High-strength bolt production heat treatment device and method

Abstract

The application discloses a high-strength bolt production heat treatment device and method, and relates to the technical field of bolt heat treatment. The device comprises a support frame and a heat treatment device installed on the top of the support frame. Two chain conveyors are installed on the inner side of the support frame, and a plurality of connecting blocks are fixedly connected to the top of the two chain conveyors. The arc-shaped surface of the outer wall of the arch-shaped metal spring piece contacts the bolt during the rotation of the adjusting sleeve. Since the arch-shaped metal spring piece is elastic, it can be adaptively attached to the bolt when contacting the bolt. Due to the rotation of the arch-shaped metal spring piece, the bolt that needs to be heat treated is driven to rotate in a circle by friction, so that the bolt can be uniformly heated during heat treatment, and local uneven heating is avoided, thereby further improving the heat treatment effect of the bolt.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bolt heat treatment, and particularly relates to a high-strength bolt production heat treatment device and method. BACKGROUND

[0002] In the modern industrial field, high-strength bolts, as key fasteners, are widely used in important scenes such as building engineering, bridge construction, mechanical manufacturing, automobile industry, and the like, and the mechanical properties (such as strength, toughness, and hardness uniformity) thereof directly determine the safety and reliability of the connected structure. With the development of industrial equipment towards large-scale and high-precision, the quality requirements for high-strength bolts are increasingly stringent, and as a core process determining the performance of the bolt, the stability and uniformity of the process effect of heat treatment become a key control point in the production process.

[0003] At present, in actual production, the traditional high-strength bolt heat treatment device generally places the bolts on a conveying belt, and then directly conveys the bolts through the conveying belt. However, this process easily causes the bolts to be stacked together and cannot be uniformly heated for heat treatment operation, and the difference in the heating area of the bolts is great. The blocked parts cannot reach the expected phase change temperature due to insufficient heat absorption, and finally form "soft spots" with low hardness and insufficient toughness. The exposed parts may be excessively heated, causing coarse grains and increasing brittleness, resulting in uneven mechanical properties of the bolts and greatly reducing the carrying capacity and fatigue resistance of the bolts. Therefore, the present application provides a high-strength bolt production heat treatment device and method to solve the above problems. SUMMARY

[0004] The present application aims at solving the problem that the bolts cannot be uniformly heated, and provides a high-strength bolt production heat treatment device and method.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a high-strength bolt production heat treatment device, comprising: a support frame and a heat treatment device mounted on the top of the support frame, two chain conveyors are mounted on the inner side of the support frame, the top of each of the two chain conveyors is fixedly connected with a plurality of connecting blocks, and the plurality of connecting blocks are distributed at equal distances around the outer wall of the chain conveyor; a support plate is fixedly connected to the inner side of the support frame and used for supporting the chain conveyor; a drive roller is arranged between every two symmetrically arranged connecting blocks, and a plurality of drive rollers are arranged at equal distances around the chain conveyor, and the bolts are conveyed through the gap between every two drive rollers; an automatic tumbler is located between the drive roller and the connecting block and used for driving the drive roller to rotate to frictionally move the processed bolts; and a transverse friction member is located on the inner side of the drive roller, so that the outer side of the drive roller moves transversely and reciprocally and frictions with the bolts.

[0006] As a further scheme of the present application: the driving roller is composed of a rotating sleeve and an adjusting sleeve, and the adjusting sleeve is slidingly connected to the outer wall of the rotating sleeve.

[0007] As a further scheme of the present application: the outer wall of the adjusting sleeve is fixedly connected with a plurality of arched metal springs, and each of the arched metal springs is arranged in an arched shape.

[0008] As a further scheme of the present application: the inner side of the support frame is fixedly connected with a stirring plate, the stirring plate is arranged above the driving roller, a gap is arranged between the stirring plate and the driving roller, and the gap is smaller than the diameter of the bolt.

[0009] As a further scheme of the present application: the automatic rolling device comprises a rotating tube fixedly connected to one end of the rotating sleeve, one end of the rotating tube penetrates into the inner side of the connecting block and is rotationally connected with the connecting block, the outer wall of the rotating tube is fixedly connected with a first small spur gear, the bottom of the connecting block is fixedly connected with a hanging seat, the inner side of the hanging seat is rotationally connected with a rotating shaft, one end of the rotating shaft is fixedly connected with a large spur gear, the large spur gear is meshed with the first small spur gear, the top of the support plate is fixedly connected with a rack meshed with the large spur gear, the length of the rack exceeds the length of the heat treatment device and is less than the length of the chain conveyor, and the inner side of the rotating sleeve is provided with a preheating assembly penetrating from the inner side of the arched metal spring for preheating the bolt.

[0010] As a further scheme of the present application: the lateral friction member comprises a limiting groove opened in the inner side of the rotating sleeve, the inner side of the limiting groove is rotationally connected with a reciprocating screw rod, one end of the reciprocating screw rod penetrates to the outside of the rotating sleeve and is rotationally connected with the rotating sleeve, one end of the reciprocating screw rod is fixedly connected with a second small spur gear, the inner end of the connecting block is fixedly connected with a gear ring meshed with the second small spur gear, the outer wall of the reciprocating screw rod is threadedly connected with a movable block matched with the limiting groove, and the top of the movable block is fixedly connected with the adjusting sleeve.

[0011] As a further scheme of the present application: the preheating assembly comprises a heat-conducting bin formed in the inner side of the rotating sleeve, a plurality of heat-conducting pipes are arranged on the inner side of the heat-conducting bin, the heat-conducting pipes are distributed equidistantly around the heat-conducting bin, a plurality of air outlets are formed in the inner side of the heat-conducting bin, and an air outlet pipe is fixedly connected to the inner side of each air outlet, and one end of the air outlet pipe is fixedly connected to the heat-conducting pipe and communicates with the heat-conducting pipe, a chute is formed in the inner side of the adjusting sleeve and penetrates through the outer side of the arc-shaped metal spring, and the chute communicates with the air outlet pipe, and an electromagnetic valve is fixedly connected to the air inlet of the heat-conducting pipe.

[0012] As a further scheme of the present application: the preheating assembly further comprises a hot air blower fixedly connected to the air inlet of the connecting block, a cavity is formed in the inner side of the connecting block and communicates with the hot air blower, and a through slot is formed in the inner side of the rotating pipe and communicates with the cavity and the heat-conducting bin.

[0013] The application further discloses a high-strength bolt production heat treatment method using the high-strength bolt production heat treatment device.

[0014] S1, when the staff pours the bolts into the top of the driving roller, the bolts inside are moved to the inside of the heat treatment device by the driving of the chain conveyor, the heat treatment device is used for heat treatment of the bolts inside, when the bolts are moved by being stacked on the driving roller, the stacked bolts are scraped by the blocking effect of the poking plate, so that the stacked bolts can continuously fall between every two driving rollers to fill the gap, so as to avoid the stacking of the bolts in the feeding process, and the uniformity of heating in the subsequent heat treatment process is ensured.

[0015] S2, the arc-shaped metal spring is made of elastic metal material, when the chain conveyor drives the lateral movement of the connecting block, the large spur gear is in contact with the straight toothed rack, the large spur gear is driven to rotate, the first small spur gear is driven to rotate the rotating sleeve through the rotating pipe, the adjusting sleeve is in contact with the bolts through the arc surface of the outer wall of the arc-shaped metal spring during rotation, the arc-shaped metal spring is elastic, and the arc-shaped metal spring can be adaptively attached to the bolts when the arc-shaped metal spring is in contact with the bolts, the arc-shaped metal spring is rotated, the bolts to be heat treated are driven to rotate in a circle through friction, and the bolts can be uniformly heated during heat treatment.

[0016] S3, when the rotating sleeve rotates circumferentially, the second small spur gear rotates circumferentially, and the spur gear ring is fixed, so that the second small spur gear drives the reciprocating wire rod to rotate through the spur gear ring, thereby driving the movable block to drive the arc-shaped metal spring to move transversely through the adjusting sleeve, so that the arc-shaped metal spring can move transversely during rotation.

[0017] S4, the hot air machine is composed of a fan, an electric heating pipe, a filter screen and the like for blowing hot air components, and since it is prior art, the present scheme does not make too much elaboration, when the bolts to be heat treated are conveyed, the hot air machine can send hot air into the rotating pipe and into the heat-conducting bin, a plurality of electromagnetic valves are opened and closed through the PLC controller, when the rotating sleeve rotates towards the bolt, the electromagnetic valves in the interval of thirty degrees of forward rotation and thirty degrees of reverse rotation of the bolt are in the open state, and the electromagnetic valves at other positions are in the closed state, so that high-pressure gas can be sprayed from the inside of the chute to the outer wall of the bolt;

[0018] And the temperature of the electric heating pipe in the hot air machine has two stages during the process of not entering the heat treatment device to moving out, the first stage temperature of not entering the heat treatment device is gradually increased according to the moving distance of the bolt, and the second stage temperature is a fixed temperature.

[0019] Compared with the prior art, the beneficial effects of the present application are:

[0020] 1, by setting the cooperation of the arc-shaped metal spring and the like parts, when the chain conveyor drives a plurality of connecting blocks to move transversely, the large gear and the rack are in contact, the large gear is driven to rotate, thereby driving the first small gear to drive the rotating sleeve to rotate through the rotating pipe, so that the adjusting sleeve is in contact with the bolt through the arc surface of the arc-shaped metal spring during rotation, since the arc-shaped metal spring itself has elasticity, it can be adaptively fitted on the bolt when in contact with the bolt, and since the arc-shaped metal spring rotates, the bolt to be heat treated is driven to rotate circumferentially through friction, so that the bolt can be evenly heated during heat treatment, avoiding local uneven heating, thereby further improving the effect of heat treatment of the bolt;

[0021] 2. By setting up drive rollers and other components, when the worker pours the bolts into the top of the drive rollers, the chain conveyor drives multiple drive rollers to move the inner bolts into the heat treatment device. The heat treatment device then performs heat treatment on the bolts that have entered the inner side. When the bolts accumulate on the drive rollers and move, the material scraping plate blocks the accumulated bolts, allowing them to fall continuously into the gaps between every two drive rollers to fill the gaps. This prevents the bolts from accumulating during the feeding process, thus ensuring the uniformity of heating during the subsequent heat treatment process and improving the effect of the subsequent heat treatment.

[0022] 3. By setting up a reciprocating screw and other parts, when the rotating sleeve rotates in a circle, it drives the second small spur gear to rotate in a circle. Since the spur gear ring is fixed, the second small spur gear drives the reciprocating screw to rotate through the spur gear ring. This drives the movable block to move laterally back and forth through the adjusting sleeve. This allows the arched metal spring to move laterally back and forth during rotation. When rotating alone, the direction of the friction force between the arched metal spring and the bolt is relatively fixed. The bolt may rotate around a certain fixed axis, resulting in localized force and heat bias. After the lateral back and forth movement is superimposed, the lateral component of the friction force will continuously change, forcing the bolt to produce a small lateral displacement or posture adjustment while rotating. This breaks the single rotation trajectory and allows all parts of the bolt to make more full contact with the surrounding environment, further avoiding uneven local heating. At the same time, when the bolt is heat-treated, the laterally moving arched metal spring can scrape the outside of the bolt. Before entering the heat treatment device, the bolt surface may be covered with impurities such as oil, oxide scale, and metal shavings. When the arched metal spring moves laterally and reciprocates and comes into contact with the bolt, the pressure generated by its elastic deformation will scrape the bolt surface, thereby removing these impurities and further improving the effect of subsequent heat treatment.

[0023] 4. By coordinating components such as solenoid valves, during the conveying process of bolts requiring heat treatment, a hot air blower delivers hot air into the rotating tube and then into the heat-conducting chamber. Multiple solenoid valves are opened and closed under the control of a PLC controller. When the rotating sleeve rotates towards the bolt, the solenoid valves within the 30-degree range of forward and reverse rotation are open, while the solenoid valves at other positions are closed. This allows high-pressure gas to be ejected from the inside of the inclined groove and blown obliquely towards the outer wall of the bolt. The high-pressure gas has a strong impact force, and when blown obliquely towards the outer wall of the bolt, it can blow off oil, iron filings, dust, and other impurities adhering to the bolt surface. If these impurities are not removed before heat treatment, they may form oxide scale during the heating process or affect the heat treatment effect on the bolt surface (such as causing uneven local carburizing / nitriding). By blowing with hot air, the bolt surface can be kept clean, ensuring that the heat treatment medium (such as quenching liquid, protective gas, etc.) can fully contact the bolt surface, thus improving the surface quality after heat treatment.

[0024] 5. By coordinating components such as the hot air blower, and ensuring the temperature of the heating element within the hot air blower varies from before the bolt enters the heat treatment apparatus until it is removed, the temperature undergoes two stages. In the first stage, before entering the heat treatment apparatus, the temperature is gradually increased according to the distance the bolt moves, thus preheating it. High-strength bolts are mostly made of alloy steel. If they are directly placed into a high-temperature heat treatment apparatus (typically reaching 800-1000℃), the sudden contact between the cold bolt and the high temperature will cause severe thermal stress due to the large temperature difference between the inside and outside, potentially leading to cracks, deformation, or even breakage. The gradually increasing preheating temperature (e.g., gradually rising from room temperature to 500-600℃) allows the internal temperature of the bolt to rise slowly. The process allows the metal crystal structure to gradually adapt to temperature changes, reducing thermal stress concentration and protecting the original mechanical properties of the bolts. The second stage temperature is highest when the bolts are removed from the heat treatment device after heat treatment, causing the temperature of the heat-treated bolts to gradually decrease as they move away from the heat treatment device, creating a "slow cooling environment." This allows the bolts to cool slowly in a relatively stable temperature field, resulting in a uniform transformation of the metal crystal structure and reducing internal stress. When high-temperature bolts are in direct contact with cold air, their surfaces are prone to rapid oxidation, forming a thick oxide scale that affects subsequent processing (such as thread accuracy) and strength. The stepped cooling hot air can form a protective airflow on the bolt surface, slowing down the oxidation rate and reducing surface quality loss, thereby improving the overall practicality of the device. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 This is a cross-sectional view of the present invention;

[0027] Figure 3 This is a cross-sectional view of the connecting block of the present invention;

[0028] Figure 4 For the application Figure 3 Enlarged view at A in the application;

[0029] Figure 5 For the application, the schematic diagram of the stirring plate structure is shown in the figure;

[0030] Figure 6 For the application Figure 5 Enlarged view at B in the application;

[0031] Figure 7 For the application, the partial sectional view of the rotating sleeve is shown in the figure;

[0032] Figure 8 For the application, the schematic diagram of the inside structure of the rotating sleeve is shown in the figure;

[0033] Figure 9 For the application Figure 8 Enlarged view at C in the application;

[0034] Figure 10 For the application, the schematic diagram of the arch-shaped metal spring piece is shown in the figure.

[0035] In the figure: 1, support frame; 2, heat treatment device; 3, support plate; 4, connecting block; 5, driving roller; 6, chain conveyor; 7, stirring plate; 8, straight rack; 9, air heater; 10, cavity; 11, rotating pipe; 12, hanging seat; 13, rotating shaft; 14, large straight gear; 15, straight gear ring; 16, first small straight gear; 17, rotating sleeve; 18, adjusting sleeve; 19, second small straight gear; 20, arch-shaped metal spring piece; 21, reciprocating screw rod; 22, movable block; 23, limiting groove; 24, heat conduction bin; 25, heat conduction pipe; 26, electromagnetic valve; 27, air outlet pipe; 28, inclined chute. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0037] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. In the description of the present application, it should be noted that unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting", "setting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. The embodiments will be described below according to the overall structure of the present application.

[0038] Please refer to Figures 1-10The embodiment provides a high-strength bolt production heat treatment device, which comprises a support frame 1 and a heat treatment device 2 installed on the top of the support frame 1, two chain conveyors 6 are installed on the inner side of the support frame 1, a plurality of connecting blocks 4 are fixedly connected to the top of the two chain conveyors 6, and the plurality of connecting blocks 4 are distributed at equal distances around the outer wall of the chain conveyor 6; a supporting plate 3 is fixedly connected to the inner side of the support frame 1 and used for supporting the chain conveyor 6 (that is, supporting the chain to avoid the loosening of the chain when the bolt is conveyed); a driving roller 5 is arranged between every two symmetrically arranged connecting blocks 4, and a plurality of driving rollers 5 are arranged, the plurality of driving rollers 5 are distributed at equal distances around the chain conveyor 6, and the bolts are conveyed through the gap between every two driving rollers 5; an automatic tumbling device is located between the driving roller 5 and the connecting block 4 and is used for driving the driving roller 5 to rotate and frictionally driving the bolts for processing to rotate, the driving roller 5 is composed of a rotating sleeve 17 and an adjusting sleeve 18, the adjusting sleeve 18 is slidingly connected to the outer wall of the rotating sleeve 17, a plurality of arched metal springs 20 are fixedly connected to the outer wall of the adjusting sleeve 18, each arched metal spring 20 is arranged in an arched shape, a stirring plate 7 is fixedly connected to the inner side of the support frame 1, the stirring plate 7 is arranged above the driving roller 5, a gap is arranged between the stirring plate 7 and the driving roller 5, and the gap is smaller than the diameter of the bolt; the automatic tumbling device comprises a rotating pipe 11 fixedly connected to one end of the rotating sleeve 17, one end of the rotating pipe 11 penetrates into the inner side of the connecting block 4 and is rotationally connected with the connecting block 4, a first small spur gear 16 is fixedly connected to the outer wall of the rotating pipe 11, a hanging seat 12 is fixedly connected to the bottom of the connecting block 4, a rotating shaft 13 is rotationally connected to the inner side of the hanging seat 12, a large spur gear 14 is fixedly connected to one end of the rotating shaft 13, the large spur gear 14 is meshingly arranged with the first small spur gear 16, a straight rack 8 meshing with the large spur gear 14 is fixedly connected to the top of the supporting plate 3, and the length of the straight rack 8 exceeds the length of the heat treatment device 2 and is smaller than the length of the chain conveyor 6.

[0039] First, the chain conveyor 6 is composed of a chain, a chain wheel, a servo motor and other parts, and the prior art is not described in detail in the scheme.

[0040] When the workers pour the bolts into the top of the driving roller 5, the bolts inside are moved to the inside of the heat treatment device 2 by the driving of the chain conveyor 6, and the bolts inside are heat treated by the heat treatment device 2. When the bolts are accumulated on the driving roller 5 and moved, the accumulated bolts are scraped by the blocking action of the poking plate 7, so that the accumulated bolts can continuously fall into the gap between every two driving rollers 5 to avoid the accumulation of the bolts during feeding, thereby ensuring the uniformity of heating during subsequent heat treatment, thereby improving the effect of subsequent heat treatment.

[0041] The arched metal spring 20 is made of elastic metal material. When the chain conveyor 6 drives the plurality of connecting blocks 4 to move transversely, the large spur gear 14 is in contact with the rack 8, the large spur gear 14 is driven to rotate, the first small spur gear 16 is driven to rotate through the rotating pipe 11 to drive the rotating sleeve 17 to rotate, and the adjusting sleeve 18 is in contact with the bolt through the arc surface of the outer wall of the arched metal spring 20 during rotation. Since the arched metal spring 20 itself has elasticity, it can adaptively fit on the bolt when in contact with the bolt. At the same time, due to the rotation of the arched metal spring 20, the bolt to be heat treated is driven to rotate in a circle by friction, so that the bolt can be uniformly heated during heat treatment, avoiding local uneven heating, thereby further improving the effect of heat treatment of the bolt.

[0042] Please refer to Figures 3-10 , the transverse friction member is located inside the driving roller 5, so that the outer side of the driving roller 5 moves transversely and reciprocally to rub the bolt. The transverse friction member includes a limiting groove 23 opened in the inside of the rotating sleeve 17, the inside of the limiting groove 23 is rotatably connected with a reciprocating screw rod 21, one end of the reciprocating screw rod 21 penetrates to the outside of the rotating sleeve 17 and is rotatably connected with the rotating sleeve 17, one end of the reciprocating screw rod 21 is fixedly connected with a second small spur gear 19, one end of the connecting block 4 is fixedly connected with a spur gear ring 15 engaged with the second small spur gear 19, the outer wall of the reciprocating screw rod 21 is threadedly connected with a movable block 22, and the movable block 22 is matched with the limiting groove 23, the top of the movable block 22 is fixedly connected with the adjusting sleeve 18.

[0043] When the rotating sleeve 17 rotates circumferentially to drive the second small spur gear 19 to rotate circumferentially, since the spur gear ring 15 is fixed, the second small spur gear 19 drives the reciprocating screw rod 21 to rotate through the spur gear ring 15, thereby driving the movable block 22 to drive the arched metal spring piece 20 to move transversely through the adjusting sleeve 18. The arched metal spring piece 20 can move transversely during rotation. When only rotating, the friction direction of the arched metal spring piece 20 relative to the bolt is relatively fixed, and the bolt can rotate around a certain fixed axis, and there is a local force and heat bias. After transverse reciprocating movement, the transverse component of the friction force will change constantly, forcing the bolt to produce a small transverse displacement or posture adjustment while rotating, breaking the single rotation trajectory, allowing the bolt to be in contact with the surrounding environment more fully, further avoiding uneven local heating. When the bolt is heat treated, the arched metal spring piece 20 can form a scratch on the outside of the bolt through transverse reciprocating movement. Since the bolt may be attached to oil stains, oxidation skin, metal debris and other impurities on the surface before entering the heat treatment device. When the arched metal spring piece 20 moves transversely and contacts the bolt, the pressure generated by the elastic deformation of the arched metal spring piece 20 will scratch the surface of the bolt, thereby stripping these impurities, thereby improving the effect of subsequent heat treatment.

[0044] Please refer to Figures 1-10 The inner side of the rotating sleeve 17 is provided with a preheating assembly for preheating the bolt, which penetrates the inner side of the arched metal spring piece 20. The preheating assembly includes a heat conduction bin 24 opened in the inner side of the rotating sleeve 17. The inner side of the heat conduction bin 24 is provided with a plurality of heat conduction pipes 25. The plurality of heat conduction pipes 25 are distributed at equal distances around the heat conduction bin 24. The inner side of the heat conduction bin 24 is provided with a plurality of gas outlets. The inner side of each gas outlet is fixedly connected with a gas outlet pipe 27. One end of the gas outlet pipe 27 is fixedly connected with the heat conduction pipe 25 and communicates with the heat conduction pipe 25. The inner side of the adjusting sleeve 18 is provided with a chute 28 penetrating to the outside of the arched metal spring piece 20, and the chute 28 communicates with the gas outlet pipe 27. The inlet of the heat conduction pipe 25 is fixedly connected with an electromagnetic valve 26. The preheating assembly further includes a hot air blower 9 fixedly connected to the inlet of the connecting block 4. The inside of the connecting block 4 is provided with a cavity 10 communicating with the hot air blower 9. The inner side of the rotating pipe 11 is provided with a through slot communicating with the cavity 10 and the heat conduction bin 24.

[0045] The hot air machine 9 is composed of a fan, an electric heating pipe, a filter screen and the like for blowing hot air components. Since it is prior art, this scheme will not be described in detail. When the bolts that need to be heat treated are transported, the hot air machine 9 can send hot air into the rotating pipe 11 and into the heat conduction bin 24. The plurality of electromagnetic valves 26 are opened and closed by the PLC controller. When the rotating sleeve 17 rotates towards the bolt, the electromagnetic valves 26 in the interval of thirty degrees of forward rotation and thirty degrees of reverse rotation of the bolt are in the open state, and the electromagnetic valves 26 at other positions are in the closed state, so that high-pressure gas can be sprayed from the inside of the chute 28 to the outer wall of the bolt at an angle. The high-pressure gas has strong impact force, and when it blows at an angle to the outer wall of the bolt, it can blow off the oil stains, iron filings, dust and other impurities attached to the surface of the bolt. If these impurities are not removed before heat treatment, they may form an oxide skin during heating or affect the heat treatment effect of the bolt surface (such as causing uneven carburizing / nitriding). By blowing the hot air, the bolt surface can be kept clean, ensuring that the heat treatment medium (such as quenching liquid, protective gas, etc.) can fully contact the bolt surface, improving the surface quality after heat treatment.

[0046] The temperature of the electric heating pipe in the hot air machine 9 has two stages during the process of entering the heat treatment device 2 and moving out. The first stage temperature before entering the heat treatment device 2 is gradually increased according to the distance of the bolt movement for preheating. The high-strength bolt material is mostly alloy steel. If the cold bolt directly enters the high-temperature heat treatment device (usually at a temperature of 800-1000°C), the sudden contact with high temperature will cause a large temperature difference between the inside and outside, resulting in severe thermal stress, which may cause the bolt to crack, deform or even break. Gradual preheating temperature (for example, gradually increasing from room temperature to 500-600°C) can slowly increase the internal temperature of the bolt, allowing the metal crystal structure to gradually adapt to temperature changes, reducing thermal stress concentration and protecting the original mechanical properties of the bolt. The second stage temperature is the highest when the bolt is removed from the heat treatment device 2 after heat treatment, so that the temperature of the heat-treated bolt gradually decreases away from the heat treatment device 2, forming a "slow cooling environment". The bolt slowly cools in a relatively stable temperature field, allowing the metal crystal structure to uniformly transform and reducing internal stress. When the high-temperature bolt directly contacts cold air, the surface is easily oxidized to form a thick oxide skin, affecting subsequent processing (such as thread accuracy) and strength. The stepwise temperature reduction of the hot air can form a protective gas flow on the surface of the bolt, slow down the oxidation rate, reduce the surface quality loss, and thus improve the overall practicality of the device.

[0047] The following provides a high-strength bolt production heat treatment method based on the above-mentioned high-strength bolt production heat treatment device, which specifically includes the following steps:

[0048] S1, when the staff pours the bolt into the top of the driving roller 5, the bolt inside is driven to the inside of the heat treatment device 2 by the driving of the chain conveyor 6, and the bolt inside is heat treated by the heat treatment device 2. When the bolt is accumulated on the driving roller 5 and moves, the accumulated bolt is scraped by the blocking action of the poking plate 7, so that the accumulated bolt can continuously fall into the gap between every two driving rollers 5 to avoid the accumulation of the bolt during feeding, thereby ensuring the uniformity of the subsequent heat treatment process;

[0049] S2, the arched metal spring 20 is made of elastic metal material. When the chain conveyor 6 drives the plurality of connecting blocks 4 to move transversely, the large straight gear 14 contacts with the straight rack 8, drives the large straight gear 14 to rotate, drives the first small gear 16 to rotate through the rotating pipe 11 to drive the rotating sleeve 17 to rotate, so that the adjusting sleeve 18 contacts with the bolt through the arc surface of the outer wall of the arched metal spring 20 during rotation. Because the arched metal spring 20 itself has elasticity, it can adaptively fit on the bolt when contacting with the bolt. At the same time, due to the rotation of the arched metal spring 20, the bolt to be heat treated is driven to rotate circumferentially by friction, so that the bolt can be uniformly heated during heat treatment;

[0050] S3, when the rotating sleeve 17 rotates circumferentially to drive the second small gear 19 to rotate circumferentially, the straight gear ring 15 is fixed, so that the second small gear 19 drives the reciprocating screw rod 21 to rotate through the straight gear ring 15, thereby driving the movable block 22 to drive the arched metal spring 20 to move transversely through the adjusting sleeve 18, so that the arched metal spring 20 can move transversely during rotation;

[0051] S4, the hot air blower 9 is composed of fan, electric heating pipe, filter screen and other hot air blowing components. Because it is prior art, this scheme does not make too much description. When the bolt to be heat treated is conveyed, the hot air blower 9 can send hot air into the rotating pipe 11 and into the heat conduction bin 24. The plurality of electromagnetic valves 26 are opened and closed by the PLC controller. When the rotating sleeve 17 rotates towards the bolt, the electromagnetic valves 26 in the interval of thirty degrees of forward rotation and thirty degrees of reverse rotation of the bolt are in the open state, and the electromagnetic valves 26 in other positions are in the closed state, so that high pressure gas can be sprayed from the chute 28 to the outer wall of the bolt;

[0052] The temperature of the electric heating tube in the hot air machine 9 has two stages from the time when it has not entered the inside of the heat treatment device 2 to the time when it is removed, the first stage temperature is gradually increased according to the moving distance of the bolt to preheat, and the second stage temperature is at a fixed temperature.

[0053] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacements or changes within the technical range disclosed by the present application according to the technical solution and the inventive concept of the present application, which should be covered within the protection scope of the present application.

Claims

1. A heat treatment apparatus for producing high-strength bolts, characterized in that, Include: Support frame (1) and heat treatment device (2) installed on the top of the support frame (1), the inner side of the support frame (1) is provided with two chain conveyors (6), the top of the two chain conveyors (6) is fixedly connected with a plurality of connecting blocks (4), and the plurality of connecting blocks (4) are distributed at equal intervals around the outer wall of the chain conveyor (6); Support plate (3), the support plate (3) is fixedly connected to the inner side of the support frame (1), used for supporting the chain conveyor (6); Drive roller (5) is arranged between every two symmetrical connecting blocks (4), and the drive roller (5) is provided with a plurality of drive rollers (5), which are distributed at equal intervals around the chain conveyor (6), and the gap between every two drive rollers (5) is used for conveying bolts; Automatic rolling device, located between the drive roller (5) and the connecting block (4), used for driving the friction generated by the self-rotation of the drive roller (5) to rotate the processed bolt; The transverse friction member is located on the inner side of the drive roller (5), so that the outer side of the drive roller (5) moves transversely and reciprocally with the bolt to generate friction; The drive roller (5) is composed of a rotating sleeve (17) and an adjusting sleeve (18), and the adjusting sleeve (18) is slidably connected to the outer wall of the rotating sleeve (17); The outer wall of the adjusting sleeve (18) is fixedly connected with a plurality of arc-shaped metal springs (20), and each arc-shaped metal spring (20) is arranged in an arc shape; The automatic rolling device includes a rotating tube (11) fixedly connected to one end of the rotating sleeve (17), one end of the rotating tube (11) penetrates into the inner side of the connecting block (4) and is rotatably connected with the connecting block (4), the outer wall of the rotating tube (11) is fixedly connected with a first small straight gear (16), the bottom of the connecting block (4) is fixedly connected with a hanging seat (12), the inner side of the hanging seat (12) is rotatably connected with a rotating shaft (13), one end of the rotating shaft (13) is fixedly connected with a large straight gear (14), and the large straight gear (14) is meshed with the first small straight gear (16), the top of the support plate (3) is fixedly connected with a straight rack (8) meshed with the large straight gear (14), and the length of the straight rack (8) exceeds the length of the heat treatment device (2) and is less than the length of the chain conveyor (6), the inner side of the rotating sleeve (17) is provided with a preheating assembly penetrating from the inner side of the arc-shaped metal spring (20) for preheating the bolt; The transverse friction piece comprises a limiting groove (23) formed in the inside of the rotating sleeve (17), the inside of the limiting groove (23) is rotationally connected with a reciprocating screw rod (21), one end of the reciprocating screw rod (21) penetrates to the outside of the rotating sleeve (17) and is rotationally connected with the rotating sleeve (17), one end of the reciprocating screw rod (21) is fixedly connected with a second small spur gear (19), the inside of the connecting block (4) is fixedly connected with a spur gear ring (15) engaged with the second small spur gear (19), the outer wall of the reciprocating screw rod (21) is threadedly connected with a movable block (22), the movable block (22) is matched with the limiting groove (23), and the top of the movable block (22) is fixedly connected with the adjusting sleeve (18).

2. The high-strength bolt production heat treatment apparatus according to claim 1, wherein The inside of the supporting frame (1) is fixedly connected with a stirring plate (7), the stirring plate (7) is arranged above the driving roller (5), a gap is arranged between the stirring plate (7) and the driving roller (5), and the gap is smaller than the diameter of the bolt.

3. The high-strength bolt production heat treatment apparatus according to claim 2, wherein The preheating assembly comprises a heat-conducting bin (24) formed in the inside of the rotating sleeve (17), the inside of the heat-conducting bin (24) is provided with a plurality of heat-conducting pipes (25), the plurality of heat-conducting pipes (25) are distributed at equal distances around the heat-conducting bin (24), the inside of the heat-conducting bin (24) is formed with a plurality of gas outlets, the inside of each gas outlet is fixedly connected with an air outlet pipe (27), one end of the air outlet pipe (27) is fixedly connected with the heat-conducting pipe (25) and communicates with the heat-conducting pipe (25), the inside of the adjusting sleeve (18) is formed with an inclined groove (28) penetrating to the outside of the arc-shaped metal spring (20), the inclined groove (28) communicates with the air outlet pipe (27), and the air inlet of the heat-conducting pipe (25) is fixedly connected with an electromagnetic valve (26).

4. The high-strength bolt production heat treatment apparatus according to claim 3, wherein The preheating assembly further comprises a hot air machine (9) fixedly connected at the air inlet of the connecting block (4), the inside of the connecting block (4) is formed with a cavity (10) communicating with the hot air machine (9), and the inside of the rotating pipe (11) is formed with a through groove communicating with the cavity (10) and the heat-conducting bin (24).

5. A heat treatment method for producing a high-strength bolt, characterized by, The high-strength bolt production heat treatment device of claim 4 comprises the following steps: S1, when the workers pour the bolts onto the top of the driving roller (5), the driving of the chain conveyor (6) drives the bolts inside the driving roller (5) to move into the heat treatment device (2), the heat treatment device (2) performs heat treatment on the bolts inside, and when the bolts accumulate on the driving roller (5) and move, the stirring plate (7) blocks the accumulated bolts to scrape the accumulated bolts, so that the accumulated bolts can continuously fall between every two driving rollers (5) to fill the gap, thereby avoiding the accumulation of the bolts during feeding, and ensuring the uniformity of the subsequent heat treatment process. S2, the arch-shaped metal spring (20) is made of elastic metal material, when the chain conveyor (6) drives the plurality of connecting blocks (4) to move transversely, the large spur gear (14) is in contact with the rack (8), the large spur gear (14) is driven to rotate, thereby driving the first pinion (16) to rotate the rotating sleeve (17) through the rotating pipe (11), thereby making the adjusting sleeve (18) in the rotating process through the arc surface of the outer wall of the arch-shaped metal spring (20) and the bolt contact, because the arch-shaped metal spring (20) itself has elasticity, so it can be adaptively fitted on the bolt when in contact with the bolt, and because the arch-shaped metal spring (20) rotates, thereby driving the bolt to rotate circumferentially by friction, so that the bolt can be evenly heated during heat treatment; S3, when the rotating sleeve (17) rotates circumferentially and drives the second pinion (19) to rotate circumferentially, because the gear ring (15) is fixed, the second pinion (19) is driven by the gear ring (15) to drive the reciprocating screw rod (21) to rotate, thereby driving the movable block (22) to drive the arch-shaped metal spring (20) to move transversely through the adjusting sleeve (18), so that the arch-shaped metal spring (20) can move transversely during rotation; S4, when the bolt to be heat treated is conveyed, the hot air machine (9) can send hot air into the rotating pipe (11) and into the heat-conducting bin (24), a plurality of electromagnetic valves (26) are opened and closed by the PLC controller, when the rotating sleeve (17) rotates towards the bolt, the electromagnetic valves (26) in the range of thirty degrees of forward rotation and thirty degrees of reverse rotation of the bolt are in the open state, and the electromagnetic valves (26) in other positions are in the closed state, so that high-pressure gas can be sprayed from the inside of the chute (28) to the outer wall of the bolt; The temperature of the electric heating tube in the hot air machine (9) has two stages from the time of entering the heat treatment device (2) to the time of moving out, the first stage temperature is gradually increased according to the distance of the bolt movement for preheating, and the second stage temperature is at a fixed temperature.

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