31results about How to "Reduce negative pressure" patented technology

The invention discloses a distillation separation mechanism and method of a cyanate ester synthesis reaction device, and belongs to the field of cyanate ester synthesizing.The mechanism comprises a distillation assembly, a first collection assembly for collecting cyanogen chloride and hydrogen chloride, a second collection assembly for collecting bisphenol compounds and a third collection assembly for collecting cyanate ester, in the second collection assembly, a second condensation pipe is connected between a second collection cylinder and the distillation cylinder, a second condensation cylinder is sleeved on the pipe, a sliding plate in the second collection cylinder is connected with a piston rod and an insertion rod, and a tension spring is arranged between the piston rod and a piston cylinder. Pressure passes through the branch pipe to enable the piston rod to move downwards, the sliding plate to descend, the volume of the communication space to descend, boiling is slowed down, the insertion rod moves downwards to enable the second collection barrel to ascend, the condensation pipe to incline and liquid drops to flow back, and the cyanate collection amount is ensured.

The invention relates to the technical field of workpiece conveying, and particularly discloses a workpiece conveying device for a laser cutting machine, which comprises a moving frame, a mounting frame and a driving part I for driving the mounting frame to move along the vertical direction, and two groups of sucking disc assemblies I which are symmetrically arranged left and right and a sucking disc assembly II which is positioned between the two groups of sucking disc assemblies I are arranged at the bottom of the mounting frame; the mounting frame is provided with a second driving piece for driving the first suction cup assemblies or the second suction cup assemblies to move in the vertical direction, and the mounting frame is further provided with a third driving piece for driving the two first suction cup assemblies to move close to each other or away from each other. According to the workpiece conveying device for the laser cutting machine, before an aluminum plate is lifted, the two side edges of the aluminum plate are tilted upwards firstly, at the moment that the aluminum plate is lifted, air can enter the position between the upper aluminum plate and the lower aluminum plate from the left side and the right side of the aluminum plate, the situation that large negative pressure is formed between the grabbed aluminum plate and the adjacent aluminum plate below is improved, and the working efficiency is improved. And the aluminum plate can be smoothly grabbed, and normal feeding of the aluminum plate is guaranteed.

The utility model relates to the field of hydraulic dams, in particular to a hydraulic dam damping flow-guiding back plate structure which comprises a gate leaf, an upper damping flow-guiding back plate and a locking device. The lower end of the gate leaf is rotationally fixed to an installation base, a water breaker is arranged at the upper end of the gate leaf, a fixing base is arranged on the back face of the gate leaf, and an upper supporting rod is arranged on the fixing base; the lower end of the upper supporting rod is connected with the lower supporting rod, the lower end of the lower supporting rod is connected with the locking device, and the upper damping flow guide back plate is arranged on the side face of the upper supporting rod. Overflowing water flow can be prevented from directly impacting an oil cylinder and other structural components behind the gate, equipment damage caused by water flow impact is prevented, and the service life of equipment is prolonged; the design of the flow guide grooves in the back plate can guide water flow to flow downstream in order, the negative pressure area formed by water flow scouring is effectively reduced, and the adverse effect of the water flow on the stability of the dam body is reduced.

The utility model relates to the technical field of breather valves, in particular to a breather valve convenient to replace, which comprises an exhalation valve body and an inspiration valve body which are fixedly communicated through a communicating pipe, a pressure relief opening and an inspiration opening are respectively arranged on the exhalation valve body and the inspiration valve body, and an exhalation valve cover and an inspiration valve cover are respectively matched at the pressure relief opening and the inspiration opening in a sliding mode. The exhalation valve cover and the inspiration valve cover are connected with the exhalation valve body and the inspiration valve body through a first elastic mechanism and a second elastic mechanism respectively, and a plurality of communicating exhalation ring grooves capable of enabling the pressure relief opening to be communicated are formed in the side, close to the exhalation valve body, of the exhalation valve cover at intervals. Therefore, the telescopic filter cover can be conveniently replaced in a state of avoiding air suction in a running state, and no impurities are sucked in the replacement process in the running state.

This invention relates to the field of automotive parts technology, and provides a dual-valve controlled PRV valve, comprising: a valve seat having an intake chamber and an exhaust chamber therein, the intersection of which forms a cavity with one end communicating with the outside air; a piston movably inserted into the cavity, with an exhaust hole penetrating the first and second parts at the center of the piston; a diaphragm movably connected to the upper end of the piston; a spring sleeved on the outer wall of the piston, with the end of the spring abutting against the diaphragm on the moving side; and a seal disposed within the cavity. Compared with the prior art, the advantage of this invention is that by providing a seal within the valve seat that seals the piston and the cavity, when the negative pressure in the cavity is high, the seal and the diaphragm together achieve a seal on the intake and exhaust chambers. Under the same operating conditions, this makes it easier to achieve the sealing function, preventing excessively low crankcase negative pressure and ensuring normal engine starting.

The utility model belongs to the technical field of cutting machines, and particularly relates to a toothless saw main shaft with cooling and lubricating functions, which comprises a main shaft cylinder, bearings mounted at two ends of the main shaft cylinder, a main shaft mounted between the two bearings, a storage cavity arranged between the main shaft and the main shaft cylinder, and end covers mounted on the main shaft cylinder and used for pressing the bearings. A fastening assembly used for locking the saw blade is installed on the main shaft, a through hole is formed in the main shaft, an air hole used for communicating the through hole with the storage cavity is formed in the main shaft, a rotary connector and a sealing cover are installed at one end of the main shaft, a plug is installed at the other end of the main shaft, and gaps are formed between the fastening assembly and the main shaft cylinder and between the sealing cover and the end cover. And in the rotating process of the main shaft, negative pressure always exists in the storage cavity, so that external dust can be prevented from entering the storage cavity, the service life is prolonged, and the cutting precision is improved.

The utility model discloses a bridge pavement cleaning device, and belongs to the technical field of bridge pavement cleaning. Comprising a movable frame; the hydraulic rod is fixedly mounted at the top of the movable frame; the mounting plate is fixedly mounted between the tops of the hydraulic rods; the cleaning mechanism is mounted on the mounting plate; the collecting mechanism is mounted on the side, away from the advancing end of the movable vehicle frame, of the mounting plate, lifting of the mounting plate is controlled through a hydraulic rod, during use, the mounting plate is lowered, so that the sweeping mechanism makes contact with the road surface, the movable vehicle frame moves forwards, and during walking, the sweeping mechanism sweeps the road surface; and dust and dirt are concentrated to the middle of the bottom face of the mounting plate, and finally, the concentrated dirt is subjected to concentrated negative pressure collection through the collection mechanism, so that concentrated collection of the dirt is facilitated.

The invention relates to the technical field of electric meter checking, and particularly discloses a portable electric energy meter data reading checking instrument device which comprises a checking instrument, an infrared receiving port is formed in one side of the outer surface of the checking instrument, and a connecting piece for fixing the checking instrument is arranged at the position, corresponding to the infrared receiving port, of the outer surface of the checking instrument. A user can liberate two hands by adsorbing the suction cups on the surface of the electric meter, meanwhile, the user can conveniently arrange other checking instruments on other electric meters, all the checking instruments are uniformly taken down after detection is completed, the user does not need to hold the checking instruments by hands to wait for data reading any more, the data reading efficiency is greatly improved, and the user experience is improved. And meanwhile, the workload of a user is reduced, and the distance between the checking instrument and the ammeter can be automatically reduced through a spring III after the suction cup is mounted in place through the design of a telescopic groove and a telescopic block, so that the gap distance is reduced, natural light is prevented from entering the gap, and the anti-interference capability of data reading is improved.

The utility model discloses a labeling machine and a labeling drilling cutting material production line, the labeling machine comprises a rack, a cross beam, a first driving module, a second driving module, a material bearing table top, a printing module, a labeling module and a blowing module, the first driving module can drive the cross beam to move back and forth on the rack in the first direction, and the second driving module can drive the cross beam to move back and forth on the rack in the second direction; the printing module comprises a printer body and a label receiving plate installed below a label outlet of the printer body, the printer body discharges printed label paper from the label outlet to the label receiving plate, the label suction device sucks the label paper from the label receiving plate from bottom to top, and the label receiving plate is provided with air holes. The air blowing module can blow the label paper upwards through the air holes. Due to the fact that the airflow provided by the air blowing module counteracts part of gravity of the label paper, the attaching degree between the label paper and the label receiving plate is reduced, and the phenomenon that the label paper and the label receiving plate are attached too tightly due to the negative pressure phenomenon is greatly reduced.

The utility model relates to a battery cell dust removal device which comprises a base, one side of the base is connected with a partition plate, the base is used for arranging a battery cell, and the partition plate is used for being arranged below a tab; the first dust collection assembly is connected to the base; in the second direction, the base, the partition plate and the first dust collection assembly are sequentially distributed at intervals. The partition plate can be arranged between the first dust collection assembly and the base, so that the transition space is increased, the negative pressure generated by the first dust collection assembly can be reduced, the bending deformation degree of the tab can be reduced, and the breakage degree of the joint of the battery cell and the tab can be reduced.

The utility model provides an anti-cracking plastic fork, and belongs to the technical field of plastic tableware. The anti-cracking plastic fork solves the problems that an existing plastic fork is prone to cracking and not environmentally friendly, and comprises a fork body provided with a grab handle, a limiting groove is formed in the upper portion of the grab handle, a mounting groove is formed in the lower portion of the grab handle, a connecting hole communicated with the limiting groove and the mounting groove is formed in the tail end of the grab handle, and a silica gel connecting piece is arranged on the grab handle. The silica gel connecting piece is clamped on the limiting groove and the mounting groove, the mounting groove is provided with a mounting limiting column, the silica gel connecting piece is provided with a clamping hole, and the silica gel connecting piece has the advantages of being high in practicability, environmentally friendly and not prone to cracking.

The invention discloses a medical melt-blown non-woven fabric performance detection device, and belongs to the technical field of melt-blown non-woven fabric production.The medical melt-blown non-woven fabric performance detection device is provided with a transmission mechanism, a solution pressurizing mechanism, a gas pressurizing mechanism and a spraying mechanism, and liquid in a liquid pressurizing cavity and gas in a gas cavity are mixed and enter a mixing channel; the gas is guided into the gas-liquid storage cavity through the mixing channel for temporary storage, the gas is accelerated under the pushing of pressure to form turbulent flow, and the turbulent flow carries the liquid to reach the guide pipes through the channel and is ejected to two surfaces of the non-woven fabric through the two guide pipes, so that the waterproofness of the front surface and the water permeability of the back surface of the non-woven fabric are simultaneously tested; the wearing comfort degree is determined by the balance of the waterproofness and the air permeability of the two sides.

The present disclosure relates to a pipeline machine. The pipeline machine comprises a machine body, a heating assembly and a flow limiting assembly. The machine body has a water inlet pipeline, a water tank and a water outlet pipeline. The water inlet pipeline is in communication with a water inlet of the water tank. The flow limiting assembly comprises a multi-stage connecting pipeline and a flow limiting pipeline. A first-stage connecting pipeline in the multi-stage connecting pipeline is in communication with a water outlet of the water tank through the heating assembly. A last-stage connecting pipeline in the multi-stage connecting pipeline is in communication with the water outlet pipeline. Adjacent two-stage connecting pipelines in the multi-stage connecting pipeline are in communication through the flow limiting pipeline. An inner diameter of the flow limiting pipeline is smaller than an inner diameter of each connecting pipeline, and the inner diameter of the flow limiting pipeline decreases or is equal along a water flow direction. The embodiment of the present disclosure can reduce the sound of bubble flow and water flow noise.

The utility model relates to an anti-pollution liquid storage bottle suitable for a cell sorter, which comprises a bottle body, a liquid taking nozzle and a filter tip are arranged at the top of the bottle body, and both the liquid taking nozzle and the filter tip protrude out of the bottle body; a soft rubber cover is mounted on the end face of the liquid taking nozzle; an air filter is installed on the end face of the filter tip and seals the filter tip. The liquid taking assembly comprises a suction pipe which penetrates through the soft rubber cover and extends into the bottle body and a connector pipe which is located outside the bottle body and used for being connected with external equipment. The liquid storage bottle has the effect of reducing the possibility that the buffer solution in the liquid storage bottle is polluted.

The utility model discloses a suction-sweeping type sweeper suction nozzle, which belongs to the technical field of sweeper suction nozzles, and comprises two suction nozzle shells, a connecting frame, a suction mechanism, a separation mechanism, a suction mechanism and a suction mechanism, the connecting frame is arranged between the two suction nozzle shells and is used for connecting the two suction nozzle shells, the suction mechanism is arranged on the suction nozzle shells and is used for sweeping leaves and dust, and the separation mechanism is arranged in the suction nozzle shells and is used for assisting the suction mechanism in sweeping. The gathering mechanism is arranged on the suction nozzle shell and used for gathering garbage, and the mounting mechanism is arranged on the top side of the suction nozzle shell and used for mounting the suction nozzle shell on the sweeping vehicle. According to the utility model, the contained garbage is sucked into the garbage truck through the negative pressure environment by utilizing the negative pressure pipe and the negative pressure chamber, meanwhile, the airflow generated when the garbage truck generates negative pressure is injected into the air blowing pipe and the inclined nozzle, and the inclined nozzle blows air to the ground within an angle range of 30-40 degrees, so that the condition that leaves are attached to the ground can be disturbed, and the effect of preventing the leaves from being attached to the ground is achieved. And the purpose of enhancing the equipment cleaning effect is achieved.

The invention relates to the technical field of deepwater sounding equipment, and discloses a deepwater depth finder probe device and an arrangement method thereof. The device comprises a flow guide cover, a first depth finder probe assembly, a second depth finder probe assembly, an anti-corrosion zinc block and a ship bottom plate. The flow guide cover comprises a bottom plate, a box wall and a partition plate; the upper edge of the box wall is connected with a ship bottom plate; the lower edge of the box wall is connected with the bottom plate; the lower edge of the partition plate is vertically connected with the bottom plate, and the interior of the flow guide cover is divided into two spaces which are used for installing the depth finder probe assemblies respectively. The method comprises the steps of selecting an arrangement area, arranging a mounting position and determining a fairing mounting angle. According to the invention, the probe is arranged in an area with minimum bubble and noise influence at the bottom of the ship by using the fairing with a relatively simple structure, so that the problem that the probe of the deepwater depth finder works abnormally under severe sea conditions is solved.

This invention discloses a control method, system, equipment, and medium for a nitrogen-sealed split-range regulating valve in a storage tank, relating to the field of petrochemical production technology. The invention includes obtaining the design pressure value P of the nitrogen-sealed storage tank. S The invention monitors the real-time pressure P inside the nitrogen-sealed storage tank. When material increases in the tank, it automatically releases nitrogen gas from the top; when material is released, it automatically replenishes nitrogen gas from the top. Specifically, based on the monitored real-time pressure inside the nitrogen-sealed storage tank, logic control is used to control the opening degree of the nitrogen regulating valve and the vent regulating valve. This invention enables the pressure of the nitrogen-sealed storage tank to be controlled within a certain range, rather than a fixed value, reducing the frequent operation of the nitrogen valve and vent valve in each segmented control valve. It also allows for quantitative control of the valve opening, reducing nitrogen and material consumption and improving safety.

A desulfurization tower system capable of avoiding smoke return is characterized in that a main machine desulfurization tower is provided with a main machine discharge pipeline which is vertically arranged downwards, an auxiliary machine desulfurization tower is provided with an auxiliary machine discharge pipeline which is vertically arranged downwards, and a section of a main machine discharge horizontal pipeline and a section of an auxiliary machine discharge horizontal pipeline which are horizontally arranged are respectively and additionally arranged between the main machine discharge pipeline and the auxiliary machine discharge pipeline. A discharge port of the main machine discharge pipeline and a discharge port of the auxiliary machine discharge pipeline are connected into the process cabin, a ventilation pipeline extends out of the top of the process cabin and is connected to a ventilation connector of the auxiliary machine desulfurization tower, and the ventilation connector is arranged in the auxiliary machine desulfurization tower and is in an inclined state from top to bottom. And exhausted smoke waste gas in the process cabin does not enter the auxiliary machine desulfurization tower any more. By increasing the flowing resistance of the main machine discharging horizontal pipeline and the auxiliary machine discharging horizontal pipeline, the discharging speed of circulating water is reduced, negative pressure formed in the pipelines can be reduced to a certain degree, and smoke exhaust gas is prevented from flowing back to a process cabin.

The present invention relates to the technical field of autonomous underwater vehicles, and more specifically, to a cage-type AUV active recovery device, including a cage frame, wherein a channel for inserting an AUV is provided in the cage frame, and a locking mechanism for fixing the AUV that has entered the channel is also provided on the cage frame; the cage frame is provided with a plurality of propulsion mechanisms for driving the cage frame to move; and the cage frame is also provided with a plurality of cameras. By providing the propulsion mechanism and the camera, an operator on the water can move the cage frame underwater by controlling the propulsion mechanism; the existing recovery device cannot actively move underwater, and can only rely on the movement of the AUV to align the AUV with the recovery device, while the cage frame in the present invention can actively move, cooperate with the actively moving AUV, so that the AUV and the channel in the cage frame can be quickly aligned, which is more efficient.

The invention provides a water changing and cleaning device for a culture pond, and relates to the technical field of culture pond water changing equipment, the water changing and cleaning device comprises a water changing driving part, and the water changing driving part is provided with a movable connecting piece; a pool bottom cleaning piece is mounted at the bottom of the movable connecting piece; the pond bottom cleaning part is used for cleaning the culture pond; an interval switching piece is mounted on the water changing driving part; a movable connecting piece is attached to the interval switching piece. An interval control piece is mounted on the water changing driving part; the device can realize interval control of mud bottom cleaning positions, guarantee uniform mud bottom cleaning and guarantee ecology, can automatically switch cleaning interval positions, guarantee cleaning comprehensiveness and prevent excessive accumulation of impurities such as excrement at intervals, and solves the problems that an existing water changing and cleaning device for the culture pond is inconvenient to automatically adjust mud bottom interval cleaning and is not convenient to use. Excessive cleaning affects ecological balance, and deterioration is easily caused if local cleaning is not performed for a long time.

Hollow hump type ecological slope protection structure: composed of a hump part and a plane part, the hump part includes a hump solid part and a hump hollow part, the plane part includes a plane solid part and a plane hollow part; the hump part is a strip boss composed of the solid parts on both sides of the hump and the plane solid parts on the top, rectangular holes are opened in the solid parts on both sides of the hump, and the hump hollow part is used for wave dissipation and water permeability; the plane part is the plane solid part at the bottom between the two humps, and rectangular holes are opened in the plane solid part, and the plane hollow part is used for wave dissipation and water permeability. The present invention has good energy dissipation effect, can effectively absorb wave energy, reduce water climbing, reduce wave height, help reduce the impact of waves on the structural stability of hydraulic structures, and control land water and overtopping. The present invention itself has good stability. Due to its high water permeability, the negative pressure is small when the wave trough acts, and the wave force it is subjected to is also relatively small.

The invention relates to a putting device and a washing machine, the putting device comprises a putting box and a negative pressure compensation structure, the putting box is provided with a water inlet, a putting opening and a mixing channel, the water inlet is communicated with the mixing channel, the putting opening is communicated with the mixing channel and a putting cavity, and the negative pressure compensation structure is arranged in the putting cavity. And the negative pressure compensation structure is used for introducing compensation gas into the mixing channel. The releasing device is high in reliability.

The invention relates to the technical field of gastroenterology department gastric lavage, and particularly discloses a gastroenterology department gastric lavage device which comprises a workbench, a coarse filter part, a fine filter part and an intubation tube, the coarse filter part and the fine filter part are connected to the workbench and used for filtering cleaning fluid, and the intubation tube is connected with the fine filter part. The cleaning liquid enters the human body by being inserted into the working table, the detection assembly is connected to the working table, the detection assembly is connected with the second conveying pipe, and the detection assembly is used for monitoring clarity of discharged liquid and detecting whether toxic waste liquid in the stomach of a patient is completely discharged or not by detecting light transmittance of excrement. When the detection assembly detects that the light transmittance reaches a standard value, the negative pressure adjusting assembly can be automatically started, the negative pressure in the first conveying pipe is reduced, the negative pressure adjusting assembly is started, the negative pressure in the first conveying pipe can be reduced, stomach cleaning is stopped, and then the situation that after stomach cleaning is completed, the stomach is still cleaned, and the stomach is prevented from being subjected to secondary damage is avoided.

The invention discloses an efficient dust removal structure. The invention discloses an efficient dust removal structure which comprises an air inducing pipe, an air inlet pipe and an air outlet pipe, a plurality of dust collection ports are formed in the gas collection hood body; the connecting pipes comprise the first connecting pipe, the second connecting pipe to the nth connecting pipe, n is a natural number larger than or equal to 2, the first connecting pipe is communicated between the two adjacent dust suction ports, the second connecting pipe is communicated between the two adjacent first connecting pipes, and the like, the nth connecting pipe is communicated between the two adjacent (n-1) th connecting pipes, and the air inducing pipe is communicated with the nth connecting pipe. The device has the advantage that the dust filtering and removing effects are improved.

The application discloses a conveying device and a surface defect detection device, and belongs to the technical field of printed circuit manufacturing equipment. In the conveying device, a first negative pressure body, a positive pressure body and a second negative pressure body are arranged along the conveying direction from the first conveying mechanism to the second conveying mechanism. The first negative pressure body provides negative pressure suction force to the first air holes on the first conveying belt to flatten the passing flexible sheet material. The second negative pressure body provides negative pressure suction force to the second air holes on the second conveying belt to transition the flexible sheet material from the first conveying belt to the second conveying belt and flatten the passing second flexible sheet material. The positive pressure body provides positive pressure blowing force to the first air holes to pre-lift the flexible sheet material. In one aspect, the flexible sheet material is more conveniently adsorbed on the second conveying belt, and the required negative pressure of the second negative pressure body is reduced. In another aspect, the bending angle of the flexible sheet material during the transition from the first conveying belt to the second conveying belt is reduced, and the phenomenon of creases on the flexible sheet material due to the excessively large bending angle is avoided.

The utility model discloses a breast suction shield and a breast pump, and relates to the technical field of mother and baby products, the breast suction shield comprises a breast suction piece and a fitting piece; a milk sucking channel with two through ends is formed in the milk sucking piece; the attaching part is connected to one end of the milk sucking part, an attaching channel communicated with the milk sucking channel is formed in the attaching part, and the attaching channel gradually shrinks in the direction close to the milk sucking part; wherein a partial pressure channel is formed in the inner wall of the attaching piece, the partial pressure channel is located at the end, close to the breast suction piece, of the attaching piece, and when the attaching piece is attached to the breast, the partial pressure channel is communicated with the breast suction channel. According to the breast suction protective cover, the pressure dividing channel is arranged at the position close to the joint of the attaching piece and the breast suction piece, the negative pressure intensity borne by the mammary areola is reduced, the problem that a circle of red marks are formed at the mammary areola after an existing adsorption protective cover is used for sucking milk is solved, and the use experience feeling of a user is improved.

The invention relates to the technical field of pesticide production, and particularly discloses a pesticide synthesis reduced pressure distillation device which comprises a negative pressure distillation retort, a heating base is arranged on the lower portion of the negative pressure distillation retort, a thermometer is installed at the upper end of the negative pressure distillation retort, a collecting container is arranged on one side of the heating base, and the collecting container is connected with the negative pressure distillation retort. A refrigerating tank is arranged on the front side of the collecting container, the lower portion of the refrigerating tank is connected with a water injection pipe, the outer end of the water injection pipe is connected with a cold water pipe, and the cold water pipe is sleeved with a circulating pipe. The condensation path is flexible and adjustable, the cooling time and the heat exchange effect are optimized, the condensation efficiency is improved, seamless connection from synthesis to distillation is achieved, the thermal decomposition risk is reduced, the recovery rate of effective components is improved, the convenience of operation and maintenance is improved through the modular design, quick replacement of parts is supported, the production requirement change is adapted, and the production cost is reduced. And the waste gas is effectively treated through multiple treatment mechanisms, so that a closed-loop system is formed, and the sustainability is enhanced.

This application provides a vaporizer and an electronic vaporization device. The vaporizer includes an outer housing, where the outer housing is internally provided with: a liquid storage chamber; a first liquid guide element, having a first surface and a second surface opposite to each other, where the first surface sucks a liquid substrate in the liquid storage chamber; a second liquid guide element, arranged close to the second surface of the first liquid guide element, and configured to contact with the second surface to suck the liquid substrate; a heating element, configured to heat at least part of the liquid substrate in the second liquid guide element to generate an aerosol; and an air channel providing a flowing path for air to cross the first liquid guide element and enter the liquid storage chamber in the longitudinal direction of the outer housing. For the above vaporizer, when the negative pressure of the liquid storage chamber exceeds a certain threshold, an air channel across the first liquid guide element supplements air to the liquid storage chamber, so as to alleviate the negative pressure in the liquid storage chamber.