JP3156789B2 - Valve train for V-type 5-valve engine - Google Patents

Description

The present invention relates to a valve train for a V-type five-valve engine,
In particular, the present invention relates to an arrangement structure of a drive mechanism capable of expanding a space in a bank.

[Conventional technology]

In a four-stroke V-type engine, a cylinder (cylinder bore) is formed in a cylinder block so as to form a V shape when viewed in the crankshaft direction, and a pair of cylinder heads and a head cover are formed on the cylinder block so as to form a V bank. The thing of the structure which carried out lamination fastening is common. A valve train in this type of engine is provided with an intake cam shaft and an exhaust cam shaft that directly drive an intake valve and an exhaust valve, respectively, and each of the cam shafts is driven by a crank shaft via a gear train, a chain, a belt, and the like. It is often configured as follows.

[Problems to be solved by the invention]

In the above-mentioned V-type engine, there are cases where various accessories and other parts of the engine are arranged in the V bank,
In such a case, it is required that the space inside the V bank can be enlarged to increase the space for arranging auxiliary equipment and that the maintenance space for the auxiliary equipment can be secured. However, depending on the arrangement of the valve operating device, the valve operating mechanism housing case portion and the like may protrude into the V-bank, and may not be able to meet the above-described request for expansion of the internal space of the bank.

The present invention has been made in view of the above conventional circumstances, and
It is an object of the present invention to provide a valve train for a 4-cycle V-type engine that can expand the space in a bank.

[Means for solving the problem]

The invention according to claim 1 has three intake valves on one side of the combustion chamber,
Two exhaust valves are arranged on the other side, and the central intake valve faces the combustion chamber so that the inclination angle with respect to the cylinder axis is smaller than the inclination angles of the intake valves on both sides of the cylinder. An intake opening and an exhaust opening that are opened and closed are respectively led inside and outside the V bank through an intake passage and an exhaust passage, and an intake cam shaft and an exhaust cam shaft that directly drive these valves are provided above the intake valve and the exhaust valve. In the valve train of a V-type five-valve engine, the distance between the intake camshaft and the cylinder axis is set smaller than the distance between the exhaust camshaft and the cylinder axis, and the rotation of the crankshaft is transmitted to the camshaft. A camshaft drive mechanism is disposed at the center of the V bank, and one first intermediate gear common to the left and right cylinders meshing with the crank gear, a second intermediate gear meshing with the first intermediate gear, and a crankshaft driving mechanism. From the cylinder axis to the exhaust side A third intermediate gear meshed with the second intermediate gear and meshing with both intake and exhaust cam gears fixed to the intake camshaft and exhaust camshaft. And a flange portion of the engine auxiliary device is bolted and fixed to a support bracket portion integrally formed with the engine.

The invention according to claim 2 has three intake valves on one side of the combustion chamber,
Two exhaust valves are arranged on the other side, and the central intake valve faces the combustion chamber so that the inclination angle with respect to the cylinder axis is smaller than the inclination angles of the intake valves on both sides of the cylinder. An intake opening and an exhaust opening that are opened and closed are respectively led inside and outside the V bank through an intake passage and an exhaust passage, and an intake cam shaft and an exhaust cam shaft that directly drive these valves are provided above the intake valve and the exhaust valve. In the valve train of a V-type five-valve engine provided, the distance between the intake camshaft and the cylinder axis is set smaller than the distance between the exhaust camshaft and the cylinder axis, and the rotation of the crankshaft is transmitted to the camshaft. The camshaft drive mechanism is provided with the left and right cylinder intermediate sprockets at positions closer to the camshaft than the crankshaft and displaced toward the exhaust side from the cylinder axis when viewed in the crankshaft direction. Tie the middle chainwheel and the crank chainwheel on one crank side As well as connected by bridging string-shaped member,
An idler is provided between the left and right intermediate sprockets to secure a winding angle around the intermediate sprocket by pressing down the intermediate sprocket portion of the crank-side timing string member, and the intake camshaft is provided. , Intake air fixed to the exhaust camshaft,
The exhaust cam wheel and the intermediate wheel are connected by a cam-side timing string member.
The engine auxiliary device is disposed in the bank and above the idler, and a flange portion of the engine auxiliary device is bolted and fixed to a support bracket portion formed integrally with the engine.

Here, the valve gear according to the second aspect of the present invention includes one using a timing chain and one using a timing belt. Therefore, the above-mentioned cam chain wheel means a cam sprocket and a cam pulley, and the above-mentioned intermediate wheel means an intermediate sprocket and an intermediate pulley. The driving of the cam shaft by the intermediate chain wheel includes various methods such as a method of connecting the intermediate sprocket to both the intake and exhaust cam sprockets with a chain, and a method of connecting the intermediate pulley to both the intake and exhaust cam pulleys with a belt. It is.

[Action]

According to the first aspect of the present invention, the first intermediate gear common to the left and right is meshed with the crank gear, and the second and third intermediate gears on the left and right are sequentially meshed with the first intermediate gear. Since only one gear is required and the first intermediate gear can be set large, the diameters of the second and third intermediate gears can be reduced while securing the required reduction ratio. As a result, the intermediate gear housing case protrudes inside the V bank. And a space for the auxiliary device in the V bank can be secured.

Further, since the second intermediate gear is displaced toward the exhaust side from the cylinder axis, a space for arranging auxiliary equipment in the V bank can be secured from this point as well.

According to the second aspect of the present invention, since the idler is disposed between the left and right intermediate sprockets, and the crank side timing string member is pressed down, the intermediate sprocket and the intake and exhaust cam chains are arranged. The cam-side timing cord-like member for connecting to the vehicle can be shortened, and a tensioner for the cord-like member can be eliminated, and the camshaft drive mechanism housing case is prevented from bulging inside the V-bank, so that the V-bank complement can be prevented. Space for container placement can be secured.

〔Example〕

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

1 to 5 are views for explaining a valve train of a four-cycle V-type engine according to a first embodiment of the present invention. FIG. 1 is a front view, FIG. 2 is a rear view, FIG. 3 is a sectional front view, FIG. 4 is a sectional front view of a cylinder head portion, and FIG. 5 is a plan view of an upper head portion.

In the figure, reference numeral 1 denotes a water-cooled type 4 employing the apparatus of this embodiment.
This is a cycle V type 8-cylinder engine having a structure in which a crankcase 3 is mounted on the lower surface of a cylinder block 2 and a pair of left and right cylinder heads 4 and a head cover 5 are stacked and fastened on the upper surface. A total of eight cylinders (cylinder bores) 6 are formed in the cylinder block 2 so as to form a V-shape when viewed in the crankshaft direction. A piston 7 inserted into each cylinder 6 is connected to a crankshaft by a connecting rod 8. 9.

The cylinder head 4 has a lower head 10 and an upper head 11
The lower head 10
A combustion recess 12 which forms a combustion chamber with the upper surface of the piston 7 is recessed on the lower surface of the piston 7. This combustion recess 12 has 3
Two intake openings 12a to 12c and two exhaust openings 12d and 12e are formed along the periphery of the combustion recess 12, and a spark plug insertion hole 12i is formed in the center. Exhaust opening 12 above
d and 12e are V of the cylinder head 4 by the exhaust passages 13d and 13e.
It is led out to the bank outer wall 10b. Also the above intake opening 1
2a to 12c are cylinder heads 4 by intake passages 13a to 13c.
And joined at an extended portion 11c extending above the upper head 11, and the joined portion 13f is formed in an elliptical shape that is horizontally long in the crankshaft direction. A fuel injection valve 30 is mounted in a mounting hole 11d formed in the central intake passage 13b, and a slide valve 39 that opens and closes the junction 13f is provided in the extension 11c.
Further, an air horn 40 is connected. Reference numeral 41 denotes a cover for preventing dust and the like from entering the air horn 41.

Further, a water cooling jacket is formed in the lower head 10 so as to cover the upper part of the combustion recess 12. The water-cooled jacket includes an intake-side jacket 31a located from the intake passages 13a to 13c to the inner wall 10a of the lower head 10, and an outer wall 10b from the exhaust passages 13d and 13e.
An exhaust-side jacket 31b is located on the side, and a central jacket 31c is located between the intake passage and the exhaust passage. A communication hole 31e is formed by drilling at a position connecting the upper ends of the center jacket 31c and the intake side jacket 31a and sandwiching the left and right intake passages 13a and 13c. The cooling water flows from the water cooling jacket (not shown) of the cylinder block 2 into the exhaust side jacket 31b, and flows out from the central jacket 31c and the intake side jacket 31a to the drain port 31d. When the supply of the cooling water is started, the air in the central jacket 31c is exhausted to the intake-side jacket 31a through the communication hole 31e.

The intake openings 12a to 12c and the exhaust openings 12d and 12e are provided with valve plates 14a and 15a of an intake valve 14 and an exhaust valve 15, respectively. The upper ends of the valve rods 14b, 15b of the valves 14, 15 are located in guide holes 11a, 11b formed in the upper head 11. The inclination angle of the central intake valve 14 'with respect to the cylinder axis C is smaller than the inclination angles of the intake valves 14 on both sides, and when viewed in the crankshaft direction, the axis of these three intake valves 14 is They intersect at the axis of an intake camshaft 24 described later. Each of the guide holes 11a and 11b is formed so as to be continuous in the radial direction by three pieces and two pieces in the radial direction, that is, the guide holes 11a and 11b are formed so as to have no boundary wall. , Exhaust inserts 16 and 17 are cast. In addition, bottomed cylindrical intake and exhaust lifters 18 and 19 are slidably inserted into sliding holes formed in the intake and exhaust inserts 16 and 17, respectively. The upper end surfaces of the valve rods 14b and 15b are in contact with the inside through the metal. Also, retainers 20, 21 are provided near the upper ends of the valve stems 14b, 15b.
The intake and exhaust urging springs 22, 23 having a dual structure are interposed between the retainers 20, 21 and spring seats 12g, 12h formed on the lower head. Thus, the intake and exhaust valves 14 and 15 are urged in a direction to close the intake opening and the exhaust opening. An intake camshaft 24 and an exhaust camshaft 25 are disposed so as to be in contact with the intake lifter 18 and the exhaust lifter 19, and the distance A from the intake camshaft 24 to the cylinder axis C is determined by the distance between the exhaust camshaft 25 and the cylinder. It is set smaller than the distance B to the axis C. Each of the camshafts 24 and 25 is supported by a bearing formed on the upper head 11 and a cam cap 32 fixed with bolts 32a. The intake valve 14 and the exhaust valve 15 are lowered by pushing down the intake and exhaust lifters 18 and 19.

The intake camshaft 24,
A camshaft orbit mechanism for driving the exhaust camshaft 25 by the crankshaft 9 via three sets of intermediate gears is provided, and the drive mechanism is covered by a gear cover 36. The drive mechanism is
The large gear 33a of the first intermediate gear 33 of the crank gear 9a formed integrally with the end of the crankshaft 9 meshes with the small gear 33b of the first intermediate gear 33 meshes with the large gear 34a of the second intermediate gear 34. The small gear 34b is meshed with the third intermediate gear 35, and the third intermediate gear 35 is meshed with the intake cam gear 24a and the exhaust cam gear 25a. Reference numeral 44a denotes a lubricating oil passage formed in the crankshaft 9, 44b denotes an oil hole for communicating the lubricating oil passage 44c with each journal, and 37 denotes a hole for closing an opening formed during machining of the hydraulic passage 44a. The plug 37 'at the downstream end in the drawing has an air vent hole 37
a is formed.

The first intermediate gear 33 is used in common for the front and rear cylinders, is located on the center of the V bank, and supports the support shaft 3 via a bearing 33c.
It is pivoted in 3d. The support shaft 33d is connected to the first intermediate gear 3
3 and is press-fitted and fixed to an end opening of a main gallery 2a as a main lubricating oil passage formed in the cylinder block 2 parallel to the crankshaft 9.
2a is closed.

The second and third intermediate gears 34 and 35 are independent of the front and rear cylinders, and the front ends thereof are supported by the gear cover 36 via bearings 44. Here, the second intermediate gear
While the support shaft 34c of 34 is located on the cylinder axis C, the support shaft 35a of the third intermediate shaft 35 is displaced by D from the cylinder axis C toward the exhaust side. Thus, the intermediate gear 35 is simultaneously meshed with the intake and exhaust cam gears 24a; 25a arranged at a distance different from A and B from the cylinder axis C.

Also, in the portion between the front and rear cylinder heads 4, 4,
A generator 54, which is an engine accessory, is provided, and its flange portion 54a is bolted and fixed to a support bracket portion 10d formed integrally with the lower head 10.

 Next, the operation and effect of this embodiment will be described.

In this embodiment, since the intake camshaft 24 is arranged closer to the cylinder axis C side than the exhaust camshaft 25, the third intermediate shaft 35 can be deviated by D from the cylinder axis C toward the exhaust side, The gear cover 36 covering the drive mechanism does not protrude inside the V bank. Therefore, the space in the bank can be expanded accordingly, relatively large accessories such as the generator 54 can be arranged in the V bank without any trouble, and the maintenance space can be secured.

The support shaft 33d of the first intermediate shaft gear 33 is connected to the main gallery 2
Since the support shaft 33d was pressed into the end of the
It can also be used for closing the end opening of 2a, and there is no need to separately provide a plug for closing.

In the above-described embodiment, the example has been described in which the rotation of the crankshaft is transmitted to the camshaft by the gear train. However, the present invention can be applied to a case using a timing chain or a timing belt.

6 and 7 are views for explaining a second embodiment according to the second aspect of the present invention. The second embodiment is an example using a timing belt, and the same reference numerals in FIGS. 1 and 2 denote the same or corresponding parts. Crank pulley 9b fixed to the end of crankshaft 9 and intake and exhaust camshafts 2
Large pulley 42a of intermediate pulley 42 arranged below 4, 25
And are connected by a first timing belt 43a. The small-diameter pulley 42b of the intermediate pulley 42 and the intake cam pulley 24
b and the exhaust cam pulley 25b and the second timing belt 43b.
Are connected by Reference numeral 42c denotes an idler for securing a winding angle around the large-diameter pulley 42a, and reference numeral 42d denotes a tensioner for adjusting the tension of the belt. These cam shaft drive mechanisms are covered by a pulley cover 36.

The distances from the cylinder axis C to the intake camshaft 24 and the exhaust camshaft 25 are A and B, respectively. The support shaft 42e of the intermediate pulley 42 is deviated by D from the cylinder axis C toward the exhaust side. Rank. Thus, also in the present embodiment, the pulley cover 36 does not protrude inside the bank, and the space for arranging accessories and the like in the bank and the space for maintenance can be expanded.

〔The invention's effect〕

As described above, according to the first aspect of the present invention, the first intermediate gear common to the left and right is meshed with the crank gear, and the left and right second and third intermediate gears are sequentially meshed with the first intermediate gear. Since the intermediate gear is deviated from the cylinder axis toward the exhaust side, only one first intermediate gear is required, and the expansion of the intermediate gear housing case to the inside of the V bank is suppressed, so that the auxiliary device in the V bank is provided. There is an effect that a placement space can be secured.

According to the second aspect of the present invention, the idler is disposed between the left and right intermediate sprockets so as to push down the crank side timing string member, so that the cam side timing string member is shortened. The tensioner can be dispensed with, and the camshaft drive mechanism housing case can be prevented from bulging inside the V-bank, so that a space for arranging auxiliary devices in the V-bank can be secured.

[Brief description of the drawings]

1 to 5 are views for explaining a valve train of a four-stroke engine according to a first embodiment of the present invention. FIG. 1 is a front view of the engine of the embodiment, and FIG. FIG. 3 is a sectional view of an intermediate gear portion, FIG. 4 is a sectional front view of a cylinder head portion, FIG. 5 is a plan view of an upper head portion, and FIGS. 6 and 7 illustrate a second embodiment. FIG. In the figure, 1 is a 4-cycle V-type engine, 9 is a crankshaft, 12a to 12c are intake openings, 12d and 12e are exhaust openings, and 13a to 13a.
13c is an intake passage, 13d and 13e are exhaust passages, 14 and 15 are intake and exhaust valves, 24 and 25 are intake and exhaust cam shafts, 24a and 24b are intake cam gears, intake cam pulleys (intake cam chain wheels), 25a and 25b. Is an exhaust cam gear, an exhaust cam pulley (exhaust cam chain), 35 and 42 are third intermediate gears and intermediate pulleys (intermediate chain), A and B are intakes,
The distance between the exhaust camshaft and the cylinder axis, C is the cylinder axis, and D is the amount of deflection.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-199203 (JP, A) JP-A-1-257703 (JP, A) JP-A-62-83558 (JP, A) JP-A-62-83558 60908 (JP, A) JP-A-2-221606 (JP, A) JP-A-2-125917 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01L 1/02 F01L 1 / 04 F01L 1/26

Claims (2)

(57) [Claims] 1. One side of a combustion chamber has three intake valves, and the other side has two intake valves.
Two exhaust valves are provided, and the central intake valve faces the combustion chamber so that the inclination angle with respect to the cylinder axis is smaller than the inclination angles of the intake valves on both sides of the cylinder. An opening and an exhaust opening are respectively drawn inside and outside the V bank through an intake passage and an exhaust passage, and an intake cam shaft and an exhaust cam shaft for directly driving these valves are arranged above the intake valve and the exhaust valve. In a valve train of a type 5 valve engine, a camshaft drive mechanism that sets a distance between an intake camshaft and a cylinder axis smaller than a distance between an exhaust camshaft and a cylinder axis and transmits rotation of the crankshaft to the camshaft. A first intermediate gear disposed at the center of the V bank and meshing with the crank gear, common to the left and right cylinders, a second intermediate gear meshing with the first intermediate gear, and the cylinder shaft as viewed in the crankshaft direction. At a position deviated from the center to the exhaust side. A third intermediate gear that meshes with the second intermediate gear and meshes with both the intake and exhaust cam gears fixed to the intake camshaft and the exhaust camshaft. A valve operating device for a V-type five-valve engine, wherein a device is arranged, and a flange portion of the engine auxiliary device is bolted and fixed to a support bracket portion formed integrally with the engine. 2. A combustion chamber having three intake valves on one side and two intake valves on the other side.
Two exhaust valves are arranged, and the combustion chamber faces the central intake valve so that the inclination angle with respect to the cylinder axis is smaller than the inclination angles of the intake valves on both sides. An opening and an exhaust opening are respectively drawn inside and outside the V bank through an intake passage and an exhaust passage, and an intake cam shaft and an exhaust cam shaft for directly driving these valves are arranged above the intake valve and the exhaust valve. In a valve train of a type 5 valve engine, a camshaft drive mechanism that sets a distance between an intake camshaft and a cylinder axis smaller than a distance between an exhaust camshaft and a cylinder axis and transmits rotation of the crankshaft to the camshaft. Are positioned closer to the camshaft than the crankshaft and displaced toward the exhaust side from the cylinder axis when viewed in the crankshaft direction, and the left and right cylinder intermediate sprockets are arranged. And crank chain wheel to one crank side timing string An idler is connected between the left and right intermediate sprockets, and an idler that secures a winding angle to the intermediate sprocket by pressing down the intermediate inter-wheel portion of the crank side timing string member between the left and right intermediate sprockets. The intake and exhaust cam shafts fixed to the intake and exhaust cam shafts are connected to the intermediate chain and the intermediate chain by a cam-side timing string member. A V-type 5 disposed above the idler, wherein a flange portion of the engine auxiliary device is bolted and fixed to a support bracket portion integrally formed with the engine.
Valve gear of valve engine.