Well type spheroidizing annealing furnace and annealing method

Abstract

The invention relates to the technical field of annealing furnaces, in particular to a well type spheroidizing annealing furnace and an annealing method.The well type spheroidizing annealing furnace comprises a furnace body, a hearth is arranged in the furnace body, a driving motor is arranged at the bottom of the furnace body, a fan is arranged on an output shaft of the driving motor, and a spiral containing frame is arranged in the hearth; the spiral containing frame is formed by winding a plurality of elastic strips arranged at intervals, a spiral circulation track is formed in the multiple elastic strips and used for containing steel balls, a supporting cylinder is coaxially arranged in the spiral circulation track, multiple layers of stirring assemblies distributed in the vertical direction are arranged on the supporting cylinder, and each layer of stirring assembly corresponds to each turn of track. The shifting assembly comprises a supporting rod, a supporting disc is arranged at the end of the supporting rod, a plurality of shifting pieces are arranged on the supporting disc, a transmission mechanism is arranged between an output shaft of the driving motor and the shifting pieces, the driving motor drives the shifting pieces to rotate through the transmission mechanism when rotating, and the steel balls can be shifted through rotation of the shifting pieces so that the steel balls can circularly move in the spiral circulating track.

Description

Technical Field

[0001] The invention relates to the technical field of annealing furnaces, in particular to a pit-type spheroidizing annealing furnace and an annealing method. Background Art

[0002] Steel balls are widely used basic components in the machinery industry, and their performance directly affects the quality, durability and reliability of the end products. The conventional heat treatment process of steel balls includes four basic steps: annealing, normalizing, quenching and tempering. By controlling the heating temperature, holding time and cooling rate, the organization and performance of the steel balls can be adjusted to achieve the expected hardness requirements.

[0003] However, in the above annealing process, the steel balls are stacked and stored together, and the adjacent steel balls are in close contact with each other, so it is difficult to ensure uniform contact between the steel balls and the gas, which affects the processing quality of the steel balls. Summary of the invention

[0004] Based on this, it is necessary to provide a pit-type spheroidizing annealing furnace and annealing method to address the technical problems of the current annealing furnace affecting the processing quality of steel balls.

[0005] The above purpose is achieved through the following technical solutions: A pit-type spheroidizing annealing furnace comprises a furnace body, the interior of the furnace body is a furnace chamber, a driving motor is arranged at the bottom of the furnace body, an output shaft of the driving motor is provided with a fan, the fan is located at the bottom of the furnace chamber, and the fan is used to evenly disperse external gas into the interior of the furnace chamber; A spiral placement rack is provided in the furnace, and the spiral placement rack is formed by winding a plurality of elastic bars arranged at intervals, and a spiral circulation track is formed inside the plurality of elastic bars. The spiral circulation track is used to place steel balls, and the axis of the spiral circulation track extends in the up-down direction, and a support cylinder is coaxially provided inside the spiral circulation track, and a plurality of toggle assemblies distributed in the up-down direction are provided on the support cylinder, and each layer of toggle assemblies corresponds to each turn of the spiral track, and the toggle assembly includes a support rod, and a support disk is provided at the end of the support rod, and the axis of the support disk extends in the up-down direction, and a plurality of paddles rotating in a circumferential direction around the support disk are provided on the support disk, and a transmission mechanism is provided between the output shaft of the drive motor and the paddle, and the drive motor drives the paddle to rotate through the transmission mechanism when rotating, and the rotation of the paddle can toggle the steel ball, so that the steel ball moves in a circulation in the spiral circulation track.

[0006] Furthermore, the spiral circulation track includes an inner spiral track and an outer spiral track, the inner spiral track is coaxially arranged inside the outer spiral track, and the rotation direction of the inner spiral track is opposite to that of the outer spiral track, the upper end of the inner spiral track is connected to the upper end of the outer spiral track, and the lower end of the inner spiral track is connected to the lower end of the outer spiral track.

[0007] Furthermore, the inner spiral track and the outer spiral track have the same structure, and each turn of the spiral track includes a spiral section and an annular horizontal section, and the spiral section and the annular horizontal section are detachably connected by bolts.

[0008] Furthermore, the central angles of the spiral section and the annular horizontal section on the same turn of the spiral track are equal, and the elastic bars of the two are staggered in the circumferential direction of the support tube.

[0009] Furthermore, each layer of support rods includes inner support rods and outer support rods, the structure of the inner support rods is the same as that of the outer support rods, the support plates of the inner support rods correspond to the spiral segments of each turn of the inner spiral track, and the support plates of the outer support rods correspond to the spiral segments of each turn of the outer spiral track.

[0010] Furthermore, a rotating disk is rotatably provided at the bottom of the support disk, and a mounting groove is provided on the rotating disk. The paddle is slidably located in the mounting groove, and a spring is provided between the paddle and the support disk, and the spring has a tendency to make the paddle slide upward along the mounting groove. An arc groove is provided at the bottom of the support disk, and when the paddle is rotated to a position corresponding to the arc groove, the lower end of the paddle is retracted into the mounting groove; when the paddle is rotated to the outside of the arc groove, the lower end of the paddle extends from the mounting groove.

[0011] Furthermore, the transmission mechanism includes a transmission shaft coaxially arranged inside the support cylinder, the rotating disk and the transmission shaft are connected by a transmission belt, and a planetary gear structure is provided between the transmission shaft and the output shaft of the driving motor, and the planetary gear structure drives the transmission shaft to perform a deceleration motion when the driving motor rotates.

[0012] Furthermore, the output shaft of the driving motor is connected to a sun gear by a spline so as to slide up and down. The sun gear is connected to a plurality of planetary gears around it for transmission. An inner ring gear is provided at the bottom of the transmission shaft, and the inner ring gear is meshed with the planetary gears. A transmission box is provided at the bottom of the supporting tube, and a plurality of fixed shafts are fixed on the bottom surface of the transmission box. The planetary gears are rotatably arranged on the fixed shafts. The sun gear, planetary gears and inner ring gear constitute the planetary gear structure.

[0013] Furthermore, the inner wall of the furnace is provided with a heat-insulating layer and a heating structure, the heat-insulating layer is used to keep the temperature inside the furnace warm, the heating structure is used to heat the furnace, and the heating structure is a resistance wire.

[0014] An annealing method, using the above-mentioned pit-type spheroidizing annealing furnace, comprises the following steps: S1. Place the steel balls in a spiral placement rack, and then place the spiral placement rack in the furnace; S2, start the driving motor, the driving motor drives the fan to rotate, and at the same time drives each paddle to rotate through the transmission mechanism, the paddle paddles the steel ball on the spiral placement frame, so that each position of the steel ball can contact the airflow; S3. Take the spiral rack out of the furnace and remove the steel balls from the spiral rack.

[0015] The beneficial effects of the present invention are: The pit-type spheroidizing annealing furnace and annealing method provided by the present invention, first, the steel balls move along the spiral placement frame under the action of the paddle, and the steel balls can not only move up and down but also move circumferentially around the spiral placement frame, so that each position of the outer surface of the steel balls can contact the airflow during the movement, and avoid that when the steel balls are statically stacked inside the furnace, the contact positions between the steel balls cannot contact the airflow, so that the steel balls are annealed evenly, thereby ensuring the annealing quality of the steel balls. At the same time, the paddle is synchronously driven by the driving motor that drives the fan, and there is no need to set up other driving mechanisms, thereby reducing the cost of the device.

[0016] Second, the set annular horizontal section can provide a buffer area for the steel balls to prevent the upper steel balls from squeezing the lower steel balls when the steel balls move along the inner spiral track or the outer spiral track under the action of gravity, causing the lower steel balls to be compressed and deformed, affecting the annealing effect, and at the same time avoid increasing the difficulty of transporting the lower steel balls upward, thereby ensuring the smoothness of the steel ball circulation transportation.

[0017] Thirdly, the spring bars of the spiral section and the annular horizontal section on the same turn of the spiral track are staggered in the circumferential direction of the support tube, so as to avoid a certain position on the surface of the steel ball being blocked all the time, thereby further making the surface of the steel ball annealed evenly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the three-dimensional structure of a pit-type spheroidizing annealing furnace provided in one embodiment of the present invention; Figure 2 A side view of a pit-type spheroidizing annealing furnace provided in one embodiment of the present invention; Figure 3 for Figure 2 Middle AA section view; Figure 4 A schematic diagram of the structure of a spiral circulation track and a toggle assembly in a pit-type spheroidizing annealing furnace provided in one embodiment of the present invention; Figure 5 A schematic diagram of the internal structure of a pit-type spheroidizing annealing furnace provided in one embodiment of the present invention; Figure 6 for Figure 5 Side view of Figure 7 for Figure 6 BB cross-sectional view; Figure 8 for Figure 7 A magnified view of the structure at X in the middle; Fig. 9 for Figure 7 A magnified view of the structure at Y in the middle; Fig.10 for Figure 5 Exploded diagram of the structure; Fig.11 An exploded schematic diagram of a toggle assembly in a pit-type spheroidizing annealing furnace provided in one embodiment of the present invention; Fig.12 An exploded view of the structure of one turn of the outer spiral track of a pit-type spheroidizing annealing furnace provided in one embodiment of the present invention; Fig.13 A top view of a spiral circulation track and a toggle assembly in a pit-type spheroidizing annealing furnace provided in one embodiment of the present invention; Fig.14 A partial structural schematic diagram of a toggle assembly in a pit-type spheroidizing annealing furnace provided in one embodiment of the present invention.

[0019] in: 100, furnace body; 200, cover plate; 210, lifting lug; 300, insulation layer; 310, resistance wire; 400, spoiler layer; 500, drive motor; 501, output shaft; 510, fan; 520, planetary gear; 530, transmission shaft; 531, inner gear ring; 540, support cylinder; 541, fixed shaft; 550, sun gear; 560, outer support rod; 570, inner support rod; 600 , outer spiral track; 610, spiral section; 611, first elastic bar; 620, annular horizontal section; 621, second elastic bar; 700, steel ball; 800, support plate; 810, rotating plate; 811, arc groove; 812, rotating hole; 820, rotating shaft; 821, mounting groove; 830, transmission belt; 840, paddle; 841, spring; 900, inner spiral track; 1000, connecting track. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present invention, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention 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 cannot be understood as a limitation to the present invention.

[0022] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0023] like Figures 1 to 14 As shown, a pit-type spheroidizing annealing furnace provided in one embodiment of the present invention comprises a furnace body 100, a cover plate 200 is provided on the top of the furnace body 100, and a lifting lug 210 is provided on the cover plate 200, and the lifting lug 210 facilitates the lifting of the cover plate 200; the interior of the furnace body 100 is a furnace chamber, a driving motor 500 is provided at the bottom of the furnace body 100, and a fan 510 is provided on the output shaft 501 of the driving motor 500, and the fan 510 is located at the bottom of the furnace chamber, and the fan 510 is used to evenly disperse the external gas into the interior of the furnace chamber; a spoiler layer 400 is provided on the inner wall of the furnace chamber, and the spoiler layer 400 is wavy to promote gas dispersion.

[0024] A spiral placement rack is provided in the furnace, and the spiral placement rack is placed at the bottom of the furnace through a support rack (not shown in the figure). The spiral placement rack is wound by a plurality of elastic bars arranged at intervals, and a spiral circulation track is formed inside the plurality of elastic bars. The spiral circulation track is used to place the steel ball 700, and the axis of the spiral circulation track extends in the up-down direction, and a support cylinder 540 is coaxially provided inside the spiral circulation track, and the support cylinder 540 is provided with multiple layers of toggle assemblies distributed in the up-down direction, and each layer of toggle assemblies corresponds to each turn of the spiral track, and the toggle assembly includes a support rod, and a support plate 800 is provided at the end of the support rod, and the axis of the support plate 800 extends in the up-down direction, and the support plate 800 is provided with a plurality of paddles 840 rotating in the circumferential direction of the support plate 800, and a transmission mechanism is provided between the output shaft 501 of the drive motor 500 and the paddle 840, and the drive motor 500 drives the paddle 840 to rotate through the transmission mechanism when rotating, and the rotation of the paddle 840 can toggle the steel ball 700, so that the steel ball 700 circulates in the spiral circulation track.

[0025] In this way, the steel ball 700 moves along the spiral placement rack under the action of the paddle 840. The steel ball 700 can not only move up and down but also move circumferentially around the spiral placement rack, so that each position of the outer surface of the steel ball 700 can contact the airflow during the movement, so as to avoid that when the steel balls 700 are statically stacked inside the furnace, the contact positions between the steel balls 700 cannot contact the airflow, so that the steel balls 700 are annealed evenly, thereby ensuring the annealing quality of the steel balls 700. At the same time, the paddle 840 is synchronously driven by the driving motor 500 that drives the fan 510, and no other driving mechanism needs to be set up additionally, thereby reducing the cost of the device.

[0026] Further, the spiral circulation track includes an inner spiral track 900 and an outer spiral track 600, wherein the inner spiral track 900 is coaxially arranged inside the outer spiral track 600, and the rotation direction of the inner spiral track 900 is opposite to that of the outer spiral track 600, and the upper end of the inner spiral track 900 is connected to the upper end of the outer spiral track 600, and the lower end of the inner spiral track 900 is connected to the lower end of the outer spiral track 600. Specifically, the two ends are connected by a connecting track 1000. The steel balls 700 in the inner spiral track 900 and the outer spiral track 600 move in opposite directions, that is, when the steel balls 700 of the inner spiral track 900 move upward, the steel balls 700 of the outer spiral track 600 move downward, or when the steel balls 700 of the outer spiral track 600 move upward, the steel balls 700 of the inner spiral track 900 move downward.

[0027] The two inner and outer spiral tracks are arranged in this way, which can accommodate more steel balls 700. At the same time, the steel balls 700 slowly rise or descend in a spiral manner, making it easier for the paddle 840 to push the steel balls 700 to move along the inner spiral track 900 or the outer spiral track 600, thereby preventing the paddle 840 from being damaged due to excessive force.

[0028] In other embodiments, the spiral circulation track includes only one spiral track, and the upper and lower ends of the spiral track are connected by a vertical track.

[0029] Furthermore, the inner spiral track 900 and the outer spiral track 600 have the same structure, and each turn of the spiral track includes a spiral section 610 and an annular horizontal section 620, and the spiral section 610 and the annular horizontal section 620 are detachably connected by bolts.

[0030] The annular horizontal section 620 can provide a buffer area for the steel ball 700 to prevent the upper steel ball 700 from squeezing the lower steel ball 700 when the steel ball 700 moves along the inner spiral track 900 or the outer spiral track 600 under the action of gravity, causing the lower steel ball 700 to be compressed and deformed, affecting the annealing effect, and at the same time avoid increasing the difficulty of transporting the lower steel ball 700 upward, thereby ensuring the smoothness of the circulation transportation of the steel ball 700.

[0031] In this embodiment, only one segment is provided for the spiral segment 610 and the annular horizontal segment 620. In other embodiments, the spiral segment 610 and the annular horizontal segment 620 may be provided with two or four segments respectively, and the spiral segment 610 and the annular horizontal segment 620 are provided alternately. In this way, the number of corresponding toggle components is also increased accordingly.

[0032] Furthermore, the central angles of the spiral section 610 and the annular horizontal section 620 on the same turn of the spiral track are equal, and the elastic bars of the two are staggered in the circumferential direction of the support tube 540. Fig.12 As described above, the spiral section 610 of the outer spiral spring bar is provided with a first spring bar 611, and the annular horizontal section 620 is provided with a second spring bar 621. The first spring bar 611 and the second spring bar 621 are staggered in the circumferential direction of the support tube 540. In this way, the shielding positions of the steel ball 700 and the first spring bar 611 and the second spring bar 621 are different during the movement, so that a certain position on the surface of the steel ball 700 is prevented from being shielded all the time, thereby further making the surface of the steel ball 700 annealed evenly.

[0033] Further, each layer of support rods includes an inner support rod 570 and an outer support rod 560, the structure of the inner support rod 570 is the same as that of the outer support rod 560, and both the inner support rod 570 and the outer support rod 560 extend radially along the support tube 540, the support plate 800 of the inner support rod 570 corresponds to the spiral segment 610 of each turn of the inner spiral track 900, and the support plate 800 of the outer support rod 560 corresponds to the spiral segment 610 of each turn of the outer spiral track 600. Since the steel ball 700 needs to overcome gravity when the spiral segment 610 rises, it is easier for the paddle 840 to drive the steel ball 700 to move.

[0034] In other embodiments, the support plate 800 may also be disposed corresponding to the annular horizontal segment 620 .

[0035] Further, a rotating disk 810 is rotatably provided at the bottom of the support disk 800, and a mounting groove 821 is provided on the rotating disk 810, and the paddle 840 is slidably located in the mounting groove 821, and a spring 841 is provided between the paddle 840 and the rotating disk 810, and the spring 841 has a tendency to make the paddle 840 slide upward along the mounting groove 821, and an arc groove 811 is provided at the bottom of the support disk 800. The arc groove 811 is a depth-gradient groove, so that the paddle 840 can move up and down slowly.

[0036] In this way, when the rotating disk 810 rotates relative to the supporting disk 800, the rotating disk 810 drives the paddle 840 to rotate. When the paddle 840 moves to the outside of the arc groove 811, the paddle 840 is squeezed by the bottom surface of the supporting disk 800, thereby overcoming the force of the spring 841 so that the lower end of the paddle 840 extends from the mounting groove 821 and can move the steel ball 700. When the paddle 840 moves to the position corresponding to the arc groove 811, the spring 841 pulls the paddle 840 to move upward, so that the lower end of the paddle 840 shrinks into the mounting groove 821. The position setting of the arc groove 811 allows the paddle 840 to just move the steel ball 700 when it is extended, and can prevent the paddle 840 from interfering with the inner spiral track 900 or the outer spiral track 600.

[0037] Furthermore, the transmission mechanism includes a transmission shaft 530 coaxially arranged inside the support cylinder 540, a rotating shaft 820 is arranged on the rotating disk 810, and the rotating shaft 820 is rotatably arranged in the rotating hole 812 of the supporting disk 800, the rotating shaft 820 of the rotating disk 810 is connected to the transmission shaft 530 through a transmission belt 830, and a planetary gear structure is arranged between the transmission shaft 530 and the output shaft 501 of the driving motor 500, and the planetary gear structure drives the transmission shaft 530 to perform a deceleration motion when the driving motor 500 rotates. In this way, the driving motor 500 is prevented from rotating too fast, which causes the paddle 840 to be moved too fast.

[0038] Furthermore, the output shaft 501 of the drive motor 500 is connected to a sun gear 550 by a spline so as to slide up and down. The sun gear 550 is transmission-connected to a plurality of planetary gears 520 around it. An inner gear ring 531 is provided at the bottom of the transmission shaft 530, and the inner gear ring 531 is meshed with the planetary gears 520. A transmission box is provided at the bottom of the support tube 540, and a plurality of fixed shafts 541 are fixedly provided on the bottom surface of the transmission box. The planetary gears 520 are rotatably set on the fixed shafts 541. The sun gear 550, the planetary gears 520 and the inner gear ring 531 constitute the planetary gear structure.

[0039] Furthermore, the inner wall of the furnace is provided with an insulation layer 300 and a heating structure, the insulation layer 300 is used to keep the temperature inside the furnace warm, and the heating structure is used to heat the furnace, and the heating structure is a resistance wire 310 .

[0040] In combination with the above embodiments, the use principle and working process of the embodiments of the present invention are as follows: First, the furnace is heated to a set annealing temperature through the resistance wire 310. The spiral placement rack is assembled, and then the steel balls 700 to be annealed are placed in the spiral circulation track, and then the spiral placement rack is supported and placed in the furnace.

[0041] Then, the driving motor 500 is started, and the driving motor 500 drives the fan 510 to rotate while driving the transmission shaft 530 to rotate. The rotation of the transmission shaft 530 drives each rotating disk 810 to rotate through the transmission belt 830, and the rotating disk 810 drives the paddle 840 thereon to rotate. When the paddle 840 moves to the outside of the arc groove 811, the upper end of the paddle 840 is squeezed by the bottom surface of the supporting disk 800, so that the paddle 840 overcomes the force of the spring 841 and the lower end of the paddle 840 extends out from the mounting groove 821. At this time, the paddle 840 just corresponds to the space between the two steel balls 700 on the spiral circulation track. As the rotating disk 810 rotates, the paddle 840 can paddle the steel ball 700 to move the steel ball 700 along the spiral circulation track. When the paddle 840 moves to the position corresponding to the arc groove 811 , the spring 841 pulls the paddle 840 upward, causing the lower end of the paddle 840 to shrink into the mounting groove 821 , so that the paddle 840 will not interfere with the elastic bars on the inner spiral track 900 or the outer spiral track 600 .

[0042] After a period of circulation, each position on the surface of each steel ball 700 is evenly exposed to the airflow, so that the temperature of each position on the surface of the steel ball 700 is basically the same, and the annealing process is completed. Finally, the spiral placement rack is removed from the furnace, and the connecting track 1000 at the bottom of the spiral placement rack is disassembled, so that the steel balls 700 can flow out automatically.

[0043] An annealing method, using the above-mentioned pit-type spheroidizing annealing furnace, comprises the following steps: S1, placing the steel ball 700 in a spiral placement rack, and then placing the spiral placement rack in the furnace; S2, start the driving motor 500, the driving motor 500 drives the fan 510 to rotate, and at the same time drives each paddle 840 to rotate through the transmission mechanism, and the paddle 840 paddles the steel ball 700 on the spiral placement frame so that each position of the steel ball 700 can contact the airflow; S3, take the spiral placement rack out of the furnace, and remove the steel ball 700 from the spiral placement rack.

[0044] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A pit type spheroidizing annealing furnace, characterized in that: The furnace body comprises a furnace, the interior of the furnace body is a furnace, a driving motor is provided at the bottom of the furnace body, an output shaft of the driving motor is provided with a fan, the fan is located at the bottom of the furnace, and the fan is used to evenly disperse external gas into the interior of the furnace; A spiral placement rack is provided in the furnace, and the spiral placement rack is formed by winding a plurality of elastic bars arranged at intervals, and a spiral circulation track is formed inside the plurality of elastic bars. The spiral circulation track is used to place steel balls, and the axis of the spiral circulation track extends in the up-down direction, and a support cylinder is coaxially provided inside the spiral circulation track, and a plurality of toggle assemblies distributed in the up-down direction are provided on the support cylinder, and each layer of toggle assemblies corresponds to each turn of the spiral track, and the toggle assembly includes a support rod, and a support disk is provided at the end of the support rod, and the axis of the support disk extends in the up-down direction, and a plurality of paddles rotating in a circumferential direction around the support disk are provided on the support disk, and a transmission mechanism is provided between the output shaft of the drive motor and the paddle, and the drive motor drives the paddle to rotate through the transmission mechanism when rotating, and the rotation of the paddle can toggle the steel ball, so that the steel ball moves in a circulation in the spiral circulation track.

2. The pit type spheroidizing annealing furnace according to claim 1, characterized in that: The spiral circulation track includes an inner spiral track and an outer spiral track. The inner spiral track is coaxially arranged inside the outer spiral track, and the rotation direction of the inner spiral track is opposite to that of the outer spiral track. The upper end of the inner spiral track is connected to the upper end of the outer spiral track, and the lower end of the inner spiral track is connected to the lower end of the outer spiral track.

3. The pit type spheroidizing annealing furnace according to claim 2, characterized in that: The inner spiral track and the outer spiral track have the same structure. Each turn of the spiral track includes a spiral section and an annular horizontal section. The spiral section and the annular horizontal section are detachably connected by bolts.

4. The pit type spheroidizing annealing furnace according to claim 3, characterized in that: The central angles of the spiral section and the annular horizontal section on the same turn of the spiral track are equal, and the elastic bars of the two are staggered in the circumferential direction of the support cylinder.

5. The pit type spheroidizing annealing furnace according to claim 3 or 4, characterized in that: Each layer of support rods includes an inner support rod and an outer support rod. The structure of the inner support rod is the same as that of the outer support rod. The support disk of the inner support rod corresponds to the spiral segment of each turn of the inner spiral track, and the support disk of the outer support rod corresponds to the spiral segment of each turn of the outer spiral track.

6. The pit type spheroidizing annealing furnace according to claim 5, characterized in that: A rotating disk is rotatably provided at the bottom of the support disk, and a mounting groove is provided on the rotating disk. The paddle is slidably located in the mounting groove, and a spring is provided between the paddle and the support disk, and the spring has a tendency to make the paddle slide upward along the mounting groove. An arc groove is provided at the bottom of the support disk, and when the paddle is rotated to a position corresponding to the arc groove, the lower end of the paddle is retracted into the mounting groove; when the paddle is rotated to the outside of the arc groove, the lower end of the paddle extends out of the mounting groove.

7. The pit type spheroidizing annealing furnace according to claim 6, characterized in that: The transmission mechanism includes a transmission shaft coaxially arranged inside the support cylinder, the rotating disk and the transmission shaft are connected by a transmission belt, and a planetary gear structure is provided between the transmission shaft and the output shaft of the driving motor. The planetary gear structure drives the transmission shaft to perform a deceleration motion when the driving motor rotates.

8. The pit type spheroidizing annealing furnace according to claim 7, characterized in that: The output shaft of the driving motor is connected to the sun gear by spline sliding up and down, and the sun gear is connected to multiple planetary gears around it. An inner ring gear is provided at the bottom of the transmission shaft, and the inner ring gear is meshed with the planetary gears. A transmission box is provided at the bottom of the support tube, and multiple fixed shafts are fixed on the bottom surface of the transmission box. The planetary gears are rotatably set on the fixed shafts. The sun gear, planetary gears and inner ring gear constitute the planetary gear structure.

9. The pit type spheroidizing annealing furnace according to claim 1, characterized in that: The inner wall of the furnace is provided with a heat-insulating layer and a heating structure. The heat-insulating layer is used to keep the temperature inside the furnace warm, and the heating structure is used to heat the furnace. The heating structure is a resistance wire.

10. An annealing method, characterized in that: The pit-type spheroidizing annealing furnace according to any one of claims 1 to 9 comprises the following steps: S1. Place the steel balls in a spiral placement rack, and then place the spiral placement rack in the furnace; S2, start the driving motor, the driving motor drives the fan to rotate, and at the same time drives each paddle to rotate through the transmission mechanism, the paddle paddles the steel ball on the spiral placement frame, so that each position of the steel ball can contact the airflow; S3. Take the spiral rack out of the furnace and remove the steel balls from the spiral rack.

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