CN220885480U - Vacuum fresh-keeping box - Google Patents

Abstract

The utility model discloses a vacuum preservation box, which comprises: a case body; a box cover; the button is movably arranged on the box cover and positioned in the mounting groove, a transition cavity is formed between the button and the inner wall of the mounting groove, and the volume of the transition cavity is changed during the movement of the button; the transition cavity is communicated with the accommodating cavity through the air extraction opening, and the unidirectional flowing direction of the one-way valve is that the accommodating cavity flows to the transition cavity; the sealing piece can seal an exhaust gap between the button and the side wall of the mounting groove, and the button drives the sealing piece to move in the moving process; in the movement of the button to reduce the volume of the transition cavity, the sealing member opens an exhaust gap between the button and the side wall of the mounting groove to communicate outside air with the transition cavity; in the movement of the button to enlarge the volume of the transition chamber, the seal seals the vent gap between the button and the side wall of the mounting groove to isolate outside air from the transition chamber. The vacuum preservation box effectively solves the problem that the vacuum preservation box in the prior art is complex in structure.

Description

Vacuum fresh-keeping box

Technical Field

The utility model relates to the technical field of vacuum preservation boxes, in particular to a vacuum preservation box.

Background

Along with the continuous progress of society, the living standard of people is continuously improved, and the vacuum fresh-keeping box is used as a new convenient fresh-keeping appliance, is more and more used by people, and is continuously moved into daily life of more and more people.

The vacuum preservation box can effectively prolong the shelf life of food and prevent the food from oxidation, mildew, worm damage, decay, damp and the like. At the same time, it can also keep the original taste and nutritive value of the food. In addition, the vacuum fresh-keeping box is healthy and harmless, has good transparency, can clearly see food in the box, and is convenient for checking the freshness of the food.

The existing vacuum preservation box generally reduces the vacuum degree of the preservation box in a mode of pumping air in the box through a vacuum pump, so that the aim of preservation is fulfilled. However, in order to match with the vacuum preservation box, an electric or manual vacuum pump is required to be carried, so that the purpose of being used at any time can be achieved.

At present, the vacuum preservation boxes in the prior art are subjected to successive vacuumizing in a mode that a plurality of one-way valves are alternately opened and closed, but the structural parts are numerous, and the one-way valves are more in use, so that the part assembly structure is complex, and the assembly structure is deformed and is easy to fail.

In summary, the vacuum preservation box in the prior art has a complex structure.

Disclosure of utility model

The embodiment of the utility model provides a vacuum preservation box, which aims to solve the problem that the vacuum preservation box in the prior art is complex in structure.

In order to achieve the above object, the present utility model provides a vacuum fresh-keeping box, comprising: the box body is provided with a containing cavity; the box cover is arranged on the box body in a covering way and seals the accommodating cavity; the box cover is provided with an air extraction opening, the air extraction opening is communicated with the accommodating cavity, and a one-way valve is arranged at the air extraction opening; the box cover is provided with a mounting groove; the button is movably arranged on the box cover and positioned in the mounting groove, a transition cavity is formed between the button and the inner wall of the mounting groove, and the volume of the transition cavity is changed during the movement of the button; the transition cavity is communicated with the accommodating cavity through the extraction opening, and the unidirectional circulation direction of the one-way valve is that the accommodating cavity circulates to the transition cavity; the sealing piece is movably arranged in the limiting groove of the button, the sealing piece can seal an exhaust gap between the button and the side wall of the mounting groove, and the button drives the sealing piece to move in the moving process; in the movement of the button to reduce the volume of the transition chamber, the seal opens a vent gap between the button and a side wall of the mounting groove to communicate outside air with the transition chamber; in the movement of the button to expand the volume of the transition chamber, the seal seals the vent gap between the button and the side wall of the mounting groove to block outside air from the transition chamber.

Further, the limiting groove of the button is provided with a first limiting inner wall and a second limiting inner wall which are oppositely arranged; the spacing direction of the first limiting inner wall and the second limiting inner wall is consistent with the moving direction of the button, the first limiting inner wall faces the transition cavity, and the second limiting inner wall faces the external space; an air flow gap communicated with the outside air is formed between the sealing piece and the button; in the movement of the button for reducing the volume of the transition cavity, the sealing piece is abutted with the first limiting inner wall and is far away from the second limiting inner wall, and the air flow gap is communicated with the opened exhaust gap; in the movement of the button to expand the volume of the transition cavity, the sealing element is abutted with the second limiting inner wall and is far away from the second limiting inner wall, and the sealing element simultaneously seals the exhaust gap.

Further, the button includes: a top cover for operation, the top cover having a first limiting plate with the first limiting inner wall; the supporting seat is movably arranged in the mounting groove and is provided with a second limiting plate, and the second limiting plate is provided with a second limiting inner wall; the top cover is fixedly connected with the supporting seat, and the limiting groove is formed between the first limiting plate and the second limiting plate.

Further, the exhaust gap is formed between the outer periphery of the support seat and the side wall of the mounting groove.

Further, a plurality of limit protrusions are connected to the first limit plate, and the limit protrusions form the bottom wall of the limit groove; the first limiting plate is provided with an airflow notch at the position of the limiting protrusion.

Further, the box cover also comprises an elastic resetting piece, wherein the elastic resetting piece is connected between the supporting seat and the box cover; the elastic reset piece is compressed in the movement of the button for reducing the volume of the transition cavity; the elastic restoring piece applies elastic acting force towards the moving direction of the button to enlarge the volume of the transition cavity.

Further, the elastic reset piece is arranged in the transition cavity and is a spring.

Further, the top cover and the supporting seat are fixedly connected through pressure fusion welding; or the top cover and the supporting seat are of an integrated structure.

Further, the limiting groove is arranged corresponding to the structural shape of the mounting groove, the limiting groove is an annular groove, and the sealing element is an annular sealing ring.

Further, a balance valve is arranged on the box cover and used for communicating or isolating the accommodating cavity and the outside air.

Further, the outer Zhou Xianwei of the box cover is connected with a deformable sealing structure; when the box cover is arranged on the box body, the deformable sealing structure is positioned between the box cover and the box body and deforms so as to seal the accommodating cavity.

When the button is pressed down, the button reduces the movement of the transition cavity volume, the sealing element is upwards offset relative to the button due to the action of friction force between the sealing element and the side wall of the mounting groove and is blocked by the limiting groove of the button, the limiting groove prevents the sealing element from being excessively offset and not separating from the button, the limiting groove can drag the sealing element to move along with the button all the time, and at the moment, the exhaust gap between the button and the side wall of the mounting groove is opened. Meanwhile, the one-way valve is pressed under the action of atmospheric pressure, so that air in the transition cavity space is extruded into the outside air due to the downward pressing of the button.

In the process of button reset, the button enlarges the movement of transition chamber volume, and the sealing member is owing to the frictional force effect with the lateral wall of mounting groove, and relative button skew down this moment to extrude in the exhaust clearance between button and the lateral wall of mounting groove, make the exhaust clearance between button and the lateral wall of mounting groove is sealed. The limit groove can drag the sealing element to move all the time and seal the exhaust gap at the same time when the button is reset. Because the button starts to move upwards from the lowest point, the air pressure value in the space of the transition cavity is smaller than the air pressure value in the space of the holding cavity, so that the one-way valve is jacked up by the pressure air in the holding cavity, and the air in the holding cavity is sucked into the transition cavity due to the reset of the button. The button sealing ring is continuously deflected and reset, so that the function of unidirectional ventilation gas is achieved, the function of the button sealing ring is the same as that of the unidirectional valve, but the vacuum preservation box structurally reduces the use of one unidirectional valve, greatly simplifies the use of parts of an air extraction structure, reduces the total number of parts of a box cover component, and is simpler in structure. The simple structure of the utility model can make the assembly, the maintenance and the disassembly more efficient, avoid the failure caused by easy deformation of the assembly structure, and solve the problems of complex structure and the problems caused by complex structure of the vacuum preservation box in the prior art.

Drawings

FIG. 1 is a schematic view showing the internal structure of a vacuum fresh-keeping box according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram showing the structural cooperation of the vacuum fresh-keeping box according to the embodiment of the utility model when the button is pressed;

FIG. 3 is a schematic diagram showing the structural cooperation of the vacuum fresh-keeping box according to the embodiment of the utility model when the button is reset;

FIG. 4 is an exploded view of the push button, seal and resilient return of the vacuum fresh box according to an embodiment of the present utility model;

fig. 5 is a schematic exploded view of the lid of the vacuum fresh-keeping box according to the embodiment of the present utility model;

Fig. 6 is a schematic diagram of the structural cooperation of the balance valve of the vacuum fresh-keeping box according to the embodiment of the utility model in the blocking state;

fig. 7 is a schematic diagram of structural cooperation of the balance valve of the vacuum fresh-keeping box according to the embodiment of the utility model in a communicating state;

FIG. 8 is a schematic illustration of the structural fit of the deformable sealing structure of the vacuum box of the present utility model when it is undeformed;

FIG. 9 is a schematic view showing the structural fit of the deformable sealing structure of the vacuum box after deformation according to the embodiment of the present utility model;

fig. 10 is a schematic view showing the structure of the opened state of the vacuum fresh-keeping box according to the embodiment of the present utility model;

fig. 11 is a schematic view showing a closed state of the vacuum fresh-keeping box according to the embodiment of the present utility model.

Detailed Description

The utility model will now be described in further detail with reference to the drawings and specific examples, which are not intended to limit the utility model thereto.

Referring to fig. 1 to 11, according to an embodiment of the present utility model, there is provided a vacuum fresh-keeping box including a box body 10, a box cover 20, a button 30, and a sealing member 40, the box body 10 having a receiving cavity a; the box cover 20 is arranged on the box body 10 in a covering manner and seals the accommodating cavity A; the box cover 20 is provided with an air extraction opening 21, the air extraction opening 21 is communicated with the accommodating cavity A, and a one-way valve 21a is arranged at the air extraction opening 21; the cap 20 is provided with a mounting groove 22. The button 30 is movably arranged on the box cover 20 and positioned in the mounting groove 22, a transition cavity B is formed between the button 30 and the inner wall of the mounting groove 22, and the volume of the transition cavity B is changed by the button 30 in the moving process; the transition cavity B is communicated with the accommodating cavity A through the air extraction opening 21, and the unidirectional circulation direction of the one-way valve 21a is that the accommodating cavity A circulates to the transition cavity B. The sealing element 40 is movably installed in the limit groove 31 of the button 30, the sealing element 40 can seal the exhaust gap d1 between the button 30 and the side wall of the installation groove 22, and the button 30 drives the sealing element 40 to move in the moving process.

In the movement of the button 30 to reduce the volume of the transition chamber B, the seal 40 opens the exhaust gap d1 between the button 30 and the side wall of the mounting groove 22 to communicate the outside air C with the transition chamber B;

in the movement of the button 30 to expand the volume of the transition chamber B, the sealing member 40 seals the exhaust gap d1 between the button 30 and the sidewall of the installation groove 22 to block the outside air C from the transition chamber B.

When the button is pressed down, the button reduces the movement of the volume of the transition cavity B, the sealing element is upwards deflected relative to the button due to the action of friction force between the sealing element and the side wall of the mounting groove and blocked by the limiting groove of the button (the moving direction of the sealing element is shown by an arrow in fig. 2), the limiting groove prevents the sealing element from being excessively deflected and not separating from the button, the limiting groove can drag the sealing element to move along with the button all the time, and an exhaust gap d1 between the button and the side wall of the mounting groove is reserved. At the same time, the one-way valve is pressed under the action of atmospheric pressure, so that air in the space of the transition cavity B is extruded into the outside air C due to the downward pressing of the button, as shown by arrow curves in FIG. 2.

In the process of button reset, the button moves to enlarge the volume of the transition cavity B, and at the moment, the sealing element is downwards deflected relative to the button due to the friction force between the sealing element and the side wall of the mounting groove and is extruded into the exhaust gap d1 between the button and the side wall of the mounting groove, so that the exhaust gap d1 between the button and the side wall of the mounting groove is sealed. The limit groove can always drag the sealing element to move and simultaneously seal the exhaust gap d1 when the button is reset. Since the button starts to move upwards from the lowest point, the air pressure value in the space of the transition cavity B is smaller than the air pressure value in the space of the accommodating cavity A, so that the one-way valve is jacked up by the air pressure of the accommodating cavity A, and at the moment, the air in the accommodating cavity A is sucked into the transition cavity B due to the reset of the button, as shown by an arrow curve in FIG. 3. The button sealing ring is continuously deflected and reset, so that the function of unidirectional ventilation gas is achieved, the function of the button sealing ring is the same as that of the unidirectional valve, but the vacuum preservation box structurally reduces the use of one unidirectional valve, greatly simplifies the use of parts of an air extraction structure, reduces the total number of parts of a box cover component, and is simpler in structure. The simple structure of the utility model can make the assembly, the maintenance and the disassembly more efficient, avoid the failure caused by easy deformation of the assembly structure, and solve the problems of complex structure and the problems caused by complex structure of the vacuum preservation box in the prior art.

As shown in fig. 2 and 3, the limiting groove 31 of the button 30 has a first limiting inner wall 31a and a second limiting inner wall 31b disposed opposite to each other; the spacing direction of the first spacing inner wall 31a and the second spacing inner wall 31B is consistent with the moving direction of the button 30, the first spacing inner wall 31a faces the transition cavity B, and the second spacing inner wall 31B faces the external space; an air flow gap d2 communicating with the outside air C is formed between the seal member 40 and the push button 30;

In the movement of the push button 30 to reduce the volume of the transition chamber B, the sealing member 40 abuts against the first limiting inner wall 31a and is away from the second limiting inner wall 31B, and the air flow gap d2 communicates with the opened air discharge gap d 1; that is, when the button is pressed, the sealing member 40 moves upward relative to the button to open the air discharge gap d1 while abutting against the first limiting inner wall 31a, and during the movement of the button, the first limiting inner wall 31a drags the sealing member 40 to maintain the relative position.

In the movement of the button 30 to expand the volume of the transition chamber B, the sealing member 40 abuts against the second limiting inner wall 31B and is away from the second limiting inner wall 31B, and the sealing member 40 simultaneously seals the exhaust gap d1. That is, when the button is reset, the sealing member 40 moves downward relative to the button to seal the exhaust gap d1, and abuts against the second limiting inner wall 31b, and during the movement of the button, the second limiting inner wall 31b drags the sealing member 40 to maintain the relative position.

The first limiting inner wall 31a and the second limiting inner wall 31b not only limit the movement range of the sealing element 40 and prevent the sealing element from being separated from the button, but also can be used as a driving structure, and in the corresponding button movement, the sealing element 40 is abutted and dragged to move synchronously with the button. The limiting groove 31 and the first and second limiting inner walls have the above-mentioned multi-purpose effect.

Preferably, the button 30 includes a top cover 32 and a supporting seat 33, the top cover 32 is used for operation, the top cover 32 has a first limiting plate 321, and the first limiting plate 321 has the first limiting inner wall 31a;

The supporting seat 33 is movably arranged in the mounting groove 22, the supporting seat 33 is provided with a second limiting plate 331, and the second limiting plate 331 is provided with a second limiting inner wall 31b;

the top cover 32 is fixedly connected with the supporting seat 33, and the limiting groove 31 is formed between the first limiting plate 321 and the second limiting plate 331.

Referring to fig. 1 and 4, the top cover 32 protrudes outside to facilitate the user's pressing. Because the top cover 32 is fixedly connected with the supporting seat 33, the supporting seat is linked when the top cover is pressed, and the whole button is further moved.

Preferably, the exhaust gap d1 is formed between the outer circumference of the support seat 33 and the side wall of the installation groove 22. As shown in fig. 2 and 3, the outer diameter of the supporting seat 33 is smaller than the diameter of the side wall of the installation groove 22, so that the supporting seat 33 can slide or move in the installation groove, and meanwhile, an exhaust gap for exhausting is formed between the outer periphery of the supporting seat and the side wall of the installation groove 22, so that the structure is more compact, and the exhaust gap d1 is not required to be designed at other positions independently, thereby simplifying the structure.

Referring to fig. 4, the first limiting plate 321 is connected with a plurality of limiting protrusions 322, and the limiting protrusions 322 form a bottom wall of the limiting groove 31; the first limiting plate 321 is provided with an airflow notch (the position of the limiting protrusion 322 in the figure) at the position of the limiting protrusion 322. The sealing member is of a sealing ring structure, firstly, the sealing member is sleeved on the supporting seat 33, secondly, the sealing member is sleeved on the limiting protrusion 322, the limiting protrusion 322 forms the bottom wall of the limiting groove 31, a distance is formed between the limiting protrusion and the sealing member 40, an air flow gap d2 is formed between the limiting protrusion and the sealing member, and after air entering from the air exhaust gap d1 enters the limiting groove 31, the air enters the outside air C after passing through the air flow gap from the air flow gap d 2.

The limiting projection 322 not only plays a limiting role on the sealing element and plays a role of mounting a clamping position, but also cooperates with the sealing element. The limiting protrusion and the first limiting plate jointly form a groove bottom wall and a side wall structure of the limiting groove, and the structure is simplified. In this embodiment, the air flow gap d2 is formed by the distance between the limiting protrusion and the sealing member, so that air and external air C can circulate conveniently.

The air flow gap d2 communicating with the outside air C is formed between the sealing member 40 and the button 30, and may be formed by a plurality of structures between the sealing member 40 and the button 30, one of which is given in the present embodiment. The structural form of forming the air flow gap d2 is not particularly limited by many other implementations.

Considering the reset problem of the button, the vacuum fresh-keeping box is convenient for the user to operate as much as possible, referring to fig. 3 and 4, and further comprises an elastic reset member 50, wherein the elastic reset member 50 is connected between the support base 33 and the box cover 20;

In the movement of the push button 30 to reduce the volume of the transition chamber B, the elastic restoring member 50 is compressed; the elastic restoring member 50 applies an elastic force toward the movement direction of the button 30 to expand the volume of the transition chamber B.

In the button resetting process, the elastic resetting piece always applies elastic acting force to reset the button, and can assist in manufacturing the pressure difference between the transition cavity B and the accommodating cavity A, so that the air extraction efficiency is improved. The elastic force of the elastic resetting piece is adapted according to the size of the accommodating cavity.

In this embodiment, the elastic restoring member 50 is disposed in the transition chamber B, and the elastic restoring member 50 is a spring. The spring is arranged in the transition cavity B, so that the space of the transition cavity B is effectively utilized, the structural space is fully utilized, and the structure is more compact. And the space occupation is reduced, the volume of the vacuum preservation box is reduced, and the vacuum preservation box is more convenient for users to use.

The top cover 32 and the supporting seat 33 are fixedly connected through pressure fusion welding. The assembly structure of the parts is simplified in a pressure welding mode, and the cost of the die is reduced.

The box cover can also be produced in a pressure welding mode, the box cover generally comprises a box cover upper cover and a box cover base, the box cover upper cover is installed on the box cover base and positioned through three positioning pins, and all structures of the box cover are welded together in the pressure welding mode, so that the effects of simplifying parts and simplifying a die are achieved.

Of course, in other embodiments not shown, the top cover 32 and the supporting seat 33 are integrally formed, and the top cover 32 and the supporting seat 33 may be integrally formed by using other forming processes. The integrated forming device has the advantages that the structural strength is improved, the assembly of parts is simplified, and the production efficiency is improved.

Preferably, the limiting groove 31 is disposed corresponding to the structural shape of the mounting groove 22, the limiting groove 31 is an annular groove, and the sealing member 40 is an annular sealing ring. The cooperation of ring seal and ring channel makes sealed effect more reliable, and overall structure is difficult for taking place to warp moreover, can satisfy the high strength needs of repeated action of bleeding, guarantees that vacuum preservation box can also guarantee effective operation after long-term the use.

The operation principle of the vacuum fresh-keeping box is specifically described with reference to fig. 1 and the specific structure of the embodiment:

The outside air C is air in the outside space, and the air pressure C is the same as the outside air atmospheric pressure. The transition cavity B is a change space, the space is airtight, and the air pressure value B changes along with the up-and-down movement of the button. The sealed cavity A is an inner space, the space is sealed, the air pressure value a is the same as the atmospheric pressure of the external air when the box cover is initially covered, and the air pressure value gradually decreases along with the exhaust.

When the button moves upward, the volume (volume) of the transition chamber B becomes large, and the air pressure value B becomes smaller as the button moves upward, and when the air pressure value B is smaller than the air pressure value a, the check valve is opened while the air in the seal chamber a enters the transition chamber B until the button moves upward to the end point and the air pressure value b=a stops.

When the button moves downwards, the volume of the transition cavity B becomes smaller, the air pressure value B becomes larger along with the downward movement of the button, when the air pressure value B is larger than the air pressure value C, the sealing element is upwards opened by upward pressure and friction force from the side wall of the mounting groove, and meanwhile, the air in the transition cavity B enters the outside air C until the button moves downwards to the bottom. The circulation is performed in this way, and the air suction operation can be completed.

Referring to fig. 6 and 7, the cover 20 is provided with a balance valve 60, and the balance valve 60 is used for communicating or blocking the accommodating chamber a with the external air C. When the vacuum preservation box needs to be opened, the balance valve is adjusted to be in a communication state, so that the accommodating cavity A is communicated with the outside air C, and the box cover can be directly opened after the pressure of the accommodating cavity A and the outside air C are equal. In the vacuumizing process, the balance valve is adjusted to be in a closed state so as to keep the holding cavity A isolated from the outside air C.

In this embodiment, fig. 6 shows a closed state of the balance valve, in which the balance valve sealing ring is tightly sleeved on the groove of the balance valve button, and the balance valve button compresses the balance valve sealing ring on the inclined surface of the corresponding hole of the box cover under the elastic action of the balance valve return spring, so that the accommodating cavity a is blocked (isolated) from the external air C. Fig. 7 shows the state of communication of the balance valve, when the balance valve button is pressed down, the balance valve seal ring is disengaged from the inclined surface, so that the accommodation chamber a communicates with the outside air C, and the air enters into the accommodation chamber a from the space between the valves as shown by arrow curves in fig. 7 until the inside and outside air pressures are balanced.

Preferably, the deformable sealing structure 70 is attached to the outer Zhou Xianwei of the lid 20; when the box cover 20 is covered on the box body 10, the deformable sealing structure 70 is located between the box cover 20 and the box body 10 and deforms to seal the accommodating cavity a.

Referring to fig. 8 to 11, when the lid is assembled to the case, since the deformable sealing structure 70 is made of a soft material and the silica gel material, the deformable sealing structure 70 is deformed by force to form an arc-shaped structure, and when air inside the case is drawn out and the atmospheric pressure applies pressure to the arc-shaped deformable sealing structure 70, the deformable sealing structure 70 is pressed against the inner wall of the case, so as to achieve the effect of enhancing sealing. The diameter of the lower cover of the box cover is larger than that of the deformable sealing structure 70, so when the cover is opened, the lower cover of the box cover can prevent the deformable sealing structure 70 from separating from the box cover under the action of friction force on the inner wall of the box body, namely, the limit connection of the deformable sealing structure 70 is realized, and the integral stable connection relation of the components is ensured.

The utility model provides a reset type vacuumizing vacuum preservation box, which repeatedly completes the same action of exhausting gas in the box through the cooperation of a button and a sealing piece, reduces the air density in the box along with the reduction of the gas quality as the volume in the box is unchanged, reduces the vacuum degree in the box along with the reduction of the gas quality, and ensures the stability of the vacuum degree in the box through a one-way valve; the tightness is improved by aiming at the structural design of the box sealing ring; the assembly structure of the parts is simplified in a pressure welding mode, and the cost of the die is reduced.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein.

Of course, the above is a preferred embodiment of the present utility model. It should be noted that it will be apparent to those skilled in the art that several modifications and adaptations can be made without departing from the general principles of the present utility model, and such modifications and adaptations are intended to be comprehended within the scope of the present utility model.

Claims (11)

1. A vacuum fresh-keeping box, characterized by comprising:

A case (10) having a housing chamber (A);

The box cover (20) is arranged on the box body (10) in a covering manner and seals the accommodating cavity (A); an extraction opening (21) is formed in the box cover (20), the extraction opening (21) is communicated with the accommodating cavity (A), and a one-way valve (21 a) is arranged at the extraction opening (21); the box cover (20) is provided with a mounting groove (22);

A button (30), wherein the button (30) is movably arranged on the box cover (20) and positioned in the mounting groove (22), a transition cavity (B) is formed between the button (30) and the inner wall of the mounting groove (22), and the volume of the transition cavity (B) is changed during the movement of the button (30); the transition cavity (B) is communicated with the accommodating cavity (A) through the air extraction opening (21), and the unidirectional circulation direction of the one-way valve (21 a) is that the accommodating cavity (A) circulates to the transition cavity (B);

A seal member (40), wherein the seal member (40) is movably arranged in a limit groove (31) of the button (30), the seal member (40) can seal an exhaust gap (d 1) between the button (30) and the side wall of the mounting groove (22), and the button (30) drives the seal member (40) to move in the moving process;

In the movement of the button (30) to reduce the volume of the transition chamber (B), the seal (40) opens a vent gap (d 1) between the button (30) and a side wall of the mounting groove (22) to communicate external air (C) with the transition chamber (B);

During movement of the button (30) to expand the volume of the transition chamber (B), the seal (40) seals an exhaust gap (d 1) between the button (30) and a side wall of the mounting groove (22) to block outside air (C) from the transition chamber (B).

2. The vacuum fresh-keeping box according to claim 1, wherein,

The limiting groove (31) of the button (30) is provided with a first limiting inner wall (31 a) and a second limiting inner wall (31 b) which are oppositely arranged; the spacing direction of the first limiting inner wall (31 a) and the second limiting inner wall (31B) is consistent with the moving direction of the button (30), the first limiting inner wall (31 a) faces the transition cavity (B), and the second limiting inner wall (31B) faces the external space; an air flow gap (d 2) communicated with the outside air (C) is formed between the sealing member (40) and the button (30);

In the movement of the button (30) to reduce the volume of the transition chamber (B), the seal (40) abuts against the first limit inner wall (31 a) and is distanced from the second limit inner wall (31B), the air flow gap (d 2) being in communication with the open exhaust gap (d 1);

During the movement of the button (30) to enlarge the volume of the transition chamber (B), the sealing element (40) abuts against the second limiting inner wall (31B) and is distant from the second limiting inner wall (31B), the sealing element (40) simultaneously sealing the exhaust gap (d 1).

3. Vacuum fresh box according to claim 2, characterized in that the push button (30) comprises:

a top cover (32), the top cover (32) being used for operation, the top cover (32) having a first limiting plate (321), the first limiting plate (321) having the first limiting inner wall (31 a);

A support seat (33), wherein the support seat (33) is movably arranged in the mounting groove (22), the support seat (33) is provided with a second limiting plate (331), and the second limiting plate (331) is provided with the second limiting inner wall (31 b);

The top cover (32) is fixedly connected with the supporting seat (33), and the limiting groove (31) is formed between the first limiting plate (321) and the second limiting plate (331).

4. The vacuum fresh-keeping box according to claim 3, wherein,

The exhaust gap (d 1) is formed between the outer periphery of the support seat (33) and the side wall of the mounting groove (22).

5. The vacuum fresh-keeping box according to claim 3, wherein,

A plurality of limit protrusions (322) are connected to the first limit plate (321), and the limit protrusions (322) form the bottom wall of the limit groove (31);

the first limiting plate (321) is provided with an airflow notch at the position of the limiting protrusion (322).

6. The vacuum fresh-keeping box according to claim 3, wherein,

The box further comprises an elastic reset piece (50), wherein the elastic reset piece (50) is connected between the supporting seat (33) and the box cover (20);

-said elastic return element (50) is compressed during the movement of said push-button (30) to reduce the volume of said transition chamber (B); the elastic return element (50) exerts an elastic force in the direction of movement of the push button (30) to expand the volume of the transition chamber (B).

7. The vacuum fresh-keeping box according to claim 6, wherein,

The elastic reset piece (50) is arranged in the transition cavity (B), and the elastic reset piece (50) is a spring.

8. A vacuum fresh-keeping box according to claim 3, wherein the top cover (32) and the support (33) are fixedly connected by means of compression welding;

Or the top cover (32) and the supporting seat (33) are of an integrated structure.

9. The vacuum fresh-keeping box according to claim 2, wherein,

The limiting groove (31) is arranged corresponding to the structure of the mounting groove (22), the limiting groove (31) is an annular groove, and the sealing piece (40) is an annular sealing ring.

10. Vacuum fresh box according to claim 1, characterized in that the box cover (20) is provided with a balancing valve (60), the balancing valve (60) being used for communicating or blocking the containing cavity (a) with the outside air (C).

11. Vacuum fresh box according to claim 1, characterized in that the outer Zhou Xianwei of the box cover (20) is connected with a deformable sealing structure (70);

When the box cover (20) is arranged on the box body (10), the deformable sealing structure (70) is positioned between the box cover (20) and the box body (10) and deforms so as to seal the accommodating cavity (A).