JP2017044070A - Lubrication structure for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication structure for an engine, for lubricating a kick shaft in an expensive configuration.SOLUTION: The lubrication structure for an engine (1) includes a crank case (2) which can be split into right and left sides, an oil passage (45) cutting sideways across the crank case, and a kick shaft (50) for transmitting rotation driving force input from the external to the crank shaft. The oil passage is provided close to the kick shaft. In the oil passage, a first ejection hole (45a) is formed to eject oil toward the kick shaft. Thus, the existing oil passage can be utilized without the need for newly providing an oil passage specific for the kick shaft.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an engine lubrication structure, and more particularly to an engine lubrication structure provided with a kick type starter device.

  Some motorcycle engines include a kick type starter device (see, for example, Patent Document 1). In the engine described in Patent Document 1, the kick shaft is rotated by the kick operation of the kick lever. The rotation of the kick shaft is transmitted to the crankshaft in the engine via a transmission mechanism such as a gear provided at the shaft end. As a result, the engine is started. In such a kick-type starter device, in order to prevent the rotation of the crankshaft after the engine is started from being transmitted to the kickshaft, a mechanism for separating the meshing of the gear with the kickshaft after the engine is started is employed. .

Japanese Patent Laying-Open No. 2015-90148

  As described above, in the engine disclosed in Patent Document 1, the rotation of the crankshaft is interrupted by releasing the meshing of the gear with respect to the kick shaft after starting, while the gear (kick-driven gear) to be disengaged is a crank. It will be rotated along with the rotation of the shaft. For this reason, lubrication between the kick driven gear and the kick shaft is indispensable.

  In conventional engines, only oil lubrication (atmosphere lubrication) within the mission was sufficient. However, recently, an engine that is small and can be rotated to a high rotation range has been studied, and the kick-driven gear also rotates at a high speed, so that further lubrication measures are required. In this case, it is conceivable to provide a dedicated oil supply path for lubricating the kick shaft, but this causes a cost increase such as a complicated configuration.

  The present invention has been made in view of this point, and an object thereof is to provide an engine lubrication structure capable of lubricating a kick shaft with an inexpensive configuration.

  An engine lubrication structure according to the present invention includes a crankcase that can be divided into left and right, an oil passage that crosses the crankcase left and right, and a kick shaft that transmits externally input rotational driving force to the crankshaft. The oil passage is provided close to the kick shaft, and the oil passage is formed with a first ejection hole for ejecting oil toward the kick shaft. It is characterized by.

  According to this configuration, since the oil passage is disposed close to the kick shaft, lubrication of the kick shaft can be realized only by forming the first ejection hole in the oil passage. Further, since the first ejection hole is formed in the middle of the oil passage, the existing oil passage can be used, and there is no need to newly provide an oil passage dedicated to the kick shaft. Therefore, the kick shaft can be lubricated with an inexpensive configuration.

  In the lubricating structure for an engine according to the present invention, it is preferable that the oil passage is located above the kick shaft. According to this configuration, the oil can be supplied to the kick shaft by utilizing its own weight, and the kick shaft can be lubricated without requiring a complicated configuration.

  In the engine lubrication structure according to the present invention, it is preferable that the first ejection hole is directed to a gap between the kick driven gear and the starter. According to this configuration, since the oil can be directly supplied toward the shaft of the kick driven gear that always rotates while the engine is driven, the lubricating effect is enhanced.

  Further, in the engine lubrication structure according to the present invention, the crankcase is formed with a second ejection hole for ejecting oil toward the piston, and the first ejection with respect to the mating surface of the crankcase. The hole angle is preferably equal to the angle of the second ejection hole with respect to the mating surface of the crankcase. According to this structure, since the angle of the 1st, 2nd ejection hole with respect to a mating surface is equal, the processing jig at the time of processing the 1st, 2nd ejection hole can be made common. For this reason, it is not necessary to prepare a processing jig for each hole to be processed.

  In the engine lubrication structure according to the present invention, it is preferable that the first ejection hole and the second ejection hole have the same shape. According to this structure, the tool which processes the 1st, 2nd ejection hole can be made shared, and an additional tool cost can be reduced.

  According to the present invention, since the oil passage is disposed close to the kick shaft and the ejection hole is formed in the oil passage, the kick shaft can be lubricated with an inexpensive configuration.

1 is a side view showing a schematic configuration of an engine of a motorcycle according to the present embodiment. It is a front view of the engine shown in FIG. It is a side view which shows the structure in the crankcase of the engine which concerns on this Embodiment. It is a perspective view which shows the structure of the kick shaft periphery which concerns on this Embodiment. It is a perspective view of the crankcase which concerns on this Embodiment. It is a fragmentary sectional view of the crankcase concerning this embodiment.

  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 lubrication structure according to the present invention is applied to a motorcycle will be described. However, the application target is not limited to this and can be changed. For example, the engine lubrication structure according to the present invention may be applied to other types of motorcycles, buggy type motorcycles and the like. Regarding the direction, the front of the vehicle is indicated by an arrow FR, the rear of the vehicle is indicated by an arrow RE, the left side of the vehicle is indicated by an arrow L, and the right side of the vehicle is indicated by an arrow R. In the following drawings, a part of the configuration is omitted for convenience of explanation.

  With reference to FIGS. 1 and 2, a schematic configuration of the engine of the motorcycle according to the present embodiment will be described. FIG. 1 is a side view showing a schematic configuration of an engine of a motorcycle according to the present embodiment. FIG. 2 is a front view of the engine shown in FIG.

  As shown in FIGS. 1 and 2, the engine 1 is an engine having a kick starter device, and includes a piston 22 (see FIG. 3) and the like in a cylinder assembly 12 including a cylinder block 10 and a cylinder head 11. Components are accommodated, and a cylinder head cover 13 is attached to the upper end of the cylinder assembly 12 (cylinder head 11). A crankcase 2 that houses the crankshaft 20 (see FIG. 3) is attached to the lower rear side of the cylinder assembly 12.

  The crankcase 2 is configured to be divided into right and left, and has a left L case 3 and a right R case 4. A clutch cover 14 that covers a clutch (not shown) is attached to the R case 4, and a flywheel cover 15 (not shown in FIG. 1) is attached to the L case 3. A water pump 16 that supplies cooling water into the engine 1 is provided in front of the clutch cover 14. A kick lever 5 constituting a part of the kick starter device is provided behind the clutch cover 14.

  Next, the configuration in the crankcase will be described in detail with reference to FIGS. FIG. 3 is a side view showing the configuration in the crankcase of the engine according to the present embodiment. FIG. 4 is a perspective view showing a configuration around the kick shaft according to the present embodiment. 3 and 4 show a state in which the L case is removed from the crankcase.

  As shown in FIG. 3, the crankcase 2 (R case 4) is configured to house various shafts for transmitting the driving force of the engine 1 (see FIG. 1) in addition to the crankshaft 20. ing. The crankshaft 20 is housed slightly in front of the center of the crankcase 2. A piston 22 is connected to the crankshaft 20 via a connecting rod 21. A balancer shaft 23 that absorbs vibration accompanying rotation of the crankshaft 20 is provided in front of the crankshaft 20. Further, a counter shaft 24, a drive shaft 25, and a kick shaft 50 are accommodated in order behind the crank shaft 20.

  A primary drive gear (not shown) is provided at the right end of the crankshaft 20, and a clutch (not shown) is provided at the right end of the counter shaft 24. The primary drive gear meshes with a primary driven gear provided coaxially with the clutch. The counter shaft 24 and the drive shaft 25 are provided with various gears that constitute a part of the transmission.

  The rotation of the crankshaft 20 is transmitted to the counter shaft 24 via the primary drive gear and the primary driven gear. The rotation of the counter shaft 24 is transmitted to the drive shaft 25 at a predetermined speed ratio by a combination of various gears. The rotation of the drive shaft 25 is transmitted to a rear wheel (not shown) via a transmission mechanism (not shown). Further, the kick shaft 50 transmits a rotational driving force input from the outside to the crank shaft 20. More specifically, the kick shaft 50 is integrally fixed to the kick lever 5 (see FIGS. 1 and 2), and the kick operation of the kick lever 5 is directly transmitted as the rotation of the kick shaft 50. The

  As shown in FIG. 4, the kick shaft 50 is provided with a starter 51 that transmits the rotation of the kick shaft 50 to the crankshaft 20 and a kick-driven gear 52 that meshes with a gear provided on the drive shaft 25. The starter 51 includes a kick drive gear 53 that can mesh with a kick driven gear 52 (a first gear portion 52a described later), a spring 54 that urges the kick drive gear 53 in the axial direction, and a C ring 55 that fixes the spring 54. And have.

  The kick drive gear 53 is configured to be movable in the axial direction between an engagement position where the kick drive gear 53 is engaged with the kick driven gear 52 and a release position where the engagement with the kick driven gear 52 is released. Further, the kick drive gear 53 is configured to be able to rotate integrally with the kick shaft 50 in accordance with a kick operation of the kick lever 5. The spring 54 is constituted by a tension coil spring, one end is connected to the kick drive gear 53, and the other end is fixed by a C ring 55. Thus, the kick drive gear 53 is always urged to the left in the axial direction, and is normally positioned at the release position.

  The kick driven gear 52 is supported so as to be rotatable relative to the kick shaft 50. The kick driven gear 52 is a first gear portion 52a that meshes with the starter 51 (kick drive gear 53) only when the kick lever 5 is operated, and a second gear that always meshes with a gear (for example, first gear) provided on the drive shaft 25. The gear portion 52b is integrally coupled. The first gear portion 52a is formed to protrude in the axial direction from the side surface of the second gear portion 52b, and has a smaller diameter than the second gear portion 52b.

  Thus, in the engine 1 provided with the kick starter device, when the kick lever 5 is kicked, the kick shaft 50 provided in the crankcase 2 is rotated. At this time, the kick drive gear 53 provided on the kick shaft 50 slides to the right in the axial direction against the biasing force of the spring 54. Accordingly, the kick drive gear 53 is positioned at the meshing position where the kick drive gear 53 meshes with the kick driven gear 52 (first gear portion 52a). The rotation of the kick shaft 50 is transmitted to the drive shaft 25 via the kick drive gear 53 and the kick driven gear 52, and further transmitted from the drive shaft 25 to the crank shaft 20 via the counter shaft 24. Thereby, the engine 1 can be started.

  By the way, in the engine 1 provided with the kick starter device as described above, the kick drive gear 53 and the kick driven gear 52 (first gear portion 52a) are engaged only when the engine 1 is started, that is, when the kick lever 5 is kicked. It is configured as follows. After the engine 1 is started, the kick drive gear 53 is slid to the release position by the urging force of the spring 54, and the engagement of the kick drive gear 53 with the kick driven gear 52 is released. As a result, the rotation of the crankshaft 20 after the engine is started can be prevented from being transmitted to the kick shaft 50.

  On the other hand, after the engine is started, the kick driven gear 52 always rotates via the counter shaft 24 and the drive shaft 25 as the crankshaft 20 rotates. In this case, friction due to relative rotation occurs between the kick driven gear 52 and the kick shaft 50. Further, with the recent increase in engine speed, aggressive lubrication of the kick shaft 50 is indispensable.

  Further, in the conventional engine, lubrication around the kick shaft is indirectly performed by oil lubrication (atmosphere lubrication) in the mission. In this case, for example, in a vehicle in which the oil level greatly fluctuates during acceleration or braking, there is a problem that the oil supply is not stable and proper lubrication to the kick shaft is not performed.

  Therefore, in the present embodiment, the kick shaft 50 and the oil passage 45 (see FIGS. 4 and 5) in the engine 1 are arranged close to each other, and an ejection hole (a first to be described later) is formed as an oil jet in the middle of the oil passage 45. An ejection hole 45a (see FIGS. 3 to 5)) is formed. As a result, oil can be actively supplied from the oil passage 45 toward the kick shaft 50, and even if the vehicle has oil level fluctuation, the kick shaft 50 is properly lubricated without being affected. It is possible to do.

  Next, a configuration for supplying oil to the kick shaft in the crankcase (R case) according to the present embodiment will be described with reference to FIGS. FIG. 5 is a perspective view of a crankcase (R case) according to the present embodiment.

  As shown in FIG. 5, a first attachment hole 40 for attaching the crankshaft 20 (see FIG. 3) is formed on the inner side of the crankcase 2 (R case 4) slightly forward from the center. A second attachment hole 41 for attaching the balancer shaft 23 (see FIG. 3) is formed in front of the first attachment hole 40. In addition, a third mounting hole 42, a fourth mounting hole 43, and a fifth mounting hole 44 are formed in order behind the first mounting hole 40. The counter shaft 24 (see FIG. 3) is mounted in the third mounting hole 42, the drive shaft 25 (see FIG. 3) is mounted in the fourth mounting hole 43, and the kick shaft is mounted in the fifth mounting hole 44. 50 (see FIG. 3 or FIG. 4) is attached.

  An oil passage 45 for supplying oil into the engine 1 is formed above the fifth mounting hole 44. The oil passage 45 is formed so as to cross the crankcase 2 from side to side. The oil passage 45 is formed with a first ejection hole 45 a through which oil is ejected toward the kick shaft 50. The first ejection hole 45a is formed in the middle of the oil passage 45 so as to penetrate downward. More specifically, as shown in FIG. 4, the first ejection hole 45 a is formed so as to face the gap between the kick driven gear 52 (first gear portion 52 a) and the kick drive gear 53.

  Thus, in the present embodiment, the kick shaft 50 and the oil passage 45 are disposed close to each other, and the first ejection hole 45a is formed in the middle of the oil passage 45, so that the kick shaft 50 that requires oil lubrication is required. The oil can be positively supplied. For this reason, the kick shaft 50 can be properly lubricated even when the engine 1 rotates at a high speed. Moreover, the 1st ejection hole 45a is formed in the middle of the oil channel | path 45 through which the oil pumped up from the oil pump (not shown) passes. Therefore, the oil can be stably ejected toward the kick shaft 50 while the engine is being driven without being affected by the change in the posture of the vehicle and the oil level fluctuation accompanying the inertia during acceleration / deceleration.

  Further, since the oil passage 45 is located above the kick shaft 50, the oil can be supplied to the kick shaft 50 by utilizing the weight of the oil. Therefore, the kick shaft 50 can be lubricated without requiring a complicated configuration. Further, as described above, since the first ejection hole 45a is directed to the gap between the kick driven gear 52 and the kick drive gear 53 (starter 51), the first driven hole 45a is attached to the shaft of the kick driven gear 52 that rotates constantly during engine driving. Oil can be supplied directly toward the vehicle, and the lubrication effect is enhanced.

  Next, with reference to FIG.5 and FIG.6, the oil ejection hole formed in a crankcase (R case) is demonstrated. FIG. 6 is a partial cross-sectional view of the crankcase according to the present embodiment. 6A is a cross-sectional view taken along line XX (X plane) of the crankcase shown in FIG. 5, and FIG. 6B is a cross-sectional view taken along line YY (Y plane) of the crankcase shown in FIG.

  As shown in FIG. 5, the piston 22 (see FIG. 3) is provided in the crankcase 2 (R case 4) in addition to the first ejection hole 45 a that ejects oil toward the kick shaft 50 (see FIG. 4). A second ejection hole 46a is formed as a piston jet that ejects oil toward the front. The second ejection hole 46a is an oil passage 46 (see FIG. 6B) formed in the vicinity of the first mounting hole 40 above the outer periphery of the first mounting hole 40 to which the crankshaft 20 (see FIG. 3) is attached. ). When the oil is ejected from the second ejection hole 46a toward the piston 22, a cooling effect on the piston 22 can be obtained.

  As shown in FIG. 6, the first ejection hole 45 a and the second ejection hole 46 a formed in this way have a common angle with respect to the mating surface 47 of the crankcase 2 (R case 4 and L case 3). ing. More specifically, the angle θ1 (see FIG. 6A) of the first ejection hole 45a with respect to the mating surface 47 is equal to the angle θ2 (see FIG. 6B) of the second ejection hole 46a with respect to the mating surface 47. . For this reason, when processing the 1st ejection hole 45a or the 2nd ejection hole 46a by using the matching surface 47 as a reference surface, the positioning processing jig can be made common. Therefore, it is not necessary to prepare a processing jig for each hole to be processed, and the cost of an additional processing jig can be suppressed. Further, by making the first ejection hole 45a and the second ejection hole 46a the same shape (same diameter), the tools for machining the first and second ejection holes can be shared. Thus, additional tool costs can be reduced.

  As described above, according to the present embodiment, since the oil passage 45 is disposed close to the kick shaft 50, the kick shaft 50 can be lubricated only by forming the first ejection hole 45a in the oil passage 45. Can be realized. Further, since the first ejection hole 45a is formed in the middle of the oil passage 45, the existing oil passage 45 can be used, and there is no need to newly provide an oil passage dedicated to the kick shaft 50. Therefore, the kick shaft 50 can be lubricated with an inexpensive configuration without increasing the weight of the engine 1 (crankcase 2).

  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, a so-called secondary kick starter device that transmits the rotation of the kick shaft 50 to the crank shaft 20 via the drive shaft 25 has been described, but the present invention is not limited to this configuration. The kick starter device may be a so-called primary kick starter device that transmits the rotation of the kick shaft to the crankshaft 20 via an idle gear.

  In the above-described embodiment, the oil passage 45 is provided above the kick shaft 50. However, the present invention is not limited to this configuration. The oil passage 45 may be provided, for example, in front of or behind the kick shaft 50 as long as it is disposed close to the kick shaft 50.

  In the above-described embodiment, the angle and hole diameter of the oil jet for the kick shaft 50 (first ejection hole 45a) and the piston jet (second ejection hole 46a) with respect to the mating surface 47 are made common. However, it is not limited to this configuration. The angle with respect to the mating surface 47 and the hole diameter may not be made common.

  In the above-described embodiment, the reference surface for processing the first ejection hole 45a and the second ejection hole 46a is the mating surface 47 of the crankcase 2 (R case 4). However, the present invention is limited to this configuration. Not. The reference surface for processing the first ejection hole 45a and the second ejection hole 46a is not limited to the mating surface 47 and can be changed as appropriate.

  In the above-described embodiment, the shapes of the first ejection holes 45a and the second ejection holes 46a are not limited to circular shapes, and may have any shape. If the shapes of the first ejection hole 45a and the second ejection hole 46a are the same, a machining tool can be shared.

  As described above, the present invention has an effect that the kick shaft can be lubricated with an inexpensive configuration, and is particularly useful for an engine lubrication structure including a kick type starter device.

DESCRIPTION OF SYMBOLS 1 Engine 2 Crankcase 20 Crankshaft 22 Piston 45 Oil passage 45a 1st injection hole 46a 2nd injection hole 50 Kick shaft 51 Starter 52 Kick driven gear

Claims (5)

An engine lubrication structure comprising: a crankcase that can be divided into left and right; an oil passage that crosses the crankcase left and right; and a kick shaft that transmits externally input rotational driving force to the crankshaft.
The oil passage is provided close to the kick shaft,
A lubricating structure for an engine, wherein the oil passage is formed with a first ejection hole for ejecting oil toward the kick shaft.   The engine lubrication structure according to claim 1, wherein the oil passage is positioned above the kick shaft.   3. The engine lubrication structure according to claim 1, wherein the first ejection hole is directed to a gap between the kick driven gear and the starter. 4. The crankcase is formed with a second ejection hole for ejecting oil toward the piston,
The engine lubrication structure according to claim 3, wherein an angle of the first ejection hole with respect to the mating surface of the crankcase is equal to an angle of the second ejection hole with respect to the mating surface of the crankcase.   The engine lubrication structure according to claim 4, wherein the first ejection hole and the second ejection hole have the same shape.

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