CN114750517A

CN114750517A - Pneumatic marking machine of accurate slender steel pipe model mark

Info

Publication number: CN114750517A
Application number: CN202210389770.4A
Authority: CN
Inventors: 孙兆松; 徐辉; 周飞; 吴立超
Original assignee: Xuzhou Global Precision Steel Tube Co ltd
Current assignee: Anhui Yuantong Precision Steel Pipe Co ltd; Xuzhou Global Precision Steel Tube Co ltd
Priority date: 2022-04-14
Filing date: 2022-04-14
Publication date: 2022-07-15
Anticipated expiration: 2042-04-14
Also published as: CN114750517B

Abstract

The invention relates to the technical field of marking machines, and discloses a pneumatic marking machine for marking models of precise slender steel pipes, which comprises a workbench, wherein a fixed seat is arranged in the middle of the top end of the workbench, a workpiece is placed above the fixed seat, concave rails are fixedly connected to two sides of the top end of the workbench, the concave rails are clamped with convex rods, pneumatic parts are fixedly connected to the top ends of the convex rods, marking parts are fixedly sleeved in the middle of the bottom ends of the pneumatic parts, and the marking parts mainly comprise outer shells, inner shells and marking needles. According to the invention, the limiting blocks are arranged on the side wall of the marking needle, and the limiting rollers and the limiting parts meshed with the limiting blocks are arranged on the wall surface of the inner shell, so that each limiting roller and the limiting part thereon synchronously rotate when the marking needle reciprocates under the pressure of gas, the integral height of the marking needle is ensured to be equal, the marking needle is prevented from deviating to one side due to vibration, the marking stability of the marking needle is effectively improved, and the marking position precision is ensured to be high.

Description

Pneumatic marking machine of accurate slender steel pipe model mark

Technical Field

The invention relates to the technical field of marking machines, in particular to a pneumatic marking machine for marking the model of a precise slender steel pipe.

Background

The steel pipe is an industrial metal material with wide application, and the steel pipe production industry is an important support for national economic development. The existing steel pipe production line comprises links such as length measurement, weighing, marking, coloring and label spraying, wherein the marking link is to mark marks or marks on the outer wall of the steel pipe so as to display relevant information such as material, model specification and the like of the steel pipe, the existing marking equipment generally adopts a pneumatic marking machine, the working principle is that the marks to be printed are input into a computer, the computer converts the content into digital control information through software and then transmits the digital control information to a controller, so that the marking head of the pneumatic marking machine is driven to move in multiple directions, and characters and patterns formed by continuous dot matrixes are marked on a steel pipe workpiece.

However, the existing pneumatic marking machine has some defects in the using process: firstly, the impact force generated by the dot matrix of the marking head is influenced, so that the marking head is easy to vibrate and deviate under the reverse action of a workpiece, and the marking position precision is poor; meanwhile, most of the marking heads are overheated due to continuous up-and-down output after working, and when the high-temperature marking heads have large impact force to impact a workpiece, the marking heads cannot guarantee that the marking heads cannot deform after being impacted when the hardness is reduced due to overheating, so that the marking heads cannot stably mark, the quality of produced products is reduced, and the service life of the products is shortened.

Disclosure of Invention

Aiming at the defects of the existing pneumatic marking machine in the use process in the background technology, the invention provides the pneumatic marking machine for the precise slender steel pipe model marks, which has the advantages of effectively reducing the surface temperature of a marking needle, prolonging the service life of the marking needle, simultaneously improving the marking stability of the marking needle and solving the technical problems in the background technology.

The invention provides the following technical scheme: a pneumatic marking machine for precise slender steel pipe model marks comprises a workbench, wherein a fixed seat is arranged in the middle of the top end of the workbench, a workpiece is placed above the fixed seat, concave rails are fixedly connected to two sides of the top end of the workbench and clamped with convex rods, a pneumatic piece is fixedly connected to the top ends of the convex rods, the marking piece is fixedly sleeved in the middle of the bottom end of the pneumatic piece and mainly comprises an outer shell, an inner shell and a marking needle, the inner shell is fixedly sleeved in the outer shell, the inner shell penetrates through the bottom end of the outer shell, a gas pipe is fixedly sleeved at the top end of the outer shell in the inner shell, a gas exhaust piece is fixedly sleeved at the bottom end of the outer shell outside the inner shell, a piston is movably sleeved in the inner shell, the bottom end of the piston is fixedly connected with the top end of the marking needle, and the bottom end of the marking needle penetrates through the bottom end of the inner shell, lie in the inside marking needle outer wall fixed connection stopper of interior casing, with the inner casing that the exhaust part corresponds the position has been seted up the cross bore, and the inner casing passes through cross bore and spacing post fixed connection, spacing roller is cup jointed in the outside activity of spacing post, the outside fixed connection locating part of spacing roller, and locating part and stopper meshing.

Preferably, the spout has been seted up to the inside of spacing post, and spacing post passes through spout and fly leaf swing joint, the fixed one-way pneumatic valve that cup joints of wall of fly leaf, through big spring coupling between fly leaf bottom lateral wall and the spout inner wall, the top both sides fixed connection air film of fly leaf, the fixed air ring that cup joints of wall of air film, the air ring is inside to cup joint with the one end activity of dead lever, and the other end of dead lever and the wall fixed connection of spacing post, is located the inside dead lever wall activity of air ring cup joints the rotating member, and the edge of rotating member contacts with the inner wall of air ring.

Preferably, the limiting part is provided with an outer air hole inside, the wall surface of the limiting roller corresponding to the position of the outer air hole is provided with an inner air hole, the limiting part positioned inside the outer air hole is provided with a movable groove, the limiting part is movably sleeved with the push plate through the movable groove, the side wall of the push plate is connected with the inner wall of the movable groove through a small spring, one side of the push plate close to the limiting roller is fixedly connected with one end of the power supply part, the other end of the power supply part is fixedly connected with the contact, one side of the push plate far away from the limiting roller is contacted with the pushing part, and the pushing part is movably sleeved on the side wall of the limiting part.

Preferably, the section of stopper is triangle-shaped, one the outer wall of marking the needle evenly is equipped with four groups of stoppers, and every group stopper quantity is the same, the height is the same, and a set of the stopper corresponds with a spacing roller.

Preferably, the quantity of fly leaf is two, and one is located the top of spacing post, one is located the below of spacing post, two the fly leaf homoenergetic is rotatory 40 degrees, the quantity of air film is two, is close to the fly leaf and the air film of marking the needle constitute the inner space, are close to the fly leaf and the air film of exhaust spare constitute outer space, are located the inner space and the outer space of the same cross section of spacing roller all have three gas ring, and the position of gas ring and outer gas port one-to-one.

Preferably, the fixing rod located in the middle of the limiting column and located inside the inner space is an electrified magnet with N-type magnetism, the two movable plates have N-type magnetism, and the magnetic attraction force between the two movable plates is smaller than the magnetic repulsion force between the movable plates and the fixing rod.

Preferably, the blades of the rotating part are designed to be an arc surface at one side and a plane at one side, and the arc surface side is close to the exhaust part and the plane side is close to the marking needle.

Preferably, the inclined angles of the two sides of the top end of the limiting part are the same as the inclined angle of the inclined plane of the limiting part, and two pushing parts are arranged in one limiting part and obliquely arranged in the limiting part.

Preferably, the pushing plate is provided with a plurality of small holes, one pushing plate, one power supply part and one contact form a group of power-on parts, and the limiting parts on the limiting rollers are electrified in a gap mode.

The invention has the following beneficial effects:

1. according to the invention, the limiting blocks are arranged on the side wall of the marking needle, and the limiting rollers and the limiting parts meshed with the limiting blocks are arranged on the wall surface of the inner shell, so that each limiting roller and the limiting part thereon synchronously rotate when the marking needle reciprocates under the pressure of gas, the integral height of the marking needle is ensured to be equal, the marking needle is prevented from deviating to one side due to vibration, the marking stability of the marking needle is effectively improved, and the marking position precision is ensured to be high.

2. According to the marking device, the air film, the fixed rod and the parts of the fixed rod are arranged in the limiting roller, when the limiting piece rotates to be positioned between the two limiting pieces, the pushing piece pushes the electrifying piece to be in contact with the fixed rod, so that the fixed rod is electrified to have N-type magnetism, the two movable plates are driven to rotate, the inner space of the limiting roller is increased, the air pressure is reduced, hot air around the marking needle is effectively sucked into the inner space, the surface temperature of the marking needle is reduced, and the service life of the marking needle is prolonged.

3. According to the invention, the volume of the outer space of the limiting roller is reduced when the two movable plates rotate, and the air in the limiting roller is exhausted into the exhaust part through the limiting part and then exhausted out of the outer shell, so that residual scraps around the workpiece are effectively cleaned, the influence of the scraps on the marking needle to carry out marking work is prevented, the heat in the marking piece is rapidly transferred out of the marking piece, the surface temperature of the marking needle is further effectively reduced, and the surface temperature of the marking needle is prevented from being aggravated due to the fact that the hot air in the limiting roller is stored and does not circulate.

Drawings

FIG. 1 is a front view of the overall structure of the present invention;

FIG. 2 is a schematic view of the internal structure of the marking part according to the present invention;

FIG. 3 is a schematic view of a partial structure of a position limiting roller according to the present invention;

FIG. 4 is an enlarged view of a portion of the structure shown in FIG. 3A according to the present invention;

FIG. 5 is an enlarged view of a portion of the structure shown at B in FIG. 3 according to the present invention;

fig. 6 is a schematic view of the top structure inside the outer shell at the height of the limiting roller in the present invention.

In the figure: 1. a work table; 11. a workpiece; 2. a pneumatic member; 21. marking a part; 3. an outer housing; 31. an inner housing; 32. an air tube; 33. an exhaust member; 4. marking a marking needle; 41. a piston; 42. a limiting block; 5. a limiting roller; 51. a limiting column; 52. a movable plate; 521. a one-way air valve; 6. a gas film; 61. a gas ring; 7. fixing the rod; 71. a rotating member; 8. a limiting member; 81. an outer air hole; 82. a pusher member; 9. a power supply element; 91. a push plate; 92. and (4) a contact.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the pneumatic marking machine for the precise slender steel pipe model marks comprises a workbench 1, wherein a fixed seat is arranged in the middle of the top end of the workbench 1, a workpiece 11 is placed above the fixed seat, concave rails are fixedly connected to two sides of the top end of the workbench 1 and clamped with a convex rod, a pneumatic piece 2 is fixedly connected to the top end of the convex rod, and a marking piece 21 is fixedly sleeved in the middle of the bottom end of the pneumatic piece 2.

Referring to fig. 2-3 and fig. 6, further, the marking member 21 mainly comprises an outer shell 3, an inner shell 31 and a marking needle 4, the inner portion of the outer shell 3 is fixedly sleeved with the inner shell 31, the inner shell 31 penetrates through the bottom end of the outer shell 3, the top end of the outer shell 3 inside the inner shell 31 is fixedly sleeved with an air pipe 32, the bottom end of the outer shell 3 outside the inner shell 31 is fixedly sleeved with an air exhaust member 33, the inner portion of the inner shell 31 is movably sleeved with a piston 41, the bottom end of the piston 41 is fixedly connected with the top end of the marking needle 4, the bottom end of the marking needle 4 penetrates through the bottom end of the inner shell 31, the outer wall of the marking needle 4 inside the inner shell 31 is fixedly connected with a limiting block 42 with a triangular section, an inclined plane between the two limiting blocks 42 can be effectively engaged with the limiting member 8, the inner shell 31 at a position corresponding to the air exhaust member 33 is provided with a transverse hole, and the inner shell 31 is fixedly connected with a limiting column 51 through the transverse hole, spacing roller 5 is cup jointed in spacing post 51's the outside activity, spacing roller 5's outside fixed connection locating part 8, and locating part 8 meshes with stopper 42, the top both sides inclination of locating part 8 is the same with stopper 42's inclined plane inclination, to sum up an outer wall of marking needle 4 evenly is equipped with four group's stopper 42, and every group stopper 42 quantity is the same, highly the same, a set of stopper 42 corresponds with a spacing roller 5, can mesh locating part 8 and stopper 42, make when marking needle 4 removes its each part of height, thereby effectively kept marking needle 4 holistic stability, prevent that it from beating skew when marking.

Referring to fig. 3-5, further, a sliding slot is formed in the limiting column 51, the limiting column 51 is movably connected to the two movable plates 52 with N-type magnetism through the sliding slot, the number of the movable plates 52 is two, one movable plate is located above the limiting column 51, and the other movable plate is located below the limiting column 51, both the two movable plates 52 can rotate 40 degrees, that is, the upper movable plate 52 can rotate 40 degrees counterclockwise from the top center of the limiting column 51, and the lower movable plate 52 can rotate 40 degrees clockwise from the bottom center of the limiting column 51, so that the original volume with the same inner and outer spaces is changed into a state with a large inner space and a small outer space, and the air around the marking needle 4 is sucked into the inner space and discharged out of the outer space, the wall surface of the movable plate 52 is fixedly sleeved with a one-way air valve 521, so that the air inside the inner space can move towards the outer space when the inner space is reduced and the outer space is enlarged, therefore, the air with heat inside the limiting roller 5 is effectively transferred, the side wall at the bottom end of the movable plate 52 is connected with the inner wall of the sliding chute through the large spring, the air film 6 is fixedly connected with two sides of the top end of the movable plate 52, the number of the air films 6 is two, the movable plate 52 close to the marking needle 4 and the air film 6 form an inner space, the movable plate 52 close to the exhaust part 33 and the air film 6 form an outer space, the inner space and the outer space are arranged to enable the limiting roller 5 to have simultaneous air suction and exhaust operations, so that the surface stability of the marking needle 4 is effectively reduced, the scraps on the workpiece 11 are effectively cleaned, the air ring 61 is fixedly sleeved on the wall surface of the air film 6, namely, the inner space and the outer space which are positioned on the same cross section of the limiting roller 5 are respectively provided with three air rings 61, the positions of the air rings 61 correspond to the outer air holes 81 when the limiting pieces 8 rotate between the two limiting pieces 42 one by one, and the outer part and the inner part of the limiting piece 5 can be driven to rotate between the two limiting pieces 42 when the limiting pieces 8 rotate between the two limiting pieces 42, The outer space is communicated to promote the air flow and transfer, the inner part of the air ring 61 is movably sleeved with one end of the fixed rod 7, the other end of the fixed rod 7 is fixedly connected with the wall surface of the limiting column 51, the fixed rod 7 which is positioned in the middle of the limiting column 51 and is positioned in the inner space is an electrified magnet with N-type magnetism, the magnetic attraction force between the two movable plates 52 is smaller than the magnetic repulsion force between the movable plates 52 and the fixed rod 7, when the fixed rod 7 is not electrified, the two movable plates 52 keep the two movable plates 52 in a vertical state under the action of the magnetic repulsion force and large spring elasticity, namely, the upper movable plate 52 is positioned at the top center of the limiting column 51, and the lower movable plate 52 is positioned at the bottom center of the limiting column 51, so that the volumes of the inner space and the outer space are kept the same, and when the fixed rod 7 is electrified, the two movable plates 52 rotate under the action of the magnetic repulsion force of the fixed rod 7, so that the inner space is increased in volume, The outer space volume reduces, thereby make the interior production of spacing roller 5 breathe in and the exhaust operation, the dead lever 7 wall activity that is located the inside of gas ring 61 cup joints rotating member 71, and the edge of rotating member 71 and the inner wall contact of gas ring 61, the blade of rotating member 71 is one side cambered surface simultaneously, the planar design of one side, and the cambered surface side is close to air discharge member 33, the plane side is close to and beats mark needle 4, make and beat mark needle 4 surperficial air can be fast outside by discharge shell body 3, and then realize thermal transfer.

Referring to fig. 3-5, further, the inside of the position-limiting member 8 is provided with an external air hole 81, the wall surface of the position-limiting roller 5 corresponding to the position of the external air hole 81 is provided with an internal air hole, the position-limiting member 8 located inside the external air hole 81 is provided with a movable groove, the position-limiting member 8 is movably sleeved with a push plate 91 through the movable groove, the push plate 91 is provided with a plurality of small holes, so that air from the outside of the position-limiting member 8 can enter the position-limiting roller 5 through the push plate 91, thereby promoting the heat transfer on the surface of the marking pin 4, the side wall of the push plate 91 is connected with the inner wall of the movable groove through a small spring, one side of the push plate 91 close to the position-limiting roller 5 is fixedly connected with one end of the power supply member 9, and the other end of the power supply member 9 is fixedly connected with a contact 92, that is a group of power supply members formed by one push plate 91, one power supply member 9 and one contact 92, the position-limiting members 8 located on the position-limiting roller 5 are provided with power supply members at intervals, that is, the current-carrying parts are not arranged in the position-limiting parts 8 at both sides of the position-limiting part 8 with the current-carrying parts, so that the interval between the on-off state and the on-off state of the fixing rod 7 is long when the position-limiting part 8 is driven by the position-limiting part 42 to rotate, and thus when the marking needle 4 moves rapidly, the parts in the inner space and the outer space can perform the air suction and exhaust work normally, one side of the push plate 91 far away from the position-limiting roller 5 is in contact with the push part 82, and the push part 82 is movably sleeved on the side wall of the position-limiting part 8, that is, two push parts 82 are arranged in one position-limiting part 8, and the push part 82 is obliquely arranged in the position-limiting part 8, so that the push part 82 is retracted in the position-limiting part 8, and further makes the push part 82 contact with the push plate 91 and pushes the push plate 91 to move, and the current-carrying of the fixing rod 7 is realized.

Fig. 3 is an integral state diagram of the inside of the limiting roller 5 and the limiting member 8 when the limiting member 8 is engaged with the limiting member 42, specifically, fig. 4 is an internal structure diagram of the middle limiting member 8 inside the external space, at this time, the small spring pushes the energizing member to move outward, so that the contact 92 is not contacted with the fixing rod 7, and meanwhile, the pushing member 82 is pushed by the pushing plate 91 and partially extends out of the limiting member 8; fig. 5 is an internal structure view of the middle position limiting member 8 inside the inner space, at this time, the pushing member 82 is abutted by the limiting member 42, so that the pushing member moves and retracts inside the limiting member 8, and pushes the electrifying member to move to the side of the limiting roller 5, so that the contact 92 is contacted with the fixing rod 7, and the fixing rod 7 is electrified to have N-type magnetism, thereby changing the inner space and the outer space, and realizing the transfer of hot air.

The using method of the invention has the following working principle:

the workpiece 11 is placed on a fixed seat of the workbench 1, the pneumatic piece 2 is started, the marking piece 21 marks the surface of the workpiece 11, in the process, the pneumatic piece 2 repeatedly enters and exits the inner shell 31 through the air pipe 32, the marking needle 4 and parts thereof are pushed, the limit pieces 42 are meshed with the limit pieces 8 at the moment, the limit rollers 5 and the limit pieces 8 are pushed to rotate, the stability of the marking needle 4 in marking is ensured, the marking precision is prevented from being poor due to vibration, meanwhile, when the side wall between the limit pieces 42 is not contacted with the limit pieces 8 with the power-on pieces, the fixed rod 7 with N-type magnetism is not powered, the two movable plates 52 are in a vertical state due to the action of the magnetic repulsion force of the two movable plates, the volumes of the inner space and the outer space are the same, when the limit pieces 8 with the power-on pieces rotate to the two limit pieces 42, the pushing pieces 82 are pressed by the side wall of the limit pieces 42 to retract and push the pushing plate 91 to move towards the limit rollers 5 side, the contact 92 is contacted with the fixed rod 7, so that the power supply part 9 is electrified to the fixed rod 7 and causes the fixed rod to have N-type magnetism, the two movable plates 52 rotate under the action of the magnetic repulsion force of the fixed rod 7, the volume of the inner space is enlarged, the volume of the outer space is reduced, the air pressure of the inner space is reduced, the hot air on the surface of the marking needle 4 positioned outside the limiting roller 5 is driven to be sucked into the inner space, the temperature on the surface of the marking needle 4 is effectively reduced, the air pressure of the outer space is increased, the air in the inner space is exhausted through the air ring 61, the inner air hole and the outer air hole 81 and is exhausted outside the outer shell 3 through the exhaust part 33, therefore, the waste scraps generated by the workpiece 11 are effectively cleaned, the marking needle 4 is prevented from being hindered from working, when the limiting block 42 is separated from the limiting part 8 with the electrified part, the electrified part integrally moves outwards, the contact 92 is not contacted with the fixed rod 7, and the fixed rod 7 is powered off, two fly leaves 52 receive magnetic repulsion and the instantaneous rotation of big spring tension effect between the two to return original vertical state, in this process, because the rotatory gas ring 61 of spacing roller 5 is sheltered from by the spacing roller 5 wall of rotation, and then make the interior, outer space be the encapsulated situation, thereby hot air atmospheric pressure in the inner space opens one-way pneumatic valve 521 and makes it shift to outer space, lay the basis for the discharge of follow-up hot air, to sum up, one side of spacing roller 5 breathes in, the carminative operation of one side effectively promotes the heat transfer on marking needle 4 surface, reduce the temperature of marking needle 4, thereby improve the precision of marking needle 4 marks.

It should be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a pneumatic marking machine of accurate long and thin steel pipe model mark, includes workstation (1), the top middle part of workstation (1) is equipped with the fixing base, and places work piece (11) in the top of fixing base, the concave rail of top both sides fixedly connected with of workstation (1), and concave rail and nose bar joint, the top fixed connection pneumatic part (2) of nose bar, the fixed marking piece (21), its characterized in that cup joints in the bottom middle part of pneumatic part (2): the marking part (21) mainly comprises an outer shell (3), an inner shell (31) and a marking needle (4), wherein the inner fixed sleeve of the outer shell (3) is connected with the inner shell (31), the inner shell (31) penetrates through the bottom of the outer shell (3), a gas pipe (32) is fixedly connected with the top end of the outer shell (3) in the inner shell (31), an exhaust part (33) is fixedly connected with the bottom end of the outer shell (3) outside the inner shell (31), a piston (41) is movably sleeved in the inner shell (31), the bottom end of the piston (41) is fixedly connected with the top end of the marking needle (4), the bottom end of the marking needle (4) penetrates through the bottom end of the inner shell (31), a limiting block (42) is fixedly connected with the outer wall of the marking needle (4) in the inner shell (31), and a transverse hole is formed in the inner shell (31) at the position corresponding to the exhaust part (33), and interior casing (31) pass through cross bore and spacing post (51) fixed connection, spacing roller (5) are cup jointed in the outside activity of spacing post (51), the outside fixed connection locating part (8) of spacing roller (5), and locating part (8) and stopper (42) meshing.

2. The pneumatic marking machine for the precise slender steel pipe type marks as claimed in claim 1, characterized in that: the inside of spacing post (51) has been seted up the spout, and spacing post (51) are through spout and fly leaf (52) swing joint, the fixed one-way pneumatic valve (521) that cup joints of wall of fly leaf (52), through big spring coupling between fly leaf (52) bottom lateral wall and the spout inner wall, the top both sides fixed connection air film (6) of fly leaf (52), air ring (61) are cup jointed to the wall fixation of air film (6), the inside one end activity with dead lever (7) of air ring (61) is cup jointed, and the other end of dead lever (7) and the wall fixed connection of spacing post (51), are located rotating member (71) are cup jointed in dead lever (7) wall activity of air ring (61) inside, and the edge of rotating member (71) and the inner wall contact of air ring (61).

3. The pneumatic marking machine for the precise slender steel pipe type marks as claimed in claim 2, characterized in that: the inner part of the limiting piece (8) is provided with an outer air hole (81), the wall surface of the limiting roller (5) corresponding to the position of the outer air hole (81) is provided with an inner air hole, the limiting piece (8) positioned in the outer air hole (81) is provided with a movable groove, the limiting piece (8) is movably sleeved with the pushing plate (91) through the movable groove, the side wall of the pushing plate (91) is connected with the inner wall of the movable groove through a small spring, one side of the pushing plate (91) close to the limiting roller (5) is fixedly connected with one end of the power supply piece (9), the other end of the power supply piece (9) is fixedly connected with the contact (92), one side of the pushing plate (91) far away from the limiting roller (5) is contacted with the pushing piece (82), and the pushing piece (82) is movably sleeved on the side wall of the limiting piece (8).

4. The pneumatic marking machine for the precise slender steel pipe type marks as claimed in claim 3, characterized in that: the section of stopper (42) is triangle-shaped, one the outer wall of marking needle (4) evenly is equipped with four groups of stopper (42), and every group stopper (42) quantity the same, the height the same, a set of stopper (42) correspond with a spacing roller (5).

5. The pneumatic marking machine for the precise slender steel pipe type marks as claimed in claim 2, characterized in that: the quantity of fly leaf (52) is two, and one is located the top of spacing post (51), one is located the below of spacing post (51), two fly leaf (52) homoenergetic is rotatory 40 degrees, the quantity of air film (6) is two, is close to fly leaf (52) and air film (6) of marking needle (4) constitute the inner space, are close to fly leaf (52) and air film (6) of exhaust (33) constitute the outer space, are located the inner space and the outer space of the same cross section of spacing roller (5) all have three gas ring (61), and the position and the outer gas pocket (81) one-to-one of gas ring (61).

6. The pneumatic marking machine for the precise slender steel pipe type marks as claimed in claim 5, characterized in that: the fixing rod (7) which is located inside the inner space and located in the middle of the limiting column (51) is a powered magnet with N-type magnetism, the two movable plates (52) have N-type magnetism, and magnetic attraction force between the two movable plates (52) is smaller than magnetic repulsion force between the movable plates (52) and the fixing rod (7).

7. The pneumatic marking machine for the precise slender steel pipe type marks as claimed in claim 6, characterized in that: the blades of the rotating piece (71) are designed to be an arc surface at one side and a plane at one side, and the arc surface side is close to the exhaust piece (33) and the plane side is close to the marking needle (4).

8. The pneumatic marking machine for the precise slender steel pipe type marks as claimed in claim 7, characterized in that: the inclined angles of two sides of the top end of each limiting part (8) are the same as the inclined angle of the inclined plane of each limiting part (42), two pushing parts (82) are arranged in one limiting part (8), and the pushing parts (82) are obliquely arranged in the limiting parts (8).

9. The pneumatic marking machine for the precise slender steel pipe type marks as claimed in claim 8, characterized in that: the pushing plate (91) is provided with a plurality of small holes, one pushing plate (91), one power supply part (9) and one contact (92) form a group of power-on parts, and the power-on parts are arranged on the limiting parts (8) on the limiting roller (5) at intervals.