Abstract:
The present invention provides a compact throttle valve device with good valve responsiveness and small unnecessary vibrations, an engine, and a vehicle. A slotless brushless motor-driven throttle valve device has a throttle body provided with a tubular portion in which an intake air passage is formed, a throttle valve disposed in the tubular portion, and a slotless brushless motor serving as a drive motor for performing opening/closing drive for the throttle valve. The throttle body housing has a hole portion into which a fixing member for fixing the throttle body to a member to be attached is inserted. The hole portion is formed in the vicinity of the outer circumferential portion of the tubular portion. The compact, narrow slotless brushless motor is disposed near the hole portion formed in the throttle body, and the throttle valve device is very compact.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a U.S. national phase application under 35 U.S.C. §371 of International Patent Application No. PCT/JP2015/076249, filed Sep. 16, 2015, and claims benefit of priority to Japanese Patent Application No. 2014-191786, filed Sep. 19, 2014. The entire contents of these applications are hereby incorporated by reference. 
     
    
     FIELD OF TECHNOLOGY 
       [0002]    The present invention relates to a slotless brushless motor-driven throttle valve device, engine, and vehicle. 
       BACKGROUND 
       [0003]    There are known motor actuators and motor-driven throttle valve devices for internal combustion engines that use such motor actuators (see, for example, Japanese Unexamined Patent Application Publication No. 2007-236037). The throttle valve device for a typical internal combustion engine has a DC cored motor, where the throttle valve is driven by the DC cored motor. 
       SUMMARY 
       [0004]    However, because the DC cored motor is relatively big, the throttle valve device that incorporates the DC cored motor is relatively big. On the other hand, it is desirable to miniaturize the throttle valve devices for internal combustion engines for automobiles, motorcycles (motor scooters), and the like. 
         [0005]    Moreover, because in a throttle valve device that as a DC cored motors the moment of inertia of the rotor of the DC cored motor is relatively large, sometimes the valve responsiveness is not good. More specifically, when a driving signal for opening or closing a valve is inputted into the DC cored motor, arriving at the prescribed valve angle may take some time, or the angle may overshoot, or chattering may occur when opening or closing the valve, which may reduce fuel consumption. 
         [0006]    Moreover, a typical throttle valve device has a structure wherein the intake manifold or engine main unit portion (the main unit portion of the internal combustion engine), or the like, is secured through attaching bolts (securing members) to an attaching member, and when the engine operates, the engine main unit portion and the throttle valve device vibrate essentially synchronously. 
         [0007]    However, when the DC cored motor is placed at a position that is far from the position of attachment of the securing member, the DC cored motor will have a relatively large moment of inertia (in respect to the position of attachment), and a vibration that is of a greater amplitude than the vibration of the engine main unit portion will act thereon, reducing the service life of the DC cored motor. A throttle valve device wherein the extraneous vibration relative to such a DC cored motor is reduced is desirable. 
         [0008]    In the present invention, the handling of such problems is an example of the problem to be solved. That is, objects are to provide a compact throttle valve device, to provide a throttle valve device with good valve responsiveness, to provide a throttle valve device that reduces extraneous vibration, to provide an engine equipped with such a throttle valve device, and to provide a vehicle equipped with such an engine. 
         [0009]    In order to achieve such an object, the slotless brushless motor-driven throttle valve device of the present invention is equipped with at least the following structures: 
         [0010]    A slotless brushless motor-driven throttle valve device comprising:
       a throttle body equipped with a tubular portion having an air intake passage formed therein;   a throttle valve that is disposed within the tubular portion; and   a slotless brushless motor, as a driving motor for driving the throttle valve open and closed, wherein:   the throttle body has a hole portion into which is inserted a securing member for securing the throttle body to an attaching member;   the hole portion is provided in the vicinity of the outer peripheral portion of the tubular portion; and   the slotless brushless motor is provided in proximity to the hole portion that is provided in the throttle body.       
 
         [0017]    The engine according to the present invention is equipped with the slotless brushless motor-driven throttle valve device according to the present invention, set forth above. 
         [0018]    Moreover, the vehicle according to the present invention equipped the engine according to the present invention, set forth above. 
         [0019]    The present invention can provide a compact throttle valve device. Moreover, the present invention can provide a throttle valve device with good valve responsiveness. Moreover, the present invention can provide an engine that is equipped with this throttle valve device. Furthermore, the present invention can provide a vehicle that is equipped with such an engine. 
     
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         [0020]      FIG. 1  is a perspective diagram illustrating an example of a throttle valve device according to an embodiment according to the present invention. 
           [0021]      FIG. 2  is a front view illustrating an example of a throttle valve device according to an embodiment according to the present invention. 
           [0022]      FIG. 3  is a cross-sectional view illustrating an example of a throttle valve device according to an embodiment according to the present invention. 
           [0023]      FIG. 4  is a cross-sectional view illustrating an example of a slotless brushless motor of a throttle valve device according to an embodiment according to the present invention. 
           [0024]      FIG. 5  is an exploded perspective diagram of a slotless brushless motor of a throttle valve device according to an embodiment according to the present invention. 
           [0025]      FIG. 6  is a conceptual diagram illustrating an example of an internal combustion engine that is equipped with a throttle valve device according to an embodiment according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    The throttle valve device according to an embodiment according to the present invention is an electronically controlled throttle valve device that is equipped with a slotless brushless motor. Moreover, an engine that is equipped with this throttle valve device can be provided. Moreover, a vehicle that is equipped with this engine can be provided. 
         [0027]    Specifically, in the slotless brushless motor, a coil that is formed into a cylinder is disposed within a stator. A magnet that is secured to a rotor is disposed within the coil. The structure is such that the rotor and the magnet are rotated through application of electric power to the coil. A small gap (an air space) is provided between the magnet and the coil, and the slotless brushless motor is compact. That is, the use of a compact slotless brushless motor enables the provision of a compact throttle valve device. 
         [0028]    Embodiments according to the present invention will be explained below, in reference to the drawings. 
         [0029]    While the embodiments of the present invention include the detail in the drawings, there is no limitation thereto. Note that in the explanations of the various drawings below, those parts that are the same as parts already explained will be assigned identical reference symbols, and redundant explanations will be partially omitted. 
         [0030]      FIG. 1  is a perspective diagram illustrating an example of a slotless brushless motor-driven throttle valve device  200  according to an embodiment according to the present invention.  FIG. 2  is a front view illustrating an example of the throttle valve device  200 .  FIG. 3  is a cross-sectional view illustrating an example of the throttle valve device  200 .  FIG. 4  is a cross-sectional view illustrating an example of a slotless brushless motor for the throttle valve device  200 .  FIG. 5  is an exploded perspective diagram of the slotless brushless motor for the throttle valve device  200 .  FIG. 6  is a conceptual diagram illustrating an example of an internal combustion engine that is equipped with the throttle valve device  200 . 
         [0031]    An engine  300  will be explained as an internal combustion engine that incorporates a throttle valve device  200  that is equipped with a slotless brushless motor  100  according to an embodiment according to the present invention (referencing  FIG. 6 ). In the below, the “slotless brushless motor” will be termed simply a “motor.” 
         [0032]    In the present embodiment, the engine  300  as an engine main unit portion  32 , such as a cylinder block, where a fuel injector  34  (a fuel injecting device), an air intake valve, an exhaust valve, a camshaft, a spark plug, a piston, a crankshaft, and the like, are provided in the engine main unit portion  32 , where an intake manifold  31  is provided on the air intake side, and a throttle valve device  200  is secured, through a securing member  41  such as an attaching bolt, to the intake manifold  31 . An air intake tube member  53 , an air filter  52 , and the like, are provided in a tubular portion  21   c  of the throttle valve device  200 . An exhaust manifold  55 , the catalyst  56 , and the like, are provided on the exhaust side of the engine main unit portion  32 . 
         [0033]    A position sensor  60 , for detecting the angle of opening of the throttle valve  22 , is provided on the throttle valve device  200 , where a signal from the position sensor  60  is outputted to an engine controlling unit  61 . An accelerator sensor  62  is connected to the engine controlling unit  61 . The accelerator sensor  62  detects the amount of depression of an accelerator pedal  63 , to output a detection signal to the engine controlling unit  61 . 
         [0034]    The engine controlling unit  61  (ECU) carries out comprehensive control of the engine  300 , as an internal combustion engine. Specifically, the engine controlling unit  61  drives the motor  100  based on a signal, outputted from the accelerator sensor  62 , that indicates the amount of depression of the accelerator pedal  63 , a signal, outputted from the position sensor  60 , that indicates the angle of opening of the throttle valve  22 , and the like, to control the angle of opening of the throttle valve  22 , the timing of ignition by the spark plug, the amount and timing of fuel injection by the fuel injector  34 , and the like. 
         [0035]    The slotless brushless motor-driven throttle valve device  200  according to the embodiment according to the present invention comprises: a throttle body  21  (housing) that is equipped with a tubular portion  21   c  with a valve hole  21   a  is formed as an air intake passage  21   b  therein; a throttle valve  22  that is disposed within the tubular portion  21   c  and that rotates so as to open and close the valve hole  21   a ; a valve rod  25  that supports the throttle valve  22  so as to enable rotation; a slotless brushless motor  100 , as a driving motor for driving the throttle valve  22  open and closed, disposed on the outside of the throttle valve  22 ; a transmission mechanism  23  (a speed reducing mechanism) that is provided with a plurality of gears, or the like, for transmitting, to the valve rod  25  (the throttle rod), the driving force of the motor  100 ; and the like. Moreover, the throttle valve  22  comprises a return spring  24  for maintaining the minimum amount of opening of the throttle valve  22  so as to be essentially constant (referencing  FIG. 1  through  FIG. 3 ). 
         [0036]    As described below, the motor  100  comprises: a long cylindrical housing  1  (a case); a magnet  3 ; a rotary shaft  4  that is supported on the housing  1  so as to be able to rotate; a cylindrical coil  5 ; and the like, wherein: the structure is one wherein the throttle valve  22  can be opened and closed by the rotational force of the rotary shaft  4 . 
         [0037]    A motor  100  is provided on the outside of the valve hole  21   a , with the axial direction of the rotary shaft  4  essentially parallel to the axial direction of the valve rod  25  (the throttle rod). The transmission mechanism  23  (the speed reducing mechanism) is equipped at a side portion on the outside of the valve hole  21   a , so as to be essentially perpendicular to the axial direction of the valve rod  25  and of the motor  100 . 
         [0038]    In the present embodiment, the motor  100  is compact, with a long-thin shape, and the throttle valve device  200  that is equipped with the motor  100  is compact. The respective axial direction lengths Lc and Lm of the coil  5  and the magnet  3  of the motor  100  are less than the total length L of the motor  100 , and greater than the diameter D (referencing  FIG. 5 ) of the housing  1  of the motor  100  (the case). In the present embodiment, the diameter D of the motor  100  is about 20 mm, where the total length L is about 60 mm, and the inner diameter (the inner peripheral diameter) L 2  of the tubular portion  21   c  is about 80 mm, where the maximum outer periphery is about 90 mm. 
         [0039]    Moreover, the housing  1  (the case) of the motor  100 , when viewed in the axial direction of the tubular portion  21   c  that forms the air intake passage  21   b  is disposed so that at least one part thereof lies toward the inside from the maximum outer periphery  21   m  of the tubular portion  21   c , and further toward the outside from the outer periphery  21   n  of the tubular portion  21   c  (referencing  FIG. 2  and  FIG. 3 ). For example, the diameter D of the housing  1  (the case) of the motor  100  (referencing  FIG. 4 ) may be structured so as to have a length that is essentially the same as the thickness Ld of the tubular portion  21   c  in the radial direction. 
         [0040]    Because the throttle valve device  200  is structured so as to open and close the throttle valve  22  through a compact slotless brushless motor  100  that is long in the axial direction, the length of extension of the slotless brushless motor  100  can be made relatively small, and an output torque of the slotless brushless motor  100  can be obtained adequately, with a surplus, relative to the rotational load of the throttle valve  22 . This makes it possible to provide a throttle valve device  200  that is compact and that has superior responsiveness. 
         [0041]    Moreover, in the throttle valve device  200 , the overall shape is a rectangular block that is almost square, enabling easy installation into a relatively narrow space, such as into an engine chamber. 
         [0042]    Furthermore, in the present embodiment, in the throttle valve device  200 , the housing  1  (the case) of the slotless brushless motor  100 , when viewed from the direction of the axis ( 21   p ) of the tubular portion  21   c  that forms the air intake passage  21   b , is disposed so that at least one part thereof overlays a connecting portion  21   k  between the throttle body main unit portion  21   g  and the tubular portion  21   c . In this case, the length of protrusion from the slotless brushless motor  100  can be made extremely small. 
         [0043]    Moreover, in the throttle valve device  200 , the throttle body  21  (the housing) has a hole portion  21   h  into which is inserted a securing member  41  (an attaching bolt) for securing the throttle body  21  to an attaching member  30  (the engine main unit portion  32 , the intake manifold  31 , or the like). This hole portion  21   h  is provided in the vicinity of the outer peripheral portion of the tubular portion  21   c . The slotless brushless motor  100  is provided in proximity to the hole portion  21   h  that is provided in the throttle body  21 . Specifically, the slotless brushless motor  100  is provided in proximity to the hole portion  21   h  that is provided between the tubular portion  21   c  and the slotless brushless motor  100 . Because the structure in the present embodiment is as described above, the distance La between the slotless brushless motor  100  and the hole portion  21   h  is short. 
         [0044]    When the engine is operating, the throttle valve device  200  and the attaching member  30 , such as the engine main unit portion  32 , the intake manifold  31 , or the like, vibrate essentially synchronously. Specifically, because the slotless brushless motor  100  is disposed at a position that is only an extremely short distance away from the attaching position (the hole portion  21   h ) for the securing member  41  (the attaching bolt), it has a relatively small moment of inertia (in respect to the position of the attachment), making it possible to reduce extremely the extraneous vibration that differs from the vibration of the attaching member  30  (the engine main unit portion  32 , the intake manifold  31 , or the like). 
         [0045]    The individual structural elements of the slotless brushless motor  100  will be explained in detail next, in reference to  FIG. 4 ,  FIG. 5 , and the like. 
         [0046]    Note that in the explanations below, “front” or “forward” refer to the output side, in the axial direction, of the rotary shaft  4  (the right side in  FIG. 4 ), and “back” or “rearward” refers to the side that is opposite from the “front” or “forward” (the left side in  FIG. 4 ). 
         [0047]    The slotless brushless motor  100 , as illustrated in  FIG. 4  in  FIG. 5 , comprises: a long cylindrical housing  1  (a case); a long cylindrical stator  2  (a yoke) that is connected, so as to be able to rotate relative to the housing  1 , to the center side thereof; a coil  5  that is formed in a cylindrical shape within the stator  2 ; a cylindrical magnet  3  that is secured to the rotor a on the inside of the coil  5 ; a rotary shaft  4  that passes through the interior of the rotor a and that is supported, so as to be able to rotate relative to the housing  1 , through supporting members  14  and  8 ; a constraining member  6  for constraining movement of the rotary shaft  4  toward the back side; a member  9  for covering the front opening portion of the housing  1 ; a metal member  7  that is provided on the backside of this member  9 ; a terminal  11 ; a washer  12 , for constraining movement of the rotary shaft  4  toward the front side; and a bearing flange  13 ; structured so as to be able to open and close the throttle valve through the rotational force of the rotary shaft  4 . 
         [0048]    The housing  1  comprises a long cylindrical cylinder portion  1   a  that is integrated with a bottom  1   b  at the position of the back end portion of the cylinder portion  1   a , to form an essentially closed-bottom cylinder from a magnetic metal material. 
         [0049]    Moreover, the stator  2  (the yoke) is a long cylindrical member formed from a magnetic metal material, with the coil  5  provided therewithin, and the housing  1  is secured through securing means, such as adhesive bonding, press fitting, or the like, to the outer peripheral surface thereof. This enables a reduction in the space through which the magnetic flux flows between the stator  2  and the magnet  3 . 
         [0050]    The magnet  3  is formed in a long cylindrical shape, having magnetic poles in mutually opposing radial directions, from an arbitrary permanent magnet material, such as, for example, and alnico magnet or a rare earth magnet. 
         [0051]    This magnet  3  is formed so that the back end side (the left end side in  FIG. 4 ) is shorter than the stator  2 . That is, the back end side of the stator  2  protrudes rearward further than the back end portion of the magnet  3 . 
         [0052]    This magnet  3  is secured to the outer peripheral portion of the cylindrical rotor a, and a rotary shaft  4  is provided in the interior of the rotor a. 
         [0053]    A slight gap s (an air space) is provided between the magnet  3  and the coil  5 , structured so that the rotor a and the magnet  3  are rotated through application of electric power to the coil  5 . 
         [0054]    The rotary shaft  4 , in a state wherein a gap is secured between the rotary shaft  4  and the inner peripheral surface of the stator  2 , is inserted coaxially within the stator  2 , and the front end side protrudes further forward than a bearing flange  13  and the back end side protrudes further rearward than the bottom  1   b.    
         [0055]    The front end side of the rotary shaft  4  is supported, so as to enable rotation, by a supporting member  8  on the center side of the bearing flange  13 , described below, of the rotary shaft  1  and the back end side of the rotary shaft  4  is supported, through a supporting member  14 , on the back end side of the stator  2 , so as to be able to rotate. The supporting member  14 , as a bearing member, may be, for example, a slide bearing, but a rolling bearing, such as a ball bearing, or the like, may be used instead. An output gear  15  is secured to the side of the rotary shaft  4  further forward from the bearing flange  13 . 
         [0056]    The cylindrical coil  5  is a coil that is structured into a long cylindrical shape, and secured by a synthetic resin, and is positioned in a space between the inner peripheral surface of the housing  1  and the outer peripheral surface of the magnet  3 , and secured to the inner peripheral surface of the stator  2 . 
         [0057]    Moreover, a lead wire, not shown, leads out from the front end side of the cylindrical coil  5 , where this lead wire is connected electrically to the terminal  11 . 
         [0058]    The bearing flange  13  supports the rotary shaft  4  so as to be able to rotate, and is a flange-shaped member that has attaching holes  13   a  on both end sides in the radial direction. The attaching holes  13   a  are used for securing the motor  100  to the throttle valve controlling unit. 
         [0059]    Given this, the motor  100 , structured as described above, rotates the rotor a and the magnet  3  smoothly, through application of electric power to the terminal  11 . 
         [0060]    The gap between the magnet and the inner peripheral surface of the cylindrical coil  5 , and the like, can be set so as to be small, to increase effectively the output power. 
         [0061]    For example, given the example illustrated in  FIG. 4 , the distance in the radial direction between the inner peripheral surface of the stator  2  and the outer peripheral surface of the magnet  3  is about 1 mm, the diameter D of the housing  1  is about 20 mm, and the total length L of the housing  1  is about 60 mm. 
         [0062]    That is, the housing  1  of the motor  100  is of a long-thin shape, with the total length L thereof being about three or four times the diameter D of the housing  1 . Such a motor  100  enables high-precision control of the throttle valve device  200  through the diameter Lt of the tubular portion  21   c  being about five times the diameter D of the housing  1 . 
         [0063]    Note that while the embodiment set forth above showed an example wherein the motor  100  illustrated in  FIG. 4  and  FIG. 5  was incorporated into the throttle valve device  200 , there is no limitation to the detailed portions of the motor  100  having these shapes. The motor  100  that is built into the throttle valve device  200  may instead be small, but long in the axial direction. 
         [0064]    Moreover, as explained above, the slotless brushless motor-driven throttle valve device  200  according to an embodiment according to the present invention comprises: a throttle body  21  (a housing) that is equipped with a tubular portion  21   c  wherein a valve hole  21   a  is formed, as an air intake passage  21   b  in the interior thereof; a throttle valve  22  that is disposed within the tubular portion  21   c ; and a slotless brushless motor  100 , as a driving motor for driving the throttle valve  22  open and closed. 
         [0065]    The throttle body  21  (the housing) has a hole portion  21   h  into which is inserted a securing member  41  (an attaching bolt) for securing the throttle body  21  to an attaching member  30  (the engine main unit portion  32 , the intake manifold  31 , or the like). This hole portion  21   h  is provided in the vicinity of the outer peripheral portion of the tubular portion  21   c . The slotless brushless motor  100  is provided in proximity to the hole portion  21   h  that is provided in the throttle body  21 . 
         [0066]    As described above, the throttle valve device  200  has a structure wherein a long-thin compact slotless brushless motor  100  is disposed in the vicinity of a hole portion  21   h  that is provided in the throttle body  21 , and thus is extremely compact. 
         [0067]    Moreover, when the engine is operating, the throttle valve device  200  and the attaching member  30 , such as the engine main unit portion  32 , the intake manifold  31 , or the like, vibrate essentially synchronously. Specifically, because the slotless brushless motor  100  is disposed at a position that is only an extremely short distance away from the attaching position (the hole portion  21   h ) for the securing member  41  (the attaching bolt), it has a relatively small moment of inertia (in respect to the position of the attachment), making it possible to provide a compact throttle valve device  200  able to reduce extremely the extraneous vibration that differs from the vibration of the attaching member  30  (the engine main unit portion  32 , the intake manifold  31 , or the like). 
         [0068]    Moreover, the housing  1  (the case) of the slotless brushless motor  100 , when viewed in the axial direction of the tubular portion  21   c  that forms the air intake passage  21   b  is disposed so that at least one part thereof lies toward the inside from the maximum outer periphery  21   m  of the tubular portion  21   c , and further toward the outside from the outer periphery  21   n  of the tubular portion  21   c  (referencing  FIG. 2  and  FIG. 3 ). 
         [0069]    Specifically, in the throttle valve device  200 , the housing  1  (the case) of the slotless brushless motor  100 , when viewed in the axial direction of the tubular portion  21   c  that forms the air intake passage  21   b , is disposed so that at least one part thereof overlays a connecting portion  21   k  between the throttle body main unit portion  21   g  and the tubular portion  21   c.    
         [0070]    That is, the structure wherein the compact slotless brushless motor  100  is disposed extremely near to the tubular portion  21   c  makes it possible to provide a compact throttle valve device  200 . 
         [0071]    Moreover, the throttle valve device  200  being equipped with the compact slotless brushless motor  100  enables the provision of a compact throttle valve device  200  wherein the valve responsiveness is good. 
         [0072]    An engine equipped with the slotless brushless motor-driven throttle valve device according to the embodiment according to the present invention can be provided. 
         [0073]    Moreover, a vehicle that is equipped with an engine according to an embodiment according to the present invention can be provided. The vehicle may be an automobile, a motorcycle, a hybrid vehicle, or the like. 
         [0074]    While the embodiments of the present invention were described in detail referencing the drawings, the specific structures are not limited to those in these embodiments, but rather design changes, and the like, within a range that does not deviate from the spirit or intent of the present invention are included within the present invention. 
         [0075]    Moreover, insofar as there are no particular contradictions or problems in purposes, structures, or the like, the details that are described for the embodiments illustrated in the various drawings described above may be combined. 
         [0076]    Moreover, the details described in each of the drawings can be respectively independent embodiments, and the embodiments of the present invention are not limited to a single embodiment combining each of the drawings.