Heat shield lifting mechanism for single crystal furnace

Abstract

The utility model relates to a heat shield lifting mechanism for a single crystal furnace, which adopts double motors to control the lifting of a heat shield in czochralski silicon single crystal furnace equipment, can avoid the asynchronous phenomenon in the prior art, is time-saving and labor-saving, and improves the transmission efficiency and simplifies the structure as the internal spiral elevator is changed into a module structure. The utility model has the advantages of reasonable structural design, small overall volume, small installation area, convenience in use and maintenance, and no need of long-term maintenance, and adopts an active lifting module form of rotation of independent motors on two sides, so that the rigidity and the positioning accuracy of the structure can be effectively improved. The lifting stability of the heat shield can be effectively guaranteed, inclination is avoided, and the crystal growth quality is guaranteed. Worm and gear transmission design is matched with a preferable self-locking nut, so that the mechanism can be effectively prevented from sliding down quickly, and potential safety hazards are reduced.

Description

Technical Field

[0001] The utility model relates to a heat screen lifting mechanism for a single crystal furnace, belonging to the technical field of single crystal furnaces. Background Art

[0002] In the existing single crystal silicon processing process, heat shields are generally used to reduce thermal radiation and heat loss, reduce thermal convection, accelerate steam volatilization, accelerate the cooling of the crystal and thus increase the crystal pulling speed.

[0003] The heat shield lifting device has a lifting function. When the heat shield is raised, more silicon materials can be loaded into the quartz crucible of the same specification. After the silicon materials are melted, the heat shield can be lowered to play its due role. After the crystal growth is completed, the heat shield is raised to accelerate the heat dissipation in the quartz crucible in the thermal system.

[0004] Prior art heat shield lifting device ( Figure 1-3 ) is mainly powered by a single motor plus a flexible shaft, but the flexible shaft connection will be out of sync, which will cause the heat shield to tilt, seriously affecting the temperature distribution inside the crucible and the growth of the crystal. At the same time, the existing heat shield lifting mechanism uses a spiral elevator transmission and a trapezoidal lead screw, which has low transmission efficiency and a relatively complicated and bulky body structure. Utility Model Content

[0005] The utility model provides a heat shield lifting mechanism for a single crystal furnace, which aims to overcome the above-mentioned deficiencies in the prior art, avoid the tilting of the heat shield during lifting and lowering, and improve the stability of the transmission structure and the transmission efficiency.

[0006] The technical solution of the utility model is a heat shield lifting mechanism for a single crystal furnace, which adopts dual motors to control the lifting and lowering of the heat shield in the direct-pull silicon single crystal furnace equipment, thereby avoiding the asynchronism phenomenon existing in the prior art, saving time and labor, and the internal spiral lifting machine is changed to a module structure, thereby improving the transmission efficiency and simplifying the structure.

[0007] Specifically, a heat shield lifting mechanism for a single crystal furnace comprises a pair of identical lifting assemblies symmetrically arranged on both sides of a top opening of a furnace cover assembly A, the lifting assembly comprising a mounting base plate fixed to the top of the furnace cover assembly A, a module mounting plate being mounted on the mounting base plate, reinforcing rib plates being connected to both ends of one side of the module mounting plate, a servo motor being connected to the outer side of the bottom end of the reinforcing rib plate through a motor mounting plate, an output end of the servo motor being connected to a worm gear reducer through a coupling, the worm gear reducer being connected to the bottom end of a ball screw, the ball screw extending in the height direction of the module mounting plate, the top end of the ball screw being connected to an encoder mounting seat through a coupling, the encoder mounting seat being connected to an encoder located at the top end of the module mounting plate, guide rails being arranged on the module mounting plates on both sides of the ball screw, a slider being mounted on the ball screw and slidably connected to the guide rails, a slider being connected to a slider mounting plate, the slider mounting plate being connected to a lifting carrier plate, reinforcing ribs being further connected between the slider mounting plate and the lifting carrier plate, the bottom end of the bellows being mounted on the mounting base plate, a servo guide sleeve being mounted on the bottom of the mounting base plate at a corresponding position through a stopper, and the lifting carrier plates on both sides being connected to a water-cooled heat shield.

[0008] Preferably, a limit switch installation slot is provided along the height direction of the reinforcing rib plate, a top limit switch assembly is installed near the top of the limit switch installation slot, a bottom limit switch assembly is installed near the bottom of the limit switch installation slot, and a limit switch trigger block is provided on the side of the lifting carrier plate near the limit switch installation slot. The lifting and lowering end points of the lifting carrier plate can be limited.

[0009] Preferably, a scale is provided along the height direction of the reinforcing rib plate, and a pointer is provided on the side of the limit switch trigger block close to the scale, so as to intuitively judge the height of the lifting carrier plate.

[0010] Preferably, the slider is provided with an external self-locking nut or an internal locking nut, which can increase the self-locking property and prevent the water-cooled heat shield from falling when the ball screw falls.

[0011] The advantages of the utility model are as follows: the structure is reasonably designed, and the active lifting module form with independent motors on both sides can effectively improve the rigidity and positioning accuracy of the structure. The overall volume is small, the installation area is small, and it is easy to use and maintain, and does not require long-term maintenance. It can effectively ensure the lifting stability of the heat shield, avoid tilting, and ensure the quality of crystal growth. The worm gear transmission design combined with the preferred self-locking nut can effectively prevent the mechanism from sliding down quickly and reduce safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The present invention is a structural schematic diagram of a heat shield lifting mechanism for a single crystal furnace in the prior art.

[0013] Figure 2 yes Figure 1 Schematic diagram of the structure of the single motor lifting assembly.

[0014] Figure 3 yes Figure 1 Schematic diagram of the structure of the middle flexible shaft lifting assembly.

[0015] Figure 4 The utility model is a structural schematic diagram of a heat screen lifting mechanism for a single crystal furnace.

[0016] Figure 5 yes Figure 4 Schematic diagram of the structure when the lifting component is lowered.

[0017] Figure 6 yes Figure 4 Schematic diagram of the structure when the lifting component is lifted.

[0018] Figure 7 yes Figure 4 Schematic diagram of the structure of the lifting transmission mechanism in the middle lifting assembly.

[0019] A in the figure is the furnace cover assembly, 1 is the mounting base plate, 2 is the module mounting plate, 3 is the reinforcing rib plate, 4 is the motor mounting plate, 5 is the servo motor, 6 is the worm gear reducer, 7 is the ball screw, 8 is the encoder mounting seat, 9 is the encoder, 10 is the guide rail, 11 is the slider, 12 is the slider mounting plate, 13 is the external self-locking nut, 14 is the lifting carrier plate, 15 is the bellows, 16 is the servo guide sleeve, 17 is the reinforcing rib, 18 is the scale, 19 is the pointer, 20 is the limit switch mounting slot, 21 is the top limit switch assembly, 22 is the bottom limit switch assembly, and 23 is the limit switch trigger block. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below in conjunction with embodiments and specific implementation methods.

[0021] like Figure 4-7 As shown, a heat shield lifting mechanism for a single crystal furnace includes a pair of identical lifting assemblies symmetrically arranged on both sides of the top opening of the furnace cover assembly A. The lifting assemblies on both sides lift the same water-cooled heat shield (not shown), and the lifting assembly includes a servo motor. In view of the defects of the above-mentioned single motor plus flexible shaft in the prior art, it is changed to a dual motor form, and the characteristics of the servo motor can be used for synchronous control and simultaneous lifting.

[0022] The lifting assembly includes a mounting base plate 1 fixed on the top of the furnace cover assembly A, a module mounting plate 2 is mounted on the mounting base plate 1, two ends of one side of the module mounting plate 2 are connected with reinforcing rib plates 3, the outer side of the bottom end of the reinforcing rib plate 3 is connected to the servo motor 5 through the motor mounting plate 4, the output end of the servo motor 5 is connected to the worm gear reducer 6 through a coupling, the worm gear reducer 6 is connected to the bottom end of the ball screw 7, the ball screw 7 extends along the height direction of the module mounting plate 2, the top end of the ball screw 7 is connected to the encoder mounting seat 8 through a coupling, and the encoder mounting seat 8 is connected to the top of the module mounting plate 2. The encoder 9 at the end, the module mounting plate 2 on both sides of the ball screw 7 is provided with a guide rail 10, the slider 11 is installed on the ball screw 7 and is slidably connected to the guide rail 10, the slider 11 is connected to the slider mounting plate 12, the slider mounting plate 12 is connected to the lifting carrier plate 14, and a reinforcing rib 17 is also connected between the slider mounting plate 12 and the lifting carrier plate 14. The lifting carrier plate 14 is installed on the top of the bellows 15, and the bottom end of the bellows 15 is installed on the mounting base plate 1, and the servo guide sleeve 16 is installed at the bottom of the mounting base plate 1 at the corresponding position through the stopper, and the lifting carrier plates 14 on both sides are connected to the water-cooled heat screen.

[0023] A limit switch installation groove 20 is provided along the height direction of the reinforcing rib plate 3, a top limit switch assembly 21 is installed near the top of the limit switch installation groove 20, a bottom limit switch assembly 22 is installed near the bottom of the limit switch installation groove 20, and a limit switch trigger block 23 is provided on the side of the lifting carrier 14 near the limit switch installation groove 20.

[0024] A scale 18 is provided along the height direction of the reinforcing rib plate 3 , and a pointer 19 is provided on the side of the limit switch trigger block 23 close to the scale 18 .

[0025] The slider 11 is provided with an external self-locking nut 13 or an internal locking nut. That is, the locking nut is externally arranged on the slider 11 or internally arranged on the slider. The self-locking property can be increased, and even if the ball screw falls off, the water-cooled heat shield will not fall off, thereby improving the safety of the equipment operation.

[0026] According to the above structure, in view of the defects of the prior art spiral elevator, it is replaced with a module form, relying on the guide rail 10 and the slider 11 as a guide, the middle ball screw 7 as a transmission, and the bottom is directly connected to the worm gear reducer 6. A coupling is installed between the servo motor 5 and the worm gear reducer 6 as compensation, which can improve the rigidity of the structure and the positioning accuracy. It has a small size and a small installation area, is easy to use and maintain, and does not require long-term maintenance.

[0027] All the components mentioned above are prior art, and those skilled in the art can use any model and existing design that can achieve their corresponding functions.

[0028] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements all fall within the protection scope of the present invention.

Claims

1. A heat shield lifting mechanism for a single crystal furnace, characterized in that: The invention comprises a pair of identical lifting assemblies symmetrically arranged on both sides of the top opening of the furnace cover assembly A, wherein the lifting assemblies comprise a mounting base plate (1) fixed to the top of the furnace cover assembly A, a module mounting plate (2) being mounted on the mounting base plate (1), and reinforcing rib plates (3) being connected to both ends of one side of the module mounting plate (2), and the outer side of the bottom end of the reinforcing rib plate (3) being connected to a servo motor (5) through a motor mounting plate (4), and the output end of the servo motor (5) being connected to a worm gear reducer (6) through a coupling, and the worm gear reducer (6) being connected to the bottom end of a ball screw (7), and the ball screw (7) extending in the height direction of the module mounting plate (2), and the top end of the ball screw (7) being connected to an encoder mounting seat (8) through a coupling, and the encoder mounting seat (8) being connected to An encoder (9) is located at the top of the module mounting plate (2), and guide rails (10) are provided on the module mounting plate (2) on both sides of the ball screw (7). A slider (11) is mounted on the ball screw (7) and slidably connected to the guide rails (10). The slider (11) is connected to the slider mounting plate (12), and the slider mounting plate (12) is connected to the lifting carrier plate (14). A reinforcing rib (17) is also connected between the slider mounting plate (12) and the lifting carrier plate (14). The lifting carrier plate (14) is mounted on the top of the bellows (15), and the bottom of the bellows (15) is mounted on the mounting base plate (1). A servo guide sleeve (16) is installed at the bottom of the mounting base plate (1) at a corresponding position through a stopper, and the lifting carrier plates (14) on both sides are connected to a water-cooled heat screen.

2. A heat shield lifting mechanism for a single crystal furnace as claimed in claim 1, characterized in that: A limit switch installation groove (20) is provided along the height direction of the reinforcing rib plate (3), a top limit switch assembly (21) is installed near the top end of the limit switch installation groove (20), a bottom limit switch assembly (22) is installed near the bottom end of the limit switch installation groove (20), and a limit switch trigger block (23) is provided on the side of the lifting carrier plate (14) near the limit switch installation groove (20).

3. A heat shield lifting mechanism for a single crystal furnace as claimed in claim 2, characterized in that: A scale (18) is provided along the height direction of the reinforcing rib plate (3), and a pointer (19) is provided on the side of the limit switch trigger block (23) close to the scale (18).

4. A heat shield lifting mechanism for a single crystal furnace according to any one of claims 1 to 3, characterized in that: The slide block (11) is provided with an external self-locking nut (13) or an internal locking nut.

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