125results about How to "Avoid gas" patented technology

A lead-acid battery comprising: at least one lead-based negative electrode; at least one lead dioxide-based positive electrode; at least one capacitor electrode; and electrolyte in contact with the electrodes; wherein a battery part is formed by the lead based negative electrode and the lead dioxide-based positive electrode; and an asymmetric capacitor part is formed by the capacitor electrode and one electrode selected from the lead based negative electrode and the lead-dioxide based positive electrode; and wherein all negative electrodes are connected to a negative busbar, and all positive electrodes are connected to a positive busbar. The capacitor electrode may be a capacitor negative electrode comprising carbon and an additive mixture selected from oxides, hydroxides or sulfates of lead, zinc, cadmium, silver and bismuth, or a capacitor negative electrode comprising carbon, red lead, antimony in oxide, hydroxide or sulfate form, and optionally other additives. The capacitor electrode may be used in asymmetric capacitors and batteries of other types.

A printed circuit board package structure includes a substrate having a first surface and a second surface, a ring-shaped magnetic element, an adhesive layer, conductive portions and conductive channels. The first and second surfaces respectively have first and second metal portions. A ring-shaped concave portion is formed on a position not covered by the first metal portions of the first surface. The ring-shaped magnetic element is placed in the ring-shaped concave portion. The adhesive layer covers the first metal portions and the ring-shaped magnetic element. The conductive portions are formed on the adhesive layer. The conductive channels penetrate the conductive portions, the adhesive layer, and the substrate, and are respectively located in an inner wall and outside an outer wall of the ring-shaped concave portion. Each of the conductive channels includes a conductive film electrically connects to the aligned conductive portion and second metal portion.

The present invention relates to a laboratory incubator, more particularly, a gassing incubator, comprising an outer housing incorporating a door and an inner housing surrounding an internal chamber, which comprises a floor, a ceiling, three side walls and a lateral surface that is capable of being closed by said door or by an additional, inner door, and in which a flow channel is present, which comprises at least one air inlet opening in an end region and at least one air outlet opening in a different end region, wherein said at least one air outlet opening is formed such that effluent air is guided along at least one of the side walls and / or the lateral surface in the peripheral region of the internal chamber, and wherein a water reservoir capable of being heated is disposed within the flow channel such that air flowing in the flow channel is passed across or through said water reservoir.

The invention provides a vehicle engine oil additive and engine oil. The additive comprises the following components: 15 to 34 weight percent of nano WS2 powder, 0 to 24 weight percent of nano MoS2 powder, 20 to 20.5 weight percent of dispersant, 0 to 0.5 weight percent of antioxidant, 0 to 1 weight percent of metal passivant and the balance of base oil, wherein the kinematic viscosity of the base oil at 40 DEG C is 70 to 190mm2 / s, and the kinematic viscosity of the base oil at 100 DEG C is 12 to 20mm2 / s. The engine oil of the invention comprises 5 to 20 weight percent of additive and 80 to 95 weight percent of petrolic oil or comprises 15 to 25 weight percent of additive and 75 to 85 weight percent of diesel engine oil. The engine oil can improve the service life of engine, reduce oil consumption and has obvious energy-saving and emission-reducing effects and other effects.

The invention belongs to the technical field of fuel cell, specifically relates to a proton exchange membrane fuel cell sealing structure. The invention further discloses a self-locking fuel cell sealing assembly structure. The structure relates to a fuel cell monomer, wherein the fuel cell monomer comprises a bipolar plate and a membrane electrode assembly. The bipolar plate comprises an upper monopolar plate and a lower monopolar plate. The proton exchange membrane fuel cell sealing structure is characterized in that: cross-section shapes of an upper sealing ring and a lower sealing ring are concave, the concave parts of the upper sealing ring and the lower upper sealing ring are arranged toward a gas flow field region; a bonding agent layer is arranged between the edge part of a proton exchange membrane and an annular support bench of a membrane electrode support part to bond and fix the edge part and the annular support bench. The structure provided by the present invention has characteristics of simpleness, reliability, easy processing, outer leakage resistance and inner leakage resistance (blow-by of the anode and the cathode).

The invention discloses an ultrasonic vibration-assisted method for precise mould pressing and shaping, comprising the following steps: 1. selecting one glass blank (5), introducing the glass blank into the lower die (6) of an ultrasonic vibration-assisted device for precise mould pressing and shaping, and irradiating by infrared ray until viscosity is 106-108dPa.s; 2. starting a servo motor (17) to drive the lower die (6) to move upwards until the glass blank (5) and an upper die (4) are compacted; 3. starting an ultrasonic vibration generator (1) to drive the upper die (4) to realize ultrasonic vibration, and then ensuring that the glass blank (5) vibrates to fill the die; 4. carrying out mould pressing again, and annealing the upper die (4) and the lower die (6); and 5. forming a finished product when the viscosity reaches 1013-1015dPa.s, moving the lower die (6) and taking out. With the method, the die with a complex molded surface can be filled, and the phenomenon of air trapping can be prevented to obtain a high-quality optical element with even structure and strength.

A vacuum pressure measuring device with an electron source has a reaction zone for forming ions by impact ionization, wherein the electron source communicates with the reaction zone via a passage for the electrons. The electron source is surrounded by an insulating housing with a vacuum chamber, and a partition part is designed as a membrane carrier, carrying a nanomembrane at least in one section, the membrane separating the vacuum chamber from the outer region in a gastight manner and being at least partially designed to be electron-permeable. The vacuum chamber has a cathode for the emission of electrons. In the region of and / or on the nanomembrane, an anode arrangement is provided such that electrons are conducted against the nanomembrane and at least partially through it. The nanomembrane abuts the vacuum chamber of the vacuum pressure measuring device.

Disclosed herein is a fire extinguishing bullet system for launching, which is capable of effectively extinguishing a fire generated at a place that is difficult to access by a person by loading a fire extinguishing bullet that generates a fire extinguishing gas having a fire extinguishing effect onto a projectile, throwing the fire extinguishing bullet loaded at a long distance from a firing point to a specific distance, and discharging the fire extinguishing gas after the fire extinguishing bullet reaches the firing point.

This invention relates to the field of the recovery of methane gas from a coal mine and conventional Natural Gas. More particularly, it involves an apparatus and method for economically recovering methane gas from a coal mine and transporting the methane gas to an end user or other location. The invention further provides an apparatus and method for economically recovering Natural Gas that is stranded due to high impurities that requires processing and / or Natural Gas that is not located near a pipeline. According to a first preferred embodiment of the invention, such methods for recovering and transporting gas comprise (a) transferring gas from a producing well to a first subterranean capacitor and storing the gas in said capacitor and (b) transferring gas from the first subterranean capacitor to a second subterranean capacitor, a pipeline, an end user, a gas processor, or a power plant.

A method of obtaining data with a sensor of an autonomous underwater vehicle (AUV), the AUV comprising a bladder which contains a gas and is exposed to ambient water pressure. A downward thrust force is generated which causes the AUV to descend through a body of water, wherein the bladder contracts as the AUV descends due to an associated increase in the ambient water pressure, the contraction of the bladder causing the gas to compress and the AUV to become negatively buoyant. Next the AUV lands on a bed of the body of water. After the AUV has landed on the bed, the sensor is operated to obtain data with the AUV stationary and negatively buoyant and a weight of the AUV supported by the bed. After the data has been obtained, an upward thrust force is generated which overcomes the negative buoyancy of the AUV and causes the AUV to ascend through the body of water, the ascent of the AUV causing the bladder to expand due to the associated decrease in the ambient water pressure, the expansion of the bladder causing the gas to decompress and the AUV to become neutrally buoyant.

The invention discloses a non-welded car frame. The non-welded car frame comprises a car platform assembly, a stand column assembly, an upper cross beam assembly and a first guide roller assembly, and further comprises a plurality of fixing members, wherein the stand column assembly is provided with a plurality of first assembling parts; and each of the car platform assembly, the upper cross beam assembly and the first guide roller assembly is provided with a second assembling part, and the plurality of fixing members are used for fixing the first assembling parts and the second assembling parts so as to assemble the car platform assembly, the upper cross beam assembly and the first guide roller assembly on the stand column assembly. The stand column assembly, the car platform assembly, the upper cross beam assembly and the first guide roller assembly are assembled through matching among the fixing members, the first assembling parts on the stand column assembly, and the second assembling parts on the car platform assembly, the upper cross beam assembly and the guide roller assembly, and no welding is used in the assembling process, thus the troubles in factory manufacture and layout caused by welding of multiple parts and large parts are avoided.

The invention relates to the technical field of dairy cow feed processing, in particular to alfalfa silage for dairy cows and a preparation method thereof. The alfalfa silage comprises, by weight, 20-40 parts of alfalfa, 60-200 parts of lolium perenne, 5-10 parts of sweet sorghum straw, 5-20 parts of fructus crataegi, 2-4 parts of astragalus polysaccharide and 4.0-7.0mg / kg of lactobacillus preparation. Rumen swelling of dairy cows caused by frequent eating of the alfalfa silage is prevented by adding hawthorn powder, and palatability of the alfalfa silage is improved by adding the sweet sorghum straw and astragalus polysaccharide. The preparation method is simple in preparation process, pH value of the silage is lowered, content of lactic acid and water-soluble carbohydrate is increased, ensiling quality of alfalfa is improved obviously, and the preparation method is an effective way to solve the problem that fresh forage grass lacks in winter during livestock production and is of important significance in reasonably utilizing alfalfa.

The invention provides a process and a device for preparing oxygen through thermal decomposition of a sulfuric acid phase in iodine-sulfur circulation, and belongs to the related technical field of hydrogen preparation through thermal chemical circulation. The process comprises a sulfuric acid phase steam stripping purification section, a rectification concentration section, a washing section and a sulfuric acid thermal decomposition and mixed gas blending process and device. According to the invention, a shell pass and a tube pass of a novel shell-and-tube heat integration composite tower are filled with a 1# filler and a 2# filler respectively, N tower sections of a composite section are coaxially connected in a sealed mode, and a sulfuric acid phase steam stripping purification section, a reaction rectification section and a washing section are coupled together, so that gradient utilization of energy is achieved; a process gas containing O2 and SO2 decomposed by sulfuric acid is blended with O2 extracted by a system, and the blended gas is used as a steam stripping purification gas which respectively enters the steam stripping purification section of the shell pass of the composite tower and an HIX steam stripping purification tower; and compared with a traditional process for preparing oxygen through sulfuric acid phase thermal decomposition, the process of the invention has the advantages that the quality and the energy utilization rate of the system are improved, the purification efficiency is improved, and the energy consumption and the production cost are reduced.

Provided is a multi-cell homogeneous-metal stacked-forging method for producing a die steel module. The problem that cast steel ingots internally have the defects of voids, cracks, segregation and the like in the ingot casting process in the prior art due to improper casting speed and casting temperature control, the forming yield is low and the die steel module quality is affected is solved. The method comprises the steps that rolled blanks serve as metal cell bodies, the stacked blank unit bodies are put into a box body formed by welding common carbon steel, and the box body is vacuumized and sealed; a forging and heating process is established according to force piece inside void type defects closing conditions to fabricate the metal blank unit bodies into a whole blank material through high-temperature pressure-maintaining welding; the box body is dismounted, then the blank unit bodies are returned to a furnace for high-temperature diffusion, and then the blank material is forged to reach the size required by the die steel module. By the adoption of the method, the common defects such as segregation, mingling, contraction cavities, loosing and cracks of cast steel ingots are avoided, the overall quality of the die steel module is improved, the utilization rate of materials is improved, energy consumption is reduced, and the economic benefits are obvious.

The invention discloses a tightly-coupled exhaust manifold assembly which comprises an exhaust manifold component and a three-way catalytic converter conducted and coupled with the exhaust manifold component. The three-way catalytic converter and the exhaust manifold component are connected through a clamshell. The exhaust manifold component comprises a first manifold, a second manifold, a third manifold and a third manifold with front ends mounted on an air inlet flange and arranged from one side to the other side sequentially. The tail ends of the first and second manifolds extend into the front end of a first convergence pipeline, the tails of the third and fourth manifolds extend into the front end of a second convergence pipeline, the tail ends of the first and second convergence pipelines extend into the clamshell, the tail end of the clamshell is connected with the three-way catalytic converter, and the bottom of the three-way catalytic converter is connected with the air inlet flange. The tightly-coupled exhaust manifold assembly is simple in structure and light in weight, number of parts is reduced, oil consumption and production cost are lowered, the temperature of the three-way catalytic converter is increased, airflow interference is avoided and engine performance is improved.

The invention provides a direct non-negative pressure steady-flow water supply equipment. The direct non-negative pressure steady-flow water supply equipment comprises a non-negative pressure steady flow tank, a negative pressure eliminator, a water pump and a control cabinet, wherein an internal seal head is arranged in the non-negative pressure steady flow tank; the non-negative pressure steady flow tank is divided into a steady flow chamber and an adjusting chamber; the steady flow chamber is connected with a water inlet pipe; the negative pressure eliminator is mounted at the upper part of the steady flow chamber; a water level sensor and a water drain valve are arranged at the bottom of the steady flow chamber; flange connection is adopted in the adjusting chamber; a rubber expansion airbag is arranged in the adjusting chamber; and a pressure gauge is mounted at the upper part of the adjusting chamber. The direct non-negative pressure steady-flow water supply equipment provided by the invention has the following advantages that: because the water supply equipment is directly connected with a pipe network in series to supply water without generating negative pressure, the energy saving effect can be reached through sufficient utilization of pipe network pressure and less space usage, lest investment and stable water supply pressure are obtained; meanwhile, the rubber expansion airbag is adopted in the adjusting chamber of the non-negative pressure steady flow tank, the gas and water are separated to avoid problems of gas loss and gas addition caused by direct contact between the gas and the water; moreover, because flange connection is adopted in the adjusting chamber, the maintenance is convenient.

The invention discloses an alfalfa silage for a cow and a preparation method of the alfalfa silage, and belongs to the field of processing of cow feeds. The silage comprises the following components by weight: 60-100 parts of fresh alfalfa, 10-15 parts of fresh stems and leaves of astragalus, 1-5 parts of fresh stems and leaves of agastache rugosus, 5-20 parts of Chinese date residue, and 1-3 parts of liquorice extract. The alfalfa silage for the cow not only prevents a rumen of the cow eating the silage often from blowing air, but also has the characteristics of aromatic flavor and good palatability; the stems and leaves of astragalus used in the processing are agricultural wastes, the Chinese date residue is an industrial leftover, and the liquorice extract is a commonly seen cheap aqueous extract of liquorice of the traditional Chinese medicine, so that the cost is relatively low, but the properties of the alfalfa silage for the cow are better improved.

The invention relates to a construction method for curing non-aqueous slurry at normal temperature in a blast furnace, which belongs to the technical field of blast furnace engineering construction. Internal self-flow casting construction is adopted at the part below a tuyere region, and the granularity and the density of the slurry are accurately adjusted in time according to the changing situation of the width between a cooling wall and a furnace shell; the gap between the cooling wall and the furnace shell of the tuyere region is small, has complicated shape and is simultaneously influenced by the installation of tuyere equipment to a larger extent, external slurry pressing construction is adopted, and a slurry pressing hole and an observation hole are arranged on the furnace shell of the tuyere region; and the grouting treatment for a thermocouple sleeve pipe is enhanced, the gas leakage of the thermocouple sleeve pipe is avoided, and meanwhile, a gas leakage passage between the cooling wall of a furnace hearth and a lining brick is filled in an auxiliary mode. The invention is applicable for newly building large blast furnaces, particularly adopts the slurry pressing of a copper-cooling wall furnace hearth structure, overcomes the defects and deficiencies of the prior art, solves the construction problem of blast furnace hearth slurry and improves the filling quality of the pressed slurry.

The invention discloses a laser stamping forming method and device, and belongs to the technical field of laser processing. The laser stamping formingdevice comprises a laser, a light guide system, aworkpiece die system and a control system. According to the laser stamping forming method, first a plate and a die are placed in a sealed cavity, a vacuum pump is used forpumping air out from the sealed cavity, so that a close-to-vacuum state is formed in a die cavity, and then the plate is formed by using laser-induced shock waves. The laser stamping forming method and device have simple equipment and donot need complicated dies,flexible processing can be realized by controlling the position of a manipulator, processing parameters are good in controllability, safe and reliable operation is achieved, and the laser stamping forming method and device have potential market application value.

The invention provides a compressor and an air conditioner. The compressor comprises an air cylinder, a roller and a sliding vane; the air cylinder is provided with a sliding vane slot and a ventilating hole, the ventilating hole is formed outside the sliding vane slot, one end of the sliding vane slot communicates with an inner cavity of the air cylinder, and high-pressure gas in the compressor is introduced into the other end of the sliding vane slot through the ventilating hole; the roller is arranged in the inner cavity, and the sliding vane is at least partially arranged in the sliding vane slot and can move in the sliding vane slot; and the two ends of the sliding vane are provided with a first end face for abutting against the roller and a second end face for bearing the pressure of the high-pressure gas entering through the ventilating hole correspondingly, and the area of the second end face is larger than that of the first end face. The compressor and the air conditioner have the advantages that the sliding vane is prevented from being separated from the roller, blow-by between a compression cavity and a suction cavity can be avoided, and noise generated by impact between the sliding vane and the roller can also be prevented.

The invention discloses a pipefitting for connecting a metal compound tubular product. The pipefitting comprises a plastic pipefitting body. At least one end of the plastic pipefitting body is a socket hot melting connecting end; the socket hot melting connecting end comprises two layers radially: separately an outer layer pipe and an inner layer pipe; the length of the outer layer pipe is greaterthan the length of the inner layer pipe; the diameter of the outer layer pipe is greater than the diameter of the inner layer pipe; a socketing portion is formed between the outer layer pipe and theinner layer pipe; the socketing portion comprises a first sealing surface, a second sealing surface and a third sealing surface; the first sealing surface is used for being in hot melting connection to a plastic inner layer of the metal compound tubular product, the second sealing surface is in hermetically contact with a metal middle layer of the metal compound tubular product, and the third sealing surface is used for being in hot melting connection to a plastic outer layer of the metal compound tubular product; and a material storage tank is also arranged in the bottom of the socketing portion. The pipefitting disclosed by the invention is low in cost and excellent in sealing property and can solve the problems of air trapping, leakage at the connection of the plastic and the metal andthe like effectively.

The invention discloses a plate type active coke regenerating device. The plate type active coke regenerating device comprises a window frame and a window sash frame. The window sash frame is locatedon the inner side of the window frame. The window frame is of a square frame structure formed by two first cross borders and two first vertical borders. First corner steel hooks are connected to the joints of the first cross borders and the first vertical borders, first seamless steel profiles are sleeved with the first cross borders and the first vertical borders, first connection pegs are arranged on the side faces of the first corner steel hooks respectively and movably embedded into ports of the first seamless steel profiles respectively, and first pin shafts penetrating through the firstseamless steel profiles and the first connection pegs are arranged on the side faces of the first cross borders and the first vertical borders. The plate type active coke regenerating device is reasonable in structure, convenient to use and good in integrity, the strength and impact resistance of the window frame and the window sash frame are effectively improved, mounting, dismounting and cyclicutilization are convenient, resources are saved, the cost is reduced, and the plate type active coke regenerating device is efficient and practical.

The invention discloses a vacuumizing structure of a compression molding die. The vacuumizing structure comprises an upper die and a lower die, wherein an upper die core is arranged in the central part of the upper die, and a die cavity is arranged on the lower die; the bottom of the die cavity is provided with a lower die core; and the bottom of the upper die is provided with a sealing sleeve, and a high-temperature-resistant sealing component is arranged between the lower die and the sealing sleeve. When the upper die is closed, the cavity between the upper die and the lower die is sealed through the sealing sleeve. A first vacuumizing channel is formed in the top of the sealing sleeve, and the first vacuumizing channel is connected with a first vacuumizing device through a connector. A second vacuumizing channel communicating with the bottom of the die cavity is formed in the bottom of the lower die, and the second vacuumizing channel is connected with a second vacuumizing device through a connector. The vacuumizing structure of the compression molding die not only is reasonable in structure and simple in processing technology, but also increases the qualified rate and the quality demand of products.

An airbag and an airbag device are provided that can effectively prevent a rise of the internal pressure of the airbag when the airbag is hindered from being normally inflated / deployed while gas is prevented from being wasted. An airbag includes a pair of side panels that form a bag by being sewn together, an insertion hole formed in the side panel, and a valve disposed on an inner side of the side panel so as to stop up the insertion hole and having two end portions connected to the side panel. While the airbag is housed in the structure, the valve is drawn to an outer side of the side panel through the insertion hole and disposed so as to stop up the insertion hole and, while the airbag is inflated / deployed, the valve is drawn to the inner side of the side panel.

The invention discloses a ballastless track disengaging-resisting elastic anti-vibration cushion. The upper surface and the lower surface of a cushion body (1), the upper surface and the lower surface of the bottom of a groove (9) and the outer surface and the inner surface of the side wall of the groove (9) are respectively provided with protrusions (6). The rigidity of the front portion (1a) and the rear portion (1c) of the cushion body (1) in the longitudinal direction is smaller than the rigidity of the middle (1b) of the cushion body (1). The cross section of the periphery of the cushion body (1) is in a fork finger shape (5) with inward notches. According to the ballastless track disengaging-resisting elastic anti-vibration cushion, impact of train loads on the cushion can be effectively buffered, damage to the elastic anti-vibration cushion due to partial disengaging between a roadbed plate and a bed plate is avoided, safe traveling of a high-speed train is better ensured, and the ballastless track disengaging-resisting elastic anti-vibration cushion is long in service life, strong in vibration and noise reduction performance, meanwhile saved in rubber use quantity, low in manufacturing cost and particularly suitable for being used in a double-block type ballastless track on a plate joist bridge with uneven rigidity and a route with poor roadbed conditions.

A water saving toilet system having a toilet including a toilet bowl having an upper portion and a lower portion, at least one valve interposed between a first water source and a second water source and the toilet bowl for controlling at least one volume of water flowing from the first water source and / or the second water source to the toilet bowl and a timing mechanism connected to the at least one valve for controlling an amount of time that the valve allows water to flow from the first water source and / or the second water source to the toilet bowl, wherein the at least one valve and the timing mechanism cooperate to adjust the flush volume.

The invention relates to the technical field of air tightness test equipment for electromagnetic valves, in particular to an air tightness test closed system for an electromagnetic valve. The air tightness test closed system comprises a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve as well as a pressure regulating system and an air reservoir which are arranged between an air source and a tested electromagnetic valve; the pressure regulating system comprises a proportional pressure regulating valve; an air inlet of the proportional pressure regulating valve is communicated with the air source; an air outlet of the proportional pressure regulating valve is communicated with an air inlet of the tested electromagnetic valve through the first electromagnetic valve and the air reservoir; a work port of the tested electromagnetic valve is communicated with the second electromagnetic valve and the third electromagnetic valve in sequence; the air tightness test closed system further comprises a fourth electromagnetic valve; an air inlet of the fourth electromagnetic valve is communicated with an air outlet of the proportional pressure regulatingvalve; and an air outlet of the fourth electromagnetic valve is communicated with an air inlet of the third electromagnetic valve. According to the air tightness test closed system disclosed by the invention, the sealing performance of the closed system is improved, and an airtight test result is enabled to be accurate and reliable.

The invention discloses an anti-cavitation refrigerating system. The anti-cavitation refrigerating system specifically comprises a condenser, an evaporator, a liquid storage device and a pump body unit; a condensation outlet of the condenser is communicated with a liquid storage inlet of the liquid storage device; a liquid storage outlet of the liquid storage device is communicated with a pump body inlet of the pump body unit; a pump body outlet of the pump body unit is communicated with an evaporation inlet of the evaporator; the pump body inlet of the pump body unit further communicates with a cooling assembly; a refrigerant flows in the cooling assembly; and the cooling assembly communicates with the condenser. When the anti-cavitation refrigerating system is started, a fan of the condenser is firstly started; the pressure of an internal pipeline of the condenser is reduced under the action of the fan; the cooling assembly communicates with the condenser, so that the pressure in the cooling assembly is correspondingly reduced, and the refrigerant in the cooling assembly is evaporated to absorb heat; furthermore, when the refrigerant in the cooling assembly evaporates, heat of a pipeline at the pump body inlet is taken away; gas is prevented from occurring at the inlet of the pump body unit; a cavitation phenomenon is avoided; and the overall service life of the pump body unit is prolonged.

The invention discloses a refrigerator door end cover and a refrigerator equipped with the same. The refrigerator door end cover comprises a top cover, a left plate, a right plate, a front plate, and a rear plate, wherein the left plate and the right plate are vertically arranged on two vertical ends of the top cover; the front plate and the rear plate are vertically arranged on two horizontal ends of the top cover; the thickness of the rear plate is 2.5-3 mm; a throttling groove which concaves towards the top cover is formed in the inner surface, adjacent to the rear plate, of the top cover. According to the embodiment of the invention, the refrigerator door end cover can effectively shorten, or even eliminate, a weld mark generated in the injection molding process; the product has a high tensile strength and a beautiful appearance.