72results about How to "Protection from being broken" patented technology

The invention belongs to the technical field of the preparation of transmission electron microscope samples of soft brittle phototransistors, and relates to a method for preparing a transmission electron microscope sample of a soft brittle phototransistor, in particular to a method for preparing a transmission electron microscope sample of a soft brittle photo semiconducting transistor. The method is characterized in that a hard brittle semiconductor with micro Vickers hardness of over 8 GPa is used as a protective layer of the soft brittle phototransistor, wherein the roughness Ra of the ultra-smooth surface of the protective layer is below 1 nanometer, and the thickness is below 650 micrometers; sand paper of 120 to 800 meshes is adopted in the coarse grinding stage, and a membrane is ground by adopting diamond of between 0.1 and 30 micrometers in the accurate grinding stage; the protective layer is bonded with the sample by adopting a hot setting adhesive which is insoluble in an organic solvent, and a first surface of the ground transmission electron microscope sample is bonded with a substrate by adopting a hot setting adhesive which is soluble in the organic solvent; and in the final stage of accurate grinding, the transmission sample and a thin area of the protective layer are obtained by a stress-free grinding method. The method has the advantages that the preparation of the transmission electron microscope sample of the soft brittle phototransistor is realized, and high-resolution transmission electron microscope atomic images are obtained.

The invention discloses a vacuum anti-siphon backflow preventing valve and relates to a fluid medium pipeline control part. The valve comprises a valve body, a water inlet and a water outlet are arranged on the valve body, a valve cavity communicated with the water inlet is arranged on the valve body, a valve opening is arranged between the valve cavity and the water outlet to communicate the valve cavity with the water outlet, and a valve clack component enabling media to flow unidirectionally from the valve cavity to the water outlet is arranged in the water outlet. An air outlet for communicating the valve cavity with the outside is arranged at the top of the valve body. A support filter screen covering the valve opening is arranged in the cavity. A buoyancy seal component is arranged at the air outlet for sealing the air outlet when media flow forward from the water inlet to the water outlet or opening the air outlet when media flow reversely from the valve cavity to the water inlet. By means of the vacuum anti-siphon backflow preventing valve, the structure is simplified, backflow is prevented effectively, air in the valve cavity can be discharged rapidly when media get back to forward flow, and functions of impurity filtering and purifying are provided. The valve is mainly applied to pipeline systems in need of anti-pollution check, such as urban water supply systems.

The invention belongs to the field of automobile part machining and particularly discloses an automobile interior trim plate bending device. The automobile interior trim plate bending device comprisesa rack which is provided with a positioning part, a bending part and a conveying part; the positioning part comprises a sliding rod, a pressing plate and a base; the bending part comprises a piston barrel, a rotating shaft and a downward pressing unit, and a first rack is connected to a piston rod; a through hole is formed in the outer wall of the piston rod; the piston barrel is connected with avortex pipe; the end face of the side, away from the piston rod, of the piston barrel is provided with a gas outflow hole which is internally provided with a second gas outflow one-way valve; a firstgear engaged with the first rack is arranged on the rotating shaft; the downward pressing unit comprises a second rack connected to the rack in a sliding manner; the second rack is engaged with the first gear; a supporting rod is connected to the top of the second rack; a bending punch is connected to the supporting rod; and the conveying part comprises a belt for conveying a first roller shaft and a second roller shaft. The scheme is adopted to meet the requirements of automation to automobile interior trim plates in the automobile interior trim plate bending process.

An adapter for test tubes is provided enabling attachment of information with identifying patient and / or test data, and which further facilitates insertion of test tubes into automated test equipment. The adapter has a cylindrical housing with two open ends into which a test tube and its attached stopper are received. In one embodiment, one end of the adapter is attached to the stopper and extends partially along the length of the test tube. In another embodiment, the adapter receives the entire test tube in a first position, and in a second position, the test tube and attached stopper are slid within the adapter housing, such that the test tube exits the housing and retains the stopper in the housing. When the assembly of the adapter and test tube is inserted into automatic test equipment, the adapter prevents the information attached to its housing associated with the sample from interfering with analysis of the sample contained in the test tube.

The invention relates to continuous monitoring of radioactive aerosols in the field of nuclear radiation detections, and specifically relates to a paper feeding and sampling apparatus for the radioactive aerosol monitor, which is capable of being used in marine environment. A filter paper tray of the paper feeding and sampling apparatus is composed of a roller pallet (19) and rollers (18). When the filter paper moves at a constant speed on the roll type filter paper tray at a certain speed, the filter paper is mainly influenced by two frictional forces, one is a rolling friction force between the filter paper and the rollers (18), the other is a sliding friction force between the rollers (18) the filter paper and the roller pallet (19), and a resultant force of the two frictional forces is far smaller than tensile strength of the filer paper after immersion, thereby guaranteeing that the filter paper is not broken even when the filter paper is affected with damp and even is wet in an extreme condition.

The invention discloses a flexible lithium ion battery. The flexible lithium ion battery comprises an electrical core and an outer packaging film which is wrapped outside the electrical core; flexible membranes are arranged between the outer packaging film and the upper surface of the electrical core and between the outer packaging film and the lower surface of the electrical core, and cover the upper surface and the lower surface of the electrical core, a plurality of buffer bulges are arranged between at least one piece of the flexible film and the outer packaging film, and concave pits are formed in the buffer bulges and correspond to the inner surface of the outer packaging film. The buffer bulges are added on the surface of the electrical core, and have certain elasticity, and the whole battery takes precedence over a pole piece to be extruded by a bending stress while bending, thereby protecting power falling and fracture of the pole piece for bearing an excessively high stress to increase the bending times of the battery.

The invention discloses high-content liquid gingerols and a preparation method thereof. In the preparation method, on the basis of the characteristics that components in high-quality pure natural ginger resin obtained through supercritical carbon dioxide extraction have greater difference in solubility in ethanol and petroleum ether with certain concentration, liposoluble impurity components are continuously extracted from an ethanol phase with the petroleum ether, and extraction separation and purification are further performed by using diethyl ether to finally obtain the high-content liquidgingerols. The high-content liquid gingerols is light brownish red liquid with worse fluidity and has the advantages of elegant and pure fragrance and durable base note, moreover, gingerols content is higher than 90%, and residual quantities of heavy metals such as arsenic, cadmium, lead, mercury and the like are all less than 0.1ppm.

The invention discloses high-performance magnesium-aluminum-alloy cutting fluid. The high-performance magnesium-aluminum-alloy cutting fluid is prepared from, by mass, 3-6 parts of a waterborne antirust agent, 1-3 parts of a chelating agent, 4-6 parts of a coupling agent, 8-12 parts of a diluent, 2-4 parts of a wetting agent, 1-3 parts of special amine, 6-8 parts of an emulsifying agent, 1-3 partsof an anti-hard-water agent, 2-3 parts of a flow-release-agent composite package, 1-2 parts of a sterilizing-agent composite package, 50-60 parts of base oil, 3-5 parts of a lubricating agent, 1-3 parts of an extreme pressure agent, 1-3 parts of a stabilizing agent, 1-3 parts of a surfactant and a 0.1-2 parts of an antifoaming-agent composite package. The high-performance magnesium-aluminum-alloycutting fluid has the good boundary and extreme-pressure lubricity, can effectively avoid screw-tap fracturing in tapping processing, and has the certain inhibiting effect on color changing of aluminum, copper and part of magnesium alloy.

The invention relates to an intelligent cable connector. The intelligent cable connector has functions of a cable extending connector and an insulated connector. Besides, the intelligent cable connector is provided with a photoelectric extending connector which comprises semiconductive photoelectric separation fingerstalls, optical fiber protective jackets, an optical fiber connector, and heat-insulation binding belts, wherein the semiconductive photoelectric separation fingerstalls are both cylindrical heat shrinking tubes which are prefabricated with selective semiconductive material and are of one-in and two-out structure or one-in and multi-out structure, and are fastened to a metal shielding layer through the heat-insulation binding belts, the optical fiber protective jackets are metal jackets replacing a temperature measuring unit, and are matched with the photoelectric separation fingerstalls to protect temperature measuring fibers from being damaged, the number of the photoelectric separation fingerstalls is two, and the photoelectric separation fingerstalls ensure photoelectric separation. According to the intelligent cable connector, an original insulator structure and an original electric field structure are not damaged, photoelectric performance of an original product is not reduced, and meanwhile a function of on-line accurate monitoring of cable temperature is achieved.

The invention relates to a continuous-wall grab bucket. The continuous-wall grab bucket comprises a machine body, a sliding mechanism, a grab bucket supporting base and a grab bucket body, wherein the sliding mechanism is arranged inside the machine body and can slide in the vertical direction relative to the machine body, the grab bucket body is hinged to the grab bucket supporting base and connected with the sliding mechanism through a connecting rod, and a crank-sliding block mechanism is formed by the grab bucket body, the sliding mechanism and the connecting rod; an elastic device is arranged between the machine body and the grab bucket supporting base, a micro elastic vibration system is composed of the machine body, the elastic device and the grab bucket supporting base together, and the grab bucket body swings slightly when the continuous-wall grab bucket is used for construction. The continuous-wall grab bucket can improve construction efficiency of an underground continuous wall project and prolong service life of the underground continuous wall.

The invention discloses an earth block punching device and belongs to the technical field of punching machining devices. The earth block punching device comprises a rack, a telescopic rod and an electric hand drill, wherein the telescopic rod is vertically fixed to the rack, and the electric hand drill is vertically fixed to the telescopic rod; the earth block punching device is characterized in that the earth block punching device further comprises an actuator used for driving the telescopic rod to stretch out and draw back, and the actuator comprises an actuating mechanism, an adjusting mechanism and a control mechanism which are connected with the telescopic rod; and the actuating mechanism and the adjusting mechanism are connected with the control mechanism correspondingly. According to the earth block punching device, punching work is automatically completed by means of the method that the electric hand drill is controlled through the actuator, stability is good, and a drill bit can be effectively prevented from being broken off; and meanwhile, the labor strength of a worker is reduced, and working efficiency is improved.

The invention discloses a method for treating arching problem of charging by an automatic control system of a yellow phosphorus furnace electrode, comprising the following steps of firstly calculating the needed smelting time according to the charging condition and smelting process, selecting the lifting time point of the electrode hereby, and controlling all electrodes to lift upwards and downwards simultaneously by a computer when each time points arrives. The method has the active effects that the large-scale arching phenomenon forming and broken electrode accidents in the furnace can be avoided, the electrodes can be effectively protected against breaking, the normal running of the smelting process is maintained and the objects of improving electric and thermal efficiency, reducing the electric consumption for smelting and improving the output can be achieved.

The invention provides a method for recognizing electrode defection of a yellow phosphorus stove electrode automatic control system, comprising the following steps: pull difference value is calculated according to pull of 3 hoisting chains of each electrode; when pull difference value of any two hoisting chains is more than a given value, the polar electrode is judged to be in a deflective state, and then the polar electrode is needed to withdraw from the automatic control state , switches to a manual control state and gives a warning prompt. The positive effect of the method is: being capable of monitoring whether the electrode is deflective or not, effectively protecting the electrode from being snapped, maintaining normal operation of smelting process, so as to achieve the purpose of improving electric and thermal efficiency, reducing smelting power consumption and improving production.

The invention discloses aluminum air battery aluminum anode slurry for 3D printing and a preparation method and application thereof. The slurry comprises metal mixed powder and slurry, the ratio of the metal mixed powder to the slurry is 1g:(0.3-1.2) mL, the slurry comprises an antioxidant, a dispersing agent, an organic solvent and an organic adhesive, the metal mixed powder comprises Sn, In, Mg and the balance Al with the purity larger than or equal to 99.99%, and the metal mixed powder comprises Al with the purity larger than or equal to 99.99%. The viscosity of the slurry is 1-100 Pa.s; and the preparation method of the slurry comprises the following steps: (1) taking metal powder, and mixing and ball-milling the metal powder and absolute ethyl alcohol; (2) drying the ball-milled mixed solution until the alcohol is completely volatilized to obtain dried metal mixed powder; and (3) adding an antioxidant, a dispersing agent, an organic solvent and an organic adhesive into the dried metal mixed powder for ball milling, and obtaining slurry. The slurry can be applied to an aluminum anode of a 3D printing aluminum air battery. The slurry can increase the porosity of the anode, reduces the self-corrosion of the aluminum anode, is stable in performance, and improves the utilization rate of the anode.

The invention discloses an exosome secretion inducer, an exosome secretion inducing culture medium, an exosome production method using the exosome secretion inducing culture medium and application of the exosome, and belongs to the technical field of biology. The exosome secretion inducing culture medium provided by the invention only contains the following components: a basic culture medium, and four additives, wherein the additives are L-ascorbic acid or salt thereof, selenium or salt thereof, NaHCO<3> and Insulin. Although the components are simple, the exosome secretion inducing culture medium is capable of remarkably increasing yield of exosome secreted by stem cells, so that the production cost of the exosome can be significantly reduced; and moreover, the produced exosome can more effectively protect neurons from being damaged, as well as improve condition of senescent cells.

The invention relates to a grab bucket of a continuous wall. The grab bucket of the continuous wall comprises a machine body, a sliding mechanism, a grab bucket support and a grab bucket body. The sliding mechanism is arranged in the internal space of the machine body and can slide in the vertical direction relative to the machine body. The grab bucket body is hinged to the grab bucket support and connected with the sliding mechanism through a connection rod. The grab bucket body, the sliding mechanism and the connection rod form a crank-sliding block mechanism. An elastic device is arranged between the machine body and the grab bucket support, and the machine body, the elastic device and the grab bucket support form a micro-amplitude elastic vibration system jointly, so that the grab bucket body makes micro-amplitude swinging during construction of the grab bucket of the continuous wall. By means of the grab bucket of the continuous wall, the construction efficiency of the underground continuous wall project can be improved, and the service life of the underground continuous wall can be prolonged.

The invention belongs to the technical field of automobile die machining, and particularly relates to a flanging die counter pull mechanism. The flanging die counter pull mechanism comprises a fixing base assembly, a rotating pair element, a spring assembly and a flanging element. One end of the rotating pair element is arranged on the fixing base assembly and can slide along the fixing base assembly, the other end of the rotating pair element is fixedly connected with the flanging element, the spring assembly is fixed to the rotating pair element, the spring assembly is connected with an upper base, the upper base is arranged above the rotating pair element, the end of the rotating pair element is fixedly connected with the flanging element, and a material contacting point of the flanging element faces the inclined lower portion and the fixing base assembly. The flanging die counter pull mechanism has the advantages that when an upper die insert is pressed thoroughly, the stress direction is good, the folded edges of a workpiece cannot be damaged by twisting, and the precision and the service life of the workpiece are guaranteed.

The invention discloses an adjustable reeled membrane carrier. The carrier includes a carrier body and an adjusting frame which is installed on the carrier body and can rotate; the carrier body comprises a carrier frame, and universal wheels capable of providing convenience for movement of the carrier body are fixedly installed on the lower end face of the carrier frame; the adjusting frame includes a frame plate, pin shafts are fixedly connected to the middle parts of the two sides of the frame plate respectively and inserted into the carrier frame, and the adjusting frame can rotate on the carrier frame with the pin shafts as the axes. The adjustable reeled membrane carrier is novel, reasonable in design, simple in structure and convenient to install and detach and is used for conveyingpacking membranes which are reeled into a cylindrical shape; meanwhile, the reeled membrane carrier is easy to manufacture and low in cost, has a great use effect and can effectively reduce the laborintensity during conveying and loading of the packing membranes; adjustment of the inclination angle of the packing membranes is convenient, the packing membranes are conveniently placed on membrane supporting rollers of a middle cladding machine during work, and the time for loading the membranes is effectively shortened.

The invention provides a medical linear type closer. The closer comprises a bracket, a nail anvil, a nail cabin, a transmission device and a firing handle, wherein the nail anvil and the nail cabin are arranged at the remote end of the bracket and are used for realizing sewing-up operation; the transmission device is arranged in the bracket and is used for pushing the nail cabin and nails in the nail cabin; the firing handle is pivotally arranged on the bracket through a rotating shaft and is connected to the transmission device; and a limiting prompt device is arranged between the bracket and the firing handle and used for limiting rotation of the firing handle around the rotating shaft. The closer has the main advantage of effectively prompting a user to press the handle with proper force so as to prevent the firing handle from being broken off due to overlarge force, and is safe and reliable.

The present invention relates to a packing device for express delivery of fragile articles. The packing device comprises a heating device (1), a vibrating device (2), a packing chamber (3) and a storage bin (4). A ventilation opening (31) is formed at one side of the packing chamber (3). The heating device (1) is connected to the packing chamber (3) by means of the ventilation opening (31). The storage bin (4) is located above the packing chamber (3). A duct (6) is located between the storage bin (4) and the packing chamber (3). The vibrating device is located at the bottom of the packing chamber (3). A material entrance (51) is formed in the packing carton (5), and located directly below the duct (6). Paraffin foam grains (7) are stored in the storage bin (4). The present invention overcomes the problem of high damage rate of fragile articles during transportation, and provides the packing device for express delivery of fragile articles to reduce the damage rate of fragile articles.

The invention discloses a bidirectional lightning-proof wire breakage protection method and device for an insulated wire. A grounding electrode is arranged at the low-voltage end of an insulator; an insulated wire and a current guide line are arranged at the high-voltage end of the insulator; the current guide line is connected with the insulated wire in parallel through puncture wire clamps; arcstriking electrodes are arranged on the two sides of the current guide line; protection gaps are formed between the arc striking electrodes and the grounding electrode. According to the bidirectionallightning-proof wire breakage protection method and device for the insulated wire of the invention, two sides of the insulator are each provided with one discharge protection gap; when any side is subjected to lightning overvoltage, both of the discharge protection gaps act and discharge; during discharging, the two wire clamps jointly provide fault current; the insulated wire, the current guide line and the arc striking electrodes are integrated; the structures of the protection gaps are stable; and therefore, the device of the invention has the advantages of stable performance, reliable action, strong through-current capability and the like, can effectively prevent the occurrence of lightning stroke disconnection faults of the insulated wire, ensures the safety of the insulated wire, andsolves the technical problems of poor power frequency follow current capability, unstable gap distances and low reliability of a single discharge protection gap.

A flexible wireless electric power induction module, at least comprises a coil in a center hollowed plane shape; a first induction board formed by combining a plurality of independent iron core blocks in a flat plate shape or a convex shape and adhering or covering at least one surface by at least one flexible material; and a first non-conductive material adhered on the coil on one surface of the first iron core block. The induction board is not broken due to dropping off.

A water-cooling fan comprises a shaft and a water-cooling main body. The shaft is connected with a fan impeller; the water-cooling main body is arranged on the position close to the fan impeller; a water-cooling jacket is arranged in an inner cavity of the water-cooling main body; and the part, extending into a high-temperature area, of the shaft penetrates through the inner cavity of the water-cooling main body. According to the water-cooling fan, on the one hand, the length of the shaft between the water-cooling main body and the fan impeller is shortened by forwards moving the water-coolingmain body, and thus the stability of rotating of the fan impeller is greatly improved; and on the other hand, the part, extending into the high-temperature area, of the shaft can be cooled completely, that is, the whole part, extending into the high-temperature area, of the shaft is not damaged or broken due to overheating, the mechanical properties of the shaft are also not affected, and the service life of the shaft is greatly prolonged.

The invention discloses a high-precision biopsy puncture device for the nephrology department and a use method of the high-precision biopsy puncture device, and belongs to the field of kidney puncture. According to the high-precision biopsy puncture device for the nephrology department, through the arrangement of a multi-point volume shrinkage ring, before kidney puncture is carried out, under the suction effect, the part, needing to be punctured, of a patient is in close contact with the multi-point volume shrinkage ring, and when a puncture position is stressed by a puncture needle, the multi-point shrinkage ring can remarkably intercept deformation fluctuation caused by skin stress at the puncture position, the skin deformation range is narrowed, offset caused by skin elasticity during puncture of the puncture needle is reduced, accuracy during kidney puncture is remarkably improved, and the success rate of kidney puncture is increased. Meanwhile, in cooperation with the effects of the inner extending ribbons and the puncture assisting stabbing rods, the inner extending ribbons are punctured when gradually getting close to the outer extending stabbing rods, the disinfection antibacterial liquid in the inner extending ribbons overflows to the skin of the punctured position, bacterium breeding caused by sweat generated when the position makes contact with the multi-point shrinkage ring is effectively avoided, then the punctured wound is effectively protected against infection, and potential safety hazards are reduced.

The invention belongs to the technical field of the preparation of transmission electron microscope samples of soft brittle phototransistors, and relates to a method for preparing a transmission electron microscope sample of a soft brittle phototransistor, in particular to a method for preparing a transmission electron microscope sample of a soft brittle photo semiconducting transistor. The method is characterized in that a hard brittle semiconductor with micro Vickers hardness of over 8 GPa is used as a protective layer of the soft brittle phototransistor, wherein the roughness Ra of the ultra-smooth surface of the protective layer is below 1 nanometer, and the thickness is below 650 micrometers; sand paper of 120 to 800 meshes is adopted in the coarse grinding stage, and a membrane is ground by adopting diamond of between 0.1 and 30 micrometers in the accurate grinding stage; the protective layer is bonded with the sample by adopting a hot setting adhesive which is insoluble in an organic solvent, and a first surface of the ground transmission electron microscope sample is bonded with a substrate by adopting a hot setting adhesive which is soluble in the organic solvent; and in the final stage of accurate grinding, the transmission sample and a thin area of the protective layer are obtained by a stress-free grinding method. The method has the advantages that the preparation of the transmission electron microscope sample of the soft brittle phototransistor is realized, and high-resolution transmission electron microscope atomic images are obtained.

The invention discloses a process for extracting high-content liquid gingerol. The process comprises the following steps: by virtue of the characteristic that the solubility degrees of different components in natural and high-quality ginger oleoresin which is extracted by using supercritical carbon dioxide are greatly different in ethanol and petroleum ether of a certain concentration, continuously extracting fat soluble impurity components in ethanol phase by using petroleum ether, further extracting by using diethyl ether, separating and purifying, thereby obtaining high-content liquid gingerol. The high-content liquid gingerol is a light brown red liquid with relatively poor flowability, is quietly elegant and pure in fragrance and long-lasting in base fragrance, the content of gingerol is greater than 90%, and the residual amounts of heavy metals such as arsenic, cadmium, lead and mercury are all less than 0.1ppm.

The invention discloses a portable pen bag. Specifically speaking, a pen cap or a plurality of pen caps and a carriage bag are arranged on a rectangular soft leather surface; a nib protection plate is arranged at an edge of the soft leather surface; a binding belt is fixed through a rivet at the center of one end of the soft leather surface, and a or a plurality of concave grooves are mounted on the binding belt; and a snap fastener convex part is fixed at the center of the other end of the soft leather surface. The portable pen bag provided by the invention has a simple structure, can hold a variety of frequently used stationery like pens, erasers and rulers, is convenient to carry when rolled to form a cylindrical shape and prevents nibs from easy damage.

The invention provides a multi-functional modular post insulator. An upper fitting 1 is crimped and fastened on the mandrel of an insulator 8; an insert 4 is closely connected with a line pressing seat 2; one end of the insert 4 passes through a hole at the upper end of the upper fitting 1; the tail of the insert 4 is sleeved with and fastened by a spring ring 5; two screw rods are fixed on the line pressing seat 2; a pressing block 3 sleeves the two screw rods; holes are formed at the upper end of the pressing block 3; the lower end of the pressing block is in the shape of a bent hook; the lower part of the multi-functional modular post insulator is provided with a steel pin 9; one side of the steel pin 9 is provided with an arc striking ball 10 ; the arc striking ball 10 faces an arc striking rod which avoids the shed discharge of the insulator and is bent inwards; an optimal discharge gap is set between the arc striking ball 10 and the arc striking rod 7; when the insulator is subjected to lightning strike, freewheeling power-frequency arc can be made to be led to the discharge gap to be burnt, and therefore, a conductor and the insulator can be protected from being burnt out; and an insulating cover 6 is provided with thin-bar-shaped bird repelling devices, so that birds can be prevented from resting and staying on the insulator, and therefore, tripping caused by pollution to a line caused by the defecation of the birds can be avoided.

The invention provides an easy-breaking direct current breaker. An arc extinguish chamber is mounted on a second case body and is provided with a side opening which is opposite to a first case body; a gas generating cover is mounted at a lower part inside the arc extinguish chamber and comprises two gas generating plates which are oppositely arranged and a baffle plate; the baffle plate is opposite to the side opening and is arranged closely to the second case body; a moving contact and a fixed contact are mounted inside an installing space; the breaking position is inside a hold space and is close to the baffle plate; when arc is generated during the breaking of the moving contact and the fixed contact, the gas generating plate and the baffle plate are triggered by the arc, and large quantity of gas is generated to push the arc to move in a direction away from the baffle plate; one side, facing the hold space, of arc extinction chute plates installed at the upper side of the inside of the arc extinguish chamber is provided with a lower part opening; the lower part opening is tapering in the direction from the second case body to the first case body; the arc is blocked during the process of moving by the arc extinction chute plates with tapering lower part opening continuously so that the arc cannot rush out from the side opening of the arc extinguish chamber but can only enter the space between the arc extinction chutes and be extinguished as soon as possible.