EP2313640B1 - Injection valve member - Google Patents

Description

The invention relates to an injection valve member for a fuel injector, which is designed in several parts and includes different functional areas.

State of the art

From the DE 10 2006 029 394 A1 The applicant is an injection valve member according to the preamble of claim 1 known. The known injection valve member has, inter alia, two guide body for guiding the injection valve member. Furthermore, from the DE 10 2004 028 617 A1 For example, a nozzle needle for a fuel injector is known having a guide portion provided with a layer of sintered metal. The known nozzle needle comprises a nozzle needle main body, which has substantially the shape of a hollow cylinder. A nozzle needle end made of sintered metal is fixed by shrinking or pressing on the nozzle needle main body.

Disclosure of the invention

The object of the invention is to reduce the manufacturing costs for a fuel injector with an injection valve member, which is designed in several parts and includes different functional areas.

The object is achieved with an injection valve member for a fuel injector with the features of claim 1. The invention is characterized in that the connecting rod extends through at least one of the guide body. For this purpose, the guide body has a central through-hole whose diameter is equal to the diameter of the connecting rod is adjusted. The connection between the guide body and connecting rod can be made non-positively, positively or materially.

The injection valve member is also referred to as a nozzle needle. The present invention relates to relatively long nozzle needles which are guided at two locations in an injector housing of the fuel injector. According to one essential aspect of the invention, the nozzle needle is of modular construction and comprises two separate guide bodies, which can be used with different connecting rods, in particular connecting rods of different lengths. This makes it possible in a simple manner to provide a modular system with different Injektorlängen.

A preferred embodiment of the injection valve member is characterized in that the connecting rod is formed of a different material than the guide body. The connecting rod is preferably formed of a material which ensures a high axial rigidity of the connecting rod. In contrast, the guide bodies are preferably formed from a material which has a high wear resistance.

Another preferred exemplary embodiment of the injection valve member is characterized in that the connecting rod is formed from a ceramic material, a simple structural steel which is readily weldable, a plastic material and / or a cast material. The connecting rod may be formed entirely from one of the mentioned materials. But it is also possible that the connecting rod is formed of different materials. The connecting rod may also have axial sections which, at least in part, are formed of different materials. According to an essential aspect of the invention, the connecting rod is designed so that it can be manufactured in a simple manner in different lengths and provided in stock.

A further preferred embodiment of the injection valve member is characterized in that the guide body of a ceramic material, a plastic material, a sintered material and / or a preferably surface hardened steel are formed. The guide bodies can be formed completely from one of the mentioned materials. But it is also possible that the guide body are formed of different materials. In particular, the guide bodies can be specially treated and / or coated on guide surfaces.

Another preferred embodiment of the injection valve member is characterized in that the injection valve member comprises a tip which is attached to the separate connecting rod. The tip has a sealing function and is, at least partially, formed of a preferably particularly wear-resistant material.

A further preferred embodiment of the injection valve member is characterized in that the connecting rod has the shape of a full or hollow, straight circular cylinder. This makes it possible in a simple manner, the production and stock supply of different lengths connecting rods. But the connecting rods can also have areas with different outer diameters. In addition, at least one collar may be provided on the connecting rods, which has, for example, a contact surface for a closing spring.

A further preferred embodiment of the injection valve member is characterized in that the guide bodies each have the shape of a full or hollow, straight circular cylinder. In the axial direction, the guide bodies preferably have a significantly smaller extent than the connecting rod. The lateral surface of the guide body represents a guide surface, with which the respective guide body is guided in a guide bore or a guide bore portion of the fuel injector in the axial direction back and forth movable. Preferably, flattenings are provided on one of the guide bodies, which allow the passage of fuel in the region of the guide.

A further preferred embodiment of the injection valve member is characterized in that at least one end of the connecting rod is disposed within one of the guide body. This end may be non-positively, positively or materially connected to the guide body. In addition, this end may alternatively or additionally be connected to one end of a pin, at the other end of which a point is provided.

A further preferred embodiment of the injection valve member is characterized in that a central part between the two guide bodies for displaying a modular system with different, for example different length, fuel injectors, the injection valve members having, for example, different lengths and / or axial stiffness, different lengths and / or stiff , According to an essential aspect of the invention, a kit is provided with different fuel injectors. Due to the variation of the middle part of the kit can be displayed particularly cost.

The invention further relates to a fuel injector for storage injection systems, for injecting high-pressure fuel into a combustion chamber of an internal combustion engine, with an injector housing, in which a previously described injection valve member is movable back and forth to inject high-pressure fuel from the fuel injector to control in a combustion chamber of an internal combustion engine. The invention relates according to an essential aspect of the invention, a kit for a fuel injector with injection valve members comprising guide body, which can be combined in a simple manner with different connecting rods, in particular different length connecting rods.

Further advantages, features and details of the invention will become apparent from the following description, in which Referring to the drawings, various embodiments are described in detail.

Short description of the drawing

Figur 1

eine stark vereinfachte Darstellung eines Kraftstoffinjektors mit einem Einspritzventilglied im Längsschnitt;

Figur 2

eine stark vereinfachte Darstellung eines Einspritzventilglieds im Längsschnitt mit unterschiedlichen Funktionsbereichen und die

Figuren 3 bis 12

Einspritzventilglieder im Längsschnitt, die gemäß verschiedenen Ausführungsbeispielen der Erfindung ausgeführt sind.

Show it:

FIG. 1

a highly simplified representation of a fuel injector with an injection valve member in longitudinal section;

FIG. 2

a highly simplified representation of an injection valve member in longitudinal section with different functional areas and the

FIGS. 3 to 12

Injection valve members in longitudinal section, which are carried out according to various embodiments of the invention.

Description of the embodiments

In FIG. 1 is a fuel injector 1 with an injector 2 greatly simplified in longitudinal section. The injector 2 is designed in several parts and protrudes with its end near the combustion chamber 3 in a combustion chamber of an internal combustion engine. In the injector housing 2, an injection valve member 4 is guided to and fro movable, which is also referred to as a nozzle needle. At its end remote from the combustion chamber, the injection valve member 4 has a tip 5 with a sealing edge, which can come into contact with a sealing surface of the injector housing. If the sealing edge on the nozzle needle tip is in contact with the associated sealing surface, then the fuel injector 1 is closed. When the pressure in a control chamber 6 at the combustion chamber remote end of the nozzle needle 4 is deliberately lowered, then opens the nozzle needle 4, wherein the tip 5 lifts off with the sealing edge of the associated sealing surface, to release a flow connection from a pressure chamber in the interior of the injector 2 in the combustion chamber.

At its end remote from the combustion chamber, the injection valve member 4 has a guide and / or sealing section 8, through which the injection valve member 4 is guided at a first guide point in the injector housing 2. At a second guide point, the nozzle needle 4 is guided in the injector housing 2 by means of a guide and / or line section 9. At the guide and / or line section 9 flats can be provided, which allow the passage of fuel.

According to one essential aspect of the invention, the two sections or surfaces 8, 9 are formed on separate guide bodies, which are both attached to a common connecting rod 10.

In FIG. 2 an injection valve member 20 is shown alone in longitudinal section, which is similar to the injection valve member 4 of Figure 1. The injection valve member 20 or the nozzle needle 20 comprises two guide bodies 21, 22 which are secured to the ends of a connecting rod 24. On the guide body 21, a tip 25 is fixed on the end facing away from the connecting rod 24. The tip 25 may also be integrally connected to the guide body 21. The tip 25 has the function Dense. The guide body 21 has the functions of guiding and optionally conveying fuel. The connecting rod 24 has the function Connect. In this case, an essential aspect is whether the connecting rod 24 changes its length during operation. The guide body 22 has the functions of guiding and sealing.

In FIG. 3 a nozzle needle 30 is shown with two guide bodies 31, 32 which are attached to a connecting rod 34. On the guide body 31, a tip 35 is attached. To increase their wear resistance, the guide bodies 31, 32 are provided with a wear-resistant coating. In addition, the tip 25 is also provided with a wear-resistant coating.

In FIG. 4 a nozzle needle 40 is shown with two guide bodies 41, 42 which are secured to the ends of a connecting rod 44. The connecting body 41 is integrally connected to a tip 45 via a connecting portion 46. On the other side of the guide body 41 is a stub 47, whose free end is fixed to the connecting rod 44. A similar stub 48 extends from the guide body 42, and serves for attachment to the other end of the connecting rod 44. The connecting rod 44 has the shape of a straight solid cylinder and is preferably made of a ceramic material, a simple structural steel, which is well weldable, or a Plastic formed. The guide bodies 41, 42 are preferably formed of a ceramic material, a plastic, a sintered material or a surface hardened steel.

In FIG. 5 a nozzle needle 50 with two guide bodies 51, 52 is shown, which are fastened to a connecting rod 54. The guide body 51 is integrally connected to a tip 55 through a connecting portion 56. The connecting rod 54 is formed of a cast material. According to a further aspect of the invention, the attachment of the guide body 51, 52 takes place on the connecting rod 54 by encapsulation. For this purpose, from the guide body 51 is a stub 57, at the end of a collar 59 is formed. Analog goes from the guide body 52 a stub 58, at the end of a collar 53 is formed. The collar 53, 59 and a portion of the associated stub 58, 57 is cast with the casting material from which the connecting rod 54 is formed. The casting material may be a steel casting material or an aluminum casting material.

In FIG. 6 An injection valve member 60 is shown in longitudinal section, which comprises two guide bodies 61, 62, both having a central through hole through which a connecting rod 64 extends therethrough. At one end of the connecting rod 64, a tip 65 is formed. The two guide bodies 61, 62 may be fixed by a press connection on the connecting rod 64. Alternatively, the two guide bodies 61, 62 can be integrally connected to the connecting rod 64.

In FIG. 7 an injection valve member 70 is shown, the injection valve member 40 from FIG. 4 similar. The injection valve member 70 includes two guide bodies 71, 72 fixed to a connecting rod 74. A tip 75 is integrally connected to the guide body 71 through a connecting portion 76. At a first separation point 73, one end of the connecting rod 74 is secured to a stub 77, which in turn is secured to the guide body 71. Another stub 78 is attached to the guide body 72 and connected at another separation point 79 in turn with the connecting rod 74.

In FIG. 8 an injection valve member 80 is shown, which the injection valve member 60 from FIG. 6 similar. The injection valve member 80 includes two guide bodies 81, 82 which are mounted on a continuous connecting rod 84. At one end of the connecting rod 84, a tip 85 is formed. The guide bodies 81, 82 are preferably made Plastic or a metal alloy, in particular with the designation 100 Cr6 formed.

In FIG. 9 an injection valve member 90 is shown with two guide bodies 91, 92 which are attached to a connecting rod 94. The two guide bodies 91, 92 each comprise a central through hole. The connecting rod 94 extends with its end remote from the combustion chamber through the guide body 92 therethrough. The combustion chamber near the end of the connecting rod 94, viewed in the axial direction, approximately in the center of the guide body 91 is arranged. At the combustion chamber near the end of the connecting rod 94 is located at a combustion chamber distal end of a pin 96, at its combustion chamber near the end of a tip 95 is formed. The pin 96 is connected to a separation point 98 preferably cohesively with the connecting rod 94 and / or the guide body 91. In this case, the guide body 91 simultaneously constitutes a connecting member between the connecting rod 94 and the pin 96 with the tip 95.

In FIG. 10 is an injection valve member 100 with two guide bodies 101, 102 shown in longitudinal section, which are mounted on a connecting rod 104. The connecting rod 104 has the shape of a straight hollow cylinder which is open at both ends. On the combustion chamber near the end of the connecting rod 104, a tip 105 is attached. The tip 105 is integrally connected via a connecting portion 106 with a pin 107 which is arranged in the connecting rod 104. The guide body 101 includes a central through hole through which the connecting rod 104 extends. From the guide body 102 is a central pin 108 goes out, which is inserted into the combustion chamber remote end of the connecting rod 104. The attachment of the tip 105 and the guide body 101, 102 on the connecting rod 104 may be cohesive, positive or non-positive.

In FIG. 11 is an injection valve member 110 with two guide bodies 111, 112 shown in longitudinal section. The two guide bodies 111, 112 are in the form of sleeves which extend around a connecting rod 114, which has the shape of a straight hollow cylinder. The connecting rod 114 is closed at its combustion chamber remote end 118 and open at its end close to the combustion chamber. In the open, near the combustion chamber end of the connecting rod 114, a tip 115 is inserted, from which a pin 116 extends, which is partially disposed in the connecting rod 114.

In FIG. 12 an injection valve member 120 is shown in two different lengths. The injection valve member 120 comprises two guide bodies 121, 122, which can be fastened to different connecting rods 124, 134. The guide body 121 has a tip 125 which is integrally connected to the guide body 121 through a connecting portion 126. From the tip 125 remote from the end face of the guide body 121 is a stub 127 goes out, which is fixed by means of a coupling sleeve 128 at the combustion chamber near the end of the connecting rod 124, 134. An analogue stub 129 starts from the combustion chamber near end face of the guide body 122. The combustion chamber near the end of the stub 129 is attached by means of a further connecting sleeve 131 at the combustion chamber remote end of the connecting rod 124, 134.

The connecting rod 134 is on the one hand shorter than the connecting rod 124. In addition, the connecting rod 134 comprises a reduced diameter portion 135, which has a smaller outer diameter than the connecting rod 124.

According to a further essential aspect of the invention, the axial stiffness of the injection valve member or the nozzle needle can be adjusted specifically. The axial stiffness significantly affects the injector function, such as the opening speed, the minimum quantity capability, etc. According to another essential aspect of the invention, it is possible to easily create a modular system with fuel injectors of different lengths. Due to the modular design of the nozzle needle according to the invention, different lengths of the nozzle needle can be provided at low cost. The connecting rod 10; 24; 34; 44; 54; 64; 74; 84; 94; 104; 114; 124; 134 has essentially the task of the two guide body 21, 22; 31, 32; 41, 42; 51, 52; 61, 62; 71, 72; 81, 82; 91, 92; 101, 102; 111, 112; 121, 122 with each other and / or with the nozzle needle tip 25; 35; 45; 55; 65; 75; 85; 95; 115; 125 to connect. The connecting rod contributes significantly to the overall rigidity of the nozzle needle in the axial direction. Core of the invention is the decoupling of the functional areas nozzle needle tip and guide body of the modular-dependent sizes needle length and axial stiffness.

The adjustment of the required length and axial rigidity takes place only in one component, the connecting rod, while the functional areas nozzle needle tip and guide body remain unchanged. Among other things, this concept provides the following advantages: More common parts, which has a positive effect on logistics and costs; Variance in a relatively simple component with lower accuracy and tolerance requirements, which has a positive cost impact. In addition, it is possible the Connecting rod made of a different material, which has a positive effect on the cost and possibly brings benefits for a desired connection technology.

In FIG. 12 It is indicated that the overall rigidity of the nozzle needle 120 is composed of the individual stiffnesses of the components 141, 142 and 143. The axial stiffness is dependent on the respective cross-sectional areas and the length of the associated component as well as the modulus of elasticity. In a longer variant, the axial stiffness of the nozzle needle 120 can be kept constant, if the individual stiffnesses 141 to 143 of the components remain constant. Since the components 141 and 143 are always kept geometrically the same, the associated stiffnesses are constant. Accordingly, the rigidity of the component 142 with the connecting rod 124; 134 remain constant. This is possible if the ratio of cross-sectional area and length of the connecting rod 124; 134 is kept constant.

The connecting rod 124; 134 can be performed as a solid cross section of rod material or as a hollow cross section of pipe material. The embodiment of the connecting rod 124; 134 as a hollow cross-section can have both functional and manufacturing advantages. The diameter at the joints should from the process engineering point of view and for a consistent strength for all variants of the connecting rod 124; 134 remain constant, as in FIG. 12 is shown. For a full cross-section, this may mean a heel to a smaller and / or larger diameter. In the case of a hollow cross-section, the adaptation of the cross-sectional area can take place via the inner diameter, while the outer diameter can remain constant.

Claims (11)

1. Injection valve member (30; 40; 50; 60; 70; 80; 90; 100; 110) for a fuel injector (1), which injection valve member (30; 40; 50; 60; 70; 80; 90; 100; 110) is configured in multiple pieces and comprises different functional regions, the injection valve member (30; 40; 50; 60; 70; 80; 90; 100; 110) comprising two guide bodies (31, 32; 41, 42; 51, 52; 61, 62; 71, 72; 81, 82; 91, 92; 101, 102; 111, 112) which are fastened to a separate connecting rod (34; 44; 54; 64; 74; 84; 94; 114), characterized in that the connecting rod (64; 84; 94; 114) extends through at least one of the guide bodies (61, 62; 81, 82; 92; 101, 102; 111, 112).
2. Injection valve member according to Claim 1, characterized in that the connecting rod (34; 44; 54; 64; 74; 84; 94; 114) is formed from a different material than the guide bodies (31, 32; 41, 42; 51, 52; 61, 62; 71, 72; 81, 82; 91, 92; 101, 102; 111, 112).
3. Injection valve member according to either of the preceding claims, characterized in that the connecting rod (34; 44; 54; 64; 74; 84; 94; 114) is formed from a ceramic material, a simple construction steel which can be welded satisfactorily, a plastic material and/or a cast material.
4. Injection valve member according to one of the preceding claims, characterized in that the guide bodies (31, 32; 41, 42; 51, 52; 61, 62; 71, 72; 81, 82; 91, 92; 101, 102; 111, 112) are formed from a ceramic material, a plastic material, a sintered material and/or a preferably case-hardened steel.
5. Injection valve member according to one of the preceding claims, characterized in that the injection valve member (30; 40; 50; 60; 80; 90; 100; 110) comprises a tip (35; 45; 55; 65; 85; 95; 105; 115) which is fastened to the separate connecting rod (34; 44; 54; 64; 84; 94; 114).
6. Injection valve member according to one of Claims 1 to 4, characterized in that one of the guide bodies (31; 41; 51; 71) is connected integrally to a tip (35; 45; 55; 75).
7. Injection valve member according to one of the preceding claims, characterized in that the connecting rod (34; 44; 54; 64; 74; 84; 94; 114) has the shape of a solid or hollow, straight circular cylinder.
8. Injection valve member according to one of the preceding claims, characterized in that the guide bodies (31, 32; 41, 42; 51, 52; 61, 62; 71, 72; 81, 82; 91, 92; 101, 102; 111, 112) in each case have the shape of a solid or hollow, straight circular cylinder.
9. Injection valve member according to one of the preceding claims, characterized in that at least one end of the connecting rod (94) is arranged within one of the guide bodies (91).
10. Injection valve member according to one of the preceding claims, characterized in that a centre part between the two guide bodies (31, 32; 41, 42; 51, 52; 61, 62; 71, 72; 81, 82; 91, 92; 101, 102; 111, 112) is configured with a different length and/or rigidity in order to produce a kit with different fuel injectors, for example of different length, which comprise injection valve members (30; 40; 50; 60; 70; 80; 90; 100; 110) with, for example, different lengths and/or axial rigidities.
11. Fuel injector (1) for common rail injection systems, for injecting fuel which is loaded at high pressure into a combustion chamber of an internal combustion engine, having an injector housing (2), in which an injection valve member (30; 40; 50; 60; 70; 80; 90; 100; 110) according to one of the preceding claims can be moved to and fro, 'in order to control an injection of fuel which is loaded at high pressure out of the fuel injector (1) into a combustion chamber of an internal combustion engine.

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