Air return device for preventing temperature drop of temperature zone interval and reflow soldering equipment

Abstract

The utility model discloses an air return device for preventing temperature drop of a temperature zone interval and reflow soldering equipment, and relates to the technical field of reflow soldering. The air return device for preventing the temperature of the temperature zone interval from dropping is used for being installed on a furnace cover of reflow soldering equipment and comprises an air return assembly, a fan and a flow guide plate. Wherein the fan is arranged on the air return assembly; the flow guide plate is arranged on the air return assembly and provided with a first air return opening, a second air return opening and air outlets, the air outlets are evenly distributed in the flow guide plate, an outlet of the fan is communicated with the air outlets, an inlet of the fan is communicated with the first air return opening, the first air return opening is located in one side of the flow guide plate in the first direction, and the second air return opening is located in the other side of the flow guide plate in the first direction. According to the reflow soldering equipment provided with the air return device, the quality of a circuit board welded by using the reflow soldering equipment provided with the air return device is relatively high.

Description

Technical Field

[0001] The utility model relates to the technical field of reflow soldering, and more specifically, to an air return device for preventing temperature drop between temperature zones. In addition, the utility model also relates to a reflow soldering device including the above-mentioned air return device for preventing temperature drop between temperature zones. Background Art

[0002] In the existing reflow soldering devices, during the lead-free solder paste soldering process, in order to form a temperature difference adjustment between adjacent temperature zones, a certain non-heating cycle interval is designed so that the adjacent temperature zones can perform temperature adjustment within a certain temperature difference range without affecting the temperature control of their respective temperature zones.

[0003] However, when using a traditional reflow soldering device for FPC soldering process, it is difficult to ensure the qualified soldering quality of FPC. After several tests, it is found that the temperature curve feedback by the reflow soldering device during operation often shows a temperature drop phenomenon at the temperature zone interval position. The reason for the above temperature drop phenomenon is that the FPC is very thin and its heat storage is very small. When the FPC is transported to the temperature zone interval position, its own temperature will be abnormal, affecting the soldering quality.

[0004] In summary, how to ensure the soldering quality of the circuit board is an urgent problem to be solved by those skilled in the art at present. Summary of the Utility Model

[0005] In view of this, the purpose of the utility model is to provide an air return device for preventing temperature drop between temperature zones, and the circuit board soldered by using the reflow soldering device provided with the air return device has a high quality.

[0006] Another purpose of the utility model is to provide a reflow soldering device including the above-mentioned air return device for preventing temperature drop between temperature zones.

[0007] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0008] An air return device for preventing temperature drop between temperature zones, which is used to be installed on the furnace cover of a reflow soldering device, is characterized in that it includes:

[0009] An air return component;

[0010] A fan, which is arranged in the air return component;

[0011] The flow deflector is provided in the air return assembly. The flow deflector has a first air return opening, a second air return opening, and an air outlet. A plurality of the air outlets are evenly distributed on the flow deflector. The outlet of the fan is communicated with the air outlet, and the inlet is communicated with the first air return opening. The first air return opening is located on one side of the flow deflector along the first direction, and the second air return opening is located on the other side of the flow deflector along the first direction, so that the gas in the adjacent temperature zones can flow into the fan through the corresponding first air return opening.

[0012] Preferably, it further includes at least two air mixing plates, and the air mixing plates have a third air return opening communicated with the inlet of the fan.

[0013] The air mixing plates are provided in the air return assembly, and at least one air mixing plate is located on one side of the flow deflector along the second direction, and at least one air mixing plate is located on the other side of the flow deflector along the second direction. The second direction is perpendicular to the first direction.

[0014] Preferably, the air return assembly includes an air mixing box and an air return box.

[0015] The air mixing plates are lapped and installed on the flow deflector, and the flow deflector is installed on the air mixing box. The top opening of the air mixing box covers the air outlets, so that a plurality of the air outlets are all communicated with the inner cavity of the air mixing box.

[0016] The air mixing box is installed on the top of the air return box, and the first air return opening, the second air return opening, and the third air return opening are all communicated with the inner cavity of the air return box.

[0017] The outlet of the fan is communicated with the inner cavity of the air mixing box, and the inlet is communicated with the inner cavity of the air return box.

[0018] Preferably, the air outlets include a first air outlet, a second air outlet, and a third air outlet arranged along the first direction. The second air outlet is located between the first air return opening and the second air return opening. The first air outlet is located on the other side of the first air return opening, and the third air outlet is located on the other side of the second air return opening.

[0019] A first spacer and a second spacer are inserted into the air mixing box. The inner cavity of the air mixing box is separated into a first chamber, a second chamber, and a third chamber corresponding to and communicated with the first air outlet, the second air outlet, and the third air outlet through the first spacer and the second spacer.

[0020] The first spacer has a first air return channel and a first air outlet channel. The first air return channel communicates the first air return opening and the inner cavity of the air return box, and the first air outlet channel communicates the first chamber and the second chamber.

[0021] The second spacer has a second return air passage and a second air outlet passage. The second return air passage communicates with the second return air opening and the inner cavity of the return air box, and the first air outlet passage communicates with the third chamber and the second chamber.

[0022] Preferably, the fan includes a hot air motor, a wind wheel and a supercharging volute;

[0023] The supercharging volute includes a connecting box and at least two air outlet cylinders. The inlet of the supercharging volute is located in the connecting box and communicates with the inner cavity of the return air box. The first end of the air outlet cylinder is arranged in the connecting box and communicates with it. The second end of the air outlet cylinder is inserted into the air mixing box, and the outlet of the supercharging volute is located at the second end of the air outlet cylinder and communicates with the inner cavity of the air mixing box. The first ends of several air outlet cylinders are evenly arranged around the circumferential surface of the connecting box, and the second ends of several air outlet cylinders are inserted into the air mixing box at intervals;

[0024] The wind wheel is coaxially arranged at the output end of the hot air motor, and the wind wheel is inserted into the connecting box and can rotate relative to it.

[0025] Preferably, the air mixing box is a rectangular box body, the second end of the air outlet cylinder is a straight-line structure, and is inserted into the air mixing box perpendicular to the bottom plate of the air mixing box;

[0026] It further includes several flow rectifying members. Several flow rectifying members block the corresponding outlets of the supercharging volute, and there is a gap between the flow rectifying members and the second ends of the air outlet cylinders to guide the gas to flow around.

[0027] Preferably, the hot air motor is installed in the return air box, the connecting box is installed in the return air box and is located in its inner cavity, and the air outlet cylinder passes through the return air box and is inserted into the air mixing box.

[0028] Preferably, the width of the guide plate along the first direction is equal to the width of the air mixing plate along the first direction, and the air mixing plate and the guide plate overlap to form a rectangular plate body, and the sequentially connected rectangular plate body, the air mixing box and the return air box are rectangular columns.

[0029] Preferably, the return air box includes a top plate, a bottom plate, two side plates and two end plates;

[0030] The two end plates are arranged oppositely, the main plate bodies of the two side plates are arranged oppositely, and one end plate, the main plate body of one side plate, the other end plate and the main plate body of the other side plate are sequentially sealed and connected to form a rectangular column;

[0031] The first end of the main board body has feet, the second end is hermetically connected to the bottom plate, the top plate is hermetically connected to the middle position of the main board body, the air mixing box is installed on the feet, and there is a return air space between the air mixing box and the top plate. The top plate has air vents to conduct the return air space and the inner cavity of the return air box.

[0032] A reflow soldering device includes a furnace cover and also includes the return air device for preventing temperature drop in the temperature interval as described in any one of the above.

[0033] For the return air device for preventing temperature drop in the temperature interval provided by the present invention, the return air assembly is used to install and support the deflector, the fan, etc. The deflector is arranged on the return air assembly. The deflector is provided with a plurality of first return air vents, second return air vents and air outlets. The beneficial effect is that the air outlets are evenly arranged on the deflector to be able to discharge the gas evenly, and the first return air vents are opened on one side of the deflector along its own width, and the second return air vents are opened on the other side of the deflector along its own width direction. When in use, the return air device is installed on the furnace cover of the reflow soldering device, and the fan is started to suck the gas in the temperature zone close to it through the first return air vent, and at the same time suck the gas in the temperature zone close to it through the second return air vent, and then recharge the mixed gas into the furnace cavity through the air outlet, so that the temperature in the original temperature interval area is close to the temperature of the adjacent temperature zone, effectively avoiding the phenomenon of temperature drop of the circuit board to ensure the welding quality of the circuit board. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0035] Figure 1 It is an exploded view of a specific embodiment provided by the present invention;

[0036] Figure 2 It is a structural schematic diagram of a specific embodiment provided by the present invention;

[0037] Figure 3 It is a schematic diagram of the air intake path of a specific embodiment provided by the present invention;

[0038] Figure 4 It is a schematic diagram of the air outlet path of a specific embodiment provided by the present invention;

[0039] Figure 5 It is a top view of a specific embodiment provided by the present invention;

[0040] Figure 6 Schematic diagram of the use of the specific embodiment provided by the present utility model.

[0041] Reference numerals:

[0042] 1 - Return air assembly; 11 - Air mixing box; 111 - First chamber; 112 - Second chamber; 113 - Third chamber; 12 - Return air box; 121 - Top plate; 1211 - Air outlet; 122 - Side plate; 123 - End plate;

[0043] 2 - Fan; 21 - Hot air motor; 22 - Wind wheel; 23 - Boosting volute; 231 - Connection box; 232 - Air outlet cylinder;

[0044] 3 - Deflector; 31 - First return air outlet; 32 - Second return air outlet; 33 - Air outlet; 331 - First air outlet; 332 - Second air outlet; 333 - Third air outlet;

[0045] 4 - Air mixing plate; 41 - Third return air outlet;

[0046] 5 - First spacer; 51 - First return air passage; 52 - First air outlet passage;

[0047] 6 - Second spacer; 61 - Second return air passage; 62 - Second air outlet passage;

[0048] 7 - Rectifying member;

[0049] 100 - Return air device; 200 - Furnace cover;

[0050] X - First direction; Y - Second direction; Z - Third direction. Specific embodiments

[0051] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0052] The core of the present utility model is to provide a return air device that prevents temperature drop in the temperature interval, and the quality of the circuit board welded using the reflow soldering equipment provided with the return air device is relatively high. Another core of the present utility model is to provide a reflow soldering equipment including the above-mentioned return air device that prevents temperature drop in the temperature interval.

[0053] Please refer to Figure 1 , the present utility model provides a return air device that prevents temperature drop in the temperature interval, which is used to be installed on the furnace cover of the reflow soldering equipment, and includes a return air assembly 1, a fan 2 and a deflector 3.

[0054] Among them, the blower 2 is arranged in the air return assembly 1; the deflector 3 is arranged in the air return assembly 1. The deflector 3 has a first air return opening 31, a second air return opening 32 and an air outlet 33. A plurality of air outlets 33 are evenly distributed on the deflector 3. The outlet of the blower 2 communicates with the air outlet 33, and the inlet communicates with the first air return opening 31. The first air return opening 31 is located on one side of the deflector 3 along the first direction, and the second air return opening 32 is located on the other side of the deflector 3 along the first direction, so that the gas in the adjacent temperature zones can flow into the blower 2 through the corresponding first air return opening 31.

[0055] Such as Figure 1 and Figure 2 As shown, the air return assembly 1 is used to install and support the deflector 3, the blower 2, etc. The deflector 3 is arranged on the air return assembly 1, and the deflector 3 is provided with a plurality of first air return openings 31, second air return openings 32 and air outlets 33. The air outlets 33 are evenly arranged on the deflector 3 to be able to discharge the gas evenly. The first air return opening 31 is opened on the left side of the deflector 3 along the X direction, and the second air return opening 32 is opened on the right side of the deflector 3 along the X direction.

[0056] It should be noted that the types of the first air return opening 31, the second air return opening 32 and the air outlet 33 are not limited, such as circular or oval or rectangular, etc. Of course, the first air return opening 31, the second air return opening 32 and the air outlet 33 can be all the same or all different.

[0057] It should also be noted that the distribution types of the first air return opening 31, the second air return opening 32 and the air outlet 33 are not limited. For example, they are arranged in a matrix. For example, among the discharge air outlets 33, a plurality of air outlets 33 are evenly arranged along the X direction, and each discharge air outlet 33 is evenly arranged along the Y direction, or they are evenly arranged around the central position, that is, a plurality of air outlets 33 are evenly arranged in several circles around the central position, and the first air return opening 31 is evenly arranged in an arc around the central position, and the second air return opening 32 is evenly arranged in an arc around the central position.

[0058] During use, install this air return device on the furnace cover of the reflow soldering equipment, such as Figure 6 As shown, start the blower 2 to suck the gas in the temperature zone close to it through the first air return opening 31, and at the same time suck the gas in the temperature zone close to it through the second air return opening 32, and then re-inject the mixed gas into the furnace cavity through the air outlet 33, so that the temperature in the original temperature interval area is close to the temperature of the adjacent temperature zone, effectively avoiding the phenomenon of temperature drop of the circuit board, ensuring the welding quality of the circuit board, and the reflow soldering equipment equipped with this air return device has strong versatility.

[0059] On the basis of the above embodiments, there are further at least two mixing air plates 4. The mixing air plate 4 has a third air return opening 41 communicating with the inlet of the fan 2. The mixing air plate 4 is arranged in the air return assembly 1, and at least one mixing air plate 4 is located on one side of the flow guiding plate 3 along the second direction, and at least one mixing air plate 4 is located on the other side of the flow guiding plate 3 along the second direction, and the second direction is perpendicular to the first direction.

[0060] As Figure 1 and Figure 2 shown, mixing air plates 4 are arranged at both ends of the flow guiding plate 3 along the Y direction, and the mixing air plate 4 is provided with a third air return opening 41. Then, when the fan 2 is started, while sucking the gas in the temperature zone close to it through the first air return opening 31 and sucking the gas in the temperature zone close to it through the second air return opening 32, the gas inside and outside the furnace cavity is sucked through the third air return opening 41. Such an arrangement is beneficial to improving the temperature uniformity in the furnace cavity.

[0061] It should be noted that the type of the third air return opening 41 is not limited, such as circular or oval or rectangular, etc.; it should also be noted that the number and arrangement mode of the third air return openings 41 are not limited. For example, as Figure 2 and Figure 5 shown, a plurality of third air return openings 41 are arranged in a matrix, and each row of the third air return openings 41 is arranged along the X direction, and a plurality of third air return openings 41 in each row of the third air return openings 41 are evenly arranged along the Y direction, or each mixing air plate 4 includes one third air return opening 41.

[0062] On the basis of the above embodiments, the air return assembly 1 includes a mixing air box 11 and an air return box 12; the mixing air plate 4 is lapped and installed on the flow guiding plate 3, and the flow guiding plate 3 is installed in the mixing air box 11. The top opening of the mixing air box 11 covers the air outlet 33 so that a plurality of air outlets 33 communicate with the inner cavity of the mixing air box 11; the mixing air box 11 is installed on the top of the air return box 12, and the first air return opening 31, the second air return opening 32 and the third air return opening 41 all communicate with the inner cavity of the air return box 12; the outlet of the fan 2 communicates with the inner cavity of the mixing air box 11, and the inlet communicates with the inner cavity of the air return box 12.

[0063] As Figure 1 and Figure 2 shown, the air return assembly 1 is a three-layer structure, which is the flow guiding plate 3 / mixing air plate 4, the mixing air box 11 and the air return box 12 from top to bottom in sequence. Specifically, as Figure 2As shown in the figure, the mixing air plate 4 overlaps and cooperates with the deflector plate 3 and is fixedly connected, and the two do not block each other's openings. The deflector plate 3 is installed at the upper opening of the mixing air box 11, and the mixing air box 11 covers all the air outlets 33, so that the gas in the mixing air box 11 can be discharged through the air outlets 33; the mixing air box 11 is installed on the top of the return air box 12 to form an integrated structure. The return air box 12 conducts the first return air opening 31, the second return air opening 32 and the third return air opening 41 through its top opening or pipeline, etc., so that the gas can flow into the return air box 12 through the first return air opening 31, the second return air opening 32 and the third return air opening 41; correspondingly, the inlet of the fan 2 is conducted to the inner cavity of the return air box 12 through a pipeline or insertion, etc., and the outlet is conducted to the inner cavity of the mixing air box 11 through a pipeline or docking, etc.

[0064] During use, when the fan 2 is started, the gas can flow smoothly along the path of the first return air opening 31 / the second return air opening 32 / the third return air opening 41, the return air box 12, the fan 2, the mixing air box 11, and the air outlet 33. With such a setting, the structure is simple and is conducive to realizing miniaturized design.

[0065] On the basis of the above embodiments, the air outlet 33 includes a first air outlet 331, a second air outlet 332, and a third air outlet 333 arranged along the first direction. The second air outlet 332 is located between the first return air opening 31 and the second return air opening 32. The first air outlet 331 is located on the other side of the first return air opening 31, and the third air outlet 333 is located on the other side of the second return air opening 32; a first spacer 5 and a second spacer 6 are inserted into the mixing air box 11. The inner cavity of the mixing air box 11 is divided into a first chamber 111, a second chamber 112, and a third chamber 113 corresponding to the first air outlet 331, the second air outlet 332, and the third air outlet 333 through the first spacer 5 and the second spacer 6; the first spacer 5 has a first return air channel 51 and a first air outlet channel 52. The first return air channel 51 communicates with the first return air opening 31 and the inner cavity of the return air box 12, and the first air outlet channel 52 communicates with the first chamber 111 and the second chamber 112; the second spacer 6 has a second return air channel 61 and a second air outlet channel 62. The second return air channel 61 communicates with the second return air opening 32 and the inner cavity of the return air box 12, and the first air outlet channel 52 communicates with the third chamber 113 and the second chamber 112.

[0066] As Figure 2 and Figure 5 shown, the first air outlet 331, the first return air opening 31, the second air outlet 332, the second return air opening 32, and the third air outlet 333 are sequentially distributed along the X direction on the deflector plate 3.

[0067] Correspondingly, as Figure 1 and Figure 3As shown in the figure, a first spacer 5 and a second spacer 6 are inserted inside the air mixing box 11, so as to divide the inner cavity of the air mixing box 11 into three relatively independent parts, namely, a first chamber 111, a second chamber 112, and a third chamber 113 arranged in sequence along the X direction. Moreover, the first air outlet 331 is opposite to and communicated with the first chamber 111, the second air outlet 332 is opposite to and communicated with the second chamber 112, and the third air outlet 333 is opposite to and communicated with the third chamber 113.

[0068] The first air return port 31 is opposite to the first spacer 5, and a first air return channel 51 is opened on the first spacer 5. As Figure 1 and Figure 3 shown, the upper opening of the first air return channel 51 is opposite to and communicated with the first air return port 31, and the lower opening of the first air return channel 51 is communicated with the inner cavity of the air return box 12. It should be noted that the way of communicating the first air return channel 51 with the inner cavity of the air return box 12 is not limited. For example, a pipeline is inserted into the first air return channel 51, and the lower end of the pipeline extends into the air return box 12. Or, the lower end of the first spacer 5 passes through the side walls of the air mixing box 11 and the air return box 12 and extends into the air return box 12, and an opening is opened at the lower end of the first spacer 5; and a first air outlet channel 52 is opened on the first spacer 5. As Figure 1 and Figure 4 shown, the first air outlet channel 52 penetrates through the first spacer 5, so as to communicate the first chamber 111 located on the left side and the second chamber 112 located in the middle along the X direction.

[0069] Similarly, the second air return port 32 is opposite to the second spacer 6, and a second air return channel 61 is opened on the second spacer 6. As Figure 1 and Figure 3 shown, the upper opening of the second air return channel 61 is opposite to and communicated with the second air return port 32, and the lower opening of the second air return channel 61 is communicated with the inner cavity of the air return box 12. It should be noted that the way of communicating the second air return channel 61 with the inner cavity of the air return box 12 is not limited. For example, a pipeline is inserted into the second air return channel 61, and the lower end of the pipeline extends into the air return box 12. Or, the lower end of the second spacer 6 passes through the side walls of the air mixing box 11 and the air return box 12 and extends into the air return box 12, and an opening is opened at the lower end of the second spacer 6; and a second air outlet channel 62 is opened on the second spacer 6. As Figure 1 and Figure 4 shown, the second air outlet channel 62 penetrates through the second spacer 6, so as to communicate the second chamber 112 located in the middle and the third chamber 113 located on the right side along the X direction.

[0070] It should be noted that the types of the first spacer 5 and the second spacer 6 are not limited, as long as the above functions can be achieved. Taking the first spacer 5 as an example, optionally, the number of the first return air channels 51 is one, and a plurality of first return air openings 31 face and communicate with one first return air channel 51. The number of the first air outlet channels 52 is two. One first air outlet channel 52 is located on the side of one end of the first return air channel 51 along the X direction, and the other first air outlet channel 52 is located on the side of the other end of the first return air channel 51 along the X direction. Preferably, the number of the first return air channels 51 is equal to the number of the first return air openings 31. A plurality of first return air channels 51 face and communicate with the corresponding first return air channels 51. A plurality of first air outlet channels 52 are evenly arranged along the X direction. With such an arrangement, it is beneficial to ensure the uniformity of the gas in the inner cavity of the mixing air box 11, so as to further ensure the uniformity of the air outlet of the return air device. The second spacer 6 is the same as the first spacer 5. It should also be noted that the second spacer 6 and the first spacer 5 may be the same or different.

[0071] During use, the fan 2 is started, and the gas flows back into the return air box 12 through three paths: the first return air opening 31 - the first return air channel 51 - the return air box 12, the second return air opening 32 - the second return air channel 61 - the return air box 12, and the third return air opening 41 - the return air box 12, and then flows out smoothly through the path of the fan 2, the mixing air box 11, the first air outlet 331 / the second air outlet 332 / the third air outlet 333. With such an arrangement, it is beneficial to improve the temperature uniformity in the furnace and further ensure the welding quality of the circuit board.

[0072] In some specific embodiments, such as Figure 5 shown, a plurality of first air outlets 331 are evenly arranged in a row along the Y direction, a plurality of third air outlets 333 are evenly arranged in a row along the Y direction, a plurality of first return air openings 31 are evenly arranged in a row along the Y direction, a plurality of second return air openings 32 are evenly arranged in a row along the Y direction, and a plurality of second air outlets 332 are arranged in a matrix. A plurality of second air outlets 332 in each row are evenly arranged along the Y direction, and a plurality of second air outlets 332 in each row are evenly arranged along the X direction. For example, 13 rows of second air outlets 332 are evenly arranged along the X direction.

[0073] Based on the above embodiments, the fan 2 includes a hot air motor 21, a wind wheel 22, and a supercharging volute 23; the supercharging volute 23 includes a connection box 231 and at least two air outlet cylinders 232. The inlet of the supercharging volute 23 is located in the connection box 231 and communicates with the inner cavity of the return air box 12. The first end of the air outlet cylinder 232 is provided in the connection box 231 and communicates with it. The second end of the air outlet cylinder 232 is inserted into the mixing air box 11, and the outlet of the supercharging volute 23 is located at the second end of the air outlet cylinder 232 and communicates with the inner cavity of the mixing air box 11. The first ends of several air outlet cylinders 232 are evenly arranged around the circumferential surface of the connection box 231, and the second ends of several air outlet cylinders 232 are inserted into the mixing air box 11 at intervals; the wind wheel 22 is coaxially arranged at the output end of the hot air motor 21, and the wind wheel 22 is inserted into the connection box 231 and can rotate relative to it.

[0074] As Figure 1 and Figure 4 shown, the inlet of the supercharging volute 23 is opened on the connection box 231 and communicates with the inner cavity of the return air box 12 through a pipeline or the like. Then, the gas in the return air box 12 can enter the inner cavity of the connection box 231, and the air outlet cylinders 232 are installed on the circumferential surface of the connection box 231. Specifically, the lower end of the air outlet cylinder 232 is provided on the connection box 231 and communicates with its inner cavity. It should be noted that the mating relationship between the air outlet cylinder 232 and the connection box 231 is not limited, as long as a conductive connection can be achieved. For example, the air outlet cylinder 232 and the connection box 231 are an integral thin shell structure, or the lower end of the air outlet cylinder 232 is inserted into a through hole opened on the circumferential surface of the connection box 231, and the lower end of the air outlet cylinder 232 is open to communicate with the inner cavity of the connection box 231; while the upper end of the air outlet cylinder 232 is inserted into the mixing air box 11, and several outlets of the supercharging volute 23 are opened at the upper ends of the corresponding air outlet cylinders 232 to communicate with the inner cavity of the mixing air box 11.

[0075] Correspondingly, as Figure 4 shown, the wind wheel 22 is inserted into the mixing air box 11, and the wind wheel 22 is connected to the output end of the hot air motor 21. During use, the hot air motor 21 is started to drive the wind wheel 22 to rotate, so as to suck the gas in the return air box 12, so that the gas enters the connection box 231 from the inlet opened on the connection box 231 and is discharged into the mixing air box 11 through several air outlet cylinders 232 and their upper outlets.

[0076] It should be noted that the type of the connection box 231 is not limited, as long as it can cooperate with the fan 2 to suck gas. For example, a cylindrical shell or a rectangular shell, etc. It should also be noted that the type of the air outlet cylinder 232 is not limited, as long as it can discharge the gas in the connection box 231 into the mixing air box 11. In some specific embodiments, one end or both ends of the air outlet cylinder 232 are connected to the connection box 231, and the other end or both ends are inserted into the mixing air box 11. For example, a cylinder in the shape of an L or an h, etc.

[0077] To further improve the air outlet uniformity, as Figure 1 and Figure 4 shown, the lower ends of a number of air outlet tubes 232 are evenly arranged around the circumferential surface of the connection box 231, so that the gas in the connection box 231 can be evenly discharged into the air outlet tubes 232, and the upper ends of the air outlet tubes 232 are inserted into different positions of the mixing box 11 at intervals, so as to guide the gas to be discharged into the mixing box 11 more evenly, which is beneficial to further improve the temperature uniformity in the furnace.

[0078] On the basis of the above embodiment, the mixing box 11 is a rectangular box body, the second end of the air outlet tube 232 is a linear structure, and is inserted into the mixing box 11 perpendicular to the bottom plate of the mixing box 11; it also includes a number of flow rectifying members 7, and the corresponding outlets of the supercharging volute 23 are blocked by the number of flow rectifying members 7, and there is a gap between the flow rectifying member 7 and the second end of the air outlet tube 232 to guide the gas to flow around.

[0079] As Figure 1 and Figure 4 shown, the mixing box 11 is a rectangular box body with an open top, and the guide plate 3 is installed at the upper opening of the mixing box 11 along the Z direction. It should be noted that the Z direction is perpendicular to the X direction and the Y direction, and the upper end of the air outlet tube 232 extends along the Z direction and is inserted on the bottom plate of the mixing box 11. Such a setting is beneficial to simplify the return air device and effectively reduce the assembly difficulty of the fan 2 with the return air box 12 and the mixing box 11.

[0080] Since the air outlet tube 232 is a thin shell structure, the outlet of the supercharging volute 23 is the open upper end of the air outlet tube 232. When the upper end of the air outlet tube 232 extends along the Z direction and is inserted on the bottom plate of the mixing box 11, the gas will be discharged and flow along the Z direction from the air outlet tube 232. To further ensure the air outlet uniformity, a flow rectifying member 7 is provided in the mixing box 11 to block the corresponding outlet of the supercharging volute 23, so that the gas will not directly pass through the opposite air outlet 33 after flowing out of the supercharging volute 23, but first flow around through the gap between the flow rectifying member 7 and the upper end of the air outlet tube 232, so as to flow to all parts of the inner cavity of the mixing box 11 and then flow out through the air outlet 33.

[0081] It should be noted that the type of the shielding member and its installation position are not limited, as long as the above functions can be achieved. For example, the shielding member includes a baffle plate, a connecting plate and a connecting rod. The baffle plate is arranged parallel to the connecting plate and connected by the connecting rod, and the connecting plate is attached to the inner surface of the bottom plate of the air mixing box 11 and installed on the bottom plate of the air mixing box 11. The connecting plate has a plugging through hole, and the air outlet cylinder 232 is inserted into the plugging through hole, and the baffle plate is opposite to the corresponding outlet of the supercharging volute 23. Or, the shielding member adopts a cover structure and is sleeved on the upper end of the air outlet cylinder 232 through a clamp. The top plate 121 of the shielding member is opposite to the upper end opening of the air outlet cylinder 232, and there is a gap between the top plate 121 of the shielding member and the upper end of the air outlet cylinder 232, so that the gas can flow out from the air outlet cylinder 232 and flow into the air mixing box 11 through the through holes on the peripheral surface of the shielding member.

[0082] Based on the above embodiments, the hot air motor 21 is installed in the return air box 12, the connection box 231 is installed in the return air box 12 and located in its inner cavity, and the air outlet cylinder 232 passes through the return air box 12 and is inserted into the air mixing box 11.

[0083] As Figure 3 and Figure 4 shown, the hot air motor 21 is located outside the return air box 12, while the connection box 231 is installed in the inner cavity of the return air box 12. The lower end of the air outlet cylinder 232 is inserted into the inner cavity of the return air box 12 and communicates with the connection box 231, and the upper end is inserted above the return air box 12 on the upper surface of the air mixing box. With such a setting, the structure is simple, and it is beneficial to realize miniaturized design and heat dissipation.

[0084] Based on the above embodiments, the width of the flow guiding plate 3 in the first direction is equal to the width of the air mixing plate 4 in the first direction, and the air mixing plate 4 and the flow guiding plate 3 overlap to form a rectangular plate body, and the sequentially connected rectangular plate body, air mixing box 11 and return air box 12 are rectangular columns.

[0085] As Figures 1 to 5 shown, the flow guiding plate 3 and the air mixing plate 4 that overlap and are fixedly connected form an integral rectangular plate body. The return air box 12 and the air mixing box 11 are both rectangular boxes. The rectangular plate body, air mixing box 11 and return air box 12 connected in sequence from top to bottom in the Z direction are rectangular columns. With such a setting, as Figure 2 shown, a plurality of such return air devices arranged in parallel are convenient for splicing the above rectangular plate bodies to form a large rectangular plate body.

[0086] Based on the above embodiments, the return air box 12 includes a top plate 121, a bottom plate, two side plates 122 and two end plates 123; the two end plates 123 are arranged oppositely, the main body plates of the two side plates 122 are arranged oppositely, and one end plate 123, the main body plate of one side plate 122, the other end plate 123 and the main body plate of the other side plate 122 are sequentially sealed and connected to form a rectangular column; the first end of the main body plate has a base foot, the second end is sealed and connected to the bottom plate, the top plate 121 is sealed and connected to the middle position of the main body plate, the mixing air box 11 is installed on the base foot, and there is a return air space between the mixing air box 11 and the top plate 121, and the top plate 121 has an air outlet 1211 to conduct the return air space and the inner cavity of the return air box 12.

[0087] As Figures 1 to 4 shown, the two side plates 122 are both L-shaped plates, and the main body plates at the lower sides of the two side plates 122 are arranged oppositely, and their corresponding ends are connected by the corresponding end plates 123 to enclose a rectangular column with a rectangular inner cavity; the mixing air plate 4 is installed on the upper base feet of the main body plates of the two side plates 122, the bottom plate is installed on the upper ends of the main body plates of the two side plates 122, and the top plate 121 is installed at the middle height position of the main body plates of the two side plates 122. Then, the above rectangular inner cavity is divided into two parts from top to bottom by the top plate 121. Among them, the space between the top plate 121 and the bottom plate is the inner cavity of the return air box 12, and the space between the top of the top plate 121 and the mixing air box 11 is the return air space.

[0088] Correspondingly, an air outlet 1211 is opened on the top plate 121, the lower ends of the first spacer 5 and the second spacer 6 both penetrate through the mixing air box 11 and are provided with openings. Then, gas can flow into the return air box 12 along the three paths of the first return air opening 31 - the first return air channel 51 - the return air space - the air outlet 1211, the second return air opening 32 - the second return air channel 61 - the return air space - the air outlet 1211, and the third return air opening 41 - the return air space - the air outlet 1211. With such a setting, the structure of the return air device is simple, the manufacturing difficulty is effectively reduced, and the self-weight is reduced.

[0089] In addition to the above return air device for preventing temperature drop in the temperature interval, the present invention also provides a reflow soldering device including the return air device 100 for preventing temperature drop in the temperature interval disclosed in the above embodiments. The reflow soldering device further includes a furnace cover 200, and the return air device 100 is arranged inside the furnace cover 200. For the structures of other parts of the reflow soldering device, please refer to the prior art and will not be elaborated herein.

[0090] It should be noted that the relational terms such as "first" and "second" described above are only used to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities; the "upper surface, lower surface, top, bottom" and the orientation words "upper, lower, left, right" described above are all defined based on the accompanying drawings of the specification; the " / " described above is a symbol indicating parallelism; the "-" described above is a symbol used for separation in a number of sequentially arranged nouns.

[0091] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0092] The above has introduced in detail the air return device and reflow soldering equipment for preventing temperature drop in the temperature interval provided by the present utility model. Specific examples are used herein to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and modifications can be made to the present utility model, and these improvements and modifications also fall within the protection scope of the present utility model.

Claims

1. A return air device for preventing temperature drop in the temperature interval, which is used to be installed on the furnace cover of a reflow soldering device, and is characterized in that, Comprising: Return air assembly (1); A fan (2), provided in the return air assembly (1); A deflector (3), provided in the return air assembly (1), the deflector (3) having a first return air inlet (31), a second return air inlet (32) and an air outlet (33), a plurality of the air outlets (33) being evenly distributed on the deflector (3), the outlet of the fan (2) being communicated with the air outlet (33) and the inlet being communicated with the first return air inlet (31), the first return air inlet (31) being located on one side of the deflector (3) along a first direction, and the second return air inlet (32) being located on the other side of the deflector (3) along the first direction, for the gas in the adjacent temperature zones to flow into the fan (2) through the corresponding first return air inlet (31).

2. The air return device for preventing temperature drop in the temperature range according to claim 1, wherein Further comprising at least two mixing plates (4), the mixing plates (4) having a third return air inlet (41) communicated with the inlet of the fan (2); The mixing plates (4) are provided in the return air assembly (1), and at least one of the mixing plates (4) is located on one side of the deflector (3) along a second direction, and at least one of the mixing plates (4) is located on the other side of the deflector (3) along the second direction, the second direction being perpendicular to the first direction.

3. The return air device for preventing temperature drop in the temperature range according to claim 2, wherein The return air assembly (1) includes a mixing box (11) and a return air box (12); The mixing plates (4) are lapped and installed on the deflector (3), and the deflector (3) is installed on the mixing box (11), the top opening of the mixing box (11) covering the air outlet (33), so that a plurality of the air outlets (33) are all communicated with the inner cavity of the mixing box (11); The mixing box (11) is installed on the top of the return air box (12), and the first return air inlet (31), the second return air inlet (32) and the third return air inlet (41) are all communicated with the inner cavity of the return air box (12); The outlet of the fan (2) is communicated with the inner cavity of the mixing box (11), and the inlet is communicated with the inner cavity of the return air box (12).

4. The return air device for preventing temperature drop in the temperature interval according to claim 3, characterized in that, The air outlet (33) includes a first air outlet (331), a second air outlet (332) and a third air outlet (333) arranged along the first direction, the second air outlet (332) being located between the first return air inlet (31) and the second return air inlet (32), the first air outlet (331) being located on the other side of the first return air inlet (31), and the third air outlet (333) being located on the other side of the second return air inlet (32); A first spacer (5) and a second spacer (6) are inserted into the mixing box (11), and the inner cavity of the mixing box (11) is divided into a first chamber (111), a second chamber (112) and a third chamber (113) corresponding to being communicated with the first air outlet (331), the second air outlet (332) and the third air outlet (333) by the first spacer (5) and the second spacer (6); The first spacer (5) has a first return air channel (51) and a first air outlet channel (52). The first return air channel (51) communicates with the first return air inlet (31) and the inner cavity of the return air box (12). The first air outlet channel (52) communicates with the first chamber (111) and the second chamber (112). The second spacer (6) has a second return air channel (61) and a second air outlet channel (62). The second return air channel (61) communicates with the second return air inlet (32) and the inner cavity of the return air box (12). The first air outlet channel (52) communicates with the third chamber (113) and the second chamber (112).

5. The return air device for preventing temperature drop in the temperature interval according to claim 3, characterized in that, The fan (2) includes a hot air motor (21), a wind wheel (22) and a supercharging volute (23). The supercharging volute (23) includes a connection box (231) and at least two air outlet cylinders (232). The inlet of the supercharging volute (23) is located at the connection box (231) and is conducted to the inner cavity of the return air box (12). The first end of the air outlet cylinder (232) is arranged at the connection box (231) and is conducted with it. The second end of the air outlet cylinder (232) is inserted into the air mixing box (11). And the outlet of the supercharging volute (23) is located at the second end of the air outlet cylinder (232) and is conducted to the inner cavity of the air mixing box (11). The first ends of several air outlet cylinders (232) are evenly arranged around the circumferential surface of the connection box (231). The second ends of several air outlet cylinders (232) are inserted into the air mixing box (11) at intervals. The wind wheel (22) is coaxially arranged at the output end of the hot air motor (21), and the wind wheel (22) is inserted into the connection box (231) and can rotate relative to it.

6. The return air device for preventing temperature drop in the temperature interval according to claim 5, characterized in that, The air mixing box (11) is a rectangular box body. The second end of the air outlet cylinder (232) is of a straight-line structure and is inserted into the air mixing box (11) perpendicular to the bottom plate of the air mixing box (11). It further includes several rectifying members (7). Several rectifying members (7) block the corresponding outlets of the supercharging volute (23), and there is a gap between the rectifying members (7) and the second ends of the air outlet cylinders (232) to guide the gas to flow around.

7. The return air device for preventing temperature drop in the temperature interval according to claim 6, characterized in that, The hot air motor (21) is installed on the return air box (12). The connection box (231) is installed in the return air box (12) and is located in its inner cavity. The air outlet cylinder (232) passes through the return air box (12) and is inserted into the air mixing box (11).

8. The return air device for preventing temperature drop in the temperature range according to claim 3, characterized in that The width of the guide plate (3) along the first direction is equal to the width of the air mixing plate (4) along the first direction. The air mixing plate (4) and the guide plate (3) overlap to form a rectangular plate body. And the sequentially connected rectangular plate body, the air mixing box (11) and the return air box (12) are rectangular columns.

9. The return air device for preventing temperature drop in the temperature interval according to claim 3, characterized in that, The return air box (12) includes a top plate (121), a bottom plate, two side plates (122) and two end plates (123). The two end plates (123) are arranged oppositely, the main body plates of the two side plates (122) are arranged oppositely, and the main body plate of one end plate (123), the main body plate of one side plate (122), the main body plate of the other end plate (123) and the main body plate of the other side plate (122) are hermetically connected in sequence to form a rectangular column body; The first end of the main body plate has a base foot, the second end is hermetically connected to the bottom plate, the top plate (121) is hermetically connected to the middle position of the main body plate, the air mixing box (11) is installed on the base foot, and there is a return air space between the air mixing box (11) and the top plate (121), and the top plate (121) has an air outlet (1211) to conduct the return air space and the inner cavity of the return air box (12).

10. A reflow soldering device, comprising a furnace cover (200), characterized in that, It further includes the return air device (100) for preventing temperature drop in the temperature interval according to any one of claims 1-9 above.

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