JPH0648147Y2 - Air flow control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is provided in a bypass passage provided between an upstream side and a downstream side of a throttle valve of an internal combustion engine, and is used for stabilizing idle speed. The present invention relates to an air flow control valve.

(Prior Art) Conventionally, there is known an idle speed control valve which is provided in a bypass passage connecting an upstream side and a downstream side of a throttle valve in an internal combustion engine, and detects an idling state of a vehicle to control a bypass air flow rate. There is known a flow rate control valve which is provided upstream of the idle speed control valve and controls the flow rate of air sent to the idle speed control valve according to the rise and decrease of the engine temperature in order to stabilize the idle speed.

A conventional example of the latter flow control valve is shown in FIG. 6 (for example, Japanese Utility Model Laid-Open No. 61-88039). This is for controlling the air flow rate in the bypass passage 1 in accordance with the engine temperature. The valve 2 is housed in the valve housing 3 so as to be slidable in the left and right directions in FIG. A water circulation passage 4 is provided. Further, a temperature sensitive stroke element 5 containing wax is fixed in the circulation passage 4, and a spring 6 is interposed between the valve 2 and the valve housing 3 so that the temperature sensitive stroke element 5 extends from the valve 2 toward the valve 2. The protruding spindle 7 is elastically biased to the left in the figure via the valve 2.

In addition, 8 is an inlet of cooling water, and 9 is an outlet similarly.

Now, when the temperature of the engine cooling water supplied to the circulation passage 4 of the valve housing 3 is low, the wax enclosed in the temperature sensitive stroke element 5 is contracted, so that the amount of protrusion of the spindle 7 is small. Therefore, the valve 2 is held at the position shown by the elastic force of the spring 6, and the bypass passage 1
Since the opening 10 is opened wide and the amount of intake air introduced into the bypass passage 1 is increased, the rotational speed of the engine can be increased.

On the other hand, when the temperature of the engine cooling water rises, the wax enclosed in the temperature sensitive stroke element 5 gradually expands and causes the spindle 7 to largely protrude, so that the valve 2 resists the elastic force of the spring 6 and is shown in the figure. Move to the right. Then, since the valve 2 largely overlaps the opening 10 of the bypass passage 1,
Since the opening degree of 10 decreases and the flow resistance of the bypass passage 1 increases and the intake air amount of the engine is decreased, the engine speed tends to decrease.

As described above, the above-mentioned flow rate control valve senses the temperature of the engine, for example, the temperature of the engine cooling water representing it, and controls the amount of air flowing through the bypass passage so as to match the temperature. Since the opening 10 of the flow rate control valve has a rectangular shape, it is easy to make the flow rate of the air flowing through the opening 10 proportional to the engine temperature by moving the valve 2.
Further, there are advantages that the shape of the opening is simple and the flow control valve can be easily designed and manufactured.

(Problems to be solved by the invention) However, in the conventional flow control valve structure as described above, the opening
Since 10 has a rectangular shape, the air flow rate can be made proportional to the engine temperature by the increase / decrease control of the opening area by the movement of the valve 2, but when the closing operation of the valve 2 proceeds, the opening 10 Since the air flow rate is blocked and the air flow rate becomes zero, it is difficult to stably secure a predetermined flow rate necessary for the engine after reaching a predetermined temperature.

(Means for Solving Problems) The present invention has been made to solve the above problems, and a rectangular main opening facing a bypass passage is provided in a mounting wall portion of a valve housing. Continuing by providing an orifice part with a width substantially narrower than the width of the main opening and a sub-opening following this in this order, and controlling the opening area of the main opening by moving the valve by the spindle of the temperature sensitive stroke element. While allowing the air flow rate to be obtained according to the engine temperature, even after the valve has fully closed the main opening, the air is directed from the sub opening toward the valve axis, and the orifice sandwiched between the mating member 14 and the valve 12. The flow is made to flow through the section to the main opening and the bypass passage, thereby ensuring the minimum flow rate required for the engine.

(Embodiment of the Invention) The present invention will be described in detail below based on the embodiment shown in FIGS. 1 to 5.

FIG. 1 is a vertical sectional view of an embodiment of the present invention, and FIG. 2 is a bottom view with the mating member 14 of FIG. 1 removed. In the figure, 11 is a bypass passage provided on the mating member 14, for example, on the idle speed control valve side, and the air flows from the upstream side of an unillustrated engine throttle valve as shown by an arrow Q to the air flow control valve V.
Through the bypass passage 11. Reference numeral 12 is a cup-shaped valve housed in a valve housing 13 so as to be slidable in the left-right direction in the figure, 15 is a circulation passage of engine cooling water, 16 is a cooling water inlet, and 17 is an outlet thereof.

Reference numeral 18 denotes a temperature-sensitive stroke element that is fixedly provided in the middle of the cooling water passage 15. For example, a wax that expands and contracts due to the rise and fall of the ambient temperature is contained inside, and a spindle 19 that appears and disappears due to the expansion and contraction of the wax (Note that the temperature-sensitive stroke element 18 may be made of bimetal.).

Reference numeral 20 is a spring that is contracted between the valve housing 13 and the valve 12.

The temperature-sensitive stroke element 18 is attached to the valve housing 13 with the set screw 21.
Is fixed by being pressed against the washer 22 inserted in the stepped portion of. 27 is an O-ring for sealing.

The mounting wall 13a of the valve housing 13 to the mating member 14 is the mounting surface 2
As shown in FIG. 2, the mounting wall 13a has a rectangular main opening 24, which is slightly smaller than the opening of the bypass passage 11, and is followed by an orifice 25. And the sub-opening 26 is provided. The lateral width of the orifice is considerably narrower than the lateral width of the main opening 24 (the distance measured in the direction perpendicular to the axis of the housing 13 in FIG. 2).

A boundary wall surface 28 with the main opening 24 that forms the orifice portion 25 is formed so as to coincide with the wall surface 29 of the bypass passage 11.

Next, the operation of this embodiment having the above configuration will be described.
When the engine cooling water temperature, which is representative of the engine temperature, is low, the spindle 19 of the temperature sensitive stroke element 18 is retracted, the valve 12 is pushed leftward in FIG. As shown in FIG. 5, the flow mainly flows through the main opening 24 to the bypass passage 11, and the flow rate at this time is the level of M in FIG. When the temperature of the cooling water reaches t ₁ in the figure, the spindle 19 starts projecting and the tip end surface (right end surface in the figure) of the valve 2 gradually closes the main opening 24 as the temperature rises. As can be seen in the figure, the opening area gradually narrows, and the air flow rate decreases as the cooling water temperature rises.
The slanted line of the figure is shown. When the temperature reaches a predetermined temperature t ₂ , the valve 12 fully closes the main opening 24. Then, the air flowing from the radial direction to the main opening portion 24 is completely blocked, but the air flows from the sub opening portion 26 through the orifice portion 25 toward the valve axial direction, and further to the main opening portion 24 and the bypass passage 11. Flows. When air flows through the orifice portion 25, it is measured by the orifice area defined by the height of the orifice portion sandwiched between the mating member 14 and the valve 12 and the lateral width of the orifice portion, and passes through the orifice portion 25 in the axial direction. The flowing air flow rate is a constant value (N level in FIG. 5). When the temperature of the cooling water further rises above t ₂ , the valve 12 moves further forward (to the right in FIG. 4), as shown in FIG.
Since the area of the sub-opening 26 has a sufficient margin for advancing the valve 12 and the valve 12 does not block the sub-opening, the air is metered and flows in the orifice 25 in the same manner as described above. Is maintained at a constant value (N level).

That is, the minimum required air flow rate N to be supplied to the idle speed control valve can be secured.

(Outline of the Invention) As described above, the present invention has the mounting wall portion 13a to the mating member 14 having the bypass passage 11 and accommodates the valve 12 slidably and communicates with the bypass passage 11. A temperature sensing stroke element 18 attached to the valve housing 13, and a spring 20 for pressing the valve 12 toward the temperature sensing stroke element 18, In the air flow rate control valve in which the opening area of the opening is changed by controlling the air flow rate by moving the valve 12 by the protrusion of the spindle 19 of the stroke element 18, the bypass is provided on the mounting wall surface 13a of the valve housing 13. A rectangular main opening 24 facing the passage 11 is provided, an office portion 25 having a width substantially narrower than the width of the main opening 24, which follows the opening 25, and an auxiliary opening 26 that follows the opening are formed in this order. When the valve 12 fully closes the main opening 24, air flows from the sub-opening 26 in the valve axial direction, the orifice portion 25 sandwiched between the mating member 14 and the valve 12, the main opening 24, the bypass passage 11 The air flow control valve is characterized in that it is configured to flow in the order of.

(Effect of the Invention) As described above, according to the present invention, by making the main opening rectangular, it is easy to make the amount of air flowing through the main opening proportional to the engine temperature by the movement of the valve. In addition, the shape of the main opening is simple, the design and manufacturing of the flow control valve are easy, and by providing the orifice part following the main opening, the engine temperature becomes higher than the predetermined temperature. Even if the main opening is closed by the valve, air is allowed to flow from the sub opening through the orifice to the main opening,
Furthermore, it is made to flow to a bypass passage, and by this, the effect of being able to secure a fixed minimum amount of air can be obtained.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a flow control valve according to an embodiment of the present invention,
FIG. 2 is a bottom view of FIG. 1 with only the mating member removed,
FIGS. 4 and 5 are explanatory views of valve operation, FIG. 5 is a flow characteristic diagram obtained by the present invention, and FIG. 6 is a longitudinal sectional view showing an example of a conventional flow control valve. 11 …… Bypass passage, 12 …… Valve 13 …… Valve housing, 13a …… Mounting wall surface 14 …… Mating member, 15 …… Cooling water circulation passage 16 …… Cooling water inlet, 17 …… Cooling water outlet 18 Temperature stroke element, 19 …… Spindle 20 …… Spring, 21 …… Set screw 22 …… Washer, 23 …… Mounting surface 24 …… Main opening, 25 …… Orifice section 26 …… Sub opening, 27 …… O-ring 28 …… Boundary wall, 29 …… Wall

Claims (1)

[Scope of utility model registration request] 1. A mating member (1) having a bypass passage (11).
A valve housing (13) having a mounting wall portion (13a) for mounting the valve (12) in a slidable manner and having a main opening portion (24) communicating with the bypass passage (11); The temperature-sensitive stroke element (18) mounted on the valve housing (13) and the valve (12) are connected to the temperature-sensitive stroke element (18).
And a spring (20) that presses the valve toward the valve, and the opening area of the opening is changed by moving the valve (12) by the protrusion of the spindle (19) of the temperature-sensitive stroke element (18) based on the rise and fall of the engine temperature. In the air flow control valve configured to control the air flow, the valve (12)
A rectangular main opening (24) communicating with the bypass passage (11) in opposition to a mounting wall (13a) of a valve housing (13) in which the airtightly slidable interior is installed, and the main opening (24). ) Which has a boundary wall surface (28) which is formed following the valve sliding direction of (1) and which coincides with the wall surface (29) of the bypass passage (11), and the valve sliding direction of this orifice portion. When the valve (12) fully closes the main opening (24) by providing an opening formed in the order of the subsequent sub opening (26), air flows from the sub opening (26) in the valve axis direction. The air flow rate control is characterized in that the orifice portion (25) sandwiched between the mating member (14) and the valve (12), the main opening portion (24), and the bypass passage (11) flow in this order. valve.