Front tension control unit of roll paper rotary press

Abstract

The utility model discloses a front tension control unit of a roll paper rotary press. The front tension control unit comprises a plurality of paper guide rollers, a driving roller, a floating roller and a tension detection roller, the driving roller is driven by a servo motor mounted on a driving side shaft head of the driving roller; the floating roller is installed between the two wall plates through a floating mechanism. The floating mechanism comprises a floating roller rotating shaft, two swing arms and two air cylinders. An encoder is mounted at one end of the floating roller rotating shaft; the upper ends of the two swing arms fixedly sleeve the two ends of the floating roller rotating shaft in a one-to-one correspondence manner; the floating roller is bridged between the lower parts of the two swing arms; the two air cylinders are connected with the lower portions of the rear ends of the two swing arms in a one-to-one correspondence mode through swing supports. The rear side arm of the swing support is connected with the front end of a piston core shaft of the air cylinder through a piston connecting piece, the top face of the front side arm of the swing support is connected with the front portion of a long-strip-shaped spring piece through a front pressing plate, and the rear portion of the spring piece is connected to the rear portion of the bottom face of the swing arm through a rear pressing plate. The tension control device can improve the stability of tension control.

Description

Technical Field

[0001] The utility model relates to a front tension control unit of a web paper rotary machine. Background Art

[0002] During the printing process on a web-fed rotary press, the web diameter constantly changes, and the web tension also fluctuates accordingly. Poor web tension control often leads to poor overprinting and folding, impacting the quality and precision of printed products. Excessive web tension can cause paper breakage, while too little tension can lead to wrinkles and misregistering. Unstable tension can cause paper movement, leading to misregistering, ghosting, and uneven folding. Therefore, web-fed rotary presses typically incorporate a tension control unit on the paper feed side of the printing unit. First, the web tension is set. If the web tension is inappropriate or fluctuates, it must be adjusted promptly using the tension control system. A traditional tension control unit consists of several paper guide rollers, a driving roller, a swingable floating roller, and a tension detection roller, located between two wall panels. The tension control unit operates as follows: Paper enters the paper feed side, where the driving roller controls the paper feed speed. At the paper exit side, tension detectors mounted on both ends of the tension detection rollers measure the paper tension. Using a PID algorithm, the real-time measured tension is fed back to the floating roller's swing drive mechanism, which controls the floating roller's swing angle to adjust the paper tension. However, the traditional swing drive mechanism, after driving the floating roller to swing a certain angle, makes the floating roller unstable and inflexible. Utility Model Content

[0003] The purpose of the utility model is to overcome the defects of the prior art and provide a front tension control unit of a web rotary machine, which can improve the stability of tension control and effectively ensure the accuracy of printing overprinting.

[0004] The purpose of the utility model is achieved as follows: a front tension control unit of a web paper rotary machine, comprising first to ninth paper guide rollers, an active roller, a floating roller and a tension detection roller arranged between two wall panels; the paper tape first enters the tension control unit along the lower surface of the first paper guide roller, and passes around the active roller clockwise, then passes around the second paper guide roller and the third paper guide roller counterclockwise, and then passes around the floating roller clockwise, the fourth paper guide roller to the seventh paper guide roller counterclockwise, then passes around the eighth paper guide roller and the tension detection roller clockwise, and finally passes around the ninth paper guide roller counterclockwise, exits the front tension control unit and enters the printing unit; the active roller is driven by a servo motor installed on the drive side shaft head of the active roller; the floating roller is installed between the two wall panels through a floating mechanism, and the floating mechanism includes a floating roller shaft, two swing arms and two cylinders; wherein,

[0005] The floating roller shaft is rotatably connected between the two wall panels, and the two ends of the floating roller shaft pass through the two wall panels one by one; an encoder is installed at one end of the floating roller shaft;

[0006] The upper ends of the two swing arms are fixedly sleeved on the two ends of the floating roller shaft in a one-to-one correspondence;

[0007] The two ends of the floating roller are rotatably mounted on the lower parts of the two swing arms in a one-to-one correspondence through supports;

[0008] The two cylinders are connected to the lower parts of the rear ends of the two swing arms in a one-to-one correspondence through swing brackets;

[0009] Each cylinder includes a cylinder body, a cylinder housing, a sealing membrane and a cylinder piston; wherein,

[0010] The cylinder body is mounted on the outer surface of the wall panel through a cylinder seat, and the front end of the cylinder body is provided with a front flange;

[0011] The cylinder housing is a sleeve structure with a front end plate. The inner diameter of the cylinder housing is the same as that of the cylinder body. The rear end of the cylinder housing is provided with a rear flange adapted to the front flange on the cylinder body, and a circle of grooves is provided on the rear end surface of the rear flange. The cylinder housing is mounted on the front end of the cylinder body by a plurality of flange screws.

[0012] The sealing membrane is in the shape of a cup with a rearward-facing mouth and a central hole at the bottom. The outer diameter of the sealing membrane matches the inner diameter of the cylinder housing, and the length of the sealing membrane matches the length of the cylinder housing. The cup mouth of the sealing membrane is provided with a thickened edge, so that the sealing membrane is fixed between the cylinder housing and the cylinder body in a manner that the thickened edge of the sealing membrane is embedded in the groove of the cylinder housing, and the sealing membrane and the cylinder body form a sealed air cavity.

[0013] The cylinder piston comprises a piston sleeve, a piston cover and a piston core shaft; the piston sleeve is a cup body with a cup mouth facing forward and a front through-hole in the center of the cup bottom, and a sealing ring is provided in the front through-hole; the outer diameter of the piston sleeve is smaller than the inner diameter of the cylinder housing, and the length of the piston sleeve is smaller than the length of the sealing membrane; the piston sleeve is provided on the front surface of the cup bottom of the sealing membrane;

[0014] The piston cover is a circular tray with a diameter smaller than the inner diameter of the sealing membrane and a rear perforation in the center. The piston cover is arranged in the inner cavity of the sealing membrane and attached to the rear surface of the cup bottom of the sealing membrane.

[0015] The front portion of the piston core shaft is inserted into the piston hole opened in the center of the front end plate of the cylinder housing, and the rear end of the piston core shaft is sequentially inserted into the front through hole, the middle through hole and the rear through hole and then fastened to the piston sleeve, the sealing membrane and the piston cover through nuts;

[0016] The swing bracket is a U-shaped block, the rear arm of the swing bracket is connected to the front end of the piston core shaft through a piston connector, the top surface of the front arm of the swing bracket is connected to the front part of a long strip spring sheet through a front pressure plate, and the rear part of the spring sheet is connected to the rear part of the bottom surface of the swing arm through a rear pressure plate;

[0017] Both ends of the tension detection roller are rotatably mounted on the inner side surfaces of the two wall panels in a one-to-one correspondence via a tension detector.

[0018] The above-mentioned front tension control unit of the web rotary machine, wherein the first paper guide roller is arranged at the paper inlet of the front tension control unit; the active roller is arranged in the front and upper part of the first paper guide roller; the second paper guide roller is arranged in the rear and upper part of the active roller; the third paper guide roller is arranged directly above the active roller; the floating roller is arranged in the front and upper part of the third paper guide roller; the fourth paper guide roller is arranged in the rear and upper part of the floating roller; the fifth paper guide roller is arranged directly above the fourth paper guide roller; the sixth paper guide roller is arranged directly in front of the fifth paper guide roller; the seventh paper guide roller is arranged directly below the sixth paper guide roller; the eighth paper guide roller is arranged in the rear and lower part of the seventh paper guide roller; the tension detection roller is arranged directly below the eighth paper guide roller; the ninth paper guide roller is arranged at the paper outlet of the front tension control unit and is located directly in front of the tension detection roller.

[0019] The above-mentioned front tension control unit of the web rotary machine, wherein the piston core shaft includes a sleeve and a screw arranged in the sleeve; the rear end head of the piston connecting part is tightly inserted into the front end of the sleeve of the piston core shaft, and the front end head of the piston connecting part is a threaded head and is installed in a threaded hole opened on the rear side arm of the swing bracket.

[0020] In the front tension control unit of the web rotary machine, each cylinder further comprises an air tank fixed on the outer side of the wall panel and connected to the air vent provided on the cylinder body through an air pipe.

[0021] The front tension control unit of the above-mentioned web rotary machine, wherein the floating mechanism also includes a limiting mechanism, which includes two stop blocks correspondingly installed on the outer surfaces of the two wall panels and correspondingly located in the front of the lower part of the two swing arms, and two limiting piles correspondingly installed on the front end plates of the cylinder casings of the two cylinders.

[0022] The front tension control unit of the above-mentioned web rotary machine, wherein the floating mechanism also includes two swing arm support seats fixed one by one on the outer sides of the two wall panels and located below the two swing arms; each swing arm support seat includes a support mounted on the outer side of the wall panel, an eccentric sleeve mounted on the outer side of the support by screws, and a plastic-coated bearing mounted on the eccentric sleeve; the plastic-coated bearing contacts the bottom surface of the corresponding swing arm.

[0023] The front tension control unit of the web paper rotary machine of the present invention has the following features:

[0024] 1. The floating roller in the unit is installed between two wall panels using a floating mechanism. The cylinder in the floating mechanism uses a thin film piston, which can more flexibly control the swing of the floating roller. The cylinder and the floating roller are connected by a spring sheet, which can reduce the vibration of the floating roller when it swings.

[0025] 2. The unit is also equipped with a tension detection roller, which can monitor the tension of the paper tape in the unit in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a side view of the front tension control unit of the web rotary machine of the present invention;

[0027] Figure 2 This is a schematic structural diagram of the floating roller in the front tension control unit of the utility model;

[0028] Figure 3 yes Figure 2 Side view of;

[0029] Figure 4 yes Figure 3 The CD view in the figure;

[0030] Figure 5 yes Figure 3 EE view in the figure;

[0031] Figure 6 yes Figure 2 AA view in the;

[0032] Figure 7 yes Figure 3 CC view in the figure;

[0033] Figure 8 yes Figure 3 FF view in the. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings.

[0035] See also Figures 1 to 8 The front tension control unit of the web rotary press of the present invention includes a first paper guide roller 11 to a ninth paper guide roller 19 , an active roller 2 , a floating roller 3 and a tension detection roller 4 , which are arranged between two wall panels 100 .

[0036] The first paper guide roller 11 is arranged at the paper inlet of the tension control unit; the active roller 2 is arranged in front of and above the first paper guide roller 1; the second paper guide roller 12 is arranged in the rear and above of the active roller 2; the third paper guide roller 13 is arranged directly above the active roller 2; the floating roller 3 is arranged in front of and above the third paper guide roller 13; the fourth paper guide roller 14 is arranged in the rear and above of the floating roller 3; the fifth paper guide roller 15 is arranged directly above the fourth paper guide roller 14; the sixth paper guide roller 16 is arranged directly in front of the fifth paper guide roller 15; the seventh paper guide roller 17 is arranged directly below the sixth paper guide roller 16; the eighth paper guide roller 18 is arranged in the rear and below of the seventh paper guide roller 17; the tension detection roller 4 is arranged directly below the eighth paper guide roller 18; and the ninth paper guide roller 19 is arranged at the paper outlet of the tension control unit and is located directly in front of the tension detection roller 4.

[0037] The paper tape 200 first enters the front tension control unit along the lower surface of the first paper guide roller 11, and then passes around the active roller 2 in a clockwise direction, then passes around the second paper guide roller 12 and the third paper guide roller 13 in a counterclockwise direction, and then passes around the floating roller 3 in a clockwise direction, the fourth paper guide roller 14, the fifth paper guide roller 15, the sixth paper guide roller 16 and the seventh paper guide roller 17 in a counterclockwise direction, then passes around the eighth paper guide roller 18 and the tension detection roller 4 in a clockwise direction, and finally passes around the ninth paper guide roller 19 in a counterclockwise direction, exits the front tension control unit and enters the printing unit.

[0038] The active roller 2 is driven by a servo motor mounted on a drive-side shaft head of the active roller 2 .

[0039] The floating roller 3 is installed between two wall panels 100 through a floating mechanism, which includes a floating roller shaft 3A, two swing arms 3B, two cylinders 3C, two swing brackets 3D, a limiting mechanism and two swing arm support seats 3E.

[0040] The floating roller shaft 3A is rotatably connected between the two wall panels 100, and the two ends of the floating roller shaft 3A pass through the two wall panels 100 one by one; an encoder 5 is installed at one end of the floating roller shaft 3A, and the encoder 5 is installed on the outer surface of the corresponding wall panel 100 through a support 50.

[0041] The upper ends of the two swing arms 3B are fixedly sleeved on the two ends of the floating roller shaft 3A in a one-to-one correspondence.

[0042] Both ends of the floating roller 3 are rotatably mounted on the lower parts of the two swing arms 3B through a support 30 and two clamping plates 31 in a one-to-one correspondence.

[0043] The two cylinders 3C are connected to the lower rear ends of the two swing arms 3B through swing brackets 3D in a one-to-one correspondence; each cylinder 3C includes a cylinder body 33, a cylinder shell 34, a sealing membrane 35, a cylinder piston and a gas tank (not shown in the figure), wherein:

[0044] The cylinder body 33 is mounted on the outer surface of the wall panel 100 through the cylinder base 32. A gasket 330 is provided between the cylinder body 33 and the cylinder base 32. The gasket 330 is coated with Loctite 480 glue. The front end of the cylinder body 33 has a front flange.

[0045] The cylinder housing 34 is a sleeve structure with a front end plate. The inner diameter of the cylinder housing 34 is the same as that of the cylinder body 33. A piston hole is provided in the center of the front end plate of the cylinder housing 34, and a threaded hole is provided next to the piston hole. The rear end of the cylinder housing 34 has a rear flange that adapts to the front flange of the cylinder body 33, and a groove is provided on the rear end surface of the rear flange. The cylinder housing 34 is mounted to the front end of the cylinder body 33 using a number of flange screws 341 and flange gaskets 342. Each flange screw 341 should be coated with Loctite 542 glue. A washer 343 is provided on the rear end surface of the front end plate of the cylinder housing 34, and this washer 343 should be coated with Loctite 480 glue.

[0046] The sealing membrane 35 is a cup-shaped body with a rearward-facing mouth and a central hole in the bottom. The surface of the sealing membrane 35 is coated with talcum powder. The outer diameter and length of the sealing membrane 35 match the inner diameter and length of the cylinder housing 34. The mouth of the sealing membrane 35 is provided with a thickened edge 350. The sealing membrane 35 is fixed between the cylinder housing 34 and the cylinder body 33 by embedding the thickened edge 350 in the groove of the cylinder housing 14. The sealing membrane 35 and the cylinder body 33 are sealed to form an air cavity.

[0047] The cylinder piston includes a piston sleeve 36, a piston cover 37, and a piston core shaft 38. The piston sleeve 36 is in the shape of a cup with a front opening facing forward and a front hole in the center of the cup bottom. A sealing ring 360 is disposed in the front hole. The outer diameter of the piston sleeve 36 is smaller than the inner diameter of the cylinder housing 34, and the length of the piston sleeve 36 is shorter than the length of the sealing membrane 35. The piston sleeve 36 is disposed on the front surface of the cup bottom of the sealing membrane 35.

[0048] The piston cover 37 is a circular tray with a diameter smaller than the inner diameter of the sealing membrane 35 and a rear perforation in the center. The piston cover 37 is disposed in the inner cavity of the sealing membrane 35 and attached to the rear surface of the cup bottom of the sealing membrane 35.

[0049] The piston core shaft 38 includes a sleeve and a screw arranged in the sleeve. The front part of the piston core shaft 38 is inserted into the piston hole of the cylinder housing 34; the rear end head of the screw of the piston core shaft 38 passes through the front through-hole, the middle through-hole and the rear through-hole in sequence and is fastened to the piston sleeve 36, the sealing membrane 35 and the piston cover 37 through the nut 380. The nut 380 should be coated with Loctite 480 glue; a large washer 381 is arranged between the nut 380 and the piston cover 37; a small washer 382 is arranged between the piston core shaft 38 and the cup bottom of the piston sleeve 36; both the large washer 381 and the small washer 382 should be coated with Loctite 480 glue.

[0050] The gas tank is fixed on the outer surface of the wall panel 100 and is connected to the vent hole provided on the cylinder body 33 through an air pipe. The gas tank and the air cavity together constitute the gas storage space of the cylinder.

[0051] The swing bracket 3D is a U-shaped block. The rear arm of the swing bracket 3D is connected to the front end of the piston core shaft 38 through a piston connector 39. The rear end head of the piston connector 39 is tightly inserted into the front end of the sleeve of the piston core shaft 38. The front end head of the piston connector 39 is a threaded head and is installed in a threaded hole opened on the rear arm of the swing bracket 3D; the top surface of the front arm of the swing bracket 3D is connected to the front part of a long strip spring sheet 300 through a front pressure plate 30a, and the rear part of the spring sheet 300 is connected to the rear part of the bottom surface of the swing arm 3B through a rear pressure plate 30b.

[0052] The limiting mechanism includes two stop blocks 3E and two limit piles 3F; the two stop blocks 3E are respectively installed on the outer surfaces of the two wall panels 100 by screws and are respectively located in front of the lower parts of the two swing arms 3B; each stop block 3E is also installed with a rubber buffer pad 30E on the rear end surface relative to the swing arm 3B by screws; the two limit piles 3F are respectively installed in the threaded holes of the front end plates of the cylinder housings 34 of the two cylinders 3C by screws and nuts, and the front end surface of the limit pile head 3F is provided with a rubber buffer head 30F.

[0053] The two swing arm support bases 3G are fixed one by one on the outer surfaces of the two wall panels 100 and are located below the two swing arms 3B; each swing arm support base 3G includes a support 301 installed on the outer side surface of the wall panel 100, an eccentric sleeve 303 installed on the outer side surface of the support 301 by screws 302, and a plastic-coated bearing 304 installed on the eccentric sleeve 303; the plastic-coated bearing 304 is in contact with the bottom surface of the swing arm 3B.

[0054] The tension detection roller 4 includes a roller shaft 41 and a roller sleeve 42; the two ends of the roller shaft 41 are respectively installed on the inner side surfaces of the two wall panels 100 through a tension detector 40, and the two ends of the roller shaft 41 are respectively installed with a bearing 43 through a shaft bushing 44 and a retaining ring 45; the roller sleeve 42 is sleeved on the two bearings 43.

[0055] The front tension control unit of the web paper rotary machine of the present invention is such that, during operation, the active roller 2 is driven by a servo motor to rotate, allowing the paper tape 200 to travel within the tension control unit. The paper feed speed is controlled by controlling the rotation speed of the servo motor (active roller 2). The difference between the surface linear velocity of the active roller 2 and the surface linear velocity of the printing cylinder in the printing unit provides tension to the paper tape 200. By injecting the same amount of air into the air storage spaces of the two cylinders 3C, the cylinder pistons of the two cylinders 3C provide an identical and constant thrust, the cylinder pistons of the two cylinders 3C extend the same amount, and the two swing arms 3B are pushed vertically in a one-to-one correspondence through the two swing brackets 3D, thereby controlling the original position of the floating roller 3. When the pulling force on the paper 200 exceeds or falls short of the thrust of the pistons in the two cylinders 3C, the two swing arms 3B swing, causing the floating roller 3 to deflect, which in turn drives the floating roller shaft 3A to rotate. An encoder 5, mounted on one end of the floating roller shaft 3A, converts the rotation angle of the floating roller shaft 3A into an analog signal and transmits it to the power control system of the web web rotary press. The power control system, after applying a PID control algorithm, automatically adjusts the speed of the servo motor of the active roller 2, thereby adjusting the tension of the paper web 200 and restoring the two swing arms 3B of the floating roller 3 to a vertical position. Tension detectors 40, mounted on both ends of the tension detection roller 4, monitor the tension of the paper web 200 in the front tension control unit in real time and provide feedback to the power control system.

[0056] The air chambers of the two cylinders 3C in the floating mechanism of this invention are formed by a cylinder body 33 and a flexible sealing membrane 35. The cylinder pistons are mounted on the sealing membrane 35. The volume of the air chambers changes as the cylinder pistons expand and contract. The pistons are stabilized in an initial position by the gas pressure within the chamber and the tension of the paper tape 200. When the tension of the paper tape 200 changes, the cylinder pistons expand and contract, overcoming the gas pressure within the chamber. Once the external pressure (the tension of the paper tape 200) on the cylinder pistons is restored, the cylinder pistons return to their original positions. This results in a fast response time for the cylinders, enabling precise and flexible control of the floating roller 3. Connecting an external air tank to the air chamber of each cylinder 3C effectively increases the air storage capacity of the chamber, reducing the resistance caused by the cylinder pistons compressing the air within the chamber when the tension of the paper tape 200 changes, further enhancing the stability of tension control.

[0057] This utility model utilizes a spring plate 300 connected between the cylinder 3C and the swing arm 3B, reducing vibration when the cylinder 3C controls the swinging of the floating roller 3, thereby ensuring stable tension control. A limiting mechanism, consisting of a stopper 3E located in front of each swing arm 3B and a limit post 344 located at the front end of each cylinder 3C, prevents the swing arm 3B from exceeding the swing amplitude limit. A swing arm support 3F located below each swing arm 3B ensures that the plastic-coated bearing 305 of the swing arm support 3F supports the swing arm 3B in both the vertical position and during swinging, thereby ensuring the stability of the floating roller 3 during swinging.

[0058] The above embodiments are only used to illustrate the present invention, rather than to limit the present invention. Those skilled in the art may make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention and should be defined by the claims.

Claims

1. A front tension control unit of a web paper rotary machine, comprising first to ninth paper guide rollers, a driving roller, a floating roller and a tension detection roller arranged between two wall panels; the paper tape first enters the tension control unit along the lower surface of the first paper guide roller, and passes around the driving roller clockwise, then passes around the second paper guide roller and the third paper guide roller counterclockwise, and then passes around the floating roller clockwise, the fourth paper guide roller to the seventh paper guide roller counterclockwise, then passes around the eighth paper guide roller and the tension detection roller clockwise, and finally passes around the ninth paper guide roller counterclockwise, exits the front tension control unit and enters the printing unit; the driving roller is driven by a servo motor installed on the driving side shaft head of the driving roller; the floating roller is installed between the two wall panels through a floating mechanism, and the floating mechanism includes a floating roller shaft, two swing arms and two cylinders; characterized in that The floating roller shaft is rotatably connected between the two wall panels, and the two ends of the floating roller shaft pass through the two wall panels one by one; an encoder is installed at one end of the floating roller shaft; The upper ends of the two swing arms are fixedly sleeved on the two ends of the floating roller shaft in a one-to-one correspondence; The two ends of the floating roller are rotatably mounted on the lower parts of the two swing arms in a one-to-one correspondence through supports; The two cylinders are connected to the lower parts of the rear ends of the two swing arms in a one-to-one correspondence through swing brackets; Each cylinder includes a cylinder body, a cylinder housing, a sealing membrane and a cylinder piston; wherein, The cylinder body is mounted on the outer surface of the wall panel through a cylinder seat, and the front end of the cylinder body is provided with a front flange; The cylinder housing is a sleeve structure with a front end plate. The inner diameter of the cylinder housing is the same as that of the cylinder body. The rear end of the cylinder housing is provided with a rear flange adapted to the front flange on the cylinder body, and a circle of grooves is provided on the rear end surface of the rear flange. The cylinder housing is mounted on the front end of the cylinder body by a plurality of flange screws. The sealing membrane is in the shape of a cup with a rearward-facing mouth and a central hole at the bottom. The outer diameter of the sealing membrane matches the inner diameter of the cylinder housing, and the length of the sealing membrane matches the length of the cylinder housing. The cup mouth of the sealing membrane is provided with a thickened edge, so that the sealing membrane is fixed between the cylinder housing and the cylinder body in a manner that the thickened edge of the sealing membrane is embedded in the groove of the cylinder housing, and the sealing membrane and the cylinder body form a sealed air cavity. The cylinder piston comprises a piston sleeve, a piston cover and a piston core shaft; the piston sleeve is a cup body with a cup mouth facing forward and a front through-hole in the center of the cup bottom, and a sealing ring is provided in the front through-hole; the outer diameter of the piston sleeve is smaller than the inner diameter of the cylinder housing, and the length of the piston sleeve is smaller than the length of the sealing membrane; the piston sleeve is provided on the front surface of the cup bottom of the sealing membrane; The piston cover is a circular tray with a diameter smaller than the inner diameter of the sealing membrane and a rear perforation in the center. The piston cover is arranged in the inner cavity of the sealing membrane and attached to the rear surface of the cup bottom of the sealing membrane. The front portion of the piston core shaft is inserted into the piston hole opened in the center of the front end plate of the cylinder housing, and the rear end of the piston core shaft is sequentially inserted into the front through hole, the middle through hole and the rear through hole and then fastened to the piston sleeve, the sealing membrane and the piston cover through nuts; The swing bracket is a U-shaped block, the rear arm of the swing bracket is connected to the front end of the piston core shaft through a piston connector, the top surface of the front arm of the swing bracket is connected to the front part of a long strip spring sheet through a front pressure plate, and the rear part of the spring sheet is connected to the rear part of the bottom surface of the swing arm through a rear pressure plate; Both ends of the tension detection roller are rotatably mounted on the inner side surfaces of the two wall panels in a one-to-one correspondence via a tension detector.

2. The front tension control unit of the web rotary machine according to claim 1, characterized in that: The first paper guide roller is arranged at the paper inlet of the front tension control unit; the active roller is arranged in the front and upper part of the first paper guide roller; the second paper guide roller is arranged in the rear and upper part of the active roller; the third paper guide roller is arranged directly above the active roller; the floating roller is arranged in the front and upper part of the third paper guide roller; the fourth paper guide roller is arranged in the rear and upper part of the floating roller; the fifth paper guide roller is arranged directly above the fourth paper guide roller; the sixth paper guide roller is arranged directly in front of the fifth paper guide roller; the seventh paper guide roller is arranged directly below the sixth paper guide roller; the eighth paper guide roller is arranged in the rear and lower part of the seventh paper guide roller; the tension detection roller is arranged directly below the eighth paper guide roller; the ninth paper guide roller is arranged at the paper outlet of the front tension control unit and is located directly in front of the tension detection roller.

3. The front tension control unit of the web rotary machine according to claim 1, characterized in that: The piston core shaft includes a sleeve and a screw arranged in the sleeve; the rear end head of the piston connector is tightly inserted into the front end of the sleeve of the piston core shaft, and the front end head of the piston connector is a threaded head and is installed in a threaded hole opened on the rear arm of the swing bracket.

4. The front tension control unit of the web rotary machine according to claim 1, characterized in that: Each cylinder further comprises an air tank fixed on the outer side of the wallboard and connected to the air vent provided on the cylinder body through an air pipe.

5. The front tension control unit of the web rotary machine according to claim 1, characterized in that: The floating mechanism also includes a limiting mechanism, which includes two stop blocks that are correspondingly installed on the outer surfaces of the two wall panels and located in front of the lower parts of the two swing arms, and two limiting piles that are correspondingly installed on the front end plates of the cylinder casings of the two cylinders.

6. The front tension control unit of the web rotary machine according to claim 1, characterized in that: The floating mechanism also includes two swing arm support seats fixed one by one on the outer sides of the two wall panels and located below the two swing arms; each swing arm support seat includes a support mounted on the outer side of the wall panel, an eccentric sleeve mounted on the outer side of the support by screws, and a plastic-coated bearing mounted on the eccentric sleeve; the plastic-coated bearing contacts the bottom surface of the corresponding swing arm.

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