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Patent

Temperature compensated stack of piezoelectric elements

TL;DR: In this paper, an actuator for injecting fuel into an automobile at a high speed and a delicate response to external operation is provided by selecting the ratio of the number of the piezoelectric elements having the positive and negative temperature dependencies.
Abstract: A piezoelectric transducer comprising a lamination of piezoelectric elements including one or more elements in which the distortion has a positive temperature dependency and one or more elements in which the distortion has a negative temperature dependency. By selecting the ratio of the number of the piezoelectric elements having the positive and negative temperature dependencies, the temperature dependency of the distortion of a transducer can be eliminated. An actuator for injecting fuel into an automobile at a high speed and delicate response to external operation is provided.
Citations
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PatentDOI
TL;DR: A vibration wave device having a resilient member and electro-mechanical energy conversion means for inducing a travelling vibration wave in the resilient member, the traveling vibration wave being used as a drive source, includes means provided on at least one member of the vibrational wave device at a location integer times or approximately integer times 1/2 of the wavelength of a vibration wave which may produce noise and making the dynamic rigidity of the member non-uniform.
Abstract: A vibration wave device having a resilient member, and electro-mechanical energy conversion means for inducing a travelling vibration wave in the resilient member, the travelling vibration wave being used as a drive source, includes means provided on at least one member of the vibration wave device at a location integer times or approximately integer times 1/2 of the wavelength of a vibration wave which may produce noise and making the dynamic rigidity of the member non-uniform.

360 citations

Patent
Guenter Dantes1, Detlef Nowak1
07 May 2002
TL;DR: In this article, a high-pressure injection valve for directly injecting fuel into a combustion chamber of a compressed-mixture, spark-ignition internal combustion engine is described, and a slit-type flow outlet is formed between the slit-forming element and a front face of the valve seat body.
Abstract: The invention relates to a fuel-injection valve, in particular a high-pressure injection valve for directly injecting fuel into a combustion chamber of a compressed-mixture, spark-ignition internal combustion engine. Said valve is characterised in that an outlet opening (23) is provided downstream of the valve seat (20), the downstream end of said opening having a slit-forming element (30) that to a great extent closes the outlet opening (23). A slit-type flow outlet (35), through which a fuel spray can be discharged in a fan-type jet, is formed between the slit-forming element (30) and a front face (34) of the valve seat body (16).

186 citations

Patent
04 Mar 1991
TL;DR: A laminar longitudinal-effect type piezoelectric or electrostrictive driver which is displaced upon application of an electric field is described in this article.The driver is suitably usable for an actuator for operating a print element of a printer, for example.
Abstract: A laminar longitudinal-effect type piezoelectric or electrostrictive driver which is displaced upon application of an electric field thereto. The driver includes laminar electro-mechanical converting elements each undergoes a displacement in a direction of the electric field due to the longitudinal mode of the reverse piezoelectric effect or the electrostrictive effect, and the temperature compensating elements each of which is interposed between the appropriate adjacent two laminar electro-mechanical converting elements. The temperature compensating elements have a higher coefficient of linear thermal expansion in the direction of the electric field or direction of displacement of the driver. The driver is suitably usable for an actuator for operating a print element of a printer, for example.

138 citations

Patent
30 May 2001
TL;DR: In this paper, a piezoelectric element, for generating drive force for an injector, is provided with a plurality of alternately stacked layers expanding and contracting in accordance with application of voltage and internal electrode layers for supplying the applied voltage.
Abstract: A piezoelectric element, for generating drive force for an injector, is provided with a plurality of alternately stacked piezoelectric layers expanding and contracting in accordance with application of voltage and internal electrode layers for supplying the applied voltage. The piezoelectric layers contain voids, but the total thickness in the stacking direction of the voids contained in any one piezoelectric layer is not more than ⅓ of the thickness in the stacking direction of the piezoelectric layer and the thickness in the stacking direction of each of the voids is not more than 50 μm.

64 citations

Patent
13 Nov 1987
TL;DR: In this paper, a wheel cylinder and brake piston are formed in the brake caliper of each wheel of a vehicle, and a piezoelectric device, which is formed of laminated PPE elements, is formed such that it is connected with the wheel cylinder.
Abstract: A wheel cylinder and brake piston are formed in the brake caliper of each wheel of a vehicle. A piezoelectric device, which is formed of laminated piezoelectric elements, is formed in the brake caliper such that it is connected with the wheel cylinder. By applying a voltage to the piezoelectric elements the piston device is made to expand and contract to thereby vary the volume of the wheel cylinder. Brake fluid is supplied from the master cylinder to the wheel cylinder via fluid passage formed in the brake caliper and a control valve for opening and closing this passage is formed in the passage. When there is a high pressure in the wheel cylinder, the piezoelectric device expands and the control valve closes. Then, by lowering the voltage the piezoelectric device contracts and the pressure in the wheel cylinder decreases.

59 citations

References
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Patent
09 Feb 1983
TL;DR: In this paper, a piezoelectric composite thin-film resonator has been proposed, which has good temperature stability and resonance response, in a fundamental thickness-extensional vibration mode.
Abstract: A piezoelectric composite thin-film resonator has good temperature stability and resonance response, in a fundamental thickness-extensional vibration mode. Spurious vibrations caused by even-number order harmonic overtones are suppressed. The resonator has a thin film of SiO2 or other materials having a resonant frequency temperature coefficient which is opposite to that of the piezoelectric material. The SiO2 layer is inserted between two thin films of ZnO, CdS, AlN, or other piezoelectric materials. This sandwiched structure is positioned between a pair of electrode films and is supported by an insulative or a semiconductive film which is in turn fixed to a substrate. The thicknesses of the thin films have values such that an overall temperature coefficient of the resonant frequency may be at or near substantially zero. In order to better remove the even-number order harmonics, it is preferable to cover the upper electrode film with a thin film of semiconductor or insulator material.

178 citations

Patent
08 Dec 1965
TL;DR: A force sensitive transducer consists of a stack of apertured Piezo electric discs, each of which has at least one aperture which may be central, and the electrodes are respectively connected to annular metal deposits on the wall 41 of the aperture, and on the periphery, 44 of the disc as mentioned in this paper.
Abstract: 1,108,846. Piezo electric transducers. KISTLER INSTRUMENTE A. G. Dec. 1, 1965 [Dec. 10, 1964], No. 50965/65. Heading G1N. A force sensitive transducer consists of a stack of apertured Piezo electric discs, each of which 35, Fig. 4, generates a voltage between its plane surfaces when stressed and has metal electrodes 39, 40 deposited or coated thereon, adjacent discs being arranged so that contacting electrodes have the same polarity as one another. Each disc has at least one aperture which may be central, and the electrodes 39, 40 are respectively connected to annular metal deposits 37, 43 on the opposite face, by means of metal coatings on the wall 41 of the aperture, and on the periphery, 44 of the disc. The electrodes on each disc are insulated from one another by non- coated annular portions 38, 42. In a stack of such plates, Fig. 5 (not shown), the coatings on the walls of the apertures link together to connect the positive electrodes to a terminal (54) in an insulating cylinder (53) of ceramic, set in a conductive end-plate (52); and the negative electrodes are connected via the peripheral coatings (44) to the end-plate (52). The end-plate (52) alternatively may be insulating, and carry a coating (57) of for example gold, on its outer curved surface. Each disc, alternatively, may have two coated apertures Fig. 3 (not shown) serving as positive and negative terminals respectively, insulating non-coated annuli (6) again being provided to isolate the electrodes. The discs of the stack are held together by high vacuum welding, or by being pre-stressed and coated with silicon varnish, the discs being arranged with their axes of minimum thermal expansion coefficient in alignment. In a further refinement Fig. 8 (not shown) the end-discs (66, 67) each have the metal coatings on opposite faces joined together via the peripheral coating. Figs. 10, 11 (not shown) to short circuit their own outputs. These discs then serve to absorb any difference in thermal expansion between the remaining stack of discs and the end members (68, 69) to reduce temperature induced stresses in the discs. In a pressure measuring transducer, Fig. 12 (not shown) a stack of discs is sealed in a housing, (92) with the end-plate (90) bearing against a gold plated diaphragm (91) the housing itself forming one terminal, and a central aperture (94) the other terminal.

91 citations

Patent
27 Jun 1967
TL;DR: In this paper, a tuning apparatus is described including a vibratory member on which layers of piezoelectric material are disposed for input and output transducers for frequency selective properties without external tuning means.
Abstract: Tuning apparatus is described including a vibratory member on which layers of piezoelectric material are disposed for input and output transducers. The vibratory member may have a flat surface on which the piezoelectric layers are disposed making the structure amenable to fabrication by techniques used for fabrication of microelectronic components. The vibratory member may be a body of semiconductive material. In addition to acting as an electromechanical tuning element, the vibratory member, when of semiconductive material, may contain elements such as an integrated amplifier circuit for frequency selective properties without external tuning means. The vibratory member may be employed in various modes of vibration including flexural and longitudinal modes.

64 citations

Patent
27 Aug 1943
TL;DR: In this article, a method and apparatus for feeding liquid fuel of any kind into cornbustion air of internal combustion engines is described, where liquid fuel is fed into a carburetor outside of the cylinder into which the liquid is injected.
Abstract: This invention relates to a method and apparatus for feeding liquid fuel of any kind into cornbustion air of internal combustion engines, Internal-combustion engines operated by volatile or light liquid fuels are ordinarily provided with a carburetor outside of the cylinder into which the liquid...

60 citations

Patent
14 Jun 1983
TL;DR: In this paper, a tubular actuator with an elongated piezoelectric member disposed in the casing is described. But, since the outer cylindrical surface has no electrode element, no flashover occurs between the outer cylinder and the inner surface of the casing.
Abstract: A piezoelectric actuator comprising a tubular casing and an elongated piezoelectric member disposed in the casing. The piezoelectric member has axially spaced ends, one of which abuts the shoulder of the casing. The piezoelectric member expands and contracts in response to an applied voltage, another end effecting a pumping operation. The piezoelectric member forms first and second longitudinal surfaces extending along substantially the entire length of axis. The piezoelectric member is formed as a lamination of a plurality of piezoelectric plates, to each of which is applied an electrode element on one of lateral surfaces. The electrode elements protrude on the first or second surfaces, alternately. First and second electrode members are located at the first and second surfaces, respectively. The first surface may be a surface of an opening which extends through the piezoelectric member, and the second surface may be a surface of an outer cylindrical surface of the piezoelectric member. Since the outer cylindrical surface is kept in contact with the inner surface of the casing, no flashover occurs between the surfaces. The second surface also may be a surface of another opening which extends through the piezoelectric member. In this embodiment, since the outer cylindrical surface has no electrode element, no flashover occurs between the outer cylindrical surface and the inner surface of the casing. A valve apparatus having the above-mentioned actuator and a method of manufacturing a piezoelectric member are also disclosed.

54 citations