JP5266087B2 - Motorcycle engine - Google Patents

Abstract

The invention relates to an engine for a two-wheel motorcycle, a suction inlet is arranged at the rear side surface of a cylinder head, an output shaft is freely-rotatably supported by a gearbox connected with the lower part and the rear part of an engine main body, an air-sucked amount adjusting assembly for adjusting the air-sucked amount is connected with the cylinder head, wherein, for increasing the output in the low and middling speed rotating area of the engine, a longer air inlet pipe is connected between the air-sucked amount adjusting assembly and the cylinder head and a support structure of a sucking system is also stabilized. The air-sucked amount adjusting assembly (44) is arranged above the output shaft (31), an installation flange (56) at one end of a metallic air inlet pipe (45) with the installation flanges (56, 57) at two ends is directly connected with the air-sucked amount adjusting assembly (44), the installation flange (57) at the other end of the air inlet pipe (45) is directly connected with the cylinder head (28).

Description

  In the present invention, an intake port is provided on a rear side surface of a cylinder head that constitutes a part of an engine body mounted on a vehicle body frame, and power is applied to a rear wheel in a transmission case that continues to the lower part of the engine body and continues to the rear. The present invention relates to a motorcycle engine in which an output shaft for transmission is rotatably supported and an intake air amount adjusting means for adjusting an intake air amount to be sucked into the intake port is connected to the cylinder head.

A motorcycle engine in which a carburetor disposed behind a cylinder head is connected to the cylinder head is known from Patent Document 1.
JP-A-8-67285

  In the one disclosed in Patent Document 1, the intake pipe length between the carburetor and the cylinder head is shortened, and in order to increase the output in the low and medium speed rotation regions of the engine, the intake amount adjustment of the carburetor and the like is adjusted. There is a desire to connect the means to the cylinder head via a long inlet pipe, and there is also a demand to stabilize the support structure of the intake system including the intake air amount adjusting means.

  The present invention has been made in view of such circumstances. In order to increase the output in the low and medium speed rotation regions of the engine, the intake air amount adjusting means and the cylinder head are connected by a relatively long inlet pipe, and the intake air is An object of the present invention is to provide a motorcycle engine having a stable support structure.

To achieve the above object, according to the present invention, an intake port is provided on a rear side surface of a cylinder head constituting a part of an engine main body mounted on a vehicle body frame, and a mission is connected to a lower portion of the engine main body. An engine for a motorcycle in which an output shaft for transmitting power to a rear wheel is rotatably supported by a case, and an intake air amount adjusting means for adjusting an intake air amount to be sucked into the intake port is connected to the cylinder head The intake air amount adjusting means is disposed above the output shaft, forms an intake passage leading to the intake port, and has an attachment flange at one end of a metal inlet pipe having attachment flanges at both ends. It is connected directly to the adjusting means, the smell that mounting flange of the other end of said inlet pipe is connected directly to the cylinder head The engine body is configured to be air-cooled so that a plurality of cooling fins are provided on the outer surfaces of the cylinder block and the cylinder head, and a rectifying fin extending in the front-rear direction is provided on the outer surface of the inlet pipe. The first feature is that a communication passage is provided from the periphery of the exhaust port provided on the front side surface of the cylinder head to the periphery of the intake port .

The present invention also provides an intake port on the rear side surface of a cylinder head constituting a part of an engine body mounted on a vehicle body frame, a transmission case connected to a lower part of the engine body, and a rear case. An engine for a motorcycle, in which an output shaft for transmitting the engine is rotatably supported, and an intake air amount adjusting means for adjusting an intake air amount to be sucked into the intake port is connected to the cylinder head, wherein the intake air amount is An adjusting means is disposed above the output shaft, forms an intake passage that communicates with the intake port, and has a mounting flange at one end of a metal inlet pipe that has mounting flanges at both ends, and is directly connected to the intake air amount adjusting means. In the case where the mounting flange at the other end of the inlet pipe is directly connected to the cylinder head, the cylinder block The engine body as a plurality of cooling fins are provided on an outer surface of the fine cylinder head is configured to air-cooled, the outer surface of the inlet pipe is provided with a rectifying fins extending in the longitudinal direction, the rectifying fins, the intake A second feature is that the inlet pipe is integrally provided on the upper outer surface and the lower outer surface such that the protruding height from the outer surface of the inlet pipe increases toward the amount adjusting means side.

Furthermore, in addition to the configuration of the first or the second feature, the present invention is such that the mounting surfaces of the mounting flanges provided at both ends of the inlet pipe to the intake air amount adjusting means and the cylinder head move away as they go upward. A third feature is that both ends of the inlet pipe are attached to the intake air amount adjusting means and the cylinder head by bolts that are inclined and are inserted into both attachment flanges from the inlet pipe side.

  The carburetor 44 of the embodiment corresponds to the intake air amount adjusting means of the present invention.

According to each of the first and second features of the present invention, the intake air amount adjusting means is disposed above the output shaft that is rotatably supported by the transmission case that is connected to the lower part of the engine body and that is connected to the rear. Therefore, the length of the inlet pipe connecting the cylinder head and the intake air amount adjusting means is relatively long, and the output in the low and medium speed rotation regions of the engine can be increased. Moreover, the metal inlet pipe has mounting flanges at both ends, and the mounting flange at one end of the inlet pipe is directly connected to the intake air amount adjusting means, and the mounting flange at the other end of the inlet pipe is directly connected to the cylinder head. Therefore, the intake system including the intake air amount adjusting means can be stably supported. Further, the number of parts can be reduced and the cost can be reduced as compared with the structure in which the intake air amount adjusting means or the cylinder head is connected to the inlet pipe via the rubber insulator.

In addition, the air-cooled engine body can be efficiently cooled. That is , since the inlet pipe is formed relatively long by the configuration of the above feature, the traveling wind is more likely to flow to the back side of the cylinder head compared to the case where the inlet pipe is relatively short. The rectifying fins provided on the engine body can smoothly guide the air to the rear, and the engine body can be effectively cooled so that no air stagnation occurs around the engine body.

In particular , according to the first feature of the present invention, since the communication passage extending from the periphery of the exhaust port to the periphery of the intake port is provided in the cylinder head, the cooling air flowing into the communication passage from the exhaust port side is supplied to the periphery of the intake port. Thus, the cooling performance of the cylinder head can be improved by smoothly discharging the cylinder head rearward.

In particular , according to the second feature of the present invention, since the rectifying fins are integrally provided on the upper outer surface and the lower outer surface of the inlet pipe, the air flowing from the left and right of the inlet pipe does not collide with each other on the rear side. The engine can be flowed smoothly and the cooling performance of the engine body can be further enhanced. Moreover, the height of the rectifying fin protruding from the outer surface of the inlet pipe is set so as to increase toward the intake air amount adjusting means, so that the attachment rigidity of the intake air amount adjusting means to the inlet pipe on the side far from the cylinder head is set. Can be increased.

Furthermore, according to the third feature of the present invention, the intake air volume adjusting means of the mounting flanges at both ends of the inlet pipe and the mounting surface to the cylinder head are formed so as to be inclined away from each other upward. Both ends of the inlet pipe are attached to the intake air amount adjusting means and the cylinder head by bolts inserted through both mounting flanges from the side, so that the mounting flange can be easily processed and the intake pipe air intake amount adjusting means and the cylinder Mounting to the head can be facilitated.

1 is a side view of a motorcycle according to a first embodiment. It is an enlarged side view of an engine. FIG. 3 is a plan view taken in the direction of arrow 3 in FIG. 2. It is a rear part side view of a cylinder head. It is a front part side view of a cylinder head. FIG. 6 is a cross-sectional view of the cylinder head taken along line 6-6 in FIG. It is a side view of an inlet pipe. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. FIG. 9 is a view taken in the direction of arrow 9 in FIG. It is an enlarged side view of the engine of Example 2. It is a side view of an inlet pipe. FIG. 12 is a view taken in the direction of arrow 12 in FIG. 11.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  The first embodiment of the present invention will be described with reference to FIGS. 1 to 9. First, in FIG. 1, a vehicle body frame F of a motorcycle supports a front fork 15 that pivotally supports a front wheel WF at a lower end portion. A left and right head pipe 16 having a front half inclined part 17a extending slightly rearward from the head pipe 16 and a rear half inclined part 17b extending steeper from the rear end of the front half inclined part 17a at a steeper slope than the front half inclined part 17a. A pair of main pipes 17, and a pair of left and right down pipes 18 that are inclined at a steeper angle than the front half inclined portion 17 a of the main pipes 17 and extend downward from the head pipe 16, and the main pipes 17. A pair of left and right rear pipes 19 extending rearward from the lower part of the rear half inclined portion 17b, and the front half slope of the main pipe 17 ... Comprises a connecting pipe 20 ... and for connecting the parts 17a ... rear and the rear pipe 19 ... intermediate portion of the.

  An engine main body 22 of an engine E that is an air-cooled single-cylinder four-cycle is supported on the body frame F at a lower portion of the rear half inclined portion 17b of the main pipe 17 and a lower portion of the down pipe 18. Mounted. Further, a fuel tank 23 is mounted above the engine body 22 on the front half inclined portions 17a of the main pipes 17 in the body frame F, and is supported by the rear pipes 19 in the body frame F behind the fuel tanks 23. In this manner, the tandem type riding seat 24 is arranged.

  Referring also to FIG. 2, the engine body 22 is coupled to a crankcase 26 that rotatably supports a crankshaft 25 having an axis along the vehicle width direction, and a front upper portion of the crankcase 26. A rising cylinder block 27, a cylinder head 28 coupled to the upper end of the cylinder block 27, and a head cover 29 coupled to the upper end of the cylinder head 28 are provided.

  Thus, a plurality of cooling fins 27a, 27a,... Arranged in the vertical direction are provided on the outer surface of the cylinder block 27, and a plurality of cooling fins 28a, 28a,.

  A transmission case 30 extending rearward is connected to a lower portion of the engine body 22, that is, a crankcase 26, and a transmission (for shifting the rotational power from the crankshaft 25) is provided in the transmission case 30. (Not shown) is accommodated, and the output shaft 31 is rotatably supported by the mission case 30.

  Referring again to FIG. 1, the front end of the swing arm 32 that pivotally supports the rear wheel WR at the rear end is swingable via the support shaft 33 at the lower part of the rear half inclined portion 17 b of the main pipe 17 of the body frame F. A rear cushion unit 34 is provided between the rear pipe 19 of the vehicle body frame F and the rear portion of the swing arm 32.

  Rotational power is transmitted from the output shaft 31 to the rear wheel WR. The drive sprocket 35 fixed to the projecting end portion of the output shaft 31 from the transmission case 30 and the axle of the rear wheel WR are provided. An endless chain 37 is wound around the driven sprocket 36.

  3 and 4 together, an intake port 40 is provided on the rear side surface of the cylinder head 28, and the intake port 40 is opened by a flange 41 provided integrally with the cylinder head 28. . An intake system 42 is connected to the flange 41. The intake system 42 includes an air cleaner 43 disposed below the front portion of the passenger seat 24 and an upstream end of the air cleaner 43, as shown in FIG. Is connected to the carburetor 44 as an intake air amount adjusting means, and an inlet pipe 45 connecting the downstream end of the carburetor 44 and the flange 41.

  Referring also to FIG. 5, an exhaust port 47 is provided on the front side surface of the cylinder head 28, and the exhaust port 47 is opened by a flange 48 provided integrally with the cylinder head 28. An exhaust system 49 is connected to the flange 48. The exhaust system 49 includes an exhaust pipe 50 extending downward from the front side surface of the cylinder head 28 and a lower part of the engine body 22, as shown in FIG. A catalytic converter 51 connected to the downstream end of the exhaust pipe 50 and an exhaust muffler 52 connected to the downstream end of the catalytic converter 51 and arranged on the right side of the rear wheel WR.

  Referring also to FIG. 6, the cylinder head 28 is provided with a communication passage 53 extending from the periphery of the exhaust port 47 provided on the front side surface thereof to the periphery of the intake port 40 on the rear side surface thereof. Sometimes, the traveling wind that flows into the communication path 53 from the front side surface of the cylinder head 28 around the exhaust port 47 flows backward from the rear side surface of the cylinder head 28 around the intake port 40.

  Incidentally, the carburetor 44 of the intake system 42 is disposed above the output shaft 31 rotatably supported by the mission case 30 as shown in FIGS. The inlet pipe 45 connecting the carburetor 44 and the cylinder head 28 is formed relatively long.

  7, 8 and 9, the inlet pipe 45 forms an intake passage 55 communicating with the intake port 40 and has attachment flanges 56 and 57 at both ends, and is formed by die casting of a metal such as an aluminum alloy. A mounting flange 56 at one end of the inlet pipe 45 is directly connected to a flange 58 provided in the vaporizer 44, and a mounting flange 57 at the other end of the inlet pipe 45 is connected to the flange of the cylinder head 28. 41 is directly connected.

  Further, the outer surface of the inlet pipe 45 is provided with rectifying fins 59 and 60 extending in the front-rear direction. In the first embodiment, the protruding height from the outer surface of the inlet pipe 45 increases toward the vaporizer 44 side. The rectifying fins 59 and 60 are integrally provided on the upper outer surface and the lower outer surface of the inlet pipe 45 so as to be large.

  Moreover, the attachment surfaces 56a and 57a of the attachment flanges 56 and 57 provided at both ends of the inlet pipe 45 to the carburetor 44 and the cylinder head 28 are formed so as to be inclined away from each other toward the upper side. One end of the inlet pipe 45 is attached to the flange 58 of the carburetor 44 by bolts 61... Inserted into one mounting flange 56 from the side, and the bolt 62. The other end of the inlet pipe 45 is attached to the flange 41 of the cylinder head 28.

  Further, a negative pressure take-out pipe 63 for taking out a negative pressure from the intake passage 55 is provided at an upper portion of the inlet pipe 45 near the cylinder head 28, and the negative pressure taken out from the negative pressure take-out pipe 63 is secondary air. In order to be used for the flow rate control, the negative pressure take-out hose 64 (see FIG. 3) is led to the engine body 22 side, and the negative pressure take-out pipe 63 is provided in the upper part of the inlet pipe 45 near the cylinder head 28. The length of the negative pressure take-out hose 64 can be short.

  Further, a pair of upper and lower reinforcing ribs 65 extending in the front-rear direction are integrally provided on the left and right side surfaces of the inlet pipe 45.

  Next, the operation of the first embodiment will be described. The carburetor 44 is disposed above the output shaft 31 that is rotatably supported by the transmission case 30 so as to transmit power to the rear wheel WR. Since the cylinder heads 28 are connected by the inlet pipe 45, the length of the inlet pipe 45 is relatively long, and the output of the engine E in the low and medium speed rotation regions can be increased.

  Moreover, the inlet pipe 45 is made of metal having an intake passage 55 communicating with the intake port 40 provided on the rear side surface of the cylinder head 28 and having attachment flanges 56 and 57 at both ends. Since the mounting flange 56 is directly connected to the flange 58 of the carburetor 44 and the mounting flange 57 at the other end of the inlet pipe 45 is directly connected to the flange 41 of the cylinder head 28, the intake system 42 including the carburetor 44 is provided. It can be supported stably. Further, the number of parts can be reduced and the cost can be reduced as compared with the structure in which the vaporizer 44 or the cylinder head 28 is connected to the inlet pipe via the rubber insulator.

  Further, the engine body 22 is configured to be air-cooled so that a plurality of cooling fins 27 a, 27 a... 28 a, 28 a... Are provided on the outer surfaces of the cylinder block 27 and the cylinder head 28. Since the rectifying fins 59 and 60 extending in the direction are provided, the air-cooled engine body 22 can be efficiently cooled. In other words, since the inlet pipe 45 is formed to be relatively long, the traveling wind is likely to flow to the back side of the cylinder head 28 as compared with the case where the inlet pipe 45 is relatively short, and the traveling wind is provided on the outer surface of the inlet pipe 45. The rectifying fins 59 and 60 can be smoothly guided rearward, and the engine main body 22 can be effectively cooled so that no air stagnation occurs around the engine main body 22.

  In addition, the cylinder head 28 is provided with a communication passage 53 extending from the periphery of the exhaust port 47 provided on the front side surface to the periphery of the intake port 40 on the rear side surface, so that the cooling that has flowed into the communication passage 53 from the exhaust port 47 side. It is possible to improve the cooling performance of the cylinder head 28 by smoothly discharging the wind from the cylinder head 28 to the rear around the intake port 40.

  Further, since the rectifying fins 59 and 60 are integrally provided on the upper outer surface and the lower outer surface of the inlet pipe 45, the air flowing from the left and right of the inlet pipe 45 flows smoothly to the rear side so that they do not collide with each other. The cooling property of the main body 22 can be further enhanced. Moreover, the height of the rectifying fins 59 and 60 protruding from the outer surface of the inlet pipe 45 is set so as to increase toward the carburetor 44 side, so the carburetor 44 to the inlet pipe 45 on the side farther from the cylinder head 28. The mounting rigidity can be increased.

  Further, the attachment surfaces 56a and 57a of the attachment flanges 56 and 57 provided at both ends of the inlet pipe 45 to the carburetor 44 and the cylinder head 28 are formed so as to be inclined away from each other toward the upper side, from the inlet pipe 45 side. Both ends of the inlet pipe 45 are attached to the flange 58 of the carburetor 44 and the flange 41 of the cylinder head 28 by bolts 61... 62 inserted through the both attachment flanges 56, 57. And the work of attaching the inlet pipe 45 to the carburetor 44 and the cylinder head 28 can be facilitated.

  A second embodiment of the present invention will be described with reference to FIG. 10 to FIG. 12, but the portions corresponding to the first embodiment are only denoted by the same reference numerals and detailed description thereof is omitted.

  First, in FIG. 10, the carburetor 44 is disposed above the output shaft 31 that is rotatably supported by the mission case 30, and is disposed at a position relatively far behind the cylinder head 28. The inlet pipe 66 connecting the carburetor 44 and the cylinder head 28 is formed relatively long.

  Referring to FIGS. 11 and 12 together, the inlet pipe 66 is formed by combining an upper half 67 and a lower half 68 formed by die casting of a metal such as an aluminum alloy, and an intake port. 40 is formed in a cylindrical shape with an intake passage 71 leading to 40, and mounting flanges 69 and 70 are provided at both ends of the inlet pipe 66. Thus, both mounting flanges 69 and 70 are formed integrally with the lower half 68, and the mounting flange 69 at one end of the inlet pipe 66 is directly connected to the flange 58 provided in the vaporizer 44, A mounting flange 70 at the other end of the inlet pipe 66 is directly connected to the flange 41 of the cylinder head 28.

  Further, rectifying fins 72 and 73 extending in the front-rear direction are provided on the outer surface of the inlet pipe 66. Unlike the first embodiment, the protruding height from the outer surface of the inlet pipe 66 is constant in the second embodiment. As described above, the rectifying fins 72 and 73 are provided on the upper outer surface and the lower outer surface of the inlet pipe 66.

  Moreover, the attachment surfaces 69a and 70a of the attachment flanges 69 and 70 provided at both ends of the inlet pipe 66 to the carburetor 44 and the cylinder head 28 are formed so as to be inclined away from each other toward the upper side. One end of the inlet pipe 66 is attached to the flange 58 of the carburetor 44 by bolts 75... That are inserted from the mounting pipe 69 to one mounting flange 69, and the bolts 76 are inserted from the inlet pipe 66 side to the other mounting flange 70. The other end of the inlet pipe 66 is attached to the flange 41 of the cylinder head 28.

  Further, a negative pressure take-out pipe 77 for taking out a negative pressure from the intake passage 71 is provided at an upper portion of the inlet pipe 66 near the carburetor 44.

  According to the second embodiment, the straightening fins 72 and 73 are provided on the upper and lower outer surfaces of the inlet pipe 66 so that the protruding height from the outer surface of the inlet pipe 66 is constant. Although the attachment rigidity of the carburetor 44 to the inlet pipe 66 on the far side cannot be increased by the rectifying fins 72 and 73, the same effects as those of the first embodiment can be obtained except for that. In addition, by dividing the inlet pipe 66 into upper and lower halves, it is easy to form bolt insertion holes in both the mounting flanges 69 and 70 at the time of die-cast molding, and the moldability can be improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

  For example, in the first and second embodiments, the case where the carburetor 44 is used as the intake air amount adjusting means has been described. However, the present invention can also be applied to the case where the throttle body is used as the intake air amount adjusting means.

22 ... Engine body 27 ... Cylinder blocks 27a, 28a ... Cooling fins 28 ... Cylinder head 30 ... Transmission case 31 ... Output shaft 40 ... Intake port 44 ... Intake amount The carburetors 45, 66, which are adjusting means, the inlet pipe 47, the exhaust port 53, the communication passages 55, 71, the intake passages 56, 57, 69, 70, the mounting flanges 56a, 57a, 69a, 70a ... Mounting surfaces 59, 60, 72, 73 ... Rectifier fins 61, 62, 75, 76 ... Bolt F ... Body frame

Claims (3)

An intake port (40) is provided on the rear side surface of the cylinder head (28) constituting a part of the engine body (22) mounted on the vehicle body frame (F), and is connected to the lower part of the engine body (22). An output shaft (31) for transmitting power to the rear wheels (WR) is rotatably supported by the transmission case (30) connected to the intake case (30), and adjusts the amount of intake air to be drawn into the intake port (40). A quantity adjusting means (44) is a motorcycle engine connected to the cylinder head (28), and
The intake air amount adjusting means (44) is disposed above the output shaft (31) to form an intake passage (55, 71) communicating with the intake port (40) and mounting flanges (56, 57; 69) at both ends. , 70), a flange (56, 69) at one end of a metal inlet pipe (45, 66) is directly connected to the intake air amount adjusting means (44), and the other end of the inlet pipe (45, 66). The mounting flanges (57, 70) are directly connected to the cylinder head (28) .
The engine body (22) is configured to be air-cooled so that a plurality of cooling fins (27a, 28a) are provided on the outer surfaces of the cylinder block (27) and the cylinder head (28), and the inlet pipe (45, 66) A rectifying fin (59, 60; 72, 73) extending in the front-rear direction is provided on the outer surface of the cylinder head, and the cylinder head (28) has an exhaust port (47) provided on the front side surface of the cylinder head (28). A motorcycle engine characterized in that a communication path (53) extending from the periphery of the engine to the periphery of the intake port (40) is provided . An intake port (40) is provided on the rear side surface of the cylinder head (28) constituting a part of the engine body (22) mounted on the vehicle body frame (F), and is connected to the lower part of the engine body (22). An output shaft (31) for transmitting power to the rear wheels (WR) is rotatably supported by the transmission case (30) connected to the intake case (30), and adjusts the amount of intake air to be drawn into the intake port (40). A quantity adjusting means (44) is a motorcycle engine connected to the cylinder head (28), and
The intake air amount adjusting means (44) is disposed above the output shaft (31) to form an intake passage (55, 71) communicating with the intake port (40) and mounting flanges (56, 57; 69) at both ends. , 70), a flange (56, 69) at one end of a metal inlet pipe (45, 66) is directly connected to the intake air amount adjusting means (44), and the other end of the inlet pipe (45, 66). The mounting flanges (57, 70) are directly connected to the cylinder head (28).
The engine body (22) is configured to be air-cooled so that a plurality of cooling fins (27a, 28a) are provided on the outer surfaces of the cylinder block (27) and the cylinder head (28), and the inlet pipe (45, 66) Rectifying fins (59, 60) extending in the front-rear direction are provided on the outer surface of the inlet pipe , and the rectifying fins (59, 60) move from the outer surface of the inlet pipe (45) toward the intake air amount adjusting means (44). as protrusion height becomes large, the inlet pipe upper outer surface and automatic two-wheeled vehicle engine characterized in that it is formed integrally with the lower outer surface (45). Mounting surfaces (56a, 57a; 69a, 69a, 69a, 57a, 69a, 70) on the intake air amount adjusting means (44) and the cylinder head (28) of mounting flanges (56, 57; 69, 70) provided at both ends of the inlet pipe (45, 66). 70a) are formed so as to be inclined away from each other toward the upper side, and bolts (61, 62; 75, 75) inserted into both mounting flanges (56, 57; 69, 70) from the inlet pipe (45, 66) side. The motorcycle engine according to claim 1 or 2, wherein both ends of the inlet pipe (45, 66) are attached to the intake air amount adjusting means (44) and the cylinder head (28) by 76).

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