Parker Products WCS-SIF-01 manual General Operation Spotwelding Units 3 ported guns, Front View

WCS-SIF-01 Training & Maintenance Manual

Description & Operation

General Description of Spotwelding Units

The spotwelding system is an integrated pneumatic controlled circuit that is specifically designed to increase production throughput, while improving weld quality and reducing decibel noise level.

Each unit consists of 2 independent, 2 position, directional control valves for retract (pre-stroke) and weld stroke. Each valve is dual pressure, with single solenoid / spring assist return or double solenoid available. Also included with each unit is a proportional / quick dump valve, a feedback sensor for initiating the welding process, and a flow control for metering the impact speed of the weld tips.

ANSI (3 Ported Cylinder Option)

Inductive Sensor / Connection: Turck

Connection Diagram Inductive Sensor

1	Brown	+4 VDC Power Supply
3	Blue	0 V Power Supply
4	Black	Switch Wire
		+		-
			1	3	4

pnp

14			14
Pr
4	R+		4	W+
			
1			1	W-
Retract (Pre-Stroke)			Weld Stroke	R-
Valve		Pw	Valve

General Operation of

Spotwelding Units – 3 ported guns

Spotwelding systems control both retract (pre-stroke) and weld stroke motions. When a 3 ported cylinder is used, the control block functions as follows:

1.The pre-stroke (retract) valve is energized, allowing the weld cylinder to extend under full line pressure by actuating the quick exhaust valve and moving to its predetermined position prior to welding.

2.The quick exhaust valve time is adjusted by the knob on top of the unit. To start, the white line on the dial is set at top dead center. Turn knob clockwise to set quick exhaust valve open time. Continuing to turn knob clockwise will lengthen time until it reaches a full 360° rotation, which covers the complete timing range.

3.The weld stroke valve is then energized using a selected weld schedule pressure. The closure speed of the weld tips is controlled by the use of an adjustable flow control, thus creating “low impact”.

4.Immediately following weld tip contact with the sheet metal, two actions take place.

Front View	Weld Stroke	Flow
	Valve	Control

Retract

(Pre-Stroke)

Valve

Feedback

Sensor

	Weld Stroke
	Valve
Back View	Quick
	Exhaust
	(Air
Retract	Operated)
(Pre-Stroke)
Valve

a. The proportional / quick dump valve that senses pressure allows the front end of the cylinder to exhaust (by-passing the flow control), providing weld schedule pressure instantly.

b. The proportional / quick dump valve also actuates a feedback sensor to start the weld cycle.

5.Once the weld cycle is complete, the weld stroke valve is de-energized, allowing the weld tips to open under full pressure.

6.The retract (pre-stroke) valve is then de-energized, allowing the weld cylinder to open completely under full line pressure.

Note: Dual pressure is provided to the control block. Line (high) pressure is used for both retract stroke and weld stroke open. Weld schedule pressure is used for weld stroke close. Dual pressure provides for weld tips to be closed for tip dressing using any pressures available, from as low as 5 PSIG to maximum line pressure.

Pneumatic

	Parker Hannifin Corporation
	Pneumatic Division
	Richland, Michigan
	www.parker.com/pneumatics