JPH088262Y2 - Throttle valve opening control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a device for controlling a throttle valve opening of an internal combustion engine, and more particularly to a fail-safe countermeasure technique for electronically controlling the throttle valve opening to a target value.

<Prior Art> Conventionally, for example, as disclosed in Japanese Patent Laid-Open No. 60-190626, there is one that electronically controls a throttle valve opening of an internal combustion engine to a target value. This one calculates the deviation between the target value of the throttle valve opening set by the operation signal of the accelerator pedal (operation amount, operation speed, etc.) and the actual valve opening, and drives the valve based on the calculation result. Is operated to control the throttle valve to a target value.

As described above, many electronic control types have been proposed in which the drive source is a motor, and the throttle valve is separated from the accelerator linkage and completely controlled by transmission and reception of an electric signal.

Also, in this type of electronically controlled throttle valve opening control device, the drive source does not work due to wire breakage of the harness, failure of the motor, etc., and sticking due to gum substance etc. causes stick and does not move with the drive force of the motor. In consideration of such a case, if the accelerator pedal is depressed by a predetermined amount or more,
It has been proposed that the throttle valve be mechanically linked to open the minimum opening so that the vehicle can travel to a safe place for the time being (Japanese Patent Laid-Open Nos. 59-122742 and 62-13).
(See Japanese Patent No. 5624).

Although the conventional electronically controlled throttle valve opening control device copes with a failure in which the drive source does not operate, in a situation where the throttle valve is excessively opened in the opening direction due to an abnormality of the drive source. I have not been able to deal with it. That is, the mechanical linkage with the throttle valve described above is linked only in the opening direction of the accelerator pedal, and not linked in the returning operation in the closing direction. However, if the accelerator pedal is connected directly to the throttle valve, the motor will not be able to drive it.

In order to deal with such a situation, a stopper that restricts the maximum opening of the throttle valve is provided in association with the return spring while being linked to the accelerator pedal, and the reaction force of the return spring drives the electric motor for driving the throttle valve. There is one in which the throttle valve is prevented from being excessively opened in the opening direction by setting the force larger than the force (see Japanese Patent Laid-Open No. 59-190440).

<Problems to be Solved by the Invention> Therefore, by combining these two types of fail-safe mechanisms, it is possible to drive the throttle valve to the minimum opening degree and prevent it from being opened excessively.

However, the structure having a combination of these two types of fail-safe mechanisms causes the following problems.

That is, in the conventional throttle valve minimum opening forced drive mechanism, since the mechanism does not work with the throttle valve unless the accelerator pedal is depressed by a predetermined amount or more, the range of the restricted accelerator operation amount from the predetermined amount to full opening is limited. It is necessary to secure the minimum required opening. Therefore, it is necessary to increase the valve opening amount per unit accelerator operation amount and therefore the rotational torque ratio (input torque / output torque) of the throttle valve, and particularly when the throttle valve is difficult to move due to sticking or the like, a large value is required. Operability is required.

Further, when a mechanism for restricting the maximum opening of the throttle valve is combined, the reaction force of the return spring applied to the accelerator pedal is set to be larger than the driving force of the electric motor, so that the minimum opening is set. If the accelerator pedal is depressed more than a predetermined amount in order to obtain it, a large reaction force is applied even by itself.

That is, when a large torque is required to rotate the throttle valve by generating a stick or the like,
Since the rotation torque ratio of the throttle valve is large, the operation force required to rotate the throttle valve by overcoming the fixed force such as sticking becomes large, and further, the position of the accelerator pedal not used for the rotation of the throttle valve. Since the reaction force of the return spring generated by the constant depression is added as an extra necessary force, an extremely large operating force may be required.

The present invention has been made in view of such a conventional problem, and can throttle the throttle valve forcibly to the minimum opening and regulate the maximum opening. An object of the present invention is to provide a throttle valve opening control device which is devised so that the throttle valve can be rotated without waste and the necessary operating force can be sufficiently reduced.

<Means for Solving Problems> Therefore, according to the present invention, a valve opening lever and a valve closing lever fixed to a rotary shaft of a throttle valve interposed in an intake system of an internal combustion engine; An accelerator drum, which is slidably and rotatably supported by a rotary shaft, and is rotationally driven in association with an accelerator pedal; and a cam axially supported by a fixed member so as to be engaged with the valve opening lever from the initial stage of accelerator operation. A first link mechanism connected between the accelerator drum and the cam, forcibly driving the throttle valve to a minimum opening degree according to an accelerator operation amount by engagement of the valve opening lever and the cam. , The maximum opening characteristic according to the accelerator operation amount, which is provided on the accelerator drum and restricts the movement of the throttle valve in the opening direction by engaging with the valve closing lever. The stopper member for giving the throttle valve is set within a range of a minimum opening degree regulated by the valve opening lever and the cam and a maximum opening degree regulated by the valve closing lever and the stopper member. One end is locked to the valve drive means that drives to the target opening and the spring assembly that is rotatably attached to the shaft that is arranged parallel to the rotation axis of the throttle valve, and the other end is locked to the fixed member. Connected to the spring assembly and the accelerator drum, and transmits the urging force of the return spring when the stopper member and the valve closing lever are engaged to the valve driving means to the throttle valve. And a second link mechanism that gives a return torque in the closing direction that is stronger than the drive torque in the opening direction of the throttle valve.

<Operation> When the accelerator pedal is depressed during normal operation, the cam stopper member is set to a position that regulates the minimum opening amount and the maximum opening amount of the throttle valve in accordance with the depression of the accelerator pedal.

On the other hand, the valve drive means drives the throttle valve via the drive of the lever so as to reach the target opening degree set between the regulated minimum opening degree and maximum throttle opening degree.

Further, even when the valve drive means fails to operate due to a disconnection or the like, or when the throttle valve sticks when the engine is stopped and a large torque in the valve opening direction is required, the first operation from the accelerator drum is performed by the accelerator operation.
Since the throttle valve is forcibly opened via the link mechanism, cam, and valve opening lever, engine operation can be continued, enabling traveling. On the other hand, even when the throttle valve is about to open beyond the target opening due to an abnormality in the valve drive means, the biasing force of the return spring causes the return spring to be biased by returning the accelerator pedal. ， Because it is transmitted to the throttle valve via the valve closing lever and can overcome the driving force of the valve driving means to close the throttle valve, it is possible to control the throttle valve opening degree that matches the engine output required by the driver. it can.

<Examples> Examples of the present invention will be described below with reference to the drawings.

1 to 3 showing the first embodiment, a throttle valve (not shown) is rotatably housed in a throttle body 1, and a valve opening lever 3 and a valve closing lever 4 are attached to a rotary shaft 2 thereof. It is fixed.

A cam 6 is rotatably supported via a shaft 7 on a plate 5 as a fixing member fixed to the end wall of the throttle body 1.

Further, an accelerator drum 8 connected to an accelerator pedal (not shown) via an accelerator wire is rotatably supported by the rotary shaft 2.

The accelerator drum 8 and a shaft 7 integrally fixing the cam 6 are connected by two links 9 and 10.

When the accelerator pedal is stepped on, the accelerator drum 8 rotates around the rotary shaft 2 via the accelerator wire, whereby the two links 9 and 10 swing and the cam 6 moves.
Rotates around axis 7.

The cam 6 is attached to a position where it can be engaged with the end face of the valve opening lever 3 on the throttle valve closing direction side, and when the cam 6 rotates by engaging with the lever 3, the lever 3 is swung. The throttle valve can be moved in a range from fully closed to a small opening via 3. Here, the minimum opening characteristic of the throttle valve due to the engagement of the cam 6 and the lever 3 with respect to the depression amount of the accelerator pedal is set as shown in A of FIG.

 Here, the links 9 and 10 form a one-link mechanism.

Further, a portion of the support shaft 11 connecting the link 9 to the accelerator drum 8 that penetrates the accelerator drum 8 and projects to the side opposite to the link 9 is the end surface of the valve closing lever 4 on the throttle valve opening direction side. It is provided at an engageable position. That is, the support shaft 11 constitutes a stopper member.

Therefore, the valve closing lever 4 is moved to the accelerator drum 8
The maximum opening of the throttle valve is regulated at the position where it is engaged with the end of the support shaft 11 fixed to, and the maximum opening characteristic of the throttle valve when the lever 4 and the support shaft 11 are engaged with respect to the depression amount of the accelerator pedal. Are set as shown in FIG. 3B.

Further, a potentiometer for detecting the opening degree of the throttle valve by the amount of rotation of the rotary shaft 2 is provided at a tip portion of the rotary shaft 2 of the throttle valve outside the mounting portion of the accelerator drum 8.
12 are connected to each other, while the other end of the rotary shaft 2 is connected to an electric motor 13 as valve driving means.

The throttle valve opening detected by the potentiometer 12 and the electric motor 13 corresponding to the deviation between the throttle valve target opening set for the accelerator pedal depression amount detected by a sensor (not shown) are set. By driving, the throttle valve is controlled to the target opening. Here, the target opening is set to a value between the minimum opening regulated by the cam 6 and the maximum opening regulated by the support shaft 11 (between line A and line B in FIG. 3). Has been done.

Further, a shaft 14 is fixed to the plate 5 in parallel with the rotary shaft 2, and a spring assembly tool 15 is rotatably supported on the shaft 14. Then, a coil-shaped return spring 16 having one end locked to the groove 15a formed in the assembly tool 15 and the other end locked to the plate 5 is assembled.

Further, the member on the return spring 16 locking side of the return spring assembly tool 15 and the accelerator drum 8 are connected by a link 17, and the return spring 16 connects the assembly tool 15 to the accelerator drum 8 via the link 17 and the accelerator drum 8. It is designed to urge the dull toward the throttle valve closing direction. The link 17 constitutes a second link mechanism.

Here, the return torque in the throttle valve closing direction transmitted from the return spring 16 via the link 17 is set to be larger than the driving torque in the throttle valve opening direction by the electric motor 13.

 Next, a series of operations of this embodiment will be described.

During normal operation, as described above, the throttle valve opening is adjusted so that the target opening is set between the minimum opening regulated by the cam 6 by the electric motor 13 and the maximum opening regulated by the support shaft 11. Is controlled.

On the other hand, when the engine is stopped at a low temperature, gum substance sticks between the rotary shaft 2 of the throttle valve and the wall of the throttle body 1 to cause sticking, and the driving force of the electric motor 13 is insufficient to open the throttle valve. Even in such a case, the cam 6 rotates due to the depression of the accelerator pedal, and the throttle valve can be forcibly opened by the valve opening lever 3 so that the stick state is released and the electric drive is performed thereafter. The throttle valve can be easily opened to the target opening degree only by the driving force of the motor 13.

In this way, since the large opening force of the throttle valve is obtained by stepping on the accelerator pedal,
The electric motor 13 has a small driving force, and a small one can be used, so that the cost can be reduced, and the fuel consumption can be reduced by saving the power consumption.

On the other hand, even when the electric motor 13 becomes inoperable due to a failure such as a wire breakage, the throttle valve can be forcibly opened to a predetermined opening by the accelerator operation, so engine stall can be prevented and engine operation can be continued. Therefore, the fail safe function can be secured.

On the contrary, even if the electric motor 13 tries to open the throttle valve 13 excessively due to a failure of the potentiometer 12 or the control system, the return torque in the closing direction of the return spring 16 exceeds the drive torque of the electric motor 13. Axis 11
The maximum opening regulated by the engine is not exceeded, and while suppressing excessive increase of the engine output by returning the accelerator pedal, the engine output required by the driver was met. The throttle valve opening can be controlled, and the throttle valve can be fully closed when the accelerator pedal is completely released. That is, in this state, the valve closing lever 3 is always engaged with the support shaft 11 by the driving force of the electric motor 13, so that the throttle valve opening can be controlled normally by an accelerator pedal operation.

By changing the shape of the accelerator drum 8 or the like, the maximum opening characteristic is set to B ′, B ″ in FIG. 3 to increase the rise of the throttle valve opening from the point where the accelerator pedal pedal depression amount Qa is small. It is also possible to make the characteristic that attaches importance to responsiveness, and also to shape the cam 6 and the valve opening lever.
3. By changing the size of the first link mechanism, it is possible to have a characteristic that the accelerator depression amount smoothly increases from fully closed to fully opened, as shown by A ′ and A ″ in FIG. Here, as shown in the characteristics of A'and A ", in the case where the minimum opening is obtained in the entire range of the accelerator operation amount from the fully closed to the fully opened, the valve opening amount per unit accelerator operation amount, that is, the throttle valve rotation The torque ratio (input torque / output torque) can be set as small as possible. On the other hand, when the minimum opening is obtained before the accelerator is fully opened as in the characteristic A, the return spring 16
The reaction force of can be reduced.

In other words, in any case, since the cam is engaged with the valve opening lever from the initial stage of the accelerator operation, the conventional example in which the accelerator pedal is depressed by a predetermined amount and then the throttle valve is forcedly rotated is required. In addition, the reaction force of the return spring is not received in the portion that is not used for rotating the throttle valve, and the accelerator operation amount can be used for rotating the throttle valve without waste.

Therefore, it is possible to keep the operating force, which is the sum of the operating force required for the rotation of the throttle valve determined by the rotational torque ratio of the throttle valve and the reaction force of the return spring, to a necessary minimum.

Further, since the mounting shaft (shaft 14) of the return spring 16 is provided offset from the rotary shaft 2 of the throttle valve, the shaft length of the entire structure can be shortened as compared with the case where the shaft is coaxial.

Further, since the valve opening lever 3 and the valve closing lever 4 are provided separately, the degree of freedom in layout is increased.

In the embodiment shown in FIG. 4, in addition to the structure of the first embodiment, the accelerator drum 8 or a member (for example, the support shaft 11) connected to the accelerator drum 8 and a member connected to the rotary shaft 2 of the throttle valve are added. For example, in this embodiment, the valve closing lever 4
It is connected by a spring 18 between.

In this way, when the electric motor 13 cannot operate, the valve closing lever 4 and the rotary shaft 2 follow the rotation of the accelerator drum 8 via the spring 18 by the depression operation of the accelerator pedal, so that the electric motor 13 is rotated. The throttle valve opening can be controlled by a normal manual method as in the case of excessive operation of.

The embodiment shown in FIG. 5 is the same as the second embodiment except that a potentiometer 12 'for detecting the throttle valve opening is provided on the electric motor 13 side. In this case, the rotation angle of the drive shaft of the electric motor 13 or the rotary shaft 2 of the throttle valve is controlled by a potentiometer via a gear mechanism.
The structure may be such that it is transmitted to the rotating shaft 12 '.

By doing so, it is possible to reduce the length of the entire structure in the two axial directions of the rotating shaft, to achieve compactness, and to increase the degree of freedom in layout.

<Advantages of Device> As described above, according to the present invention, during normal operation, the valve drive means drives the throttle valve to the target opening to obtain good opening characteristics, while the first link mechanism minimizes The opening characteristic is guaranteed, the engine can continue to operate, and the vehicle can run.

Further, the stopper member, the return spring and the second
With the link mechanism, a valve closing biasing force larger than the driving force of the valve driving means can be applied, and even if the valve driving means causes the throttle valve to open excessively,
It is possible to control to a desired throttle valve opening by an accelerator return operation.

Also, because the return spring is provided on the shaft offset from the rotary shaft of the throttle valve, the overall length can be shortened to achieve compactness, and the valve opening lever and the valve closing lever are provided independently. This also has the advantage of increasing the freedom of layout of the link mechanism. In addition, the cam used for the mechanism that forcibly opens the throttle valve to the minimum opening is configured to engage the valve opening lever from the beginning of the accelerator operation, so that a stick etc. is generated and the throttle valve is difficult to move. However, the operating force can be kept to the minimum necessary.

[Brief description of drawings]

FIG. 1 is a front view showing the overall construction of the first embodiment of the present invention, FIG. 2 is a left side view of FIG. 1, and FIG. 3 is a graph showing the throttle valve opening characteristic of the same embodiment. FIG. 4 is a left side view showing a second embodiment of the present invention, and FIG. 5 is a front view showing the overall construction of a third embodiment of the present invention. 2 ... Rotary shaft, 3 ... Valve opening lever, 4 ... Valve closing lever, 5 ... Plate, 6 ... Cam, 8 ... Axel drum, 9,10 ... Link, 11 ... Spindle , 13 …… electric motor, 14 …… shaft, 15 …… spring assembly, 16 …… return spring, 17 …… link

Front page continuation (72) Inventor Naohiko Inoue 2 Takaracho, Kanagawa-ku, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Akira Shibata 1671 Kasukawa-cho, Isesaki-shi Gunma Prefecture 1 Inside Nippon Electric Equipment Co., Ltd. (56 ) Reference JP 59-122742 (JP, A) JP 59-190440 (JP, A) JP 62-135624 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A valve opening lever and a valve closing lever fixed to a rotary shaft of a throttle valve interposed in an intake system of an internal combustion engine, and slidably and rotatably supported by the rotary shaft of the throttle valve, An accelerator drum that is rotationally driven in association with an accelerator pedal, a cam that is axially supported by a fixing member that engages the valve opening lever from the beginning of accelerator operation, and between the accelerator drum and the cam. A first link mechanism connected to the valve opening lever and the cam for forcibly driving the throttle valve to a minimum opening degree according to the accelerator operation amount; and a valve closing mechanism provided on the accelerator drum. The stopper member that restricts the movement of the throttle valve in the opening direction by engaging with the lever for the throttle valve and provides the maximum opening characteristic according to the accelerator operation amount, and the throttle valve. Drive the valve to a target opening degree set within a range of a minimum opening degree restricted by the valve opening lever and the cam and a maximum opening degree restricted by the valve closing lever and the stopper member. A valve drive means, a return spring having one end locked to a spring assembly tool rotatably attached to a shaft arranged parallel to the rotary shaft of the throttle valve and the other end locked to a fixing member, The spring assembly is connected between the accelerator assembly and the accelerator drum, and when the stopper member and the valve closing lever are engaged, the biasing force of the return spring is transmitted to the throttle valve in the throttle valve opening direction of the valve driving means. A throttle valve opening control device comprising: a second link mechanism that applies a return torque in the closing direction that is stronger than the drive torque.