Method of manufacturing a modular damper

Abstract

A piston valve assembly for a damper comprises a piston having a central hole and a fluid passageway spaced from the hole. A deflection disc having a central aperture is aligned with the hole. A hub, common across different dampers, includes a neck that is arranged in the hole and the aperture of the deflection disc. A retainer abuts an unthreaded outer surface of the hub. During assembly, the retainer is received on the cylindrical outer surface in a slip fit relation and secured to the hub under a predetermined clamp load. Throughout the manufacturing process, components of the piston valve assembly are marked with identifying information that may be compared to other identifying information on the piston assembly throughout the manufacturing process to ensure integrity of the piston valve assembly. The piston valve assembly and other assemblies can be sent to another OEM facility near the customer to manufacture dampers that satisfy build requests for low volume dampers.

Description

BACKGROUND OF THE INVENTION [0001] This application is a divisional application of U.S. Ser. No. 10 / 894,442, filed on Jul. 19, 2004.[0002] This invention relates to dampers such as vehicle suspension shock absorbers, struts and the like. More particularly, the invention relates to a common hub design for piston valve arrangements enabling a more modular damper. [0003] Dampers such as shock absorbers and struts are used in vehicles to absorb inputs from the roadway to provide a desirable vehicle ride. Typically, vehicle dampers employ a piston that moves through a cylinder having hydraulic fluid. The fluid flows through fluid passageways and valves in the piston, which absorbs the roadway inputs in the form of heat. The piston size, valves, and piston rod are selected based upon the particular vehicle and vehicle application, which requires the damper OEM to stock numerous parts for different vehicles and even for different suspension packages for the same vehicle. [0004] One common ...

AI Technical Summary

Benefits of technology

The present invention provides a piston valve assembly for a damper that includes a piston, a deflection disc, and a hub. The hub is a common component across different piston valve assemblies and is used in different dampers. A retainer abuts the hub and is secured to it using a weld bead. The hub is manufactured with an inventive method and components of the assembly are marked with identifying information for comparison and correlation during manufacturing. The invention allows for cost-effective manufacturing of small lot size dampers and reduces the number of components stocked for different dampers while providing consistent loading of the piston valve assembly.

Problems solved by technology

This same problem applies to damper base valves and other damper subassemblies.

The damping characteristics of the damper are adversely affected if the deflection discs are not properly loaded against the piston.

One problem is that it may difficult to consistently control the predetermined torque resulting in failure of the finally assembled damper during its final test, which results in scrap at the OEM.

Moreover, the load on the deflection discs may decrease even after the predetermined torque has successfully been achieved and the damper has passed the final test.

Another problem with the proliferation of damper components is that it is difficult to manufacture low volume dampers cost effectively.

OEMs typically can only efficiently build dampers in large lot sizes.

As a result, the OEMs have contracted with outside companies to build the unprofitable smaller lots.

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