CN114406433B

CN114406433B - Double-end pressure equipment welding set of straight tube spare

Info

Publication number: CN114406433B
Application number: CN202210082948.0A
Authority: CN
Inventors: 吴剑斌; 覃晶晶
Original assignee: Jiangxi Avonflow Heating Ventilation Technology Co ltd
Current assignee: Jiangxi Avonflow Heating Ventilation Technology Co ltd
Priority date: 2022-01-25
Filing date: 2022-01-25
Publication date: 2023-05-09
Anticipated expiration: 2042-01-25
Also published as: CN114406433A

Abstract

A double-end press-fitting welding device for straight pipe fittings comprises a placing table for bearing the straight pipe fittings; the press-fitting assembly is arranged at two ends of the straight pipe fitting in a right-facing manner and comprises an installation table, a clamping die system for clamping the plug and a first air cylinder are arranged on the installation table, a pneumatic output port of the first air cylinder is provided with a rotary press shaft, and the rotary press shaft is connected with the clamping die system; the transfer welding assembly is coaxially arranged with the straight pipe and comprises an outer gear ring, the annular surface of the outer gear ring is provided with teeth, one side facing the press-fit assembly is fixedly provided with Shi Hanqiang, the inner gear ring is coaxially arranged in the outer gear ring, the outer annular surface of the inner gear ring is provided with teeth, and a first gear is meshed between the outer gear ring and the inner gear ring; the straight pipe and the welding gun rotate relatively. The invention realizes synchronous press fitting and welding of plugs at two ends of an original straight pipe, can be simultaneously suitable for brazing and electric welding, is only different in the structural function of a welding gun, and is provided with three linkage groups so that the welding efficiency is improved in multiple and the welding quality is more ensured.

Description

Double-end pressure equipment welding set of straight tube spare

Technical Field

The invention relates to the field of heating ventilation, in particular to a straight pipe double-head press-fitting welding device.

Background

The drying rack and the towel rack are used as an indispensable living article in life, are closely related to the life of people, are formed by overlapping a plurality of pipes, two ends of each pipe are required to be welded and plugged, the pipe of the towel rack is mainly a circular pipe, the end of the pipe is sealed by press-fitting and welding plugs, and fluid flows in the pipe, so that the welding performance requirement of welding joints of the pipe is severe.

The main modes of welding in the prior art are electric welding and brazing. The brazing is a welding method that after brazing filler metal lower than the melting point of a weldment and the weldment are heated to the melting temperature of the brazing filler metal, gaps of solid workpieces are filled with liquid brazing filler metal, so that an oxide film and oil stains on a contact surface of a base metal are removed firstly during brazing, capillary tubes can play a role after the brazing filler metal is melted, wettability and capillary mobility of the brazing filler metal are improved, but a press-fit welding surface of a plug and a pipe is an annular surface, and feeding is difficult, so that the method is rarely adopted at present; for electric welding, the welding surface is a ring surface, a manual welding mode is often adopted, the welding surface is required to be positioned at the side of the plug during manual welding, if the plug press fitting and welding are synchronous, the structure of the press fitting plug can affect welding personnel, so that the existing equipment is separated from the plug press fitting and welding process, the process efficiency is low, the manual welding quality cannot be ensured, delay stress exists at the welding position, and post treatment such as heat treatment is required to be independently carried out at the later stage, so that the process efficiency is further reduced.

Disclosure of Invention

According to the problems set forth in the background art, the invention provides a double-head press-fitting welding device for straight pipe pieces, and the invention is further described below.

A straight pipe double-end press-fitting welding device comprises:

the placing table is used for bearing the straight pipe fitting;

the press-fitting assembly is arranged at two ends of the straight pipe fitting in a right-facing manner and comprises an installation table, a clamping die system for clamping the plug and a first air cylinder are arranged on the installation table, a pneumatic output port of the first air cylinder is provided with a rotary press shaft, and the rotary press shaft is connected with the clamping die system;

the rotary welding assembly is coaxially arranged with the straight pipe and comprises an outer gear ring, a first tooth is arranged on the inner surface of the outer gear ring, shi Hanqiang is fixed on one side of the outer gear ring facing the press-fit assembly, an inner gear ring is coaxially arranged inside the outer gear ring, a second tooth is arranged on the outer surface of the inner gear ring, and a first gear is meshed between the outer gear ring and the inner gear ring;

the straight pipe and the welding gun rotate relatively.

Preferably, the straight pipe rotates to fix the welding gun; the outer gear ring is arranged on the base, a second gear is connected to the rotary pressing shaft in a synchronous rotation mode, a driving motor is fixed on the mounting table, the output of the driving motor is connected with a third gear, the second gear is meshed with the third gear, and the rotary pressing shaft is in non-rotation connection with the clamping die system;

the rotary pressing shaft is provided with a key protrusion, a blind hole of the second gear is provided with a key groove, and the key protrusion is matched with the key groove; the function is to make the rotation-pressing shaft and the second gear rotate synchronously.

Preferably, a positioning seat is fixed on the mounting table, a positioning groove is formed in the positioning seat, and the bottom part of the second gear is positioned in the positioning groove; the function is to avoid the second gear and the third gear from sliding relatively at the meshing surface to be disengaged.

Preferably, the straight pipe is not rotated and the welding gun is rotated by taking the straight pipe as an axis; the inner gear ring is fixed in position, the outer gear ring is arranged on the base, the driving motor is fixed on the base, the output shaft of the driving motor is fixed with a fourth gear, the fourth gear is meshed with the teeth of the outer gear ring, the outer gear ring can be driven to rotate through the driving motor, and then the welding gun is driven to rotate, and the matching surfaces of the plug and the straight pipe fitting are welded. The tooth width of the teeth is larger than the sum of the tooth widths of the fourth gear and the first gear, and the fourth gear and the first gear are staggered on the teeth; the driving motor connected with the fourth gear and the fixed connecting rod are positioned at the other side of the outer gear ring which is different from Shi Hanqiang.

Preferably, the teeth can be divided into two parts which are respectively meshed with the fourth gear and the first gear, and the middle is separated by a partition; the isolating function comprises the functions of strengthening the bearing capacity of the outer gear ring and separating the fourth gear from the first gear.

Preferably, a limiting protrusion is arranged on the base, and a limiting groove is arranged on the outer ring surface of the outer tooth ring, and the limiting protrusion is matched in the limiting groove; the function is to axially position the external gear ring.

The invention can be simultaneously applied to brazing and electric welding, and the difference is only the structural function of a welding gun: when brazing is adopted, shi Hanqiang extrudes brazing filler metal to a welding position, and liquid brazing filler metal fills a matching gap between the plug and the straight pipe so as to connect the plug and the straight pipe; when electric welding is adopted, a welding wire feeding structure and a protective gas spraying structure are matched, and the matching surfaces of the plugs and the straight pipe are melted and welded.

Preferably, the number of the Shi Hanqiang gears and the first gears is three, and a single Shi Hanqiang gear and the first gears form a group of linkage groups; a coaxial rotating shaft is arranged in the first gear, a ball joint is arranged on one side of the rotating shaft, and the welding gun penetrates through the ball joint and is used for limiting the position of the rotating shaft through connection with the welding gun; the clamping groove is arranged on the rotating shaft and matched with the clamping spring, so that the axial position of the first gear is limited; the welding efficiency is improved by times by arranging three groups of linkage groups, and for electric welding, the rotation amplitude of a single group of linkage groups is small to avoid winding of a wire feeding mechanism, and the welding efficiency is more important in that the effect of segmented welding is achieved, the internal stress of welding is reduced, and the occurrence probability of delayed cracks and reheat cracks is reduced.

Preferably, the straight pipe is coaxially provided with a temperature adjusting ring outside, and the temperature adjusting ring is connected to the inner toothed ring; the temperature-adjusting ring is used for electrifying and heating to change the temperature of the environment where the welding part is located, and can melt the brazing filler metal in the brazing process and perform preheating before welding and heat treatment after welding in the spot welding process.

Preferably, the inner annular surface of the inner tooth ring is fixedly connected with a ceramic pad, and the ceramic pad is used for realizing heat insulation of the inner tooth ring and reflecting heat to the straight pipe.

Preferably, the press-fit assembly further comprises a bottom table, a sliding rail and a second air cylinder are arranged on the bottom table, the mounting table is connected to the sliding rail, and an output rod of the second air cylinder is connected to the mounting table; the bottom of the base is arranged on the base table in a sliding way and is fixedly connected with the mounting table. The purpose is that change the restriction that first cylinder action range is little, increase two pressure equipment subassembly's interval, the manipulator of being convenient for can directly place the straight tube on placing the bench and realize automatic material loading and get the material.

The beneficial effects are that: compared with the prior art, the invention realizes synchronous press fitting and welding of plugs at two ends aiming at the original straight pipe, is applicable to brazing and electric welding, has high welding efficiency and ensures welding quality.

Drawings

Fig. 1: the structure of the invention is schematically shown;

fig. 2: a structural schematic diagram of the press-fit assembly;

fig. 3: a structural schematic diagram of a transfer welding assembly of a single-group welding gun is arranged;

fig. 4: a view of the transfer welding set in the structure of the base;

fig. 5: a structural schematic diagram of a transfer welding assembly provided with three groups of welding guns;

fig. 6: shi Hanqiang and the first gear;

in the figure: the welding machine comprises a placing table 1, a press-fitting assembly 2, a rotary welding assembly 3, an installing table 4, a plug 5, a clamping die system 6, a first cylinder 7, a rotary pressing shaft 8, a key boss 801, an outer tooth ring 9, a first tooth 901, a partition 902, a welding gun 10, an inner tooth ring 11, a first gear 12, a base 13, a limiting boss 131, a second gear 14, a driving motor 15, a third gear 16, a positioning seat 17, a fourth gear 18, a fixed connecting rod 19, a rotating shaft 20, a ball joint 21, a clamp spring 22, a temperature adjusting ring 23, a ceramic pad 24, a base table 25, a sliding rail 26, a second cylinder 27 and a straight pipe 28.

Detailed Description

A specific embodiment of the present invention will be described in detail with reference to fig. 1-6.

Referring to fig. 1, a double-end press-fitting welding device for pressing and welding plugs and synchronously at the end parts of a drying rack straight pipe fitting 28 comprises a placing table 1, a straight pipe fitting to be press-fitted and welded is placed on the placing table, press-fitting assemblies 2 are arranged at the two ends of the straight pipe fitting in a right-facing manner, and a rotary welding assembly 3 coaxial with the straight pipe fitting is further included.

Referring to fig. 2, the press-fitting assembly 2 includes an installation table 4, on which a clamping system 6 for clamping the plug 5 is disposed, and the press-fitting assembly mainly includes a clamping die sleeved in the clamping die sleeve, the plug 5 to be press-fitted is clamped by the clamping die, the clamping die system is not described too much in the embodiment of the prior art, a first air cylinder 7 is further fixed on the installation table 4, a pneumatic output port of the first air cylinder 7 is provided with a rotary press shaft 8, and the other end of the rotary press shaft 8 is connected with the clamping die system 6 to drive the clamping die system to act, including pushing the clamping die system to move, and press-fitting the plug 5 to the end of the straight pipe.

The transfer welding assembly 3 comprises an outer gear ring 9, a first tooth 901 is arranged on the inner annular surface of the outer gear ring 9, a welding gun 10 is fixed on one side facing the press-fit assembly 2, an inner gear ring 11 is coaxially arranged inside the outer gear ring 9, a second tooth is arranged on the outer annular surface of the inner gear ring 11, a first gear 12 meshed with the teeth is arranged between the outer gear ring 9 and the inner gear ring 11 in a circumferential array, and the first gear 12 plays a role of supporting the inner gear ring to keep the inner gear ring coaxial with the outer gear ring 9.

In this embodiment, the path to be welded after the plug and the straight pipe are pressed is in a circle shape, and the effect of one-time welding is achieved by adopting the action characteristic that the straight pipe and Shi Hanqiang have relative rotation.

Referring to fig. 2-3, in an embodiment 1, the straight pipe rotates to fix the position of the welding gun 10, and the specific scheme is as follows: the outer gear ring 9 is arranged on the base 13, and Shi Hanqiang is preferably arranged at the top position of the outer gear ring 9 to keep the position of the welding gun 10 fixed; the rotary pressing shaft 8 is synchronously and rotatably connected with a second gear 14, a driving motor 15 is fixed on the mounting table 4, a third gear 16 is rotatably connected to an output shaft of the driving motor 15, the second gear 14 is meshed with the third gear 16, and the rotary pressing shaft 8 is rotatably connected with the clamping system 6, so that the straight pipe fitting can rotate under the driving of the driving motor 15.

The action of the rotary pressing shaft 8 in the scheme comprises axial displacement under the air pressure of the first air cylinder 7 and rotation under the driving of the driving motor 15, and the synchronous rotation connection of the rotary pressing shaft 8 and the second gear 14 can adopt a key connection mode, for example, a key protrusion 801 is arranged on the rotary pressing shaft 8, a key groove is arranged in a blind hole of the second gear 14, and the synchronous rotation effect of the rotary pressing shaft 8 and the second gear 14 is achieved through the cooperation of the key protrusion 801 and the key groove.

Further, a positioning seat 17 is fixed on the mounting table 4, a positioning groove is formed in the positioning seat 17, the bottom portion of the second gear 14 is located in the positioning groove, the positioning groove is used for fixing the position of the third gear 16, and the rotating and pressing shaft 8 moves axially, so that the position of the third gear 16 can be limited, the second gear 14 and the third gear 16 are prevented from sliding relatively at the meshing surface to be disengaged, and at the moment, the rotating and pressing shaft 8 and the second gear 14 slide relatively in the key groove surface.

Referring to fig. 3-4, in another embodiment 2, the straight pipe is not rotated, and the welding gun 10 rotates around the straight pipe as an axis, and the specific scheme is as follows: the straight pipe is fixed at the position under the pressure of the press-fit assemblies 2 at the two sides; the inner gear ring 11 is fixed in position, the outer gear ring 9 is arranged on the base 13, a driving motor is also fixed on the base 13, a fourth gear 18 is fixed on an output shaft of the driving motor, the fourth gear 18 is meshed with the first teeth 901 of the outer gear ring 9, the outer gear ring 9 can be driven to rotate through the driving motor, and then the welding gun 10 is driven to rotate, so that the matching surfaces of the plug and the straight pipe fitting are welded.

It should be noted that, based on the fixed position of the inner gear ring 11, the fourth gear 18 and the first gear 12 are both meshed with the first teeth 901, and for realizing 360-degree welding, the welding gun 10 will rotate at least one circle, while the inner gear ring 11 is fixed in position, the meshing transmission makes the first gear 12 also rotate circumferentially, and for avoiding interference with the fourth gear 18, the tooth width of the first teeth 901 is greater than the sum of the tooth widths of the fourth gear 18 and the first gear 12, and the fourth gear 18 and the first gear 12 are dislocated on the first teeth 901; the inner gear ring 11 can be connected to the base 13 through a fixed connecting rod 19 in a fixed position; based on Shi Hanqiang rotation at least once, the drive motor connected to the fourth gear 18 and the fixed link 19 are located on the other side of the outer toothed ring 9 than Shi Hanqiang.

Preferably, the first teeth 901 can be divided into two parts respectively meshed with the fourth gear 18 and the first gear 12, the middle is separated by a partition 902, and the functions of the partition 902 include strengthening the bearing capacity of the outer gear ring 9 and separating the fourth gear 18 from the first gear 12.

The external tooth ring 9 is arranged on the base 13, the rotation freedom degree exists, the limiting boss 131 is arranged on the base 13, meanwhile, the limiting groove is formed in the outer ring surface of the external tooth ring 9, and the limiting boss 131 is matched in the limiting groove and is used for axially positioning the external tooth ring 9.

Both the embodiment 1 and the embodiment 2 can be simultaneously applied to brazing and electric welding, and the difference is only that the structural function of the welding gun 10 is applied, when the brazing is adopted, the Shi Hanqiang is used for extruding brazing filler metal to the welding part, and the liquid brazing filler metal fills the matching gap between the plug and the straight pipe so as to connect the plug and the straight pipe; when electric welding is adopted, a welding wire feeding structure and a protective gas spraying structure are matched, and the matching surfaces of the plugs and the straight pipe are melted and welded. The welding principle and structure of the brazing and electric welding are the prior art, and the embodiment is not described. When the embodiment 2 adopts electric welding, if the welding component 3 rotates too many cycles, the welding wire feeding structure has the problem of winding, so the embodiment 2 can adopt opposite rotation directions to eliminate when welding the front and rear straight pipe pieces; while embodiment 2 has the advantage over embodiment 1 that the rotation speed is easy to control, and the outer ring gear 9 can be controlled to rotate slowly through the gear ratio, so that the brazing or electric welding speed is stable, and the welding effect is better.

Referring to fig. 5-6, the number of the welding gun 10 and the first gear 12 is three, a single Shi Hanqiang and the first gear 12 form a group of linkage groups, a coaxial rotating shaft 20 is arranged in the first gear 12, and during the rotation of the first gear 12, on one hand, rotation taking a straight pipe as an axis and on the other hand, rotation taking the own axis as an axis caused by meshing exist, namely, relative rotation exists between the first gear 12 and the rotating shaft 20; a ball joint 21 is arranged on one side of the rotating shaft 20, the welding gun 10 penetrates through the ball joint, the function is to limit the position of the rotating shaft through connection with the welding gun 10, a clamping groove is formed in the rotating shaft 20, a clamping spring 22 is matched with the clamping groove, and the function is to limit the axial position of the first gear 12.

The three groups of linkage groups are arranged, so that the welding efficiency is improved in a multiplied manner, and particularly for electric welding, the rotation amplitude of the single group of linkage groups is small, the winding of a wire feeding mechanism is avoided, the effect of segmented welding is achieved, the symmetrical welding points are easy to reduce the internal stress of welding, and the occurrence probability of delayed cracks and reheat cracks is reduced.

Whether brazing or electric welding, requires heat treatment: for brazing, the brazing filler metal is required to be placed near or between joint gaps, the end part of the straight pipe and the plug are heated together with the brazing filler metal to a temperature slightly higher than the melting point of the brazing filler metal, the brazing filler metal is melted, the straight pipe and the plug are not melted, the brazing filler metal is sucked into and fills the gaps of the straight pipe and the plug by capillary action, the liquid brazing filler metal and the metal are mutually diffused and dissolved, and a brazing joint is formed after condensation, so that the welding is completed; for electric welding, the welding part needs to be preheated before welding, and heat treatment is needed to be carried out after welding so as to reduce delayed cracks and reheat cracks.

The temperature adjusting ring 23 is coaxially arranged outside the straight pipe fitting, the temperature adjusting ring 23 is connected to the inner toothed ring 11, and the temperature adjusting ring has the function that the temperature adjusting ring can be electrified and heated to change the temperature of the environment where the welding part is located, and can melt brazing filler metal in a brazing process and perform preheating before welding and heat treatment after welding in an electric welding process.

The inner ring surface of the inner gear ring 11 is fixedly connected with a ceramic pad 24, and the ceramic pad 24 has the functions of realizing heat insulation of the inner gear ring and reflecting heat to the straight pipe.

The press-fit assembly 2 further comprises a bottom table 25, a sliding rail 26 and a second air cylinder 27 are arranged on the bottom table 25, the mounting table 4 is connected to the sliding rail 26, an output rod of the second air cylinder 27 is connected to the mounting table 4, the second air cylinder 2 controls the mounting table 4 and parts arranged on the mounting table 4 to act, and the bottom of the base 13 is arranged on the bottom table 25 in a sliding manner and fixedly connected with the mounting table 4; the purpose is that change the restriction that first cylinder action range is little, increase the interval of two pressure equipment subassemblies 2, base 13 and mount table 4 synchronous motion for the straight tube is placed the controllable interval of two pressure equipment subassemblies 2 before placing the platform 1 and is greater than the length of straight tube, and the manipulator can directly place the straight tube and place on placing the platform 1 and realize automatic material loading and get the material, and the second cylinder 27 moves earlier after the straight tube is placed, advances base 13 and mount table 4, and the straight tube tip is located the welding subassembly 3 inside, and then the pressure equipment to the end cap is realized to first cylinder 7 action.

The invention realizes synchronous press fitting and welding of plugs at two ends of the original straight pipe, is applicable to brazing and electric welding, has high welding efficiency and ensures welding quality.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A straight pipe double-end press-fitting welding device is characterized by comprising

A placing table (1) for carrying straight pipe fittings;

the press-fitting assembly (2) is arranged at two ends of the straight pipe fitting in a right-facing manner and comprises an installation table (4), a clamping die system (6) for clamping the plug and a first air cylinder (7) are arranged on the installation table (4), a rotary pressing shaft (8) is arranged at a pneumatic output port of the first air cylinder (7), and the rotary pressing shaft (8) is connected with the clamping die system (6);

the transfer welding assembly (3) is coaxially arranged with the straight pipe and comprises an outer gear ring (9), a first tooth (901) is arranged on the inner ring surface of the outer gear ring (9) and a Shi Hanqiang (10) is fixed on one side facing the press-fit assembly (2), an inner gear ring (11) is coaxially arranged in the outer gear ring (9), a second tooth is arranged on the outer ring surface of the inner gear ring (11), and a first gear (12) is meshed between the outer gear ring (9) and the inner gear ring (11);

the straight pipe and the welding gun (10) rotate relatively;

the straight pipe rotates to fix the position of the welding gun (10); the outer gear ring (9) is arranged on the base (13), the rotary pressing shaft (8) is synchronously connected with a second gear (14) in a rotating way, a driving motor (15) is fixed on the mounting table (4), the output of the driving motor (15) is connected with a third gear (16), the second gear (14) is meshed with the third gear (16), and the rotary pressing shaft (8) is in non-rotating connection with the clamping die system (6); the rotary pressing shaft (8) is connected with the second gear (14) through a key, a key protrusion (801) is arranged on the rotary pressing shaft (8), a key groove is formed in a blind hole of the second gear (14), and the key protrusion (801) is matched with the key groove.

2. The double-ended press-fit welding device of claim 1, wherein:

a positioning seat (17) is fixed on the mounting table (4), a positioning groove is formed in the positioning seat (17), and the bottom part of the second gear (14) is positioned in the positioning groove.

3. The double-ended press-fit welding device of claim 2, wherein:

the straight pipe fitting does not rotate, and the welding gun (10) rotates by taking the straight pipe fitting as an axis;

the inner gear ring (11) is fixed in position, the outer gear ring (9) is arranged on the base (13), a driving motor is fixed on the base (13), a fourth gear (18) is fixed on an output shaft of the driving motor, and the fourth gear (18) is meshed with the first teeth (901) of the outer gear ring (9);

the tooth width of the first tooth (901) is larger than the sum of the tooth widths of the fourth gear (18) and the first gear (12), and the fourth gear (18) and the first gear (12) are staggered on the first tooth (901); the driving motor connected with the fourth gear (18) and the fixed connecting rod (19) are positioned at the other side of the outer gear ring (9) different from Shi Hanqiang (10).

4. The double-ended press-fit welding device of claim 3, wherein:

the first tooth (901) can be divided into two parts which are respectively meshed with the fourth gear (18) and the first gear (12), and the middle is separated by a partition (902).

5. The double-ended press-fit welding device of claim 4, wherein:

the base (13) is provided with a limiting protrusion (131), the outer ring surface of the outer gear ring (9) is provided with a limiting groove, and the limiting protrusion (131) is matched in the limiting groove.

6. The double-ended press-fit welding device of any one of claims 2-5, wherein:

the number of the Shi Hanqiang (10) and the first gears (12) is three, and a single Shi Hanqiang (10) and the first gears (12) form a group of linkage groups;

a coaxial rotating shaft (20) is arranged in the first gear (12), a ball joint (21) is arranged on one side of the rotating shaft (20), and the Shi Hanqiang (10) penetrates through the ball joint; the rotating shaft (20) is provided with a clamping groove and is matched with a clamping spring (22).

7. The double-ended press-fit welding device of claim 6, wherein:

the outside of the straight pipe fitting is coaxially provided with a temperature adjusting ring (23), and the temperature adjusting ring (23) is connected to the inner toothed ring (11).

8. The double-ended press-fit welding device of claim 7, wherein:

the inner ring surface of the inner gear ring (11) is fixedly connected with a ceramic pad (24).

9. The double-ended press-fit welding device of claim 8, wherein:

the press-fit assembly (2) further comprises a base table (25), a sliding rail (26) and a second air cylinder (27) are arranged on the base table (25), the mounting table (4) is connected to the sliding rail (26), and an output rod of the second air cylinder (27) is connected to the mounting table (4); the bottom of the base (13) is arranged on the bottom table (25) in a sliding way and is fixedly connected with the mounting table (4).