JPH0234449Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a cylinder block structure for an engine equipped with a balancer shaft in which a balancer shaft case is integrally formed on the outer wall of the cylinder block.

(Prior art) In order to eliminate the vibrations of a reciprocating piston engine,
Engine cylinder block structures are already known in which a balancer shaft equipped with a balance weight is arranged parallel to the crankshaft, and a balancer shaft case for housing the balancer shaft is integrally formed on the outer wall of the cylinder block (for example, 57
-Refer to Publication No. 44863).

However, with the above cylinder block structure,
For example, in the case of a four-cylinder engine, the balancer shaft extends from the front end side to approximately the center of the cylinder block, so a raised portion of the balancer shaft case is formed on the outer wall of the cylinder block from the front end side to approximately the third cylinder. On the rear end side (fourth cylinder) of the block, that is, on the output shaft side, a space is created where the raised part of the balancer shaft case is missing. Therefore, the rigidity of the cylinder block is strengthened in the part of the balancer shaft case that has the raised part, but the rigidity is not strengthened in the space where the raised part is missing, which causes problems in terms of the strength of the cylinder block as a whole. be pointed out.

(Purpose of the invention) The present invention has been made in view of the above points, and its purpose is to attach the output shaft from the end face of the balancer shaft case to the outer wall of the cylinder block in the space where the raised part by the balancer shaft case is missing. This is an attempt to solve the problem regarding the strength of the cylinder block as a whole by providing reinforcing ribs extending in the direction of the cylinder block.

(Structure of the invention) The present invention to achieve the above object includes a balancer shaft case that is integrally formed on the outer wall of the cylinder block and that houses the balancer shaft in a manner that bulges outward. In the engine cylinder block structure formed to have a space without a raised part, a reinforcing rib is fixed to the outer wall of the cylinder block in the space so as to extend from the end face of the balancer shaft case in the output shaft direction. This is the cylinder block structure of the engine.

(Example) An example of the present invention will be described below based on the drawings.

In Figures 1 to 3, 1 is a cylinder block of a 4-cylinder reciprocating piston engine, 2 is a piston, 3 is a crankshaft, 4 is a connecting rod,
Reference numeral 5 denotes a balancer shaft that is arranged in parallel on both sides of the crankshaft 3, and forms a balance weight 6 having a fan-shaped cross section in the portion that spans the second and third cylinders. Reference numeral 7 denotes a partition wall between cylinders that is integrally formed in the cylinder block 1 and supports the crankshaft 3 and balancer shaft 5.

Reference numeral 8 designates a balancer shaft case for housing the balancer shaft 5, which has a raised portion integrally formed on the outer wall of the cylinder block 1 from its front end side to the third cylinder, and has a rear end surface 8a at its rear end.

9 is a space provided in the outer wall of the cylinder block 1 rearward in the direction of the output shaft of the balancer shaft case 8;
This is the missing part of the protrusion caused by the case 8.

Reference numeral 10 denotes a reinforcing rib made of a substantially triangular plate, which is fixed to the outer wall of the cylinder block 1 in the space 9 so as to extend in the output shaft direction with its vertical side aligned with the rear end surface 8a of the balancer shaft case 8. . Therefore, the reinforcing rib 10 is supported by the rear end surface 8a of the balancer shaft case 8 and reliably strengthens the rigidity of the outer wall of the cylinder block 1 in the space 9.

In addition, 11 is another auxiliary rib, which is the reinforcing rib 1.
It consists of a triangular plate similar to 0, but the space 9
It is arranged on the side of the cylinder block 1 quite far away from the cylinder block 1, and its vertical side is fixed to the rear end flange part 12 to which the clutch housing (not shown) of the cylinder block 1 is connected. It is useful for strengthening.

In addition, 13 is a cooling waterway, 14 is a cylinder, and 15
is the main bearing cap.

(Effects of the invention) According to the invention, in an engine cylinder block structure in which a balancer shaft case for storing a balancer shaft on the outer wall of the cylinder block is integrally formed by protruding outward, the above-mentioned balancer shaft case on the outer wall of the cylinder block Since reinforcing ribs are fixedly installed in the space formed in the direction of the output axis of the raised part where the raised part is missing, so as to extend from the end face of the balancer shaft case in the direction of the output shaft, the cylinder block in the space is fixed. This has the effect of increasing the rigidity of the outer wall and improving the strength problems of the cylinder block as a whole.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a cylinder block according to the present invention, Fig. 2 is a view taken in the direction of - arrow in Fig.
The figure is a sectional view taken along the line -- in FIG. 1... Cylinder block, 5... Balancer shaft, 8... Balancer shaft case, 8a...
Rear end surface, 9...space, 10...reinforcement rib.

Claims (1)

[Scope of utility model registration request] An engine cylinder block in which a balancer shaft case for storing a balancer shaft is integrally formed on the outer wall of the cylinder block with an outwardly raised balancer shaft case, and the case is formed so as to have a space where the raised part is missing in the direction of the output shaft. A cylinder block structure for an engine equipped with a balancer shaft, characterized in that a reinforcing rib is fixed to the outer wall of the cylinder block in the space so as to extend from the end face of the balancer shaft case in the direction of the output shaft.