JP4378684B2 - Electronically controlled throttle device - Google Patents

Description

  The present invention opens and closes a throttle valve installed in an engine intake system for a vehicle by an electronic control system, and when an abnormality or failure has occurred in the electronic control system that makes it impossible to open or close the throttle valve. The present invention relates to an electronically controlled throttle valve device having means for preventing vehicle stoppage and runaway and for safety.

  In order to control the engine with high precision, instead of mechanically opening and closing the throttle valve by the driver's accelerator operation, a technology for opening and closing electronically using an electronic control system is widely known. The control system includes an actuator that opens and closes the throttle valve to a target opening position, and a control unit that sends a required drive signal to the actuator based on the accelerator operation amount and the throttle valve position.

  Here, in order to avoid a situation in which the vehicle becomes unable to run or runaway when an abnormality or failure occurs in the electronic control system, one excitation winding is used for an actuator using a stepping motor. When an abnormality occurs in the wire, another normal exciting winding is used to hold the throttle valve at a constant small opening (see Patent Document 1), and the opening signal storage unit of the throttle valve for the control unit When an abnormality occurs, an alternative opening signal corresponding to the accelerator operation amount is calculated and output to the actuator, or when an abnormality occurs in the control unit or the actuator, the actuator is operated using the auxiliary control unit (Patent Document) 2)) has been proposed.

However, the former is a countermeasure means only in a very specific case when an abnormality occurs in one of the two excitation windings of the stepping motor, and the accident is not avoided because it is fixed at a constant low speed. I am worried. In contrast, the latter has the advantage that it can continue to open and close by electronic control and travel at an arbitrary vehicle speed, but this has the advantage that an abnormality has occurred in the control unit or an actuator. This is a countermeasure only in the case of a very specific case where control is possible. Therefore, it is not possible to cope with any abnormality of the control unit or the failure of the actuator that makes the opening / closing operation by electronic control of the throttle valve impossible. Furthermore, when mechanical element parts such as actuator bearings and reduction gears are damaged, there is a concern that the throttle valve is fixed at the opening position at the time of the damage and the vehicle may run away depending on the opening position. It is not possible to deal with it.
Japanese Patent Laid-Open No. 6-213012 JP-A-6-137206

  The present invention has been made in order to solve the above-mentioned problems, and when an abnormality or failure occurs in the electronic control system and the throttle valve cannot be opened / closed, the driver's accelerator operation is performed. It is an object of the present invention to provide an electronically controlled throttle valve device having switching means that can mechanically open and close the throttle valve from fully closed to fully open according to the amount and can run at an arbitrary vehicle speed.

  The present invention includes a control unit and an actuator, and an electronically controlled throttle device in which the actuator is operated to open and close the throttle valve to a target opening position according to a command issued by the control unit in accordance with a driver's accelerator operation amount. The above-mentioned problem was solved by doing as follows.

That is, the electronically controlled throttle device according to the present invention is a clutch means for coupling / separating an actuator operated by a command output from the control unit in accordance with an accelerator operation amount with a throttle valve shaft; An accelerator driven shaft which is rotated and is fixed to the accelerator lever and supports the driven shaft lever so as to be freely rotatable and movable in the axial direction; a coupling mechanism for coupling the accelerator lever and the driven shaft lever, the driven shaft lever Is in contact with one end surface of a bearing that is rotatably held on the accelerator driven shaft, a piston spring is applied to the opposite end surface of the bearing, and the cylinder chamber is connected to a pressure source by a pressure line having an on-off valve. It is, pressed and moved for moving the cylinder chamber of the piston in the axial direction for coupling with an accelerator lever driven shaft lever Structure, and it comprises a switching means including an interlocking mechanism for interlocking constantly and throttle valve shaft and the driven shaft lever. When the electronic control system including the control unit and the actuator is normal When the clutch means connects the actuator and the throttle valve shaft, and the coupling mechanism is disconnected, causing an abnormality or failure in the electronic control system The clutch means separates the actuator and the throttle valve shaft and operates the pressing movement mechanism to connect the driven shaft lever and the accelerator lever by the coupling mechanism, thereby mechanically opening and closing the throttle valve via the interlocking mechanism.

  The coupling mechanism is composed of a fitting protrusion provided in one of the two levers and a fitting hole provided in the other at opposite positions when the accelerator lever and the driven shaft lever are in the same phase. It is assumed that the lever is elastically held at a predetermined protruding length and attached.

  Examples of abnormalities and failures in the electronic control system include control unit abnormalities or failures that make the actuator uncontrollable, and failures such as disconnection or seizure of the actuator. Open / close control becomes impossible. Secondly, the failure of mechanical elements such as the gears and bearings of the actuator is exemplified. In such a case, the throttle valve is fixed at the opening position at the time of the failure and cannot be opened and closed, so that the vehicle may run away.

  When such an abnormality or failure occurs, the path for transmitting the rotation from the actuator to the throttle valve shaft is divided by the disengagement of the clutch means, and the accelerator driven shaft is always mechanically rotated by the driver's accelerator operation. Is connected to the throttle valve shaft via a coupling mechanism and interlocking mechanism, so that the throttle valve can be opened and closed over the entire opening range regardless of the location where the throttle valve shaft cannot be opened or closed. It can be performed mechanically and run at a desired vehicle speed. Further, at this time, since the actuator is separated from the throttle valve shaft, the force required for the accelerator operation does not change greatly, and the operation can be performed with almost the same operation force without a sense of incongruity.

  At the time of switching, the phase of the accelerator lever corresponding to the driver's accelerator operation may not match the phase of the driven shaft lever corresponding to the throttle valve target opening position commanded by the control unit. In such a state, when the driven shaft lever is moved toward the accelerator lever by the pressing and moving mechanism, the fitting protrusion held elastically hits the other lever and shortens the protrusion length. The accelerator operation for slightly rotating the accelerator lever can be performed without a large resistance to match the fitting hole and can be easily and completely coupled.

  It should be noted that the detection of an abnormality or failure, the disconnection of the clutch means, and the operation of the switching means can be easily implemented by appropriately using or applying the well-known abnormality detection, failure diagnosis, fail safe, and abnormality occurrence notification means as appropriate. it can.

  As described above, according to the present invention, when an abnormality or failure that makes it impossible to open and close the throttle valve occurs in the electronic control system, it is easy to perform mechanical opening and closing operations by operating the accelerator regardless of the occurrence location. In addition, since the throttle valve is opened and closed from fully closed to fully open by reliably switching, it is possible to run at a safe vehicle speed or at an arbitrary vehicle speed according to the surrounding conditions.

  An embodiment of the present invention will be described with reference to the drawings. A throttle valve shaft lever 6 is fixedly attached to one end of a throttle valve shaft 5 that is rotatably supported by a throttle body 2 across an intake passage 1. The throttle valve return spring 7 formed of a torsion coil spring engages with the throttle valve shaft lever 6 to urge the rotational force in the direction to close the throttle valve 4. A throttle valve position sensor 8 is provided on the throttle valve shaft 5.

  The other end of the throttle valve shaft 5 is coupled to a driven body 10b of the clutch means A comprising an electromagnetic clutch, and the drive body 10a of the clutch means A is coupled to the output shaft of an actuator 11 comprising a DC motor. The electric circuit 13 for supplying a current to the coil of the clutch means A is closed when the electronic control system B described later is normal, and when an abnormality or failure occurs, it is manually operated by a command from the control unit 12 or manually. A circuit breaker 14 that is opened by operation is installed.

  An accelerator driven shaft 15 is supported on the mounting base 3 at a distance from the throttle valve shaft 5 so as to freely rotate. An accelerator lever 18 connected to the accelerator pedal 16 and a wire 17 is fixedly attached to the accelerator driven shaft 15. The driven shaft lever 20 is mounted so as to be freely rotatable and movable in the axial direction. An accelerator return spring 19 formed of a torsion coil spring is engaged with the accelerator lever 18 to urge the accelerator driven shaft 15 to return to the accelerator non-operation position. An accelerator position sensor 21 is provided on the accelerator driven shaft 15.

  Based on the throttle valve position detected by the throttle valve position sensor 8 and the accelerator operation amount detected by the accelerator position sensor 21, the actuator 11 opens and closes the throttle valve 4 to the target opening position by a drive signal output from the control unit 12. This embodiment of the invention constitutes a well-known electronic control system B.

  Further, the throttle valve shaft lever 6 and the driven shaft lever 20 are connected to each other by a link member 22 of adjustable length whose both ends are coupled to each other so as to freely rotate. 5 and the driven shaft lever 20 constitute an interlocking mechanism 9 that always rotates in conjunction with each other.

  Further, the accelerator lever 18 and the driven shaft lever 20 are provided with a fitting hole 24 and a fitting protrusion 25 fitted and engaged therewith in the depression amount of the accelerator pedal 16 and the opening position of the throttle valve 4 corresponding thereto. These are provided so as to face each other, and these constitute a coupling mechanism 23. In the embodiment shown in FIGS. 1 to 4, the fitting hole 24 is a round hole provided in the accelerator lever 18, and the fitting protrusion 25 is a cylindrical piece attached to the driven shaft lever 20 with a variable projection length. The diameter of the fitting hole 24 is almost the same. The fitting protrusion 25 has a guide shaft 26 extending rearward, and is fitted to the bottomed cylindrical holding cylinder 28 fixed to the driven shaft lever 20 with the tip portion protruding, and is a pressing spring comprising a compression coil spring. 29, the stopper 27 of the guide shaft 26 is placed at a position where it comes into contact with the bottom surface of the holding cylinder 28, and holds a predetermined protruding length.

  Furthermore, a bottomed cylindrical push-out member 31 is fitted to the shaft end of the accelerator driven shaft 15 so as to rotate integrally and move in the axial direction, and the bottom end portion of the cylinder block 32 attached to the mount 3 is a cylinder. It protrudes into the chamber 33 and contacts the piston 34. The distal end of the pushing member 31 is in contact with one end surface of a bearing 35 that rotatably holds the driven shaft lever 20 on the accelerator driven shaft 15, and a piston spring 36 is applied to the opposite end surface of the bearing 35. The cylinder chamber 33 is connected to a pressure source 37 by a pressure line 39 having an opening / closing valve 38, and the pushing member 31, the cylinder chamber 33, and the piston 34 constitute an pushing movement mechanism 30.

  The interlocking mechanism 9, the coupling mechanism 23, the pressing and moving mechanism 30, and the circuit breaker 14 constitute switching means C that switches from coupling the throttle valve shaft 5 to the actuator 11 to coupling to the accelerator driven shaft 15.

  In this embodiment configured as described above, when the electronic control system B is normal, the rotation of the actuator 11 driven by the drive signal output from the control unit 12 is transmitted to the throttle valve shaft 5 via the clutch means A. To do. At this time, the driven shaft lever 20 is pushed away from the accelerator lever 18 by being pushed by the piston spring 36. Therefore, the driven shaft lever 20 is independent of the rotation of the accelerator lever 18 and the accelerator driven shaft 15 due to the driver's depression of the accelerator pedal, and the throttle valve shaft. The throttle valve shaft lever 6 rotates freely according to the rotation of the throttle valve shaft lever 6. FIG. 2 is a side view showing one state at that time, and the phase of the driven shaft lever 20 when the throttle valve 4 is moved to the target opening position by electronic control, and the accelerator pedal depression amount at that time The phase of the accelerator lever 18 rotated corresponding to is different. This indicates that the accelerator pedal 16 can be operated without being constrained by the throttle valve shaft 5 when electronic control is being performed, and therefore without any increase or decrease in the stepping force.

  When an abnormality or failure occurs in the electronic control system B and the throttle valve 4 cannot be controlled to be opened or closed or is fixed at a certain opening position, the control unit 12 detects these and mechanically depends on the driver's accelerator operation. Switch to open / close throttle valve. This switching is performed automatically or manually by the driver who has been notified of the occurrence of an abnormality. In this embodiment, the circuit breaker 14 is opened and the on-off valve 38 is opened. It can be switched with a simple operation.

  That is, by opening the circuit breaker 14, the driving body 10a and the driven body 10b of the clutch means A are disconnected, and the coupling between the actuator 11 and the throttle valve shaft 5 is disconnected. Further, by opening the on-off valve 38, the pressure fluid of the pressure source 37 is introduced into the cylinder chamber 33, the pushing member 31 is pushed via the piston 34, the driven shaft lever 20 is brought close to the accelerator lever 18, and the fitting protrusion By inserting 25 into the fitting hole 24, the driven shaft lever 20 and the accelerator lever 18 are coupled. The state at this time is shown in FIGS. 3 and 4, and the accelerator lever 18 and the driven shaft lever 20 rotate integrally corresponding to the depression amount of the accelerator pedal 16, and the throttle valve is connected via the link member 22. By rotating the shaft lever 6, the throttle valve 4 can be arbitrarily opened / closed from fully closed to fully opened according to the accelerator operation amount.

  When the aforementioned switching is performed, if the phases of the accelerator lever 18 and the driven shaft lever 20 are different as shown in FIG. 2, the fitting protrusion 25 shown in FIG. When the driven shaft lever 20 is brought closer to the accelerator lever 18 from the state of being in contact with the accelerator lever 18 at the portion where the fitting protrusion 25 is eccentric from the fitting hole 24, the push spring 29 is moved as shown in FIG. It compresses and retracts into the holding cylinder 28. At this time, since the spring force of the push spring 29 only slightly increases the resistance against the depression of the accelerator pedal 16, the accelerator lever 18 can be easily rotated by operating the accelerator pedal 16 with a substantially normal force. . When the fitting hole 24 is aligned with the fitting protrusion 25 by this operation, the fitting protrusion 25 is pushed out of the holding cylinder 28 by the push spring 29 and is fitted into the fitting hole 24 to be coupled as shown in FIG. It becomes a state.

  FIG. 6 is a view showing a different embodiment of the coupling mechanism 23, in which the fitting hole 44 is a notch provided in the accelerator lever 18, and the fitting projection 45 is attached to the driven shaft lever 20 with a variable projection length. The claw-like pieces thus formed have substantially the same width dimension. The fitting protrusion 45 is sandwiched between brackets 46 formed on the driven shaft lever 20 at the base end portion and is rotatably supported by a pin shaft 47 penetrating through the bracket 46. The fitting projection 45 is wound around the pin shaft 47 and driven at both ends. The presser spring 48 engaged with the shaft lever 20 and the fitting protrusion 45 holds the posture protruding from the driven shaft lever 20 at a right angle.

  When the driven shaft lever 20 is moved closer to the accelerator lever 18 at the time of switching, if these phases are different, the fitting protrusion 45 hits the accelerator lever 18 at a portion eccentric from the fitting hole 44 and is approached as shown in FIG. As shown in FIG. 4, the presser spring 48 rotates against the spring force. Since the spring force of the presser spring 48 does not greatly increase the resistance against depression of the accelerator pedal, the accelerator lever 18 can be easily rotated by operating the accelerator pedal with a substantially normal force. Then, when the fitting hole 44 matches the fitting protrusion 45 by this operation, the fitting protrusion 45 is restored to the right-angle protruding position by the presser spring 48, and is fitted into the fitting hole 44 and shown in FIG. It becomes a combined state.

  According to the coupling mechanism 23 described in the two embodiments, the fitting protrusions 25 and 45 are held at a predetermined protrusion length by the spring force, that is, the maximum protrusion length, and linearly or rotationally move when hitting the mating lever. Since the protrusion length is shortened, it can be easily matched with the fitting holes 24 and 44 without causing inconvenience such as biting on the other lever and making phase alignment difficult or impossible. At this moment, the predetermined projection length is restored by the spring force, so that the accelerator lever 18 and the driven shaft lever 20 can be completely and reliably connected, and the operation can be switched to the mechanical opening / closing operation of the throttle valve by the driver's accelerator operation.

  Examples of the pressure source 37 for operating the piston 34 of the pressing movement mechanism 30 include vehicle brake pressure air, engine lubricating oil, and pressure air or pressure oil generated by a separately prepared pump. To do. Alternatively, the pushing member 31 or the driven shaft lever 20 is pressed and moved by using the linear motion of the linear motor mover or the movable iron core of the electromagnetic solenoid, or the driver manually moves the driven shaft lever 20. Can also be coupled to the accelerator lever 18. In addition, when switching, the circuit breaker 14 and the on-off valve 38 in the illustrated embodiment are opened by an electric signal generated by the control unit 12 or the driver, or manually by the driver. be able to.

The longitudinal cross-sectional view when the electronic control which shows embodiment of this invention is performed. The side view explaining the relationship of each lever of FIG. The longitudinal cross-sectional view when the throttle valve is mechanically opened and closed in the form of FIG. The side view explaining the relationship of each lever of FIG. The figure explaining operation | movement of the connection mechanism in the form of FIG. The embodiment from which a connection mechanism differs is shown, (A) is a front view of a fitting hole, (B) and (C) are the longitudinal cross-sectional view and top view of a fitting protrusion. The figure explaining operation | movement of the connection mechanism in the form of FIG.

Explanation of symbols

4 throttle valve, 5 throttle valve shaft, 6 throttle valve shaft lever, 9 interlocking mechanism, 11 actuator, 12 control unit, 15 accelerator driven shaft, 16 accelerator pedal, 18 accelerator lever, 20 driven shaft lever, 22 link member, 23 connection Mechanism, 24, 44 fitting hole, 25, 45 fitting projection, 29 push spring, 30 push moving mechanism, 48 presser spring, A clutch means, B electronic control system, C switching means

Claims (3)

Clutch means for coupling / separating an actuator that operates according to a command output from the control unit in accordance with an accelerator operation amount, with a throttle valve shaft;
An accelerator driven shaft that is always rotated in conjunction with the driver's accelerator operation, and the accelerator lever is fixed and the driven shaft lever is supported to be freely rotatable and axially movable;
A coupling mechanism that couples the accelerator lever and the driven shaft lever, and the driven shaft lever is in contact with one end surface of the bearing that is rotatably held on the accelerator driven shaft, and a piston spring acts on the opposite end surface of the bearing. The cylinder chamber is connected by a pressure line having an on-off valve to a pressure source, and a pressure moving mechanism for moving the driven shaft lever in the axial direction to couple the driven shaft lever with the accelerator lever by the piston of the cylinder chamber; Switching means including an interlocking mechanism that always interlocks the valve shaft and the driven shaft lever, and when the electronic control system including the control unit and the actuator is normal, the clutch means connects the actuator and the throttle valve shaft. The connection mechanism is disconnected and the electronic control system is abnormal or faulty. The clutch means separates the actuator and the throttle valve shaft and operates the pressing and moving mechanism to connect the driven shaft lever and the accelerator lever by the coupling mechanism, thereby restricting the throttle through the interlocking mechanism. It is assumed that the valve opens and closes mechanically,
The coupling mechanism includes a fitting protrusion provided on one of the two levers and a fitting hole provided on the other at a position facing when the accelerator lever and the driven shaft lever are in the same phase. Is attached to the one lever while being elastically held at a predetermined protruding length,
An electronically controlled throttle valve device.   2. The fitting projection is a cylindrical piece, is linearly movable and is held at a predetermined projection length by a pressing spring, and the fitting hole is a round hole having substantially the same diameter as the fitting projection. The electronically controlled throttle valve device described in 1.   The fitting protrusion is a claw-like piece that is rotatable and is held at a predetermined protrusion length by a presser spring, and the fitting hole is a notch having substantially the same width as the fitting protrusion. The electronically controlled throttle valve device according to 1.

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