JPH06330807A - Cylinder block structure of water cooled internal combustion engine - Google Patents

Abstract

PURPOSE:To increase productivity, rigidity or cooling ability of an open deck type cylinder block. CONSTITUTION:An upper deck (reinforcing mamber) 20, which is interposed in the opening part 9 of a water jacket 2 for a deck part 11, is provided as a separate body from a cylinder block 1, this upper deck 20 is combined with a cylinder wall 12 and the outer wall 13 of the block by welding, and mutually connecting plural rings 21 to be arranged round each cylinder wall 12 in one- body on the upper deck 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a cylinder block structure of a water-cooled internal combustion engine.

[0002]

2. Description of the Related Art As a conventional cylinder block structure of a water-cooled internal combustion engine, there is, for example, that shown in FIG. 9 (see Japanese Patent Laid-Open No. 64-78693).

To explain this, an open deck type cylinder block 1 is formed by opening a water jacket 2 formed around a cylinder bore 4 to a deck portion 11 joined to a cylinder head.

When manufacturing a cylinder block made of an aluminum alloy, a die-cast manufacturing method using a die is often used because the shape accuracy can be increased and the post-processing can be reduced. However, the die-cast manufacturing method is disintegratable. Since it is not preferable to use the sand core, it is necessary to form the water jacket in the mold part protruding from the mold inner wall on the deck side into the cavity. Therefore, the cylinder block manufactured by the die cast manufacturing method. Is the open deck type described above.

However, in the open-deck type cylinder block 1, the end portion of the cylinder wall portion 12 defining the cylinder bore 4 and the water jacket 2 on the side of the deck portion 11 is a free end, and therefore the block of the water jacket 2 is formed. The cylinder wall portion 12 whose temperature rises larger than the outer wall portion 13 expands in the cylinder direction due to its thermal expansion, and partially lifts the cylinder head, causing a problem such as deterioration of the sealing property of the head gasket. .

As a countermeasure against this, a plurality of deck reinforcement pieces 3 are interposed at the open end of the water jacket 2 on the deck portion 11 side, and both end portions of the deck reinforcement piece 3, the cylinder wall portion 12 and the block outer wall portion 13 are It is welded with a high-energy beam such as an electron beam or a laser beam, and is fixed by two welded portions 6.

As shown in FIG. 10, the cylinder block 1
Is a so-called Siamese type in which adjacent cylinder walls are joined to each other, and the cylinder lengths are made as close to each other as possible to reduce the overall length of the engine.

The cooling water sent from the water pump flows in from an inlet (not shown) provided at the end of the water jacket 2 in the cylinder row direction, flows around each cylinder wall portion 12 in the order close to the inlet, and flows into each cylinder wall portion. The heat of the cylinder head 12 is absorbed, and the heat of the cylinder head is diverted from the opening 9 on the deck portion 11 side of the water jacket 2 to the water jacket in the cylinder head through the communication hole provided in the cylinder head (not shown). It is supposed to do.

[0009]

However, in such a conventional open-deck type cylinder block 1, the deck reinforcing piece 3 has a block shape, and two or around the respective cylinder wall portions 12 or. Since three pieces are provided, the number of parts to be assembled in one cylinder block 1 is increased, so that the process of assembling each deck reinforcing piece 3 into the cylinder block 1 is troublesome and the productivity is poor. was there.

Further, in the case of the Siamese type cylinder block 1, the cooling performance of the inter-cylinder joint 14 where adjacent cylinder wall portions 12 are joined to each other is deteriorated, and the temperature of the inter-cylinder joint portion 14 is different from that of the cylinder wall 12. The height may be higher than that of the portion, and the cylinder bore 4 may be deformed.

The present invention has been made in view of the above problems, and an object thereof is to improve the productivity, rigidity, or cooling property of an open deck type cylinder block.

[0012]

The invention according to claim 1 is
In a cylinder block of a water-cooled internal combustion engine, an upper part of which is joined to a cylinder head, and a cylinder wall part that defines a water jacket opened to the cylinder head side and a block outer wall part are integrally formed, and a plurality of ring parts are mutually connected. A reinforcing member that is connected and integrally formed is interposed in an opening in the upper portion of the water jacket, and the reinforcing member is joined to the cylinder wall portion and the block outer wall portion by welding.

According to a second aspect of the present invention, a plurality of convex portions connecting the cylinder wall portion and the block outer wall portion are formed on the reinforcing member at least on the thrust side and the anti-thrust side of the cylinder bore, and the adjacent convex portions are formed. A water jacket outlet communicating with a water jacket provided in the cylinder head is formed between the parts.

According to a third aspect of the present invention, an inter-cylinder joint connecting the cylinder wall portions adjacent to the cylinder block is integrally formed, and an inter-ring joint connecting the ring portions adjacent to the reinforcing member is integrally formed. Is connected to the inter-cylinder joint, and at least one of the inter-cylinder joint and the inter-ring joint is formed with a cooling water passage groove for communicating water jackets located on both sides of each cylinder wall.

[0015]

In the present invention, in the open deck type cylinder block having the upper portion of the water jacket opened, the temperature rises because the cylinder wall portion and the block outer wall portion are joined at the deck portion side ends. It is possible to prevent the large cylinder wall portion from expanding in the cylinder direction due to its thermal expansion and partially lifting the cylinder head, and to maintain the sealability of the head gasket.

According to the first aspect of the present invention, the reinforcing member is integrally formed with a plurality of ring portions arranged around each cylinder wall portion so as to be connected to each other and integrally formed, so that the cylinder block can be easily assembled. You can Furthermore, by integrating the ring parts of the reinforcing member, it becomes possible to automate using a plurality of welders at the same time in the process of welding the reinforcing member to the cylinder block, and to shorten the time required for this welding. You can

According to the second aspect of the present invention, since the end of the cylinder wall is connected to the block wall on the thrust side and the anti-thrust side of the cylinder bore by the respective convex portions of the reinforcing member, the cylinder against the vibration force of the piston. The rigidity of the wall portion can be effectively increased, and vibration and noise generated from the cylinder wall portion can be suppressed.

According to the third aspect of the invention, at least one of the inter-cylinder joint portion and the inter-ring joint portion is formed with a cooling water passage groove for communicating water jackets located on the left and right of each cylinder wall portion. Dissipation of heat from the inter-joint portion to the cooling water flowing through the cooling passage groove is promoted, and the temperature of the inter-cylinder joint portion is prevented from becoming higher than other parts of the cylinder wall, and the temperature distribution of the cylinder wall is made uniform,
Deformation of the cylinder wall can be suppressed, the piston gap can be made uniform, friction can be reduced, and oil consumption can be reduced.

[0019]

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

As shown in FIGS. 5 and 6, the cylinder block 1 has four cylinder walls 12 arranged in series. The cylinder block 1 is of a so-called Siamese type in which adjacent cylinder walls 12 are joined to each other, and the cylinder walls 12 are arranged as close to each other as possible to reduce the overall length of the engine.

The cylinder block 1 includes each cylinder wall 12
A water jacket 2 that circulates cooling water is provided around the. The cylinder block 1 includes each cylinder wall 12
And a block outer wall portion 13 defining the water jacket 2 therebetween. An inlet 5 is formed at the front end of the block outer wall portion 13.

The cooling water sent from the water pump flows into the water jacket 2 from the inlet 5 and flows in the cylinder row direction in the water jacket 2, and from the opening 9 on the deck portion 11 side of the water jacket 2 to a cylinder (not shown). The heat is absorbed in the cylinder head by diverting it to a water jacket in the cylinder head through a communication hole provided in the head.

In FIG. 3, reference numeral 33 is a bearing portion for a crankshaft (not shown). In FIG. 6, 17 is a clan case part, and 18 is an oil gallery.

The cylinder block 1 is of a so-called open deck type in which the end portion of the water jacket 2 on the deck portion 11 side is opened as an opening 9. The cylinder block 1 is made of aluminum alloy and is cast by a die-cast manufacturing method using a die.

The cylinder block 1 has a deck portion 11 to which a cylinder head is joined at its upper end, and a plurality of screw holes 15 are opened in the deck portion 11. The cylinder block 1 and the cylinder head are fastened to each other via head bolts (not shown) that are screwed into the screw holes 15.

As shown in FIGS. 1 and 2, the cylinder wall portion 12 defining the water jacket 2 and the block outer wall portion 1 are formed.
An upper deck 20 as a reinforcing member provided as a separate body from the cylinder block 1 is interposed between the respective end portions of the deck block 3 on the side of the deck portion 11.

As shown in FIG. 7, in the upper deck 20, four ring portions 21 arranged around each cylinder wall portion 12 are integrally connected to each other, and the adjacent ring portions 21 are connected to each other 3 It has two inter-ring joints 22.

In the upper deck 20, the inner peripheral surface 26 of each ring portion 21 is fitted to the outer peripheral surface 19 of the cylinder wall portion 12, and each convex portion 23 protruding radially from each ring portion 11,
24 and 25 are fitted to the inner wall surface 16 of the block outer wall portion 13.

The four convex portions 23 are formed on the thrust side of each ring portion 21 orthogonal to the piston pin (not shown), and the four convex portions 24 are located on the anti-thrust side of each ring portion 21. The two convex portions 25 are formed at the front and rear ends of the front and rear ring portions 21, respectively.

Each convex portion 23, 24 of the upper deck 20,
Ten water jacket outlets 8 are defined between the block 25 and the block outer wall portion 13. The water is discharged from each water jacket outlet 8 to a water jacket in the cylinder head through a communication hole provided in a cylinder head (not shown).

On the cylinder wall portion 12 and the block outer wall portion 13, the ring portion 21 of the upper deck 20 and each convex portion 2 are provided.
Steps 27 and 28 are formed to be joined to the lower ends of the plates 3 and 24, respectively.

Cylinder block 1 and upper deck 20
The joints are joined intermittently or continuously by high-density energy welding such as electron beam welding or laser welding.

The cylinder block 1 is an upper deck 20.
After they are joined by welding, the deck portion 11 and the upper deck 20 are processed to be flush with each other. A head gasket is interposed between the deck portion 11 and the upper deck 20 and the cylinder head, and the sealing performance of each cylinder bore 4 and the water jacket 2 is ensured through this head gasket.

As shown in FIG. 3, the Siamese type cylinder block 1 has an inter-cylinder joint 14 in which adjacent cylinder wall portions 12 are joined to each other, and each inter-cylinder joint 14 has a deck portion 11 side. The cooling water passage groove 30 is formed.

As shown in FIG. 4, the upper deck 20
A cooling water passage groove 29 is formed on the lower surface of the inter-ring joint portion 22 that connects the adjacent ring portions 21.

A cooling water passage having a predetermined cross-sectional area is defined by the cooling water passage groove 30 and the cooling water passage groove 29, and the water jackets 2 located on the left and right of each cylinder wall portion 12 are communicated with each other by this cooling water passage. It

With the above construction, the operation will be described.

Open deck type cylinder block 1
Since the end portions of the cylinder wall portion 12 and the block outer wall portion 13 on the deck portion 11 side are coupled via the upper deck 20, the temperature rise is large under operating conditions in which high load operation is performed from the cold start. It is possible to prevent the cylinder wall portion 12 from expanding in the cylinder direction due to its thermal expansion and partially lifting the cylinder head, and to maintain the sealing property of the head gasket.

Since the cylinder wall portion 12 and the block outer wall portion 13 are respectively formed with step portions 27 and 28 which are joined to the lower end portion of the ring portion 21 of the upper deck 20, the upper deck 20 can be positioned with respect to the cylinder block 1. Cylinder wall 12 during operation of the engine
Is prevented from expanding in the cylinder direction due to thermal expansion with respect to the block outer wall portion 13.

Further, since the rigidity of the cylinder block 1 is increased via the upper deck 20, vibration and noise generated from the cylinder wall portion 12 or the block outer wall portion 13 can be suppressed.

The piston is pressed against the thrust side of the cylinder bore 4 in the process of moving from the top dead center to the bottom dead center in response to the combustion pressure, while the piston moves in the opposite direction of the cylinder bore 4 in the process of moving from the bottom dead center to the top dead center. It is pressed against the thrust side.
The cylinder wall portion 12 is vibrated by the alternating pressing force of the piston.

Since the end portion of the cylinder wall portion 12 is connected to the block wall portion 12 on the thrust side and the anti-thrust side by the convex portions 23 and 24 of the upper deck 20, the rigidity against the vibration force of the piston is effectively made. The vibration of the cylinder wall portion 12 can be enhanced and the vibration of the cylinder wall portion 12 can be sufficiently reduced.

The upper deck 20 includes the cylinder wall portions 1
The four ring portions 21 arranged around the two are connected to each other and integrally formed, so that the upper deck 20
The rigidity of the cylinder block 1 can be increased, and the work of assembling the cylinder block 1 can be performed more easily than the conventional device for assembling the plurality of deck reinforcing pieces 3 shown in FIGS.

Further, the upper deck 20 is automated by simultaneously using a plurality of welders in the process of welding the upper deck 20 to the cylinder block 1 by integrating the ring portions 21 and the convex portions 23, 24, 25. Therefore, the time required for this welding can be significantly reduced.

Further, the cooling water flowing from the inlet 5 into the water jacket 2 flows in the cylinder row direction in the water jacket 2 and absorbs the heat of each cylinder wall portion 12, while each convex portion 23 of the upper deck 20. The water is diverted to the water jacket in the cylinder head through ten water jacket outlets 8 which are opened between 24 and 25 and the block outer wall portion 13.

In the case of the Siamese type cylinder block 1, the cooling performance of the inter-cylinder joint 14 where the adjacent cylinder wall portions 12 are joined to each other deteriorates, and the inter-cylinder joint 1
The temperature of No. 4 becomes higher than other parts of the cylinder wall 12, and the cylinder bore 4 may be deformed.

As a countermeasure against this, the inter-cylinder joints 14
By forming the cooling water passage grooves 30 and 29 in the inter-ring joint portion 22, respectively, heat dissipation from the cylinder wall portion 12 to the cooling water flowing through the cooling passage grooves 29, 30 is promoted,
It is possible to prevent the temperature of the inter-cylinder joint portion 14 from becoming higher than that of other portions of the cylinder wall 12. By making the temperature distribution of the cylinder wall 12 uniform in this way, the cylinder wall 1
The deformation of No. 2 is suppressed, the piston gap is made uniform, the friction is reduced, and the oil consumption is suppressed to be small.

Next, another embodiment shown in FIG. 8 will be described. The parts corresponding to those in FIG. 1 are designated by the same reference numerals.

The upper deck 40 includes the cylinder wall portions 1
The four ring portions 41 arranged around 2 are integrally formed so as to be connected to each other and have an inter-ring joint portion 42 that connects the adjacent ring portions 41.

In the upper deck 40, the outer peripheral surface 46 of each ring portion 41 is fitted to the inner wall surface 16 of the block outer wall portion 13 over the entire circumference, and each convex portion 43 projecting from each ring portion 41 in the inner diameter direction, 44 and 45 are fitted to the outer peripheral surface 19 of the cylinder wall portion 12, and the joint portion between the cylinder block 1 and the upper deck 10 is intermittently or continuously joined by electron beam welding, laser welding or the like.

The four convex portions 43 are formed on the thrust side of the ring portions 41, and the four convex portions 44 are formed on the anti-thrust side of the ring portions 21, respectively. The parts 45 are formed at the front and rear ends of the front and rear ring parts 41, respectively.

Each convex portion 43, 44 of the upper deck 40,
Ten water jacket outlets 48 are defined between 45 and the cylinder wall 12.

As shown in FIG. 4, the deck portion 11 of the inter-cylinder joint portion 14 of the Siamese type cylinder block 1 is shown.
The cooling water passage groove 30 is formed on the side, while the cooling water passage groove 49 is formed on the lower surface of the inter-ring joint portion 42 of the upper deck 40. The cooling water passage groove 30 and the cooling water passage groove 49 define a cooling water passage having a predetermined cross-sectional area, and the cooling water passages connect the water jackets 2 located on the left and right of each cylinder wall portion 12 to each other. .

With the above construction, the operation will be described below.

The cooling water flowing into the water jacket 2 from the inlet 5 flows in the cylinder row direction in the water jacket 2 and absorbs the heat of each cylinder wall portion 12, while also projecting the convex portions 43, 44 of the upper deck 40. The water is branched to the water jacket in the cylinder head through ten water jacket outlets 48 opened between the block 45 and the block outer wall portion 13.

In this case, each water jacket outlet 48
Is desired to be defined between each ring portion 41 of the upper deck 40 and the cylinder wall portion 12, so that the cooling water flows along the cylinder wall portion 12 toward the respective water jacket outlets 48 in the water jacket 2. Therefore, in combination with the effect that the cooling water flows through the cooling passage groove 30 formed in the cylinder wall portion 12, heat dissipation from the Linda wall portion 12 to the cooling water is promoted, and the temperature distribution of the cylinder wall 12 is made uniform. Thus, the deformation of the cylinder wall 12 can be suppressed, the piston gap can be made uniform, the friction can be reduced, and the oil consumption can be suppressed to be small.

[0057]

As described above, according to the first aspect of the invention, the upper portion is joined to the cylinder head, and the cylinder wall portion and the block outer wall portion that define the water jacket formed by opening the cylinder head side are integrated. In a cylinder block of a water-cooled internal combustion engine to be formed, a reinforcing member integrally formed by connecting a plurality of ring portions to each other is interposed in an opening in the upper portion of the water jacket, and the reinforcing member is provided on the cylinder wall portion and the block. Since it is joined to the outer wall by welding, the rigidity of the open deck type cylinder block is increased through the reinforcing member, and thermal deformation is suppressed to maintain the sealability of the head gasket, while the cylinder block of the reinforcing member is manufactured. Can be easily assembled, and the time required for welding can be shortened to improve productivity. .

According to a second aspect of the present invention, a plurality of convex portions connecting the cylinder wall portion and the block outer wall portion are formed on the reinforcing member at least on the thrust side and the anti-thrust side of the cylinder bore, and the adjacent convex portions are formed. Since the water jacket outlet communicating with the water jacket provided in the cylinder head is formed between the portions, the end portion of the cylinder wall portion can effectively increase the rigidity against the vibration force of the piston by the convex portions of the reinforcing member, Vibration and noise generated from the cylinder wall can be sufficiently suppressed.

According to a third aspect of the present invention, an inter-cylinder joint connecting the cylinder wall portions adjacent to the cylinder block is integrally formed, and an inter-ring joint connecting the ring portions adjacent to the reinforcing member is integrally formed. Is connected to the inter-cylinder joint, and at least one of the inter-cylinder joint and the inter-ring joint is formed with a cooling water passage groove for communicating water jackets located on both sides of each cylinder wall. The heat dissipation from the cooling water to the cooling water flowing through the cooling passage groove is promoted, and the temperature of the inter-cylinder joint is prevented from becoming higher than the other parts of the cylinder wall, so that the temperature distribution on the cylinder wall is made uniform and The deformation of the wall is suppressed, the piston gap is made uniform, the friction is reduced, and the oil consumption is reduced.

[Brief description of drawings]

FIG. 1 is a plan view of a cylinder block and an upper deck showing an embodiment of the present invention.

FIG. 2 is a transverse sectional view of a cylinder block and an upper deck of the same.

FIG. 3 is a vertical sectional view of a cylinder block and an upper deck.

FIG. 4 is an enlarged vertical sectional view of a part of the cylinder block and the upper deck.

FIG. 5 is a plan view of a cylinder block of the same.

FIG. 6 is a transverse sectional view of the cylinder block.

FIG. 7 is a plan view of the upper deck.

FIG. 8 is a plan view of an upper deck showing another embodiment.

FIG. 9 is a cross-sectional view of a cylinder block showing a conventional example.

FIG. 10 is a plan view of a cylinder block of the same.

[Explanation of symbols]

 1 Cylinder Block 2 Water Jacket 4 Cylinder Bore 5 Water Jacket Inlet 8 Water Jacket Outlet 9 Water Jacket Opening 11 Deck Part 12 Cylinder Wall 13 Block Outer Wall 14 Cylinder Joint 20 Upper Deck (Reinforcing Member) 21 Ring Part 22 Ring Indirect Joint part 23 Thrust side convex part 24 Anti thrust side convex part 25 Front and rear convex part 29 Cooling passage groove 30 Cooling passage groove

Claims (3)

[Claims] 1. A cylinder block of a water-cooled internal combustion engine, wherein an upper part is joined to a cylinder head, and a cylinder wall part that defines a water jacket opened to the cylinder head side and a block outer wall part are integrally formed. A reinforcing member integrally formed by connecting the ring portions of the above is interposed in an opening in the upper portion of the water jacket, and the reinforcing member is joined to the cylinder wall portion and the block outer wall portion by welding. Cylinder block structure for water-cooled internal combustion engine. 2. A plurality of convex portions connecting the cylinder wall portion and the block outer wall portion are formed on the reinforcing member at least on the thrust side and the anti-thrust side of the cylinder bore,
2. A cylinder block structure for a water-cooled internal combustion engine according to claim 1, wherein a water jacket outlet communicating with a water jacket provided in the cylinder head is formed between adjacent convex portions. 3. An inter-cylinder joint that connects the cylinder wall portions adjacent to the cylinder block is integrally formed, and an inter-ring joint portion that connects the ring portions adjacent to the reinforcing member is formed into the inter-cylinder joint portion. 3. A cooling water passage groove communicating with water jackets located on both sides of each cylinder wall is formed in at least one of the inter-cylinder joint and the inter-ring joint. A cylinder block structure of the water-cooled internal combustion engine described.