Vacuum welding cavity of vacuum reflow soldering equipment

Abstract

The utility model discloses a vacuum welding cavity of vacuum reflow soldering equipment, which comprises an upper cavity, a lower cavity and an opening and closing power mechanism, a first sealing ring and a second sealing ring are arranged on the closed surface of the upper cavity and the closed surface of the lower cavity at intervals, and a pressure dividing space is formed between the first sealing ring and the second sealing ring; a plurality of pressure dividing mechanisms are arranged on the upper cavity and / or the lower cavity, and each pressure dividing mechanism comprises a piston containing cavity, a piston and a pressure dividing hole. When the pressure dividing mechanism works in the vacuum welding cavity, negative pressure is automatically generated in the pressure dividing space, the pressure difference between the inner side and the outer side of the vacuum welding cavity acts on the first sealing ring and the second sealing ring in a sharing mode, the pressure difference between the inner side and the outer side of the first sealing ring and the second sealing ring is small, air leakage caused by deformation is not prone to occurring, and the sealing effect is good. And the service lives of the first sealing ring and the second sealing ring are prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of vacuum reflow soldering equipment manufacturing, in particular to a vacuum soldering cavity of vacuum reflow soldering equipment. Background Art

[0002] See also Figure 1 The structure of the vacuum reflow soldering equipment 100 can be roughly divided into a preheating section 101, a vacuum welding chamber 102, and a cooling section 103. The circuit board first passes through the preheating section 101 from the feed port 104 to be preheated by the hot air heating system, then enters the vacuum welding chamber 102 for soldering, and finally passes through the cooling section 103 to be quickly cooled and output from the discharge port 105.

[0003] The vacuum welding chamber 102 is an important part of the vacuum reflow soldering equipment 100, and its chamber sealing performance will directly affect the production of circuit boards. The chamber sealing of the existing vacuum welding chamber 102 is usually achieved by a rubber sealing ring arranged on the chamber closing surface.

[0004] When the vacuum welding chamber 102 is working, the outside is at atmospheric pressure, and the inside is at a vacuum negative pressure environment, and the pressure difference between the inside and outside is large. The pressure difference between the inside and outside is all applied to the same sealing ring. Due to the large pressure difference between the inside and outside of the sealing ring, the sealing ring is prone to deformation and leakage, which affects the sealing effect of the vacuum welding chamber 102. At the same time, long-term exposure to a large pressure difference will cause the sealing ring to age faster, and the replacement frequency of the sealing ring is high. Utility Model Content

[0005] The utility model aims to provide a vacuum welding chamber of vacuum reflow soldering equipment.

[0006] In order to achieve the above utility model purpose, the utility model adopts the following technical solutions:

[0007] A vacuum welding chamber of a vacuum reflow soldering device comprises an upper chamber, a lower chamber, and an opening and closing power mechanism, wherein a first sealing ring and a second sealing ring are arranged on the closed surfaces of the upper chamber and the lower chamber, and a pressure-dividing space is formed between the first sealing ring and the second sealing ring;

[0008] The upper cavity and / or the lower cavity is provided with several groups of pressure dividing mechanisms, and the pressure dividing mechanism includes a piston cavity, a piston, and a pressure dividing hole. One end of the pressure dividing hole is connected to the pressure dividing space, and the other end of the pressure dividing hole is connected to the piston cavity. The piston cavity is opened on the upper cavity or the lower cavity from the inner side of the vacuum welding cavity. A cover plate is provided at the opening of the piston cavity, and a through hole is provided on the cover plate. The piston is accommodated in the piston cavity and is located between the pressure dividing hole and the through hole.

[0009] As a further improved technical solution of the utility model, the pressure dividing mechanisms are at least 4 groups, and the pressure dividing mechanisms are evenly arranged at circumferential intervals in the pressure dividing space.

[0010] As a further improved technical solution of the utility model, a third sealing ring is provided on the outer periphery of the piston, and the third sealing ring is tightly matched with the inner wall of the piston cavity.

[0011] As a further improved technical solution of the utility model, the cover plate is detachably arranged at the opening of the piston cavity.

[0012] As a further improved technical solution of the utility model, a guide rod is fixedly provided in the piston cavity, the piston is penetrated on the guide rod, and a fourth sealing ring is provided between the piston and the guide rod.

[0013] As a further improved technical solution of the utility model, the piston cavity and the axial cross-section of the piston are both circular.

[0014] Compared with the prior art, the technical effects of the utility model are:

[0015] When the utility model works in the vacuum welding chamber through the pressure dividing mechanism, negative pressure is automatically generated in the pressure dividing space, so that the pressure difference between the inside and outside of the vacuum welding chamber is shared and acts on the first and second sealing rings. The pressure difference between the inside and outside of the first and second sealing rings is small, and it is not easy to leak due to deformation, so the sealing effect is better, and at the same time, it helps to extend the service life of the first and second sealing rings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional structural schematic diagram of vacuum reflow soldering equipment;

[0017] Figure 2 It is a three-dimensional structural schematic diagram of a vacuum welding chamber of a vacuum reflow soldering device in an embodiment of the utility model;

[0018] Figure 3 It is a partial cross-sectional structural schematic diagram of a vacuum welding chamber of a vacuum reflow soldering device in an embodiment of the utility model. DETAILED DESCRIPTION

[0019] The present invention will be described in detail below in conjunction with the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional changes made by a person skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0020] See also Figure 2, a vacuum welding chamber 102 of a vacuum reflow soldering device, comprising an upper chamber 1, a lower chamber 2, and an opening and closing power mechanism 3. The upper and lower chambers are both composed of a top plate (bottom plate) and side plates arranged along the edge of the top plate (bottom plate). When the upper chamber 1 and the lower chamber 2 are pressed together, the bottom surface of the side plate of the upper chamber 1 and the top surface of the side plate of the lower chamber 2 are close to each other and closed, and a cavity is formed inside the upper and lower chambers. In this embodiment, the lower chamber 2 is fixed in position, and the upper chamber 1 can move up and down driven by the opening and closing power mechanism 3.

[0021] See also Figure 3 , Figure 3 This is a schematic diagram of the partial cross-sectional structure of the vacuum welding chamber 102, which shows the closed state of the upper chamber 1 side plate and the lower chamber 2 side plate. The left and right directions in the figure are the thickness directions of the upper and lower chamber side plates. The left side of the figure is the outside of the vacuum welding chamber 102, and the right side of the figure is the inside of the vacuum welding chamber 102.

[0022] A first sealing ring 4 and a second sealing ring 5 are disposed on the closed surfaces of the upper cavity 1 and the lower cavity 2 , and a pressure dividing space 6 is formed between the first sealing ring 4 and the second sealing ring 5 .

[0023] The first sealing ring 4 and the second sealing ring 5 are both closed-loop sealing rings arranged along the closed surface (or along the contour of the side plate), the first sealing ring 4 is located on the outer periphery, and the second sealing ring 5 is located on the inner periphery, and the pressure dividing space 6 is a flat closed-loop space formed by the first sealing ring 4, the second sealing ring 5, the bottom surface of the side plate of the upper cavity 1, and the top surface of the side plate of the lower cavity 2.

[0024] The upper cavity 1 and / or the lower cavity 2 is provided with several groups of pressure dividing mechanisms, and the pressure dividing mechanisms include a piston cavity 7, a piston 8, and a pressure dividing hole 9. One end of the pressure dividing hole 9 is connected to the pressure dividing space 6, and the other end of the pressure dividing hole 9 is connected to the piston cavity 7. The piston cavity 7 is opened on the upper cavity 1 or the lower cavity 2 from the inner side of the vacuum welding cavity 102. A cover plate 10 is provided at the opening of the piston cavity 7. The cover plate 10 is provided with a through hole 11 connecting the internal cavity of the vacuum welding cavity 102 and the piston cavity 7. The piston 8 is accommodated in the piston cavity 7 and is located between the pressure dividing hole 9 and the through hole 11.

[0025] It should be noted that when the internal cavity of the vacuum welding chamber 102 is at normal pressure, the piston 8 is located in the piston chamber 7 near the outer side (such as Figure 3 As shown), when the internal cavity of the vacuum welding chamber 102 is in a vacuum state, the piston 8 can move inward in the piston cavity 7 to generate negative pressure in the pressure dividing space 6.

[0026] The working principle of the pressure-sharing mechanism is that the piston chamber 7 located inside the piston 8 is connected to the internal cavity of the vacuum welding chamber 102 through the through hole 11. When the vacuum welding chamber 102 is evacuated, the air in the piston chamber 7 inside the piston 8 is also evacuated, and the air pressure in the piston chamber 7 inside the piston 8 is reduced to vacuum together with the air pressure inside the vacuum welding chamber 102. In this process, the piston 8 moves inward under the action of negative pressure, and the space of the piston chamber 7 located outside the piston 8 becomes larger. Since the space of the piston chamber 7 located outside the piston 8 is connected to the pressure-sharing space 6 through the pressure-sharing hole 9, part of the air inside the pressure-sharing space 6 will enter the piston chamber 7, and the air pressure in the pressure-sharing space 6 is reduced. At this time, the air pressure in the pressure-sharing space 6 is between atmospheric pressure and vacuum, that is, the air pressure in the pressure-sharing space 6 is lower than atmospheric pressure but higher than the vacuum environment. The pressure difference on both sides of the first sealing ring 4 is the pressure difference between the atmospheric pressure and the pressure in the pressure-dividing space 6, and the pressure difference on both sides of the second sealing ring 5 is the pressure difference between the pressure in the pressure-dividing space 6 and the vacuum environment, and both pressure differences are smaller than the pressure difference between the atmospheric pressure and the vacuum environment. Therefore, with the help of the pressure-dividing mechanism, the pressure difference on both sides of the first sealing ring 4 and the second sealing ring 5 is small during operation, and it is not easy to deform due to excessive pressure difference, thereby causing air leakage, which helps to improve the sealing effect. At the same time, due to the small pressure difference, the first sealing ring 4 and the second sealing ring 5 are less likely to age and have a longer service life.

[0027] It should be noted that the negative pressure in the pressure-dividing space 6 does not reach a vacuum state, and the degree of the negative pressure depends on the ratio of the volume of the pressure-dividing space 6 to the sum of the volumes of the piston cavities 7 of all the pressure-dividing mechanisms.

[0028] When the vacuum welding chamber 102 returns to normal pressure, the piston 8 automatically moves outward and resets under the negative pressure in the pressure-dividing space 6. In some embodiments, to help the piston 8 reset quickly, the vacuum pump can be driven in reverse to slightly inflate and pressurize the vacuum welding chamber 102.

[0029] Furthermore, in the present embodiment, there are four groups of pressure dividing mechanisms, and the four groups of pressure dividing mechanisms are evenly spaced in the circumferential direction of the pressure dividing space 6 .

[0030] Furthermore, a third sealing ring 12 is provided on the outer periphery of the piston 8, and the third sealing ring 12 is tightly matched with the inner wall of the piston chamber 7. The third sealing ring 12 is used for sealing the matching surface between the piston 8 and the inner wall of the piston chamber 7.

[0031] Further, the cover plate 10 is detachably arranged at the opening of the piston chamber 7. The cover plate 10 is used to cover the opening of the piston chamber 7 to prevent the piston 8 from escaping from the piston chamber 7. The cover plate 10 can be fixed at the opening of the piston chamber 7 by bolts.

[0032] Furthermore, a guide rod 13 is fixedly provided in the piston cavity 7, the piston 8 is inserted on the guide rod 13, and a fourth sealing ring 14 is provided between the piston 8 and the guide rod 13. The two ends of the guide rod 13 are respectively embedded in the bottom (outside) of the piston cavity 7 and the grooves on the cover plate 10. After the cover plate 10 is installed and fixed, the guide rod 13 is supported and fixed in the piston cavity 7. The purpose of the guide rod 13 is to guide the movement of the piston 8 and reduce the probability of the thinner piston 8 flipping during the inward and outward movement. Of course, when a thicker piston 8 is used, the guide rod 13 may not be provided. The fourth sealing ring 14 is used for sealing on the matching surface of the piston 8 and the guide rod 13.

[0033] Furthermore, the axial cross-sections of the piston cavity 7 and the piston 8 are both circular.

[0034] Compared with the prior art, the technical effects of the utility model are:

[0035] When the utility model works in the vacuum welding chamber 102 through the pressure dividing mechanism, negative pressure is automatically generated in the pressure dividing space 6, so that the pressure difference between the inside and outside of the vacuum welding chamber 102 is shared and acts on the first and second sealing rings. The pressure difference between the inside and outside of the first and second sealing rings is small, and it is not easy to cause leakage due to deformation. The sealing effect is better, and at the same time, it helps to extend the service life of the first and second sealing rings.

[0036] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned implementation modes, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned implementation modes, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various implementation modes of the utility model.

Claims

1. A vacuum welding chamber of a vacuum reflow soldering device, comprising an upper chamber, a lower chamber, and an opening and closing power mechanism, characterized in that: A first sealing ring and a second sealing ring are provided on the closed surfaces of the upper cavity and the lower cavity, and a pressure dividing space is formed between the first sealing ring and the second sealing ring; The upper cavity and / or the lower cavity is provided with several groups of pressure dividing mechanisms, and the pressure dividing mechanism includes a piston cavity, a piston, and a pressure dividing hole. One end of the pressure dividing hole is connected to the pressure dividing space, and the other end of the pressure dividing hole is connected to the piston cavity. The piston cavity is opened on the upper cavity or the lower cavity from the inner side of the vacuum welding cavity. A cover plate is provided at the opening of the piston cavity, and a through hole is provided on the cover plate. The piston is accommodated in the piston cavity and is located between the pressure dividing hole and the through hole.

2. The vacuum soldering chamber of the vacuum reflow soldering equipment according to claim 1, characterized in that: The pressure dividing mechanisms are at least 4 groups, and the pressure dividing mechanisms are evenly arranged at circumferential intervals in the pressure dividing space.

3. The vacuum soldering chamber of the vacuum reflow soldering equipment according to claim 1, characterized in that: A third sealing ring is arranged on the outer periphery of the piston, and the third sealing ring is tightly matched with the inner wall of the piston cavity.

4. The vacuum soldering chamber of the vacuum reflow soldering equipment according to claim 1, characterized in that: The cover plate is detachably arranged at the opening of the piston cavity.

5. The vacuum soldering chamber of the vacuum reflow soldering equipment according to claim 1, characterized in that: A guide rod is fixedly arranged in the piston cavity, the piston is penetrated on the guide rod, and a fourth sealing ring is arranged between the piston and the guide rod.

6. The vacuum soldering chamber of the vacuum reflow soldering equipment according to claim 1, characterized in that: The piston cavity and the axial cross-section of the piston are both circular.

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