JP4419610B2 - Engine case structure - Google Patents

Description

  The present invention relates to an engine case structure.

  In an engine mounted on a two-wheeled vehicle, a four-wheeled vehicle, etc., gas accompanied by pressure generated in the cylinder bore leaks into the engine case little by little through a gap between the piston and the cylinder bore. Further, the pressure of the gas in the engine case constantly fluctuates with the sliding of the piston. Therefore, when the engine case is in a sealed state, the pressure of the gas in the engine case, so-called blow-by gas, hinders the movement of the piston. . Therefore, it is necessary to provide a means for releasing the pressure in the engine case to the outside and separating the atomized oil (oil mist) mixed in the blow-by gas from the gas, that is, a breather device.

  In order to improve the separation performance (gas-liquid separation performance) of the oil content in blow-by gas, it is desirable to increase the capacity of the breather chamber that constitutes the breather device and to make the breather chamber have a maze structure.

  As a specific example of the structure of the breather device, a breather chamber is formed by combining a concave chamber formed in the mating surface of both half cases with the upper part of the engine (crank) case formed by combining the left and right half cases. There is what formed. (For example, refer to Patent Document 1).

  Recently, blow-by gas is returned to the air cleaner and recombusted to prevent air pollution.

  On the other hand, the engine number is written on the engine for management. The engine number is usually stamped on the main engine parts such as a crank / engine case and a cylinder block using a stamping machine.

For example, as shown in FIG. 5, in the case of the engine case 1, the number of the stamping seat 2 can be visually recognized in a state where the engine 3 is mounted on the vehicle, the space for arranging the stamping machine 4 can be secured, and several Since there is a restriction condition that the presser foot 5 is placed on the back surface of the stamping seat 2 in order to receive a punching force that reaches tons, the stamping machine 4 can be determined from the profile of the cover mating surface 6 such as a transmission. The stamping seat 2 having a height up to the vicinity of the height of the cover mating surface 6 is formed at a location where the space 7 is separated.
JP-A-3-175110 (Page 4, FIGS. 1 and 2)

  However, when the capacity of the breather chamber is increased in order to improve the gas-liquid separation performance of blow-by gas, there arises a problem that the weight and material cost increase.

  On the other hand, when a stamping seat having a height close to the height of the cover mating surface is formed, there is a problem that the weight and the material cost are similarly increased.

  The present invention has been made in consideration of the above-described circumstances, and can improve the gas-liquid separation performance of blow-by gas without significantly increasing the weight and material cost, and at the same time can secure the engine seat of the engine number. The purpose is to provide a structure.

In order to solve the above-described problem, an engine case structure according to the present invention is configured to separate blow-by gas into an upper part of an engine case having a half-case alignment structure as described in claim 1. to comprise a breather chamber, Oite the engine case structure exhaust pipe is connected to the front side of the cylinder assembly with the cylinder assembly in the front portion of the engine case is arranged in a forwardly inclined state, the outer wall surface of the semi-case of the bulged portion from the side along the mating surface of the semi-case is protruded toward the outside lateral form the breather chamber, the exhaust pipe which extends laterally of the engine case rearward the bulged portion is disposed in the vicinity below the, it is characterized in that it is provided with electrical components in the engine case wall portion serving as a negative with respect to the exhaust pipe of the expanded portion Engine case structure.

Further, provided in order to solve the above problems, as described in claim 2, provided with a belt case for housing the transmission device to the cylinder assembly behind the engine case side, an air cleaner above the cylinder assembly On the other hand, the bulging portion is formed on the side surface of the rear portion of the engine case located above the belt case, and the upper surface of the bulging portion is substantially parallel to the upper surface of the engine case and in the front-rear direction. It is extended.

In order to solve the above-described problem, as described in claim 3 , the engine is configured so as to surround the electrical component from below or from the side in cooperation with the bulging portion on the side of the engine case. A fitting is provided.

Further, in order to solve the above-mentioned problem, as described in claim 4 , a flat surface having a predetermined surface area on the end surface of the bulging portion facing the side of the engine case and intersecting the protruding direction. A surface is formed, and this flat surface is set as a marking range such as an engine number.

Furthermore, in order to solve the above-described problem, as described in claim 5 , a belt case that houses a transmission device is provided on a side portion of the engine case, and the bulging portion is disposed on the front and rear sides of the engine case. In a state seen from the direction, it extends to a position that is flush with the mounting surface of the engine case and the belt case, and the flat surface is removed so as to be seen from the outline of the belt case in a side view. Are arranged.

  According to the engine case structure according to the present invention, since the capacity of the breather chamber is increased, the flow rate of blow-by gas is reduced, and the gas-liquid separation performance is also improved. Also, the cooling efficiency of the engine case is improved.

  Furthermore, since the bulging portion blocks the heat of the exhaust pipe, the durability and accuracy of the electrical component provided at that position is improved. In addition, it becomes difficult for dirt or muddy water to directly touch the members of the electrical component, and the durability of these members is improved and the appearance thereof is also improved.

  And the gas-liquid separation performance of blow-by gas can be improved without significantly increasing the weight and material cost, and at the same time, the engine number stamping seat can be secured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a right side perspective view showing an example of a saddle riding type vehicle to which the present invention is applied, and FIG. 2 is a same plane perspective view.

  As shown in FIGS. 1 and 2, the saddle riding type vehicle 11 includes a body frame 12 made of, for example, a steel pipe. The vehicle body frame 12 includes a pair of left and right upper frames 13 and a lower frame 14, a pair of left and right rear vertical frames 15 that vertically connect the rear ends of the frames 13 and 14, and the rear vertical frame 15 and the lower frame 14. A pair of left and right rear horizontal frames 16 that are connected in the front-rear direction to the substantially central portion of the frame, a pair of left and right front vertical frames 17 that are connected in the vertical direction between the upper frame 13 and the lower frame 14 at the front, It includes a pair of left and right front horizontal frames 18 that connect the front vertical frame 17 and the front portion of the upper frame 13 in the front-rear direction, and a plurality of bridge members 19 that connect the pair of left and right members. Constructed in a cage shape.

  A straddle-type seat 20 is installed on the upper rear side of the upper frame 13 constituting the vehicle body frame 12, and a steering handle 21 as a steering device for the vehicle 11 is provided in front of the seat. In addition, a pair of left and right front wheels 22 and rear wheels 23 with wide and low-pressure tires are respectively provided on the front and rear of the vehicle body frame 12 via a suspension mechanism (not shown). A steering handle 21 is provided between the front and rear wheels 22 and 23. The engine unit 24 is mounted substantially at the center lower portion of the vehicle body frame 12 so as to be located behind the vehicle body frame 12.

  A front cover 25 is provided at the front of the vehicle body so as to cover the front upper portion of the vehicle body frame 12, and a front fender 26 that covers the left and right front wheels 22 is integrally or integrally formed. A rear cover 27 covering the upper side is provided, and a rear fender 28 covering the left and right rear wheels 23 is formed integrally or integrally. These covers 25 to 28 are, for example, synthetic resin molded products.

  For example, the engine unit 24 is configured integrally with an engine main body 29 and a belt case 30 that is an engine outfitting equipped with a belt-type continuously variable transmission that is a transmission device (not shown). The engine body 29 is, for example, a water-cooled four-cycle single-cylinder engine, and includes an engine case 31 and a cylinder assembly 32 that is arranged in a largely forward-tilted state in front of the upper surface.

  An engine intake system 33 is disposed above the cylinder assembly 32 and below the seating seat 20. The engine intake system 33 is disposed on the rear side of the cylinder head 34 constituting the cylinder assembly 32 via an intake pipe 35, and is disposed above the throttle body 36 and in front of the seating seat 20. And an air cleaner 38 connected to the upstream side of the throttle body 36.

  On the other hand, an engine exhaust system 39 is disposed on one side of the engine main body 29, in the present embodiment, on the right side. The engine exhaust system 39 includes an exhaust pipe 40 connected to the front side of the cylinder head 34 and an exhaust muffler device 41 connected to the downstream end of the exhaust pipe 40, and the exhaust pipe 40 is once in front of the cylinder head 34. After extending toward the right and rearward, the right side of the engine unit 24 extends substantially horizontally toward the rear along the upper frame 13 of the vehicle body frame 12 and is a belt type continuously variable transmission. The upper frame 13 is displaced from the inner side to the outer side in the vicinity of the rear upper side. Further, the exhaust muffler device 41 is disposed, for example, above the rear wheel 23 and below the rear fender 28 (or the rear cover 27) in a side view.

  On the other hand, the belt type continuously variable transmission includes a transmission cooling system 42. The transmission cooling system 42 is provided between the front upper portion of the vehicle body frame 12 and the front cover 25, and the cooling air inlet 43 is provided at the front upper portion thereof so as to open close to the lower surface of the front cover 25. In addition, for example, an induction box 46 of a synthetic resin molded product, and an introduction duct 46 that introduces cooling air into the belt case 30 by connecting the induction box 44 and an intake port 45 that opens to the front of the belt case 30. And a lead-out duct 48 connected to an exhaust port 47 that opens at the rear part of the belt case 30 and guides exhaust air after cooling the belt-type continuously variable transmission.

  The outlet duct 48 extends rearward substantially horizontally from the exhaust port 47 of the belt case 30 and then changes its direction almost vertically upward near the upper portion of the axle 49 of the right rear wheel 23. Further, the seating seat In the vicinity immediately below the rear end of the vehicle 20, the direction is once changed to the right side of the vehicle body and further downwardly changed in the direction substantially perpendicularly, and the cooling air discharge port 50 is opened at the most downstream end.

  A heat exchanger 51 (oil cooler, radiator, etc.) of the engine body 29 is installed near the frontmost part of the vehicle body frame 12, and a cooling fan 52 for the heat exchanger 51 is installed behind the heat exchanger 51.

  FIG. 3 is a right side view of the engine case 31 with the belt case 30 removed. 4 is a cross-sectional view taken along line IV-IV in FIG.

  As shown in FIG. 3 and FIG. 4, the engine case 31 has a middle alignment structure of a plurality of split left and right half cases 53 </ b> L and 53 </ b> R that can be divided in the horizontal direction in the present embodiment. Further, the belt case 30 that houses a belt-type continuously variable transmission (not shown) is disposed on the side of the engine case 31, in the present embodiment, on the right side in the traveling direction of the vehicle 11. Further, the right side portion of the belt case 30 is covered with a case cover 54. The engine case 31 is integrally provided with a transmission case 55 that houses a transmission mechanism (not shown) in the latter half thereof.

  Inside the uppermost part of the engine case 31, a breather device 56 that separates the oil content in the blow-by gas that accumulates in the engine case 31 from the gas content and releases the pressure in the engine case 31 to the outside includes left and right half cases 53L, Formed by 53R. The breather device 56 includes a breather chamber 58 having a labyrinth structure with a plurality of ribs 57, and a breather hose 59 for returning a gas component to the air cleaner 38 is connected to the upper surface of the breather chamber 58.

  Of the outer wall surfaces of the half cases 53L and 53R forming the breather chamber 58, a bulging portion is formed from the side surface along the mating surface 66 of the half cases 53L and 53R at the rear of the engine case 31 located above the belt case 30. 60 is formed to protrude outward. Further, the bulging portion 60 extends substantially in parallel and in the front-rear direction so that the upper surface thereof is flush with the upper surface of the engine case 31.

  Further, the bulging portion 60 is disposed so as to be positioned near and below the exhaust pipe 40, and a gear position switch 61 is provided on the wall of the engine case 31 that is behind the exhaust pipe 40 of the bulging portion 60, for example. Etc. are disposed. Furthermore, the belt case 30 is disposed on the side of the engine case 31 so as to surround the electrical component 61 from below or from the side in cooperation with the bulging portion 60.

  A flat surface 62 having a predetermined surface area and intersecting the projecting direction is formed on the end surface of the bulging portion 60 directed to the side of the engine case 31, and this flat surface 62 is set as an engine number marking range. It will be the engraved seat.

  Further, the stamping seat 62 (flat surface) of the bulging portion 60 extends to a position near the mounting surface 63 of the engine case 31 and the belt case 30 when the engine case 31 is viewed from the front-rear direction. Is issued. Further, the stamping seat 62 (flat surface) is disposed at a position away from the outer shape line 64 of the belt case 30 in a side view.

  Next, the operation of this embodiment will be described.

  When the engine body 29 is started, gas accompanied by pressure generated in a cylinder bore (not shown) leaks into the engine case 31 little by little through a gap between a piston (not shown) and the cylinder bore. A gas leaked into the engine case 31, so-called blow-by gas, is mixed with a sprayed oil component (oil mist), and is introduced into a breather chamber 58 provided at the uppermost part in the engine case 31.

  As shown by the arrow 65 in FIG. 4, the blow-by gas guided to the breather chamber 58 is separated from the oil when passing through the labyrinth structure formed by a plurality of ribs 57, and the oil falls in the engine case 31. For example, while returning to an oil pan (not shown), the gas component is recirculated from the upper surface of the breather chamber 58 to the air cleaner 38 via the breather hose 59, sent into the cylinder bore, and recombusted.

  Of the outer wall surfaces of the half cases 53L and 53R forming the breather chamber 58, the bulging portion 60 is formed to protrude outward from the side surface along the mating surface 66 of the half cases 53L and 53R. The inner space 60 can be used as an expansion chamber of the breather chamber 58, and the capacity of the breather chamber 58 is increased. As a result, the flow rate of blow-by gas is reduced, and the gas-liquid separation performance is also improved.

  Further, the bulging portion 60 is formed on the side surface of the rear portion of the engine case 31 located above the belt case 30, and the upper surface of the bulging portion 60 is substantially parallel to the upper surface of the engine case 31 and in the front-rear direction. As a result, the surface area of the rear portion of the engine case 31 can be increased, and the heat conduction capacity can be increased. As a result, the cooling efficiency of the engine case 31 due to the passing air flowing between the lower surface of the air cleaner 38 and the cylinder assembly 32 from the front of the vehicle 11 is improved, and heat accumulation inside the engine case 31 can be prevented, The temperature of the blow-by gas inside the breather chamber 58 is also lowered, and the gas-liquid separation performance is improved.

  Further, the bulging part 60 is arranged so as to be positioned near and below the exhaust pipe 40, and an electrical component such as a gear position switch 61 is provided on the wall of the engine case 31 that is a shadow of the exhaust pipe 40 of the bulging part 60. By disposing the product, the bulging portion 60 blocks the heat of the exhaust pipe 40 to the electrical component 61, so that the durability and accuracy of the electrical component 61 are improved.

  Furthermore, the belt case 30 is disposed on the side of the engine case 31 so as to surround the gear position switch 61 from the lower side or the side in cooperation with the bulging portion 60, so that the electrical component 61 is not shown. Wiring and clamps can be covered. As a result, dirt, muddy water, or the like is difficult to directly touch these members, and the durability of these members is improved and the appearance thereof is also improved.

  Then, a flat surface 62 having a predetermined surface area and intersecting the projecting direction is formed on the end surface of the bulging portion 60 directed to the side of the engine case 31, and this flat surface 62 is set as a marking range such as an engine number. Thus, even if the surface of the tip of the bulging portion 60 is wide or narrow and narrow, the area of the flat surface 62 can be effectively utilized.

  Further, the stamping seat 62 (flat surface) of the bulging portion 60 is in a state where it is flush with the mounting surface 63 of the engine case 31 and the belt case 30 when the engine case 31 is viewed from the front-rear direction. Even when the engine unit 24 is mounted on the vehicle 11, the engine number is extended by disposing the stamping seat 62 (flat surface) so as to be seen from the outline 64 of the belt case 30 in a side view. You can easily check the stamp.

  As described above, the bulging portion 60 is formed so as to protrude from the side surface of the engine case 31, the inner space of the bulging portion 60 is used as the expansion chamber of the breather chamber 58, and the flat surface 62 of the outer end surface is stamped with the engine number. If it is used as a seat, the gas-liquid separation performance of blow-by gas can be improved without significantly increasing the weight and material costs, and at the same time, the engine number stamping seat 62 can be secured.

1 is a right side perspective view of a saddle-ride type vehicle showing an embodiment of an engine case structure according to the present invention. FIG. 2 is a plan perspective view of the saddle riding type vehicle shown in FIG. 1. The right view of the engine case of the state which removed the belt case. Sectional drawing which follows the IV-IV line of FIG. The longitudinal cross-sectional view of the engine case which shows the conventional engine number stamping seat.

Explanation of symbols

11 straddle-type vehicle 24 engine unit 29 engine body 30 belt case (engine equipment)
31 Engine case 32 Cylinder assembly 38 Air cleaner 40 Exhaust pipe 53L, 53R Half case 56 Breather device 58 Breather chamber 60 Swelling portion 61 Gear position switch (electrical equipment)
62 Stamping seat (flat surface)
64 Belt case outline 66 Half case mating surface

Claims (5)

A breather chamber for gas-liquid separation of blow-by gas is provided in the upper part of the engine case having a middle structure of a plurality of half cases, and a cylinder assembly is disposed in a forward inclined state at the front of the engine case. Oite of the engine case structure exhaust pipe is connected to the front, of the outer wall surface of the semi-case, the is protruded toward the bulging portion on the outer side from the side along the mating surface of the semi-case breather A portion that forms a chamber and is arranged in the vicinity of the exhaust pipe that extends rearward from the side of the engine case in the rear, and is located behind the exhaust pipe in the bulge portion An engine case structure in which electrical components are disposed on the engine case wall . Provided with a belt case for housing the transmission device to the cylinder assembly behind the engine case side, while having the air cleaner above the cylinder assembly, the bulging portion of the rear the engine case is located above the belt case The engine case structure according to claim 1, wherein the engine case structure is formed on a side surface and extends in a front-rear direction so as to be substantially parallel to an upper surface of the engine case. The engine case structure according to claim 1 , wherein an engine fitting is disposed on a side portion of the engine case so as to surround the electrical component from below or from the side in cooperation with the bulging portion. 2. A flat surface that has a predetermined surface area and intersects the protruding direction is formed on an end surface of the bulging portion that faces the side of the engine case, and the flat surface is set as a marking range such as an engine number. The engine case structure described. A belt case that houses a transmission device is provided on a side portion of the engine case, and the bulging portion is flush with a mounting surface of the engine case and the belt case in a state in which the engine case is viewed from the front-rear direction. 5. The engine case structure according to claim 4 , wherein the engine case structure is disposed at a position where the flat surface is removed so as to be seen from an outline of the belt case in a side view.

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