239 results about "Arc resistance" patented technology

A consumable electrode arc-welding machine comprising an arc resistance calculating part that calculates an arc resistance from a welding current and a welding voltage to develop an arc resistance signal, wherein the welding current and welding voltage are controlled by a short-circuit waveform control signal and an arc waveform control signal that vary in accordance with the arc resistance signal. In this way, the spatter control and the arc stability can be achieved. During an arc period, if the arc resistance signal exhibits a level greater than a predetermined level for a predetermined period, a constant current control signal is developed to perform a constant current control of the welding current by use of a predetermined current value that is higher than the current value developed during the development of the arc waveform control signal, thereby preventing the arc from going off.

The invention relates to non-halogen flame-resistant glass fiber reinforced epoxy molding compound. According to the weight parts, the material of the non-halogen flame-resistant glass fiber reinforced epoxy molding compound comprises 20 parts to 25 parts of epoxy resin, 7 parts to 9 parts of phenolic resin, 1.4 parts to 3.4 parts of curing agent, 60 parts to 75 parts of mineral filler, 4 parts to 7.5 parts of phosphate, 0.8 parts to 2 parts of metal oxide, 1.8 parts to 2.5 parts of mould releasing agent and 15 parts to 20 parts of reinforced fiber. The non-halogen flame-resistant glass fiber reinforced epoxy molding compound has advantages that because halogen is not contained in the formulation, when being burnt, noxious gas and harmful gas can not be generated, and the physical safety and the environmental protection can be ensured; the shrinkage ratio is 0.4 percent to 0.7 percent, the bending strength is 105 to 120 MPa, the notched impact strength is greater than 2.2 KJ per m<2>, the resistance is 1X10<12> Omega, the proof tracking index is greater than 600 V, the arc resistance is greater than 180 s, the electrical strength is greater than 10 MV per m, the flame-resistant performance reaches grade UL-94-V-0 (1.6 mm), and the non-halogen flame-resistant glass fiber reinforced epoxy molding compound can be suitable for the sealing material for manufacturing automobile commutators and electronic products.

This invention relates to one 2D displacement measurement method, which comprises the following steps: according to Wheatstone bridge circuit test principle to distribute the bridge resistance wire into direct or arc shape and the direct resistance wire is to test line displacement; the arc resistance wire is to test arc length change volume and then according to the relationship between arc length and radium to get test point rotary angle; through testing points in electrode coordinate displacement change to realize 2D displacement. The 2D displacement sensor comprises the test bridge line resistance wire and arc resistance wire fixed onto one structure around axis and it also comprises data transmission line.

The invention discloses a solvent-free anti-pollution flashover organic silicon coating which comprises the following components in parts by weight: 100 parts of polysiloxane containing at least two silicon vinyl groups, 1-20 parts of polysiloxane containing at least two silicon oxygen groups, 5-25 parts of white carbon black, 10-40 parts of a flame-retardant filler, 10-35 parts of a vinyl-containing silicon resin, 2-8 parts of a water repellent, 0.1-10 parts of platinum catalyst and 1-5 parts of a tackifier, wherein the specific surface area of silica in the white carbon black is 150-250m<2>/g, and the average particle size does not exceed 20 microns. The invention also discloses a method for preparing the solvent-free anti-pollution flashover organic silicon coating. The method comprises the following steps: (a), preparing a basic sizing material and (b) mixing the glue; or (a) preparing a basic sizing material; (b), preparing a component A; (c) preparing a component B; and (d) mixing the glue. After being subjected to room temperature or medium temperature curing, the solvent-free anti-pollution flashover organic silicon coating is dried, fine, smooth and bright in surface and excellent in hydrophobic property and has excellent self-cleaning performance, and the surface rainwater and floating dust can be automatically flushed away. In addition, the solvent-free anti-pollution flashover organic silicon coating has excellent aging performance, mechanical properties, high/low-temperature resistance, arc resistance, electric insulation performance and the like.

Optionally dyed woven fabrics and garments are disclosed that exhibit fire resistance, arc resistance, moisture management (water release rate and wicking), and abrasion resistance without the undesirable addition of topical treatments. Certain embodiments of the woven fabric are disclosed that comprise a plurality of weft yarns comprising a blend of fibers with inherently fire resistant fibers with superior moisture management properties and a plurality of warp yarns, optionally dyed, comprising cellulose derivatives. The woven fabrics are particularly useful in denim work clothes because they are comfortable to wear and exhibit fire resistance and abrasion resistance

The invention provides an apparatus for testing cable heating and combustion characteristics under effect of simulating fault arc. The apparatus mainly comprises a cable testing platform and a corresponding power supply loop; the cable testing platform comprises a to-be tested cable sample, a cable channel and an arc starting device; the cable channel is capable of adjusting the space included angle of a cable, and a mass measurement device is disposed below the cable channel; and the arc starting device is capable of precisely controlling the artificial fault arc state in the cable sample. Through the arc heat effect, the state developing mode of processes of being heated, combustion, fire propagating and the like of the cable sample with different space arrangement inclination angle and critical conditions are determined, and therefore the heating combustion behavior of various cables under fault arc effect is researched, and basis is provided for cable arc resistance testing and classification standard.

The invention relates to a modeling method for a GIS disconnecting switch high frequency voltaic arc resistance model, the method holds that a high frequency voltaic arc consists of three stages, namely pre-breakdown, arcing and arc blowout; voltaic arc resistance decreases according to an exponential form in the pre-breakdown stage, is a stable value in the arcing stage, and increases according to the exponential law when entering the arc blowout stage. By SF6 gap high frequency arcing tests, the effect law of a stable arcing resistance, a current peak, air pressure and a voltaic arc length on the voltaic arc resistance is obtained so as to build a steady state arcing resistance math model; by GIS disconnecting switch hot-line operation tests, the time varying law and parameter of the voltaic arc resistance are obtained so as to build a double exponential time varying math model of the GIS disconnecting switch voltage arc resistance; and by carrying out emulation calculation on very fast transient overvoltage generated by GIS disconnecting switch hot-line operation, in comparison with a GIS disconnecting switch test result, the effectiveness of the GIS disconnecting switch high frequency voltaic arc resistance match model is verified, and the scientific nature and accuracy degree of the very fast transient overvoltage are obviously improved.

An electrochemical grinding electrode comprises an electrically conductive material; an arc resistance material; and an abrasive material different from the arc resistance material. An electrochemical grinding apparatus and a method are also presented.

The invention provides a simulating analog device of a transmission line secondary arc and a method thereof, which adopt the following technical proposal: the arcing situation of an arc channel is simulated by adopting a nonlinear time-varying resistance, and the arc channel resistance satisfies a dynamic equation which is established according to arc conservation of energy; a real-time secondary arc length is obtained according to arc movement characteristics by analyzing electrodynamic power, wind load and air resistance of an arc in movement and is used for modifying an arc length in the arc resistance equation; and by combining the characteristics of secondary arc current, whether self-extinguishing of the arc can be achieved is judged according to a change rate of the arc channel resistance when the arc current runs through a zero zone. A nonlinear differential equation which applies mathematical methods to solve the arc resistance occurs the electromagnetic transient process of the secondary arc with a computing system connected with an external circuit, and an the self-extinguishing time of the secondary arc is obtained by the arc channel resistance criterion during the zero-rest period of the arc current.

The invention relates to the technical field of preparation of alloy materials, in particular to a tellurium copper alloy material. The high-conductivity, arc-resistance and free-cutting leadfree tellurium copper alloy material is prepared by the following raw materials in percentage by weight: 0.4-0.7% of Te, 0.01-0.015% of P, and the balance of Cu. As the technical scheme is adopted, the prepared tellurium copper alloy gives consideration to excellent free-cutting performance, excellent electricity and heat conductivity and higher toughness, corrosion resistance and electric ablation resistance, has equivalent arc resistance with a silver-copper alloy, is better in cold and hot machinability, and can be forged, extruded, drawn, punched and molded.

The invention discloses a grounding switch contact, which comprises a static contact conductor, a shielded static contact, a contact spring, a static arcing contact, a guide cylinder, a guide block, a buffer spring, an insulating gasket, and a grounding switch moving contact. Head, moving contact seat. The contact spring is sleeved on the outer wall of the middle hole of the shielded static contact, the guide cylinder and the static arc contact are sleeved in the inner cavity of the shielded static contact, and the buffer spring sleeve Connected to the outer end of the guide rod, the two ends of the buffer spring respectively lean against the inner wall of the cup-shaped conductor and the spring stop steps of the guide cylinder, and an insulating gasket is provided between the buffer spring and the inner wall of the cup-shaped conductor; The conductive rod is movably nested in the movable contact seat, and the arc-resistant alloy of the movable contact on the conductive rod can abut against the arc-resistant alloy of the static arc-starting contact on the cup-shaped conductor to realize the closing of the switch. Because the electric contact of the present invention adopts the end face of the static arcing contact to contact with the front face of the moving contact of the earthing switch, the contact is more reliable.

An alloy material of Cu-tungsten carbide-C-Ti-RE is consists of Cu, WC, C, Ti, rare-earth. The material decrease the content of the 'WC' and increase the content of 'Cu' so improve the conductance, as a result, it can control the temperature of the material. The material which added proper C and Ti, RE can improve the non-fusibility, wearability, arc resistance, life of the electricity. The process can improve the fine structure of the histology so the material can be used from the high-current switch, circuit breaker to majority medium-current switch. Especially, it can save the silver and have good market future.

The invention relates-an environmentally-friendly underfill adhesive having a low dielectric constant, and a preparation method thereof, and belongs to a one-component epoxy resin adhesive. The underfill adhesive comprises, by weight, 30-38 parts of epoxy resin, 8-20 parts of a curing agent, 33-46 parts of a filler, 2-5 parts of a diluent, 6-9 parts of a toughener, 0.3-0.5 part of a silane coupling agent, 0.3-0.5 part of an antifoaming agent and 0.2-0.8 part of a pigment. The underfill adhesive prepared in the invention has the advantages of low halogen content, low dielectric constant, high arc resistance, high weather resistance and the like, so packaging components have a high environmental protection property, a high electrical insulation property and a high reliability.

The invention relates to PRTV durability anti-pollution flashover paint, which comprises the following components by part by weight: 40 to 50 parts of dihydric polydimethylsiloxane, 2 to 6 parts of nano Si02, 2 to 6 parts of cross-linking agent, 0.02 to 1 part of catalyst, 20 to 30 parts of aluminum hydroxide, 5 to 8 parts of decabromodiphenyl, 40 to 50 parts of solvent and 1 to 2 parts of pigment. The paint uses dihydric polydimethylsiloxane as base rubber and has the good properties of ageing resistance, corrosion resistance, water resistance, moisture prevention, no toxin, insulation, shake resistance, excellent simulation, demolding, extremely low contractibility rate and the like. Because nano Si02 is added to the paint, the weather fastness, the ultraviolet resistance and the ageing resistance of a coating are improved. The aluminum hydroxide and the decabromodiphenyl are used as excellent composite fire retardants for the paint, thereby remarkably enhancing the arc resistance of the paint and helping to increase the thickness of the coating. Therefore, inflaming retarding and ageing resistance become more stable.

The invention relates to the field of an electric locomotive, in particular to a preparation method of a high-speed locomotive pantograph carbon slide plate material. The preparation method of the material comprises the steps of graphite powder copper plating, mixing and kneading, shaping, roasting, soaking and secondary roasting. In the mixing and kneading process, aggregates are prepared from 30to 50 percent of graphite powder with the granularity being 65 to 71 mu m and 3 to 5 percent of carbon black with the particle diameter being 40 to 50 mu m; bonding agents are 15 to 20 percent of resin bonding agents; impregnating agents are impregnating asphalt; the copper plating graphite powder content is 20 to 30 percent. The graphite copper plating stable process is used; the graphite has good conductivity, arc resistance, friction resistance and anti-corrosion performance; the service life is long; the friction force on a conducting wire is small; the conducting wire can be well protected; the material can completely replace a conventional carbon slide plate to be used.

The invention discloses a discharge gap device for preventing surface flashover of an insulator, which can solve the problem that the surface flashover of the insulator is cuased under the overvoltage to burn the insulator. The technical scheme of the invention is as follows: the discharge gap device comprises a high voltage arc initiating ring, an arcing horn, a pressing plate and a fastening piece; the high voltage arc initiating ring is arranged at a high voltage end of the insulator; a fixing plate and the pressing plate are arranged at a low voltage end of the insulator; and the arcing horn is connected with the fixing plate by the fastening piece, and the other end of the arcing horn bends downwards to form a discharge gap with the high voltage arc initiating ring. The discharge gap device not only can be directly fixed on fittings of two ends of a composite insulator, but also can be fixed on a cross yoke plate by installing holes to be connected with a ceramic insulator. The invention provides the novel discharge gap device adaptive to the composite insulator and the ceramic insulator and having rapidness in installation, adjustable gap, stable discharge voltage and good arc resistance and arc quenching performance.

The invention relates to an epoxy resin casting insulating material. The epoxy resin casting insulating material comprises the following raw materials in parts by mass: 7-13 parts of epoxy resin, 5-11parts of a curing agent, 20-30 parts of modified silicon dioxide powder and 2-8 parts of mica powder. The epoxy resin casting insulating material has an excellent formation processing property, is suitable for an APG technology and a vacuum casting technology, and suitable for manual casting moulding. An insulating component prepared by the material has a good insulating property and excellent arc resistance, and is capable of solving a technical problem that the arc resistance of an epoxy casting material is poor, wherein the arc resistance of the material can reach more than 210 s. The material has a lower curing shrinkage rate which is 0.1%-0.05% only. An overlarge stress is prevented from being generated between a metal insert and an insulator through the smaller curing shrinkage rate, and a problem that a product is cracked in a place of the metal insert is prevented from happening. The insulating component formed and prepared by using the insulating material has higher strengthand toughness, and is good in secondary machining property.