Valve for dosing a fluid, in particular fuel injection valve

Abstract

The invention proposes a valve, in particular a fuel injection valve, which is characterized in that it has improved temperature stability in the region of the valve components which are subjected to high temperatures. The fuel injection valve (1) comprises an actuator (15) which can be excited for actuating a valve closure body (12) which forms a sealing seat together with a valve seat face (14) formed on a valve seat body (13), and an injection opening (4) which is formed downstream of the valve seat face (14). Furthermore, the valve has a valve seat carrier (10) which receives the valve seat body (13), forms part of a valve housing (22) and is connected to the valve seat body (13). The valve seat carrier (10), which is composed of a metallic material, and the valve seat body (13), which is composed of a ceramic material, are fixedly connected to one another indirectly via a clamping sleeve (30). The fuel injection valve is particularly suitable for direct injection of fuel into the combustion chamber of a mixed compression, externally ignited internal combustion engine.

Description

Technical Field

[0001] The present invention starts with a valve for dispensing fluids, particularly a fuel injection valve. Background Technology

[0002] Figure 1 The image exemplarily illustrates a fuel injection device known in the prior art, in which a fuel injection valve is provided, mounted in a receiving port in the cylinder head of an internal combustion engine. This fuel injection device is particularly suitable for fuel injection systems in hybrid compression externally ignited internal combustion engines. The valve has a valve body, which in particular includes a valve seat carrier fixedly connected to and receiving a valve seat body. These two components are fixedly connected to each other by a weld. In the assembled state, the valve seat body rests against the inner stop shoulder of the valve seat carrier, thereby maintaining a radial annular gap between the two components on their outer periphery (e.g., DE 10 2005 052 255 A1).

[0003] A fuel injection valve is known from DE 10 2005 061 424 A1. This fuel injection valve has a magnetic circuit with a magnetic core, an electromagnetic coil and an armature, and a movable valve needle having a valve closing body that interacts with a fixed valve seat. The valve seat is formed on a valve seat body, which is fixedly connected to a valve seat carrier, and the valve seat body is inserted into the valve seat carrier. The valve seat body is made of ceramic material and has a serrated structure on its outer periphery for establishing a fixed connection with the valve seat carrier, which is made of plastic. This achieves a plastic-ceramic mating connection between the two components. The serrated structure of the ceramic component, the valve seat body, penetrates into the plastic of the valve seat carrier, and then the plastic relaxes. Summary of the Invention

[0004] This invention proposes a valve for metering fluids, particularly a fuel injection valve for fuel injection equipment of an internal combustion engine, especially for directly injecting fuel into the combustion chamber. The valve has an actuable actuator for operating a valve closing body, which, together with a valve seat surface formed on a valve seat body, constitutes a sealing seat; at least one injection opening formed downstream of the valve seat surface; and a valve seat carrier that receives the valve seat body, forms part of the valve housing, and is connected to the valve seat body, wherein the valve seat carrier and the valve seat body are indirectly and fixedly connected to each other via a clamping sleeve.

[0005] The valve for metering fluids according to the invention has the advantage of improved temperature stability in areas of the valve components subjected to high temperatures. The fuel injection valve accordingly relates to a valve seat body facing the combustion chamber. At the valve end on the injection side of this valve seat body, the valve advantageously possesses high resistance to chemical corrosion, which, in the case of a direct injection fuel injection valve, is affected by the corrosive combustion chamber environment due to its proximity to the combustion chamber. According to the invention, the valve seat carrier and valve seat body, which belong to the valve housing, are indirectly connected to each other only by a clamping sleeve.

[0006] Advantageous extensions and improvements to the valve of the present invention can be achieved through preferred embodiments.

[0007] Of particular advantage, the valve seat body is made of ceramic material to achieve the desired improved temperature stability in the high-temperature regions of the valve component. For example, Ceramic is a suitable material for the valve seat body. Other alternative ceramics may also be considered. The valve seat carrier and clamping sleeve are both made of metal. The clamping sleeve is a sleeve-shaped component with a bottom region that is bent at approximately 90° at its lower end. This bottom region engages the shoulder of the valve seat body from below and receives the valve seat body. The valve seat body rests against the flat lower end side of the valve seat carrier.

[0008] Particularly advantageous is that a tapered extension region is provided at least sectionally on the lower end side of the valve seat carrier, and the rounded upper end side of the valve seat body works in conjunction with this tapered extension region to form a universal joint support. In this way, the valve seat body can be centered and oriented relative to the valve seat carrier. The design feature of a universal joint support can also be implemented well on other components. A flat extension section is joined either radially inward or radially outward on the tapered extension region on the lower end side of the valve seat carrier. The tapered extension region terminates with a chamfer.

[0009] To seal the valve seat body against the metal valve seat carrier, one or more, for example, circumferential shrinkage welds or tension welds are advantageously arranged on the outer periphery of the clamping sleeve. The shrinkage welds alter the microstructure in these regions of the clamping sleeve such that the material is slightly compressed and the length of the clamping sleeve components is reduced.

[0010] The valve seat carrier and the clamping sleeve are advantageously and securely connected to each other in their lap joint area by means of a weld, which is achieved because the clamping sleeve has a larger axial extension than the axial extension dimension of the valve seat body. In this way, the valve seat body, which cannot be welded, is indirectly fixed to the valve seat carrier. Attached Figure Description

[0011] Embodiments of the invention are simplifiedly illustrated in the accompanying drawings and described in detail in the following description. The accompanying drawings show:

[0012] Figure 1 A schematic cross-sectional view of a fuel injection valve configured with a known valve seat body having an injection opening at the downstream valve end.

[0013] Figure 2 As shown in the enlarged diagram Figure 1 The first embodiment of the downstream valve end of section II,

[0014] Figure 3 As shown in the enlarged diagram Figure 1 The second embodiment of the downstream valve end of section II,

[0015] Figure 4 Shown in enlarged diagram Figure 3 The part marked with IV in the middle,

[0016] Figure 5 As shown in the enlarged diagram Figure 1 The third embodiment of the downstream valve end of part II,

[0017] Figure 6 Shown in enlarged diagram Figure 5 The part marked with VI in the middle. Detailed Implementation

[0018] Fuel injection valve 1 in Figure 1 The known example shown is implemented in the form of a fuel injection valve 1 in a fuel injection device for a hybrid compression ignition internal combustion engine. The fuel injection valve 1 is particularly suitable for injecting fuel directly into a combustion chamber 25 (not shown in detail) of the internal combustion engine. Generally, the invention can be applied to valves used for metering fluids.

[0019] The fuel injection valve 1 is mounted downstream into the receiving hole 20 of the cylinder head 9. It is made of Teflon. The manufactured sealing ring 2 is responsible for the optimized sealing of the fuel injector 1 relative to the wall of the receiving hole 20 of the cylinder head 9.

[0020] The fuel injection valve 1 has a plug-in connection at its inflow-side end 3 to a fuel distributor line (not shown), which is sealed by a sealing ring 5 between the fuel distributor line's connecting pipe and the fuel injection valve 1's inflow pipe 7. The fuel injection valve 1 has an electrical connection plug 8 for operating the fuel injection valve 1.

[0021] A decoupling element 24 is placed between the shoulder 23 of the valve housing 22 and the receiving port 20, the shoulder extending, for example, at a right angle to the longitudinal extension of the receiving port 20. This decoupling element compensates for manufacturing and assembly tolerances and also ensures support without lateral forces when the fuel injection valve 1 is slightly angled. Furthermore, optimized noise decoupling is thus achieved. The decoupling element 24 is secured, for example, by means of a retaining shim 39.

[0022] The valve housing 22 of the fuel injection valve 1 is primarily composed of the inlet pipe 7, but also of the nozzle body 10, in which a valve needle 11 is arranged. The valve needle 11 is in operative connection with, for example, a spherical valve closing body 12, which, together with a valve seat surface 14 arranged on a valve seat body 13, forms a sealing seat. In this embodiment, the fuel injection valve 1 is an inwardly opening fuel injection valve 1 having at least one injection opening 4, but typically having at least two injection openings 4. However, the fuel injection valve 1 is ideally implemented as a multi-hole injection valve and therefore has four to thirty injection openings 4.

[0023] For example, an electromagnetic circuit containing an electromagnetic coil 15 as an actuator is used as the driver. The electromagnetic coil is enclosed in a coil housing and wound on a coil carrier surrounding an inner pole 16. Furthermore, an armature 17, also part of the electromagnetic circuit, is arranged on the valve needle 11. In the stationary state of the fuel injection valve 1, the armature 17 is loaded by a return spring 18 in the opposite lifting direction, such that the valve closing body 12 is held in a sealing manner against the valve seat surface 14. When the electromagnetic coil 15 is energized, it establishes a magnetic field that causes the armature 17 to move in the lifting direction against the spring force of the return spring 18. The armature 17 also carries the valve needle 11 in the lifting direction. The valve closing body 12, connected to the valve needle 11, is lifted from the valve seat surface 14, and fuel is ejected through the injection opening 4.

[0024] If the coil current is cut off, the armature 17 falls from the inner pole 16 due to the pressure of the return spring 18 after the magnetic field has sufficiently decayed, thereby causing the valve needle 11 to move in the opposite lifting direction. As a result, the valve closing body 12 is placed on the valve seat surface 14 and the fuel injection valve 1 is closed.

[0025] This embodiment of the fuel injection device is a system for direct gasoline injection via a fuel injection valve 1, as shown, which can be operated by means of an electromagnetic actuator or a piezoelectric actuator and can be used, for example, in a constant pressure system.

[0026] The nozzle body 10 is also a valve component that can be called a valve seat carrier, because the valve seat carrier receives the valve seat body 13. Figure 2 As shown in the enlarged diagram Figure 1The downstream valve end of section II, however, is as described in the first embodiment according to the invention. Advantageously, the valve seat body 13 is made of ceramic material. In comparable known valves, the valve seat body 13 is made of metallic materials such as stainless steel. At high valve seat temperatures, the strength of such metallic materials decreases, necessitating careful adherence to temperature limits on these components when using such metals. Therefore, ceramic material should be used for the valve seat body 13 as a high-temperature stable material. Furthermore, advantageously, the valve exhibits high chemical corrosion resistance at its valve end subjected to the combustion chamber environment.

[0027] Because the valve seat carrier 10, as part of the valve housing 22, should also be made of a metallic material such as stainless steel, as is common in such valves, the valve seat carrier 10 and the valve seat body 13 cannot be fixedly connected to each other by weld. Therefore, according to the invention, the valve seat carrier 10 and the valve seat body 13 are indirectly connected to each other, specifically by a clamping sleeve 30. The clamping sleeve 30 is a sleeve-shaped member having a bottom region 31 that is bent at 90° at its lower end. The bottom region 31 has a large opening that partially passes through the valve seat body 13. Thus, the remaining portion of the bottom region 31 forms an annular flange that engages below the shoulder 32 of the valve seat body 13 and thus receives the valve seat body 13. The valve seat body 13 is suspended in the clamping sleeve 30 until it rests against the flat lower end side 33 of the valve seat carrier 10 and is then fixed. For example, fixation is achieved in their overlapping area by means of a surrounding weld 34 between the metal valve seat carrier 10 and the metal clamping sleeve 30, since the clamping sleeve 30 has a larger axial extension than the axial extension dimension of the valve seat body 13.

[0028] To seal the valve seat body 13 against the valve seat carrier 10, one or more, for example, circumferential shrinkage welds or tension welds 38 are arranged on the outer periphery of the clamping sleeve 30. The shrinkage welds 38 alter the microstructure in these regions of the clamping sleeve 30 such that the material is slightly compressed and the length of the clamping sleeve 30 is reduced. The axial clamping thus achieved in the stop region of the valve seat body 13 and the valve seat carrier 10 must be designed such that the clamping connection between the valve seat body 13 and the valve seat carrier 10 is sealed against hydraulic system pressures, for example, up to 500 bar.

[0029] exist Figure 3 The enlarged diagram is shown as Figure 1 The second embodiment of the downstream valve end of section II. This embodiment is similar to... Figure 2The difference in the illustrated embodiment is particularly that the lower end side 33 of the valve seat carrier 10 is not flat. Instead, the end side 33 of the valve seat carrier 10 facing the valve seat body 13 has a stepped geometry. Starting radially outward, the end side 33 extends flat in a certain section, perpendicular to the longitudinal axis of the valve seat carrier 10, and then transitions radially inward into a tapered extension region 35, which tapers radially inward facing the valve seat body 13. The tapered extension region 35 of the end side 33 of the valve seat carrier 10 and the rounded upper end side 36 of the valve seat body 13 work together to form a universal joint support. In this way, the valve seat body 13 can be centered and oriented relative to the valve seat carrier 10. After the valve seat body 13 and the valve seat carrier 10 are precisely oriented relative to each other, they are fixed by means of the weld 34 between the valve seat carrier 10 and the clamping sleeve 30. In this external sealing design, one or more, for example, circumferential shrinkage welds 38 can be provided on the outer periphery of the clamping sleeve 30 to achieve axial compression in the stop area of ​​the valve seat body 13 and the valve seat carrier 10 and thus achieve the desired seal. Figure 4 As shown in the enlarged image Figure 3 The section marked with IV is used to explain the universal joint type support.

[0030] exist Figure 5 In the enlarged view, it is shown as... Figure 1 The third embodiment of the downstream valve end of section II. This embodiment is similar to... Figure 3 The difference in the illustrated embodiment is particularly that the lower end side 33 of the valve seat carrier 10 is implemented in a reverse, but not continuously flat, manner in some regions. Furthermore, the end side 33 of the valve seat carrier 10 facing the valve seat body 13 also has a stepped geometry. Starting radially outward, the end side 33 has a tapered extension region 35 extending radially inward, which then continues radially inward into a section perpendicular to the longitudinal axis of the valve seat carrier 10. The tapered extension region 35 tapers radially inward away from the valve seat body 13. The tapered extension region 35 of the end side 33 of the valve seat carrier 10 is aligned with... Figure 3 and 4 A similar arrangement as in the example above, working together with the rounded upper end side 36 of the valve seat body 13, forms a universal joint support. In this way, the valve seat body 13 can be centered and oriented relative to the valve seat carrier 10. After the valve seat body 13 and the valve seat carrier 10 are precisely oriented relative to each other, they are secured by the weld 34 between the valve seat carrier 10 and the clamping sleeve 30. In this internal sealing design, one or more, for example, circumferential shrinkage welds 38 can also be provided on the outer periphery of the clamping sleeve 30 to achieve axial compression in the stop region of the valve seat body 13 and the valve seat carrier 10, thereby achieving the desired seal. Figure 6 As shown in the enlarged image Figure 5 The part marked with VI is used to explain the universal joint support.

[0031] As shown, the tapered region 35 can also terminate with chamfers. Alternatively, the end side 33 can be configured as a tapered extension region 35 without flat sections along its entire radial extension scale.

[0032] All the design features described above regarding the geometry of the universal joint support between the valve seat body 13 and the valve seat carrier 10 can also be implemented on another component in the exact opposite way, without failing to ensure the desired functionality.

Claims

1. A valve for dispensing fluid, the valve having: - An actuator (15) that can be excited to operate a valve closing body (12), the valve closing body and the valve seat surface (14) formed on the valve seat body (13) together forming a sealing seat; and - At least one injection opening (4) is formed downstream of the valve seat surface (14); and - Valve seat carrier (10), which receives the valve seat body (13), forms part of the valve housing (22), and is connected to the valve seat body (13). in, The valve seat carrier (10) and the valve seat body (13) are indirectly and fixedly connected to each other through a clamping sleeve (30). Its features are, The clamping sleeve (30) has a larger axial extension than the axial extension dimension of the valve seat body (13), and the valve seat carrier (10) and the clamping sleeve (30) are fixedly connected to each other in the overlapping area between the valve seat carrier and the clamping sleeve by means of a weld (34), wherein one or more shrinkage welds (38) are arranged on the outer periphery of the clamping sleeve (30), and the component length of the clamping sleeve (30) can be reduced by means of the shrinkage welds.

2. The valve according to claim 1, Its features are, The valve seat body (13) is made of ceramic material and the valve seat carrier (10) and the clamping sleeve (30) are respectively made of metal material.

3. The valve according to claim 1 or 2, Its features are, The clamping sleeve (30) is a sleeve-shaped component having a bottom region (31) that is bent at about 90° at its lower end. The clamping sleeve engages the shoulder (32) of the valve seat body (13) from below with the bottom region and thereby receives the valve seat body (13).

4. The valve according to claim 1 or 2, Its features are, The valve seat body (13) rests against the flat lower end side (33) of the valve seat carrier (10).

5. The valve according to claim 4, Its features are, At least a section of tapered extension region (35) is provided on the lower end side (33) of the valve seat carrier (10), and the rounded upper end side (36) of the valve seat body (13) and the tapered extension region work together to form a universal joint support.

6. The valve according to claim 5, Its features are, A flat extending section is connected on the tapered extension region (35) of the lower end side (33) of the valve seat carrier (10), either radially inner or radially outer.

7. The valve according to claim 5 or 6, Its features are, The tapered extension region (35) terminates with a chamfer.

8. The valve according to any one of claims 1, 2, 5 and 6, Its features are, One or more circumferential shrinkage welds (38) are arranged on the outer periphery of the clamping sleeve (30).

9. The valve according to any one of claims 1, 2, 5 and 6, Its features are, The valve is configured as a fuel injection valve (1) for a fuel injection device for an internal combustion engine.

10. The valve according to claim 9, Its features are, The fuel injection valve (1) is configured to inject fuel directly into the combustion chamber.

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