June 2012 Archives

When automating assembly that was once performed manually (low-cost automation), mechanical designers tend to forget the expertise involved in manual processes. Complex mechanisms and controls are required in order to replicate this expertise using automated technology, resulting in disadvantages such as: (1) lengthened production takt time; (2) increased failure stoppage of automated equipment; and (3) increased investment expenditures. This tutorial describes the key considerations for part design that allows the need for expertise in insertion assembly to be minimized.

(1)Key considerations for part design for easy insertion assembly

In order to improve the competitiveness of automated assembly equipment, designers of automated equipment must provide product designers with guidance regarding part design that will provide for easy assembly, as well as displaying leadership in understanding the importance of such design. The following table summarizes the key considerations.

This tutorial describes insertion assembly technology, our third representative example of a component technology for assembly automation.
Low-cost automation of assembly procedures consists of automating multiple simple component procedures in combination. Three representative examples of component technologies for assembly procedure automation are described in these technical tutorials: swaging technology, screw tightening technology, and insertion assembly technology.

(1) What is insertion assembly technology?

- The term "insertion assembly technology" refers to techniques for performing the following types of procedures, whether manually or using tools/machinery.

- Interference fits and other press fits are insertion assembly methods enabling a range of functionality, including: (1) fixation, (2) positioning, (3) posture holding, and (4) force transmission.

- Clearance fits and other insertions are insertion assembly methods with a range of uses, including: (1) positioning, (2) guidance, (3) preprocessing such as joining, and (4) coupling.

(2) Characteristics of insertion assembly technology

1. Advantages

• - Insertion assembly is suited to use as a component technology for automated assembly, because it generally involves movement in a single direction.
• - High-precision assembly automation can be effected with ease, according to the level of precision of the parts used. (See Fig.1.)
• - Disassembly/re-assembly is possible after assembly.

2. Disadvantages

• - Insertion assembly is greatly affected by the design form and quality (such as precision or surface conditions) of the two individual parts to be assembled.
• - It is extremely difficult to automate exacting procedures requiring highly skilled manual work.
• - Disassembly is difficult if faults (such as biting) occur during insertion assembly mechanical procedures.