JPS62246672A - Idling speed control device for automobile - Google Patents

Abstract

PURPOSE:To obtain the displacement of a valve being in proportion to a current by providing a driving negative pressure control means which controls the driving negative pressure acting on a diaphragm in response to an electric signal being input into solenoid. CONSTITUTION:When an electric input is given to a solenoid 20, a plunger 19 is displaced, and the passage 30 formed in the center of a valve 25 is closed by a valve body 29 provided at the end of the plunger, so that the negative pressure in an intake pipe is introduced into a diaphragm chamber 36. Then, the pressure difference between both ends of a diaphragm 33 is diminished, and the valve 25 is acted by the pressure difference between the front and back of the valve to come away from its seat 23. When the valve 25 comes away from its seat, the passage 30 having been closed opens again, and accordingly the plunger 19 follows up as much as the displacement of the valve, and the action as described above is repeated. Thus, the position of the valve 25 is controlled in response to the input of a solenoid 20, and the flow rate corresponding to the position thereof is measured and output.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to the idle speed of an automobile based on the operating state of the engine (
The present invention relates to an idle rotation control device that automatically controls the rotation speed to a set value according to water temperature or outside air temperature, and relates to an electronically controllable actuator.

[Conventional technology]

The conventional idle rotation control device is disclosed in Japanese Patent Application Laid-Open No. 56/1169.
As described in No. 66, two metering valves were provided which were configured to generate forces in opposite directions to eliminate the effects of negative pressure acting on the metering valves.

[Problem that the invention seeks to solve]

The above conventional technology has the problem that the balance of the force applied to the valve is lost due to the shape of the air passage, the shape of the valve, etc. due to an increase or decrease in the air flow rate, and it is difficult to obtain a displacement of the valve proportional to the applied current. Ta.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bypass air flow control device capable of obtaining valve displacement proportional to current.

[Means for solving problems]

The above purpose uses the force due to the pressure difference applied to the valve,
This is achieved by attaching a diaphragm that generates a force in the opposite direction to the force applied to the valve to the shirt that fixes the valve, and providing a valve that adjusts the pressure difference between the diaphragms.

[Effect]

A force is applied to the valve in one direction due to the pressure difference.

The diaphragm is arranged so that it receives a force in the opposite direction to this force, and the position of the valve relative to the solenoid plunger adjusts the pressure difference across the diaphragm, so that the force applied to the central axis of the valve is always balanced. Therefore, no force is applied to the solenoid.

(Example〕 The basic configuration and operation of the first embodiment will be explained below.

A passage is provided in the center of a valve that is provided in an air passage that bypasses the intake pipe and opens and closes the air passage, and one end opening of this passage faces a valve body provided at the tip of a plunger shaft in a solenoid. The opening and closing of the opening is controlled by the displacement of the plunger. The other end of the passage is formed to extend through the diaphragm and into the diaphragm chamber. The diaphragm chamber is communicated with the atmosphere through the passage, and negative pressure in the intake pipe is introduced into the diaphragm chamber through an orifice.

When electrical input is applied to the solenoid, the plunger is displaced,
The valve body at the tip of the plunger closes the passage formed in the center of the valve, and negative pressure in the intake pipe is introduced into the diaphragm chamber. Then, the pressure difference between both ends of the diaphragm disappears, and the valve operates due to the pressure difference before and after the valve, and is removed from the seat. When the valve separates, the blocked passage opens again, so the plunger follows and repeats the above operation 6. In other words, the valve is controlled in position according to the input. , the flow rate corresponding to this position is measured and output.

In order to facilitate understanding of the present invention, prior to a detailed explanation of the present invention, conventional application examples, conventional configurations, 9 operations, etc. will be explained.

FIG. 4 shows an example of application of the conventional device, in which 1 is an engine provided with an intake pipe 2 and an exhaust pipe 3. The intake pipe 2 is provided with a throttle valve chamber 6 having a throttle valve 4 and a bypass passage 5 . Furthermore, on the upstream side, an air flow meter 9 consisting of a vane 7 that measures the amount of air and a potentiometer 8 that converts the rotation angle of the vane 7 into an electrical output is provided.Further upstream, an air cleaner 10 is installed. be done.

Reference numeral 11 denotes an EGR which is left in the middle of a passage connecting the intake pipe 2 and the exhaust pipe 3, and is used to recirculate a part of the exhaust gas to the intake system.
It's a valve. However, this EGR valve is not directly related to the present invention, and is merely explained as one component around the engine.

12 is a water temperature sensor that detects the temperature of the cooling water of the engine 1 and converts it into an electrical output; 13 is a crank angle sensor that detects the rotation speed of the engine 1 and converts it into an electrical output; 14 receives various input signals; This is an arithmetic processing circuit (computer) that processes this and supplies predetermined outputs to the idle rotation control device 15 and fuel injection valve 16, and is in charge of the central part of the electronic control of the engine. The input is supplied by

The idle rotation control device 15 is installed in the bypass passage 5 of the throttle valve chamber 6, and controls the amount of bypass air that bypasses the throttle valve 4.

Figure 2 is a conventional idle rotation control device! 15, in which a core 18 and a plunger 19 are arranged at the center of a cylindrical coil 17, and the opposing surfaces of both are conical, and the amount of electricity supplied to the coil 17 is mechanically controlled. A body 22 having a solenoid 20 for changing the desired position, an air passage or fluid passage '21 to be controlled, a pair of seats 23, 24 formed in the middle thereof, a pair of valves 25.
26, and a flow rate control mechanism section 28 equipped with a spring 27, and is controlled by the output signal of the arithmetic processing circuit 14 which receives the signals from the water temperature sensor 12 and the crank angle sensor 13 and performs predetermined arithmetic processing to control the desired engine speed. It has a function to adjust the bypass air to maintain the rotation speed.

That is, it has a function of detecting water temperature and engine rotation speed and automatically and continuously controlling the engine rotation speed to a predetermined value.

The measuring section of this device is composed of a pair of seats 23, 24 and a pair of valves 25, 26, so both valves 23, 24
It has the feature of canceling out the negative pressures acting on the two sides by making them equal in magnitude and in opposite directions.

On the other hand, if emphasis is placed on negative pressure cancellation, the linearity of the output characteristics will deteriorate significantly as shown in FIG. 3.

This is not a practical problem because the rotation speed control can incorporate feedback control, but as the number of engine types increases and it is attempted to adapt individual flow characteristics for each, there is a lack of flexibility and However, it has disadvantages such as a long development period.

The present invention proposes a new device to replace these conventional devices, and in explaining the present invention based on the embodiments shown in the drawings below, the same reference numerals as in the conventional devices represent the same or equivalent components.

In the embodiment shown in FIG. 1, a valve body 29 made of an elastic material such as rubber is provided at the tip of a shaft 28 fixed to one end of the plunger 19, and the valve body 29 is brought into contact with the tip of the valve 25. Placed.

A spring 27 is disposed between the valve body 29 and the body 21,
It is configured to balance the electromagnetic force with the solenoid 20 and generate a stroke proportional to the input.

A pressure communication passage 3o is provided at the axial center of the valve 25. Furthermore, a diaphragm retainer 3 is installed on the negative pressure side of the valve 25.
1.32, the other end of the diaphragm valve 25 extends to a diaphragm chamber 36 and is slidably supported on a support 38 provided on the cover 37. On the other hand, an orifice 39 is provided on the shaft of the valve 25, and a passage 30 and a diaphragm chamber 36 are provided.
By communicating with the valve 25 and sliding the valve 25, this orifice 39 cooperates with the support 38 and has the function of a variable orifice whose area changes.

Further, the diaphragm 33 is provided with an orifice 4° that communicates the negative pressure passage 35 and the diaphragm chamber 36, and these constitute a flow metering mechanism. 41 is an atmospheric communication hole provided in the diaphragm chamber, and 42 is an orifice between the cover 37 and the diaphragm chamber. The spring provided between the diaphragms 33 and 33 has the function of returning the diaphragm 33.

In such a configuration, the input to the solenoid 20 is O,
When a predetermined negative pressure is applied to the negative pressure passage 35, the plunger 19 does not operate as shown in FIG. 1, and the valve body 29 is separated from the shaft tip of the valve 25 to form a gap 43.

Therefore, the atmosphere from the passage 21 is transferred to this gap 43, the passage 3
0, is led to the diaphragm chamber 36 via the orifice 39, and a predetermined differential pressure is generated at both ends of the diaphragm 33.

Since the diaphragm 33 receives a force in the direction of arrow 44 due to this differential pressure, the valve 25 fixed to the diaphragm 33 also receives a force in the same direction, and the valve 25 remains in close contact with the seat 23.

Here, a predetermined input is applied to the solenoid 20, for example, 0.3A.
, the plunger 19, shaft 28, and valve body 29 move toward the core 18 against the spring force of the spring 27. Then, the valve body 29 and the shaft of the valve 25 come into contact, and the valve body 29 seals the passage 30. When the passage 30 is sealed, the negative pressure from the negative pressure passage 35 enters the diaphragm chamber 36 through the orifice 40, so that the atmospheric pressure in the chamber becomes negative pressure, and after a certain period of time, the atmospheric pressure from the negative pressure passage 35 enters the diaphragm chamber 36. , and the differential pressure across the diaphragm 33 becomes zero.

As a result, the force in the direction of arrow 44 disappears, and the valve 25 receives a force in the direction of arrow 45 due to the pressure difference between its ends, and moves in the direction of arrow 45 in an instant.

When the valve 25 moves in the direction of the arrow 45, it separates from the valve body 29 again, creating a gap 43. Atmospheric air is sucked in through the gap 43, and then flows into the diaphragm chamber 26 through the passage 30.
The pressure inside becomes atmospheric pressure.

As a result, a force in the direction of arrow 44 acts on the diaphragm 33 to try to push the valve 25 back.

However, the gap 43 occurs until the plunger 19 and the valve body 29 move by a position proportional to the input applied to the solenoid 20.

When the plunger 19 and the valve body 29 reach a position proportional to the input, the above-mentioned repeated operation of the valve 25 becomes smaller, and the meteor flowing between the valve 25 and the seat 23 is measured to a value corresponding to the input.

As described above, in this embodiment, the solenoid 20 performs linear electrical-position conversion, and the pressure is controlled by controlling the position, and the driving force of the valve 25 is operated by the pressure difference of the valve itself. This operating force is pressure-corrected by a correction mechanism composed of a diaphragm.

Next, the variable orifice 39 will be explained in detail.

The size of the orifice 39 affects when the valve body 29 and the tip of the shaft of the valve 25 do not come into contact with each other, that is, when a gap 43 exists.

Therefore, when the input is zero, if the orifice 39 is made large and a large force is applied to the diaphragm 33 in the direction of the arrow 44, the valve 25 will come into close contact with the seat 23, which will prevent initial leakage when the input is zero.

That is, 81 of the curve a in FIG. 5 can be made small as az.

However, in the high input range, when the passage is on/off controlled by the valve body 29, if the opening area of the orifice 39 is large, the return force generated in the diaphragm 33 in the direction of the arrow 44 also becomes large, and the return force per unit The controlled flow rate becomes large, causing hunting as shown in curve 88 in FIG. 5, and becoming uncontrollable.

From the above, it can be understood that it is desirable to continuously vary the opening area of the orifice 39 according to the stroke of the valve shaft.

In the embodiment of the present invention, the opening area of the orifice 39 is continuously variable by the support 38 as the shaft of the valve 25 strokes.

As a result, excellent linear flow characteristics with small initial leakage, as shown by the curve in FIG. 5, can be obtained.

In addition to these basic effects, by adopting a variable orifice, the correction force of the diaphragm can be changed according to the input, resulting in small initial leakage and stable flow characteristics with excellent linearity up to high flow rates. be.

A second embodiment of the present invention will be described below with reference to FIG. 6. A passage 102 of the case 101 communicates with the downstream side of the throttle valve, and a passage 103 communicates with the upstream side of the throttle valve. A central shaft 105 formed at the center of the valve 104 is held by a bearing fixed to the case 101 so as to be movable in the axial direction. A valve 104 is a seat 107 fixed to the case 101
By contacting the passage 2 and the passage 3, it is possible to completely close the space between the passage 2 and the passage 3. A plate 108 and a plate 109 are fixed to the central shaft 105, and a diaphragm 110 is sandwiched between the plates 108 and 109.

Plate 108 and plate 109 are provided with orifices 1.11 leading to passage 103. The outer ring portion of the diaphragm 110 is sandwiched between the case 101 and the cover 112. A spring 113 is provided between the plate 109 and the cover 112. A solenoid is fixed to the cover 112. The solenoid includes a plunger 114 movable in the same direction as the central axis 105, a core 115 that attracts the plunger 114, a coil 116 formed to surround the core 115 and the plunger 114, a shaft 117 fixed to the plunger 114, and a shaft 117 that pushes the shaft 117. A spring 118, an adjustment screw 119 for adjusting the set load of the spring 118, and a molded material 1 forming the whole.
Consists of 20. A valve body 121 is fixed to the plunger 114.

In this configuration, the solenoid is a near solenoid, and its displacement with respect to current is linear. As the current increases, the plunger 114 moves toward the solenoid. Since the valve body 121 also moves together with the plunger 114, the valve body 12 moves from the end of the central shaft 115.
1 leaves, the negative pressure in the passage 102 is introduced through the hole 122 and through the passage in the shaft 105 into the chamber 123 between the diaphragm 110 and the cover 112. Although some negative pressure is released through the orifice 111, the amount of negative pressure introduced is large, so the inside of the chamber 123 remains under negative pressure, and the passage 10
3 pulls the diaphragm 110 and opens the valve 104 through the shaft 105. The balance between the negative pressure leaking from the orifice 111 and the valve 21 causes the central shaft 105 to move in close contact with the plunger 114.

The spring 113 has the effect of preventing the valve 121 from moving due to vibrations, etc., and the adjustment screw 119 provided at the rear end of the solenoid, in addition to the spring 118, keeps the valve closed and the orifice closed even if the diaphragm 110 is torn. Even if the valve 111 is clogged, the valve will not open as long as the valve 121 is closed.

In this way, when each part fails, the valve 104 has the effect of being closed.

〔Effect of the invention〕

According to the present invention, since the electromagnetic force of the solenoid is used only for pressure control, the linearity of the solenoid is not impaired, and this linearity possessed by the solenoid can be derived as an output characteristic.

Furthermore, the driving force of the valve that controls the flow rate is driven by the pressure difference applied to the valve itself, and is corrected by the pressure difference in the diaphragm according to this movement, so the flow rate characteristics are not determined uniquely by the valve profile. This has the effect of increasing the flexibility with respect to the required flow rate of the engine.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of an idle rotation control device of the present invention, FIG. 2 is a cross-sectional view of a conventional idle rotation control device, FIG. 3 is a flow characteristic diagram thereof, and FIG. 4 is a cross-sectional view of a conventional idle rotation control device. A control system diagram of an automobile internal combustion engine to which the idle speed control device of the present invention is applied, FIG. 5 is a flow rate characteristic diagram of the first embodiment device, and FIG. 6 is a second embodiment of the idle speed control device of the present invention. FIG.

Claims (1)

[Claims] 1. A device that is provided in an air passage that bypasses an intake pipe and controls the amount of air passing through the air passage in accordance with an electric signal input to a solenoid, including a diaphragm; a drive negative pressure control means for controlling the acting negative pressure in accordance with an electric signal input to the solenoid; and a drive negative pressure control means that is attached to the diaphragm that is displaced in accordance with the drive negative pressure to change the drive negative pressure and is input to the solenoid. and a valve that controls the flow rate of air flowing through the air passage in proportion to an electric signal generated by the vehicle. 2. In the invention set forth in claim 1, the drive negative pressure control device includes a plunger driven by the solenoid, a valve body formed at the tip of the plunger, the diaphragm, and the valve. a shaft that supports the diaphragm in a coaxial relationship and transmits the displacement of the diaphragm to the valve; and a shaft that passes through the center of the shaft, one end opening opposite the valve body, and the other end partitioned by the diaphragm. and a through hole opening into a negative pressure chamber connected to the downstream side of the valve, and the diaphragm is configured to resist the force of the negative pressure acting on the diaphragm and against a spring in the closing direction of the valve. An idle rotation control device for an automobile, characterized in that the device is biased. 3. In the invention set forth in claim 1, the driving negative pressure control device includes a plunger driven by the solenoid, a valve body formed at the tip of the plunger, the diaphragm, and the valve. a shaft that supports the diaphragm in a coaxial relationship and transmits the displacement of the diaphragm to the valve; and a shaft that passes through the center of the shaft and has one end opened downstream of the valve and the other end partitioned by the diaphragm. a through hole opening into a negative pressure chamber and facing the valve body within the negative pressure chamber; An idle rotation control device for an automobile, characterized in that it is biased by a spring. 4. A device that is installed in an air passage that bypasses an intake pipe and controls the amount of air passing through the air passage in accordance with an electric signal input to a solenoid, which includes a diaphragm and a driving negative pressure that acts on the diaphragm. a drive negative pressure control means that controls according to an electric signal input to the solenoid; and a drive negative pressure control means that is attached to the diaphragm that is displaced according to the drive negative pressure, and that changes in proportion to the electric signal input to the solenoid. and a correction means for correcting the displacement of the diaphragm according to the intake pipe negative pressure so as to cancel the intake pipe negative pressure acting on the valve. An automobile idle speed control device characterized by: 5. A plunger with a core and a valve body at one end is placed in the center of the cylindrical coil, and the body has a solenoid that converts the amount of electricity input to the coil into position output, and an air passage to be controlled. a flow metering mechanism including a seat, a valve, and a diaphragm fixed to the valve, and a pressure compensation mechanism formed by the atmospheric side of the air passage and the diaphragm at the axial center of the valve. A passage communicating with the diaphragm chamber is formed, and an end of the passage is provided with a variable orifice whose opening area changes continuously according to the position of the valve, and the other end of the passage is provided with a variable orifice that communicates with the diaphragm chamber. An idle rotation control device characterized in that a valve body whose position changes depending on the magnitude of an input electric signal supplied to the idle rotation control device is disposed facing each other. 6. The device according to claim 5, wherein the variable orifice is controlled by the stroke of the valve, and the variable orifice is arranged so that the larger the stroke, the smaller the opening area. Idle rotation control device. 7. The apparatus according to claim 5 or 6, wherein the diaphragm is fixed to form a part of a side wall of an air inlet passage. Device. 8. A solenoid, a plunger driven by the solenoid, and a valve that controls the air flow rate of the air passage bypassing the intake pipe according to the displacement of the plunger, in which a valve is provided within the central axis of the valve. A through hole is provided through the shaft, a diaphragm is fixed to the shaft in which the through hole is formed, the diaphragm is placed in the air inflow side passage of the air passage, and the diaphragm is disposed between the diaphragm and a case covering the outside of the diaphragm. , a negative pressure chamber is provided on which negative pressure is applied, which is introduced from the air outlet side passage of the air passage through a hole in the center axis of the valve, and a leak passage that releases negative pressure in the negative pressure chamber is used as the air inflow side passage. An idle rotation control device for an automobile, characterized in that a valve body is provided between the side passage and the end of the plunger of the solenoid so as to face an end of the through hole at the center of the shaft. 9. An idle rotation control device for an automobile according to claim 8, wherein the diaphragm is fixed so as to form a part of a side wall of an air outlet passage. 10. The idle rotation control device for an automobile according to claim 8, wherein the leak passage is provided in a diaphragm. 11. The idle rotation control device for an automobile according to claim 8, characterized in that a spring is provided between the diaphragm and the case to bias the valve in a closing direction. 12. The idle rotation control device for an automobile according to claim 8, further comprising an adjusting mechanism for adjusting the load of a spring built into the solenoid.