition region between the conical sealing surface and the stem of the valve body, gas exchange is already considerably more difficult in the stem region. bodies.

When using a thermal protective plate, it is preferably plate-shaped and results in a central recess at the edge of the through hole, whereby the volume remaining therein is as small as possible.

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

Overlayed images on rows

The invention is explained in more detail below in five exemplary embodiments of a fuel injector for internal combustion engines according to the invention in conjunction with the drawing.

and ⁱⁿ figure 1 shows a first exemplary embodiment, in a recess of the fuel injector, in which the diameter of the flat end face of the valve body is greater than the diameter of the hole it průchozí4 clamping nut.

FIG. 2 shows a second embodiment in which the diameter of the flat face of the valve body is as large as the diameter of the through hole of the clamping nut.

FIG. 3 shows a third embodiment in which the conical sealing surface of the valve body extends into the through hole of the clamping nut.

FIG. 4 shows a fourth embodiment, analogous to FIG. 3, in which the conical sealing surface on the valve member is divided into two regions having different inclination angles.

FIG. 5 shows a fifth exemplary embodiment in which a heat shield plate having the form of a disc spring is clamped between the sealing surface of the valve body and the clamping nut.

The fuel injector for internal combustion engines and a cylindrical valve body, which, together with the intermediate disc 3, is clamped by means of a clamping nut 5 against the view of the cutter 7 in FIG. 11Το5ΰϊΰ1Έ) αΐΛΓ1] β1ΐΓρϊnaclí - has you ^ 5 ....

and..

provided with an inner annular arm 7 which engages an outer annular arm 9 of the valve body 1. The clamping nut 5 further has an external thread 11 in the region of the inner annular arm T. In this case, the brazed internal combustion engine is connected to the bore of the brazed internal combustion engine. On the circumferential sleeve extension 17 of the clamping nut 5, which surrounds the valve body under J. internal annular shoulder 2 »i ^e a retaining of monetary RA 19, which is assembled in the fuel injection valve by a sealing ring 21 pressed against the support arm 23 in the built-bore 13 .

The first embodiment shown in FIG. 1 is designed as a so-called pin-type throttle nozzle, and alternatively, perforated nozzles are also possible in which a valve member which is axially displaceable in a guide opening (not shown) and which is open inwards is provided with a throttle pin 25 which, in the closed state of the fuel injector, protrudes from the outlet opening forming the injection cross section, i.e. the fuel exit port of the guide opening on the front face 27 of the combustion chamber side 1. The injection section is narrowed in a known manner to a narrow annular gap. In such fuel injectors, the face 27 of the valve body 2 on the combustion chamber side must be particularly well cooled in order to minimize the carbonization of the injection cross-section. For this purpose, in the fuel injector according to the invention, the transition between the sleeve nut 17 of the clamping nut 5 surrounded by the stem of the valve body 1 and between its flat face on the combustion chamber side is conical, the conical transition region forming a conical an intermediate sealing surface 29 which cooperates with a conical bearing surface 31 which extends 6 below the face 27 of the valve body 1 and the inwardly directed annular flange 30 of the clamping nut 5. The bearing surface 31 of the clamping nut 5 is radially inwardly up an aperture 33 in the annular flange 30 that overlaps the flat face 27 of the valve body 1 surrounding the throttle pin 25 of the valve member to allow firing of the combustion chamber adjacent to that face 35 of the annular flange 30 up NaCl nut 5 which faces away from the valve body the first

In order to maintain a closed volume within the through-hole 33 and a flow-through face 27 of the valve body 3

As low as possible, the angle of inclination of the tapered transverse sealing surface 29 of the valve body 1 relative to its axis 3 'is smaller than the angle θ of the contact surface 31 of the clamping nut 5 to the axis of the valve body 1. between the sealing surface 29 and the abutment surface 31 is arranged as close as possible to the through hole 33. f *. ...........

The angle of inclination tn11 to the axis of the valve body 11 is preferably about 45 ° to 60 ° and the angle of inclination θ relative to the axis of the valve body 11 is greater by about 2.5 ° to 5 ° than the angle 25 of inclination.

In addition, the diameter D of the flat face 27 of the valve body 1, which is limited by the sealing surface 29, in the embodiment shown in FIG. 1 is greater than the diameter d of the through hole 33 of the clamping nut 5.

The second exemplary embodiment shown in FIG. 2 differs from the first exemplary embodiment only in the diameter D and diameter d dimensions of the same size, thereby reducing the volume of the through hole 33 inside the clamping nut 5 compared to FIG. 1, which also makes it possible to reduce the free, straight face 27 of the valve body 11 with the combustion gases.

In this case, the dimension with the gaps between the flat face 27 of the valve body 1 and the face 35 of the clamping nut 5 on the combustion chamber side in the region of the through hole 33 should preferably be 0.5 mm to 0.9 mm * 1 of the third example. 3, the diameter D of the valve face 27 on the combustion chamber side is smaller than the diameter d of the through hole 33 of the clamping nut 5, so that the sealing surface 29 of the valve body 1 extends into the through hole 33. In this way the dead volume within the through hole 33 can be reduced once more, and in addition, without great precision in machining the bearing surface 31 and sealing surface 29, the sealing edge formed here by the end of the bearing surface 31 can be arranged as long as

R may further be radially inward.

The fourth exemplary embodiment shown in Fig. 4 differs from the third example only in the embodiment of the sealing surface 29 of the valve body 1 and the bearing surfaces 31 of the clamping nut which now have two conical regions with different angles of inclination, inserting the sealing surface 29 of the through hole 33 for immediate requirements. ^In addition, in the embodiment of FIG. 4, a narrow gap 39 is provided between the cylindrical peripheral surface of the valve body 1 and between the inner wall of the clamping nut 5, which advantageously adjoins the sealing surface 29 and thus makes it difficult to exchange hot combustion gases flowing through the sealing. The amount of gas which is in the region of the stem of the valve body 1, thereby less heating the valve body in the region of the stem # 1, is between the sealing surface between the sealing surface and the fifth embodiment shown in FIG. 29 of the valve body 1 and the intermediate seating plate 31 of the clamping sheath 3 are clamped by a thermal protective plate 41. This thermal protective plate 41 is formed in the opening of the through hole 33 as fast as possible in the assembled state, so that, with its end faces, it almost bears against the sealing surface 29 and the contact surface ^ 31 Heat protecting plate 41 while a central opening 43 who ---------------- advantages rice is designed to 'his' stitch ~ ~ is in the "closure.

with the wall of the through hole 33.

Thus, by means of the fuel injector according to the invention, it is possible to reduce the valve face 27

.........— bodies l-bypassed by the hot combustion gases and at the same time reduce through-hole 33 the dead volume generated in the clamping nut 5 for better mixture preparation and combustion ·

Claims (8)

PATENT CLAIMS A fuel injector for internal combustion engines having a valve body provided with a guide bore in which the valve member is axially slidably guided and a clamping nut that clamps the valve body against the valve holder, having a valve body surrounding the housing extension and an annular flange that it extends below the valve body end face, which is on the combustion chamber side, which is bent inwards, and which has a central through hole in the region of the axial overlap of the combustion chamber face surface » The valve body (1) has at least one conical transition sealing surface (29) on its combustion end adjacent the combustion chamber to the flat face (27) in which it is adjusted the fuel outlet and also bears conical v formed seating surface (31) of the annular flange (30) enclosing the space formed between the valve body (1) and the clamping nut (o), wherein the angle (<*) of the tapered transition sealing surface (29) to the axis of the valve body (l) is less than the inclination angle (β) of the conical bearing surface (31) of the annular flange (30) to the axis of the valve body (I). 2. The fuel injector according to claim 1, wherein the angle (Ck.) Of the sealing surface forming the conical transition sealing surfaces (29) on the valve body (1) relative to the axis of the valve body (1) is 45 °. to 60 ³ , wherein the inclination angle i / o of the bearing surface (31) formed by the conical portion on the annular flange (30) of the clamping nut (5) is greater by approximately 2.5 ° to the axis of the valve body (1). 5 ° - Angle of inclination (RP) Tilt angle of sealing surface (29) * 3. The fuel injector as recited in claim 2, wherein the diameter (D) of the planar region of the face (27) on the valve body (1) is greater than the diameter (d ') of the through holes (33). a nut (5), wherein an edge formed between the conical transition sealing surface (29) and the plane face (27) on the valve body (1) is adapted as a bearing surface (31) of the clamping nut (3) (37). Fuel injection valve according to claim 2, characterized in that the diameter (D) of the planar region of the face (27) on the valve body (1) is of the same size as the diameter íd) of the through hole (33) of the clamping nut (33). 5), wherein the cross-sectional transitions in the region of the two diameters (D, d) each form one interacting sealing edge (37), Fuel injector according to claim 2, characterized in that the diameter (D) of the planar region of the face (27) on the valve body (1) is smaller than the diameter (d) of the through hole (33) of the clamping nut (5). 1), wherein the radially inner end of the bearing surface (31) forms a sealing edge (37) in the region of the diameter (1d) of the through hole (33) cooperating with the sealing surface (23) on the valve body. ___ forest— (i) "--------- · - ---------" · -__; of; .? ..... z.zzz ^- 'z Fuel injector according to claim 2 or 5, characterized in that two adjacent conical transition sealing surfaces (29) are provided on the valve body (1), the two conical contact surfaces (3Ϊ) of which are adjacent to each other at different angles of inclination. assigned to the clamping nut (5). 7. The fuel injector as recited in claim 1, wherein, in the region of the transition between the cylindrical portion of the valve body (1) and the conical transition sealing surface (29), between the wall of the clamping nut (5) and the valve body (1) is provided. narrow gap (39). Caliva fuel injector according to claim 1, characterized in that a thermal protective plate (41) is clamped between the conical transition sealing surface (23) of the valve body (1) and the abutment surface (31) formed on the conical part of the clamping nut (5). ) in the form of a disc spring which in the assembled state of the fuel injector fully abuts the sealing surface (29) and the abutment surface (31) and which delimits, through an annular edge adjacent to its central opening (43), ) on the clamping nut (5) against the inside of the clamping nut (o). 9. The fuel injector as recited in claim 1, wherein the dimension (s) of the gap between the planar face (27) of the valve body (1) and the face (35) of the clamping nut (5) on the combustion chamber side. has a height of 0.5 mm to 0.9 mm in the region of the through hole (33).