JP2018141420A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt interlock mechanism which achieves high slip prevention performance.SOLUTION: An internal combustion engine includes a crank pulley 7. An ISG 8 is disposed at one side across a cylinder bore axis 16. An auto tensioner 18 for adjusting a tensile force of a first belt 17 wound around an ISG pulley 11 has: a tension pulley 19 connected to an arm 25; and an absorber 23 which biases the arm 25. The arm 25 is connected to a housing 15 of the ISG. When the arm 25 is pushed by the absorber 23, the tension pulley 19 moves closer to the ISG pulley 11. Thus, a contact length between the first belt 17 and the ISG pulley 11 becomes longer to achieve dramatically high slip prevention performance.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an internal combustion engine provided with an electrical auxiliary machine such as an ISG (Integrated Starter Generator, generator with motor function), and particularly suitable for a vehicle (automobile) internal combustion engine. ing.

  An internal combustion engine for a vehicle is accompanied by an auxiliary machine such as an alternator or an ISG, and this auxiliary machine is interlocked with a crank pulley by a belt. However, in order to prevent slippage between the pulley and the belt, the belt is tensioned. The pulley is brought into contact. In particular, since the ISG and the motor generator have a large torque and slip easily occurs between the pulley and the belt, it is essential to apply a high tension to the belt with the tension pulley.

  In the case of an auto tensioner, a tension pulley is rotatably attached to a rotating arm (link), and the arm is biased by a spring means so that the tension pulley is kept in contact with the belt. There are many. Examples thereof are disclosed in Patent Documents 1 to 3.

JP 2013-108377 A Japanese Patent Laying-Open No. 2011-017393 (FIG. 2) JP, 2006-191365, A

  In each patent document, the arm is connected to the engine body, and even if the belt is pushed by the tension pulley, the contact length between the pulley and the belt of an electric auxiliary machine such as a motor generator or an alternator is hardly changed. Therefore, it can be said that there is a limit to improving the reliability of power transmission between the pulley and the crank pulley of the electric auxiliary machine.

  The present invention has been made in view of such a current situation, and a main object is to improve the reliability of power transmission between the electric auxiliary machine and the crank pulley.

The present invention is
An electric auxiliary machine is arranged on one side of the cylinder bore axis as viewed from the crank axis direction so as to be located outside the engine body, and a pulley and a crank pulley provided in the electric auxiliary machine A tension pulley that is rotatably connected to a rotating arm is in contact with the belt wound around
This is the basic configuration.

  And, the arm is pivotally connected to a housing constituting the electric auxiliary machine, or is it rotatably connected to a bracket for attaching the electric auxiliary machine to the engine body, Alternatively, the electric auxiliary machine is connected to a portion attached to the engine body in a tightened state, and the tension pulley moves relative to the pulley of the electric auxiliary machine by rotating the arm. It has become. The electric auxiliary machine includes an ISG, a motor generator, an alternator and the like having a rotor.

  When fastening the electric auxiliary machine and the arm together, when fastening the housing and the arm together with the bracket, when fastening the bracket and the arm together with the engine body, and between the housing and the arm body. Both of the cases of directly tightening together are included.

  The tension pulley may always be pressed against the belt by a spring means, or may be configured to move to and from the belt by an actuator such as an electromagnetic solenoid.

  In the present invention, since the tension pulley moves to and away from the pulley of the electric auxiliary machine by the rotation of the arm, if the tension pulley moves so that the belt is stretched strongly, the amount of the electric auxiliary machine pulley held by the belt increases. . That is, the contact length between the belt and the electric auxiliary pulley (contact length in the circumferential direction of the pulley) becomes longer. For this reason, the frictional force between the electric auxiliary pulley and the belt can be increased as compared with the prior art. As a result, slippage between the electric auxiliary pulley and the belt can be prevented, and the reliability of power transmission can be improved.

  And since the housing of electrical auxiliary machines, such as ISG, is a structure strong in the property which hold | maintains a rotor rotatably, an arm can be attached to a housing, without requiring another reinforcement member. Therefore, problems such as an increase in weight and an increase in the number of assembly steps do not occur. The same applies when mounted on a bracket or when fastened together with an electric auxiliary machine.

It is a front view of an internal combustion engine. It is a partial enlarged front view of an internal combustion engine. (A) is a sectional view taken along line IIIA-IIIA in FIG. 1, and (B) is a sectional view taken along line IIIB-IIIB in FIG. It is the figure which looked at FIG. 2 from the IV-IV viewing direction (belt is abbreviate | omitted). FIG. 5 is a cross-sectional view taken along line VV in FIG. 1.

(1). Outline Next, an embodiment of the present invention will be described with reference to the drawings. First, an outline of the internal combustion engine will be described mainly based on FIGS. The internal combustion engine of the present embodiment is mounted on a vehicle, and includes a cylinder block 1, a cylinder head 2 fixed to the upper surface thereof, and a front cover 3 fixed to the front surface thereof as an engine body. The timing chain is covered with a front cover 3. A head cover 4 is fixed to the upper surface of the cylinder head 2, and an oil pan 5 is fixed to the lower surface of the cylinder block 1. These head cover 4 and oil pan 5 also constitute an engine body.

  A crankshaft 6 is rotatably held on the cylinder block 1. One end of the crankshaft 6 passes through the front cover 3 and is exposed to the front, and the crank pulley 7 is fixed to the exposed end. In this embodiment, an ISG 8, a water pump 9, and an air conditioner compressor 10 are provided as auxiliary machines, and these include pulleys 11, 12, and 13, respectively.

  FIG. 1 is a front view as viewed from the crankshaft direction. In this front view, the ISG 8 is arranged on the left outer side of the engine body, and the water pump 9 is located on the left side of the engine body with the cylinder bore axis 14 in between It is arranged at the part which approached. On the other hand, the air conditioner compressor 10 is disposed outside the engine body on the right side with the cylinder bore axis O interposed therebetween. Therefore, the ISG 8 and the water pump 9 are arranged close to the left, and the air conditioner compressor 10 is arranged close to the right.

  The ISG 8 is an example of an electric auxiliary machine, and includes a housing 15 that rotatably holds the rotor and an ISG pulley 11 that is fixed to the rotor. Therefore, the ISG pulley 11 corresponds to the electric auxiliary pulley described in the claims. The housing 15 is fixed to the front cover 3 and the cylinder block 1 via a bracket 16. A first belt 17 is wound around the ISG pulley 11 and the crank pulley 7, and a tension pulley 19 of an auto tensioner 18 is in contact with the first belt 17 so as to be freely rotatable from above. The first belt 17 corresponds to the belt recited in the claims.

  The main body (pump chamber, etc.) of the water pump 9 is built in the front cover 3, the water pump pulley 12 fixed to the rotating shaft is exposed, and the second belt 20 is connected to the water pump pulley 12 and the crank pulley 7. Is wrapped around. The air conditioner compressor 10 is fixed to the cylinder block 1 via a bracket 21, and a third belt 22 is wound around the pulley (air conditioner pulley) 13 and the crank pulley 7 of the air conditioner compressor 10.

  As shown in FIG. 5, the three belts 17, 20, and 22 are such that the second belt 20 is closest to the front cover 3, and the third belt 22 is farthest from the front cover 3. Is located between the two. For this reason, the crank pulley 7 is formed with three pulley portions 7a, 7b, and 7c. The inner surfaces of the belts 17, 20, and 22 have a sawtooth cross section, and therefore, the outer peripheral surfaces of the pulleys 7, 11, 12, and 13 also have a sawtooth cross section.

(2) Tensioner, etc. The auto tensioner 18 includes a telescopic absorber (elastic device) 23 in which a spring and an oil damper are housed in a case fitted in a relatively movable manner, and a distal end (lower end) of the absorber 23. And a plate-like arm (bracket) 25 connected by a first pin 24, and a tension pulley 19 is rotatably connected to a lower end of the arm 25 by a second pin (shaft) 26. Yes. The arm 25 has a copper bowl shape with a circular arc at the bottom, and the right end of the upper end that is closer to the cylinder bore axis 14 is connected to the tip of the absorber 23 by the first pin 24, and the upper end Of these, the left end portion away from the cylinder bore axis O is connected to the housing 15 of the ISG 8 by a third pin 27.

  Since the arm 25 is separated from the housing 15 of the ISG 8 toward the front, as clearly shown in FIG. 4, a boss 28 protruding toward the front (in a direction away from the engine body) is integrally formed on the housing 15 of the ISG 8. The arm 25 is connected to the boss 28 by a third pin 27. It is also possible to connect the arm 25 to the housing 15 via a collar without providing the integral boss 28.

  The bracket 16 may be formed integrally with the housing 15 or may be configured separately from the housing 15. In either case, the arm 25 can be connected to the bracket 16 (in this case, it is preferable to form a boss on the bracket 16). When the bracket 16 is formed integrally with the housing 15, it is necessary to connect the bracket 16 to the engine body with pins and bolts. At this connection point, the arms are jointly fastened with common pins and bolts (integrally Can also be connected). In this case, there is no particular problem because the bracket 16 does not rotate even if the arm 25 is rotated even if only the pins are connected.

  When the bracket 16 is configured separately from the housing 15, the arm 25 may be fastened together at the connection point between the bracket 16 and the housing 15, or may be fastened together at the connection point between the bracket 16 and the engine body. Is also possible.

  An upper end portion of the absorber 23 in the auto tensioner 18 is connected to the front cover 3 by a fourth pin 29. In this case, as shown in FIG. 3, a front projecting portion 31 having a lower surface as an inclined surface 30 is formed on the upper portion of the front cover 3, and a receiving seat 32 formed on the inclined surface 30 of the front projecting portion 31 is formed. The upper end of the absorber 23 is connected to the fourth pin 29 so as to be rotatable. Accordingly, in plan view, a substantial portion of the auto tensioner 18 is hidden by the forward projecting portion 31.

  The tension pulley 19 of the auto tensioner 18 is disposed on the rear surface of the arm 25. Therefore, the tension pulley 19 is covered with the arm 25 from the front, but the arm 25 is set to a size that covers the entire tension pulley 19.

  As clearly shown in FIG. 2, the tension pulley 19 has an axial center that connects the axial center of the ISG pulley 11, the axial center of the crank pulley 7, and the axial center of the water pump pulley 12 when viewed from the crank axis direction. It is located inside a triangle 33 surrounded by a line. For this reason, it is possible to effectively use the space by collecting the interlocking mechanism in a compact manner. In addition, a part of the tension pulley 19 overlaps a part of the second belt 20 in a front view as viewed from the crank axis direction. This configuration also contributes to the compactness by effectively using the space.

  As in the embodiment, when the arm 25 is formed in a plate shape and substantially in the shape of a copper bowl, the arm 25 serves as a cover for the tension pulley 19 and the second belt 20, so that the protection function of the tension pulley 19 and the second belt 20 is provided. There is an advantage that can be improved.

  In the present embodiment, the arm 25 moves along an arc trajectory 34 centering on the left end portion close to the ISG pulley 11 among the upper end portions thereof, so that the tension pulley 19 approaches the ISG pulley 11 when the absorber 23 extends. I will try. For this reason, the contact length of the 1st belt 17 and the ISG pulley 11 is lengthened (the tension pulley 19 is greatly embraced by the 1st belt 17), and the high slip prevention effect is realizable.

  In FIG. 2, a state in which one belt is wound around the crank pulley 7, the ISG pulley 11, and the water pump pulley 12 is indicated by a one-dot chain line 35 as a virtual belt. Since the portion is within the range surrounded by the virtual belt 35, the interlocking mechanism using the first belt 17 and the second belt 20 as transmission means can be made more compact. The entire arm 25 may be disposed inside the virtual belt 35.

  Furthermore, in this embodiment, the expansion / contraction direction 36 of the absorber 23 and the pushing direction 37 of the first belt 17 by the tension pulley 19 are obliquely inclined in the same direction with respect to the cylinder bore axis 14 when viewed from the crank axis direction. It is in the downward direction. For this reason, the elastic restoring force (spring force) of the absorber 23 can be transmitted straight to the tension pulley 19. Therefore, the absorber 23 is not twisted, and the tension state of the first belt 17 can be accurately maintained.

  That is, the ISG 8 has three states, a state functioning as a motor, a state functioning as a generator, and a state in which the ISG 8 is idling, and when the state changes, the tension state of the first belt 17 also changes. In the embodiment, the movement of the crank pulley 7 in response to the change in the tension state is performed with good responsiveness without the absorber 23 being twisted.

  Since the ISG 8 and the air-conditioning compressor 10 are arranged at opposite positions, the bending force acting on the crankshaft 6 by the first belt 17 and the bending force acting on the crankshaft 6 by the third belt 22 cancel each other. Thus, the burden on the crankshaft 6 can be reduced.

  While the embodiments of the present invention have been described above, the present invention can be embodied in various ways. For example, in the above embodiment, the tension pulley is connected to the rotary arm, but the tension pulley may be attached to a slider that slides in the same direction as the expansion / contraction direction of the absorber. As the tensioner device, a remote control type in which the tension pulley is moved by an actuator such as an electromagnetic solenoid can be adopted.

  The arm does not have to be plate-like, and a rod-like shape or a bell crank-like shape can also be adopted.

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

1 Cylinder block constituting the engine body 2 Cylinder head constituting the engine body 3 Front cover constituting the engine body (chain cover)
6 Crankshaft 7 Crank pulley 8 ISG as an example of electric auxiliary equipment
DESCRIPTION OF SYMBOLS 9 Water pump 11 ISG pulley as an example of electric system auxiliary pulley 17 1st belt which is a belt of Claim 18 Auto tensioner as an example of a tensioner device 19 Tension pulley 23 Absorber of auto tensioner 25 Auto tensioner arm 27 Pin ( Shaft, bolt)
28 Boss

Claims (1)

An electric auxiliary machine is arranged on one side of the cylinder bore axis as viewed from the crank axis direction so as to be located outside the engine body, and a pulley and a crank pulley provided in the electric auxiliary machine A tension pulley that is rotatably connected to a rotating arm is in contact with the belt wrapped around the belt,
The arm is rotatably connected to a housing constituting the electric auxiliary machine, or is rotatably connected to a bracket for attaching the electric auxiliary machine to the engine body, or The electric auxiliary machine is connected to a part attached to the engine body in a tightened state,
The tension pulley is adapted to move far and near with respect to the pulley of the electric auxiliary machine by the rotation of the arm.
Internal combustion engine.

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