JPH03213659A - Auxiliary intake air quantity control valve for engine - Google Patents

Abstract

PURPOSE:To enhance the restarting properties of an engine at high temperature by providing a communication port at the tip end of a valve body in a valve housing the valve body which is interlocked with a thermo-sensible section, in a valve case provided with both an inlet port and an outlet port which are opened at the up and downstream positions of a throttle valve. CONSTITUTION:An auxiliary intake air quantity control valve to be fixed on one side of a throttle valve housing includes a valve case 5 provided with an inlet port 6 and an outlet port 7 which are opened at the up and downstream positions of a throttle valve, and the inside of the valve case 5 is partitioned into the inlet port 6 side and the outlet port 7 side by a valve seat 9 provided with a valve port 10. When cooling water is low in temperature at the time of starting an engine, an actuating rod 14a is retreated owing to the thermal contraction of thermo-wax within the thermosensible section 13, a valve body 22 is retreated by the spring force of a restoring spring 26, and the valve port 10 is then opened to a great extent so that bypass intake air is thereby supplied to the engine. In this case, the tip end of the valve body 22 is formed with a communication port 30 so that bypass intake air can thereby be supplied to the engine through the communication port 30 at the time of restarting the engine at high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an auxiliary intake air amount control valve for an internal combustion engine that controls the amount of intake air by bypassing a slot valve in an intake passage of an internal combustion engine. Technology] There is a system in which an internal combustion engine is provided with a thrower/9 valve in the intake passage, and fuel is injected and supplied by a fuel injection valve provided in the intake manifold.

In this case, idling becomes unstable at low temperatures, so
An auxiliary intake air amount control valve is installed in a passage that passes through the throttle valve section seven bays, allowing bypass intake air to pass through at low temperatures to slightly increase the idling speed.

As this kind of known technology, for example, Japanese Patent Publication No. 63-1969
Publication No. 5 is mentioned. FIG. 4 shows a vertical sectional view of this conventional auxiliary intake air amount control valve for an engine. In the figure, 1#i
In an engine such as an automobile, intake air is supplied through an intake passage 2a formed by a throttle valve housing (hereinafter referred to as "housing") 2. 3 is a throttle valve.

The housing 2 has a bypass air population 4a.

An air outlet 4b is provided. A valve case 5 is attached to the housing 2 via a seal member 8, and is provided with an inlet 6 and an outlet lower. Reference numeral 9 denotes a valve seat that partitions the inlet 6 II and the outlet '7 till, and a valve port 10 is provided therein. 11 is the bladder that closes the valve case 5, 1
2 is a thermally responsive actuator fixed in the valve case 5 with an engagement pin 19, which includes a heat-sensitive part 13 sealed with thermowax, a cylinder part 14, and an actuating rod 14a guided and supported within the cylinder. 015 is a gap between the valve case 75 and the heat sensitive part 13, 16Fi is an O-ring for liquid-tight sealing, 17 is a cooling water inflow pipe, and 18 is a cooling water outflow pipe, through which the cooling water of the engine 1 is diverted. and passed.

20 is a valve stem, which is connected to the rear cylinder part 21j) S/
The valve element 022, which is movably supported by the cylinder part 14 and has a conical large diameter part 20a at its tip, is a cylindrical valve body whose tip end is approximately conical. 020b, which is fixed and locks the large diameter portion 20a from the rear side with the tongue piece 24, is a relief portion of the large diameter portion 20a when the valve stem 20 moves forward. 25 is a connection spring inserted between the valve stem 20 and the grate 23, and 26 is a return spring inserted between the valve body 22 and the valve seat 9 to separate and open the valve body 22 from the valve hole IO. It's pressing.

Next, the operation of the above conventional control valve will be explained.

When the engine 1 is started and the cooling water temperature is low, the actuating rod 14a is freely retractable due to thermal contraction of the thermowax. Therefore, the valve body 22 is retracted by the spring force of the return spring 26, and the valve stem 20 is also retracted via the connection spring 25. As a result, at startup, the valve hole 10 is opened wide by the retreat of the valve body 22, and even if the throttle valve 3 is fully closed, bypass intake air is passed from the air inlet 4a through the valve hole 10 in the valve case 5, allowing air to flow through the valve hole 10 in the valve case 5. At this time, the amount of fuel is increased by a fuel injection device (not shown), which increases the output of the engine 1 and improves starting performance.The engine 1 starts. As the warm-up operation progresses, the temperature of the cooling water gradually increases.
The heat sensitive section 13 of No. 2 senses the temperature, thermally expands the thermowax, and moves the actuating rod 14a forward.

Therefore, the valve rod 20 is moved forward and the valve body 22 is moved forward via the connection spring 12, thereby gradually reducing the opening degree of the valve hole 10. Therefore, the amount of intake air in the bypass is gradually reduced.

When warm-up is completed and the cooling water temperature reaches the set temperature,
The valve body 22 moves further forward and acts, completely closing the valve hole 10,
Cut off the bypass intake air supply. After completing this warm-up operation,
Air is taken into the engine 1 through the throttle valve 3, resulting in a normal idling state.

When the cooling water temperature rises even higher than the set temperature, the large diameter portion 20a at the tip of the valve stem 20 resists the connection spring 25 and escapes into the relief portion 20b within the valve body 22.

The relationship between the intake air flow rate and the engine cooling water temperature according to the conventional intake air amount control valve is shown in FIG. 815. After the engine 1 reaches a predetermined temperature, the valve remains fully closed and does not perform any function for the engine 1.

By the way, in cars with electronically controlled fuel injection, an air flow control valve using an electromagnetic actuator is installed to handle various electrical loads, air conditioner loads, etc. when restarting the engine and stabilizing the idle. It is often controlled electronically.

However, these id 1v 21 degree control valves (engineering 8C valves)
etc., the output may decrease due to the influence of ambient temperature.

On the other hand, in the delivery pipe of the fuel system, fuel bubbles occur at high temperatures and the fuel pressure decreases, which often reduces the amount of injection charge and impairs high-temperature restartability.

Therefore, when restarting the engine 1 at a high temperature after high-load operation, etc., even in cars with electronically controlled fuel injection, the control amount of the engine 8C valve is increased, and the idle speed is set to be high. It was necessary to ensure restart and subsequent idle stability.0 In a fuel injection type car such as the one mentioned above, if the control amount of the SC valve is increased in anticipation of a decrease in the flow rate of the SC valve at high temperatures. , fail-safe cannot be achieved in the event of an abnormal situation (valve sticking in the fully open position, etc.) at normal temperature.
This may lead to over-speeding.

Further, since the valves and the like that function only to prevent the air conditioner from idling are under ON-OFF control, if there is no support from other valves, there is a risk that the engine will stop due to insufficient intake air flow. Furthermore, it is not easy to improve high-temperature restartability in vehicles that are not equipped with a mechanical SC valve or the like, under the load of an air conditioner, etc.

[Problem to be solved by the invention]

Conventional intake air flow control valves such as those described above have the problem that it is difficult to configure a system that can smoothly restart the engine at high temperatures and that does not cause overspeeding even under normal conditions. Ta.

This invention was made to solve these problems, and improves the restartability of the engine at high temperatures.
The objective is to obtain an auxiliary intake air flow control valve for engines that improves idle stability after a high-temperature restart and does not require the addition of new parts.

[Failure to solve the problem]

The auxiliary intake air amount control valve for an engine according to the present invention has a flow hole at the tip of the valve body, and bypass intake air is supplied through the flow hole when the cooling water is at a high temperature.

[Effect]

In this invention, when the engine is at a low temperature, the valve body moves back to open the valve hole in the valve seat, allowing bypass intake air to flow through. At this time, the large diameter part of the valve stem is locked to the plate, which prevents the flow of the valve body to the flow hole.When the engine is at a medium temperature, the actuator moves the valve stem forward through the operating rod.
The valve body 22 is advanced to close the valve hole and suppress the flow of bypass intake air. When the engine is at a high temperature, the actuator's even greater movement causes the valve stem to move forward through the actuating rod, causing the large diameter portion of the tip of the valve stem to separate forward from the grate of the valve body that closes the valve hole, thereby opening the bypass suction. Air is guided to the circulation hole of the valve body and circulated. In this way, even when the engine is at low or high temperatures, bypass intake air is supplied with a controlled flow rate, making starting easier.

〔Example〕

FIG. 1(a) shows an embodiment of the auxiliary intake air amount control valve for an engine according to the present invention, and shows portions 5 to 5, 9 to 26, and 14a.

20a and 20b are the same as the conventional ones mentioned above.

A flow hole 30f is provided at the tip of the valve body 22 and escapes! 15
20b and the lower outflow side are communicated with each other.

This intake air amount control valve is attached to the housing 2 shown in FIG. 4 above.

When the cooling water is at low or medium temperature, the valve stem 20 is at the retreated or intermediate forward position, and the large diameter portion 20a is locked to the grate 23, closing the passage from the inlet 6ijll to the relief portion 20b. .

Next, the operation of the intake air amount control valve of the above embodiment will be explained.

First, when the engine cooling water temperature is low, the state shown in FIG. 1(a) occurs. That is, due to the action of thermal contraction by the actuator 12 and the spring pressure of the return spring 26, the actuating rod 14a, the valve rod 20, and the valve body 22 are retracted, opening the valve hole 10 and allowing the bypass intake air to flow. At this time,
The large diameter portion 20a of the valve stem 20 is engaged with the plate 23 to close the flow to the relief portion 20b.

Next, the cooling water temperature of the engine is set to a medium temperature (for example, 50~b) due to the thermal expansion effect of the actuator 12.
is advanced. ), move the valve body 22 feet forward via the valve stem 20 and thread spring 25, and open the valve hole.

Closes and prevents the flow of bypass intake air, resulting in a constant amount of air leakage. At this time, the large diameter portion 20a of the valve stem 2o is
3), the flow of this part remains closed.

Furthermore, when the cooling water temperature of the engine 1 exceeds a high temperature (for example, 80''C), the actuating rod 14a is further advanced by the thermal expansion effect of the actuator unit 2.

Therefore, the valve rod 2o moves further forward, and the large diameter portion 20a opens forward from the plate 23, leading the bypass intake air to flow through the flow hole 3o to the outflow lower.

As a result, if you estimate the amount of air required for restarting at a high temperature (for example, over 80 degrees Celsius) using each intake air amount control valve method, then the amount of air required will be increased by using the intake air amount control valve using the heat-sensitive actuator. can be replenished.

This can be done regardless of whether a mechanical SC valve is installed or not, and regardless of the electronically controlled fuel injection method.

FIG. 3 shows the relationship between the intake air flow rate and the engine cooling water temperature according to the intake air amount control valve of the above embodiment.

In this way, an appropriate amount of intake air is supplied even when the engine is at low or high temperatures, making it easier to start.

FIGS. 2(a) and 2(b) are a front view and a side sectional view of the tip of a plate and a valve stem according to a second embodiment of the present invention. The plate 23 is provided with a radial notch 31 through which the small diameter portion of the valve stem 20 passes.

In this case, the plate 23 may be divided into two semicircular parts, which may be assembled and fixed later.

In addition, the large diameter portion 20a of the valve stem 20 and the tongue piece 24 of the plate portion
The abutting surface with the abutting surface need not be more tapered as in the above embodiment, but may be abutting with a flat surface.

By adjusting the load of the connection spring 26 in advance, the humidity at which the valve stem 2Q separates from the plate 23 can be set. Also, in the above embodiment, the t&population 6 is set to the middle side of the valve case 5. In the above, the outflow loft was provided on the front end side of the valve case 5, but the position of both may be reversed.

Furthermore, in the embodiment described above, the grate 23 may be fixed to the valve body 22 and held by being pressed into contact with the connecting spring 25.

Furthermore, in the above embodiments, a thermo-wax sealed actuator was used as the heat-sensitive actuator, but an actuator using bimetal fi/or shape memory alloy may also be used.

Further, in the above embodiment, the intake air amount control valve was directly attached to the slot μ valve housing 2, but it was installed at a different location, and a bypass passage pipe from the slot valve housing 2 to the slot ρ valve 3 was provided. It may be connected to the inlet and outlet of the valve case 23.

Furthermore, the internal combustion engine is not limited to use in automobiles, but can also be applied to other uses.

〔Effect of the invention〕

As described above, according to the present invention, the flow hole is provided at the tip of the valve body, and when the engine is at low temperature, the valve body retreats to open the valve hole.
Bypass intake air is allowed to flow through the valve, and at medium temperatures, the valve body moves forward and closes the valve hole, suppressing bypass intake air. At high temperatures, the valve stem moves further and the large diameter part at the tip separates from the plate, guiding bypass intake air to the valve. Since the supply is made to flow through the flow holes in the body, only extremely simple machining is required and no new parts are required, and the restartability of the engine at high temperatures is improved. Idle stability is improved0

[Brief explanation of drawings]

FIGS. 1(a), (b), and (c) are cross-sectional views of an embodiment of the auxiliary intake air amount control valve for an engine according to the present invention at low, medium, and high temperatures; FIG. 2(, L) and (b) is a front view and side sectional view of the large diameter portion at the tip of the valve stem and the plate portion inside the valve body, showing another embodiment of the present invention, and FIG. A curve diagram showing the relationship between the intake air flow rate, Figure 4 is a sectional view showing the conventional auxiliary intake air flow rate control valve attached to the throttle valve housing, and Figure 5 is the intake flow rate versus cooling water temperature using the control valve in Figure 4. It is a curve diagram showing the relationship. 1... Engine, 2... Throttle valve housing, 3...
...Throttle valve, 4a...Air inlet, 4b...
Air outlet, 5...Valve case, 6...Inflow port, 7...
・Outlet port, 9...valve seat, 10...valve hole, 12...
Thermal responsive actuator, 14a... Actuation rod, 2
0... Valve stem, 20a... Large diameter part, 22... Valve body,
23... Plate, 25... Connection spring, 26
. . . Return spring, 30 . . . Communication hole. In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A valve case that is provided with an inlet and an outlet that are connected to the bypass passage of the throttle valve part of the intake passage to the engine, and the cooling water of the engine that is accommodated in this valve case is branched and circulated, and is operated according to the water temperature. A thermally responsive actuator, a valve seat provided in the valve case that partitions the inlet side and the outlet side and has a valve hole, supported movably in the axial direction by the actuator, and a thermally responsive actuator. an actuating rod that is advanced by action; a valve stem that is provided with a large diameter portion at its tip and that is advanced by the advancement of the actuating rod;
A valve body that is cylindrical in shape and has a substantially conical tip end, is pushed forward by a connecting spring interposed between the valve stem and the rear part of the valve stem, and opens and closes the valve hole by the outer periphery of the tip side; the rear part of the valve body; and a return spring that is interposed between the valve seat and the valve seat, and is pressed against a stepped portion in the valve body by the return spring that causes the valve body to retreat and open the valve hole when the operating rod retreats, and the connection spring. One end surface on the inner diameter side corresponds to the rear surface of the large diameter portion of the valve stem, and when the cooling water is at low or medium temperature, the rear surface of the large diameter portion is brought into contact with the large diameter portion, and when the temperature is high, the large diameter portion is moved further forward by the valve stem. In an auxiliary intake air amount control valve for an engine equipped with a plate that allows air to escape forward, a flow hole is provided at the tip of the valve body, and when the cooling water is at a high temperature, the valve stem is advanced by a large advance of the actuating rod, and the large diameter portion is moved forward. An auxiliary intake air amount control valve for an engine, wherein the auxiliary intake air amount control valve for an engine is characterized in that the bypass intake air is opened forward from the plate to guide bypass intake air and flow through the circulation hole.