Vacuum system of lithium electric heating shaping oven

Abstract

The utility model relates to a lithium electric heating shaping oven vacuum system, which comprises a first vacuumizing pump set, a second vacuumizing pump set and a control unit, the first vacuumizing pump set is respectively communicated with a plurality of ovens through a first pipeline, the second vacuumizing pump set is used for maintaining air pressure in the ovens, so that the air pressure is kept in a required vacuum degree range, and the control unit is used for controlling the vacuum degree of the ovens. The second vacuumizing pump set communicates with the multiple drying ovens through second pipelines. The first vacuumizing pump set and the second vacuumizing pump set are respectively and electrically connected with the control unit, and the control unit is respectively and electrically connected with the first vacuumizing pump set and the second vacuumizing pump set and used for controlling the first vacuumizing pump set and the second vacuumizing pump set to operate in a switching mode. And the first vacuumizing pump set stops exhausting air, the second vacuumizing pump set is switched to operate, and the vacuum degrees in the multiple drying ovens are kept within the needed range.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium battery baking and vacuum pumping, specifically to the vacuum system of a lithium battery thermal shaping oven. Background Art

[0002] In the thermal shaping and baking process of a lithium-ion battery factory, the baking vacuum degree has a great influence on the baking time. Currently, most enterprises control the baking vacuum degree at 50 - 100 Pa. However, the baking time required to reduce the moisture of the battery cells to the qualified standard at this vacuum degree is very long. To improve production efficiency, the vacuum degree of the thermal shaping equipment is increased to 5 - 20 Pa, which can greatly reduce the baking time.

[0003] In the existing production line, in the early stage of baking, when the vacuum pump group pumps the oven cavity to 5 Pa and then switches the valve to pump another cavity, and the original cavity closes the valve to maintain pressure, due to the continuous evaporation of moisture and other volatile substances in the oven cavity, the time for the pressure in the original cavity to remain at 5 - 20 Pa is very short, generally 60 - 100 s. While it generally takes about 4 minutes for the vacuum pump group to pump the oven cavity from atmospheric pressure to 5 Pa. This results in the inability of the original cavity to maintain the pressure at 5 - 20 Pa during the period when the other cavity is being evacuated from atmospheric pressure.

[0004] The thermal shaping oven needs to break the vacuum by introducing nitrogen every once in a while. To meet the vacuum requirement of 5 - 20 Pa for the thermal shaping equipment in the early stage of baking, generally one set of vacuum pump group is configured for each cavity. If a thermal shaping production line is equipped with 8 thermal shaping devices, and each thermal shaping device has two cavities, then 16 sets of vacuum pump groups are required to meet the production demand for a thermal shaping production line. However, the evaporation rate will decrease significantly in the later stage of baking, directly causing waste of the vacuum pump capacity and greatly increasing the operation cost and investment cost. Summary of the Invention

[0005] In view of the above problems, the utility model provides a control system for vacuum pumping and maintaining the vacuum degree range configured for multiple shaping devices in a thermal shaping production line. The specific solution is as follows:

[0006] The vacuum system of the lithium battery thermal shaping oven includes a first vacuum pump group for sequentially pumping the air pressure in multiple ovens to the required vacuum degree. The first vacuum pump group is respectively connected to multiple ovens through a first pipeline. There is also a second vacuum pump group and a control unit.

[0007] The second vacuum pump group is respectively connected to multiple ovens through a second pipeline, and is used to maintain the air pressure in multiple ovens so that the air pressure remains within the required vacuum degree range.

[0008] The control unit is electrically connected to the first vacuum pump group and the second vacuum pump group respectively, and is used to control the switching operation of the first vacuum pump group and the second vacuum pump group.

[0009] Furthermore, each oven includes two drying chambers, and the first pipeline and the second pipeline are respectively communicated with each drying chamber.

[0010] Furthermore, a first main pipe is provided in the first pipeline. A plurality of first branch pipes are communicated with the first main pipe, and the plurality of first branch pipes are respectively and correspondingly communicated with a plurality of drying chambers. A first valve and a first check valve are sequentially arranged on each first branch pipe. The first valve is a pneumatic valve, and the plurality of first valves are respectively electrically connected to a control unit.

[0011] Furthermore, a second main pipe is provided in the second pipeline. A plurality of second branch pipes are communicated with the second main pipe, and the plurality of second branch pipes are respectively and correspondingly communicated with a plurality of drying chambers. A second valve and a second check valve are sequentially arranged on each second branch pipe. The second valve is a pneumatic valve, and the plurality of second valves are respectively electrically connected to a control unit.

[0012] Furthermore, there are N first vacuum pump sets, and each first vacuum pump set is respectively electrically connected to the control unit. The diameter of the first branch pipe is greater than or equal to the diameter of the air extraction pipe of the first vacuum pump set. A third valve for distributing a plurality of first branch pipes is arranged at intervals on the first main pipe. The number of the third valves is N - 1, and the first main pipe is divided into N zones through the third valves. The N first vacuum pump sets are respectively and correspondingly communicated with the N zones.

[0013] Furthermore, there are a plurality of second vacuum pump sets, and each second vacuum pump set is respectively electrically connected to the control unit. The diameter of the second branch pipe is greater than or equal to the diameter of the air extraction pipe of the second vacuum pump set.

[0014] Furthermore, there are X second vacuum pump sets. A fourth valve for distributing a plurality of second branch pipes is arranged at intervals on the second main pipe. The number of the fourth valves is X - 1, and the second main pipe is divided into X zones through the fourth valves. The X second vacuum pump sets are respectively and correspondingly communicated with the X zones.

[0015] Furthermore, there are two second vacuum pump sets, and the two second vacuum pump sets are respectively connected in parallel to one end of the second main pipe. The diameter of the second main pipe is twice the diameter of the second branch pipe.

[0016] Furthermore, a third branch pipe is connected to each drying chamber, and the third branch pipe is communicated with the corresponding first branch pipe and second branch pipe.

[0017] Furthermore, the control unit is a PLC, and a timing module is provided in the PLC.

[0018] Compared with the prior art, the advantages of the present utility model are as follows:

[0019] 1. In the solution of this application, the first vacuum pump group is used to evacuate multiple drying ovens in sequence to reach the required vacuum degree. When the air pressure in the drying oven reaches the required vacuum degree, the first vacuum pump group stops pumping air, and the operation is switched to the second vacuum pump group to keep the vacuum degrees in multiple drying ovens within the required range.

[0020] 2. In the solution of this application, through the switching control of the control unit on the first valve and the second valve, the first vacuum pump group and the second vacuum pump group are respectively responsible for the working conditions of evacuating the drying oven cavity from atmospheric pressure to 5 Pa and from 20 Pa to 5 Pa during the pressure holding period. This avoids the situation that while one vacuum pump group evacuates one cavity from atmospheric pressure to 5 Pa, the air pressure in another cavity has exceeded 20 Pa due to the time difference of evacuating the two working conditions, overcomes the influence of the high evaporation rate of volatile substances in the early stage of baking, makes full use of the air pumping capacity of the vacuum pump, and greatly reduces the input cost and operation cost.

[0021] 3. In the solution of this application, a check valve is provided on the branch pipe, which avoids the possibility of air leakage and has a low failure rate.

[0022] 4. In the solution of this application, corresponding multiple vacuum pumps are set according to the number of drying ovens, and the responsible areas of each vacuum pump on the main pipe are divided through valves, and then the control unit controls the operation of each vacuum pump, which has the advantage of improving the tooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of the vacuum pump system of Embodiment 1 of the present utility model;

[0024] Figure 2 It is a schematic structural diagram of the vacuum pump system of Embodiment 2 of the present utility model;

[0025] Figure 3 It is a schematic structural diagram of the vacuum pump system of Embodiment 3 of the present utility model;

[0026] Figure 4 It is a schematic structural diagram of the vacuum pump system of Embodiment 4 of the present utility model;

[0027] Figure 5 It is a schematic structural diagram of the vacuum pump system of Embodiment 5 of the present utility model;

[0028] REFERENCE MARKS:

[0029] 1 - drying chamber, 2 - first vacuum pump group, 3 - first main pipe, 31 - third valve, 4 - first branch pipe, 41 - first valve, 42 - first check valve, 5 - second vacuum pump group, 6 - second main pipe, 61 - fourth valve, 7 - second branch pipe, 71 - second valve, 72 - second check valve, 8 - control unit, 9 - third branch pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The specific implementation manners of the present utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. The embodiments described by referring to the accompanying drawings are illustrative and are intended to explain the present utility model, and should not be construed as limiting the present utility model.

[0031] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", "front", "rear", "end", "bottom", "side", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation. Therefore, it should not be construed as limiting the present utility model.

[0032] In the present utility model, unless otherwise clearly defined and limited, terms such as "connection" and "installation" should be understood in a broad sense. For example, it can be a fixed connection, a direct connection, or a connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0033] Secondly, the so-called "one embodiment" or "embodiment" of the present utility model refers to specific features, structures or characteristics that can be included in at least one implementation manner of the present utility model. The "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0034] The specific implementation manners of the present utility model will be further described in detail below in conjunction with the accompanying drawings. The following embodiments are used to illustrate the present utility model, but are not used to limit the scope of the present utility model. Embodiment 1

[0035] As Figure 1 shown, the lithium electrothermal shaping oven vacuum system includes an oven line, which is composed of 3 ovens. Each oven is provided with two drying chambers 1, for a total of 6 drying chambers 1. The required range of vacuum degree in the drying chamber 1 is between 5 and 20 Pa. An air pressure detection sensor is respectively provided in each drying chamber 1, and the air pressure detection sensor is electrically connected to the control unit 8.

[0036] The vacuum pumping system includes a first vacuum pumping unit 2 for successively pumping the air pressure in three ovens to the required vacuum degree. The first vacuum pumping unit 2 is electrically connected to the control unit 8. The first vacuum pumping unit 2 is connected to the three ovens respectively through a first pipeline. A first main pipe 3 is provided in the first pipeline. Six first branch pipes 4 are connected to the first main pipe 3. The diameter of the first branch pipe 4 is greater than or equal to the diameter of the air suction pipe of the first vacuum pumping unit 2. The six first branch pipes 4 are respectively connected to a plurality of drying chambers 1 correspondingly, that is, each first branch pipe 4 is connected to a corresponding drying chamber 1. A first valve 41 and a first check valve 42 are successively provided on each first branch pipe 4. The first valve 41 is a pneumatic valve. The six first valves 41 are respectively electrically connected to the control unit 8.

[0037] A second vacuum pumping unit 5 is also provided for maintaining the air pressure in the three ovens within the required vacuum degree range. The second vacuum pumping unit 5 is electrically connected to the control unit 8. The second vacuum pumping unit 5 is connected to the three ovens respectively through a second pipeline. A second main pipe 6 is provided in the second pipeline. A plurality of second branch pipes 7 are connected to the second main pipe 6. The diameter of the second branch pipe 7 is greater than or equal to the diameter of the air suction pipe of the second vacuum pumping unit 5. The six second branch pipes 7 are respectively connected to the three ovens correspondingly, that is, each second branch pipe 7 is connected to a corresponding drying chamber 1. A second valve 71 and a second check valve 72 are successively provided on each second branch pipe 7. The second valve 71 is a pneumatic valve. The six second valves 71 are respectively electrically connected to the control unit 8.

[0038] The control unit 8 is used to control the switching operation of the first vacuum pumping unit 2 and the second vacuum pumping unit 5. The control unit 8 is a PLC, and a timing module is provided in the PLC.

[0039] During the use process, the first vacuum pumping unit 2 and the second vacuum pumping unit 5 are placed in the hot shaping workshop or on the second floor roof of the hot shaping workshop. Both the first vacuum pumping unit 2 and the second vacuum pumping unit 5 adopt a combined pump of an oil-free screw and a two-stage Roots.

[0040] During the operation of the first vacuum pumping unit 2 and the second vacuum pumping unit 5, according to the loading sequence of the six drying chambers 1 in the oven line, the control unit 8 successively opens the corresponding first valves 41. After the first vacuum pumping unit 2 pumps the vacuum in the drying chamber 1 from normal pressure to 5 Pa, the control unit 8 will automatically close the first valve 41; when the internal pressure in a certain one of the six drying chambers 1 exceeds the required 20 Pa, the control unit 8 will automatically open the corresponding second valve 71, and the second vacuum pumping unit 5 will pump the air pressure in the drying chamber 1 to 5 Pa. During this period, the total time for the first vacuum pumping unit 2 to pump the air pressure in each drying chamber 1 on the oven line to 5 Pa in sequence is just less than or equal to the interval time for the hot shaping oven to break the vacuum. Embodiment 2

[0041] AsFigure 2 As shown in the figure, the oven line consists of 6 ovens, and each oven is provided with two drying chambers 1, for a total of 12 drying chambers 1. The required vacuum range in the drying chamber 1 is between 5 and 20 Pa. A pressure detection sensor is respectively provided in each drying chamber 1, and the pressure detection sensor is electrically connected to the control unit 8.

[0042] The vacuum pumping system includes a first vacuum pump group 2 for sequentially pumping the air pressure in the 6 ovens to the required vacuum degree. The first vacuum pump group 2 is electrically connected to the control unit 8. The first vacuum pump group 2 is respectively connected to the 6 ovens through a first pipeline. A first main pipe 3 is provided in the first pipeline. 12 first branch pipes 4 are connected to the first main pipe 3. The diameter of the first branch pipe 4 is greater than or equal to the diameter of the air extraction pipe of the first vacuum pump group 2. The 12 first branch pipes 4 are respectively connected to the 6 ovens correspondingly, that is, each first branch pipe 4 is connected to a corresponding drying chamber 1. A first valve 41 and a first check valve 42 are sequentially provided on each first branch pipe 4. The first valve 41 is a pneumatic valve, and the 12 first valves 41 are respectively electrically connected to the control unit 8.

[0043] A second vacuum pump group 5 is also provided for maintaining the air pressure in the 6 ovens within the required vacuum range. There are two second vacuum pump groups 5, which are respectively electrically connected to the control unit 8. The two second vacuum pump groups 5 are both connected to a second pipeline. A second main pipe 6 is provided in the second pipeline. The two second vacuum pump groups 5 are connected in parallel to one end of the second main pipe 6. 12 second branch pipes 7 are connected to the second main pipe 6. The diameter of the second main pipe 6 is twice the diameter of the second branch pipe 7. The purpose of the improvement plan is to match the air extraction power when the two second vacuum pump groups 5 operate simultaneously at the end of the second main pipe 6 by increasing the diameter of the second main pipe 6. The diameter of the second branch pipe 7 is greater than or equal to the diameter of the air extraction pipe of the second vacuum pump group 5. The 12 second branch pipes 7 are respectively connected to the 6 ovens correspondingly, that is, each second branch pipe 7 is connected to a corresponding drying chamber 1. A second valve 71 and a second check valve 72 are sequentially provided on each second branch pipe 7. The second valve 71 is a pneumatic valve, and the 6 second valves 71 are respectively electrically connected to the control unit 8.

[0044] The control unit 8 is used to control the switching operation of the first vacuum pump group 2 and the second vacuum pump group 5. The control unit 8 is a PLC, and a timing module is provided in the PLC.

[0045] During the use process, the first vacuum pump group 2 and the two second vacuum pump groups 5 are placed in the hot shaping workshop or on the second floor roof of the hot shaping workshop. The first vacuum pump group 2 and the two second vacuum pump groups 5 both adopt a combined pump of oil-free screw and two-stage roots.

[0046] During the operation of the first vacuum pump group 2 and the second vacuum pump group 5, according to the loading sequence of the 6 drying chambers 1 in the oven line, the control unit 8 sequentially opens the corresponding first valves 41. After the first vacuum pump group 2 pumps the vacuum in the drying chamber 1 from atmospheric pressure to 5 Pa, the control unit 8 will automatically close the first valve 41. When the internal pressure in a certain one of the 6 drying chambers 1 exceeds the required 20 Pa, the control unit 8 will automatically open the corresponding second valve 71, and the two second vacuum pump groups 5 located at the end of the second main pipe 6 will operate together to pump the air pressure in the drying chamber 1 to 5 Pa. During this period, the total time for the first vacuum pump group 2 to pump the air pressure in each drying chamber 1 on the oven line to 5 Pa in sequence is just less than or equal to the interval time for the hot shaping oven to break the vacuum. Embodiment 3

[0047] As Figure 3 shown, the oven line consists of 6 ovens, and each oven is provided with two drying chambers 1, for a total of 12 drying chambers 1. The required vacuum degree range in the drying chamber 1 is between 5 and 20 Pa. Each drying chamber 1 is respectively provided with a gas pressure detection sensor, and the gas pressure detection sensor is electrically connected to the control unit 8.

[0048] The vacuum pumping system includes a first vacuum pump group 2 for sequentially pumping the air pressure in the 6 ovens to the required vacuum degree. The first vacuum pump group 2 is electrically connected to the control unit 8. The first vacuum pump group 2 is connected to the 6 ovens through the first pipeline respectively. The first main pipe 3 is provided in the first pipeline. 12 first branch pipes 4 are connected to the first main pipe 3. The diameter of the first branch pipe 4 is greater than or equal to the diameter of the air extraction pipe of the first vacuum pump group 2. The 12 first branch pipes 4 are respectively connected to the 6 ovens correspondingly, that is, each first branch pipe 4 is connected to a corresponding drying chamber 1. A first valve 41 and a first check valve 42 are sequentially provided on each first branch pipe 4. The first valve 41 is a pneumatic valve, and the 12 first valves 41 are respectively electrically connected to the control unit 8.

[0049] There is also a second vacuum pump group 5 for maintaining the air pressure in the 6 drying ovens within the required vacuum range. There are two second vacuum pump groups 5, which are respectively electrically connected to the control unit 8. Both second vacuum pump groups 5 are connected to the second pipeline. A second main pipe 6 is provided in the second pipeline. 12 second branch pipes 7 are connected to the second main pipe 6. The diameter of the second branch pipes 7 is greater than or equal to the diameter of the suction pipes of the second vacuum pump group 5. The 12 second branch pipes 7 are respectively connected to the 6 drying ovens correspondingly, that is, each second branch pipe 7 is connected to a corresponding drying chamber 1. A second valve 71 and a second check valve 72 are successively provided on each second branch pipe 7. The second valve 71 is a pneumatic valve. The 12 second valves 71 are respectively electrically connected to the control unit 8. A fourth valve 61 for distributing the 12 second branch pipes 7 is provided at intervals on the second main pipe 6. There is one fourth valve 61. The second main pipe 6 is divided into 2 zones by the fourth valve 61. The two second vacuum pump groups 5 are respectively connected to the 2 zones correspondingly. This solution allows one second vacuum pump group 5 to be responsible for the 6 second branch pipes in one zone and sequentially extract the vacuum of the 6 drying chambers 1, and there is no need to increase the diameter of the second main pipe 6, which has the advantages of improving work efficiency and reducing costs. If the number of drying ovens in the drying line needs to be further increased, the number of second vacuum pump groups 5 needs to be further increased. The specific solution is as follows:

[0050] There are X second vacuum pump groups 5. A fourth valve 61 for distributing multiple second branch pipes 7 is provided at intervals on the second main pipe 6. The number of the fourth valves 61 is X - 1. The second main pipe 6 is divided into X zones by the fourth valves 61. The X second vacuum pump groups 5 are respectively connected to the X zones correspondingly. The number of second branch pipes 7 in the zones is adaptively distributed according to the volume of the drying chamber 1 and the time for the second vacuum pump group 5 to evacuate the drying chamber 1.

[0051] The control unit 8 is used to control the switching operation of the first vacuum pump group 2 and the second vacuum pump group 5. The control unit 8 is a PLC, and a timing module is provided in the PLC.

[0052] During use, the first vacuum pump group 2 and the two second vacuum pump groups 5 are placed in the hot shaping workshop or on the second floor roof of the hot shaping workshop. The first vacuum pump group 2 and the two second vacuum pump groups 5 both adopt a combined pump of oil-free screw and two-stage Roots.

[0053] During the operation of the first vacuum pump group 2 and the second vacuum pump group 5, according to the loading sequence of the 12 drying chambers 1 in the oven line, the control unit 8 sequentially opens the corresponding first valves 41. After the first vacuum pump group 2 pumps the vacuum in the drying chamber 1 from atmospheric pressure to 5 Pa, the control unit 8 will automatically close the first valve 41; the fourth valve 61 is in the closed state. When the internal pressure of a certain drying chamber 1 in the partition exceeds the required 20 Pa, the control unit 8 will automatically open the corresponding second valve 71 and control the second vacuum pump group 5 responsible for this partition to pump the air pressure in the drying chamber 1 to 5 Pa. The two second vacuum pump groups 5 can work synchronously. Example 4

[0054] In this embodiment, further improvements are made to the design positions of the first vacuum pump group 2 and the second vacuum pump group 5. As Figure 3 shown, the first vacuum pump group 2 and the second vacuum pump group 5 can be respectively arranged on both sides of the drying line; as Figure 4 shown, the first vacuum pump group 2 and the second vacuum pump group 5 are arranged on the same side. Among them, each drying chamber 1 is connected with a third branch pipe 9, and the third branch pipe 9 is communicated with the corresponding first branch pipe 4 and second branch pipe 7. Example 5

[0055] As Figure 5 shown, the oven line is composed of 8 ovens, and each oven is provided with two drying chambers 1, with a total of 16 drying chambers 1. The required range of vacuum degree in the drying chamber 1 is between 5 and 20 Pa. Each drying chamber 1 is respectively provided with a gas pressure detection sensor, and the gas pressure detection sensor is electrically connected to the control unit 8.

[0056] The vacuum pumping system includes two first vacuum pumping groups 2 for successively pumping the air pressure in 8 ovens to the required vacuum degree. The two first vacuum pumping groups 2 are respectively electrically connected to the control unit 8. The two first vacuum pumping groups 2 are respectively communicated with 8 ovens through the first pipelines. A first main pipe 3 is provided in the first pipelines. 16 first branch pipes 4 are communicated with the first main pipe 3. The 16 first branch pipes 4 are respectively correspondingly communicated with 8 ovens, that is, each first branch pipe 4 is communicated with a corresponding drying chamber 1. The diameter of the first branch pipe 4 is greater than or equal to the diameter of the air extraction pipe of the first vacuum pumping group 2. A first valve 41 and a first check valve 42 are successively provided on each first branch pipe 4. The first valve 41 is a pneumatic valve. The 16 first valves 41 are respectively electrically connected to the control unit 8. A third valve 31 for distributing 16 first branch pipes 4 is provided at intervals on the first main pipe 3. There is one third valve 31. The first main pipe 3 is divided into 2 zones through the third valve 31. The two first vacuum pumping groups 2 are respectively correspondingly communicated with the 2 zones. This scheme can enable one first vacuum pumping group 2 to be responsible for successively pumping the vacuum of 6 drying chambers 1 by 6 first branch pipes in one zone, and there is no need to increase the diameter of the first main pipe 3, which has the advantages of improving work efficiency and reducing costs. If the number of ovens in the drying line needs to be further increased, the number of the first vacuum pumping groups 2 needs to be further increased. The specific scheme is as follows:

[0057] There are N first vacuum pumping groups 2. A third valve 31 for distributing multiple first branch pipes 4 is provided at intervals on the first main pipe 3. The number of the third valves 31 is N - 1. The first main pipe 3 is divided into N zones through the third valves 31. The N first vacuum pumping groups 2 are respectively correspondingly communicated with the N zones. The number of the first branch pipes 4 in the zones is adaptively distributed according to the volume of the drying chamber 1 and the time for the first vacuum pumping group 2 to pump the vacuum of the drying chamber 1.

[0058] The control unit 8 is used to control the switching operation of the first vacuum pumping group 2 and the second vacuum pumping group 5. The control unit 8 is a PLC, and a timing module is provided in the PLC.

[0059] During the use process, the two first vacuum pumping groups 2 and the second vacuum pumping group 5 can be placed in the hot shaping workshop or on the second floor roof of the hot shaping workshop. Both the first vacuum pumping group 2 and the second vacuum pumping group 5 adopt a combined pump of an oil-free screw and a two-stage Roots.

[0060] During the operation of the first vacuum pump group 2 and the second vacuum pump group 5, the third valve 31 is in the closed state. According to the loading sequence of the 16 drying chambers 1 in the oven line, the control unit 8 sequentially opens the corresponding first valves 41. The two first vacuum pump groups 2 operate synchronously to evacuate the vacuum in the drying chambers 1 within the responsible partition from atmospheric pressure to 5 Pa in sequence. Then, the control unit 8 will automatically close the first pneumatic valve. During this period, the total time for the first vacuum pump group 2 to evacuate the air pressure in each drying chamber 1 on the oven line to 5 Pa in sequence is just less than or equal to the interval time for the hot shaping oven to break the vacuum.

[0061] The solution of this embodiment can also be combined with the layout scheme of multiple second vacuum pump groups 5 in Embodiment 3 to further improve the working efficiency.

[0062] As Figure 5 shown, there is also a second vacuum pump group 5 for maintaining the air pressure in 8 ovens within the required vacuum range. There are 3 second vacuum pump groups 5, which are respectively electrically connected to the control unit 8. The 3 second vacuum pump groups 5 are all connected to the second pipeline. There is a second main pipe 6 in the second pipeline. 16 second branch pipes 7 are connected to the second main pipe 6. The diameter of the second branch pipes 7 is greater than or equal to the diameter of the suction pipes of the second vacuum pump groups 5. The 16 second branch pipes 7 are respectively connected to 8 ovens correspondingly, that is, each second branch pipe 7 is connected to a corresponding drying chamber 1. A second valve 71 and a second check valve 72 are sequentially arranged on each second branch pipe 7. The second valve 71 is a pneumatic valve. The 16 second valves 71 are respectively electrically connected to the control unit 8. There are 2 fourth valves 61 for distributing the 16 second branch pipes 7 at intervals on the second main pipe 6. The second main pipe 6 is divided into 3 partitions through the fourth valves 61. The 3 second vacuum pump groups 5 are respectively connected to the 3 partitions correspondingly. The numbers of second branch pipes 7 distributed in the 3 partitions are 6, 4, and 6 respectively.

[0063] During operation, the fourth valve 61 is in the closed state. When the internal pressure of a certain drying chamber 1 in the partition exceeds the required 20 Pa, the control unit 8 will automatically open the corresponding second valve 71 and control the second vacuum pump group 5 responsible for this partition to evacuate the air pressure in this drying chamber 1 to 5 Pa. The 3 second vacuum pump groups 5 can work synchronously.

[0064] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. Lithium electrothermal shaping oven vacuum system, including a first vacuum pump group (2) for successively pumping the air pressure in multiple ovens to the required vacuum degree, the first vacuum pump group (2) is respectively connected to multiple ovens through a first pipeline, and is characterized in that, There is also a second vacuum pump group (5) and a control unit (8). The second vacuum pump group (5) is respectively connected to multiple drying ovens through a second pipeline, and is used to maintain the air pressure in the multiple drying ovens so that the air pressure is kept within the required vacuum range. The control unit (8) is electrically connected to the first vacuum pump group (2) and the second vacuum pump group (5) respectively, and is used to control the switching operation of the first vacuum pump group (2) and the second vacuum pump group (5).

2. The lithium thermal shaping oven vacuum system according to claim 1, characterized in that, Each drying oven includes two drying chambers (1), and the first pipeline and the second pipeline are respectively connected to each drying chamber (1).

3. The lithium thermal shaping oven vacuum system according to claim 2, wherein A first main pipe (3) is provided in the first pipeline, and a plurality of first branch pipes (4) are connected to the first main pipe (3). The plurality of first branch pipes (4) are respectively connected to the corresponding multiple drying chambers (1). A first valve (41) and a first check valve (42) are sequentially provided on each first branch pipe (4). The first valve (41) is a pneumatic valve, and the multiple first valves (41) are respectively electrically connected to the control unit (8).

4. The lithium thermal shaping oven vacuum system according to claim 2, characterized in that, A second main pipe (6) is provided in the second pipeline, and a plurality of second branch pipes (7) are connected to the second main pipe (6). The plurality of second branch pipes (7) are respectively connected to the corresponding multiple drying chambers (1). A second valve (71) and a second check valve (72) are sequentially provided on each second branch pipe (7). The second valve (71) is a pneumatic valve, and the multiple second valves (71) are respectively electrically connected to the control unit (8).

5. The lithium thermal shaping oven vacuum system according to claim 3, wherein There are N first vacuum pump groups (2), and each first vacuum pump group (2) is respectively electrically connected to the control unit (8). The diameter of the first branch pipe (4) is greater than or equal to the diameter of the air extraction pipe of the first vacuum pump group (2). A third valve (31) for distributing the plurality of first branch pipes (4) is provided at intervals on the first main pipe (3). The number of the third valves (31) is N - 1. The first main pipe (3) is divided into N zones through the third valves (31), and the N first vacuum pump groups (2) are respectively connected to the N zones correspondingly.

6. The lithium thermal shaping oven vacuum system according to claim 4, wherein There are multiple second vacuum pump groups (5), and each second vacuum pump group (5) is respectively electrically connected to the control unit (8). The diameter of the second branch pipe (7) is greater than or equal to the diameter of the air extraction pipe of the second vacuum pump group (5).

7. The lithium thermal shaping oven vacuum system according to claim 6, characterized in that, There are X second vacuum pump groups (5). A fourth valve (61) for distributing the plurality of second branch pipes (7) is provided at intervals on the second main pipe (6). The number of the fourth valves (61) is X - 1. The second main pipe (6) is divided into X zones through the fourth valves (61), and the X second vacuum pump groups (5) are respectively connected to the X zones correspondingly.

8. The lithium thermal shaping oven vacuum system according to claim 7, wherein There are two second vacuum pump groups (5), and the two second vacuum pump groups (5) are respectively connected in parallel to one end of the second main pipe (6). The diameter of the second main pipe (6) is twice the diameter of the second branch pipe (7).

9. The lithium thermal shaping oven vacuum system according to claim 3 or 4, characterized in that A third branch pipe (9) is connected to each drying chamber (1), and the third branch pipe (9) is connected to the corresponding first branch pipe (4) and second branch pipe (7).

10. The vacuum system of the lithium thermal forming oven according to claim 2 or 3, characterized in that, The control unit (8) is a PLC, and a timing module is provided in the PLC.

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