Engineering Communication

Transcription

1 Engineering Communication Main Design Project - Foldable Mountain Bike Final Report Williams Khozouei Fan Introduction: Mountains Bikes are very popular as a source of amusement as well as being an economical, and clean way of travelling. A foldable mountain bike allows the user to compact the size of the bike so it can be stored in minimal space when not in use. Final Design: The final design that was adopted because it was quick, easy and simple to assemble. It features front suspension; a spring-loaded covered hinge joint; 26-inch wheels and hand brakes. The front suspension is used to absorb vibration from the front wheel and reduce the force transferred to the users wrists whilst riding the bike. It is built into the front forks and is made up of a simple spring and plunger set. The hinge joint is in the middle of the frame of the bike and allows the bike to fold up. The hinge is a three-piece system with a cover that holds the hinge in place whilst the bike is in use. The brakes for bike are located on the handlebars and are hand operated. They are of a lever design and use cables to operate the brake pads. Folding the Mountain Bike: As previously stated the bike is quick, easy and very simple to fold up. To fold the bike up; pull back the spring loaded hinge cover towards the handlebars. This exposes the hinge joint; the bike can then be folded in two and the cover released. To unfold the bike simply pull back the hinge cover, move the bike so that the frame is straight and release the hinge cover. Note that both neither wheel is detached from the bike when it is folded up. Williams Khozouei Ng king hin Fan

2 Problem Solving: The major problem that had to be overcome was how and where to make the bike fold. After researching various designs by different manufacturers it was decided that, in order to keep the bike simple and easy to assemble, the cut should be in the middle of the frame. This essentially cut the bike in half allowing the storage space needed to be halved as well. Cutting the bike in the middle of the frame also means that the chain, gears and front suspension could remain intact when the bike is folded. This avoids any complicated folding mechanisms. The problem with a simple hinged joint in the middle of the bike is that is does not allow enough space for the bike frame to fully fold up. The hinge joint is shown below. The solution was to place an extra hinge piece in the join to enable more space between each half of the bike frame. The final design for the hinged join is shown below. The other problem that arose during the design of the bike was the lower part of the frame called the single pipe got in the way of the sprocket and chain and also made the bike hard to fold up. The original design was a straight tube inline with the bike frame. The solution was to make the single pipe an L shape so that it is slightly offset to allow room for the sprocket and chain. The new design also helps fold the bike up. Williams Khozouei Ng king hin Fan

3 Front Fork Suspension Part front_fork.prt Handle Bar Grip Part handlebar_clamp.prt Handle Bar Part handelbar.prt Part sock.asm Part Front Multi-view Drawing Part Side Multi-view Drawing frontforkdraw1.drw frontforkdraw2.drw Brakes Brakes Grip Part brakegrip.prt Bike\ Assembling Brake Handle Part proper_handel.prt Bike\ Assembling Assembled Brakes brake.asm Same as above Brake grip Multi veiw Drawing brake_grip_multiveiw.drw Williams Khozouei Ng king hin Fan

4 Rear Forks Rear Fork Part something.prt Front veiw Drawing rearforkdrawing.drw Side view drawing rearforkside.drw Top view drawing rearforkbottom.drw Single Pipe Single Pipe n_single_pipe.prt Part Ball n_ball.prt Screw n_screw.prt Single Pipe Multi view drawing dw-screw.drw Ball Multi view drawing dw-ball.drw Screw Multi view drawing dw-screw.drw Hinge Piece Hinge Piece Part join_fin.prt Williams Khozouei Ng king hin Fan

5 Hinge Piece Multi-view Drawing join_multiveiw.drw Pins Pins Part pin.prt Project\pins Pins Multi-view Drawing pindrawing.drw Project\pins Front Bar Front Bar Part front_part_with_hinge.prt Project\ Front bar w- hinge Front Bar Multi-view drawing frontbar.drw Project\ Front bar w- hinge Cover Multi-view Drawing hingecoverdraw.drw Project\ Hinge Cover Bike Unfolded Assembly of constructed bike openme.asm Bike\Unfolded Bike Folded Bike Assembly Assembly of folded bike openme.asm Bike\Folded Assembly diagram of all parts of the bike openme.asm Williams Khozouei Ng king hin Fan