Eight common mechanical faults and troubleshooting of gravure printing machine for hardcover books

Source: 隆印集团Author: adminTime: 2020-07-30 21:47:52

Eight common mechanical faults and troubleshooting of gravure printing machine for hardcover books
1、 A / b reel connection failure rate of hardcover book printing and unwinding machine is high
① it is necessary to check whether the A / b reel is synchronized and whether the transmission part (synchronous belt) is effectively transmitted; ② measure the actual coil diameter and compare it with the system self-test to see whether the coil diameter is consistent; ③ whether the connection position between the connecting arm and the winding machine is normal. Whether the radio eye and reflection eye work normally and whether the detection position is correct; ④ whether the action of connecting cutter and pressing roller is smooth and consistent, whether there is advance or lag phenomenon, whether there is water vapor or low air pressure in the air pipe, which affects the normal operation of the cylinder; ⑤ whether the material roll slips, which affects the electric eye detection (this problem will directly lead to large fluctuation of finishing tension and poor color registration accuracy) )。 When checking whether the coil is installed, the operating thimble at the power side and the operation side is not fixed tightly; and (6) the collector ring surface is oxidized or the carbon brush is worn seriously, and the electric signal output and input are weak, which affects the electrifying action and feedback of components. It is necessary to carry out corresponding treatment to make the parts power on and contact normally, and power-off operation is required for maintenance; and (7) the adhesive tape is insufficient and needs to be replaced.
2、 Hard cover book printing traction device failure
(1) the steel roller traction is not synchronous
   ① Check whether the rubber roller presses the steel roller and whether the rubber layer of the rubber roll is aged; ② whether the pressing pressure reaches the specified air pressure and whether there is air leakage or obstruction in the air circuit; ③ whether the speed of the steel roller is synchronized with the speed of the equipment, and whether the transmission parts (synchronous belt) can effectively transmit power; ④ whether the electric encoder works normally (traction asynchrony will directly affect the tension and chromatic accuracy).
(2) Poor cooling effect
Whether the cooling water temperature is maintained at 20 ~ 25 ℃ or cooling water is used at 5 ~ 15 ℃; ② whether the water quantity meets the requirements and there is enough cooling water circulation; ③ whether the scale in the cooling roller is blocked due to long-term use, the high-pressure cleaning pump can be used to carry out high-pressure dissolving cleaning with acid solution to keep the good cooling water pipe unblocked.
3、 The mechanism failure of hardcover book printing
(1) Gearbox heating
   ① It is necessary to check the lubricating oil in the gearbox in time. The lubricating oil can effectively maintain the lubrication of the transmission parts in the gearbox, and the cooling parts fail; ② when the gearbox is hot and accompanied by the noise increase of the gearbox, it may be that there is wear or damage of the transmission parts inside the gearbox, and it is necessary to stop the machine in time for inspection; ③ check whether there is ink or solvent flowing into the gearbox from the bevel and jacking rod of the gearbox, Cause bearing damage or other transmission parts damage.
(2) The horizontal register accuracy of plate shaft is poor
(1) the structure of the power side cone plug is in the form of cylinder cone top, and whether the manual valve rotates under the cylinder exit (intake) state. Whether the cone plugging is well fitted with the plate cylinder, whether there is a slip gap, whether the scratching or heating occurs at the joint of the cone and the cylinder, whether or not there is any abnormal phenomenon in the horizontal axis automatic permanent magnet low-speed motor, and (3) to check the movement by manual color register, and also to adjust the color automatically after the adjustment of the manual register. ④ Plate or plate loading accuracy reasons.
4、 Imprint mechanism failure
(1) Poor ink transfer effect
(1) impression force. Check whether the actual impression force is consistent with the pressure value of the control valve, and the cylinder output pressure corresponding to the corresponding pressure gauge value can be calculated through the cylinder diameter. In case of inconsistency, it is necessary to check the pneumatic components, the main air pressure and whether there are mechanical resistance obstacles; ② due to the poor quality of the imprint cylinder and the surface adhesion impurities, the roller should be replaced.
(2) The problem of register precision
① The imprint cylinder is a passive component, and the cylinder and the plate should be in synchronous state under the pressing state. If it is not synchronized, it is necessary to check whether the rolling bearing rotates flexibly and whether there is jamming phenomenon; ② check whether the imprint cylinder acts normally when starting printing; ③ check whether the imprint cylinder and plate cylinder fit well.
5、 Scraper mechanism
When the ink scraping effect becomes poor, the following aspects can be checked and eliminated: ① confirm whether the screw, bolt, fixed hand wheel, handle and scraper clip of the scraper mechanism are all locked and tightened; ② check whether the screw rod, worm and worm gear pair of the frequently operated parts such as the lifting, back and forth and swing of the scraper are worn, and whether there is gap; ③ whether there is transmission and transmission The moving parts are stuck and the work is not flexible. Whether the sliding bearing, transmission parts and rotating parts are lubricated enough; ④ whether the scraper works without ink. The ink acts as a lubricant between the scraper blade and the cylinder, but when the blade is in rigid contact with the cylinder without ink, it will cause high friction and heat of the scraper blade, and at the same time, it will cause damage to the cylinder; ⑤ whether the blade swings smoothly. Scraper swing is to transfer the power of scraper swing through the output shaft under the gearbox. This position is converted from circular motion to linear motion, and this part is easy to be ignored, so special attention should be paid to keep the flexibility of the part. The equipment is used for a long time, and it is easy to cause mechanical resistance due to grease aging or dust accumulation.
6、 Ink tray lifting fault
The purpose of lifting and self-locking is to achieve lifting and self-locking through worm gear pair and gear rack. Usually, the failure of lifting device is caused by insufficient lubrication, large lifting resistance, asynchronous lifting of power side and operation side. The flexibility of transmission parts can be maintained by lubricating or cleaning the dust and ink on the transmission parts. The parts must be installed with both ends at the same level.
7、 Upper ink roller failure
① Upper ink roller rotation fault. If the motor is overheated and noisy, and the ink roller shakes (excluding the rubber quality problem of the upper ink roller and the runout problem of the ink roller itself), the transmission parts can be inspected and repaired.
② Press on failure of upper ink roller. The pressing / leaving state of the upper ink roller depends on the action of the air cylinder. The working height of the upper ink roller can be satisfied by adjusting the limit nut on the cylinder. If there is a problem with the component, it is necessary to check whether the air circuit is blocked, whether the air pressure meets the requirements, whether the limit is correct, and whether the movable parts are flexible.
③ Upper ink roller speed fault. The transmission ratio in the upper ink roller mechanism is a fixed value. The speed of speed is adjusted by potentiometer. The control source of potentiometer is inverter. The frequency converter controls the motor frequency to meet the required speed. Relevant electrical data can be understood and overhauled according to electrical instructions.
8、 Failure of longitudinal rectifying mechanism
The longitudinal offset correction is driven by a permanent magnet low-speed motor, and the signals are transmitted to the encoder of the register system to ensure the overprint accuracy by mutual feedback. When the longitudinal color registration accuracy is poor (the premise is not caused by the color registration system) and the correction reaction is not flexible, the following aspects can be checked: ① check whether the color encoder is faulty; ② check whether the low-speed permanent magnet motor is faulty; ③ check whether the film feeding route is normal; ④ check whether the worm gear pair works flexibly, whether there is jamming, high resistance, etc. Whether the ball screw works flexibly and effectively, whether the left and right ball screws are in a horizontal state, and whether there is obvious obstruction or sluggish movement when the motor drives both ends of the lead screw to rise or fall at the same time. Attention should be paid to the maintenance and lubrication of the worm gear pair; ⑤ the manual position of the color registration system can be selected, and the automatic color matching can be selected after the color matching is qualified to watch the color deviation and longitudinal deviation correction.