UV flatbed printer is a pigment printing device, used to print a variety of patterns, complete the manufacturing of personalized products such as signs, refrigerator stickers, mobile phone cases. The system accurately controls two servo systems through the motion control board card to complete the operation of two axes and realize the accurate printing of patterns. SIGRINERSIGRINER AC servo system originated in Germany, deep in Asia. With the advantages of high precision, high response speed, self - tuning, it is more and more applied to the field of industrial control. This paper mainly introduces the application of SIGRINERSIGRINER Ω6 pulse servo in UV flatbed printer.

Key words: UV flatbed printer; Ω6 pulse servo; SIGRINER; inkjet

Figure 1 Flatbed printer

As shown in the figure, the multi-color pigment spraying device is driven by the servo system and synchronous belt wheel combined transmission device to realize longitudinal and horizontal movement, printing various patterns.

Figure 2. UV flatbed printer spraying device & transmission device

The lateral motion of spraying device has high acceleration and deceleration switching and high response requirements. The red dotted coil is the spraying device.

Figure 3 Running state of UV flatbed printer

After presetting the content to be printed, the printer starts to run. First, it returns to the origin position of the device. After selecting automatic operation, the two-axis and spraying module will automatically run and reciprocate printing all the content until it is completed. Electric operation mode can also be selected to test each shaft.

Figure. 4 System process flow chart

The electrical system is mainly composed of motion control board, servo driver, servo motor, multi-color spraying device, etc.

Figure 5 Schematic diagram of the system electrical system

The X axis and Y axis servo drive the multi-color spraying device to reciprocate horizontally and longitudinally respectively. The multi-color spraying device sprays different colors of pigments according to the target pattern and controls the amount of pigments.

The SigrinerSIGRINER Ω6s-AP series pulse AC servo system is adopted in this scheme. The configuration list of the servo system is shown in Table 1.

Table 1 Servo system configuration

SIGRINERΩ6s-AP series used in UV flat printing advantages:

• Product performance is strong enough: speed loop bandwidth 3.5kHz, current loop refresh frequency 1MHz.

• Ω6s-AP servo adopts 16M pulse control interface, which can improve the control accuracy by 4 times. Adopt 3 channels 16 bit analog instruction input, can distinguish 2mv voltage change, control accuracy can be improved 16 times.

• Abundant output power, easy to cope with: 115% continuous load overload, 350% instantaneous overload.

• Friction compensation + overquadrant bulge suppression, easy to deal with precision machining, positive roundness increased by 80%.

• To provide comprehensive safety protection for the harsh application environment of multiple electrical interference and oil pollution in inkjet printing field: independent cooling air duct + temperature monitoring system + thickened UV coating. Through more than 300 rigorous tests in HASS and HALT experiments, it still operates stably in the face of various harsh environments; The products have passed CE certification and meet the safety requirements of relevant equipment in European and American markets.

Because the motor drives the pulley with the spraying device to move back and forth, the force condition of the spraying device near the motor is different from that of the reversing and returning. The longer running distance and the soft transmission property of the belt make it impossible to solve this problem with only one set of PID. The Ω6s-AP servo system has the gain switching function, and two sets of gain parameters can be set. Forward running and reverse running each set of parameters, a good solution to the problem.

After long-term testing and summary, SigrinerSIGRINER customizes a set of matching UV flat printing application site servo system parameters, Ω6s-AP series of newly developed debugging free automatic setting function, saving 90% equipment debugging time. Processing results as shown in the figure below, to meet the customer's ideal demand.

Figure 6 Print effect

Scheme summary

The comprehensive performance of AC servo system determines the printing speed, printing accuracy and printing stability of uv flatbed printer. For example, the high response performance of servo ensures the rapid and accurate execution of mechanical instructions. At the same time, vibration suppression can be used to solve the resonance risk caused by high response. In addition, if there are mechanical material or installation problems caused by mechanical static friction force or internal stress inconsistency, can be solved through the servo system's differentiated friction compensation; The inhibition function of the servo quadrant is used to make up for the gap problem during mechanical reversing. Others such as model vibration control, load variation suppression, gain switching and so on have corresponding application scenarios.

Ω6s-AP series servo drivers with its high cost performance, high responsiveness, high precision and ease of use and other advantages are widely used in general industrial control occasions, in addition to the shared UV flatbed printer application effect has been recognized by customers, Also in the industrial robot, engraving machine, LED splitter and other fields have been a good application effect and consistent user praise.

SIGRINER integrates related interface equipment with drive control as the core, and provides overall automation control solutions to meet the needs of customers in various industry segments to improve quality, expand capacity and reduce costs.