摘要:
A fuel injector has an actuator for generating a lifting movement and a lift translator filled with a hydraulic medium and deformable in the lifting direction, for transferring the lifting movement of the actuator to a valve needle, provision being made for a compensating chamber for the hydraulic medium, the compensating chamber being connected to an interior space of the lift translator via a throttle opening and enclosed by an elastic casing. Thus, temperature-related quasistatic deformations of actuator, lift translator, and/or valve needle can be compensated for by an exchange of the hydraulic medium between the interior space of the lift translator and the compensating chamber, while the comparatively fast lifting movements of the actuator are transmitted to the valve needle essentially without damping.
摘要:
A fuel injector for fuel injection systems of internal combustion engines has a valve-closure member that is in working engagement with a valve needle and that coacts with a valve-seat surface positioned in an orifice of a valve-seat member to form a sealing seat. The fuel injector has at least one spray discharge opening positioned in the valve-seat member. Between the valve-seat surface and the spray discharge opening, a second surface that make a more acute angle with the center axis of the fuel injector than the valve-seat surface, is formed by the orifice of the valve-seat member. A closure element extension whose enveloping surface forms an obtuse angle with the contiguous contour of the valve-closure member is positioned at the downstream end of the valve-closure member.
摘要:
A fuel injector, e.g., an injector for fuel injection devices in internal combustion engines, has a valve needle with a valve-closure member which cooperates with a valve seat surface in a valve seat body to form a sealing seat, in which the valve seat body has a plurality of injection orifices that are isolated from the fuel supply by sealing seat. The valve-closure member has a pressure element in a recess facing the valve seat body, which is pre-tensioned against the valve seat body by a spring which is supported on the valve-closure member and presses a disc spring against the valve seat body, in such manner that the disc spring covers at least one of the injection orifices, and the spring element uncovers this injection orifice when the tension exerted by the pressure element is removed.
摘要:
The invention relates to a process for metering fuel with a fuel injector (1), in particular an injector for fuel injection systems of internal combustion engines. The fuel injector has an actuator (14) and a valve closing body (6) which can be activated by the actuator (14) to produce a valve stroke, and the valve closing body cooperates with a valve seat face (5) to form a sealing seat. The valve closing body (6) and/or valve seat face (5) has at least one swirl element (27; 41) to produce a swirling flow. In order to vary the fuel distribution of fuel injected by the fuel injector (1), the valve stroke triggered by the actuator (14) has a variable opening speed, whereby a transition from an at least approximately swirl-free preliminary flow of the injected fuel to a swirling flow of the injected fuel is produced by varying the opening speed.
摘要:
A fuel injector, particularly for direct injection of fuel into a combustion chamber of a mixture-compressing, spark-ignited internal combustion engine, includes an actuator, a valve needle actuatable by the actuator for actuation of a valve-closure member, which, together with a valve-seat surface forms a sealing seat, and a swirl disk which has at least one swirl channel. An elastic membrane is arranged upstream from the swirl disk in such a way that a metering cross-section of the at least one swirl channel is variable as a function of the fuel pressure prevailing in the fuel injector during operation.
摘要:
The invention relates among others to a method for producing outlet openings (32) in a valve, in particular a fuel injection valve. The injection valve has a fuel inlet (2), an excitable actuating device (1, 2, 19) by which a valve closing member (28) is movable, a fixed valve seat (27) embodied on a valve seat element (26), with which seat the valve closing member (28) cooperates to open and close the valve, and at least one outlet opening (32), as a fuel outlet, provided downstream of the valve seat (27). The at least one outlet opening 32 is produced in such a way that in a first method step, a through hole is created in the valve seat element (26), and in a second method step, from the ejection end of the through hole, an outlet region is created that is altered in shape and/or size and/or contour compared to the through hole.
摘要:
A fuel injector, in particular, an injector for fuel injection systems of internal combustion engines, having an actuator, which cooperates with a valve needle, has a first valve closure member that is arranged on the valve needle, the valve closure member cooperating with a first valve seat surface on a valve body forming a first sealing seat. A second valve closure member cooperates with a second valve seat surface in the valve seat body forming a second sealing seat. The valve needle, or the first valve closure member, has a limit stop, against which, after a partial stroke of the valve needle, a counter limit stop of the second valve closure member strikes, lifting the second valve closure member from the second sealing seat in response to a further stroke of the valve needle.
摘要:
The invention relates to a hydraulically actuated cutoff valve which is provided as an intake valve for switching between a master cylinder and an intake side of a feed pump of a slip-controlled vehicle brake system. The invention sets forth that the cutoff valve is embodied with a valve closing body that has a valve tappet which passes through an annular actuating element and is in engagement with a rocker element embodied as a cup spring, which rests on an annular pivot bearing. If the actuating element is acted upon by pressure, it presses down an outer edge of the rocker element, and as a result a middle of the actuating element executes a pivoting motion in the opposite direction that closes the cutoff valve. The invention has the advantage of an economical cutoff valve that has only a small number of components, and the invention can be used in a hydraulic vehicle brake system.
摘要:
Conventional devices have a valve needle and a shape memory element which, by the application of a controllable magnetic field, executes a control stroke travel that operates the actuator, and having a coil that excites the magnetic field which is situated in a magnet housing which, at its end face, is bordered with respect to an actuating axis by a front wall in each case, the front walls having a through opening radially within the coil. It is a disadvantage that the magnetic field excited around the coil is conducted unfavorably, so that at most a slight magnetic field develops in the shape memory element. The shape memory element has a magnetic field flowing through it, in the direction of its longitudinal extension, if at all. Since the shape memory element has a high magnetic resistance and is developed to be very long in the axial direction, only a very weak magnetic field can be induced in the shape memory element. In response to the magnetic field that is weak at most, the shape memory element can generate only a very slight lift of the valve needle. In the device according to the present invention, a strong magnetic field is conducted through the shape memory elements, and in this way, a large control stroke travel is achieved. The shape memory element(s) is/are positioned generally only in the through opening(s).
摘要:
A device for injecting pressurized fuel includes an electrodynamic actuator having a movably situated coil, an outwardly opening needle which opens and closes a cross section on a valve seat, a connecting device which connects the needle to the movably situated coil, a pressure chamber which is situated at the needle upstream from the valve seat and contains pressurized fuel, a low-pressure chamber from which, fuel is dischargeable, and a gap seal which is provided at an outer peripheral region of the needle, the gap seal (16) providing a connection between the pressure chamber and the low-pressure chamber.