JPH0774617B2 - Throttle valve opening control device for internal combustion engine - Google Patents

Description

The present invention relates to a throttle valve opening control device for an internal combustion engine, and more particularly to a so-called linkless throttle type throttle valve with a highly safe control mechanism. .

[Prior Art] In a linkless throttle, that is, in a throttle valve mechanism in which an accelerator pedal and a throttle valve are not directly and mechanically connected, a target opening degree corresponding to an accelerator operation amount or an automatic drive control device is various. There is known a system in which a throttle valve control device adjusts the opening degree of a throttle valve by an actuator such as an electric motor according to a target opening degree set based on a detection value of a sensor.

However, in this system, if an abnormality occurs in the control system, the accelerator pedal may not be able to control the rotation of the internal combustion engine.

Therefore, a proposal is made to determine an abnormality from the deviation between the target opening and the actual opening value and execute a predetermined countermeasure (JP-A-59-19).
0445), or a proposal to prevent abnormal control in the opening direction by providing a mechanical limiting means for the movement of the throttle valve in the opening direction according to the accelerator pedal (JP-A-59-59).
190440) has been made.

[Problems to be Solved by the Invention] However, in such a device, when the actuator fails and stops, the opening of the throttle valve is maintained in the state at the time of the failure, and the output control of the internal combustion engine is performed. It may be impossible to do so. For example, short-circuit or disconnection of electric wiring, biting due to foreign matter entering the actuator,
Etc.

In such a case, if the rotation of the throttle valve is stopped and is stopped in the open state, the internal combustion engine may have an abnormally high rotation speed.

Therefore, the present invention adopts the following configuration in order to solve the above problems.

[Means for Solving Problems] That is, the gist of the present invention is, as illustrated in FIG. 1, an urging for urging a throttle valve M1 for adjusting an intake air amount of an internal combustion engine in a closing direction. Means M2 and rotation output means M3 that outputs torque by rotating
And a throttle valve M1 from the rotation output means M3 provided between the rotation output means M3 and the throttle valve M1.
Based on the non-contact joint M4 that transmits the torque in the opening direction to the throttle valve M1 side according to the rotation speed of the rotation output means M3 and the command value from the outside, the above-mentioned throttle valve M1
Of the internal combustion engine, which is characterized by including a rotation speed control means M5 for controlling the rotation speed of the rotation output means M3 so that the opening degree of the throttle valve M1 becomes the target opening degree. It is in the throttle valve opening control device.

[Operation] The biasing means M2 constantly applies a biasing force to the closing direction of the throttle valve M1, and the throttle valve M1 is trying to close unless another acting force acts. When the throttle valve M1 is opened to an opening degree according to a command value from the outside, the rotation speed control means M5 controls the rotation speed of the rotation output means M3 so as to be a predetermined rotation speed corresponding to the opening degree. Then, the non-contact joint M4 transmits the torque in the opening direction according to the rotation speed to the throttle valve M1. Therefore, the throttle valve M1 is stopped at the position where the torque and the biasing force of the biasing means M2 are balanced. This control may be open loop control, and the stop position of the throttle valve M1, that is, the opening degree is detected by the opening degree detection means, and the rotational speed control means M5 is set so as to become the target opening degree based on the command value from the outside. May perform feedback control.

If the rotation output means M3 or the rotation speed control means M5 fails and the rotation of the rotation output means M3 stops, the torque transmitted by the non-contact joint M4 becomes zero and the throttle valve M1
Since only the biasing force of the biasing means M2 acts on the throttle valve M1, the throttle valve M1 is fully closed. In this way, it is possible to prevent the internal combustion engine from falling out of control at high speed.

Next, examples of the present invention will be described. The present invention is not limited to these, and includes various embodiments without departing from the scope of the invention.

[Embodiment] FIG. 2 shows an embodiment in which the throttle valve opening control device for an internal combustion engine of the present invention is applied to an internal combustion engine for an automobile.

The accelerator pedal operation amount from the driver is the accelerator sensor 1
Thus, the amount of depression is detected as an analog voltage value. An analog voltage signal indicating the amount of depression is read by the electronic control circuit 3, processed with other data, and outputs a rotation speed signal of the electric motor 5. The electric motor 5 rotates at a rotation speed according to the rotation speed signal, and the rotation output is applied as torque to the rotating shaft 11 of the throttle valve 9 as torque in the opening direction of the throttle valve 9 via the non-contact joint 7. A mainspring 13 is provided on the rotary shaft 11 to apply a biasing force to the throttle valve 9 in the closing direction. Therefore, the throttle valve 9 is stopped at an opening in which the torque from the non-contact joint 7 and the urging force of the mainspring 13 are in balance.

The opening of the throttle valve 9 is detected by the opening sensor 15 as an analog voltage value, and the analog voltage signal is read by the electronic control circuit 3.

The electronic control circuit 3 is configured as a logical operation circuit centering on the CPU 17, ROM 19, RAM 21, etc., is connected to the input section 25 via the common bus 23, and is connected to the accelerator sensor 1 and the opening sensor 15 from the outside, as necessary. In response, signals such as the load of the internal combustion engine and the rotation speed of the internal combustion engine are input, and a command signal is output to the drive circuit 27 to control the rotation speed of the electric motor 5. The input section 25 is provided with a waveform shaping circuit, a multiplexer, an A / D converter, etc., if necessary.

Next, as the electric motor 5, various motors whose power is electric and whose rotation speed can be controlled can be used. For example,
A step motor, a DC motor, or an AC motor such as an induction motor or a synchronous motor can be used.

The non-contact joint 7 is a fluid joint 7A as shown in FIG.
Can be used. Fig. 3 shows a disk-shaped fluid coupling 7A
FIG. 3 is a schematic cross-sectional view taken along a plane including the output shaft 5 a of the electric motor 5 and the axis of the throttle valve 9 rotating shaft 11. The fluid coupling 7A is mechanically directly connected to the output shaft 5a of the electric motor 5 and is rotated integrally with the output shaft 5a.
And a turbine 33 that rotates integrally with the turbine 33. pump
A cover 37 that covers the turbine 33 and seals the working oil 35 is provided on the outer periphery of the 31. The cover 37 is in a sliding state with respect to the rotary shaft 11 of the throttle valve 9.

Torque is transmitted from the output shaft 5a of the electric motor 5 to the rotary shaft 11 of the throttle valve 9 by the sealed hydraulic oil 35.
Done through. That is, when the pump 31 rotates,
The hydraulic oil 35 sent out by the blade 31a on the 31st side is transferred to the turbine 33
By the blade 33a on the side being received, torque is transmitted according to the rotation speed of the pump 31. Since the pump 31 and the turbine 33 are not mechanically directly connected, the output shaft of the electric motor 5
5a and the rotary shaft 11 of the throttle valve 9 can rotate independently of each other.

As another example of the non-contact joint, a joint utilizing electromagnetic induction is shown in FIGS. 4 (a) and 4 (b). FIG. 4 (a) is a schematic sectional view of the disc-shaped electromagnetic coupling 7B taken along a plane including the output shaft 5a of the electric motor 5 and the rotation shaft 11 of the throttle valve 9. The electromagnetic coupling 7B is a disk-shaped permanent magnet 41 that is mechanically directly connected to the output shaft 5a of the electric motor 5 by press fitting and rotates integrally with the output shaft 5a, and a rotary shaft of the throttle valve 9.
It is composed of an aluminum disk 43 and an iron disk 45 that are mechanically directly connected to the shaft 11 by press fitting and rotate integrally with the rotary shaft 11. The aluminum disc 43 and the iron disc 45 are provided with short cylindrical peripheral portions 43a and 45a around the periphery thereof. Iron disc 45
A cover 47 that covers the permanent magnet 31, the aluminum disc 43, and the iron disc 45 is provided on the short cylindrical circumferential portion 45a of the electric motor 5. The cover 47 is in a sliding state with respect to the output shaft 5a of the electric motor 5. It is in.

The torque is transmitted from the output shaft 5a of the electric motor 5 to the rotary shaft 11 of the throttle valve 9 by electromagnetic induction. That is, as the eight-pole permanent magnet 41 shown in FIG. 4 (b) rotates, the magnetic lines of force forming a magnetic path between the permanent magnet 41 and the iron disc 45 move across the aluminum disc 43. By doing so, an eddy current is generated in the aluminum disc 43. As a result, the torque on the permanent magnet 41 side is transmitted to the aluminum disc 43 side according to the rotation speed of the permanent magnet 41. Since the permanent magnet 41 and the aluminum disc 43 are not directly connected, the output shaft 5a of the electric motor 5 and the rotary shaft 11 of the throttle valve 9
And can rotate independently of each other.

Further, the main spring 13 has its outer end locked to the intake pipe 50 and its inner end locked to the rotary shaft 11 of the throttle valve 9, so that the throttle valve 9 is biased in the closing direction. is doing.

Next, the control executed by the electronic control circuit 3 will be described.

FIG. 5 shows a flowchart of the throttle valve opening control processing.

First, when the process is started, in step 100, various flags and variables are initialized. Next, at step 110, the output of the accelerator sensor 1 is detected as the accelerator operation amount. Next, at step 120, the target throttle opening TAR is calculated based on the accelerator operation amount. Next, at step 130, the actual throttle opening TA is detected from the output value of the opening sensor 15.

Then, at step 140, it is judged if the actual throttle opening TA is smaller than the target throttle opening TAR.
If the determination is affirmative, in step 150, a process of increasing the operation value MS for operating the rotation speed of the electric motor 5 by a predetermined value α is performed. If a negative determination is made in step 140, then it is determined in step 160 whether the actual throttle opening TA is larger than the target throttle opening TAR.
If the determination is affirmative, in step 170, the operation value MS of the electric motor 5 is decreased by a predetermined value β. If a negative determination is made in step 160, the actual throttle opening TA
And the target throttle opening TAR match, nothing is done to the operation value MS.

After steps 150 and 170, or after a negative determination is made in step 160, an output corresponding to the operation value MS is output to the electric motor 5 in step 180, and the process returns to step 110 again.
The same process is repeated thereafter.

Therefore, if the opening degree of the slot valve 9 is smaller than the desired opening degree, the operation amount MS is increased to increase the rotation speed of the electric motor 5, and the torque applied to the throttle valve 9 side via the non-contact joint 7 is increased. Raise. On the contrary, if the opening of the throttle valve 9 is larger than the desired opening, the manipulated variable MS
Is decreased to decrease the rotation speed of the electric motor 5 and the torque applied to the throttle valve 9 side via the non-contact joint 7 is decreased.

The addition and subtraction values α and β may be the same value, or the responsiveness may be adjusted to different values. Further, the values of α and β may be changed according to the value of MS. For example, as shown by the dotted line in FIG. 6, when MS is low, α and β are made small in order to perform delicate vehicle speed adjustment at low speed operation, and when MS is high,
α and β may be increased. However, the solid line in FIG. 6 is α,
Shows the relationship between MS and TA when β is a fixed value.

Also, the time increment / decrement (differential value) ΔMS of MS is detected, and Δ
You may set α and β according to MS. For example, | ΔMS |
When is large, α and β are increased, and when | ΔMS | is small, α and β are decreased.

Since the present embodiment is configured as described above, when the electric motor 5 fails and stops, the fluid coupling 7A or the electromagnetic coupling 7B stops transmitting torque. Therefore, only the biasing force of the mainspring 13 acts on the throttle valve 9, and the throttle valve 9 is fully closed. The speed is high, and the output of the internal combustion engine becomes the minimum state. The electronic control circuit 3 becomes abnormal,
The same effect is obtained when the operation output is stopped.

Further, when the electric motor 5 is a direct current motor, the opening of the throttle valve is substantially constant in the conventional configuration such as during normal running of the vehicle, so that the brush keeps contacting with a specific place of the commutator, and the corresponding position is maintained. Although the wear at the contacting portions is great and the life of the motor is shortened, in the above-mentioned configuration, the electric motor 5 may continue to rotate in one direction, and the opening and closing of the throttle valve 9 can be controlled by the high and low rotation speed. Since it is controlled, the commutator portion is not locally worn unlike the conventional case. That is, the life of the electric motor is extended. In addition, when the electric motor 5 is a pulse motor, if the wiring is short-circuited or disconnected, it is likely to be electrically locked, but it is unlikely to continue to rotate, and the combination of the pulse motor and the non-contact joint is a safety measure. ,
Especially effective. Further, since the opening degree of the throttle valve 9 depends on the rotation speed of the electric motor 5, the accuracy of the electric motor 5 depends on the control accuracy of the rotation speed. Therefore, since the angular resolution of the motor itself is basically irrelevant, it is expensive,
A low-priced, small-sized PM type can be used as the electric motor 5 instead of the large-sized, high-resolution HB type.

In the above-mentioned embodiment, the example in which the values of α and β are changed according to the MS is given, but the combination of the non-circular gears 201 and 203 as shown in FIG. And throttle valve 9 can be placed to achieve a similar effect. Here, the gear 201 is on the non-contact joint 7 side, and the gear 203 is on the throttle valve 9 side. That is, at the meshing position where the opening degree of the throttle valve 9 is low, the distance m1 from the tooth surface 201b of the portion meshing with the shaft 201a of the gear 201 is the tooth surface 2 of the portion meshing with the shaft 203a of the gear 203.
It is longer than the distance L1 with 03b, but the throttle valve 9
At a meshing position where the opening degree is high, the distance m2 between the gear 201 and the tooth surface 201b of the portion meshing with the shaft 201a is
It is shorter than the distance L2 between the tooth surface 203b of the portion meshing with the shaft 203a. Therefore, when the opening of the throttle valve 9 is low, the torque of the electric motor 5 is reduced to 20%.
Even though the throttle valve 9 does not move in the opening direction in spite of the increase in the rotation speed, the torque of the electric motor 5 is reduced when the opening degree of the throttle valve 9 is increased.
It is transmitted to 203 relatively high, and the throttle valve 9 easily moves in the opening direction as the rotation speed increases.

Furthermore, when the gear 201 causes excessive rotation of the electric motor 5,
The shortest (m3) part 201c from the shaft 201a to its periphery
Comes into contact with the gear 203 on the throttle valve 9 side, but the portion 201c having the shortest distance to the peripheral edge has no teeth and is a smooth surface, so the meshed state is released and the gear 203 side is the mainspring. Due to the action of the spring 13, the original throttle valve 9 is fully closed. In this way, there is an effect that safety can be ensured even when the electric motor 5 is excessively rotated. Although the opening of the throttle valve 9 is controlled according to the accelerator operation amount in the above embodiment, the present invention may be applied to an automatic drive control device to control according to a target opening automatically set. A similar effect occurs.

In addition to the feedback control, the control device may simply control the electric motor 5 in an open loop to set the opening degree of the throat valve 9.

In the above embodiment, the mainspring 13 corresponds to the biasing means M2, the electric motor 5 corresponds to the rotation output means M3, the fluid coupling 7A and the electromagnetic coupling 7B correspond to the contacted coupling M4, and the electronic control circuit 3 It corresponds to the rotation speed control means M5.

As described above, the present invention allows the torque in the opening direction to be transmitted from the rotation output means M3 via the non-contact joint M4 to the throttle valve M1 which is biased in the closing direction by the biasing means M2. Since it is configured, when the rotation output means M3 is stopped (locked), the non-contact joint M4 does not transmit the torque from the rotation output means M3 to the throttle valve M1.
Even without providing a device for detecting the lock failure of M3, the throttle valve M3 can be fully closed by the biasing means M2, and abnormal overspeed of the internal combustion engine does not occur,
The safety can be improved.

Further, as the rotation output means M3, one having a low rotational position accuracy can be applied, and in order to keep rotating further, for example, when a brush type DC motor is used as the rotation output means M3,
Wear that concentrates on one part is unlikely to occur, and the service life is extended.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a basic configuration of the present invention, FIG. 2 is a schematic configuration diagram of an embodiment thereof, FIG. 3 is a schematic sectional view of a fluid coupling, and FIG. 4 (a) is a schematic sectional view of an electromagnetic coupling. 4 (b) is an explanatory view of the disk-shaped permanent magnet, FIG. 5 is a flowchart of throttle valve opening control processing executed by an electronic control circuit, and FIG. 6 is a motor rotation speed MS and throttle opening. Degree TA
FIG. 7 is a graph showing the relationship with the above, and FIG. 3 ... Electronic control circuit, 5 ... Electric motor 7A ... Fluid coupling, 7B ... Electromagnetic coupling 9 ... Throttle valve, 13 ... Mainspring 15 ... Throttle valve opening sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsunori Takao 1-1, Showa-cho, Kariya city, Aichi Nihon Denso Co., Ltd. (56) Reference JP-A-59-153945 (JP, A) JP-A-61 -237842 (JP, A)

Claims (4)

[Claims] 1. A biasing means for biasing a throttle valve for adjusting an intake air amount of an internal combustion engine in a closing direction, a rotation output means for outputting a torque by rotating, a rotation output means and the throttle valve. The torque in the opening direction of the throttle valve from the rotation output means, depending on the rotation speed of the rotation output means,
Based on a non-contact joint transmitted to the throttle valve side and a command value from the outside, the target opening of the throttle valve is obtained, and the rotation output means is rotated so that the opening of the throttle valve becomes the target opening. A throttle valve opening control device for an internal combustion engine, comprising: a rotational speed control means for controlling a speed. 2. The throttle valve control device according to claim 1, wherein the non-contact joint is a fluid joint that transmits torque by using a fluid. 3. The throttle valve opening control device for an internal combustion engine according to claim 1, wherein the non-contact joint is a joint that transmits torque by utilizing electromagnetic induction. 4. The rotation speed control means increases the rotation speed of the rotation output means when the actual opening of the throttle valve is smaller than a target opening, and the actual opening of the throttle valve is larger than the target opening. The throttle valve opening control device for an internal combustion engine according to claim 1, 2 or 3, further comprising means for reducing the rotation speed of the rotation output means.