CN212327145U

CN212327145U - Direct-acting medical demand valve

Info

Publication number: CN212327145U
Application number: CN202020652929.3U
Authority: CN
Inventors: 胡跃钢; 缪立峰; 屈勇
Original assignee: Gentec Shanghai Corp
Current assignee: Gentec Shanghai Corp
Priority date: 2020-04-26
Filing date: 2020-04-26
Publication date: 2021-01-12
Anticipated expiration: 2030-04-26

Abstract

The utility model discloses a medical demand valve of direct action type, it includes the valve body, sets up the case subassembly in the valve body, the upper valve cover subassembly of being connected with the cooperation of valve body upper portion, the lower valve cover subassembly of being connected with the cooperation of valve body lower part, the case subassembly includes lever drive assembly and pressure regulating spring subassembly. According to the scheme, a lever driving assembly arranged in a valve body is matched with a pressure regulating spring assembly, and weak pressure change is generated at a valve outlet to sense the requirement of a patient for gas transmission and gas cutoff; the pressure regulating spring assembly can regulate the opening force of the valve and can deliver gas according to the demand of a patient; be provided with spring button and lever drive assembly cooperation in the valve upper cover subassembly, when the patient does not breathe voluntarily, can force to press the button and carry out the gas transmission, improved patient's survival rate.

Description

Direct-acting medical demand valve

Technical Field

The utility model relates to the technical field of medical equipment, concretely relates to medical demand valve of direct action type.

Background

As pressure reducing equipment for gas storage, the gas pressure reducing valves are applied more and more, and the application fields are wider and wider. In addition to conventional compressed gas supply, the invention also has application in the field of gas control and in particular applications. In the field of medical oxygen inhalation therapy, a gas pressure reducing valve is generally used to reduce the pressure of gas to a pressure required for use, and a flow meter is used to set a required flow rate for open type oxygen inhalation of a patient. However, in some special applications, such as field or battlefield emergency situations, it is necessary to effectively utilize the carried oxygen, prolong the oxygen inhalation time of patients and wounded persons, and wait for rescue.

Different from the conventional mode, the patient adopts a closed breathing mask to supply oxygen, the gas is not set to be supplied with the gas by a flowmeter after being decompressed, and the oxygen supply is supplied with the gas by a following Demand Valve (Demand Valve) according to the Demand. For a patient with spontaneous breathing, when an inspiratory demand exists and an inspiratory action is sent, the demand valve automatically opens to supply air after sensing the inspiratory action. When the patient stops inhaling or exhaling, the demand valve is automatically closed, and the air source is saved. In addition, for patients without spontaneous respiration, artificial respiration can be performed through manual operation. Until the patient resumes spontaneous breathing. Can greatly reduce the working intensity of medical staff and improve the survival rate of patients.

As mentioned above, the medical demand valve operates by sensing the patient's inspiratory effort, i.e., the small pressure changes produced at the valve outlet. In actual use, the air supply pressure is low for safety, but the air supply volume is large for patients and wounded persons to breathe. Conventional pressure relief valve designs do not meet the requirements. Therefore, all the existing demand valves are designed into pilot type pressure reducing valve structures, and a pilot small valve is used for controlling a main valve, so that the requirement of large output flow is met.

Referring to fig. 1, a conventional pilot valve structure is shown, and the conventional pilot valve structure is shown, wherein components including a valve upper cover 10, a button spring 11, a diaphragm 12 and the like are arranged in the valve upper cover component, and a throttle hole 10 is arranged in a valve body.

When the pilot valve structure is used, the opening and closing of the main valve are controlled by pressure difference formed after the pilot valve is opened. On one hand, the pressure difference is controlled by the size and the proportion of the drift diameter and the throttling aperture of the pilot valve. The pressure stability of the pilot valve is improved by the limitation of the air inlet pressure, and the drift diameter of the pilot valve is required to be as small as possible. The throttling aperture cannot be made smaller due to the limitation of the processing technology.

On the other hand, as mentioned above, the negative pressure generated by the patient is rather weak and the pressure difference across the main valve flap cannot be too great. Therefore, the main valve of the demand valve can only be sealed by a soft rubber diaphragm to adapt to smaller valve clack acting force. However, the actual main valve opening degree varies greatly due to the influences of rubber hardness, use temperature, dimensional accuracy, and valve seat assembling accuracy. The adjustment is needed during the assembly process to control the sealing force of the main valve. When the sealing force of the main valve is too large, the main valve flap can not be opened by smaller valve flap operating force or the main valve flap can not be opened in place, and the main valve can not work normally. If the main valve sealing force is too small, the main valve sealing is poor and may leak directly.

Therefore, for the demand valve, the pilot valve structure scheme has the new problems that the pressure is weak and the operation force is difficult to control, the control difficulty for adjusting the sealing force of the main valve in the assembly is high, the production efficiency is low, and the cost is high.

SUMMERY OF THE UTILITY MODEL

Aiming at the problems existing in the prior medical demand valve adopting a pilot valve type structure, a new scheme of the medical demand valve is needed.

Therefore, the utility model aims to provide a medical demand valve of direct action type, it can realize that the opening force of valve is adjustable, can solve the problem of valve operating force undersize and the big problem of the debugging degree of difficulty.

In order to achieve the purpose, the utility model provides a direct-acting medical demand valve, which comprises a valve body, a valve core assembly arranged in the valve body, an upper valve cover assembly which is matched and connected with the upper part of the valve body, a lower valve cover assembly which is matched and connected with the lower part of the valve body, a two-stage series lever arranged in the valve body, a diaphragm arranged in the valve body and a pressure regulating spring assembly arranged in the valve body, wherein the upper valve cover assembly is arranged at the upper end of the valve body; the valve core assembly is arranged in the valve body through the pressure regulating spring assembly and is in contact fit with the diaphragm through the two-stage series lever, the air pressure sensed by the diaphragm is amplified through the two-stage series lever, and the valve is operated to open and close; the lower valve cover assembly is arranged at the lower end of the valve body and is matched with the valve core assembly.

Furthermore, the diaphragm is a rubber flexible diaphragm with wave shape, and a metal disc is pasted at the center of the lower part of the diaphragm.

Furthermore, the two-stage series lever comprises a first-stage lever and a second-stage lever, and a power point at the tail part of the second-stage lever is matched with the middle part of the first-stage lever and is a resistance point of the first-stage lever.

Furthermore, the head of the secondary lever is provided with a hinge shaft hole as a fulcrum, the tail end of the secondary lever is provided with a power point, and a screw hole in the middle close to the fulcrum is provided with a resistance point.

Furthermore, the secondary lever is provided with an adjusting jackscrew and is matched with the top of a valve guide rod in the valve core assembly as a resistance point of the secondary lever.

Furthermore, the head of the primary lever is provided with a hinge shaft hole as a fulcrum, the tail end of the primary lever is provided with a power point, and the middle side close to the fulcrum is provided with a resistance point.

The safety spring is arranged in a central concave cavity of the central cap, the central cap is arranged in the movable sleeve, the button is in a circular cap shape, the upper edge part of the button is covered and arranged above the movable sleeve, the lower central concave cavity is attached to the safety spring, the safety spring is screwed into the movable sleeve in a threaded mode through the button, the reset spring is arranged in a lower annular cavity of the movable sleeve, the movable sleeve is arranged in the screw cap, and the upper button is screwed into the central cavity of the upper cover of the valve in a threaded mode.

Furthermore, the lower valve cover assembly mainly comprises a lower valve cover, a breathing valve clack, an air suction valve and a valve screw; the valve screw penetrates into the air suction valve and is screwed into a central screw hole of the exhalation valve clack in a threaded manner to fix the air suction valve; the exhalation valve flap is then placed in the recess in the lower valve cover.

Further, the valve core assembly mainly comprises a valve rod, a valve seat seal, a valve seat and a valve guide rod, wherein the valve seat seal is embedded in an inner cavity at the lower part of the valve seat; the valve guide rod is arranged in a circular hole in the center of the valve seat, the lower part of the valve guide rod is matched with the upper end of the valve rod to be mutually extruded to transmit lever power, and the non-full-circle valve guide rod is matched with the circular hole in the center of the valve seat to form an air passage.

Furthermore, the pressure regulating spring assembly comprises a lock nut, a regulating piston, a sealing ring, a spring pad and a valve rod spring; the sealing ring and the spring pad are arranged in the adjusting piston, and the adjusting piston is fixed by a locking nut and matched with the valve rod spring.

The utility model provides a medical demand valve of direct action type adopts the lever to enlarge faint outlet pressure signal and enlargies, and the direct operation is in opening of valve to but the power of opening of governing valve can solve the problem of current valve operating force undersize and the big problem of the debugging degree of difficulty, realizes the function of demand valve.

Meanwhile, the direct-acting medical demand valve can also eliminate the acting force of the change of the air inlet pressure on the valve core, and ensure sufficient output flow.

Drawings

The invention is further described with reference to the following drawings and detailed description.

FIG. 1 is a schematic diagram of a pilot demand valve;

FIG. 2 is a schematic cross-sectional view of a direct acting medical demand valve according to an embodiment of the present invention;

fig. 3 is an exploded view of a direct acting medical demand valve according to an embodiment of the present invention;

fig. 4 is a schematic view of the air suction working flow of the direct-acting medical demand valve in the embodiment of the present invention;

fig. 5 is a schematic view of the exhalation workflow of the direct-acting medical demand valve in the embodiment of the present invention;

fig. 6 is a schematic view of the manual air supply working process of the direct-acting medical demand valve in the embodiment of the present invention;

fig. 7 is a schematic view of the working flow of stopping manual air supply of the direct-acting medical demand valve in the embodiment of the present invention;

fig. 8 is a schematic view of the manual air supply protection working flow of the direct-acting medical demand valve in the embodiment of the present invention;

Detailed Description

In order to make the technical means, creation features, achievement purposes and functions of the present invention easy to understand and understand, the present invention is further explained by combining with the specific drawings.

Referring to fig. 2 and 3, a schematic sectional view and an exploded view of the direct-acting medical demand valve of the present invention are shown.

As can be seen from the figure, the present invention comprises a valve body 400, a valve upper cover assembly 100, a valve core assembly 200 and a valve lower cover assembly 300, wherein the valve core assembly 200 and the valve body 400 which are built in the valve body 400 are matched with each other to form an upper connection valve upper cover assembly 100 and a lower connection valve lower cover assembly 300.

The valve body 400 constitutes the whole demand valve main body, and is used for bearing the upper valve cover assembly 100, the valve core assembly 200 and the lower valve cover assembly 300.

The whole body is cylindrical, the upper port of the valve body 400 is annular, the outer part is provided with connecting threads, and the inner part is a concave cavity. The center of the bottom surface of the lower concave cavity is provided with a small concave cavity, and the bottom surfaces of the lower concave cavity and the small concave cavity are provided with screw hole nails. The lower end of the small concave cavity is small in the middle, the two ends of the small concave cavity are large, the center of the small concave cavity is a rotary cavity, and the large end of the outer side of the rotary cavity is provided with internal threads. The side of the valve body 400 is provided with an air inlet, and the bottom of the air inlet is provided with an inclined hole communicated with the middle part of the central rotating cavity. The lower end of the valve body 400 is also annular, and is externally provided with connecting threads, the inside of the valve body is provided with a concave cavity, the center of the concave cavity is raised into an annular shape, and the outer edge of the annular shape is provided with threads. The edge of the upper concave cavity of the valve body is provided with a straight hole which is communicated with the lower concave cavity of the valve body.

The valve upper cover assembly 100 in this example is mainly formed by matching a central cap 106, a movable sleeve 103, a safety spring 107, a button 105, a screw cap 102, a return spring 104 and the valve upper cover 101, wherein the central cap 106, the movable sleeve 103, the safety spring 107, the button 105, the screw cap 102 and the return spring 104 are mutually matched and are arranged in the valve upper cover 101.

The valve upper cover 101 is a dome-shaped valve, and has a concave cavity at the center, a connection internal thread at the lower part, a ring-shaped center, an internal connection thread at the upper part, and a side hole leading to the outside at the side.

The screw cap 102 is an annular body with an upper edge, an external thread and an internal step.

The movable sleeve 103 is annular as a whole, and the lower part of the movable sleeve is provided with an annular concave cavity and the upper part is internally threaded.

The return spring 104 is a cylindrical coil spring.

The button 105 is generally in the shape of a circular cap, with an upper rim, a lower central concave cavity, and external threads.

The central cap 106 is generally cup-shaped with an upper rim, central concave cavity.

The relief spring 107 is a cylindrical coil spring.

Thus, the safety spring 107 in the valve upper cover assembly 100 is arranged in the central concave cavity of the central cap 106, the central cap 106 is arranged in the movable sleeve 103, the button 105 is in a round cap shape, the upper edge part of the button is covered and arranged above the movable sleeve 103, the lower central concave cavity is attached to the safety spring 107, the safety spring 107 is screwed into the movable sleeve 103 by the button 105 in a threaded manner, the return spring 107 is arranged in the lower annular cavity of the movable sleeve 103, the movable sleeve 103 is arranged in the screw cap 102, and the upper button 105 is screwed into the central cavity of the valve upper cover 101 by the upper button 105 in a threaded manner, so that the upper cover assembly 100 is formed by the structure.

The valve core assembly 200 in this example is mainly formed by the mutual cooperation of a valve rod 202, a valve seat seal 203, a valve seat 204, a valve guide rod 205, a diaphragm 206, a diaphragm pressing plate 207, a lock nut 208, a regulating piston 209, a sealing ring 210, a sealing ring 211, a spring pad 212, a valve rod spring 213, a round seat plate 214, a regulating jackscrew 215, a long pin shaft 216, a secondary lever 217, a square seat plate 218, a short pin shaft 219, a screw 220 and a primary lever 221.

Wherein, the valve rod 202 adopts a multi-step rod-shaped revolving body, and the upper end and the lower end are cylindrical; the middle upper part is a conical sealing surface, and the middle part and the middle lower part are multi-step cylinders. The lower cylindrical diameter coincides with the orifice of the valve seal seat 203.

The valve seat seal 203 is an annular sealing pad, and an inner hole is a valve port and has the same size as the diameter of the lower end of the valve rod 202.

The valve seat 204 is in the shape of a screw with a central circular hole, the upper part of the valve seat is provided with a straight groove, and the lower part of the valve seat is provided with an annular cavity.

The valve guide 205 is a cylindrical body with a raised head at the lower part and a non-whole round shape with a guide at the side surface of the cylindrical body.

The diaphragm 206 is a rubber flexible membrane with wave shape, and a metal disk for improving rigidity is attached to the center of the lower part.

The diaphragm press 207 is preferably an annular sheet.

The lock nut 208 is preferably a through-hole nut.

The adjusting piston 209 is in the shape of a hollow piston with lower adjusting threads, a central double-step hole, an outer circle ring-shaped groove piston at the upper part, adjusting threads at the lower part, and an operating hole for adjusting arranged at the lower end surface.

The O-

ring seals

210 and 211 are preferably used, but other shapes of seals may be used instead.

The spring washer 212 is preferably an annular washer.

The valve rod spring 213 is a cylindrical spring of a corresponding specification.

The circular seat plate 214 is preferably a disk-shaped plate with a mounting hole, a centrally open channel, and a small sink.

The head of the secondary lever 217 is provided with a hinge shaft hole as a fulcrum, the tail end of the secondary lever is provided with a power point, and a screw hole at the side close to the fulcrum in the middle of the secondary lever is provided with a resistance point.

The square base plate 218 has a square plate with rounded corners, mounting holes, and a small sink.

The screws 220 are used to fix the round seat plate 214 and the square seat plate 218.

The head of the first-stage lever 221 is provided with a hinge shaft hole as a fulcrum, the tail end of the first-stage lever is provided with a power point, and the middle side close to the fulcrum is provided with a resistance point.

The valve seat seal 203 of the present assembly is inserted into the lower annular cavity of the valve seat 204 and screwed into the upper thread of the rotary chamber in the center of the valve body 400 from above. The valve guide 205 is placed in the central hole of the valve seat 204, and the lower part of the valve guide is matched with the upper end of the valve rod 202 to transmit lever power. A vent passage is formed between the non-full circular valve guide 205 and the central circular hole of the valve seat 204.

The diaphragm 206 is a corrugated flexible rubber sheet, the deformation amount of the diaphragm is large, the diaphragm is arranged on an annular opening in the upper portion of the valve body 400, the diaphragm pressing plate 207 is arranged on the diaphragm 206, the diaphragm pressing plate 207 is screwed and sealed with the valve body 400 through the upper valve cover assembly 100 in a connection thread mode, and the diaphragm pressing plate 207 is used for preventing the diaphragm 206 from being twisted in the screwing process.

Secondly, the diaphragm 206, the first-stage lever 221, the short pin shaft 219, the square seat plate 218, the second-stage lever 217, the round seat plate 214, the long pin shaft 216, the adjusting jackscrew 215 and the screw 220 in the valve core assembly 200 are matched with each other to form a corresponding lever driving assembly.

The round seat plate 214 is arranged in the small concave cavity of the valve body 400, the long pin shaft 216 penetrates into a hinged shaft hole at the head of the secondary lever 217, the long pin shaft 216 and the head of the secondary lever 217 are arranged in a small sunk groove of the round seat plate 214 together, and the round seat plate 214 and the long pin shaft 216 are fixed in the small concave cavity of the valve body 400 together by the screw 220.

The short pin roll 219 penetrates into a hinge shaft at the head of the first-level lever 221, the short pin roll 219 and the head of the first-level lever 221 are together arranged in a small-sized sinking groove of the square seat plate 218, the square seat plate 218 and the short pin roll 219 are together fixed in a concave cavity of the valve body 400 by the screw 220, a power point at the tail of the second-level lever 217 is matched with the middle of the first-level lever 221 and is a resistance point of the first-level lever 221, and the first-level lever 221 can extrude the second-level lever.

Further, the adjusting top thread 215 is screwed into a screw hole of the secondary lever 217, and is matched with the top of the valve guide rod 205 as a resistance point of the secondary lever 217.

In cooperation with this, the corrugated flexible rubber diaphragm of the diaphragm 206 in this example allows a large amount of deformation, and a metal disk for increasing rigidity is attached to the center of the lower portion of the diaphragm, and the metal disk is engaged with the power point at the rear of the primary lever 221 to drive the primary lever 221. Meanwhile, the adjustable jackscrew 215 is screwed into a screw hole of the secondary lever 217, the fit clearance between the secondary lever 217 and the valve guide rod 205 can be adjusted by tightening or loosening the adjustable jackscrew 215, the idle stroke of the diaphragm 206 and the primary lever 221 is eliminated, and the idle stroke serves as a resistance point of the secondary lever 217 and is matched with the top of the valve guide rod 205 to extrude the valve guide rod 205, so that the opening displacement of the valve guide rod 205 is driven.

The lock nut 208, the adjusting piston 209, the sealing ring 210, the sealing ring 211, the spring pad 212 and the valve rod spring 213 in the valve core assembly 200 are matched with each other to form a corresponding pressure adjusting spring assembly.

Wherein, a seal ring 210 and a spring 212 are arranged in the central hole of the adjusting piston 209 in a cushioning manner, and a seal ring 211 is arranged in a groove at the piston position of the excircle of the adjusting piston 209. The valve rod spring 213 is sleeved outside the lower end rod of the valve rod 202, and is inserted into the center of the adjusting piston 209 together. The assembled adjusting piston 209 is screwed into the rotating cavity in the center of the valve body 400 from the lower end of the valve body 400, the adjusting piston 209 has a certain adjusting range, and the pre-tightening force of the valve rod spring 213 can be adjusted within a certain range by rotating the adjusting piston 209 to control the opening pressure of the demand valve. The adjusting piston 209 is locked and fixed by the lock nut 208 after the adjustment is completed.

Further, the lower end of the valve rod 202 penetrates through the sealing ring 210, penetrates out of the adjusting piston 209 and is communicated with the lower cavity of the valve body 400, the diameter of the lower end of the valve rod 202 is consistent with that of the sealing hole of the valve seat 204, axial force of air inlet and outlet pressure acting on the valve rod 202 is completely balanced, axial acting force of the air inlet and outlet pressure on the valve rod 202 is close to zero, and influence of the air inlet and outlet pressure on axial movement of the valve rod 202 is eliminated. The sealing ring 211 will adjust the seal between the piston 209 and the valve body 400.

The lower valve cover assembly 300 in this example is mainly composed of a lower valve cover 301, a breathing valve flap 302, an inhalation valve 303 and a valve screw 304, which are fitted to each other, and has a breathing valve mechanism.

The valve lower cover 301 is in a cover shape with a conical outlet pipe at the center of the lower part, a concave cavity and an annular boss are arranged at the center of the upper part, an inner connecting thread is arranged at the edge, and the annular boss and the outer edge are hollowed out.

The exhalation valve flap 302 is preferably double-ring-shaped, the outer ring is made of flexible rubber material, the inner ring is hollowed to form an air channel, the center is a threaded hole, and the inner ring and the outer ring are connected through rubber sheets.

The suction shutter 303 is preferably a thin flexible rubber disk with a central hole.

The shutter screw 304 is in the shape of a cylindrical screw with a long screw head.

Thus, the present valve screw 304 is threaded through the inhalation valve 303 and into the central threaded hole of the exhalation valve flap 302 to secure the inhalation valve 303. The exhalation valve 302 is then placed within an internal cavity of the valve bottom cover 301, which forms the valve bottom cover assembly 300. The lower valve cover assembly 300 is tightly locked to the lower end of the valve body 400, and the exhalation valve flap 302 is fixed and sealed.

The direct-acting medical demand valve formed by the method adopts a diaphragm type pressure reducing valve structure, and the two-stage serial lever is used for amplifying the air pressure sensed by the diaphragm and operating the opening and closing of the valve. The valve rod adopts a conical sealing structure, so that the sealing force is increased, and the sealing performance is ensured.

During specific implementation, the pretightening force of the valve core reset spring can be selected according to the hardness of the valve seat sealing material, and the total lever ratio is selected according to the pretightening force and the diaphragm area, so that the opening and closing of the valve are ensured.

The valve seal seat is embedded in the valve seat, the applicability is wider, different sealing materials are selected according to different air inlet pressures, and the sealing is more reliable.

In order to compensate for the negative influence of the reduction of the valve opening after the force of the lever is amplified, the through diameter of the valve is increased, and the over-flow rate is increased. In order to eliminate the influence of inlet pressure generated by increasing the drift diameter of the valve on the opening and closing force of the valve, the valve core in the scheme adopts a complete balance structure.

The adjusting screw rod (adjusting the jackscrew promptly) of valve rod control is further increased to this scheme, eliminates the idle stroke on valve rod upper portion, effectively utilizes the less displacement of lever, increases the flexibility of diaphragm simultaneously, improves the deflection of diaphragm, through increasing the diaphragm deflection, increases the valve and opens the displacement, ensures that the valve during operation has sufficient degree of opening.

In addition, the adjusting device is additionally arranged in the scheme, so that the loading adjustment of the spring force of the valve rod is facilitated, and the influence of factors such as processing and assembly on the opening pressure of the demand valve is eliminated. The opening force of the control valve is effectively adjusted.

When the medical demand valve with the direct-acting structure is applied, a weak outlet pressure signal is amplified by a lever, the valve is directly opened by operation, the opening force of the valve can be adjusted, the problems of over-small valve operation force and high debugging difficulty can be solved, and the function of the demand valve is realized; meanwhile, the valve core adopts a complete balance type structure, the acting force of the change of the intake pressure on the valve core is eliminated, the valve opening is enlarged, and the sufficient output flow is ensured.

The operation of the direct acting demand valve is exemplified below.

Referring to fig. 4, it shows the working process schematic diagram of the present invention during inspiration.

As can be seen, the outlet is connected to the patient breathing mask, and when the patient exhales, a certain negative pressure is generated in the breathing mask and is transmitted to the air outlet of the valve. Under the action of negative pressure, the air suction valve 303 is opened first, and is transmitted into the concave cavity at the upper part of the valve body 400 through the vertical hole in the valve body 400 to act below the diaphragm 206.

The negative pressure and the air pressure generated by the communication between the upper part of the diaphragm 206 and the atmosphere through the side hole of the valve upper cover 101 generate pressure difference between the upper part and the lower part of the diaphragm 206, and the pressure generated by the atmosphere is higher than the negative pressure, so that the diaphragm 206 is pushed to move downwards. The metal disk at the center of the lower portion of the diaphragm 206 drives the power point at the tail of the primary lever 221, the primary lever 221 rotates downward around the pivot short pin 219, and the force is amplified. The power point at the tail part of the secondary lever 217 is matched with the middle part of the primary lever 221, is a resistance point of the primary lever 221, acts on the power point at the tail part of the secondary lever 217 on the resistance point of the primary lever 221, and drives the secondary lever 217 to rotate downwards around the fulcrum long pin shaft 216.

By loosening and tightening the adjusting jackscrew 215, the fit clearance between the secondary lever 217 and the valve guide rod 205 can be adjusted, the idle stroke between the diaphragm 206 and the primary lever 221 is eliminated, the idle stroke serves as a resistance point of the secondary lever 217 and is matched with the top of the valve guide rod 205 to extrude the valve guide rod 205, and the acting force is amplified again. Since the axial force of the valve stem 202 is fully balanced, the valve stem 202 is driven to open downward by the amplified force overcoming the pre-set force of the spring.

The inlet air enters from the inlet, passes through the opening of the opening valve, enters the upper concave cavity of the valve body 400 through the air passage between the valve guide rod 205 and the valve seat 204, is guided into the lower concave cavity of the valve body 400 through the vertical hole in the valve body 400, passes through the hollow hole of the exhalation valve flap 302, opens the air suction valve 303, is output from the outlet, and is delivered to the patient.

The induced force of the vertical pressure of the diaphragm 202 is amplified and balanced with the biasing force of the spring 213. The magnitude of the negative pressure for opening the valve is directly related to the pre-tightening elastic force of the spring 213. The magnitude of the pre-tightening spring force of the spring 213 can be adjusted by adjusting the piston 209, so that the required negative pressure value for opening the valve can be adjusted.

When the patient stops breathing, the pressure at the air outlet is restored to the atmospheric pressure, as shown in fig. 2, the inspiration valve 103 returns to the original closed state, the pressure difference generated above and below the diaphragm 206 disappears, the valve rod 202 is reset under the driving of the elastic force of the spring 213, the valve is closed, and the air supply is stopped. The diaphragm 206, the valve guide 205, and the lever mechanism are simultaneously reset to return to the initial state.

Referring to fig. 5, it shows the working process of the present invention during expiration.

When a patient exhales, the exhaled air enters the concave cavity at the lower part of the valve body 400, and due to the closing of the inspiration valve 303, the inner ring of the exhalation valve flap 302 is blown up under the action of the exhalation pressure, and the exhaled air is exhausted to the atmosphere through the hollow hole at the edge of the valve lower cover 301. The gas can be supplied and cut off according to the requirements of the patients in a cycle.

Referring to fig. 6-8, artificial respiration can be performed by the present device when the patient is unable to breathe spontaneously.

As can be seen from FIG. 6, when the button 105 is manually pressed, the center cap 106 pushes the diaphragm 206 to move downward forcibly through the relief spring 107, thereby opening the demand valve. After the air supply is finished, as shown in fig. 7, the button 105 is released, the movable sleeve 103 is reset under the action of the reset spring 104, and the button 105, the safety spring 107 and the center cap 106 are reset to return to the initial state. The valve rod 202 is reset under the driving of the elastic force of the spring, the valve is closed, and the air supply is stopped. Under the action of the residual air pressure in the patient body, the residual air pressure acts on the inspiration valve 303 and the expiration valve 302 in turn, and the expiration valve 302 is blown open to exhaust the residual air to the atmosphere.

When manual air supply is performed by pressing the button 105 with manual breath, if the air supply pressure reaches the required air supply pressure and then continues to rise beyond the air supply requirement, as shown in fig. 8, the air supply pressure pushes the diaphragm 206 and the center cap 106 back, overcomes the elastic force of the safety spring 107, resets the diaphragm 206 and the center cap 106, closes the valve, and stops air supply, so as to prevent the patient from being injured due to excessive manual air supply pressure.

The direct-acting valve scheme of the embodiment adopts a structure that two-stage levers are connected in series to amplify the inductive force of the diaphragm and drive the valve to open, the two-stage levers are reasonably arranged, the structural layout is realized, and the operation reliability is higher; different lever ratios can be selected according to different operating force requirements, and the valve is suitable for different air inlet pressures; meanwhile, a cone valve rod type structure is adopted to increase the sealing force and improve the sealing effect of the valve.

In the scheme of the embodiment, a balanced valve core structure is adopted, so that the influence of the change of the air inlet pressure on the work of the valve is eliminated. The opening negative pressure value of the valve is stable, the flow is stable, the output performance of the valve is not affected by the inlet and the outlet, the opening of the valve can be larger, and the flow of the valve can be larger.

In the scheme of the embodiment, the assembly clearance is eliminated by adjusting the jackscrew, the stroke of the lever is fully utilized, and the valve is ensured to have enough opening and sufficient output flow.

Still adopt adjusting piston and lock nut, sealing washer, the regulation structure that the cooperation of spring pad constitutes in this example scheme for the opening negative pressure value of valve can conveniently be adjusted, reaches best function and effect, eliminates parts machining error's influence, and the debugging is more convenient, and production efficiency is high.

Finally, it should be noted that the present solution is not limited to the above-mentioned embodiments, but various modifications and changes may be made within the scope of the appended claims or their equivalents, according to design requirements and other factors, such as the lever position, form and arrangement of the lever seat, the arrangement of the inlet and outlet positions, the arrangement of other valve core structures, the structural form of the regulating piston, the combination and disassembly of parts, etc.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that the foregoing embodiments and descriptions are provided only to illustrate the principles of the present invention without departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A direct-acting type medical demand valve is characterized by comprising a valve body, a valve core assembly arranged in the valve body, an upper valve bonnet assembly, a lower valve bonnet assembly, a two-stage series lever, a diaphragm and a pressure regulating spring assembly, wherein the upper valve bonnet assembly is connected with the upper part of the valve body in a matched mode; the valve core assembly is arranged in the valve body through the pressure regulating spring assembly and is in contact fit with the diaphragm through the two-stage series lever, the air pressure sensed by the diaphragm is amplified through the two-stage series lever, and the valve is operated to open and close; the lower valve cover assembly is arranged at the lower end of the valve body and is matched with the valve core assembly.

2. A direct-acting medical demand valve according to claim 1, wherein the diaphragm is a rubber flexible diaphragm with a wave shape, and a metal disc is attached to the center of the lower portion.

3. The direct-acting medical demand valve according to claim 1, wherein the two-stage series lever comprises a primary lever and a secondary lever, and a power point at the tail of the secondary lever is matched with the middle part of the primary lever and is a resistance point of the primary lever.

4. The direct-acting medical demand valve according to claim 3, wherein the head of the secondary lever is provided with a hinge shaft hole as a fulcrum, the tail end power point is provided with a screw hole at the middle side close to the fulcrum as a resistance point.

5. The direct-acting medical demand valve according to claim 3, wherein the secondary lever is provided with a regulating jackscrew and is matched with the top of a valve guide rod in the valve core assembly as a resistance point of the secondary lever.

6. The direct-acting medical demand valve according to claim 3, wherein the head of the primary lever is provided with a hinge shaft hole as a fulcrum, the tail end power point is provided with a resistance point at the middle side close to the fulcrum.

7. The direct-acting medical demand valve according to claim 1, wherein the valve upper cover assembly mainly comprises a central cap, a movable sleeve, a safety spring, a button, a screw cap, a return spring and a valve upper cover, the safety spring is arranged in a central concave cavity of the central cap, the central cap is arranged in the movable sleeve, the button is in a round cap shape, an upper edge part is covered and arranged above the movable sleeve, a lower central concave cavity is attached to the safety spring, the safety spring is screwed into the movable sleeve by the button in a threaded manner, the return spring is arranged in a lower annular cavity of the movable sleeve, the movable sleeve is arranged in the screw cap, and the upper button is screwed into the central cavity of the valve upper cover together in a threaded manner.

8. The direct-acting medical demand valve according to claim 1, wherein the lower valve cover assembly mainly comprises a lower valve cover, a breathing valve flap, an inhalation valve flap and a valve flap screw; the valve screw penetrates into the air suction valve and is screwed into a central screw hole of the exhalation valve clack in a threaded manner to fix the air suction valve; the exhalation valve flap is then placed in the recess in the lower valve cover.

9. The direct-acting medical demand valve according to claim 1, wherein the valve core assembly mainly comprises a valve rod, a valve seat seal, a valve seat and a valve guide rod, wherein the valve seat seal is embedded in an inner cavity at the lower part of the valve seat; the valve guide rod is arranged in a circular hole in the center of the valve seat, the lower part of the valve guide rod is matched with the upper end of the valve rod to be mutually extruded to transmit lever power, and the non-full-circle valve guide rod is matched with the circular hole in the center of the valve seat to form an air passage.

10. The direct-acting medical demand valve according to claim 1, wherein the pressure regulating spring assembly comprises a lock nut, a regulating piston, a seal ring, a spring washer and a valve rod spring; the sealing ring and the spring pad are arranged in the adjusting piston, and the adjusting piston is fixed by a locking nut and matched with the valve rod spring.