JP2566683B2 - V-type engine cylinder block structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder block structure of a V-type engine in which cylinders are arranged in a V-shape.

[0002]

2. Description of the Related Art In the conventional V-type engine,
For example, as shown in FIGS. 2 and 4 of JP-B-57-40332, the crankcase is formed with an open end on the oil pan side in the direction perpendicular to the crankshaft. Therefore, although the dimension between the crankshafts can be shortened, it is necessary to make a hole larger than the outer diameter of the crank web in the side wall of the crankcase for assembling the crankshaft and to mount the bearing retainer in the hole after inserting the crankshaft. Therefore, it takes time and effort to assemble the crankshaft, and the amount of padding around the bearing increases, which causes an increase in weight.

Further, since the oil pan side of the crankcase has an open end, the crankcase and the cylinder are formed separately, which increases the work steps during assembly and increases the weight.

The reason why the cylinder and the crankcase cannot be integrally formed as described above in the conventional apparatus is that the core and the die for forming the crankcase and the die for forming the cylinder are both cranked. This is because they are included in the same plane perpendicular to the axis. That is, even if an attempt is made to integrally form the cylinder and the crankcase, the total total stroke of the cores and the mold becomes too large, and a casting machine having such a large total stroke cannot be actually provided.

[0005]

It is an object of the present invention to facilitate the casting of a cylinder block and reduce the weight by forming one end of the crankcase in the crankshaft direction at the open end and integrally molding the cylinder with the crankcase. Another object of the present invention is to facilitate the assembling and to accurately and surely form the water supply passage communicating with the water jacket of the cylinder in the water-cooled V-type engine.

[0006]

To achieve the above object, in the present invention, in a cylinder block of a V-type engine having a pair of cylinders arranged in a V-shape, the entire surface of one end of the crankcase in the crankshaft direction is opened. While forming as an end, each cylinder and crankcase are made of aluminum die-casting integrally molded, and a water jacket of a shape in which the end face on the cylinder head side is fully opened and becomes wider toward the cylinder head side in the peripheral wall of the cylinder,
A water supply passage formed in parallel with the cylinder center line direction so that it can be die-cut, and communicating with the water jacket and projecting from the inside of the cylinder peripheral wall to the crankcase opening side in parallel with the crankshaft,
The cylinder peripheral wall is formed so that it can be cut parallel to the direction of the crank axis, and the water supply channel for each cylinder is formed at a position that is the shortest distance between the left and right jackets, and the tip of each water supply channel is cranked. The cylinder block structure of the V-type engine is characterized in that it is formed on the same surface as the end surface of the case in the crankshaft direction on the release side.

[0007]

FIG. 1 shows a cylinder block of a water-cooled V-type vertical axis engine to which the present invention is applied. A pair of left and right cylinders 1, 1 are arranged in V-shape, and a space between both cylinders 1 is shown. The angle θ is set to 90 degrees. A water jacket 23 for cooling is formed in the cylinder peripheral wall, and a water supply passage 24 communicating with the jacket 23 is formed.
A cooling water pump 26 is connected to the water supply passage 24 via a water supply pipe 25. The vertical axis type crankshaft 5 is arranged in the crankcase 3 in a vertical posture. The skirt portion 1a of the cylinder 1 projects into the crankcase 3, and one camshaft 7 is provided between the end portions of the skirt portions 1a that are closest to each other, that is, the innermost crankcase portion of the V-shaped portion. Will be placed. The cam shaft 7 is arranged parallel to the crank shaft 5.

The crankcase 3 is formed integrally with each cylinder 1 by aluminum die-casting molding.
As described above, the entire surface of one end of the crankcase 3 in the crankshaft direction is opened to form an open end surface 3a. That is, the crankcase 3 is the end wall 3 on the other end side in the crankshaft direction.
b, the bottom wall 3c, both side walls 3d perpendicular to the crankshaft 5, and the top wall 3e are die-cast with the cylinders 1 by a die, and the end wall 3b has a bearing boss 8 for supporting the crankshaft and a cam. A bearing boss 10 for supporting the shaft is integrally formed.

In FIG. 2 showing the II-II cross section of FIG. 1, a case lid 11 is detachably fixed to the open end surface 3a of the crankcase 3, and a bearing boss 13 and a cam for supporting the crankshaft are attached to the case lid 11. A bearing boss 15 for supporting the shaft is formed. A space S for accommodating the cam gear is formed on a side surface of the cylinder skirt portion 1a protruding into the crankcase 3 on the crankcase open end surface 3a side, and the cam gear 16 is accommodated in the space S. The crankshaft 5 is supported by bearings (not shown) for supporting the crankshafts 8 and 13, and the camshaft 7 is supported by bosses 10 and 15 for supporting the camshafts through bearings (not shown). To be done. Cam gear 16
Is fixed to the cam shaft 7 and meshes with the cam drive gear 18 of the crank shaft 5.

The bottom wall 3c of the crankcase 3 is formed in an inclined shape so that the core for forming the crankcase can be easily pulled out in the Y1 direction and gradually separated from the crankshaft 5 in the Y1 direction. .

The water jacket 23 of each cylinder 1 is formed parallel to the center line O of the cylinder 1, and the end faces on the cylinder head side (arrow A1 side and arrow A2 side, respectively) are open. The water jacket 23 is formed so as to become wider toward the cylinder head 20 side. Therefore, the core for forming the water jacket can be pulled out in the same direction (A1, A2 direction) as the core for forming the cylinder at the time of molding the mold. The water supply passage 24 is molded on the side surface of the cylinder on the side of the crankcase open end surface 3a, and the water supply passage 24 is formed parallel to the crankshaft 5, and its tip end surface is the same as the open end surface 3a of the crankcase 3. Is formed on the surface.

Next, the molding method and assembly will be described. When the integral block of the cylinder 1 and the crankcase 3 is molded by a die, the A1 and A2 directions in FIG. 1 are the cylinder core removal directions, and the Y1 direction in FIG. 2 is the crankcase core removal. Direction. Also, the whole mold is
For example, A1 and A2 directions in FIG.
It is composed of six mold members in which the four directions and the Y1 and Y2 directions in FIG. 2 are the drawing directions. Or X in FIG.
It can also be composed of six mold members having the drawing directions in the 1, X2, Z1, Z2 directions and the Y1, Y2 directions in FIG.

According to this structure, the core withdrawing directions A1, A2, Y1 which require a large stroke that influences the selection of the casting machine are different from each other. Can be a small size mold. In this case, Y2 is a fixed type.

The water jacket core is removed in the same direction as the cylinder core extraction directions A1 and A2, so that the cylinder core and the cylinder mold are removed at the same time. Further, the extraction direction of each water supply channel core is the same as the removal direction Y1 direction of the crankcase core, so the mold is simultaneously removed from the crankcase.

When the engine is assembled, the crankshaft 5, the camshaft 7 and the like are placed in the crankcase 3 with the open end surface 3a.
Then, the case lid 11 is fixed to the open end surface 3a.

[0016]

As described above, the present invention is as follows: (1) In a cylinder block of a V-type engine, the entire surface on one end side in the crankshaft direction of the crankcase is formed as an open end, and each cylinder and the crankcase are formed. Since the main part is that it is an aluminum die-cast integrally molded product, the drawing direction of the crankcase mold and core is perpendicular to the drawing direction of each cylinder, and the stroke direction of each mold and core can be dispersed in different directions, The strokes of the cores of the mold do not overlap in the same direction, and the cylinder and the crankcase can be integrally molded by a compact set of molds having a short mold stroke. As a result, the manufacturing process and the assembling process can be rationalized, and the manufacturing cost can be saved.

(2) Since one end side in the crankshaft direction is an open end, the crankcase is attached to the crankcase end wall as compared to the conventional crankcase in which the end face on the oil pan side perpendicular to the crankshaft is open. It is not necessary to make a hole larger than the diameter of the web, and it is not necessary to install a crankshaft supporting retainer after inserting the crankshaft. Therefore, the crankshaft can be easily assembled and the camshaft can be easily mounted. Further, since it is not necessary to mount the retainer for supporting the crankshaft, unnecessary wall thickness around the bearing is reduced and the weight can be reduced.

(3) In the water-cooled V-type engine, the water supply passage communicating with the water jacket in the cylinder peripheral wall is formed parallel to the crankshaft on the end face of the crankcase open end side. It is possible to remove the mold at the same time as the case, and thus to prevent water leakage in the water supply channel. Further, since the inlets of the water supply passages of both jackets are aligned on the same side and are flush with the open end surface 3a of the crankcase, the end face of the water supply passage can be processed at the same time as the processing of the open end surface. In addition, the sealing property is improved.

(4) The shape of the water jacket 23 formed in the peripheral wall of the cylinder 1 becomes wider toward the cylinder head side of the opening side, and the tip of the water supply passage 24 parallel to the crank axis direction of each cylinder 1. Since the portion is formed on the same surface as the end surface of the crankcase 3 in the crankshaft direction in the crankshaft direction, the manufacturing at the time of molding the die can be facilitated.

(5) Since the water supply passage 24 of each cylinder 1 is formed at a position which is a substantially shortest distance between the left and right water jackets, the water supply passage and the entire engine can be made compact.

(6) Since the water supply passage 24 is formed on the peripheral wall of the cylinder 1 so as to project from the peripheral wall to the crankcase opening side in parallel with the crankshaft, the wall forming the water supply passage 24 is the crankcase. Will make up one wall,
The rigidity of the crankcase is improved.

[Brief description of drawings]

FIG. 1 is a plan view of a water-cooled V-type engine including a cylinder block to which the present invention is applied.

FIG. 2 is a sectional view taken along line II-II of FIG.

[Explanation of symbols]

 1 Cylinder 1a Skirt 3 Crankcase 3a Open End 5 Crankshaft 7 Camshaft 16 Camgear 23 Water Jacket 24 Water Supply Channel

Claims (1)

(57) [Claims] 1. In a cylinder block of a V-type engine having a pair of cylinders arranged in a V-shape, an entire surface of one end of the crankcase in the crankshaft direction is formed as an open end, and each cylinder and the crankcase are die-cast. As an integrally molded product, in the peripheral wall of the cylinder, a water jacket having a shape in which the end surface on the cylinder head side is opened at the same time and becomes wider toward the cylinder head side is formed in parallel with the cylinder center line direction so that it can be die-cut. A water supply passage that communicates with the water jacket and projects from the cylinder peripheral wall parallel to the crankshaft to the crankcase opening side is formed in the cylinder peripheral wall portion so that it can be die-cut parallel to the crankshaft direction, and the water supply passage for each cylinder is formed. , The left and right jackets at a position that is approximately the shortest distance between them, and close the tip of each water supply channel. Cylinder block structure of the V-type engine, characterized in that it is formed on the same surface as the release-side end face of the crankshaft direction of Nkukesu.