63results about How to "Reduced Depth Requirements" patented technology

The invention provides a method and system of the prediction of time series data. The method comprises the steps that wavelet decomposition is conducted on the sequence formed by t-1 moment data, n subsequences are obtained; stationary detection is conducted on n subsequences respectively; for non-stationary time series, an advance learning LSTM model is built using the t-1 moment data, and the values of t moment are predicted respectively, and forecasts of the non-stationary part are obtained by summing; similarly, for stationary sequences, ARMA models are respectively built and the values of t moment are predicted, and the forecasts on stationary part are obtained by summing; finally the prediction values of the non-stationary part and the stationary part at t moment are summed, to obtain the final forecast value. By the method and system of the prediction of time series data, by wavelet decomposition, the advantages of LSTM and ARMA are combined, in comparison with traditional methods, better effects are provided in dealing with non-stationary time series. In addition, by benefiting from the unique LSTM structure in the model, the forecasting and the generalization ability of the method is better, and the method is suitable for time series prediction in various fields.

The invention relates to a grooved semiconductor rectifier and a manufacturing method thereof. The grooved semiconductor rectifier comprises a semiconductor baseplate, a first conduction type substrate and a first conduction type drift region, wherein one or more grooves extend from the first main plane to the first conduction type drift region, one or more mesa parts are limited at the upper part of the first conduction type drift region, and the upper part of the mesa part is provided with a first conduction type injection layer; the inner wall of the groove is covered with an insulation oxide layer, and a first electrode is deposited in the groove covered with the insulation oxide layer; the first conduction type drift region is provided with a second conduction type enclosure layer corresponding to the bottom of the groove, and the bottom of the groove is coated by the second conduction type enclosure layer; a first metal layer corresponding to the upper part of the first plane is deposited on the semiconductor baseplate; and the second plane of the semiconductor baseplate is covered with a second metal layer. The invention has the advantage of low manufacturing cost, and reduces the reverse leakage current and the forward conduction voltage drop of the Schottky rectifier.

The present invention belongs to the field of lift technology, and discloses method of increasing safety overhaul space in lift pit. The method is to set a support plane capable of being eliminated and interlinking with the cage buffer in the lift well space over the cage buffer supporting plane so as to ensure minimum vertical distance between the lift pit bottom and the cage bottom of 0.50 m. The present invention also discloses one kind of protecting system for maintenance in lift pit, and the protecting system consists of a lift pit pedestal, a buffer seat, a cage buffer and a maintenance protector mounted movably onto the cage buffer supporting plane. The present invention has effective utilization of the lift pit depth and saving in building cost, and can reduce the required lift pit depth and raise the maintenance safety.

The invention relates to a rotatable lift car toe guard, solving the problem that the retractable toe guard in the prior art is easy to be damaged upon collision with the ground and possibly cannot be returned in place. The lift car toe guard comprises an upper toe guard piece and a lower toe guard piece articulated to each other, wherein a stop rod mechanism rotating along with the downward movement of the lift is arranged on the upper toe guard piece; a cam coaxially connected with the stop rod mechanism is further arranged on the upper toe guard piece; and a link mechanism capable of pulling the lower toe guard piece for turnover along with the rotation of the cam is arranged on the cam. The design of the stop rod mechanism, the cam and the link mechanism of the toe guard provided by the invention realizes transformation from rotation to linear movement so that the toe guard rotates at a certain angle; in this way, the demand for the depth of the foundation pit is reduced; the toe guard does not need to collide with the ground surface of the foundation pit; and damage on the toe guard and accidental harm on people are avoided.

The invention relates to a double-acting lift-positioning energy-saving gas stove, and the technical scheme thereof is as follows: at least two outward-tilting bars are evenly arranged at the bottom of a hearth along the circumferential direction and are evenly distributed on the outer edge of a cavity cover; at least two inward-tilting bars are evenly arranged at the bottom of a lift fire tray along the circumferential direction and are evenly distributed on the inner edge of the cavity cover; the outward-tilting bars and the inward-tilting bars correspond to each other in a one-to-one manner and are in matched connection via a tilting plate respectively, the middle part of the tilting part is arranged on the cavity cover in a hinged manner, the outer end of the tilting end props upwardsand supports the outward-tilting bar, the inner end of the tilting plate props upwards and supports the inward-tilting bar, and the hearth and the lift fire tray are lifted relatively; and the lower end of the cavity cover is connected with a diverter, the upper part of the diverter is provided with a gas transmission conduit, the lower part of the lift fire tray is provided with a guide sleeve, and the gas transmission conduit is arranged in the guide sleeve to form a sliding guide pair. The invention has the advantages of simple and reasonable structure, safety, environment protection, energy conservation, no noise in the lift process, manufacturing materials saving and light overall quality, and is suitable for pans in various specifications.

The invention belongs to the technical field of a bridge attachment, in particular to a bridge expansion joint with multidirectional displacement function, wherein a fixed comb jointing unit and a movable expansion comb jointing unit are unit modules, horizontal mutual-insert ratcheting connection pairs are formed at the clearance end of two adjacent beam bodies, a fixed comb body is arranged in a T-shaped way, a movable comb body is arranged in a reversed-T-shaped way, not only can the horizontal displacement requirement for a longitudinal bridge direction be satisfied, but also through a related flexible connection, the rotation of the movable expansion comb jointing unit relative to a rotating bearer of a mounting seat, the transverse bridge direction sliding in a sliding groove, and the rotation relative to a connecting shaft are satisfied, therefore the outstanding features of the requirements for the longitudinal direction, transverse direction, twisting, vertical turning and seismic displacement of the bridge, the concrete pouring is not required, the requirement for the rabbet depth is reduced, the installation is rapid and convenient, the installation engineering jobs are fully optimized, and the construction efficiency and the safety are improved.

The invention provides a rotatable lift car toe guard. The rotatable lift car toe guard comprises an upper toe guard piece (1) and a lower toe guard piece (2) which are hinged to each other, the lower portion of the lower toe guard piece (2) is provided with a bent portion (21) which is bent towards the inner side of a lift car, a torsion spring (5) is further connected between the upper toe guard piece (1) and the lower toe guard piece (2), a bent edge (211) is arranged at the joint of the upper end of the bent portion (21) and the lower toe guard piece (2), an upper rolling part (42) capable of rotating along the axial direction thereof is fixedly mounted on the bent edge (211), the lower end of the bent portion (21) is provided with a lower edge (212), and a lower rolling part (41) capable of rotating along the axial direction thereof is fixedly mounted on the lower edge (212). The lower toe guard piece can rotate relatively to the upper toe guard piece under the rolling action of the upper rolling part and the lower rolling part, rotational restoring force is provided through the torsion spring to enable the lower toe guard piece and the upper toe guard piece to restore to an unfolded state from a rotational state, and the rotatable lift car toe guard is simple in structure, low in cost, easier to manufacture and mount and more stable and reliable in working.

The invention discloses a focus detection model training method based on a generative adversarial network, a device, equipment and a readable storage medium. According to the method, two ideas are adopted to reduce the requirements of the generative adversarial network for data: on one hand, a normal image, a focus and a focus mask are synthesized into three-channel image data to serve as the input of the network, and the three channels respectively contain different prior information, so that the difficulty of image generation is reduced; and on the other hand, a local evaluation mode is adopted in the evaluator of the generative adversarial network, and the requirement on the depth of the network is reduced in the mode, so that the requirement on the sample size is also reduced. Finally,the method achieves the purpose of completing the training of the generative adversarial network by using the small sample, thereby effectively expanding the training sample of the focus detection model, and facilitating the improvement of the detection performance of the focus detection model.

The invention provides a construction process for shipping large sinking pipes by a self-propelled semi-submerged ship for transporting the sinking pipes from a sinking pipe prefabrication factory to a foundation trench region for sinking pipe mounting construction. A mooring and outfitting region is arranged next to the foundation trench region, the semi-submerged ship loads the sinking pipes in a deep dock of the sinking pipe prefabrication factory and transports the same to the mooring and outfitting region, and after an outfitting step of the sinking pipes in the mooring and outfitting region is finished, the sinking pipes are transported to the foundation trench region in a floating manner through a sinking pipe mounting ship and a tug. According to the construction process for shipping large sinking pipes by the self-propelled semi-submerged ship provided by the invention, the floating transportation distance of the sinking pipe is greatly reduced, and the work efficiency of transporting the sinking pipe to 3-4 times; secondly, as draft of the semi-submerged ship which transports the sinking pipes is smaller compared with that of sinking pipe floating transportation in the prior art, the requirement on channel depth is greatly reduced. The channel needs not to be excavated, so that the time and economical costs are further saved; furthermore, the requirements on natural conditions such as a water wave flow by transporting the sinking pipes by the semi-submerged ship are relatively low, the limiting condition of transporting the sinking pipes is reduced, and the work efficiency of transporting the sinking pipes is further improved.

The invention discloses an LED optical structure for car lamps. The LED optical structure comprises a pattern structural face which is arranged on the front face of an LED lamp body and used for diffusing light types and an LED light source which is arranged behind the LED lamp pattern structural face. The LED optical structure is characterized in that a light guide inner lens is arranged right behind the LED lamp pattern structural face; the LED light source is arranged on one side of the light guide inner lens, namely, the LED light source is arranged on the rear side of the LED lamp pattern structural face; and a reflecting surface with a free curved surface is formed in the side, corresponding to the LED light source, of the light guide inner lens to ensure that the light from the LED light source reaches the LED lamp pattern structural face of the light guide inner lens after being totally reflected on the reflecting surface with the free curved surface. According to the LED optical structure for car lamps, the composite lighting effects of light sources with different colors are continuous and uniform so as to form continuous and uniform light emitting light bands.

The invention discloses an elevator sedan. The elevator sedan comprises two vertical beams and an upper beam and lower beam which are separately connected between the two vertical beams, a sedan front strutting piece and a sedan back strutting piece are separately fixed on the front and back sides of the lower beam, the upper surfaces of the sedan front strutting piece and the sedan back strutting piece are not higher than the upper surface of the lower beam and the lower surfaces of the sedan front strutting piece and the sedan back strutting piece are not lower than the lower surface of the lower beam, thus saving installment space in vertical direction and reducing the demand on depth of a pit; and the lower beam is welded with the sedan front strutting piece and the sedan back strutting piece on the front and back sides to commonly support the elevator sedan, thus the stability is high. Compared with the method using a sedan bottom frame to support the elevator sedan in the background technology, the sedan bottom frame is only welded on the upper surface of the lower beam in the elevator sedan of the invention without installing a diagonal member structure, thus increasing the beauty of the scenic elevator and avoiding the interference problem caused by installing an operation box in the elevator on a side wall.

The invention discloses an oil buffer, which comprises an oil cylinder, a first plunger, a first elastic part, a second elastic part, and a second plunger, wherein the first plunger is sleeved on the surface of the oil cylinder; the second plunger is sleeved on the surface of the first plunger; the first elastic part is arranged between the oil cylinder and the first plunger; the second elastic part is arranged between the first plunger and the second plunger; and the first plunger and the second plunger are provided with plunger oil holes. The whole height of the buffer is greatly reduced, and the depth of a well pit is reduced.

The embodiment of the invention provides a multichannel signal synchronization method of a digital oscilloscope. The multichannel signal synchronization method comprises the steps of firstly determining the delay deviation of data in each receiving channel, synchronizing the delay of all receiving channels except for a main channel to the main channel according to the delay deviation of data in each receiving channel so as to realize clock alignment of the channels, and then performing delay compensation on the data in each receiving channel. based on the scheme, the other channels are synchronized to the main channel before delay compensation is performed on the data, so that depth requirements for FIFO (First In First Out) are greatly reduced in delay compensation for the data, thus delay compensation for the data is enabled not to be restricted by the depth of FIFO, and problem that the data is different in path delay is also avoided. The embodiment of the invention further provides a digital oscilloscope.

The invention discloses a novel elevator falling prevention device. The novel elevator falling prevention device is connected with an elevator lifting rod; a support is arranged at the bottom of a cage; the sides of the supports are provided with a left brake arm, a right brake arm and a connecting rod; the two brake arms are symmetrically arranged on two sides of a T-shaped guide rail; the outer ends of the brake arms are provided with chutes which are movably pivoted with fixed pin rolls on the support; the inner ends of the brake arms are friction ends having certain gaps with the two sides of the T-shaped guide rail; the middles of the brake arms are connected with the connecting rod through transmission pin rolls; and two ends of the connecting rod are symmetrically pivoted with left and right brake arms. The novel elevator falling prevention device has constant brake deceleration, can ensure riding comfortableness and safety, simplifies elevator design requirements, has a simple and compact structure, greatly simplifies the conventional structural form of combining clamping springs with brake blocks / guide sliders, saves manufacturing working hour cost, contributes to energy conservation and environmental friendliness, and improves working reliability of products.

The invention discloses a turbulent flow energy-dissipating anti-scouring open caisson and a construction method thereof, and relates to the technical field of bridge deepwater open caisson foundations. The turbulent flow energy-dissipating anti-scouring open caisson comprises an open caisson body, a bottom-expanded stepwell, concrete cover plates and turbulent flow dimension stones, wherein the open caisson body comprises an open caisson bottom section and an open caisson upper section which are connected to each other, and a top cover plate is arranged on the open caisson upper section. Thebottom-expanded stepwell is arranged along the periphery of the open caisson bottom section and comprises a bottom-expanded stepwell outer wall plate and a bottom-expanded stepwell inner wall plate connected to the outer wall of the open caisson bottom section, the bottom-expanded stepwell inner wall plate divides the space between the bottom-expanded stepwell outer wall plate and the outer wall of the open caisson bottom section into a plurality of bottom-expanded stepwell units, the concrete cover plate is arranged in every bottom-expanded stepwell unit, flow guide brackets are arranged at the top of the bottom-expanded stepwell outer wall plate and positioned above the concrete cover plates, and the turbulent flow dimension stones are laid on the concrete cover plates. The turbulent flow energy-dissipating anti-scouring open caisson can dissipate energy of scouring waterflow to prevent an open caisson foundation from being destroyed by scouring, thereby being low in construction difficulty and highly economic.

An axle box external subway bogie with an integrated swing bolster and a hoisting support device belongs to the field of railway vehicle bogie devices and comprises a framework, the swing bolster, a wheel set device, a trapezoidal axle box device and a secondary suspension system. A cross beam and a side beam of the framework are of a box-shaped structure. The cross beam upper cover plate also serves as a side beam middle upper cover plate, a motor lifting seat upper cover plate and a gear box lifting seat upper cover plate, and the cross beam lower bottom plate also serves as a side beam middle lower bottom plate, a motor lifting seat lower bottom plate and a gear box lifting seat lower bottom plate; and trapezoidal axle box devices are arranged on the outer sides of wheels of the wheel set devices, upper cover plates in the middles of side beams are fixedly connected with hoisting supporting devices, and side bearings with grooves are fixedly connected to the tops of swing bolsters. The number of welding seams is effectively reduced, stress concentration is reduced, the efficiency of car falling and overhauling procedures is improved, and the overhauling and debugging process of height matching and leveling of the swing bolster and the car body floor end face and the platform after wheel turning is remarkably improved; and the wheel can be effectively protected, and the service life of the side bearing is long.

The invention discloses an elevator lower beam structure with car bottom wheels. The elevator lower beam structure comprises a car frame lower beam (1), and two car bottom wheel fixing seats (6) distributed at the two ends of the car frame lower beam (1) are arranged at the bottom of the car frame lower beam (1). The car bottom wheels are arranged on the car bottom wheel fixing seats (6) respectively. One end of an axle of each car bottom wheel (2) is fixed to the corresponding car bottom wheel fixing seat (6), and the other ends of the axles are fixed to the bottoms of car bottom wheel supporting pieces (4). A buffer plate (3) is fixed to the middle of the bottom of the car frame lower beam (1). The car bottom wheel fixing seats (6) are of a hollow structure, and safety tongs (5) are arranged in the car bottom wheel fixing seats (6). Notches corresponding to tong openings of the safety tongs (5) are formed in the upper ends and the lower ends of the car bottom wheel fixing seats (6). The elevator lower beam structure is simple, high in space utilization rate and small in occupied height, and therefore the requirement of an elevator for pit depth can be reduced, and then civil engineering cost is reduced.

The invention belongs to the technical field of a bridge attachment, in particular to a bridge expansion joint with multidirectional displacement function, wherein a fixed comb jointing unit and a movable expansion comb jointing unit are unit modules, horizontal mutual-insert ratcheting connection pairs are formed at the clearance end of two adjacent beam bodies, a fixed comb body is arranged in a T-shaped way, a movable comb body is arranged in a reversed-T-shaped way, not only can the horizontal displacement requirement for a longitudinal bridge direction be satisfied, but also through a related flexible connection, the rotation of the movable expansion comb jointing unit relative to a rotating bearer of a mounting seat, the transverse bridge direction sliding in a sliding groove, and the rotation relative to a connecting shaft are satisfied, therefore the outstanding features of the requirements for the longitudinal direction, transverse direction, twisting, vertical turning and seismic displacement of the bridge, the concrete pouring is not required, the requirement for the rabbet depth is reduced, the installation is rapid and convenient, the installation engineering jobs are fully optimized, and the construction efficiency and the safety are improved.

The invention discloses an elevator installed in an existing building. The inner portion of a base of a bottom pit is provided with a bottom section steel structure, the steel at the upper portion of the bottom section steel structure is provided with at least one section of middle section steel structure, and the upper portion of the middle section steel structure is provided with a top section steel structure. At least one upright column in the bottom section steel structure, at least one upright column in the middle section steel structure and at least one column in the top section steel structure are all provided with flanging of heavy auxiliary guide rail as integrated mineral powders. The bottom section steel structure, the middle section steel structure and the top section steel structure forms steel structure hoistway of the elevator, a carriage system is arranged in the steel structure hoistway through a main orbit, the upper end of the top section steel structure is provided with a mainframe and a plurality of guide wheels through a load bearing beam, and the carriage system moves up and down driven by the mainframe and the guide wheels. A portion of the steel structure is used as a counterweight rail, no guide rail support is needed, the elevator hoistway is manufactured by sections, the installation of the steel structure hoistway and the elevator is conducted at the same time at the site, time and effort are saved, and construction period is reduced.

The invention provides a self-assembled spiral elevator. A structure of the self-assembled spiral elevator comprises an elevating platform base and power devices, wherein a box body is arranged on the lifting platform base; two storing devices, which are correspondingly used for storing a vertical lifting belt and a horizontal lifting belt, are arranged in the box body; the power devices are correspondingly used for driving the vertical lifting belt and the horizontal lifting belt to be pulled from the corresponding storing devices and then sequentially pass through an extrusion wheel and a cam to form a cylindrical lifting body. The self-assembled spiral elevator is simple and ingenious in structure; the working principle of the self-assembled spiral elevator is greatly different from an existing spiral elevator, namely, the two lifting belts of the self-assembled spiral elevator are mutually clamped to form a lifting body, and two steel belts continuously spirally convey and recover to achieve load increasing and decreasing; the height and size of the self-assembled spiral elevator are much less than those of an existing elevator under the same stroke. The self-assembled spiral elevator has a small requirement on the depth of a foundation pin, and is low in maintenance cost.

The invention discloses a method for prefabricating pipe joints of an immersed tube tunnel. The method comprises the following steps that 1, steel bars are bound in a shallow dry dock, and the pipe joints are poured; 2, a steel end shell, a steel end sealing wall and a guiding device are arranged at the two ends of each pipe joint; 3, a waterproof layer of each pipe joint is constructed; 4, prefabricated plates are prefabricated in a prefabricated site beside an assembling platform; 5, a dock door is opened, the pipe joints are conveyed to the assembling platform in a floating mode, and a hoisting system is arranged on the assembling platform; 6, the prefabricated plates are hoisted to the corresponding positions of the pipe joints through the hoisting system; 7, the waterproof layers areapplied above the prefabricated plates; and 8, the pipe joints are dragged to designated positions for reassembling and then sinking. According to the method, the pipe joint floating process is shallow in draft depth, the temporary project is little, the dredging amount in water or dredging is not needed, the environment influence is small, and streamlined operation can be carried out.

The invention relates to the field of shared bicycles, and discloses a shared bicycle operation management method based on parking equipment arranged in a foundation pit and a central management system in data connection with the parking equipment. The parking equipment comprises a plurality of longitudinal parking platforms stacked in the foundation pit, shared bicycles are sequentially parked onto the parking platforms from top to bottom, the parking platforms parked with the shared bicycles rise and stop in air, and a user parks or takes a bicycle by establishing data connection with the central management system; in the taking process, the user takes away the shared bicycle from the corresponding parking platform which is flush with the opening of the foundation pit and parked with theshared bicycle, and in the parking process, the user parks the shared bicycle onto the corresponding parking platform which is flush with the opening of the foundation pit and has a vacant space. Byadopting the method, the density of shared bicycle parking and taking points can be increased, in other words, the distance between every two adjacent parking and taking points can be reduced, so thatthe method is similar to a pile-free bicycle operation mode in the bicycle returning link and is superior to the pile-free bicycle operation mode in the bicycle borrowing link, thereby bringing convenience to consumers.

The invention discloses a wall-mounted infinity swimming machine and relates to the technical field of swimming machine devices. The wall-mounted infinity swimming machine comprises a semi-closed boxbody used for being horizontally fixed with the inner wall of a swimming pool, wherein an inner cavity of the box body is divided into a water outlet bin and a water inlet bin which can communicate with each other through a partition plate; an opening of the box body corresponding to the water inlet bin is a slope and is sealed by a protection panel with a mesh; a water pumping device is arrangedin the inner cavity of the box body and is used for pumping water in the lower layer of the swimming pool into the water inlet bin and outputting the water to the upper layer of the swimming pool along the water outlet bin to form a water circulation of the swimming pool; and the water pumping device is controlled by a main control electric box. The device is simple in structure and convenient toinstall, and is suitable for installation and use of various swimming pools on the market.

The invention provides a power assembly lubricating device. Two or more than two suction filters are provided, so that during specific use, different suction filters can be started up as required to ensure that under various running conditions of a car, such as braking / speed reducing, starting / accelerating, running at uniform speed / keeping still and going uphill / downhill / on flat roads, the suction opening of at least one suction filter is always below the liquid level in an oil pan, accordingly, during design of the oil pan, the demand on the depth of the oil pan is lowered, a relatively large ground clearance is guaranteed for the car, and the car passing ability is improved. Meanwhile, the two suction filters are controlled to be started in a switching manner under the different running conditions of the car to ensure that the suction filters can always suck a lubricant in the oil pan, and accordingly, the power assembly of the car is guaranteed to be always well lubricated.

The invention relates to a seamless steel pipe formed by cold rolling and a manufacturing method thereof. The seamless steel pipe is processed and manufactured by carrying out diameter reduction rolling on the outer surface of a seamless steel pipe blank with uniform wall thickness and smooth inner and outer surfaces via at least two rollers in the environment at 5-40 DEG C. The outer diameter and the inner diameter of the rolled pipe blank are compressed and reduced to form a seamless steel pipe with helical grooves formed in the outer surface and convex-concave ripples in the inner surface. A cold rolling forming process is characterized in that rollers of rolling equipment are symmetrically arranged along the axis of the pipe blank; the rollers rotate along self axes and compress the outer diameter of the steel pipe; the inner diameter and the outer diameter of the pipe blank are subjected to plastic deformation; a plurality of spaced protrusions are formed in the outer circle of a middle section and a rear section of each roller; when the outer diameter of the pipe blank is reduced and the appropriate-sized helical grooves are formed in the surface of the pipe blank, the inner diameter of the pipe blank is also reduced and the convex-concave ripples are formed; the seamless steel pipe is further process and manufactured into a grouting connection sleeve of an FRP rib or a steel rib applied to buildings; the seamless steel pipe is low in mechanical cutting processing amount, low in cost and high in performance.

The invention provides an intelligent clothes hanger control system, and belongs to the technical field of intelligent homes. The system comprises an outer shell embedded into a wall; a drying chamber is arranged in the outer shell; a sealing door assembly is arranged at the front side of the drying chamber; and a moisture removal assembly connected with the drying chamber is further arranged on the side portion of the outer shell. A clothes airing rod is divided into a plurality of clothes airing parts through supporting rods, each clothes airing part is provided with a corresponding electric heating bar, after the electric heating bars are powered on by a power source, the electric heating bars can heat air in a hot air channel, the hot air channel is externally connected with a draught fan, and the draught fan can dry clothes hung on the clothes airing rod through the heated air through the drying holes. Due to the arrangement of the multiple electric heating bars, the electric heating bars can heat the whole clothes airing rod and can also independently heat the clothes airing parts on the clothes airing rod, so that the energy consumption for airing a small amount of clothes is greatly reduced.

The invention discloses a self-weight-adjustable immersed tube of a reinforced concrete embedded tube and a design and construction method. The self-weight-adjustable immersed tube is applied to the technical field of immersed tube tunnels. The immersed tube structure comprises an immersed tube structure body and pipelines arranged in the immersed tube structure body, and the pipelines are used for pouring ballast fluid into the immersed tube structure body. The design method comprises the steps that B1, the number of groups of the pipelines is selected, and the weight range of the immersed tube structure is determined and adjusted; B2, the ballast fluid is selected, and the weight range of the immersed tube structure is determined and adjusted; and B3, the ballast fluid is poured into the immersed tube structure body through the selected groups of pipelines, and the self weight of the immersed tube structure is adjusted. The construction method comprises the steps that S1-S3, the immersed tube structure is formed through pouring; and S4-S7, navigation and installation construction are conducted. According to the self-weight-adjustable immersed tube of the reinforced concrete embedded tube and the design and construction method, the self weight in the immersed tube structure can be adjusted, the draft of the immersed tube structure is automatically adjusted, navigation is convenient, the requirement for the navigation water depth is lowered, the requirement for the foundation trench depth is lowered, the construction difficulty of the immersed tube tunnel is also lowered, and construction is more convenient.

The invention discloses a hydraulic oil cylinder buffering piston for an elevator. The hydraulic oil cylinder buffering piston for the elevator comprises a base, and a hydraulic oil cylinder arranged on the base. The hydraulic oil cylinder buffering piston further comprises a multi-stage plunger piston which is embedded in the hydraulic oil cylinder in a sleeving manner, wherein the multi-stage plunger piston is formed by embedding and sleeving at least two plunger pistons from top to bottom; a compressing returning spring is arranged between the plunger pistons at every two stages, and the compressing returning spring is also arranged between the plunger piston at the lowest stage and the hydraulic oil cylinder; with the adoption of the compressing returning springs, each compressed plunger piston can be returned to an uncompressed extending state; an oil returning rod is arranged at the inner bottom part of the hydraulic oil cylinder; oil running holes through which the oil running rod passes are formed in the bottom part of the plunger pistons at all stages. According to the hydraulic oil cylinder buffering piston for the elevator, the multi-stage embedding and sleeving type plunger piston structure and the oil running rod structure are adopted to ensure that the overall compressing stroke of a buffer can be decomposed into the compressing stroke of the plunger piston at each stage on the premise that the compressing stroke can be met as the same requirement, thus the overall height of the oil cylinder and the compressed buffer can be effectively reduced, and as a result, the requirement of an elevator hoistway on the depth of a bottom pit can be reduced.

The present invention belongs to the field of lift technology, and discloses method of increasing safety overhaul space in lift pit. The method is to set a support plane capable of being eliminated and interlinking with the cage buffer in the lift well space over the cage buffer supporting plane so as to ensure minimum vertical distance between the lift pit bottom and the cage bottom of 0.50 m. The present invention also discloses one kind of protecting system for maintenance in lift pit, and the protecting system consists of a lift pit pedestal, a buffer seat, a cage buffer and a maintenanceprotector mounted movably onto the cage buffer supporting plane. The present invention has effective utilization of the lift pit depth and saving in building cost, and can reduce the required lift pit depth and raise the maintenance safety.