Lecture 4 Flashcards
What is a vibratory bowl feeder used for in automatic assembly?
A vibratory bowl feeder is used to orient parts for automatic assembly, often handling and sorting asymmetrical parts that need specific orientations.
What are the main cost factors in high-speed automatic assembly?
- Equipment cost
- Number of operators and technicians
- Assembly rate
What does the formula Cf = 60Fr / Rf calculate?
This formula calculates the cost of feeding each part in automatic assembly, where Fr is the required feed rate, and Rf is the feeder cost rate.
How is the maximum feed rate (Fm) calculated in automatic assembly?
Fm = 1500 * E / l, where E is the orienting efficiency, and l is the part dimension in the direction of feeding.
What is the purpose of classification charts in automatic assembly?
Classification charts are used to determine part orientation efficiency (E) and relative feeder cost (Cr) based on part geometry and handling complexity.
What is a rotational part in geometric classification for automatic assembly?
A rotational part has a basic shape that is a cylinder or regular polygon, allowing it to repeat its orientation when rotated about its axis.
What factors can add additional feeder costs for parts in automatic handling?
Factors include part flexibility, delicacy, stickiness, weight, tendency to nest, tangle, or overlap, and abrasiveness.
What does the insertion cost formula Ci = 60Fr / Ri calculate?
This formula calculates the cost of inserting each part, where Fr is the required feed rate, and Ri is the workhead cost rate.
What are general rules for product design in automatic assembly?
- Minimize part count.
- Use a stable base part.
- Build in layers, assembling from above.
- Provide chamfers or tapers for easy positioning.
- Avoid time-consuming fastening methods.
What is a “base part” in automatic assembly?
A base part is a stable component with a low center of gravity, providing a foundation to build the assembly upon.
Why are chamfers and tapers important in automatic assembly?
Chamfers and tapers help guide parts into the correct position, ensuring smooth alignment and reducing jamming.
What are examples of robot assembly applications?
Applications include automotive components, consumer electronics, medical devices, and household appliances.
What are common types of robot assembly systems?
- Single-station with one robot arm
- Single-station with two robot arms
- Multi-station with robots, specialized workheads, and manual stations
What design rules are specific to robot assembly?
- Reduce part count.
- Use leads, lips, and chamfers for self-aligning parts.
- Design parts for single gripper use.
- Assemble parts from above (z-axis).
- Avoid reorienting parts after initial placement.
How are parts classified based on symmetry in automatic assembly?
Parts are classified as alpha-symmetric if they do not require end-to-end orientation and beta-symmetric if they do not need orientation around their principal axis.
