Week 5:- Rest Unit & Clamp Unit Design Challenge

REST UNIT AND CLAMP UNIT DESIGN -

OBJECTIVE- 1) Design three different types of power clamp unit with different type of riser , blade and clamp arm for given car panel .

2) Design two different types of rest unit for the given car panel .

INTRODUCTION -

Clamp unit -

- Clamp unit is designed to clamp/hold car panel with NC blocks/Mylars/rest by using a pneumatic clamp cylinder .

- Clamp unit consist of Finger , back-up / rest mylar , shims/spacer , clamp arm , block , pneumatic clamp cylinder , riser .

- There two types of clamp unit ,power clamp and swivel clamp .

Fundamentals of clamp unit design -

• It is preferred to design clamp unit with pivot centreline in line with clamp surface .when possible upto 25mm offset is acceptable .
• For a single angular clamping , it is recommended that the centreline of clamp pivot be positioned on plane that is created by surface being clamped , upto 15 degree off normal pivot location can be used in extreme cases where recommendded clamping condition cannot be achieved .

Below are the parts included in the clamp unit -

1) - Finger / clamp mylar -

• It is a NC block mounted on the th clamp arm of the cylinder .
• It is used for clamping / holding the car panel .
• It will press the car panel towards rest .

2) - Backup / Rest mylar -

• It is a NC block fixed to the unit to support the car panel .
• It helps in resisting the clamping force of panel , thus clamping the panel .

3) - Clamp arm -

• Clamp arm is a part of the clamp cylinder and it is a brought out part .
• All th movable parts in a clamp unit is fixed to the clamp arm .
• Clamp arm is different for different bore size of cylinder , it is also available in different hole pitch .

4) - Clamp cylinder -

• Clamp cylinder is a pneumatic device which works with the flow of pressurised air .
• Clamp cylinder is a brought out part and some manufacurers are destaco , tuenkers etc .
• The clamp cylinder is used to open and close the moving part in the clamp unit .
• The clamp cylinder in general is in 40 , 50 , 63 , 80 bore capacity .
• Clamp cylinder opens upto 135 degree for horizontal clamp mounting , and it opens upto 105 degree for vertical clamping .

DESIGN METHODOLOGY -

Input

Above is the workpiece for which we need to design the clamp units and rest units following the 3-2-1 principle . the units should properly clamp the workpiece during the welding operation . we will examine our workpiece and determine which surace we would use as our clamping points .

so we have identified the points on the workpiece where we will be likely to put our clamping units . also we have identified the resting points on the workpiece where we would place the resting units .

We have created 3 clamp units and 2 rest units making sure that the workpiece will be properly clamped during the welding operation. below is the detail view of the various clamping points on the workpiece .

Clamp units -

1) Clamp unit 1-

clamp unit 1 consits of cylinder , clamp arm , 2 clamp mylars , 1 rest mylars , blade , riser . two clamp mylars are used for the clamping on two points on workpiece . as we can see in the below images , the opening and the closing position of the clamp unit is shown .

2) Clamp unit 2 -

Clamp unit 2 consist of cylinder , clamp mylar , rest mylar , riser . this clamp unit will clamp on one point on workpiece . in the below images we can see the open and close position of the clamp unit .

3) Clamp unit 3 -

Clamp unit 3 consist of riser ,blade , rest mylar , clamp mylars , clamp arm , cylinder . this unit is similar to the clamp unit 1 but it has different type of riser and blade . this unit will also be clamping in two points on workpiece .

Rest units -

We have devloped 2 rest units for the worlpiece as we are going to have two resting points on the workpiece . rest unit 1 consist of rest mylar , block , riser and shims . rest unit 2 consist of rest mylar ,riser , shims .

Above images is showing the parts in rest unit 1 and rest unit 2 . in the below image we can see the workpiece rested on the rest units .