JPH05180071A - Cylinder block structure for engine - Google Patents

Abstract

PURPOSE:To improve rigidity without impeding lightness in weight of a power plant even in the case of providing a lower block, which constitutes a cylinder block of an engine, integrally with a case of a transmission, in the power plant formed by parallelly arranging the engine and the transmission. CONSTITUTION:A pair of vertical wall parts 41, 42 opposed to each other are provided by interposing a space part 40, into which a lower block 6 is recessed, in a reverse surface side of the lower block 6 and in a transmission side of crankshaft bearing parts 39, 39. These vertical wall parts 41, 42 are connected by a 2-sheet set of reinforcing ribs 43, 44 in a position adjacent to the crankshaft bearing part 39, and also a space between these reinforcing ribs 43, 44 is gradually spread from an engine side toward the transmission side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine cylinder block structure, and more particularly to an engine cylinder block structure in a power plant in which an engine and a transmission are arranged in parallel.

[0002]

2. Description of the Related Art As a power plant including an engine and a transmission connected to the engine, for example, Japanese Patent Laid-Open No. 63-103 is known.
As described in Japanese Patent Publication No. 735/735, the engine and the transmission are arranged in parallel, the axis of the transmission (main shaft) is located in front of the center line of the differential gear, and the axis of the engine (crankshaft). There is known a power plant of a type in which the center line of the differential gear is arranged on or behind the center line of the differential gear. According to this power plant, the load distribution of the front wheels is improved and the steering characteristics are improved, and since the engine and the transmission are arranged in parallel, the power plant of the power plant can be compared to the case where both are arranged in series. The overall length is shortened, and the layout property is improved.

[0003]

By the way, in the power plant in which the engine and the transmission are arranged in parallel as described above, the lower block forming the cylinder block of the engine is provided integrally with the case of the transmission. There is. By using the lower block as the case of the transmission as described above, the number of parts is reduced, but the following problems occur.

That is, in recent years, there has been a strong demand for reducing the weight of the engine or power plant, and the lower block of the engine has also been reduced in weight by reducing the thickness thereof. In this case, for example, if a valley portion is provided on the bottom surface side of the lower block at the boundary between the engine side and the transmission side, excess extraneous meat is scraped off by that amount, and weight reduction is promoted. Will be. However, since a bending load due to the rotational phase difference between the engine and the transmission acts on the above-mentioned boundary part, the rigidity is conversely insufficient due to the provision of the trough for weight reduction. Become.

The present invention addresses the above-mentioned problems in a power plant in which an engine and a transmission are arranged in parallel. When the lower block forming the cylinder block of the engine is provided integrally with the transmission case. Also in this, it aims at improving rigidity, without inhibiting weight reduction of a power plant.

[0006]

That is, a cylinder block structure of an engine according to claim 1 of the present application is a lower block which constitutes a cylinder block of an engine in a power plant in which an engine and a transmission are arranged in parallel. The lower case is integrally provided with a transmission case, and a pair of longitudinally facing each other with a cavity in which the lower block is recessed is provided on the back side of the lower block between the engine forming section and the transmission forming section. It is characterized in that a wall is provided and a reinforcing rib is provided so as to extend between the vertical wall portions.

The engine cylinder block structure according to claim 2 of the present application is such that, in a power plant in which an engine and a transmission are arranged in parallel, a transmission case is mounted on a lower block constituting the engine cylinder block. Provided integrally, on the back surface side between the engine constituent portion and the transmission constituent portion of the lower block, a pair of vertical wall portions facing each other with a space in which the lower block is recessed is provided, One set of two reinforcing ribs is provided across these vertical wall portions, and the space between these reinforcing ribs is widened from the engine side toward the transmission side. ..

Further, in the cylinder block structure of the engine according to claim 3 of the present application, in the structure of claim 2, the engine-side vertical wall portion between the reinforcing ribs is provided so as to be inclined more than the transmission-side vertical wall portion. It is characterized by

According to a fourth aspect of the cylinder block structure for an engine of the present application, in a power plant in which an engine and a transmission are arranged in parallel, a transmission case is mounted on a lower block constituting the engine cylinder block. It is characterized in that it is integrally provided, and an engine accessory is attached to the bottom surface of the lower block, and a rib is provided on the upper surface side of the attachment portion of the engine accessory in the block.

[0010]

That is, according to the first to third aspects of the invention, the lower block is opposed to each other with the cavity in which the lower block is recessed on the back side between the engine component and the transmission component in the lower block. Since a pair of vertical wall portions are provided and reinforcing ribs are provided across these vertical wall portions, a box-shaped space is formed by both vertical wall portions and adjacent reinforcing ribs. Therefore, the bending rigidity of the boundary portion between the engine side and the transmission side in the lower block is improved. As a result, it is not necessary to unnecessarily increase the thickness of the boundary portion, and the weight reduction and strength of the lower block are compatible with each other at a high level, which in turn improves the rigidity of the engine or power plant. ..

According to the second aspect of the invention, the distance between the pair of reinforcing ribs provided between the engine-side vertical wall portion and the transmission-side vertical wall portion of the lower block is changed from the engine side. Since it is expanded toward the machine side, the box-shaped space formed by the vertical wall portion and the reinforcing rib has a substantially trapezoidal shape, which improves the bending rigidity of the lower block without anisotropy.

Further, according to the third aspect of the invention, the vertical wall portion on the engine side between the pair of reinforcing ribs facing each other is more inclined than the vertical wall portion on the transmission side. Even if the interval between the wall portions is small, the cross-sectional area is secured and the strength of the relevant portion is not impaired.

On the other hand, according to the fourth aspect of the invention, the case of the transmission is integrally provided on the lower block which constitutes the cylinder block of the engine, and the engine accessory is attached to the bottom surface of the lower block. By providing a rib on the upper surface side of the attachment part of the engine auxiliary machine in, while lowering the overall thickness of the lower block,
It is possible to avoid lowering the rigidity of the lower block due to the attachment of engine accessories.

[0014]

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

As shown in FIG. 1, an engine 1 according to this embodiment constitutes a power plant 3 integrally with a transmission 2 arranged at the rear part thereof, and this power plant 3 is as shown in the figure. The cylinder head 4 is installed so as to slant backward.

Between the upper block 5 and the lower block 6 constituting the power plant 3, a crankshaft 7 of the engine 1 is arranged in the orthogonal direction on the front side thereof, and at the rear of the crankshaft 7. At the position, the transmission output shaft 8 is arranged in parallel with the crankshaft 7. An oil pan 9 common to the engine 1 and the transmission 2 is connected to the lower surface of the lower block 6. An oil filter element 10 and a thermostat 11 are attached to the front side of the oil pan 9.

Further, a surge tank 12 is arranged at a side position on the side opposite to the transmission side of the power plant 3 close to the lower block 6. Then, a plurality of independent intake pipes 13 ... 1 connected to the surge tank 12
13 is connected to a cylinder head 4 installed in the upper part of the upper block 5 in a state of being curved forward, and in the space portion 14 formed between the intake pipes 13 ... 13 and the upper block 4, A throttle valve body 15 for adjusting the amount of intake air flowing into the surge tank 12 is arranged.

The power plant 3 includes a crankshaft 7
A compressor 16 for air conditioning is provided below the engine, and an alternator 17 is also provided at a lateral position on the transmission side with respect to the crankshaft 7. The alternator 17 and the compressor 16 are provided respectively. The driven pulleys 18 and 19 provided and the crankshaft 7
A transmission belt 21 made of rubber is stretched between the crank pulley 20 and the crank pulley 20 attached to the protruding end. An idler 22 is disposed between the compressor 16 and the alternator 17 at a position close to the crank pulley 20, and the transmission belt 21 is wound around the idler 22 on the crank pulley side.

An automatic tensioner 23 for automatically adjusting the tension of the transmission belt 21 is arranged above the crankshaft 7, and a tension pulley 24 provided on this automatic tensioner 23 is used for the crankshaft 7 and the alternator. The transmission belt 21 is elastically biased downward between the transmission belt 21 and the transmission belt 17. Here, assuming that the crankshaft 7 rotates in the clockwise direction in the figure, the above-mentioned auto tensioner 2
The third tension pulley 24 is arranged on the tension loosening side of the transmission belt 21.

A crankshaft sprocket 25 for driving a camshaft is fixed to the crankshaft 7 at the inner side of the crank pulley 20, and the crank sprocket 25 and the cylinder head 4 are rotatably supported by the shaft. A first chain 27 for power transmission is wound between the supported first intermediate sprocket 26, a second intermediate sprocket 28 having a small diameter that rotates integrally with the first intermediate sprocket 26, and a camshaft. A second chain 33 is wound around the camshaft drive sprockets 31 and 32 which are fixedly mounted on 29 and 30, respectively.

Here, as shown in FIG. 2, an oil pan 9 is attached to the transmission-side bottom surface of the lower block 6 from a position close to the clutch housing 34 to an intermediate position in the crankshaft direction. The compressor 16 is attached to one end side where the oil pan 9 is not attached. The compressor 16 is fixed to the lower block 6 by mounting flanges 35 to 35 provided at four corners of the main body as shown in FIG. Therefore, as shown in FIG. 4, bolt holes 36 to 36 for fixing the compressor 16 are formed on the rear surface side of the lower block 6 at positions corresponding to the mounting flanges 35 to 35. Ribs 38 to 38 are provided on the bottom wall 37 of the lower block 6 so as to be located above the compressor 16. As a result, the lower block 6 is prevented from being deformed even when the load of the compressor 16 acts, and the lower block 6 is prevented.
The rigidity is secured even if the overall thickness and weight are reduced.

Further, on the back surface side of the lower block 6, as shown in FIG. 4, the lower block 6 is located on the transmission side of the crankshaft bearing portions 39, 39, and the space 40 in which the lower block 6 is recessed is sandwiched therebetween. A pair of facing vertical wall portions 41, 4
Two are provided. These vertical wall portions 41, 42 are connected by a pair of reinforcing ribs 43, 44 at a position close to the crankshaft bearing portion 39, and the distance between these reinforcing ribs 43, 44 is on the engine side. It gradually expands from the transmission side. As shown in FIG. 5, the engine-side vertical wall portion 41 is provided so as to be inclined more than the transmission-side vertical wall portion 42 in the space 43, 44 between the reinforcing ribs. As a result, the cross-sectional area is secured even if the space between the vertical wall portions 41 is small, and the strength of that portion is not impaired.

In this way, a pair of vertical wall portions 41, 42 facing each other with the space 40 interposed therebetween on the back surface side of the lower block 6.
Is provided, and these vertical wall portions 41 and 42 are connected by two sets of reinforcing ribs 43 and 44, so that the reinforcing rib 4 is formed.
A box-shaped space is formed by 3, 44 and the vertical wall portions 41, 42, and good rigidity can be obtained even though the space 40 is provided between the engine 1 and the transmission 2. It will be.

In particular, as in the embodiment, a pair of reinforcing ribs 4
The rigidity of the lower block 6 is improved without anisotropy by widening the gap between the engine 3 and 44 from the engine 1 side toward the transmission 2 side.

[0025]

As described above, according to the first to third aspects of the present invention, the lower block is provided with a cavity in which a lower block is recessed on the back surface side between the engine component and the transmission component of the lower block. While providing a pair of vertical wall portions that sandwich each other,
Since the reinforcing ribs are provided across these vertical wall portions, a box-shaped space is formed by both the vertical wall portions and the reinforcing ribs adjacent to each other. And the bending rigidity of the boundary portion on the transmission side is improved. As a result, it is not necessary to unnecessarily increase the thickness of the boundary portion, and the weight reduction and strength of the lower block are compatible with each other at a high level, which in turn improves the rigidity of the engine or power plant. ..

According to the second aspect of the invention, the distance between the pair of reinforcing ribs provided between the engine-side vertical wall portion and the transmission-side vertical wall portion of the lower block is changed from the engine side. Since it is expanded toward the machine side, the box-shaped space formed by the vertical wall portion and the reinforcing rib has a substantially trapezoidal shape, which improves the bending rigidity of the lower block without anisotropy.

Further, according to the third aspect of the invention, the vertical wall portion on the engine side between the pair of reinforcing ribs facing each other is inclined more than the vertical wall portion on the transmission side. Even if the interval between the wall portions is small, the cross-sectional area is secured and the strength of the relevant portion is not impaired.

On the other hand, according to the structure of claim 4, the case of the transmission is integrally provided on the lower block which constitutes the cylinder block of the engine, and the engine auxiliary equipment is attached to the bottom surface of the lower block, and the block is formed. By providing a rib on the upper surface side of the attachment part of the engine auxiliary machine in, while lowering the overall thickness of the lower block,
It is possible to avoid lowering the rigidity of the lower block due to the attachment of engine accessories.

[Brief description of drawings]

FIG. 1 is a front view of a power plant according to an embodiment.

FIG. 2 is a side view showing a configuration of a lower block and its periphery.

FIG. 3 is a plan view of a lower block alone taken along line AA of FIG.

FIG. 4 is a bottom view of the lower block alone cut along the line BB in FIG.

5 is a cross-sectional view of the lower block taken along the line CC of FIG.

[Explanation of symbols]

 1 Engine 2 Transmission 3 Power Plant 6 Lower Block 16 Compressor 37 Bottom Wall 38 Rib 41 Vertical Wall Part 42 Vertical Wall Part 43 Reinforcing Rib 44 Reinforcing Rib

Claims (4)

[Claims] 1. A cylinder block structure of an engine in a power plant in which an engine and a transmission are arranged in parallel, wherein a lower case constituting the cylinder block of the engine is integrally provided with a case of the transmission. , A pair of vertical wall portions facing each other across a cavity in which the lower block is recessed is provided on the back surface side between the engine component and the transmission component in this lower block, and these A cylinder block structure for an engine, wherein reinforcing ribs are provided across the vertical wall portions. 2. A cylinder block structure of an engine in a power plant, in which an engine and a transmission are arranged in parallel, wherein a transmission case is integrally provided on a lower block constituting the cylinder block of the engine. , A pair of vertical wall portions facing each other across a cavity in which the lower block is recessed is provided on the back surface side between the engine component and the transmission component in this lower block, and these One set of two reinforcing ribs is provided across the vertical wall portion, and a space between the reinforcing ribs is widened from the engine side toward the transmission side. Engine cylinder block structure. 3. The cylinder block structure for an engine according to claim 2, wherein the vertical wall portion on the engine side between the reinforcing ribs is provided so as to be inclined more than the vertical wall portion on the transmission side. 4. A cylinder block structure of an engine in a power plant, in which an engine and a transmission are arranged in parallel, wherein a transmission case is integrally provided on a lower block constituting the cylinder block of the engine. A cylinder block structure of an engine, wherein an engine accessory is attached to a bottom surface of the lower block, and a rib is provided on an upper surface side of an attachment portion of the engine accessory in the block.