JPH05332196A - Water jacket structure for engine - Google Patents

Abstract

PURPOSE:To reduce radiation noise from a cylinder by parallelly arranging an engine main body and a transmission to each other and integrally to an engine housing. CONSTITUTION:A water jacket wall 52 is arranged continuingly to a mission case 18b which houses a transmission 15, which water jacket wall 52 is provided on an outer periphery of a cylinder of an engine main body 11 in an engine housing 18. Interruption performance of the mission case is thus utilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine water jacket structure in which an engine body and a transmission are integrally installed in a common engine housing.

[0002]

2. Description of the Related Art Conventionally, when an engine is mounted on a vehicle, for example, as disclosed in Japanese Patent Laid-Open No. 1-36553, the engine main body is placed horizontally, and the engine main body is placed parallel to the rear side of the engine main body. A structure in which a transmission and a differential device are installed in the vehicle is known.

[0003]

However, when the drive system such as the transmission or the differential device is installed in parallel with the crankshaft of the engine body as in the above-mentioned prior example, the entire engine is formed compactly, When the water jacket is made thin, there is a problem that engine noise increases, which is an obstacle to weight reduction.

That is, in a water jacket of a normal engine, a cylinder liner is cast by a base material of a cylinder block and a cooling water passage is formed on the outer periphery of the cylinder liner to form a relatively large thickness of the water jacket. Although the combustion noise and cooling water flow noise are prevented from being propagated to the outside at some parts, from the viewpoint of reducing the weight of the engine or increasing the cooling effect, for example, the water jacket is used to directly cool the cylinder liner. If the thickness is made thin, the externally radiated sound becomes large and the engine noise increases.

In view of the above circumstances, the present invention provides a water jacket structure for an engine, which reduces the noise emitted from the water jacket by utilizing a structure in which the engine body and the transmission are integrated in parallel. The purpose is.

[0006]

In order to achieve the above object, in a water jacket structure for an engine of the present invention, an engine body and a transmission are arranged in a common engine housing so that a crank shaft and a transmission shaft are parallel to each other. In addition, the engine housing is configured by connecting a water jacket wall on the outer circumference of the cylinder of the engine body, a transmission case portion that houses the transmission and covers the engine body from above to below.

[0007]

In the engine water jacket structure as described above, the water jacket wall and the transmission case portion accommodating the transmission are connected to each other, and the engine body and the transmission are arranged in the common engine housing. By covering the jacket with this mission case, the radiation noise to the outside can be absorbed and blocked, and engine noise can be reduced. This simplifies the structure of the water jacket and, for example, directly cools the cylinder liner with cooling water. The structure can be adopted to reduce the weight of the engine and improve the cooling performance.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic side structure of an engine having a water jacket structure according to an embodiment. In this example, a lateral FF engine is shown, and the vehicle is mounted so that the left side of the drawing is the front of the vehicle. 2 is a front view seen from diagonally above in FIG. 1, and FIG. 3 is a sectional view taken along line AA in FIG.

The engine 10 has an engine body 11 having a cylinder head 12 and a drive system 17 including a transmission 15 and a differential device 16 arranged in an engine housing 18 which is integrated. The engine body 11 has a crankshaft 21 installed along the lateral direction of the vehicle, and an upper portion of the engine body 11 is inclined rearward. Further, balancer shafts 22 and 23 are arranged on the engine body 11 at both upper sides of the engine housing 18 for the purpose of reducing engine vibration. On the other hand, behind the engine body 11, the transmission shaft 24 of the transmission 15 is parallel to the crank shaft 21.
And a drive shaft 25 (differential shaft) extending from the differential device 16 to both sides.

The engine housing 18 comprises a front crankcase portion 18a forming a cylinder block portion of the engine body 11 and a rear transmission case portion 18b for accommodating the drive system 17, and the engine housing 18 Is linearly divided vertically into a main housing 19 and a lower housing 20 at a position passing through the center of the crankshaft 21, and an oil pan 26 is attached to a lower portion of the lower housing 20. Main housing 19 and lower housing 20 above
The bearing portion 27 of the crankshaft 21 is formed on the split mating surface with the bearing surface 29, and the bearing portion 29 of the drive shaft 25 of the drive system 17 is formed on the rear side so as to support the respective rotary shafts. Has been done.

That is, the upper surface of the lower housing 20 is, as shown in FIG. 3, a crankcase portion 18a having bearing portions 27 for supporting the crankshaft 21 of the engine body 11 at both ends and between the cylinders, and a gear of the transmission 15. A lower portion of the row portion and a mission case portion 18b surrounding the lower half of the differential device 16 are integrally formed, and a lower surface thereof is formed in an opening shape smaller than an opening portion of the upper surface and conforming to the upper surface shape of the oil pan 26. The bottom surface of the oil pan 26 is formed such that the front portion is deep and the rear portion is shallow, and the lower surface is formed to be a substantially horizontal surface in the mounted state.

Further, at one end of the engine body 11,
A clutch 31 is arranged in an extension portion of the crankshaft 21, and an output of the clutch 31 is input to a transmission shaft 24 of the transmission 15 via an outer gear 32 (see FIG. 3).
The output after shifting is output to drive the front wheels from the drive shafts 25 on both sides which extend laterally in the lower rear part through the differential device 16. When driving the rear wheels, a center differential may be arranged adjacent to the differential device 16 (front differential), and a propeller shaft may be installed from the center differential to the rear via a transfer. Is.

Further, the engine 10 is provided with various auxiliary machines. This accessory is mainly arranged in the left side portion of the oil pan 26 where there is a space in the side portion, and is a belt hung from the crank pulley 21a fixed to the end of the crankshaft 21. Driven by 36. That is, in the front part of the engine housing 18, an alternator 37 is installed in the upper part and a water pump 38 is installed in the lower part, and an air conditioner compressor 39 is installed in the lower center part of the engine housing 18, and the respective pulleys 37 are installed.
The belt 36 is wound around a to 39a and driven. An idler 40 is provided between the crankshaft 21 and the air conditioner compressor 39. Further, a pipe 41 for supplying cooling water is connected from the water pump 38 to approximately the center of the upper part of the engine housing 18 (cylinder block) of the engine body 11.

On the other hand, from the crankshaft 21, the camshaft 43 above the cylinder head 12 and the engine housing
18 A transmission mechanism for driving the balancer shafts 22 and 23 on the upper part is formed. That is, first, the intermediate shaft 45 is driven from the crankshaft 21 by the first chain 44, the camshaft 43 above the intermediate shaft 45 is decelerated by the second chain 46, and the balancer below the intermediate shaft 45 is driven. Axis 2
The second chain 23 and the second chain 23 are configured to be accelerated and driven.

A clutch 31 is installed on the right side of the engine housing 18.
An oil pump 50 is installed below the oil pan 26 on the side of the oil pan 26, and supplies the oil in the oil pan 26 to each part.

Next, as shown in the sectional structure of the water jacket portion in FIG. 4, the water jacket for cooling the cylinder of the engine body 11 is formed as a wet liner structure in which the back surface of the cylinder liner 51 comes into direct contact with cooling water. Has been done.

That is, a cylinder-shaped cylinder liner 51 is inserted into a bore portion of each cylinder with respect to a crankcase portion 18a of an engine housing 18 which constitutes a cylinder block of the engine body 11. A water jacket wall 52 is formed so as to be connected, and a cooling water passage 53 (water jacket) is formed inside the water jacket wall 52. Further, at the rear portion of the engine body 11, the water jacket wall 52 is integrally connected to the front portion side of a transmission case portion 18b that houses the transmission 15. Then, on the front side of the engine body 11, one balancer shaft 22 is disposed under the water jacket wall 52, and on the rear side of the engine body 11, the mission case portion 18b in the upper part of the water jacket wall 52 is formed. The other balancer shaft 23 is disposed at the connection part of the.

In the structure of the water jacket wall 52, a thin cylindrical space liner cooling water passage 53a is formed so as to surround the outer circumference of the cylinder liner 51, and the liner of each cylinder is provided on the front side of the engine body 11. A communication cooling water passage 53b is formed which communicates with the cooling water passage 53a, and the communication cooling water passage 53b is formed.
A cooling water pipe 41 from the water pump 38 is connected to the cooling water introduction port 53c formed in the above to supply the cooling water. On the other hand, a collecting passage 53d is formed on the rear side of the engine body 11 so as to communicate with the liner cooling water passage 53a, and the collecting passage 53d and the mission side cooling water passage 54 formed in the mission case portion 18b communicate with each other through the communication port 53e. Are connected via.

The transmission side cooling water passage 54 has a double-layer outer peripheral wall extending from the main housing 19 of the engine housing 18 to the transmission case 15b of the lower housing 20 and surrounding the transmission case portion 18b surrounding the differential device 16. It is formed inside it.

The cooling water pipe 41 is connected to the center of the engine body 11 in the longitudinal direction, and introduces cooling water from the inlet 53c to the liner cooling water passage 53a of each cylinder on both sides by the communication cooling water passage 53b. At the same time, the cooling water is supplied to the cylinder head 12 side from the communication port 53f opened on the upper end surface. The cooling water flowing into the liner cooling water passage 53a flows on the outer periphery of the cylinder liner 51 toward the rear side of the engine body 11 and flows into the collecting passage 53d. Then, it flows into the mission side cooling water passage 54 formed over the entire circumference of the mission case portion 18b from this collecting passage 53d, and cools the drive system 17 having low cooling performance by the traveling cooling air. In particular, the communication port 54e from the collecting passage 53d to the mission side cooling water passage 54 is also formed substantially at the center in the longitudinal direction.

Incidentally, the main housing 19 and the lower housing of the engine housing 18 on the center side of the engine
A cooling water passage 55 is also formed at the connecting portion between the crankcase portion 18a and the transmission case portion 18b at the connecting portion with the cooling water passage 20.

Due to the above structure, the engine body 11
Side water jacket wall 52 and mission case section 18b
And the transmission case portion 18b covers the outer circumference of the cylinder to reduce the radiated sound. In particular, the transmission side cooling water passage 54 is also formed in the transmission case portion 18b to improve the sound insulation. As a result, the wet liner structure that directly contacts the cooling water to the cylinder liner 51 reduces the noise emitted to the outside even if the noise increases, and the adoption of the above wet liner structure realizes the reduction of weight and size. The cooling efficiency can be improved.

Further, the inflow of the cooling water by the cooling water pipe 42 and the inflow of the cooling water to the mission side cooling water passage 54 are performed substantially at the center in the longitudinal direction of the engine, so that the flowability of the cooling water as a whole is improved and The temperature rise due to stagnation can be improved, and the cooling performance can be improved.

[Brief description of drawings]

FIG. 1 is a schematic side view of an engine having a water jacket structure according to an embodiment of the present invention.

FIG. 2 is a schematic front view seen from diagonally above in FIG.

FIG. 3 is a cross-sectional view taken along line AA of FIG. 1 in which auxiliary machinery is omitted.

FIG. 4 is a side sectional view of a main part of a water jacket part.

[Explanation of symbols]

 10 engine 11 engine body 15 transmission 16 differential device 17 drive system 18 engine housing 18a crankcase part 18b mission case part 21 crankshaft 24 transmission shaft 25 drive shaft 51 cylinder liner 52 water jacket wall 53,54 cooling water passage

Claims (1)

[Claims] 1. An engine main body and a transmission are arranged in a common engine housing such that a crank shaft and a transmission shaft are parallel to each other, and the engine housing includes a water jacket wall around a cylinder of the engine main body and a transmission. And a transmission case portion that covers the engine body from above to below and is connected to the engine body.