A low pressure vacuum carburizing furnace

Abstract

The present invention relates to the technical field of carburizing processing, and in particular to a low-pressure vacuum carburizing furnace, comprising a furnace body, wherein a fixing seat is fixedly provided on the outer wall of the furnace body, and a rotating shaft is rotatably provided in the fixing seat, an arc rod is fixedly provided on the outer wall of the rotating shaft, and a mounting ring is fixedly provided on the end of the arc rod, a furnace door is movably provided in the mounting ring, a limiting groove is provided on the inner wall of the mounting ring, a limiting block is fixedly provided on the outer side of the furnace door, and the limiting block is located in the limiting groove. When closing the furnace door, the present invention first rotates the mounting ring, and when the mounting ring rotates to a state that is aligned with the end of the furnace body, the furnace door in the mounting ring is pushed, so that the sealing gasket on the outer wall of the furnace door is stuck in the sealing groove at the end of the furnace body, and at the same time, the furnace door and the end of the furnace body can be closely fitted by means of a locking mechanism, and a secondary sealing is performed through a secondary sealing mechanism, thereby effectively improving the sealing between the furnace body and the furnace door, and achieving a better use effect.

Description

Technical Field

[0001] The invention relates to the technical field of carburizing processing, in particular to a low-pressure vacuum carburizing furnace. Background Art

[0002] Carburizing is a surface hardening treatment that increases the hardness and wear resistance of metals by penetrating carbon atoms into the surface of the metal. Conventional carburizing processes are usually carried out at atmospheric pressure and involve placing the workpiece in a medium containing carbon, such as charcoal or kerosene, and then heating it at high temperatures. Although effective, this method has some disadvantages, such as difficulty in controlling the penetration depth of carbon, uneven surface quality, long processing time, high energy consumption, and potential pollution to the environment. To overcome these limitations, low-pressure vacuum carburizing technology was developed. In low-pressure vacuum carburizing, the workpiece is placed in a sealed vacuum chamber and then evacuated to a low pressure state. In this low-pressure environment, a carburizing agent (such as propane or acetylene) is introduced and reacts with the surface of the workpiece, resulting in uniform carbon diffusion under controlled conditions. Low-pressure vacuum carburizing furnaces provide more precise control of carbon concentration and depth, while reducing processing time and energy consumption.

[0003] During the design process of the low-pressure vacuum carburizing furnace, in order to maintain the vacuum in the furnace body, the sealing of the carburizing furnace is very important. At present, the furnace doors of the existing furnace bodies are mostly flip-type furnace doors. It is necessary to ensure that the furnace door is completely parallel to the end of the furnace body when closed to achieve the density of the furnace body. However, when the flip-type furnace door is used for many times, its accuracy will inevitably be affected, and then its sealing will be affected, and the use effect is poor. Therefore, it is urgent to design a low-pressure vacuum carburizing furnace to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to solve the defects in the prior art and to propose a low-pressure vacuum carburizing furnace.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A low-pressure vacuum carburizing furnace comprises a furnace body, wherein a fixing seat is fixedly arranged on the outer wall of the furnace body, and a rotating shaft is rotatably arranged in the fixing seat, an arc-shaped rod is fixedly arranged on the outer wall of the rotating shaft, and a mounting ring is fixedly arranged on the end of the arc-shaped rod, a furnace door is movably arranged in the mounting ring, a limiting groove is arranged on the inner wall of the mounting ring, a limiting block is fixedly arranged on the outer side of the furnace door, and the limiting block is located in the limiting groove, a handle is fixedly arranged on the outer wall of the furnace door, a sealing groove is arranged at the end of the furnace body, a sealing gasket matched with the sealing groove is fixedly arranged on the inner wall of the furnace door close to the furnace body, a bracket is fixedly arranged on the inner wall of the furnace body, and a placement plate is placed above the bracket, and further comprises:

[0007] A supporting mechanism, which is arranged above the placement plate and is used to support the steel piece to be carburized;

[0008] A limiting mechanism, which is arranged in the furnace body and is used to limit the position of the placement plate;

[0009] A secondary sealing mechanism, which is arranged at the end of the furnace body and is used to enhance the sealing between the furnace body and the furnace door;

[0010] The locking and sealing mechanism is arranged on the outer side of the furnace body and is used to lock and seal the furnace door so that the furnace door and the end of the furnace body are closely fitted.

[0011] As a further solution of the present invention: the supporting mechanism includes a vertical plate, a shaft rod is rotatably arranged in the vertical plate, and the end of the shaft rod is fixedly connected to the upper surface of the placement plate, the outer wall of the vertical plate is provided with a mounting groove, and a supporting plate is rotatably arranged in the mounting groove, and a supporting assembly is also arranged in the vertical plate for supporting the vertical plate to maintain a vertical state.

[0012] As a further solution of the present invention: the outer wall of the support plate is provided with movable openings distributed at equal distances, and the side wall of the support plate is penetrated by telescopic rods distributed at equal distances, a fixing rod is fixedly provided at one end of the telescopic rod, and a baffle is fixedly provided at the other end of the telescopic rod, and the baffle is located in the movable opening.

[0013] As a further solution of the present invention: the support assembly includes a support frame, a fixing groove is opened on the lower surface of the vertical plate, and the support frame is located in the fixing groove, a mounting rod is fixedly provided on the top inner wall of the fixing groove, and the mounting rod passes through the support frame, and an anti-dropping piece is fixedly provided on the end of the mounting rod.

[0014] As a further solution of the present invention: the limiting mechanism includes a stake fixedly arranged on the lower surface of the placement plate, and the stake is conical, the upper surface of the bracket is provided with a slot matching the stake, the side wall of the placement plate is provided with a V-groove, and the bottom inner wall of the furnace body is fixedly provided with a baffle rod, and the baffle rod is located in the V-groove.

[0015] As a further solution of the present invention: the secondary sealing mechanism includes an annular groove opened at the end of the furnace body, and the end of the furnace body is also fixedly provided with a first gasket and a second gasket, the second gasket is located in the first gasket, and the annular groove is between the first gasket and the second gasket, and the outer wall of the furnace body is also fixedly provided with an exhaust pipe connected to the annular groove.

[0016] As a further solution of the present invention: the locking mechanism includes a first side plate fixed to the outer wall of the furnace body in an annular shape with equal distances, a sleeve is movably arranged through the outer wall of the first side plate, a telescopic column is movably arranged in the sleeve, a second side plate distributed in an annular shape with equal distances is also fixedly arranged on the outer wall of the furnace body, and the telescopic column penetrates the second side plate, a movable plate is fixedly arranged on the end of the telescopic column away from the sleeve, a telescopic cylinder is fixedly arranged through the outer wall of the second side plate, and the telescopic end of the telescopic cylinder is connected to the outer wall of the movable plate, a first tooth groove distributed in equal distances is opened on the outer wall of the telescopic column, a gear is rotatably arranged on the outer wall of the sleeve, and the gear is meshed with the first tooth groove, a third side plate is also fixedly arranged on the outer wall of the sleeve, and the outer wall of the third side plate penetrates A toothed plate is movably arranged through the sleeve, and a second tooth groove is provided on the outer wall of the toothed plate with equal distances, and the gear and the second tooth groove are meshed with each other. An ear seat is fixedly arranged at the end of the sleeve, and a blocking piece is rotatably arranged in the ear seat. A moving opening is provided on the side wall of the blocking piece, and a sliding rod is movably arranged in the moving opening. The end of the toothed plate and the sliding rod are fixedly connected by a connecting rod, and a stop block is also fixedly arranged at the end of the sleeve. A fourth side plate is fixedly arranged on the side wall of the sleeve, and a movable rod is movably arranged on the outer wall of the fourth side plate, one end of the movable rod is fixedly connected to the outer wall of the second side plate, and a stop block is fixedly arranged on the other end of the movable rod, a spring is sleeved on the outer side of the movable rod, one end of the spring is connected to the stop block, and the other end of the spring is connected to the fourth side plate.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention provides a low-pressure vacuum carburizing furnace, in which the carburized steel parts to be processed can be placed on a placing plate, and then the placing plate can be placed on a bracket in the furnace body by a forklift, and the position of the placing plate can be quickly limited by means of a limiting mechanism in the furnace body. When the position of the placing plate is limited, the furnace door can be closed. In the process of closing the furnace door, the mounting ring can be rotated first. When the mounting ring is rotated to a state aligned with the end of the furnace body, the handle can be held and the furnace door in the mounting ring can be pushed, so that the sealing gasket on the outer wall of the furnace door is inserted into the sealing groove at the end of the furnace body. At the same time, the locking mechanism can be used to make the furnace door and the end of the furnace body fit tightly, and a secondary sealing mechanism can be used for secondary sealing, so as to effectively ensure the sealing between the furnace body and the furnace door, and the use effect is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic structural diagram of a low-pressure vacuum carburizing furnace from a first perspective provided by an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of a half-section structure of a low-pressure vacuum carburizing furnace provided in an embodiment of the present invention;

[0021] Figure 3 for Figure 2 A is an enlarged structural diagram;

[0022] Figure 4 A schematic structural diagram of a material supporting mechanism in a low-pressure vacuum carburizing furnace provided in an embodiment of the present invention;

[0023] Figure 5 A schematic structural diagram of a neutral plate of a low-pressure vacuum carburizing furnace provided in an embodiment of the present invention;

[0024] Figure 6 A structural schematic diagram of a locking mechanism in a low-pressure vacuum carburizing furnace provided by an embodiment of the present invention;

[0025] Figure 7 A schematic diagram of a half-section structure of a locking mechanism in a low-pressure vacuum carburizing furnace provided by an embodiment of the present invention;

[0026] Figure 8 A second perspective structural schematic diagram of a low-pressure vacuum carburizing furnace provided in an embodiment of the present invention.

[0027] In the figure: 101-furnace body, 102-fixed seat, 103-rotating shaft, 104-arc rod, 105-mounting ring, 106-furnace door, 107-handle, 108-limiting groove, 109-limiting block, 110-sealing groove, 111-sealing gasket, 112-bracket, 113-placing plate, 201-vertical plate, 202-axial rod, 203-mounting groove, 204-support plate, 205-movable port, 206-fixed rod, 207-telescopic rod, 208-blocking plate, 301-insertion pile, 302-blocking rod, 303-V-groove, 401-fixed groove, 402-mounting rod, 403-anti-slip sheet , 404-support frame, 501-first gasket, 502-second gasket, 503-annular groove, 504-exhaust pipe, 601-first side plate, 602-sleeve, 603-telescopic column, 604-second side plate, 605-gear, 606-first tooth groove, 607-third side plate, 608-tooth plate, 609-second tooth groove, 610-ear seat, 611-locking seal, 612-moving port, 613-sliding rod, 614-connecting rod, 615-block, 616-fourth side plate, 617-movable rod, 618-spring, 619-block, 620-telescopic cylinder, 621-moving plate. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0029] like Figure 1-Figure 8As shown, a low-pressure vacuum carburizing furnace provided by an embodiment of the present invention includes a furnace body 101, a fixing seat 102 is fixedly provided on the outer wall of the furnace body 101, and a rotating shaft 103 is rotatably provided in the fixing seat 102, an arc rod 104 is fixedly provided on the outer wall of the rotating shaft 103, and a mounting ring 105 is fixedly provided on the end of the arc rod 104, a furnace door 106 is movably provided in the mounting ring 105, a limiting groove 108 is provided on the inner wall of the mounting ring 105, a limiting block 109 is fixedly provided on the outer side of the furnace door 106, and the limiting block 109 is located in the limiting groove 108, a handle 107 is fixedly provided on the outer wall of the furnace door 106, a sealing groove 110 is provided at the end of the furnace body 101, and the furnace door 106 is close to the furnace body 1 A sealing gasket 111 matching the sealing groove 110 is fixedly provided on the inner wall of one side of the furnace body 101, a bracket 112 is fixedly provided on the inner wall of the furnace body 101, and a placement plate 113 is placed above the bracket 112, and also includes: a supporting mechanism, the supporting mechanism is arranged above the placement plate 113, and is used to support the steel parts to be carburized; a limiting mechanism, the limiting mechanism is arranged in the furnace body 101, and is used to limit the position of the placement plate 113; a secondary sealing mechanism, the secondary sealing mechanism is arranged at the end of the furnace body 101, and is used to enhance the sealing between the furnace body 101 and the furnace door 106; a locking mechanism, the locking mechanism is arranged on the outer side of the furnace body 101, and is used to lock the furnace door 106, so that the furnace door 106 and the end of the furnace body 101 are closely fitted.

[0030] The carburized steel parts to be processed can be placed on the placement plate 113, and then the placement plate 113 can be placed on the bracket 112 in the furnace body 101 by a forklift, and the position of the placement plate 113 can be quickly limited by means of the limiting mechanism in the furnace body 101. When the position of the placement plate 113 is limited, the furnace door 106 can be closed. In the process of closing the furnace door 106, the mounting ring 105 can be rotated first. When the mounting ring 105 is rotated to a state aligned with the end of the furnace body 101, the handle 107 can be held and the furnace door 106 in the mounting ring 105 can be pushed, so that the sealing gasket 111 on the outer wall of the furnace door 106 is inserted into the sealing groove 110 at the end of the furnace body 101. At the same time, the locking mechanism can be used to make the furnace door 106 and the end of the furnace body 101 fit tightly, and a secondary sealing mechanism can be used for secondary sealing, thereby effectively ensuring the sealing between the furnace body 101 and the furnace door 106, and the use effect is better.

[0031] As an embodiment of the present invention, please refer to Figure 4 and Figure 5The supporting mechanism includes a vertical plate 201, a shaft 202 is rotatably provided in the vertical plate 201, and the end of the shaft 202 is fixedly connected to the upper surface of the placement plate 113, a mounting groove 203 is provided on the outer wall of the vertical plate 201, and a supporting plate 204 is rotatably provided in the mounting groove 203, and a supporting assembly is also provided in the vertical plate 201 to support the vertical plate 201 to maintain a vertical state. When a small-volume steel part needs to be carburized, the vertical plate 201 can be erected through the supporting assembly, and the supporting plate 204 can be moved from the vertical plate 201 to the vertical plate 201. The support plate 204 is taken out from the mounting groove 203 on one side of the vertical plate 201 so that the support plate 204 remains horizontal, and then the small-volume steel parts can be placed on the support plate 204 to achieve the purpose of carburizing the small-volume steel parts. When carburizing operations are required on large-volume steel parts, the support assembly for the vertical plate 201 can be first released, and then the vertical plate 201 can be turned over to one side. At this time, the support plate 204 will be automatically stored in the mounting groove 203, and then the large-volume steel parts can be directly placed on the placement plate 113, which is more flexible to use.

[0032] As an embodiment of the present invention, please refer to Figure 4 and Figure 5 The outer wall of the support plate 204 is provided with movable openings 205 distributed at equal distances, and the side wall of the support plate 204 is movably provided with telescopic rods 207 distributed at equal distances. A fixed rod 206 is fixedly provided at one end of the telescopic rod 207, and a baffle 208 is fixedly provided at the other end of the telescopic rod 207, and the baffle 208 is located in the movable opening 205. The telescopic rod 207 can be pulled out from the movable opening 205, so that some small-volume steel parts can be placed above the telescopic rod 207 to increase the number of single-carburized steel parts and achieve better use effect.

[0033] As an embodiment of the present invention, please refer to Figure 4 and Figure 5 The support assembly includes a support frame 404. A fixing groove 401 is provided on the lower surface of the vertical plate 201, and the support frame 404 is located in the fixing groove 401. A mounting rod 402 is fixedly provided on the top inner wall of the fixing groove 401, and the mounting rod 402 passes through the support frame 404. An anti-slip sheet 403 is fixedly provided on the end of the mounting rod 402. When the vertical plate 201 is erected, the support frame 404 in the fixing groove 401 can be rotated so that the support frame 404 and the vertical plate 201 maintain a cross distribution, which can play a role in supporting the vertical plate 201. When the support frame 404 is rotated again, it can be stored in the fixing groove 401, so that the vertical plate 201 can be completely flat, which is very convenient to use.

[0034] As an embodiment of the present invention, please refer to Figure 2 , Figure 4 and Figure 5The limiting mechanism includes a plugging stake 301 fixedly arranged on the lower surface of the placement plate 113, and the plugging stake 301 is conical. The upper surface of the bracket 112 is provided with a slot that matches the plugging stake 301. The side wall of the placement plate 113 is provided with a V-shaped groove 303. The bottom inner wall of the furnace body 101 is fixedly provided with a blocking rod 302, and the blocking rod 302 is located in the V-shaped groove 303. When the forklift lifts the placement plate 113 and sends it into the furnace body 101, the V-shaped groove 303 on one side of the placement plate 113 will move. To the outside of the blocking rod 302, and as the placement plate 113 is continuously fed into the furnace body 101, the blocking rod 302 can calibrate the position of the placement plate 113, so that the plugging stakes 301 under the placement plate 113 are just aligned with the slots. When the forklift is placing the placement plate 113 downward, the plugging stakes 301 under the placement plate 113 can be directly inserted into the slots, which can effectively and quickly define the position of the placement plate 113 and maintain the stability of the placement plate 113 after placement, resulting in better use effect.

[0035] As an embodiment of the present invention, please refer to Figure 3 The secondary sealing mechanism includes an annular groove 503 opened at the end of the furnace body 101, and a first gasket 501 and a second gasket 502 are fixedly arranged at the end of the furnace body 101. The second gasket 502 is located in the first gasket 501, and the annular groove 503 is between the first gasket 501 and the second gasket 502. The outer wall of the furnace body 101 is also fixedly provided with an exhaust pipe 504 connected to the annular groove 503, and the exhaust pipe 504 is connected to the negative pressure unit of the carburizing furnace. When the negative pressure unit evacuates the furnace body 101 to a vacuum, the air between the first gasket 501 and the second gasket 502 can be extracted through the annular groove 503 with the help of the exhaust pipe 504, and the negative pressure principle is used to make the furnace door 106 and the first gasket 501 and the second gasket 502 tightly adsorbed, and the use effect is better.

[0036] As an embodiment of the present invention, please refer to Figure 6 , Figure 7 and Figure 8The locking mechanism includes a first side plate 601 fixed to the outer wall of the furnace body 101 in an annular shape with equal distances, a sleeve 602 is movably provided on the outer wall of the first side plate 601, a telescopic column 603 is movably provided in the sleeve 602, a second side plate 604 distributed in an annular shape with equal distances is fixedly provided on the outer wall of the furnace body 101, and the telescopic column 603 penetrates the second side plate 604, a movable plate 621 is fixedly provided on the end of the telescopic column 603 away from the sleeve 602, a telescopic cylinder 620 is fixedly provided on the outer wall of the second side plate 604, and the telescopic end of the telescopic cylinder 620 is connected to the outer wall of the movable plate 621, the outer wall of the telescopic column 603 is provided with first tooth grooves 606 distributed in equal distances, a gear 605 is rotatably provided on the outer wall of the sleeve 602, and the gear 60 5 and the first tooth groove 606 are meshed, the outer wall of the sleeve 602 is also fixedly provided with a third side plate 607, and the outer wall of the third side plate 607 is movably provided with a tooth plate 608, the outer wall of the tooth plate 608 is provided with second tooth grooves 609 distributed at equal distances, and the gear 605 is meshed with the second tooth groove 609, the end of the sleeve 602 is fixedly provided with an ear seat 610, and a blocking member is rotatably provided in the ear seat 610, the side wall of the blocking member is provided with a moving opening 612, and a sliding rod 613 is movably provided in the moving opening 612, the end of the tooth plate 608 and the sliding rod 613 are fixedly connected by a connecting rod 614, the end of the sleeve 602 is also fixedly provided with a stopper 615, the side wall of the sleeve 602 is fixedly provided with a fourth side plate 616, and the fourth side plate A movable rod 617 is movably provided through the outer wall of 616, one end of the movable rod 617 is fixedly connected to the outer wall of the second side plate 604, and a stopper 619 is fixedly provided at the other end of the movable rod 617, a spring 618 is sleeved on the outer side of the movable rod 617, one end of the spring 618 is connected to the stopper 619, and the other end of the spring 618 is connected to the fourth side plate 616. When the telescopic cylinder 620 drives the telescopic column 603 to move toward the sleeve 602, the movement of the sleeve 602 can be hindered under the action of the elastic force of the spring 618, and when the telescopic column 603 moves in the sleeve 602, it can drive the gear 605 to rotate, and the gear 605 drives the tooth plate 608 to move toward the direction close to the furnace body 101, and the tooth plate 608 can pull the slide through the connecting rod 614. The locking member 611 is then released and the locking member 612 is released, and the locking member 613 is released, so that the locking member 611 is released and the locking member 612 is released.The spring 618 on the outer side of the movable rod 617 is stretched, and the blocking member parallel to the furnace door 106 also abuts against the furnace door 106, thereby achieving the purpose of blocking the furnace door 106, and the use effect is better.

[0037] When in use, the carburized steel parts to be processed can be placed on the placement plate 113, and then the placement plate 113 can be placed on the bracket 112 in the furnace body 101 by a forklift, and the position of the placement plate 113 can be quickly limited by means of the limiting mechanism in the furnace body 101. When the position of the placement plate 113 is limited, the furnace door 106 can be closed. In the process of closing the furnace door 106, the mounting ring 105 can be rotated first. When the mounting ring 105 is rotated to a state where it is aligned with the end of the furnace body 101, the handle 107 can be held and the furnace door 106 in the mounting ring 105 can be pushed, so that the sealing gasket 111 on the outer wall of the furnace door 106 is inserted into the sealing groove 110 at the end of the furnace body 101. At the same time, the locking mechanism can be used to make the furnace door 106 and the end of the furnace body 101 fit tightly, and a secondary sealing mechanism can be used for secondary sealing, thereby effectively ensuring the sealing between the furnace body 101 and the furnace door 106, and the use effect is better.

[0038] It should be particularly noted that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A low-pressure vacuum carburizing furnace, comprising a furnace body, characterized in that: The outer wall of the furnace body is fixedly provided with a fixing seat, and a rotating shaft is rotatably provided in the fixing seat, an arc-shaped rod is fixedly provided on the outer wall of the rotating shaft, and a mounting ring is fixedly provided on the end of the arc-shaped rod, a furnace door is movably provided in the mounting ring, a limiting groove is provided on the inner wall of the mounting ring, a limiting block is fixedly provided on the outer side of the furnace door, and the limiting block is located in the limiting groove, a handle is fixedly provided on the outer wall of the furnace door, a sealing groove is provided at the end of the furnace body, a sealing gasket matched with the sealing groove is fixedly provided on the inner wall of the furnace door close to the furnace body, a bracket is fixedly provided on the inner wall of the furnace body, and a placement plate is placed above the bracket, and also includes: The support mechanism is arranged above the placement plate and is used for supporting the steel workpiece to be carburized, the support mechanism comprises a vertical plate, an axle rod is rotatably arranged in the vertical plate, and the end of the axle rod is fixedly connected to the upper surface of the placement plate, the outer wall of the vertical plate is provided with a mounting groove, and a support plate is rotatably arranged in the mounting groove, and a support assembly is also provided in the vertical plate for supporting the vertical plate to maintain a vertical state, the outer wall of the support plate is provided with movable openings distributed at equal distances, and the side wall of the support plate is penetrated by movably arranged telescopic rods distributed at equal distances, one end of the telescopic rod is fixedly provided with a fixing rod, and the other end of the telescopic rod is fixedly provided with a baffle, and the baffle is located in the movable opening, the support assembly comprises a support frame, a fixing groove is arranged on the lower surface of the vertical plate, and the support frame is located in the fixing groove, a mounting rod is fixedly arranged on the top inner wall of the fixing groove, and the mounting rod penetrates the support frame, and an anti-slip sheet is fixedly arranged on the end of the mounting rod; A limiting mechanism, which is arranged in the furnace body and is used to limit the position of the placement plate; A secondary sealing mechanism, which is arranged at the end of the furnace body and is used to enhance the sealing between the furnace body and the furnace door; The locking and sealing mechanism is arranged on the outer side of the furnace body and is used to lock and seal the furnace door so that the furnace door and the end of the furnace body are closely fitted.

2. A low-pressure vacuum carburizing furnace according to claim 1, characterized in that: The limiting mechanism includes a plugging stake fixedly arranged on the lower surface of the placement plate, and the plugging stake is conical, the upper surface of the bracket is provided with a slot matching the plugging stake, the side wall of the placement plate is provided with a V-shaped groove, and the bottom inner wall of the furnace body is fixedly provided with a blocking rod, and the blocking rod is located in the V-shaped groove.

3. A low-pressure vacuum carburizing furnace according to claim 1, characterized in that: The secondary sealing mechanism includes an annular groove opened at the end of the furnace body, and a first gasket and a second gasket are fixedly arranged at the end of the furnace body. The second gasket is located in the first gasket, and the annular groove is between the first gasket and the second gasket. The outer wall of the furnace body is also fixedly provided with an exhaust pipe connected to the annular groove.

4. A low-pressure vacuum carburizing furnace according to claim 1, characterized in that: The locking mechanism includes a first side plate fixed to the outer wall of the furnace body in an annular shape with equal distances, a sleeve is movably provided through the outer wall of the first side plate, a telescopic column is movably provided in the sleeve, a second side plate distributed in an annular shape with equal distances is also fixedly provided on the outer wall of the furnace body, and the telescopic column passes through the second side plate, a movable plate is fixedly provided on the end of the telescopic column away from the sleeve, a telescopic cylinder is fixedly provided through the outer wall of the second side plate, and the telescopic end of the telescopic cylinder is connected to the outer wall of the movable plate, a first tooth groove distributed in equal distances is opened on the outer wall of the telescopic column, a gear is rotatably provided on the outer wall of the sleeve, and the gear is meshed with the first tooth groove, a third side plate is also fixedly provided on the outer wall of the sleeve, and a gear is movably provided through the outer wall of the third side plate The tooth plate has a second tooth groove distributed at an equal distance from the outer wall of the tooth plate, and the gear and the second tooth groove are meshed with each other. An ear seat is fixedly provided at the end of the sleeve, and a blocking piece is rotatably provided in the ear seat. A moving opening is provided on the side wall of the blocking piece, and a sliding rod is movably provided in the moving opening. The end of the tooth plate and the sliding rod are fixedly connected by a connecting rod, and a stop block is also fixedly provided at the end of the sleeve. A fourth side plate is fixedly provided on the side wall of the sleeve, and a movable rod is movably provided through the outer wall of the fourth side plate, one end of the movable rod is fixedly connected to the outer wall of the second side plate, and a stop block is fixedly provided on the other end of the movable rod, a spring is sleeved on the outer side of the movable rod, one end of the spring is connected to the stop block, and the other end of the spring is connected to the fourth side plate.

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