JPH0210266Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a liquid intrusion prevention structure for a timing case, which is used to prevent liquid from intruding into the timing case.

[Conventional technology]

Conventionally, as shown in Fig. 3, the crankshaft 1
A timing pulley 2 and a crank pulley 3 are inserted into the front end of and fixed with bolts 4.
A timing belt 7 is suspended between the timing pulley 2 and a timing pulley of a camshaft (not shown), and the timing pulley 2 and the timing belt 7 are housed in a timing case 5. The timing case 5 consists of a case body 5A and a timing cover 6 attached to the case body 5A. The crank pulley 3 consists of a boss part 31 protruding from the center, an arm part 11 extending from the boss part 31, and a rim part 11A formed at the outer edge of the arm part 11. is fitted into the fitting hole 6A of the timing cover 6 of the timing case 5. Furthermore, an oil pan 12 is connected to the lower part of the timing case 5.

[Problem that the invention attempts to solve]

In the above conventional configuration, timing case 5
A gap 10 exists between the fitting hole 6A of the timing cover 6 and the boss portion 31 of the crank pulley 3, and a gap 10 exists between the timing cover 6 and oil pan 12 and the arm portion 11 and rim portion 11A of the crank pulley 3. There is also a gap 13 between the two, so when the car is running, droplets from puddles on the road adhere to the lower part of the car body.
The timing case 5 reaches the boss portion 31, passes through the boss portion 31, and enters the timing case 5 through the gap 10.
Then, a problem occurs in that the timing pulley 2 and the timing belt 7 are damaged by the solid content such as mud contained in the splashes.

[Means for solving problems]

The present invention provides a timing case that incorporates a timing pulley 2 and a timing belt 7 suspended on the timing pulley 2 as a means for solving the above-mentioned conventional problems and preventing liquid such as splashes from entering the timing case. 5, and a crank pulley 3A connected to the timing pulley 2.
A boss portion 31A having a liquid guide groove 33A formed in an outer peripheral surface 32A protrudes from the center of the crank pulley 3A.
provides a liquid intrusion prevention structure for the timing case 5 which is fitted into the fitting hole 6A of the timing case 5.

[Effect]

The operation of the present invention based on the above configuration is as follows.

When the car is running, droplets from road puddles that adhere to the lower part of the car flow down between the crank pulley 3A and the timing case 5 when the engine is stopped, and are deposited on the boss part 31A of the crank pulley 3A.
The liquid guide groove 33A on the outer peripheral surface 32A of the boss portion 31A reaches the upper surface and enters the timing case 5 through the gap between the fitting hole 6A of the timing case 5 and the boss portion 31A along the boss portion 31A.
The liquid flows down inside the liquid guide groove 33A and drips to the outside from near the bottom.

[Effect of idea]

Therefore, in the present invention, it is possible to reliably prevent liquid from entering the timing case without particularly requiring a separate member such as a shielding plate.

〔Example〕

The present invention will be explained in detail below.

A first embodiment of the present invention is shown in FIG. In the figure, a timing pulley 2 and a crank pulley 3A are inserted into the front end of a crankshaft 1 and fixed with bolts 4, and a timing belt 7 is placed between the timing pulley 2 and a timing pulley of a camshaft (not shown). The timing pulley 2 and the timing belt 7 are housed in a timing case 5. The timing case 5 consists of a case body 5A and a timing cover 6 attached to the case body 5A. The crank pulley 3A consists of a boss portion 31A protruding from the center, an arm portion 11 extending from the boss portion 31A, and a rim portion 11A formed at the outer edge of the arm portion 11. An oil pan 12 is connected to the lower part of the oil pan 12. The boss portion 31A is fitted into the fitting hole 6A of the timing cover 6 of the timing case 5, and an annular groove 33A for liquid guide is formed on the outer peripheral surface 32A, and the end surface 34A is close to the timing belt 7. This serves as a misalignment prevention surface for the timing belt 7.

In the above configuration, as in the conventional case, there is a gap 1 between the fitting hole 6A of the timing cover 6 of the timing case 5 and the boss portion 31A of the crank pulley 3A.
Furthermore, a gap 13 also exists between the timing cover 6 and the arm portion 11 and rim portion 11A of the crank pulley 3A. When the car is running, droplets from puddles on the road adhere to the lower part of the car, and when the engine is stopped, the droplets flow down the gap 13 as shown by arrow A, reach the upper surface of the boss part 31A of the crank pulley 3A, and move past the boss part 31A. The liquid then attempts to enter the timing case 5 through the gap 10, but is blocked by the liquid guide groove 33A of the boss portion 31A, and drips outside from near the bottom of the liquid guide groove 33A. .

FIG. 2 shows a second embodiment of the present invention, in which the crank pulley 3
A spiral groove 33B for liquid guide is formed on the outer peripheral surface 32B of the boss portion 31B of B. The spiral groove 33B has a winding direction opposite to the direction of rotation of the crank pulley 3B, and when the crank pulley 3B in the groove 33B rotates in the direction of arrow B, it flows in the direction of arrow C, which is opposite to the rotation direction. It moves to the side opposite to the timing case 5 and drips as shown by arrow D.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the first embodiment of the present invention, Figure 2 is a perspective view of the crank pulley of the second embodiment, and Figure 3 is a perspective view of the crank pulley of the second embodiment.
The figure is a sectional view of a conventional example. 2 in the diagram...Timing pulley, 3A, 3B...
...Crank pulley, 5...Timing case,
7...Timing belt, 31A, 31B...Boss portion, 32A, 32B...Outer peripheral surface, 33A, 33
B...Groove for liquid guide.

Claims (1)

[Claims for Utility Model Registration] (1) Consisting of a timing case containing a timing pulley and a timing belt suspended on the timing pulley, and a crank pulley connected to the timing pulley, the crank pulley has a 1. A liquid intrusion prevention structure for a timing case, characterized in that a boss portion in which a liquid guide groove is formed on an outer circumferential surface protrudes, and the boss portion is fitted into a fitting hole of the timing case. (2) The groove on the outer circumferential surface of the boss portion of the crank pulley has a helical shape in a direction opposite to the direction of rotation of the crank pulley. Prevention structure.