Beer barrel with automatic pressure maintaining and cooling functions

Abstract

The invention relates to the technical field of liquid packaging containers, in particular to an automatic pressure maintaining and cooling beer can. Comprising a barrel body, a barrel cover is installed at the upper end of the barrel body, the barrel cover comprises a cover body fixedly connected to an opening of the barrel body and a wine spear arranged in the center of the cover body, and a pressure balancing device used for supplementing pressure is arranged in an inner cavity of the barrel body. The pressure balancing device comprises an air tank with a telescopic trigger rod, an air bag used for driving the trigger rod and an air bag support connected between the air tank and the air bag, and the air bag support is connected to the wine spear in a clamped mode. According to the beer barrel, automatic pressure maintaining and cooling can be achieved by releasing gas in the gas tank, so that the temperature and the carbon dioxide content of beer in the barrel are kept at a proper level, and the taste of the drunk beer is improved; the sealed air bag detects the pressure in the barrel body and controls the action of the air tank at the same time, the action is reliable and free of leakage, and lubricating oil pollution can be eradicated.

Description

Technical Field

[0001] The invention relates to the technical field of liquid packaging containers, and more specifically, to an automatic pressure-maintaining and temperature-reducing beer can. Background Art

[0002] A beer keg is a container for holding beer, usually used for large gatherings or group dinners. The original material used was wood, and modern packaging materials also use aluminum alloy, tinplate or plastic. In view of the particularity of beer drinks, the barrel body of the beer keg is usually a drum or spindle shape with a tight structure and can withstand a certain pressure. The barrel mouth valve is installed at the upper end of the barrel body. During filling, the barrel mouth valve is connected to the filling machine to inject beer into the barrel body. During consumption, the barrel mouth valve is connected to the beer spear to release the beer in the barrel body. For example, another Chinese patent 2024213824348 of the applicant discloses "A fresh-keeping explosion-proof beer barrel", with the announcement number CN222311401U. The explosion-proof beer barrel includes a barrel body made of PET blow molding, and a barrel cover is installed on the upper end of the barrel body. The barrel cover includes a cover body fixedly connected to the opening of the barrel body, and a beer spear arranged in the center of the cover body. The beer spear includes a valve cover installed in the center of the cover body, a core tube slidably inserted in the center of the valve cover, and a large spring seat is installed at the lower end of the core tube. A large spring is arranged between the large spring seat and the valve cover; a valve hole is arranged in the center of the valve cover, and a valve plate is installed in the valve hole. The upper end of the core tube is fixedly connected to the valve plate, and a pressure relief valve is installed in the center of the valve plate. The beer barrel can add a pressure relief valve to the PET beer barrel without changing the production mold of the existing barrel body, so as to limit the pressure within the upper limit of the barrel body pressure resistance and eliminate the hidden danger of barrel explosion. However, the function of the pressure relief valve of the beer keg is limited to relieving and reducing the pressure when the pressure in the keg increases due to the increase of external temperature or shaking or impact, and it cannot automatically replenish the pressure when the pressure in the keg decreases to maintain a certain pressure level. Beer kegs are usually used for large gatherings or large gatherings. They are used for a long time and often need to be sealed for a period of time before drinking again. Although the keg has sufficient pressure after each beer filling by the production plant through the injection of carbon dioxide gas, a certain amount of beer and carbon dioxide will be released each time the consumer drinks through the beer spear, causing the pressure in the keg to decrease, affecting the taste of the beer.

[0003] Another Chinese patent 2023223576848 discloses "A gas pressurizing device for a beverage container", with the authorization announcement number CN220578916U. The device includes a gas cylinder and a top cover. The gas cylinder is provided with a cylindrical gas nozzle for controlling gas outlet. A piston is slidably arranged in the top cover. A trigger is arranged between the piston and the gas nozzle. The piston can push the gas nozzle to open through the trigger. The trigger includes a ring-shaped body, which is sleeved and fixed on the outer peripheral surface of the gas nozzle. The body has two relatively arranged and elastic pins, and the pins have a limiter. The limiter is against the gas outlet end of the gas nozzle to limit the body from moving downward relative to the gas nozzle. When the air pressure in the container is reduced, the trigger is used to push the control valve to move, open the gas cylinder to release gas, and ensure that a certain pressure is maintained in the container. However, the trigger in the device can only be inserted into the cylindrical gas nozzle from the upper end of the cylindrical gas nozzle of the gas cylinder when it is installed. The installation direction of the trigger is consistent with the force direction of the trigger gas nozzle, and it is easy to trigger the gas nozzle by mistake to cause gas leakage in the gas cylinder. In addition, the piston mechanism used to drive the trigger member in the device has problems such as poor sealing, easy leakage of gas in the piston causing malfunction, and food contamination caused by the lubricating oil in the piston. Summary of the invention

[0004] The purpose of the present invention is to provide a beer keg with automatic pressure-maintaining and temperature-reducing function which is simple to assemble and highly reliable, thereby avoiding the problem of the triggering member accidentally triggering the gas cylinder during assembly, and the triggering member driving mechanism operates reliably without leakage, thereby preventing the lubricating oil from contaminating the beer.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] The present invention discloses an automatic pressure-maintaining and temperature-reducing beer keg, comprising a keg body, a keg cover being installed at the upper end of the keg body, the keg cover comprising a cover body fixedly connected to the opening of the keg body, and a beer spear arranged at the center of the cover body, a pressure balancing device for supplementing pressure being arranged in the inner cavity of the keg body, the pressure balancing device comprising a gas tank with a telescopic trigger rod, an air bag for driving the trigger rod, and an air bag bracket connected between the gas tank and the air bag, the air bag bracket being clamped on the beer spear.

[0007] Through this solution, the beer keg can automatically maintain pressure and cool down by releasing the gas in the gas tank. The sealed air bag detects the pressure in the barrel and controls the movement of the gas tank at the same time. The movement is reliable and leak-free and can prevent lubricating oil pollution.

[0008] Preferably, the airbag bracket is a barrel-shaped structure with a cover plate on the upper end and an open lower end, and the cover plate is provided with a mounting hole; the lower end of the airbag bracket is provided with an open clamping ring adapted to the neck slot of the gas tank, and the airbag is a columnar airbag adapted to the inner cavity of the airbag bracket, a connecting piece adapted to the mounting hole is fixedly provided at the upper end of the airbag, and a trigger clamping plate adapted to the trigger rod is provided at the lower end of the airbag.

[0009] This solution can facilitate the assembly of the airbag and the airbag bracket, so that the assembled airbag is in a working position capable of triggering the air tank.

[0010] Preferably, the mounting hole is a circular hole passing through the cover plate, and grooves passing through the cover plate are symmetrically arranged on both sides of the circular hole; the connecting piece is a cylinder adapted to the mounting hole, and protrusions are symmetrically arranged on both sides of the upper end of the cylinder, and the cross-sectional shape of the protrusions is adapted to the grooves on both sides of the mounting hole.

[0011] This solution can facilitate the assembly of the airbag and the airbag bracket, make the installation of the airbag directional, and facilitate the orientation of the triggering clamping plate toward the triggering rod of the gas tank.

[0012] Preferably, the trigger card plate is perpendicular to the axis of the airbag, and a card plate center hole is provided in the center of the trigger card plate, the diameter of the card plate center hole is smaller than the trigger rod, and a snap fit for the trigger rod is provided between the card plate center hole and the side of the trigger card plate, and the other side of the trigger card plate corresponding to the snap fit is fixedly connected to the edge of the airbag through a support plate.

[0013] With this solution, the trigger clamping plate is clamped into the trigger rod of the gas tank from the side during assembly, which can avoid accidental triggering of the gas tank and causing gas leakage.

[0014] Preferably, the side wall of the airbag is a flexible bellows-shaped structure.

[0015] Through this solution, when the pressure in the barrel changes, the airbag produces axial telescopic movement.

[0016] Preferably, a coil spring is provided in the side wall of the airbag.

[0017] Through this solution, the reliability and accuracy of the airbag action can be improved.

[0018] Preferably, the upper end of the airbag bracket is connected to the wine spear clamp ring through the upper extension section of the bracket, the wine spear clamp ring is eccentrically arranged with the airbag bracket, and the wine spear clamp ring is used to clamp onto the lower end of the wine spear.

[0019] Through this solution, the airbag bracket is connected to the wine spear, the structure is compact and can be used in conjunction with the existing wine spear.

[0020] Preferably, a downwardly extending clamp section is provided on one side of the wine spear clamp, the clamp section is parallel to the axis of the wine spear clamp, the lower end of the clamp section is fixedly connected to the upper end of the airbag bracket, and the side surface of the clamp section is fixedly connected to the upper section of the bracket.

[0021] Through this solution, the airbag bracket is located on one side of the wine spear, which does not hinder the work and use of the traditional wine spear.

[0022] Due to the adoption of the above structure, the beer keg can automatically maintain pressure and cool down by releasing the gas in the gas tank, so that the temperature and carbon dioxide content of the beer in the keg are maintained at appropriate levels, thereby improving the taste of drinking beer; the sealed air bag detects the pressure in the keg body and controls the movement of the gas tank at the same time, the movement is reliable and leak-free, and lubricating oil pollution can be eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a partial cross-sectional structural schematic diagram of an embodiment of the present utility model.

[0024] Figure 2 It is a three-dimensional structural schematic diagram of the cover body and the pressure balancing device.

[0025] Figure 3 It is a schematic diagram of the three-dimensional structure of the airbag bracket.

[0026] Figure 4 It is a schematic diagram of the cross-sectional structure of the airbag bracket.

[0027] Figure 5 It is a top view structural schematic diagram of the airbag bracket cover.

[0028] Figure 6 It is a schematic diagram of the three-dimensional structure of the airbag.

[0029] Figure 7 It is a schematic diagram of the partial structure of the gas tank.

[0030] Figure 8 It is a schematic diagram of the planar structure of the trigger card. DETAILED DESCRIPTION

[0031] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0032] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0033] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0034] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0035] like Figure 1As shown, the automatic pressure-maintaining and temperature-reducing beer keg described in the present invention includes a barrel body 1, which can be made of PET plastic blow molding, or can be made of thin aluminum alloy or tinplate. A barrel cover is installed on the upper end of the barrel body 1, and an extension tube 8 is arranged in the inner cavity of the barrel body 1, and the extension tube 8 extends from the barrel cover to the bottom of the barrel body 1. The barrel cover includes a cover body 2 fixedly connected to the opening of the barrel body 1, and a beer spear arranged in the center of the cover body 2. The beer spear is a beer discharging valve for a draft beer barrel, which is used to discharge beer from a draft beer barrel. There are many structural forms in the prior art. Each beer spear can be used in conjunction with a corresponding dispenser to achieve the purpose of discharging beer. Its structure and working principle are prior art and will not be described one by one here.

[0036] like Figure 1 , Figure 2 As shown, a pressure balancing device for supplementing pressure is provided in the inner cavity of the barrel body 1, and the pressure balancing device includes a gas tank 3 with a telescopic trigger rod 31, an air bag 4 for driving the trigger rod 31, and an air bag bracket 5 connected between the gas tank 3 and the air bag 4. The air bag bracket 5 is made of plastic injection molding, and the air bag bracket 5 is clamped on the beer spear when in use. In order to supplement the loss of carbon dioxide in beer, high-pressure carbon dioxide or dry ice is stored in the gas tank 3. Of course, other gases can also be stored in the gas tank 3 as needed. Figure 7 As shown, the upper end of the gas tank 3 is provided with a collar 32 for mounting the airbag bracket 5, and the collar 32 is a raised circular ring structure, and a concave neck groove is formed at the connection between the outer ring of the collar 32 and the tank body, and a push-type gas tank valve is arranged at the center of the collar 32, and a trigger rod 31 with a hollow structure is installed on the push-type gas tank valve. The structures of the push-type gas tank valve and the gas tank body are both existing technologies and will not be described in detail here.

[0037] When there is no external force, the push-type gas tank valve is closed and the gas in the gas tank will not leak; when the trigger rod 31 is pressed, the push-type gas tank valve is opened and the gas in the gas tank is released through the hole in the center of the trigger rod 31. When the gas tank 3 releases carbon dioxide into the barrel 1, it can not only add carbon dioxide to the beer, but also cool the beer through gas expansion, thereby improving the taste of the beer.

[0038] like Figure 3 , Figure 4 As shown, the airbag bracket 5 is a barrel-shaped structure with a cover plate 51 at the upper end and an open lower end, and a mounting hole 52 is provided on the cover plate 51; Figure 4 , Figure 5 As shown, the mounting hole 52 is a circular hole penetrating the cover plate 51, and grooves 521 penetrating the cover plate 51 are symmetrically arranged on both sides of the circular hole; the mounting hole 52 and the grooves 521 symmetrically arranged on both sides thereof together constitute a special-shaped hole penetrating the cover plate 51. Four triangular stoppers 57 are arranged around the special-shaped hole.

[0039] In addition, the lower end of the airbag support 5 is provided with an open snap ring 53 adapted to the neck slot of the neck ring 32 of the gas tank 3. The open snap ring 53 is integrally injection molded with the airbag support 5 and is perpendicular to the axis of the airbag support 5. The inner diameter of the open snap ring 53 is adapted to the neck slot so that the open snap ring 53 can be stably clamped on the neck slot. The opening of the open snap ring 53 is slightly smaller than the diameter of the neck slot so that it can be clamped into the neck slot under a certain external force and will not fall off easily. A notch 58 is provided on the side wall of the airbag support 5 above the open snap ring 53 to allow the upper end of the gas tank 3 to enter and exit. The notch 58 can move the gas tank 3 horizontally so that the upper end of the gas tank 3 moves from the outside of the airbag support 5 to the inner cavity of the airbag support 5 when the open snap ring 53 is aligned with the neck slot of the neck ring 32 of the gas tank 3.

[0040] like Figure 6 As shown, the airbag 4 is a columnar airbag adapted to the inner cavity of the airbag bracket 5, made of plastic with good toughness, and the side wall of the airbag 4 is a flexible corrugated tube structure. A coil spring can also be arranged in the side wall of the airbag 4 to improve the reliability of the airbag action. A connector 41 adapted to the mounting hole 52 is fixedly arranged at the upper end of the airbag 4, and a trigger clamp 42 adapted to the trigger rod 31 is arranged at the lower end of the airbag 4.

[0041] With respect to the structure of the above-mentioned mounting hole 52, the connecting member 41 is a cylinder adapted to the mounting hole 52, and protrusions 45 are symmetrically arranged on both sides of the upper end of the cylinder, and the cross-sectional shape of the protrusions 45 is adapted to the grooves 521 on both sides of the mounting hole 52. In this way, the cross-sectional shape of the connecting member 41 is the same as the shape of the special-shaped hole penetrating the cover plate 51, so that the connecting member 41 can pass through the cover plate 51 from bottom to top, and the upper end of the connecting member 41 together with the protrusions 45 extend to the upper surface of the cover plate 51, and then the connecting member 41 can be prevented from being separated from the mounting hole 52 by rotating a certain angle to make the protrusions 45 deviate from the grooves 521. If the protrusions 45 deviate from the grooves 521 and pass over a block 57 and get stuck between the two blocks 57, it can play a role in positioning the connecting member 41 and prevent the connecting member 41 from rotating and loosening. Of course, as other embodiments of the present invention, other structural forms can also be used to connect the airbag 4 and the airbag bracket 5 together.

[0042] The triggering plate 42 is perpendicular to the axis of the airbag 4, and the triggering plate 42 moves when the airbag 4 expands and contracts along the axis. Figure 8As shown, the center of the trigger card plate 42 is provided with a card plate center hole 43, the diameter of which is smaller than the outer diameter of the trigger rod 31, but the edge of the card plate center hole 43 is provided with a notch 431, so that it can expand and be stuck on the trigger rod 31; a bayonet 432 adapted to the trigger rod 31 is provided between the card plate center hole 43 and the side of the trigger card plate 42, and the diameter of the bayonet 432 is slightly smaller than the outer diameter of the trigger rod 31 and is symmetrical with the notch 431. The trigger rod 31 can be slid into the card plate center hole 43 by aligning the bayonet 432 with the trigger rod 31 and applying a little force, so that the trigger card plate 42 is positioned on the trigger rod 31.

[0043] like Figure 6 , Figure 8 As shown, the other side of the triggering card plate 42 corresponding to the bayonet 432 is fixedly connected to the edge of the airbag 4 through a support plate 44 .

[0044] like Figure 2 , Figure 3 As shown, the upper end of the airbag bracket 5 is connected to the wine spear clamp ring 55 through the bracket upper extension 54. The wine spear clamp ring 55 is eccentrically arranged with the airbag bracket 5, and its axis is biased to one side of the airbag bracket 5. The wine spear clamp ring 55 is provided with a buckle 551 for clamping on the lower end of the wine spear, and the buckle 551 is adapted to the clamping groove arranged on the outer wall of the wine spear. When assembling, the wine spear clamp ring 55 is put on the lower end of the wine spear until the buckle 551 is clamped into the clamping groove on the outer wall of the wine spear, as shown in FIG. Figure 2 As shown, after the wine spear clamp 55 is installed, the extension tube 8 connected to the lower end of the wine spear is still located on the central axis of the wine spear, and the airbag bracket 5 is biased to one side, which does not affect the normal use of the wine spear.

[0045] In addition, if Figure 3 As shown, a downwardly extending clamp section 56 is provided on one side of the wine spear clamp 55. The clamp section 56 and the bracket upper section 54 are both semicircular arc-shaped, with a firm structure and small space occupation. The clamp section 56 is parallel to the axis of the wine spear clamp 55, the lower end of the clamp section 56 is fixedly connected to the upper end of the airbag bracket 5, and the side of the clamp section 56 is fixedly connected to the bracket upper section 54.

[0046] like Figure 1 , Figure 2As shown, when in use, first install the airbag bracket 5 on the lower end of the wine spear 21 through the wine spear snap ring 55, then install the airbag 4 on the airbag bracket 5 through the connecting piece 41, rotate the airbag 4 so that the protrusion 45 on the connecting piece 41 is stuck between the two blocks 57, at this time, the position of the airbag 4 is fixed, and the snap opening 432 on the trigger card plate 42 at the lower end of the airbag 4 faces the notch 58 at the lower end of the airbag bracket 5. At this time, the snap opening 432 on the trigger card plate 42 and the open snap ring 53 on the airbag bracket 5 are parallel to each other and have the same opening direction, the position of the trigger card plate 42 is slightly higher than the open snap ring 53, align the neck snap ring of the gas tank 3 with the open snap ring 53, and align the root of the trigger rod 31 of the gas tank 3 with the snap opening 432 on the trigger card plate 42, move the gas tank 3 horizontally, and snap the open snap ring 53 into the neck snap ring, and snap the trigger card plate 42 into the root of the trigger rod 31 to complete the installation of the gas tank 3. When installing the gas cylinder 3 , the trigger rod 31 will be subjected to the horizontal shear force of the trigger clamping plate 42 , but there will be no longitudinal pressure, so there will be no problem of leakage of the gas cylinder 3 due to misoperation.

[0047] After the beer spear with the gas tank 3 is installed on the barrel body 1, beer and carbon dioxide are injected into the barrel body 1 through the beer spear, as in the common production process, so that the pressure in the barrel body 1 gradually increases. The pressure in the barrel body 1 increases, causing the airbag 4 to compress, and the trigger card plate 42 at the lower end of the airbag 4 to rise. At this time, since the gas tank 3 is in a closed state, the trigger rod 31 is at the top dead center. When the trigger card plate 42 rises, the trigger rod 31 does not move accordingly. The trigger card plate 42 rubs against the outer wall of the trigger rod 31 until the pressure in the barrel body 1 reaches a preset value, and the trigger rod 31 is separated from the card plate center hole 43 of the trigger card plate 42, and the card plate center hole 43 is located directly above the trigger rod 31. When the pressure in the barrel body 1 remains stable, the trigger card plate 42 is always located directly above the trigger rod 31 and will not trigger the gas tank 3.

[0048] When consumers drink beer, beer is discharged through the valve connected to the beer spear, causing the pressure in the barrel body 1 to decrease; the pressure reduction in the barrel body 1 will cause the airbag 4 to expand, and the trigger card plate 42 will be lowered. When the pressure drops to the lower limit, the lowered trigger card plate 42 will press the trigger rod 31 of the gas tank 3, open the gas tank valve, and release carbon dioxide into the barrel body 1 through the hole in the center of the trigger rod 31. Since the diameter of the card plate center hole 43 on the trigger card plate 42 is smaller than the outer diameter of the trigger rod 31, the trigger card plate 42 can push the trigger rod 31 downward when the position is lowered without being covered on the trigger rod 31. In addition, when the trigger card plate 42 presses the trigger rod 31, the card plate center hole 43 is aligned with the hole in the center of the trigger rod 31 to avoid blocking the carbon dioxide channel.

[0049] The gas tank 3 releases carbon dioxide into the barrel body 1, causing the pressure of the barrel body 1 to increase and the temperature to decrease. When the pressure of the barrel body 1 returns to the preset value, the airbag 4 contracts, the trigger card 42 rises, the trigger rod 31 is released, the trigger rod 31 returns to its original position, and the gas tank 3 is closed again, waiting for the next working cycle.

[0050] Although some specific embodiments of the present invention have been described in detail through specific embodiments, those skilled in the art should understand that the above examples are only for illustration and are not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A beer keg capable of automatically maintaining pressure and cooling down, comprising a keg body (1), a keg cover being installed at the upper end of the keg body (1), characterized in that: The barrel cover comprises a cover body (2) fixedly connected to the opening of the barrel body (1), and a wine spear arranged at the center of the cover body (2); a pressure balancing device for supplementing pressure is arranged in the inner cavity of the barrel body (1); the pressure balancing device comprises a gas tank (3) with a telescopic trigger rod (31), an air bag (4) for driving the trigger rod (31), and an air bag bracket (5) connected between the gas tank (3) and the air bag (4); the air bag bracket (5) is clamped on the wine spear.

2. The beer keg with automatic pressure-maintaining and temperature-reducing function according to claim 1, characterized in that: The airbag bracket (5) is a barrel-shaped structure with a cover plate (51) at the upper end and an open lower end, and the cover plate (51) is provided with a mounting hole (52); the lower end of the airbag bracket (5) is provided with an open clamping ring (53) adapted to the neck clamping groove of the gas tank (3); the airbag (4) is a columnar airbag adapted to the inner cavity of the airbag bracket (5); the upper end of the airbag (4) is fixedly provided with a connecting piece (41) adapted to the mounting hole (52), and the lower end of the airbag (4) is provided with a trigger clamping plate (42) adapted to the trigger rod (31).

3. The automatic pressure-maintaining and temperature-reducing beer keg according to claim 2, characterized in that: The mounting hole (52) is a circular hole penetrating the cover plate (51), and grooves penetrating the cover plate (51) are symmetrically arranged on both sides of the circular hole; the connecting piece (41) is a cylinder adapted to the mounting hole (52), and protrusions are symmetrically arranged on both sides of the upper end of the cylinder, and the cross-sectional shape of the protrusions is adapted to the grooves on both sides of the mounting hole (52).

4. The beer keg with automatic pressure-maintaining and temperature-reducing function according to claim 2 or 3, characterized in that: The trigger card plate (42) is perpendicular to the axis of the airbag (4); a card plate center hole (43) is arranged at the center of the trigger card plate (42); the diameter of the card plate center hole (43) is smaller than the outer diameter of the trigger rod (31); a bayonet adapted to the trigger rod (31) is arranged between the card plate center hole (43) and the side of the trigger card plate (42); the other side of the trigger card plate (42) corresponding to the bayonet is fixedly connected to the edge of the airbag (4) through a support plate (44).

5. The beer keg with automatic pressure-maintaining and temperature-reducing function according to any one of claims 1 to 3, characterized in that: The side wall of the airbag (4) is a flexible bellows-shaped structure.

6. The beer keg with automatic pressure-maintaining and temperature-reducing function according to claim 5, characterized in that: A coil spring is arranged in the side wall of the airbag (4).

7. The automatic pressure-maintaining and temperature-reducing beer keg according to any one of claims 2-3, characterized in that: The upper end of the airbag bracket (5) is connected to the wine spear clamp ring (55) through the bracket upper extension section (54), the wine spear clamp ring (55) is eccentrically arranged with the airbag bracket (5), and the wine spear clamp ring (55) is used to clamp the lower end of the wine spear.

8. The beer keg capable of automatically maintaining pressure and cooling according to claim 7, characterized in that: A downwardly extending clamping ring section (56) is provided on one side of the wine spear clamping ring (55), and the clamping ring section (56) is parallel to the axis of the wine spear clamping ring (55). The lower end of the clamping ring section (56) is fixedly connected to the upper end of the airbag bracket (5), and the side surface of the clamping ring section (56) is fixedly connected to the bracket upper section (54).

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