An inlet and outlet air control device for a vacuum sintering furnace sealing box

Abstract

The utility model discloses an inlet and outlet gas control device for vacuum sintering furnace sealing box relates to sintering furnace technical field, include: set up on the air hole of the sealing box's box wall, the air hole will the inside space of sealing box with the outside space of sealing box intercommunication, cover, the cover is located in the vacuum sintering furnace and is located sealing box outside, the cover is opposite the air hole and can the air hole block, with the fixed connection of vacuum sintering furnace drive arrangement, the drive arrangement is used for driving the cover relative air hole moves. Through the initiative control sealing box inside and outside gas exchange speed, fundamentally avoided the cracking or broken problem of sealing box in the vacuum extraction and inflation process because of the too big pressure difference, significantly improved the service life of sealing box and the safety of vacuum sintering furnace operation.

Description

Technical Field

[0001] This utility model relates to the field of sintering furnace technology, and in particular to an inlet and outlet gas control device for a vacuum sintering furnace sealing box. Background Technology

[0002] In the continuous development of the powder metallurgy field, vacuum sintering furnaces are increasingly widely used in industrial production. As the core component for processing products in a vacuum sintering furnace, the sealing box's operating status directly determines the product yield. The core function of the sealing box is to construct a precisely controllable "isolation space," providing ideal conditions for material sintering by isolating the external environment and regulating internal parameters such as atmosphere, pressure, and temperature.

[0003] During the sintering process, the sealed box needs to undergo a pressure cycle of "vacuuming (negative pressure) → heating (internal gas expansion) → filling with atmosphere (positive pressure) → cooling (pressure drop)". The internal pressure may change from negative pressure (below atmospheric pressure) to positive pressure (such as pressurizing to 0.1~0.5MPa). Therefore, the structural design of the sealed box must be pressure resistant to avoid deformation or rupture due to sudden pressure changes.

[0004] However, during the initial vacuuming process inside the sintering furnace, the vacuum pump exhausts gas through the external vacuum pipes of the sealed box, causing a rapid decrease in external pressure. Since the inside of the sealed box is initially at atmospheric pressure and has good sealing properties, and because the inlet valves are all one-way valves, the internal gas can only be discharged slowly through seepage. This means the pressure inside the sealed box cannot decrease as rapidly as the external pressure, resulting in a pressure difference of tens of kPa. When this pressure difference exceeds the sealing box's own pressure-bearing capacity, it can cause the sealed box to crack or even break.

[0005] Furthermore, during the operation of the sintering furnace, such as in the sintering or cooling stages, rapid gas charging is often initiated initially, followed by switching to flow meter-based gas intake as the pressure approaches the set point. In some cases, rapid charging is even used throughout the entire process. During the rapid charging phase, the external pressure of the sealing chamber increases rapidly due to the fast charging speed. However, the internal pressure of the sealing chamber, due to its better sealing properties and smaller inlet valve diameter, increases significantly slower than the external pressure, resulting in a large pressure difference between the inside and outside of the sealing chamber. When this pressure difference exceeds the strength of the sealing chamber itself, it can also lead to cracking or even breakage of the sealing chamber.

[0006] Therefore, how to prevent the sealing box from cracking under the condition of drastic changes in internal and external pressure difference during the operation of the vacuum sintering furnace is an urgent technical problem to be solved. Utility Model Content

[0007] The purpose of this invention is to provide an inlet and outlet gas control device for a vacuum sintering furnace sealing box, so as to solve the problems existing in the prior art and avoid the sealing box from cracking due to drastic changes in internal and external pressure difference during the operation of the vacuum sintering furnace.

[0008] To achieve the above objectives, this utility model provides the following solution:

[0009] This utility model provides an inlet and outlet gas control device for a vacuum sintering furnace sealing box, comprising:

[0010] A vent is provided on the wall of the sealed box, which connects the internal space of the sealed box with the external space of the sealed box;

[0011] A cover is located inside the vacuum sintering furnace and outside the sealed box, the cover is directly opposite the vent hole and can block the vent hole;

[0012] A drive device fixedly connected to the vacuum sintering furnace, the drive device being used to drive the cover to move relative to the vent hole.

[0013] Preferably, the vent is located at the top center of the sealed box.

[0014] Preferably, the driving device is a linear driving device, and the driving device is connected to the cover through a push-pull mechanism; the push-pull mechanism includes a push-pull shaft, a pressure block, and a pad block, one end of the push-pull shaft is fixedly connected to the output end of the driving device, the pressure block and the cover block are slidably sleeved on the push-pull shaft, the pad block is fixedly connected to the push-pull shaft, and the pressure block, the cover block, and the pad block are distributed sequentially from top to bottom; the gap between the pressure block and the push-pull shaft is a first annular gap, and the gap between the cover block and the push-pull shaft is a second annular gap, the annular width of the first annular gap is smaller than the annular width of the second annular gap.

[0015] Preferably, the driving device is a cylinder.

[0016] Preferably, the materials of the cap, the pressure block, and the pad are all graphite.

[0017] Preferably, the width of the first annular gap is less than 0.1 mm.

[0018] Preferably, the vacuum sintering furnace body is provided with a flange corresponding to the drive device, the drive device is fixedly connected to a flange end cover, the flange end cover is connected to the flange by multiple bolts, and a sealing sleeve is also installed on the flange end cover, through which the piston rod of the cylinder passes.

[0019] Preferably, a sealing ring is sandwiched between the piston rod and the sealing sleeve, a sealing ring is sandwiched between the sealing sleeve and the flange end cover, and a sealing ring is sandwiched between the flange end cover and the flange.

[0020] Preferably, the system also includes a control unit and an alarm; the piston of the cylinder is made of magnetic material, and the cylinder is equipped with a first non-contact magnetic sensor and a second non-contact magnetic sensor. When the piston is at its furthest position from the sealed box, the first non-contact magnetic sensor can be triggered, and when the piston is at its closest position to the sealed box, the second non-contact magnetic sensor can be triggered. The first non-contact magnetic sensor, the second non-contact magnetic sensor, and the alarm are respectively connected to the control unit, and the control unit can also control the operation of the cylinder.

[0021] Preferably, the push-pull shaft is fixedly connected to the output end of the drive device via a bushing.

[0022] The present invention achieves the following technical advantages over the prior art:

[0023] This utility model relates to an inlet / outlet gas control device for a vacuum sintering furnace sealing box. By incorporating vent holes in the sealing box wall and a movable cover controlled by a drive device, it precisely regulates the gas flow inside and outside the sealing box according to the operating conditions of the vacuum sintering furnace. During the vacuuming phase, the drive device moves the cover away from the vent holes, allowing gas inside the sealing box to be quickly discharged through the vent holes. This prevents the internal pressure from failing to decrease in time due to only allowing gas to seep in, effectively eliminating excessive negative pressure differences caused by vacuuming. During the filling phase (including rapid filling and the phase approaching the set pressure), the drive device moves the cover to open the vent holes, allowing external gas to quickly enter the sealing box. This solves the problem of slow pressure increase due to sealing limitations and the air inlet valve, preventing the positive pressure difference from exceeding the sealing box's pressure-bearing capacity. Simultaneously, in process stages where rapid gas flow is not required, the drive device can move the cover to block the vent holes, ensuring the sealing box's airtightness meets process requirements.

[0024] This invention, by actively regulating the gas exchange rate inside and outside the sealed box, fundamentally avoids the problem of cracking or breaking of the sealed box due to excessive pressure difference during vacuuming and gas filling, significantly improving the service life of the sealed box and the safety of vacuum sintering furnace operation; moreover, the overall structure is simple, and automatic control can be achieved through a drive device, adapting to the pressure regulation requirements of different sintering processes, and has strong practicality and economy. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of the structure of a vacuum sintering furnace equipped with the inlet and outlet gas control device of this utility model for the sealing box of a vacuum sintering furnace;

[0027] Figure 2 This is a schematic diagram of the air inlet and outlet control device for the sealing box of a vacuum sintering furnace in the state of the vent opening.

[0028] Figure 3 This is a schematic diagram of the structure of the inlet and outlet air control device for the sealing box of a vacuum sintering furnace in the closed state of the air vent.

[0029] Figure 4 This is a partial structural schematic diagram of the gas inlet and outlet control device for the sealing box of a vacuum sintering furnace according to this utility model.

[0030] In the diagram: 100, furnace body; 101, insulation layer; 200, sealing box; 300, internal space of the box; 400, external space of the box; 500, inlet and outlet gas control device for the sealing box of the vacuum sintering furnace;

[0031] 1. Drive unit; 2. Bushing; 3. Push-pull shaft; 4. Flange; 5. Pressure block; 6. Cover; 7. Gasket; 8. Top plate; 9. Vent hole; 10. Piston rod; 11. Flange end cover; 12. Sealing sleeve; 13. Sealing ring; 14. Retaining ring; 15. First non-contact magnetic sensor; 16. Second non-contact magnetic sensor. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] The purpose of this invention is to provide an inlet and outlet gas control device for a vacuum sintering furnace sealing box, so as to solve the problems existing in the prior art and avoid the sealing box from cracking due to drastic changes in internal and external pressure difference during the operation of the vacuum sintering furnace.

[0034] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] like Figures 1 to 4 As shown, this embodiment provides an inlet / outlet gas control device 500 for a vacuum sintering furnace sealing box, which can prevent the sealing box 200 from cracking or breaking due to excessive internal and external pressure difference during the operation of the vacuum sintering furnace. The inlet / outlet gas control device 500 for the vacuum sintering furnace sealing box in this embodiment includes a vent 9, a cover 6, and a drive device 1.

[0036] The vent 9 is located on the wall of the sealed box 200, connecting the internal space of the sealed box 200 (referred to as the inner space 300) with the external space of the sealed box 200 (referred to as the outer space 400). To facilitate gas flow and reduce gas flow resistance, the vent 9 is preferably located at the center of the top of the sealed box 200. This is because placing the vent 9 at the center of the top facilitates the flow of gas inside the box in different directions, and also facilitates the flow of gas outside the box into the sealed box 200 from various directions through the vent 9, enabling more efficient gas exchange between the inner space 300 and the outer space 400.

[0037] The cover 6 is located inside the vacuum sintering furnace and outside the sealed box 200. The cover 6 is directly opposite the vent 9 and can be used to block or open the vent 9 during movement. The size of the cover 6 must be compatible with the vent 9 to ensure good sealing when blocking.

[0038] The drive unit 1 is fixedly connected to the vacuum sintering furnace and is used to drive the cover 6 to move relative to the vent hole 9, thereby controlling the opening and closing state of the vent hole 9. The drive unit 1 is preferably a linear drive device, such as a cylinder. The linear drive method can make the movement of the cover 6 more stable and precise, and facilitates the control of the position of the cover 6.

[0039] In this embodiment, to achieve the connection and power transmission between the drive device 1 and the cover 6, a push-pull mechanism is used to connect the two. Specifically, the push-pull mechanism includes a push-pull shaft 3, a pressure block 5, and a pad 7. One end of the push-pull shaft 3 is fixedly connected to the output end of the drive device 1. The push-pull shaft 3 passes through the insulation layer 101 on the inner wall of the furnace body 100. The pressure block 5 and the cover 6 are slidably sleeved on the push-pull shaft 3, and the pad 7 is fixedly connected to the push-pull shaft 3. The pressure block 5, the cover 6, and the pad 7 are distributed sequentially from top to bottom. The gap between the pressure block 5 and the push-pull shaft 3 is a first annular gap, and the gap between the cover 6 and the push-pull shaft 3 is a second annular gap. The width of the first annular gap is smaller than the width of the second annular gap, which can maximize the sealing performance. The pressure block 5 is used to apply downward pressure to the cover 6 when the cover 6 blocks the vent hole 9, thereby improving the sealing effect of the cover 6 on the vent hole 9.

[0040] In the optional solutions of this embodiment, it is more preferred that the pad 7 and the push-pull shaft 3 are threaded together. This not only achieves a stable connection between the pad 7 and the push-pull shaft 3, but also facilitates the assembly and disassembly of the pad 7 and the push-pull shaft 3.

[0041] In the optional solutions of this embodiment, it is more preferred that the width of the first annular gap is less than 0.1 mm.

[0042] It is worth noting that the diameter of the through hole on the cover 6 through which the push-pull shaft 3 passes is larger than the diameter of the push-pull shaft 3. This ensures that even if the top surface of the top plate 8 of the sealing box 200 is not completely perpendicular to the axis of the push-pull shaft 3 when the cover 6 closes the vent hole 9, the cover 6 and the push-pull shaft 3 will not get stuck, thus improving the stability during use.

[0043] To ensure the airtightness of the vacuum sintering furnace, a flange 4 is installed on the furnace body 100 corresponding to the position of the drive device 1. A flange end cover 11 is fixedly connected to the drive device 1, and the flange end cover 11 is connected to the flange 4 by multiple bolts. A sealing sleeve 12 is also installed on the flange end cover 11, and the piston rod 10 of the cylinder passes through the sealing sleeve 12. At the same time, a sealing ring 13 is sandwiched between the piston rod 10 and the sealing sleeve 12, between the sealing sleeve 12 and the flange end cover 11, and between the flange end cover 11 and the flange 4. These sealing rings 13 can effectively prevent gas leakage inside the furnace and ensure the vacuum environment or specific atmosphere conditions inside the vacuum sintering furnace. A retaining ring 14 is fixed on the flange end cover 11 to limit the sealing sleeve 12 and prevent the sealing sleeve 12 from falling off the flange end cover 11.

[0044] In the optional embodiments of this example, more preferably, to facilitate the detection of whether the device is operating normally, the device of this example also includes a control unit and an alarm; the piston of the cylinder is made of magnetic material, and the cylinder is provided with a first non-contact magnetic sensor 15 and a second non-contact magnetic sensor 16. When the piston is at the position furthest from the sealed box 200, the first non-contact magnetic sensor 15 can be triggered (in this state, the cover 6 is away from the vent hole 9, and the vent hole 9 is in the open state). When the piston is at the position closest to the sealed box 200, the second non-contact magnetic sensor 16 can be triggered (in this state, the cover 6 blocks the vent hole 9, and the vent hole 9 is in the closed state). The first non-contact magnetic sensor 15, the second non-contact magnetic sensor 16 and the alarm are respectively connected to the control unit, and the control unit can also control the operation of the cylinder. The control unit controls the operation of the cylinder by evacuating and inflating the rodless chamber (as this is common knowledge regarding cylinder control, it will not be elaborated upon in this embodiment). During the process of the control unit inflating the rodless chamber of the cylinder to move the piston towards the sealing box 200, if the second non-contact magnetic sensor 16 is eventually triggered, it indicates that the device is working normally. Conversely, if the second non-contact magnetic sensor 16 is not triggered within the set time, it indicates that the device is malfunctioning, and the control unit will control the alarm to issue an alarm signal. Similarly, during the process of the control unit evacuating the rodless chamber of the cylinder to move the piston away from the sealing box 200, if the first non-contact magnetic sensor 15 is eventually triggered, it indicates that the device is working normally. Conversely, if the first non-contact magnetic sensor 15 is not triggered within the set time, it indicates that the device is malfunctioning, and the control unit will control the alarm to issue an alarm signal.

[0045] In this embodiment, the connection between the push-pull shaft 3 and the output end of the drive device 1 can be achieved through the bushing 2, and the push-pull shaft 3 is fixedly connected to the output end of the drive device 1 through the bushing 2.

[0046] Furthermore, the materials of the cover 6, the pressure block 5, and the pad 7 are preferably graphite. Graphite has good high-temperature resistance and sealing properties, which can adapt to the high-temperature environment inside the vacuum sintering furnace. At the same time, it can ensure a good sealing effect when the cover 6 blocks the vent hole 9. In addition, graphite is wear-resistant, which can extend the service life of the components. Furthermore, it is worth noting that the first annular gap between the pressure block 5 and the push-pull shaft 3 has a negligible impact on the sealing performance.

[0047] The working process of the inlet and outlet gas control device 500 for the vacuum sintering furnace sealing box in this embodiment is as follows:

[0048] During the initial vacuuming stage of the vacuum sintering furnace, the drive device 1 drives the push-pull shaft 3 to move the cover 6, causing the cover 6 to leave the vent hole 9 and the vent hole 9 to open. At this time, the gas inside the sealed box 200 can be quickly discharged through the vent hole 9, so that the gas pressure inside the sealed box 200 can be reduced rapidly along with the external pressure, avoiding an excessive pressure difference between the inside and outside of the sealed box 200. When the vacuuming process is completed and the subsequent process stage begins, the drive device 1 drives the cover 6 to move to the position of blocking the vent hole 9 to ensure the sealing of the sealed box 200.

[0049] During the inflation stage, if it is in the rapid inflation stage or needs to accelerate the increase of internal pressure in the sealing box 200, the drive device 1 drives the cover 6 to open the vent hole 9, and external gas can quickly enter the sealing box 200 through the vent hole 9, so that the internal pressure of the sealing box 200 can increase rapidly and synchronize with the external pressure to prevent excessive pressure difference; when the inflation approaches the set pressure and it is necessary to switch to flow meter air intake or enter other stages that do not require rapid inflation, the drive device 1 drives the cover 6 to block the vent hole 9 to meet the process requirements for the sealing performance of the sealing box 200.

[0050] Through the above structure and working method, the inlet and outlet gas control device 500 for the vacuum sintering furnace sealing box in this embodiment can flexibly control the opening and closing of the vent 9 according to different process stages of the vacuum sintering furnace, effectively avoiding the problem of cracking or breaking of the sealing box 200 due to excessive internal and external pressure difference, and ensuring the stable operation of the vacuum sintering furnace.

[0051] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. An inlet and outlet gas control device for a vacuum sintering furnace sealing box, characterized in that, include: A vent is provided on the wall of the sealed box, which connects the internal space of the sealed box with the external space of the sealed box; A cover is located inside the vacuum sintering furnace and outside the sealed box, the cover is directly opposite the vent hole and can block the vent hole; A drive device fixedly connected to the vacuum sintering furnace, the drive device being used to drive the cover to move relative to the vent hole.

2. The inlet and outlet gas control device for a vacuum sintering furnace sealing box according to claim 1, characterized in that: The vent is located at the center of the top of the sealed box.

3. The inlet and outlet gas control device for a vacuum sintering furnace sealing box according to claim 1 or 2, characterized in that: The driving device is a linear driving device, which is connected to the cover via a push-pull mechanism. The push-pull mechanism includes a push-pull shaft, a pressure block, and a pad. One end of the push-pull shaft is fixedly connected to the output end of the driving device. The pressure block and the cover are slidably sleeved on the push-pull shaft, and the pad is fixedly connected to the push-pull shaft. The pressure block, the cover, and the pad are distributed sequentially from top to bottom. The gap between the pressure block and the push-pull shaft is a first annular gap, and the gap between the cover and the push-pull shaft is a second annular gap. The width of the first annular gap is smaller than the width of the second annular gap.

4. The inlet and outlet gas control device for a vacuum sintering furnace sealing box according to claim 3, characterized in that: The drive device is a cylinder.

5. The inlet and outlet gas control device for a vacuum sintering furnace sealing box according to claim 3, characterized in that: The cap, the pressure block, and the pad are all made of graphite.

6. The inlet and outlet gas control device for a vacuum sintering furnace sealing box according to claim 3, characterized in that: The width of the first annular gap is less than 0.1 mm.

7. The inlet and outlet gas control device for a vacuum sintering furnace sealing box according to claim 4, characterized in that: The vacuum sintering furnace body is provided with a flange corresponding to the drive device. A flange end cover is fixedly connected to the drive device. The flange end cover is connected to the flange by multiple bolts. A sealing sleeve is also installed on the flange end cover. The piston rod of the cylinder passes through the sealing sleeve.

8. The inlet and outlet gas control device for a vacuum sintering furnace sealing box according to claim 7, characterized in that: A sealing ring is sandwiched between the piston rod and the sealing sleeve, a sealing ring is sandwiched between the sealing sleeve and the flange end cover, and a sealing ring is sandwiched between the flange end cover and the flange.

9. The inlet and outlet gas control device for a vacuum sintering furnace sealing box according to claim 4, characterized in that: It also includes a control unit and an alarm; the piston of the cylinder is made of magnetic material, and the cylinder is equipped with a first non-contact magnetic sensor and a second non-contact magnetic sensor. When the piston is at the position furthest from the sealed box, the first non-contact magnetic sensor can be triggered, and when the piston is at the position closest to the sealed box, the second non-contact magnetic sensor can be triggered. The first non-contact magnetic sensor, the second non-contact magnetic sensor, and the alarm are respectively connected to the control unit, and the control unit can also control the operation of the cylinder.

10. The inlet and outlet gas control device for a vacuum sintering furnace sealing box according to claim 3, characterized in that: The push-pull shaft is fixedly connected to the output end of the drive device via a bushing.

Images