Vacuum heat treatment furnace for machining super-large and super-heavy workpieces

Abstract

The invention belongs to the field of vacuum heat treatment equipment, and particularly relates to a vacuum heat treatment furnace for machining super-large and super-heavy workpieces. A traditional vacuum heat treatment furnace is only enlarged in size and cannot meet the requirement for machining oversized and overweight materials. Therefore, the vacuum heat treatment furnace for machining the super-large and super-heavy workpieces comprises a furnace body shell, a heating thermal field is arranged in the furnace body shell, a lower furnace door is arranged at the bottom of the furnace body shell, a bearing platform is arranged on the lower furnace door, and a material bearing assembly made of tungsten alloy and used for bearing materials is arranged on the bearing platform; the heating thermal field comprises a heating assembly and a heat preservation assembly, the heat preservation assembly comprises an upper blocking screen, a side blocking screen and a lower blocking screen, and the heating assembly comprises a side heating belt set and a lower heating belt set; according to the technical scheme, the good bearing effect on oversized and overweight materials is achieved, the safety in equipment is guaranteed under the condition of a high-temperature oversized furnace body, and the possibility that the conditions such as heating belt deformation, fixing piece breakage or equipment short circuit occur is reduced.

Description

Technical Field

[0001] The invention belongs to the field of vacuum heat treatment equipment, and in particular relates to a vacuum heat treatment furnace for processing super-large and super-heavy workpieces. Background Art

[0002] Vacuum heat treatment furnace is a special heat treatment equipment that can complete annealing, tempering, quenching, solution treatment and other heat treatment processes for workpieces in a vacuum environment or an inert gas protective atmosphere below standard atmospheric pressure. Compared with traditional atmospheric heat treatment furnaces, using vacuum heat treatment furnaces to heat treat workpieces can significantly eliminate surface contamination and oxidation of workpieces and improve the quality of processed products.

[0003] The existing vacuum heat treatment equipment technical solutions for processing oversized or overweight workpieces are not perfect enough, and the following problems are common: First, since most vacuum heat treatment furnaces use electric heating belts as heating elements, they will produce a certain amount of thermal expansion during operation. As the size of the furnace increases and the operating temperature rises, the thermal deformation of the heating belt will cause the heating belt itself and the mounting fixtures to deform or even break, seriously affecting the safety and stability of the equipment; Second, during the operation of the vacuum heat treatment furnace, the volatiles in the furnace body will deposit on the surface of the ceramic insulating parts used to install the fixed heating belt and form a conductive layer, which can easily cause a short circuit in the equipment; Third, under high temperature conditions, the material-bearing system in the furnace, which is made of conventional structures and materials, is not strong enough to meet the processing requirements of overweight parts. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a new vacuum heat treatment furnace for processing oversized and overweight parts, which can achieve a good load-bearing effect on oversized and overweight materials, and ensure the safety inside the equipment under the condition of high temperature and oversized furnace body, and reduce the possibility of deformation of the heating belt, breakage of fixings or short circuit of equipment.

[0005] To achieve the above object, the present invention adopts the following specific scheme, including a furnace shell, a heating field is arranged inside the furnace shell, a lower furnace opening is arranged at the bottom of the furnace shell, a lower furnace door is arranged through the lower furnace opening, a bearing platform is arranged on one side of the lower furnace door facing the inside of the furnace shell, and a material bearing component for bearing materials is arranged on the bearing platform; The heating thermal field includes a heating component and a heat preservation component. The heat preservation component includes an upper baffle arranged above the inside of the furnace body shell, a plurality of side baffles arranged on the inner side walls of the furnace body shell, and a lower baffle arranged on the supporting platform. The heating component includes a side heating belt group arranged on the side of the side baffle facing the inside of the furnace body shell and a lower heating belt group arranged on the lower baffle.

[0006] As a preferred solution of the present invention, the material-bearing assembly includes a plurality of load-bearing pillars and a plurality of load-bearing beams, a material-bearing tray for carrying materials is arranged through the load-bearing pillars and the load-bearing beams, a plurality of pillar fixing sleeves are arranged on the load-bearing platform, and the load-bearing pillars are fixed to the load-bearing platform through the pillar fixing sleeves.

[0007] As another preferred embodiment of the present invention, the lower heating belt group is composed of several sections of lower heating belts, the lower heating belt group is coiled in a star-shaped structure, and the lower heating belt group is sequentially provided with three layers of star-shaped structures from the inside to the outside. The lower heating belt group is connected to the lower baffle through a ceramic fixing component arranged at the bend of the star-shaped structure.

[0008] As a third preferred embodiment of the present invention, the plurality of side screens are evenly arranged along the vertical direction on the inner wall of the furnace body shell, there is a gap between adjacent side screens, a first gap screen and a second gap screen are arranged in the gap between two adjacent side screens, the first gap screen and the second gap screen are staggered, and the shielding widths of the first gap screen and the second gap screen are both greater than one half of the gap width.

[0009] As a fourth preferred embodiment of the present invention, a plurality of corresponding mounting holes are arranged on the side heating belt of the side heating belt group and the side baffle, and the side heating belt of the side heating belt group is connected with the side baffle through a split ceramic component, and the split ceramic component comprises a first ceramic tube, a second ceramic tube and a connecting rod, the first ceramic tube comprises a first large diameter section and a first small diameter section, a first annular groove is arranged on the side of the first large diameter section facing the first small diameter section, and a first step and a second step are arranged on the inner and outer sides of the first annular groove, an outer diameter of the second step is larger than the mounting hole diameter of the side heating belt, and an outer diameter of the first small diameter section is smaller than the mounting hole diameter of the side heating belt; the second ceramic tube comprises a second large diameter section and a second small diameter section, a second annular groove is arranged on the side of the second large diameter section close to the second small diameter section, a third step is arranged on the outer side of the second annular groove, and a countersunk hole is arranged on the side of the second large diameter section away from the second small diameter section; The first ceramic tube and the second ceramic tube are both provided with a through hole along the axial direction, and the diameter of the through hole is larger than the diameter of the connecting rod; One end of the connecting rod is provided with a fixing wire installed through a radial through hole, and the other end is provided with an external thread.

[0010] As a fifth preferred embodiment of the present invention, the load-bearing pillars, the load-bearing beams and the material receiving tray are all made of tungsten alloy.

[0011] As a sixth preferred embodiment of the present invention, the side heating belts of the side heating belt group and the lower heating belt of the lower heating belt group are both made of molybdenum alloy.

[0012] As a seventh preferred solution of the present invention, the upper baffle, the side baffle and the lower baffle are all made of molybdenum alloy.

[0013] Beneficial effects of the present invention: The present invention is provided with baffles on the upper part, side walls and lower part of the furnace body, and heating belt groups are provided at the side baffles and lower baffles to achieve a good heating effect, wherein the lower heating belt group is wound between the load-bearing pillars of the bearing assembly in a three-layer star-shaped structure to make the workpiece heated more evenly; The material bearing component of the present invention is used to bear materials. The load-bearing pillars, load-bearing beams and material bearing trays are made of tungsten alloy. The material bearing component of this structure and this material can maintain good strength and rigidity under high temperature conditions, meeting the heat treatment requirements of overweight workpieces. The present invention connects the side heating belt and the side baffle through a split ceramic part. The split ceramic part is designed with a gap structure in the thermal expansion direction of the heating belt, leaving a margin space for the expansion of the heating belt, which can effectively solve the deformation and fracture problems that may occur in the heating belt and its mounting fixtures after heat expansion; in addition, the main structure of the split ceramic part, the first ceramic tube and the second ceramic tube, are both designed with an annular groove structure, which can effectively prevent short circuit and leakage caused by the deposition of volatiles in the furnace on its surface, thereby improving the stability and safety of processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention provides a schematic cross-sectional view of a furnace body structure of a vacuum heat treatment furnace for processing super-large and super-heavy workpieces.

[0015] Figure 2 This is a schematic structural diagram of the lower furnace door of a vacuum heat treatment furnace for processing super-large and super-heavy workpieces proposed by the present invention.

[0016] Figure 3 This is a disassembly diagram of the parts of a split ceramic component in a vacuum heat treatment furnace for processing super-large and super-heavy workpieces proposed by the present invention.

[0017] Figure 4 This is a schematic diagram of the structure of a split ceramic component in a vacuum heat treatment furnace for processing super-large and super-heavy workpieces proposed by the present invention.

[0018] Figure 5 The present invention provides a schematic diagram of the assembly relationship between a split ceramic component and a heating thermal field in a vacuum heat treatment furnace for processing super-large and super-heavy workpieces.

[0019] Figure 6 for Figure 1 Schematic diagram of the heating thermal field side shield gap in the I area marked in FIG.

[0020] In the attached drawings, 100 is the furnace shell; 200 is the heating field; 210 is the upper baffle; 220 is the side baffle; 230 is the side heating belt group; 300 is the lower furnace door; 310 is the material bearing structure; 311 is the load-bearing pillar; 312 is the load-bearing beam; 313 is the material bearing plate; 321 is the pillar fixing sleeve; 322 is the bearing platform; 330 is the lower heat insulation baffle; 340 is the lower heating belt group; 341 is the lower heating belt; 342 is the ceramic A fixing assembly; 400 is a split ceramic part; 410 is a first ceramic tube; 411 is a first step; 412 is a second step; 413 is a first annular groove; 420 is a second ceramic tube; 421 is a third step; 422 is a second annular groove; 423 is a countersunk hole; 430 is a connecting rod; 431 is a radial through hole 431; 440 is a fixing wire; 450 is a nut; 510 is a first gap screen; 520 is a second gap screen. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention clearer, a clearer and more complete description will be given below in conjunction with specific embodiments and corresponding figures. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] It should be understood that the orientation or positional relationship indicated by the terms in the description of this embodiment is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this embodiment and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0023] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "setting", "connection", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0024] Vacuum heat treatment equipment can be divided into annealing, quenching, tempering, carburizing, nitriding and other types according to specific processes and uses. The vacuum heat treatment furnace described in the embodiments of the present invention is not limited to a specific type, and some of the structures and components described therein can be used in various types of vacuum heat treatment equipment.

[0025] The furnace structure is the core component of the vacuum heat treatment furnace equipment. Its main function is to provide the required process environment and conditions for the workpiece being processed; Figure 1As shown, the outermost layer of the furnace body is the furnace body shell 100, and the furnace body shell 100 is provided with various interfaces that can be connected with the vacuum system, cooling system, gas system, electrical system, etc.; a heating thermal field 200 is provided inside the furnace body shell 100, and a lower furnace port is provided at the bottom of the furnace body shell 100, and a lower furnace door 300 is provided through the lower furnace port. Workpieces are loaded and unloaded into the furnace through the lower furnace port, and the equipment is conveniently maintained and repaired. The lower furnace door 300 and the furnace body shell 100 can be locked and sealed by a locking ring structure and a sealing structure; a carrying platform 322 is provided on the side of the lower furnace door 300 facing the inside of the furnace body shell 100, and a material bearing component 310 for carrying materials is provided on the carrying platform 322; The heating thermal field 200 includes a heating component and a heat preservation component. The heat preservation component includes an upper baffle 210 arranged above the inside of the furnace shell 100, a plurality of side baffles 220 arranged on the inner side wall of the furnace shell 100, and a lower baffle 330 arranged on the bearing platform 322. The upper baffle 210 and the lower baffle 330 are both composed of a plurality of molybdenum plates arranged in parallel. The side baffle 220 is composed of a group of molybdenum plates curled into a cylindrical shape and arranged coaxially. A certain distance is separated between two adjacent layers of molybdenum plates to reflect the heat radiation inside the thermal field and play a role in heat preservation and insulation. The heating assembly includes a side heating belt group 230 disposed on the side of the side shield 220 facing the inside of the furnace shell 100 and a lower heating belt group 340 disposed on the lower shield 330 .

[0026] like Figure 2 As shown, as a preferred embodiment of the present invention, the material-bearing component 310 includes a plurality of load-bearing pillars 311 and a plurality of load-bearing beams 312, and a material-bearing tray 313 for bearing materials is provided through the load-bearing pillars 311 and the load-bearing beams 312, and a plurality of pillar fixing sleeves 321 are provided on the bearing platform 322, and the load-bearing pillars 311 are fixed to the bearing platform 322 through the pillar fixing sleeves 321; all the load-bearing beams 312 are arranged divergently in the form of angular equidistance with the center of the bearing platform 322 as the center point, and jointly bear the upper circular material-bearing tray 313, so as to achieve the purpose of dispersing local stress and further enhance the overall strength and bearing capacity of the material-bearing structure.

[0027] The load-bearing pillars 311 , the load-bearing beams 312 and the receiving tray 313 are all made of tungsten alloy, which can maintain high strength and rigidity under high temperature conditions and meet the requirements for high-temperature processing of overweight parts.

[0028] As another preferred embodiment of the present invention, the lower heating belt group 340 is composed of several sections of lower heating belts. The lower heating belt group 340 is in a star-shaped structure and is coiled in the gap of the load-bearing pillar 311. The lower heating belt group 340 is sequentially provided with three layers of star-shaped structures from the inside to the outside. The lower heating belt group 340 is connected to the lower baffle 330 through a ceramic fixing component 342 arranged at the bend of the star-shaped structure, thereby ensuring the uniformity of the heating temperature below the receiving tray 313 during the operation of the thermal field.

[0029] like Figure 3 and Figure 4 As shown in the figure, as a third preferred embodiment of the present invention, a plurality of side heating belts are installed on the inner wall of the side shield 220, and the side heating belts are bent into a ring shape and are coaxially arranged with the side shield 220 at a certain interval; a plurality of corresponding mounting holes are provided on the side heating belts of the side heating belt group 230 and the side shield 220, and the side heating belts of the side heating belt group 230 are connected to the side shield 220 through a split ceramic component 400, and the split ceramic component 400 includes a first ceramic tube 410, a second ceramic tube 420 and a connecting rod 430, the first ceramic tube 410 includes a first large diameter section and a first small diameter section, and the second ceramic tube 420 includes a first large diameter section and a first small diameter section. A first annular groove 413 is provided on the side of a large diameter section facing the first small diameter section, and a first step 411 and a second step 412 are provided on the inner and outer sides of the first annular groove 413. The outer diameter of the second step 412 is larger than the diameter of the side heating belt installation hole, and the outer diameter of the first small diameter section is smaller than the diameter of the side heating belt installation hole; the second ceramic tube 420 includes a second large diameter section and a second small diameter section, and a second annular groove 422 is provided on the side of the second large diameter section close to the second small diameter section, and a third step 421 is provided on the outer side of the second annular groove 422, and a countersunk hole 423 is provided on the side of the second large diameter section away from the second small diameter section; The first ceramic tube 410 and the second ceramic tube 420 are both provided with a through hole along the axial direction, and the diameter of the through hole is larger than the diameter of the connecting rod 430; One end of the connecting rod 430 is provided with a fixing wire 440 installed through a radial through hole 431, and the other end is provided with an external thread.

[0030] like Figure 5 As shown, during installation, the first small diameter section is passed through the mounting hole on the side heating belt and inserted into the countersunk hole 423 on the second large diameter section, and the first small diameter section is against the bottom of the countersunk hole 423; the through hole of the first ceramic tube 410 is aligned with the mounting hole on the side baffle 220, and the second small diameter section is against the inner wall of the side baffle 220; the fixing wire 440 is passed through the radial through hole 431 on the connecting rod 430 and fastened, and then the connecting rod 430 is passed from the end with an external thread into the through hole of the first large diameter section, and then passed out from the mounting hole of the side baffle 220 toward the end outside the furnace body, and until the fixing wire 440 is stuck on the end face of the first large diameter section, the nut 450 is screwed on the end with an external thread of the connecting rod 430 to fix it by the nut 450.

[0031] The distance between the second step 412 on the first ceramic tube 410 and the second largest diameter section of the second ceramic tube 420 is greater than the thickness of the side heating belt. Therefore, under high temperature conditions, the side heating belt can expand freely within this range, thereby avoiding problems such as deformation and cracking of the heating belt itself or ceramic parts caused by the large thermal expansion of the long heating belt inside the large equipment under high temperature conditions; in addition, under high temperature conditions, there are a certain amount of polluted gases and suspended particles inside the thermal field. These pollutants accumulate on insulating parts such as ceramic parts for a long time and easily form a conductive layer, causing leakage and short circuit of the equipment; the first annular groove 422 structure on the first ceramic tube 410 and the second annular groove 422 on the second ceramic tube 420 can effectively avoid such situations, thereby greatly improving the reliability and safety of the equipment.

[0032] like Figure 6 As shown, as a fourth preferred embodiment of the present invention, the plurality of side baffles 220 are evenly arranged on the inner wall of the furnace shell 100 along the vertical direction, there is a gap between the adjacent side baffles 220, and a first gap baffle 510 and a second gap baffle 520 are arranged at the gap between the two adjacent side baffles 220, the first gap baffle 510 and the second gap baffle 520 are also assembled from a plurality of molybdenum plates, the number of molybdenum plate layers of the first gap baffle 510 and the second gap baffle 520 is the same as or close to the number of molybdenum plate layers of the side baffle 220, and the thickness of the first gap baffle 510 and the second gap baffle 520 is less than half of the thickness of the side baffle; The first gap baffle 510 and the second gap baffle 520 are arranged alternately, wherein the first gap baffle 510 is connected to a section of the side baffle 220 above the gap and is installed close to the outer side of the side baffle 220, and the second gap baffle 520 is connected to a section of the side baffle 220 below the gap and is installed close to the inner side of the side baffle 220; the two gap baffle metal plates are arranged in an interlaced manner with the side baffle 220 metal plates, and are fixed and installed respectively by connecting rods 430 adjacent to the gap; the shielding widths of the first gap baffle 510 and the second gap baffle 520 are both greater than half of the gap width, thereby blocking the internal heat radiation of the thermal field while accommodating the larger axial thermal expansion of the large-size baffle under high temperature conditions, thereby avoiding structural deformation and fracture caused thereby.

[0033] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces, comprising a furnace shell (100), wherein a heating field (200) is arranged inside the furnace shell (100), characterized in that: A lower furnace opening is provided at the bottom of the furnace shell (100), a lower furnace door (300) is provided through the lower furnace opening, a carrying platform (322) is provided on a side of the lower furnace door (300) facing the inside of the furnace shell (100), and a material bearing assembly (310) for bearing materials is provided on the carrying platform (322); The heating thermal field (200) comprises a heating component and a heat preservation component, the heat preservation component comprising an upper baffle (210) arranged above the interior of a furnace shell (100), a plurality of side baffles (220) arranged on the inner side walls of the furnace shell (100), and a lower baffle (330) arranged on a carrying platform (322), and the heating component comprises a side heating belt group (230) arranged on the side of the side baffle (220) facing the interior of the furnace shell (100), and a lower heating belt group (340) arranged on the lower baffle (330).

2. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces as claimed in claim 1, characterized in that: The material bearing assembly (310) comprises a plurality of load-bearing pillars (311) and a plurality of load-bearing crossbeams (312); a material bearing tray (313) for bearing materials is arranged via the load-bearing pillars (311) and the load-bearing crossbeams (312); a plurality of pillar fixing sleeves (321) are arranged on the bearing platform (322); and the load-bearing pillars (311) are fixed to the bearing platform (322) via the pillar fixing sleeves (321).

3. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces as claimed in claim 1, characterized in that: The lower heating belt group (340) is formed by splicing a plurality of lower heating belt sections, the lower heating belt group (340) is coiled in a star-shaped structure, the lower heating belt group (340) is provided with three layers of star-shaped structures in sequence from the inside to the outside, and the lower heating belt group (340) is connected to the lower baffle (330) via a ceramic fixing assembly (342) provided at a bend of the star-shaped structure.

4. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces as claimed in claim 1, characterized in that: The plurality of side shields (220) are evenly arranged along the vertical direction on the inner wall of the furnace shell (100); a gap exists between adjacent side shields (220); a first gap shield (510) and a second gap shield (520) are arranged at the gap between two adjacent side shields (220); the first gap shield (510) and the second gap shield (520) are arranged alternately; and the shielding widths of the first gap shield (510) and the second gap shield (520) are both greater than half of the gap width.

5. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces as claimed in claim 1, characterized in that: The side heating belts of the side heating belt group (230) and the side baffle (220) are provided with a plurality of corresponding mounting holes. The side heating belts of the side heating belt group (230) and the side baffle (220) are connected via a split ceramic component (400). The split ceramic component (400) comprises a first ceramic tube (410), a second ceramic tube (420) and a connecting rod (430). The first ceramic tube (410) comprises a first large diameter section and a first small diameter section. A first annular groove (413) is provided on the side of the first large diameter section facing the first small diameter section. The inner and outer sides of the annular groove (413) are a first step (411) and a second step (412); the outer diameter of the second step (412) is larger than the diameter of the mounting hole of the side heating belt; the outer diameter of the first small diameter section is smaller than the diameter of the mounting hole of the side heating belt; the second ceramic tube (420) comprises a second large diameter section and a second small diameter section; a second annular groove (422) is provided on the side of the second large diameter section close to the second small diameter section; the outer side of the second annular groove (422) is a third step (421); and a countersunk hole (423) is provided on the side of the second large diameter section away from the second small diameter section; The first ceramic tube (410) and the second ceramic tube (420) are both provided with through holes along the axial direction, and the diameter of the through holes is greater than the diameter of the connecting rod 430; One end of the connecting rod (430) is provided with a fixing wire 440 installed through a radial through hole 431, and the other end is provided with an external thread.

6. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces as claimed in claim 2, characterized in that: The material of the load-bearing pillar (311), the load-bearing crossbeam (312) and the material receiving tray (313) are all tungsten alloy.

7. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces as claimed in claim 1, characterized in that: The side heating belts of the side heating belt group (230) and the lower heating belt of the lower heating belt group (340) are both made of molybdenum alloy.

8. A vacuum heat treatment furnace for processing super-large and super-heavy workpieces as claimed in claim 1, characterized in that: The upper shield (210), the side shield (220) and the lower shield (330) are all made of molybdenum alloy.

Images