摘要:
A fuel injecting device and method of controlling the fuel injection device. The fuel injection device includes a cylindrical body, a needle whose end includes with a head forming a valve on a seat supported by the end of the cylindrical body, an actuator made of an electroactive material, including a rod and that displaces the head such that the valve is opened, and a prestressing device holding the needle and a counterweight such that they are pressed against the rod opposite end. The needle extends coaxially to the cylindrical body in a form of a rigid bar and axially resonates when exposed to axial pulses at a determined excitation frequency by the actuator.
摘要:
An ultrasonic transducer includes a stack of flat electrodes between which are interposed ceramic wafers of substantially same surface area as the electrodes, stacked contours of the ceramic wafers and electrode wafers defining substantially flat or cylindrical side faces of the stack. A method of manufacturing the transducer includes: alternatively stacking a ceramic wafer and an electrode wafer, placing between each ceramic wafer and its two neighboring electrodes a composition of which at least 75% by weight, or at least 80% by weight, that includes silver nanoparticles having a grain size of smaller than or equal to 80 nanometers, or smaller than or equal to 60 nanometers; and compressing the stack by heating to a temperature of less than or equal to 280° C., or between 200° C. and 250° C.
摘要:
A fluid injection device including a protruding needle. One end of the needle forms a valve and can be moved between a closed position, in which the valve seals the fluid-release opening, and an open position, in which the valve is positioned at a controlled distance from the opening. Movement of the valve between the closed position and the open position is produced by the controlled intrinsic extension of the protruding needle.
摘要:
A process for producing an actuator configured to generate powerful ultrasonic waves and that includes a stack of alternating intermediate electrode layers and piezoelectric material layers. The method includes: forming an initial stack of alternating intermediate electrode layers and piezoelectric material layers, each end of the stack being a piezoelectric material layer or an intermediate electrode layer; firmly attaching adjacent layers to one another; cutting the initial stack into elementary blocks; and connecting the intermediate electrode layers together, in each elementary block.
摘要:
A device for injecting fuel over a cylinder head of an engine, including a tubular body, an injection nozzle forming an extension of the tubular body, a needle extending coaxially to the nozzle in a form of a rod, an end of which includes a head forming a valve on a seat supported by the injection nozzle, and an actuator configured to cause a movement of the head so as to open the valve, the needle configured to axially resonate when the same is subjected to axial pulses at a predetermined nominal frequency by the actuator. A system for mounting the device includes a spacer for bearing on the cylinder head, as well as on a front surface of the tubular body at the connection to the nozzle.
摘要:
A device for injecting fuel over a cylinder head of an engine, including a tubular body, an injection nozzle forming an extension of the tubular body, a needle extending coaxially to the nozzle in a form of a rod, an end of which includes a head forming a valve on a seat supported by the injection nozzle, and an actuator configured to cause a movement of the head so as to open the valve, the needle configured to axially resonate when the same is subjected to axial pulses at a predetermined nominal frequency by the actuator. A system for mounting the device includes a spacer for bearing on the cylinder head, as well as on a front surface of the tubular body at the connection to the nozzle.
摘要:
The invention relates to an injector including a needle mounted in a nozzle and having an end defining a valve, the needle being connected at the other end to an actuator including first, second and third portions, the first and third portions being provided on either side of the second portion, the three portions being tightened together in order to form a block having two axially opposite limits, the first portion being connected with the needle at one of said limits, and an excitation means for vibrating the second portion according to setpoint period τ. According to the invention, the length between the two limits of the block is such that the propagation time T of the acoustic waves generated by the vibrations of the second portion of the actuator and running along that length meets the equation: T=n*[τ/2], where n is an integer positive multiplication coefficient different from zero.
摘要翻译:本发明涉及一种注射器,其包括安装在喷嘴中并具有限定阀的端部的针,该针在另一端连接到包括第一,第二和第三部分的致动器,第一和第三部分设置在两侧 所述第三部分被紧固在一起以形成具有两个轴向相对限制的块,所述第一部分在所述限制中的一个限制下与所述针连接;以及激励装置,用于根据设定周期振动所述第二部分 τ。 根据本发明,块的两个极限之间的长度使得由致动器的第二部分的振动产生的声波的传播时间T沿着该长度满足以下等式:T = n * [ τ/ 2],其中n是不同于零的整数正乘法系数。
摘要:
An injection device for injecting pressurized fluid includes a housing, an actuator, and an energizing unit. The housing includes at least one axial cavity filled with pressurized fluid. The actuator includes a stack with a first transverse face extended axially by a penetrating member and a second transverse face axially opposite the first. The stack includes at least one electroactive part including an electroactive material. The member includes a piston engaged in the cavity and forming a fluidic connection between the actuator and the housing. The energizing unit sets the electroactive part of the actuator in vibration with a set period τ. The penetrating member includes an axial length such that the propagation time T of the acoustic waves produced by the vibrations of the electroactive part of the actuator and traveling along this length satisfies the following equation: T=[2n+1]*[τ/4], where n is a positive integer coefficient.
摘要:
A fluid injection device having a main injection axis and including at least: a housing; an actuator axially mounted in the housing and including a stack with two axially opposed front faces and including at least one electro-active portion with an electro-active material; and a pre-stressing mechanism adapted for at least partially pre-stressing the stack. The pre-stressing mechanism includes at least a tightening clamp outside the stack and provided between the stack and the housing.
摘要:
An improved fluid drop ejector is disclosed which includes one wall including a thin elastic membrane having an orifice defining a nozzle and elements responsive to electrical signals for deflecting the membrane to eject drops of fluid from the nozzle.