JPS6350437Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a cylinder block for a water-cooled reciprocating piston engine, and more particularly to a cylinder block in which a cylinder portion and a crankcase portion are manufactured separately and joined together.

The cylinder block of a water-cooled reciprocating piston engine has a complex shape, so it is generally manufactured by casting, and the material used is mostly cast iron, with some light alloys being used. It is also common for the cylinder part and crankcase part to be cast as one piece.
However, cast iron has the disadvantage of being heavy;
Light alloys have the drawbacks of poor wear resistance on the bore surface and large thermal expansion. Therefore,
In order to reduce weight while ensuring productivity, a structure has been proposed in which the cylinder part, which takes advantage of the advantages of iron, is manufactured separately and the crankcase part, which takes advantage of the advantages of light alloy, are combined. .

For example, in the invention related to Japanese Patent Application No. 56-109045 (which has not yet been published), a cylinder made of a steel plate and a cooling water jacket are welded together to form a cylinder part, and the cylinder part is made of a light alloy. Although the bottom of the cylinder is connected to the crankcase portion by casting or bolting, there are still some unsatisfactory points in such a cylinder block. That is, there is room for improvement in the connection between the cylinder part and the crankcase part in terms of rigidity, vibration characteristics, and productivity, and a simple cooling water jacket may be considered in conjunction with this. This point is especially true for automobile engines.

The purpose of this invention is to strengthen the connection between the two parts of the cylinder block, which is constructed by manufacturing the cylinder part and the crankcase part separately, and to make the cooling water jacket lightweight and simple. It is about forming.

In order to achieve this purpose, this invention has the following structure. That is, a cylinder made of a steel plate,
A crankcase made of a light alloy is connected to a cylinder part consisting of upper and lower fixing plates made of steel plates fixed to the upper and lower parts thereof, extending in a plane perpendicular to the axis of the cylinder, and having a circumference larger than the outer circumference of the cylinder. In this case, a rail made of iron material is cast and fixed to the crankcase part, and this rail is connected to a fixing plate at the bottom of the cylinder part, and this rail is fixed to the crankcase part. A frame body is fitted around the frame body, and packings are respectively clamped between the frame body and the upper and lower fixing plates. In this configuration, the fixation between the cylinder and the upper and lower fixing plates and the connection between the rail and the lower fixing plate are all done by welding.

Next, referring to the drawings, one embodiment of this invention will be described in detail for an in-line four-cylinder engine.

In FIG. 1, 20 is a cylinder section, 40 is a crankcase section, and 10 is a cylinder block formed by joining these two sections. The cylinder part 20 is made up of three parts: a cylinder 21, and an upper fixing plate 22 and a lower fixing plate 31, which are shrink-fitted to the cylinder 21 at their upper and lower ends and are fixed by welding. They are all made of steel plates.

As shown in FIG. 2, the upper fixing plate 22 is made up of a flat part 23 and a hem part 24 formed from the flat part 23 by press working. 4 drilled in the flat part 23
The four large holes 25 fit the cylinders 21 to regulate the mutual positions of the cylinders, and the circumference 26 of the plane part 23 is a rectangle wider than the range that envelops the four large holes 25. A number of small holes 27 are bored between the large hole 25 and the cooling water.
This flat portion 23 is perpendicular to the axis of the cylinder 21, and a cylinder head (not shown) is fastened to this surface via a gasket. Additionally, there are ten small holes 28 around the flat part 23.
A nut 29 is welded to the inside of the hem portion 24 in alignment with these small holes to receive a tension bolt (not shown) for tightening the cylinder head.

As shown in FIG. 4, the lower fixing plate 3 has a flat plate shape. The four large holes 32 bored in alignment with the large holes 25 of the upper fixing plate 22 fit the cylinders 21 and work together with the upper fixing plate to regulate the mutual positions of the cylinders. 4 large holes 32
and the upper fixing plate 2
The outline 26 of 2 is a similar rectangle. The lower fixing plate 31 is parallel to the upper fixing plate 22.

FIG. 3 shows the arranged state of the cylinders 21. After welding to the upper and lower fixing plates, a small piece of steel plate 21A is inserted into the gap between adjacent cylinders and welded.
They are interconnected. The bore surface of the cylinder 21 is plateau honed and nitrocarburized to ensure lubricity and wear resistance.

As shown in FIG. 1, the crankcase portion 40 is a light alloy casting that ends with a ceiling portion 41 on the upper side. This ceiling part 41 has four lower fixing plates.
A long hole 42, which is slightly larger than the area surrounding the large holes 32, is formed by casting to receive the hem of the cylinder 21, and its upper surface 43 is a plane parallel to the axis 44 of the crankshaft (not shown). It is. A rail 45 is fixed to the ceiling portion 41 by means of a casting. The rail 45 is made of a frame-shaped steel plate with an L-shaped cross section and a rectangular overall shape. The circumference of the rectangular inner periphery 46 is the same as the circumference 33 of the lower fixing plate, and the upper end 47 of the L-shaped upright surface is
It stands out slightly from 3. Note that the other parts except for the ceiling part 41 are basically the same as those in the case where they are cast integrally with the cylinder part, so their explanation will be omitted.

Then, the lower fixing plate 31 of the cylinder 20 assembled as described above is placed on the upper surface 43 of the crankcase part 40, and the rim 33 of the lower fixing plate 31 and the upper end 47 of the rail 45 are welded together. The cylinder part and crankcase part are integrated.

Adding to the above-mentioned welding as a means of fixing and joining, in order to suppress distortion caused by welding, welding by laser or electron beam is preferable, and TIG welding can also be used. In this embodiment, the cylinder 21, the upper fixing plate 22, and the lower fixing plate 31 are partially welded 22W and 31W, respectively, the upper fixing plate 22 and the nut 29 are welded 29W, and the cylinder 21 and the small piece are welded. 21A
What is partial welding 21W, lower fixing plate 31 and rail 4
The upper end 47 of 5 was welded 47W.

FIG. 5 shows a frame 50 made of a thin steel plate surrounding the cylinder portion 20. As shown in FIG. Basically, the overall shape is a rectangular frame, and the upper part 51 is the outline 26 of the upper fixing plate 22.
The lower part 52 is slightly larger than the circumference of the outer periphery 48 of the rail 45, and its height extends over the upper and lower fixed plates. Note that 53 is a reinforcing rib welded to the outside.

Reference numeral 60 denotes a gasket secured to the gap between the upper part 51 of the frame 50 and the upper fixing plate 22, and 70 to the gap between the lower part 52 of the frame 50 and the outer periphery 48 of the rail 45, both of which are made of resin. Molded from elastic material. In this embodiment, thermoplastic elastomer (TPE) is used, which is suitable for its heat resistance and elasticity. These packings have a rectangular frame shape as a whole, and the upper packing 60 has an L-shaped cross section and is glued to the hem 24 of the upper fixing plate 22, and the lower packing 70 has an L-shaped cross section and an inverted L shape.
It is glued to the upper surface of the lower fixing plate 31 in a continuous form with the letters. In this embodiment, epoxy resin is used as a suitable adhesive in terms of heat resistance and water resistance.

Next, the aforementioned frame body 50 is placed over and press-fitted from the direction of the upper fixing plate 22, and the lower edge 54 of the frame body 50 comes into contact with the upper surface 43 of the crankcase portion 40, so that the frame body 50 is settled in a predetermined position. In this state, compressive force acts on both the upper packing 60 and the lower packing 70, and the frame body 50 and the cylinder part 20
The space divided between the two is watertightly sealed to form a cooling water jacket 55.

As is clear from the detailed explanation of the first embodiment, when the structure of this invention is used, the cylinder part is made of a steel plate, so it has high strength and rigidity, a thin plate is sufficient, and the cylinder part can be made smaller and lighter. Not only is this possible, but the cooling of the cylinder itself is also excellent. Moreover, since the upper and lower fixing plates are the same as hoops fitted into the cylinder, they suppress deformation and vibration of the cylinder. In addition, since these upper and lower fixing plates have a circumference larger than the outer circumference of the cylinder, the space defined by the outer circumference of the cylinder can form a cooling water jacket by itself by simply fitting the frame, and the jacket can be There is no need for any special design.

On the other hand, the rails in the crankcase part are cast, so the rails are firmly fixed. In addition, the rail is made of the same iron material as the cylinder and is welded to the lower fixing plate of the cylinder, so it is easy to weld and the connection to the cylinder is strong, even if it is cast as one piece. A cylinder block having the rigidity and vibration characteristics of the same sugar is obtained. Furthermore, the welding between the cylinder and the upper and lower fixing plates and the welding between the lower fixing plate and the rail can be done without fitting the frame or in a bare state, so that it is reliable and easy.

After the cylinder part and the crankcase part are connected in this way, the frame body can simply be fitted into the cylinder part, so it is sufficient that the frame body is lightweight enough to withstand the water pressure of the cooling water. Moreover, watertightness between the upper and lower fixing plates can be achieved by simple packing, and production is also extremely easy by molding.

Furthermore, with this idea, for multiple types of engines that have the same basic structure but slightly different displacements, only the cylinder section can be manufactured to match each engine, while the crankcase section can be made common. It's easy. Regarding the cylinder part, by changing only the large holes of the cylinder and the upper and lower fixing plates, the frame body can also be made common, which is advantageous for improving productivity and reducing costs. Furthermore, those skilled in the art can easily understand that this invention can be applied not only to single-cylinder engines but also to V-type engines, opposed piston engines, and the like.

To explain the example with some additional information, the second
The upper fixing plate 22 shown in the figure has a rectangular circumference 26 and a nut 29 welded to the inside of the hem 24. A design can be adopted in which this ring is recessed in a wave shape toward the large hole 25 at the position of the nut, and the nut is welded to the recess, that is, to the outside of the recessed hem. With this design, the rigidity of the upper fixing plate itself is further increased, and the elastic strain generated by tightening the cylinder head is reduced, which in turn reduces the elastic strain of the cylinder. Also, with this design, packing 6
For 0, it is necessary to create a wave-shaped protrusion to match the hem, but this can be easily done because it is molded. Also,
The lower fixing plate 31 shown in FIG. 4 may have a flat plate shape, or may be designed to have a hem formed by drawing it like the upper fixing plate to increase its rigidity.

Furthermore, when the above-mentioned nuts are welded to the lower fixing plate instead of the upper fixing plate (in FIG. 4, only two are illustratively drawn as 34 in imaginary lines) and a long tension bolt is used, The cylinder portion 20 receives compressive force in the direction of the axis of the cylinder and can increase its rigidity. If the tension bolt is erected as a stud bolt on the ceiling 41 of the crankcase section 40, an even stronger structure of the engine as a whole with the cylinder head tightened can be realized.

The joining of the cylinders by welding the small pieces 21A of steel plates in FIG. 3 increases the torsional rigidity of the cylinder, but the position and number of the small pieces can be arbitrarily selected. If instead of a small piece, we use a piece that has the same shape as the lower fixing plate 31 but only the circumference is smaller than that, it would mean that a hoop was fitted into the cylinder even at a position midway between the upper and lower fixing plates. This also has the effect of further suppressing deformation and vibration of the cylinder.

In this embodiment, the rails 45 are frame-shaped with a rectangular overall shape, but rails 45 may be provided only on the left and right sides parallel to the axis 44 of the crankshaft. In this case, there is an advantage that not only the rail itself can be machined, but also the upper surface 43 of the ceiling part 41 which is sandwiched between the rails and which is the contact surface of the lower fixing plate 31 can be machined with high precision. The seating condition of the cylinder part 20 with respect to the part 40 becomes extremely good. Furthermore, in this embodiment, the frame body 5
0 used a thin steel plate, but it may also be molded from a resin material that has heat resistance and appropriate elasticity. In this case, there is an advantage that the upper packing 60 and the lower packing 70 are extremely simple or can be omitted.

[Brief explanation of drawings]

The figure shows one embodiment of the invention, and Fig. 1 shows the second embodiment.
A vertical cross-sectional view of the cylinder block taken along the plane II in the figure, and FIGS. 2 to 5 are perspective views of the upper fixing plate, the cylinder, the lower fixing plate, and the frame, respectively. 21... Cylinder, 22... Upper fixing plate, 31
... Lower fixing plate, 20 ... Cylinder part, 40 ...
Crankcase part, 45...rail, 50...frame, 60...packing, 70...packing,
10...Cylinder block.

Claims (1)

[Scope of utility model registration request] A cylinder made of a steel plate, an upper fixed plate made of a steel plate fixed to the upper end of the cylinder, extending in a plane perpendicular to the axis of the cylinder and having a circumference larger than the outer circumference of the cylinder, and a lower part of the cylinder. A lower fixing plate made of a steel plate fixed to the upper fixing plate and extending in a plane parallel to the upper fixing plate and having a circumference larger than the outer circumference of the cylinder is coupled to a crankcase part made of a light alloy. In the cylinder block for a water-cooled reciprocating piston engine, the lower fixing plate is welded and connected to a rail made of iron material cast and fixed to the crankcase portion, and the upper fixing plate and the lower fixing plate A frame body that straddles the plates and surrounds both fixing plates is fitted into the cylinder part, and packings made of a resin elastic material are respectively clamped between the frame body and the upper fixing plate and the lower fixing plate. A cylinder block for a water-cooled reciprocating piston engine.