Challenge

Week 5:- Rest Unit & Clamp Unit Design Challenge

IImtiyaj Mathakiya16 Mar 2023

Rest Unit & Clamp Unit Design

AIM:-To design 3 Different types of Power Clamp Unit with Different Riser, Blade, and Clamp Arm and design 2 Different types of Rest Unit for the given Car Panel.

CLAMP UNITS DESIGN.

A clamp unit is a unit designed to clamp/ hold the car panel with NC BLOCK / Mylar / Rest by using a pneumatic clamp cylinder.

below are the different parts of a clamo unit.

INTRODUCTION

A Clamp is a device that is used to hold the part tightly, yet, firmly in the assembly, The clamp prevents any sought of movement of the assembly in the fixture and ensures proper operation on the part without any distortion.

The clamp must be placed in such a way that it does not interpret the operation.

The clamp plan is the data provided by the customer. The clamp plan provides information on the location of pins, rest units, Clamp units, Dumps, etc.

It gives the details of the exact position of the clamping locations in form of coordinates

The clamp position in some cases will be in such a way that it might damage the tool, or very near to pin position. In such cases, We should not take the decision to change the clamp plan without discussing it with the customer.

Typical parts of a clamp unit :-

FINGER:- Afinger is a NC Block, which is mounted on the clamp arm of the cylinder, and will press the car panel towards the rest, so that it holds the car panel.

REST :- A rest is a NC block, which is fixed to the unit to support the car panel, also it resists the clamping force of the finger and thus clamp the car panel.

Clamp Arm :- A clamp arm is a bought out part, to which all the movable parts are fixed. in general a clamp arm is apart of clamp cylinder.

clamp arms are different for different bore of the cylinder
clamp arms are available in different hole pitch
clamp arms are available as
Middle Arm-A10
Right Arm-A11
Left Arm-A12

Clamp Cylinder :-

A clamp cylinder is a pneumatic device works with pressurised air. the clamp cylinder is used to open and close the parts fixed to the clamp arm fixed to the clamp body.

Clamp cylinder are bought out parts, some of the manufactures are Tunkers and Destaco
Clamp cylinder are in general 40,50,63 and 80 bore capacity.
open up to 135 deg for horizontal clamp mounting.
open up to 105 deg for vertical clamp mounting.

3-2-1 Principle

The 3-2-1 method is a work-holding principle where three pins are located on the 1st principle plane, i.e. either XY, YZ, ZX. And two pins are located on the 2nd plane which is perpendicular to the 1st plane, and at last one pin on the plane which is mutually perpendicular to the 1st and 2nd planes. The ultimate goal is to constrain the movement of the workpiece along all three axes.

3.Minimum

From the above figure, We can see three locator blocks positioned at the primary locating surface. These three locators restrict the axial upward and downward movement along with it the two radial movements both clockwise and Anti clockwise are also restricted. So, a total of four radial movements is restricted to the two mutually perpendicular axes.

The three locators, on the whole, have restricted six Degrees of freedom.

2.Round Locating Pin

The pin added in the location of the hole restricts the axial movements of two perpendicular axes (both positive and negative). Thus, restricting Four Degrees of freedom.

1.Round Locating Pin

The round locating pin is added to the slot in order to restrict the remaining radial movement in both clockwise and anti-clockwise. This, therefore, restricts the remaining two degrees of freedom.

Thus, the 3-2-1 principle is used to restrict the 12 degrees of freedom of a part.

DESIGN METHODOLOGY

Rest Mylar
Clamp Mylar
Bought the cylinder from Tuenkers
Riser
Shims

Note:- All the part should be Isolate.and some sharp edge give champfer or edge fillet so material cost low.

Rest Unit

The rest units are designed to support the car panels using Mylar.
The primary purpose of the rest unit is to rest the car panel.

The parts of the rest units are as follows

Mylar
Blade
Risers

Mylar

Mylar is the part that holds the panel from above and below during the operation.
The top side of Mylar is called the clamping Mylar. Whereas, the bottom side Mylar is known as resting Mylar.
Every Clamping Mylar will have a resting Mylar.
It holds the panel in such a way that it does not deform during the welding process.
The below image shows basic Clamping and Resting Mylar.

Riser

A riser is a part that is used to raise the height of the fixture.
The raiser is fixed to the base of the fixture and the blade is mounted on the riser
There are two types of raisers 1.L type riser 2.Square Tube risers.

Blade