JPH048833A - Throttle valve device for engine intake air - Google Patents

Abstract

PURPOSE:To obtain a throttle valve device which makes it difficult for a valve plate to stick on to a deposit and enables to eliminate the deposit completely by dividing a body for supporting a throttle valve into an upstream body and a downstream body along a flat which passes through the axial core of a valve axis and thinning the outer peripheral rim of the valve plate. CONSTITUTION:A body (throttle body) 1 consists of an upstream body 3 and a downstream body 6 divided along a flat which passes through the axial core of the valve axis 22 of a throttle valve 21 and is at right angle to the central axis shaftline of an intake air passage 2 and flanges 4, 7 confronting to each other on the divided surface and half-divided bearing ports 5, 8 are provided so as to be separable but airtightly connected together by nuts and a gasket. On the other hand, in the throttle valve 21, a valve axis 22 is provided protrusively from both sides confronting to each other on the diameter of a disk shaped valve plate 23, forming the outer peripheral rim 24 of the valve plate 23 in the state of semi-circle shape arc in its section. Thus, even if tar, or the like is stuck to and piled on the inner surface of the intake air passage 2 at the side of the valve plate 23, and a deposit is stuck to the outer peripheral rim 24 of the valve plate 23, they are easily separated to make the valve open due to a small contact area.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a throttle valve device installed in an intake pipe to control the amount of intake air in order to control the rotational speed of an engine.

[Prior Art] The throttle valve installed in the intake pipe to control the amount of intake air in order to control the rotational speed of the engine, and the body surrounding it, have a small gap between them, allowing tar content in the gaseous fuel to be absorbed during idle or low speed. Carbon and oil in the recirculated exhaust gas and blow-by gas tend to adhere and accumulate, which reduces the amount of intake air in the throttle valve low opening range, especially during idling, leading to problems such as over-rich mixture and engine malfunction.

As a countermeasure, it is suggested in Japanese Utility Model Publications No. 55-4535 and No. 55-28860 to make the throttle valve and intake pipes shaped and structured so that the above-mentioned components are difficult to adhere to. Even if the reduction is effective, a considerable amount will accumulate if the engine operation is extended for a long time. If the countermeasure is to increase the gap between the parts where the fuel sticks easily, there is a problem that the amount of intake air during idling under normal conditions increases.

In addition, the above-mentioned components mainly adhere to and accumulate on the inner surface of the fuselage, and if they accumulate in large quantities, they may bite the valve plate placed in the closed position while the engine is stopped, causing the valve to open incorrectly when the engine is running. There is a concern that it will open wide the instant it leaves the deposits, causing problems such as causing the engine rotational speed to rise rapidly. Therefore, even if an attempt is made to remove the deposits, the work is extremely difficult because the deposits are quite hard and adhere to the inside of the body, and it is impossible to completely remove them.

[Problem to be Solved by the Invention] The problem to be solved by the present invention is that when a large amount of tar, carbon, and oil accumulates on the inner surface of the fuselage, there is a risk that the valve plate of the throttle valve will bite and cause trouble. , and that such deposits cannot be completely removed.

That is, an object of the present invention is to provide a throttle valve device in which the valve plate is less likely to be bitten by deposits and the deposits can be easily removed completely.

[Means for Solving the Problems] The present invention provides a structure in which a body that supports a throttle valve is divided into an upstream body portion and a downstream body portion that are separably coupled along a plane passing through the axis of the valve shaft. A means to solve the above problem was to make the outer peripheral edge of the plate thinner.

It is preferable that the throttle valve has no valve stem along the valve plate, and that the valve plate and the valve stems on both sides thereof are integrally molded.

[Function] Even if tar, carbon, and oil are deposited on the inner surface of the fuselage and the outer periphery of the valve plate of the throttle valve placed in the closed position is bitten by the deposits while the engine is stopped, the contact area between them will be reduced. Because of the small amount of force, the valve does not come apart with a small force when opening, and does not cause valve opening failure.
Additionally, the upper body and the lower body are separated and deposits adhering to their inner surfaces and valve plates are removed.

[Example] The present invention will be described in detail with reference to the drawings.

Figures 1 to 4 show an example in which the present invention is implemented in a throttle valve device consisting of a throttle valve and a throttle body installed in an intake system equipped with a low-pressure fuel injection valve to control engine speed. ing.

The body 1 consists of an upstream body part 3 and a downstream body part 6, which are divided along a plane that passes through the axis of the valve shaft 22 of the throttle valve 21 and is perpendicular to the central axis of the intake passage 2, and these parts face each other in the dividing plane. It has a flange 4.7 and a half-split bearing hole 5.8, and is separably and airtightly connected by bolts, nuts, and gaskets (not shown).

The throttle valve 21 has a configuration in which a valve shaft 22 is protruded from both sides of a disc-shaped valve plate 23 facing each other on one diameter, and there is no valve shaft along the valve plate 23. As shown in FIG. 2, the outer peripheral edge 24 is formed in an arc shape with a semicircular cross section. In addition, it is preferable for such a throttle valve 21 to be an integrally molded product in which a round bar is forged to form a valve plate 23, and valve stems 22 are integrally protruded from both sides of the valve plate 23. However, these may be made separately and joined by welding.

If the throttle valve 21 is used without a valve stem along the valve plate 23, the passage resistance when fully opened is equal to the thickness of the valve plate 23. This has the advantage that it is possible to measure output improvement.

Then, in the throttle valve device of this embodiment, with the upstream body 3 and the downstream body 6 separated, for example, a half circumference portion of the valve shaft 22 is fitted into the bearing hole 8 of the downstream body 6, and then the upstream body 3, the remaining half circumference of the valve shaft 22 is fitted into the bearing hole 5, and the flange 4.7 is tightened and connected with bolts and nuts.

According to this embodiment with such a configuration, tar, carbon, and oil adhere to the inner surface of the intake passage 2 on the side of the valve plate 23 at the idle position or low opening position and gradually accumulate, and when the engine is stopped, Even if the outer peripheral edge 24 of the valve plate 23 bites into deposits, since the contact area is small, the valve is easily separated and opened the next time the engine is operated. That is, the valve opening resistance when deposits adhere to the valve plate 23 is approximately proportional to the contact area with the valve plate 23;
This is because in this embodiment, the outer peripheral edge 24 of the valve plate 23 is formed into an arc shape, so that the contact area with the deposits is small, and therefore the valve opening resistance is small.

In addition, the amount of intake air at idle is significantly reduced, and the valve plate 2
3, the upstream body part 3 and the downstream body part 6 are separated and the deposits adhering to the area of their separation and the deposits adhering to the valve plate 23 are removed. do.

FIG. 5.6 shows a different embodiment of the present invention, in which the body 11 is connected to the valve shaft 22 of the throttle valve 21.
The upstream body 13 and the downstream body 16 are divided along a plane that passes through the axis of the valve and is substantially parallel to the valve plate 23 in the closed position.
．． 17, and are separably and airtightly connected by bolts, nuts, and gaskets (not shown).

As in the previous embodiment, the throttle valve 21 has a structure in which the valve shaft 22 is integrally protruded on both sides of the valve plate 23, and there is no valve shaft along the valve plate 23, and the outer peripheral edge 25 of the valve plate 23 is As shown in FIG. 6, it is formed into a narrow planar shape by the peripheral thin plate portion. This throttle valve 21 is supported by the body 11 by the same means as in the previous embodiment, and opens and closes the intake passage 12.

Also in this embodiment, when the valve plate 23 adheres to deposits on the inner surface of the intake passage 12, the contact area is small and the valve can be easily separated and opened with a small force. The deposits can be removed by separating the

In addition, since the body is divided by a plane passing through the axis of the valve shaft,
A conventional throttle valve in which a valve plate is screwed to a valve stem passing through the body can also be easily incorporated. In addition, as a means of thinning the outer periphery to reduce the contact area,
Needless to say, design changes such as making the outer peripheral edge the top edge of a triangular cross section or the top edge of a trapezoid cross section are possible.

[Effects of the Invention] According to the present invention, even if the valve plate is bitten by deposits consisting of tar, carbon, and oil, the contact area is small because the outer periphery of the valve plate is thin.

As a result, the valve opening resistance is reduced, and the valve can be opened easily by separating the valve plate from the deposits with a small force during engine operation, eliminating concerns about problems such as valve opening failures and sudden increases in engine speed. In addition, since the body is divided at the part where deposits occur, deposits attached to the inner surface of the intake passage and the valve plate can be exposed, making it extremely easy and complete to remove them and normalize the intake air amount at idle. It is possible to maintain this condition and further prevent biting.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention, and FIG.
Enlarged partial views of the figures, Figures 3 and 4 are X-X of Figure 1.
5 is a longitudinal sectional view showing a different embodiment of the present invention, and FIG. 6 is an enlarged partial view of FIG. 5. Figure 1

Claims (1)

[Claims] 1. The body supporting the throttle valve is divided into an upstream body and a downstream body that are separably connected along a plane passing through the axis of the valve shaft, and the outer periphery of the valve plate An engine intake throttle valve device characterized by having a thin structure. 2. Claim 1: The throttle valve does not have a valve stem along the valve plate, and the valve plate and the valve stems on both sides thereof are integrally molded.
The engine intake throttle valve device described.