JP2014047768A - Cylinder head, and saddle-straddling type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head and a saddle-straddling type vehicle in which an exhaust pipe can be connected to the cylinder head to be inclined relative to a sidewall while suppressing an increase in the size of the cylinder head.SOLUTION: An exhaust passage portion 240 defines an exhaust passage 241 through which gas exhausted from a combustion chamber is introduced to an exhaust pipe. The exhaust passage portion 240 projects from a sidewall 202. The exhaust pipe is fitted into an exhaust pipe fitting portion 242 of the exhaust passage portion 240. A bolt for attaching the exhaust pipe is fixed to a bolt fixing portion 243 of the exhaust passage portion 240. At least part of the bolt fitting portion 243 is provided outside of the exhaust pipe fixing portion 242 in the exhaust passage radial direction as viewed from a cylinder axial direction. A downstream end surface 242e of the exhaust pipe fitting portion 242 in an exhaust passage axial direction 241z is formed to be inclined relative to the sidewall 202 as viewed from the cylinder axial direction. A downstream end surface of the bolt fixing portion 243 in the exhaust passage axial direction 241z is formed at a further upstream position than the downstream end surface 242e of the exhaust pipe fitting portion 242.

Description

  The present invention relates to a cylinder head and a saddle-ride type vehicle including the same.

  In a vehicle including an engine, an exhaust pipe is attached between an exhaust pipe attachment portion of a cylinder head and a muffler. Exhaust gas generated from the combustion chamber of the engine is discharged to the outside through an exhaust pipe and a muffler from the exhaust port of the cylinder head (see, for example, Patent Document 1).

JP 2010-7645 A

  In the cylinder head described in Patent Document 1, the axis of the exhaust pipe mounting portion is formed so as to incline to the right with respect to the front-rear direction of the motorcycle. As a result, the cylinder head can be connected to the muffler provided on the right rear side of the motorcycle through the exhaust pipe.

  However, according to this configuration, the exhaust pipe mounting portion of the cylinder head largely protrudes from the side wall of the cylinder head in order to mount the exhaust pipe so as to be inclined with respect to the front-rear direction of the motorcycle. This increases the size of the cylinder head in the front-rear direction of the motorcycle.

  An object of the present invention is to provide a cylinder head and a saddle-ride type vehicle that can be connected so that an exhaust pipe is inclined with respect to a side wall while suppressing an increase in size.

  (1) A cylinder head according to a first aspect of the present invention is a cylinder head provided in a single-cylinder engine, and includes a side wall that defines at least a part of a space that accommodates a valve operating mechanism, and gas discharged from a combustion chamber. An exhaust passage section that divides an exhaust passage leading to the exhaust pipe and protrudes from the side wall, and the exhaust passage section is configured to fix the exhaust pipe fitting bolt and the exhaust pipe mounting bolt. A bolt fixing portion, and at least a part of the bolt fixing portion is provided outside the exhaust pipe fitting portion in the exhaust passage radial direction when viewed from the cylinder axial direction, and the exhaust pipe in the exhaust passage axial direction. The downstream end surface of the fitting portion is formed to be inclined with respect to the side wall when viewed from the cylinder axial direction, and the downstream end surface of the bolt fixing portion in the exhaust passage axial direction is more than the downstream end surface of the exhaust pipe fitting portion. Is that formed on the upstream side in the air passage axial direction.

  In this cylinder head, an exhaust passage for guiding the gas discharged from the combustion chamber to the exhaust pipe is defined by the exhaust passage portion. The exhaust passage portion protrudes from the side wall. An exhaust pipe is fitted into the exhaust pipe fitting portion of the exhaust passage portion. An exhaust pipe mounting bolt is fixed to the bolt fixing portion of the exhaust passage portion. At least a part of the bolt fixing portion is provided outside the exhaust pipe fitting portion in the exhaust passage radial direction when viewed from the cylinder axial direction. The downstream end surface of the exhaust pipe fitting portion in the exhaust passage axial direction is formed to be inclined with respect to the side wall when viewed from the cylinder axial direction. Thereby, the exhaust pipe can be attached to the cylinder head in a compact manner.

  Further, the downstream end surface of the bolt fixing portion is formed upstream of the downstream end surface of the exhaust pipe fitting portion in the exhaust passage axial direction. Thereby, the distance from the side wall to the farthest part of the bolt fixing portion is reduced as compared with the case where the downstream end surface of the bolt fixing portion and the downstream end surface of the exhaust pipe fitting portion are arranged on the same plane. Therefore, the cylinder head is downsized in the direction perpendicular to the side wall.

  As a result, it is possible to connect the exhaust pipe so as to be inclined with respect to the side wall of the cylinder head while suppressing an increase in size of the cylinder head.

  (2) The exhaust passage portion may further include a component mounting portion for mounting components. In this case, the components can be attached to the cylinder head by effectively using the exhaust passage portion. This prevents an increase in the size of the cylinder head due to the attachment of components.

  (3) The downstream end surface of the exhaust pipe fitting portion has a first portion farthest from the side wall and a second portion closest to the side wall when viewed from the cylinder axial direction. It may be provided at a position closer to the first portion than the second portion in the path diameter direction.

  In this case, the exhaust passage portion has a larger area on the side of the first part farthest from the side wall than on the side of the second part closest to the side wall. Thereby, a component can be attached to a component attachment part, without interfering with a side wall.

  (4) The cylinder head may further include a flange portion formed at the upper end of the side wall, and the component mounting portion may be disposed outside the outer peripheral portion of the flange portion when viewed from the cylinder axial direction.

  In this case, a component having a shape extending beyond the flange portion can be attached to the component attachment portion. Further, it is possible to easily attach the component to the component attachment portion and remove the component from the component attachment portion from the direction of the flange portion of the side wall.

  (5) The downstream end surface of the bolt fixing portion includes first and second bolt seat surfaces, and the first bolt seat surface is provided at a position farther from the side wall than the second bolt seat surface. The bolt seat surface may be provided at a position closer to the side wall than the end surface of the flange portion.

  In this case, the exhaust pipe mounting bolt is attached to the first and second bolt seat surfaces. Thereby, an exhaust pipe can be reliably connected to an exhaust passage part. Further, the second bolt seat surface is provided at a position closer to the side wall than the end surface of the flange portion, whereby the first bolt seat surface approaches the side wall. Therefore, the cylinder head can be downsized in the direction perpendicular to the side wall. Furthermore, since the first bolt seat surface is provided at a position farther from the side wall than the second bolt seat surface, a sufficient space for the component mounting portion can be secured at a position far from the side wall in the exhaust passage portion. As a result, the component can be attached to the component attachment portion without interfering with the side wall.

  (6) When viewed from the cylinder axial direction, the first bolt seat surface may be formed such that the surface including the first bolt seat surface intersects the component mounting portion. In this case, since the first bolt seating surface is sufficiently close to the side wall, the cylinder head can be sufficiently downsized in the direction perpendicular to the side wall.

  (7) The component may include an oxygen sensor. In this case, the oxygen concentration of the gas discharged from the combustion chamber can be measured by the oxygen sensor. The oxygen sensor is heated by the heat in the combustion chamber. Thereby, the rise time of an oxygen sensor can be shortened.

  (8) The exhaust pipe fitting portion has a contact surface with which the end face of the exhaust pipe can come into contact with the upstream side of the downstream end face in the exhaust passage axial direction inside the downstream end face of the exhaust pipe fitting portion, The downstream end surface of the bolt fixing portion may be formed on the upstream side of the contact surface in the exhaust passage axial direction.

  In this case, since the downstream end surface of the bolt fixing portion is formed upstream of the contact surface in the exhaust passage axial direction, the cylinder head can be reliably downsized in the direction perpendicular to the side wall.

  (9) The downstream end surface of the exhaust pipe fitting portion may have a notch cut out in the exhaust passage radial direction at a portion overlapping the downstream end surface of the bolt fixing portion in the exhaust passage radial direction.

  In this case, since the downstream end surface of the bolt fixing portion is formed to be continuous with the downstream end surface of the exhaust pipe fitting portion, the bolt hole of the bolt fixing portion is fitted into the exhaust pipe in the exhaust passage radial direction of the exhaust pipe fitting portion. It can be formed at a position close to the center of the part. Thereby, it can prevent that a volt | bolt fixing | fixed part becomes large in an exhaust passage radial direction.

  (10) A saddle-ride type vehicle according to a second invention is connected to a vehicle main body, a single cylinder engine provided in the vehicle main body, a cylinder head according to the first invention provided in the engine, and an exhaust passage portion of the cylinder head. And an exhaust pipe.

  In this saddle-ride type vehicle, a single cylinder engine is provided in the vehicle body. Gas discharged from the combustion chamber of the engine is guided to the exhaust pipe through the exhaust passage portion of the cylinder head.

  In the cylinder head, the downstream end face of the exhaust pipe fitting portion in the exhaust passage axial direction is formed to be inclined with respect to the side wall when viewed from the cylinder axial direction. Thereby, the exhaust pipe can be attached to the cylinder head in a compact manner.

  Further, the downstream end surface of the bolt fixing portion is formed upstream of the downstream end surface of the exhaust pipe fitting portion in the exhaust passage axial direction. Thereby, the distance from the side wall to the farthest part of the bolt fixing portion is reduced as compared with the case where the downstream end surface of the bolt fixing portion and the downstream end surface of the exhaust pipe fitting portion are arranged on the same plane. Therefore, the cylinder head is downsized in the direction perpendicular to the side wall.

  As a result, it is possible to connect the exhaust pipe so as to be inclined with respect to the side wall of the cylinder head while suppressing an increase in size of the cylinder head.

  (11) A silencer provided on the exhaust pipe is further provided. The silencer is provided on one side in the width direction of the vehicle body, and the downstream end surface of the exhaust pipe fitting portion of the cylinder head is viewed from the vertical direction of the vehicle body. In this case, it may be formed so as to be inclined with respect to the longitudinal direction of the vehicle body.

  In this case, since the downstream end surface of the exhaust pipe fitting portion of the cylinder head is inclined with respect to the front-rear direction of the vehicle body, the exhaust pipe and the silencer can be easily attached and the exhaust pipe can be easily handled.

  According to the present invention, it is possible to connect the exhaust pipe so as to be inclined with respect to the side wall of the cylinder head while suppressing an increase in size.

1 is a side view of a motorcycle according to an embodiment of the present invention. FIG. 2 is a plan view of the motorcycle of FIG. 1 as viewed from above. It is the figure of the cylinder head seen from the cylinder axial direction. It is the figure of the cylinder head seen from the side of the exhaust passage part of FIG. It is an enlarged view of the exhaust passage part of FIG. It is an enlarged view of the exhaust passage part of FIG. FIG. 4 is a cross-sectional view of the exhaust passage portion of FIG. 3 along the exhaust passage axial direction. It is a figure which shows the directional relationship of a cylinder head and a motorcycle.

  Hereinafter, a cylinder head and a motorcycle according to an embodiment of the present invention will be described with reference to the drawings.

(1) Configuration of Motorcycle FIG. 1 is a side view of a motorcycle according to an embodiment of the present invention. FIG. 2 is a plan view of the motorcycle shown in FIG. 1 as viewed from above. 1 and 2 show a state where the motorcycle 100 stands up perpendicularly to the road surface. The front-rear direction L of the motorcycle 100 is indicated by an arrow. In FIG. 2, the width direction W of the motorcycle 100 is indicated by an arrow.

  As shown in FIG. 1, the motorcycle 100 includes a body frame 80 including a main frame 80a and a sub frame 80b. A head pipe 85 is provided at the front of the body frame 80, and a handle 81 is provided at the upper end of the head pipe 85. A front fork 82 is attached to the lower end of the head pipe 85.

  In this state, the front fork 82 can rotate within a predetermined angle range around the axis of the head pipe 85. A front wheel 83 is rotatably supported at the lower end of the front fork 82. A rear wheel 84 is rotatably supported at the rear portion of the vehicle body frame 80. A single-cylinder engine 50 is provided at the center of the body frame 80. The engine 50 includes a cylinder 51, a crank box 52, and a cylinder head 200. A combustion chamber is formed in the cylinder 51. An axial direction of the cylinder 51 (hereinafter referred to as a cylinder axial direction C) is indicated by a one-dot chain line. In the present embodiment, engine 50 is attached to body frame 80 such that cylinder axis direction C is inclined forward from the vertical direction. In the cylinder head 200, a valve operating mechanism 260 and an intake valve and an exhaust valve described later are provided. The valve mechanism 260 includes an intake cam, an exhaust cam, and a camshaft. The rear wheel 84 is rotated by the rotational force of the engine 50.

  An exhaust device 10 that guides exhaust gas to the outside is connected to the cylinder head 200 of the engine 50. The exhaust device 10 includes an exhaust pipe 20 and a muffler (silencer) 30. An exhaust passage portion 240 is provided at the front portion of the cylinder head 200.

  As shown in FIG. 2, the muffler 30 is disposed on one side of the vehicle center line L <b> 1 in the width direction W. In the present embodiment, the muffler 30 is disposed on the right side of the vehicle center line L1 in the width direction W. Therefore, the exhaust pipe 20 of FIG. 1 is provided so as to extend obliquely forward and rightward from the exhaust passage portion 240, curve backward, and further extend rearward to the muffler 30. The muffler 30 is provided so as to extend from the downstream end of the exhaust pipe 20 to the side of the rear wheel 84.

  The upstream end of the exhaust pipe 20 is connected to the exhaust passage portion 240 of the cylinder head 200 of the engine 50. The downstream end of the exhaust pipe 20 is inserted into the upstream end (inlet) of the muffler 30. The muffler 30 is fixed to the exhaust pipe 20 by tightening the outer peripheral portion of the upstream end of the muffler 30 with an attachment member.

  Exhaust gas generated by combustion of the air-fuel mixture in the combustion chamber of the cylinder 51 is sent to the muffler 30 through the exhaust pipe 20. Exhaust gas is discharged into the atmosphere through the muffler 30. As described above, the exhaust path of the engine 50 includes the exhaust passage 241, the exhaust pipe 20, and the muffler 30 of the cylinder head 200 in order from the upstream side to the downstream side.

(2) Configuration of Cylinder Head FIG. 3 is a diagram of the cylinder head 200 viewed from the cylinder axis direction. FIG. 4 is a view of the cylinder head 200 as viewed from the exhaust passage portion side of FIG. Hereinafter, the configuration of the cylinder head 200 according to the present embodiment will be described with reference to FIGS. 3 and 4. In FIG. 3, the front-rear direction L and the width direction W are indicated by arrows. The cylinder axial direction C in FIG. 1 is a direction perpendicular to the paper surface of FIG. In FIG. 4, the cylinder axial direction C is indicated by an arrow.

  As shown in FIG. 3, the cylinder head 200 has side walls 201, 202, 203, and 204. The side walls 201 and 202 are formed to face each other and extend in the width direction W. The side walls 203 and 204 are formed so as to face each other and connect both side ends of the side wall 201 and both side ends of the side wall 202. The space V is partitioned by the four side walls 201-204. In the space V of the cylinder head 200, one or more (two in this example) intake valves 210, one or more (two in this example) exhaust valves 220, and the valve mechanism 260 of FIG. The In FIG. 3, the valve mechanism 260 is not shown. The plurality of intake valves 210 are provided in a plurality of intake holes so as to be opened and closed, and the plurality of exhaust valves 220 are provided in a plurality of exhaust holes so as to be opened and closed. The plurality of intake valves 210 and the plurality of exhaust valves 220 are opened and closed by the valve operating mechanism 260 of FIG.

  As shown in FIG. 4, flange portions 205 projecting outward are formed at the upper ends of the side walls 201 to 204. The upper surface of the flange portion 205 is formed perpendicular to the cylinder axial direction C and flat. The upper opening of the cylinder head 200 is closed by a cylinder head cover 250 shown in FIG. At this time, the lower surface of a cylinder head cover 250 of FIG.

  As shown in FIG. 3, the outer surfaces of the side walls 201 and 202 are formed in parallel to the width direction W. An intake passage portion 230 is formed so as to protrude rearward from the side wall 201. The intake passage portion 230 defines a part of an intake passage (not shown) that guides air to the combustion chamber of the cylinder 51 of FIG. Air is supplied to the combustion chamber through the intake passage and the plurality of intake holes.

  An exhaust passage portion 240 is formed so as to protrude obliquely forward from the side wall 202. The exhaust passage section 240 defines a part of the exhaust passage 241 that guides the exhaust gas discharged from the combustion chamber to the exhaust pipe 20 of FIG. In the present embodiment, the exhaust passage 241 is formed so as to merge from the two exhaust holes and further open at the downstream end of the exhaust passage portion 240 through the exhaust passage portion 240. Exhaust gas is discharged to the exhaust pipe 20 of FIG. 1 through the plurality of exhaust holes and the exhaust passage 241.

  The exhaust passage portion 240 includes an exhaust pipe fitting portion 242, a plurality of bolt fixing portions 243, and a component attachment portion 244. The exhaust pipe 20 shown in FIG. 1 is fitted into the exhaust pipe fitting portion 242. The plurality of bolt fixing portions 243 are used for fixing the exhaust pipe mounting bolts 21 of FIG. In the present embodiment, two bolt fixing portions 243 are provided in the exhaust passage portion 240. The oxygen sensor 40 is attached to the component attachment portion 244.

  FIG. 5 is an enlarged view of the exhaust passage portion 240 of FIG. FIG. 6 is an enlarged view of the exhaust passage portion 240 of FIG. In FIG. 5, the axial direction of the exhaust passage 241 is referred to as an exhaust passage axial direction 241z. In FIG. 6, the radial direction of the exhaust passage 241 is referred to as an exhaust passage radial direction 241r.

  As shown in FIG. 5, the exhaust passage 241 in the exhaust passage portion 240 is provided such that the exhaust passage axial direction 241 z is inclined with respect to the front-rear direction L when viewed from the cylinder axial direction C. In the present embodiment, the exhaust passage 241 in the exhaust passage portion 240 is provided such that the exhaust passage axial direction 241z is inclined obliquely right forward with respect to the front-rear direction L.

  The exhaust pipe fitting portion 242 has a circular recess. The circular recess is constituted by a circular bottom surface and an annular protrusion that partially surrounds the bottom surface. In the exhaust passage axial direction 241z, the end surface of the annular projecting portion becomes the downstream end surface 242e of the exhaust pipe fitting portion 242. The downstream end surface 242e of the exhaust pipe fitting portion 242 in the exhaust passage axial direction 241z is formed so as to be inclined with respect to the side wall 202 when viewed from the cylinder axial direction C. The bottom surface in the recess of the exhaust pipe fitting part 242 serves as a contact surface 242C with which the end face of the exhaust pipe 20 can contact. The contact surface 242C is located upstream of the downstream end surface 242e in the exhaust passage axial direction 241z. An exhaust passage 241 opens at the center of the contact surface 242C.

  The downstream end surfaces of the two bolt fixing portions 243 include bolt seat surfaces 243A and 243B, respectively. The bolt seat surfaces 243A and 243B are formed on the upstream side of the contact surface 242C of the exhaust pipe fitting portion 242 in the exhaust passage axial direction 241z.

  Here, the bolt seat surface 243A is provided at a position farther from the side wall 202 than the bolt seat surface 243B, and the bolt seat surface 243B is provided at a position closer to the side wall 202 than the end face of the flange portion 205. That is, the distance LA from the bolt seat surface 243A to the side wall 202 is longer than the distance LB from the bolt seat surface 243B to the side wall 202. In this case, the bolt seat surface 243 </ b> B is provided closer to the side wall 202 than the end surface of the flange portion 205, so that the bolt seat surface 243 </ b> A approaches the side wall 202. Therefore, the cylinder head 200 can be downsized in the direction perpendicular to the side wall 202.

  As shown in FIGS. 3 and 6, the bolt seat surfaces 243A and 243B of the bolt fixing portion 243 are provided outside the exhaust pipe fitting portion 242 in the exhaust passage radial direction 241r when viewed from the cylinder axial direction. Bolt holes 243h are formed in the central portions of the bolt seat surfaces 243A and 243B. The exhaust pipe mounting bolts 21 of FIG. 8 described later are inserted into the bolt holes 243h, respectively.

  On the downstream end surface 242e (annular protrusion) of the exhaust pipe fitting portion 242, notches 242A and 242B are formed at portions overlapping with the bolt seat surfaces 243A and 243B in the exhaust passage radial direction 241r, respectively. In this case, the bottom surfaces in the notches 242A and 242B are formed so as to be continuous with the bolt seat surfaces 243A and 243B. Accordingly, the bolt holes 243h of the bolt seat surfaces 243A and 243B can be formed at positions close to the center of the exhaust pipe fitting portion 242 in the exhaust passage radial direction 241r. As a result, the bolt fixing portion 243 can be prevented from becoming large in the exhaust passage radial direction 241r.

  As shown in FIG. 5, the portion of the downstream end surface 242e of the exhaust pipe fitting portion 242 farthest from the side wall 202 when viewed from the cylinder axial direction C is referred to as a first portion 244A. Similarly, when viewed from the cylinder axial direction, the portion of the downstream end surface 242e of the exhaust pipe fitting portion 242 closest to the side wall 202 is referred to as a second portion 244B. That is, of the downstream end surface 242e of the exhaust pipe fitting portion 242, the distance from the first portion 244A to the side wall 202 is the longest, and the distance from the second portion 244B to the side wall 202 is the shortest.

  In the present embodiment, since bolt seat surface 243A is provided at a position farther from side wall 202 than bolt seat surface 243B, a sufficient space for component mounting portion 244 is secured at a position far from side wall 202 in exhaust passage portion 240. be able to.

  Here, the component attachment portion 244 is provided at a position closer to the first portion 244A than the second portion 244B in the exhaust passage radial direction 241r. In this case, the exhaust passage portion 240 has a larger area on the first portion 244A side than on the second portion 244B side. As a result, the oxygen sensor 40 can be attached to the component attachment portion 244 without interfering with the side wall 202, and an increase in the size of the cylinder head 200 due to the attachment of the oxygen sensor 40 is prevented.

  Further, when viewed from the cylinder axial direction C, the component mounting portion 244 is disposed outside the outer peripheral portion of the flange portion 205. In this case, the oxygen sensor 40 having a shape extending beyond the flange portion 205 can be attached to the component attachment portion 244. Further, the attachment of the component to the component attachment portion 244 and the removal of the component from the component attachment portion 244 can be easily performed from the direction of the flange portion 205 of the side wall 202.

  When viewed from the cylinder axial direction C, the bolt seat surface 243A may be formed such that a surface including the bolt seat surface 243A intersects the component mounting portion 244. Alternatively, the bolt seat surface 243A may be formed so that the surface including the bolt seat surface 243A is positioned upstream of the component mounting portion 244 when viewed from the cylinder axial direction. In this case, since the bolt seating surface 243A sufficiently approaches the side wall 202, the cylinder head 200 can be sufficiently downsized in the direction perpendicular to the side wall 202.

  FIG. 7 is a cross-sectional view taken along the exhaust passage axial direction 241z of the exhaust passage portion 240 of FIG. As shown in FIG. 7, the oxygen sensor 40 is attached to the component attachment portion 244 of the exhaust passage portion 240 in parallel with the cylinder axial direction C. Here, an oxygen detector provided at the tip of the oxygen sensor 40 is disposed in the exhaust passage 241. In this case, the oxygen concentration of the exhaust gas discharged from the combustion chamber of the cylinder 51 through the exhaust passage 241 can be measured by the oxygen sensor 40. The oxygen sensor 40 is heated by the heat of the combustion chamber. Thereby, the rise time of the oxygen sensor 40 can be shortened.

(3) Directional relationship between cylinder head and motorcycle FIG. 8 is a diagram showing a directional relationship between the cylinder head 200 and the motorcycle 100. As shown in FIG. 8, the cylinder head 200 is provided on the vehicle body frame 80 such that the side walls 201 and 202 face the rear and the front of the motorcycle 100, respectively.

  A cylinder head cover 250 is attached to the upper surface of the flange portion 205 of FIG. The exhaust pipe 20 is fitted into the recess of the exhaust pipe fitting portion 242. In this state, the exhaust pipe 20 is fixed to the bolt holes 243h of the bolt seating surfaces 243A and 243B of the bolt fixing portion 243 by the exhaust pipe mounting bolts 21. As a result, the exhaust pipe 20 is connected to the exhaust pipe fitting portion 242.

  According to this configuration, the downstream end surface 242e of the exhaust pipe fitting portion 242 of the cylinder head 200 is one side (rightward in the present embodiment) with respect to the front-rear direction L when viewed from the vertical direction of the motorcycle 100. Side). As shown in FIG. 1, the muffler 30 is provided on one side (the right side in the present embodiment) in the width direction of the body frame 80. As a result, the mounting operation of the exhaust pipe 20 and the muffler 30 becomes easy and the handling of the exhaust pipe 20 becomes easy.

(4) Effect In the cylinder head 200 according to the present embodiment, the exhaust passage portion 240 protrudes from the side wall 202. Here, the bolt seat surfaces 243A and 243B of the bolt fixing portion 243 of the exhaust passage portion 240 are provided outside the exhaust pipe fitting portion 242 of the exhaust passage portion 240 in the exhaust passage radial direction 241r. The downstream end surface 242e of the exhaust pipe fitting portion 242 in the exhaust passage axial direction 241z is formed so as to be inclined with respect to the side wall 202 when viewed from the cylinder axial direction C. Thereby, the exhaust pipe 20 can be attached to the cylinder head 200 in a compact manner.

  Further, the bolt seat surfaces 243A and 243B of the bolt fixing portion 243 are formed on the upstream side of the downstream end surface 242e of the exhaust pipe fitting portion 242 in the exhaust passage axial direction 241z. Thereby, the distance from the side wall 202 to the farthest part of the bolt fixing portion 243 is smaller than when the bolt seat surfaces 243A and 243B and the downstream end surface 242e of the exhaust pipe fitting portion 242 are arranged on the same plane. Therefore, the cylinder head 200 is downsized in the direction perpendicular to the side wall 202, that is, in the front-rear direction L of the motorcycle 100 body.

  As a result, the exhaust pipe 20 can be connected to be inclined with respect to the side wall 202 of the cylinder head 200 while suppressing an increase in size of the cylinder head 200. Further, the cylinder head 200 is downsized in the direction perpendicular to the side wall 202. Thereby, when manufacturing the cylinder head 200 by casting, the number of the cylinder heads 200 which can be manufactured with one metal mold | die may be able to be increased. As a result, the productivity of the cylinder head 200 can be improved.

(5) Other Embodiments (5-1) In the above embodiment, the oxygen sensor 40 is attached to the component attachment portion 244, but is not limited thereto. Instead of the oxygen sensor 40, other components may be attached to the component attachment portion 244. Alternatively, the oxygen sensor 40 may be attached to a member located downstream of the exhaust passage portion 240 such as the exhaust pipe 20. In this case, the component attachment portion 244 may not be provided in the exhaust passage portion 240.

  (5-2) In the above embodiment, the oxygen sensor 40 is attached to the component attachment portion 244 of the exhaust passage portion 240 in parallel to the cylinder axial direction C, but is not limited to this. The oxygen sensor 40 may be attached to the component attachment portion 244 of the exhaust passage portion 240 so as to be inclined with respect to the cylinder axial direction C.

  (5-3) In the above embodiment, the notches 242A and 242B are formed on the downstream end surface 242e of the exhaust pipe fitting portion 242, but the present invention is not limited to this. For example, when a bolt having a small diameter is used, the notches 242A and 242B may not be formed on the downstream end surface 242e of the exhaust pipe fitting portion 242.

  (5-4) Although the motorcycle 100 has been described as an example of a saddle-ride type vehicle in the above embodiment, the present invention is not limited to this. The present invention may be applied to other saddle-ride type vehicles such as an automatic tricycle or an ATV (All Terrain Vehicle).

(6) Correspondence between each constituent element of claims and each part of the embodiment Hereinafter, an example of correspondence between each constituent element of the claim and each constituent element of the embodiment will be described. It is not limited to examples.

  The engine 50 is an example of an engine, the cylinder head 200 is an example of a cylinder head, the valve mechanism 260 is an example of a valve mechanism, the space V is an example of a space, and the side wall 202 is an example of a side wall. The flange portion 205 is an example of a flange portion. The exhaust pipe 20 is an example of an exhaust pipe, the exhaust passage 241 is an example of an exhaust passage, the exhaust passage 241 is an example of an exhaust passage part, and the exhaust pipe fitting part 242 is an example of an exhaust pipe fitting part. .

  The exhaust pipe mounting bolt 21 is an example of an exhaust pipe mounting bolt, the bolt fixing portion 243 is an example of a bolt fixing portion, and the bolt seat surfaces 243A and 243B are examples of first and second bolt seat surfaces, respectively. is there. The exhaust passage radial direction 241r is an example of the exhaust passage radial direction, the exhaust passage axial direction 241z is an example of the exhaust passage axial direction, the downstream end face 242e is an example of the downstream end face of the exhaust pipe fitting portion, and the cylinder axial direction C is an example in the cylinder axial direction.

  The oxygen sensor 40 is an example of a component or an oxygen sensor, the component mounting portion 244 is an example of a component mounting portion, the first portion 244A is an example of a first portion, and the second portion 244B is a second portion. It is an example of a part. The contact surface 242C is an example of a contact surface, the notches 242A and 242B are examples of notches, the body frame 80 is an example of a vehicle, the motorcycle 100 is an example of a saddle-ride type vehicle, and a muffler 30 is an example of a silencer.

  The present invention can be effectively used for a saddle-ride type vehicle including a cylinder head.

DESCRIPTION OF SYMBOLS 10 Exhaust device 20 Exhaust pipe 21 Exhaust pipe attachment bolt 30 Muffler 40 Oxygen sensor 50 Engine 51 Cylinder 52 Crankbox 80 Body frame 80a Main frame 80b Subframe 81 Handle 82 Front fork 83 Front wheel 84 Rear wheel 85 Head pipe 100 Motorcycle 200 Cylinder heads 201 to 204 Side wall 205 Flange portion 210 Intake valve 220 Exhaust valve 230 Intake passage portion 240 Exhaust passage portion 241 Exhaust passage 241r Exhaust passage radial direction 241z Exhaust passage axial direction 242 Exhaust pipe fitting portions 242A, 242B Notch portion 242C Surface 242e Downstream end surface 243 Bolt fixing portion 243A, 243B Bolt seating surface 243h Bolt hole 244 Parts mounting portion 250 Cylinder head cover 260 Valve mechanism C Sunda axis direction L longitudinal direction L1 vehicle center line LA, LB distance V space W width direction

Claims (11)

A cylinder head provided in a single cylinder engine,
A side wall defining at least a part of a space for accommodating the valve operating mechanism;
An exhaust passage section that defines an exhaust passage that guides exhaust gas discharged from the combustion chamber to an exhaust pipe and projects from the side wall, and
The exhaust passage portion has an exhaust pipe fitting portion into which the exhaust pipe is fitted, and a bolt fixing portion for fixing an exhaust pipe mounting bolt,
At least a part of the bolt fixing portion is provided outside the exhaust pipe fitting portion in the exhaust passage radial direction when viewed from the cylinder axial direction,
The downstream end surface of the exhaust pipe fitting portion in the exhaust passage axial direction is formed so as to be inclined with respect to the side wall when viewed from the cylinder axial direction.
A cylinder head, wherein a downstream end surface of the bolt fixing portion in the exhaust passage axial direction is formed upstream of the downstream end surface of the exhaust pipe fitting portion in the exhaust passage axial direction. The cylinder head according to claim 1, wherein the exhaust passage portion further includes a component mounting portion for mounting components. The downstream end surface of the exhaust pipe fitting portion has a first portion farthest from the side wall and a second portion closest to the side wall when viewed from the cylinder axial direction,
The cylinder head according to claim 2, wherein the component mounting portion is provided at a position closer to the first portion than the second portion in the exhaust passage radial direction. Further comprising a flange portion formed at the upper end of the side wall,
4. The cylinder head according to claim 2, wherein the component mounting portion is disposed outside an outer peripheral portion of the flange portion when viewed from a cylinder axial direction. The downstream end surface of the bolt fixing portion includes first and second bolt seat surfaces,
The first bolt seat surface is provided at a position farther from the side wall than the second bolt seat surface,
The cylinder head according to claim 4, wherein the second bolt seat surface is provided at a position closer to the side wall than an end surface of the flange portion. 6. The cylinder head according to claim 5, wherein the first bolt seat surface is formed such that a surface including the first bolt seat surface intersects the component mounting portion when viewed from the cylinder axial direction. The cylinder head according to any one of claims 2 to 6, wherein the component includes an oxygen sensor. The exhaust pipe fitting portion has a contact surface with which the end face of the exhaust pipe can come into contact with the upstream side of the downstream end face in the exhaust passage axial direction inside the downstream end face of the exhaust pipe fitting portion. ,
The cylinder head according to any one of claims 1 to 7, wherein a downstream end surface of the bolt fixing portion is formed upstream of the contact surface in the exhaust passage axial direction. The downstream end surface of the exhaust pipe fitting portion has a cutout portion cut out in the exhaust passage radial direction at a portion overlapping the downstream end surface of the bolt fixing portion in the exhaust passage radial direction. The cylinder head according to claim 1. A vehicle body and a single cylinder engine provided in the vehicle body;
A cylinder head according to any one of claims 1 to 9, provided in the engine,
A saddle-ride type vehicle comprising: an exhaust pipe connected to the exhaust passage portion of the cylinder head. Further comprising a silencer provided in the exhaust pipe,
The silencer is provided on one side in the width direction of the vehicle body,
The saddle riding type vehicle according to claim 10, wherein the downstream end surface of the exhaust pipe fitting portion of the cylinder head is formed to be inclined with respect to the vehicle body longitudinal direction when viewed from the vehicle body vertical direction. .

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