DRAWBAR

 

The drawbar menu provides functions to generate drawbars on the die surface.  There are three types of drawbars available:

 

1.       DRAW BAR ENDS WITH A SPHERICAL SHAPE (TEAR DROP HEAD). Figure 6.5.9 shows the control parameters in the dialog box.

 

2.       DRAW BAR ENDS WITH A CONICAL SHAPE (TEAR DROP TAIL). Figure 6.5.10 shows the parameters in the dialog box.

Figure 6.5.9 Parameters for Tear Drop Head

 

Figure 6.5.10 Parameters for Tear Drop Tail

 

3.        TEAR DROP (DRAW BAR WITHOUT MAIN BODY).  Figure 6.4.11 shows the parameters in the dialog box.

Figure 6.5.11 Parameters for Tear Drop

 

Control Parameters:

Rs:   Drawbar Radius

Rf:    Fillet Radius

Wh:  Wall Height (can be zero)

Sw:   Top Strip Width (can be zero)

A:     Wall Angle (default of 6 degrees)

Rt:    Tail Circle Radius

Lt:    Length of Tear Drop

 

The steps to create a drawbar are listed as following:

 

·         Click on the DRAWBAR function from the DFE MODIFICATION dialog box to display the DRAWBARD dialog box as illustrated in Figure 6.5.12a.  If the user wishes to define the element size of the drawbar, toggle off checkbox of the AUTO ELEMENT SIZE option.  As illustrated in Figure 6.5.12b, the user can enter the element size in the input field.

 

·         Select one type of drawbar. The default selection is DRAW BAR ENDS WITH A SPHERICAL SHAPE (TEAR DROP HEAD).

 

·         Click on the PARAMETERS button to display the corresponding dialog box as illustrated in Figures 6.5.9-6.5.11.

      

(a)                                          (b)

Figure 6.5.12 Drawbar dialog box (a) With Auto Element Size  (b) With User Defined Element Size

 

·         The CREATE DRAWBAR SURFACE option enables the user to generate drawbar surfaces.  This option is selected as default.  The user may disable the option if the drawbar surfaces are not required.

 

·         Define the centerline of the drawbar.  The centerline is the center of the drawbar’s main body, including both ends.

 

·         If centerline is available in the current database, click on the SELECT CENTER LINE button to select the centerline. Else, click on the CONSTRUCT CENTER LINE button to create a line by selecting nodes on the mesh.

 

·         After the drawbar parameters and centerline are defined, click on the APPLY button to generate the drawbar. Select YES to keep the drawbar mesh or NO to reject the mesh.  The REVERSE button is used to reverse the drawbar on the opposite side of the tool.  If the CREATE DRAWBAR SURFACE option is selected, the drawbar surface will be generated together with the mesh.

 

If the tear drop drawbar is selected, the dialog box as illustrated in Figure 6.5.13 is displayed.  Click on the SELECT TWO NODES button to select two nodes to define the direction of the centerline.  The head of the tear drop will be placed at the first selected node.  The length of the tear drop is determined by the parameters defined in the PARAMETER window.  

 

 

Figure 6.5.13 Tear Drop

 

Figure 6.5.14 shows the details of three types of drawbars.

 

Figure 6.5.14 Three Types of Drawbars