JP4962789B2 - Intake control device - Google Patents

Description

  The present invention relates to an intake control device for an internal combustion engine that adjusts an intake air amount to the internal combustion engine in accordance with a load state of the internal combustion engine and an open / close state of an intake valve of the internal combustion engine.

  Adjusting the intake air amount in a timely manner according to the load condition of the internal combustion engine and the open / close state of the intake valve enhances the intake pulsation, especially in the low and medium speed ranges, thereby improving the engine output by increasing the volume efficiency and combustion by increasing the intake flow velocity This will lead to improvements and smoke reduction, and is expected to improve fuel economy. Conventionally, as a technique for adjusting the amount of intake air, a method of providing an intake control valve upstream of the intake valve in the intake passage and appropriately opening and closing the intake control valve has been used. The intake control valve according to such a method is provided in the intake passage with a predetermined rotatable clearance, and needs to close the intake passage when the valve is closed. Moreover, it is necessary to repeat valve closing, valve opening, and valve closing at high speed for each cycle of the internal combustion engine. Therefore, it is necessary to dispose the intake control valve with high accuracy in the intake passage, and it is necessary to suppress the influence of the rotational inertia. As a technique for reducing such rotational inertia, there is an intake control device for an internal combustion engine (for example, Patent Document 1).

  An intake control valve included in an intake control device for an internal combustion engine described in Patent Document 1 is formed in a racetrack shape, and is opened and closed around a long axis when performing intake control. The intake control valve formed in such a racetrack shape can reduce the distance from the rotation axis to the farthest outer circumference compared to the intake control valve formed in a circular shape with the same area. Can be reduced. Therefore, it is possible to improve the responsiveness of the intake control valve when opening and closing the intake passage.

JP-A-8-218906 (paragraph numbers 0008, 0011, etc.)

  Although the intake control valve has a racetrack shape as described above, it is possible to reduce the rotation inertia and improve the response of the intake control valve when opening and closing the intake passage. Is required to have a higher responsiveness. As one method for improving the responsiveness of the intake control valve, for example, a method of increasing the output of a rotary motor that rotationally drives the intake control valve can be considered. However, increasing the output of the rotary motor may increase the size of the rotary motor, which may increase the cost of the intake control device. Alternatively, it is possible to use a rotary motor of the same size. However, in this case, since the current to be supplied to the rotary motor becomes large, it may be necessary to change to a rotary motor having a large rated current, and in particular, the components constituting the control unit that controls the current are rated. There is a risk of changing to a part having a large current.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an intake control device capable of high-speed response without increasing the cost and without having to increase the energized current. .

  The characteristic configuration of the intake control device according to the present invention for achieving the above object is to adjust an intake air amount to the internal combustion engine according to a load state of the internal combustion engine and an open / close state of the intake valve of the internal combustion engine, A valve that is rotatably provided in the intake passage and adjusts an opening area of the intake passage, and an inner peripheral surface thereof serves as the intake passage, and the intake passage is fully closed by the valve along the rotation direction of the valve. A cylindrical bore having a dead zone region for maintaining the predetermined angle and accommodating the valve, and a valve stop region in which the dead zone region is provided on the far side in the fully closed state, and the valve The valve acceleration / deceleration region is adjacent to the stop region and adjacent to the fully closed state.

  With such a characteristic configuration, since a predetermined clearance is ensured at any position in the dead zone, the sealing performance is not affected. Here, as an index of responsiveness from the closed state to the open state of the valve, it can be considered as the time from when the valve escapes from the dead zone region to the fully open position where the full open state is reached. The speed of the valve gradually accelerates due to the influence of rotational inertia after energizing a rotary motor or the like that changes the open / close state of the valve. When the valve is closed, the valve is stopped in the valve stop region provided at the far end of the fully closed state of the dead zone, and the stop position is set to the valve start position at the time of opening the valve. The region can be a valve acceleration / deceleration region.

  Accordingly, since the speed of the valve can be accelerated while passing through the valve acceleration / deceleration region until the valve escapes from the dead zone region, the time until the intake passage is fully opened by the valve can be shortened. . That is, it is possible to improve responsiveness during intake, which is particularly important for valve opening control. Also, when performing control from the fully open state to the fully closed state, the speed of the valve can be reduced in the valve acceleration / deceleration region provided on the near side of the dead zone in the fully closed state. Therefore, since it is not necessary to reduce the speed of the valve before the valve enters the valve acceleration / deceleration region, the time required for the transition from the fully open state to the fully closed state can be shortened. That is, it is possible to improve the responsiveness related to the valve closing control.

  Further, it is preferable that the valve stop region is configured to include a cogging stable position of a rotary motor that drives the valve.

  With such a configuration, it is easy to stop and hold the valve at a position where the intake passage is closed. Therefore, it is possible to easily perform valve closing control of the intake passage.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a view schematically showing an internal combustion engine 100 provided with an intake air control device 1 according to the present invention. The intake control device 1 is provided in an internal combustion engine 100 such as an automobile engine. The intake control device 1 adjusts the amount of intake air introduced into the combustion chamber by adjusting the opening area of the intake passage 101 of the internal combustion engine 100.

  As indicated by the white arrow in FIG. 1, the intake air is introduced into the combustion chamber through the intake valve 102 together with the fuel injected from the injector 106 as the piston 105 of the internal combustion engine 100 descends. As the piston 105 of the internal combustion engine 100 rises, the exhaust gas after combustion passes through the exhaust passage 104 through the exhaust valve 103 and is recirculated as necessary, and finally discharged from the internal combustion engine 100 to the outside. . In this way, the valve 4 adjusts the flow rate of the intake air that is guided to the combustion chamber through the intake passage 101.

  The optimum flow rate of the intake air introduced into the combustion chamber varies depending on the engine speed and load. By controlling the opening and closing of the valve 4 in synchronization with the opening and closing timing of the intake valve 102, the volumetric efficiency and output when the engine is in a low and medium speed range and a high load can be improved. In particular, when the engine is in a low speed region and a low load, combustion improvement can be expected by restricting the valve 4 and increasing the flow rate of the intake air.

  The intake control device 1 mainly includes a body 2, a bore 3, a valve 4, a shaft 5 and a bolt 7. That is, the bore 3 is provided inside the body 2, the body 2 and the bore 3 constitute a part of the intake passage 101, and the valve 4 is provided inside the bore 3. Here, the valve 4 passes through the bore 3 and is fixed to a shaft 5 provided on the body 2 with a bolt 7. Therefore, the valve 4 is rotatably supported by the shaft 5 and the opening area of the intake passage 101 can be adjusted. One end of the shaft 5 is connected to the rotary motor 50 (details will be described later). The bore 3 has an inner circumferential surface serving as an intake passage 101 and is formed of a cylindrical member that houses the valve 4. The body 2 holds the bore 3 from the outer peripheral surface and both end surfaces in the axial direction, communicates with the bore 3, and forms an intake passage 101.

  FIG. 2 is an enlarged cross-sectional view of the bore 3, and particularly shows the valve 4 in a fully open state and a fully closed state. FIG. 2A shows a sectional view of the bore 3 when the valve 4 is fully opened. As shown in FIG. 2A, the valve 4 is rotatably supported by a shaft 5 that passes through the intake passage 101 and adjusts the opening area of the intake passage 101. The shaft 5 is connected to the rotary motor 50 by a universal joint (not shown) or the like in the extending direction. The rotary motor 50 is controlled by a control unit (not shown) based on the engine load, the control state of the intake valve 102 of the engine, and the like.

  The bore 3 has an intake passage 101 on its inner peripheral surface, and the fully closed state of the intake passage 101 by the valve 4 is a predetermined angle along the rotation direction of the valve 4 as shown in FIGS. 2 (b) and 2 (c). It has a dead zone region 6 made of a concave shape for maintaining over θ, and is made of a cylindrical member that houses the valve 4. The body 2 includes a member that holds the bore 3 from one end face side and the outer peripheral face side and communicates with the bore 3 to form the intake passage 101.

  The bore 3 is held on its outer peripheral surface via a body 2 and an O-ring (elastic seal member) 8. The O-ring 8 ensures airtightness in the intake passage 101 and absorbs rattling that occurs between the body 2 and the bore 3. The body 2 and the bore 3 are arranged coaxially with respect to the shaft 5, and the valve 3 is fastened to the shaft 5 passing through the center of the valve 3 by a bolt 7.

  As described above, the dead zone region 6 is formed in a concave shape on the inner surface of the bore 3. When the disk-shaped valve 4 rotates and the end of the disk-shaped valve is located in the dead zone 6, the intake passage 101 is fully closed by the valve 4. For example, even when the valve 4 is in a rotational position perpendicular to the direction along the intake passage 101, that is, in the center position, the end of the valve 4 is located in the dead zone region 6. Closed. The dead zone region 6 is formed in a concave shape so that the front and rear θ / 2 (± θ / 2) in the rotation direction with respect to the central position is the dead zone region 6. This concave shape is formed by cutting the inner surface of the bore 3 so as to be arcuate when viewed along the shaft 5 in accordance with the locus of the end of the rotating valve 4. Therefore, the inner surface of the bore 3 and the end portion of the valve 4 always have the same clearance in the front and rear θ / 2 (± θ / 2) when the valve 4 is in the vertical rotation position (center position). The fully closed state of the passage 101 is maintained. The predetermined angle θ is preferably 20 to 40 degrees (± 10 to 20 degrees), for example. It is preferable that the bore 3 and the valve 4 have a particularly small clearance when the valve is closed to reduce the amount of intake air leakage. In addition, it is preferable to suppress as much as possible the influence of the rotary inertia on the valve closing state of the intake passage 101 when the leak amount is reduced in this way.

  The valve 4 has substantially the same shape as the orthogonal cross section of the intake passage 101. As described above, since the dead zone 6 needs to be formed in a concave shape, the bore 3 is formed, for example, with a slight increase in thickness in the vertical direction shown in FIG. For this reason, the intake air flowing from the body 2 toward the bore 3 may collide with the end face of the bore 3 and become resistance. Therefore, it is preferable that a chamfered portion 9 is provided at the end of the bore 3 in order to reduce this resistance.

  As described above, FIG. 2A shows a cross-sectional view of the bore 3 when the valve 4 is fully opened. In the fully open state, the disk-shaped valve 4 is in a rotational position parallel to the direction along the intake passage 101 so that the opening area through which the intake air communicates with the bore 3 is maximized in the intake passage 101. These are fixed by a rotary motor 50 (not shown).

  Here, the rotation range of the valve 4 will be described with reference to the drawings. FIG. 3 is a diagram schematically showing the rotation range of the valve 4. As described above, the valve 4 rotates about the shaft 5 as an axis. In FIG. 3, the center point M corresponds to the axis. Further, an intake passage 101 is provided along the horizontal direction (A-A line) in FIG. 3, and an area of ± θ / 2 with respect to the CC line corresponds to the dead zone 6.

  As shown in FIG. 2A, in order for the valve 4 to fully open the intake passage 101, the shaft 5 is rotated around the center point M by the rotary motor 50, and on the line AA in FIG. The valve 4 is controlled to be positioned. On the other hand, in order to close the intake passage 101, the valve 4 needs to be positioned in the dead zone 6 as described above. That is, as shown in FIG. 2B and FIG. 2C, the valve 4 needs to be rotated within θ forming the dead zone region 6. Therefore, in FIG. 3, when the valve 4 is located in the valve opening region I, the intake passage 101 is at least in a valve open state.

  Here, the dead zone region 6 includes a valve stop region III provided on the far side of the fully closed state and a valve acceleration / deceleration region II adjacent to the valve stop region III on the near side of the fully closed state. As described above, if the valve 4 is located in the dead zone 6, the intake passage 101 is fully closed. Also in the dead zone 6, a valve stop region III for stopping the valve 4 is provided particularly on the back side, that is, the side away from the valve opening region I, and particularly on the front side of the dead zone 6, that is, the valve stop region III and the valve opening region. Between the region I, a valve acceleration / deceleration region II for accelerating / decelerating the valve 4 is provided. The intake control device 1 stops the valve 4 in the valve stop region III when stopping the valve 4 in the fully closed state of the intake passage 101.

  When the intake control device 1 changes the intake passage 101 from the fully closed state to the fully open state (corresponding to the state of FIG. 2A), the valve 4 that starts from the valve stop region III is in the valve acceleration / deceleration region II. It is accelerated by. Therefore, when the valve 4 escapes from the valve acceleration / deceleration region II, the speed of the valve 4 is accelerated, so that the time required for the valve 4 to pass through the valve opening region I can be shortened. Therefore, the responsiveness from the fully closed state on the BB line to the fully open state on the AA line can be improved.

  On the other hand, when the intake passage 101 is changed from the fully open state to the fully closed state, the valve 4 is decelerated in the valve acceleration / deceleration region II, and the valve 4 stops in the valve stop region III. Therefore, when the valve 4 is in the valve opening region I, it is not necessary to decelerate more than necessary, so that the time required for the valve 4 to pass through the valve opening region I can be shortened. Therefore, the responsiveness from the fully open state on the AA line to the fully closed state on the BB line can be improved. In this case, as shown in FIG. 2 (c), control is performed so as to stop at the innermost position of the valve stop region III.

  As described above, the intake control device 1 is controlled so that the valve 4 is stopped at a position within the valve stop region III of the dead zone region 6 when the intake passage 101 is fully closed. The control of the stop position can be realized by including the cogging stable position of the rotary motor 50 that drives the valve 4 in the valve stop region III.

  Here, the cogging stable position appears at every predetermined angle due to the interaction between the iron core (slot 16) of the rotary motor 50 and the permanent magnet 22 when the rotor 52 is rotated with the rotary motor 50 in a non-energized state. It is a stable position. Hereinafter, the stable cogging position will be described with reference to the drawings. FIG. 4 is a cross-sectional view of the rotary motor 50 that drives the valve 4. In FIG. 4, the rotary motor 50 is a six-pole motor including a stator 51 and a rotor 52 arranged concentrically in the internal space of the stator 51 via a rotation gap. The stator 51 includes a stator core 19 that includes nine slots 16 and yokes 18 that connect the nine slots 16 and the teeth 17 formed between the slots. Each of the teeth 17 includes a stator core 19. Each stator coil 20 is wound and configured.

  On the other hand, the rotor 52 includes a rotor core 21 formed by laminating a rotor core sheet made of a high permeability material such as iron or an electromagnetic steel plate. The rotor core 21 is provided with six magnet insertion holes 23 in the circumferential direction on the center side of the rotor 52 for inserting permanent magnets 22 extending in the axial direction in the vicinity of the outer peripheral portion thereof. And it inserts in each magnet insertion hole 23 so that the polarity of the permanent magnet 22 adjacent to the circumferential direction may become a mutually reverse polarity. That is, the permanent magnets 22 facing the outer peripheral surface of the rotor 52 are inserted into the magnet insertion holes 23 so that the polarities thereof are alternated. Then, both sides of each permanent magnet 22 are filled with a nonmagnetic material such as an air layer or resin.

In the rotary motor 50 thus formed, when a current controlled by a switching circuit (not shown) or the like flows through each stator coil 20 of the stator 51, a rotating magnetic field is generated inside the stator 51, and this rotating magnetic field causes The rotor 52 provided with the permanent magnet 22 rotates about the rotation shaft 25. The rotary shaft 25 is connected to a shaft 5 to which the valve 4 is fixed via a universal joint (not shown) or the like. Therefore, the rotation of the valve 4 is controlled according to the rotational power output from the rotary motor 50 or the cogging torque.

  On the other hand, as shown in FIGS. 5A, 5 </ b> B, and 5 </ b> C, the rotating motor 50 changes the flow of magnetic flux depending on the positional relationship between the rotor 52 and the stator 51, and changes cogging torque due to the change in magnetic flux. Will occur. That is, when the teeth 17 of the stator 51 and the salient poles 24 of the rotor 52 are in the positional relationship shown in FIG. 5A, the magnetic resistance on the left side of the salient poles 24 is larger than that on the right side. Produces a clockwise torque. On the other hand, when the teeth 17 of the stator 51 and the salient poles 24 of the rotor 52 are in the positional relationship shown in FIG. 5B, the left and right magnetic resistances of the salient poles 24 are equal, and no rotational force is generated. Further, when the teeth 17 of the stator 51 and the salient pole 24 of the rotor 52 are in the positional relationship of FIG. 5C, the magnetic resistance on the right side of the salient pole 24 is larger than that on the left side. Produces counterclockwise torque.

  Thus, for example, when the teeth of the stator 51 of the rotary motor 50 are 9 slots and the permanent magnet 22 of the rotary motor 50 has 6 poles (so-called 6 poles 9 slots), the cogging stable position is 20 Appears every time. By configuring such a stable cogging position so that the valve 4 is included in the valve stop region III of the dead zone 6, the valve 4 can be stopped in the dead zone 6 without energizing the rotary motor 50. It is possible to stop at the position of region III.

  When the valve 4 is stopped at the cogging stable position as described above, the valve 4 is started from the valve stop region III of the dead zone region 6 when the intake passage 101 is changed from the fully closed state to the fully open state. It will be. To start the valve 4 from the valve stop region III and open the intake passage 101, first, the stator coil 20 of the rotary motor 50 is energized. On the other hand, a valve acceleration / deceleration region II is provided between the valve stop region III of the above-described dead zone region 6 and the valve opening region I in which the intake passage 101 is at least in a valve open state. Therefore, the valve 4 always passes through the valve acceleration / deceleration region II when the intake passage 101 is switched to the valve open state. The valve 4 is gradually accelerated until it escapes from the valve acceleration / deceleration region II, and the rotation speed increases. Therefore, high-speed response can be ensured in switching from the fully closed state to the fully open state.

Next, when the valve 4 is started from the valve stop region III of the dead zone 6, the time from when the rotary motor 50 is energized until the valve 4 exits the dead zone 6, and when the dead zone 6 is escaped. The relationship with the speed of the valve 4 will be described with reference to FIG. First, between the time t ₋₁ and the time t ₀ , the rotary motor 50 is not energized. Therefore, as described above, the valve 4 is stopped in the valve stop region III of the dead zone region 6 including the cogging stable position by the iron core (slot 16) and the permanent magnet 22, and the intake passage 101 is fully closed.

Then, when the valve 4 is stopped at the center position of the dead zone 6, assuming that electric power is supplied to the rotation motor 50, time t ₁ required for the valve 4 to escape dead zone 6, the valve 4 is deadband It is assumed that the speed when escaping from the region 6 is v ₁ . On the other hand, when the valve 4 is stopped at the farthest position of the valve stop region III in the dead zone 6 and the rotation motor 50 is energized, the time required for the valve 4 to escape from the dead zone 6 is t. ₂ , the speed at which the valve 4 escapes from the dead zone 6 is v ₂ . Thus, the speed at which the valve 4 escapes from the dead zone 6, that is, the speed of the valve 4 when switching from the fully closed state to the fully open state greatly depends on the starting position of the valve 4. Therefore, by starting the valve 4 from the valve stop region III of the dead zone region 6, particularly from the deepest position, the speed of the valve 4 after escape from the dead zone 6 can be further increased. For this reason, it is possible to realize an intake control device capable of high-speed response without increasing the cost and without having to increase the current rating of the rotary motor 50. Incidentally, in comparison with the time t ₁ when the valve 4 is stopped at the center position of the dead zone 6, longer towards the time t ₂ when the valve 4 has been stopped at the innermost position of the dead zone 6 It has become. The responsiveness related to the opening / closing control of the intake passage 101 is determined by the time required for the intake passage 101 to be fully opened after the intake passage 101 is opened, so that the time required for escape (for example, t ₂ ) If the time is shorter than the time required for valve opening / closing control of the intake valve 102 of the engine 100, there is no problem. Therefore, the responsiveness related to the opening / closing control depends on the speed at which the valve 4 escapes from the dead zone 6. In the dead zone 6, the valve 4 is stopped and started at a deeper position. Is preferred.

[Other Embodiments]
In the above embodiment, the quantity relationship between the valve 4 of the intake control device 1 and the cylinder of the internal combustion engine 100 is not limited. When the internal combustion engine 100 has a plurality of cylinders, the intake control device 1 can be provided with the valve 4 in each cylinder, and intake control can be performed on several cylinders with one valve 4. It is also possible to do this.

  In the above embodiment, in the description of the stable cogging position, the description has been given assuming that the rotary motor 50 has a configuration of 6 poles and 9 slots. However, the scope of application of the present invention is not limited to this. For example, 8 poles and 9 slots may be used, 10 poles and 9 slots, 10 poles and 12 slots, 14 poles and 12 slots, and other combinations are also possible. Even in such a case, it is naturally possible to configure the cogging stable position to be included in the valve stop region III of the dead zone 6 according to the angle at which the cogging stable position appears.

  In the above embodiment, the dead zone region 6 is configured by a valve stop region III provided on the far side of the fully closed state and a valve acceleration / deceleration region II adjacent to the front side of the fully closed state with respect to the valve stop region III. As explained. It is preferable to set the respective ranges of the valve acceleration / deceleration region II and the valve stop region III so that at least the range of the valve acceleration / deceleration region II is larger than the range of the valve stop region III. With such a configuration, it is possible to sufficiently accelerate or decelerate the valve 4 in the large valve acceleration / deceleration region II, and it becomes easy to improve the responsiveness associated with the opening / closing control.

  In the above embodiment, in the description of the stable cogging position, it is assumed that the stable position appears at every predetermined angle due to the interaction between the iron core (slot 16) provided in the stator 51 and the permanent magnet 22 provided in the rotor 52. explained. However, the scope of application of the present invention is not limited to this. Of course, the present invention can be applied even to the rotary motor 50 formed so that the stator 51 is provided with the permanent magnet 22 and the rotor 52 is provided with the iron core (slot 16).

The figure which showed typically the internal combustion engine provided with the intake control device Diagram showing the cross section of the bore when the valve is fully open Schematic illustration of valve rotation range The figure which shows the section of the rotary motor which drives the valve Diagram showing stable cogging position Diagram showing the speed of the valve when exiting the dead zone area

Explanation of symbols

1: intake control device 2: body 3: bore 4: valve 5: shaft 7: bolt 8: O-ring 100: internal combustion engine 101: intake passage 102: intake valve 103: exhaust valve 104: exhaust passage 105: piston 106: injector

Claims (1)

An intake control device that adjusts an intake air amount to the internal combustion engine according to a load state of the internal combustion engine and an open / close state of an intake valve of the internal combustion engine,
A valve rotatably provided in the intake passage, and adjusting an opening area of the intake passage;
An inner circumferential surface serves as the intake passage, and a cylinder that houses the valve with a dead zone region for maintaining the fully closed state of the intake passage by the valve over a predetermined angle along the rotation direction of the valve. And a bore with a shape,
The dead zone region is composed of a valve stop region provided on the back side of the fully closed state, and a valve acceleration / deceleration region adjacent to the front side of the fully closed state with respect to the valve stop region ,
The intake control device , wherein the valve stop region includes a cogging stable position of a rotary motor that drives the valve .

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