Introduction to the basic functions of glue coating equipment in the automotive industry

program

The program contains the process parameters necessary for the gluing operation. Before starting the gluing cycle, the higher-level control selects the program and determines the general process parameters for the gluing cycle. The program cannot be changed or altered during the gluing cycle. The setpoints set in the selected program must remain unchanged until the end of the current gluing cycle.

A program includes:

•Program number

• Program name (text name of the program)

• Set capacity, upper and lower limits

• Rubber flow setting value (when adjusting flow)

• Compound pressure setpoint (when pressure regulation is performed), upper and lower limits

• Air ratio, injection air delay

•Preload setting value

• Deviation of unit capacity (when pre-pressure adjustment is performed by capacity)

•Specify the glue application time, and the pre-pressure adjustment should be carried out according to this time

• Parameter group (Rubber flow coefficient, pre-pressure coefficient, injection air coefficient (optional).)

Parameter groupsProcess parameters can be defined via parameter groups. These can be changed during the gluing cycle. For example, by selecting the desired parameter group, the glue flow rate can be increased or decreased during the gluing process.

The coefficients for the following process parameters are determined in the parameter groups.

• Rubber flow

• Pre-pressure

• Air ratio (optional)

Preload

After the start of the gluing cycle input signal is given, a pre-pressure is first built up in the metering machine. When the pre-pressure value is reached, the control unit SYS 6000 reports that the pre-pressure has been reached. The glue gun can be switched on independently of the pre-pressure. By building up the pre-pressure, the gluing operation can be optimized at the start of gluing.

Adjust the preload pressure by:

• Pre-stress process parameters for the selected program

• Preload coefficient for the selected parameter group

Automatic pre-pressure adjustment For some adhesives, it is not sufficient to adjust the pre-pressure only once at the beginning of the application, since the pre-pressure may change during the application process. Therefore, it is necessary to adjust the pre-pressure frequently.

If the "Pre-pressure adjustment" function is activated, the system automatically adjusts the pre-pressure to the application pressure. The automatic pre-pressure adjustment can be triggered in different situations:

• After a certain period of time during the application process (depending on the program)

• A robot signal (trigger signal) (depending on the program)

• After a certain system downtime

• Deviation of the amount of glue discharged from the setpoint glue amount

• Short joints at the end of the application, depending on the amount of glue discharged (compared to the setpoint glue amount set in the program) (depending on the program) The automatic pre-pressure adjustment function is activated or deactivated by the control unit.

Although the values ​​entered here are for automatic pre-pressure adjustment after a certain downtime, they are also valid for all other pre-pressure adjustment methods. Glue flow During gluing, the glue flow is determined by:

• The process parameter "Glue flow" of the selected program

• The glue flow coefficient of the selected parameter group

• The glue setpoint ( analog value) of the superior control The process parameter glue flow is program-specific. The glue flow coefficient is defined in the parameter group. Example:

By switching parameter groups, the glue flow rate can be changed within a gluing cycle. The glue flow rate to be set also depends on certain operating parameters, such as the robot's operating speed. The robot adjusts the glue flow rate to the robot speed via a speed proportional value.

Amount of glue applied

The actual amount of adhesive applied depends on the following factors:

• Process parameter "Material flow" of the selected program

• The compound flow coefficient for the selected parameter group

• Rubber material setpoint (analog value) of the upper control device

• Time for input signal “glue gun open”

• Turn off the pre-pressure in the glue gun

Reaction time

After mixing the base adhesive and the hardener components, the two-component adhesive can be processed normally. However, after a certain period of time, the processability of the two-component adhesive decreases. The permitted reaction time has expired.

The control monitors the time remaining until the permitted reaction time has expired (remaining time {0}) and issues a fault message if the permitted reaction time has been exceeded.

If the two-component adhesive is applied after the permitted reaction time has expired, uneven application of the adhesive may occur. Therefore, the two-component adhesive should be replaced with a new, more processable adhesive after the permitted reaction time has expired (flushing).

If this is not done, the two-component adhesive will continue to harden. After a certain degree of hardening, the two-component adhesive can no longer be processed and damage to the gluing system occurs. The maximum reaction time has expired.

The control monitors the time from the expiration of the permitted reaction time to the expiration of the maximum reaction time (timeout). If the maximum reaction time has been reached, the control issues a category 3 fault message. The system is locked and gluing can only be resumed after the mixer is replaced.

Fault analysis

At the end of each gluing cycle, the control unit performs a fault analysis. During the fault analysis, the system checks whether the amount of glue discharged is within the tolerance range or whether there is a glue fault.

If the output signal gluing cycle ends is issued, this output signal informs the user of normal gluing through status information after the gluing cycle or outputs a fault message. The occurrence of fault messages of category 2 or 3 must be acknowledged before starting the next gluing cycle. At

the beginning of the next gluing cycle, the control unit will acknowledge the fault message caused by the volume analysis. These faults are saved in the database.

Pressure monitoring

The process parameters minimum pressure and maximum pressure are used to monitor the glue pressure. If the pressure exceeds the minimum and maximum permissible range during gluing, the fault messages glue pressure below minimum value and glue pressure exceeding maximum value are issued. After the fault is detected, the control unit will react as follows:

• Display the fault message on the control panel.

• Send the fault message to the higher-level control unit and reset the corresponding output signal.

• Record in the fault memory.

In the control unit, it can be configured whether exceeding the program-defined pressure limit value leads to an interruption of the gluing process or at least whether only a fault message is generated when the pressure falls below the permissible pressure of the metering machine. The gluing process is interrupted at the latest after the maximum permissible pressure of the metering machine is exceeded to prevent damage to the mechanical structure.

The program parameters volume, lower limit and upper limit of the glue quantity monitoring have no influence on the glue quantity. They are only used for monitoring functions. As soon as the control unit detects a situation where the upper limit is exceeded or the lower limit is fallen below, it reacts as follows:

• Display of a fault message on the control panel.

• Sending of a fault message to the higher-level control unit and resetting of the corresponding output signal. The processing depends on the configuration interface.

• Entry in the fault memory.