Guide device of wire feeder
By installing the guide mechanism and adjustment components on the wire feeder catheter, the problem of catheter rupture is solved, and efficient guidance is achieved without the need to replace the catheter, reducing costs and workloads, and improving service life.
Patent Information
- Application Number
- CN202421079028.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-16
- Publication Date
- 2024-12-20
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The wire feeder conduit breaks due to friction between the alloy wire and the conduit and needs to be replaced regularly, which increases the workload and maintenance costs.
Design a wire feeder guide device, including installing a guide mechanism on the wire feeding conduit, by opening upper and lower mounting holes on the conduit, the mounting shaft and guide roller are fixed in these holes, the guide roller can be rotatable, and is made of stainless steel material And a chrome layer is plated for improved wear resistance, combining height adjustment components and limiting parts to ensure the correct position and guidance effect of the guide roller.
No need to remove and replace the wire feeding conduit, which reduces cost and workload, improves the guidance effect and service life, and can be installed directly on the ruptured conduit, saving maintenance processes.
Smart Images
Figure CN222205303U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of wire feeding machine guide devices, and more specifically, to a wire feeding machine guide device. Background Art
[0002] The wire feeder is also called a wire feeding machine. It is used to inject the alloy core wire into the deep of the molten steel at an appropriate speed and a set amount to make it evenly dispersed, so as to achieve the purpose of deoxidation, changing the inclusion morphology, and fine-tuning the composition. The wire feeder is used to accurately control the wire transmission process on the processing equipment.
[0003] The wire feeding machine is connected with a wire feeding guide tube for guiding the alloy wire. During long-term operation, the alloy wire rubs against the wall of the wire feeding guide tube, causing the wall of the wire feeding guide tube to wear and crack. The crack of the wire feeding guide tube can easily cause the alloy wire to get stuck during the feeding process, affecting production. To ensure smooth production, the wire feeding guide tube needs to be replaced regularly, which increases the workload and maintenance costs. Utility Model Content
[0004] The utility model aims to overcome the defects of the prior art and provide a wire feeding machine guide device for solving the technical problem that the wire feeding tube needs to be replaced regularly due to the breakage of the wire feeding tube caused by the friction between the alloy wire and the wire feeding tube.
[0005] The technical solution adopted by the utility model is a wire feeding machine guide device, comprising a wire feeding duct and a plurality of guide mechanisms installed on the wire feeding duct; an upper mounting hole and a lower mounting hole are arranged on the wall of the wire feeding duct; the guide mechanism comprises a mounting shaft and a guide roller, the guide roller is rotatably mounted on the mounting shaft, the top end of the mounting shaft is fixed in the upper mounting hole by an upper fixing assembly, the bottom end of the mounting shaft is fixed in the lower mounting hole by a lower fixing assembly, and the diameter of the guide roller is smaller than the diameter of the upper mounting hole.
[0006] During installation, only two opposite holes need to be opened on the wire feeding duct, namely the upper mounting hole and the lower mounting hole, and then the mounting shaft and the guide roller are dropped into the wire feeding duct through the upper mounting hole, and then the top end of the mounting shaft is fixed in the upper mounting hole through the upper fixing assembly, and the bottom end of the mounting shaft is fixed in the lower mounting hole through the lower fixing assembly to complete the installation. This method only requires two holes to be opened on the wire feeding duct for installation. After installation, the alloy wire is guided by the guide roller. There is no need to disassemble and replace the wire feeding duct, which can effectively reduce costs. Moreover, it can be directly installed on a broken wire feeding duct, which reduces costs, has strong practicality, and saves the process of disassembly and replacement.
[0007] Furthermore, a limit piece is fixed at the lower part of the installation shaft, and the limit piece has a curved surface end and a flat surface end. The curved surface end of the limit piece can be spliced with the inner wall surface of the wire feeding duct at the lower installation hole, and the flat surface end of the limit piece is used to support the guide roller. During installation, the guide roller is sleeved on the installation shaft, and the limit piece supports the guide roller to ensure the position of the guide roller on the installation shaft, so that there is a certain distance between the guide roller and the inner wall surface of the lower installation hole, so as to prevent the lower end of the guide roller from interfering with the inner wall of the wire feeding duct.
[0008] Furthermore, a height adjustment assembly is installed on the limiter to adjust the distance from the guide roller to the plane end of the limiter. After the guide roller is installed in the wire feeding duct, it is necessary to ensure that it has an equal distance from the upper mounting hole and the lower mounting hole, respectively, to achieve a better guiding effect. Therefore, when the diameter of the wire feeding duct is large, the height adjustment assembly is used to increase the distance between the guide roller and the plane end of the limiter to ensure that it has an equal distance from the upper mounting hole and the lower mounting hole, respectively; similarly, when the diameter of the wire feeding duct is small, the height adjustment assembly is used to reduce the distance between the guide roller and the plane end of the limiter to achieve the effect of centering the guide roller.
[0009] Furthermore, the height adjustment assembly includes a threaded hole, a locking nut and a threaded sleeve. The plane end of the limiter is provided with a threaded hole, a threaded sleeve is threadedly connected in the threaded hole, a locking nut is threadedly connected on the threaded sleeve, and the locking nut cooperates with the plane end of the limiter to lock the threaded sleeve; the threaded sleeve is coaxially arranged with the guide roller, and the top of the threaded sleeve is rotatably connected with the bottom end of the guide roller. The distance between the threaded sleeve and the limiter can be changed by rotating the threaded sleeve, so that the guide roller can be adjusted. After the adjustment is in place, the locking nut is rotated to squeeze and fit with the plane end of the limiter to lock the threaded sleeve. This thread adjustment method can fine-tune any distance, which is more convenient for adjusting the height of the guide roller on the mounting shaft.
[0010] Furthermore, a spherical annular groove is arranged at the top end of the threaded sleeve, and annularly distributed guide balls are installed at the bottom end of the guide roller, and the annularly distributed guide balls are all in rolling cooperation with the spherical annular groove.
[0011] Furthermore, the outer peripheral surface of the guide roller is a curved surface, and the end diameter of the guide roller is larger than the middle diameter. This arrangement is mainly to improve the guiding effect of the alloy wire core, and during the guiding process, the alloy wire core can be prevented from escaping from the two ends of the guide roller.
[0012] Furthermore, a bearing is provided inside the top end of the guide roller, and the installation shaft is rotatably connected to the top end of the guide roller through the bearing. The bearing is used to reduce the friction between the guide roller and the installation shaft, which can effectively increase the service life of the guide roller.
[0013] Furthermore, the guide roller is made of stainless steel, and the outer peripheral surface of the guide roller is provided with a chrome-plated layer.
[0014] The stainless steel material will not rust and can prevent rust from entering the wire feeder along the wire feeding duct. The chrome plating layer can increase the wear resistance of the guide roller, thereby increasing the service life of the guide roller.
[0015] Furthermore, the lower fixing assembly includes a lower locking nut and a lower center hole cylindrical pad; the diameter of the lower center hole cylindrical pad is larger than the diameter of the lower mounting hole, and the lower center hole cylindrical pad has a curved surface end spliced with the outer wall of the wire feeding catheter. During installation, the lower locking nut is threadedly connected to the lower threaded end of the mounting shaft, and the lower center hole cylindrical pad is sleeved on the mounting shaft between the lower locking nut and the outer wall of the wire feeding catheter, and the curved surface end of the lower center hole cylindrical pad is spliced with the outer wall of the wire feeding catheter. When the lower locking nut is continuously tightened, the curved surface end of the limiter is spliced with the inner wall of the wire feeding catheter at the lower mounting hole, and the lower center hole cylindrical pad closes the lower mounting hole, and the lower end of the mounting shaft is firmly fixed.
[0016] Furthermore, the upper fixing assembly includes an upper locking nut and an upper center hole cylindrical pad; the diameter of the upper center hole cylindrical pad is larger than the diameter of the upper mounting hole, and a curved truncated cone is provided on the upper center hole cylindrical pad. During installation, the upper locking nut is threadedly connected to the upper threaded end of the mounting shaft, and the upper center hole cylindrical pad is sleeved on the mounting shaft between the upper locking nut and the outer wall of the wire feeding conduit, and the curved truncated cone of the upper center hole cylindrical pad is plugged into the upper mounting hole. When the upper locking nut is screwed, the curved truncated cone of the upper center hole cylindrical pad is plugged into the upper mounting hole, closing the upper mounting hole and realizing the positioning and fixation of the upper end of the mounting shaft.
[0017] Compared with the prior art, the beneficial effects of the utility model are as follows: only two opposite holes, namely the upper mounting hole and the lower mounting hole, need to be opened on the wire feeding duct, and then the mounting shaft and the guide roller are dropped into the wire feeding duct through the upper mounting hole, and then the top end of the mounting shaft is fixed in the upper mounting hole through the upper fixing assembly, and the bottom end of the mounting shaft is fixed in the lower mounting hole through the lower fixing assembly to complete the installation. In this method, only two holes need to be opened on the wire feeding duct for installation. After installation, the alloy wire is guided by the guide roller. There is no need to disassemble and replace the wire feeding duct, which can effectively reduce costs. Moreover, it can be directly installed on a broken wire feeding duct, which reduces costs, has strong practicality, and saves the process of disassembly and replacement. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model.
[0019] Figure 2 It is a structural schematic diagram of the guide mechanism of the utility model.
[0020] Figure 3 For this utility model Figure 2 A magnified view of the local structure at point A.
[0021] Figure 4 For this utility model Figure 2 A magnified view of the local structure at point B in the middle.
[0022] In the figure: 1. wire feeding guide tube, 2. guide mechanism, 3. upper mounting hole, 4. lower mounting hole, 5. mounting shaft, 6. guide roller, 7. upper fixing assembly, 8. lower fixing assembly, 9. limiter, 10. height adjustment assembly, 11. threaded hole, 12. locking nut, 13. threaded sleeve, 14. spherical ring groove, 15. guide ball, 16. bearing, 17. lower locking nut, 18. lower center hole cylindrical block, 19. upper locking nut, 20. upper center hole cylindrical block, 21. curved frustum. DETAILED DESCRIPTION
[0023] The drawings of the present invention are only used for illustrative purposes and cannot be construed as limiting the present invention. In order to better illustrate the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.
[0024] like Figure 1 As shown, the present solution discloses a wire feeding machine guide device, comprising a wire feeding guide tube 1 and a plurality of guide mechanisms 2 installed on the wire feeding guide tube 1.
[0025] like Figure 2 As shown, an upper mounting hole 3 and a lower mounting hole 4 are provided on the wall of the wire feeding duct 1; the guide mechanism 2 includes a mounting shaft 5 and a guide roller 6, the guide roller 6 is rotatably mounted on the mounting shaft 5, the top end of the mounting shaft 5 is fixed in the upper mounting hole 3 through an upper fixing assembly 7, and the bottom end of the mounting shaft 5 is fixed in the lower mounting hole 4 through a lower fixing assembly 8, the diameter of the guide roller 6 is smaller than the diameter of the upper mounting hole 3, and after installation, the guide roller 6 is located in the wire feeding duct 1.
[0026] During installation, it is only necessary to open two opposite holes on the wire feeding guide tube 1, namely the upper mounting hole 3 and the lower mounting hole 4, and then the mounting shaft 5 and the guide roller 6 are dropped into the wire feeding guide tube 1 through the upper mounting hole 3, and then the top end of the mounting shaft 5 is fixed in the upper mounting hole 3 through the upper fixing component 7, and the bottom end of the mounting shaft 5 is fixed in the lower mounting hole 4 through the lower fixing component 8 to complete the installation. The guide roller 6 is located in the wire feeding guide tube 1, which can play a good guiding role for the alloy wire core. This method only requires opening two holes on the wire feeding guide tube 1 for installation, and the guiding mechanism 2 has a simple structure and low manufacturing cost. After installation, the alloy wire is guided by the guide roller 6, and there is no need to disassemble and replace the wire feeding guide tube 1, which can effectively reduce the cost, and it can be directly installed on the broken wire feeding guide tube 1, which reduces the cost, has strong practicality, and saves the disassembly and replacement process.
[0027] like Figure 2 and 4 As shown, a limiter 9 is fixed at the lower part of the installation shaft 5, and the limiter 9 has a curved end and a flat end. The curved end of the limiter 9 can be spliced with the inner wall of the wire feeding duct 1 at the lower installation hole 4, and the flat end of the limiter 9 is used to support the guide roller 6. During installation, the guide roller 6 is sleeved on the installation shaft 5, and the limiter 9 supports the bottom end of the guide roller 6 to ensure the position of the guide roller 6 on the installation shaft 5, so that there is a certain distance between the guide roller 6 and the inner wall of the lower installation hole 4, so as to prevent the lower end of the guide roller 6 from interfering with the inner wall of the wire feeding duct 1.
[0028] The lower fixing assembly 8 includes a lower locking nut 17 and a lower center hole cylindrical pad 18; the diameter of the lower center hole cylindrical pad 18 is larger than the diameter of the lower mounting hole 4, and the lower center hole cylindrical pad 18 has a curved surface end spliced with the outer wall of the wire feeding catheter 1. During installation, the lower locking nut 17 is threadedly connected to the lower threaded end of the mounting shaft 5, and the lower center hole cylindrical pad 18 is sleeved on the mounting shaft 5 between the lower locking nut 17 and the outer wall of the wire feeding catheter 1, and the curved surface end of the lower center hole cylindrical pad 18 is spliced with the outer wall of the wire feeding catheter 1. When the lower locking nut 17 is continuously tightened, the curved surface end of the limiter 9 is spliced with the inner wall of the wire feeding catheter 1 at the lower mounting hole 4, and the lower center hole cylindrical pad 18 closes the lower mounting hole 4, and the lower end of the mounting shaft 5 is firmly fixed.
[0029] The upper fixing assembly 7 includes an upper locking nut 19 and an upper center hole cylindrical pad 20; the diameter of the upper center hole cylindrical pad 20 is larger than the diameter of the upper mounting hole 3, and a curved truncated cone 21 is provided on the upper center hole cylindrical pad 20. During installation, the upper locking nut 19 is threadedly connected to the upper threaded end of the mounting shaft 5, and the upper center hole cylindrical pad 20 is sleeved on the mounting shaft 5 between the upper locking nut 19 and the outer wall of the wire feeding conduit 1, and the curved truncated cone 21 of the upper center hole cylindrical pad 20 is plugged into the upper mounting hole 3. When the upper locking nut 19 is screwed, the curved truncated cone 21 of the upper center hole cylindrical pad 20 is plugged into the upper mounting hole 3, closing the upper mounting hole 3, and realizing the center positioning and fixation of the upper end of the mounting shaft 5.
[0030] like Figure 2 and 4 As shown, a height adjustment component 10 is installed on the limiter 9, which is used to adjust the distance between the guide roller 6 and the plane end of the limiter 9. After the guide roller 6 is installed in the wire feeding duct 1, it is necessary to ensure that the guide roller 6 is centered, that is, the guide roller 6 has an equal distance from the upper mounting hole 3 and the lower mounting hole 4, respectively, to achieve a better guiding effect. Therefore, when the diameter of the wire feeding duct 1 is large, the height adjustment component 10 is used to increase the distance between the guide roller 6 and the plane end of the limiter 9 to ensure that it has an equal distance from the upper mounting hole 3 and the lower mounting hole 4, respectively; similarly, when the diameter of the wire feeding duct 1 is small, the height adjustment component 10 is used to reduce the distance between the guide roller 6 and the plane end of the limiter 9, and the distance between the guide roller 6 and the wire feeding duct 1 is changed to achieve the effect of centering the guide roller 6.
[0031] The height adjustment assembly 10 includes a threaded hole 11, a locking nut 12 and a threaded sleeve 13. The plane end of the limiter 9 is provided with a threaded hole 11, the threaded sleeve 13 is threadedly connected in the threaded hole 11, the locking nut 12 is threadedly connected on the threaded sleeve 13, the locking nut 12 cooperates with the plane end of the limiter 9 to lock the threaded sleeve 13; the threaded sleeve 13 is coaxially arranged with the guide roller 6, and the top end of the threaded sleeve 13 is rotatably connected with the bottom end of the guide roller 6. The threaded sleeve 13 is rotated to cause the threaded sleeve 13 to be displaced in the threaded hole 11, so that the distance between the threaded sleeve 13 and the limiter 9 can be changed, and the guide roller 6 can be adjusted. After the adjustment is in place, the locking nut 12 is rotated to squeeze and fit with the plane end of the limiter 9 to lock the threaded sleeve 13. This thread adjustment method can fine-tune any distance, which is more convenient for adjusting the position of the guide roller 6 on the mounting shaft 5.
[0032] As a way of rotationally connecting the top of the threaded sleeve 13 and the bottom of the guide roller 6: the top of the threaded sleeve 13 is provided with a spherical annular groove 14, and the bottom of the guide roller 6 is provided with annularly distributed guide balls 15, and the annularly distributed guide balls 15 are all rollingly matched with the spherical annular groove 14. This rolling matching method has small resistance and long service life, and can realize the separation of the guide roller 6 and the threaded sleeve 13, and is more convenient for installation and maintenance.
[0033] like Figure 2 As shown, the outer peripheral surface of the guide roller 6 is a curved surface, and the end diameter of the guide roller 6 is larger than the middle diameter. This arrangement is mainly to improve the guiding effect of the alloy wire core, and to prevent the alloy wire core from falling out of the two ends of the guide roller 6 during the guiding process.
[0034] like Figure 3 As shown, a bearing 16 is provided inside the top of the guide roller 6, and the mounting shaft 5 is rotatably connected to the top of the guide roller 6 through the bearing 16. The bearing 16 is used to reduce the friction between the guide roller 6 and the mounting shaft 5, which can effectively improve the service life of the guide roller 6 and the smoothness during guiding.
[0035] The guide roller 6 is made of stainless steel, and a chrome-plated layer is provided on the outer peripheral surface of the guide roller 6. The stainless steel material will not rust, and can prevent rust from entering the wire feeder along with the wire feeding guide tube 1. The chrome-plated layer can increase the wear resistance of the guide roller 6, thereby improving the service life of the guide roller 6.
[0036] When the wire feeding guide tube 1 is worn and cracked, it is improved. First, the upper mounting hole 3 and the lower mounting hole 4 are drilled on the wire feeding guide tube 1. The axes of the upper mounting hole 3 and the lower mounting hole 4 pass through a chord of the wire feeding guide tube 1. The position of the guide roller 6 on the mounting shaft 5 is adjusted by the height adjustment component 10 according to the diameter of the wire feeding guide tube 1. Specifically, the adjustment is made by screwing the threaded sleeve 13. After the adjustment, the threaded sleeve 13 is locked by screwing the locking nut 12. Then, the mounting shaft 5 with the limiting member 9 and the height adjustment component 10 is put into the wire feeding guide tube 1 from the upper mounting hole 3, and the lower end of the mounting shaft 5 is inserted into the lower mounting hole 4. The curved end of the limiting member 9 is spliced with the inner wall surface of the wire feeding guide tube 1. The upper and lower center-hole cylindrical pads 18 are sleeved on the outer mounting shaft 5, and the upper and lower locking nuts 17 are threadedly connected at the lower threaded end of the mounting shaft 5. The lower locking nut 17 is screwed to fix the lower end of the mounting shaft 5 in the lower mounting hole 4; the guide roller 6 is sleeved on the mounting shaft 5, and the guide ball 15 at the bottom end of the guide roller 6 cooperates with the spherical ring groove 14. The upper end of the guide roller 6 is rotatably connected to the mounting shaft 5 through the bearing 16, and then the upper center-hole cylindrical pad 20 is sleeved on the upper end of the mounting shaft 5, and the upper locking nut 19 is screwed on the threaded end of the mounting shaft 5. After screwing in the upper locking nut 19, the curved frustum 21 is inserted into the upper mounting hole 3, and the upper center-hole cylindrical pad 20 closes the upper mounting hole 3. The upper end of the mounting shaft 5 is fixed, and the installation is completed.
[0037] Obviously, the above embodiments of the utility model are only examples for clearly explaining the technical solution of the utility model, and are not intended to limit the specific implementation methods of the utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the utility model shall be included in the protection scope of the claims of the utility model.
Claims
1. A wire feeding machine guide device, characterized in that: It comprises a wire feeding conduit (1) and a plurality of guide mechanisms (2) installed on the wire feeding conduit (1); An upper mounting hole (3) and a lower mounting hole (4) are provided on the wall of the wire feeding guide tube (1); the guide mechanism (2) comprises a mounting shaft (5) and a guide roller (6); the guide roller (6) is rotatably mounted on the mounting shaft (5); the top end of the mounting shaft (5) is fixed in the upper mounting hole (3) through an upper fixing assembly (7); the bottom end of the mounting shaft (5) is fixed in the lower mounting hole (4) through a lower fixing assembly (8); and the diameter of the guide roller (6) is smaller than the diameter of the upper mounting hole (3).
2. A wire feeding machine guide device according to claim 1, characterized in that: A limiting member (9) is fixed at the lower part of the mounting shaft (5), and the limiting member (9) has a curved end and a flat end. The curved end of the limiting member (9) can be spliced with the inner wall surface of the wire feeding guide tube (1) at the lower mounting hole (4), and the flat end of the limiting member (9) is used to support the guide roller (6).
3. A wire feeder guide device according to claim 2, characterized in that: The limiting member (9) is provided with a height adjustment assembly (10) for adjusting the distance between the guide roller (6) and the plane end of the limiting member (9).
4. A wire feeder guide device according to claim 3, characterized in that: The height adjustment component (10) comprises a threaded hole (11), a locking nut (12) and a threaded sleeve (13); the plane end of the limit member (9) is provided with a threaded hole (11); the threaded sleeve (13) is threadedly connected to the threaded hole (11); the threaded sleeve (13) is threadedly connected to the locking nut (12); the locking nut (12) and the plane end of the limit member (9) cooperate to lock the threaded sleeve (13); the threaded sleeve (13) and the guide roller (6) are coaxially arranged; the top end of the threaded sleeve (13) is rotatably connected to the bottom end of the guide roller (6).
5. A wire feeder guide device according to claim 4, characterized in that: The top end of the threaded sleeve (13) is provided with a spherical annular groove (14), and the bottom end of the guide roller (6) is provided with annularly distributed guide balls (15), and the annularly distributed guide balls (15) are all in rolling cooperation with the spherical annular groove (14).
6. A wire feeder guide device according to claim 5, characterized in that: A bearing (16) is arranged inside the top end of the guide roller (6), and the mounting shaft (5) is rotatably connected to the top end of the guide roller (6) via the bearing (16).
7. A wire feeding machine guide device according to claim 1, characterized in that: The outer peripheral surface of the guide roller (6) is a curved surface, and the end diameter of the guide roller (6) is larger than the middle diameter thereof.
8. A wire feeder guide device according to claim 1, characterized in that: The guide roller (6) is made of stainless steel, and the outer peripheral surface of the guide roller (6) is provided with a chrome-plated layer.
9. A wire feeding machine guide device according to any one of claims 1 to 8, characterized in that: The lower fixing assembly (8) comprises a lower locking nut (17) and a lower center hole cylindrical pad (18); the diameter of the lower center hole cylindrical pad (18) is larger than the diameter of the lower mounting hole (4), and the lower center hole cylindrical pad (18) has a curved surface end spliced with the outer wall surface of the wire feeding catheter (1); during installation, the lower locking nut (17) is threadedly connected to the lower threaded end of the mounting shaft (5), the lower center hole cylindrical pad (18) is sleeved on the mounting shaft (5) between the lower locking nut (17) and the outer wall surface of the wire feeding catheter (1), and the curved surface end of the lower center hole cylindrical pad (18) is spliced with the outer wall surface of the wire feeding catheter (1).
10. A wire feeding machine guide device according to any one of claims 1 to 8, characterized in that: The upper fixing assembly (7) comprises an upper locking nut (19) and an upper center hole cylindrical pad (20); the diameter of the upper center hole cylindrical pad (20) is larger than the diameter of the upper mounting hole (3), and a curved frustum (21) is provided on the upper center hole cylindrical pad (20); during installation, the upper locking nut (19) is threadedly connected to the upper threaded end of the mounting shaft (5), the upper center hole cylindrical pad (20) is sleeved on the mounting shaft (5) between the upper locking nut (19) and the outer wall surface of the wire feeding guide tube (1), and the curved frustum (21) of the upper center hole cylindrical pad (20) is plugged into the upper mounting hole (3).