MECHANICAL DESIGN 1

Mechanical Design

Institution of Afiliation

Product Design Specification

The design of the master cylinder and it’s accompanying cylinder has a significant effect on how effective the braking system in a vehicle is. It therefore has to be designed with regard to a wide array of constranits and criteria. These factors govern how they operate and consequently how much torque is transmitted to the slave cylinder. Depending on the type of vehicle being designed for, these constraints may vary accordingly. For this problem, the following factors were considered:

Performance, Quality and Reliability

With all factors considered, they all build up to one thing: performance. All drivers desire a braking system that offers them the best performance and hence the master cylinedr has to be designed with this in mind. The mode of operation was designed to be operational with the least number of actions. The driver need only step on the pedal once for the braking system to be set in motion and stop the vehicle.In addition to this, the product has been desgined toenable adulst to carry out the actions without the need for additional tools. It is also meant to guarantee constant vibrations throughout driving without any random shocks to allow for normal streering operations.

Life in service

The performance was also viewed in terms of the product lifetime. The cylinder should be able to last for at least 10 years so as to offer the user a long lifetime over which they can effectively use the brake with minimal maintenance costs.

Ergonomics

It is always a desirable thing for the driver to be comfortable when operating the master cylinder to stop the vehicle. In designing the components, this was focused on and therefore it does not interfere with the driver in any way and also does not introduce any wiggles which might prevent them from driving well.

The safety of the vehicle’s occupants depends on how effective this master cylinder is for maximum performance. To prevent abrupt movements, it is made in such a way that it remains in the locked position not only during normal operations but also in case of an accident. It has also been made with a quick release system to enable the occupants escape quickly.

Size and weight

The dimensions of the master cylinder and its resevoir have been kept at a bare minimum to ensure that they occupy the least space possible. The materials to be used for its manufacture have also been carefully chosen so as to use the least heavy yet strong ones. These two considerations ensure that it properly fits in the cockpit.

Sketches for the 4 Design Concepts

Concept 1

mechanical design

Concept 2

mechanical design 1

Concept 3

mechanical design 2

Concept 4

mechanical design 3

Evaluation of concepts

Concept 1

The first concept is labeled as Design A and is by far the simplest design among the four. The pedal is linearly connected to the master cylinder which is in addition connected to the reservoir that is angularly shaped. It is based on a single reservoir design and therefore the brake fluid is shared between the primary and secondary cylinders. This makes it easy maintain as once the fluid is refilled, it can provide lubrication for both cylinders. However, it has a major drawback in that if the master cylinder fails, then braking control will be lost in the whole vehicle therefore exposing the occupants to danger.

Concept 2

This second concept shows the sectional view of one half of a dual reservoir master cylinder. This is a development of the design illustrated in concept 1. The reservoirs are connected, allowing for spillovers to flow from one side to another. The force is passed from the pedal by way of a piston which is connected to a loaded spring. The spring transmits the force through a plate to the slave cylinder. It is therefore capable of exerting a large amount of torque and can therefore offer great stoppage power.

Concept 3

It is also a dual-reservoir master cylinder but the two cylinders are not connected in any way. The lower (shown) one supplies lubricant to the master cylinder is split from the upper one which supplies the slave cylinder. It has a lever that detects how high the lubricant is to indicate whether there is need for any refills. It also has a gauge which controls the amount of lubricant that gets into the cylinders. The stopping torque is supplied to the slave cylinder from through a loaded spring that wraps around a metal component.

Concept 4

The final design is labeled as Design D and like A, is a single reservoir master cylinder. The force from the pedal is transferred by way of a piston which is connected to a plate. The piston has a loaded spring that returns it back to its original position after each cycle. On the other hand, the plate is connected to the slave cylinder through a piston consisting of leaf springs. These effectively store and release the force that is supplied to them thereby facilitating the fast release and stopping, which is one of the desired attributes in such a system.

It is not possible to use all these designs on one vehicle due to budgetary and technical constraints. Based on the mentioned features, however, it is clear that the third concept (Design C) is the most appropriate one in this scenario. This is because the loaded spring can be able to transmit a large amount of torque yet achieve fast release speeds. It therefore guarantees the user of not only great stopping power but also little action time.

Detailed drawing of Design C

The third concept was selected as the most appropriate one, with the drawing below showing the detailed features on it:

mechanical design 4mechanical design 5mechanical design 6mechanical design 7mechanical design 8mechanical design 9mechanical design 10mechanical design 11mechanical design 12mechanical design 13mechanical design 14mechanical design 15

holds the springShaft-

The force from the pedals is transmitted from the piston to this spring. Consequently, it holds the force and transmits it to the slave piston. The force is finally spread to the slave cylinder, which initiates the brakes.

The level of the fluid present in the reservoirs determines how much can be released into the cylinder and if there is need for refilling. This lever checks and indicates these parameters.

It contains the brake fluid that is supplied to the master cylinder.

Reservoir

The user exerts pressure on the piston, which then delivers it to this piston. The piston therefore supplies the resultant force to the load spring.

Pedal Piston

This component regulates the amount of lubricant that is released from the reservoir into the cylinder. It therefore prevents it from being flooded by too much of the fluid, which would reduce its efficiency.

mechanical design 16

Manufacturing Techniques

In order to fully manufacture the master cylinder and reservoir defined by concept 3, there are different manufacturing techniques that will have to be used (Groover, 2010). One of these is casting which will be used to produce the outer casing of the cylinder. A molding with the appropriate dimensions will be developed before its liquefied material is poured into the mold and allowed to cool. This yields the outer casing.

It is also necessary to use molding for creating the shaft along which the spring is wrapped. The hot liquid metal will be poured into the required mold of appropriate length and diameter and left to solidify. A similar technique will be used for manufacturing the reservoir and pedal piston, but using different materials and dimensions.

Finally, the manufacturer will also employ various machining processes to forge the lever and gauge. For the gauge, the different parts will have to be milled, bored, turned on a mill, and reamed among others to develop them. Likewise, the lever consists of some parts which will require processes such as electroplating, shaping and planning. These may vary from one part to another and the final outcome largely depends on how well it is executed.

Reference

Groover, M.P (2010). Fundamentals of Modern Manufacturing. John Wiley & Sons.