Untitled record

Positive pressure air respirator

Technical field

[0001] The present invention relates to a personal protective air respirator for fire rescue use, and more particularly to an air respirator for use by an escaper in emergency situations such as fire, dust and toxic gas on site.

Background technique

[0002] A positive pressure air breathing apparatus is used by firefighters and rescue personnel to prevent inhalation of harmful smoke, toxic gases, suspended substances in the air, or an oxygen-deficient atmosphere during fire extinguishing and rescue operations. Air respirator. Positive pressure air respirator can effectively prevent harmful toxic gas outside the mask from intruding into the hood. It has high safety and reliable protection performance. It mainly includes compressed air bottle, bottle head pressure reducing valve, piggyback plate and comprehensive In the hood, a full-face hood is provided with an air supply valve for supplying breathing air into the hood. The air supply valve opens or closes as the user breathes, so that the decompressed air can be used for breathing through the mask. The air supply valve's air supply stability and respiratory resistance are very important for the comfort and safety of the entire air breathing apparatus.

[0003] The air supply valve is one of the key components of a positive pressure air breathing apparatus, and it directly relates to the use performance of the air breathing apparatus and the user's breathing smoothness and safety. Chinese utility model patent 89212025.7 discloses a "positive pressure breathing apparatus positive pressure mechanism", which is mainly composed of a diaphragm, a liner, a rocker, an intake valve, and a pressure spring, and when the user inhales air, inhales negative The pressure-driven diaphragm and the lever move downwards together, and the diaphragm moves downwards and pushes the rocker to open the air inlet valve. The supply valve inputs air into the mask. This structure is used to push the diaphragm in sequence by means of suction negative pressure. , Lever and Joystick to open the intake valve block and supply air to the hood. There are many linkage mechanisms, low sensitivity, and need special training; in particular, the air supply is to make the air supply valve block produce a slant gap clearance through the joystick deflection. The supply, the seal is not strict, prone to leakage, both the waste of fresh air, but also may cause the infiltration of harmful gases. The opening or closing of the air supply valve in the above structure depends on the position of the rocker. When the respirator is in a non-use state, the rocker may become unstable due to movement or placement of the mask, which may still cause the air intake valve not to be tightly sealed. And there is a leak. Chinese utility model patent No. 200920126137.6 also discloses a "positive air respirator supply valve", which also includes a diaphragm, a piston, a piston body, a return spring and a transmission mechanism. When the diaphragm is used, the diaphragm acts on one end of the piston through a transmission mechanism. The other end of the piston is connected to the valve head. The valve head controls the opening or closing of the valve port. Although the structure has good sealing performance and the structure is compact, the transmission mechanism of the control valve head is complicated, the transmission resistance and the valve head are closed and opened. The thrust is large; therefore, the breathing resistance is relatively large, and the crowd is restricted, thereby affecting its practicability; at the same time, in the non-use condition, the valve head is effectively locked, and valve leakage is easily formed. Utility model content

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a positive pressure type air respirator whose mask air supply valve not only has a sensitive action, a small breathing resistance, but also has a good sealing performance. Achieve reliable sealing and locking.

[0005] In order to solve the above technical problems, the positive pressure type air breathing apparatus of the present invention comprises a back plate assembly and a gas bottle assembly fixed on the back plate assembly. The gas bottle assembly is provided with a pressure reducing valve assembly and a face mask. The air supply hose leads to an air supply valve of a respirator. The air supply valve of the respirator is installed on a mask. The air supply valve of the respirator includes a body of the air supply valve, and is fixedly mounted on the air supply valve body through an air supply valve top cover. On the diaphragm, an air guide tube slide seat is fixed on the air supply valve body, an air guide tube is slidably installed on the air guide tube slide seat, and an air supply seal gasket is provided on the outer end of the air guide tube. Through the seal seat is mounted on the air tube slide seat; the air tube slide seat is sealed with a gas supply pipe joint, the air supply passage on the air supply pipe joint passes through the air seal gasket to the gas guide tube; the inner end of the air guide tube and the air supply pull rod The outer ends are connected, and the inner end of the air supply pull rod is movably connected to the locking hook. A gas supply extension spring is installed between the locking hook and the air supply valve body; a locking plate is fixedly installed on the air supply valve body, The locking plate is provided with a locking hole, the locking hook The hook portion corresponds to the position of the lock hole; an air supply lever is hingedly supported on the air supply valve body, and the other end of the air supply lever opposite to the hinge support end is connected to the diaphragm; and the air supply lever is in contact with the outer end of the air supply pull rod. Connected; in the air supply valve body is also provided with a locking hook push rod, the front end of the locking hook push rod corresponding to the locking hook, the locking hook push rod and the air supply valve body is provided with a hook return rod return spring; A bypass valve stem is supported on the air guide tube slide, an inner end of the bypass valve stem is connected with a seal seat, and an outer end of the bypass stem is connected with a bypass valve hand wheel. The bypass valve handle The wheel is screwed onto the air tube slide.

[0006] In the above structure, the respirator supply valve on the mask of the positive pressure type air respirator is provided with an air supply gasket at the outer end of the air guide tube, and the air guide tube is slidably supported on the air guide tube slide seat. The air guide tube reciprocally slides in the axial direction. When the outer end of the air tube is separated from the air supply seal, a ventilation gap is formed. When the two are attached, the air path is closed. In this case, the air tube and the seal are constructed. In the valve type structure, a reliable seal ring line is formed between the air guide tube nozzle and the air supply gasket, which not only makes the air supply valve pass through smoothly and has little breathing resistance, greatly improves the comfort of use, but also closes the seal tightly, and has good protection performance. A reliable closing or opening of the air supply valve is achieved. In addition, the lever swinging fulcrum is formed due to the hinged air supply lever on the air supply valve body, and the other end of the air supply lever is connected to a diaphragm reciprocally inflated with the user's breath, and the pressure in the air supply valve during exhalation is increased. The diaphragm makes the diaphragm move outwards, and the diaphragm pushes the air tube close to the air supply gasket to cut off the gas path through the air supply lever; When inhaling, the diaphragm moves inwards, and the air tube makes the outlet of the air guide tube leave the air supply gasket by means of the air supply extension spring, forming a supply air gap between the two, and fresh air provides fresh air for the user through the space. The force amplification effect of the air lever, the easy breathing action can promote the air tube movement through the lever action, effectively improve the sensitivity of the air tube, the air tube movement is flexible, and the breathing resistance is reduced. Also, since the locking plate is fixed on the air supply valve body, the locking plate is provided with a locking hole, and the hook portion of the locking hook can just snap into the locking hole. When the air supply valve is in a non-use state, the lock hook is pushed before the push rod Move the hook of the locking hook into the locking hole of the locking plate, and the locking hook sticks the air pipe tightly to the air supply gasket through the air supply pull rod, so that the air supply valve is in a closed state, and effective sealing and locking are realized. When the air supply valve needs to enter the use state, the inwardly agitated diaphragm touches the top of the hook of the locking hook, the hook of the locking hook disengages from the locking hole, and enters a normal breathing air supply state, and the mechanism can achieve locking. The utility model is closed, easy to open, compact and convenient to use. In the air supply valve of the utility model, the bypass valve stem connecting the air supply seal gasket is supported on the air guide tube slide seat, and the emergency valve is screwed The valve-opening handwheel can enable the bypass valve stem to drive the seal seat and the air supply seal on the seal valve seat away from the air guide tube. The new air in the compressed air bottle can be smoothly introduced into the mask for human breath without air conduction. Gasket structure composed of the control valve, so that when the valve fails, the user can still ensure the intake of fresh air in a critical environment, thus greatly enhancing the safety and reliability of use. The respirator supply valve of the utility model has the advantages of exquisite design, flexible and reliable action, small breathing resistance and safe and reliable use.

[0007] According to a further embodiment of the present invention, the pressure reducing valve assembly is installed at the bottle mouth of the gas cylinder assembly, and a high pressure air interface and a low pressure air interface are disposed on the valve body of the pressure reducing valve assembly. The high-pressure air interface communicates with the residual gas display alarm device; the low-pressure air interface is connected in parallel with the mask air supply hose and the other gas supply pipe. The structure can promptly remind the user of the compressed air remaining in the cylinder, thereby protecting the user's safety; and in the emergency, the two can share a compressed gas cylinder and implement his rescue.

[0008] In a further embodiment of the present invention, a digital display device is mounted on the mask. The user can mask the window to see important information such as the use of gas cylinders without having to look down to ensure user safety.

[GG09] In a preferred embodiment of the present invention, the locking hook is provided with a waist-shaped hole, the inner end of the air supply pull rod is locked in the waist-shaped hole of the locking hook, and the pull rod compression spring is supported on the inner end of the air supply pull rod; The air supply lever is hinged on the air supply valve body through a lever support; the air supply lever seat is mounted on the diaphragm, and the air supply lever is connected to the air supply lever seat. The shape of the hole on the locking hook and the compression spring of the tension rod can ensure that the air tube and the air supply gasket are tightly attached during exhalation, so as to improve the sealing performance. The structure also improves the assembly performance and is easy to manufacture. assembly. The structure is simple and reasonable, easy to manufacture and assembly.

[0010] According to a further embodiment of the present invention, an annular air supply passage is provided on the air guide tube slide seat, a seal ring is installed on both sides of the annular air supply passage, and the air supply tube joint passes the seal. The ring is sealedly mounted on the air guide tube slide, and the air supply passage of the air supply tube connector is communicated with the air supply passage on the air tube slide seat. The sealing structure is simple and reasonable, and flexible gas supply is provided to the gas supply valve in multiple directions through the gas supply pipe joint.

[0011] According to a further embodiment of the present invention, the by-pass valve stem is sealed and sealed on the air-bearing tube slide seat via a valve stem, a by-pass compression spring is mounted on the bypass valve stem, and the by-pass valve stem is There is a positioning ratchet pawl mechanism between the bypass valve handles. Reasonable structure, easy to use and operate.

According to a preferred embodiment of the present invention, the backboard assembly includes a backboard body, a backplane rib is disposed at a symmetrical line position of the backboard body, and a cylinder upper support is respectively disposed on the backplane ribs. And a lower supporter of the gas bottle; a hand-carrying hand hole is arranged on the back plate body; a collision-preventing pad is fixedly installed at the lower end of the back plate body; and a belt and a gas bottle fixing belt are also connected to the back plate body; the waist belt passes the lumbar pad The buckle belt is connected with a waist cushion, and a shoulder cushion is connected with the shoulder belt; one end of the shoulder belt is connected with the upper end of the back board body, and the other end of the shoulder belt is connected with the belt. In the above structure, the back plate ribs are arranged on the back plate body, and the gas bottle upper bearing and the gas bottle lower bearing are arranged on the ribs of the back plate. On the other hand, the setting of the ribs of the back plate not only improves the back plate Stiffness and strength provide reliable support for the fixation of the cylinders; and the arrangement of the backplane ribs can reduce the weight and material of the backplane, effectively reduce the user's exercise burden, and improve the user's work comfort and working time; on the other hand, The upper and lower cylinders and the cylinder fixing band on the back plate ribs can form a reliable fixation of the gas cylinder. The setting of the upper and lower cylinders of the gas cylinder changes the uncertainty of the support and fixation of the gas bottle by the traditional back plate, so that the The fixing of the gas bottle is more reliable, and the shaking of the gas cylinder on the back plate during use is avoided, which not only increases the safety performance but also improves the comfort of use. Moreover, shoulder cushions and waist cushions are added at the corresponding positions of the shoulder straps and the belts to avoid the urgency of the shoulder straps and belts and the human body, and to ensure the full fit of the straps and the belts to the human body and to prevent the cylinders from shaking. The discomfort caused by the bearer's center of gravity is more comfortable and more comfortable to wear. In addition, since the crash pad is fixedly installed at the lower end of the backboard body, and the bottle hand hole is also arranged on the back plate body, the lifting hand hole on the back plate body is convenient for the user to lift and wear the air breathing apparatus. It is easy to grasp and hold, and the crash pad located at the lower end of the back plate body can effectively reduce the impact shock to the ground when removing the back plate body, and prevent the gas cylinder from moving on the back plate. The gas bottle body and the bottle head pressure regulating valve cause unsafe hidden dangers to the ground impact damage. Therefore, the backboard assembly of the utility model not only facilitates the lifting and is comfortable to wear, but also can form an effective protection for the cylinder body and the backboard, and the use is more safe.

In a further embodiment of the present invention, the back plate body is provided with a bottle head valve seat, and the bottle head valve seat is located above the crash pad. It can reliably fix and effectively protect cylinders and bottle valves.

[0014] In a preferred embodiment of the present invention, the shoulder has two straps which are respectively located on two sides of the back plate body; the strap ends of the waist straps extend to both sides of the back plate body, respectively, on the belt. The belt end is equipped with a buckle; the waist cushion penetrates from the belt position on the side of the back board body to the other belt on the back board body. The shoulder straps are evenly weighted, light and comfortable to carry; they are firmly fixed and comfortable. In a further embodiment of the head with a new Sk, the two belt ends of the gas cylinder fixing band respectively extend to both sides of the back plate body, one end of the gas cylinder fixing band is a connecting ring, and the other end of the gas cylinder fixing band is connected with bristles The buckle; the position of the holder on the gas cylinder corresponds to the position of the cylinder fixing band. The gas bottle can be reliably supported and fixed, and it is easy to fix.

Description of the drawings

[0016] The positive pressure air breathing apparatus of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0017] FIG. 1 is a schematic structural view of a specific embodiment of a positive pressure air breathing apparatus according to the present invention;

[0018] FIG. 2 is a schematic structural view of a ventilator air supply valve in a positive pressure air breathing apparatus according to the present invention; [0019] FIG. 3 is a respirator air supply valve shown in FIG. 2 in a locked non-use condition; Schematic;

[0020] FIG. 4 is a schematic structural view of a specific embodiment of a backplane assembly in a positive pressure air breathing apparatus according to the present invention;

[0021] FIG. 5 is an enlarged schematic view of the cross-sectional structure of AA in the structure shown in FIG. 4;

[0022] FIG. 6 is an enlarged schematic view of the cross-sectional structure of B-B in the structure shown in FIG.

[0023] In the figures, 1 cylinder assembly, 2 - back panel assembly, 201 - back panel body, 202 - waist cushion buckle, 203 - belt, 204 - waist cushion, 205 - cylinder fixing belt, 2 inches 6—snag buckle, 207—shoulder cushion, 208—strap, 209—cylinder upper bearing, 210—connecting ring, 211—back rib, 212—lifting bottle hand hole, 213—buckle , 214—Cylinder Lower Support, 215—Bottle Valve Support, 2ie—Crash Pad, 3—Pressure Relief Valve Assembly, 4 One He Supply Air Valve, 5—Face Mask Air Supply Hose, 6— Respiratory air supply valve, 601 - air supply valve body, 602 - lock hook push rod return spring, 603 - lock hook push rod, 604 - gas supply tension spring, 605 - diaphragm, 6 〇 6 - clamp hoops, 6 〇7—Gas supply valve top cover, 608—Top cover partition plate, 609—Top cover air hole, 610—Air supply lever seat, 611—Locking hook, 612—Pull pressure spring, 613—Air supply lever, 614—Lathe waist Holes, 615 - air supply pull rods, 616 - lever supports, 617 - air tube slides, 618 - air tubes, 619 - slide seals, 620 - air supply seals, 621 - seal seats, 622 - bypass Compression spring, 623—bypass valve handwheel, 624—side Stem, 625 - retainer, 626 - bypass top cover, 627 - stem seal, 628 - supply pipe fitting, 629 - lock hole, 630 - lock plate, 631 - mask valve seal, 7 - mask, 8- Digital display, 9 a residual display alarm.

detailed description

[0024] A positive pressure air breathing apparatus as shown in FIG. 1 includes a backboard assembly 2 on which a gas cylinder assembly 1 is bundled and fixed, and a decompression chamber is installed on the cylinder port of the gas cylinder assembly 1 . In the valve assembly 3, a high-pressure air interface and a low-pressure air interface are disposed on the valve body of the pressure reducing valve assembly 3, and the high-pressure air interface communicates with the residual gas display alarm device 9. The low-pressure air interface is provided with a face mask air supply in parallel. The pipe 5 and his rescue gas pipe 4 . The compressed air in the gas cylinder assembly 1 passes through the pressure reducing valve assembly 3 and the mask air supply hose 5 leads to the respirator supply valve 6, and the respirator supply valve 6 is mounted on the mask 7 through the mask valve seal ring 631. One end of the mask air supply hose 5 is connected to the low pressure air port of the pressure reducing valve assembly 3, and the other end is connected to the air supply pipe joint 628 of the respirator supply valve 6. The mask 7 is provided with a digital display 8 which is a HUD head-up digital display located below the mask window of the mask 7 .

[0025] FIG. 2 shows a breathing air supply valve 6 of a positive pressure type air respirator, which includes an air supply valve body 601 made by injection molding. The lower end of the air supply valve body 601 has a tubular structure through which the tubular portion passes. The O-ring on it seals the air supply valve to the mask body. A diaphragm 605 is disposed on an upper mouth portion of the air supply valve body 601, an air supply valve top cover 607 is further provided above the mouth of the air supply valve body 601, and the diaphragm 6 〇 5 is clamped by the air supply valve top cover 607. The air valve body 601 is mounted on the air supply valve body 610, and the air supply valve body 601 and the air supply valve top cover 607 thereon are fixedly connected to each other through the clamp hoops 6 〇 6. A plurality of top cover air holes 609 are provided at the top of the air supply valve top cover 6 〇 7, and a top cover partition 608 is installed inside the air supply valve top cover 607.

[0026] An airway tube slide 617 is fixedly installed at a left position of the air supply valve body 601. The air tube slideway 617 has a substantially tubular structure, and its centerline is perpendicular to the centerline of the tube portion of the air supply valve body 601. An annular air supply passage is provided outside the middle position of the air duct slide 617 . The bottom of the air supply channel is provided with a plurality of vent holes that pass through the wall of the air guide tube. Both sides of the annular air supply channel are equipped with a slide seat seal ring 619, and the slide seat seal rings 61g are all 〇-type seal rings. The air supply pipe joint 628 is sealedly installed on the air guide pipe seat 7 through two slide sealing rings 619. The tubular air supply passage of the air supply pipe joint 628 is communicated with the annular air supply passage of the air guide pipe slide seat 617, and the air supply pipe joint is connected. The centerline of the tubular air supply passageway of the 628 is perpendicular to the centerline of the tube portion of the air duct slide 6 7. The air supply connector 628 communicates with the pressure regulator on the compressed air bottle through the air supply hose.

[0027] An air pipe 618 is slidably installed at the core position of the air pipe sliding seat 617. The air pipe 618 is a circular tubular metal pipe, and a gas supply gasket 62 is provided at the outer end of the air pipe 618 at the outer end of the nozzle. The air supply gasket 620 is movably mounted on the air tube slide 617 through a seal seat 621 . The seal seat 621 is fixedly attached to the left end of the bypass valve stem 624, and the bypass stem 624 is sealed and mounted on the right side of the tube bore of the air guide slide 7 through the stem seal 627. A bypass valve handwheel 623 is threadedly connected to the air tube slide 617, and the bypass valve rod 624 is fixedly connected to the bypass valve handwheel 623 through the clamping spring 63⁄4. The bypass valve handwheel 623 is equipped with an external end. The bypass top cover 6 is equipped with a bypass compression spring 622 on the bypass valve stem 4, and a common ratchet pawl for positioning and locking is provided between the bypass valve stem 624 and the bypass valve handle wheel 3 like. mechanism. Turning the bypass valve handwheel 623 can drive the bypass stem 624 to move axially; the ratchet pawl mechanism can lock the bypass valve stem or the bypass valve handwheel 623 in a certain position.

[0028] The inner end of the air pipe eiS is connected with a gas supply rod 615, and the outer end of the rod 5 of the gas supply rod is bent to 90. , and from the tube through the corresponding snap hole in the wall of the air tube 61S tube extends to the outside of the wall. A waist hole is provided in the locking hook 611, and the inner end of the air supply rod 615 is movably connected to the waist hole of the locking hook 611. The front end of the locking hook is a hook portion. The rear end of the locking hook is in a “T” shape. The lever compression spring 612 is supported at the end of the air supply rod 615 at the inner end of the waist hole, and the other end of the tension rod compression spring 612 is supported. In the position of the T-shaped portion of the locking hook 611, the tension bar compression spring 612 is a cylindrical compression spring which always presses the air supply pull rod 615 toward the right end position of the waist hole. An air supply extension spring 604 is installed between the rear end of the locking hook 611 and the left position of the air supply valve body 601. The air supply extension spring 604 forms a pull-off air supply gasket 620 to the air guide tube 618 through the air supply pull rod 615. trend. An air supply lever 613 is hingedly supported on the air supply valve body 601 via a lever support 616. This structure facilitates assembly and maintenance, and can obtain a relatively large lever ratio, which is advantageous for reducing respiratory resistance. The other end of the air supply lever 613 opposite to the hinged support end is connected to the air supply lever seat 610, and the air supply lever seat 610 is mounted on the diaphragm 605 through the diaphragm backing plate. The air supply lever 613 is in close contact with the bent end of the air supply pull rod 615 at a position corresponding to the outer end of the air supply pull rod 615 . When exhaling, the diaphragm 5 bulges outward and drives the air supply lever 613 to lift. During the swing of the air supply lever 613 about the hinge point, the air supply lever 613 pushes the bent end of the air supply lever 615, and then pushes the air guide lever 613 forward. The end of the air pipe 618 is affixed to the air supply gasket 620 to achieve sealing; when the air is sucked, the diaphragm 605 is driven downward and drives the air supply pull rod 613 to hem, and at this time, under the action of the air supply tension spring 604, the air supply tension spring 604, pulling the air pipe 618 away from the air supply gasket 620 through the locking hook 611 and the air supply pull rod 615, so that a ventilation gap is created between the air pipe 618 nozzle and the air supply gasket 620, fresh air from the air supply pipe joint 628. An annular airway on the airway slide 617 enters the airway tube 618 and supplies air into the mask.

As shown in FIG. 3, a lock plate 630 is fixed on the air supply valve body 601. The lock plate 630 is located below the diaphragm 605, and the lock hook 611 is located below the lock plate 630. A locking hole 629 is provided on the locking plate 630. The position of the locking hole 629 corresponds to the position of the hook of the locking hook 611, so that the hook of the locking hook 611 can be hooked into the locking hole 629. The air supply valve body 601 is further provided with a lock hook push rod 603 movable in the axial direction, and a lock hook push rod return spring 602 is provided between the lock hook push rod 603 and the air supply valve body 6 〇 1 . The front end of the lock hook push rod 603 is provided with a shoulder portion, and the rear end of the lock hook push rod 603 is extended to the outside of the air supply valve body 601 . When the latch hook push rod return spring 602 is pushed inwardly from the rear end of the latch hook push rod 603 and compressed, the shoulder portion of the latch hook push rod 603 pushes the lower end of the "T"-shaped portion of the latch hook 611, and the latch hook 611 is deflected. The hook of the locking hook 611 is hooked into the locking hole 629 of the locking plate 630. Since the locking hook 611 is locked in the axial position of the locking hook 629 hooked into the locking hole 629, the nozzle of the air tube 618 is tightly attached to the air supply gasket 620, and the air supply extension spring 604 cannot pull the air tube 618 away from the air supply gasket 620. The air supply lever 613 can also not press the air tube 618 further toward the air supply gasket 620 , and the air respirometer air supply valve can only be in a non-operating state. When the respirometer air supply valve is used for the first time, the diaphragm 605 is in contact with the hook end of the locking hook 611 during the lower drum, and the hook end of the locking hook is pressed away from the locking hole 629, and the locking hook 611 is decoupled. The air supply valve starts continuous normal operation. When the use is stopped, the hook lever 603 is pushed to hook the hook of the locking hook into the locking hole 629 again.

[0031] FIG. 4 shows a positive pressure air respirator back plate assembly 2, which includes a back plate body 201, which is formed by injection molding. In FIG. 4 , the front side is the cylinder mounting surface of the back plate assembly, and the reverse side is the negative side that is in contact with the human body. The upper portion of the back plate body 201 has an arcuate shape that is curved outwards corresponding to the shoulder. The lower portion of the back plate body 201 is curved inwardly corresponding to the position of the waist so that the longitudinal direction of the back plate body 201 is S-shaped. The board body 201 has a narrow upper and lower structure so as to meet the ergonomic design concept and is more comfortable to wear.

[0032] The back plate body 201 adopts a symmetrical structure. A back plate rib 211 is disposed at the symmetrical line position of the back plate body 201, and an edge rib is also provided on the rim of the back plate body 201. A gas bottle upper support 209 is disposed at the back of the back plate rib 211, and a gas bottle lower support 214 is disposed at the waist of the back plate rib 211. As shown in FIG. 5, the top surface of the lower support 214 of the gas cylinder is an arc surface, and the top surface of the upper support 209 of the gas cylinder is also an arc surface. The radius of the circular arc surface and the outer cylinder surface of the cylinder body are the same. Anastomosis for good contact with the cylinder body. A lifting bottle hand hole 2 2 is arranged on both sides of the back plate rib 211 of the back plate body 201 at the connecting position of the shoulder portion and the waist portion. The lifting bottle hand hole 2 2 is a through hole, and the periphery of the through hole is also provided. The hand hole flange not only enhances the strength and rigidity of the back plate body 201 but also enhances the comfort of the hand hole.

[0033] As shown in FIG. 6, a crash pad 216 is set and fixed at a top position of the lower end of the back plate body 201. The crash pad 216 is made of a rubber material with elasticity. A bottle head valve seat 215 is disposed above the crash pad 216. The bottle head valve seat 215 disposed on the back plate body 201 is used for fixedly installing the compressed air bottle head valve, and makes the bottle head valve The lowest point is still above the bottom end of the crash pad 216, thereby protecting the bottle head valve from being damaged by the impact.

[0034] The waist belt 203 is fastened to both sides of the waist position of the backboard body 201. Both ends of the waistband 203 extend toward both sides of the backboard body 201, respectively, and buckles 213 that can be mutually inserted are installed at the belt ends of the waistbands 2 and 3. A waist cushion 2〇4 is provided on the back side of the back panel body 2〇1 corresponding to the waist belt 203. The waist cushion 2〇4 is penetrated from one side of the waist belt to the other side of the waist belt, and the waist cushion 204 is provided. Both ends are connected to the waistband 203 by means of a lumbar cushion strap 202 on the lumbar cushion 2/4.

A strap 208 is fastened to the upper end of the backboard body 201, and the other end of the shoulder strap 208 is sewn and connected to the extension of the corresponding side waistband 2〇3. There are two shoulder straps 208. Two shoulder straps 2〇8 are respectively located on two sides of the backboard body 201. On both shoulder straps 2〇8, shoulder pads 2〇7 are provided. Both the waist cushion 204 and the shoulder cushion 207 are made of flame-retardant cloth and flame-retardant polypropylene.

[0036] A gas cylinder fixing band 205 is fastened on both sides of the shoulder position of the back plate body 201, and the two band ends of the gas cylinder fixing band 205 extend to both sides of the back plate body 2 〇 1, respectively. A metal connecting ring 210 is connected to one end of the fixing band 2〇5, and a buckle 2〇6 is connected to the other end of the gasket fixing band 2〇5 to facilitate fastening of the gas bottle. The gas cylinder upper support 2 〇 9 is located on the connecting line of the gas cylinder fixing tape 2 〇 5 on both sides, so that the position of the gas cylinder upper support 2 〇 9 corresponds to the position of the gas cylinder fixing tape 205 .

[0037] The foregoing merely describes the technical solutions of the present invention by non-limiting technical examples. Improvements and equivalent replacements by those skilled in the art still fall within the protection scope of the present invention.