60results about How to "Avoid overfilling" patented technology

The invention relates to a gas dispensation automatic control method and a liquefied natural gas vehicle gas dispenser. The gas dispenser comprises a pipeline system and a control system, wherein the pipeline system comprises a liquid inlet pipeline system and a gas return pipeline system; the liquid inlet pipeline system comprises an added liquid mass flowmeter, a gas dispensation hose and a gas dispensation gun; the gas return pipeline system comprises a gas return hose, a pressure regulating valve and a return gas mass flowmeter; a first control valve is arranged between the added liquid mass flowmeter and the gas dispensation hose, and a pressure transmitter is arranged between the pressure regulating valve and the gas return hose; and the control system comprises a judging and executing unit and is used for controlling the on-off of the first control valve according to a signal of a return gas mass flowmeter or the pressure transmitter. The invention realizes the automatic control of the gas dispenser through setting the judging and executing unit, avoids the excess filling of a vehicle-mounted low-temperature gas bottle, solves the problem of pressure jump in the gas bottle, which is brought by excess filling, to ensure that the pressure in the vehicle-mounted low-temperature gas bottle can be controlled after gas dispensation and guarantees the running safety and reliability of the vehicle-mounted low-temperature gas bottle.

The invention discloses a road repairing device and repairing method. The road repairing method comprises the following steps that: 1) enabling two width adaption board components to be separated fromground, and fixing the positions of the two width adaption board components; 2) adding asphalt into an asphalt storage barrel, pushing a movement cart to a to-be-filled silt on a road, driving a flattening mechanism to work when the movement cart moves, and driving a stirring mechanism by the flattening mechanism to stir the asphalt to enable the asphalt to be smoothly conveyed outwards; 3) screwing out two positioning bolts to be separated from two threaded hole seats, enabling two vertical edge boards to downwards extend into a groove; 4) regulating a width locking mechanism, separating thewidth locking mechanism from two width self-adaption bottom board frames, enabling the two width self-adaption bottom board frames to outwards expand to drive the two width adaption board componentsto be attached to the inner wall of a to-be-filled groove; and 5) after the two width adaption board components outwards expand, outwards discharging the asphalt in the asphalt storage barrel into thegroove, slowly pushing the movement cart to outwards convey the asphalt step by step, and meanwhile, flattening the asphalt by the flattening mechanism.

The invention relates to a pump-valve integration machine for a pneumatic waist support of an automobile seat. The pump-valve integration machine for the pneumatic waist support of the automobile seatcomprises a gas pump, a pump-valve connecting seat, an electromagnetic gas valve lower base, a normally open electromagnetic gas valve, an electromagnetic gas valve upper cover and a control circuitboard, wherein a one-way gas outlet structure is processed on the pump-valve connecting seat; the one-way gas outlet structure on the pump-valve connecting seat is opposite to and communicate with a gas outlet of the gas pump; the electromagnetic gas valve lower base is fixed onto the gas pump; an installation groove is processed on the bottom part of the electromagnetic gas valve lower base; thepump-valve connecting seat is arranged in the installation groove; a gas passing hole is processed at the position, opposite to the one-way gas outlet structure of the pump-valve connecting seat, on the electromagnetic gas valve lower base; the normally open electromagnetic gas valve is arranged on the electromagnetic gas valve lower base; a gas inlet end of the normally open electromagnetic gas valve corresponds to the gas passing hole of the electromagnetic gas valve lower base; the electromagnetic gas valve upper cover is arranged above the normally open electromagnetic gas valve; and a gasoutlet connector of the electromagnetic gas valve upper cover corresponds to a valve element of the normally open electromagnetic gas valve. The pump-valve integration machine is complete in performances and can be used for simultaneously inflating and deflating multiple gas bags.

The invention relates to a construction method of a complex inclined rock and boulder geological bored pile. The construction method comprises the following steps of: S1, drilling first drill holes ina foundation and boulders on the pile side by using a coring machine; S2, manufacturing an explosive tube; S3, burying wall protecting tubes in the first drill holes every other first drill hole; S4,mounting a lifting rope at the top of a limiting rod; S5, sleeving the outer side of the limiting rod with a steel casing to the highest point of the rock surface; S6, pre-cracking and loosening rocks by using a static crushing agent; S7, lifting the lifting rope to recover the limiting rod and a PVC tube for secondary utilization; S8, arranging a geotextile bag at the position, corresponding toa boulder hole, of a reinforcement cage; S9, arranging water-swellable rubber between a first iron sheet and a second iron sheet; and S10, sinking the assembled reinforcement cage to a designated position, and pouring concrete. The construction method has the advantages that the limiting rod is arranged on the inclined rock and boulders, so that the casing can be prevented from deflecting; and when a drill bit is ejected and deflects to affect the casing, the drill bit can be limited by the limiting rod, so that the perpendicularity of a pile hole is improved.

The invention provides a feeding system and method for block-shaped food. The feeding system comprises a feeding device, a reclaiming device and a discharging device which are arranged in sequence. The feeding device comprises a vibration feed hopper and an acceleration conveying belt connected with the vibration feed hopper. The reclaiming device comprises a rack arranged at the end of the acceleration conveying belt in a covering mode, a visual identity device arranged above the rack and above the acceleration conveying belt and a reclaiming robot arranged inside the rack. The reclaiming robot is in communicating connection with the visual identity device. The discharging device comprises a trough conveying belt. The end of the trough belt is arranged inside the rack and is arranged below the reclaiming robot. According to the technical scheme provided by the feeding system and method for the block-shaped food, the problems that manually feeding cost for the block-shaped food is high, the efficiency is low, the quality is bad, and the sanitation is bad in the traditional technology in the traditional technology are solved.

An underground water recharge well anti-jamming system, the invention relates to an underground water recharge well device and aims at solving the problems that once the recharge well is jammed the recharged water quantity into a single well becomes less and less and the water even cannot recharged; the well pipe filtering device is arranged underground and then the cleaning and maintaining are inconvenient as these works obstruct the application of underground water-supply heat pumps. A first well (1) of the invention is connected through pipelines with a first-class cyclone desander (2), two second-class filters (3) are connected in parallel, then one end is connected through the pipeline with the first-class cyclone desander (2) and the other end is connected through pipeline with a water-supply heat pump heat-exchanging mechanism (6) which is connected with pipeline with a second well (5). With the first-class cyclone desander and the second-class filters of the invention, the suspension substances in the first well can be filtered to prevent thin sands, etc. suspension substances from jamming the second well and to avoid the problem that the recharged water quantity into the single well becomes less and less and the water even cannot recharged, so as to lead the underground water-supply heat pump to be applied well.

The invention discloses a gray scale compensation method and device of a driving TFT, a display panel and a display device thereof. The method comprises the following steps: obtaining a detection current-voltage ratio of each gray scale of the driving TFT; confirming the maximum value in each detection current-voltage ratio as a first K value; determining the gray scale corresponding to the firstK value as an intermediate gray scale; acquiring a plurality of detection current-to-voltage ratios corresponding to the low gray scales, and performing fitting processing on the detection current-to-voltage ratios corresponding to the low gray scales to obtain a second K value; when the to-be-compensated gray scale of the driving TFT is a low gray scale, performing data compensation on the to-be-compensated gray scale according to the second K value; when the to-be-compensated gray scale of the driving TFT is the high gray scale, data compensation is performed on the to-be-compensated gray scale according to the first K value, so that low gray scale K value compensation of the driving TFT is realized, overcompensation of the low gray scale K value compensation stage of the driving TFT isavoided, and uniform display of the display equipment in the low gray scale and the high gray scale is realized.

The invention discloses a method for the low-voltage thyristor reactive compensation switching of a metallurgical electric furnace, which comprises: firstly, dividing capacitors and reactor groups in a reactive compensation device into a plurality of groups according to A, B, C phases under a condition that the current in each group is less than or equal to 200 amperes, wherein two thirds of the capacity of each phase is fixed switching; assembling a thyristor and a trigger circuit with a radiating fins, wherein the radiating fins adopt a water cooling circulation mode; connecting and fixing the thyristor, the capacitors and reactors by using copper conductors to form a group of thyristor ractive compensation switching unit; and finally, determining the number of static fixed thyristor switching compensation unit groups by using a thyristor reactive compensation switching controller according to a requirement that a power factor cos phi is equal to 0.9. The method has the advantages that: the demands for reactive compensation are satisfied when the normal production process conditions of the metallurgical electric furnace are met; the service life of the device is prolonged; the possibilities for undercompensation are eliminated; and overcompensation is avoided.

The invention relates to the technical field of storage battery production equipment, in particular to an efficient lead-acid storage battery cast-welding production process which is characterized by comprising the following steps: S1, a shunting procedure: a storage battery is automatically conveyed forwards by a feeding conveying system, and a plurality of cast-welding production systems are arranged on the side of the feeding conveying system; and S2, a cast-welding alternating procedure: each cast-welding production system comprises a cast-welding mechanism, a plurality of sets of lead dipping mechanisms and cast-welding molds which are arranged in one-to-one correspondence with the lead dipping mechanisms and can be conveyed and transferred between the cast-welding mechanism and the corresponding lead dipping mechanisms, the cast-welding mechanisms bear storage battery packs conveyed by a shunting mechanism in a shunting mode, the cast-welding molds obtain molten lead liquid from the lead dipping mechanisms to the cast-welding mechanisms to be subjected to cast-welding work with the storage battery packs, and the multiple cast-welding molds alternately change the cast-welding mechanisms to convey the lead liquid needed by cast-welding. Cast-welding flow production of the storage battery is achieved, the cast-welding molds are matched to alternately conduct cast-welding on the cast-welding mechanisms, and the production time is shortened.

The invention relates to an underwater concrete sampler of an engineering stake, which comprises a hand rocking handle, a measurement rope box, a measurement rope, a depth coder, a suspension ring, an iron ring, reinforcing steel bars, a chassis, etc. When the sampler is used for sampling, a drill is first used for drilling to reach designed depth, and then concrete is perfused to reach the depth of the stake top of a designed engineering stake. Next, a pulley is arranged at the edge of the drill, and the measurement rope is put on the pulley. Then, the sampler is put on the mouth of the drill, and the jointing point of the suspension ring and the measurement rope is used as the start depth of zero. Meanwhile, a zero position is ensured to be parallel to the ground. After that the hand rocking handle is rocked, scales of the depth on the depth coder or on the measurement rope can be observed as the measurement rope is put downwards. When the jointing point of the suspension ring and the measurement rope reaches the designed concrete surface or the stake top of the engineering stake, the measurement rope is lifted and then is put downwards, at last the sampler is lifted. If carpolites of the concrete are in an iron cage, the concrete is proved to exist on the jointing point of the suspension ring and the measurement rope. Thus, the sampler has the advantages of simple operation and accurate judgments.

The invention relates to the field of pile foundation construction, and aims to avoid the over-irrigation and guarantee the quality of the pile head. The method comprises the following steps: Step 1,making a steel mold; Step 2, installing the steel mold at the designing top of the pile; Step 3, pouring the concrete into the pile hole through the steel mold, after the concrete reaches the pile top, while observing the state of the flowing concrete until the concrete flowing out from the drainage hole is dense concrete, then the pouring can be stopped; Step 4, vibrating the concrete from the top of the pile with a vibrating rod to make it denser; Step 5, removing the steel mold. According to the invention, the steel mold is installed at the designing top of the pile, and the upper floatingslurry flows out from the drainage hole when the height of the pouring concrete is reaching the height of drainage hole. Finally, the concrete is vibrated and compacted by means of vibrating, which avoids over-irrigation and saves the concrete and the working procedure of breaking the pile head. At the same time, the compactness of the pile head is ensured by vibrating.

The invention discloses a reactive power compensation algorithm for solving low-load reactive power over-compensation and under-compensation problems. When the reactive power is less than or equal tozero, capacitors are cut off from small to large until the reactive power is recovered and an over-compensation state is eliminated; and if all capacitors are not put into practice and the reactive power is still negative, a phase sequence error is determined and wiring has a problem. On the contrary, when the reactive power is greater than zero, if the power factor is in a set range, the system is determined to be normal; otherwise, the capacitors are put from large to small until the current reactive power is less than the minimum capacitance or no capacitor is put, so that a system stable state is realized. Therefore, setting of a reactive upper limit and a reactive lower limit is reduced; whether switching is carried out is determined automatically by the device based on parameters, sothat the automation degree is high; over compensation and under compensation of reactive power on the low-load condition are avoided; and whether the phase sequence is correct is determined automatically and thus a wiring error of a sampling signal is avoided.

The invention discloses land reclamation equipment based on a green mine. The land reclamation equipment comprises a shell; a rectangular through opening is formed in the upper portion of the front end face of the shell, a box is installed at the position, outside the rectangular through opening, of the front end face of the shell, a rectangular discharging opening is formed in the left end face of the box, and a collecting shell is installed at the position, outside the rectangular discharging opening, of the left end face of the box. A collecting box is placed on the bottom end face in the collecting shell. Through cooperation of the rotary plow, the linkage mechanism, the screening plate and the collecting box, stones doped in soil can be automatically separated and collected, so that manual picking is not needed, the stone picking efficiency can be improved by at least 60% through the reclamation equipment, and the practicability of the reclamation equipment is improved; the problem that traditional reclamation equipment cannot effectively and rapidly collect stones doped in soil, so that when the stones in the soil are collected, manual picking is still needed, and the practicability of the reclamation equipment is reduced is solved.

The invention relates to the technical field of chemical products, in particular to chemical product filling equipment with a quantifying function. A shell is included, the upper surface of the shellis slidably connected with a bearing frame, the upper surface of the bearing frame is slidably connected with a pressing plate, and the lower surface of the pressing plate is fixedly connected with asupporting seat. A telescopic rod is slidably connected into the supporting seat, limiting columns are fixedly connected to the position, located on the outer side of the bearing frame, in the shell,and a master control switch is fixedly connected to the middle position of the bottom end of the inner surface of the shell. When worm wheels rotate in sliding rails, the worm wheels push poking pieces to slide on sliding rods, meanwhile, when the poking pieces slide, the distance of resistance tubes connected into a circuit is increased, along with the increase of the resistance tubes connected into the circuit, the resistance on the circuit becomes larger and larger, and when the resistance is gradually increased, the filling equipment gradually stops filling, excessive filling caused by thefilling equipment during filling is avoided, and resource waste is avoided.

The invention relates to the technical field of medical instruments, and particularly relates to a skull drill. The skull drill comprises a supporting table; a round hole is formed in the center of the supporting table; a second mounting frame is fixedly connected to the bottom wall of the supporting table; threaded rods are fixedly connected to the two bottom walls of the second mounting frame; a first mounting frame is movably mounted on one side of the second mounting frame through two threaded rods; the first mounting frame and the second mounting frame are symmetrically arranged; and fastening nuts are spirally mounted at one ends, extending out of the second mounting frame, of the two threaded rods. According to the invention, the position of a drilling machine is adjusted through a rotating mechanism, a supporting frame is driven by a rotating disc to rotate in a circular rail, the position of a movable frame can be adjusted through an arc-shaped rail, and meanwhile, the position of a limiting frame can be adjusted through a horizontal rail, and thus, the skull drill can be convenient for medical staff to adjust the position of the drilling machine and convenient to drill, and meanwhile, the stability of the drilling machine can be improved, so that the drilling precision can be improved, and treatment of a patient is facilitated.

The invention discloses a preparation method of a flexible ceramic heavy anti-corrosion coating, which comprises the following steps of: S1, adding epoxy resin, liquid polysulfide rubber, a dispersing agent, xylene and an epoxy active diluent into a production cylinder, and stirring for 5-10 minutes at the speed of 600-800 revolutions per minute; and S2, adding ceramic whiskers, ceramic powder, carbon nanotubes, glass flakes, fumed silica, polyamide wax and a coupling agent while stirring at the speed of 600-800 revolutions per minute, and dispersing at the high speed of 800-1000 revolutions per minute for 10-15 minutes. According to the invention, the structure is scientific and reasonable, the use is safe and convenient. The liquid polysulfide rubber and the high chlorinated polyethylene are adopted, the epoxy resin is modified by the curing reaction of the epoxy resin and a phenolic aldehyde amine curing agent, and the obtained coating has characteristics of good flexibility and good corrosion resistance under the action of the ceramic whisker and the carbon nanotubes. Meanwhile, the glass flakes further improve the corrosion resistance of the coating, and the ceramic powder and the whiskers effectively improve the corrosion resistance of the coating and improve the impact resistance of the coating.

The invention relates to a three-phase imbalance and low-voltage treatment device and system, and a compensation loop switching method. The system comprises a collection unit for collecting three-phase current and voltage, a control unit, and an imbalance compensation unit. The imbalance compensation unit comprises at least one compensation circuit connected between any two phases. Each compensation circuit is provided with an imbalance compensation capacitor and a control switch in a series manner. The control unit is in control connection with the control switches. The method comprises an imbalance compensation capacitor switching-in and switching-off method, and the switching-in and switching-off of the corresponding capacitor is achieved through the corresponding control method. The device comprises a controller, and the controller employs the above imbalance compensation capacitor switching-in and / or switching-off method. The method provided by the invention can achieve the quick and accurate switching-in or switching-off of the capacitor, thereby effectively improving the power factor of each phase and guaranteeing the stability and reliability of reactive compensation.

The invention discloses a quantitative lubricating grease bottling device. The quantitative lubricating grease bottling device comprises a base; a storage table is welded to the middle of the outer wall of the top end of the base; a vertical supporting column is welded to the other side of the outer wall of the top end of the base, and a storage box is fixed to the end, away from the base, of thesupporting column through screws; the outer wall of the top end of the storage box is provided with an opening, and a grease feeding pipe is connected to the opening in a sleeved mode; a grease discharging pipe is welded to the outer wall of the bottom end of the storage box, an elastic rigid sheet is welded to the inner wall of one side of the grease discharging pipe, a first round hole is formedin one side of the outer wall of the bottom end of the grease discharging pipe, a sleeve is sleeved with the inner wall of the first round hole and internally provided with a reset spring, and a vertical pull rod is sleeved with the reset spring. According to the quantitative lubricating grease bottling device, the structure is simple, through the whole design, whether a bottle is full of greaseor not can be judged accurately during filling, a grease path can be cut off quickly, the overfilling situation is avoided, accordingly, the production speed is not influenced, and accurate and quantitative filling is achieved.

The invention provides an anti-submergence concealed tuna seine ecological type artificial fish gathering device. The artificial fish gathering device comprises a hard framework raft body, a pluralityof floats, a locating buoy, a sinker and a self-buoyant device, wherein palm leaves are arranged on at least one degradable rope, connected with the hard framework raft body, of the sinker; and the self-buoyant device is fixed onto the hard framework raft body and is provided with a water inlet pipe, a gas generator and a gasbag, an agent and a liquid level sensor are arranged in the gas generator, one end of the gas generator is connected with seawater through the water inlet pipe, the other end of the gas generator is connected with the gasbag through a non-return valve, a pneumatic diaphragm and an electromagnetic valve are arranged in the internal cavity of the water inlet pipe, and the electromagnetic valve is connected with the liquid level sensor. According to the artificial fish gathering device, a valve body part is suspended in water, the concealment performance of FADs is improved, and thus, an anti-theft effect is achieved; and the self-buoyant device is bound to the uppersurface of the raft body and is used for providing reserved buoyancy for the raft body and preventing the FADs from submerging, so that the risk of destroying marine habitats is lowered.

The invention discloses a ball type automatic balance device for rotating machinery. The ball type automatic balance device comprises a damping base, fixing bars, a slideway and a damping platform andis characterized in that a first drive motor is mounted on the left side inside the damping base, the output end flange of the first drive motor is connected with a smooth rotary shaft, a connectingsleeve is mounted at the upper end of the smooth rotary shaft, a second drive motor is mounted on the right side inside the damping base, a second gear is connected to the outer wall of a threaded rotary shaft in a threaded manner, and the damping platform is fixedly welded above the damping base. The ball type automatic balance device has the advantages that due to the fact that the outer walls of the smooth rotary shaft and a lock block and the inner walls of the connecting sleeve and a lock groove are threaded, the smooth rotary shaft is connected with the connecting sleeve in a threaded manner, the smooth rotary shaft can be conveniently and firmly connected with the connecting sleeve, and a second reinforcing lock can be provided for the connection between the smooth rotary shaft andthe connecting sleeve by the lock groove and the lock block which correspond to each other.

The invention discloses a dynamic comprehension device of split-phase reactive power, comprising a dynamic controller. The dynamic comprehension device is characterized in that the dynamic controller is respectively connected with a current-sampling unit, a voltage-sampling unit, a dynamic comprehension unit and a temperature collection and control unit, wherein the current-sampling unit, the voltage-sampling unit and the dynamic comprehension unit are connected with a three-phase circuit; the dynamic comprehension unit comprises a plurality of capacitor-switching circuits and connected comprehension capacitors; and thyristor switches are connected between the dynamic comprehension unit and the three-phase circuit and controlled by an external thyristor-switching circuit. The three-phase lines of the dynamic comprehension device of split-phase reactive power are respectively used for current and voltage sampling and mixed comprehension to greatly improve the comprehension effect and avoid the defects of over-comprehension, undercompensation, and the like caused by three-phase shared comprehension.

The grouting device for hydraulic engineering construction comprises a center control integrated device, the center control integrated device comprises a center control box, a fixing through hole located in the left end of the center control box is formed in the bottom face of the center control box, a centralizing plate located at the bottom of the center control box is fixedly connected to the inner wall of the center control box, and an overturning hole located in the left end of the centralizing plate is formed in the centralizing plate; the liquid level height of slurry in a drill hole can be monitored in real time through the monitoring mechanism, so that the state locking mechanism is triggered when necessary, the state of the switching mechanism can be controlled through the state locking mechanism, and the problem that the slurry overflows due to overfilling is solved; the grouting device for hydraulic engineering construction can directly stand on a construction surface around a drill hole, and the standing height of the grouting device for hydraulic engineering construction can be controlled through the standing locking mechanism, so that the grouting device for hydraulic engineering construction is suitable for various complex construction surfaces; and the practicability of the grouting device for hydraulic engineering construction is improved.

The invention discloses a separation device for waste incineration. The separation device comprises an incinerator body, wherein a feed pipe is arranged at the top end of the incinerator body; an incineration chamber is arranged at the top end in the incinerator body; a rotary door is arranged at the bottom end of the incineration chamber; refrigeration blocks are symmetrically arranged at the bottom end of the incineration chamber; a first motor is arranged at one side in the incinerator body; and a groove is arranged in the other side in the incinerator body. The separation device has the beneficial effects that through the arrangement of a second motor, a second rotating shaft, a second connecting shaft, a second fixed block and a connecting rod, a filter case is effectively pushed backand forth, small stones and other large impurities in the filter case are stored in the filter case, some fine slag leaks out of the filter box, and the slag separation effect is improved; and a turnover door is arranged on the outer surface of the incinerator body, a supporting plate is arranged at the bottom end of the filter case, the filter case can be taken out, the situation that small stones and other large impurities in the filter case are overfilled is avoided, and the filtering effect of the filter case is reduced.

The present invention provides a dual-station alternate casting and welding production process, which is characterized by comprising the following steps: a dual-station alternate casting and welding production process, characterized in that it includes the following steps: S1, alternate casting and welding, and in the casting process The casting and welding system provided at the welding area includes a casting and welding unit, a plurality of groups of lead immersion units, and casting and welding molds arranged in a one-to-one correspondence with the lead soaking units. The molten lead obtained from the lead unit is sent to the casting and welding unit and the battery pack for casting and welding. Multiple casting and welding molds alternately transport the lead liquid required for casting and welding to the casting and welding unit. When one group of molds is cast and welded at the casting and welding station, the other group of molds is dipped in lead synchronously in another lead-dipping mechanism and waits to be transported, so alternately travel for casting and welding, which greatly saves production time.

The invention provides a hydraulic oil filtering device utilizing negative pressure. The device is provided with a negative pressure oil tank, and the negative pressure oil tank is provided with an upper end cover, a lower end cover and a tank body. The upper end cover is provided with an extraction opening, and the extraction opening is sequentially connected with a negative pressure meter, a control hand valve and a pneumatic connector; the lower end cover of the negative pressure oil tank is provided with an oil suction port and an oil discharge port, and the oil suction port is sequentially connected with three filters and a hand valve; the oil discharge port is connected with the electromagnetic valve; o-shaped rings are used for sealing between two end covers of the negative pressure oil tank and the tank body; according to the device, hydraulic oil is filtered through the pressure difference generated by negative pressure, due to the fact that the pressure difference generated by the negative pressure is limited, under the same negative pressure condition, when the oil return speed becomes slow, it is prompted that the filter needs to be cleaned, and it is prevented that the clean filter is detached due to misjudgment. Due to the fact that the negative pressure changes along with the change of the volume of the hydraulic oil in the oil tank, if the negative pressure is not increased manually when the oil tank is about to be filled with oil, the pressure difference enabling the hydraulic oil to pass through the filter cannot be provided, and the situation that the oil tank is filled with excessive oil can be avoided.