CN113827104A

CN113827104A - Primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature

Info

Publication number: CN113827104A
Application number: CN202111363312.5A
Authority: CN
Inventors: 孟庆楷
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-11-17
Filing date: 2021-11-17
Publication date: 2021-12-24

Abstract

The invention relates to the technical field of coffee machine boilers, and discloses a primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature, which comprises a base, wherein a hollow pot body is arranged on the base, an inner pot with an opening top is fixedly connected to the top of the inner wall of the pot body, and a heating cavity for heating the inner pot is formed between the outer surface of the inner pot and the inner wall of the pot body; the first water adding hole is formed in one side of the top of the pot body and communicated with the heating cavity so as to add water into the heating cavity; the heating element is arranged on the base and can heat the bottom of the pot body; the air release hole is arranged on one side of the top of the pot body, which is far away from the water filling hole, and is communicated with the inside of the heating cavity. According to the invention, through the arrangement of the air leakage hole and the blocking block, the device can control the boiling point of water in the heating cavity by controlling the pressure in the heating cavity, so that the temperature of the internal boiler can be accurately controlled.

Description

Primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature

Technical Field

The invention belongs to the technical field of coffee machine boilers, and particularly relates to a primary-secondary double-layer coffee machine boiler capable of controlling temperature by utilizing air pressure.

Background

The boiler of the Italian coffee machine is responsible for heating water temperature, is the key for controlling the stability of extraction temperature, and the semi-automatic coffee machine sold and used in the market can be basically divided into: the primary-secondary boiler (also called a heat exchange boiler), the double boiler and the multiple boilers are three types, the single boiler is generally used for household, and most of the common semi-automatic coffee machines are mainly used as the primary-secondary boiler.

The main boiler and the sub boiler work on the principle of 'water-proof heating'. The main boiler heats water to about 120 ℃, and the auxiliary boiler is heated to about 92 ℃ in a hot water heat conduction mode, but because the heating module is arranged on the main boiler, and the water temperature is mainly controlled by the main boiler, the temperature is not easy to control during extraction, and the fluctuation of the boiler temperature can directly influence the quality of products, so that the design of the main-auxiliary double-layer coffee machine boiler utilizing air pressure to control the temperature is necessary to solve the problem.

Disclosure of Invention

The invention aims to: in order to solve the problems in the background art, the invention provides a primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature.

In order to achieve the purpose, the invention provides the following technical scheme: a primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature comprises a base, wherein a hollow boiler body is arranged on the base, an inner boiler with an opening at the top is fixedly connected to the top of the inner wall of the boiler body, and a heating cavity used for heating the inner boiler is formed between the outer surface of the inner boiler and the inner wall of the boiler body; the first water adding hole is formed in one side of the top of the pot body and communicated with the heating cavity so as to add water into the heating cavity; the heating element is arranged on the base and can heat the bottom of the pot body; the hole loses heart, the hole of disappointing is seted up at pot body top and is kept away from one side of the water filling hole and is linked together with heating intracavity portion, and the internal portion of pot is gaseous can be discharged to the external world through the hole of disappointing, just it is downthehole to lose heart to be provided with to be the jam piece that coniform structure and pointed end down and can reciprocate to lose heart.

Further, top one side fixedly connected with of the pot body is located disappointing hole directly over and is the support of "concave" style of calligraphy structure of standing upside down, the block slides to peg graft on the support and has and is vertical axial threaded rod, the bottom fixed connection of threaded rod is at the piece top of stopping up, be connected with the threaded sleeve who cup joints on the threaded rod through the screw through the bearing rotation on the support, be provided with on the support and be used for driving the threaded sleeve and carry out pivoted slewing mechanism, can drive the threaded rod through the cooperation of screw when the threaded sleeve rotates and go up and down to drive the jam piece and carry out corresponding lift in disappointing the hole, thereby play the effect that changes jam piece and disappointing hole opening interval, reach the effect of adjusting the speed that loses heart.

Furthermore, the hole has been seted up at the top center department of support, just the threaded rod passes through the hole and alternates on the support, the stroke groove has been seted up along its length direction on the circumferential surface of threaded rod, the inner wall of hole is formed with the stopper of pegging graft in the stroke groove to form the block sliding connection of threaded rod in the hole.

Furthermore, slewing mechanism includes the motor of fixed mounting at the support top, the output shaft of motor is up and its end fixedly connected with driving gear, the telescopic circumference fixed surface of screw thread has cup jointed the driven gear who meshes with the driving gear mutually, and the driving gear can drive driven gear through the cooperation of tooth and carry out corresponding rotation to realize driving screw thread sleeve pivoted purpose.

Further, the inner wall of interior pot is installed and is used for carrying out the temperature sensor who monitors to the inside temperature of interior pot, the top fixed mounting of base has the LED display screen, still install the PLC controller on the base, the input of PLC controller links to each other with temperature sensor's output electrical property in order to be used for receiving the temperature signal that temperature sensor monitored, the output of PLC controller and the input electric connection of LED display screen, with can with temperature signal converts the temperature value into and shows through the LED display screen, and like this, the staff can know the inside temperature variation of interior pot through observing the LED display screen.

Further, the heating member includes the electric heating board of fixed mounting at the base top, just the top heating surface at the electric heating board is installed to the pot body, and produced heat can transmit the water to heating the intracavity through pot body bottom after the electric heating board ohmic heating, plays the effect to water heating.

Furthermore, a water feeding hole II communicated with the inside of the inner pot is formed in the top of the pot body, and sealing covers are inserted into the water feeding hole I and the water feeding hole II through threads so as to conveniently seal the water feeding hole I and the water feeding hole II during working.

Further, the steam extraction pipe that is linked together with heating intracavity portion is seted up at the top of the pot body, the one end fixed mounting that the pot body was kept away from to the steam extraction pipe has the steam stick that is used for the bubble of suckleing to can utilize the produced steam in heating chamber, further improve the device's practicality.

Furthermore, the top of the pot body is provided with air adding holes communicated with the inside of the inner pot, the top of the pot body is inserted with a water outlet pipe, one end of the water outlet pipe, which is positioned in the pot body, extends into the inner pot, and a distance smaller than 1cm is formed between the end of the water outlet pipe, which is positioned in the pot body, and the bottom of the inner pot, which is positioned in the inner pot, is pressurized through the air adding holes, so that water can enter the water outlet pipe to be led out under the action of pressure, one end of the water outlet pipe, which is positioned outside the pot body, is provided with a filter assembly for filtering the water, the filter assembly comprises a filter box I sleeved at one end of the water outlet pipe through threads and a filter box II sleeved on the filter box I through threads, the bottom of the filter box I is provided with four arc-shaped holes distributed in an equidistant annular array, and the bottom of the filter box II is densely provided with a plurality of filter holes, so that the water is not stranded but drips, and each dripping water can be fully contacted with the coffee, thereby improving the taste of the coffee.

Further, the inner wall fixedly connected with annular plate one of gas pocket and the annular plate two that is located directly over the annular plate one, be provided with the ball sealer of contradicting in annular plate two inner peripheral side bottoms between annular plate one and the annular plate two, the top of annular plate one is provided with the spring, just the top of spring is contradicted in the ball sealer bottom, plays the effect of sealing the gas pocket, and the air in avoiding interior pot can be let out through the gas pocket.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, through the arrangement of the air release hole and the blocking block, water in the heating cavity can be heated to boil and can play a role in heating the inner boiler, the boiling of the water in the heating cavity is a phenomenon of violent liquid gasification, gas generated by heating can be continuously discharged outwards through the air release hole so as to release the pressure in the heating cavity, at the moment, because the upper diameter and the lower diameter of the blocking block are different, the size of a gap between the surface of the blocking block and the inner wall of the air release hole can be changed through the lifting of the blocking block in the air release hole, so that the effects of regulating the gas discharge speed in the air release hole and controlling the pressure in the heating cavity are achieved, the device can control the boiling point of the water in the heating cavity through the pressure in the heating cavity, and further accurately control the temperature of the inner boiler.

2. According to the invention, through the arrangement of the temperature sensor and the LED display screen, a worker can know the temperature change in the inner pot by observing the LED display screen, so that the blocking block can be correspondingly lifted and the pressure in the heating cavity can be changed according to the process requirements, and the purpose of reasonably controlling the temperature is achieved.

3. According to the invention, due to the arrangement of the filtering component, the first filtering box can enable water to uniformly flow around, and the second filtering box is densely provided with the plurality of filtering holes at the bottom, so that the water is not reserved in a strand, but is dropped, and each dropping water can fully contact with coffee, thereby improving the taste of the coffee.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic perspective view of the present invention;

FIG. 2 is a schematic top view of the structure of the present invention;

FIG. 3 is a schematic view of the cross-sectional structure taken along the direction A-A of the present invention;

FIG. 4 is an enlarged view of the structure at B in FIG. 3 according to the present invention;

FIG. 5 is a disassembled view of the inner structure of the pot body and the inner pot of the present invention;

FIG. 6 is an enlarged view of the structure at C of FIG. 5 according to the present invention;

FIG. 7 is an exploded view of the support structure of the present invention;

FIG. 8 is an exploded view of the first and second annular plates of the present invention;

FIG. 9 is an exploded view of the filter assembly of the present invention;

in the figure: 1. a base; 2. a pan body; 3. an inner pot; 4. a heating cavity; 5. a first water adding hole; 6. a heating member; 61. an electrical heating plate; 7. a temperature sensor; 8. an air release hole; 9. a support; 10. a threaded rod; 11. a plugging block; 12. a threaded sleeve; 13. a stroke slot; 14. a hole; 15. a limiting block; 16. a motor; 17. a driving gear; 18. a driven gear; 19. a steam exhaust pipe; 20. a steam wand; 21. a water feeding hole II; 22. a sealing cover; 23. air holes are added; 24. a water outlet pipe; 25. a first annular plate; 26. a second annular plate; 27. a sealing ball; 28. a spring; 29. a filter assembly; 30. a first filter box; 31. a second filter box; 32. an arc-shaped hole; 33. a filtration pore; 34. a needle valve; 35. and an LED display screen.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments; all other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 9, the primary-secondary double-layer coffee maker boiler using air pressure to control temperature according to the present embodiment includes a base 1, a hollow pot body 2 is disposed on the base 1, an inner pot 3 with an open top is fixedly connected to the top of the inner wall of the pot body 2, and a heating cavity 4 for heating the inner pot 3 is formed between the outer surface of the inner pot 3 and the inner wall of the pot body 2; the water feeding hole I5 is formed in one side of the top of the pot body 2, communicated with the interior of the heating cavity 4 and used for feeding water into the heating cavity 4; the heating element 6 is arranged on the base 1, and can heat the bottom of the pot body 2; the air release hole 8 is arranged on one side of the top of the pot body 2, which is far away from the water filling hole 5, and is communicated with the inside of the heating cavity 4, the air in the pot body 2 can be discharged to the outside through the air release hole 8, and the blocking block 11 which is in a conical structure, the tip of which is downward and can move up and down is arranged in the air release hole 8, through the design, water can be injected into the heating cavity 4 through the water filling hole 5, and the pot body 2 is heated through the heating element 6, so that the water in the heating cavity 4 can be heated and boiled and can heat the inner pot 3, the boiling of the water in the heating cavity 4 is a phenomenon of violent gasification of liquid, the air generated by the heating can be continuously discharged outwards through the air release hole 8, so as to drop the pressure in the heating cavity 4, at the moment, because the upper diameter and the lower diameter of the blocking block 11 are different, the size of a gap between the surface of the inner wall of the air release hole 8 can be changed through the lifting of the blocking block 11 in the air release hole 8, thereby reach the effect of regulation and control gas exhaust speed in the gas escape hole 8 and control pressure in the heating chamber 4 for the device can be through controlling the boiling point of its inside water to the inside pressure in heating chamber 4, and then the temperature of accurate control inside boiler.

Specifically, referring to fig. 4, 6 and 7, in order to lift the blocking block 11 to change the amount of exhaust in the air release hole 8, in some embodiments, a support 9 located right above the air release hole 8 and having an inverted "concave" shape is fixedly connected to one side of the top of the pot body 2, a threaded rod 10 having a vertical axial direction is inserted into the support 9 in a clamping and sliding manner, the bottom end of the threaded rod 10 is fixedly connected to the top of the blocking block 11, a threaded sleeve 12 sleeved onto the threaded rod 10 through a thread is rotatably connected to the support 9 through a bearing, a rotating mechanism for driving the threaded sleeve 12 to rotate is arranged on the support 9, when the threaded sleeve 12 rotates, the threaded rod 10 is driven to rotate correspondingly through the matching of the thread, and since the threaded rod 10 is connected into the hole 14 in a clamping and sliding manner, the threaded rod cannot rotate and can only slide along the axial direction of the hole 14, therefore, the threaded rod 10 can lift along with the rotation of the threaded sleeve 12 and drive the blocking block 11 to correspondingly lift in the air release hole 8, so that the effect of changing the opening distance between the blocking block 11 and the air release hole 8 is achieved, and the effect of adjusting the air release speed in the heating cavity 4 is achieved.

The specific connection mode between the threaded rod 10 and the hole 14 is as follows, the hole 14 is formed in the center of the top of the support 9, the threaded rod 10 penetrates through the hole 14 on the support 9, the stroke groove 13 is formed in the circumferential surface of the threaded rod 10 along the length direction of the threaded rod, and the limiting block 15 inserted in the stroke groove 13 is formed on the inner wall of the hole 14 so as to form clamping sliding connection of the threaded rod 10 in the hole 14, so that the threaded rod can only move up and down in the hole 14 and cannot rotate.

In order to drive the threaded sleeve 12 to rotate, in some embodiments, it is provided that the rotating mechanism includes a motor 16 fixedly mounted on the top of the bracket 9, an output shaft of the motor 16 faces upward, and a driving gear 17 is fixedly connected to an end of the motor 16, a driven gear 18 engaged with the driving gear 17 is fixedly sleeved on a circumferential surface of the threaded sleeve 12, when the output shaft of the motor 16 rotates, the driving gear 17 can be driven to rotate, and the driving gear 17 can drive the driven gear 18 to rotate correspondingly through matching of teeth, so as to drive the threaded sleeve 12 to rotate.

Preferably, please refer to fig. 1 and 3, the inner wall of the inner pot 3 is provided with a temperature sensor 7 for monitoring the internal temperature of the inner pot 3, the top of the base 1 is fixedly provided with an LED display screen 35, the base 1 is further provided with a PLC controller, the input end of the PLC controller is electrically connected with the output end of the temperature sensor 7 to receive the temperature signal monitored by the temperature sensor 7, the output end of the PLC controller is electrically connected with the input end of the LED display screen 35 to convert the temperature signal into a temperature value and display the temperature value through the LED display screen 35, thus, the worker can know the internal temperature change of the inner pot 3 by observing the LED display screen 35, so as to correspondingly lift the plugging block 11 according to the process requirements and change the pressure in the heating chamber 4, and achieve the purpose of reasonably controlling the temperature.

As for the specific mode of heating the pot body 2, as shown in FIG. 3, the heating element 6 comprises an electric heating plate 61 fixedly installed on the top of the base 1, and the pot body 2 is installed on the top heating surface of the electric heating plate 61, the heat generated after the electric heating plate 61 is electrified and heated can be transferred to the water in the heating cavity 4 through the bottom of the pot body 2, so as to heat the water, and the design is more reasonable.

Specifically, 2 tops of the pot body are provided with two water filling holes 21 communicated with the inside of the inner pot 3, so that water can be filled into the inner pot 3 through the two water filling holes 21, and meanwhile, the sealing covers 22 are inserted into the water filling holes 5 and the two water filling holes 21 through threads, so that the water filling holes 5 and the two water filling holes 21 are conveniently sealed at the working time.

As shown in fig. 1, the top of the pot body 2 is provided with a steam exhaust pipe 19 communicated with the inside of the heating chamber 4, and one end of the steam exhaust pipe 19 far away from the pot body 2 is fixedly provided with a steam rod 20 for frothing milk so as to utilize the steam generated by the heating chamber 4, thereby further improving the practicability of the device.

In order to lead out water in the inner pot 3 for brewing coffee, in some embodiments, it is provided that the top of the pot body 2 is provided with a gas filling hole 23 communicated with the inside of the inner pot 3, the top of the pot body 2 is inserted with a water outlet pipe 24, so that the inside of the inner pot 3 can be pressurized through the gas filling hole 23, water can enter the water outlet pipe 24 to be led out under the action of pressure, one end of the water outlet pipe 24, which is positioned in the pot body 2, extends into the inner pot 3 and forms a distance smaller than 1cm with the bottom of the inner wall of the inner pot 3, one end of the water outlet pipe 24, which is positioned outside the pot body 2, is provided with a filter assembly 29 for filtering water, the filter assembly 29 comprises a filter box I30 sleeved at one end of the water outlet pipe 24 through threads and a filter box II 31 sleeved on the filter box I30 through threads, the bottom of the filter box I30 is provided with four arc-shaped holes 32 distributed in an equidistant annular array, the water flows around uniformly, the bottom of the second filter box 31 is densely provided with a plurality of filter holes 33, the water is not reserved as a strand, but drips, each drip can be fully contacted with the coffee, and the taste of the coffee is improved.

In addition, a needle valve 34 may be mounted on the outlet pipe 24 to control the outlet water velocity and the stability of the water flow.

Meanwhile, in order to ensure the tightness of the inner pot 3, in some embodiments, it is provided that a first annular plate 25 and a second annular plate 26 located right above the first annular plate 25 are fixedly connected to the inner wall of the air adding hole 23, a sealing ball 27 abutting against the bottom of the inner periphery of the second annular plate 26 is arranged between the first annular plate 25 and the second annular plate 26, a spring 28 is arranged at the top of the first annular plate 25, and the top end of the spring 28 abuts against the bottom of the sealing ball 27, so that when water is injected into the inner pot 3 through the air adding hole 23, the sealing ball 27 is pressed downward by the water to be separated from the second annular plate 26, so that the water can flow through the air adding hole 23, and after the water is injected, the sealing ball 27 abuts against the second annular plate 26 through the elastic action of the spring 28, so as to achieve the effect of closing the air adding hole 23, and prevent the air in the inner pot 3 from being leaked through the air adding hole 23.

In the device, all electric devices and drivers matched with the electric devices are arranged, and all driving parts, namely power elements, the electric devices and adaptive power supplies, are connected through leads by a person skilled in the art, and specific connecting means refer to the above expression that the electric devices are electrically connected in sequence, and detailed connecting means thereof are well known in the art.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A primary and secondary double-layer coffee machine boiler utilizing air pressure to control temperature is characterized by comprising:

the pot comprises a base (1), wherein a pot body (2) with a hollow inner part is arranged on the base (1), an inner pot (3) with an opening top is fixedly connected to the top of the inner wall of the pot body (2), and a heating cavity (4) for heating the inner pot (3) is formed between the outer surface of the inner pot (3) and the inner wall of the pot body (2);

the first water adding hole (5) is formed in one side of the top of the pot body (2) and communicated with the interior of the heating cavity (4) so as to add water into the heating cavity (4);

the heating element (6) is arranged on the base (1), and can heat the bottom of the pot body (2);

disappointing hole (8), disappointing hole (8) are seted up and are kept away from with water hole (5) one side and be linked together with heating chamber (4) are inside at pot body (2) top, and the inside gas of the pot body (2) can be discharged through disappointing hole (8) to the external world, just be provided with in disappointing hole (8) and be the circular cone type structure and most advanced down and can reciprocate block up piece (11).

2. The primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature according to claim 1, characterized in that a support (9) which is located right above an air leakage hole (8) and is of an inverted concave-shaped structure is fixedly connected to one side of the top of the pot body (2), a threaded rod (10) which is vertical and axial is inserted in a sliding mode in the support (9), the bottom end of the threaded rod (10) is fixedly connected to the top of a plugging block (11), a threaded sleeve (12) which is sleeved on the threaded rod (10) through threads is connected to the support (9) in a rotating mode through a bearing, and a rotating mechanism which is used for driving the threaded sleeve (12) to rotate is arranged on the support (9).

3. The primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature according to claim 2, characterized in that a hole (14) is formed in the center of the top of the support (9), the threaded rod (10) is inserted into the support (9) through the hole (14), a stroke groove (13) is formed in the circumferential surface of the threaded rod (10) along the length direction of the threaded rod, and a limit block (15) inserted into the stroke groove (13) is formed on the inner wall of the hole (14).

4. The primary-secondary double-layer coffee machine boiler utilizing air pressure temperature control according to claim 2, characterized in that the rotating mechanism comprises a motor (16) fixedly installed on the top of the bracket (9), the output shaft of the motor (16) faces upwards, the tail end of the motor is fixedly connected with a driving gear (17), and the circumferential surface of the threaded sleeve (12) is fixedly sleeved with a driven gear (18) engaged with the driving gear (17).

5. The primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature according to claim 1, characterized in that a temperature sensor (7) for monitoring the internal temperature of the inner pot (3) is installed on the inner wall of the inner pot (3), an LED display screen (35) is fixedly installed at the top of the base (1), a PLC controller is further installed on the base (1), the input end of the PLC controller is electrically connected with the output end of the temperature sensor (7) to receive the temperature signal monitored by the temperature sensor (7), and the output end of the PLC controller is electrically connected with the input end of the LED display screen (35) to convert the temperature signal into a temperature value and display the temperature value through the LED display screen (35).

6. A primary and secondary double-layered coffee machine boiler using air pressure temperature control according to claim 1, wherein said heating element (6) comprises an electric heating plate (61) fixedly installed on the top of the base (1), and said pot (2) is installed on the top heating surface of the electric heating plate (61).

7. The primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature according to claim 1, characterized in that a second water feeding hole (21) communicated with the inside of the inner pot (3) is formed at the top of the pot body (2), and a sealing cover (22) is inserted into the first water feeding hole (5) and the second water feeding hole (21) through threads.

8. The primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature according to claim 1, characterized in that a steam exhaust pipe (19) communicated with the inside of the heating cavity (4) is arranged at the top of the boiler body (2), and a steam rod (20) for milk frothing is fixedly arranged at one end of the steam exhaust pipe (19) far away from the boiler body (2).

9. The primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature according to claim 1, characterized in that an air adding hole (23) communicated with the inside of the inner pot (3) is formed in the top of the pot body (2), an water outlet pipe (24) is inserted into the top of the pot body (2), one end of the water outlet pipe (24) positioned in the pot body (2) extends into the inner pot (3) and forms a space smaller than 1cm with the bottom of the inner wall of the inner pot (3), one end of the water outlet pipe (24) positioned outside the pot body (2) is provided with a filter assembly (29) for filtering water, the filter assembly (29) comprises a first filter box (30) sleeved on one end of the water outlet pipe (24) through threads and a second filter box (31) sleeved on the first filter box (30) through threads, the bottom of the first filter box (30) is provided with four arc-shaped holes (32) distributed in an equidistant annular array, and a plurality of filter holes (33) are densely formed at the bottom of the second filter box (31).

10. The primary-secondary double-layer coffee machine boiler utilizing air pressure to control temperature according to claim 9, wherein a first annular plate (25) and a second annular plate (26) located right above the first annular plate (25) are fixedly connected to the inner wall of the air charging hole (23), a sealing ball (27) abutting against the bottom of the inner peripheral side of the second annular plate (26) is arranged between the first annular plate (25) and the second annular plate (26), a spring (28) is arranged at the top of the first annular plate (25), and the top end of the spring (28) abuts against the bottom of the sealing ball (27).