Automobile Designer Interview Questions And Answers

It is used to limit a broken section. For short break an uneven freehand thick line is recommended and for long breaks a long thin ruled dashes joined by freehand ‘ Zig Zags’ are used.

Generally draft angle is used in moldings and drop forgings, parts of which maybe left un-machined.

It is a curve which is generated by a point in the plane of a circle that rolls along a straight line.

Third angle projection

The torsion equation is derived on the basis of following assumptions:
☛ > The shaft material is uniform, throughout the shaft.
☛ > Even after loading the shaft circular remains circular.
☛ > After the application of torques the plain section of a shaft remains plain.
☛ > Any twist that occurs in the shaft remains uniform and constant.
☛ > After the application of torque the distance between any two cross-sectional references remains constant.
☛ > The elastic limit value of a shaft is never exceeded even after the

☛ (a) Isometric projection
☛ (b) Oblique projection
☛ (c) Perspective projection.

Development is the drawing of all the surfaces of an object on a plane to make a pattern. If it is folded or rolled it will form the required object. The main applications are in sheet metal work,sheet plastic fabrication and many other industrial applications.

It shows the essential shape, size and specifications required for the construction of each unit of a product.

If one solid penetrates into the other solid of the same or different cross section then surfaces of the both solids come in contact and outline of the penetrating solid can be seen which is called interpenetration of solid.

The cross section of an object obtained by passing an imaginary cutting plane through the object is called sectional view.

Vertical plane(VP) and Horizontal plane (HP) are generally used in orthographic projection. These planes of an object are obtained to describe it clearly with all dimensions. These are known as principle planes and the position of an object can be fixed by following four quadrants:
☛ (1) First Quadrant: It is above HP and in front of VP.
☛ (2) Second Quadrant: It is above HP and behind VP.
☛ (3) Third Quadrant: It is below HP and behind VP.
☛ (4) Fourth Quadrant: It is below HP and in front of VP.

It is the method of representing the exact shape of an object in two or more views on planes. In this projection all the projectors are parallel to each other and perpendicular to the plane of projection. Projectors are assumed to come from infinity. It is generally used in machine drawing.

It is plane closed figure having many sides and angles. A regular polygon has equal sides and equal angles.

Some of the important properties to lookout for in the material for sliding contact bearings are as follows:
☛ > Compressive Strength: In order to prevent the permanent deformation and intrusion of the bearing the material selected should be possess a high compressive strength to bear the max bearing pressure.
☛ > Fatigue Strength: the material selected for the bearing should be able to withstand loads without any surface fatigue cracks getting created. This is only possible if the material has a high level of fatigue strength.
☛ > Comfortability: The material should be able to adjust or accommodate bearing inaccuracies and deflections without much wear and heating.
☛ > Embeddability: The material should allow the embedding of small particles without effecting the material of the journal.
☛ > Bondability: The bearings may be created by bringing together ( bonding ) multiple layers of the material. Due to the above reason the bondability of the material should be sufficiently high.
☛ > Thermal conductivity and corrosion resistance: Thermal conductivity is an essential property for bearing materials as it can help in quickly dissipating the generated heat. Also the material should have a level of corrosion resistance against the lubricant.

(c) Contact stress on two contact surfaces

(c) Amount by which the width of a tooth space exceeds the thickness of the engaging tooth on pitch circle

(a) Keeping the core dia of threads equal to the dia of unthreaded portion of bolt

(b) Buckling consideration

(d) Velocity

The following values are needed to be determined:
☛ > Thickness of the cylinder wall: The cylinder walls in an engine is made witness to gas pressure and the side thrust of a piston. This results in two types of stresses: longitudinal and circumferential stress. Both the types of stresses are perpendicular to each other and hence it is aimed to reduce the resulting stress as much as possible.
☛ > Length and bore of the cylinder: The length of the cylinder and the length of the stroke is calculated on the basis of the formula: length of cylinder L = 1.15 times the length of the stroke (l). L = 1.15(l)
☛ > Cylinder flange and studs: The cylinders are always cast integral as a part of the upper crankcase or in some cases attached to it by means of nuts and bolts. The flange is integral to a cylinder and henceforth its thickness should be greater than that of the cylinder wall. The thickness of flange should generally be between 1.2t-1.4t where t is the cylinder thickness.
The stud diameter is calculated by equating gas load ( due to max pressure ) to the grand total of all the resisting forces of the studs.

The advantages of the Cycloidal gears are as follows:
☛ > Having a wider flank as compared to Involute gears they are considered to have more strength and hence can withstand further load and stress.
☛ > The contact in case of cycloidal gears is between the concave surface and the convex flank. This results in less wear and tear.
☛ > No interference occurs in these types of gears.
☛ The advantages of Involute gears are as follows:
☛ > The primary advantage of involute gears is that it allows the changing of the centre distance of a pair without changing the velocity ratio.
☛ > The pressure angle remains constant from start to end teeth, this results in less wear and smooth running of the gears.
☛ > The involute gears are easier to manufacture as they can be generated in a single curve ( the face and flank ).

☛ 1) Pattern detail drawings
☛ 2) Stamping detail drawings
☛ 3) Casting detail drawings
☛ 4) Welding detail drawings
☛ 5) Forging detail drawings

Generally hidden lines are omitted from the sectional view and not essential to show all hidden lines in assembly drawing. If it is necessary to show more clearly a hidden part in the section or aiding in dimensioning the view, they may be drawn.

The steps required to calculate the force are as follows:
☛ > The reaction at the support has to be first calculated.
☛ > Once the reaction is calculated the direction of force of the member is made to make it tensile. On getting the result to be negative the direction assumed is wrong and this implies the force being compressive in nature.
☛ > A joint needs to be selected whose 2 members are not known. The lami`s theorem is used on the joint on which less than three forces are acting.
☛ > After the above process is complete the free body diagrams of the joint needs to be made. Since the system is in equilibrium the condition of Summation of V and H must result in zero.
☛ > After the above step the resolution of forces method needs to be used on the joint on which more than 4 forces are acting.

It is a curve which is generated by a point moving at uniform rate around and advancing parallel to, or at varying distances from an axis.