WO2023159196A1

WO2023159196A1 - Furnace

Info

Publication number: WO2023159196A1
Application number: PCT/US2023/062842
Authority: WO
Inventors: Weizhou LIU; Chuanbo WANG; Wenbo Wang
Original assignee: Illinois Tool Works Inc.
Priority date: 2022-02-18
Filing date: 2023-02-17
Publication date: 2023-08-24
Also published as: CN116625116A; TW202346774A; WO2023159196A8

Abstract

This application discloses a furnace. The furnace includes a housing, a furnace chamber, a conveyor belt and a gas curtain device. The furnace chamber includes a furnace chamber inlet and a furnace chamber outlet. The conveyor belt is provided in the furnace chamber and is capable of conveying a component to be processed from the furnace chamber inlet to the furnace chamber outlet. The gas curtain device is provided on at least one of the furnace chamber inlet and the furnace chamber outlet. The gas curtain device includes a gas curtain seat and a gas curtain movably connected to the gas curtain seat, and the gas curtain is configured to open a space that is above the conveyor belt and that is of at least one of the furnace chamber inlet and the furnace chamber outlet when the component to be processed is about to pass through at least one of the furnace chamber inlet and the furnace chamber outlet, and block a space that is above the conveyor belt and that is of at least one of the furnace chamber inlet and the furnace chamber outlet after the component to be processed passes through at least one of the furnace chamber inlet and the furnace chamber outlet. The furnace of this application is provided with the gas curtain, so that when the gas curtain is in a blocking position, the furnace chamber can be blocked, a nitrogen atmosphere in the furnace chamber is maintained, and heat loss of the furnace chamber is reduced.

Description

FURNACE

Technical Field

[0001] This application relates to a furnace.

Background

[0002] The furnace includes a housing. A furnace chamber extends through the housing. The furnace chamber has a furnace chamber inlet and a furnace chamber outlet. The furnace chamber has a heater that heats the furnace chamber to maintain a certain temperature in the furnace chamber. However, heat in the furnace chamber is lost through the furnace chamber inlet and the furnace chamber outlet, and energy is required to maintain the temperature in the furnace chamber.

Summary

[0003] Examples of this application may address at least some of the abovedescribed issues. For example, this application provides a furnace including a housing, a furnace chamber, a conveyor belt, and a gas curtain device. The furnace chamber extends through the housing, and the furnace chamber includes a furnace chamber inlet and a furnace chamber outlet located on two opposite sides of the housing. The conveyor belt is provided in the furnace chamber and is configured to convey a component to be processed from the furnace chamber inlet to the furnace chamber outlet. The gas curtain device is provided on at least one of the furnace chamber inlet and the furnace chamber outlet. The gas curtain device includes a gas curtain seat and a gas curtain, the gas curtain seat is connected to the housing, the gas curtain is movably connected to the gas curtain seat, and the gas curtain is configured to open a space that is above the conveyor belt and that is of at least one of the furnace chamber inlet and the furnace chamber outlet when the component to be processed is about to pass through at least one of the furnace chamber inlet and the furnace chamber outlet, and block a space that is above the conveyor belt and that is of at least one of the furnace chamber inlet and the furnace chamber outlet after the component to be processed passes through at least one of the furnace chamber inlet and the furnace chamber outlet. [0004] According to the furnace of this application, the gas curtain device is provided above the conveyor belt and is movable up and down relative to the gas curtain seat.

[0005] According to the furnace of this application, it further includes a detection device and a control device. The detection device is configured to detect whether there is the component to be processed on the conveyor belt that is about to pass through at least one of the furnace chamber inlet and the furnace chamber outlet to generate a detection signal. The control device is in communication with the detection device and receives the detection signal. The control device is configured to control upward movement of the gas curtain according to the detection signal sent by the detection device and to control downward movement of the gas curtain after a predetermined time interval after receiving the detection signal.

[0006] According to the furnace of this application, the predetermined time interval is determined by a conveying speed of the conveyor belt, a distance between two adjacent components to be processed, and a length of the component to be processed.

[0007] According to the furnace of this application, the detection device is provided on the gas curtain seat and is located upstream of the gas curtain in a conveying direction of the conveyor belt.

[0008] According to the furnace of this application, it further includes a power device connected to the gas curtain. The power device is in communication with the control device and configured to drive movement of the gas curtain relative to the gas curtain seat.

[0009] According to the furnace of this application, the power device includes at least one cylinder.

[0010] According to the furnace of this application, the power device includes two cylinders arranged along a width direction of the furnace.

[0011] According to the furnace of this application, the gas curtain includes at least two barrier plates, and adjacent barrier plates of the at least two barrier plates are arranged at a distance. [0012] According to the furnace of this application, the gas curtain device is configured to have the bottom of the gas curtain located below the gas curtain seat when the gas curtain moves downward relative to the gas curtain seat.

[0013] The furnace of this application is provided with the gas curtain, so that when the gas curtain is in a blocking position, the furnace chamber can be blocked, a nitrogen atmosphere in the furnace chamber is maintained, and heat loss of the furnace chamber is reduced.

Brief Description of Drawings

[0014] These and other features and advantages of the present application may be better understood by reading the following detailed description with reference to the accompanying drawings, in which same reference numerals represent some parts throughout the accompanying drawings, where:

[0015] Figs. 1A-1 B are perspective views of a furnace of this application;

[0016] Fig. 2A is a perspective view of a gas curtain device shown in Fig. 1A with a gas curtain in an open position;

[0017] Fig. 2B is a perspective view of the gas curtain device shown in Fig. 2A to show components in a gas curtain seat;

[0018] Fig. 2C is a perspective view of the gas curtain device shown in Fig. 2A with the gas curtain in a blocking position;

[0019] Fig. 3 is a simplified schematic view of one example of the gas curtain device shown in Fig. 2B; and

[0020] Fig. 4 is a perspective view of the furnace shown in Fig. 1 A with the gas curtain in the blocking position.

Detailed Description

[0021] Various specific embodiments of the present application will be described below with reference to the attached drawings that form a part of the present specification. In the following drawings, the same parts use the same reference numerals. [0022] It should be understood that while terms denoting orientation, such as “front,” “rear,” “upper,” “lower,” “left,” “right,” “top,” “bottom,” “inside,” “outside,” etc., are used in the present application to describe various exemplary structural parts and elements of the present application, these terms are used herein for convenience of illustration only and are determined based on the exemplary orientations shown in the attached drawings. Since the examples disclosed in the present application may be disposed in different orientations, these terms denoting orientation are for illustrative purposes only and should not be considered as limiting.

[0023] Ordinal words such as “first” and “second” used in this application are used for distinction and identification only and have no other meaning, and do not represent a particular order or association unless specifically specified. For example, the term “first rod” by itself does not imply presence of a “second rod” and the term “second rod” by itself does not imply presence of a “first rod.”

[0024] Figs. 1A-1 B are perspective views of a furnace 100 of this application, where Fig. 1A shows a perspective view of the furnace 100 from a first perspective (i.e. , a furnace chamber inlet 116) and Fig. 1 B shows a perspective view of the furnace 100 from a second perspective (i.e., a furnace chamber outlet 118). As shown in Figs. 1A-1 B, the furnace 100 includes a housing 101 and a furnace chamber. The furnace chamber extends through the housing 101. In particular, the housing 101 includes an upper housing 102 and a lower housing 104. The upper housing 102 and the lower housing 104 both extend in a first direction (i.e., a length direction). The section of the upper housing 102 is generally inverted U-shaped and the section of the lower housing 104 is generally U-shaped. The lower housing 104 is provided below the upper housing 102 and encloses with the upper housing 102 to form the furnace chamber. The furnace chamber includes the furnace chamber inlet 116 and the furnace chamber outlet 118 located on two opposite sides of the housing 101. The furnace chamber inlet 116 and the furnace chamber outlet 118 are located at both ends of the furnace 100 in the first direction, respectively. A heater (not shown) is provided in the upper housing 102 and/or the lower housing 104 to heat the furnace chamber to a predetermined temperature. The furnace 100 also includes a conveyor belt 106. The conveyor belt 106 is provided in the furnace chamber and is formed along the first direction. The conveyor belt 106 is movable relative to the furnace chamber and is used to carry a component to be processed (not shown) to convey the component to be processed from the furnace chamber inlet 116 to the furnace chamber outlet 118.

[0025] The furnace 100 also includes two gas curtain devices 112. One gas curtain device 112 is provided at the furnace chamber inlet 116 and the other gas curtain device 112 is provided at the furnace chamber outlet 118. The two gas curtain devices 112 are capable of opening or blocking a space that is of the furnace chamber inlet 116 and the furnace chamber outlet 118 and that is above the conveyor belt 106 to separate the furnace chamber from the external environment to retain heat in the furnace chamber. In the example of this application, the gas curtain device 112 is provided above the conveyor belt 106. As one example, the gas curtain device 112 is connected to the upper housing 102.

[0026] Figs. 2A-2C are perspective views of the gas curtain device 112 shown in Fig. 1A. Fig. 2A is used to illustrate an overall profile of the gas curtain device 112. A portion of a gas curtain seat 202 in Figs. 2B and 2C is not shown, showing components housed in the gas curtain seat 202. As shown in Figs. 2A-2C, the gas curtain device 112 includes the gas curtain seat 202, a power device 204, and a gas curtain 206. The gas curtain seat 202 is generally a cuboid having a downward opening and defines a chamber 203 in communication with the downward opening. The power device 204 and the gas curtain 206 are disposed in the chamber 203. The power device 204 is connected to the gas curtain 206 and configured to drive the gas curtain 206 to move in a second direction (i.e. , an up-down direction) generally perpendicular to the first direction relative to the gas curtain seat 202. The gas curtain 206 has an open position and a blocking position. When the gas curtain 206 is in the open position (as shown in 2B), the gas curtain 206 opens the space that is of the furnace chamber inlet 116 and the furnace chamber outlet 118 and that is above the conveyor belt 106; and when the gas curtain 206 is in the blocking position (as shown in 2C), the gas curtain 206 blocks the space that is of the furnace chamber inlet 116 and the furnace chamber outlet 118 and that is above the conveyor belt 106. Further, as the gas curtain 206 moves downward relative to the gas curtain seat 202 to the blocking position, the bottom of the gas curtain 206 is located below the gas curtain seat 202. [0027] It should be noted that although the gas curtain seat 202 in this application is a cuboid, the gas curtain seat of any shape is within the protection scope of this application.

[0028] In this application, the power device 204 has two cylinders disposed in an upper portion of the gas curtain 206. The two cylinders are arranged at a distance along the width direction of the furnace 100. Each cylinder includes a first rod 213 and a second rod 214. An upper portion of the first rod 213 is connected to the top of the gas curtain seat 202. The first rod 213 has an accommodating portion (not shown) recessed upward from a lower surface of the first rod 213 to accommodate the second rod 214. The second rod 214 is connected to the first rod 213 and is movable in the second direction relative to the first rod 213. A lower portion of the second rod 214 is connected to the top of the gas curtain 206, thereby driving the gas curtain 206 to move in the second direction.

[0029] It is to be noted that while the power device 204 in this application includes two cylinders, in other examples, the power device 204 including at least one cylinder is within the protection scope of this application. Further, any power device capable of driving the movement of the gas curtain 206 is within the protection scope of this application.

[0030] As shown in Fig. 2C, the gas curtain 206 includes a top plate 221 and three barrier plates 222. The top plate 221 is disposed on upper portions of the three barrier plates 222. The upper surface of the top plate 221 is connected to the second rod 214 and the lower surface of the top plate 221 is connected to the three barrier plates 222. The three barrier plates 222 extend in the second direction and are arranged parallel to each other in the first direction, forming two spacer channels 224 extending in the second direction. When the gas curtain device 112 is disposed at the furnace chamber inlet 116 and the furnace chamber outlet 118, the spacer channel 224 can further separate the surrounding environment from the furnace chamber, thereby reducing heat loss of the furnace chamber.

[0031] It is to be noted that although the gas curtain device 112 of this application includes three barrier plates 222, in other examples, at least two barrier plates are within the protection scope of this application. Adjacent barrier plates of the at least two barrier sheets are arranged at a distance in the first direction. [0032] As shown in Figs. 2A-2C, the gas curtain device 112 further includes a detection device 232 and a control device 236. The power device 204, the detection device 232, and the control device 236 are communicatively connected. More specifically, the control device 236 is in communication with the power device 204 via a wire 241 and the control device 236 is in communication with the detection device 232 via a wire 242. The detection device 232 is provided in the chamber 203 and on the gas curtain seat 202. The detection device 232 is located upstream of the gas curtain 206 in the conveying direction of the conveyor belt 106. The detection device 232 is configured to detect whether there is the component to be processed that is about to pass through the furnace chamber inlet 116 or the furnace chamber outlet 118. When the detection device 232 detects that an object is about to pass through the furnace chamber inlet 116 or the furnace chamber outlet 118, the detection device 232 generates a detection signal and sends same to the control device 236. The control device 236 receives the detection signal and starts the power device 204, thereby controlling the upward movement of the gas curtain 206, moving the gas curtain 206 from the blocking position to the open position. After a predetermined time interval after the control device 236 receives the detection signal (e.g., after the control device 236 receives the detection signal for five seconds), the control device 236 starts the power device 204, thereby controlling the downward movement of the gas curtain 206, moving the gas curtain 206 from the open position to the blocking position. The predetermined time interval is determined according to the conveying speed of the conveyor belt 106, the distance between two adjacent components to be processed (i.e. , separation distance in the first direction), and the length of the component to be processed (i.e., the length in the first direction).

[0033] Fig. 3 is a simplified schematic view of one example of the control device 236 of Fig. 2B. As shown in Fig. 3, the control device 236 includes a bus 302, a processor 304, an input interface 306, an output interface 308, and a memory 314 having a control program 316. The various components of the control device 236, including the processor 304, the input interface 306, the output interface 308, and the memory 314, are in communication with the bus 302 to enable the processor 304 to control the operation of the input interface 306, the output interface 308, and the memory 314. Specifically, the memory 314 is used to store programs, instructions, and data, while the processor 304 reads the programs, the instructions, and the data from the memory 314 and can write data to the memory 314.

[0034] The input interface 306 receives external signals and data via the wire 242, including detection signals sent from the detection device 232. The output interface 308 sends control signals externally via the wire 241 , including a starting control signal to the power device 204. A control program and data are stored in the memory 314 of the control device 236.

[0035] Fig. 4 is a perspective view of the furnace 100 shown in Fig. 1 A with the gas curtain 206 in the blocking position. The operation of the gas curtain device 112 disposed at the furnace chamber inlet 116 is described below with reference to Figs. 1 A and 4. As shown in Figs. 1 A and 4, when there is a component to be processed (the cylinder as shown in Fig. 1 A) coming into the furnace chamber, the detection device 232 detects that the component to be processed is about to pass through the furnace chamber inlet 116. The detection device 232 sends a detection signal to the control device 236. The control device 236 starts the power device 204 according to the signal, thereby controlling the upward movement of the gas curtain 206, moving the gas curtain 206 from the blocking position to the open position. As such, the component to be processed can enter the furnace chamber inlet 116, thereby entering the furnace chamber. Subsequently, after a predetermined time interval after the control device 236 receives the detection signal, the control device 236 starts the power device 204, thereby controlling the down movement of the gas curtain 206, moving the gas curtain 206 from the open position to the blocking position. The gas curtain 206 located in the blocking position blocks the space of the furnace chamber inlet 116 above the conveyor belt 106, thereby separating the furnace chamber from the external environment. The spacer channel 224 formed in the gas curtain 206 can further separate the surrounding environment from the furnace chamber, thereby reducing the heat loss of the furnace chamber.

Furthermore, since the conveyor belt 106 is still moving, conveying the component to be processed, there is a gap between the bottom of the gas curtain 206 and the upper surface of the conveyor belt 106. As an example, the gap is 5-10 mm.

[0036] Although only the working situation of cooperation between the gas curtain device 112 provided at the furnace chamber inlet 116 and the detection device 232 is described in this application, those skilled in the art can understand that the working situation of cooperation between the gas curtain device 112 provided at the furnace chamber outlet 118 and the detection device 232 is similar to the working situation of the gas curtain device 112 provided at the furnace chamber inlet 116, and this will not be described here.

[0037] It should be noted that although the gas curtain device 112 is provided at the furnace chamber inlet 116 and the furnace chamber outlet 118 in this application, in other examples, the gas curtain device 112 is provided at the furnace chamber inlet 116 or the furnace chamber outlet 118.

[0038] It is also noted that although the gas curtain device 112 in this application is provided above the conveyor belt, the gas curtain 206 is movable up and down relative to the gas curtain seat 202 and the housing 101 . However, in other examples, the gas curtain device 112 may be disposed in other positions (e.g., on one side of the conveyor belt in the left-right direction), and the gas curtain 206 may be movable (e.g., move and rotate) relative to the gas curtain seat 202 and the housing 101 to block or open the space that is of the furnace chamber inlet 116 or the furnace chamber outlet 118 and that is above the conveyor belt 106.

[0039] In the prior art, the furnace chamber inlet 116 and the furnace chamber outlet 118 of the furnace 100 are normally open (i.e. remain open), so the component to be processed can enter or exit the furnace chamber at any time. However, this arrangement results in more heat loss from the furnace chamber. Further, the higher the height of the component to be processed, the more heat is lost from the furnace chamber inlet 116 and the furnace chamber outlet 118.

[0040] The gas curtain device 112 of this application is provided with the gas curtain 206, enabling the component to be processed to be allowed to enter the furnace chamber when the gas curtain 206 is in the open position, and to block the furnace chamber when the gas curtain 206 is in the blocking position, thereby reducing the heat loss from the furnace chamber.

[0041] In addition, for a reflow furnace processing a PCB board, nitrogen is injected into the furnace chamber. However, the normally open furnace chamber inlet 116 and furnace chamber outlet 118 cause air within the outside environment to enter the furnace chamber. Provided with the movable gas curtain 206, the gas curtain device 112 of this application maintains a nitrogen atmosphere in the furnace chamber when the furnace chamber processes a PCB board, to prevent solder oxidation and improve welding quality.

[0042] Although the present disclosure has been described in connection with examples of the examples outlined above, various alternatives, modifications, variations, improvements, and/or substantial equivalents, whether known or foreseeable now or in the near future, may be apparent to those having at least ordinary skill in the art. In addition, the technical effects and/or technical problems described in the present specification are exemplary and not limiting; therefore, the disclosure in the present specification may be used to solve other technical problems and have other technical effects and/or may solve other technical problems.

Therefore, examples of the present disclosure as set forth above are intended to be illustrative and not limiting. Various changes may be made without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is intended to include all known or earlier developed alternatives, modifications, variations, improvements and/or substantial equivalents.

Claims

CLAIMS What is claimed is:

1. A furnace (100) comprising: a housing (101); a furnace chamber extending through the housing (101), the furnace chamber comprising a furnace chamber inlet (116) and a furnace chamber outlet (118) located on two opposite sides of the housing (101); a conveyor belt (106) disposed in the furnace chamber and configured to convey a component to be processed from the furnace chamber inlet (116) to the furnace chamber outlet (118); and a gas curtain device (112) disposed on at least one of the furnace chamber inlet (116) and the furnace chamber outlet (118); wherein the gas curtain device (112) comprises a gas curtain seat (202) and a gas curtain (206), the gas curtain seat (202) is connected to the housing (101), the gas curtain (206) is movably connected to the gas curtain seat (202), and the gas curtain (206) is configured to open a space that is above the conveyor belt (106) and that is of at least one of the furnace chamber inlet (116) and the furnace chamber outlet (118) when the component to be processed is about to pass through at least one of the furnace chamber inlet (116) and the furnace chamber outlet (118), and block a space that is above the conveyor belt (106) and that is of at least one of the furnace chamber inlet (116) and the furnace chamber outlet (118) after the component to be processed passes through at least one of the furnace chamber inlet (116) and the furnace chamber outlet (118).

2. The furnace (100) according to Claim 1 , wherein: the gas curtain device (112) is provided above the conveyor belt (106) and the gas curtain (206) is movable up and down relative to the gas curtain seat (202).

3. The furnace (100) according to Claim 1 , further comprising: a detection device (232) configured to detect whether there is the component to be processed on the conveyor belt (106) that is about to pass through at least one of the furnace chamber inlet (116) and the furnace chamber outlet (118) to generate a detection signal; and a control device (236) in communication with the detection device (232) and receiving the detection signal; wherein the control device (236) is configured to control upward movement of the gas curtain (206) according to the detection signal sent by the detection device (232) and to control downward movement of the gas curtain (206) after a predetermined time interval after receiving the detection signal.

4. The furnace (100) according to Claim 3, wherein: the predetermined time interval is determined by a conveying speed of the conveyor belt (106), a distance between two adjacent components to be processed, and a length of the component to be processed.

5. The furnace (100) according to Claim 3, wherein: the detection device (232) is provided on the gas curtain seat (202) and is located upstream of the gas curtain (206) in a conveying direction of the conveyor belt (106).

6. The furnace (100) according to Claim 3, further comprising: a power device (204) connected to the gas curtain (206); wherein the power device (204) is in communication with the control device (236) and configured to drive movement of the gas curtain (206) relative to the gas curtain seat (202).

7. The furnace (100) according to Claim 6, wherein: the power device (204) comprises at least one cylinder.

8. The furnace (100) according to Claim 7, wherein: the power device (204) comprises two cylinders arranged along a width direction of the furnace (100).

9. The furnace (100) according to Claim 1 , wherein: the gas curtain (206) comprises at least two barrier plates (222), and adjacent barrier plates (222) in the at least two barrier plates (222) are arranged at a distance.

10. The furnace (100) according to Claim 2, wherein: the gas curtain device (112) is configured to have the bottom of the gas curtain (206) located below the gas curtain seat (202) when the gas curtain (206) moves downward relative to the gas curtain seat (202).