JP2001115836A - Main unit structure for water-cooled engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve forming into compactness of an engine and cooling performance of the total unit. SOLUTION: A water pump storage recessed part 54 storing partly or fully a water pump 1 is formed to one sideward in the front surface of a cylinder block 50, a thermostat storage recessed part 53 storing a thermostat is formed adjacently to the water pump storage recessed part 54 in a side wall in one sideward of the cylinder block 1. A heater return passage 51 from a heater 2 communicating with a cooling water passage extended from one side to the other sideward in the front surface of the cylinder block 50 from the thermostat storage recessed part 53 over to the water pump storage recessed part 54 is formed under a water jacket 56 in a cylinder height H1 in the front surface of the cylinder block 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a body structure of a water-cooled engine, and more particularly to a cooling water passage structure for circulating cooling water.

[0002]

2. Description of the Related Art As a main body structure of a conventional water-cooled engine, for example, Japanese Utility Model Publication No. Hei 5-13944, a water pump housing recess and a thermostat housing recess are provided on one side of the front surface of a cylinder block. Is disclosed.

[0003]

However, in the above prior art, the cooling water passage to the heater is formed by connecting another pipe line to the water jacket, so that the engine is not sufficiently compact, and Since the cooling water passage to the heater is separate, there is also a problem that the passage cannot be shortened and the amount of cooling water cannot be reduced.

The present invention has been made in view of the above problems, and has as its object to reduce the size of the engine, shorten the cooling water passage, reduce the amount of cooling water, and further improve the heat dissipation in the storage case of the endless transmission member. The object is to provide a body structure of a water-cooled engine to be enhanced.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems and achieve the object, the main structure of the water-cooled engine of the present invention has the following configuration. That is, a first recess for accommodating at least a part of the water pump is provided near one side of the front surface of the cylinder block, and a second recess for accommodating a thermostat adjacent to the first recess on one side wall of the cylinder block. And a water pump suction side of the first recess communicates with the second recess, while a cover case of an endless transmission member for driving a camshaft is fastened to the front surface of the cylinder block. The depth of the water jacket formed on the outer periphery of the cylinder on the front surface of the cylinder block is set to the middle of the cylinder height, and the other side of the front surface of the cylinder block is located below the water jacket in the cylinder height section on the front surface of the cylinder block. From the heater extending from the second recess and connected to a cooling water passage extending from the second recess to the first recess. It provided with a passage.

Preferably, the depth of the water jacket on one side of the cylinder block is substantially the same as the depth of the water jacket on the front surface of the cylinder block, and the lower side of the water jacket in the cylinder height section,
Further, a radiator bypass passage extending from the rear side of the cylinder block to the second concave portion is provided at a height position of the second concave portion.

[0007] Preferably, a connection portion of an external pipe for introducing cooling water with a small circulation amount is provided at the uppermost position of the thermostat case or the second concave portion fastened to the cylinder block.

Preferably, the engine is placed laterally with respect to the vehicle body such that the direction of the cylinders is aligned with the axle direction, and the front side of the vehicle is located on one side of the front surface of the cylinder block, and is disposed on the front side of the vehicle. The radiator and the thermostat case were connected, and the heater disposed on the vehicle rear side of the engine and the other side of the return passage were connected.

[0009] Preferably, a blow-by gas recirculation passage is provided adjacent to the radiator bypass passage so as to intersect the radiator bypass passage in a vertical direction.

[0010]

As described above, according to the first aspect of the present invention, the depth of the water jacket formed on the outer periphery of the cylinder on the front surface of the cylinder block is set to halfway of the cylinder height, and the cylinder height on the front surface of the cylinder block is reduced. By providing a return passage from a heater extending from the other side of the front surface of the cylinder block and connected to a cooling water passage extending from the second concave portion to the first concave portion below the water jacket in the section, the engine is made compact. In addition to shortening the cooling water passage and reducing the amount of cooling water, the heat dissipation in the storage case of the endless transmission member can be enhanced, and the cooling performance of the entire engine can be improved.

According to the second aspect of the present invention, the depth of the water jacket on one side of the cylinder block is substantially equal to the depth of the water jacket on the front surface of the cylinder block. By providing a radiator bypass passage extending from the rear side of the cylinder block to the second recess at the height of the recess, the engine can be made compact, the cooling performance of the entire cylinder block can be improved, the cooling water passage can be shortened, and the amount of cooling water can be reduced. Can be reduced.

According to the third aspect of the present invention, the thermostat case fastened to the cylinder block or the uppermost portion of the second recess is provided with a connection portion of an external pipe for introducing cooling water having a small circulation amount. The suction side of the concave portion is arranged to be offset downward with respect to the second concave portion, so that the air staying in the concave portion can be discharged from the connection portion at the time of initial cooling water introduction.

According to the fourth aspect of the present invention, the engine is placed laterally with respect to the vehicle body such that the direction of the cylinders is aligned with the axle direction, and the front side of the vehicle is defined as one side of the front surface of the cylinder block.
By connecting the radiator and thermostat case arranged on the vehicle front side, and connecting the heater arranged on the vehicle rear side of the engine and the other side of the return passage,
It is possible to shorten the cooling water passage and reduce the amount of cooling water for the entire vehicle.

According to the fifth aspect of the present invention, a blow-by gas recirculation passage vertically intersecting with the radiator bypass passage is provided adjacent to the radiator bypass passage, thereby forming the radiator bypass passage. The rigidity of the part can be increased.

[0015]

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

FIG. 1 is a cooling water system diagram of a water-cooled engine according to an embodiment of the present invention. FIG. 2 is a side view of the water-cooled in-line four-cylinder engine according to the present embodiment as viewed from the cylinder row direction. FIG. 3 is a sectional view taken along line II of FIG. FIG. 4 is a side view of FIG. 2 viewed from the X direction. FIG. 5 is a partial cross-sectional view of the water-cooled in-line four-cylinder engine of the present embodiment as viewed from the cylinder row direction. FIG. 6 is a detailed sectional view of the front surface of the cylinder block of FIG. [Description of Cooling Water Circulation Path] As shown in FIG. 1, the water-cooled in-line four-cylinder engine of the present embodiment has one side (the radiator 4 side) on the front side (front side) of the cylinder block 50.
, A water pump 1 is provided.

The cooling water discharged from the water pump 1 circulates through the water jacket inside the cylinder block 50 and rises up to the water jacket inside the cylinder head (not shown), and flows on the rear surface (rear side) of the cylinder head.
From the heater 2, the radiator 4 or the radiator bypass passage 52, the idle speed control valve (ISC
Valve 5) and the oil cooler 6 return to the thermostat storage recess 53 for storing at least a part of the thermostat 3 and are sucked into the water pump 1 to circulate the same path again.

The cooling water circulating to the heater 2 flows from the upstream heater passage 2a communicating with the cooling water passage outlet at the rear surface of the cylinder head to the heater 2, and from the heater 2 to the downstream heater passage 2b to the front of the cylinder block 50. From the heater return passage 51 formed, the thermostat storage recess 5 is formed.
3 and returns to the thermostat downstream passage 54.

The heater return passage 51 communicates with the thermostat downstream passage 54 formed on one side wall from the other side wall on the other side of the front surface of the cylinder block 50.

When the water pump 1 is driven, cooling water is always circulated to the heater 2 regardless of whether the heater 2 is on or off.

The cooling water circulating to the ISC valve 5 is used to prevent the valve from freezing when the outside air is low.
a flows from the upstream ISC passage 5a branching from a to the ISC valve 5 (exactly, in the vicinity of the ISC valve 5).
The valve 5 returns to the space above the thermostat housing recess 53 through the downstream ISC passage 5b.

The cooling water circulating to the oil cooler 6 is used for oil cooling in a very hot area where the outside air temperature is high.
SC passage 5a (or upstream bypass passage 52a to be described later)
Flows from the upstream oil cooler passage 6a branched from the oil cooler 6 to the oil cooler 6, passes through the oil cooler passage 6b from the oil cooler 6, and is inserted into the thermostat housing recess 53 with the thermostat 3 interposed therebetween. Return to passage 66.

The cooling water circulating to the radiator 4 flows from the upstream radiator passage 4a communicating with the cooling water passage outlet on the rear surface of the cylinder head to the radiator 4, is cooled by the radiator 4, passes through the downstream radiator passage 4b, and enters the thermostat cover. It returns to the thermostat upstream passage 66 in 65.

A radiator bypass passage 52 is formed in the other side wall of the cylinder block 50 in the cylinder row direction, and cooling water flowing from a cooling water passage outlet on the rear surface of the cylinder head is supplied to the upstream side radiator passage 4a through a part of the upstream side radiator passage 4a. The water flows from the passage 52a through the radiator bypass passage 52 to the thermostat storage recess 53.

When the temperature of the cooling water in the thermostat housing recess 53 is equal to or lower than a predetermined temperature, the thermostat 3 closes the passage leading from the downstream radiator passage 4b to the water pump 1 and opens the radiator bypass passage 52 of the thermostat housing recess 53. By opening the section, the cooling water is circulated from the cooling water outlet on the rear surface of the cylinder head to the radiator 4, and the cooling water is circulated through the radiator bypass passage 52 to circulate the cooling water inside the engine. When the temperature of the cooling water in the thermostat housing recess 53 exceeds a predetermined temperature, a passage leading from the downstream radiator passage 4b to the water pump 1 is opened, and the opening of the radiator bypass passage 52 of the thermostat housing recess 53 is closed to cool the radiator 4. The cooling water cooled by the radiator 4 is mixed with the cooling water flowing from another path in the thermostat storage recess 53 and guided to the water pump 1.

When the temperature of the cooling water in the thermostat housing recess 53 becomes lower than the desired temperature, the passage from the downstream radiator passage 4b to the water pump 3 is closed again to cut off the circulation of the cooling water to the radiator 4.

The configuration in which the thermostat 3 is disposed on the downstream side of the radiator passage 4b and on the suction side of the water pump 1 (inside of the cylinder block 50 and the inlet of the water jacket in the cylinder head) (a so-called inlet thermo configuration) is adopted. A configuration in which a thermostat is arranged at the cooling water outlet on the rear surface of the cylinder head (so-called outlet thermo configuration)
For the thermostat 3 when the temperature exceeds the predetermined temperature.
There is an advantage that opening and closing hatching can be prevented.

That is, the cooling water cooled by the radiator 4 affects the thermostat after circulating inside the engine in the outlet thermo configuration, whereas the cooling water directly affects the thermostat 3 in the inlet thermo configuration. It depends. [Detailed Structure of Cylinder Head] As shown in FIGS. 2 to 6, the water-cooled four-cylinder engine of the present embodiment is placed horizontally with respect to the vehicle body (cylinder row direction is the axle direction). The radiator 4 is arranged on the side (front side of the vehicle), and the radiator 4 and the thermostat cover 65 are arranged.
Are connected via the downstream radiator passage 4b, and the heater 2 disposed on the other side (rear side of the vehicle) of the cylinder block 50 and the connecting portion 51a protruding on the other side of the heater return passage 51 are connected to the downstream side. It is connected via a heater passage 2b.

A water pump housing recess 54 that houses a part of the water pump 1 (or may house the whole water pump) near one side (radiator side) of the front surface of the cylinder block 50.
A thermostat housing recess 53 for housing the thermostat 3 is formed adjacent to the water pump housing recess 54 on one side wall of the cylinder block 50.

The water pump 1 is rotationally driven by a pulley 61 by transmitting a driving force from a crankshaft 62.

The cooling water suction side of the water pump housing recess 55 and the thermostat housing recess 53 communicate with each other through a thermostat downstream passage 54, and the cylinder block 50.
On the front is a chain case 7 for driving a camshaft.
0 has been concluded.

A water jacket 56 is formed on the four cylinders 57 arranged in series so as to straddle the outer circumferences of the cylinders 57. The depth of the water jacket 56 from the upper end surface of the cylinder block 50 is determined by the cylinder. The half jacket 57 has a cylinder height H1 up to an intermediate height H2 over the entire outer periphery (or a part thereof) of the cylinder 57.

Below the water jacket 56 at the cylinder height H1 on the front of the cylinder block 50, the other side of the front of the cylinder block 50 (the heater 2 on the rear side of the vehicle).
A heater return passage 51 from the heater 2 which extends from one side (radiator side) to one side (radiator side) and is communicated with the thermostat downstream side passage 54 is formed.

As described above, by forming the heater return passage 51 on the front surface of the cylinder block 50, the engine can be made compact and the overall cooling performance can be improved, and in particular, the heat radiation inside the chain case for driving the camshaft can be improved. ,
Since the external piping is shortened, it is possible to shorten the heater return passage and reduce the amount of cooling water.

In the water pump storage recess 55,
Discharge port side of water pump 1 and water jacket 56
And a water pump discharge passage 58 through which the cooling water discharged from the water pump 1 flows through the water jacket 56.

The depth of the water jacket 56 formed on one side wall and the other side wall of the cylinder block 50 is also
The radiator bypass passage 52 extends from the rear surface of the cylinder block 50 to the thermostat storage recess 53 below the water jacket 56 in the range of the cylinder height H1. ing.

An opening 52b is formed near the rear surface of one side wall of the cylinder block 50 and connects the upstream bypass passage 52a branched from the upstream radiator passage 4a and the radiator bypass passage 52.

The thermostat storage recess 53 has a thermostat cover 65 for storing and covering the thermostat 3 fastened to the cylinder block 50.

At the uppermost part of the thermostat storage recess 53, a connection portion 5c of the downstream ISC passage 5b is provided by an external pipe for introducing cooling water with a small circulation amount.

The connection part 5c is connected to the thermostat housing recess 53.
As shown in FIG. 7, the suction side of the water pump housing recess 55 (the uppermost position of the thermostat downstream passage 54) is located at the uppermost portion of the thermostat housing recess 53, as shown in FIG.
Is disposed below the uppermost position, and air staying above the thermostat storage recess 53 can be discharged from the connection portion 5c at the time of initial cooling water introduction. Further, even when an external pipe is connected to the connection portion 5c, air can be discharged from the radiator 4 if the radiator cap portion of the radiator 4 is at the uppermost position.

Further, a thermostat cover 65 forming a thermostat upstream passage 66 upstream of the thermostat 3 has a connecting portion 6c of the downstream oil cooler passage 6b.
Is provided, and an external thermostat cover 65 is provided.
If the specification without the connecting portion 6c is provided, the specification without the oil cooler 6 can be supported only by changing the thermostat cover 65.

A blow-by gas recirculation passage 59 is formed substantially at the center of one side wall of the cylinder block 50, adjacent to the radiator bypass passage 52 and intersecting the radiator bypass passage 52 in the vertical direction.

The blow-by gas recirculation passage 59 communicates with an oil separator chamber 60 formed above the passage.

Thus, the (radiator bypass passage 52)
And the blow-by gas recirculation passage 59), the rigidity of the cylinder block side wall can be further increased.

It should be noted that the present invention can be applied to a modification or a modification of the above embodiment without departing from the gist of the invention.

[Brief description of the drawings]

FIG. 1 is a cooling water system diagram of a water-cooled engine according to an embodiment of the present invention.

FIG. 2 is a side view of the water-cooled in-line four-cylinder engine according to the present embodiment as viewed from a cylinder row direction.

FIG. 3 is a sectional view taken along line II of FIG. 2;

FIG. 4 is a cross-sectional view of FIG. 2 viewed from an X direction.

FIG. 5 is a partial cross-sectional view of the water-cooled in-line four-cylinder engine according to the present embodiment as viewed from a cylinder row direction.

FIG. 6 is a detailed sectional view of the front surface of the cylinder block of FIG. 3;

FIG. 7 is a diagram illustrating a layout example of a thermostat housing recess and a water pump housing recess.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water pump 2 Heater 3 Thermostat 4 Radiator 5 Idle speed control valve 6 Oil cooler 50 Cylinder block 51 Heater return passage 52 Radiator bypass passage 53 Thermostat storage recess 55 Water pump storage recess 59 Blow-by gas recirculation passage

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) F02F 1/10 F02F 1/10 D (72) Inventor Katsunobu Miyakoshi 3-1, Fuchu-cho, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Inventor Tomohisa Handa 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture F-term (reference) 3G024 AA39 BA24 BA27 BA29 CA03 DA18 EA05 FA00 FA01

Claims (5)

[Claims] 1. A first recess for accommodating at least a part of a water pump is provided near one side of a front surface of a cylinder block, and a thermostat is housed on one side wall of the cylinder block adjacent to the first recess. A body of a water-cooled engine provided with a second recess, communicating the water pump suction side of the first recess with the second recess, and fastened with a cover case of an endless transmission member for driving a cam shaft on the front surface of the cylinder block. In the structure, the depth of the water jacket formed on the outer periphery of the cylinder on the front surface of the cylinder block is set to halfway of the cylinder height, and the lower part of the water jacket in the cylinder height section on the front surface of the cylinder block is provided with the front surface of the cylinder block. A heater extending from the other side and connected to a cooling water passage extending from the second recess to the first recess; Body structure of a water-cooled engine, characterized in that a return passage. 2. The water jacket depth on one side of the cylinder block is substantially the same as the water jacket depth on the front surface of the cylinder block, and the height of the lower portion of the water jacket and the height of the second recess in the cylinder height section. The body structure of a water-cooled engine according to claim 1, wherein a radiator bypass passage extending from a rear side of the cylinder block to the second concave portion is provided at a position. 3. A connecting part of an external pipe for introducing cooling water having a small circulation amount is provided at the uppermost part of the thermostat case or the second concave portion fastened to the cylinder block. Body structure of the described water-cooled engine. 4. A radiator and a thermostat disposed on the front side of the cylinder block, wherein the engine is disposed laterally with respect to the vehicle body such that the direction of the cylinders is aligned with the axle direction. The water-cooled engine according to any one of claims 1 to 3, wherein a case is connected, and the heater disposed on the vehicle rear side of the engine is connected to the other side of the return passage. Body structure. 5. The water cooling system according to claim 1, wherein a blow-by gas recirculation passage vertically intersecting with the radiator bypass passage is provided adjacent to the radiator bypass passage. The main structure of the expression engine.