Siemens rotating head gas path structure is mainly composed of real air path, blow gas path, vacuum/blow gas conversion unit three parts (Figure 1). True air path: including vacuum generator, vacuum distributor, vacuum detection. After four channels of compressed air pass through the vacuum generator, two channels of vacuum are formed, which are respectively connected to the vacuum dispenser through two gas pipes, one big and one small. Among them, the small one is dedicated to PICK UP and PLACEMENT, and provides vacuum for that segment when taking materials. The large one is used for HOLDING CIRCUIT, and the vacuum distributor divides the large one vacuum into eleven vacuum paths for HOLDING components. This gives twelve vacuums for twelve segments. In addition, the vacuum dispenser is connected to the vacuum detector by two air pipes to detect the vacuum values of PICK-UP, PLACEMENT and REJECT.
Blowing air path: Receiving compressed air next to the vacuum generator and controlling it through a solenoid valve switch, the air is divided into two ways, all the way to the REJECT CIRCUIT, and the air pressure transmitted to the NOZZLE is 0. 2BAR; The other goes all the way to the vacuum/blowout converter unit and NOZZLE goes to zero. 15BAR, for PLACEMENT, with an air blow sensor to detect the pressure. In addition, the size of the air pressure can be adjusted by the air pressure adjustment screw shown in Figure 1.
Vacuum/blow conversion unit: As shown in Figure 2, the stepping motor drives a small eccentric bearing to control PLUNGER in and out, so as to realize the conversion of vacuum/blow two states. When PLUNGER is pushed out, the Vacuum supply is cut off, and the air blow supply and segment are connected, as shown in FIG. 2 -- 1. When PLUNGER is pulled out, the air blow supply is cut off, and the Vacuum supply is connected with the segment, as shown in Figure 2-2. The O-ring is a rubber ring that acts as a seal to prevent air leakage.
Let's take a look at the three processes closely related to the rotating head gas path: the picking process - PICK-UP, the placing process - PLACEMENT, and the throwing process - REJECT.
PICK-UP process - Pick-up: Siemens mounter mounting head gas path explanation
First, the SLEEVE is turned to the Angle of material taking at the Dp-station, and then the rotating head continues to rotate. At the same time, the X and Y axes are also moving toward the target material taking position. After the last END SIGNAL in the rotating head, X and Y axes is transmitted, the Z axis begins to move downward. Then the downward light barrier of Z axis is activated to send out an END SIGNAL, the stepping motor rotates 180 degrees immediately, PLUNGER is pulled out, the segment is connected to the vacuum, the vacuum is transmitted to the NOZZLE to suck up the material, and the pick-up vacuum detection is carried out. After the stepper motor rotates 180 degrees, keep it still, and send an END SIGNAL, the Z axis will move upward and backward, and the upward light barrier of the Z axis will be activated to send an END SIGNAL, and the rotating head will continue to rotate and enter the next feeding cycle.
PLACEMENT process -- PLACEMENT: Siemens placement head gas path explanation
After the NOZZLE is photographed, the SLEEVE is rotated to the Angle of placement at the Dp-station and the rotating head continues to rotate. At the same time, the X and Y axes are also moving towards the target placement position. After the last END SIGNAL of the rotating head, X and Y axes is sent out, the placement vacuum detection is carried out. The air blow solenoid valve opens (the opening time is about 65ms), at the same time, the Z-axis begins to move down, and the downward light barrier of the Z-axis is activated to send out an END SIGNAL, the stepper motor immediately rotates 180 degrees, the PLUNGER is propelled, and the plunger is pushed forward. The segment is connected to the blowing air path, and the material on the NOZZLE is attached to the circuit board; After the stepper motor rotates 180 degrees, hold it still, and send an END SIGNAL, the Z axis will move upward and backward, and the upward light barrier of the Z axis will be activated to send an END SIGNAL, and the rotating head will continue to rotate to enter the next Posting cycle.
Throwing process - REJECT: Siemens mounter mounting head gas path explanation
There are two reasons for throwing material, vacuum detection error and photographic identification error, and the throwing process is the same. First, move the X and Y axes to the Reject position, and rotate the head to the position of the third segment. The air blow solenoid valve opens, the stepper motor rotates 180 degrees, PLUNGER is propelled, the segment is connected to the air path, and the material on the NOZZLE is blown off.
Let's take a look at some common problems and countermeasures related to the gas path in the production process of the machine.
Error message: 2452 RV-head: leak in segment after placement.
Reason analysis:
1. plunger and its moving inner cavity wall are not well matched or there is dirt, or the O-ring that plays a sealing role on plunger is excessively worn, causing air leakage, resulting in low vacuum value.
2. There is dirt in the gas pipe of the true air path or the pipe connection is not close enough, resulting in a low vacuum value.
3, the vacuum generator performance is unstable.
Countermeasure:
1. Clean plunger and its moving inner cavity wall or exchange plunger or replace plunger.
2, clean the gas pipe of the real air path, and closely connect the gas pipe.
3. Clean the vacuum generator or replace it.
Error message: 2478 (9) RV-head: Air kiss pressure during placement too low (high).
Reason analysis:
1. The air blow supply pipe in Figure 1 is loosely connected.
2. NOZZLE pressure is not calibrated and is less than or greater than 0. 15BAR.
3, the dynamic performance of the solenoid valve is unstable or broken.
Countermeasure:
1. Connect the air blow supply pipe closely.
2. Use Siemens special air pressure tester to calibrate NOZZLE pressure to 0. 15BAR.
3. Replace the solenoid valve.
