JP4900665B2 - AC generator cooling structure - Google Patents

Description

  The present invention relates to a cooling structure for an AC generator, and more particularly to a cooling structure for an AC generator that can maintain cooling performance during traveling with a simple configuration.

  2. Description of the Related Art Conventionally, in an AC generator (alternator) attached to an engine or the like, it is generated during operation by a cooling fan that is provided with an intake port and an exhaust port in a casing forming its outer shell and rotates integrally with an input shaft. A configuration is known in which heat is released from the exhaust port to the outside of the casing. However, in this configuration, if high-temperature exhaust gas is sucked from the intake port due to the reason that the intake port and the exhaust port are adjacent to each other, a desired cooling performance may not be obtained.

Patent Document 1 discloses a configuration in which high-temperature exhaust from an exhaust port is not sucked from the intake port by opening the intake port in a cover that covers the engine side portion and separating intake and exhaust. Is disclosed.
JP-A-8-331806

  However, in the case where a cover or the like is not provided in the vicinity of the AC generator as in Patent Document 1, it is necessary to provide another consideration for intake and exhaust, and rectification of the intake and exhaust at the casing of the AC generator is desired. It was.

  An object of the present invention is to solve the above-described problems of the prior art and provide a cooling structure for an AC generator that can maintain cooling performance during traveling with a simple configuration.

  In order to achieve the above-described object, the present invention provides a cooling structure for an AC generator including a casing provided with an intake port for taking in air for cooling and an exhaust port for discharging air used for cooling. There is a first feature in that the casing includes a heat shield means standing between the intake port and the exhaust port and configured to cover the upper side of the exhaust port.

  Further, the AC generator is attached to the engine so that the intake port is located on the rear side of the vehicle body from the exhaust port, and the heat shield means is provided with a folded portion directed toward the front side of the vehicle body. There is a second feature.

  The engine is provided with a transmission case having a flat portion on the front side of the vehicle body, and the third feature is that the AC generator is attached so that the intake port is close to the flat portion. There is.

  Further, the heat shield means is a fourth feature in that it is a thin plate member separate from the casing of the AC generator.

  According to the first invention, the casing is provided with the heat shield means standing between the intake port and the exhaust port and configured to cover the upper side of the exhaust port. It is possible to prevent the exhaust from the exhaust port from being sucked in from the intake port at a high temperature even when the traveling wind hits the vicinity of the exhaust port without being shared with the exhaust port. . As a result, the cooling performance of the AC generator can be prevented from deteriorating during traveling. In addition, even when the casing around the exhaust port comes into contact with the exhaust and becomes hot, the shielding means standing between the intake port and the exhaust port diffuses this heat. The transmission is prevented, and the cooling performance of the AC generator can be maintained.

  According to the second aspect of the invention, the AC generator is attached to the engine so that the intake port is located on the rear side of the vehicle body from the exhaust port, and the heat shield means is provided with the folded portion directed toward the front side of the vehicle body. The exhaust from the exhaust port is guided to the front side of the vehicle body, and the exhaust from the exhaust port can be more reliably prevented from being sucked in from the intake port at a high temperature during traveling. Further, since the exhaust from the exhaust port is sufficiently cooled while being guided to the front side of the vehicle body, the exhaust gas flowing to the rear side of the vehicle body after being bypassed by the heat shield means can be used for intake.

  According to the third invention, the engine is provided with a transmission case having a flat portion on the front side of the vehicle body, and the AC generator is attached so that the intake port is close to the flat portion. It is possible to improve the cooling performance by positively sucking the exhaust gas sufficiently cooled by the heat shield means from the intake port using the convection generated by the traveling wind hitting the part.

  According to the fourth aspect of the invention, the heat shield means is a thin plate member that is separate from the casing of the AC generator, so that the cooling performance of the AC generator can be maintained with a simple configuration. Further, a heat shield means that can be easily retrofitted to an existing AC generator can be obtained.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a motorcycle 1 to which an AC generator according to an embodiment of the present invention is applied. The motorcycle 1 has a front wheel WF and a rear wheel WR as drive wheels that are rotatably supported at the lower ends of a pair of left and right front forks 2 and 2. Below the fuel tank 3 is disposed a V-type four-cylinder engine 5 having a crankshaft (not shown) disposed in the longitudinal direction of the vehicle body. The engine 5 is provided with a cell motor 6 that rotates the crankshaft at the start and an AC generator 7 that generates AC power by rotating the input shaft with the driving force transmitted from the crankshaft. Further, the cowling 4 that covers the engine 5 is provided with a large opening on the front side of the vehicle body so that running wind generated when the motorcycle 1 travels flows to the rear side of the vehicle body while cooling the engine 5. It is configured.

  FIG. 2 is a perspective view of the engine 5 as seen from the front side of the vehicle body. In this figure, an air cleaner, a fuel injection device, a cylinder head cover, and the like are not shown. The V-type four-cylinder engine 5 has a configuration in which a left cylinder head 10 on the left side of the vehicle body and a right cylinder head 11 on the right side of the vehicle body are coupled to a crankcase 8 integrated with a cylinder. Between the right and left cylinder heads 10 and 11 where the intake ports 12 for two cylinders are formed, there is provided a transmission case 14 in which driving means (not shown) for transmitting driving force from the crankshaft is housed. It has been. The AC generator 7 is configured such that the input shaft (see FIG. 3) is pivotally supported by the casing. The AC generator 7 has a flat surface portion (provided on the vehicle body front side of the transmission case 14) in a direction in which the input shaft is substantially parallel to the crankshaft. (See FIG. 5). One end of the input shaft of the AC generator 7 is inserted into the transmission case 14 and is connected to driving means for transmitting the driving force of the crankshaft, whereby the driving force of the crankshaft is transmitted to the AC generator 7. Will be communicated. Note that a pulley and a belt, a sprocket and a chain, a gear train, and the like can be arbitrarily applied to the driving means.

  Traveling wind generated when the motorcycle 1 travels is applied to a crankcase cover 9 or the like disposed at an end of the crankcase 8 on the vehicle body front side to cool the entire engine 5. Similarly, the traveling wind passing between the left and right cylinder heads 10 and 11 cools the intake port 12, the AC generator 7, the transmission case 14, and the like. And between the AC generator 7 and the transmission case 14, the heat insulation plate 30 as the heat insulation means concerning this invention is attached. A protective cover 13 that prevents the AC generator 7 from touching moisture, dust, or the like is attached to the end of the AC generator 7 on the front side of the vehicle body.

  FIG. 3 is a partial cross-sectional top view of the AC generator 7. An AC generator 7 that rotatably supports an input shaft 15 on a cylindrical casing 16 includes a stator 19 fixed to the inner wall surface of the casing 16 and a rotor 18 that rotates integrally with the input shaft 15. The brushes 21 and 21 for supplying an excitation current to the rotor 18 are disposed on the upper end side of the input shaft 15 in the figure. The input shaft 15 is attached with an impeller 20 that rotates integrally with the input shaft 15 to generate an air flow and cools the AC generator 7. Further, a plurality of intake ports 22 and exhaust ports 23 arranged in the circumferential direction are formed in the cylindrical portion of the casing 16 in the vicinity of the rear side end surface 24 from which one end side of the input shaft 15 protrudes. When the impeller 20 rotates with the rotation of the input shaft 15, as shown by a thick arrow on the left side of the figure, a new intake air 50 is taken in from the intake port 22 and becomes hot due to heat generated by the AC generator 7. The exhaust gas 51 is exhausted from the exhaust port 23.

  However, since the AC generator 7 according to the present embodiment is attached to the transmission case 14 (see FIG. 2) with the upper portion in the drawing facing the front side of the vehicle body, the intake port 22 is located on the rear side of the vehicle body from the exhaust port 23. It will be. Accordingly, the AC generator 7 receives the traveling wind 53 from above in the figure when the motorcycle 1 is traveling, and when the exhaust 51 is pushed away to the rear of the vehicle body by the traveling wind 53, as indicated by the arrow 52 shown on the right side of the figure. Furthermore, there is a possibility that the high temperature exhaust gas is directly sucked from the intake port 22 and the cooling performance is lowered. Further, since the flat surface portion (see FIG. 5) of the transmission case 14 is provided toward the front side of the vehicle body, convection is generated when the traveling wind collides with the flat surface portion. The degree to which the exhaust gas was directly sucked from the intake port was sometimes increased. In the cooling structure for an AC generator according to the present invention, a heat shield plate 30 as a heat shield means as shown by a broken line is disposed between the intake port 22 and the exhaust port 23 for the above-described problem. This is characterized in that the flow of exhaust gas indicated by the arrow 52 is changed.

  4A, 4 </ b> B, and 4 </ b> C are a front view, a top view, and a rear view, respectively, seen from the front side of the vehicle body in the heat shield plate 30. The heat shield plate 30 is configured by bending a metal thin plate formed by a press or the like at a plurality of locations. The body portion 31 arranged in the direction perpendicular to the input shaft 15 of the AC generator 7 is disposed such that a substantially arc-shaped portion having irregularities matching the shape of the casing 16 abuts or substantially abuts the casing 16. The high-temperature exhaust discharged from the exhaust port 23 (see FIG. 3) plays a role of guiding the casing 16 radially outward. In addition, a folded portion 32 is provided at an outer end portion of the body portion 31 so as to be bent at a substantially right angle toward the vehicle body front side with respect to the body portion 31 and to guide the exhaust from the exhaust port 23 toward the vehicle body front side. . Further, on the left and right sides of the folded-back portion 32, leg portions 36 and 36 that are bent in accordance with the shape of the casing 16 are provided. Mounting portions 33, 33 having mounting holes 34, 34 are provided on the vehicle body front side of the leg portions 36, 36, and exhaust received by the body portion 31 is disposed on the vehicle body rear side. Shielding portions 35, 35 are provided to close the left and right gaps so as not to miss.

  FIG. 5 is a top view showing a state in which the AC generator 7 and the heat shield plate 30 are attached to the engine 5. The same reference numerals as those described above denote the same or equivalent parts. As described above, the AC generator 7 is attached so that the rear end face 24 of the casing 16 abuts on the flat surface portion 14 a provided on the vehicle body front side of the transmission case 14. The heat shield plate 30 is attached to the AC generator 7 by mounting screws 34a and 34a penetrating the mounting holes 34 and 34 shown in FIG. According to the above configuration, the exhaust gas 51 discharged from the exhaust port 23 (see FIG. 3) along with the operation of the AC generator 7 passes along the inner wall of the heat shield plate 30 in the radially outward direction of the casing 16 and in the forward direction of the vehicle body. Led. Therefore, the exhaust air pushed to the rear side of the vehicle body by the traveling wind 53 from the left in the drawing is prevented from being sucked into the intake port 22 at a high temperature, and the AC generator 7 maintains the desired cooling performance. Will be able to.

  Further, in the configuration in which the flat portion 14a of the transmission case 14 disposed on the front side of the vehicle body and the intake port 22 are mounted close to each other as in the present embodiment, the traveling wind 53 collides with the flat portion 14a. The convection generated by the air pressure promotes a phenomenon in which high-temperature exhaust gas is sucked from the intake port 22. However, in the present embodiment, the exhaust 51 that was hot immediately after the exhaust is also sufficiently cooled while being guided to the front side of the vehicle body along the inner wall of the heat shield plate 30. If convection is generated by low-temperature exhaust from the vehicle to the rear side of the vehicle body, intake air from the intake port is promoted using traveling wind, and the cooling performance of the AC generator 7 can be improved. Become.

  As described above, according to the cooling structure for an AC generator according to the present invention, the shape is formed so as to cover the exhaust port between the intake port and the exhaust port provided in the casing of the AC generator, and on the front side of the vehicle body. A heat-shielding plate with a folded part for guiding exhaust is provided, so that high-temperature exhaust from the exhaust port is not sucked from the intake port, and the cooling performance of the AC generator is maintained even when the motorcycle is running An AC generator cooling structure that can be obtained is obtained.

  In addition, the shape and attachment location of the heat shield plate as the heat shield means are not limited to the above-described embodiment. For example, the heat shield plate can be attached to a crankcase or a transmission case, or the heat shield plate can be attached to the casing of the AC generator. Of course, various modifications are possible, such as forming them integrally. In the present embodiment, the AC generator is described as an example of the heat source. However, the heat source is not limited to this.

1 is a perspective view of a motorcycle according to an embodiment of the present invention. 1 is a partially enlarged view of a motorcycle according to an embodiment of the present invention. It is a partial cross section top view of the AC generator concerning one embodiment of the present invention. It is the front view, top view, and back view of the heat shield plate which concern on one Embodiment of this invention. It is a top view which shows the state which attached the AC generator and the heat shield plate to the engine.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 7 ... AC generator, 8 ... Crankcase, 12 ... Intake port, 13 ... Protective cover, 14 ... Transmission case, 16 ... Casing, 22 ... Inlet, 30 ... Heat shield plate (heat shield means), 34a ... Mounting screw, 50 ... Intake, 51 ... Exhaust, 53 ... Running wind

Claims (3)

In the cooling structure of the AC generator (7) including a casing (16) provided with an intake port (22) for taking in air for cooling and an exhaust port (23) for discharging air used for cooling,
The casing (16) is provided with a heat shield means (30) standing between the intake port (22) and the exhaust port (23) and configured to cover the upper side of the exhaust port (23). Equipped ,
The AC generator (7) is positioned at the upper surface of the crankcase (8) between the left and right cylinder heads (10, 11) of the V-type engine with the crankshaft oriented in the longitudinal direction of the vehicle body , and the intake port (22) is It is attached to the engine (5) with its input shaft (15) oriented in the longitudinal direction of the vehicle body so as to be located on the vehicle body rear side from the exhaust port (23),
On the upper surface of the crankcase (8), there is housed a driving means for transmitting the driving force of the crankshaft to the input shaft (15), and a flat portion for inserting the input shaft (15). A transmission case (14) is provided,
The intake port (22) is formed so as to be close to the flat surface portion (14a) when the AC generator (7) is attached to the transmission case (14).
A cooling structure for an AC generator , wherein a protective cover (13) is attached to an end of the casing (16) of the AC generator (7) on the front side of the vehicle body. The AC generator (7) is attached to the engine (5) such that the intake port (22) is located on the rear side of the vehicle body from the exhaust port (23) .
The cooling structure for an AC generator according to claim 1, wherein the heat shield means (30) is provided with a folded portion (32) toward the front side of the vehicle body. The cooling structure for an AC generator according to claim 1 or 2 , wherein the heat shield means (30) is a thin plate member separate from the casing (16 ) of the AC generator (7) .

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