JP5436186B2 - Seal structure between cylinder head and cylinder head cover - Google Patents

Description

  The present invention relates to a seal structure between a cylinder head and a cylinder head cover.

  Conventionally, in a sealing structure in which a gasket is provided between a cylinder head and a cylinder head cover and fastened, a fastening surface between the cylinder head and the cylinder head cover is inclined and bulges toward the flat plane portion and the cylinder head cover side. Some have a bulging portion (see, for example, Patent Document 1). In patent document 1, the gasket of the shape matched with the shape of the said bulging part was used.

Japanese Utility Model Publication No. 60-188854

However, in the conventional sealing structure between the cylinder head and the cylinder head cover, the tightening force acting on the gasket differs between the bulging portion and the flat portion due to the shape of the fastening surface. There was a problem in that it was easy to form a gap on the surface and the seal was uniform.
The present invention has been made in view of the above-described circumstances, and an object of the present invention is to prevent a gap from being generated on a seal surface between a cylinder head and a cylinder head cover and to perform uniform sealing.

To achieve the above object, the present invention provides a cylinder head cover (133A) fastened to a cylinder head (132A) by a fastener (85), and the cylinder head (132A) in the tightening direction of the fastener (85). A gasket (82) interposed in a fastening surface (79) between the cylinder head cover (133A) and the gasket (82) is connected to a cylinder head side sealing surface (by a tightening force of the fastener (85)). 83) and the cylinder head cover side seal surface (84), and a protrusion (82B) provided on the gasket (82) on either the cylinder head (132A) side or the cylinder head cover (133A) side, , Formed in the cylinder head (132A) or the cylinder head cover (133A) The projection (82B) is fitted with a recessed groove (91), and a part of the fastening surface (79) is formed on either the cylinder head (132A) side or the cylinder head cover (133A) side. In the sealing structure of the cylinder head and the cylinder head cover having the protruding bulge portion (86), the fastening surface (79) is adjusted by adjusting the thickness of the gasket (82) corresponding to the bulge portion (86). The gasket (82) is deformed with respect to the tightening load applied to the gasket (82) so that the flat surface portion (83A) and the inclined surface portion (86C) of the gasket (82) have the same thickness. Projecting from the base (82A) and the base (82A) in contact with the cylinder head side seal surface (83) and the cylinder head cover side seal surface (84). And the height of the projection (82B) and the base (82A) is determined by the tightening load applied to the fastening surface (79). The smaller the component force perpendicular to the fastening surface (79), the lower the height is .
According to this configuration, by adjusting the thickness of the gasket corresponding to the bulging portion, even in the bulging portion where a part of the fastening surface protrudes, the thickness of the gasket after deformation with respect to the tightening load applied to the fastening surface Since this is the same as the other fastening surfaces, it is possible to prevent gaps from occurring in the cylinder head side seal surface and the cylinder head cover side seal surface, and to seal uniformly. In addition, the smaller the component force perpendicular to the fastening portion, the lower the height of the protrusion and base, so that the thickness of the gasket after deformation can be appropriately adjusted according to the load on the fastening surface, and the cylinder head side sealing surface and It is possible to prevent a gap from being generated on the cylinder head cover side sealing surface.

In the above configuration, the depth of the concave groove (91) may be the same throughout the circumference, and the thickness of the gasket (82) may be changed.
In this case, since the depth of the groove is the same all around, the groove can be easily processed .

Further, the shape of the bulging portion (86) may be a trapezoidal shape in which the bottom side (86A) is longer than the top side (86B) .
In this case, since the fastening surface on the upper side of the bulging part is formed in a straight line, the load generated on the gasket is the same on the fastening surface on the upper side and the straight fastening surface on the bottom side, and the thickness of the gasket can be made the same. , Gasket molding is easy

The seal structure between a cylinder head and a cylinder head cover according to the present invention, by adjusting the thickness of the gasket corresponding to the bulging portion, even in the bulge portion of the fastening surface is projected, the clamping exerted on the fastening surface Since the thickness of the gasket after deformation with respect to the load is the same between the flat surface and the inclined surface of the gasket, it is possible to prevent gaps from occurring on the cylinder head side seal surface and the cylinder head cover side seal surface, and to seal uniformly. it can. In addition, the smaller the component force perpendicular to the fastening portion, the lower the height of the protrusion and base, so that the thickness of the gasket after deformation can be appropriately adjusted according to the load on the fastening surface, and the cylinder head side sealing surface and It is possible to prevent a gap from being generated on the cylinder head cover side sealing surface.
Moreover, since the depth of the groove is the same over the entire circumference, the groove can be easily processed .

Also, is formed upper side of the fastening surface of the bulging portion is a straight line, it will be identical loads occurring gasket between the upper side of the fastening surface and the bottom side of the straight fastening surface, since it is possible the thickness of the gasket in the same The gasket is easy to mold.

1 is a right side view showing a motorcycle to which a seal structure between a cylinder head and a cylinder head cover according to an embodiment of the present invention is applied. It is the figure which looked at the internal structure of the engine from the side. It is a figure which expands and shows the internal structure of the front bank of FIG. It is the cross-sectional view which looked at the engine from the upper part. It is a right view of the upper part of the front bank. It is the top view which looked at the head cover from the upper part. It is sectional drawing of the vicinity of a bulging part. It is an enlarged view of the fastening surface vicinity of the bulging part in FIG. It is a top view of a gasket. It is the side view which looked at the gasket from the side by the side of the bulging part. It is XI-XI sectional drawing of FIG. 10 which shows the cross section of a gasket slope part. It is XII-XII sectional drawing of FIG. 10 which shows the cross section of a gasket plane part. It is the side view which looked at the gasket from the side by the side of the sensor side bulging part.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the description, descriptions of directions such as front and rear, right and left and up and down are for the vehicle body.
FIG. 1 is a right side view showing a motorcycle to which a seal structure between a cylinder head and a cylinder head cover according to an embodiment of the present invention is applied. The motorcycle 10 includes a body frame 11, a pair of left and right front forks 13 rotatably supported by a head pipe 12 attached to a front end portion of the body frame 11, and a top that supports an upper end portion of the front fork 13. A steering handle 15 attached to the bridge 14, a front wheel 16 rotatably supported by the front fork 13, an engine 17 as an internal combustion engine supported by the vehicle body frame 11, and exhaust pipes 18 </ b> A and 18 </ b> B to the engine 17. Exhaust mufflers 19A and 19B connected through a rear swing arm 21, a rear swing arm 21 supported by a pivot 20 at the lower rear portion of the vehicle body frame 11 so as to swing up and down, and a rear end portion of the rear swing arm 21 are rotatable. And a rear wheel 22 supported by the rear wheel 22. Deployment 23 is disposed. The handle 15 is provided with a throttle 15A operated by the operator, and the engine 17 is controlled by the operation of the throttle 15A.

  The vehicle body frame 11 includes a main frame 25 extending rearward and downward from the head pipe 12, a pair of left and right pivot plates (also referred to as a center frame) 26 connected to the rear portion of the main frame 25, and a downward extension from the head pipe 12. And a down tube 27 which is bent and extends and connected to the pivot plate 26. The fuel tank 28 is supported so as to straddle the main frame 25, the rear of the main frame 25 extends to the upper part of the rear wheel 22 and the rear fender 29 is supported, and the seat 30 is supported between the rear fender 29 and the fuel tank 28. . In FIG. 1, reference numeral 31 denotes a radiator supported by the down tube 27, reference numeral 32 denotes a front fender, reference numeral 33 denotes a side cover, reference numeral 34 denotes a headlight, reference numeral 35 denotes a taillight, and reference numeral 36 denotes an occupant step. .

  The engine 17 is supported in a space surrounded by the main frame 25, the pivot plate 26 and the down tube 27. The engine 17 is a front-rear V-type two-cylinder water-cooled four-cycle engine in which cylinders (cylinders) are banked back and forth in a V shape. The engine 17 is supported by the vehicle body frame 11 via a plurality of engine brackets 37 (only part of which is shown in FIG. 1) so that the crankshaft 105 is oriented in the horizontal direction with respect to the vehicle body. The power of the engine 17 is transmitted to the rear wheel 22 via a drive shaft (not shown) disposed on the left side of the rear wheel 22.

The engine 17 is formed with an angle between the front bank 110A and the rear bank 110B (also referred to as a bank angle) constituting each cylinder at an angle smaller than 90 degrees (for example, 52 degrees). The valve gears of the banks 110A and 110B are both configured in a 4-valve double overhead camshaft (DOHC) system.
In a V-shaped V bank space K formed between the front bank 110A and the rear bank 110B, an air cleaner 41 and a throttle body 42 that constitute an engine intake system are disposed. The throttle body 42 supplies the air purified by the air cleaner 41 to the front bank 110A and the rear bank 110B. The banks 110A and 110B are connected to exhaust pipes 18A and 18B constituting an engine exhaust system. The exhaust pipes 18A and 18B pass through the right side of the vehicle body and exhaust mufflers 19A and 19B are connected to the rear ends thereof. Exhaust gas is discharged through the exhaust pipes 18A and 18B and the exhaust mufflers 19A and 19B.

2 is a view of the internal structure of the engine 17 as viewed from the side, and FIG. 3 is an enlarged view of the internal structure of the front bank 110A of FIG.
In FIG. 2, the front bank 110A and the rear bank 110B of the engine 17 have substantially the same structure. In FIG. 2, the front bank 110A shows the periphery of the piston, and the rear bank 110B shows the periphery of the cam chain. In FIG. 2, reference numeral 121 indicates an intermediate shaft (rear balancer shaft), reference numeral 123 indicates a main shaft, and reference numeral 125 indicates a counter shaft. These shafts 121, 123, and 125 including the crankshaft 105 are arranged in parallel with each other by shifting in the longitudinal direction and the vertical direction of the vehicle body, and in the crankcase 110C that supports these shafts, the rotation of the crankshaft 105 is intermediate shaft. A gear transmission mechanism is configured to transmit 121, the main shaft 123, and the counter shaft 125 in this order.

  As shown in FIG. 2, the front cylinder block 131A and the rear cylinder block 131B are arranged on the upper surface of the crankcase 110C of the engine 17 so as to form a predetermined sandwich angle between the front and the rear of the vehicle body, and the upper surfaces of these cylinder blocks 131A and 131B. The cylinder head 132A and the cylinder head 132B are coupled to each other, and head covers 133A and 133B (cylinder head covers) are mounted on the upper surfaces of the cylinder heads 132A and 132B, respectively, so that the front bank 110A and the rear bank 110B are configured.

Each cylinder block 131A, 131B is formed with a cylinder bore 135, and a piston 136 is slidably inserted into each cylinder bore 135. Each piston 136 is connected to the crankshaft 105 via a connecting rod 137.
Combustion recesses 141 constituting the top surface of the combustion chamber 140 formed above the piston 136 are formed on the lower surfaces of the cylinder heads 132A and 132B, and the spark plugs 142 face the tips of the combustion recesses 141. Arranged. The spark plug 142 is provided substantially coaxially with the cylinder axis C.

The engine 17 is an in-cylinder injection engine that directly injects fuel into the combustion chamber 140 from an injector 143 provided in each combustion recess 141. Each injector 143 is inserted from the V bank inner side surface of each cylinder head 132A, 132B, and is arranged with its tip facing each combustion recess 141. The injector 143 is attached in a state of being laid down with respect to the cylinder axis C.
A fuel pump 144 is provided above the cylinder head 132A, and fuel is supplied from the fuel pump 144 to each injector 143 through the fuel pipe 144A.

  Each cylinder head 132A, 132B has a front intake port 301 and a rear intake port 302 that communicate with each combustion chamber 140 through a pair of openings 145A, respectively, and an exhaust port 146 that communicates with each combustion chamber 140 through a pair of openings 146A. (The exhaust port of the cylinder head 132B is not shown). The front intake port 301 and the rear intake port 302 are disposed between the cylinder axis C and the injector 143.

  The front intake port 301 and the rear intake port 302 merge at the intake chamber 43, and the intake chamber 43 is connected to the throttle body 42. The exhaust port 146 of the cylinder head 132A is connected to the exhaust pipe 18A (see FIG. 1), and the exhaust port of the cylinder head 132B is connected to the exhaust pipe 18B (see FIG. 1).

  The cylinder heads 132A and 132B include a pair of intake valves 147 that open and close the openings 145A of the front intake port 301 and the rear intake port 302, and a pair of exhaust valves 148 that open and close the openings 146A of the exhaust port 146. Each is arranged. The intake valve 147 and the exhaust valve 148 are urged by valve springs 149 and 149 in the direction of closing the ports. The valve bodies 147 and 148 are driven by a valve gear 50 that can change valve operating characteristics such as opening / closing timing and lift amount. The valve gear 50 includes intake and exhaust camshafts 151 and 152 that are rotatably supported by the cylinder heads 132 </ b> A and 132 </ b> B and rotate in conjunction with rotation of the crankshaft 105. Here, the camshafts 151 and 152 rotate in the counterclockwise direction in FIGS. 2 and 4 respectively.

  An intake cam 153 is integrally formed on the camshaft 151. The intake cam 153 includes a base circle portion 153A that forms a circular cam surface, and a cam peak portion 153B that forms a cam surface protruding from the base circle portion 153A toward the outer peripheral side. An exhaust cam 154 is integrally formed on the camshaft 152. The exhaust cam 154 includes a base circle portion 154A that forms a circular cam surface, and a cam peak portion 154B that protrudes from the base circle portion 154A toward the outer peripheral side to form a mountain-shaped cam surface.

  As shown in FIG. 2, the intermediate shaft 158 is rotatably supported at one end side in the width direction of the cylinder heads 132 </ b> A and 132 </ b> B, and the intermediate sprockets 159 and 160 are fixed to the intermediate shaft 158. A driven sprocket 161 is fixed to one end of the camshaft 151, a driven sprocket 162 is fixed to one end of the camshaft 152, and a driving sprocket 163 is fixed to both ends of the crankshaft 105. A first cam chain 164 is wound between the sprockets 159 and 163, and a second cam chain 165 is wound between the sprockets 160 to 162. These sprockets 159 to 163 and cam chains 164 and 165 are accommodated in a cam chain chamber 166 formed on one end side of each of the banks 110A and 110B.

  The reduction ratio from the drive sprocket 163 to the driven sprockets 161 and 162 is set to 2, and when the crankshaft 105 rotates, the drive sprocket 163 rotates together with the crankshaft 105 and the driven sprocket 161 via the cam chains 164 and 165. , 162 are rotated at half the rotational speed of the crankshaft 105. Then, the intake valve 147 and the exhaust valve 148 open and close the front and rear intake ports 301 and 302 and the exhaust ports 146 of the banks 110A and 110B, respectively, according to the cam profiles of the camshafts 151 and 152 that rotate integrally with the driven sprockets 161 and 162.

  A generator (not shown) is provided at the left end portion of the crankshaft 105, and a drive gear (hereinafter referred to as a crank side drive gear) 175 is provided at the right end portion of the crankshaft 105 on the inner side (left side of the vehicle body) of the right drive sprocket 163. Is fixed. The crank side drive gear 175 meshes with a driven gear (hereinafter referred to as an intermediate side driven gear) 177 provided on the intermediate shaft 121, and transmits the rotation of the crankshaft 105 to the intermediate shaft 121 at a constant speed. The intermediate shaft 121 is rotated at the same speed and in the opposite direction.

The intermediate shaft 121 is rotatably supported below the rear side of the crankshaft 105 and below the front side of the main shaft 123.
An oil pump drive sprocket 181, the intermediate driven gear 177, and a drive gear (hereinafter referred to as an intermediate drive gear) 182 having a smaller diameter than the driven gear 177 are attached to the right end portion of the intermediate shaft 121 in order. ing.
The oil pump drive sprocket 181 is located behind the intermediate shaft 121 and is connected to the driven sprocket 186 fixed to the drive shaft 185 of the oil pump 184 disposed below the main shaft 123 via the transmission chain 187. The rotational force of 121 is transmitted and the oil pump 184 is driven.

  Further, the intermediate drive gear 182 meshes with a driven gear (hereinafter referred to as a main driven gear) 191 that is relatively rotatable with the main shaft 123 to reduce the rotation of the intermediate shaft 121 and thereby a clutch mechanism (not shown). Is transmitted to the main shaft 123. That is, the reduction ratio from the crankshaft 105 to the main shaft 123, that is, the primary reduction ratio of the engine 17 is set by the reduction ratio of the intermediate drive gear 182 and the main driven gear 191.

The main shaft 123 is rotatably supported on the rear upper side of the crankshaft 105, and a counter shaft 125 is rotatably supported substantially behind the main shaft 123. A transmission gear group (not shown) is disposed across the main shaft 123 and the counter shaft 125, and these constitute a transmission.
The left end portion of the counter shaft 125 is connected to a drive shaft (not shown) extending in the front-rear direction of the vehicle body. Thereby, the rotation of the counter shaft 125 is transmitted to the drive shaft.

  As shown in FIG. 3, the valve gear 50 is provided symmetrically independently on the intake side and the exhaust side about the cylinder axis C. Since the valve gears 50 of the front bank 110A and the rear bank 110B have substantially the same structure, in this embodiment, the valve gear 50 on the intake side of the front bank 110A will be described.

FIG. 4 is a cross-sectional view of the engine 17 as viewed from above. In FIG. 4, the front and rear banks 110A and 110B are viewed from above the engine 17 along the cylinder axis C (see FIG. 2).
As shown in FIGS. 3 and 4, the valve gear 50 includes a camshaft 151 (the camshaft 152 on the exhaust side), an intake cam 153 that rotates integrally with the camshaft 151 (an exhaust cam 154 on the exhaust side), an intake air A rocker arm 51 that opens and closes a valve 147 (exhaust valve 148 on the exhaust side), a valve cam 52 that is supported by the camshaft 151 so as to be relatively rotatable, and that opens and closes the intake valve 147 via the rocker arm 51, and around the camshaft 151 Is swingably supported by the holder 53, the link mechanism 56 that swings the valve cam 52 is transmitted to the valve cam 52 by transmitting the valve driving force of the intake cam 153 to the valve cam 52, and the holder 53. And a drive mechanism 60 (see FIG. 4). Further, the link mechanism 56 includes a sub rocker arm 54 connected to the holder 53, and a connect link 55 that connects the sub rocker arm 54 and the valve cam 52 so as to be swingable.

  The rocker arm 51 is formed wide, and the pair of intake valves 147 are opened and closed by one rocker arm 51. The rocker arm 51 is swingably supported at one end by a rocker arm pivot 51A fixed to the cylinder head 132A. A roller 51 </ b> C that contacts the valve cam 52 is rotatably supported at the center of the rocker arm 51.

  As shown in FIG. 4, a driven sprocket 161 is fixed to one end side of a camshaft 151 extending in the vehicle width direction, and an intake cam 153 and an intake cam 153 are provided at an axial intermediate portion of the camshaft 151. An adjacent valve cam 52 is provided. The valve cam 52 has a base circle portion 52A that maintains the intake valve 147 in a closed state, and a cam peak portion 52B that opens the valve by pushing down the intake valve 147, and is rotatable relative to the camshaft 151. It is pivotally supported. The valve cam 52 is connected to a holder 53 via a link mechanism 56. When the holder 53 is rotated relative to the camshaft 151 by the drive mechanism 60, the valve cam 52 rotates relative to the camshaft 151. . Further, the valve operating cam 52 is connected to a valve operating cam return spring 57 (see FIG. 4). The valve operating cam 52 is configured such that the cam nose 52B is moved from the roller 51C of the rocker arm 51 by the valve operating cam return spring 57. It is urged to rotate away.

The holder 53 includes first and second plates 53A and 53B disposed at a predetermined interval in the axial direction of the camshaft 151 with the intake cam 153 and the valve cam 52 interposed therebetween, and the first and second plates 53A, And a connecting member 59 for connecting 53B in the axial direction of the camshaft 151. One end of the sub rocker arm 54 is rotatably connected to a connecting member 59.
In addition, a connection link member 63 that connects the holder 53 to the drive mechanism 60 is connected to the second plate 53B.

The sub rocker arm 54 is disposed between the first and second plates 53A and 53B together with the intake cam 153 and the valve cam 52, and is rotatably supported by the connecting member 59 at one end thereof, with the connecting member 59 as the center. It swings. A roller 54A that contacts the intake cam 153 and presses the base circle portion 153A and the cam peak portion 153B is rotatably supported at the center of the sub rocker arm 54. A connect link 55 is connected to the other end of the sub rocker arm 54, and a valve cam 52 is connected to the other end of the connect link 55 in a swingable manner.
Further, the sub rocker arm 54 is biased by a sub rocker arm return spring 58 housed in the cylindrical housing portion 74 of the connecting member 59, and the roller 54 A of the sub rocker arm 54 is always pressed against the intake cam 153.

  The drive mechanism 60 for swinging the holder 53 includes an electric actuator 70 connected to an ECU (not shown) as an electronic control unit of the vehicle, and a ball screw 61 extending in the front-rear direction perpendicular to the camshafts 151 and 152. , Two nuts 62 that are movable in the axial direction on the ball screw 61 are provided. Each nut 62 is connected to each holder 53 of the valve operating device 50 on the intake side and the exhaust side via each connection link member 63 (see FIG. 4). When the ball screw 61 is rotated by driving the electric actuator 70, each nut 62 moves on the ball screw 61, and each holder is connected via a connecting link member (not shown) that connects each nut 62 and each holder 53. 53 is swung.

The drive mechanism 60 is provided along one side surface of the cylinder head 132A, and the electric actuator 70 is fixed to the outer side surface of the cylinder head 132A, and via a gear train 70A provided over the inside and outside of the side wall of the cylinder head 132A. The ball screw 61 is driven.
A sensor 76 that detects the amount of rotation of the ball screw 61 is provided at the end of the ball screw 61. The sensor 76 is fixed to a side wall portion located in the V bank space K of the cylinder head 132A.
The drive mechanism 60 is controlled by the ECU and swings the holder 53 in accordance with the operating state of the engine 17 to change the valve operating characteristics of the intake valve 147 and the exhaust valve 148 to change desired combustion conditions. Realize.

Here, the opening and closing operations of the valve gear 50 will be described.
In the valve operating apparatus 50 configured as described above, referring to FIG. 3, when the camshaft 151 is rotated counterclockwise in the drawing, the cam peak portion of the intake cam 153 that rotates integrally with the camshaft 151 is shown. By 153B, the sub rocker arm 54 is pushed up via the roller 54A and swings about the connecting member 59, and accordingly, the valve cam 52 is centered on the camshaft 151 via the connect link 55 in FIG. Rotate clockwise. As the valve cam 52 rotates, the cam crest 52B pushes down the intake valve 147 together with the rocker arm 51 via the roller 51C, and the intake valve 147 is opened.
When the camshaft 151 is further rotated and the base circle portion 153A of the intake cam 153 is in contact with the roller 54A, the sub rocker arm 54 is pushed down by the sub rocker arm return spring 58 and the valve cam 52 is moved. The base 57 is brought into contact with the roller 51C by being rotated counterclockwise in FIG. 3 by the spring 57. As a result, the intake valve 147 is pushed up by the valve spring 149 and closed.

Next, the operation for changing the valve operating characteristics in the valve gear 50 will be described.
As shown in FIG. 3, the holder 53 is moved in the direction of arrow A or arrow B in FIG.
When the holder 53 swings in the direction of arrow A or B, the link mechanism 56 swings around the camshaft 151. By changing the position of the link mechanism 56, the roller 54 </ b> A and the valve cam 52 swing around the camshaft 151, and the positions are displaced in the circumferential direction with respect to the camshaft 151. The phase of the swing of the valve cam 52 with respect to the rotation and the initial position of the swing are changed. Here, the initial position of the swing of the valve cam 52 is that the roller 54A is in contact with the base circle 153A of the intake cam 153 and the sub rocker arm 54 is not pushed up by the cam peak 153B. The swing position of the cam 52 is indicated.
In this way, by changing the rocking phase and rocking position of the valve cam 52 with respect to the intake cam 153, the timing, period, and cam peak at which the cam peak portion 52B of the valve cam 52 abuts on the roller 51C. Since the amount by which the portion 52B pushes down the roller 51C can be changed, the opening / closing timing, the valve opening period, and the lift amount of the intake valve 147 can be changed.

FIG. 5 is a right side view of the upper portion of the front bank 110A. FIG. 6 is a plan view of the head cover 133A as viewed from above. In FIG. 6, the upward direction in the figure corresponds to the front direction of the vehicle.
As shown in FIGS. 5 and 6, the head cover 133 </ b> A is a box-shaped cover having an opening on one side, and has a substantially rectangular top surface 80 and side walls 81 erected from the edge of the top surface 80. have. The lower surface of the side wall 81 of the head cover 133A is formed in a frame shape, and the valve cover 50 mounted on the cylinder head 132A is formed by covering the head cover 133A so that the lower surface of the frame shape is aligned with the upper surface of the cylinder head 132A. Covering.

The fastening surface 79 between the cylinder head 132A and the head cover 133A is provided with a frame-like gasket 82 that seals the space between the cylinder head 132A and the head cover 133A in a sealed state. Here, the gasket 82 is made of an elastic material such as nitrile rubber or acrylic rubber.
Further, the gasket 82 seals the space above the cylinder head 132A formed by the head cover 133A, so that a large pressure difference does not occur between the inside and outside of the head cover 133A, and the valve gear 50 in the head cover 133A and the like. What is necessary is just to be able to seal so that the lubricating oil supplied to is not leaked to the outside.
A frame-like cylinder head side seal surface 83 that contacts the gasket 82 is formed on the upper surface of the cylinder head 132A, and a frame-like head cover side seal surface 84 that contacts the gasket 82 is formed on the lower surface of the side wall 81 of the head cover 133A. Cylinder head cover side sealing surface) is formed.

The head cover 133 </ b> A is fixed to the cylinder head 132 </ b> A by a plurality of bolts 85 (fasteners) provided on the top surface 80 and fastened to the cylinder head 132 </ b> A, and the gasket 82 is sealed to the head cover side sealing surface 84 by the fastening force of the bolts 85. And the cylinder head side sealing surface 83 to be deformed by being pressed and sealed, and the fastening surface 79 is sealed. The bolts 85 are respectively provided at four seats 78 in the vicinity of the four corners of the head cover 133A, and are arranged on the inner side of the outer edges of the cylinder head side seal surface 83 and the head cover side seal surface 84 in plan view. As described above, since the bolts 85 are provided at the four positions in the vicinity of the four corners of the head cover 133 </ b> A, the fastening force can be applied uniformly over the entire circumference of the fastening surface 79.
In addition, the top surface 80 is provided with a plug hole 65 into which the ignition plug 142 is inserted and a pump fixing portion 66 to which the fuel pump 144 is fixed.

  As shown in FIGS. 4 and 5, an electric actuator 70 is provided on the right side surface of the cylinder head 132A, and a portion to which the electric actuator 70 is fixed at the upper part of the cylinder head 132A is fastened on the cylinder head 132A side. A part of the wall portion constituting the surface 79 is a bulging portion 86 protruding to the head cover 133A side. A mounting portion 87 protruding outward in the vehicle width direction is formed on the bulging portion 86, and the electric actuator 70 is fixed to the mounting portion 87.

  The bulging portion 86 extends from the front portion on the right side surface of the cylinder head 132A in the front-rear direction to the middle portion on the front and rear sides, and extends to the vicinity of the top surface 80 in the vertical direction. The bulging portion 86 is formed in a trapezoidal shape, and the bottom side portion 86A (bottom side) of the trapezoidal shape is formed longer than the upper side portion 86B (upper side) near the top surface 80. In addition, the bottom portion 86A and the upper side portion 86B of the bulging portion 86 are connected by a slope portion 86C that extends so as to taper from the bottom side portion 86A to the upper side portion 86B. Specifically, the slope portion 86C and the upper side portion 86B are smoothly connected by the curved surface portion 86D. The upper side portion 86B, the inclined surface portion 86C, and the curved surface portion 86D constitute a part of the cylinder head side seal surface 83 formed on the upper surface of the cylinder head 132A.

As shown in FIGS. 4 and 5, a sensor 76 is provided on the side wall of the cylinder head 132A on the V bank space K side, and a portion of the cylinder head 132A where the sensor 76 is fixed is a cylinder. A part of the wall portion of the head 132A is a sensor-side bulged portion 88 that bulges toward the head cover 133A. The sensor 76 is located in the middle of the height of the head cover 133 </ b> A, and the sensor side bulging portion 88 extends slightly above the sensor 76. The upper edge portion of the sensor side bulging portion 88 constitutes a part of the cylinder head side sealing surface 83.
The cylinder head side seal surface 83 other than the upper side portion 86B and the slope portion 86C of the bulge portion 86 and the sensor side bulge portion 88 is a flat portion 83A that extends flatly along the lower surface of the head cover side seal surface 84. Yes.

A concave portion 90 is formed at a position corresponding to the bulging portion 86 in the side wall 81 of the head cover 133A so as to be aligned with the bulging portion 86 in the assembled state and to seal the fastening surface 79. The concave portion 90 has a cover side upper side portion 90B, a cover side inclined portion 90C, and a cover side curved surface portion 90D corresponding to the upper side portion 86B, the inclined surface portion 86C, and the curved surface portion 86D of the bulging portion 86, respectively. Yes.
The lower surface of the head cover side seal surface 84 is a cover side flat surface portion 84 </ b> A corresponding to the flat surface portion 83 </ b> A of the cylinder head side seal surface 83.

FIG. 7 is a cross-sectional view of the vicinity of the bulging portion 86. Here, in FIG. 7, illustration of the electric actuator 70 and the mounting portion 87 is omitted.
As shown in FIG. 7, in the bulging portion 86, the gasket 82 is provided between the upper side portion 86 </ b> B of the cylinder head side sealing surface 83 and the cover side upper side portion 90 </ b> B of the head cover side sealing surface 84. In portions other than the bulging portion 86 and the sensor-side bulging portion 88 (see FIG. 5), the gasket 82 is provided between the flat portion 83A and the cover-side flat portion 84A.

FIG. 8 is an enlarged view of the vicinity of the fastening surface 79 of the bulging portion 86 in FIG. FIG. 9 is a plan view of the gasket 82.
As shown in FIG. 8, the gasket 82 has a plate-like base 82A and a protrusion 82B protruding from the base 82A toward the head cover side seal surface 84. The protrusion 82B is erected at the center in the width direction of the base 82A. Further, the base portion 82A has a convex portion 82C that protrudes toward the cylinder head side seal surface 83 on the opposite side to the protruding portion 82B. A plurality of convex portions 82C are formed side by side in the width direction of the base portion 82A, and the protruding amount of the protruding portion 82C is smaller than the protruding amount of the protruding portion 82B. As shown in FIG. 9, the gasket 82 is continuously formed in a frame shape, and has a base 82A, a protrusion 82B, and a protrusion 82C shown in FIG. 8 in any cross section of the frame shape.

  As shown in FIG. 8, the cylinder head side sealing surface 83 is formed flat, and is flat over the entire circumference of the frame shape. On the other hand, the head cover side sealing surface 84 is formed with a concave groove 91 that is recessed on the opposite side to the gasket 82 side, and a protrusion 82B of the gasket 82 is fitted into the concave groove 91. The concave groove 91 is formed over the entire circumference of the head cover side sealing surface 84 formed in a frame shape.

The depth of the concave groove 91 is set to be smaller than the protruding amount of the protrusion 82B in the natural state before being assembled to the head cover 133A. In the assembled state, the protrusion 82B is formed on the base 82A by the concave groove 91. It is compressed to the side and is in a contracted state. Moreover, since the depth of the concave groove 91 is the same over the entire circumference, the concave groove 91 can be easily processed. Here, the natural state of the gasket 82 refers to a state in which the gasket 82 is not assembled and the gasket 82 is not compressed.
Further, in the assembled state, the base portion 82A is in contact with both the cylinder head side seal surface 83 and the head cover side seal surface 84, and is compressed and contracted. Thus, since the fastening surface 79 is sealed in a state where the base portion 82A and the protrusion 82B of the gasket 82 are compressed, the fastening surface 79 can be reliably sealed.

FIG. 10 is a side view of the gasket 82 as viewed from the side surface on the bulging portion 86 side.
As shown in FIGS. 5 and 10, the gasket 82 is formed to be bent so as to match the shape of the cylinder head side seal surface 83, and the gasket bulge portion 92 that contacts the bulge portion 86, the sensor side A sensor-side gasket bulge portion 93 that abuts against the bulge portion 88 and a gasket flat surface portion 94 that abuts against the flat surface portion 83A of the cylinder head side seal surface 83 are provided.
Specifically, the gasket bulging portion 92 includes a gasket upper side portion 92B that contacts the upper side portion 86B of the bulging portion 86, a gasket inclined surface portion 92C that contacts the inclined surface portion 86C, and a gasket curved surface portion 92D that contacts the curved surface portion 86D. have.

Here, the deformation state of the gasket 82 when the head cover 133A is assembled will be described.
When the head cover 133A is assembled to the cylinder head 132A, as shown in FIG. 10, the fastening force F (tightening load) parallel to the fastening direction of the bolt 85 is applied to the head cover 133A over the entire circumference by fastening the bolt 85. The gasket 82 is pressed against the cylinder head side seal surface 83 via the head cover side seal surface 84.

Then, the clamping force F acts on the surface of the gasket flat surface portion 94 in contact with the flat surface portion 83A of the cylinder head side seal surface 83 as it is through the cover side flat surface portion 84A. In addition, the tightening force F acts on the surface of the gasket upper side portion 92B in contact with the upper side portion 86B of the bulging portion 86 as it is through the cover side upper side portion 90B.
On the other hand, in the gasket slope portion 92C that contacts the slope portion 86C of the bulging portion 86, the fastening force F acts on the gasket slope portion 92C via the cover side slope portion 90C, but the surface of the slope portion 86C has a fastening force F. Therefore, the magnitude of the tightening force F does not act as it is on the surface of the gasket slope portion 92C. In the inclined surface portion 86C, the gasket inclined surface portion 92C is deformed by the component force C1 that acts perpendicularly to the surface of the inclined surface portion 86C among the component force of the tightening force F. The component force C1 is a tightening force that compresses and deforms the gasket inclined surface portion 92C perpendicularly to the surface of the inclined surface portion 86C.

When the bulging portion 86 is thus included, the magnitude of the load acting on the gasket flat surface portion 94, the gasket upper side portion 92B, the gasket inclined surface portion 92C, and the gasket curved surface portion 92D is different. For example, the gasket flat surface portion 94, the gasket upper side portion 92B, the gasket slope portion 92C, and the gasket curved surface portion 92D are set to different thicknesses.
In the present embodiment, the thickness of each part of the gasket 82 is set so that the thickness of each part of the gasket 82 after deformation with respect to the tightening force F (tightening load) parallel to the tightening direction of the bolt 85 is substantially the same. ing.

  The above-mentioned component force C1 is obtained by FcosA1 when the inclination angle of the gasket inclined surface portion 92C (inclined surface portion 86C) with respect to the gasket flat surface portion 94 is A1. That is, the component force C1 decreases as the inclination angle A1 of the gasket inclined surface portion 92C increases. For this reason, the vertical tightening load on the surface of the gasket slope portion 92C is smaller than the vertical tightening load on the surfaces of the gasket flat surface portion 94 and the gasket upper side portion 92B.

11 is a cross-sectional view taken along the line XI-XI in FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 11 and 12, the gasket 82 in a state of being assembled and deformed is indicated by a two-dot chain line.
In this configuration, the gasket 82 is molded by changing the thickness of each portion of the gasket 82 according to the magnitude of the vertical tightening load on the fastening surface 79, so that the gasket 82 is crushed at each portion in the assembled state. The amount (deformation amount) is changed.
As shown in FIG. 11, the natural thickness Ta of the base portion 82A in the gasket slant portion 92C is the reference thickness T1 of the base portion 82A in the gasket flat portion 94 shown in FIG. When the crushing amount of the base portion 82A is the crushing amount E1, for example, as shown in the following formula (1), it is determined by a predetermined arithmetic expression.
Ta = T1 + E1cosA1 (1)
Further, the thickness Tb (see FIG. 11) of the protrusion 82B on the gasket slant portion 92C is the reference thickness T2 (see FIG. 12), and the gasket flat surface portion 94 is the reference thickness of the protrusion 82B on the gasket flat surface portion 94. When the crushing amount of the projecting portion 82B is the crushing amount E2, for example, as shown in the following equation (2), it is determined by a predetermined arithmetic expression.
Tb = T2 + E2cosA1 (2)

Here, the reference thicknesses T1 and T2 are the thicknesses when the gasket 82 is assembled to the fastening surface 79 and compressed, and are the thicknesses obtained by subtracting the amount of crushing from the thickness of the gasket 82 in the natural state. The units of the thicknesses Ta, T1, Tb, T2 and the crushing amounts E1, E2 are the thickness (mm), and the unit of the inclination angle A1 is the angle (°).
The thickness of the gasket slope portion 92C is a thickness obtained by adding the thickness Ta of the base portion 82A and the thickness Tb of the protrusion 82B calculated by the equations (1) and (2).

As can be seen from the above formulas (1) and (2), the amount of crushing at the gasket inclined surface portion 92C is reduced by the inclination angle A1 with respect to the amount of crushing E1 and E2 at the gasket flat surface portion 94. Corresponding to the ratio of the force C1 to the tightening force F, the crushing amount is set to be smaller than the crushing amounts E1 and E2. Then, the thickness Ta of the base portion 82A and the thickness Tb of the protrusion 82B are respectively added to the reference thickness T1 and the thickness T2 of the gasket flat surface portion 94 and the crushing amount set corresponding to the component force C1. Is determined. That is, the height (thickness) of the base portion 82A and the protrusion 82B is formed to be lower than the gasket flat surface portion 94 in proportion to the component force C1 perpendicular to the slope portion 86C. Further, the height of the base portion 82A and the protruding portion 82B is formed to be low in proportion to the component force C1 perpendicular to the inclined surface portion 86C, but the thickness capable of maintaining the function as a gasket for sealing the fastening surface 79 is maintained. Is done.
Here, the gasket sloped portion 92C on the left side of FIG. 10 has been described, but the above-described equation (on the basis of the inclination angle A1 between the gasket sloped portion 92C and the gasket plane portion 94 also applies to the gasket sloped portion 92C on the right side in FIG. The height of the base 82A and the protrusion 82B is set by 1) and (2).

Next, an example of the thickness of the gasket 82 is shown.
For example, the reference thickness T1 of the base portion 82A is 2.0 (mm), the reference thickness T2 of the protrusion 82B is 3.0 (mm), and the crushing amount E1 at the gasket flat portion 94 is 0.5 (mm). ), When the crushing amount E2 is set to 0.6 (mm), the thickness of the gasket flat surface portion 94 is obtained by adding these to be 6.1 (mm). Here, as an example, the inclination angle A1 is 70 (°), and the amount of crushing at the gasket inclined surface 92C is determined by the relationship between E1 cos A1 and E2 cos A1, respectively. It is 0.21 (mm) in the part 82B. The thickness of the gasket slope portion 92C is obtained by adding the reference thickness T1, the reference thickness T2, and the amount of crushing at the gasket slope portion 92C, and is 5.38 (mm).
The crushing amount of the gasket 82 may be, for example, rounded off to the second decimal place of the above value to be 0.2 (mm) at the base 82A and 0.2 (mm) at the protrusion 82B.

  The gasket 82 is nipped and assembled to the fastening surface 79 by the tightening force of the bolt 85. In this state, the thickness of the gasket 82 becomes the reference thicknesses T1 and T2 over the entire circumference of the frame shape. In 82, the base 82A is compressed to 2.0 (mm), and the protrusion 82B is compressed to 3.0 (mm). In this way, in the assembled state, the thickness of the gasket 82 is a constant reference thickness over the entire circumference, so that the head cover 133A is not tilted and fixed with respect to the fastening surface 79, and can be reliably sealed.

In the present embodiment, the ratio of the magnitude of the component force C1 to the magnitude of the tightening force F is set equal to the ratio of the collapse amount at the gasket inclined surface portion 92C to the collapse amounts E1 and E2 at the gasket flat surface portion 94. The thickness of the gasket 82 is set so that the ratio of the deformation amount of the gasket 82 to the fastening load applied perpendicularly to the fastening surface 79 is the same over the entire circumference of the gasket 82. Thereby, also in the slope part 86C of the bulging part 86 from which a part of the fastening surface 79 protrudes, the ratio of the deformation amount of the gasket slope part 92C to the component force C1 is relative to the fastening force F of the flat part 83A and the upper side part 86B. Since the deformation ratios of the gasket flat surface portion 94 and the gasket upper side portion 92B are the same, it is possible to prevent gaps from occurring in the cylinder head side seal surface 83 and the head cover side seal surface 84, and to perform uniform sealing. Here, the ratio of the deformation amount of the gasket inclined surface portion 92C to the component force C1 is assumed to be the same as the ratio of the deformation amount of the gasket flat surface portion 94 and the gasket upper side portion 92B to the tightening force F of the flat surface portion 83A and the upper side portion 86B. As described above, the ratios of these deformation amounts do not have to be completely the same, and may be changed depending on the dimensional accuracy and accuracy setting of the gasket 82 and the concave groove 91, or may be substantially the same.
Further, the fastening surface 79 of the bulging portion 86 and the sensor side bulging portion 88 to which the electric actuator 70 and the sensor 76 of the valve operating device 50 are respectively attached can be reliably sealed by the gasket 82, and the electric actuator 70 and the sensor 76 are connected to the cylinder. It can be arranged outside the head 132A. For this reason, the assembly property and maintenance property of the engine 17 can be improved.

  In the present embodiment, as described above, the crushing amount of the protrusion 82B at the gasket inclined surface 92C is set to 0.21 (mm). For example, this crushing amount is set to the magnitude of the component force C1. When not set correspondingly and set to the same 0.5 (mm) as that of the gasket flat surface portion 94, the ratio of the deformation amount of the gasket inclined surface portion 92C to the component force C1 applied to the inclined surface portion 86C is the other fastening surface 79 The ratio of the deformation amount of the gasket 82 with respect to the tightening force F becomes larger, and the gasket 82 is not completely crushed, which may cause a problem in assembling property or may deteriorate the sealing performance.

  Also, as shown in FIG. 10, the gasket 82 has a gasket curved surface portion 92D. In this gasket curved surface portion 92D, the thickness of the base portion 82A and the protrusion 82B is continuous from the gasket slope portion 92C to the gasket upper side portion 92B. It is connected smoothly so that it becomes thick. For this reason, since the ratio of the deformation amount of the gasket curved surface portion 92D due to the tightening force applied to the gasket curved surface portion 92D is substantially the same as the ratio of the deformation amount of the gasket 82 to the tightening force F of the other fastening surface 79, the cylinder head side It is possible to prevent a gap from being generated in the seal surface 83 and the head cover side seal surface 84, and to seal uniformly.

FIG. 13 is a side view of the gasket 82 as seen from the side surface on the sensor side bulging portion 88 side. In FIG. 13, the contour line of the cylinder head side seal surface 83 is indicated by a two-dot chain line.
As shown in FIGS. 5 and 13, the sensor-side bulging portion 88 protrudes upwardly toward the top surface 80, and has an arcuate curved surface portion 88 </ b> A formed on the upper portion and an arcuate shape. A sensor-side inclined surface 88B that connects the curved surface portion 88A and the gasket flat surface portion 94 is provided.
The sensor-side gasket bulge portion 93 of the gasket 82 is provided along the contour of the sensor-side bulge portion 88, and includes a gasket arcuate curved surface portion 93A along the arcuate curved surface portion 88A and a gasket slope surface along the sensor side inclined surface portion 88B. Part 93B.

  The gasket inclined surface portion 93B is provided with an inclination angle A2 with respect to the gasket flat surface portion 94, and the inclination angle A2 is larger than the inclination angle A1 of the gasket inclined surface portion 92C. For this reason, the thickness of the base portion 82A and the protrusion 82B in the gasket slope portion 93B is set smaller than that of the gasket slope portion 92C based on the above formulas (1) and (2). Moreover, since the top 93C of the gasket arcuate curved surface portion 93A is a surface perpendicular to the tightening force F, the thickness of the top 93C is set to be the same as the gasket flat surface portion 94.

In the gasket arcuate curved surface portion 93A, the thickness of the base portion 82A and the protruding portion 82B is smoothly connected so as to continuously increase from the upper end of the gasket slope portion 93B to the top portion 93C. For this reason, the ratio of the deformation amount of the gasket arcuate curved surface portion 93A due to the tightening force applied to the gasket arcuate curved surface portion 93A is substantially the same as the ratio of the deformation amount of the gasket 82 to the tightening force F of the other fastening surface 79. Further, it is possible to prevent a gap from being generated in the cylinder head side seal surface 83 and the head cover side seal surface 84 and to perform uniform sealing.
In FIG. 13, the outline of the cylinder head side seal surface 83 is shown below the gasket 82 in order to avoid overlapping of the lines indicating the gasket 82 and the cylinder head side seal surface 83, but the cylinder head side seal surface is shown. 83 is formed along the gasket 82.

  As described above, according to the embodiment to which the present invention is applied, the thickness of the base portion 82A and the protrusion 82B in the gasket slope portion 92C corresponding to the slope portion 86C of the bulging portion 86 is adjusted, and the gasket plane portion 94 and the base 82A and the protrusion 82B at the upper side 92B of the gasket are made thinner than the thickness of the base 82A and the protrusion 82B so that the bulging portion 86 from which a part of the fastening surface 79 between the cylinder head 132A and the head cover 133A protrudes is also fastened. The ratio of the deformation amount of the gasket inclined surface portion 92 </ b> C to the component force C <b> 1 of the tightening force F by the bolt 85 applied to the surface 79 is the same as the ratio of the deformation amount of the gasket 82 to the tightening force F of the other fastening surface 79. For this reason, the gasket 82 can be stably deformed over the entire circumference and a gap can be prevented from being generated in the cylinder head side seal surface 83 and the head cover side seal surface 84, so that the fastening surface 79 can be uniformly sealed. .

Further, in the gasket slope portion 92C, the height of the protrusion 82B of the gasket slope portion 92C is set to be perpendicular to the component force C1 of the fastening force F acting perpendicularly to the surface of the gasket slope portion 92C. Since the gasket is formed lower than the gasket flat part 94 and the protrusion 82B of the gasket upper side part 92B, the deformation amount of the gasket 82 can be appropriately set according to the tightening load applied to the fastening surface 79. For this reason, it can prevent that a clearance gap produces in the cylinder head side sealing surface 83 and the head cover side sealing surface 84. FIG. Further, since the thickness of the gasket 82 can be adjusted only by changing the height of the protrusion 82B, the gasket 82 can be easily formed.
Further, the upper side portion 86B of the bulging portion 86 is formed in a straight line, and the fastening force F generated in the gasket 82 becomes the same in the upper side portion 86B and the straight gasket flat surface portion 94 on the bottom side, and the thickness of the gasket 82 is increased. Since it can be made the same, the molding of the gasket 82 is easy.

In addition, the said embodiment shows the one aspect | mode which applied this invention, Comprising: This invention is not limited to the said embodiment.
In the above embodiment, the projection 82B of the gasket 82 provided on the head cover 133A side is described as fitting into the concave groove 91 on the head cover 133A side, but the present invention is not limited to this. The protruding portion of the gasket 82 provided on the cylinder head 132A may be fitted into a concave groove formed on the cylinder head 132A side.
In the above embodiment, the bulging portion 86 has been described as a portion of the wall portion constituting the fastening surface 79 on the cylinder head 132A side bulging to the head cover 133A side. However, the bulging portion may be a portion in which a wall portion constituting the fastening surface 79 on the head cover 133A side bulges toward the cylinder head 132A.

Furthermore, although the above embodiment has been described as adjusting the thickness of the protrusion 82B of the gasket 82, the present invention is not limited to this. For example, the thickness of the protrusion 82B is set to the thickness of the gasket 82. and constant over the entire circumference, with a depth adjusting pollock Rukoto groove 91 which protrusion 82B is fitted, as the proportion of the amount of deformation of the gasket 82 against the clamping load applied to the fastening surface 79 are the same May be. In this case, since the thickness of the protrusion 82B of the gasket 82 can be made constant, the molding of the gasket 82 becomes easy.
In the above embodiment, the height (thickness) of the base portion 82A and the protrusion portion 82B of the gasket 82 is described as being formed low by the gasket slope portion 92C. However, the present invention is not limited to this, and the height of the base portion 82A is set. The height may be constant over the entire circumference of the gasket 82, and only the height of the protrusion 82 </ b> B may be formed low in the gasket slope portion 92 </ b> C. In this case, in order to make the height of the base portion 82A constant and to make the height of the projection 82B low, the distance between the cylinder head side seal surface 83 and the head cover side seal surface 84 is made constant by the base portion 82A. Since the thickness of the gasket 82 can be adjusted only by changing the height of the protrusion 82B, the gasket 82 can be easily formed.
In the above-described embodiment, the bulging portion 86 has been described as a part of the wall portion constituting the fastening surface 79 on the cylinder head 132A side bulging to the head cover 133A side. The bulging portion may be one in which a component different from the cylinder head 132A is provided integrally with the cylinder head 132A.
Of course, other detailed configurations of the motorcycle 10 can be arbitrarily changed.

79 Fastening surface 82 Gasket 82A Base 82B Projection 83 Cylinder head side sealing surface 84 Head cover side sealing surface (Cylinder head cover side sealing surface)
85 bolts (fasteners)
86 bulge 86A bottom (bottom)
86B Upper side (upper side)
91 Concave groove 132A Cylinder head 133A Head cover (Cylinder head cover)
C1 Component force F Tightening force (Tightening load)

Claims (3)

A cylinder head cover (133A) fastened to the cylinder head (132A) by a fastener (85), and fastening between the cylinder head (132A) and the cylinder head cover (133A) in the fastening direction of the fastener (85) A gasket (82) interposed on the surface (79), and the gasket (82) is connected to the cylinder head side seal surface (83) and the cylinder head cover side seal surface (84) by the fastening force of the fastener (85). And a protrusion (82B) provided on either the cylinder head (132A) side or the cylinder head cover (133A) side of the gasket (82), and the cylinder head (132A) or the cylinder head cover The protrusion (82B) formed on (133A) is fitted. A cylinder head comprising a groove (91) and having a bulging portion (86) in which a part of the fastening surface (79) protrudes on either the cylinder head (132A) side or the cylinder head cover (133A) side In the seal structure between the cylinder head cover and
The thickness of the gasket (82) corresponding to the bulging portion (86) is adjusted, and the thickness of the gasket (82) after deformation with respect to the tightening load applied to the fastening surface (79) is determined by the gasket ( 82) and the flat surface portion (83A) and the slope portion (86C) are formed to be the same ,
The gasket (82) includes a base (82A) that contacts the cylinder head side seal surface (83) and the cylinder head cover side seal surface (84), and projects from the base (82A) into the concave groove (91). The protrusion (82B) to be fitted,
The height of the protrusion (82B) and the base (82A) is formed such that the smaller the component force perpendicular to the fastening surface (79) of the fastening load applied to the fastening surface (79), the lower the height. is being done,
A cylinder head and cylinder head cover sealing structure. The depth of the concave groove (91) is the same all around, and the thickness of the gasket (82) is changed,
The seal structure between a cylinder head and a cylinder head cover according to claim 1. The shape of the bulging portion (86) is a trapezoid whose base (86A) is longer than the top (86B);
The seal structure between the cylinder head and the cylinder head cover according to claim 1 or 2 .

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