JPS645185Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a curved duct that connects ducts that are orthogonally arranged, such as an intake pipe of a turbocharger in an automobile engine and an intake duct that connects to an air cleaner. It is.

[Conventional technology]

As disclosed in Utility Model Application Publication No. 57-96875,
This type of duct is constructed by embedding a coil spring in a bellows-shaped tube, and is connected to two ducts that intersect at both ends. Since the coil spring is embedded inside the tube, it is quite rigid.
Installing the duct in a curved manner is not easy to work with, and there are limits to the degree of curvature. Furthermore, when subjected to vibrations such as in the intake duct of an engine, the rubberized cloth that holds the coil springs may peel off due to vibration fatigue.

As shown in FIG. 1, a tube 8 made of rubber or the like is molded in advance into a bellows-like and curved state, and a coil spring 9 that provides shape retention is fitted inside the tube 8. It is known that the winding axis of the coil spring 9 is held in a curved shape by locking rod-shaped tension fittings 12 to both ends of the coil spring 9 in the curved portion.

However, even in this curved duct, when the amount of air sucked into the turbocharger increases during overload operation of the engine, the pressure inside the tube 8 decreases, the tube 8 is crushed, and the coil spring is released at the maximum curvature part of the tube 8. 9 is forced toward one end, and as shown in FIG. 1, the tube 8 is further crushed, resulting in a problem in that the air flow is significantly restricted. The same can be said of the curved duct disclosed in Japanese Utility Model Publication No. 33-13254.

[Problem that the invention attempts to solve]

An object of the present invention is to provide a curved duct that is easy to manufacture and install and that does not collapse due to internal pressure changes.

[Means for solving problems]

In order to achieve the above object, the structure of the present invention is such that a coil spring is fitted inside a bellows-shaped flexible tube curved into an arc, and both ends of the coil spring are connected at the minimum curvature part of the flexible tube. An arcuate tension fitting that narrows the coil spacing is fixed to the coil spring, while stay fittings that widen the coil spacing are fixed to both ends of the coil spring at the maximum curvature portion.

[Effect]

By locking the tension fittings 12 to both ends of the coil spring 9 at the minimum curvature portion of the flexible tube 8, the inner space surrounding the coil spring 9 is held in a curved state.

Also, at the maximum curvature portion of the flexible tube 8, stay metal fittings 10 are attached to both ends of the flexible tube 8.
By locking, the spacing between the coils of the coil spring 9 is widened, so the coil spring 9 is not pushed toward one end, and the flexible tube 8 is prevented from collapsing.

[Example of idea]

As shown in FIG. 2, the curved duct according to the present invention is composed of a flexible tube 8 and a coil spring 9 fitted inside the flexible tube 8. The flexible tube 8 made of rubber or the like is provided with extensible bellows-shaped rims or bent portions 4 at predetermined intervals, and is curved in an arc shape as a whole, with one end is made somewhat smaller in diameter from the stepped portion 7 to form the tube portion 5. In the case of an engine, the tube portion 5 of the flexible tube 8 is fitted onto the inlet tube 6 of the turbocharger and fixed with a known band or the like. The other end of the tube 8 has a larger diameter than the tube portion 5, and forms a tube portion 3 whose central axis intersects with the tube portion 5 at a predetermined angle. The tube section 3 is fitted onto the intake duct 2 and fixed by the same means as the tube section 5.

A coil spring 9 is fitted inside the tube 8 so that the tube 8 always maintains a uniform cross section. The end portion 9a of the coil spring 9 is connected to the step portion 7 described above.
is collided with. A tension fitting 12 is locked between the end portion 9a and the end portion 9b. The tension fitting 12 is arranged at the minimum curvature part of the tube 8, and is made of a wire rod or a strip plate curved into an arc shape, and one end portion 12a is bent and locked to the end portion 9a of the coil spring 9. The other end 12b is a coil spring 9
It is bent and locked at the end 9b of.

A rod-shaped stay fitting 10 is arranged at the maximum curvature portion of the tube 8, and both ends 10a (FIG. 3) are locked to both ends 9a and 9b of the coil spring 9.

When actually installing the coil spring 9, after fitting and fixing the tube 8 to the inlet pipe 6, connect the ends of the tension fitting 12 and the stay fitting 10 to the end 9a of the coil spring 9 in advance. 8 and press the end 9a against the step 7 of the tube 8. Then, the tension fitting 12 and the stay fitting 10
The other end is locked to the end 9b of the coil spring 9.
Finally, the pipe portion 3 is fitted and fixed to the intake duct 2.

[Effect of idea]

As described above, the present invention involves fitting a coil spring inside a bellows-shaped flexible tube curved into an arc, and creating a coil spacing at both ends of the coil spring at the minimum curvature portion of the flexible tube. While the arc-shaped tension fittings that narrow the gap are locked, the stay fittings that widen the coil spacing are locked at both ends of the coil spring at the maximum curvature part of the flexible tube, making it easy to manufacture and assemble each component. The coil spring inserted into the flexible tube is stably held in a curved state by the tension fitting and the stay fitting.

Especially in the part of maximum curvature of the flexible tube,
Since both ends of the coil spring are pushed apart by the stay fittings, the coil spring is not pushed toward one end. Since the movement of the coil spring is suppressed, the flexible tube will not collapse due to internal pressure changes and the air flow path will not be narrowed. Compared to a normal flexible tube with embedded coil springs, it is reasonable to have a smaller curvature and has excellent durability.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view of a conventional curved duct in a collapsed state, FIG. 2 is a side cross-sectional view of a curved duct according to the present invention, and FIG. 3 is an enlarged view of the same essential parts. 2...Intake duct, 3, 5...Pipe part, 4...Bent part, 6...Inlet pipe, 7...Step part, 8...Tube, 9...Coil spring, 10...Stay fitting, 1
2...Tension fittings.

Claims (1)

[Scope of utility model registration request] A coil spring is fitted inside a bellows-shaped flexible tube curved into an arc, and an arc-shaped tension fitting that narrows the coil spacing is locked at both ends of the coil spring at the minimum curvature part of the flexible tube. On the other hand, a curved duct characterized in that a stay fitting for widening the coil interval is fixed to both ends of the coil spring at the maximum curvature part.