Kabushiki Kaisha Riken

Other

Akira Kunimoto

Masaharu Hasei

Yongtie Yan

Yunzhi Gao

Takashi Ono

Yukio Nakanouchi

Hideyuki Kurosawa

Masaki Moronuki

Norio Miura

Toshikatsu Hayashi

Noboru Yamazoe

To provide a combination of a cylinder made of a hypereutectic Al&#x2014;Si alloy and a hard-carbon-coated piston ring both exhibiting excellent wear resistance, the piston ring is provided with a laminate coating at least on an outer peripheral sliding surface thereof; the laminate coating comprising a metal layer, a metal-containing, hard carbon layer, and a metal-free, hard carbon layer in this order from the substrate side; the laminate coating having Martens' hardness (indentation hardness) HMs of 5-13 GPa, indentation modulus E of 70-200 GPa, and a deformation ratio Rpe of 0.45 or less, which is expressed by a ratio (Wp/We) of plastic deformation energy Wp to elastic deformation energy We; and a ratio (Tmf/Tm) of the thickness Tmf of the metal-free, hard carbon layer to the thickness Tm of the metal-containing, hard carbon layer being 2-8.

Combination of cylinder and piston ring

A combined oil control ring comprising a pair of circular side rails each having a gap, and a spacer expander longitudinally sandwiched by the side rails, which has seating tabs for pushing inner surfaces of the side rails on the inner side, a side rail-pushing surface of each seating tab being provided with one or more grooves extending substantially longitudinally; each of the side rail-pushing surfaces including the grooves being provided with a nitride layer, and the depth d (&#x3bc;m) of the grooves, the surface hardness h (micro-Vickers hardness HV0.1) of the nitride layer, and the thickness t (&#x3bc;m) of the nitride layer having micro-Vickers hardness HV0.1 of 700 or more meeting the relation of the0.05&#x2266;1000&#xd7;/()&#x2266;0.45&#x2003;&#x2003;(1).

Combined oil control ring

A low-cost solid polymer electrolyte fuel cell unit including a metal separator is provided. The cell unit has a structure that may have high corrosion resistance and durability. The solid polymer electrolyte fuel cell unit includes a polymer electrolyte membrane, a pair of gas-diffusible electrodes fixed at opposing surfaces of the polymer electrolyte membrane, a pair of gas-diffusible porous conductive graphite collectors fixed in contact with the outer sides of the electrodes; a pair of aluminum separators for introducing a fuel gas and an oxygen-containing gas to the electrodes separately from one another, and porous conductive buffer layers provided between the separator and the graphite collector, and having flexibility and air permeability. The separator surfaces in contact with the buffer layers are each provided with a conductive coating having a thickness in the range from 0.01 &#x3bc;m to 20 &#x3bc;m.

Solid polymer electrolyte fuel cell unit

A bipolar current collector separator for a fuel cell composed of a metal plate having flow channels and contact faces that come into contact with electrodes or collectors, wherein a corrosion-resistant layer such as an anodized aluminum layer and a heat-resistant polymer layer is disposed on each of the flow channels.

Embossed current collector separator for electrochemical fuel cell

A gas-detecting element comprising an oxygen-ion-conductive solid electrolyte substrate, a sensing electrode fixed onto said solid electrolyte substrate and active with a detection object gas and oxygen, and a reference electrode fixed onto said solid electrolyte substrate and active with at least oxygen, for detecting potential difference between the sensing electrode and the reference electrode to determine the concentration of the detection object gas, the sensing electrode and/or the reference electrode being covered by an electrode-coating layer made of an oxygen-ion-conductive solid electrolyte, and the electrode-coating layer having a portion bonded to the solid electrolyte substrate directly or via an electrode underlayer made of an oxygen-ion-conductive solid electrolyte.

Gas-detecting element and gas-detecting device comprising same

The present invention discloses a NOx sensor for accurately detecting the total concentration of nitrogen oxides in a measured gas without being affected by interference gases. The sensor comprises a gas treatment chamber arranged at the prior stage of the gas detection chamber , an inorganic porous member loaded in the gas treatment chamber, and a NOx conversion pumping cell and/or an oxygen supplying pumping cell which supplies oxygen into the gas treatment chamber. When the measured gas is introduced in the gas treatment chamber, the interference gases contained in the measured gas are effectively oxidized by the supplied oxygen under the assistance of the catalytic activity of inorganic porous member. The total amount of the nitrogen oxides is measured in the gas detection chamber while NOx in the measured gas are converted into a single component (NO or NO) by the NOx conversion pumping cell after the interference gases are oxidized.

NOx sensor

A radio wave absorber unit includes two or more molded bodies in a pyramid or wedge shape whose radius at the tip end is from 0.5 mm to 7.5 mm and a base. A radius at the trough between adjacent molded bodies is 7.5 mm or less. A unit including molded bodies and the base is integrally formed from propylene-based conductive expanded beads. The bases of adjacent units are connected by fitting their recessed and raised portions to each other. The expanded bead size is in the range from 2 mm to 10 mm, and beads with two or more different bead diameters can be used. A hollow molded body can be formed by providing a hollow structure inside.

Radio wave absorber

The present invention discloses a gas sensing device, an oxygen pumping cell, and a gas detection apparatus using the same for detecting lower ranges of gas concentration with high accuracy and stability. An under layer made of oxygen-ion-conductive solid electrolyte was formed between an electrolyte substrate and a sensing electrode, a conversion electrode or a gas treatment electrode. This allows the physical and chemical adhesion between these electrodes and the electrolyte substrate, thereby improving the sensing properties and stability.

Gas sensing and oxygen pumping device, and apparatus using the same

A gas sensor for measuring concentration of a gas component in a measured gas, including a solid electrolytic substrate and at least two electrodes fixed to the substrate. At least a first electrode of the electrodes is disposed in the environment of the measurement gas, at least one of electrodes is polarized by applying a bias current or bias voltage, and a change in the potential of the polarized electrode is measured to thereby measure the concentration of the target gas.

Measuring NOx concentration

A combined gas sensor of the invention is equipped with a second oxygen sensing electrode active only to oxygen, which is disposed on a solid electrolyte substrate such that it is directly exposed to detection gases. Sensor disorder is detected by measuring an electromotive force (signal output ) generated between a reference electrode and the second oxygen sensing electrode as an oxygen concentration in an exhaust gas atmosphere, and comparing and judging the detected result with a signal output corresponding to an electromotive force between a first oxygen sensing electrode and the sit reference electrode , or with a signal output of an oxygen pump current.

Composite sensor

A nitrogen oxide gas sensor wherein an alloy electrode of platinum and rhodium or a cermet electrode of platinum, rhodium, and zirconia or of a rhodium alloy and zirconia is used as the gas sensing electrode. The electrode of the sensor is suitable for measuring nitrogen oxide such as NO and NO in an exhaust gas.

Nitrogen oxide gas sensor

A nitrogen oxide sensor enabled to enhance the measurement concentration of a total of nitrogen oxides by oxidizing or reducing the nitrogen oxides on the surfaces of electrodes in addition to the control of an oxygen concentration by an oxygen pump. An electrode (,) in a gas chamber (,) constructing an oxygen pumping portion (,) is made of a material (e.g., Pt-3 wt % Rh) having a function to oxidize a nitrogen oxide gas.

Nitrogen oxide sensor

A nitrogen oxide sensor includes a solid electrolytic substrate exhibiting oxygen ion conductivity, a noble-metal reference electrode, which is active only to oxygen, formed on one side of the solid electrolytic substrate, and a sensing electrode, which is active to NOx and oxygen, formed on the opposite side of the solid electrolytic substrate. A potential difference across the sensing electrode and the reference electrode is output as a signal indicative of NOx concentration. Nitrogen oxides in a gas to be examined or measured gas are converted to NO,and to peroxides of nitrogen such as N,O,and NO,, after which the nitrogen oxides in the gas to be examined or measured gas are sensed by the sensing electrode as the peroxides of nitrogen such as N,O,and NO,or as a mixed gas of NO,and the peroxides of nitrogen.

Gas sensor

A stable sensor designed to detect accurately the total NOx concentration under 100 ppm in terms of the NO gas concentration is made up of a first cell and a second cell with a gas diffusion aperture provided between the two cells. The first cell has a partition wall of a substrate of oxygen ion conductor containing zirconia as the main component and permitting a gas to be detected to enter the zirconia substrate; oxygen pumping electrodes are also formed on the first cell substrate which functions to expel oxygen in an atmosphere of the first cell to the outside and to reduce NO.sub.2 of the NOx gas to be detected to NO gas. While NO gas entering through a gas diffusion aperture between the two cells flows into the second cell, a measurement is made of an electromotive force between a NO detection electrode formed in the second cell and a counter electrode also formed therein or a counter electrode formed on the reverse side of the zirconia substrate, since such electromotive force corresponds to the level of the NO gas concentration and thus provides the total NOx concentration.

Growing community of inventors

Kumagaya, Japan

Akira Kunimoto