JPH11117807A - Engine with balancer shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the rigidity of a cylinder block in an engine with balancer shafts. SOLUTION: In an engine, balancer shaft bearings 21, 22 are continuously connected to a head bolt boss 16 at a cylinder block 3. In this case, ribs 41, 42, 43 are formed to project from the side wall of the cylinder block 3 in the connection of a joining flange 35 on the head side to the balancer shaft bearings 21, 22, wherein the ribs 41, 42, 43 are slantwise continuously connected to the balancer shaft bearings 21, 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine with a balancer shaft.

[0002]

2. Description of the Related Art Some automobile engines and the like rotate a balancer shaft having an unbalanced mass in synchronization with the rotation of the engine to cancel inertial force of a piston or the like.

A conventional cylinder block structure of an engine with a balancer shaft is disclosed, for example, in Japanese Utility Model Laid-Open Publication No. 3-30558.
Is disclosed in Japanese Patent Application Laid-Open Publication No. HEI 9-203 (1995). The balancer shaft bearing for supporting the balancer shaft projects from the side wall of the cylinder block. The balancer shaft bearing is formed so as to be connected to the head bolt boss of the cylinder block.

[0004]

However, in such a conventional device, the balancer shaft bearing is
Since the structure protrudes from the side wall of the cylinder block, if the rigidity is low, the load received from the balancer shaft during operation of the engine causes the engine to fall down in the front-rear direction or the vertical direction, thereby increasing the friction of the balancer shaft.

Further, since the balancer shaft bearing is formed so as to be connected to the head bolt boss, the bore of the cylinder wall is deformed due to the deformation of each balancer shaft bearing, thereby increasing the friction of the piston.

The present invention has been made in view of the above problems, and has as its object to increase the rigidity of a cylinder block of an engine with a balancer shaft.

[0007]

According to a first aspect of the present invention, there is provided an engine with a balancer shaft including a balancer shaft that is driven to rotate in synchronization with a crankshaft. An engine with a balancer shaft for forming a head bolt boss for screwing a head bolt for fastening a head and a balancer shaft bearing for supporting a balancer shaft, and connecting the balancer shaft bearing to the head bolt boss. A rib protruding from the side wall of the cylinder block is formed by connecting the side joining flange and the balancer shaft bearing, and the rib is inclined and connected to the balancer shaft bearing.

According to a second aspect of the present invention, in the engine with the balancer shaft according to the first aspect, a pair of ribs are connected to the balancer shaft bearing in a V-shape.

According to a third aspect of the present invention, in the engine with a balancer shaft according to the first or second aspect, the upper end of the rib is connected to the head-side joining flange at a position crossing the cylinder bore center plane. And

An engine with a balancer shaft according to a fourth aspect of the present invention includes a balancer shaft which is driven to rotate in synchronization with a crankshaft, and distributes lubricating oil to a cylinder block to a journal portion of the crankshaft or the balancer shaft. And a head bolt boss for screwing a head bolt for fastening the cylinder head, and a balancer shaft bearing for supporting the balancer shaft, and an engine with a balancer shaft for connecting the balancer shaft bearing to the head bolt boss. A main gallery wall is formed to protrude from the side wall of the cylinder block into a cylindrical shape to define a main gallery, and the main gallery wall is connected to the balancer shaft bearing substantially perpendicularly.

An engine with a balancer shaft according to a fifth aspect of the present invention includes a balancer shaft that is driven to rotate in synchronization with the crankshaft, and distributes lubricating oil to a cylinder block to a bearing portion of the crankshaft or the balancer shaft. And an introduction-side oil passage for guiding the lubricating oil sent from the oil pump to the main gallery, a head bolt boss for screwing a head bolt for fastening the cylinder head, and a balancer shaft bearing for supporting the balancer shaft. In an engine with a balancer shaft that connects a balancer shaft bearing to a head bolt boss, an introduction-side oil passage wall that bulges cylindrically from a side wall of the cylinder block to define an introduction-side oil passage, Balance the inlet side oil passage wall with the balancer shaft bearing Along it was assumed to be connected to.

An engine with a balancer shaft according to a sixth aspect of the present invention includes a balancer shaft that is driven to rotate in synchronization with a crankshaft, and distributes lubricating oil to a cylinder block to a bearing portion of the crankshaft or the balancer shaft. A head-side oil passage for guiding lubricating oil from the main gallery to the lubrication portion of the valve train, a head bolt boss for screwing a head bolt for fastening the cylinder head, and a balancer shaft bearing for supporting the balancer shaft. In the engine with a balancer shaft that connects and connects the balancer shaft bearing to the head bolt boss, a head-side oil passage wall that bulges cylindrically from the side wall of the cylinder block to define a head-side oil passage is formed. And a balancer shaft bearing on the oil passage wall on the head side. It was assumed to be connected along the.

According to a seventh aspect of the present invention, an engine with a balancer shaft includes a balancer shaft rotatably driven in synchronization with a crankshaft, and a balancer housing for accommodating the balancer shaft between the cylinder block and the cylinder block. A housing-side joining flange to the balancer housing, a head bolt boss for screwing a head bolt for fastening the cylinder head, and a balancer shaft bearing for supporting the balancer shaft, and the balancer shaft bearing is formed by a head bolt boss. In the engine with a balancer shaft connected to the balancer, the housing-side joining flange is connected to a balancer shaft bearing.

An engine with a balancer shaft according to a eighth aspect of the present invention includes a balancer shaft that is driven to rotate in synchronization with a crankshaft, and a balancer housing that accommodates the balancer shaft between the cylinder block and the cylinder block. A housing-side joining flange to the balancer housing, a main gallery for distributing lubricating oil to a bearing portion of the crankshaft or the balancer shaft, an oil passage for guiding lubricating oil to and from the main gallery, and a head bolt for fastening the cylinder head. A head bolt boss part to be combined and a balancer shaft bearing part for supporting the balancer shaft are formed, and in an engine with a balancer shaft that connects the balancer shaft bearing part to the head bolt boss part, the cylinder block has a cylindrical shape from the side wall part. A main gallery wall that defines the main gallery and an oil passage wall that defines an oil passage are formed, and the housing-side joining flange, the main gallery wall, and the oil passage wall are connected to a balancer shaft bearing. It was formed in a frame shape.

[0015]

In the engine with the balancer shaft according to the first aspect, the rib protruding from the side wall of the cylinder block extends obliquely by connecting the balancer shaft bearing to the head-side joining flange.
The falling rigidity of the balancer shaft bearing is increased, and the deformation of the balancer shaft bearing can be suppressed.

[0016] By suppressing the falling deformation of the balancer shaft bearing during machining of the balancer shaft bearing or during operation of the engine, coaxiality of the balancer shaft bearing with respect to the journal of the balancer shaft is ensured.
Lubricity of the balancer shaft can be maintained during operation of the engine, and the friction of the balancer shaft can be kept small. Further, the deformation of the bore of the cylinder wall portion via the head bolt boss portion or the like due to the falling deformation of the balancer shaft bearing portion can be suppressed small, and the lubrication of the piston can be maintained to keep the friction of the piston small.

In the engine with a balancer shaft according to the present invention, the pair of ribs projecting from the side wall of the cylinder block extend in a V-shape so as to sandwich the balancer shaft bearing from both sides, and are connected to the head-side joining flange. Thereby, the falling rigidity of the balancer shaft bearing is increased, and the falling deformation of the balancer shaft bearing can be suppressed.

In the engine with the balancer shaft according to the third aspect, the rib is connected to the head side joining flange at a position crossing the cylinder bore center surface with the upper end portion to increase the falling rigidity of the balancer shaft bearing portion. At the same time, the rigidity of the head-side joining flange can be effectively increased. Effectively transmit the axial force of the head bolt from the head bolt boss to the ribs, equalize the surface pressure applied to the gasket interposed between the head side joining flange corresponding to the cylinder bore center surface and the cylinder head,
The sealing property of this part can be sufficiently ensured.

In the engine with a balancer shaft according to the fourth aspect, the main gallery wall bulging cylindrically from the side wall of the cylinder block is connected to the balancer shaft bearing at right angles to the balancer shaft bearing. To reduce the deformation of the balancer shaft bearing in the engine front-rear direction.

In the engine with a balancer shaft according to the fifth aspect, the introduction-side oil passage wall portion bulging cylindrically from the side wall portion of the cylinder block is connected along the balancer shaft bearing portion to thereby provide the balancer shaft bearing. The rigidity of the parts is increased, and the deformation of the balancer shaft bearings in the vertical direction of the engine is suppressed.

In the engine with a balancer shaft according to the present invention, the head-side oil passage wall bulging from the side wall of the cylinder block in a cylindrical shape is connected along the balancer shaft bearing to thereby provide the balancer shaft bearing. The rigidity of the parts is increased, and the deformation of the balancer shaft bearings in the vertical direction of the engine is suppressed.

In the engine with a balancer shaft according to the seventh aspect, the housing-side joint flange projecting in a rib shape from the side wall of the cylinder block is connected to the balancer shaft bearing to increase the falling rigidity of the balancer shaft bearing. The deformation of the balancer shaft bearing portion from falling down is suppressed.

In the engine with a balancer shaft according to the present invention, the rigidity of the main gallery wall, the oil passage wall, and the housing-side joining flange projecting in a frame shape from the side wall of the cylinder block can be mutually increased. By connecting with the balancer shaft bearing portion, the falling rigidity of the balancer shaft bearing portion is increased, and deformation of the balancer shaft bearing portion from falling down is suppressed.

[0024]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 2, the in-line four-cylinder engine has two balancer shafts 2 on the left and right sides of a cylinder block 3.
Are provided in parallel with the crankshaft 1.

2 and 3, reference numeral 20 denotes a bearing for supporting the crankshaft 1. Five bearing portions 20 are provided between the cylinders of the cylinder block 3 and at front and rear ends.

In FIG. 1, reference numerals 21 and 22 denote bearing portions before and after supporting the right balancer shaft 2. The front bearing 21 is provided at the front end of the cylinder block 3, and the rear bearing 22 is provided between the # 1 cylinder and the # 2 cylinder.

As shown in FIG. 6, a crank sprocket 83, a pump sprocket 84, a balancer sprocket 85, and a relay sprocket 86 are provided at the front of the engine, and a chain 87 is wound around these. The crank sprocket 83 is connected to the front end of the crankshaft. Pump sprocket 84 is connected to the drive shaft of oil pump 9. The balancer sprocket 85 is connected to the right balancer shaft 2. Relay sprocket 8
6 is a left balancer shaft 2 via gears 88 and 89.
The torque is transmitted to Each balancer shaft 2 rotates at twice the speed of the crankshaft 1, cancels inertial forces of pistons, connecting rods and the like by centrifugal force acting on the respective unbalance masses, and suppresses engine vibration.

A crank sprocket 81 and two cam sprockets 82 are provided at the front of the engine.
The chain 80 is looped over these. The crank sprocket 81 is connected to the front end of the crankshaft 1. Each cam sprocket 82 is connected to a front end of a cam shaft for driving an intake / exhaust valve (not shown) to open and close. As the chain 80 circulates clockwise in FIG. 7, the rotation of the crankshaft 1 is reduced to half the rotation speed and transmitted to each camshaft.

As shown in FIG. 4, balancer housings 6 and 7 for accommodating the balancer shafts 2 are attached to the left and right side walls of the cylinder block 3, respectively.

The right balancer shaft 2 is arranged higher than the left balancer shaft 2. By arranging the left and right balancer shafts 2 at different heights, engine vibration can be effectively suppressed in a high rotation range.

An oil pump 9 is arranged in front of the cylinder block 3 below the right balancer shaft 2. The oil pump 9 is attached to the front of the cylinder block 3 via a plurality of bolts 19.

The right balancer housing 7 houses the balancer shaft 2 and the oil pump 9. As shown in FIG. 5, the balancer housing 7 includes a semi-cylindrical cylindrical portion 51 surrounding the balancer shaft 2, a semi-cylindrical cylindrical portion 52 surrounding the oil pump 9, and each cylindrical portion 5.
The two ribs 55 connecting the first and the second 52 and the cylinder block 3
And a joining flange 54 for a chain case (not shown) and the like, which are integrally formed using an aluminum alloy as a material.

The left balancer housing 6 is formed in a semi-cylindrical shape surrounding the balancer shaft 2 and has a plurality of bolts 8.
Through the cylinder block 3.

A chain case (not shown) is attached to the front of the cylinder block 3 and the balancer housings 6 and 7 to define a chain chamber.

During operation of the engine, lubricating oil stored in an oil pan (not shown) is sucked up by an oil pump 9. The lubricating oil discharged from the oil pump 9 passes through a relief valve 61, passes through an oil filter (not shown) attached to an oil pan, passes through an oil passage 63 formed in the cylinder block 3, passes through a main gallery 64, and passes through a crankshaft. 20 and the bearing portion of each balancer shaft 2. Main gallery 64
Is supplied to a valve operating system on a cylinder head (not shown) through a head-side oil passage 65.

As shown in FIG. 3, a part of the lubricating oil supplied to the main gallery 64 is supplied to the bearing 21 of the crankshaft 20 through the through hole 66 to lubricate each journal of the crankshaft 20. And the through hole 66
And is supplied to the bearing of the left balancer shaft 2 to lubricate the front and rear journals of the balancer shaft 2.

As shown in FIG. 2, a part of the lubricating oil supplied to the main gallery 64 is supplied to the bearing 21 of the right balancer shaft 2 through the through hole 68 and the like, and the front and rear journals of the balancer shaft 2 The part is lubricated.

The lubricating oil that has lubricated the front and rear journals of the right balancer shaft 2 is collected on the cylinder block 3 side via the balancer housing 7 as shown by the arrow in FIG. Flow down.

The cylinder block 3 comprises a cylinder wall 10 for accommodating the piston slidably, and each cylinder wall 10
Outer wall 11 defining water jacket 4 around
And a water jacket bottom wall portion 12 that connects the outer wall portion 11 and the middle of the cylinder wall portion 10, a crankcase portion 13 that defines a crank chamber, and the like. The cylinder block 3 has a siamese portion 18 in which adjacent cylinder wall portions 10 are joined to each other, and the cylinder wall portions 10 are made as close as possible to reduce the front-rear length of the engine.

The cylinder block 3 is a so-called open deck type in which an end of the water jacket 2 on the deck portion 14 side is opened. The cylinder block 3 is made of an aluminum alloy and is cast by a die casting method using a mold.

Cooling water sent from a water pump (not shown) passes through the water jacket 4 and the cylinder wall 1.
0, while absorbing the heat of the cylinder wall portion 10, through a communication hole provided in a cylinder head (not shown) from the opening on the deck portion 14 side of the water jacket 4, and through the water jacket in the cylinder head. To absorb the heat of the cylinder head.

The water jacket 4 is formed around the upper portion of the cylinder wall 10 by a structure in which the water jacket bottom wall 12 that defines the bottom of the water jacket 4 is connected to the middle of the cylinder wall 10. The bottom has been made. By making the water jacket 2 shallower,
Excessive cooling of the cylinder wall 10 can be prevented, and fuel efficiency of the engine can be reduced. In addition, the temperature rise of the cooling water during warm-up can be accelerated to improve exhaust performance and heater performance.

A head bolt boss portion 16 is formed on the outer wall portion 11. Each head bolt boss 16 is formed between the cylinders or at the front and rear ends. Head bolt boss 1
A head bolt (not shown) penetrates the cylinder head and is screwed into the screw hole 15 opened in 6, and the cylinder head and the cylinder block 3 are fastened via a gasket.

As shown in FIG. 1, the rear end of the cylinder block 3 has a transmission case side joining flange 31 for a transmission case (not shown). The front end of the cylinder block 3 has a chain case side joining flange 32 for the chain case. The upper end of the cylinder block 3 has a head-side joining flange 35 for the cylinder head. A mounting boss 33 for an engine mount is provided on a side wall of the cylinder block 3.
Having.

A housing-side joining flange 34 for the balancer housing 7 is provided on the right side wall of the cylinder block 3.
Are formed to protrude in a rib shape. In the side view of FIG. 1, the housing-side joining flange 34 includes a horizontally extending flange upper portion 47, a vertically extending flange rear portion 48 behind the balancer shaft bearing portion 22, and a respective balancer shaft bearing portion 21, 22. And a lower flange portion 49 that extends at an angle to the horizontal at the lower portion.

Since the front and rear balancer shaft bearings 21 and 22 protrude from the side wall of the cylinder block 3, if the rigidity thereof is low, the balancer shaft bearings 21 and 22 may fall down in the front-rear direction or the vertical direction during machining or engine operation. As a result, the coaxiality with respect to the balancer shaft 2 is deteriorated, and the friction of the balancer shaft 2 is increased during operation of the engine.

The cylinder block 3 has a structure in which the water jacket bottom wall portion 12 is connected to the middle of the cylinder wall portion 10. Therefore, the head bolt boss portion 16 and the outer wall portion 11 are formed by the collapse deformation of the balancer shaft bearing portions 21 and 22. And the cylinder wall 10 via the water jacket bottom wall 12.
Bores deform and increase the friction of the piston.

As a countermeasure, a rib 41 connecting the upper portion of the balancer shaft bearing 21 and the head-side joining flange 35 is formed to protrude from the right side wall of the cylinder block 3. Further, ribs 42 and 43 connecting the upper portion of the balancer shaft bearing portion 22 and the head-side joining flange 35 later.
Are formed to protrude from the right side wall of the cylinder block 3.

In the side view of FIG. 1, each rib 41, 4
Reference numerals 2 and 43 are inclined at approximately 45 ° with respect to the vertical line. The rib 41 extends obliquely from the upper portion of the front balancer shaft bearing portion 21 to the upper rear portion of the engine. The ribs 42 and 43 extend in a V-shape with the balancer shaft bearing portion 22 therebetween.

In FIG. 1, the cylinder bore center plane C
Is a plane including the center line of the cylinder wall portion 10 of each cylinder and orthogonal to the center line of the crankshaft. Each rib 4
The upper ends of 1, 42, and 43 are connected to the head-side joining flange 35 at a position crossing the cylinder bore center plane C.

A main gallery wall 44 defining a main gallery 64 is formed on the side wall of the cylinder block 3 so as to protrude in a cylindrical shape. The main gallery wall portion 44 is formed so as to be connected to a lower portion of each of the balancer shaft bearing portions 21 and 22. In the side view of FIG. 1, the main gallery wall 4
4 extends in the horizontal direction, and each balancer shaft bearing 21,
22 are formed orthogonally.

On the side wall of the cylinder block 3, an introduction-side oil passage wall 45 defining an introduction-side oil passage 63 is formed to bulge in a cylindrical shape. The introduction-side oil passage wall portion 45 is formed continuously along the balancer shaft bearing portion 22. In the side view of FIG. 1, the introduction-side oil passage wall 45 extends in the vertical direction, and is arranged on the same straight line as the balancer shaft bearing 22.

A head-side oil passage wall 46 that defines a head-side oil passage 65 is provided on the side wall of the cylinder block 3.
Are bulged into a cylindrical shape. The head-side oil passage wall 46 is formed continuously along the rear part of the front balancer shaft bearing 21. In the side view of FIG. 1, the head-side oil passage wall portion 46 extends in the vertical direction and is arranged in parallel with the balancer shaft bearing portion 21.

The housing-side joining flange upper portion 47 for the balancer housing 7 is formed so as to be connected to the upper portions of the front and rear balancer shaft bearings 21 and 22. In the side view of FIG. 1, the housing-side joining flange upper portion 47 is orthogonal to the balancer shaft bearings 21 and 22.

The lower portion 49 of the housing-side joint flange with respect to the balancer housing 7 is formed so as to be connected to the lower portion of the balancer shaft bearing 22 later. In the side view of FIG. 1, the lower part 49 of the housing-side joining flange intersects with the balancer shaft bearing 22 at an angle.

Front and rear balancer shaft bearings 21 and 22
The main gallery wall portion 44, the introduction-side oil passage wall portion 45, the head-side oil passage wall portion 46, and the housing-side joining flange upper portion 47 for the balancer housing 7 are mutually rectangular from the side wall portion of the cylinder block 3. It protrudes in a shape.

Next, the operation will be described.

During operation of the engine, each balancer shaft 2 rotates at twice the speed of the crankshaft 1, and the centrifugal force acting on each unbalance mass cancels out the inertial force of the piston, the connecting rod, etc., and suppresses engine vibration.

However, the balancer shaft 2 bends and deforms due to the centrifugal force acting on the unbalance mass, and the balancer shaft bearings 21 and 22 tend to be deformed to fall in the front-back direction or the up-down direction.

In response to this, the ribs 41, 42, 43 projecting from the side wall of the cylinder block 3 extend obliquely by connecting the upper portions of the balancer shaft bearings 21, 22 and the head side joining flange 35. Thereby, the rigidity of each balancer shaft bearing 21 and 22 is increased, and the deformation of each balancer shaft bearing 21 and 22 falling in the front-rear direction and the vertical direction is suppressed.

Each of the ribs 41, 42, and 43 has an upper end connected to the head-side joint flange 35 at a position crossing the cylinder bore center plane C, thereby effectively increasing the rigidity of the head-side joint flange 35. The surface pressure applied to a gasket (not shown) interposed between the head-side joining flange 35 and the cylinder head by the fastening force of the head bolt is made uniform, and the sealing performance of this portion is enhanced.

The main gallery wall portion 44 bulging from the side wall portion of the cylinder block 3 in a cylindrical shape is connected to the lower portion of each of the balancer shaft bearing portions 21 and 22 and extends in the front-rear direction, thereby forming each balancer shaft bearing portion 21. , 22 and suppresses the deformation of the balancer shaft bearings 21 and 22 from falling down in the front-rear direction.

The introduction-side oil passage wall 45 which defines the introduction-side oil passage 63 and bulges cylindrically from the side wall of the cylinder block 3 extends vertically in connection with the lower portion of the balancer shaft bearing 22. Thereby, the rigidity of the balancer shaft bearing portion 22 is increased, and the balancer shaft bearing portion 22 is increased.
Suppresses the deformation that falls down.

A head-side oil passage wall 46 which defines a head-side oil passage 65 and bulges in a cylindrical shape from the side wall of the cylinder block 3 is connected to the rear portion of the balancer shaft bearing portion 21 and extends vertically. Thus, the rigidity of the balancer shaft bearing 21 is increased, and deformation of the balancer shaft bearing 21 falling in the vertical direction is suppressed.

A housing-side joining flange upper portion 47 for the balancer housing 7 projects in a rib shape from a side wall portion of the cylinder block 3 so as to protrude from each balancer shaft bearing portion 2.
By connecting to the upper portions of the balancer shafts 1 and 22, the rigidity of the balancer shaft bearings 21 and 22 is increased, and deformation of the balancer shaft bearings 21 and 22 falling in the front-rear direction is suppressed.

The lower part 49 of the housing-side joint flange with respect to the balancer housing 7 protrudes from the side wall of the cylinder block 3 in a rib shape.
2, the rigidity of the balancer shaft bearing portion 22 is increased, and deformation of the balancer shaft bearing portion 22 falling in the front-rear direction is suppressed.

Further, the front and rear balancer shaft bearings 2
Reference numerals 1 and 22 denote a main gallery wall portion 44, an introduction-side oil passage wall portion 45, a head-side oil passage wall portion 46, and a housing-side joining flange upper portion 4 for the balancer housing 7.
By projecting in a frame shape from the side wall of the cylinder block 3 together with 7, the rigidity of each can be increased mutually, and deformation of the balancer shaft bearings 21 and 22 from falling down can be suppressed.

By suppressing the falling deformation of the balancer shaft bearings 21 and 22 during machining and operation of the engine, the coaxiality of the balancer shaft bearings 21 and 22 with respect to the balancer shaft 2 is increased. The lubrication of the journal portion 2 is maintained, and the increase in friction of the balancer shaft 2 can be suppressed.

The cylinder block 3 has a structure in which the bottom wall 12 of the water jacket is connected in the middle of the cylinder wall 10, and the head bolt boss 16 and the outer wall 11 are formed by the deformation of the balancer shaft bearings 21, 22. And the cylinder wall 10 via the water jacket bottom wall 12.
Of the balancer shaft bearings 21,
By suppressing the falling deformation of 22, the deformation of the bore of the cylinder wall 10 is suppressed, and the lubrication of the piston is maintained, and the increase in the friction of the piston is suppressed.

[Brief description of the drawings]

FIG. 1 is a side view of a cylinder block showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG. 1;

FIG. 3 is a sectional view taken along the line BB of FIG. 1;

FIG. 4 is a front view of a cylinder block and the like.

FIG. 5 is a side view of a cylinder block and the like.

FIG. 6 is a front view showing a chain and the like.

[Explanation of symbols]

 2 Balancer shaft 3 Cylinder block 10 Cylinder wall 16 Head bolt boss part 21 Balancer shaft bearing part 22 Balancer shaft bearing part 34 Housing side joining flange 35 Head side joining flange 41 Rib 42 Rib 43 Rib 44 Main gallery wall part 45 Introducing oil passage Wall 46 Head side oil passage wall

Claims (8)

[Claims] A balancer shaft rotatably driven in synchronization with a crankshaft; a head-side joining flange to a cylinder block, a head bolt boss for screwing a head bolt for fastening the cylinder head to a cylinder block; An engine with a balancer shaft that forms a balancer shaft bearing portion for supporting the balancer shaft and connects the balancer shaft bearing portion to the head bolt boss portion, wherein a side wall of a cylinder block is formed by connecting the head side joining flange and the balancer shaft bearing portion. An engine with a balancer shaft, wherein a rib protruding from the portion is formed, and the rib is inclined and connected to the balancer shaft bearing portion. 2. The apparatus according to claim 1, wherein a pair of ribs are connected to the balancer shaft bearing portion in a V-shape.
An engine with a balancer shaft according to item 1. 3. The engine with a balancer shaft according to claim 1, wherein an upper end of the rib is connected to a head side joining flange at a position intersecting a cylinder bore center plane. 4. A main gallery for distributing lubricating oil to a journal portion of a crankshaft or a balancer shaft, comprising: a balancer shaft which is rotationally driven in synchronization with a crankshaft; and a head bolt for fastening a cylinder head to a cylinder block. An engine with a balancer shaft that forms a head bolt boss to be screwed and a balancer shaft bearing that supports the balancer shaft, and connects the balancer shaft bearing to the head bolt boss. An engine with a balancer shaft, characterized in that a main gallery wall portion that bulges out to define a main gallery is formed, and the main gallery wall portion is connected to the balancer shaft bearing portion substantially orthogonally. 5. A main gallery for distributing lubricating oil to a bearing portion of a crankshaft or a balancer shaft, comprising a balancer shaft rotatably driven in synchronization with a crankshaft, and a lubricating oil sent from an oil pump. An introduction oil passage leading to the main gallery, a head bolt boss for screwing a head bolt for fastening the cylinder head, and a balancer shaft bearing for supporting the balancer shaft are formed. An engine with a balancer shaft connected to the cylinder block, wherein an introduction-side oil passage wall that swells cylindrically from the side wall of the cylinder block to define an introduction-side oil passage is formed, and the introduction-side oil passage wall is formed by a balancer shaft bearing. Balancer connected along the part Engine with shaft. 6. A main gallery for distributing lubricating oil to a bearing portion of a crankshaft or a balancer shaft in a cylinder block, comprising: a balancer shaft rotatably driven in synchronization with a crankshaft; and a valve operating lubricating oil from the main gallery. A head-side oil passage leading to a lubrication part of the system, a head bolt boss for screwing a head bolt for fastening the cylinder head, and a balancer shaft bearing for supporting the balancer shaft are formed. An engine with a balancer shaft connected to a boss portion, wherein a head-side oil passage wall portion that bulges cylindrically from a side wall portion of the cylinder block to define a head-side oil passage is formed. A balancer which is connected along a shaft bearing. Engine with shaft. 7. A balancer shaft rotatably driven in synchronization with a crankshaft, and a balancer housing for accommodating the balancer shaft between the cylinder block and the cylinder block, a housing-side joining flange to the balancer housing, An engine with a balancer shaft that forms a head bolt boss for screwing a head bolt for fastening a cylinder head, and a balancer shaft bearing for supporting a balancer shaft, and connects the balancer shaft bearing to the head bolt boss. An engine with a balancer shaft, wherein the housing-side joining flange is connected to the balancer shaft bearing. 8. A balancer shaft rotatably driven in synchronization with a crankshaft, and a balancer housing for accommodating the balancer shaft between the cylinder block and a cylinder block, a housing-side joining flange to the balancer housing, A main gallery for distributing lubricating oil to a bearing portion of a crankshaft or a balancer shaft; an oil passage for guiding lubricating oil to and from the main gallery; a head bolt boss for screwing a head bolt for fastening a cylinder head; and a balancer shaft. A balancer shaft bearing portion for supporting the balancer shaft bearing portion, the balancer shaft bearing portion being connected to the head bolt boss portion, the engine having a balancer shaft, wherein the main gallery bulges cylindrically from a side wall portion of the cylinder block to define a main gallery. An oil passage wall defining an oil passage and an oil passage is formed, and the housing-side joint flange, the main gallery wall, and the oil passage wall are formed in a frame shape connected to the balancer shaft bearing. Engine with balancer shaft.