Gas valve

Abstract

The invention relates to a gas valve for dispensing gaseous fuel in a metered manner, comprising a valve body (1) in which a gas chamber (2) which can be filled with gaseous fuel and has a valve element (3) which is arranged in a longitudinally movable manner therein is formed. The valve element (3) has a disc-shaped end section (6) which interacts with a valve seat (7) formed on the valve body (1) in order to open and close an annular flow cross-section (9). A cylindrical sleeve (10) surrounding the valve body (1) has a base section (11) forming an end of the sleeve (10) and a circumferential surface (12) joining the base section (11), the base section (11), the sleeve (12) and the disc-shaped end section (6) delimiting a chamber (15). According to the invention, the chamber (15) has a blow-in opening (16), which is formed in the base section (11) and in the circumferential surface (12) of the cylindrical sleeve (10).

Description

Technical Field

[0001] The invention relates to a gas valve, such as a gas valve for metering gaseous fuel into a combustion chamber or into an intake manifold of an internal combustion engine. Background Art

[0002] When an internal combustion engine is operated using gaseous fuel, the fuel is metered into the engine's intake system or directly into the combustion chamber under injection pressure. To this end, a gas valve with a longitudinally movable valve element is typically used. This valve element is moved by an electric actuator against the force of a closing spring and interacts with the valve seat. This longitudinal movement releases the annular flow cross section or, after the actuator is deactivated, closes it again. Here, the valve element opens outward, i.e., an opening movement occurs, causing the valve element to exit the gas valve. The electric actuator is typically an electromagnet that interacts with a solenoid armature or a submerged armature and thus applies an opening force to the valve element. Instead of so-called direct control (in which the magnetic force acts directly on the solenoid armature fixedly connected to the valve element), the valve element can also be controlled indirectly via a servo-hydraulic mechanism. In this case, for example, a piezoelectric actuator can also be used, as its short stroke is sufficient.

[0003] Precise metering and accurate timing are particularly important when injecting fuel directly into the combustion chamber to achieve efficient and low-pollutant combustion. Furthermore, for optimal combustion, the distribution of the gaseous fuel in the combustion chamber is crucial, ensuring thorough mixing with the air in the combustion chamber and preventing areas with a significant excess of fuel or air. For example, DE 10 20 21 20 1 085 A1 discloses providing a chamber downstream of (downstream of) the valve seat in a gas valve, from which the fuel flows outward through an injection opening. The injection opening can be designed as a channel that is inclined relative to the longitudinal axis of the gas valve to deflect the gas stream in the desired direction.

[0004] Because the gas valve protrudes into the combustion chamber with its end, its length and, therefore, the installation space, is limited. To achieve a sufficient deflection effect with the angled blow-in opening, on the one hand, the blow-in opening must be as long as possible, thus having a large length-to-diameter ratio (L / D). On the other hand, a large diameter is necessary to be able to deliver the required amount of gas at the right time within a short period of time. Blow-in openings with a large L / D ratio and a large diameter correspondingly require a large installation space, which is often unavailable. This means that the angled blow-in opening can only achieve a small deflection effect on the gas stream, making it difficult to optimally distribute the gaseous fuel in the combustion chamber. Summary of the Invention

[0005] The gas valve according to the present invention has the following advantages: it is possible to effectively deflect the outflowing gas stream within a relatively small installation space so as to optimally distribute the gaseous fuel in the combustion chamber. To this end, the gas valve comprises a valve body, in which a gas chamber that can be filled with gaseous fuel is constructed, and the gas chamber has a valve element arranged longitudinally therein. The valve element has a disc-shaped end section that cooperates with a valve seat constructed on the valve body to open and close an annular flow cross section. The valve body is surrounded by a cylindrical sleeve, which has a bottom section forming the end of the sleeve and a circumferential surface (circumferential wall) connected to the bottom section, wherein the bottom section, the sleeve and the disc-shaped end section delimit a chamber. The sleeve has an inlet opening through which the gaseous fuel flows out of the chamber, wherein the inlet opening is constructed in the bottom section and in the circumferential surface.

[0006] After the flow cross section is released, the fuel flows from the gas chamber of the gas valve into the cavity and from there through the blow-in opening into the combustion chamber of the internal combustion engine. By forming the blow-in opening in the circumference of the sleeve, a lateral opening relative to the longitudinal axis of the valve body is formed. This lateral opening effectively deflects the gas jet laterally, even with a small aspect ratio of the blow-in opening. The sleeve requires only a small wall thickness, thus requiring little installation space. As a result, the gas jet also enters the edge region of the combustion chamber and mixes optimally with the air therein, which contributes to efficient and low-pollutant combustion.

[0007] In a first advantageous embodiment of the invention, the blowing opening is formed by a hole formed in the bottom section of the cylindrical sleeve and a lateral opening in its circumference, which together form the blowing opening. This allows for a targeted configuration of the lateral opening, thereby easily optimizing the lateral deflection of the gas jet through it.

[0008] In another advantageous embodiment of the invention, the blowing opening is formed by a cylindrical hole extending in the base section and in the circumference. Here, the blowing opening is formed by a single hole that extends in the cylindrical sleeve such that, in addition to the base section, the circumference is also penetrated, thereby producing the desired lateral opening, which can be produced in this way in a single processing step.

[0009] In another advantageous embodiment, the bore is configured obliquely relative to the longitudinal axis of the sleeve or valve body. In addition to the effect of the lateral opening, the deflection of the gas stream can also be optimized and enhanced by the oblique cylindrical bore. The cylindrical bore preferably has a circular cross-section and an aspect ratio (L / D) of 0.75 to 2.5.

[0010] In another advantageous embodiment, the cylindrical bore has an oval or rectangular cross section. This configuration can be advantageous for optimally distributing the gaseous fuel in large or specially shaped combustion chambers. This shaping of the inlet opening can also be advantageous if the gas valve does not extend precisely centered into the combustion chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings illustrate various embodiments of the gas valve according to the invention.

[0012] Figure 1 A gas valve known from the prior art is shown,

[0013] Figure 2a and Figure 2b shows a first embodiment of a gas valve according to the present invention, and

[0014] Figure 3 In with Figure 1 Another exemplary embodiment is shown in the same figure. DETAILED DESCRIPTION

[0015] Figure 1 A gas valve known in the prior art for blowing gaseous fuel into a combustion chamber or intake mechanism of an internal combustion engine is shown, wherein only the main components of the gas valve are shown. The gas valve has a valve body 1, which is substantially cylindrical and in which a gas chamber 2 is constructed, which can be filled with gaseous fuel under injection pressure. A rotationally symmetrical valve element 3 is arranged longitudinally movably in the gas chamber 2, and the valve element has a disc-shaped end section 6 extending from the valve body 1 at its end. A sealing surface 8 facing the valve body 1 is constructed on the disc-shaped end section 6. When the valve element 3 is in its position as shown in FIG. Figure 1 In the open position shown, the valve element 3 interacts with its sealing surface with a valve seat 7 formed at the combustion chamber-side end (the lower end in the figure) of the valve body 1 to open and close a controlled flow cross section 9 between the sealing surface 8 and the valve seat 7. To move the valve element 3 in the longitudinal direction, a recessed armature 5 is arranged on the valve element 3. This recessed armature interacts with an electromagnet 4 formed in the valve body 1 so that when the electromagnet 4 is energized, the valve element 3 moves out of the valve body 1 in the opening direction. This movement occurs against the force of a closing spring (not shown in the figure), which, when the electromagnet is switched off, presses the valve element 3 into the closed position, so that it abuts against the valve seat 7.

[0016] The valve body 1 is surrounded by a cylindrical sleeve 10, which protrudes beyond the valve body 1 on the combustion chamber side. The cylindrical sleeve 10 has a bottom section 11 and a circumferential surface 12 adjoining the bottom section. The bottom section 11, the circumferential surface 12, and the disk-shaped end section 6 of the valve element 3 delimit a chamber 15. In the open position of the valve element 3, the disk-shaped end section 6 extends into this chamber, allowing gaseous fuel to flow from the gas chamber 2 into the chamber 15. From the chamber 15, the fuel enters the combustion chamber (not shown in detail) of the internal combustion engine or the intake manifold via an inlet opening 16. The inlet opening 16 is designed as a cylindrical bore 18 in the bottom section 11. The axis 21 of the cylindrical bore 18 encloses an angle α with the longitudinal axis of the valve body 1, which serves to laterally deflect the gas jet exiting the inlet opening 16.

[0017] The ratio of the length L of the hole 18 to its diameter (L / D ratio) is less than 1 here, which limits the lateral deflection of the gas jet, because the greater the L / D ratio, that is, the longer the hole 18 is compared to its diameter, the greater the deflection effect. In gas valves of this type known from the prior art, the deflection caused by the tilting of the hole is only slight.

[0018] Figure 2a A first embodiment of a gas valve according to the invention is shown in FIG. Figure 1 In the bottom section 11, a cylindrical hole 18 is formed, and in the circumferential surface 12, a lateral opening 19 is formed, which together form the injection opening 16, through which the gaseous fuel enters the combustion chamber from the chamber 15. Figure 2a As shown in FIG, the lateral openings 19 in the circumferential surface 12 enhance the deflection effect and deflect the gas stream 17 significantly to the right. Figure 2b A side plan view of a gas valve or cylindrical sleeve 10 is shown, wherein the view is relative to Figure 2a Rotated 90°. This configuration of the lateral opening 19 can be realized independently of the cylindrical bore 18, which provides a great deal of freedom in the configuration. By selectively optimizing the lateral opening 19, this effect can be optimally adapted to the respective combustion chamber, for example in particularly large or specially shaped combustion chambers.

[0019] Figure 3 Another embodiment of the gas valve according to the present invention is shown in the same figure, wherein only the embodiment thereof and the embodiment thereof will be described below. Figure 2a. Here, the blow-in opening 16 is designed as a single cylindrical hole 18. Thus, the cylindrical hole 18 can be realized in a single manufacturing step by forming a hole with a correspondingly large diameter and at an inclination angle α to the longitudinal axis 20, extending both in the bottom section 11 and in the circumferential surface 12 of the cylindrical sleeve 10. This easily allows the blow-in opening 16 to be lateral, which, as previously mentioned, significantly enhances the lateral deflection of the outflowing gas jet. Here, the L / D ratio can also be relatively small, ranging from 0.75 to 2.5, which saves space compared to longer blow-in openings. The resulting short design of the gas valve reduces the risk of overheating at the end of the cylindrical sleeve 10 due to combustion chamber gases.

[0020] As in the illustrated embodiment, the cylindrical hole 10 can have a circular cross section. However, it is also possible to configure the cylindrical hole 10 with an elliptical or rectangular cross section, which is another parameter for optimizing the distribution of the gaseous fuel in the combustion chamber. Within the scope of the present invention, a "cylindrical hole" is a shape that results when a closed curve is moved along a straight path.

Claims

1. A gas valve for metering gaseous fuel, comprising: a valve body (1), in which a gas chamber (2) which can be filled with gaseous fuel is formed, the gas chamber having a valve element (3) arranged therein so as to be longitudinally movable, wherein: The valve element (3) has a disk-shaped end section (6) which cooperates with a valve seat (7) formed on the valve body (1) for opening and closing an annular flow cross section (9); a cylindrical sleeve (10) surrounding the valve body (1), the cylindrical sleeve having a bottom section (11) forming the end of the sleeve (10) and a circumferential surface (12) adjoining the bottom section (11), wherein the bottom section (11), the sleeve (12) and the disk-shaped end section (6) delimit a chamber (15), It is characterized in that the chamber (15) has a blowing opening (16) which is formed in the bottom section (11) and in the circumferential surface (12) of the cylindrical sleeve (10).

2. The gas valve according to claim 1, characterized in that The blowing opening (16) is formed by a cylindrical hole (18) formed in the bottom section (11) and a lateral opening (19) formed in the circumferential surface (12).

3. The gas valve according to claim 1, characterized in that The blowing opening is formed by a cylindrical hole (18) extending in the bottom section (11) and in the circumferential surface (12).

4. The gas valve according to claim 2 or 3, characterized in that: The center axis (21) of the hole (18) is inclined at an angle α relative to the longitudinal axis (20) of the valve body (1).

5. The gas valve according to any one of claims 2 to 4, characterized in that The cylindrical hole (18) has a circular cross section.

6. The gas valve according to claim 5, characterized in that The ratio (L / D) of the length (L) to the diameter (D) of the cylindrical hole (18) is between 0.75 and 2.

5.

7. The gas valve according to any one of claims 2 to 4, characterized in that The cylindrical hole (18) has an elliptical or rectangular cross section.

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