JP2015224613A - Vehicle internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine in which the belt of a motor-generator is held between a pair of tension pulleys in an auto-tensioner from back side, capable of making compact the internal combustion engine by placing the motor-generator close to an engine body as much as possible while avoiding the interference of the tension pulleys with the other components.SOLUTION: A pair of tension pulleys 29 is attached to arms 42 and 43, respectively, and the arms 42 and 43 are attached to a base 41 so as to rotate about a common axial center. A rotation center 50 of the arms 42 and 43 is deviated from an axial center 51 of an accessory pulley 15 by a size E. Since the motor generator 9 can be placed close to the engine body 1 to a certain degree without changing positions of the tension pulleys 29, it is possible to make an internal combustion engine compact and improve the attachment strength of the motor-generator 9.

Description

  The present invention relates to an internal combustion engine for a vehicle in which an accessory drive belt is sandwiched between pendulum tension pulleys.

  2. Description of the Related Art It is known that an internal combustion engine for a vehicle is equipped with a motor / generator (motor generator), which also serves as a starter, and assists the rotation of a crankshaft. Power transmission between the motor generator and the crankshaft is performed by a belt. For this reason, a crank pulley is provided on the crankshaft, and a motor generator pulley is provided on the motor generator.

  A feature of the belt wound around the crank pulley and the motor generator pulley is that the tension side and the slack side are switched when the motor generator functions as a generator and when it functions as a motor.

  Therefore, in order to obtain necessary friction between the belt and the motor generator pulley in any usage mode, for example, a pendulum type auto tensioner having a pair of tension pulleys as disclosed in Patent Document 1 is used as a motor. It is arranged near the generator and the belt is sandwiched with a tension pulley from the back side.

  In this pendulum type auto tensioner, a pair of tension pulleys are each attached to an arm, and both arms are attached to the main body so as to rotate about a common rotation axis. The motor generator auto tensioner is set so that the rotational axis of the arm coincides with the rotational axis of the motor generator pulley.

Japanese translation of PCT publication No. 2003-521639

  Now, since an auxiliary machine equipped with an auto tensioner such as a motor generator is often large and heavy, it should be placed as close to the engine body as possible in terms of fixing strength and vibration suppression of the internal combustion engine. preferable. On the other hand, when the auto tensioner is brought close to the engine body, the tension pulley may hit or approach another member such as a pulley.

  For this reason, in the conventional configuration in which the tension pulley of the auto tensioner is rotated concentrically with the auxiliary pulley, the auxiliary machine such as the motor generator cannot be brought close to the engine body due to the restriction of the arrangement of the auto tensioner. Problems such as an increase in the size of the internal combustion engine and a decrease in the fixing strength of the auxiliary machine may occur.

  On the other hand, the two tension pulleys constituting the auto tensioner are designed to completely overlap (located in the same plane) when viewed from the direction orthogonal to the rotational axis, but errors in the assembly process Due to the processing error of the member, the design position may shift in the axial direction. That is, misalignment may occur.

If the misalignment amount is large, the belt may come into contact with the tension pulley and the belt may be unevenly worn, or vibration or noise may occur due to the flap of the arm. In particular, when a strong tension is applied to the belt, such as when an engine is started with a motor generator or when the motor generator is driven as a generator, uneven wear, vibration, or abnormal noise is likely to occur. As a matter of fact, if the auto tensioner is assembled precisely so that misalignment does not occur, the work will be time-consuming and the cost will increase.

  The present invention has been made to improve the current situation.

  The present invention relates to an internal combustion engine for a vehicle, and the internal combustion engine includes a crank pulley that is fixed to one end of a crankshaft protruding from the front surface of the engine body, and an auxiliary pulley that rotates about an axis parallel to the crankshaft. And a belt wound around these pulleys, and a pair of tension pulleys that sandwich a portion of the belt near the auxiliary pulley from the back side of the belt.

  In the first aspect of the present invention, the pair of tension pulleys are respectively attached to the arms, and the both arms rotate together around an axis parallel to the rotation axis of the auxiliary pulley. The rotation centers of the arms are shifted in the direction facing the engine body across the axis of the auxiliary pulley.

  According to a second aspect of the present invention, in the first aspect, the auxiliary machine is disposed on the left or right outside of the engine body as viewed from the crank axis direction, and the pair of tension pulleys are orthogonal to the crank axis line. It is arranged in front of the front surface of the engine body as seen from the direction.

  According to a third aspect of the present invention, in the second aspect, a plurality of crank pulleys offset in the axial direction are fixed to one end portion of the crank shaft, and a belt wound around each crank pulley is attached to the engine body. The nearest first belt is wound around the auxiliary machine belt and sandwiched between the pair of tension pulleys.

  In the present invention, the rotation axis of the tension pulley is shifted in the outer direction of the engine body with respect to the rotation axis of the auxiliary pulley, thereby preventing the tension pulley from hitting other members and As close as possible to the main body. That is, the auxiliary machine can be brought as close to the engine body as possible without being restricted by the arrangement of the auto tensioner. Since the auto tensioner is much smaller and lighter than the auxiliary machine, even if the rotation axis of the auto tensioner is shifted with respect to the rotation center of the auxiliary pulley, the center of gravity of the internal combustion engine may be shifted. Will not get in the way.

  Therefore, according to the present invention, the internal combustion engine can be made compact, the fixing strength of the auxiliary machine can be increased, the robustness of the internal combustion engine can be improved, and the vibration can be suppressed. In particular, when the configuration of claim 2 is adopted, the auxiliary machine can be arranged close to the side of the engine body, so that the compactness and the improvement of the supporting strength of the auxiliary machine can be ensured.

  In addition, when an internal combustion engine is mounted on a vehicle with the crankshaft in a sideways posture, if there is an auxiliary machine with a sturdy structure on the rear surface of the engine body, the auxiliary machine will move backward on the engine body when the vehicle collides. It is feared that the bulkhead will be pushed backward and may break through the bulkhead and protrude into the vehicle, which may adversely affect the passenger. However, in the invention of claim 2, the auxiliary machine is attached to the engine body as much as possible. Because it can be approached, there can be a space behind the auxiliary machine that allows the auxiliary machine to move backward when the vehicle collides with something. It can be improved.

  FIG. 8A shows a state in which the belt 19 is wound around the auxiliary pulley and the idle pulley 30 according to the embodiment. When the auxiliary pulley 15 acts as a resistance, the belt 19 becomes large. It tries to shift from a bent state to a stretched state as shown by a one-dot chain line (actually, it does not shift to a taut state but shifts to a slightly bent state).

  Accordingly, the tension pulley 29 is pushed by the belt 19 in the direction indicated by the white arrow. However, if the rotation center 50 of the tension pulley 29 is shifted outward from the rotation center 51 of the auxiliary pulley 15, the tension pulley 29 is Inevitably, the tension pulley 29 is closer to the auxiliary pulley 15 than when the rotation center of the tension pulley 29 is concentric with the rotational center of the auxiliary pulley 15.

  Then, the divergence angles θ1 and θ2 between the direction A in which the tension pulley 29 is pushed by the belt 19 and the movable directions A and B of the tension pulley 29 are such that the rotation center 50 of the tension pulley 29 is away from the rotation center 51 of the auxiliary pulley 15. The case where it has shifted is larger.

  Therefore, if the force with which the tension pulley 29 is pushed by the belt 19 is F0 as shown in (B), the force that contributes to the rotation of the tension pulley 29 in F0 is F0 when the rotation center 50 is concentric.・ F0 and cos θ2 are smaller when the rotation center 50 is deviated than cos θ1, and therefore the tension pulley 29 has a case where the rotation center 50 is concentric with the auxiliary pulley 15. Compared with, it is more difficult to rotate when it is displaced.

  Therefore, in the present invention, when a phenomenon occurs in which the tension pulley is pushed out due to the momentary tension of the belt, for example, when the tension is applied to the belt by operating the motor generator as a generator, the pushing force against the tension pulley By suppressing the phenomenon, it is possible to prevent or suppress the phenomenon that the tension pulley is ejected. As a result, it is possible to suppress the fluttering phenomenon (dance phenomenon / rage phenomenon) of the belt and the tension pulley.

  When misalignment occurs in which the position of the tension pulley is shifted from the design position in the axial direction due to assembly errors or processing errors, the effect of misalignment becomes smaller as the tension pulley moves away from the rotation center of the auxiliary pulley. . In other words, when the distance from the axis of the auxiliary pulley increases, the misalignment amount with respect to the distance (span) from the axis of the auxiliary pulley to the tension pulley (the amount by which the tension pulley and belt are displaced in the belt width direction) ) Ratio is small, and the amount of twisting of the belt due to misalignment is small. For this reason, adverse effects due to misalignment such as the occurrence of uneven wear and abnormal noise can be suppressed.

  In the present invention, if the tension pulley is rotated in the same manner as when rotating around the axis of the auxiliary pulley, the center of rotation of the tension pulley is deviated. As the tension pulley moves away from the auxiliary pulley as can be understood from the two rotation trajectories of FIG. 8, the twist amount of the belt decreases in proportion to the rotation amount of the tension pulley. Therefore, the influence of misalignment can be suppressed.

  On the other hand, when a plurality of crank pulleys are provided on the crankshaft and a plurality of types of auxiliary machines are driven by different belts, there are advantages that torque control and the like can be facilitated and the burden on the belt can be reduced. In the invention of claim 3, when a plurality of crank pulleys are provided in this way, the tension pulley is arranged on the first belt closest to the engine body, and the tension pulley can be arranged as close to the engine body as possible. This can further contribute to the downsizing of the internal combustion engine.

  The pair of tension pulleys are necessary for the auxiliary machine to be driven by the belt or to drive the belt, and the auxiliary machine is often large like a motor generator. By doing so, it is possible to prevent the auxiliary machine from protruding in front of the engine body, and thus it is possible to further contribute to downsizing.

1 is an overall schematic front view of an embodiment. It is a top view of an internal combustion engine. It is a plane sectional view of a crank pulley. It is the front view which looked at the pendulum type auto tensioner from the rotation axis direction. FIG. 5 is a rough side view of FIG. 3 viewed from the V-V viewing direction. FIG. 6 is a sectional view taken along line VI-VI in FIG. 4. It is a figure explaining a motion of a tension pulley. It is a figure for demonstrating an effect | action.

(1). Outline Next, an embodiment of the present invention will be described with reference to the drawings. First, an outline will be described based on FIGS. In the following description, the front / rear / left / right terms are used to specify the direction. The front / rear direction is the direction of the crank axis O1, and the left / right direction is a direction orthogonal to the cylinder axis O2 and the crank axis O1. In the internal combustion engine of the embodiment, the cylinder axis O2 is slightly inclined (slant) with respect to the vertical line O3, but in the figure, the cylinder axis O2 is displayed in a vertical posture for convenience. .

  The basic configuration of the internal combustion engine is the same as the conventional one. The engine body 1 is fixed with a cylinder block 2 and a cylinder head 3 fixed to the upper surface thereof as main elements, and a number of bolts 4 at one end face thereof. A front cover (chain cover, chain case) 5 is provided. A head cover 6 is fixed to the upper surface of the cylinder head 3, and an oil pan 7 is fixed to the lower surface of the cylinder block 2.

  One end of the crankshaft 8 protrudes outside the front cover 5, and a motor generator (ISG) 9 as an example of an auxiliary machine is arranged on the left side of the engine body 1 in front view. The air conditioner compressor 10 is arranged on the right side. In addition, a water pump 11 is disposed in a portion of the front cover 5 that is substantially in the middle of the upper and lower sides and on the left side.

  As shown in FIG. 1, the engine body 1 is disposed in the engine room of the vehicle in such a posture that the side on which the air conditioner compressor 10 is provided faces forward and the side on which the motor generator 9 is provided faces rearward. Accordingly, the crank 8 has a left-right longitudinal posture in the traveling direction of the vehicle (therefore, the longitudinal direction of the vehicle is different from the longitudinal direction of the engine body 1 by 90 degrees).

  The motor generator 9 is fixed to the cylinder block 2 and the front cover 5 via a plurality of brackets (described later), and the air conditioner compressor 10 is connected to the cylinder block 2 (or / and the front cover 5) via a bracket (not shown). It is fixed to. The water pump 11 also serves as a pump housing for the front cover 5, and the water pump 11 is configured by fixing a pump cover 12 (see FIG. 1) to the front cover 5.

  The motor generator 9, the air conditioner compressor 10, and the water pump 11 include pulleys 15, 16, and 17 fixed to the rotation shaft, respectively, and the first belt 19 is wound around the motor generator pulley 15 and the first crank pulley 18. The second belt 21 is wound around the pulley 16 and the second crank pulley 20 of the air conditioner compressor 10, and the third belt 23 is wound around the pulley 17 and the third crank pulley 22 of the water pump 11. It has been. In the present embodiment, the motor generator pulley 15 corresponds to the auxiliary pulley described in the claims.

  The first crank pulley 18 and the second crank pulley 20 have substantially the same diameter, and the motor generator pulley 15 has an outer diameter that is substantially half that of the first crank pulley 18. Therefore, when functioning as a generator, the motor generator 9 is driven at a rotational speed several times the rotational speed of the crankshaft 8, and when the motor generator 9 functions as a motor, the crankshaft 8 is equal to the number of motor generators 9. Driven at 1 / rev.

  A portion of the first belt 19 near the motor generator pulley 15 is sandwiched by two tension pulleys 29 in a pendulum type auto tensioner 28 from the back side. In this case, in order for the auto tensioner 28 to function, it is necessary for the first belt 19 to spread as it moves away from the motor generator pulley 15, and in order to ensure the spread angle of the first belt 19, An idle pulley 30 is attached to the upper side of the water pump 11. Therefore, the water pump 11 is disposed in an area surrounded by the first belt 19.

  Although the motor generator 9 is disposed on the left side of the engine body 1, the motor generator pulley 15 is disposed in front of the engine body 1 so that power transmission with the first belt 19 is allowed. The tension pulley 29 of the auto tensioner 29 is also arranged in front of the engine body 1. Further, since the first crank pulley 18 is disposed at a position close to the engine main body 1, the motor generator pulley 15 and the tension pulley 29 are positioned in front of the engine main body 1, but to the front of the engine main body 1. The overhang dimension is as small as possible. Accordingly, the entire motor generator 9 can be disposed beside the engine body 1.

  The motor generator 9 is located above the crankshaft 8, and the water pump 11 and the idle pulley 30 are located above the motor generator 9 and the first crank pulley 18. The idle pulley 30 and the water pump 11 are arranged in an area closer to the motor generator 9 than the cylinder axis O2 in a front view.

  As shown in FIG. 3, the first crank pulley 18, the second crank pulley 20, and the third crank pulley 22 are formed integrally with the crankshaft O 1, and are fixed to the crankshaft 9 with bolts 32. . The first crank pulley 18 is closest to the front cover 5, the third crank pulley 22 is farthest from the front cover 5, and the second crank pulley 20 is located between the two.

  Each belt 19, 21, 23 uses a multi-type V-belt having a plurality of angle ribs, and the groove width of each belt 19, 21, 23 is wider than that of the second belt 21 in the first belt 19. Thus, the second belt 21 is wider than the third belt 23.

  The motor generator 9 is attached to the side surface of the engine body 1 at two locations, an upper portion and a lower portion. In the upper part, as shown in FIG. 2, the lower part of the bracket 34 is fixed to the left and right ribs 33 provided on the casing of the motor generator 9 with bolts 25, and the upper part of the bracket 34 projects from one side of the cylinder head 3. The boss 36 is fixed with a bolt 37 and is fixed to a laterally extending portion 38 provided on the front cover 5 with a bolt 39.

(2) Configuration of Auto Tensioner As shown in FIGS. 4 to 6, the auto tensioner 28 includes a ring-shaped base (main body) 41 on which the motor generator pulley 15 is loosely fitted, and a tension pulley 29 that is rotatably held. Two arms 42, and the two arms 42, 43 are mounted on the base 41 in a state of being overlapped so that the tension pulley 29 can move forward and backward, and two substantially U-shaped springs 44 The distance between the arms 42 and 43 is maintained. A cover plate 45 is attached to the base 41.

  The two tension pulleys 29 can rotate around the axis of the base 41 together with the spring 44 and can move independently of each other by deforming the spring 44. A plurality (three) of cylindrical foot portions 46 are provided on the portion of the base 41 opposite to the tension pulley 29, and the foot portions 46 are fixed to the outer surface of the motor generator 9 with bolts (not shown). Has been. The foot 46 is fixed to a top bracket plate 47 indicated by a one-dot chain line in FIG. The top bracket plate 47 is connected to the rear bracket plate 48 and the reinforcing rod 49.

  The shaft center 50 (rotation center of the arms 42 and 43) 50 of the auto tensioner 28 has a slight dimension E on the opposite side of the tension pulley 19 with the shaft center 51 of the motor generator pulley 15 in between. It is only shifted. In other words, the rotation center 50 of the arms 42 and 43 is displaced from the front cover 5 and the crankshaft 8 by a dimension E with respect to the shaft center 51 of the pulley 15 in the motor generator 9.

(3) Summary In FIG. 7, the solid lines indicate the engine stop state and the reference state in which no load is applied to the motor generator 9. In this state, the first belt 19 acting on the two tension pulleys 29. The tension is balanced.

  On the other hand, a fine dotted line indicates a state where the motor generator 9 works as a generator. In this state, the motor generator 9 becomes a load with respect to the rotation of the first belt 19, and thus the first belt 19. Since the tension between the motor generator pulley 15 and the idle pulley 30 increases, the tension pulley 29 moves upward from the reference state.

  The rough dotted line indicates a state where the motor generator 9 operates as a motor. In this state, the first belt 19 is driven by the motor generator 9, and therefore the first belt 19 is connected to the motor generator pulley. The tension between the first crank pulley 20 and the first crank pulley 20 increases, and the two tension pulleys 29 move downward from the reference state.

  If the rotation center 50 of the tension pulley 29 is concentric with the rotation center 51 of the motor generator pulley 15, the tension pulley 29 is too close to the pulley 17 of the water pump 11 when the motor generator 9 is brought close to the engine body 1. However, since the rotation center 50 is shifted to the outside of the engine body 1 with respect to the rotation center 51, the necessary distance between the tension pulley 29 of the auto tensioner 28 and the pulley 17 of the water pump 11. The motor generator 9 can be brought as close to the engine body 1 as possible while freeing up.

  Therefore, the internal combustion engine can be made as compact as possible, and the mounting strength of the motor generator 9 can be improved. As described above, the flutter of the first belt 19 can be suppressed and the influence of misalignment can be suppressed.

In the present embodiment, even if the motor generator 9 is arranged beside the engine body 1 (behind the engine body 1 when viewed from the direction of the vehicle), a space can be made beside the motor generator 9 (behind). The engine body 1 may move backward when the vehicle collides with something in the front, but in this embodiment, even if the engine body 1 moves backward, a partition that partitions the engine room and the vehicle interior chamber Since the space between the motor generator 9 can be made as large as possible, it is possible to prevent or suppress the partition from being pierced by the motor generator 9 or protruding rearward. As a result, occupant safety during a collision can be improved.

  Since three crank pulleys 18, 20, and 22 are provided on the crankshaft 8 and the motor generator 9, the air conditioner 10, and the water pump 11 are driven by separate belts 19, 21, and 23, the belts 19, 21 are provided. , 23 and the outer diameters of the crank pulleys 18, 20, 22 can be arbitrarily set according to necessary conditions. For this reason, each auxiliary machine can be appropriately driven without being affected by other auxiliary machines.

  Further, since the first belt 19 to which the largest load is applied is disposed closest to the engine body 1, the dimension of the motor generator pulley 15 protruding in front of the engine body 1 can be minimized. The bending moment acting on the crankshaft 8 and the moment acting on the motor generator pulley 15 can be suppressed as much as possible. As a result, the durability of the crankshaft 8 and the rotating shaft of the motor generator 9 can be reduced and the durability thereof can be improved. Further, since the tension pulley 29 can also be arranged close to the engine body 1, it can further contribute to the downsizing of the internal combustion engine.

  In the present embodiment, the idle pulley 30 is moved toward one side of the cylinder axis O2, and the motor generator 9 is also moved to the side of the engine body 1, so that a power transmission system having the motor generator 9 can be obtained. Although the size can be reduced, the line connecting the upper and lower tension pulleys 29 is inclined in the same direction as the line connecting the idle pulley 30 and the crankshaft 8, so the upper and lower sides of the first belt 19 sandwiching the motor generator pulley 15. The first belt 19 can be held in an appropriate bent state by balancing the balance of tension at the points. This is also one of the advantages of this embodiment.

  In the above embodiment, the tension pulley is applied to a belt for a motor generator, but the present invention can also be applied to a case where a winding belt is sandwiched between other auxiliary pulleys with a tension pulley.

  The present invention can be embodied in an internal combustion engine for a vehicle. Therefore, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Engine main body 2 Cylinder block as engine main body 3 Cylinder head as engine main body 9 Motor generator (auxiliary device of claim)
10 Compressor for air conditioner 11 Water pump 15 Motor generator pulley (auxiliary pulley in claims)
17 Pulley of water pump 18 First crank pulley (crank pulley of claim)
19 First belt (claimed belt)
28 Auto tensioner 29 Tension pulley 30 Idle pulley 41 Base 42, 43 Arm 44 Spring

Claims (3)

A crank pulley fixed to one end of the crankshaft protruding from the front surface of the engine body, an auxiliary pulley that rotates around an axis parallel to the crankshaft, a belt wound around the pulley, and the belt A pair of tension pulleys sandwiching a portion near the auxiliary pulley from the back side of the belt,
Each of the pair of tension pulleys is attached to an arm, and both the arms are configured to rotate together around an axis parallel to a rotation axis of the auxiliary pulley,
The rotational center of both arms is shifted in the direction facing the engine body across the axis of the auxiliary pulley,
Internal combustion engine for vehicles. The auxiliary machine is disposed on the left or right outer side of the engine body as viewed from the crank axis direction, while the pair of tension pulleys are located in front of the front surface of the engine body as viewed from the direction orthogonal to the crank axis line. Arranged in the
The internal combustion engine for a vehicle according to claim 1. A plurality of crank pulleys offset in the axial direction are fixed to one end of the crankshaft, and the first belt closest to the engine body among the belts wound around each crank pulley is the auxiliary belt. Wrapped and sandwiched between the pair of tension pulleys,
An internal combustion engine for a vehicle according to claim 2.

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