JP2017141774A - engine - Google Patents

Abstract

To secure a space for arranging a turbocharger without impairing steering stability. An engine (2) includes a supercharger (27) using exhaust as a drive source, a crankshaft (23) rotating in a direction opposite to the vehicle traveling direction, and an axis ( And a cylinder (21) provided with C2). The supercharger is disposed in front of the cylinder. As a result, a space (S2) for disposing the supercharger in front of the cylinder can be secured, and the rotational inertia caused by the rotation of the tire or wheel can be offset. [Selection] Figure 2

Description

  The present invention relates to an engine, and more particularly to an engine equipped with a supercharger.

  Some motorcycles equipped with a supercharger use engine exhaust as a drive source for the supercharger (see, for example, Patent Documents 1-3). In the motorcycle described in Patent Literatures 1-3, an exhaust manifold is attached to an exhaust port formed on the front side of the cylinder head, and a supercharger (turbocharger) is attached to the exhaust manifold.

JP-A-60-240523 JP-A-60-240524 JP2015-83429A

  By the way, when it is going to arrange | position a supercharger ahead of an engine (cylinder head), it is difficult to ensure the clearance gap with a radiator or a front wheel. In this case, it is conceivable to shift the entire engine rearward in order to secure the gap. However, since the position of the center of gravity of the entire motorcycle also moves backward, there is a problem that steering stability is deteriorated as a result of the reduction of the shared load of the front wheels.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an engine capable of securing a supercharger arrangement space without impairing steering stability.

  An engine according to the present invention includes a turbocharger that uses exhaust as a drive source, a crankshaft that rotates in a direction opposite to the vehicle traveling direction, and a cylinder that is provided with an axis behind the center of the crankshaft, The supercharger is disposed in front of the cylinder.

  According to this configuration, since the cylinder axis is offset rearward from the center of the crankshaft, a space for arranging the supercharger in front of the cylinder can be secured. Moreover, the piston side pressure by combustion pressure is reduced by offsetting a cylinder, and the mechanical loss of a piston can be suppressed. Furthermore, the rotation inertia by rotation of a tire or a wheel can be canceled by reversely rotating the crankshaft with respect to the traveling direction. As a result, steering stability is improved.

  The engine according to the present invention further includes a counter shaft for transmitting rotation of the crankshaft, and a balancer shaft for reducing rotational vibration of the crankshaft, and the rotation of the crankshaft is performed on the balancer shaft. Is preferably transmitted to the countershaft. According to this configuration, the reversely rotated crankshaft can be converted to normal rotation by the balancer shaft. For this reason, it is not necessary to newly provide a shaft for changing the rotation direction of the crankshaft, and the configuration is simplified.

  In the engine according to the present invention, it is preferable that the balancer shaft is disposed above a straight line connecting the center of the crank shaft and the center of the counter shaft. According to this configuration, the balancer shaft can be prevented from being immersed in oil, and an increase in mechanical loss of the balancer shaft can be suppressed.

  The engine according to the present invention further includes a crankcase that houses the crankshaft, and a radiator that cools cooling water, and the supercharger is disposed above the crankcase, and the radiator It is preferable that it is disposed above the supercharger. According to this configuration, since the cylinder is offset, the arrangement space for the supercharger is secured above the crankcase, and the radiator can also be arranged close to the cylinder side.

  According to the present invention, the crankshaft is reversely rotated, and the cylinder is offset to the rear, so that it is possible to secure the space for arranging the supercharger without impairing the steering stability.

1 is a side view showing a schematic configuration of a motorcycle to which an engine according to an embodiment is applied. It is a mimetic diagram showing an example of arrangement of a shaft in an engine, and arrangement of peripheral parts.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following, an example in which the engine according to the present invention is applied to a naked type motorcycle will be described, but the application target is not limited to this and can be changed. For example, the engine according to the present invention may be applied to other types of motorcycles, buggy type automobile tricycles, automobiles and the like. Regarding the direction, the front of the vehicle is indicated by an arrow FR, and the rear of the vehicle is indicated by an arrow RE. In the following drawings, a part of the configuration is omitted for convenience of explanation.

  With reference to FIG. 1, a schematic configuration of a motorcycle to which the engine according to the present embodiment is applied will be described. FIG. 1 is a side view showing a schematic configuration of a motorcycle to which an engine according to the present embodiment is applied. In FIG. 1, the configuration around the engine is schematically shown.

  As shown in FIG. 1, a motorcycle 1 according to the present embodiment is a motorcycle including a supercharger 27 that uses exhaust of an engine 2 as a drive source, a so-called turbocharger. The motorcycle 1 is configured by suspending an engine 2 on a twin-spar body frame 10 made of steel or aluminum alloy on which components such as a power unit and an electrical system are mounted.

  A fuel tank 11 is disposed on the upper part of the body frame 10. A driver seat 12 and a passenger seat 13 are disposed behind the fuel tank 11 together with a rear cowl 14. A pair of left and right front forks 30 and a handle bar 31 are supported on the front head of the vehicle body frame 10 so as to be steerable. A headlamp 32 is provided in front of the handle bar 31. A front wheel 33 is rotatably supported at the lower portion of the front fork 30, and the front wheel 33 is covered with a front fender 34.

  A swing arm 40 is coupled to the rear portion of the body frame 10 so as to be swingable up and down. A rear wheel 41 is rotatably supported at the rear portion of the swing arm 40. A driven sprocket (not shown) is provided on the left side of the rear wheel 41, and the power of the engine 2 is transmitted to the rear wheel 41 by the drive chain 42. The upper portion of the rear wheel 41 is covered with a rear fender 43 provided at the rear portion of the rear cowl 14.

  The engine 2 is composed of, for example, a single cylinder or multi-cylinder four-cycle engine. The engine 2 includes an engine body 20 to which a crankcase 22 is attached below a cylinder assembly 21 (hereinafter simply referred to as a cylinder 21) in which a cylinder block, a cylinder head, and the like are combined. Components such as a piston (not shown) are accommodated in the cylinder 21. In the crankcase 22, various shafts (a counter shaft 24, a drive shaft 25, a balancer shaft 26 described later) and the like that transmit rotation of the crankshaft 23 are accommodated in addition to the crankshaft 23.

  A turbocharger 27 is provided in front of the cylinder 21 and above the crankcase 22. Specifically, the supercharger 27 is attached to an exhaust port (not shown) provided on the front surface of the engine body 20 (cylinder 21) via an exhaust manifold (not shown). The supercharger 27 has a turbine rotated by exhaust gas and a compressor (both not shown) for compressing intake air.

  An exhaust pipe 15 is connected to a side surface of the supercharger 27 (more specifically, a side surface on the turbine side). The exhaust pipe 15 extends downward from the supercharger 27, bends below the crankcase 22, and extends rearward of the vehicle body. A muffler 16 is attached to the rear end of the exhaust pipe 15. Exhaust gas after combustion is discharged to the outside through the supercharger 27, the exhaust pipe 15 and the muffler 16.

  Furthermore, the engine 1 according to the present embodiment is a water-cooled engine, and includes a radiator 28 that cools the cooling water heated in the engine 2. The radiator 28 is provided in front of the engine body 20 (cylinder 21) and above the supercharger 27. The radiator 28 cools the cooling water by receiving the traveling wind of the vehicle.

  In the motorcycle 1 configured as described above, exhaust from the engine 2 is introduced into the supercharger 27 (turbine) through the exhaust manifold in response to the occupant's throttle operation, while outside air is introduced into the air cleaner (non-reactor). It is introduced into the supercharger 27 (compressor) through the figure.

  In the supercharger 27, the turbine is rotated at a high speed by the flow of the exhaust gas, and the exhaust gas is discharged outside through the exhaust pipe 15 and the muffler 16, while the intake air is compressed by the rotation of the compressor along with the rotation of the turbine. . The compressed intake air is introduced into the engine 2 through an intake pipe (not shown).

  Thus, by compressing the intake air with the supercharger 27, an air-fuel mixture exceeding the total displacement of the engine 2 can be sent into the engine 2. As a result, more fuel can be burned and the output of the engine 2 can be increased.

  By the way, in a motorcycle equipped with a supercharger, it is difficult to place the supercharger in front of the engine body because there is a restriction on the gap between the engine body and the front wheel. For example, it is conceivable to secure an arrangement space for the supercharger by moving the engine body to the rear of the vehicle. However, if the engine body is shifted rearward, the center of gravity of the entire vehicle is concentrated on the rear wheel side. As a result, the shared load on the front wheel side is reduced, which may affect the steering stability. There is also a problem that the longitudinal length of the entire vehicle becomes large.

  Furthermore, an engine equipped with a supercharger needs to increase the amount of heat dissipated by the radiator as compared with a naturally aspirated engine, so that the radiator becomes large. In addition, the radiator is preferably provided in front of the engine body in order to receive traveling wind. In this case, as described above, there is a restriction on the gap between the engine main body and the front wheels, so that it is difficult to arrange the radiator in front of the engine main body. In particular, it is necessary to secure a certain gap between the supercharger, which is a heat generating component, and the radiator, so that there is a problem that the longitudinal length of the entire vehicle becomes large as described above.

  Therefore, in the present embodiment, the configuration is such that the axis of the cylinder 21 is offset backward from the center of the crankshaft 23. Thereby, the arrangement space of the supercharger 27 and the radiator 28 can be secured in front of the cylinder 21. In particular, since the space for arranging the supercharger 27 and the radiator 28 can be secured while the crankshaft 23 that is a heavy load is brought close to the front wheel 33 side, the shared load of the front wheel 33 is not reduced. As a result, steering stability is not impaired. Further, since the supercharger 27 and the radiator 28 are arranged in the arrangement space described above, the longitudinal length of the vehicle is not increased.

  Moreover, in this Embodiment, it was set as the structure which reversely rotates the crankshaft 23 with respect to the advancing direction of a vehicle. Thereby, the rotation inertia by rotation of a tire or a wheel can be canceled by the rotation inertia of the crankshaft 23. As a result, steering stability (handling performance) is improved. As described above, by combining the offset cylinder and the reverse rotation crank, it is possible to realize both the securing of the arrangement space for the supercharger 27 and the radiator 28 and the improvement of the steering stability while reducing the mechanical loss. .

  Next, the layout of engine components will be described with reference to FIG. FIG. 2 is a schematic diagram showing an example of the arrangement of shafts and peripheral components in the engine. 2A is a layout diagram of an engine according to a comparative example, and FIG. 2B is a layout diagram of the engine according to the present embodiment. In FIG. 2A and FIG. 2B, since the layouts of the components are different, the names of the components are the same. Therefore, description of the already described configuration is omitted.

  First, the engine 5 according to the comparative example will be described. As shown in FIG. 2A, a crankshaft 53, a countershaft 54, a drive shaft 55, and a balancer shaft 56 are accommodated in the crankcase 52. The crankshaft 53 is arranged slightly forward from the center in the crankcase 52. A balancer shaft 56 that reduces rotational vibration of the crankshaft 53 is disposed in front of and below the crankshaft 53. A countershaft 54 that transmits the rotation of the crankshaft 53 is disposed behind the crankshaft 53. A drive shaft 55 that transmits the rotation of the counter shaft 54 to the rear wheels is disposed behind the counter shaft 54.

  The crankshaft 53 is provided with a primary drive gear 53a, and the balancer shaft 56 is provided with a balancer gear 56a. The balancer gear 56a meshes with the primary drive gear 53a. The counter shaft 54 is provided with a primary driven gear 54a. Primary driven gear 54a meshes with primary drive gear 53a. The counter shaft 54 and the drive shaft 55 are provided with a plurality of transmission gears 55a that constitute a part of the transmission (the transmission gear of the counter shaft 54 is not shown).

  In the comparative example, the crankshaft 53 is normally rotated in the same direction as the vehicle traveling direction (clockwise shown in FIG. 2A). The rotation of the crankshaft 53 is transmitted to the countershaft 54 via the primary drive gear 53a and the primary driven gear 54a. The rotation of the crankshaft 53 can be connected / disconnected by a clutch (not shown) provided on the countershaft 54. The rotation of the counter shaft 54 is transmitted to the drive shaft 55 at a predetermined speed ratio by a combination of a plurality of transmission gears 55a. The rotation of the drive shaft 55 is transmitted to the rear wheel 41 (see FIG. 1) via the drive chain 42 (see FIG. 1).

  A cylinder 51 is provided above the crankshaft 53. The cylinder 51 is disposed such that the axis C1 (the axial center line of the cylinder 51) passes through the center of the crankshaft 53 and is tilted forward.

  In the engine body 50 according to the comparative example, the center of the crankshaft 53 is separated from the rear edge of the front wheel 33 by a distance D1. A space S <b> 1 is provided between the front wheel 33 and the engine body 50 in front of the engine body 50. Here, it is assumed that when the radiator 28 is provided in the space S1, it is necessary to ensure a gap D2 between the front wheel 33 and the radiator 28.

  In this case, the radiator 28 is too close to the engine body 50 side, and the gap D3 between the radiator 28 and the cylinder 51 is hardly ensured. As a result, the radiator 28 is not so preferable because it is affected by the heat of the exhaust manifold (not shown), and the passage efficiency of the traveling wind passing through the radiator 28 is deteriorated and the cooling efficiency is lowered. Further, there is no room for arranging the supercharger in the space S1.

  On the other hand, in the engine 2 according to the present embodiment, as shown in FIG. 2B, the crankshaft 23 is accommodated on the front side in the crankcase 22. A counter shaft 24 is disposed behind the crank shaft 23. A drive shaft 25 is disposed behind the counter shaft 24. These three axes are provided on a substantially straight line in the longitudinal direction of the vehicle. A balancer shaft 26 is disposed on the rear upper side of the crankshaft 23.

  The primary drive gear 23 a of the crankshaft 23 meshes with the balancer gear 26 a of the balancer shaft 26. The balancer gear 26 a meshes with the primary driven gear 24 a of the counter shaft 24. The counter shaft 24 and the drive shaft 25 are provided with a plurality of transmission gears 25a that constitute a part of the transmission (the transmission gear of the counter shaft 24 is not shown).

  In the present embodiment, the crankshaft 23 is reversely rotated in the direction (counterclockwise shown in FIG. 2B) opposite to the traveling direction of the vehicle (the direction of rotation of the front wheels 33). The rotation of the crankshaft 23 is transmitted to the balancer shaft 26 via the primary drive gear 23a and the balancer gear 26a. The rotation of the balancer shaft 26 is transmitted to the counter shaft 24 through the balancer gear 26a and the primary driven gear 24a.

  At this time, the rotation direction of the crankshaft 23 that is reversely rotated is converted into a normal rotation by the balancer shaft 26. Thereby, the rotation direction of the counter shaft 24 is converted into the same direction as the rotation direction of the counter shaft 54 according to the comparative example (counterclockwise direction shown in FIG. 2). Since the rotation of the crankshaft 23 is thus transmitted to the counter shaft 24 via the balancer shaft 26, the reversely rotated crankshaft 23 can be converted to normal rotation by the balancer shaft 26. As a result, it is not necessary to newly provide a shaft for changing the rotation direction of the crankshaft 23, and the configuration is simplified.

  The rotation of the counter shaft 24 is transmitted to the drive shaft 25 at a predetermined gear ratio by a combination of a plurality of transmission gears 25a, as in the comparative example. The rotation of the drive shaft 25 is transmitted to the rear wheel 41 via the drive chain 42.

  A cylinder 21 is provided above the crankshaft 23. In the present embodiment, the cylinder 21 is disposed such that the axis C2 is inclined forward and is offset backward by a distance E with respect to the axis C1 according to the comparative example. Specifically, the cylinder 21 is offset so that the axis C2 is located behind the center of the crankshaft 23. As in the comparative example, the center of the crankshaft 23 is separated from the rear edge of the front wheel 33 by a distance D1.

  In the present embodiment, as described above, the cylinder 21 is offset rearward, and the balancer shaft 26 is provided below the crankshaft 23. For this reason, the space S2 larger than the space S1 according to the comparative example can be secured in front of the cylinder 21 and the crankcase 22 (engine body 20). As a result, the supercharger 27 can be disposed close to the cylinder 21 in the space S2 in front of the cylinder 21.

  In this way, the turbocharger 27 can be disposed while securing the distance D1 between the crankshaft 23 and the rear edge of the front wheel 33 and bringing the crankshaft 23 closer to the front wheel 33 side. Accordingly, there is no need to shift the engine body 20 rearward, and the center of gravity of the entire vehicle is not concentrated on the rear wheel side. Therefore, the shared load of the front wheel 33 is ensured and the steering stability is not affected.

  In addition, above the supercharger 27, the cylinder 21 is offset rearward in the same manner as described above, so that the radiator 28 can also be arranged in the space S2 in front of the cylinder 21. Specifically, the clearance D4 between the radiator 28 and the cylinder 21 can be secured by the amount that the cylinder 21 is offset rearward, while the clearance D2 between the front wheel 33 and the radiator 28 is secured.

  Thus, it became possible to ensure a gap D4 that is larger than the gap D3 between the radiator 28 and the cylinder 51 according to the comparative example. Thereby, it is possible to make it difficult for the radiator 28 to be affected by the heat from the cylinder 21. Further, in the space S2 between the cylinder 21 and the front wheel 33, the radiator 28 can be arranged as close to the cylinder 21 as possible.

  The balancer shaft 26 is disposed above a straight line L connecting the center of the crankshaft 23 and the center of the counter shaft 24. For this reason, it is possible to prevent the balancer shaft 26 from being immersed in oil in an oil pan (not shown). As a result, an increase in mechanical loss of the balancer shaft 26 can be suppressed. Further, since the balancer shaft 26 is disposed between the three shafts (crank shaft 23, counter shaft 24, drive shaft 25) disposed in the longitudinal direction of the vehicle, the longitudinal length of the engine body 20 is longer than that of the comparative example. Can be shortened.

  As described above, according to the present embodiment, the axis C2 of the cylinder 21 is offset rearward from the center of the crankshaft 23, so that the space S2 for disposing the supercharger 27 in front of the cylinder 21 is reduced. Can be secured. Moreover, piston side pressure by combustion pressure is reduced by offsetting the cylinder 21, and the mechanical loss of a piston can be suppressed. Furthermore, the rotation inertia by rotation of a tire or a wheel (wheel 33) can be canceled by reversely rotating the crankshaft 23 with respect to the traveling direction. As a result, steering stability is improved.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the above-described embodiment, the balancer shaft 26 is provided on the rear upper side of the crankshaft 23, but is not limited to this configuration. The balancer shaft 26 may be provided, for example, below the crankshaft 23. Further, the balancer shaft 26 is not necessarily provided. In this case, it is preferable to provide an idle gear in order to return the rotation (reverse rotation) of the crankshaft 23 to the normal rotation.

  As described above, the present invention has an effect that it is possible to secure the arrangement space of the supercharger without impairing the steering stability, and is particularly useful for an engine equipped with a supercharger.

DESCRIPTION OF SYMBOLS 1 Motorcycle 2, 5 Engine 20, 50 Engine main body 21, 51 Cylinder 23, 53 Crankshaft 24, 54 Countershaft 26, 56 Balancer shaft 22, 52 Crankcase 27 Supercharger 28 Radiator 33 Front wheel C1, C2 Cylinder axis D1 Distance between the crankshaft and the front wheel D2 Distance between the radiator and the front wheel D3, D4 Distance between the cylinder and the radiator L Straight line connecting the center of the crankshaft and the center of the countershaft S1, S2 Space

Claims (4)

A turbocharger using exhaust as a drive source;
A crankshaft rotating in a direction opposite to the vehicle traveling direction;
A cylinder provided with an axis behind the center of the crankshaft,
The engine, wherein the supercharger is disposed in front of the cylinder. A countershaft for transmitting rotation of the crankshaft;
A balancer shaft that reduces rotational vibration of the crankshaft;
The engine according to claim 1, wherein the rotation of the crankshaft is transmitted to the countershaft through the balancer shaft.   The engine according to claim 2, wherein the balancer shaft is disposed above a straight line connecting a center of the crankshaft and a center of the counter shaft. A crankcase that houses the crankshaft;
A radiator for cooling the cooling water;
The supercharger is disposed above the crankcase;
The engine according to any one of claims 1 to 3, wherein the radiator is disposed above the supercharger.

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