FI113079B - spray valve - Google Patents

Description

113079

shower valve

Explanation

The invention relates to a jet valve according to the preamble of claim 1 for injecting fuel into a combustion engine combustion chamber.

State of the art

DE 3 824 467 C2 discloses such a jet valve. The spray channels in the nozzle sheath are arranged in two planes and are held by coaxial nozzle needles. In this arrangement, the hollow drilled outer needles 10 are pressed against the seat by a prestressed spring. The hydraulically controlled actuator can adjust the spring preload opening pressure arbitrarily. Thus, the opening pressure created for the partial loading area of this nozzle needle is adjustable. In order to adjust the spring preload, the injection pressure can be optimized for the partial load. In high-speed drive 15, an inner needle for drilling the first needle is further opened. In this operating mode, all nozzle channels for fuel injection are released. For a positive effect of combustion, the biasing force of the spring acting on the outer nozzle needle requires an expensive hydraulic control device in this solution.

! OBJECT OF THE INVENTION The object of the invention is to achieve the opening pressure of a nozzle needle; ; acting on part load operation in a simpler way - avoiding expensive hydraulic control and steering.

This problem is solved according to the invention by the features of claim 1. ···, 25.

By adjusting the number of jets in the loading area and adjusting the jet pressure in accordance with the invention, part-load combustion optimizes and reduces pollutant emissions.

By adjusting the opening pressure of the nozzle needle for part load operation in accordance with the invention, i.e., the biasing force of the compression spring which compresses the hollow needle on its seat is produced by mechanical means, expensive and disruptive hydraulics can be dispensed with. - • # · from the implement. Installation is substantially simplified, since no guide tubes are needed, and no adjustment wires and structural space for other components remain available.

2 113079

The low cost and uncomplicated mechanical design lowers the cost of a reliable shower system.

examples

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in more detail below.

Figure 1 shows a longitudinal section through the jet valve 1 according to the invention. The valve body 2 is shown only in the relevant paragraphs. In the lower part of the valve body 2, the injection holes of the first and second spray channel groups 12, 13 are drilled into the nozzle housing at different levels in each case. A hollow needle 11 is inserted into the center bore of the longitudinal axis of the valve body 2 to close the nozzle interior 14 with respect to the nozzle shell. The bore of the hollow needle 11 is formed with an axially movable valve needle 10 which prevents the flow of fuel to the second jet channel channel group 13. The ability to separate the valve needle 10 from the hollow needle 11 determines the pressure at which the fuel is further injected through the second jet channel channel group 13. The opening pressure of the valve needle 10 is determined by the fluid pressure in the space above the control piston 6. This fluid pressure is adjustable regardless of the fuel pressure. Through the lower end of the regulating piston 6, the axial force components of the fluid pressure are transmitted to a pressure bar 8 which presses the valve needle 10 against its seat, respectively.

20 At partial load, the first is sprayed alone. through the jet channel group 12, wherein the hollow needle 11 is formed to control the injection pressure. Further, the hollow needle 11 is pressed by the biasing of the compression spring 7 through the lower clamping piece 9 against the seat. By adjusting the biasing force of the compression spring 7, the opening pressure of the hollow needle 11 is adjustable. The biasing force of the compression spring 7 varies. _ at the axial position of the clamping piece 5, which is determined by the screwing depth 4 * of the adjusting screw. In addition, the adjusting screw 4 is inserted into the threads of the valve body 2, through which it acts via the clamping body 5 also intermediate: v. However, a direct action of the adjusting screw 4 on the compression spring 7 would also be conceivable. The more the press piece 5 prestresses the • • compression spring 7, the greater the opening pressure of the hollow needle 11. The adjusting screw • ·: 'i 4 can be used to determine the optimum start of spraying for a given part load operation. To prevent unwanted change, fasten. adjust the position of the adjusting screw 4 to the nut thread of the valve body 2 by turning the locking nut 35 against the nut.

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Claims (4)

A jet valve (1) having two groups of spray channels, each of which is subject to adjustable injection pressure, wherein the first group provided with the hollow needle (11) is controlled by the variable bias of the compression spring (7) and the second group by the valve needle (10), which is controllable by a fuel independent pressure fluid, characterized in that the biasing force of the compression spring (7), which presses the hollow needle (11) on its seat, is produced by mechanical means. A jet valve according to claim 1, characterized in that the mechanical force means is formed by an adjusting screw (4) which is directed to the valve body (2) and acts directly or indirectly on the compression spring (7). Jet valve according to Claim 1, characterized in that the mechanical power means is a rotatably-mounted eccentric member which acts directly or indirectly on the compression spring (7). 3, 113079 Jet valve according to claim 1, characterized in that the mechanical force means is a lever which acts directly or indirectly on the compression spring (7). • r ♦ t 1 • '»I ·> • • • • 1 • · * ·» t «t · M I I I • • t 4 113079