JPH0255872A - Intake air flow controller for engine - Google Patents

Abstract

PURPOSE:To make a fear of causing a vehicle's runaway due to intake air flow sharply increased preventable by performing intake air flow control at a time when a throttle valve is in low opening by means of turning motion of a piston. CONSTITUTION:In a box body 12 being formed in an intake passage 1, there is provided with a cylindrical hole 13 which is opened to an inner circumferential surface of this intake passage 1 in opposition to an outer circumferential edge of a throttle valve 2 existing in a full-close position. A piston 14 is set up in this hole 13 free of rotation, and it is turned round together with a turning shaft 4-1 of a motor 4. Here a recess is formed in an inner end face of this piston 4, and when opening of the throttle valve 2 is small, a flow passage section area of intake air being formed in a gap with an outer circumferential edge of the throttle valve 2 can be varied by turning motion of the piston 4. With this constitution, since a range, where intake air flow is controlled, is restricted by a diameter of the piston 4, such a fear that the intake air flow is sharply increased by a malfunction of an actuator or a control circuit as in the case of being controlled by the opening of the throttle valve 2 is thus brought to nothing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an engine intake flow rate control device, which is provided in a housing that forms an intake passage of an engine and includes a throttle valve.
A piston having a recess formed on the inner end surface is disposed in a cylindrical hole opening in the inner circumferential surface of the intake passage at a position facing the outer circumferential edge of the throttle valve in the fully closed state, and rotation of the piston is provided. According to the configuration of the intake passage, the intake flow rate can be controlled by changing the cross-sectional area of the intake passage formed between the inner end surface of the piston and the outer peripheral edge of the throttle valve when the throttle valve is opened at a low opening degree. Regarding.

[Prior Art] Conventionally, intake flow rate control devices for controlling the rotational speed of an automobile engine during idling operation have the following configuration.

(1) A control circuit that inputs an actual rotational speed signal of the engine to a control circuit, compares it with a set rotational speed, and operates an actuator based on the signal output from the control circuit to control the opening degree of the throttle valve. In the figure, code 1 is the intake passage.
2 is a throttle valve, 3 is a rotating shaft of the throttle valve, 4 is an actuator, 5 is a rod of the actuator that moves forward and backward, and 6 is a lever fixed to the rotating shaft 3 of the throttle valve, which moves the rod 5 forward and backward. The throttle valve 2 is opened and closed in response to this. The configuration in which the idling speed is controlled by opening and closing the throttle valve 2 is disclosed in Japanese Patent Application Laid-Open No. 63
-27535, JP-A-56-20730, JP-A-5
No. 1-2834, Japanese Unexamined Patent Publication No. 18240/1983, Japanese Unexamined Patent Publication No. 18240/1983
It is disclosed in each publication of No. 8-5934.

(2) The intake air flow rate is not controlled by the opening degree control of the throttle valve 2, but by inputting the actual rotational speed signal of the engine into the control circuit, comparing it with the set rotational speed, and using the signal output from the control circuit. There is a system that controls the intake air Am flowing through a bypass intake passage that connects the upstream side and the downstream side of the throttle valve 2 in the intake passage 1. For example, in FIG. 13, the reference numeral 1 is the intake passage.

2 is a throttle valve, 7 is a bypass intake passage, and the intake flow rate flowing through the bypass intake passage 7 is controlled by an intake flow rate control valve 8 whose opening/closing is controlled by an actuator 4 (Japanese Utility Model Publication No. 58-9948) ), as shown in FIG. 14, the flow rate of intake air flowing through the bypass intake passage 7 is controlled by a valve 9 that operates with negative pressure, and the negative pressure in the negative pressure chamber 10 that operates the valve 9 is driven by the actuator 4. There is a configuration (Japanese Unexamined Patent Application Publication No. 49-40886) in which the throttle valve 2 is controlled by the valve 11 that moves forward or backward by the rod 5 of the actuator 4.
The configuration shown in Fig. 12, which controls the opening degree of Therefore, there is a risk that a malfunction of the actuator 4 or the control circuit will cause the throttle valve to open more than necessary, significantly increasing the intake flow rate and causing the vehicle to run out of control. In addition, when the engine is idling, even if the cable that rotates the throttle valve 2 is given some slack by the movement of the accelerator, the accelerator pedal will move as the throttle valve 2 opens and closes due to the operation of the actuator. Because it moves, it makes the driver worry that the vehicle will run out of control.

On the other hand, in the idle rotation speed control device of the type that controls the flow rate of intake air flowing through the bypass intake passage 7 connecting the upstream side and the downstream side of the throttle valve 2 shown in FIG. 13 or 14, the upstream side of the throttle valve 2 When the pressure difference between the intake air and the downstream side is constant, the flow rate of intake air flowing through the intake passage 1 changes as shown in the curve shown in FIG. 15 as the opening degree of the throttle valve 2 changes. In Fig. 15, the vertical axis shows the intake flow rate, and the horizontal axis shows the throttle valve opening degree.Curve 1 shows the outer peripheral edge of the throttle valve 2 and the intake air, and curve C shows the intake flow rate that is the sum of both. . The flow rate of the intake air flowing through the bypass intake passage 7, indicated by the curve vAb, is controlled almost independently of the driver's accelerator operation.
When accelerating or decelerating during a first idle period, that is, when warming up has not yet been completed, it not only gives the driver a driving sensation that is different from the driving sensation that occurs after warm-up has been completed, but also causes anxiety. The flow rate of intake air flowing through the bypass intake passage 7 due to malfunction of the control circuit or actuator 4,
That is, when the intake air flow rate shown by curve gb increases significantly, the total intake air flow rate shown by curve C also increases, which may cause the vehicle to run out of control. Further, in the configuration shown in FIGS. 13 and 14, it is necessary to specifically provide the bypass intake passage 7, which makes the structure complicated and disadvantageous in terms of manufacturing cost. Therefore, the diameter of the throttle valve 2 is too large to be used for controlling a small intake flow rate such as during idling.

Moreover, unlike the idling control device having the configuration shown in FIG. 12, which uses the throttle valve 2 that is linked to the accelerator pedal, there is no fear of the vehicle running out of control, and the driver does not feel anxious about the vehicle running out of control. Furthermore, as in the configuration shown in FIG. 13 or 14, the bypass intake passage 7 has a complicated structure and gives a sense of uneasiness during acceleration/deceleration before completion of warm-up, or may cause the vehicle to run out of control. The throttle valve does not control the intake flow rate of the throttle valve 2, but instead of controlling the opening degree of the throttle valve 2, the throttle valve 2 controls the intake flow rate when the opening is small, as shown in Fig. 16.

As the throttle valve 2 increases its opening from the opening during idling, the intake flow rate controlled by the means decreases, and when the throttle valve 2 reaches a certain opening, it becomes zero and the intake passage 1 The intake flow rate is controlled by configuring a flow rate control device when the throttle valve is opened at a small opening, which does not affect the total flow rate of the intake air flowing through the engine. Pot function control.

It is an object of the present invention to obtain an intake flow rate control device that can also perform so-called feedback air-fuel ratio control using a 0.02 sensor. In addition, in Fig. 16,
Of the symbols attached to each curve, a and C indicate the same content as in FIG. 15, and d indicates an intake flow rate controlled by a change in shape of a part of the inner wall surface of the intake passage 1. 1st
6 will be further referred to after the detailed description of the invention.

[Means for Solving the Problem] A housing forming an intake passage of an engine including a throttle valve 2 is provided with a casing forming an intake passage on an inner circumferential surface of the intake passage opposite to an outer circumferential edge of the throttle valve in a fully closed state. A cylindrical hole that opens is bored, and a piston having a recess formed on the inner end surface and rotating by the operation of the actuator is arranged in the cylindrical hole, so that the inner end surface of the piston and the throttle valve 2 are connected to each other. The cross-sectional area of the passage changes between the piston and the outer peripheral edge due to rotation of the piston. The actuator is configured to operate the actuator and rotate the piston in response to an output signal from a control circuit that forms an intake flow path when the engine is operated with a low opening of the throttle valve and inputs engine operating parameters.

[Function] When the throttle valve 2 is at a low opening, the intake flow rate is controlled by the rotation of the piston, and the throttle valve 2, which is mechanically linked to the accelerator, does not rotate, so the idle rotation speed is controlled and the fast idle is used. When controlling the rotation speed, the accelerator does not move and the idle rotation speed and fast idle rotation speed are controlled without causing anxiety to the driver.

Since the intake flow rate range controlled by the rotation of the piston is limited by the diameter of the piston, there is no risk of the vehicle running out of control due to malfunction of the actuator or control circuit.

The opening range of the throttle valve 2 in which the rotation of the piston affects the intake flow rate is limited to the opening range in which the outer peripheral edge of the throttle valve 2 faces the inner end surface of the piston, that is, the opening of the cylindrical hole. If the opening is larger than that, for example 20 degrees or more, the rotation of the piston has no effect on the intake flow rate. Does not cause any disturbing changes in sensation.

[Embodiment] FIG. 1 is a sectional view of an embodiment of an engine intake flow rate control device according to the present invention, and reference numeral 1 indicates an intake passage.

2 is a throttle valve; 3 is a rotating shaft of the throttle valve 2; 4 is an actuator; in the embodiment shown in FIG. 13 is a cylindrical hole bored in the casing 12 and opens into the inner peripheral surface of the intake passage 1 opposite to the outer periphery of the throttle valve 2 in the fully closed position; 14 is a piston; , is rotatably disposed within the cylindrical hole 13 and rotates together with the rotation shaft 4-1 of the motor 4. 4-2 is a rotation angle sensor of the motor 4. A recess is formed in the inner end surface of the piston 14, and when the opening degree of the throttle valve 2 is small, the intake air formed between the piston 14 and the outer peripheral edge of the throttle valve 2 due to rotation of the piston 14 is formed. The cross-sectional area of the flow path can be changed. In the embodiment shown in FIG. 1, a half-moon-shaped recess is formed in the inner end surface of the piston 14. FIG. 2 is a cross-sectional view taken along line U-11 in FIG. 1, and shows a situation in which the cross-sectional area of the flow path changes as the piston 14 rotates. Assuming that the intake air flows in the direction of arrow 15 in Fig. 1, in (a), even if the inflow side (upstream side of throttle valve 2) is open, the outflow side (downstream side of throttle valve 2) is closed. Therefore, the intake flow rate is the minimum (including zero flow rate),
(When the piston 14 rotates in the direction of arrow 16 from the state shown in FIG. 1), it becomes the state shown in FIG.

The downstream side of the throttle valve 2 is opened, and the intake air flowing into the cylindrical hole 13 from the upstream side of the throttle valve 2 in the intake passage 1 flows through the throttle valve 2.
flows into the intake passage 1 on the downstream side of the

Inspiratory flow rate increases. When the piston 14 further rotates in the direction of arrow 16 from the state of (b), it becomes the state of C1,
Inspiratory flow rate is maximum. Therefore, the rotation axis 4-1 of the motor 4
By controlling the rotation of the piston 14, the intake flow rate when the throttle valve 2 is fully closed or slightly opened can be controlled by the rotation of the piston 14, and the idle rotation speed or fast idle rotation speed can be controlled. . The relative position between the outer periphery of the throttle valve 2 and the concave portion of the inner end surface of the piston 14 for controlling the intake flow rate when the throttle valve 2 is fully closed or at a small opening is not necessarily limited to the relative position shown in FIG. Alternatively, it is also possible to do as shown in FIG. That is, in FIG. 3, the intake flow rate is the minimum at ta+
Now, the upstream side of throttle valve 2 is closed, and from this state arrow 1
The piston 14 rotates in six directions, and after passing through the state of bl, t
The intake flow rate is maximum in the c+ state. The shape of the recess on the inner end surface of the piston 14 is not limited to the half-moon shape shown in the embodiment of FIG.
The characteristics of the intake flow rate with respect to the rotation angle of the piston 14 can be made different, and the shape of the recess on the inner end surface illustrated in FIG. 4 can be determined experimentally. The shape of the recess and the effective opening area (or
To illustrate the relationship between the intake flow rate and the intake flow rate assuming that the pressure difference between the upstream side and the downstream side of the throttle valve 2 is constant, FIG. Piston 14
The horizontal axis represents the rotation angle θ of the piston 14, and the vertical axis represents the effective opening area relative to the maximum effective opening area (effective opening area when rotated 90 degrees). A ratio (percentage) is taken, and this value is proportional to the rotation angle of the piston 14 if the depth of the axial recess of the piston 14 is sufficiently deep with respect to the diameter of the cylindrical hole 13. . However, the recess shaped as shown in FIG. 4(a) is
The shape is simplified for convenience in explaining the present invention in detail, and in order to accurately control the idle rotation speed,
When the rotation angle of the piston 14 is Js, the change in the effective opening area with respect to the change in rotation angle must be small. In FIG. 4, (bl FCl (el (
The shape of the recess indicated by f+ is such that by limiting the depth of the recess, the change in the effective opening area with respect to the change in rotation angle is reduced. , the cross-sectional shape reduces the rate of change in the effective opening area when the rotation angle of the piston 14 is small.
FIG. 4 is a diagram qualitatively showing the relationship between the rotation angle of the piston 14 and the effective opening area in the case of the village shown in the figure. Until the piston 14 rotates in the direction of the arrow 16 from the position of the rotation angle O shown in FIG. 7 to the position shown in FIG. 8, as the rotation angle increases, the piston 14 becomes downstream of the throttle valve 2. Curved surface 14- forming a recess
Since the length of the chord of the cross-sectional curve 1 gradually increases, the rate of increase in the effective opening area as the rotation angle increases gradually increases as the rotation angle increases. When rotating in 16 directions, since the rotation angle and the opening area are proportional, the relationship between the rotation angle and the effective opening area is a curve shown in FIG. This invention relates to the configuration of an intake passage for controlling the intake flow rate, and includes a function to control the first idle rotation speed when the engine is cold and the idle rotation speed after warm-up, as well as feedback of the air-fuel ratio. Although it is possible to provide a control function and a function as a dashpot during deceleration, the operation will be explained below by taking only the control of the first idle rotation speed and the idle rotation speed as an example. FIG. 9 shows the connection relationship between the intake flow rate control device of the present invention and the engine, where 1 is the intake passage, 2 is the throttle valve, 3 is the rotating shaft of the throttle valve 2, and 4 is the control device for controlling the intake flow rate control device. The fact that it is a motor is the same as in the case of Fig. 1, and 17
is an engine; 18 is a control circuit; the control circuit 18 includes an output signal of the engine rotational speed sensor 19, an output signal of the engine temperature sensor 2o, an on/off signal of the starting motor 21, an on/off signal of the near conditioner 22; , throttle valve 2
The signal of the opening sensor 23 of the motor 4, the rotation angle sensor 2 of the motor 4
4, a signal indicating whether the vehicle transmission 25 is in the neutral position, etc. are input, and a disturbance signal to the motor 4 is output.

The operation of the motor 4 will be explained with reference to the flowcharts shown in FIGS. 10 and 11.

For example, based on the signal from the engine speed sensor 19 or the engine temperature sensor 20, it is determined whether the engine 17 is already being operated (step 26), and the engine 1
If it is determined that the engine 7 is already in operation, the process proceeds to step 27, and if it is not in operation, the process proceeds to step 28.In step 27, it is determined whether the engine temperature is in a warm-up completed state,
At 8, it is determined whether an operation to start the engine is being performed based on the on or off signal of the starting motor 21, and when the engine is started, the first idle rotational speed is controlled by the motor 4 during the warm-up period. However, this will be discussed later. If it is determined in step 28 that the engine 17 has not been started, the motor 4 will not operate. In step 27 the engine 17
When it is determined that the temperature of the vehicle has been warmed up, the process proceeds to step 29, and when it is determined that the lever of the vehicle transmission 25 is in the neutral position, the process proceeds to step 30, where the opening sensor 23 of the throttle valve 2 If it is determined by the signal that the throttle valve 2 is at the idling opening, the routine shifts to the idling rotational speed control routine shown in FIG. When it is determined in step 29 that the lever of the vehicle's transmission 25 is not in the neutral position, and in step 30 that the opening degree of the throttle valve 2 is not at the idling opening degree, another control, that is, feedback of the air-fuel ratio is performed. Control or control as a dashpot during deceleration is performed, but the explanation will be omitted. When it is determined in step 28 that the engine has started, the process proceeds to step 31, where the output signal to the motor 4 is looked up in response to the signal from the temperature sensor 20 of the engine 17, and the process proceeds to step 32, where the output signal is determined based on the output signal. Rotate motor 4. The process proceeds to step 33, where it is determined whether or not the motor 4 has rotated by the required amount, based on the signal from the rotation angle sensor 24 of the motor 4. If it is determined that the motor 4 has rotated by the required amount, the process proceeds to step 34, where the motor 4 is stopped. If it is determined that the required amount of rotation has not been made, the process proceeds to step 35, where the process further rotates and returns to step 33. Incidentally, when it is determined in the above-mentioned step 27 that the temperature of the engine 17 is not in the warm-up completed state, the process moves to step 31, and the first idle rotational speed during the warm-up period is controlled.

Next, the idle rotation speed control routine will be explained with reference to FIG. Ne is the difference between the target rotational speed Ns and the actual rotational speed Na of the engine, that is, Ns-Na, and A is the deviation of the engine rotational speed from the allowable range. In step 36, it is determined whether the difference between the target rotational speed and the actual rotational speed of the engine 17 is within an allowable range.

If it is within the allowable range, the process proceeds to step 37 and the motor 4 does not rotate, and if it is outside the allowable range, the process proceeds to step 38 to determine the amount by which the target rotational speed of the engine is out of the allowable range.
That is, the amount n by which the motor 4 should be rotated is looked up from the value of A, and n is determined as a function f (A) of A. Next, proceed to step 39 and engine 17
It is determined whether the actual rotational speed Na is larger or smaller than the target rotational speed Ns, and if the actual rotational speed Na is smaller than the target rotational speed Ns (Ne=Ns-Na>0), proceed to step 4o. If the motor 4 rotates forward n rotations and rotates the piston 14 in the direction of increasing the intake flow rate (normal rotation is defined as the motor rotation), the process proceeds to step 41, and when it is confirmed that the motor 4 has rotated forward n rotations, the process proceeds to step 42. The motor stops rotating and returns to the start, and if it is determined in step 41 that the rotation is insufficient, the process proceeds to step 43, where it further rotates and returns to step 41. On the other hand, if it is determined in step 39 that the actual rotational speed Na of the engine 17 is larger than the target rotational speed Ns (Ne<O), the process proceeds to step 44, where the motor reversely rotates n rotations, and the process proceeds to step 45. If it is determined that the motor has rotated in the opposite direction, the process proceeds to step 46, where the motor stops rotating and returns to the start, and if it is determined that the rotation is insufficient in step 45, the process proceeds to step 47, where the motor further rotates in the reverse direction. Then, the process returns to step 45. Returning to FIG. 16, in the configuration of the embodiment shown in FIG. 1, the outer circumferential edge of the throttle valve 2 reaches the lower end position of the cylindrical hole 13 in which the piston 14 is disposed (as shown by the broken line in FIG. 1). When the throttle valve 2 opens, the passage structure consisting of the inner end surface of the piston and the outer periphery of the throttle valve 2 disappears, and the flow rate of intake air flowing through the intake passage 1 is controlled exclusively by the inner periphery of the intake passage 1 and the throttle. This is done by valve 2. Point P on the horizontal axis indicates the minimum opening position of the throttle valve 2 at which the rotation of the piston does not affect the intake flow rate. Even if the position of the recess on the inner end surface of No. 14 remains at the maximum effective opening area position, the curve C will change to curve No. 11 at the opening degree shown at point P or more. a, that is, the total intake flow rate matches the intake flow rate controlled only by the throttle valve 2, and there is no risk of the vehicle running out of control.

The opening degree of the throttle valve 2 indicated by P is when the diameter of the intake passage 1 is 50mm,
The outer diameter of the piston 14, and therefore the diameter of the cylindrical hole 13, is 10
In the case of a combination in which the cutting angle of the throttle valve 2 is 10 degrees, it is approximately 15 degrees from the idling opening (indicated by ○ in Fig. 16).
It becomes an open angle.

[Effects of the Invention] When the throttle valve 2 is slightly opened or fully closed, the piston whose inner end surface forms part of the inner wall surface of the intake passage 1 facing the outer peripheral edge of the throttle valve 2 rotates. (1) Since the range in which the intake flow rate is controlled is limited by the diameter of the rotating piston, the idle rotation speed and fast idle rotation speed are controlled by the opening degree of the throttle valve. (2) When idle rotation speed and fast idle rotation speed are controlled by a throttle valve Like.

By controlling the idle rotation speed and first idle rotation speed, the accelerator is not moved and the driver does not feel uneasy.

(3) The range in which the rotation of the piston affects the intake air flow rate is limited to the small opening range of the throttle valve, so the driving sensation during acceleration and deceleration is different after warm-up is completed and before warm-up is completed. There is no significant difference in the speed, the driver does not feel anxious, and there is no fear of the vehicle running out of control. (Comparison with controlling the intake flow rate through the bypass intake passage)

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG.
l (bl (C1 and fat (bl (C
1 is a cross-sectional view taken along the line ■-n in FIG. 1, showing the cross-sectional shape of the flow path that changes with the rotation of a piston that has a half-moon-shaped recess on its inner end surface. FIG. 4 is an example of the shape of the inner end surface of the piston. FIG. 5 is a diagram showing the relationship between the rotation angle and the effective opening area of a piston having a half-moon-shaped recess on its inner end surface.
Figure 6 is a diagram showing the relationship between the rotation angle and effective opening area of a piston having a recess shaped as shown in Fig. A diagram showing the rotation progress of a piston having a concave portion, FIG. 9 is a diagram showing the connection relationship when the engine intake flow rate control device of the present invention is used in an engine, and FIGS. 10 and 11 are diagrams showing the motor (actuator). A flowchart showing the operation progress of ';i'
r Figures 12, 13, and 14 are diagrams showing the conventional configuration of an idle rotation control device, and Figure 15 shows the intake flow rate and total intake flow rate of an idle rotation speed control device with a conventional configuration that controls the bypass intake flow rate. FIG. 16 is a diagram showing the relationship between the intake flow rate control by the rotation of the piston and the total intake flow rate when the throttle valve is opened at a small opening according to the present invention. Explanation of symbols: 1... Intake passage, 2... Throttle valve, 3... Throttle valve rotation axis, 4... Motor (actuator), 4-1... Motor rotation axis, 12...Housing. 13... Cylindrical hole, 14... Piston. Applicant: Mikuni Makino Kogyo Co., Ltd. Houkijuku Zu No. Koku No. 6 Sekikan δ Map'ff-* Figure 5 5th row ÷ 10th square / 3 Figure broom! ″′y figure

Claims (1)

[Claims] The throttle valve (2) in a fully closed state is attached to a housing (12) that is provided with a throttle valve (2) and forms an intake passage (1) of the engine.
A cylindrical hole (13) opening in the inner circumferential surface of the intake passage (1) is bored opposite to the outer circumferential edge of the cylindrical hole (
13), a recess is formed on the inner end surface, and the actuator (
A piston (14) that rotates by the operation of step 4) is disposed, and a passage is cut off between the inner end surface of the piston (14) and the outer peripheral edge of the throttle valve (2) by the rotation of the piston (14). The actuator (4) is actuated by the output signal of the control circuit (18) which forms an intake flow path during engine operation with a small opening of the throttle valve and inputs engine operating parameters, and the area changes, and the piston ( 14)
An engine intake flow control device that rotates the engine.