Heat treatment tool for preventing deformation of large shell part

Abstract

The invention belongs to the technical field of heat treatment equipment, and particularly discloses a heat treatment tool for preventing deformation of a large shell part, which comprises a base, a bearing unit attached to the lower surface of the large shell part is arranged in the middle of the upper surface of the base, and side plates supporting each other are arranged on the two sides of the bearing unit. The lower portions of the two symmetrical side plates are fixedly connected with the base, and a plurality of fixing shafts used for fixing large shell parts are arranged between the two side plates. According to the heat treatment tool for the large shell part, the supporting and fixing effects of the tool in the heat treatment process can be achieved, the baffles symmetrically arranged on the two sides can prevent the large shell part from bending and deforming outwards, and the heat treatment tool plays an important role in vacuum heat treatment of the large shell part; and the method is of great significance in improving the treatment quality of the large shell part and improving the production efficiency of heat treatment.

Description

Technical Field

[0001] The invention relates to the technical field of heat treatment equipment, and in particular to a heat treatment tool for preventing deformation of large shell parts. Background Art

[0002] Most of the landing gear related parts involved in the aviation manufacturing industry are various types of shell-type key parts, whose service life directly affects the service life of the entire aircraft landing gear system. Such key parts are the guarantee of the landing gear. Vacuum heat treatment technology controls the phase change, microstructure and residual stress of key parts by adopting heating, cooling, vacuum degree and other technologies to give key parts performance or extreme performance. Therefore, vacuum heat treatment technology is a key technology to achieve long life, high reliability and structural weight reduction of key basic parts. Key parts that have undergone vacuum heat treatment can not only ensure the required organization, mechanical properties and process properties, but also deeply tap the potential of key parts, ensure and improve the quality and life of key parts, and maximize the potential of materials. Vacuum heat treatment can realize almost all heat treatment processes, such as quenching, annealing, tempering, carburizing, chromizing, nitriding and precipitation hardening; in the quenching process, gas quenching, oil quenching, nitrate quenching, water quenching, degassing, etc. can be realized.

[0003] Heat treatment production is inseparable from fixtures, but various types of fixtures, trays, baskets, racks, etc. for heating furnaces must be heated together with the workpiece. Sometimes the heat taken away is equal to or greater than the heat of the workpiece, accounting for about 18% to 29% of the total heat, which undoubtedly increases the cost of heat treatment production. Heat treatment production is carried out at high temperatures, and various auxiliary fixtures must be used to complete the loading and unloading of workpieces, quenching, workpiece transfer and other actions. Various auxiliary fixtures are important tools to ensure the smooth progress of heat treatment production, the quality of workpiece heat treatment, and the safety of heat treatment operations. To this end, it is necessary to design and produce a variety of fixtures according to different furnace types, different workpiece structures and different process requirements. A typical example of a variety of fixtures is composed of nearly hundreds of various fixtures and workpieces. There are actually a lot of manufacturing errors. At the same time, for the heat treatment of a small number of sporadic workpieces, heat treatment process personnel or heat treatment workers often need to rely on production experience and actual conditions to temporarily make simple fixtures. Heat treatment fixtures are a kind of vulnerable parts, and the main failure form is high-temperature oxidation thinning and severe strength reduction. Welding and casting are commonly used to make heat treatment tools. Controlling tooling materials and tooling production costs is an important aspect of controlling heat treatment production costs. Since high temperature strength refers to the tooling that loads workpieces and is heated for a long time at high temperature, it needs to bear the weight of the heated workpiece, and the tooling cannot be severely deformed or even fall apart. The high temperature strength of the tooling is guaranteed by the material and tooling structure, but if the structure is too strong, the weight is large and the heat energy absorbed is large, which increases the unit energy consumption of the workpiece, prolongs the heating time, and leads to an increase in production costs. Because the metal tray is heavy (such as the tray for vacuum carburizing and quenching furnace) and has a large heat capacity, the quenching liquid temperature increases and reduces its cooling capacity. In addition, the tray is repeatedly heated and carburized and quenched, and phase changes will occur inside it, causing tissue stress. In addition, due to thermal fatigue, cracks appear in the tray, and the service life is greatly reduced. At the same time, the metal tray is heavy and has a large heat capacity, which adds additional energy. The tooling fixture for vacuum furnaces made of alloy materials at high temperatures (1200℃) has a short service life. Practice shows that the correct heat treatment process can obtain excellent organization, and excellent organizational morphology can ensure excellent mechanical properties. Appropriate process methods can effectively control the deformation and cracking of heat treatment tools. It is found from practice that during the heating and cooling process of heat treatment tools, the difference between the surface temperature and the core temperature of the heat treatment workpiece (uneven heating and uneven cooling) is the main factor causing the deformation of the heat treatment tooling. (The vacuum furnace has the ability to control the heating rate and cooling rate). Different process methods can make the heat treatment tooling meet different use conditions and different performance requirements.

[0004] The manufacture of heat treatment tooling involves a number of manufacturing and processing technologies and equipment. It is used to complete the loading, entering and exiting the furnace, quenching, and transfer of workpieces. It is also an important tool to ensure the smooth progress of production, the quality of workpiece heat treatment, and the safety of operation. Heat treatment tooling is generally divided into two types, one is general tooling and the other is special tooling. General tooling is designed and manufactured based on the adaptability of the furnace type, and is suitable for the heat treatment of commonly used large quantities of workpieces. Its function is to complete the entry and exit of the furnace and the clamping during the heating and cooling process, reduce the deformation of the workpiece during heat treatment, and complete certain auxiliary work of heat treatment. Special tooling is mainly based on the pertinence of the workpiece, and is designed and manufactured in combination with the furnace type to meet the special loading requirements of the workpiece. Due to the different shapes and sizes of heat treatment workpieces and the various types of heat treatment furnaces, the tooling used for heat treatment is also diverse. For workpieces with complex shapes and strict dimensional requirements, in order to ensure the dimensional accuracy of certain special requirements, special tooling needs to be designed. For some large and heavy workpieces, in order to facilitate the entry and exit of the furnace, and for some workpieces to maintain vertical heating and vertical quenching during heat treatment, special tooling needs to be designed according to the furnace type. The functions of general tooling and special tooling are very different, so they cannot be mixed at will.

[0005] Heat treatment fixtures are prone to cracking, collapse, and burnout at high temperatures and are scrapped, and the manufacturing cost is high. In addition, in existing heat treatment fixtures, most of the hanging plates on the upper side are fixed, which cannot meet the heat treatment requirements of shell parts of different sizes. There is no doubt that shell-type workpieces will produce serious flexural deformation during the actual heat treatment process. In order to solve this problem, it is necessary to consider the placement of workpieces in the height direction. In addition, the specific gravity of the heat energy required for heating fixtures is generally 18% to 29%. Therefore, reducing the weight of fixtures is of great significance to improving heating efficiency. One way to reduce weight is to improve the structure of fixtures.

[0006] At present, the key parts of aviation shell workpieces are large in size, with various shapes and sizes, narrow width and thin wall thickness. Under the heat treatment heating temperature, the steel parts will have a certain amount of expansion, and a large-scale sagging deformation occurred in the hot furnace test. The structural cross-sectional size changes are relatively drastic, the deformation is large after heat treatment, the plane warping is large, and it is difficult to correct after heat treatment. The ultra-high strength steel material parts are heated to a predetermined temperature in a vacuum quenching furnace and then quenched for a period of time to obtain a martensitic structure. Although this method can make the parts achieve high strength and high hardness, the deformation is increased and cracks are prone to occur during straightening. Summary of the invention

[0007] The purpose of the present invention is to provide a heat treatment tooling with simple structure, small footprint, strong operability, good durability, and the ability to prevent deformation of large shell parts for loading shell-type heat treatment parts. The heat treatment tooling can meet the requirements of heat treatment process capabilities and improve the processing efficiency of parts in subsequent processing.

[0008] The present invention is achieved through the following technical scheme: a heat treatment tool for preventing deformation of large shell parts, including a base, a bearing unit that is in contact with the lower surface of the large shell part is arranged in the middle of the upper surface of the base, and side panels that support each other are arranged on both sides of the bearing unit. The lower parts of the two symmetrical side panels are fixedly connected to the base, and a number of fixed shafts for fixing the large shell parts are arranged between the two side panels.

[0009] In order to better realize the present invention, further, the front end of the base is also provided with a slide groove abutting against the front of the carrying unit, and a U-shaped support block capable of reciprocatingly sliding in the slide groove is arranged in the slide groove, and the upper surface of the U-shaped support block is in contact with the corresponding lower surface position of the large shell part.

[0010] In order to better realize the present invention, further, the bearing unit is composed of a plurality of groups of longitudinally spaced support members, each group of the support members is composed of at least two bosses with the same structure and spaced apart, and the upper surfaces of the bosses are in contact with the corresponding lower surface positions of the large shell parts.

[0011] In order to better implement the present invention, further, the side panel includes an upper support plate and a lower fixed edge, the middle portion of the support plate is a hollow structure, and the fixed edge is fixedly connected to the base by a plurality of screws.

[0012] In order to better realize the present invention, further, the fixed shaft includes an axis core embedded in the two side plates, and a nut threadedly connected to the end of the axis core, a support sleeve is also embedded in the middle of the axis core, and axis sleeves are also embedded on the axis core on both sides of the support sleeve, and one side of the two axis sleeves are respectively abutted against the inner wall of the side plate on the corresponding side.

[0013] In order to better implement the present invention, further, the base and the upper bearing unit are in an integrated structure.

[0014] In order to better realize the present invention, further, the main material of the heat treatment tooling is Ni3Al alloy, and the main components of the Ni3Al alloy, calculated by mass percentage, include Ni of 35% to 88%, Al of 8% to 12%, and Cr of 20% to 26%.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0016] The present invention provides a heat treatment tool for large shell parts, which can realize the supporting and fixing function of the tool during the heat treatment process. The baffles symmetrically arranged on both sides can prevent the large shell parts from bending and deforming outward, which plays an important role in the vacuum heat treatment of large shell parts, and is of great significance for improving the treatment quality of large shell parts and improving the production efficiency of heat treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments with reference to the following drawings:

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0019] Figure 2 It is a schematic diagram of the split structure of the present invention;

[0020] Figure 3 FIG is a schematic diagram of the three-dimensional structure of the present invention in use;

[0021] Figure 4 It is a schematic diagram of the three-dimensional structure of the base and the carrying unit in the present invention;

[0022] Figure 5 It is a schematic diagram of the three-dimensional structure of the side panel in the present invention.

[0023] Among them: 1—base, 11—slide groove, 2—bearing unit, 3—side plate, 31—support plate, 32—fixed edge, 4—fixed shaft, 41—shaft core, 42—nut, 43—support sleeve, 44—shaft sleeve, 5—U-shaped support block, 6—large shell part, 7—screw. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] Embodiment 1:

[0028] The main structure of this embodiment is as follows: Figure 1 , Figure 2 As shown, it includes a base 1, a bearing unit 2 is arranged in the middle of the upper surface of the base 1 and is in contact with the lower surface of the large shell part 6, and side panels 3 supporting each other are arranged on both sides of the bearing unit 2. The lower parts of the two symmetrical side panels 3 are fixedly connected to the base 1, and a plurality of fixed shafts 4 for fixing the large shell part 6 are arranged between the two side panels 3.

[0029] Specific usage, such as Figure 3 As shown, the fixed large shell part 6 is placed on the load-bearing unit 2 between the two side plates 3 so that the lower part of the large shell part 6 fits with the upper surface of the load-bearing unit 2, and then the large shell part 6 is fixed by passing the fixed shaft 4 through it, and then the heat treatment tooling of the fixed large shell part 6 is placed in a vacuum furnace for heat treatment.

[0030] Embodiment 2:

[0031] Based on the above embodiments, this embodiment further defines the structure of the base 1, such as Figure 1 , Figure 3 As shown, the front end of the base 1 is also provided with a slide groove 11 that abuts against the front of the carrying unit 2. A U-shaped support block 5 that can slide back and forth in the slide groove 11 is placed in the slide groove 11. The upper surface of the U-shaped support block 5 fits with the corresponding lower surface position of the large shell part 6. The main function of the U-shaped support block 5 is to support the protruding structure of the large shell part 6. The U-shaped support block 5 can slide in the slide groove 11 at the front end of the base 1, so that it can better support the large shell part 6. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0032] Embodiment 3:

[0033] Based on the above embodiments, this embodiment further defines the structure of the carrying unit 2, such as Figure 4As shown, the bearing unit 2 is composed of a plurality of groups of support members arranged at intervals in the longitudinal direction, and each group of the support members is composed of at least two bosses of the same structure and at intervals, and the upper surfaces of the bosses are both in contact with the corresponding lower surface positions of the large shell part 6. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0034] Embodiment 4:

[0035] Based on the above embodiment, this embodiment further defines the structure of the side plate 3, such as Figure 5 As shown, the side plate 3 includes an upper support plate 31 and a lower fixed edge 32, the middle of the support plate 31 is a hollow structure, and the fixed edge 32 is fixedly connected to the base 1 by a plurality of screws 7. The side plate 3 is mainly used to prevent the large shell part 6 from bending and deforming outward. The other parts of the embodiment are the same as the above embodiment and will not be repeated.

[0036] Embodiment 5:

[0037] Based on the above embodiment, this embodiment further defines the structure of the fixed shaft 4, such as Figure 2 As shown, the fixed shaft 4 includes a shaft core 41 inserted on the two side plates 3, and a nut 42 threadedly connected to the end of the shaft core 41, a support sleeve 43 is also embedded in the middle of the shaft core 41, and shaft sleeves 44 are also embedded on the shaft core 41 on both sides of the support sleeve 43, and one side of the two shaft sleeves 44 is respectively abutted against the inner wall of the side plate 3 on the corresponding side. The other parts of this embodiment are the same as the above embodiment and will not be repeated.

[0038] Embodiment 6:

[0039] Based on the above embodiments, this embodiment further defines the relationship between the base 1 and the carrying unit 2, such as Figure 4 As shown, the base 1 is an integral structure with the upper bearing unit 2. The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0040] Embodiment 7:

[0041] Based on the above embodiments, this embodiment further defines the material of the heat treatment fixture. The main material of the heat treatment fixture is Ni3Al alloy. The main components of the Ni3Al alloy, by mass percentage, include 35% to 88% Ni, 8% to 12% Al, and 20% to 26% Cr. The life of Ni3Al components is more than twice that of heat-resistant steel. This alloy material has excellent thermal strength, creep resistance, and carburization resistance. The fixture obtains an ideal structure and high-temperature strength to reduce heat loss and increase furnace loading. It has high thermal strength, good high-temperature creep resistance, good thermal fatigue performance, and long service life. Moreover, they can withstand embrittlement and other factors caused by different heat treatment atmospheres such as oxidation, carburizing, and nitriding. Ni3A l The manufactured components can also improve the heat treatment production efficiency by 10% due to the extended service life and reduced mass, so Ni3Al alloy is preferably used as the material of the heat treatment tooling. The other parts of this embodiment are the same as the above embodiment and will not be described in detail.

[0042] It is understandable that the working principles and working processes of the heat treatment tooling structure according to an embodiment of the present invention, such as the nut 42 and the screw 7, are prior art and well known to those skilled in the art, and will not be described in detail here.

[0043] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A heat treatment tool for preventing deformation of large shell parts, characterized in that: The invention comprises a base (1), wherein a bearing unit (2) is arranged in the middle of the upper surface of the base (1) and is in contact with the lower surface of a large shell part (6), and side panels (3) supporting each other are arranged on both sides of the bearing unit (2), the lower parts of the two symmetrical side panels (3) are fixedly connected to the base (1), and a plurality of fixed shafts (4) for fixing the large shell part (6) are arranged between the two side panels (3).

2. A heat treatment tool for preventing deformation of large shell parts according to claim 1, characterized in that: The front end of the base (1) is also provided with a slide groove (11) that abuts against the front of the carrying unit (2), and a U-shaped support block (5) that can slide back and forth in the slide groove (11) is arranged in the slide groove (11), and the upper surface of the U-shaped support block (5) is in contact with the corresponding lower surface position of the large shell part (6).

3. A heat treatment tool for preventing deformation of large shell parts according to claim 1 or 2, characterized in that: The bearing unit (2) is composed of a plurality of groups of support members arranged at intervals in the longitudinal direction, each group of the support members is composed of at least two bosses of the same structure and spaced apart, and the upper surfaces of the bosses are both in contact with the corresponding lower surface positions of the large shell part (6).

4. A heat treatment tool for preventing deformation of large shell parts according to claim 1 or 2, characterized in that: The side plate (3) comprises an upper support plate (31) and a lower fixed edge (32); the middle portion of the support plate (31) is a hollow structure; and the fixed edge (32) is fixedly connected to the base (1) via a plurality of screws (7).

5. A heat treatment tool for preventing deformation of large shell parts according to claim 1 or 2, characterized in that: The fixed shaft (4) comprises a shaft core (41) inserted into the two side plates (3), and a nut (42) threadedly connected to the end of the shaft core (41); a support sleeve (43) is also embedded in the middle of the shaft core (41); shaft sleeves (44) are also embedded in the shaft core (41) on both sides of the support sleeve (43); one side of the two shaft sleeves (44) respectively abuts against the inner wall of the side plate (3) at the corresponding side.

6. A heat treatment tool for preventing deformation of large shell parts according to claim 1 or 2, characterized in that: The base (1) and the upper bearing unit (2) are in an integrated structure.

7. A heat treatment tool for preventing deformation of large shell parts according to claim 1 or 2, characterized in that: The main material of the heat treatment tool is Ni3Al alloy, and the main components of the Ni3Al alloy, calculated by mass percentage, include Ni of 35% to 88%, Al of 8% to 12%, and Cr of 20% to 26%.

Images