JP2015206263A - Full close position learning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that it is difficult to set a DUTY value simultaneously satisfying two conditions that "more than torque to eliminate backlash of gear train and conversion mechanism" and "less than torque not opening valve", when a temperature condition of a motor changes.SOLUTION: A prescribed second DUTY value satisfying both conditions that "more than driving torque to eliminate backlash of gear train and scotch yoke" and "less than driving torque not opening poppet valve", can be set as a driving DUTY value to a motor driving circuit, by adjusting a temperature of a motor to an arbitrary temperature by heat generation of the motor itself, even when a temperature condition of the motor changes by temperature environment around the motor.

Description

  The present invention relates to a valve fully closed position learning device for opening and closing a flow path communicating with a cylinder of an internal combustion engine, and in particular, a part of exhaust gas (exhaust gas) discharged from a cylinder of the internal combustion engine (engine) is EGR gas. The present invention relates to a fully closed position learning device for an EGR valve used in an exhaust gas (exhaust) circulation device that is recirculated to an intake pipe.

[Conventional technology]
Conventionally, for example, in an internal combustion engine (engine) such as a diesel engine, a part of exhaust gas (exhaust gas) discharged from a cylinder of the engine is recirculated (refluxed) as an EGR gas to an intake passage in an intake pipe, and an air cleaner is An exhaust gas (exhaust) circulator (EGR system) that suppresses the generation of NOx by reducing the combustion temperature by mixing in the intake air (new air) that has passed is mounted.

By the way, if the EGR gas is recirculated to the intake passage, the ignitability of the air-fuel mixture in the engine cylinder is lowered and the engine output is reduced. Therefore, the flow rate of the EGR gas introduced into the engine cylinder is reduced. It is necessary to adjust according to the driving situation.
Therefore, in the EGR system, an EGR gas flow rate control valve (hereinafter referred to as an EGR control valve) is installed in the middle of an exhaust passage pipe (EGR gas pipe) connecting the exhaust passage in the exhaust pipe and the intake passage in the intake pipe, and EGR control is performed. The flow rate of the EGR gas introduced into the cylinder of the engine is controlled by adjusting the opening of the poppet valve that is the valve body of the valve.

Here, in order to stabilize the combustion state of the engine when the engine operating region is a predetermined operating region (for example, the engine load is low and the engine rotational speed is low), the EGR gas against the fresh air is The introduction is stopped (EGR cut).
Also, when the driver depresses the accelerator pedal and wants to maximize the output of the engine, in order to avoid a decrease in the engine output caused by the introduction of EGR gas into the combustion chamber formed in the engine cylinder. In addition, the introduction of EGR gas to fresh air is stopped (EGR cut).
At the time of this EGR cut, the opening degree of the poppet valve of the EGR control valve becomes the fully closed opening degree.

On the other hand, as described above, an EGR control valve that variably controls the flow rate of EGR gas is installed in the EGR system (see, for example, Patent Document 1).
The EGR control valve includes an electric actuator having an electric motor (hereinafter referred to as a motor) and a gear train, an output shaft connected to the output gear of the gear train so as to be integrally rotatable, and a flat plate-like shape connected to the output shaft so as to be integrally rotatable. A plate cam, a follower fitted in the cam groove of the plate cam, a pin for rotatably supporting the follower, and a poppet valve having a valve shaft (valve shaft) coupled to the pin so as to be movable together.

The EGR control valve includes an annular valve seat on which the valve head of the poppet valve can be seated, a return spring that urges the valve head against the valve seat, that is, a valve spring closing side with respect to the valve shaft. And a rotation angle sensor that outputs a sensor output value (sensor output voltage) corresponding to the rotation angle of the output shaft of the gear train to the electronic control unit (ECU).
Here, at the time of the above EGR cut, that is, when the EGR control valve is fully closed, the valve head of the poppet valve and the entire circumference of the valve seat come into contact with each other, and the gap between the valve head and the valve seat is hermetically sealed. The EGR gas leakage flow rate when the control valve is fully closed is minimized.

[Conventional technical problems]
However, in the conventional EGR control valve (described in Patent Document 1), from the “rotation stop angle of the output shaft” where the rotation of the output shaft of the gear train to the valve body closing side is regulated by the cam stopper, the valve of the poppet valve It has a backlash range up to the “fully closed angle of the output shaft” at the fully closed position immediately before the head starts to open.
In the backlash range, the urging force of the return spring is received by the valve seat via the poppet valve, so that the urging force of the return spring is not applied to the output shaft.

  That is, since the “fully closed position corresponding to the fully closed opening of the poppet valve” and the “sensor output value of the rotation angle sensor at the fully closed angle of the output shaft” do not match, the fully closed position of the poppet valve is output as a sensor. When trying to learn by value, satisfy the two conditions (both conditions) that are "more than the torque that eliminates the backlash between the gear train and the plate cam" and "below the torque that the poppet valve does not open" A method of learning a sensor output value when a predetermined duty value that can be applied to the motor is applied as a fully closed position of the poppet valve is conceivable.

However, the generated torque of the motor changes depending on the temperature condition of the motor (see FIG. 7). The lower the motor temperature, the greater the generated torque of the motor, and the higher the motor temperature, the smaller the generated torque of the motor.
That is, when the predetermined duty value described above is applied to the motor, if the motor temperature is high, the generated torque of the motor becomes small, so that both the conditions of “backlash elimination” and “valve not open” are satisfied. On the contrary, when the motor temperature is low, the generated torque of the motor increases, so that “backlash elimination” is established, but “valve does not open” is not established.
For this reason, it is difficult to set a predetermined duty value that satisfies the above two conditions at the same time, even if the motor temperature conditions vary, depending on the temperature environment around the motor.

JP 2014-043852 A

  The object of the present invention is “the torque exceeding the backlash between the gear train and the conversion mechanism” and “the valve does not open even when the temperature condition of the motor changes depending on the temperature environment around the motor. An object of the present invention is to provide a fully-closed position learning device capable of setting electric power that can simultaneously satisfy two conditions of “below torque”.

According to the invention described in claim 1 (fully closed position learning device), first, electric power capable of generating torque toward the valve body closing side is supplied to the motor, and the valve is closed on the valve body closing side. (First process).
Next, the temperature of the motor is adjusted to an arbitrary temperature by heat generated by supplying power to the motor while maintaining the state of the first process for a certain time or longer (second process).
Next, after this second process (process for adjusting the temperature of the motor to an arbitrary temperature) is completed, the valve opens with a torque that is greater than the torque that eliminates backlash between the gear train and the conversion mechanism. Electric power capable of satisfying both conditions below the torque not to be generated is supplied, and the valve fully closed learning is performed (third process).
By performing the above first to third processes, even if the temperature condition around the motor changes, the motor temperature is kept within a certain range (as shown in FIG. 7) due to the heat generated by the motor itself. It is possible to adjust the temperature within the temperature range (high temperature) raised above, hold the valve in the fully closed position, and perform the valve fully closed learning with high accuracy.

As a result, even if the temperature condition of the motor changes depending on the temperature environment around the motor, it is “more than the torque that eliminates backlash between the gear train and the conversion mechanism” and “below the torque that the valve does not open”. Power that can satisfy the two conditions (both conditions) at the same time (power to drive and drive the motor: motor applied voltage applied to the internal conductor of the motor or motor drive current supplied to the internal conductor of the motor) Can be supplied.
Therefore, even when the temperature condition of the motor changes depending on the temperature environment around the motor, the generated torque of the motor is smaller than when the motor temperature is low, so the valve fully closed learning is performed stably. be able to.

(Example 1) which is the schematic diagram which showed the fully-closed operation | movement of the poppet valve of an EGR control valve. It is sectional drawing which showed the EGR control valve used for an EGR system (Example 1). FIG. 3 is a sectional view taken along the line III-III in FIG. 2 (Example 1). (Example 1) which is the perspective view which showed the electric actuator and the poppet valve. (Example 1) which is the perspective view which showed the electric actuator and the poppet valve. (Example 1) which is the block diagram which showed the rotation angle sensor, ECU, and a motor. (Example 1) which was the change figure of the drive DUTY value with respect to motor temperature and motor torque. (Example 1) which is the explanatory drawing which showed the relationship between valve lift amount, load torque, drive DUTY value, and lever rotation angle (sensor output voltage). It is the flowchart which showed the fully closed position learning method (Example 1). It is the flowchart which showed the fully closed position learning method (Example 1). (Example 2) which is the schematic diagram which showed the fully closed operation | movement of the poppet valve of an EGR control valve. It is sectional drawing which showed the EGR control valve (Example 2). (Example 2) which was the top view which removed the sensor cover and showed the inside of an actuator. (Example 2) which is the explanatory drawing which showed the relationship between valve lift amount, load torque, drive DUTY value, and cam rotation angle (sensor output voltage).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Configuration of Example 1]
1 to 10 show an EGR valve control device (Embodiment 1) to which the fully closed position learning device of the present invention is applied.

The internal combustion engine control apparatus (engine control system) of the present embodiment recirculates (refluxs) EGR gas, which is part of exhaust gas (exhaust gas), from an exhaust pipe of an internal combustion engine (engine) such as a diesel engine to an intake pipe. The exhaust gas circulation device (EGR system) is provided.
The engine is, for example, a vehicle traveling engine mounted on a vehicle such as an automobile, and a multi-cylinder diesel engine having a plurality of cylinders is employed.

The EGR system includes an EGR gas pipe that recirculates EGR gas from an exhaust passage in the exhaust manifold or the exhaust pipe to an intake passage in the intake manifold or the intake pipe. In the EGR gas pipe, an EGR gas flow path is formed through which EGR gas flows from the exhaust passage to the intake passage.
The EGR gas pipe is provided with an EGR control valve that variably controls the flow rate of the EGR gas flowing through the EGR gas flow path.

  Here, the EGR system is used as an EGR valve control device (an EGR control device for an internal combustion engine) that controls opening and closing of a poppet valve (poppet type EGR valve) of an EGR control valve based on the operating state of the engine. This EGR valve control device includes an electric motor (DC motor: hereinafter referred to as a motor) M incorporated in an electric actuator that reciprocates a valve body 1 and a valve shaft 2 of a poppet valve in an axial direction (axial direction) of the valve shaft 2. An engine control unit (motor control device, electronic control device: hereinafter referred to as ECU) 3 that controls in conjunction with other systems (for example, an intake system, a supercharging pressure control system, etc.) is provided.

  The EGR control valve includes a poppet valve that regulates the flow rate of the EGR gas flowing through the EGR gas flow path, an electric actuator that drives the valve shaft 2 of the poppet valve in its reciprocating direction, a poppet valve, an electric actuator, A scotch yoke 4 having a letter shape (or a rectangular cross section) and a housing 7 that houses (incorporates) a return spring 6 are provided. The housing 7 is provided with a recess for accommodating the electric actuator between the sensor cover 9 on which the rotation angle sensor 8 that is an EGR opening degree sensor is mounted.

  The poppet valve includes an annular valve body 1 that opens and closes (changes the opening area) an EGR gas flow path (described later) in the housing 7, and a valve shaft 2 that supports and fixes the valve body 1. An input portion to which the rotational power (drive torque, drive force) of the motor M is transmitted from the electric actuator via the scotch yoke 4 is provided at the proximal end portion of the valve shaft 2 in the axial direction.

The scotch yoke 4 is press-fitted (coupled) and fixed to the outer periphery (the upper outer periphery in the figure) of the input portion of the valve shaft 2 so as to be movable together with the valve shaft 2. Or it is connected and fixed so that it can move integrally with the valve shaft 2 using coupling means, such as laser welding.
In addition, the scotch yoke 4 includes two first and second arms 11 and 12 that are arranged to face each other with a predetermined space (yoke groove 10) therebetween, and the first and second arms 11 and 12. An arm connecting portion 13 or the like for connecting the base end portions is provided.

The housing 7 is integrally provided with a valve body 14 that houses a poppet valve, a motor case 15 that houses a motor M, a gear case 16 that houses a gear train, and the like.
Of these, an annular valve seat 18 on which the valve body 1 can be seated is press-fitted and fixed to the inner periphery of the partition wall 17 of the valve body 14.
Here, the valve body 1 of the poppet valve contacts and separates from the valve seat 18 of the housing 7 to close and open the EGR gas flow path (inlet port 21 → flow path holes 22-25 → outlet port 26 (see FIG. 12)). It is a valve head (valve body) to perform.

The valve shaft 2 is a valve stem (valve shaft) that reciprocates in the central axis direction of the poppet valve in conjunction with the rotational displacement of an output member (33, 35-38, 41-43) described later. An input portion that receives the driving torque of the electric actuator (motor M) from the scotch yoke 4 is provided at the proximal end portion of the valve shaft 2 in the axial direction.
Further, an output portion for outputting a driving torque of the electric actuator (motor M) to the valve body 1 of the poppet valve is provided at the tip end portion of the valve shaft 2 in the axial direction.
An intermediate portion in the axial direction of the valve shaft 2 is slidably supported by a bearing holder 28 of the housing 7 via a metal bearing (bearing) 27.

  The electric actuator includes a motor M that is energized and driven by duty ratio control of a control signal (pulse signal: PWM signal), a reduction mechanism (gear train) that reduces the rotation of the motor shaft 29 of the motor M by two stages, A conversion mechanism (link mechanism) that drives and connects the gear train and the scotch yoke 4, an output member that includes a part of the gear train and the conversion mechanism, and outputs the drive torque of the motor M to the yoke side; A rotation angle detecting device for detecting the rotation angle of the output member.

  The motor M is a brushed DC motor in which an inner rotor is disposed on the inner peripheral side of the outer stator so as to be relatively rotatable, and an inner rotor (armature) having a motor shaft (hereinafter referred to as a motor shaft) 29 that extends straight in the rotation axis direction. A cylindrical stator that surrounds the armature in the circumferential direction (motor circumferential direction), and a pair of power supply brushes (hereinafter referred to as first and second brushes) housed and held in a brush holder fixed to the stator. Brush).

The stator of the motor M includes a motor case (such as a motor yoke) that rotatably houses an armature motor shaft 29, and a plurality of field magnets fixed to the inner peripheral surface of the motor yoke.
The pair of first and second brushes constitute the inner conductor of the motor M, and are disposed at intervals of 180 ° in the circumferential direction of the motor and opposed to each other. Moreover, the 1st brush is connected to the positive electrode side (VCC side) of an external power supply (battery) via one brush terminal and an electric power supply line. The second brush is connected to the negative electrode side (ground side, GND side) of the battery via the other brush terminal and a power supply line.

  The armature of the motor M is disposed on the radially inner side of the stator via a predetermined gap. The armature includes a motor shaft 29 that is rotatably supported by bearing support portions (bearing holders) of the front bracket and the motor yoke via bearings (metal bearings), and a magnetism in the direction of the rotation axis of the motor shaft 29. An armature core (armature core) formed by laminating a plurality of steel plates, an armature winding (armature core) which is a motor winding portion wound around the armature core, and a pair of first, And a commutator that is pressed against the second brush.

The armature core is formed of a laminated iron core, and has a cylindrical (or rectangular tube) fitting portion that is press-fitted to the outer periphery of the motor shaft 29, and a plurality of teeth that protrude from the outer peripheral surface of the fitting portion. have.
Between each tooth adjacent to the circumferential direction of the armature core, a plurality of slots for accommodating the phase coils of the armature coil are formed.
The armature coil constitutes the inner conductor of the motor M together with the brush terminal, the motor terminal, the first and second brushes, and the commutator, and is wound around each tooth winding portion of a plurality of teeth by a concentrated winding method. The multi-phase coils are accommodated in the slots. Each phase coil is wound around the outside of each tooth winding part via an insulator.

  The gear train includes a pinion gear 31 fixed on the outer periphery of the motor shaft 29 of the motor M, an intermediate gear 32 that rotates in mesh with the pinion gear 31, an output gear 33 that rotates in mesh with the intermediate gear 32, and a motor shaft. 29, an intermediate shaft 34 arranged in parallel with the motor 29, an output shaft 35 arranged in parallel with the motor shaft 29 and the intermediate shaft 34, and the like.

The output member transmits the driving torque of the motor M to the poppet valve via the valve shaft 2. The output member includes an output gear 33 that rotates in response to the driving torque of the motor M, and an output shaft 35 that is installed on the rotation center axis of the output gear 33 and is coupled to the output gear 33 so as to be integrally rotatable. ing.
The output member is connected to the output shaft 35 so as to rotate together with the output shaft 35, an eccentric pin (hereinafter referred to as a pivot pin) 37 held on the protruding end of the output lever 36, and the outer periphery of the pivot pin 37. A freely-supported ball bearing (hereinafter referred to as a follower) 38, dual ball bearings 41 and 42 that support the output shaft 35 so as to be slidable in the rotational direction, and press-fitted into the outer periphery of these double ball bearings 41 and 42 And a cylindrical collar 43 to be fixed.

The EGR control valve includes a return spring 6 that urges the poppet valve toward the valve body closing side (valve full closing side) with respect to the valve shaft 2. The return spring 6 is a coiled compression spring that generates a biasing force (elastic force, restoring force) that biases the valve body 1 in the valve closing (full closing) direction with respect to the valve shaft 2.
The return spring 6 includes a spring seat portion of an annular spring seat 44 and a bottom portion of the housing 7 (cylindrical concave groove on the outer peripheral side of the bearing holder 28) which are locked to a step (annular step) on the upper end side of the valve shaft 2. A coil portion wound in a spiral shape between the spring seat portion and the spring seat portion. The return spring 6 is installed so as to surround the periphery of the valve shaft 2 on the upper end side in the figure and the periphery of the bearing holder 28 in a spiral shape (spiral shape).

The housing 7 is integrally formed with a valve body 14 that movably accommodates a poppet valve (valve body 1, valve shaft 2), a scotch yoke 4, a return spring 6, and the like. Inside the valve body 14, an inlet port 21 → channel holes 22 to 25 → outlet port 26 constituting a part of the EGR gas channel are formed.
Further, in the valve body 14, the EGR gas flow path in the valve body 14 is a first flow path (housing inlet-side flow path: inlet port 21, which is located upstream of the valve seat 18 in the EGR gas flow direction. A circle divided into a flow path hole 22) and a second flow path (housing outlet side flow path: flow path holes 24 and 25, outlet port 26) located downstream of the valve seat 18 in the EGR gas flow direction. An annular (cylindrical) partition (partition) 17 is formed.

An annular circumferential groove is formed in the inner peripheral portion of the partition wall 17 of the valve body 14 so as to surround the periphery of the valve seat 18 in the circumferential direction. The outer periphery of the annular valve seat 18 is press-fitted and fixed to the bottom surface (circumferential wall) of the circumferential groove. An annular valve seat on which the valve body 1 can be seated is provided at the seat edge of the valve seat 18.
Further, the valve seat 18 communicates with the first flow path (inlet port 21, flow path hole 22) and the second flow path (flow path holes 24, 25, outlet port 26), and the EGR gas flows. A passage hole (valve hole of EGR control valve, communication hole) 23 is formed.

The valve body 14 is integrally formed with a cylindrical bearing holder 28 that holds the outer periphery of the metal bearing 27. The bearing holder 28 is disposed so as to surround the circumference of the metal bearing 27 in the circumferential direction.
A coupling flange 46 is provided on the lower end side (valve seat side) of the valve body 14 in the figure. The coupling flange 46 has a coupling end surface that is attached to an attachment member (fixing member) of the EGR control valve, and is fastened and fixed to the attachment surface of the fixing member using a fastener such as a bolt. As a result, the EGR control valve is fixed to a fixing member on the engine side (vehicle side) such as an EGR gas pipe or an intake pipe.

The housing 7 is integrally formed with a bottomed cylindrical motor case 15 that houses and holds the motor M. The motor case 15 is opened at a cylindrical side wall portion that surrounds the periphery of the motor yoke of the motor M in the circumferential direction, and at one end side of the side wall portion, and is an opening for inserting the motor M into the motor housing chamber during assembly. Part (motor insertion port). The motor insertion opening is closed by the front bracket 47 of the motor M.
The front bracket 47 is fastened and fixed to the periphery of the opening of the motor insertion opening of the motor case 15 using bolts or the like. As a result, the motor M is housed and held in the motor housing chamber.

  The housing 7 is formed with a gear case 16 that accommodates the gear train. The gear case 16 is integrally formed with a cylindrical bearing holder 48 for holding the double ball bearings 41 and 42 and the outer ring portion of the cylindrical collar 43. The bearing holder 48 is disposed so as to surround the double ball bearings 41 and 42 and the cylindrical collar 43 in the circumferential direction. Further, the gear case 16 has an opening for inserting the electric actuator into the gear housing chamber during assembly. This opening is closed by a synthetic resin sensor cover 9.

  The sensor cover 9 has an internal connection connector for electrical connection between the pair of first and second brush terminals 49 protruding from the front bracket 47 of the motor M and the pair of first and second motor terminals (not shown). And a pair of first and second motor terminals and a plurality of sensor terminals of the rotation angle sensor 8 and an external connection connector for electrical connection with an external circuit (ECU 3 or battery).

  The electric actuator includes a motor M that generates a driving torque for opening and closing the poppet valve, a gear train that decelerates the rotation of the motor shaft 29 of the motor M to two stages and transmits the output to the output shaft 35, and an output gear 33 of the gear train. A power conversion mechanism (conversion mechanism) that converts the rotational reciprocating (rotating) motion into a linear reciprocating motion of the poppet valve (reciprocating motion of the poppet valve in the axial direction), and a rotational angle detecting device that detects the rotational angle of the output shaft 35; It has. As described above, the gear train includes the pinion gear 31, the intermediate gear 32, the output gear 33, the intermediate shaft 34, and the output shaft 35.

The pinion gear 31 is fixed to the outer periphery of the tip of the motor shaft 29 by press fitting. A large number of pinion gear teeth 51 that mesh with the intermediate gear 32 are formed on the entire outer periphery of the pinion gear 31 in the circumferential direction.
The intermediate gear 32 is fitted on the outer periphery of the intermediate shaft 34 so as to be relatively rotatable. The intermediate gear 32 has a cylindrical portion that is rotatably fitted to the outer periphery of the intermediate shaft 34 and rotates around the central axis of the intermediate shaft 34. A large-diameter gear tooth 52 that meshes with the pinion gear tooth 51 is formed at one end in the axial direction of the cylindrical portion. A small-diameter gear tooth 53 that meshes with the output gear 33 is formed at the other end of the cylindrical portion in the axial direction.

A cylindrical cylindrical boss 54 is integrally formed on the inner peripheral portion of the output gear 33. Further, the output gear 33 has a partially cylindrical (fan-shaped) tooth forming portion on the outer side in the radial direction from the cylindrical boss 54. Output gear teeth 55 that mesh with the small-diameter gear teeth 53 of the intermediate gear 32 are formed on the outer periphery of the tooth forming portion.
The output gear 33 is integrally provided with a shaft coupling portion 56 so as to close an opening on one end side (valve side) of the cylindrical boss 54. In the central portion of the shaft coupling portion 56, a fitting hole having a two-surface width (a structure for preventing the output shaft 35 from rotating idly and a rotation preventing structure) is formed through. The shaft coupling portion 56 is fitted and fixed in a state where the input portion of the output shaft 35 (the first protruding shaft portion 57 of the output shaft 35) is prevented from rotating.

One end of the intermediate shaft 34 in the axial direction is press-fitted (fixed) into the fitting recess of the gear case 16 of the housing 7. The other end of the intermediate shaft 34 in the axial direction is press-fitted (fixed) into the fitting recess of the sensor cover 9.
The output shaft 35 is rotatably or slidably accommodated in the bearing holder 48 of the housing 7 via the cylindrical collar 43 and the double ball bearings 41 and 42. The output shaft 35 includes first and second projecting shaft portions (small-diameter shaft portions) 57 and 58 on both sides in the rotation axis direction. An axial portion (intermediate shaft portion) disposed in the bearing holder 48 of the housing 7 is provided between the first and second projecting shaft portions 57 and 58. The inner rings of the double ball bearings 41 and 42 are fitted and held on the outer circumference of the intermediate shaft portion of the output shaft 35 by press-fitting.

The conversion mechanism includes the scotch yoke 4, the output lever 36, the pivot pin 37, the follower 38, and the like.
The scotch yoke 4 includes two first and second arms 11 and 12 extending so as to protrude from the proximal end side toward the distal end side, and openings on the proximal end sides of the first and second arms 11 and 12. The arm connection part 13 etc. which block | close the part are provided.

The scotch yoke 4 receives the driving torque of the motor M from the pivot pin 37 via the follower 38 and reciprocates in the axial direction of the valve shaft 2. The scotch yoke 4 is connected to the valve shaft 2 so as to be movable together.
As shown in FIG. 1 and FIG. 8A, the scotch yoke 4 is “motor of the electric actuator” when the poppet valve of the EGR control valve is fully closed (closed) when the motor M is energized (ON). When the poppet valve is fully closed (closed) using “the driving torque of M + the urging force of the return spring 6 (spring force)”, the follower 38 of the conversion mechanism rotates to the valve body closing side (valve closing direction). It is driven and slidably contacts the inner surface (side surface of the yoke groove) of the first arm 11.

Further, as shown in FIGS. 1 and 8B and 8C, the Scotch yoke 4 is “electric actuator” when the poppet valve of the EGR control valve is opened when the motor M is energized (ON). When the poppet valve is opened using the “drive torque of the motor M of the motor M”, the follower 38 of the conversion mechanism is rotationally driven to the valve body opening side (the valve opening direction), and the inner surface of the second arm 12 (side surface of the yoke groove). ) And slidably contact.
Note that the scotch yoke 4 uses only “the urging force (spring force) of the return spring 6” when the poppet valve of the EGR control valve is fully closed (closed) when the energization of the motor M is stopped (OFF). When the poppet valve is urged toward the valve body closing side (valve closing direction), the follower 38 is slidably brought into contact with the inner surface (side surface of the yoke groove) of the second arm 12.

The scotch yoke 4 has an U-shaped input section that receives the driving force of the output member via the follower 38, and an output section that transmits the driving force of the output member to the valve shaft 2.
The input portion of the scotch yoke 4 has a polyhedral shape (a cross-sectional U-shape) having at least four first to fourth side surfaces in addition to the two surfaces facing the insertion direction in which the pivot pin 37 and the follower 38 are inserted during assembly. Shape or circular cross section).
The input portion of the scotch yoke 4 may be formed in an annular cross section so as to surround the follower 38 in the circumferential direction.

The yoke groove 10 has an opening 61 for inserting the follower 38 into the yoke groove 10 while linearly moving the output member when the output member, particularly the follower 38, is assembled to the scotch yoke 4.
A bottomed circular (or square) cylindrical fitting portion 62 is integrally provided at the output portion of the scotch yoke 4. Inside the fitting portion 62, a press-fit groove 63 into which a base end portion (input portion) in the axial direction of the valve shaft 2 is press-fitted is formed.

The output lever 36 is provided so as to protrude outward in the radial direction of the output shaft 35. The output lever 36 is a link lever that drives and connects the output shaft 35, the pivot pin 37, and the follower 38, and transmits the driving torque of the motor M to the pivot pin 37 and the follower 38.
A first fitting hole is provided at the base end of the output lever 36. The second protruding shaft portion 58 of the output shaft 35 is press-fitted into the first fitting hole. As a result, the output lever 36 is coupled to the output shaft 35 so as to be integrally rotatable.

Further, a second fitting hole is provided at the tip of the output lever 36. A pivot pin 37 is press-fitted into the second fitting hole. As a result, the pivot pin 37 is coupled to the output lever 36 so as to be integrally rotatable. The second fitting hole is provided at a position eccentric from the rotation center axis of the second protruding shaft portion of the output shaft 35 by a predetermined distance.
The pivot pin 37 is driven into the second fitting hole of the output lever 36 and is press-fitted and fixed to the output portion of the output lever 36. The pivot pin 37 supports the follower 38 rotatably. The pivot pin 37 is inserted into the yoke groove 10 of the scotch yoke 4 together with the follower 38.

The follower 38 is slidably accommodated between two inner races that are press-fitted and fixed to the outer periphery of the pivot pin 37, an outer race that is in sliding contact with the groove side surface of the yoke groove 10 of the scotch yoke 4, and an inner race and an outer race. It is a ball bearing provided with a plurality of steel balls.
The follower 38 is rotatably supported on the outer periphery of the pivot pin 37 and is slidably (rolled) into the yoke groove 10 of the scotch yoke 4. The follower 38 is provided at a position eccentric from the rotation center axis of the second protruding shaft portion 58 of the output shaft 35 by a predetermined distance. Further, the follower 38 is coupled to the output lever 36 through the output lever 36 and the pivot pin 37 so as to be integrally rotatable.

Here, the motor M which is a power source of the electric actuator is electrically connected to an external power source (battery) mounted on a vehicle such as an automobile via a motor drive circuit electronically controlled by the ECU 3.
The ECU 3 includes a microcomputer having a known structure including functions of a CPU, a memory (ROM, RAM, and EEPROM), an input circuit (input unit), an output circuit (output unit), a power supply circuit, a timer circuit, and the like. Is provided.
The ECU 3 corresponds to “learning control means” and “first and second setting means” in the claims.

The motor drive circuit is configured by an H bridge circuit in which, for example, four semiconductor switching elements are bridge-connected. The motor drive circuit is a drive circuit unit that energizes and drives the motor M based on a control signal, and supplies power to the motor M with respect to a control signal (for example, duty ratio of a PWM signal) given from a microcomputer of the ECU 3. (Motor drive current or motor applied voltage) is variably controlled.
Here, the control signal (for example, the duty ratio of the PWM signal) given to the motor drive circuit means that the actual valve lift amount (actual valve position or actual opening or actual EGR rate) is the target valve lift amount (target valve position or target opening). ON period during which the internal conductor (motor winding part: armature coil, etc.) of the motor M is energized in the generation period (PWM period) of the PWM signal (pulse width modulation signal) so as to be equal to or the target EGR rate. And the OFF period during which the energization of the internal conductor of the motor M is stopped (ON / OFF ratio).

The CPU performs various numerical calculation processes, information processing (for example, valve position information processing) and control (for example, valve position control, motor energization control), and the like according to a program (see FIGS. 9 and 10).
The ROM stores in advance programs necessary for various numerical arithmetic processing, information processing, and control of the CPU.
In the RAM, intermediate information obtained by the arithmetic processing of the CPU is temporarily recorded, and the stored information disappears when the ignition switch (engine switch) is turned off.

The EEPROM stores information necessary for various numerical computation processing, information processing, control, and the like by the CPU.
Specifically, a fully closed learning DUTY value (see FIG. 7) set in advance is stored in advance in the EEPROM.
Correspondence between the valve lift amount of the EGR control valve, the lever rotation angle (sensor output signal output from the rotation angle sensor 8: sensor output voltage) and the load torque (motor torque) applied to the valve shaft 2 of the poppet valve. Initial data such as a data table (see FIG. 8) representing the relationship in a predetermined format is stored in advance in the EEPROM. The data stored in the data table can be rewritten (updated).

A sensor output signal (analog voltage) from the rotation angle sensor 8 and a sensor output signal (electric signal) from various sensors are A / D converted by an A / D conversion circuit, and then input to the input unit of the microcomputer. It is configured to be entered.
Here, not only the rotation angle sensor 8 but also an air flow meter 71, a crank angle sensor 72, an accelerator opening sensor 73, a throttle opening sensor 74, an intake air temperature sensor 75, a water temperature sensor 76, and a discharge are included in the input portion of the microcomputer. A gas sensor (air-fuel ratio sensor, oxygen concentration sensor: not shown) and the like are connected.

The ECU 3 constitutes a stroke amount (or flow rate) detecting means for detecting a stroke amount (valve lift or flow rate) of the poppet valve based on a sensor output signal (sensor output voltage) output from the rotation angle sensor 8. .
The ECU 3 constitutes a lever angle detection unit that detects the rotation angle (lever rotation angle) of the output lever 36 based on the sensor output signal (sensor output voltage) output from the rotation angle sensor 8.

The crank angle sensor 72 includes a pickup coil that converts the rotation angle of the crankshaft of the engine into an electric signal. For example, a sensor output signal (hereinafter referred to as NE pulse signal) is sent to the ECU 3 every 15 ° or 30 ° CA (crank angle). Is output.
The ECU 3 is a rotational speed detection means for detecting the engine rotational speed (engine rotational speed: NE) by measuring the interval time of the NE pulse signal output from the crank angle sensor 72.

The accelerator opening sensor 73 is an engine load detection means for outputting an electric signal (sensor output signal) corresponding to the accelerator pedal depression amount (accelerator opening: ACCP) to the ECU 3. If the throttle opening sensor 74 is mounted, the throttle opening sensor 74 may be used as an engine load detection means.
The intake air temperature sensor 75 is an intake air temperature detector that outputs an electric signal (sensor output signal) corresponding to the temperature of intake air (intake air) sucked into each cylinder of the engine (hereinafter referred to as intake air temperature: THA) to the ECU 3. .

The water temperature sensor 76 is water temperature detection means for outputting an electric signal (sensor output signal) corresponding to the engine cooling water temperature (hereinafter referred to as water temperature: THW) to the ECU 3.
Here, when the ignition switch is turned on (IG / ON), the ECU 3 first outputs various sensor output signals necessary for calculating (calculating) the operating state (engine information) or the operating condition (state) of the engine. Obtained (input) and configured to electronically control the driving torque of the motor M of the electric actuator based on the operating state or operating condition of the engine and the program stored in the ROM.

The rotation angle detection device includes a cylindrical magnetic circuit unit, and a rotation angle (valve opening) sensor 8 that detects the valve position information (valve opening) of the EGR control valve by measuring the rotation angle of the magnetic circuit unit; A change in the relative rotation angle between the magnetic circuit unit and the rotation angle sensor 8 is detected by a magnetic change applied to the rotation angle sensor 8 from the magnetic circuit unit.
The rotation angle sensor 8 is sandwiched and held between facing portions of a pair of stator cores installed in the sensor mounting portion of the sensor cover 9. This rotation angle sensor 8 is mainly composed of a Hall IC that outputs a sensor output signal (analog voltage signal: sensor output voltage) corresponding to the magnetic flux density interlinking the magnetic sensing surface of the semiconductor Hall element to the ECU 3. Yes.

The Hall IC is a magnetic sensor in which a Hall element and an integrated circuit are integrated as a single IC chip (semiconductor chip). Instead of the Hall IC, a non-contact type magnetic detection element such as a Hall element alone or a magnetoresistive element may be used.
The magnetic circuit section includes a pair of partial cylindrical sensor yokes 81 that are divided into two in the diameter direction of the cylindrical boss 54, and a pair of magnetic poles that are disposed in the same direction in the divided section (opposing section) of the sensor yoke 81. And a sensor magnet (permanent magnet) 82.
This magnetic circuit portion is fixed to the inner periphery of the cylindrical boss 54 of the output gear 33 with an adhesive or the like. In the case where the cylindrical boss 54 of the output gear 33 is made of synthetic resin, the magnetic circuit portion may be insert-molded on the cylindrical boss 54.

  The ECU 3 determines the engine operating status (for example, the fresh air amount measured from the sensor output signal (intake flow rate signal) output from the air flow meter 71 and the engine speed (NE) measured from the NE signal of the crank angle sensor 72). Correspondingly, the control target value (target opening) is calculated (determined), and the actual opening (actual valve position or actual EGR rate) measured from the sensor output voltage output from the rotation angle sensor 8 and the target opening ( A control signal (for example, duty ratio of PWM signal: drive DUTY value = drive duty setting value (hereinafter, referred to as “drive duty”)) is used for the motor drive circuit using known PID control so that there is no deviation from the target valve position or target EGR rate. DUTY = ± α%))), that is, the drive DUTY value to be applied to the motor drive circuit is set to the actual opening (actual The generated torque (drive force, drive torque), motor rotation direction, motor rotation speed, etc. of the motor M are controlled by variably controlling based on the deviation between the valve position) and the target opening (target valve position). .

  Then, the ECU 3 generates a driving torque (opening-side motor torque) of the motor M for opening the valve body 1 of the poppet valve against the urging force (spring force) of the return spring 6 from the ECU 3 to the motor driving circuit. When a drive duty setting value (DUTY = + α%) is given, electric power (motor drive current or motor applied voltage) corresponding to DUTY = + α% is supplied to an internal conductor (such as an armature coil) of the motor M, and the motor A motor driving current in the valve opening direction (opening side of the valve body 1) flows through the M armature coil. As a result, as shown in FIG. 7, the poppet valve (valve body 1, valve shaft 2) is driven to open toward the opening side against the urging force of the return spring 6.

  When the drive DUTY value is changed from the minimum value (DUTY = 0%) to the maximum value (DUTY = 100%), the poppet valve operates from the fully closed position to the fully open position (see FIG. 7). ). Further, in the EGR control valve of this embodiment, the rotation of the output shaft 35 of the gear train to the valve body closing side is restricted by a mechanical (fixed) stopper (not shown). Backlash range (valve fully closed) from "stop angle = fully closed angle of scotch yoke 4" to "fully closed angle of output shaft 35 and output lever 36" in the fully closed position immediately before the valve body 1 of the poppet valve begins to open. But with backlash).

  Further, the ECU 3 generates a driving torque (closing motor torque) of the motor M toward the closing side of the valve body 1 of the poppet valve, which assists the urging force (spring force) of the return spring 6 with respect to the motor driving circuit. When a drive duty setting value (DUTY = −α%) is given, power (motor drive current or motor applied voltage) corresponding to DUTY = −α% is supplied to the internal conductor (armature coil, etc.) of the motor M. The motor driving current in the valve closing direction (the valve body 1 closing side) flows through the armature coil of the motor M. As a result, as shown in FIG. 7, the valve body 1 and the valve shaft 2 are driven to close to the closing side while assisting the urging force of the return spring 6.

[Control Method of Example 1]
Next, a control method of the fully closed position learning apparatus according to the present embodiment will be briefly described with reference to FIGS.
Here, FIG. 9 and FIG. 10 are flowcharts showing the fully closed position learning method by the ECU 3. The control routines of FIGS. 9 and 10 are repeatedly executed at predetermined control cycles after the ignition switch is turned on (IG • ON).

  By the way, the ECU 3 of this embodiment does not match the “fully closed position of the poppet valve (valve fully closed position)” with the “sensor output voltage at the fully closed position of the Scotch yoke 4 (scotch yoke fully closed position)”. A fully closed position learning device is provided which learns the fully closed position of the poppet valve with the sensor output voltage output from the rotation angle sensor 8 every time the engine is started.

First, when the ignition switch is turned on (IG / ON), the ECU 3 detects various sensor output signals and motors necessary for determining the operation state of the poppet valve (valve body 1, valve shaft 2) and the operating state of the engine. A drive DUTY value (DUTY (%)) given to the drive circuit is acquired.
In addition, instead of DUTY (%), the valve main body is measured by measuring the motor applied voltage applied to the inner conductor (armature coil) of the motor M and the motor driving current flowing through the inner conductor (armature coil) of the motor M. The valve opening degree (actual opening degree) of the EGR control valve that is the operation state 1 may be determined.

  Here, when the control routine of FIG. 9 starts or when the fully closed position learning condition is satisfied, the “fully closed position of the poppet valve” and the “sensor output signal (sensor output voltage) output from the rotation angle sensor 8”. The fully closed position learning command flag (FLAG) is output so as to learn the fully closed position of the poppet valve. That is, FLAG = ON is set (step S1).

Next, it is determined whether or not the valve body 1 of the poppet valve is in the fully closed position (step S2). If the determination result of step S2 is NO, the determination process of step S2 is repeated.
If the determination result in step S <b> 2 is YES, the sensor output (water temperature) signal output from the water temperature sensor 76 is acquired, and the water temperature is obtained from the sensor output (water temperature) signal of the water temperature sensor 76.

Next, it is determined whether or not the obtained water temperature is equal to or lower than X (° C.) (step S3). If the determination result of step S3 is NO, the process proceeds to step S7.
If the determination result in step S3 is YES, the sensor output (intake air temperature) signal output from the intake air temperature sensor 75 is acquired, and the intake air temperature is calculated from the sensor output (intake air temperature) signal of the intake air temperature sensor 75. Ask. Next, it is determined whether or not the obtained intake air temperature is equal to or lower than Y (° C.) (step S4). When the determination result of this step S4 is NO, it progresses to the process of step S7.

If the determination result in step S4 is YES, the motor M is supplied with electric power capable of generating a driving torque toward the valve body closing side, and the poppet valve (valve body 1, valve shaft 2) is supplied. ) Is urged to the valve closing side.
Specifically, a predetermined first DUTY value that generates a driving torque toward the valve body closing side is set as a drive DUTY value for the motor drive circuit (first setting means).
Then, the set first DUTY value is applied as the drive DUTY value for the motor drive circuit, and the poppet valve (valve body 1, valve shaft 2) is urged toward the valve body closing side (first control process: step S5). ).

Next, it is determined whether or not the count value counted in the control routine of FIG. 10 is equal to or greater than Z (for example, 2 seconds) (second control process: step S6). If the determination result of step S6 is NO, the determination process of step S6 is repeated.
At this time, the power (motor drive current or motor applied voltage) corresponding to the first DUTY value to the internal conductor (armature coil, etc.) of the motor M is maintained while maintaining the state of the first control process for a certain time (Zsec) or more. The temperature of the motor M is adjusted to an arbitrary temperature by the heat generation of the inner conductor (armature coil or the like) of the motor M by the supply.

If the determination result in step S6 is YES, “the driving torque is more than the driving torque that eliminates the backlash between the gear train and the scotch yoke 4” and the “poppet valve (valve body 1, valve shaft 2) is opened. Supply power that can satisfy both the conditions of "no driving torque or less".
Specifically, after the adjustment process (second control process) for adjusting the temperature of the motor M to an arbitrary temperature is completed, the drive DUTY value for the motor drive circuit is set to “backlash between the gear train and the scotch yoke 4. Predetermined second DUTY value (fully closed learning DUTY value) that satisfies both the conditions of "the driving torque to be eliminated" or more and "the driving torque that the poppet valve (valve body 1, valve shaft 2) does not open" is set. (Second setting means).
Then, the set fully closed learning DUTY value is applied as the drive DUTY value for the motor drive circuit (third control process: step S7).

The fully closed learning DUTY value is preliminarily calculated on a desk in advance (before factory shipment or the like), set in advance, and stored (stored) in RAM or EEPROM.
Also, the characteristic line (I) shown in FIG. 7 shows a change in DUTY value that can eliminate backlash as the motor temperature rises, and the characteristic line (II) shown in FIG. 7 shows the motor temperature. The change of the DUTY value in which a poppet valve does not open is shown as the rise of. As shown in FIG. 7, by learning the fully closed position by using the preset fully closed learning DUTY value by raising the motor temperature so that the motor temperature falls within a predetermined temperature range. be able to.

  Next, the fully closed learning of the poppet valve (valve body 1 and valve shaft 2) is performed to acquire a sensor output signal (sensor output voltage) output from the rotation angle sensor 8, and the acquired sensor output voltage is It is determined whether it is within the sensor output range not less than the lower limit value (A: for example 0.8V) and not more than the upper limit value (B: for example 1.2V) (step S8). If the determination result in step S8 is NO, learning of the fully closed position of the poppet valve is interrupted or stopped. That is, FLAG is turned OFF and the control routine of FIG. 9 is exited.

  If the determination result in step S8 is YES, the sensor output voltage acquired in step S8 is learned (updated to EEPROM) as a poppet valve fully closed position learning value (currently learned value: threshold value). Recording (memory) is performed (step S9). Thereafter, the fully closed position learning control of the poppet valve is terminated. That is, FLAG is turned OFF and the control routine of FIG. 9 is exited.

  On the other hand, when the timing for starting the control routine of FIG. 10 is reached, first, in step S1 of FIG. 9, it is determined whether or not a fully closed learning command is output. That is, it is determined whether or not FLAG is ON (step S11). If the determination result in step S11 is NO, the count value count in the timer circuit is reset. That is, the timer count (T) is returned to 0 (step S12). Thereafter, the control routine of FIG. 10 is exited.

If the determination result in step S11 is YES, in step S5 of FIG. 9, “apply a predetermined first DUTY that generates a drive torque toward the valve closing side” is applied as the drive DUTY value for the motor drive circuit. It is determined whether or not there is (step S13). When the determination result of this step S13 is NO, it progresses to the count process of step S12.
If the determination result in step S13 is YES, the count value in the timer circuit is incremented. That is, the timer count (T) is added for t seconds (step S14). Thereafter, the control routine of FIG. 10 is exited.

[Effect of Example 1]
As described above, in the ECU 3 used as the fully closed position learning device of the present embodiment, first, as a drive DUTY value for the motor drive circuit, a predetermined first DUTY value that generates a drive torque toward the valve body closing side is first used. Set and supply electric power (motor driving current or motor applied voltage) corresponding to the first DUTY value to the inner conductor (armature coil, etc.) of the motor M, and the poppet valve (valve body 1, valve shaft 2) Energize toward the body closing side (first control process). Next, the temperature of the motor M is set to an arbitrary temperature (as shown in FIG. 7) due to heat generated by the motor drive current to the armature coil of the motor M while maintaining the state of the first control process for a certain time or more. The temperature of M is adjusted to a temperature range (high temperature) increased by a predetermined value or more (second control process).

  Next, after the process of adjusting the temperature of the motor M to an arbitrary temperature is completed, the drive DUTY value for the motor drive circuit is “more than the drive torque that eliminates the backlash between the gear train and the scotch yoke 4”, and A predetermined second DUTY value that satisfies both conditions (two conditions) of “the driving torque at which the poppet valve (valve body 1, valve shaft 2) does not open” is set, and the armature coil of the motor M is set. Electric power (motor drive current or motor applied voltage) corresponding to the second DUTY value is supplied to perform fully closed learning of the poppet valve (third control process).

By executing the first to third control processes described above, the temperature of the motor M is kept within a certain range (the motor temperature shown in FIG. Thus, the poppet valve can be held in the fully closed position and the fully closed learning of the poppet valve can be performed with high accuracy.
As a result, even if the temperature condition of the motor M changes depending on the temperature environment around the motor, the drive DUTY value for the motor drive circuit is adjusted by adjusting the temperature of the motor M within a certain range by the heat generated by the motor itself. As described above, a predetermined second DUTY that satisfies both of the conditions (two conditions) of “the driving torque that eliminates the backlash between the gear train and the scotch yoke 4” and “the driving torque that does not open the poppet valve” is satisfied. A value (power for energizing and driving the motor M) can be set.
Therefore, even when the temperature condition of the motor M changes depending on the temperature environment around the motor, the torque generated by the motor M becomes smaller than when the temperature of the motor M is low, so that the poppet valve fully closed learning is stabilized. Can be implemented.

[Configuration of Example 2]
11 to 14 show an EGR valve control device (Embodiment 2) to which the fully closed position learning device of the present invention is applied.
Here, the same reference numerals as those in the first embodiment indicate the same configuration or function, and the description thereof is omitted.

  The EGR control valve of the present embodiment has a motor M that generates a driving torque for driving a poppet valve (the valve body 1 and the valve shaft 2), and a gear train that decelerates the rotation of the motor M and transmits it to the output shaft 35. An electric actuator, a return spring 6 that biases the valve body 1 against the valve seat 18 against the valve shaft 2 (valve element closing side), and a housing 7 that houses the electric actuator inside. The ECU 3 is configured to control the position of the poppet valve (the valve body 1 and the valve shaft 2) by electronically controlling the motor drive circuit.

In addition, a voltage signal corresponding to the rotation angle of the plate cam 5 of the conversion mechanism, which will be described later, is sent to the ECU 3 on the sensor mounting portion of the sensor cover 9 that closes the opening side of the recess (actuator housing chamber) of the housing 7 of the EGR control valve. A rotation angle sensor 8 is mounted.
Further, the EGR control valve has a conversion mechanism for converting the rotational motion of the output shaft 35 into the linear reciprocating motion of the valve shaft 2 between the output shaft 35 of the electric actuator and the valve shaft 2 that is the valve shaft of the poppet valve. I have.
The conversion mechanism includes a plate-like plate cam 5 that can rotate integrally with the output shaft 35, a follower 91 that is movably inserted into a cam slot (cam groove) 83 of the plate cam 5, and the follower 91. A pivot pin (support shaft) 92 that receives the driving torque of the motor M from the plate cam 5 and reciprocally drives the valve shaft 2 in the axial direction thereof is provided.

When the poppet valve is in the fully closed position, the rotational position (cam angle) of the plate cam 5 is in the fully closed state (cam fully closed position). When the poppet valve is in the fully open position, the rotational position (cam angle) of the plate cam 5 is in the fully open state (cam fully open position). Further, the plate cam 5 has two first and second cam protruding pieces 84 and 85 which are arranged to face each other with a predetermined space (cam slot 83) therebetween, and these first and second cam protruding pieces. A cam connecting portion 86 and the like for connecting the base end portions 84 and 85 are provided.
The plate cam 5 has an annular input portion that surrounds the outer periphery of the medium diameter portion of the output shaft 35 in the circumferential direction. A square hole-shaped fitting hole is formed through the input portion. As a result, the plate cam 5 is fixed in a state in which the plate cam 5 is prevented from rotating at the middle diameter portion of the output shaft 35. Further, the input portion of the plate cam 5 is sandwiched between the step (annular step surface) of the output shaft 35 and the annular end surface of the metal collar 93, and is a predetermined axial distance from the output gear 33. It is separated and fixed to the outer periphery of the medium diameter portion of the output shaft 35.

The plate cam 5 is provided with a fan-shaped output part so as to partially surround the periphery of the input part. A curved cam slot 83 corresponding to the poppet valve operation pattern (the poppet valve lift amount with respect to the rotation angle (cam angle) of the plate cam 5) is formed through the output portion in the plate thickness direction of the plate cam 5. Has been.
The plate cam 5 or an interlocking member (the output gear 33, the output shaft 35, the output gear lever 94, etc.) connected to the plate cam 5 so as to be integrally rotatable is engaged with a fully open stopper 95 which is a mechanical (fixed) stopper. A fully open stopper portion 96 is integrally provided.

As shown in FIG. 11 and FIG. 14A, the plate cam 5 is “motor of electric actuator” when the poppet valve of the EGR control valve is fully closed (closed) when the motor M is energized (ON). When the poppet valve is fully closed (closed) using the “M driving torque + the biasing force of the return spring 6 (spring force)”, the follower 91 of the conversion mechanism rotates to the valve body closing side (valve closing direction). It is driven and positioned on the back side (cam connecting portion 86) of the cam slot 83. The plate cam 5 uses only “the urging force (spring force) of the return spring 6” when the poppet valve of the EGR control valve is fully closed (closed) when the energization of the motor M is stopped (OFF). When the poppet valve is urged in the fully closing direction, the follower 91 moves to the valve body closing side (valve closing direction) and is positioned on the back side (cam connecting portion 86) of the cam slot 83.
Further, as shown in FIG. 11 and FIGS. 14B and 14C, the plate cam 5 is provided with an “electric actuator” when the poppet valve of the EGR control valve is opened when the motor M is energized (ON). When the poppet valve is opened using the “drive torque of the motor M”, the follower 91 of the conversion mechanism is rotationally driven to the valve body opening side (the valve opening direction) to open the cam slot 83 (the cam connecting portion). Position on the opposite side of 86).

The output gear lever 94 is insert-molded inside the output gear 33 made of synthetic resin. The output gear lever 94 is formed with a fitting hole having a two-sided width (a structure for preventing the output shaft 35 from rotating idly and a structure for preventing the rotation). Accordingly, the output gear 33 is fixed in a state in which the output gear 33 is prevented from rotating around the small diameter portion of the output shaft 35 via the output gear lever 94.
The full-open stopper 95 is a shaft of the full-open stopper 95 so as to project into the recess from the end surface of the outer wall portion of the gear case 16 of the housing 7 (a cylindrical peripheral wall portion surrounding the periphery of the recess that houses the electric actuator). The part is screwed and fixed. The full-open stopper 95 has not only a function as a full-open position stopper of the plate cam 5 but also a function as a valve full-open position stopper that defines the full-open position (full lift amount) of the poppet valve.

Here, when the drive DUTY value applied to the motor drive circuit is changed from the minimum value (DUTY = 0%) to the maximum value (DUTY = 100%), from the fully closed position to the fully open position of the valve body 1 of the poppet valve. The opening side operation is performed (see FIG. 13). Further, when the drive DUTY value applied to the motor drive circuit is changed from the maximum value (DUTY = −0%) to the minimum value (DUTY = −100%), the fully open position of the valve body 1 of the poppet valve is fully closed. Close side operation is performed (see FIG. 13).
Further, in the EGR control valve of this embodiment, the rotation of the output shaft 35 of the gear train to the valve body closing side is regulated by a mechanical (fixed) stopper (not shown). A backlash range (valve fully closed but with backlash) from "fully closed angle of cam 5" to "fully closed position immediately before valve body 1 of poppet valve starts to open" is provided.

  As described above, in the ECU 3 used as the fully closed position learning device of the present embodiment, first, as a drive DUTY value for the motor drive circuit, a predetermined first DUTY value that generates a drive torque toward the valve body closing side is first used. Set and supply electric power (motor driving current or motor applied voltage) corresponding to the first DUTY value to the inner conductor (armature coil, etc.) of the motor M, and the poppet valve (valve body 1, valve shaft 2) Energize toward the body closing side (first control process). Next, the temperature of the motor M is adjusted to an arbitrary temperature by the heat generated by the motor drive current to the armature coil of the motor M while maintaining the state of the first control process for a predetermined time or longer (second control process). .

Next, when the temperature of the motor M is adjusted to an arbitrary temperature, the driving DUTY value for the motor driving circuit is “over the driving torque that eliminates the backlash between the gear train and the plate cam 5” and “poppet” A predetermined second DUTY value that satisfies both conditions (two conditions) of the valve (valve body 1 and valve shaft 2 below the drive torque at which the valve does not open) is set, and the second DUTY is set for the armature coil of the motor M. Electric power (motor drive current or motor applied voltage) corresponding to the value is supplied to perform fully closed learning of the poppet valve (third control process).
As described above, the fully closed position learning device of the present embodiment has the same effects as those of the first and second embodiments.

[Modification]
In this embodiment, the example of applying the fully closed position learning device of the present invention to the fully closed position learning device of the poppet valve incorporated in the EGR control valve of the EGR system is shown. The present invention may be applied to a valve fully closed position learning device incorporated in an exhaust throttle valve of an exhaust system or an intake throttle valve of an intake system.
Further, the fully closed learning command may be executed every time the engine is started, or may be output when the engine is operated, that is, when EGR is cut and when EGR gas is introduced. It may be output only once a year, once a year, at regular inspections, and at vehicle inspections.
Further, it may be output every time the travel distance of a vehicle such as an automobile reaches a predetermined travel distance (for example, every 10 to 5000 km), or at any setting of an operator such as a driver (for example, a dedicated switch (When the switch is turned on, when an existing switch is pressed for a long time, or when a plurality of switches are pressed simultaneously).

Further, as the intake throttle valve or the intake control valve, a throttle valve, a tumble control valve, a swirl control valve, or the like can be considered.
Further, examples of the exhaust throttle valve or the exhaust control valve include a waste gate valve, a scroll flow path switching valve, an exhaust flow control valve, an exhaust pressure control valve, and an exhaust switching valve.
Poppet valves are used as the EGR control valve and exhaust control valve body. By using a conversion mechanism between the valve and the shaft, butterfly valves, flap valves, plate valves, rotary valves, etc. A rotary valve may be employed. A double poppet valve may be employed.

Moreover, you may employ | adopt the poppet valve which comprised the valve body 1 and the valve shaft 2 by the integral component. Moreover, although the poppet valve is adopted as the valve constituting the valve body of the EGR control valve, a double poppet valve may be adopted. Moreover, you may use the operating rod extended in an axial direction instead of the valve shaft 2 as a valve shaft of a valve.
Further, as the internal combustion engine (engine), a multi-cylinder gasoline engine may be used instead of the multi-cylinder diesel engine. Moreover, you may apply to a single cylinder engine.

M motor (power source of electric actuator)
1 Valve body (valve body) of poppet valve
2 Valve shaft (valve shaft) of poppet valve
3 ECU (learning control means)
4 Scotch yoke 5 Plate cam 6 Return spring 8 Rotation angle sensor 18 Valve seat 23 Channel hole (valve hole)

Claims (11)

(A) A valve body (1) that opens and closes a flow path (23) communicating with a cylinder of the internal combustion engine, and a valve shaft that supports the valve body (1) and extends in the axial direction of the valve body (1) ( 2)
Valves (1, 2) capable of reciprocating in the axial direction of the valve body (1) and the valve shaft (2);
(B) When supplied with electric power, the motor (M) that generates torque for driving the valves (1, 2) to the valve body opening side or the valve body closing side, and the torque of the motor (M) is transmitted to the valve (1 2) A gear train (31 to 35) transmitted to the side, and a conversion mechanism (4) for converting the rotational motion of the output shaft (35) of the gear train (31 to 35) into the linear motion of the valves (1, 2). Actuators (M, 4, 5, 10, 29-38) having 5, 10, 36-38);
(C) a sensor (8) that outputs a signal corresponding to a rotation angle of the output shaft (35) or the conversion mechanism (4, 5, 10, 36 to 38);
(D) learning control means (3) for performing fully closed learning of the valves (1, 2), which associates the fully closed position of the valves (1, 2) with the output signal of the sensor (8); In the fully closed position learning device provided,
The learning control means (3)
A first process of supplying electric power capable of generating torque toward the valve body closing side to the motor (M), and urging the valves (1, 2) toward the valve body closing side; ,
A second process for adjusting the temperature of the motor (M) to an arbitrary temperature by heat generated by supplying power to the motor (M) while maintaining the state of the first process for a certain period of time;
After the completion of the second process, the motor (M) has a torque greater than the torque that eliminates backlash between the gear train (31 to 35) and the conversion mechanism (4, 5, 10, 36 to 38). And a third process for supplying the electric power capable of satisfying both the conditions of the torque below the torque at which the valves (1, 2) do not open and performing the fully closed learning of the valves (1, 2); A fully-closed position learning device characterized in that The fully closed position learning device according to claim 1,
In the first process,
A first setting means for setting a first duty value for generating torque toward the valve element closing side as a driving duty value for the motor (M);
A fully closed position learning device that applies the first duty value to the motor (M) and biases the valves (1, 2) toward the valve body closing side. In the fully closed position learning apparatus according to claim 1 or 2,
In the second process,
The temperature of the motor (M) is adjusted to an arbitrary temperature by heat generated by the drive current or applied voltage to the motor (M) while maintaining the state of the first treatment for a certain time or more. Closed position learning device. In the fully-closed position learning apparatus according to any one of claims 1 to 3,
In the third process,
After the process of adjusting the temperature of the motor (M) to an arbitrary temperature is completed,
The driving duty value for the motor (M) is equal to or greater than the torque that eliminates backlash between the gear train and the conversion mechanism (4, 5, 10, 36 to 38), and the valves (1, 2) are opened. Having a second setting means for setting a second duty value that satisfies both conditions of the torque not to be output or less,
A fully-closed position learning device that applies the second duty value to the motor (M) and performs fully-closed learning of the valves (1, 2). In the fully closed position learning device according to any one of claims 1 to 4,
The conversion mechanism is coupled to the output shaft (35) so as to be integrally rotatable, a lever (36) protruding outward in the radial direction of the output shaft (35), and an eccentric pin ( 37), the follower (38) rotatably supported on the outer periphery of the eccentric pin (37), and the torque of the motor (M) from the eccentric pin (37) via the follower (38). Receiving and reciprocatingly moving in the axial direction of the valve shaft (2), and having a yoke (4) connected to the valve shaft (2) so as to be movable together,
The fully closed position learning device according to claim 1, wherein the lever (36) holds the eccentric pin (37) at a position eccentric from a rotation center axis of the output shaft (35). In the fully closed position learning apparatus according to claim 5,
The yoke (4) has a yoke groove (10) into which the follower (38) can be inserted,
The fully closed position learning device characterized in that the follower (38) is rotatably supported on the outer periphery of the eccentric pin (37) and is slidably inserted into the yoke groove (10). . In the fully closed position learning apparatus according to claim 5 or 6,
The fully closed position learning device according to claim 1, wherein the sensor (8) outputs a signal corresponding to a rotation angle of the lever (36). In the fully closed position learning device according to any one of claims 1 to 4,
The conversion mechanism has a cam (5) that can rotate integrally with the output shaft (35),
The fully closed position learning device according to claim 1, wherein the cam (5) has a slot (83) having a shape corresponding to an operation pattern of the valves (1, 2). The fully closed position learning device according to claim 8,
The conversion mechanism receives the torque of the motor (M) from the cam (5) via the follower (91) movably inserted into the slot (83) and the follower (91). A fully closed position learning device comprising a support shaft (92) for reciprocatingly driving the valve shaft (2) in the axial direction thereof. In the fully closed position learning apparatus according to claim 8 or 9,
The fully closed position learning device according to claim 1, wherein the sensor (8) outputs a signal corresponding to a rotation angle of the cam (5). The fully closed position learning device according to any one of claims 1 to 10, wherein the flow path (23) through which the exhaust discharged from the cylinder of the internal combustion engine flows is formed in an annular seat. (18)
A fully-closed spring comprising a spring (6) for generating a biasing force for biasing the valve (1, 2) against the seat (18) or the valve body closing side. Position learning device.

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