JPS63205434A - Idle control valve for internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent abnormal increase of engine rotation, in an idle control valve being arranged in an auxiliary air path which bypasses a throttle valve, by providing a stopper member which can displace corresponding to engine temperature and limit the upper limit opening position of the idle control valve. CONSTITUTION:An idle control valve has a valve body 26 for opening/closing an opening 24 communicating between auxiliary air paths 22A, 22B which bypass a throttle valve. The valve body 26 is secured integrally with a rotor 29 arranged with open-valve and close-valve coils 30, 31 on the circumference thereof such that it can be opened or closed through duty control of power supply to respective coils 30, 31. Here, a stopper 41 for limiting the valve open position of the valve body 26 is arranged, rotatably with respect to the rotor 29, on the outer circumference of the rotor 29. The stopper 41 is moved by means of a helical bimetal 42 corresponding to engine temperature so as to enable variation of the valve open position which is limited by the stopper 41.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to an idle control valve for an internal combustion engine.

<Prior art> In an electronically controlled fuel injection type internal combustion engine, in order to maintain the idle speed at an optimum level and improve fuel efficiency, an idle control valve ( An ISC valve (hereinafter referred to as an ISC valve) is installed to adjust the auxiliary air flow rate by controlling its opening degree to increase or decrease depending on the engine condition (see Japanese Utility Model Publication No. 134841/1983).

An example of such an ISO valve is shown in FIG. 6 and will be described.

In the figure, a housing 1 includes an upstream auxiliary air passage 2 connected to an intake passage upstream of the throttle valve, and a downstream auxiliary air passage (not shown) connected to an intake passage downstream of the throttle valve. The upstream auxiliary air passage 2 and the downstream auxiliary air passage communicate with each other through an opening formed in a valve seat (not shown) whose sealing surface is a part of the cylindrical surface.

The valve body 3, whose sealing surface is a part of the cylindrical surface facing the valve seat, is fixed to a hollow rotor that is rotatably supported on a fixed shaft 4 via a needle hair ring 5.6.

A valve-opening yoke 10 and a valve-closing yoke 11 are arranged around the rotor 7, which generate magnetic forces in different directions by energizing the valve-opening coil 8 and the valve-closing coil 9, respectively. The convex portions 7A and 7B formed in a rotor shape facing each yoke 10.11 are attracted by the magnetic force generated in each yoke 10.11, thereby causing the yoke 7 to rotate. Reference numeral 12 represents an intermediate yoke interposed between the coils 8 and 9 for opening and closing the valve, and reference numeral 13 represents a helical return spring having one end fixed to the housing 1 and the other end fixed to the rotor.

According to the ISC valve having such a configuration, drive pulse signals are alternately supplied to both the valve opening and valve closing coils 8.9, and the energization time ratio to each coil 8.9, that is, the drive pulse signal By changing the duty ratio according to the engine operating state, the rotational position of the rotor 7 changes, and the valve body 3
is controlled to a predetermined opening degree.

<Problems to be Solved by the Invention> Incidentally, in recent years, a system has been put into practical use in which the above-mentioned ISC valve is provided with an auxiliary air control function such as an air regulator, and the auxiliary air is controlled by one ISC valve. .

In this case, the flow rate control range of the auxiliary air is set wider than in the case where only the idle speed control function is used. For this reason, if, for example, the control unit goes out of control and a fully open signal is given to the ISC valve during idle link operation, excessive auxiliary air will be supplied, causing the engine speed to rise more than necessary. There was a possibility that the vehicle would run out of control.

The present invention was made in view of the above-mentioned circumstances, and it is possible to regulate the auxiliary air flow rate according to the engine temperature so that the engine speed does not increase more than necessary even if a full open signal is given due to a control unit running out of control. The purpose of the present invention is to provide an idle control valve that can secure a minimum amount of auxiliary air flow.

<Means for Solving the Problems> Therefore, the first invention provides a stopper member that regulates the upper limit position of the valve opening, and a stopper that variably controls the upper limit position by moving the stopper member according to engine temperature. The structure includes a member moving means.

Further, in the second invention, there is provided a stopper member that regulates the upper limit position of the valve opening degree, a stopper member moving means that moves the stopper member according to engine temperature to variably control the upper limit position, and a stopper member that moves the stopper member. It was constructed by providing regulatory means to regulate the scope.

Thus, according to the configuration of the first invention, the stopper member moves according to the engine temperature, and the upper limit position of the valve opening corresponds to the maximum allowable auxiliary air flow rate at the engine temperature at that time. The position can be adjusted.

Further, according to the configuration of the second invention, by regulating the movement range of the stopper member that moves according to the engine temperature, further movement of the stopper member is stopped when the engine temperature reaches a predetermined value. This ensures the minimum necessary amount of auxiliary air and prevents engine stalling.

<Example> Hereinafter, an example of the present invention will be described based on FIGS. 1 to 5.

In FIG. 1 showing the overall view of the TSC valve of this embodiment, the housing 21 includes an upstream auxiliary air passage 22A connected to an upstream intake passage of a throttle valve (not shown);
A downstream auxiliary air passage 22B that connects to the downstream intake passage of the throttle valve is formed, and both auxiliary air passages 22A, 22B are connected to each other through an opening 24 formed in the valve seat 23 whose sealing surface is a part of the cylindrical surface. are communicating. Furthermore, a bypass auxiliary air passage 22C is formed that bypasses a valve body 26 (described later) that opens and closes the opening 24 and connects to the intake passage on the downstream side of the throttle valve.
2C is equipped with an adjustment screw 25 for adjusting the air flow rate, and prevents engine stalling by setting the lower limit of the auxiliary air flow rate in a no-load state when the load of the air conditioner etc. is off.

The aforementioned valve body 26, which has a part of its cylindrical surface facing the valve seat 23 as a sealing surface, is attached to a rotor 29 that is rotatably supported by a fixed shaft 27 fixed to the housing 21 via a needle bearing 28. fixed in one piece. Around this rotor 29, there is a valve opening coil 30° and a valve closing coil 3.
1, and a valve-opening yoke 32 and a valve-closing yoke 33 that generate magnetic force when both coils 30 and 31 are energized, respectively. Further, on the outer periphery of the rotor 29 facing each yoke 32, 33, a convex portion 29A,
29B are formed so that when magnetic force is generated in each yoke 32, 33, the corresponding convex portions 29A, 29B are attracted, and the rotor 29 is rotated in a predetermined direction based on the difference in the attraction force. It has become. 34 is an intermediate yoke interposed between both the valve opening and valve closing coils 30 and 31.

Furthermore, an inflow pipe 35 is provided on the outer periphery of the housing 21.
and a water jacket 37 to which an outflow pipe 36 is connected.
is formed, and engine cooling water is circulated and supplied.

Further, on the outer periphery of the rotor 29, a first stopper 41 is rotatably attached to the rotor 29 and serves as a stopper member for regulating the valve opening position of the valve body 26;
a helical-shaped bimetal 42 as a stopper member moving means for moving the valve according to the engine temperature, for example, the temperature of the engine cooling water in the water jacket 37, and changing the valve opening position regulated by the first stopper 41, and the hanging 21. A second stopper 43 is disposed as a regulating member that is fixed to and regulates the range of movement of the first stopper 41 by the bimetal 42 .

The first and second stoppers 41, 43 and the bimetal 4
The details of the second mounting structure are shown in FIG. 2 and will be explained below.

The first stopper 41 has a substantially cylindrical shape, and has opposing convex portions 41A and 41B protruding toward the valve body 26 as shown in FIG.
It can be fitted with the side protrusions 26A and 26B.

Further, the inner end of the bimetal 42 is fixed to the outer periphery by resin molding. The outer end of the bimetal 42 is fixed to the housing 21.
It is fixed to the terracerto 44 by spot welding. The second stopper 43 is arranged on the outer periphery of the first stopper 41 and is fixed to the housing 21 via the bracket 44, and as shown in FIG. are formed, and can be engaged with convex portions 41C and 41D formed on the outer periphery of the first stopper 41. 45 is a washer for preventing the second stopper 43 from being removed.

Next, the action of the first stopper, which is a feature of the first invention, will be explained as follows.
This will be explained with reference to the figures.

As shown in FIG. 3, the two protrusions 41 of the first stopper 41
The distance between A and 41B is 01, and each convex portion 26 of the valve body 26
Assuming that the respective widths of A and 26B are θ2, the rotation range of the valve body 26, that is, the change range θ of the valve opening is θ months - θ1 - θ2.
becomes. If the arrow A direction in the figure is the valve opening direction, and the arrow B direction is the valve closing direction, the lower (upper) end surface 41a (41b) in the figure of the convex portion 41A (41B) corresponds to the upper limit position of the valve opening. However, the upper (lower) end surface 41a''(41b'') in the figure of the convex portion 41A (41B) corresponds to the lower limit position of the valve opening.

Now, assuming that the engine is in the state shown in the third figure at a certain engine temperature, when the engine temperature rises, the water jacket 37
The bimetal 42 is displaced by the temperature rise of the engine cooling water inside the engine, and the first stopper 41 is moved in the direction B in the figure.

As a result, the positions of the convex portions 41A and 41B move in the same direction, so that the upper limit position (end surfaces 41a, 41a') and lower limit position (end surfaces 41b, 41b') of the valve opening regulated by the first stopper 41 are both It moves in the valve closing direction, that is, in the air flow rate decreasing direction.

Therefore, the upper limit of the air flow rate can be reduced as the engine temperature increases and the engine required air amount decreases.
Even if the control unit runs out of control and a full open signal is given, the action of the first stopper 410 prevents the supply of air flow that exceeds the upper limit position at that time, thereby preventing the engine from running out of control.

Next, the action of the second stopper, which is a feature of the second invention, will be explained as follows.
This will be explained with reference to the figures.

The distance between the two convex parts 43A and 43B of the second stopper 43 is 03, and each convex part 41C and 4]D of the first stopper 41
If the respective widths of are θ4, then the movement range θ6 of the first stopper 41 is θ6-θ3-θ4.

Further, the right (left) end surface 43a'(43b'') of the convex portion 43A (43B) in the figure corresponds to the maximum position on the valve closing side.

The maximum valve opening position is set at a position where an air flow rate that is slightly higher than the maximum required air flow rate of the engine is obtained, and the maximum valve closing position is set when a load such as an air conditioner is turned on. Set it at a position that will ensure the minimum necessary air flow rate when the

Now, as mentioned above, the first stopper 41 moves in the valve closing direction (arrow B direction in the figure) as the engine temperature rises, but when the engine temperature reaches a predetermined temperature (for example, 70°C), the second
The facing end surfaces of the convex portions 41C and 41D of the first stopper 41 are brought into contact with the end surfaces 43a' and 43b' of the stopper 43 and locked, so that the first stopper 41 cannot be moved even if the engine temperature rises further. It has become. Therefore, the valve opening does not decrease beyond the lower limit position set by the second stopper 43, and the minimum required air flow rate can be ensured.

FIG. 5 shows the engine required air flow rate and engine required rotational speed depending on the engine temperature.

<Effects of the Invention> As described above, according to the first invention, as the engine temperature rises, the stopper member is moved in the direction of decreasing the valve opening to lower the upper limit value of the air flow rate. Even if a full-open signal is input due to malfunction, the air flow rate will not increase more than necessary, and therefore the engine speed will not increase abnormally, thereby preventing the vehicle from running out of control.

Further, according to the second invention, the stopper member is prevented from moving indefinitely as the engine temperature rises, and the minimum necessary air flow rate can be secured, so that the engine stalls, etc. can be prevented.

[Brief explanation of the drawing]

FIG. 1 is an overall cross-sectional view of the idle control valve of the present invention, FIG. FIG. 5 is a diagram showing the relationship between engine temperature, required air amount, and required rotational speed of the engine, and FIG. 6 is an overall sectional view showing a conventional example. 21...Housing 26...Valve body 27...
・Fixed shaft 29... Rotor 30... Valve opening coil 31... Valve closing coil 32... Valve opening yoke 33... Valve closing yoke 37... Water jacket 41... 1st stopper 41A, 4
1B, 41C, 41D... Convex portion 42... Bimetal 43... Second stopper 43A.

Claims (2)

[Claims] (1) In the idle control valve of an internal combustion engine, which is installed in an auxiliary air passage that bypasses a throttle valve installed in the intake passage, and whose valve opening is controlled according to the duty ratio of a drive pulse signal, the valve opening is An idle control valve for an internal combustion engine, comprising: a stopper member for regulating an upper limit position; and a stopper member moving means for variably controlling the upper limit position by moving the stopper member according to engine temperature. (2) In the idle control valve of an internal combustion engine, which is installed in an auxiliary air passage that bypasses a throttle valve installed in the intake passage, and whose valve opening is controlled according to the duty ratio of a drive pulse signal, the valve opening is A stopper member for regulating the upper limit position of the stopper member, a stopper member moving means for variably controlling the upper limit position by moving the stopper member according to engine temperature, and a regulating means for regulating the movement range of the stopper member. An idle control valve for an internal combustion engine characterized by: