JP2006242132A - Engine starter and one-way clutch for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine starter A, which drives a crank shaft through an endless transmitting member such as a belt, of simple and inexpensive structure capable of reducing driving loss during engine operation without having a trouble in durability. <P>SOLUTION: A one-way clutch C is structured by installing a case 10 in a guide wheel 1 freely to rotate around an axis X and wrapping a flat belt 50 between a friction surface 40a of a swing plate 40, which is swingably supported by a needle roller 30 supported by the case 10, and a friction surface 1a of the guide wheel 1, and the swing plate 40 is turned by inertia force generated with rotation of the case 10 to push one span of the flat belt 5 to give the initial tension. Ferrous powder is mixed in a rubber layer of the flat belt 50, and a magnet 60 energizes the flat belt outward in the radial direction to separate the flat belt from the friction surface 1a of the guide wheel 1. The case 10 of the one-way clutch C is integrally structured with a crank pulley P1, and arranged on the crank shaft 70. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an engine starter configured to drive an engine crankshaft via an endless transmission member, and more particularly to the technical field of the structure of a one-way clutch used in the starter.

  2. Description of the Related Art Conventionally, a control system (idle stop system) in which an engine is automatically stopped at the time of idling for the purpose of reducing fuel consumption and suppressing CO2 emission is widely known. In such a system, the engine must be started immediately in response to an engine restart request such as a start operation, but in a general configuration in which the crankshaft is driven by the starter motor, the pinion gear of the starter motor is pushed out. Time lag is likely to occur due to delays in response of solenoids, etc., and there is a tendency that the start-up time is slightly longer.

  In addition, if the engine is stopped and restarted every time the engine is in an idle state, high-frequency noise due to the meshing of the pinion gear and the flywheel gear is generated every time the vehicle stops due to a signal or traffic jam and restarts. There is also a problem that it occurs and gives discomfort to the occupant.

  Furthermore, compared to a normal system that starts only when the ignition switch is operated, the number of times the engine starts is significantly increased, so the number of meshes between the pinion gear and the flywheel gear is significantly increased, resulting in durability. There is also a possibility that this problem may occur.

  Therefore, a system has been proposed in which a starter motor and an engine crankshaft are connected by an endless transmission member such as a V-ribbed belt and the crankshaft is driven via the belt or the like when the engine is started (for example, Patent Documents). 1). In order to prevent the starter motor from rotating as the crankshaft rotates after starting the engine, a general mechanical type is used between the crankshaft and the crank pulley or between the output shaft of the starter motor and the motor pulley. A directional clutch is provided to block transmission of power.

  By the way, as a conventionally known one-way clutch, in addition to the above-mentioned general mechanical type, for example, as described in Patent Document 2, the belt is wound through a belt wound between two shafts. There is one (hereinafter also referred to as a belt-type one-way clutch) that applies the principle of a two-axis belt transmission mechanism that transmits torque between two axes.

  In the belt type one-way clutch, two rotating members assembled so as to be rotatable relative to each other are connected to a driving side and a driven side, respectively, and a friction transmission belt is wound between both to adjust the tension. When the two rotating members try to rotate relative to each other in a predetermined direction, torque is transmitted between the rotating members via the belt, while the rotating members rotate relative to each other in the opposite direction. Attempting to do so causes the belt to loosen and the rotating member to idle, thereby interrupting the torque.

Such belt-type one-way clutches are manufactured at low cost because they require fewer parts and require a higher accuracy than general mechanical one-way clutches, which are precision instruments. There is a merit that you can.
JP 2001-153010 A Japanese Patent Laid-Open No. 9-317796

  By the way, when the mechanical one-way clutch is disposed on the crankshaft or the motor shaft as in the conventional engine starting device (the one disclosed in Patent Document 1), the following problems occur. That is, first, when the one-way clutch is disposed on the crankshaft (that is, between the crankshaft and the crank pulley), the crank pulley has a relatively large diameter, so that a considerably large load torque is applied when starting the engine. It is difficult to ensure reliability.

  In addition, since the difference in engine speed is small between when the engine is started and during, for example, idling after the engine is started, it is difficult to connect / disconnect the clutch using the difference in the rotational speed when it is placed on the crankshaft. Because of this, the clutch connection (engagement) may be poor at the start of the engine, and conversely, the power cut-off may be incomplete during idle operation, etc., leading to reduced durability due to wear of parts. There is a risk of doing.

  Further, even if a belt type as in Patent Document 2 is used instead of the mechanical one-way clutch, the frictional surface of the rotating member that idles as described above when the power is cut off in this one. Since the friction transmission belt and the friction transmission belt keep slipping during the operation of the engine, there is a concern that the durability may be reduced due to wear as in the case of the mechanical type.

  On the other hand, regardless of the mechanical type or belt type, if a one-way clutch is provided on the motor side, the pulley diameter on the motor side is smaller than that on the crank side, thus avoiding the problems of large load torque and poor engagement. Although there is a possibility that the power can be cut off on the motor side in this case, the belt is always driven by the crankshaft during the operation of the engine, and wasteful energy loss occurs. The belt durability is also disadvantageous.

  As described in the prior art document (Patent Document 1), the use of an electromagnetic clutch for switching the power connection / disconnection in the engine starting device significantly increases the cost, increases the size of the engine, and the vehicle weight. There are problems in many respects, such as an increase in the number, and it is difficult to say that it is realistic.

  The present invention has been made in view of these points, and an object of the present invention is to provide a driving force for an engine starter in which a crankshaft is driven via an endless transmission member such as a belt. An object is to devise a structure of a one-way clutch for transmitting only in one direction, and to reduce a driving loss during engine operation without causing a problem of durability with a simple and inexpensive configuration.

  In order to achieve the above-mentioned object, the present invention has improved the known belt-type one-way clutch so that the friction transmission belt is kept in a non-contact state with the friction surface of the rotating member when the power is cut off. This was disposed between the crankshaft of the engine and the input / output member.

  Specifically, according to the first aspect of the present invention, an engine starter in which a crankshaft is driven by a motor via an endless transmission member when the engine is started, and the endless transmission member is connected to the crankshaft and the motor. The input / output members respectively disposed on the output shafts are engaged with each other and transmitted, and at least during the rotation of the input / output members, the driving force in the rotational direction is transferred to the crankshaft between the crank shaft and the input / output members. A one-way clutch is provided for transmission.

  The one-way clutch is integrally connected to the crankshaft and integrally connected to the crankshaft, and has a first rotating member having a circular cross-sectional friction surface on the outer peripheral side and an input / output member of the crankshaft. And a second rotating member assembled to the first rotating member so as to be rotatable around a center axis of the friction surface, and wound around the friction surface of the first rotating member, and is radially outside the friction surface. A friction transmission belt that engages with an engaging portion provided on the second rotating member so as to be spaced apart from each other and forms two spans between the two rotating members; and the second rotating member is separated from the motor. One of the friction transmission belts which is operated by an inertial force accompanying the rotation and becomes a loose side span by relative rotation of the second rotating member with respect to the first rotating member. A belt-type member that includes a movable member that presses and a biasing means that biases the friction transmission belt radially outwardly away from the friction surface of the first rotating member. .

  With the configuration described above, when the motor is activated at the start of the engine and the input / output member on the output shaft rotates, this rotation is transmitted to the input / output member on the crankshaft via the endless transmission member. The second rotating member of the one-way clutch rotates together with the member. Then, the movable member is operated by an inertial force (for example, centrifugal force) accompanying the rotation and presses one span of the friction transmission belt, whereby the friction transmission belt is pressed against the friction surface of the first rotation member, A friction force acts between the two.

  Thus, when the rotation of the second rotating member starts, the first rotating member connected to the crankshaft is stopped, so that the relative rotation of the second rotating member with respect to the first rotating member causes winding between the two. One of the two spans of the applied friction transmission belt is on the loose side and the other is on the tension side, but one belt span on the loose side is pressed by the movable member as described above. The tension of the friction transmission belt is maintained or increased, and the torque is transmitted between the first and second rotating members via the friction transmission belt, that is, the one-way clutch transmits the torque. It becomes a state. Thereby, the driving torque from the motor is transmitted to the crankshaft, and the engine is started.

  When the motor stops after the engine is started, the input / output member and the endless transmission member on the motor shaft stop, and the input / output member on the crankshaft also stops rotating. Since the first rotating member connected to the crankshaft rotates in the directional clutch, the first rotating member rotates relative to the second rotating member stopped together with the input / output member in a direction opposite to that at the start of the start. Will do.

  At this time, since the second rotating member is stopped as described above, the movable member does not operate, and the belt is not pressed by the movable member as described above. A state in which torque is not transmitted to one rotating member is established. That is, even if the one-way clutch is in a state where the torque is cut off and the crankshaft is rotating, not only the motor but also the endless transmission member is not rotated, so that no loss of engine driving force is generated.

  At this time, the first rotating member connected to the crankshaft rotates inside the one-way clutch, but the slack friction transmission belt as described above is urged radially outward by the urging means, Since it is separated from the friction surface of the first rotating member and the both are kept in a non-contact state and do not slide, the durability is not deteriorated due to wear.

  Note that immediately after the engine is started, the second rotating member rotates by inertia, and the movable member operates by this, but with the crankshaft rotating independently, the relative rotation of the first and second rotating members in the one-way clutch is increased. Since the direction is opposite to that at the time of starting, one span of the friction transmission belt pressed by the operation of the movable member becomes a tension side span, and the tension is maintained in the other belt span which is the loose side at this time. Since this is not possible, the friction transmission belt quickly loosens and moves away from the friction surface of the first rotating member.

  The belt-type one-way clutch as described above can easily increase the load resistance compared to a mechanical type by increasing the tensile strength of the friction transmission belt and increasing the strength of the member that receives the axial load of the belt. There is no problem even if it is arranged on the crankshaft where a considerably large load torque is applied when the engine is started.

  Further, when viewed from the starter as a whole, the endless transmission member meshes with the input / output members of the crankshaft and the motor shaft, so that the crank drive load torque at the start of the engine, such as cold, is the largest. Slip does not occur and the engine can be started reliably.

  Specifically, the endless transmission member may be a toothed belt and the input / output member may be a toothed belt pulley as the member that meshes and transmits as described above (Invention of Claim 2). In this way, quiet and reliable power transmission can be performed at a lower cost than using a silent chain and a sprocket.

  Next, as a more specific configuration of the one-way clutch, the engaging portion of the second rotating member has a friction surface having an arcuate cross section on the outer periphery located radially outward of the friction surface of the first rotating member. Assuming that the friction transmission belt does not have an end portion, the friction transmission belt may be wound around the friction surface of the first rotating member and the friction surface of the engaging portion of the second rotating member. Invention of 3). In this case, when the first and second rotating members are assembled, the endless friction transmission belt is wound around the friction surfaces of the both to make the assembly of the one-way clutch relatively easy.

  In this case, it is preferable that a shaft portion is provided on the second rotating member so as to extend parallel to the central axis of the friction surface on the radially outer side of the friction surface of the first rotating member, and the second rotating member. The engaging portion of the rotating member is supported by the shaft portion so as to be swingable separately from the second rotating member, and this is used as a movable member. Further, the movable member is used for the rotation of the second rotating member. It is configured to rotate around the shaft portion by the accompanying inertial force and to press one span of the friction transmission belt from the inner peripheral side (invention of claim 5).

  If comprised in this way, the movable member for giving initial tension to a friction transmission belt can be combined with the engaging part on which the belt is wound, and the structure of a one-way clutch is further simplified. be able to. This further reduces the cost.

  Alternatively, as another specific configuration of the one-way clutch, both end portions of the friction transmission belt wound around the friction surface of the first rotating member are fixed to the engaging portions of the second rotating member, respectively. (Invention of claim 4).

  Further, the urging means for urging the friction transmission belt in the one-way clutch radially outward of the friction surface of the first rotating member is provided with, for example, a magnetic body on the friction transmission belt and the friction of the first rotating member. By providing a magnet on the second rotating member so as to be spaced outward in the radial direction of the surface, it can be configured relatively easily (invention of claim 6).

  The invention of claim 7 of the present application is a belt-type one-way clutch that is improved so that it can be used in the engine starting device as described above. Specifically, a first rotating member having a friction surface having a circular cross section on the outer periphery and connected to one of the driving side and the driven side, and the first rotating member around the central axis of the friction surface And a second rotating member that is rotatably coupled to the other of the driving side and the driven side, and parallel to the central axis of the friction surface on the radially outer side of the friction surface of the first rotating member. A shaft portion provided on the second rotating member so as to extend to the outer periphery, and a friction surface having an arc-shaped cross section on the outer periphery located radially outward of the friction surface of the first rotating member. A movable member supported so as to be swingable about an axis, and a friction transmission belt wound around the friction surface of the first rotating member and the friction surface of the movable member so as to form two spans. A one-way clutch of the belt type, wherein the movable member is It is configured to rotate in the direction of pressing one span of the friction transmission belt around the shaft portion by an inertial force accompanying rotation of the member, and the friction transmission belt is rotated in the first rotation. It is characterized by further comprising urging means for urging radially outwardly away from the friction surface of the member.

  The belt-type one-way clutch configured as described above is disposed on the crankshaft of the engine, and when the engine is started, a driving force is input from the motor side to an input / output member such as a crank pulley via an endless transmission member. Thus, the same operation as that of the first aspect of the invention can be obtained.

  As described above, according to the one-way clutch according to the present invention and the engine starter using the clutch, the belt-type one-way clutch is disposed between the crankshaft of the engine and the input / output member. In the directional clutch, an urging means for urging radially outward so as to separate the friction transmission belt from the friction surface of the first rotating member connected to the crankshaft is provided, and the friction transmission belt rotates first when power is cut off. Since the friction surface of the member is kept in a non-contact state, the durability is not reduced due to wear of both members.

  Further, since the torque can be interrupted by the one-way clutch provided on the crankshaft, the endless transmission member does not rotate even when the crankshaft is rotated, and no loss of engine driving force is generated.

  Furthermore, by using a belt type one-way clutch that is relatively simple and inexpensive, the cost can be reduced and the tensile strength of the belt and the strength of the member that receives the axial load can be increased. It can withstand load torque.

  In particular, in the invention of claim 3, since it is only necessary to wrap the endless friction transmission belt so as to straddle the friction surfaces of the two rotating members, the one-way clutch can be easily assembled.

  Further, according to the invention of claim 5, since a part of the member around which the friction transmission belt is wound can be used as a movable member for applying initial tension to the belt as described above, the cost can be reduced by simplifying the configuration. Further reduction is achieved.

According to the sixth aspect of the present invention, the biasing means for keeping the friction transmission belt in a non-contact state with the friction surface of the first rotating member can be easily constituted by a magnetic body and a magnet.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  FIG. 1 shows a schematic configuration of an engine starter A according to an embodiment of the present invention. The starter A is composed of a synchro pulley (toothed belt pulley) on a crankshaft 70 of an engine (not shown). While a crank pulley P1 is provided, a motor pulley P2 composed of a synchro pulley is also provided on an output shaft S of a starter motor (not shown), and a sync belt B (toothed belt) is provided between the pulleys P1 and P2. ).

  A one-way clutch C is provided between the crankshaft 70 and the crank pulley P1 so as to transmit the driving force in the rotation direction of the crank pulley P1 (clockwise direction in the drawing) to the crankshaft 70. Thus, when the engine is started, the crankshaft 70 can be rotationally driven by the motor via the synchro belt B, while the rotation of the crankshaft 70 is not transmitted to the motor side after the engine is started.

  In addition, the code | symbol P3 of illustration is a tension pulley for pressing the slack side span of the synchro belt B, and maintaining it in a predetermined tension state, In addition, although not illustrated in the engine of this embodiment, An auxiliary machine drive system for driving the auxiliary machine via the belt by the crankshaft 70 is provided side by side.

  2 and 3 show the structure of the one-way clutch C disposed on the crank pulley P1. The one-way clutch C is a guide wheel 1 composed of a flat pulley having a friction surface 1a having a circular cross section on the outer periphery. (First rotating member) and a hollow donut-shaped case 10 (second rotating member) that is assembled to the guide wheel 1 so as to be rotatable about the axis X and accommodates the outer peripheral side of the guide wheel 1. I have. The guide wheel 1 is coaxially connected to the crankshaft 70 of the engine on the driven side, while the case 10 has a plurality of pitches corresponding to the tooth profile of the synchro belt B over the entire outer circumference. Groove portions 10a, 10a,... (Only one is shown in FIG. 2) are formed, and themselves constitute a crank pulley P1 that meshes with the synchro belt B.

  The guide wheel 1 is connected to the crankshaft 70 at the boss portion 2 thereof. A connecting hole 3 for inserting the crankshaft 70 is provided in the boss part 2 so as to penetrate the boss part 2 in the axial direction, and the crankshaft 70 guides the inner periphery of the connecting hole 3. A keyway 4 (shown only in FIG. 3) for keying the wheel 1 is provided. In addition, a disc-like disc portion 6 projecting outward in the radial direction is provided at the center in the axial direction of the outer periphery of the boss portion 2, and the disc portion 6 is provided at the periphery of the disc portion 6. A cylindrical portion 7 is provided so as to cover from the outer peripheral side, and the outer peripheral surface of the cylindrical portion 7 is the friction surface 1a.

  Further, bearing seat surfaces 5 and 5 having a smaller diameter than the outer periphery of the axial center portion of the boss portion 2 are formed on the outer circumferences of both end portions in the axial direction of the boss portion 2, respectively. , 5, an inner ring of a pair of bearings 20, 20 for rotatably attaching the case 10 to the guide wheel 1 is attached in an externally fitted state so as to rotate integrally with the guide wheel 1.

  On the other hand, the case 10 is divided into two on one side and the other side in the axial direction of the guide wheel 1, and the one side case member 11 located on the right side and the other side case member 12 located on the left side in FIG. Consists of. On the inner peripheral side of the case members 11 and 12, cylindrical inner peripheral wall portions 11a and 12a that are respectively fitted onto the outer rings of the corresponding bearings 20 are provided so as to face each other in the axial direction. The peripheral wall portions 11a and 12a are coupled to each other on the corresponding outer ring of the bearing in a state of being integrally fitted to the outer periphery.

  Further, cylindrical outer peripheral wall portions 11b and 12b are provided on the outer peripheral side of the case members 11 and 12 so as to face each other in the axial direction, and the front end portions of the outer peripheral wall portions 11b and 12b are joined to each other. Thus, the two integrally form the outer peripheral portion of the case 10. That is, the outer peripheral wall portion 11b of the one-side case member 11 is provided with four female screw holes opened at the end surface of the outer peripheral wall portion 11b at equal intervals in the circumferential direction. Bolt holes are formed through the outer peripheral wall portion 12 b of 12. The four bolts 13 are inserted into the bolt holes of the other case member 12, and the tip ends of the bolts 13 are screwed into the female screw holes of the one case member 11. The members 11 and 12 are joined together.

  The outer peripheral wall portion 11b of the one side case member 11 is formed longer than the other side case member 12 in the axial direction, and the tooth of the synchro belt B is formed on the outer peripheral wall portion 11b of the one side case member 11. Are formed so as to mesh with each other.

  In the one-way clutch C of this embodiment, the needle roller 30 which is a shaft member is separated from the friction surface 1a of the guide wheel 1 radially outward (upward in FIG. It arrange | positions along the axial center Q extended in parallel. Both end portions of the needle roller 30 are respectively formed on the boss portions 14 and 15 formed on the inner surfaces of the body portions of the case members 11 and 12 (perforated disk-shaped portions connecting the inner and outer peripheral wall portions). The needle roller 30 is inserted into the shaft hole so that the needle roller 30 rotates integrally with the case 10 (the shaft member may be integrally formed with the case 10).

  The needle roller 30 includes a swing plate 40 as a movable member having a friction surface 40 a having a circular arc cross section on the outer periphery located radially outward of the friction surface 1 a of the guide wheel 1. It is supported so as to be able to swing around the center Q. Specifically, a through hole 41 is provided to extend in the axial direction at a position deviated toward one end side in the circumferential direction (left end side in FIG. 3) with respect to the central portion in the circumferential direction of the swing plate 40. The needle roller 30 is inserted into the through hole 41 and supports the swing plate 40.

  A friction transmission belt is formed by forming two spans between the guide wheel 1 and the swing plate 40 across the friction surface 1a of the guide wheel 1 and the friction surface 40a of the swing plate 40. A flat belt 50 is wound around. The flat belt 50 is made of rubber, and has a core wire 51 embedded therein, and a canvas layer (not shown) is provided on the inner peripheral surface of the belt. Furthermore, iron powder which is a magnetic material is kneaded into the flat belt 50 of this embodiment so as to be dispersed in the rubber layer.

  As shown in FIG. 3, the rocking plate 40 is seen along the axis X of the guide wheel 1 and the other end in the circumferential direction of the rocking plate 40 with respect to the axis Q of the needle roller 30 that is the rocking center. The center of gravity G is located on the side (the right end side in FIG. 3). For this reason, when a centrifugal force (inertial force in the radial direction of the shaft center X) acts by the rotation of the case 10, the swing plate 40 rotates around the needle roller 30 in the counterclockwise direction in the figure, The other circumferential end (right end in the figure) of the rocking plate 40 presses one span (the right span in the figure) of the flat belt 50 from the inner circumference.

  That is, when the case 10 (crank pulley P1) of the one-way clutch C is rotated clockwise through the synchro belt B by the driving force from the motor, the swinging plate 40 is thereby loosened on the loose side. One span of the flat belt 50 (the right span in the figure) is pressed to apply an initial tension to the flat belt 50.

  In the one-way clutch C of this embodiment, the friction surface is located on the opposite side (downward in FIG. 3) from the friction surface 1a of the guide wheel 1 on the opposite side (downward in FIG. 3). A magnet 60 is disposed so as to surround the flat belt 50 wound around 1a. That is, the extending wall portion 16 extending in the axial direction from the inner surface of the main body portion of the one-side case member 11 is formed in a semicircular cross section so as to surround the friction surface 1a of the guide wheel 1 over a substantially half circumference with a predetermined interval. The magnet 60 is fixed to the inner peripheral surface of the extending wall portion 16 by bonding or the like.

  Since the magnet 60 is disposed so as to surround the flat belt 50 wound around the guide wheel 1 as described above, iron powder is mixed in the rubber layer of the flat belt 50. The magnetic force acts to pull it away from the friction surface 1a of the guide wheel 1 radially outward. Therefore, the flat belt 50 is separated from the friction surface 1a of the guide wheel 1 and is not in contact with the friction surface 1a except when the loose side span is pressed by the rotation of the swing plate 40 as described above. It will be kept in a state.

  In other words, the one-way clutch C of this embodiment is separated from the iron powder mixed in the rubber layer of the flat belt 50 and radially outward of the friction surface 1a of the guide wheel 1 from the flat belt 50. An urging means for urging the flat belt 50 radially outward so as to leave the friction surface 1a is provided.

  Next, the operation of the engine starter A including the one-way clutch C having the above-described configuration will be described in detail with reference to FIGS. 4 and 5, particularly the operation state of the one-way clutch C.

  First, when the engine is started, the motor pulley P2 is rotated by the operation of the motor, and this rotation is transmitted to the crank pulley P1, that is, the case 10 of the one-way clutch C by the synchro belt B, and the case 10 is shown in FIG. Rotate clockwise. Since the guide wheel 1 connected to the crankshaft 70 is stopped at the moment when the rotation starts, the two relative rotations of the flat belt 50 wound between the two by the relative rotation of the case 10 with respect to the guide wheel 1. One of the spans (the right span in the figure) is the loose side.

  Further, due to the centrifugal force F generated by the rotation of the case 10, the rocking plate 40 rotates counterclockwise in the figure around the needle roller 30, and the other end in the circumferential direction (the right end side in the figure). However, one span (span on the right side of the drawing) of the flat belt 50 on the loose side is pressed from the inner peripheral side. As a result, the flat belt 50 is pressed against the friction surface 1a of the guide wheel 1 and the friction surface 40a of the swing plate 40, and a gripping force is ensured (that is, initial tension is applied to the flat belt 50). ).

  Then, due to the relative clockwise rotation of the case 10 with respect to the guide wheel 1, the span on the left side of the flat belt 50 is pulled toward the case 10, and this span becomes the tension side span. As a result, the counterclockwise rotational force in the figure acts on the swing plate 40. That is, the other circumferential side end (the right end side in the figure) of the rocking plate 40 more strongly presses the slack side span on the right side of the flat belt 50 toward the outside in the radial direction. As the tension of 50 increases, the torque is transmitted from the guide wheel 1 to the case 10 via the flat belt 50, that is, the one-way clutch C is in a state of transmitting torque. Thereby, the crankshaft 70 is driven and the engine is started.

  When the engine is started, the crankshaft 70 starts to rotate independently, and the guide wheel 1 connected thereto rotates clockwise in the drawing. Then, when the rotational speed of the crankshaft 70 suddenly increases due to a blow-up immediately after start-up, even if the case 10 is coasting due to inertia in the one-way clutch C, the crankshaft 70, that is, the guide wheel is rotated. 1 is overtaken, and the guide wheel 1 and the case 10 rotate relative to each other in the opposite direction to that at the start.

  At that time, if the case 10 rotates by inertia as described above, the swinging plate 40 rotates and presses the flat belt 50 by the centrifugal force. Since the direction of relative rotation with respect to the case 10 is opposite to that at the start, this time, the right-hand span of the flat belt 50 is pulled toward the guide wheel 1 in accordance with the rotation of the guide wheel 1. The oscillating plate 40 rotates clockwise in FIG.

  In other words, contrary to the engine start, the right side span of the flat belt 50 is the tension side span, so that the other end in the circumferential direction of the swing plate 40 (the right end side in the same figure) has centrifugal force. Even if it is received, it is pushed toward the guide wheel 1 by the tension side span of the flat belt 50 and displaced inward in the radial direction. That is, the swinging plate 40 rotates around the needle roller 30 in the clockwise direction in the drawing, whereby the tension of the flat belt 50 is greatly reduced.

  At this time, one end in the circumferential direction of the swing plate 40 (the left end side in the figure) is displaced outward in the radial direction, so that the loose side span is pressed by that amount. Since one end side in the circumferential direction is shorter than the other end side in the circumferential direction, it cannot be pressed to the extent that the tension of the flat belt 50 is increased. As a result, the tension rapidly decreases, and the flat belt 50 swings with the guide wheel 1. Torque is not transmitted to or from the moving plate 40.

  As a result, torque transmission between the guide wheel 1 connected to the crankshaft 70 and the case 10, that is, the crank pulley P1 in the one-way clutch C is cut off. As shown, the motor pulley P2, the synchro belt B, and the crank pulley P1 (the case 10 of the one-way clutch C) all stop quickly so that only the guide wheel 1 connected to the crankshaft 70 rotates clockwise. Become. In this way, even when the engine is in operation, not only the motor but also the synchro belt B does not rotate with the crankshaft 70, so that no unnecessary loss of engine driving force occurs.

  At that time, since the case 10 of the one-way clutch C is stopped as described above, centrifugal force does not act on the swinging plate 40, and the swinging plate 40 causes the flattening as in the engine start. The belt 50 is not pressed. For this reason, the flat belt 50 is slackened, and the lower half-circumferential part of the drawing is attracted by the magnet 60 and is separated from the friction surface 1a of the guide wheel 1 so that both are kept in a non-contact state. Thus, during engine operation, the friction surface 1a of the guide wheel 1 and the flat belt 50 do not slip inside the one-way clutch C, and there is no possibility of causing a decrease in durability due to wear.

  Therefore, according to the engine starting device A according to the present embodiment, first, the synchro belt B is wound around the crank pulley P1 and the motor pulley P2 each formed of a synchro pulley, thereby transmitting the torque of the motor to the crankshaft 70 of the engine. Thus, even when the crank driving load torque at the time of starting the engine becomes the largest, for example, when cold, for example, slipping does not occur and the engine can be started reliably.

  On the other hand, since the torque can be cut off by the one-way clutch C provided on the crankshaft 70 during the operation of the engine, not only the motor but also the synchro belt B is not rotated, and a waste of engine driving force is generated. do not do.

  Moreover, the one-way clutch C is a belt type, and when the torque is cut off by this, the magnet 60 rotates the outer side in the radial direction so that the flat belt 40 is separated from the friction surface 1a of the guide wheel 1 on the crankshaft side. Since the flat belt 50 is kept in a non-contact state with the friction surface 1a, the durability is not deteriorated due to wear of the both.

  Further, by using a belt type one-way clutch C that is relatively simple and inexpensive, the cost can be reduced and the tensile strength of the flat belt 50 and the strength of the member that receives the axial load in the one-way clutch C can be reduced. If it is increased, there is no problem even if it is disposed on the crankshaft 70 that receives a large load torque at the time of starting.

  In the above-described embodiment, the synchro belt B is wound around the crank pulley P1 and the motor pulley P2 to transmit the motor torque to the crankshaft 70. However, the present invention is not limited to this, and a chain or sprocket is used. You can also

  Moreover, in the said embodiment, although the 1st rotation member of the one-way clutch C is comprised by the guide wheel 1 which consists of a flat pulley, the shape of a 1st rotation member is designed suitably according to the conditions etc. which are requested | required. be able to.

  Further, in the above-described embodiment, the case 10 of the one-way clutch C is configured by the two case members 11 and 12. However, if it is not necessary to divide as such, the case 10 may be integrally formed. Even when it divides | segments into a some member, about the number of the members to divide | segment, the shape of each division | segmentation member, etc., it can design suitably as needed.

  In the above embodiment, the case 10 of the one-way clutch C constitutes the second rotating member, and the crank pulley P1 is also integrally formed. However, the shape of the second rotating member is not particularly limited. However, the case 10 and the crank pulley P1 may be separately configured and combined.

  Further, in the one-way clutch C of the above-described embodiment, the swing plate 40 that is a movable member is rotated by a centrifugal force generated by the rotation of the case 10 (second rotating member), that is, by an inertial force in the radial direction. However, in addition to this, the inertial force acting in the circumferential direction when the case 10 starts rotating from the stopped state can be rotated in the same direction as the centrifugal force.

  That is, in the above embodiment, as shown in FIG. 3, the center of gravity G of the swing plate 40 is located radially inward of the shaft center X with respect to the shaft center Q of the needle roller 30 that is the swing center. Therefore, the moment when the case 10 starts to rotate in the clockwise direction from the stopped state, as shown schematically in FIG. 6A, the circumferential force f1 acting from the needle roller 30 and the apparent force In addition, the reaction force f2 (circumferential inertial force) acting on the center of gravity G generates a rotational moment in the clockwise direction (opposite to the centrifugal force) around the axis Q.

  Therefore, as shown in FIG. 2B, a deformed rocking plate 44 having a structure in which a weight portion 44b is added to the outer peripheral side of the plate main body 44a is adopted, and its center of gravity G is set to the axis Q of the needle roller 30. If the axial center X is positioned radially outward, the circumferential force f1 and the apparent reaction force f2 (inertial force) are applied to the swing plate 44 at the moment when the case 10 starts to rotate clockwise in the figure. ) Causes a rotational moment in the counterclockwise direction (the same direction as the centrifugal force) in the figure to press the flat belt 50. As a result, when the engine is started, the one-way clutch C enters a state in which the driving force from the motor is transmitted to the crankshaft 70 earlier, and the starting time is shortened.

  In the one-way clutch C of the above embodiment, the flat belt 50 is wound around the swing plate 40 that is swingably supported by the case 10, and one span of the flat belt 50 is rotated around the swing plate 40 itself. However, the present invention is not limited to this, and a movable member for pressing one span of the flat belt 50 is provided separately from a portion (engagement portion) around which the flat belt 50 is wound. Also good.

  Further, the endless flat belt 50 is not wound around the guide wheel 1 and the swing plate 40, but both ends of the flat belt 50 wound around the guide wheel 1 are fixed to the engaging portions on the case 10 side. You may make it do.

  Furthermore, in the one-way clutch C of the above embodiment, the friction transmission belt is constituted by the rubber flat belt 50. However, the friction transmission belt has the necessary tensile strength and flexibility. As long as it can generate the required frictional force between the friction surfaces, it is not particularly limited, for example, a metal one.

  In the one-way clutch C of the above embodiment, iron powder is mixed into the rubber layer of the flat belt 50, and the flat belt 50 is moved radially outward by the magnet 60 so as to be separated from the friction surface 1a of the guide wheel 1. However, the present invention is not limited to this, and a magnetic body such as an iron plate may be attached to the belt 50 and pulled by the magnet 60.

  In addition, in the above-described embodiment, the engine starter A for automobiles has been described. However, the engine starter according to the present invention is not limited to automobiles and can be applied to various engines.

  As described above, the present invention is an engine starter configured to drive a crankshaft via a belt or the like, and has a simple and inexpensive configuration without causing a problem of durability. Since the driving loss can be reduced, it is useful in various engines, and is particularly suitable for a hybrid vehicle having a high engine start frequency.

It is sectional drawing which shows schematic structure of the engine starting apparatus which concerns on embodiment of this invention. It is sectional drawing of the one way clutch in the II-II line | wire of FIG. It is a figure which shows the state which removed the other case member etc. from the one way clutch and was seen from the opposite side to a crankshaft. It is a schematic diagram which shows the state which transmits the driving torque from a motor at the time of engine starting. FIG. 5 is a view corresponding to FIG. 4 showing a state in which the torque from the crankshaft is interrupted after the engine is started. It is explanatory drawing of the rocking | fluctuation plate which concerns on other embodiment made to rotate in the same direction as centrifugal force with the inertial force of the circumferential direction at the time of the rotation start of a case.

Explanation of symbols

A Engine starter B Synchro belt (toothed belt)
C One-way clutch P1 Crank pulley (pulley for toothed belt)
P2 Motor pulley (pulley for toothed belt)
1 Guide wheel (first rotating member)
1a Friction surface 10 Case (second rotating member)
30 Shaft member (shaft)
40 Oscillating plate (movable member)
40a Friction surface 50 Flat belt (friction drive belt)
60 Magnet (biasing means)
70 Crankshaft X Rotational axis (center axis of friction surface of first rotating member)

Claims (7)

An engine starter configured to drive a crankshaft by a motor via an endless transmission member when starting the engine,
The endless transmission member meshes with and transmits input / output members respectively disposed on the crankshaft and the output shaft of the motor,
A one-way clutch is provided between the crankshaft and the input / output member so as to transmit a driving force in the rotational direction to the crankshaft at least during rotation of the input / output member.
The one-way clutch
A first rotating member that is integrally connected to the crankshaft and has a friction surface with a circular cross section on the outer periphery;
A second rotating member that is coupled to the input / output member of the crankshaft in a rotationally integrated manner and is assembled to the first rotating member so as to be rotatable about a central axis of the friction surface;
Engaged with the engaging portion provided on the second rotating member so as to be wound around the friction surface of the first rotating member and spaced radially outward of the friction surface, A friction transmission belt forming two spans;
When the second rotating member is rotated by a driving force from the motor, the second rotating member operates by an inertial force accompanying the rotation, and becomes a loose side span by relative rotation of the second rotating member with respect to the first rotating member. A movable member that presses one span of the friction transmission belt;
Biasing means for biasing the friction transmission belt radially outwardly away from the friction surface of the first rotating member;
An engine starting device characterized by comprising: The engine starter according to claim 1,
An engine starter characterized in that the endless transmission member is a toothed belt and the input / output member is a pulley for a toothed belt. The engine starting device according to claim 1 or 2,
The engaging portion of the second rotating member has a friction surface with a circular arc cross section on the outer periphery located radially outward of the friction surface of the first rotating member,
The friction transmission belt does not have an end, and is wound around the friction surface of the first rotating member and the friction surface of the engaging portion of the second rotating member. Engine starter. The engine starting device according to claim 1 or 2,
An engine starter characterized in that both ends of a friction transmission belt wound around a friction surface of a first rotating member are respectively fixed to engaging portions of a second rotating member. The engine starting device according to claim 3,
A shaft portion is provided on the second rotating member so as to extend parallel to the central axis of the friction surface on the radially outer side of the friction surface of the first rotating member,
The movable member is configured such that the engaging portion of the second rotating member is separated from the second rotating member and supported by the shaft portion so as to be swingable. The engine starting device is configured to rotate around the shaft portion by the inertial force accompanying the pressure to press one span of the friction transmission belt from the inner peripheral side. The engine starting device according to any one of claims 1 to 5,
The urging means is composed of a magnetic body provided on the friction transmission belt and a magnet provided on the second rotating member spaced outward in the radial direction of the friction surface of the first rotating member. Starting device. A first rotating member having a friction surface having a circular cross section on the outer periphery and connected to one of the driving side and the driven side;
A second rotating member which is assembled to the first rotating member so as to be rotatable around a central axis of the friction surface, and is connected to the other of the driving side and the driven side;
A shaft portion provided on the second rotating member so as to extend parallel to the central axis of the friction surface on the radially outer side of the friction surface of the first rotating member;
A movable member having a friction surface with a circular arc cross section on the outer periphery located radially outward of the friction surface of the first rotating member, and supported by the shaft portion so as to be swingable about its axis;
A friction transmission belt wound around the friction surface of the first rotating member and the friction surface of the movable member so as to form two spans between the two members;
The movable member is configured to rotate around the shaft portion in a direction of pressing one span of the friction transmission belt by an inertial force accompanying rotation of the second rotating member,
The one-way clutch, further comprising a biasing means for biasing the friction transmission belt radially outwardly away from the friction surface of the first rotating member.

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