Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/80—Constructional details
  • H10N30/88—Mounts; Supports; Enclosures; Casings
  • H10N30/886—Additional mechanical prestressing means, e.g. springs
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/50—Piezoelectric or electrostrictive devices having a stacked or multilayer structure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
  • F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
  • F02M47/027—Electrically actuated valves draining the chamber to release the closing pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
  • F02M63/0012—Valves
  • F02M63/0014—Valves characterised by the valve actuating means
  • F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
  • F02M63/0026—Valves characterised by the valve actuating means electrical, e.g. using solenoid using piezoelectric or magnetostrictive actuators

Definitions

• Piezo actuator for actuating a mechanical component
• the invention relates to a piezo actuator for actuating a mechanical component, in particular for an injection injector for metering fuel in an internal combustion engine, according to the generic features of the main claim.
• a piezo element can be constructed from a material with a suitable crystal structure using the so-called piezo effect. When an external electrical voltage is applied, the piezo element reacts mechanically. which, depending on the crystal structure and the contact areas of the electrical voltage, represents a push or pull in a predeterminable direction.
• injection nozzles or valves for fuel metering of an internal combustion engine have pressure or control bolts which require high pressures and quick and precise reaction times.
• Such an injection device is described, for example, in “Kraftfahrtechnisches Taschenbuch”, VDI-Verlag 1987, 20th edition, pages 391, 392.
• it is particularly important that the arrangement has the smallest possible diameter due to the small space available in the engine compartment of the internal combustion engine having .
• the piezo actuator described at the outset for actuating a mechanical component, in particular for an injection injector for metering fuel in an internal combustion engine advantageously has an optimally dimensionable, in particular a very slim housing in which the piezo actuator is held.
• the slim design also permits the arrangement of a central high-pressure connection for the fuel, particularly in the case of an injection system.
• the piezo actuator which is held axially movably in a housing, is advantageously provided with at least one spring element, preferably a corrugated spring, which is preloaded in tension and which in the axial direction between the piezo element and an upper fixation is arranged in the housing.
• the required preload can be applied to the piezo element, wherein actuation of the piezo actuator leads to an axial expansion of the piezo element and thus to an axial movement of the pressure pin against the force of the wave spring.
• the at least one corrugated spring must take part in the stroke of the piezo element, but the stiffness of the corrugated spring should be very small in relation to the preload.
• the piezo actuator is fixed at the upper end to the housing and enclosed with a tensioning strap as a tensioning arrangement, which is firmly connected at the upper end to a holder of the wave spring, so that the tensioning strap has a tensile force on the wave spring when the piezo actuator is axially expanded exercises.
• a closed housing can also be provided here in a simple manner, which encloses the piezo element.
• the piezo actuator can be fixed, for example, via a central bolt, which is firmly connected to the upper fixing of the corrugated spring, with two corrugated springs advantageously being arranged symmetrically on both sides of the bolt.
• the piezo actuator can also be fixed by means of a fixing disk which bears on a fixing edge in the direction of the corrugated spring on the housing and through which the tensioning band can be guided in a movable manner.
• FIG. 1 shows a section through a piezo actuator for actuating an injection injector for fuel metering in an internal combustion engine with two wave springs and a fixation of the piezo actuator with a bolt;
• FIG. 2 shows a section through a piezo actuator in a modification of the example according to FIG. 1 with a wave spring and a fixation of the piezo actuator on a fixing edge of the housing and
• Figure 3 shows another embodiment with a housing as a clamping device.
• the piezo element 2 is constructed here from a quartz material with a suitable crystal structure, so that a mechanical reaction of the piezo element 2 takes place when an external electrical voltage is applied, using the so-called piezo effect. Due to the slim design of the piezo actuator 1 in the housing 3, a high-pressure line 4 for the fuel supply to an internal combustion engine is also arranged here.
• the piezo element 2 is enclosed between a lower rounded pressure pin 5 with an actuating plunger 6 and an upper pressure pin 7.
• corrugated springs 10 and 11 according to FIG. 1 are firmly connected, for example welded, to the disk 8 at one end and the plate 13 at the other end, and are fixed on the one hand by the fixation on the fixing edge 14 and the rigid connection via the bolt 12.
• the pressure bolt 7, the piezo element 2, the tensioning band 8 and the washer 9, on the other hand, are subjected to a pretension in the pulling direction.
• FIG. 2 A further exemplary embodiment according to FIG. 2 is provided with the same reference numerals with regard to parts having the same effect.
• an upper pressure bolt 15 is designed as a fixing washer, which bears against a fixing edge 16 of the housing.
• the bolt 12 necessary in the exemplary embodiment according to FIG. 1 is thus dispensed with and a centrally arranged corrugated spring 17 can be provided.
• the mode of operation here is the same as in the exemplary embodiment according to FIG. 1, it only being necessary to ensure that the tensile force of the strap 8 is transmitted to the disc 9 as a holder for the corrugated spring 17.
• a closed housing 18 for the piezo element 2 is provided as a tensioning device for transmitting the tensile force.

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• Fuel-Injection Apparatus (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=7911888

Family Applications (1)

Country Status (6)

Families Citing this family (3)

Family Cites Families (5)

• 1999
  • 1999-06-19 DE DE19928186A patent/DE19928186B4/de not_active Expired - Fee Related
• 2000
  • 2000-06-10 WO PCT/DE2000/001915 patent/WO2000079609A1/de not_active Application Discontinuation
  • 2000-06-10 JP JP2001505074A patent/JP2003502565A/ja active Pending
  • 2000-06-10 CZ CZ2001577A patent/CZ2001577A3/cs unknown
  • 2000-06-10 EP EP00949081A patent/EP1110251A1/de not_active Withdrawn
  • 2000-06-10 KR KR1020017001995A patent/KR20010072696A/ko not_active Application Discontinuation

Non-Patent Citations (1)

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