86results about How to "Improve negative pressure effect" patented technology

The invention discloses a biological safety centrifugal machine. The biological safety centrifugal machine comprises a box body, a box cover, a centrifugal device and a refrigerating device, wherein an air inlet is formed on the box cover; a filter is arranged in the air inlet; an air outlet is formed on the box body; a fan is arranged in the box body and is opposite to the air outlet; a filtering device is arranged in the box body; and the filtering device is arranged between the air inlet and the air outlet. The biological safety centrifugal machine can solve the problems that in the prior art, the centrifugal machine cannot ensure that the environment in a laboratory is not polluted and cannot ensure operators are not attacked by bacteria and virus fundamentally.

The invention discloses a conical cylinder type soil screening device for soil remediation. The conical cylinder type soil screening device comprises a support device, a driving device and a screeningbody, wherein the driving device is erected on the support device; the screening body comprises a screen mesh, a first side plate and a second side plate, the screen mesh is enclosed into a circulartruncated cone structure, the first side plate and the second side plate are respectively fixed to the large end surface and the small end surface of the circular truncated cone structure of the screen mesh, and the size of the first side plate is greater than that of the second side plate; and the driving device is used for driving a rotating shaft so as to drive the screening body to rotate around the axis. According to the conical cylinder type soil screening device for soil remediation, the automatic soil screening is realized, the feed and discharge are convenient, additionally, the accumulation of soil can be effectively avoided, and the soil screening efficiency is greatly improved.

Disclosed is a fluid mixer for mixing fluids of different types having a tube member in which a mixing portion for mixing the fluids of different types is installed and a nozzle member for introducing a fluid into the tube member. The nozzle member inn the fluid mixer includes a varying portion for varying a fluid flow.

The invention relates to a mechanical arm for transferring a solar cell piece basket and a double-head transfer device for transferring the solar cell piece basket. The double-head transfer device comprises mechanical arms, a portal frame, a vertical lifting mechanism fixedly arranged on the portal frame, and a lateral movement mechanism. Each mechanical arm comprises a vertically-arranged installing plate, a top plate fixedly arranged on the installing plate, an installing frame arranged on the top plate through a horizontal slide rail, a rotary table horizontally arranged on the bottom of the installing frame, a micromotion mechanism, a rotating mechanism arranged on the installing frame, and a vacuum system. A negative pressure sucker group adsorbs cell pieces by means of negative pressure provided by a vacuum generator. After the cells are adsorbed, the mechanical arms may start the rotating mechanism as required in a moved process in order to overturn a group of cell pieces by 180 degrees, thereby simplifying downstream work flows. Two baskets directly reach downstream equipment to be processed so that the downstream equipment configuration is simplified.

The invention discloses a squatting pan without a water tank, which comprises a squatting urinal, a water flushing part, a water delivery part and a negative pressure generating and driving device. The squatting urinal comprises a bedpan and a drain pipe provided with a drain trap, the water flushing part comprises a water duct and a water flushing pipe which is communicated with the water duct and arranged in the squatting urinal, the drain pipe is provided with the drain trap and provided with an opening above or below the drain trap, and the negative pressure generating and driving device is arranged at the opening and is linked with the water delivery part. The squatting pan without the water tank has the advantages of simple structure, stable performance, convenient use, clean flushing and water saving; and can be widely used in houses.

The invention relates to the technical field of ventilation, and discloses an underground garage auxiliary ventilation system. The system comprises a plurality of speed limiting grooves arranged in the bottom of a garage. Press blocks and air storage pieces matched with the speed limiting grooves are arranged in the speed limiting grooves, the press blocks are located above the air storage pieces, and reset springs are arranged in the air storage pieces. When a main ventilation system in the garage is shut down, the underground garage auxiliary ventilation system can make part of harmful gas be exhausted out under the effect of automobile kinetic energy, air in the garage is assisted in exchanging with the external air, the natural ventilation effect is improved, meanwhile, the absorbed gas and exhausted gas are both harmful gas at the bottom of the garage, the situation that the harmful gas which is heavier than air and mainly consists of gaseous organic matters is accumulated at the bottom the garage is avoided, therefore the overall content of TVOC in the garage is reduced, the negative pressure effect in the garage is improved, the harmful gas in the garage can be prevented from entering an adjacent room, and finally, a speed limiting function is achieved.

The invention discloses a grouting structure capable of filling a soluble crystal and a construction method. The structure comprises a water permeating section and a grouting section, wherein a water-stop component is arranged between the water permeating section and the grouting section; a water permeating tube is arranged in the water permeating section; the solid-state soluble crystal is filledin the water permeating section; a water inlet of a water drainage tube is arranged in the water permeating section; and elevation of the water inlet of the water drainage tube is greater than that of the water outlet of the water drainage tube. The grouting structure is beneficial for increasing grouting pressure, reduces cracks of the grouting section, and improves sealing effect, so that negative-pressure effect of the water permeating section is improved; during grouting, the water-stop component can be effectively supported, and slurry is prevented from entering the water permeating section to disturb formation of a negative-pressure environment, so that blockage of the water permeating tube is avoided, the water-stop component is prevented from greater displacement as a result of extrusion, and continuous water drainage effect of a slope deep layer is favorably guaranteed, and therefore, the grouting structure is of great significance on solving the water drainage and control problem of a large slope.

The invention discloses a tunnel water seepage and harmful gas discharge structure and a semi-closed ice-filled drilling construction method. The structure includes a permeable pipe arranged in a permeable section of a drilling hole. The drilling hole includes the permeable section and a grouting section, the drilling hole is drilled from the side wall of a tunnel, a water stop member is arrangedbetween the permeable section and the grouting section, the permeable pipe is filled with ice, and the permeable section is internally provided with an water inlet of a drainage pipe; and the elevation of the water inlet of the drainage pipe is higher than the elevation of a water outlet of the drainage pipe, and the lift of the drainage pipe is less than the height of a water column correspondingto the atmospheric pressure. According to the tunnel water seepage and harmful gas discharge structure, harmful gases in the surrounding rock in the drainage link can be effectively discharged, the situation that the harmful gas escapes or is greatly accumulated in the surrounding rock is reduced, the safety risk is reduced, and the water-stop member can be effectively supported during grouting,the structure is beneficial to increase the grouting pressure, the negative pressure effect of the permeable section improved, and the tunnel water seepage and harmful gas discharge structure is conducive to ensuring continuous drainage and exhaust effects and is of great significance to solving the problem of tunnel water seepage and gas leakage.

The invention discloses an anode roasting furnace belonging to the production field of carbon used for aluminum, in particular to a flame path partition device of an anode roasting furnace. The structure of the flame path partition device of the anode roasting furnace is as flows: a plurality of furnace face function holes are arranged on the channels of the intersection of cross walls and flame paths among a plurality of furnace chambers and between the two rows of location pulling bricks; isolation positions are arranged on the channels among the furnace chambers underneath the furnace face function holes; a plurality of pressure bladders are arranged in the isolation positions; and the pressure bladders are communicated with a plurality of charging connectors arranged in the function holes. The invention has the advantages of simple structure, less weight, easy operation when being installed and discharged, low operation cost, high product quality, energy saving and good sealability even if the isolation positions are distorted at the high temperature.

The invention relates to the technical field of film laminating plate polishing equipment, in particular to a surface polishing device for film laminating plate production and processing. The surface polishing device for film laminating plate production and processing comprises a sanding machine body, wherein mounting structures are arranged on two sides of the sanding machine body; a discharging structure is arranged at the top end of each mounting structure; a driving structure is arranged in the sanding machine body; a polishing structure is arranged in the sanding machine body; a first collecting structure is arranged on one side of the sanding machine body; and a second collecting structure is arranged in the sanding machine body. The mounting structures are matched with the discharging structures for use, so that the discharging efficiency of a film laminating plate is improved, and the polishing efficiency of the film laminating plate is further improved; the polishing structure is driven to operate through the driving structure, and the surface of the film laminating plate is polished through the polishing structure; and the first collecting structure and the second collecting structure are used for collecting waste chips generated during polishing, so that the cleaning efficiency of the waste chips is improved, the situation that normal operation of the machine is affected by the polishing waste chips is avoided, and then the polishing effect of the polishing structure is improved.

The invention discloses a low-nitrogen combustor. A gas injection mechanism divides the fuel into a main fuel area located in the center and ejecting the fuel from a gas main nozzle and a peripheral fuel area located around and ejecting the fuel from an auxiliary gas outlet hole of an annular gas outlet pipe, part of combustion-supporting air is mixed with fuel gas of the main fuel area to form acentral combustion area, part of combustion-supporting air is mixed with fuel gas of the peripheral fuel area to form a peripheral combustion area, generation of nitrogen oxide can be inhibited through the peripheral combustion area, the combustion temperature is lower, and meanwhile the emission effect of the nitrogen oxide is reduced; a plurality of groups of auxiliary gas outlet holes which areannularly distributed are formed in the annular gas outlet pipe, so that the temperature of the peripheral combustion area can be more uniform, and the local high temperature can be avoided; and under the action of a rotational flow mechanism, negative pressure is formed in the central combustion area, timely backflow of high-temperature flue gas is guaranteed, combustion is more sufficient, flame disturbance is enhanced, and combustion efficiency is improved.

The invention discloses an automatic numerical control machine tool for bolt production, and relates to the technical field of automatic production. The automatic numerical control machine tool for bolt production comprises a bottom plate, a lifting clamp and a mounting frame are fixed to the top of the bottom plate, and a driving motor is fixed to the top of the inner side of the mounting frame. According to the automatic numerical control machine tool for bolt production, in the forward rotation cutting process of a machining device, an auxiliary channel can suck air outside the machining device and then convey the sucked air to the inner side of the machining device, so that air circulation of the inner side of the machining device is improved, and the temperature of a bolt and a machining cutting tool bit is effectively reduced. When the machining device rotates reversely to enable the machining cutting tool bit to be separated from the bolt, the machining cutting tool bit can push out scrap iron in the threads, and mutual movement between air outside the machining device and air inside the auxiliary channel can enable the interior of the auxiliary channel to be in a certain negative pressure state, so that the scrap iron is separated from the machining device through the auxiliary channel.

The invention particularly relates to a mist convection type mining efficient wet dust collector which solves the problem that an existing dust removal device is low in dust-settling efficiency. The mist convection type mining efficient wet dust collector comprises a columnar machine frame, a coal dust suction port is formed in the lower left end of the columnar machine frame, a sewage collection pond is arranged at the lower right end of the columnar machine frame, and lugs are arranged on the left side and the right side of the upper end of the columnar machine frame. An anti-explosion motor is arranged in the columnar machine frame, fans are arranged on a left output shaft and a right output shaft of the anti-explosion motor respectively, nozzles in the same plane are evenly distributed on the portions, on the right sides of the fans, of the inner wall of the columnar machine frame, a filter screen is arranged on the portion, on the right side of the nozzle, in the columnar machine frame, and a dehydration cylinder communicated with the sewage collection pond is arranged on the portion, on the right side of the filter screen, in the columnar machine frame. The dust collector is reasonable and reliable in structural design, negative pressure capacity for sucking dust-containing airflow is enhanced through phase difference rotation, and by means of the convection action of a rotary spray field and a dust-containing wind filed, the aim of high-efficiency setting of dust, particularly respirable dust, is achieved.

A fire cupping jar includes a cup portion and a lamp that is provided in the cupping jar. The cupping jar can be repeatedly used without needing to be replenished with alcohol and can use fire capable of providing uniform flame.

The invention discloses a multistage cyclic drying system used for feeding particle aureomycin. The multistage cyclic drying system comprises a draft fan, a dust remover, a cyclone separator, a multistage drying mechanism and a preheater, wherein inlets and outlets of the parts are sequentially communicated through pipelines; the pipeline between the multistage drying mechanism and the preheater is a first pipeline; the first pipeline is provided with a pelletizer; a dust exhaust opening of the cyclone separator is provided with air seal machinery; an inlet of the air seal machinery is communicated with the dust exhaust opening of the cyclone separator through the pipeline; an outlet of the air seal machinery is provided with a three-way valve; the three-way valve comprises a first interface, a second interface and a third interface; the first interface and the outlet of the air seal machinery are communicated through the pipeline; the second interface and the multistage drying mechanism are communicated through the pipeline; and the third interface of the three-way valve is provided with a material collecting device. The multistage cyclic drying system can be used for realizing multistage cyclic drying of feeding particle aureomycin, is good in drying effect, and time-saving and labor-saving.

The invention discloses a novel soil sampler which is composed of a ring cutter, a sampling tube, an end cover and a joint. The ring cutter is fixed at the bottom of the sampling tube, the end cover is sealed on the top of the sampling tube, and the joint is fixed on the top of the end cover. The ring cutter is inserted into the bottom of the sampling tube composed of two semicircular segments. The end cover is inserted into a tube cavity of the sampling tube and connected by a fixing screw, and the bottom surface of the end cover is provided with a cylindrical limiting groove. The surface ofthe end cover is provided with a venting hole communicated with the limiting groove, the top of the end cover is provided with a joint groove, and the joint is embedded in the joint groove. A throughhole is respectively opened in the central axes of the joint and the end cover, and the piston rod is inserted into the ring cutter through the through hole in the joint. A piston is fixed at the bottom of the piston rod. The bottom surface of the piston is flush with the bottom surface of the ring cutter, the top surface of the piston is provided with a limiting protrusion, and the outer diameterof the limiting protrusion is equal to the inner diameter of the limiting groove. The soil sampler is simple in structure, capable of preventing failure of sampled soil and preventing sampling failure caused by scattering of the sampled soil in the lifting process.

The invention belongs to the field of new energy automobiles and particularly relates to a high-performance vehicle-mounted refrigerator for a new energy automobile. The high-performance vehicle-mounted refrigerator comprises a box and a box door hinged to the box. A negative pressure barrel is fixedly installed at the upper end of the box. A slider is connected to the inner side wall of the negative pressure barrel slidably in a sealed mode. The two ends of the negative pressure barrel each fixedly communicate with a one-way exhaust pipe. A negative pressure cavity is formed in the box and communicates with the negative pressure barrel through two one-way gas suction channels. The two one-way gas suction channels are formed on the two sides of the slider correspondingly. A plurality of negative pressure holes are formed in the side wall of the negative pressure cavity. The other ends of the negative pressure holes communicate with the outside world. Two sliding grooves are formed in the side wall, close to the box, of the box door. Sealing strips are slidably connected to the side walls of the sliding grooves. The box door can be tightly attached to the box through a negative pressure effect, the box door is prevented from being opened automatically under the inertia effect, the sealing effect between the box door and the box is improved, outward leakage of cold air is prevented, and energy is saved.

The invention belongs to the technical field of grinding machine tools, and particularly discloses a grinding machine tool for a drum type brake pad. The grinding machine tool comprises a machine toolbody and a base, and further comprises a grinding mechanism and a horizontal telescopic air cylinder, wherein the grinding mechanism is matched with the base, and the horizontal telescopic air cylinder controls the grinding mechanism to horizontally move; the grinding mechanism comprises a grinding unit and a negative pressure unit, wherein the negative pressure unit processes waste scraps of thegrinding unit; the grinding unit comprises a motor; an output shaft of the motor is coaxially connected with a plurality of grinding wheel units; a cover is arranged outside each grinding wheel unit;each grinding wheel unit is composed of two grinding wheel machines, and a gap is formed between every two grinding wheel machines; and the negative pressure unit comprises a fan, a bevel gear set, ablocking sheet and a connecting mechanism of the blocking sheet, wherein the fan generates the negative pressure, the bevel gear set can enable the fan to act accurately, and the blocking sheet blocks the waste scraps. According to the technical scheme of the grinding machine tool, the technical problem that normal operation of other mechanisms is influenced due to the fact that the waste scrapsspatter in the grinding process of the drum type brake pad can be solved, and therefore the grinding machine tool can be widely used for grinding the drum type brake pad.

The invention discloses a polishing vacuum absorption device capable of improving absorption efficiency. The device comprises a negative-pressure cavity, an absorption cover plate, and a conveying belt positioned above the absorption cover plate; the absorption cover plate is provided with multiple rows of absorption holes in the motion direction of the conveying belt; each row of absorption holes are uniformly distributed at intervals; the conveying belt is provided with multiple rows of open holes corresponding to each row of absorption holes on the lower side; each row of open holes are uniformly distributed at intervals; the negative-pressure cavity is provided with an air sucking port for connecting with vacuumizing equipment by a pipeline; the absorption cover plate is provided with staggered absorbing areas; a gap between front and back adjacent absorption holes in each row is a; the length of each absorption hole is L; a gap between front and back adjacent open holes in each row on the conveying belt is b; the length of each open hole is l; L is bigger than l and smaller than 2l+b; meanwhile, a is smaller than 2l+b and bigger than b; a, L, b and l are all bigger than 0; and when the conveying belt is operated, only part of open holes always communicate with the absorption holes in the staggered absorption areas. The device can achieve excellent absorption efficiency without needing to increasing the power of the vacuumizing equipment.

The invention discloses a two-stage hydrogen fuel cell stack gas supply device driven by a motor. The two-stage hydrogen fuel cell stack gas supply device comprises a drive motor, a primary compressor, a secondary compressor and an interstage communicating pipeline. The drive motor comprises a motor shell, a motor stator, a motor main shaft and a high-speed motor rotor; gas is exhausted by a hydrogen fuel cell and enters a turbine, the turbine drives a coaxially rotating gas compressor to reduce the power consumption of the gas compressor and reduce the gas temperature the gas exhausted by thehydrogen fuel cell through the heat release of the turbine, and the gas exhausted by the hydrogen fuel cell enters the drive motor to perform heat exchange for a high-speed motor rotor to reduce thetemperature of the high-speed motor rotor, increase the stability of the motor and improve the negative pressure capacity and the service time of the motor. The two-stage hydrogen fuel cell stack gassupply device cools the system by employing the energy of the tail gas of the fuel cell to improve the power generation efficiency of the fuel cell while reducing the cooling energy consumption.

The invention discloses a disc type cleaning device with an inner ring seal. The disc type cleaning device comprises a machine shell, at least one negative pressure part is arranged on the inner side of the inner bottom face of the machine shell, an inner seal cleaning part corresponding to the negative pressure part is annularly arranged on the outer surface of the bottom of the machine shell, and the inner seal cleaning part is used for assisting in cleaning and improving the negative pressure effect of the negative pressure part. At least two sides of the inner seal cleaning part are respectively provided with at least one displacement cleaning unit, the displacement cleaning units are used for providing power for displacement of the cleaning device and cleaning and flattening the surface of an object, and at least symmetrical edges of the bottom face of the machine shell are respectively provided with at least one edge detection unit. Barrier detection units are at least arranged on the two symmetrical sides of the machine shell, the negative pressure part, the displacement cleaning unit, the edge detection unit and the barrier detection units are electrically connected with a main control unit, the cleaning device can work on the surface of a flat object more stably, the barrier and edge detection precision is enhanced, and the cleaning effect is greatly improved.

The invention discloses a full-automatic coating system for a conformal coating and a control method of the full-automatic coating system. The full-automatic coating system comprises a coating machinerack, a three-axis moving platform, a PCB transmitting and positioning component, a control box, a conformal coating harmful gas filter system and a spraying valve; a ball screw and pneumatic slidingtable component in the Z direction of the three-axis moving platform is installed on a ball screw moving component in the X direction; the ball screw moving component in the X direction is installedon a ball screw moving component in the Y direction; the ball screw moving component in the Y direction is installed on a supporting plate through a portal frame; the spraying valve is installed on the ball screw and pneumatic sliding table component in the Z direction; the PCB transmitting and positioning component is installed on the supporting plate; and the conformal coating harmful gas filtersystem is installed in a lower box body. The full-automatic coating system disclosed by the invention can realize a uniform coating effect, high marginal definition and high coating thickness precision and is reasonable in structural design; the negative-pressure effect of the equipment is obvious; waste gases are emitted to the atmosphere after secondary filtration; and the environmental protection is greatly improved.

The invention discloses a device for needle core withdrawing together with vacuum suction in one-handed performance for puncture biopsy, including a tube body, a hollow puncture needle, a flexible puncture needle core, a piston rod, a rubber piston sleeve, a piston driving rod and a gear component; a division plate divides the space in the tube body into a piston rod socket and a piston driving rod socket, the puncture needle is mounted on a needle connection tube, the piston rod includes piston rod teeth, the piston driving rod includes piston driving rod teeth, the piston rod is provided with a piston rod needle core socket, the rubber piston sleeve is provided with a rubber piston sleeve needle core socket, a tube body needle core socket and tube body needle core thread holes are arranged on the tube body, tube body needle-core clamping screws are arranged on the tube body needle-core thread holes, and a needle core guide pulley device is arranged on the piston rod. Therefore, lifting and thrusting of the puncture needle can be realized, and the puncture needle core withdrawing together with vacuum suction can be carried out at the same time.

The invention belongs to the technical field of drawing tools, in particular to an easy-to-use drawing tool for calculus curve modeling, comprising a drawing blackboard, a drawing compasses and a fixing frame, the drawing blackboard is fixed on the wall by bolts, the The fixed frame is installed on the drawing compasses; the drawing compasses include compasses legs, extension rods, pen caps, connecting sleeves, handles and No. 1 suction cup; the present invention makes the No. 1 suction cup be adsorbed on the drawing blackboard surface, thereby making the compasses legs The end is fixed to prevent the end of the compass leg from sliding during the drawing process; and the fixing sleeve makes the compass leg limited, so as to avoid the change of the angle between the compass leg and the drawing blackboard during the drawing process, thereby avoiding The curve to be drawn is skewed, which affects the accuracy of the calculus curve model, thus affecting the teaching effect.

The invention provides a pressurizing shower head. The pressurizing shower head comprises an upper face cover, a lower face cover and a handholding portion, and the upper face cover and the handholding portion are integrally formed; the upper face cover and the lower face cover are fixedly connected; the portion, close to the handholding portion, of the lower face cover is provided with an air inlet hole in the water outlet direction; the portion, directly facing the air inlet hole, of the upper face cover is provided with a water isolating part, an air inlet cavity is formed between the waterisolating part and the lower face cover, and the air inlet cavity communicates with the air inlet hole; a negative-pressure mold cavity is formed between the upper face cover and the lower face coverand communicates with the air inlet cavity; the portion, close to the handholding portion, of the upper face cover is provided with an air inlet groove in the water outlet direction; and the air inlet groove communicates with the negative-pressure mold cavity and a water inlet way. By applying the technical scheme, the purpose of being arranged on the face covers can be achieved, and water flow can be blocked from flowing out from the air inlet hole.

The invention discloses a novel integrated stove with a vacuum device. The novel integrated stove comprises a gas stove table and an air inlet cavity arranged on the gas stove table; a negative pressure cavity is arranged below the air inlet cavity, a waste heat device is arranged at the bottom of the gas stove table, and the vacuum device is arranged at the position, below the waste heat device,in the negative pressure cavity; a centrifugal fan system is arranged at the position, below the vacuum device, in the negative pressure cavity; and lampblack generated at the position of the gas stove enters the negative pressure cavity along the air inlet cavity to make contact with the waste heat device, the lampblack moves downwards under the action of gravity after being heated, part of the lampblack is treated through the vacuum device, and the other part of the lampblack is treated through the centrifugal fan system. The integrated stove has the beneficial effects that a set of waste heat device is arranged at the bottom of the gas cooker table, waste heat generated by cooking is introduced, a heat exchange pipe makes contact with lampblack, so that the lampblack is not prone to condensation, then grease is prevented from being condensed and attached to the interior of the negative pressure cavity of the integrated stove, and the lampblack suction effect is improved.

The invention relates to the technical field of film-coated board grinding equipment, in particular to a surface grinding device for film-coated board production and processing, comprising a sander body, two sides of the sander body are provided with installation structures, the installation The top of the structure is provided with a blanking structure, the interior of the sander body is provided with a drive structure, the interior of the sander body is provided with a grinding structure, and one side of the sander body is provided with a first collection structure , the inside of the sander body is provided with a second collection structure; the installation structure is used in conjunction with the blanking structure to improve the blanking efficiency of the film-coated board, thereby improving the grinding efficiency of the film-coated board; The structure drives the grinding structure to operate, and grinds the surface of the film-coated plate through the grinding structure; the waste generated by grinding is collected by the first collecting structure and the second collecting structure, which improves the cleaning efficiency of the waste and prevents the grinding waste from affecting the machine. normal operation, thereby improving the grinding effect of the grinding structure.

In a nozzle deposit removing device and a method of nozzle deposit removal, compressed air is supplied to an air supply hole of a negative pressure generating unit from an air supply source, and compressed air is released to outside via an other end of a release hole from the air supply hole, thereby generating a flow of negative pressure directed from a tapered section of a nozzle insertion member toward the release hole via a through-hole. Next, a tip section of the nozzle is inserted into the tapered section of the nozzle insertion member, thereby forming a gap between the tapered section communicating with the through-hole and the tip section of the nozzle.