JPS6114572Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of a muffler for a motorcycle.

Generally speaking, motorcycles that are raced on rough terrain, such as motocross vehicles, use upturned mufflers to increase road clearance. As shown in Figure 1, the up muffler is
A muffler C extends downward from the exhaust hole connecting part B in a U-shape, then extends upward, and then bends and extends backward.
It has a shape like this, passes under the motorcycle's tank, and is connected to the second muffler D at the rear end. Because of this shape, moisture contained in the exhaust gas accumulates in the U-shaped downward part. Normally, this water is blown backwards by the pressure of the exhaust gas, but in cold regions, water that accumulates when not in use can freeze and block the passage, preventing exhaust gas from passing through the next time you try to start the engine. If the engine is not able to do so, it may not be possible to start the engine.

This invention has been improved in view of these points, and an embodiment of the invention shown in FIG. 2 will be described below.

The muffler 1 is of an up muffler type, and extends in a U-shape from the engine exhaust hole connecting portion 2, once downward, upward, and then bent rearward. A second muffler is connected to the rear end of the muffler 1.
Accordingly, in the present invention, the exhaust hole connecting portion 2 and the U-shaped curved portion extending upward are connected and communicated by a horizontally thin bypass pipe 3.

The effect will be explained.

When the muffler 1 is not used in a cold region, the moisture inside the muffler 1 may flow into the U-shaped low part and freeze, causing the muffler 1 passage to be blocked by the U-shaped low part. There is. In this case, when the engine is started, the exhaust gas flows backward through the bypass pipe 3;
This ensures the flow of exhaust gas, making it possible to start the engine. When the muffler 1 is warmed up in this state, the muffler 1 is heated by the heat of the exhaust gas, and this heat melts the water frozen in the lower part of the U-shaped curve. Once the frozen water thaws, the pressure of the exhaust gas blows the water backwards, ensuring a passage for the muffler 1 and allowing normal operation. Note that since the bypass pipe 3 is thin, it has little effect on output during normal operation.

As explained above, this idea is based on the muffler, which extends downward in a U-shape from the engine's exhaust hole connection, then extends upward, and then bends and extends rearward. The parts that curve upwards are connected by a bypass pipe, so even if water collects and freezes in the lower part of the U-shape, the bypass pipe will ensure an exhaust gas passage and allow the engine to start. . When the engine starts, the exhaust gas heats up the muffler as it warms up, and the water that has frozen in the low U-shaped part thaws and is blown away by the exhaust gas pressure, ensuring a clear muffler passage. It is now possible to operate normally, there is no need to use special equipment to heat the muffler before starting, and the cost increase is also small because the bypass pipe is simply additionally welded.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a conventional example, and FIG. 2 is a perspective view showing an embodiment of the present invention. 1...muffler, 2...exhaust hole connection section, 3...bypass pipe.

Claims (1)

[Scope of utility model registration request] In a muffler that extends downward in a U-shape from the engine's exhaust hole connection, then extends upward, and then bends back, the bypass pipe connects the exhaust hole connection and the part that bends in a U-shape and extends upward. A motorcycle muffler characterized by communicating with each other.