Automatic Four-Point Spot Welding Machine for Shock Absorber Connecting Rods

This machine was built for one specific part on a large automotive production line. The customer - a major vehicle manufacturer producing both new energy and conventional passenger vehicles, with its own large-scale component machining lines - needed to weld shock absorber connecting rods, each part requiring four separate welds. The existing setup could no longer keep up with the quality and output targets that came with expansion, so PDKJ designed, built and commissioned a dedicated automatic four-point spot welding machine. It has now completed delivery and commissioning and is running in the customer's workshop as a permanent station.

Application Overview

Customer Welding Requirements

Customer Background

The customer is one of China's large vehicle manufacturers, covering the R&D, manufacturing and batch production of new energy and conventional passenger vehicles and their matching components. It runs several large-scale component machining lines, and parts like the shock absorber connecting rod are welded under automotive quality-control standards where every weld is expected to be identical, part after part.

Project Background

With market orders growing, the customer planned to expand component capacity. The connecting rod family requires four welds per part. Under the existing production conditions, completing this operation on current equipment could no longer meet the quality and efficiency requirements that followed the expansion. To unblock the line, the customer approached PDKJ for a customized four-point welding machine matched to the workpiece and the workshop.

Pain Points and Problems

After reviewing the workpiece structure, the existing line flow and the staffing on site, three problems had to be solved by the same machine:

• Inconsistent multi-point weld quality. With manual positioning and clamping, the weld positions drifted and the nugget sizes varied from part to part. Quality fluctuation meant heavy downstream inspection and rework.
• A fragmented process that limited the line speed. Welding the four points in separate setups meant repeated clamping and part handling, long single-piece cycle times, and a station that became the bottleneck of the whole line.
• High dependence on manual work. Repeated positioning relied heavily on operator skill, labor intensity was high, and with skilled welders increasingly hard to recruit, long-term stability was difficult to guarantee.

The Automatic Four-Point Spot Welding Machine

PDKJ sized the machine around the workpiece dimensions, the welding process and the capacity target, then delivered a four-point spot welding machine whose core value is simple: one clamping cycle, four finished welds.

1. Four welds in one synchronized cycle. A dedicated fixture positions the part precisely, and the machine completes all four welds simultaneously. Removing the repeated manual re-clamping removes its errors with it: nuggets come out uniform and stable, the reject rate drops, and rework falls - matching the strict quality-control standards automotive components demand.

2. A closed automatic loop that releases line capacity. Once the part is loaded and positioned, the machine completes clamping, four-point welding, release and unloading as one flow. The intermediate manual handling disappears, the single-piece cycle shortens, and the bottleneck that held back the line is removed.

1. Adjustable process parameters with room to grow. Welding current, pressure and weld time are adjustable through a visual interface. When the part goes through a minor revision, the change is absorbed by adjusting the parameters - not by re-engineering the machine - which extends the useful life of the equipment.

2. Built for long shifts, easy to run and maintain. The machine passed factory inspection before delivery and is built for continuous production. The interface is simple enough that operators come up to speed with short training, and PDKJ's standard after-sales system covers later maintenance and parameter support.

How the Machine Solves the Customer's Pain Points

1. Position errors are designed out.. The dedicated fixture, not the operator's eye, defines the weld positions, so the four nuggets land in the same place on every part.

2. Four setups become one.. One clamping cycle replaces repeated re-fixturing, cutting the single-piece cycle time and freeing the line from its slowest station.

3. Quality stops depending on who is on shift.. Parameter-controlled welding with synchronized heads produces the same energy and the same force on every weld, independent of operator proficiency.

4. Inspection and rework loads fall.. Uniform nuggets mean fewer suspect parts moving downstream, which lowers the hidden cost of quality on top of the visible cycle-time gain.

5. Expansion absorbs without a new machine.. Parameter-based flexibility covers minor part revisions instead of a redesign.

Welding Process

Why Choose a Customized Four-Point Welding Machine?

A general-purpose spot welder makes one weld at a time and depends on the operator for positioning. When a part needs four welds per piece at automotive volumes, the customization is what pays for itself: the fixture, the synchronized welding heads and the control logic are designed together around the workpiece, so consistency and cycle time stop being a matter of operator skill.

Key Advantages

• Four synchronized spot welds per clamping cycle on a dedicated fixture.
• Closed automatic loop: clamp, weld, release and unload with minimal manual handling.
• Adjustable current, pressure and time through a visual interface, with recallable settings.
• Factory-tested build for continuous automotive production shifts.
• Simple operation and short operator training, supported by PDKJ after-sales.

Potential Applications

The same approach applies to any part that needs several fixed-position welds per piece: brackets, linkages, seat frames, sub-assembly brackets and other automotive or sheet-metal components where multi-point consistency and cycle time decide the cost of the part.

From Design to Production

The machine completed delivery and commissioning and entered regular production in the customer's workshop. Feedback from the line confirms the original goals: more stable four-point weld quality on the connecting rods, a simplified process flow, less repeated manual handling, and a station that no longer limits the output of the line.

From solution design to a machine running on the floor, PDKJ keeps the work grounded in the actual production conditions so the equipment fits the line, not the other way round.

PDKJ continues to provide customized laser welding and resistance welding solutions based on different materials, workpiece structures, welding requirements, and production applications.

Related Products

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• DTB-80 Industrial Vertical Medium Frequency Inverter Spot Welder
• Platform Type Intermediate-Frequency Inverter Seamless Spot Welding Machine

Contact PDKJ

If your parts need several welds per piece at production volume, send us the drawing, material and thickness - PDKJ will evaluate whether a four-point machine, a multi-head design or a different customized solution fits best, with sample welding available before you decide.

WhatsApp: +86 136 1279 3248

Email: pdkj101@gd-pw.com

Website: https://www.spotlaserwelding.com/contactus.html

Address: 1-2F, Building 3, Qichen Industrial Park, No. 26 Luxi 1st Road, Liaobu Town, Dongguan City, Guangdong Province, China

Guangdong Pudian Automation Technology Co., Ltd (PDKJ) - 20 years in resistance spot welding machines, laser welding machines and automated welding equipment.