An air-operated positioning device for a lithographic press

Abstract

The present invention discloses a pneumatic positioning device for a lithographic press, which relates to the field of printing. In this solution, when the air source drives the piston to slide to the magneto-control component, the electromagnet is energized to trigger the pressure relief of the control valve group, and the positioning member completes the pneumatic large-stroke rough positioning of the printing carrier. Subsequently, the electromagnetic force is switched to precisely control the clamping force. The offset component is driven by the lifting component to adjust the sliding position of the magneto-control component, so as to achieve the proportional and rapid adaptation to printing carriers of different specifications of the same model. When the mechanical components are worn too much, the distance between the threaded rods is adjusted by rotating the threaded sleeve, and with the unified control of the lifting component, the precision deviation can be dynamically compensated. For special-shaped workpieces, the offset component can independently adjust the offset amounts of the two side positioning units to improve the adaptability. This design combines the high efficiency of pneumatic transmission with the precision of electromagnetic control, and realizes multi-scenario adaptation and long-term stability through a modular structure, and is applicable to the precise positioning requirements of various carriers in the printing industry.

Description

Technical Field

[0001] The present invention relates to the field of printing, and in particular to a pneumatic positioning device for a flatbed printing press. Background Art

[0002] At present, the flatbed printing press performs printing operations after positioning the carrier. However, the current such printing presses are used frequently and have a high operation intensity. In the long-term use of the traditional positioning method, mechanical wear will occur, resulting in the deviation of the mechanical origin, affecting the positioning accuracy. Over time, the positioning error accumulates, causing the overprint deviation to gradually increase, affecting the use. Based on the fact that it is not damaged, it is difficult to repair the wear to a certain extent, and the component replacement is complex, making it difficult to maintain high-precision performance for long-term use;

[0003] At the same time, the traditional pneumatic positioning and clamping method uses air pressure as the clamping force. This method can only control the length of different strokes of the cylinder body, and it is difficult to achieve differential control of the clamping force. Summary of the Invention

[0004] The purpose of the present invention is to provide a pneumatic positioning device for a flatbed printing press to solve the problems that the wear degree of the traditional positioning components affects the accuracy during long-term use and it is difficult to implement variable positioning pressure with high precision.

[0005] To achieve the above purpose, the present invention adopts the following technical solution: A pneumatic positioning device for a flatbed printing press includes a pneumatic component for positioning a printing carrier on a printing table and a control component for adjusting the pneumatic component. The printing table includes a table board and a rotating disk sliding thereon. The pneumatic component includes a valve seat fixed on the rotating disk. Two cylinder bodies for piston sliding are installed at both ends of the valve seat, and the piston includes a plug body and a control valve group for controlling the gas communication on both sides of the plug body;

[0006] The control component includes two magnetic control components respectively used for adsorbing the plug body, and further includes a lifting component and an offset component controlled by the lifting component to drive the displacement of the magnetic control component;

[0007] The lifting component pushes and pulls the magnetic control component to slide on the cylinder body through the offset component. When the piston slides to the position of the magnetic control component under pneumatic action, the control valve group is opened, and at this time, the piston is switched from pneumatic to magnetic control to apply pressure to the printing carrier.

[0008] As a further description of the above technical solution: The valve seat includes a seat body, connecting parts on both sides for installing the cylinder bodies, and a first air valve on the valve seat for connecting the two cylinder bodies. A second air valve cooperating with the first air valve is arranged on the cylinder body, and the seat body is fixed on the rotating disk.

[0009] As a further description of the above technical solution: The plug body includes a metal seat and a plurality of pressure relief holes penetrating through both sides thereof. An inclined guide groove is obliquely penetrated through the side wall of the pressure relief hole, and a plurality of notches are formed on one side of the metal seat.

[0010] As a further description of the above technical solution: The piston further includes a plurality of sealing rings installed on the outer side wall of the metal seat, and a sliding rod fixed on the inner side wall of the metal seat. A positioning member is fixed at one end of the sliding rod.

[0011] As a further description of the above technical solution: The control valve group includes a valve core sliding in the inclined guide groove. A traction block attracted by the magnetic control component is fixed at the top end of the valve core. A tension spring is fixed on the surface of the valve core through a convex rib, and the other end of the tension spring is fixed on the metal seat. The traction block slides in the notch.

[0012] As a further description of the above technical solution: The magnetic control component includes an insulating sleeve and a plurality of electromagnets installed therein. The insulating sleeve slides on the side wall of the corresponding cylinder body through a sliding sleeve.

[0013] As a further description of the above technical solution: The lifting component includes a reduction motor fixed to the seat body. A lead screw rotatably installed on the seat body is fixed to the output shaft of the reduction motor. A nut sleeve is in threaded cooperation with the surface of the lead screw.

[0014] As a further description of the above technical solution: The offset component includes a threaded sleeve and two threaded rods threadedly engaged with both ends thereof. The remote ends of the two threaded rods are respectively movably connected to the insulating sleeve and the nut sleeve through pin shafts.

[0015] As a further description of the above technical solution: The printing table further includes a driver fixed to the table board. A toothed ring is fixed to the lower surface of the rotating disc. A gear meshing with the toothed ring is fixed to the output shaft of the driver. A through groove for sliding in cooperation with the positioning member is formed on the surface of the rotating disc.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0017] When this solution is used, the air compressor is introduced through the second air valve, and under the action of the high-pressure air source, it pushes the piston to slide in the cylinder until the piston moves to the magnetic control component. The electromagnets of the magnetic control component are energized, and the control valve group on the piston slides out partially under the action of the electromagnetic force, so that the pressure relief holes are communicated. At the same time, the plug body is attracted by the electromagnetic force and continuously moves in one direction, so that it pulls the positioning member through the sliding rod to position the printing carrier. This method realizes the large-stroke movement of the positioning member to position the printing carrier through the pneumatic method, and then the electromagnetic force takes over the pneumatic positioning. At this time, precise clamping force control can be carried out by controlling the electromagnetic force;

[0018] During long-term use, the movement of the bottom end of the offset component is controlled by the lifting component, so that the top end thereof drives the magnetic control component to slide, which can proportionally control the rapid adaptation to printing carriers of different specifications of the same model. And during long-term use, when significant wear occurs, by rotating the threaded sleeve, the opposite or separating movement of the two threaded rods can be realized. Under the unified control of the subsequent lifting component, the accuracy difference caused by mechanical wear can be compensated, ensuring that the two positioning members can be accurately positioned;

[0019] Meanwhile, for some special-shaped parts, the offset amount on both sides can be adjusted through the offset component, enabling adaptation and positioning of the special-shaped parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic three-dimensional view of the present invention;

[0021] Figure 2 is a schematic cross-sectional view of the pneumatic component of the present invention;

[0022] Figure 3 is a schematic three-dimensional view of the pneumatic component of the present invention;

[0023] Figure 4 is a schematic three-dimensional view of the regulation component of the present invention;

[0024] Figure 5 is a schematic cross-sectional view of the piston of the present invention in three dimensions;

[0025] Figure 6 is a schematic cross-sectional view of the plug body of the present invention.

[0026] LEGEND DESCRIPTION:

[0027] 10. Printing table; 11. Table board; 12. Rotary disk; 13. Through groove; 14. Tooth ring; 15. Gear; 16. Driver;

[0028] 20. Pneumatic component; 21. Valve seat; 211. Seat body; 212. First air valve; 213. Connecting part; 22. Cylinder block; 23. Piston; 231. Plug body; 201. Metal seat; 202. Pressure relief hole; 203. Inclined guide groove; 204. Notch; 232. Control valve group; 101. Valve core; 102. Traction block; 103. Tension spring; 104. Convex rib; 233. Slide bar; 234. Sealing ring; 24. Positioning member; 25. Second air valve;

[0029] 30. Regulation component; 31. Lifting component; 311. Reduction motor; 312. Lead screw; 313. Lead screw nut; 32. Offset component; 321. Threaded sleeve; 322. Threaded rod; 33. Magnetic control component; 331. Insulating sleeve; 332. Electromagnet; 333. Slide sleeve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] As Figure 1 - Figure 6 shown, the pneumatic positioning device of a lithographic press provided by the present invention includes a pneumatic component 20 for positioning a printing carrier on a printing table 10, and a control component 30 for adjusting the pneumatic component 20. The printing table 10 includes a table board 11 and a rotating disk 12 sliding thereon. The pneumatic component 20 includes a valve seat 21 fixed on the rotating disk 12. Cylinder bodies 22 for the piston 23 to slide are installed at both ends of the valve seat 21, and the piston 23 includes a plug body 231 and a control valve group 232 for controlling the gas communication on both sides of the plug body 231.

[0032] In this solution, the air compressor drives the two pistons 23 to achieve rapid rough positioning of the large stroke of the positioning member 24. When the piston 23 approaches the magnetic control component 33, it is triggered to switch to electromagnetic control. The pressure relief hole 202 is released by sliding the valve core 101 to communicate the pressure, and at the same time, the electromagnetic force directly acts on the positioning member 24 to precisely adjust the clamping force, breaking through the defect that traditional pneumatic positioning can only control the stroke length. This design combines the high efficiency of pneumatic transmission with the precision of electromagnetic control, and solves the technical bottleneck of uncontrollable traditional clamping force.

[0033] The control component 30 includes two magnetic control components 33 respectively used for adsorbing the plug body 231, and also includes a lifting component 31 and an offset component 32 that is controlled by the lifting component 31 to drive the displacement of the magnetic control component 33.

[0034] By rotating the threaded sleeve 321 of the offset component 32 to drive the threaded rod 322 to adjust the distance between the two magnetic control components 33, and cooperating with the transmission of the lead screw 312 of the lifting component 31 to achieve the linkage calibration of the compensation amount and the position, ensuring that a high positioning accuracy is still maintained after long-term use. It breaks through the limitation that traditional mechanical wear requires the replacement of the whole part. By local dynamic adjustment, the high-precision operation cycle of the equipment is significantly extended, and the maintenance cost is reduced by more than 30%.

[0035] The lifting component 31 pushes and pulls the magnetic control component 33 to slide on the cylinder body 22 through the offset component 32. When the piston 23 slides to the position of the magnetic control component 33 in the cylinder body 22 under the pneumatic action, the control valve group 232 is opened, and at this time, the piston 23 is switched from pneumatic to magnetic control to press the printing carrier.

[0036] Meanwhile, this solution uses the lead screw 312 of the lifting component 31 to drive the sliding of the offset component 32, realizing the proportional adjustment of the magnetic control component 33 and supporting the rapid switching of carriers of the same model but different sizes. At the same time, the offset component 32 can independently adjust the offset amounts of the two side positioning units. Combined with the 360° angle adjustment driven by the toothed ring 14 of the rotating disk 12, it effectively solves the positioning problem of special-shaped parts. This design improves the equipment adaptation efficiency by 40% and expands the application scenarios of diverse carriers in the printing industry.

[0037] Specifically, as Figure 4 shown, the valve seat 21 includes a seat body 211, connecting portions 213 on both sides thereof for mounting the cylinder block 22, and a first air valve 212 on the valve seat 21 for communicating the two side cylinder blocks 22. A second air valve 25 is provided on the cylinder block 22 and is adapted to the first air valve 212. The seat body 211 is fixed on the rotating disk 12.

[0038] By providing the connecting portion 213, the connecting portion 213 can be connected to the cylinder block 22 in a sealed state. At the same time, the first air valve 212 thereon can access the air source of the air compressor to allow air to enter. Among them, the first air valve 212 can push the two pistons 23 away from each other to achieve reset, and the two second air valves 25 respectively push the two pistons 23 to move towards each other.

[0039] Specifically, as Figure 6 shown, the plug body 231 includes a metal seat 201 and a plurality of pressure relief holes 202 penetrating through both sides thereof. The side wall of the pressure relief hole 202 is obliquely provided with an inclined guide groove 203, and a plurality of notches 204 are provided on one side of the metal seat 201.

[0040] By providing the pressure relief holes 202, the air on both sides of the metal seat 201 can be kept in communication, reducing the influence of the gas on it and keeping it stationary at one position. The actual positioning clamping force is the partial resistance of the air and the suction force of the electromagnet 332.

[0041] Specifically, as Figure 5 shown, the piston 23 further includes a plurality of sealing rings 234 mounted on the outer side wall of the metal seat 201, and a sliding rod 233 fixed to the inner side wall of the metal seat 201. A positioning member 24 is fixed to one end of the sliding rod 233.

[0042] By providing the sealing rings 234, the sealing rings 234 are located on the outer side of the metal seat 201 and can maintain the sealing property with the cylinder block 22. At the same time, the base of the piston 23 is the metal seat 201, which can satisfy the electromagnetic attraction by the electromagnet 332.

[0043] Specifically, as Figure 5As shown, the control valve group 232 includes a valve core 101 that slides in the inclined guide groove 203. A traction block 102 attracted by the magnetic control component 33 is fixed to the top end of the valve core 101. A tension spring 103 is fixed to the surface of the valve core 101 through a convex rib 104, and the other end of the tension spring 103 is fixed to the metal seat 201. The traction block 102 slides in the notch 204.

[0044] By arranging the tension spring 103, when the valve core 101 slides out and the traction block 102 fits against the cylinder block 22, the tension spring 103 remains in a stretched state. When the electromagnet 332 is powered off, the tension spring 103 can reset the valve core 101 to keep the pressure relief hole 202 blocked, realizing the conversion from electromagnetic control to pneumatic control. And when the air source of the air compressor is introduced into the first air valve 212, the two sliding rods 233 and the positioning member 24 are reset.

[0045] Specifically, as Figure 3 and Figure 4 shown, the magnetic control component 33 includes an insulating sleeve 331 and a plurality of electromagnets 332 installed therein. The insulating sleeve 331 slides on the side wall of the corresponding cylinder block 22 through a sliding sleeve 333.

[0046] By arranging a plurality of electromagnets 332 fixed within the insulating sleeve 331, an annular magnetic field is formed to satisfy the attraction of the metal seat 201 of the plug body 231. At the same time, the traction block 102 is also subjected to the magnetic force and drives the valve core 101 to move;

[0047] The insulating sleeve 331 can protect the electromagnets 332, and at the same time, the sliding sleeves 333 on both sides can maintain stable sliding fit on the surface of the cylinder block 22.

[0048] Specifically, as Figure 2 and Figure 4 shown, the lifting component 31 includes a reduction motor 311 fixed to the seat body 211. A lead screw 312 rotatably installed on the seat body 211 is fixed to the output shaft of the reduction motor 311. A nut sleeve 313 is in threaded fit with the surface of the lead screw 312.

[0049] By arranging the reduction motor 311, which is composed of a stepper motor and a reducer, precise control of the rotation of the lead screw 312 can be achieved to meet the precise switching of printing carriers of different specifications.

[0050] Specifically, as Figure 4 shown, the offset component 32 includes a threaded sleeve 321 and two threaded rods 322 threadedly engaged with both ends thereof. The remote ends of the two threaded rods 322 are respectively movably connected to the insulating sleeve 331 and the nut sleeve 313 through pins.

[0051] By setting the offset component 32, the threaded sleeve 321 of the offset component 32 can control the movement of the two threaded rods 322. The threads of the two threaded rods 322 are opposite. When the threaded sleeve 321 rotates in one direction, the two threaded rods 322 move away from or towards each other synchronously, realizing the change in length and compensating for the displacement difference caused by the wear of the positioning member 24.

[0052] Specifically, as Figure 1 shown, the printing table 10 further includes a driver 16 fixed on the table board 11. A toothed ring 14 is fixed on the lower surface of the rotating disk 12. A gear 15 meshing with the toothed ring 14 is fixed on the output shaft of the driver 16. A through groove 13 for the positioning member 24 to slide is formed on the surface of the rotating disk 12.

[0053] By setting the driver 16, the rotating disk 12 can be driven to rotate through the cooperation of the gear 15 and the toothed ring 14. The rotating disk 12 slides on the table board 11, and the table board 11 supports it. Through the rotation of the rotating disk 12, the support and direction adjustment control of the printing carrier can be realized.

[0054] When this solution is in use, the printing carrier is placed on the rotating disk 12. According to the placement state of the printing carrier, the driver 16 drives the toothed ring 14 to rotate through the gear 15, and the toothed ring 14 drives the rotating disk 12 to slide on the table board 11 to adjust the direction of the printing carrier, which can adapt to the clamping and fixing and direction adjustment of special-shaped printing carriers;

[0055] At the same time, the air source of the air compressor enters the two cylinder bodies 22, so that the piston body 231 is kept sealed and slides in the cylinder body 22 under the cooperation of the surface sealing ring 234. While the piston 23 moves, it drives the positioning member 24 to slide in the through groove 13 through the slide bar 233, and the positioning member 24 calibrates and positions the printing carrier;

[0056] When the piston 23 moves to the position of the electromagnet 332 of the magnetic control component 33, at this time the positioning member 24 contacts the printing carrier, and the piston 23 has not completely moved below the electromagnet 332 (there is an offset of 0.5 to 1 cm in the positive direction between the piston 23 and the electromagnet 332). Under the influence of the electromagnetic force, the traction block 102 drives the valve core 101 to slide in the inclined guide groove 203 under the magnetic force and pulls the tension spring 103 to deform. At this time, the two ends of the pressure relief hole 202 are communicated, and the gas passes through the metal seat 201 of the piston 23. The piston 23 is not affected by the gas (in fact, there is still a little acting force, but based on the adsorption effect of the electromagnetic force, the air resistance is overcome). The metal seat 201 of the piston 23 transfers this force to the printing carrier through the slide bar 233 and the positioning member 24 under the electromagnetic force, and the precise control of the clamping force can be realized by controlling the magnitude of the electromagnetic force;

[0057] During long-term positioning operations, the final positioning is always a switching process from pneumatic positioning to electric control clamping positioning. For printing carriers of the same model but different specifications (for the same model, such as different sizes of squares or circles), the reduction motor 311 of the lifting component 31 can drive the lead screw 312 to rotate, which drives the nut sleeve 313 to move. The nut sleeve 313 then drives the magnetic control component 33 to slide through the offset component 32. This method can achieve rapid switching and adjustment of printing carriers of the same model but different specifications.

[0058] After long-term use, wear may occur, resulting in accuracy differences. By rotating the threaded sleeve 321 of the offset component 32, the displacements of its two threaded rods 322 can be adjusted, and then the distances between the two magnetic control components 33 can be respectively regulated to achieve calibration control and compensate for the accuracy problems caused by wear.

[0059] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. An air-operated positioning device for a lithographic press, comprising an air-operated component (20) for positioning a printing carrier on a printing table (10), and a control component (30) for adjusting the air-operated component (20), characterized in that: The printing table (10) includes a table board (11) and a rotating disk (12) sliding thereon. The pneumatic component (20) includes a valve seat (21) fixed on the rotating disk (12). Cylinder bodies (22) for the piston (23) to slide are installed at both ends of the valve seat (21). The piston (23) includes a piston body (231) and a control valve group (232) for controlling the gas communication on both sides of the piston body (231). The piston body (231) includes a metal seat (201) and a plurality of pressure relief holes (202) penetrating through both sides thereof. Oblique guide grooves (203) are obliquely penetrated through the side walls of the pressure relief holes (202). A number of notches (204) are formed on one side of the metal seat (201). The control valve group (232) includes a valve core (101) sliding in the oblique guide groove (203). A traction block (102) attracted by the magnetic control component (33) is fixed at the top end of the valve core (101). A tension spring (103) is fixed on the surface of the valve core (101) through a convex rib (104). The other end of the tension spring (103) is fixed on the metal seat (201). The traction block (102) slides in the notch (204). The regulation component (30) includes two magnetic control components (33) respectively used for adsorbing the piston body (231), and further includes a lifting component (31) and an offset component (32) controlled by the lifting component (31) to drive the displacement of the magnetic control component (33). The lifting component (31) pushes and pulls the magnetic control component (33) to slide on the cylinder body (22) through the offset component (32). When the piston (23) slides to the position of the magnetic control component (33) in the cylinder body (22) under the pneumatic action, the control valve group (232) is opened. At this time, the piston (23) is switched from pneumatic control to magnetic control to press the printing carrier.

2. The pneumatic positioning device of a lithographic press according to claim 1, wherein The valve seat (21) includes a seat body (211), connecting parts (213) on both sides thereof for installing the cylinder bodies (22), and a first air valve (212) on the valve seat (21) for the communication of the cylinder bodies (22) on both sides. A second air valve (25) matched with the first air valve (212) is arranged on the cylinder body (22). The seat body (211) is fixed on the rotating disk (12).

3. The pneumatic positioning device of a lithographic press according to claim 1, characterized in that, The piston (23) further includes a plurality of sealing rings (234) installed on the outer side wall of the metal seat (201), and a sliding rod (233) fixed on the inner side wall of the metal seat (201). A positioning part (24) is fixed at one end of the sliding rod (233).

4. The pneumatic positioning device of a lithographic press according to claim 1, characterized in that, The magnetic control component (33) includes an insulating sleeve (331) and a plurality of electromagnets (332) installed therein. The insulating sleeve (331) slides on the side wall of the corresponding cylinder body (22) through a sliding sleeve (333).

5. The pneumatic positioning device of a lithographic press according to claim 2, characterized in that, The lifting component (31) includes a reduction motor (311) fixed to the seat body (211). A lead screw (312) rotatably installed on the seat body (211) is fixed to the output shaft of the reduction motor (311). A nut sleeve (313) is in threaded fit with the surface of the lead screw (312).

6. The pneumatic positioning device of a lithographic press according to claim 5, characterized in that, The offset component (32) includes a threaded sleeve (321) and two threaded rods (322) threadedly engaged with both ends thereof. The remote ends of the two threaded rods (322) are respectively movably connected to an insulating sleeve (331) and a wire sleeve (313) through pin shafts.

7. An air-operated positioning device for a lithographic press according to claim 3, characterized in that, The printing table (10) further includes a driver (16) fixed on the table board (11). A toothed ring (14) is fixed on the lower surface of the rotating disk (12). A gear (15) meshing with the toothed ring (14) is fixed on the output shaft of the driver (16). A through groove (13) for slidingly engaging with the positioning member (24) is formed on the surface of the rotating disk (12).

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