JP3057419B2 - Siamese cylinder cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a siamese cylinder of a multi-cylinder engine. Provide what can be achieved.

[0002]

2. Description of the Related Art In recent years, the interval between cylinder bores has to be narrowed to reduce the size and weight of a multi-cylinder engine, or the cylinder bore has to be increased by increasing the cylinder bore to increase the engine output by increasing the displacement. Siamese cylinders with thinner walls have been adopted. Examples of this type of prior art include, for example, Japanese Utility Model Application Laid-Open No.
The one disclosed in Japanese Patent Publication No. 46-46 is known.

FIG. 6 shows the above conventional example, FIG. 6 (A) is a longitudinal sectional view of a main part of a siamese cylinder, and FIG. 6 (B) is a cross-sectional plan view taken along line BB in FIG. 6 (A). FIG. 6C is a perspective view of a water channel forming member cast into the continuous wall portion of the siamese cylinder. In this conventional example, a plurality of cylinders 3 are arranged side by side in a cylinder block 1 and adjacent cylinders 3 are connected by a continuous wall portion 4 to form a siamese cylinder 2. The siamese cylinder 2 is surrounded by the siamese cylinder 2. A cylinder jacket 8 is formed on the continuous wall portion 4.
The channel forming member 110 is cast into the container.

[0004] The water channel forming member 110 is shown in FIG.
(B) As shown in (C), a pair of left and right jacket communication passages 112, 112 and each of the jacket communication passages 112, 11 are provided.
2, a pair of left and right cooling water inlets 113, 113 located on the lower side of the cylinder jackets 8 and opening toward the respective cylinder jackets 8, 8.
The cooling water passage 115 includes a pair of left and right cooling water passages 115 communicating with each of the jacket communication passages 112 and the cooling water introduction port 113. The cooling water passages 115 are formed flat in a front view, vertically long in a longitudinal side view, and formed in a bag shape. The cooling water in the cylinder jackets 8.8 and the cooling water inlets 113
15.115 and a pair of left and right jacket communication passages 112.1
12 and a pair of left and right communication holes 23, 23 formed in the upper surface of the head leaning portion 4a in order to flow out to the head jacket, and the head leaning portion 4a of the continuous wall portion 4 therebetween.
Is configured to cool.

[0005]

In the above conventional example, the opening of the jacket communication passage 112 formed in the water channel forming member 110 and the lower end opening of the communication hole 23 formed on the upper surface of the head-side portion 4a coincide with each other. Because it has a step,
The smooth flow of the cooling water flowing from the jacket communication passage 112 to the head jacket via the communication hole 23 is impeded.
Therefore, the opening of the communication hole 23 is connected to the jacket communication passage 112.
It is conceivable to increase the opening of the communication hole 23 so as to correspond to the opening of the cylinder. However, if the opening of the communication hole 23 is increased, the pressing surface of the sealing member interposed between the cylinder block 1 and the cylinder head at the head side portion 4a is secured. You will not be able to do it.

[0006] The present invention has been made in view of such circumstances, and while ensuring a required pressing surface at a head-side portion of a seal member interposed between a cylinder block and a cylinder head, cooling water is supplied. It is a technical object to improve the cooling performance by smoothly flowing out of a jacket communication path to a head jacket through a communication hole.

[0007]

In order to solve the above-mentioned problems, the present invention is configured as follows. That is, claim 1
The water channel forming member 10 is cast into the head-side portion 4a of the continuous wall portion 4 of the siamese cylinder 2 and the cooling water in the cylinder jackets 8 is formed into a pair of left and right channels formed on the water channel forming member 10. Cooling of a siamese cylinder configured to flow out to the head jacket 22 located above the continuous wall portion 4 via the cooling water introduction portions 13, 13, the cooling water passages 15, and the jacket communication passages 12, in that order. In the apparatus, the water channel forming member 10
Is a pair of left and right jacket communication paths 12 located in the upper half.
Between the pair of left and right cooling water introduction portions 13 and 13 which are located below the jacket communication passages 12 and open toward the respective cylinder jackets 8; And left and right cooling water introduction parts 13
And the left and right communication holes 23, 23 are spaced apart from each other by an interval D between the left and right inner openings as approaching from the lower end to the upper end. It is characterized in that the lower end opening is made to match the opening of the jacket communication passages 12.

According to a second aspect of the present invention, in the cooling device for a siamese cylinder according to the first aspect, the cross-sectional shape of each of the jacket communication passages 12 and each of the communication holes 23 is formed such that two sides thereof have an arc shape of the cylinder bore 3a. It is formed in a substantially triangular shape along.

According to a third aspect of the present invention, in the cooling device for a siamese cylinder according to the first or second aspect, each of the communication holes 23 is provided with a core 23 a formed of cast sand and formed in each of the jacket communication passages 12. It is constructed by forming a mold by extending upward from the upper end.

According to a fourth aspect of the present invention, in the cooling device for a siamese cylinder according to the first or second aspect, each communication hole 23 extends upward at an upper end portion of each jacket communication passage 12. Thereby, it is formed integrally with the jacket communication passage 12.

[0011]

According to the present invention, since the left and right communication holes 23 are formed so as to be spaced apart from each other by the inner opening distances D on the left and right as they approach the upper end from the lower end thereof, the left and right communication holes 23 are formed in an upwardly tapered shape. The upper end openings of the left and right communication holes 23 are made smaller in an upwardly tapered manner, so that a required pressing surface at a head-side portion of a seal member interposed between the cylinder block and the cylinder head can be secured.

Conversely, the left and right communication holes 23 are formed so that the left and right inner opening distances D approach each other as they approach from the upper end to the lower end, so as to form a divergent shape. Since the cross-section opening can be enlarged, a large amount of cooling water flows out of the jacket communication passage 12 to the head jacket via the communication hole 23. In addition, since the lower end openings of the communication holes 23 formed in the upper convergent shape are made coincident with the openings of the jacket communication passages 12, the step is eliminated, so that the cooling water flows through the communication holes 23 from the jacket communication passage 12. Through the head jacket smoothly.
Thereby, the cooling performance can be improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a waterway forming member according to a first embodiment of the present invention, FIG. 1 (A) is a perspective view of the waterway forming member, and FIG. 1 (B) is a main part of a siamese cylinder into which the waterway forming member is cast. It is a top view. 2 shows a main part of a vertical multi-cylinder engine provided with a siamese cylinder cooling device according to the present invention. FIG. 1 (A) is a partial vertical sectional view, and FIG. 2 (B) is a part of the cylinder block. It is a top view. FIG. 3 is a longitudinal sectional view of a main part of a vertical multi-cylinder engine equipped with a siamese cylinder cooling device according to the present invention.

As shown in FIG. 3, the vertical multi-cylinder engine E has a cylinder head 20 fixed on a cylinder block 1 integrally formed with a crankcase with a head bolt 6, and a cylinder formed on the cylinder block 1. The jacket 8 and the head jacket 22 formed on the cylinder head 20 are communicated with each other through a large number of jacket communication holes 24 formed on portions other than the continuous wall portion 4, and the cylinder head 20 is cooled with cooling water that has cooled the cylinder block 1. It is configured to be.

The siamese cylinder cooling device according to the present invention has the same basic configuration as that of the conventional example. That is,
As shown in FIGS. 2 and 3, a plurality of cylinders 3 are arranged side by side in the cylinder block 1,
Are continued by the continuous wall portion 4 to form the siamese cylinder 2, and a cylinder jacket 8 is formed so as to surround the siamese cylinder 2. A water channel forming member 10 described below is cast into the continuous wall portion 4.

Hereinafter, the characteristic configuration of the present apparatus will be described. As shown in FIG. 1 (A), the water channel forming member 10 is formed by vertically stacking two metal plate bodies 10a, 10a formed symmetrically in the front-rear direction by press molding, facing each other. Non-hollow portions 11 are integrally formed by welding outer edge joint portions 17 formed so as to protrude outwardly and vertically at outer edges of the left and right jacket communication passages 12. Thereby, it is possible to simply manufacture the two metal plate-shaped bodies 10a, 10a molded into the same shape simply by fixing them together.

The water channel forming member 10 is provided with a pair of left and right jacket communication passages 12 and 12 located in the upper half part, and is positioned below the jacket communication passages 12 and 12 toward the respective cylinder jackets 8. Non-hollow portions alternately formed in upper and lower multi-stages between a pair of left and right cooling water introduction portions 13 and 13, between the left and right jacket communication passages 12 and 12 and between the left and right cooling water introduction portions 13 and 13. 11 and cooling water channel 1
The cooling water in the cylinder jackets 8.8 is supplied to a pair of left and right cooling water introduction portions 13 and 13 and the cooling water passage 1.
5, 15 and the jacket communication passages 12 and the communication holes 23
13 to flow out to the head jacket 22 located above the continuous wall portion 4 in order.

The non-hollow portion 11 formed in the upper and lower tiers as described above functions as a rib for mechanically reinforcing the continuous wall portion 4, and the cooling water passages 15 formed in the upper and lower tiers alternately with the non-hollow portion 11. As compared with the flat and vertically long cooling water channel 115 of the conventional example, the mechanical strength is significantly increased. As a result, there is no possibility that partial distortion will occur in the drilling of the cylinder bore 3a.

Also, a pair of left and right cooling water introduction portions 13, 13 are provided.
Is a pair of front and rear cooling water guide plates 14.
4 is expanded along each outer peripheral surface 3b of the adjacent cylinder 3.3. As a result, the frontage of the cooling water introduction portions 13 is formed large, and most of the cooling water flows from the cooling water introduction portions 13 extending toward the cylinder jackets 8.8 through the cooling water passage 15 and the jacket communication passage 12. Flows in large quantities into

As shown in FIGS. 1B, 2A and 2B, the left and right jacket communication passages 12 are located inside a pair of left and right boss portions 5.5. As shown in FIG. 1 (A), the left and right communication holes 23, 23 for communicating the left and right jacket communication passages 12, 12 with the head jacket 22 are provided with cores 23a formed of casting sand. It is formed by forming a mold by extending upward from the upper end portion. As the communication holes 23 approach the upper end from the lower end, the left and right inner opening intervals D
Are formed so as to be spaced apart from each other to form an upper taper, and the lower end opening thereof is made to coincide with the openings of the jacket communication passages 12.

Although the present invention is not limited to the above embodiment, as shown in FIG. 1B, the cylinder head fastening bosses 5 and the right and left side portions of the head-side portion 4a are made continuous. There is an advantage that a large amount of cooling water can be circulated by increasing the diameter of the communication hole 23 formed in the upper end wall of the cylinder block 1 and the pair of jacket communication passages 12.

As described above, the left and right communication holes 23, 23
, The required pressing surface of the head-side portion 4a of the seal member 21 interposed between the cylinder block 1 and the cylinder head 20 can be secured. The sectional shape of each of the jacket communication passages 12 and each of the communication holes 23 is such that two sides thereof are the cylinder bores 3.
It is formed in a substantially triangular shape along the arc shape of a. In the case where the communication holes 23 are formed as a mold with casting sand as described above, each communication hole 23 can have an arbitrary cross-sectional shape.

Conversely, these communication holes 23 are spaced apart from each other as the distance from the upper end to the lower end decreases.
Are formed close to each other to form a divergent shape, and the cross-sectional opening of the jacket communication passages 12 and 12 can be enlarged, so that a large amount of cooling water flows out of the jacket communication passage 12 to the head jacket 22 through the communication holes 23. Can be done. Moreover, the communication hole 23,
Since the lower end opening of 23 is made coincident with the openings of the jacket communication passages 12 and the step is eliminated, the cooling water flows out smoothly from the jacket communication passage 12 to the head jacket via the communication hole 23. During that time, the head-side portion 4a of the continuous wall portion 14 is strongly cooled.

That is, since the piston ring can be strongly cooled through the cylinder wall by strongly cooling the head-side portion 4a, the top ring is brought as close as possible to the top surface of the piston to combust the outer periphery of the top portion of the piston. The ring-shaped dead space that does not contribute can be reduced as much as possible to improve the air utilization rate. In addition, the sticking of the top ring due to the carbonization of the unburned portion of the fuel can be eliminated.

Further, as the top ring is brought as close as possible to the piston top surface, the position of the piston pin is brought as close as possible to the piston top surface, and the swinging dimension of the crankshaft is lengthened accordingly. It is possible to reduce the size of the connecting rod engine without changing its height, increase the piston stroke, and increase the displacement. Further, since the head-side portion 4a can be cooled strongly, the displacement can be increased by increasing the diameter of the cylinder bore.

Further, by applying the present invention to a multi-cylinder engine or the like equipped with a turbocharger,
It is possible to reduce the size and increase the output of the engine. Conversely, when the piston stroke is not changed, the connecting rod can be set longer by an amount corresponding to the position of the piston pin closer to the piston top surface, so that the pressure on the piston side can be reduced, and as a result, the friction loss can be reduced.

As shown in FIG. 1 (B), one outer edge joint 17 of the jacket communication passages 12 is provided between one cylinder 3 and the cylinder head fastening boss 5 and the other outer edge joint. 17 is cast between the other cylinder 3 and the cylinder head fastening boss portion 5 so as to be displaced toward one and the other cylinder 3.3 respectively. That is, since the interval between the left and right cylinder head fastening bolts 6 is constant, when the joining portion 17 is overlapped on the outside of the left and right jacket communication passages 12 as in the conventional example (FIG. 6C), the jacket connection is made. Since the substantial passage cross section of the passage 12 becomes narrower, by displacing the outer edge joints 17 toward one and the other cylinder 3.3 as described above,
The substantial passage cross section of the jacket communication passage 12 can be increased.

FIG. 4 shows a channel forming member according to a second embodiment of the present invention. FIG. 4 (A) is a perspective view of the channel forming member, and FIG. 4 (B) is a siamese cylinder into which the channel forming member is cast. FIG. In this embodiment, the upper end of the non-hollow portion 11 and the upper end of the left and right jacket communication passages 12 extend upward, and the extended portion is formed as a communication hole 23 in an upwardly tapered shape. Thereby, the jacket communication passage 12 and the communication hole 23 are integrally formed. In this case, the head-side portion 4 of the continuous wall portion 4
4A and the upper end surface of the waterway forming member 10 are simultaneously cut and finished to be flush with each other, as shown in FIG.
The top surface of appears. Other points are the same as those of the first embodiment (FIG. 1).

FIG. 5 shows a channel forming member according to a third embodiment of the present invention. FIG. 5 (A) is a perspective view of the channel forming member, and FIG. 5 (B) is a continuous wall into which the channel forming member is cast. It is a top view of the wall part 4. In this embodiment, only the upper end portions of the left and right jacket communication passages 12 are extended upward, and the extended portions are formed as communication holes 23 in an upwardly tapered shape. It is formed integrally with the communication hole 23. In this case, FIG.
As shown in (2), the upper end surfaces of the left and right communication holes 23 formed integrally with the water channel forming member 10 appear on the upper end surface of the head-side portion 4a.

In this embodiment, FIG.
(B) As shown in FIG.
5 are formed in a wedge-like shape in plan view, and are configured symmetrically to the left and right such that the front end thereof faces the center. In other words, the thickness of the continuous wall portion 4 is the thinnest at the center portion and the thickest at both left and right ends, but the cooling water passage 15 is formed in a wedge-like shape in plan view in accordance with the thickness of the continuous wall portion 4. The water channel forming member 10 can be made as thin as possible by making it symmetrical so that the tip is directed to the center, and thus the continuous wall portion 4 can be made as thin as possible. Thereby, the thickness of the continuous wall portion 4 can be made thinner than the conventional example, and the pitch between the cylinder bores can be reduced. Alternatively, the displacement can be increased and the output can be increased by increasing the diameter of the cylinder bore.

The above-mentioned pair of left and right cooling water passages 15 are shown in FIG.
As shown in (A), the upper edge 15b is formed so as to be upwardly sloped outward in the left-right direction. That is, even when the cooling water boils in each cooling water passage 15 and steam is generated, the steam moves upward along the upper edge 15b of each cooling water passage 15 formed in an upward gradient, and communicates with the jacket communication passage 12. It escapes to the head jacket 22 through the hole 23. This keeps the cooling performance high. Note that reference numeral 16 in FIG.
Are holes for connecting the front and rear wall portions of the continuous wall portion 4. The present invention is not limited to the one having the front and rear wall connecting holes 16, but if the front and rear wall connecting holes 16 are provided, the additional wall acting on the continuous wall 4 at the time of machining the cylinder bore and at the time of operating the engine. There is an advantage that pressure can be more strongly countered.

In the above embodiments, the cooling water passages are formed in multiple stages in the vertical direction and the cooling water introduction plate is expanded in the left and right directions. However, the present invention is not limited to this. Further, in the above-described embodiments, the two metal plate-shaped members are opposed to each other and fixed to form a waterway forming member. However, the waterway forming member is integrally molded by, for example, precision casting. No problem.

[Brief description of the drawings]

1A and 1B show a water channel forming member according to a first embodiment of the present invention. FIG. 1A is a perspective view of the water channel forming member, and FIG. 1B is a perspective view of a siamese cylinder into which the water channel forming member is cast. It is a partial plan view.

FIG. 2 shows a main part of a vertical multi-cylinder engine equipped with a siamese cylinder cooling device according to the present invention,
2A is a partial longitudinal sectional view, and FIG. 2B is a partial plan view of the cylinder block.

FIG. 3 is a longitudinal sectional view of a main part of a vertical multi-cylinder engine including a siamese cylinder cooling device according to the present invention.

FIG. 4 is a diagram corresponding to FIG. 1 according to a second embodiment of the present invention.

FIG. 5 is a diagram corresponding to FIG. 1 according to a third embodiment of the present invention.

6A shows a conventional example, FIG. 6A is a longitudinal sectional view of a main part of a siamese cylinder of a vertical engine, and FIG.
FIG. 6A is a cross-sectional plan view taken along line BB in FIG. 6A, and FIG. 6C is a perspective view of a channel forming member.

[Explanation of symbols]

1: Cylinder block, 2: Siamese cylinder, 3
... Cylinder, 3a ... Cylinder bore, 3b ... Outer circumferential surface of cylinder, 4 ... Continuous wall part, 4a ... Head-side part of continuous wall part, 8 ... Cylinder jacket, 10 ... Water channel forming member,
11: non-hollow portion, 12: jacket communication passage, 13: cooling water introduction portion, 15: cooling water passage, 17: outer edge joint portion, 22 ...
Head jacket, 23: communication hole, 23a: core formed of cast sand, D: inner opening interval between left and right communication holes.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Osamu Yoshii 64 Ishizukitamachi, Sakai City, Osaka Prefecture, Kubota Sakai Factory Co., Ltd. (72) Inventor Akira Hayaya 64 Ishizukitamachi, Sakai City, Osaka Prefecture 64 Kubota Sakai Factory Co., Ltd. (72 ) Inventor Kazuyoshi Morioka 64 Ishizukitamachi, Sakai City, Osaka Prefecture Inside Kubota Sakai Works (56) References JP-A-6-344112 (JP, A) JP-A-63-253156 (JP, A) JP-A-6- 147002 (JP, A) Fully open sho 60-57758 (JP, U) Fully open sho 59-107946 (JP, U) Fully open sho 59-79536 (JP, U) Really open sho 59-68154 (JP, U) Actually open sho 59-7242 (JP, U) Actually open sho 54-93605 (JP, U) Actually open sho 57-117742 (JP, U) Actually open sho 59-68155 (JP, U) (58) (Int.Cl. ⁷ , DB name) F02F 1/00-1/42 F01P 3/02

Claims (4)

(57) [Claims] 1. A water channel forming member (1) is provided on a head-side portion (4a) of a continuous wall portion (4) of a siamese cylinder (2).
0), and the cooling water in the cylinder jackets (8) and (8) is supplied to the pair of left and right jacket communication passages (12) and (12) formed in the channel forming member (10) and the head-side portion (4a). A pair of left and right communication holes (23) drilled on the upper surface
(23) in order to flow out to the head jacket (22) located above the continuous wall portion (4) through the cooling wall of the siamese cylinder, wherein the water channel forming member (10) A pair of left and right jacket communication passages (12) and (12) located in the half portion, and located below the jacket communication passages (12) and (12), and open toward the respective cylinder jackets (8) and (8). A pair of left and right cooling water inlets (13), (13) and between the jacket communication passages (12), (12) and the left and right cooling water inlets (1).
3) A cooling water passage (15) located between (13), and the left and right communication holes (23) (23) are provided with a left and right inner opening interval (23) as approaching from the lower end to the upper end. D) are formed so as to be spaced apart from each other in an upper tapered shape, and the lower end opening thereof is made to coincide with the openings of the jacket communication passages (12), (12). . 2. A sectional shape of each of the jacket communication passages (12) and each of the communication holes (23), two sides of which are cylinder bores (3).
2. The cooling device for a siamese cylinder according to claim 1, wherein the cooling device is formed in a substantially triangular shape along the arc shape of a). 3. Each of the communication holes (23) is formed by forming a mold by extending a core (23a) formed of cast sand upward from an upper end portion of each of the jacket communication passages (12). The cooling device for a siamese cylinder according to claim 1 or 2. 4. Each of the communication holes (23) is formed integrally with the jacket communication passage (12) by extending an upper end of the jacket communication passage (12) upward. 4. A cooling device for a siamese cylinder according to 4.