CN113357926A - Vacuum reflow soldering furnace with gas combustion device and operation method thereof - Google Patents

Abstract

The invention discloses a vacuum reflow soldering furnace with a gas combustion device and an operation method thereof, relating to the technical field of vacuum reflow soldering, comprising a vacuum chamber, a vacuum baffle valve, an air discharge pipeline, a combustion discharge pipeline and a gas combustion device which are connected in sequence, wherein the bottom of the vacuum chamber is provided with a nitrogen gas charging inlet, nitrogen gas can be introduced into the air discharge pipeline, the gas combustion device comprises a cooling cylinder, the top of the cooling cylinder is connected with a combustion nozzle, the top of the cooling cylinder is connected with a plurality of support columns which are arranged around the combustion nozzle, the top of each support column is provided with a housing, the housing is provided with a pulse igniter close to the top of the combustion nozzle, the side wall of the cooling cylinder is provided with a telescopic mechanism A, the top of the telescopic mechanism A is provided with a pilot burner, the pilot burner is close to the combustion nozzle of the pilot burner and the pulse igniter, the side wall of the housing is provided with a movable port, the pilot burner passes through the movable port and can move up and down in the movable port, the invention has the advantages of avoiding the risk of explosion and explosion, and avoiding secondary oxidation damage of welding devices caused by air flowing back into the vacuum chamber.

Description

Vacuum reflow soldering furnace with gas combustion device and operation method thereof

Technical Field

The invention relates to the technical field of vacuum reflow soldering, in particular to a vacuum reflow soldering furnace with a gas combustion device and an operation method thereof.

Background

Vacuum reflow soldering, also called vacuum/controlled atmosphere eutectic furnace, has large thermal capacity and extremely small temperature difference of PCB surface, and is widely applied to the fields of Europe and America aviation, aerospace, military industry and electronics and the like. The infrared radiation heating principle is adopted, the welding machine has the characteristics of uniform and consistent temperature, ultralow-temperature safe welding, no temperature difference, no overheating, reliable and stable process parameters, no need of complex process tests, low environmental protection cost operation and the like, and meets the requirements of military products on various welding, small-batch welding and high reliability.

In the welding process of the existing vacuum reflow soldering (eutectic furnace), the pressure of reducing combustible gas filled in a vacuum chamber is 2000-5000PA absolute pressure, so the method has the following defects: (1) the filled reducing gas is insufficient, so that the reduction of a welding device is not thorough; (2) after the reduction of the combustible gas is finished, when combustion treatment is carried out, air flows back into an exhaust pipeline or a vacuum cabin at the moment when a vacuum partition valve is opened, so that a deflagration phenomenon occurs in the vacuum cabin, and great abnormal sound is generated due to instant combustion to influence the normal work of workers; (3) the burner tip is always in close contact with burning flame during burning, and is easy to age after long-term use.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a vacuum reflow oven with a gas combustion device and an operation method thereof, so as to achieve the effects of avoiding secondary oxidation damage of welding devices caused by air flowing back into a vacuum chamber and reducing the aging of a combustion nozzle.

In order to solve the technical problems, the invention adopts the following technical scheme:

a vacuum reflow soldering furnace with a gas combustion device comprises a vacuum chamber, a vacuum baffle valve, an air discharge pipeline, a combustion discharge pipeline and the gas combustion device, wherein the bottom of the vacuum chamber is provided with a nitrogen gas charging inlet, the vacuum baffle valve is arranged at the top of the vacuum chamber, the air discharge pipeline is connected with the vacuum baffle valve, nitrogen gas can be introduced into the air discharge pipeline, the combustion discharge pipeline is connected with the air discharge pipeline, the gas combustion device comprises a cooling cylinder connected with the combustion discharge pipeline, the top of the cooling cylinder is connected with a combustion nozzle, the top of the cooling cylinder is connected with a plurality of support columns arranged around the combustion nozzle, the top of each support column is provided with a housing, the housing is of a hollow structure, the top of the combustion nozzle is positioned in the housing, the housing is provided with a pulse igniter close to the top of the combustion nozzle, the side wall of the cooling cylinder is provided with a telescopic mechanism A, the top of the telescopic mechanism A is provided with a pilot burner, one end of the igniter is close to the top of the burner and the ignition end of the pulse igniter, a movable opening is formed in the side wall of the housing, the igniter penetrates through the movable opening and can move up and down in the movable opening, and a combustion chamber is arranged at the top of the housing.

Preferably, the combustion chamber is made of transparent materials, and an exhaust fan is arranged at the top of the combustion chamber.

Preferably, telescopic machanism A top is provided with the fixing base, and the ignitor sets up on the fixing base, still is provided with temperature sensor on the fixing base, and temperature sensor's one end is close to the burner tip top.

Preferably, the air discharge pipeline comprises an air pipe connected between the vacuum baffle valve and the combustion discharge pipeline, and the outer wall of the air pipe is connected with a nitrogen gas inlet pipe.

Preferably, the vacuum baffle valve comprises a vacuum joint arranged at the top of the vacuum cabin, the vacuum joint is connected with a valve body, and the valve body is connected with an air pipe.

Preferably, the combustion exhaust pipeline comprises a corrugated pipe connected with the air pipe, the corrugated pipe is connected with an elbow pipe, and the cooling cylinder is connected to the top of the elbow pipe.

Preferably, the cooling cylinder includes outer barrel, and the support column all sets up at outer barrel top, is provided with interior barrel in the outer barrel, and interior barrel intercommunication forms the cooling chamber between elbow pipe and burner tip, outer barrel and interior barrel, and the cooling chamber is connected with coolant and inserts pipe and coolant and connect the exit tube respectively.

Preferably, the top of the vacuum chamber is an inclined plane with inclination, and the vacuum joint is connected with one end of the top of the vacuum chamber, which inclines upwards.

Preferably, the outer wall of the vacuum chamber is provided with a locking mechanism, the locking mechanism comprises a telescopic mechanism B, the top of the telescopic mechanism B is provided with a tensioning seat, the top of the tensioning seat is hinged to a tensioning ring, the side wall of the top cover of the vacuum chamber is provided with a tensioning buckle positioned above the tensioning seat, and the top of the tensioning buckle is provided with a clamping groove matched with the tensioning ring.

A method of operating a vacuum reflow oven with a gas combustion apparatus, comprising the steps of:

step S1: in the production and welding process, the reductive combustible gas in the vacuum chamber is filled to positive pressure, and the range of the positive pressure is normal pressure 2000PA-0.5 MPA;

step S2: introducing nitrogen into the air discharge pipeline to discharge the air in the combustion discharge pipeline;

step S3: igniting one end of the pilot burner by using a pulse igniter, and keeping the pilot burner in a normal combustion state, wherein when a temperature sensor detects the combustion temperature at one end of the pilot burner, the telescopic mechanism A rises, the temperature sensor and the pilot burner are lifted, and the flame at the tail end of the pilot burner is positioned right above a combustion nozzle;

step S4: and opening the vacuum baffle valve to enable the reduced combustible gas in the vacuum chamber to move to the combustion nozzle towards the combustion discharge pipeline, and simultaneously filling nitrogen into the vacuum chamber by using a nitrogen filling inlet at the bottom of the vacuum chamber to enable the pressure in the vacuum chamber to be always greater than the normal pressure in the combustion chamber.

The invention has the beneficial effects that:

1. before the reductive combustible gas in the vacuum chamber is discharged, nitrogen is filled into the air discharge pipeline to discharge the air in the combustion discharge pipeline, so that oxygen molecules in the pipeline from the vacuum baffle valve to the burner nozzle are avoided, the oxygen molecules in the air are controlled outside the burner nozzle, the igniter is ignited by the pulse igniter to be in a normal combustion state, the igniter is enabled to rise above the burner nozzle, then the vacuum baffle valve is opened, and meanwhile, the nitrogen is filled into the vacuum chamber through the nitrogen filling port, so that the pressure in the vacuum chamber is always greater than the normal pressure in the combustion chamber, the air is prevented from flowing back into the vacuum chamber to cause secondary oxidation damage of welding devices, and the risk of explosion and explosion is prevented. Simultaneously, when the gaseous emission concentration of reduction combustible gas is less than combustible concentration in the vacuum chamber, when combustible gas passes through the naked light, combustible gas can carry out abundant burning equally, and burner tip internal pressure is greater than its external pressure, therefore the burning can only be accomplished in the burner tip outside, because of the pressure reason, the outer flame of burning will go on above the burner tip to reduce the ageing of burner tip.

2. The exhaust fan can discharge a large amount of heat generated by combustion and waste gas which is not completely combusted to the outside or a smoke treatment system for treatment, so that the condition that reductive combustible gas leaks to the inside and harms the safety of workers is avoided.

3. Can let in coolant in the cooling cylinder to cooling down the inside high-temperature gas that passes through, avoiding whole gas combustion device to produce the damage trouble because of high temperature, improve life, and the cooling chamber in the cooling cylinder can continuously let in coolant, guarantees the cooling effect.

4. The top in the vacuum chamber is designed into an inclined plane with inclination, so that dead angles of discharging the reduced combustible gas are avoided, and the reduced combustible gas is discharged from the vacuum joint in a fully centralized manner.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1 is a schematic structural view of a vacuum reflow oven with a gas combustion apparatus according to the present invention;

FIG. 2 is a schematic view showing the internal structure of the vacuum chamber according to the present invention;

FIG. 3 is a schematic view showing the structure of a gas combustion apparatus according to the present invention;

FIG. 4 is a schematic front view of the gas combustion apparatus according to the present invention;

FIG. 5 is a schematic view showing the internal structure of the gas combustion apparatus according to the present invention;

FIG. 6 is a schematic structural view of the top view of FIG. 4;

FIG. 7 is a schematic view showing the internal structure of the cooling cylinder according to the present invention;

fig. 8 is a schematic structural view of the locking mechanism of the present invention.

Reference numerals:

100-vacuum chamber, 110-nitrogen charging inlet, 120-inclined surface, 200-vacuum flapper valve, 210-vacuum joint, 220-valve body, 300-air discharge pipeline, 310-air pipe, 320-nitrogen gas access pipe, 400-combustion discharge pipeline, 410-corrugated pipe, 420-elbow pipe, 500-gas combustion device, 510-cooling cylinder, 511-outer cylinder, 512-inner cylinder, 513-cooling cavity, 514-cooling medium access pipe, 515-cooling medium access pipe, 520-burner tip, 530-support column, 540-cover, 541-movable port, 550-pulse igniter, 560-telescoping mechanism A, 570-igniter, 580-fixed seat, 590-temperature sensor, 600-combustion chamber, 700-exhaust fan, 800-locking mechanism, 810-telescopic mechanism B, 820-tensioning seat, 830-tensioning ring, 840-tensioning buckle and 841-clamping groove.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the embodiments of the present invention, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or the orientations or positional relationships that the products of the present invention are usually placed in when used, the orientations or positional relationships are only used for convenience of describing the present invention and simplifying the description, but the terms do not indicate or imply that the devices or elements indicated must have specific orientations, be constructed in specific orientations, and operate, and therefore, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical", "overhang" and the like do not require that the components be absolutely horizontal or overhang, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the embodiments of the present invention, it should be further noted that unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Example 1

As shown in fig. 1-8, the present embodiment provides a vacuum reflow oven with a gas combustion apparatus, which includes a vacuum chamber 100, a vacuum flapper valve 200, an air discharge pipeline 300, a combustion discharge pipeline 400 and a gas combustion apparatus 500, wherein the bottom of the vacuum chamber 100 is provided with a nitrogen gas charging inlet 110, the vacuum flapper valve 200 is disposed at the top of the vacuum chamber 100, the air discharge pipeline 300 is connected to the vacuum flapper valve 200, nitrogen gas can be introduced into the air discharge pipeline 300, the combustion discharge pipeline 400 is connected to the air discharge pipeline 300, the gas combustion apparatus 500 includes a cooling cylinder 510 connected to the combustion discharge pipeline 400, the top of the cooling cylinder 510 is connected to a combustion nozzle 520, the top of the cooling cylinder 510 is connected to a plurality of support columns 530 arranged around the combustion nozzle 520, the top of the support columns 530 is provided with a casing 540, the casing 540 is of a hollow structure, the top of the combustion nozzle 520 is disposed in the casing 540, the casing 540 is provided with a pulse igniter 550 near the top of the combustion nozzle 520, the side wall of the cooling cylinder 510 is provided with a telescopic mechanism A560, the top of the telescopic mechanism A560 is provided with a pilot device 570, one end of the pilot device 570 is close to the top of the burner 520 and the ignition end of the pulse igniter 550, the side wall of the housing 540 is provided with a movable port 541, the pilot device 570 penetrates through the movable port 541 and can move up and down in the movable port 541, and the top of the housing 540 is provided with a combustion chamber 600.

In this embodiment, before the reduced combustible gas in the vacuum chamber 100 is exhausted, the air in the combustion exhaust line 400 is exhausted (from the top of the combustion chamber 600) by charging nitrogen gas into the air exhaust line 300, thereby preventing oxygen molecules from being present in the line from the vacuum flapper valve 200 to the burner tip 520, and controlling oxygen molecules in the air to be outside the burner tip 520, meanwhile, nitrogen is filled into the vacuum chamber 100 through the nitrogen filling port 110, so that the pressure inside the vacuum chamber 100 is always higher than the atmospheric pressure (i.e., one atmospheric pressure) in the combustion chamber 600, the end of the burning time process of reducing the combustible gas can be controlled using a flow meter or a time conversion of the size of the nitrogen gas charging port 110, when the gas combustion apparatus 500 is operated, the backflow of air into the vacuum chamber 100 may be prevented from causing secondary oxidation damage of the soldered devices, thereby preventing the risk of explosion due to deflagration.

Meanwhile, before the reducing combustible gas in the vacuum chamber 100 is discharged, the igniter 550 is used for igniting the igniter 570, the igniter is in a normal combustion state, the igniter 570 is made to rise above the burner tip 520, then the vacuum baffle valve 200 is opened to begin to discharge the reducing combustible gas in the vacuum chamber 100, when the emission concentration of the reducing combustible gas in the vacuum chamber 100 is lower than the combustible concentration, the combustible gas can be fully combusted when passing through open fire, and the internal pressure of the burner tip 520 is higher than the external pressure of the burner tip 520, so that the combustion can be finished only outside the burner tip 520, and due to the pressure, the combustion outer flame can be carried out above the burner tip 520, so that the aging of the burner tip 520 is reduced, and the pulse igniter 550 is far away from a high-temperature zone and is not easy to age and damage.

Tests show that when the invention is applied to a production welding process, the reductive combustible gas in the vacuum chamber 100 can be filled to the positive pressure range of the normal pressure 2000PA-0.5MPA, so that sufficient reductive gas can be filled, and the complete reduction of a welding device is ensured.

The telescoping mechanism a560 is an air cylinder, a hydraulic cylinder, an electric push rod, or the like, and realizes an automatic lifting function.

Specifically, the combustion chamber 600 is made of transparent materials, so that the internal combustion condition can be conveniently observed, and the combustion chamber 600 is generally made of quartz glass, wherein the quartz glass has an extremely low thermal expansion coefficient, high temperature resistance, excellent chemical stability, excellent electrical insulation, low and stable ultrasonic delay performance, optimal ultraviolet spectrum transmission performance, visible light transmission performance and near infrared spectrum transmission performance, mechanical performance higher than that of common glass, and meets the use requirement.

The top of the combustion chamber 600 is provided with an exhaust fan 700, and the exhaust fan 700 can discharge a large amount of heat generated by combustion and exhaust gas which is not completely combusted to the outside or a smoke treatment system for treatment, so that the reduction combustible gas is prevented from leaking into the room, and the safety of workers is prevented from being damaged.

Specifically, a fixing seat 580 is disposed at the top of the telescopic mechanism a560, the igniter 570 is disposed on the fixing seat 580, a temperature sensor 590 is further disposed on the fixing seat 580, one end of the temperature sensor 590 is close to the top of the burner 520, and when the telescopic mechanism a560 is lifted, the igniter 570 and the temperature sensor 590 on the fixing seat 580 can be driven to lift integrally.

When temperature sensor 590 detects the burning flame temperature of ignitor 570 department, can rise the ignition nozzle through telescopic machanism A560, can set up PLC controller (not drawn in the figure) here, temperature sensor 590 and telescopic machanism A560 all with PLC controller electric connection to realize the function of auto-induction automatic rising, reduce manual operation, intelligent degree is high.

Specifically, the air discharging pipeline 300 includes an air pipe 310 connected between the vacuum flapper valve 200 and the combustion discharging pipeline 400, the outer wall of the air pipe 310 is connected with a nitrogen gas access pipe 320, the nitrogen gas access pipe 320 is used for externally connecting nitrogen gas storage equipment (not shown in the figure), so that nitrogen gas is conveniently introduced into the air pipe 310 through the nitrogen gas access pipe 320 through the nitrogen gas storage equipment, at this time, the vacuum flapper valve 200 is in a closed state, and the nitrogen gas can clean and discharge the air in the combustion discharging pipeline 400.

Specifically, the vacuum flapper valve 200 includes a vacuum connector 210 disposed at the top of the vacuum chamber 100, the vacuum connector 210 is connected to a valve body 220, the valve body 220 is connected to an air pipe 310, and the valve body 220 is opened to discharge the reduced combustible gas in the vacuum chamber 100.

Specifically, the combustion exhaust pipe 400 includes a corrugated pipe 410 connected to the air pipe 310, the length of the corrugated pipe 410 is adaptively adjustable, so that the corresponding installation position can be adjusted for the installation environment, and the versatility is improved, the corrugated pipe 410 is connected to an elbow pipe 420, the cooling cylinder 510 is connected to the top of the elbow pipe 420, the gas combustion apparatus 500 is connected to the elbow pipe 420, and the gas combustion apparatus 500 maintains a vertical state to adapt to the vertical state of the combustion flame.

Specifically, the cooling cylinder 510 includes an outer cylinder 511, the supporting columns 530 are all disposed on the top of the outer cylinder 511, an inner cylinder 512 is disposed in the outer cylinder 511, the inner cylinder 512 is communicated between the elbow pipe 420 and the burner tip 520, a cooling chamber 513 is formed between the outer cylinder 511 and the inner cylinder 512, and the cooling chamber 513 is connected with a cooling medium inlet pipe 514 and a cooling medium outlet pipe 515 respectively.

Can let in coolant in the cooling cylinder 510 to the high temperature gas that passes through to lower the temperature to inside, avoid whole gas combustion device 500 to produce because of the high temperature and damage the trouble, improve life, during the operation, coolant inserts pipe 514 and coolant connects out pipe 515 and connects the cooling tube respectively, thereby continuously lets in coolant, guarantees the cooling effect, and coolant can adopt liquid or gaseous state medium here, generally adopts the cooling water.

Specifically, the inner top of the vacuum chamber 100 is an inclined surface 120 having an inclination, and the vacuum connector 210 is connected to an end of the vacuum chamber 100 inclined upward. The top of the vacuum chamber 100 is designed to be an inclined plane 120 with inclination, so as to avoid dead discharge angles of the reducing combustible gas and ensure that the reducing combustible gas is discharged from the vacuum joint 210 in a sufficiently concentrated manner.

Specifically, the outer wall of the vacuum chamber 100 is provided with a locking mechanism 800, the locking mechanism 800 comprises a telescopic mechanism B810, the top of the telescopic mechanism B810 is provided with a tensioning seat 820, the top of the tensioning seat 820 is hinged to a tensioning ring 830, the side wall of the top cover of the vacuum chamber 100 is provided with a tensioning buckle 840 located above the tensioning seat 820, and the top of the tensioning buckle 840 is provided with a clamping groove 841 matched with the tensioning ring 830.

When the vacuum chamber 100 needs to be locked, the telescopic mechanism B810 drives the tensioning seat 820 and the tensioning ring 830 to move upwards integrally, the tensioning ring 830 is sleeved on the clamping groove 841 of the tensioning buckle 840, then the telescopic mechanism B810 moves downwards to enable the tensioning ring 830 to be tensioned on the clamping groove 841 of the tensioning buckle 840, so that the top cover of the vacuum chamber 100 is locked, and similarly, the telescopic mechanism B810 can also adopt a cylinder, a hydraulic cylinder or an electric push rod and the like, so that the operation is convenient and fast, and the automation degree is high.

Example 2

As shown in fig. 1 to 8, the present embodiment provides a method of operating a vacuum reflow oven with a gas combustion apparatus, comprising the steps of:

step S1: in the production welding process, the reductive combustible gas in the vacuum chamber 100 is filled to positive pressure, and the range of the positive pressure is normal pressure 2000PA-0.5 MPA;

step S2: introducing nitrogen into the air discharge line 300 to discharge the air in the combustion discharge line 400;

step S3: the pulse igniter 550 is used for igniting one end of the igniter 570, the igniter is in a normal combustion state, when the temperature sensor 590 detects the combustion temperature at one end of the igniter 570, the telescopic mechanism A560 is lifted, the temperature sensor 590 and the igniter 570 are lifted, and the flame at the tail end of the igniter 570 is positioned right above the burner tip 520;

step S4: the vacuum flapper valve 200 is opened to allow the reduced combustible gas in the vacuum chamber 100 to move to the burner tip 520 toward the combustion discharge line 400, and the nitrogen gas is simultaneously introduced into the vacuum chamber 100 through the nitrogen gas inlet 110 at the bottom of the vacuum chamber 100, so that the pressure inside the vacuum chamber 100 is always greater than the atmospheric pressure in the combustion chamber 600.

In step S1, the pressure sensor may detect the pressure in real time, and in step S4, when the pressure inside the vacuum chamber 100 is always higher than the atmospheric pressure in the combustion chamber 600, the flow meter or the nitrogen gas inlet 110 may be used to convert the time to control the end of the combustion time process for reducing the combustible gas.

In this embodiment, when the vacuum reflow oven with the gas combustion apparatus in embodiment 1 is used in the production and welding process, the pressure range can be increased to 2000PA-0.5MPA at normal pressure, so that sufficient reducing gas can be filled, and the reduction of the welding device is ensured to be complete. Meanwhile, the method has the advantages that secondary oxidation damage of welding devices caused by air flowing back into the vacuum chamber 100 can be avoided, explosion risks caused by deflagration can be prevented, aging of the burner 520 can be reduced by lifting the igniter 570 during combustion, the pulse igniter 550 is far away from a high-temperature zone, aging and damage are not prone to occurring, and the method has multiple advantages and has great market popularization value.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.

Claims (10)

1. A vacuum reflow oven with a gas combustion apparatus, comprising:

the bottom of the vacuum chamber is provided with a nitrogen charging port;

a vacuum flapper valve disposed at the top of the vacuum chamber;

the air discharge pipeline is connected with the vacuum baffle valve, and nitrogen can be introduced into the air discharge pipeline;

a combustion exhaust line connected with the air exhaust line; and

gas combustion device, gas combustion device includes the cooling cylinder of being connected with burning discharge line, the cooling cylinder top is connected with the burner tip, the cooling cylinder top is connected with a plurality of support columns of arranging around the burner tip, the support column top is provided with the housing, the housing is hollow structure, the burner tip is located the housing, be provided with the pulse ignition ware near the burner tip on the housing, the cooling cylinder lateral wall is provided with telescopic machanism A, telescopic machanism A top is provided with the pilot burner, the ignition end of burner tip top and pulse ignition ware is close to the one end of pilot burner, the opening has been seted up to the housing lateral wall, the pilot burner passes the opening and can reciprocate in the opening, the housing top is provided with the combustion chamber.

2. The vacuum reflow oven with gas combustion apparatus of claim 1, wherein the combustion chamber is made of transparent material, and an exhaust fan is disposed on the top of the combustion chamber.

3. The vacuum reflow oven with gas combustion device of claim 2, wherein the top of the telescopic mechanism A is provided with a fixed seat, the igniter is arranged on the fixed seat, the fixed seat is further provided with a temperature sensor, and one end of the temperature sensor is close to the top of the burner tip.

4. The vacuum reflow oven with gas combustion apparatus of claim 1, wherein the air exhaust line includes an air pipe connected between the vacuum flapper valve and the combustion exhaust line, and a nitrogen gas inlet pipe is connected to an outer wall of the air pipe.

5. A vacuum reflow oven with gas combustion apparatus in accordance with claim 4, wherein the vacuum flapper valve comprises a vacuum connection disposed at the top of the vacuum chamber, the vacuum connection having a valve body connected to a gas tube.

6. The vacuum reflow oven with gas combustion apparatus of claim 4, wherein the combustion exhaust line includes a bellows connected with a gas pipe, the bellows is connected with an elbow pipe, and the cooling cylinder is connected to a top of the elbow pipe.

7. The vacuum reflow oven with gas combustion apparatus of claim 6, wherein the cooling cylinder comprises an outer cylinder, the support pillars are all disposed on top of the outer cylinder, an inner cylinder is disposed in the outer cylinder, the inner cylinder is communicated between the elbow pipe and the burner tip, a cooling cavity is formed between the outer cylinder and the inner cylinder, and the cooling cavity is connected with a cooling medium inlet pipe and a cooling medium outlet pipe respectively.

8. The vacuum reflow oven with gas burning apparatus of claim 1, wherein the vacuum chamber has an inclined top, and the vacuum connector is connected to an end of the vacuum chamber inclined upward.

9. The vacuum reflow oven with the gas combustion device according to claim 1, wherein the outer wall of the vacuum chamber is provided with a locking mechanism, the locking mechanism comprises a telescopic mechanism B, a tensioning seat is arranged at the top of the telescopic mechanism B, a tensioning ring is hinged at the top of the tensioning seat, a tensioning buckle located above the tensioning seat is arranged on the side wall of the top cover of the vacuum chamber, and a slot matched with the tensioning ring is arranged at the top of the tensioning buckle.

10. A method of operating a vacuum reflow oven with a gas combustion apparatus in accordance with claim 3, comprising the steps of:

step S1: in the production and welding process, the reductive combustible gas in the vacuum chamber is filled to positive pressure, and the range of the positive pressure is normal pressure 2000PA-0.5 MPA;

step S2: introducing nitrogen into the air discharge pipeline to discharge the air in the combustion discharge pipeline;

step S3: igniting one end of the pilot burner by using a pulse igniter, and keeping the pilot burner in a normal combustion state, wherein when a temperature sensor detects the combustion temperature at one end of the pilot burner, the telescopic mechanism A rises, the temperature sensor and the pilot burner are lifted, and the flame at the tail end of the pilot burner is positioned right above a combustion nozzle;

step S4: and opening the vacuum baffle valve to enable the reduced combustible gas in the vacuum chamber to move to the combustion nozzle towards the combustion discharge pipeline, and simultaneously filling nitrogen into the vacuum chamber by using a nitrogen filling inlet at the bottom of the vacuum chamber to enable the pressure in the vacuum chamber to be always greater than the normal pressure in the combustion chamber.

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