JP2001098944A - Method of manufacturing water-cooled engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assemble different thermostat cases from only three types of separate part for two types of engine having different mounting heights of a pump chamber, by providing the thermostat cases with a two-piece structure and using a single type of thermostat storage part. SOLUTION: For manufacturing a plurality of types of water-cooled engine having different mounting heights of a pump chamber 1a of a water pump 1, the manufacturing method for water-cooled engines needs a single type of thermostat storage part 2b with a bypass outlet 2a and a plurality of types of mounting flange part 2c with different heights. In a water-cooled engine having a low mounting height of the pump chamber 1a, a short thermostat case 2e is used, which is a combination of the short mounting flange part 2c and the thermostat storage part 2b. In a water-cooled engine having a high mounting height of the pump chamber 1a, a tall thermostat case is employed, which is a combination of the tall mounting flange part and the thermostat storage part 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a water-cooled engine.

[0002]

2. Description of the Related Art Conventionally, a water-cooled engine shown in FIGS. 5 and 6 has been known. These water-cooled engines include a water pump case 101, a thermostat case 102, and a bypass pipe 103. The water pump case 101 includes a pump chamber 101a and a bypass inlet 101b. The thermostat case 102 includes a bypass outlet 102a and a mounting flange. 102g, and is attached to the cylinder head 106 with the attachment flange 102g.
a and the bypass inlet 101b. 5 and 6
Each of the water-cooled engines has a different mounting height of the pump chamber 101a of the water pump case 101. In the water-cooled engine of FIG. 5, the center 101c of the pump chamber 101a is located at the same height as the boundary 114 between the cylinder block 105 and the cylinder head 106. In the water-cooled engine in FIG. 6, the center 101c of the pump chamber 101a is higher than the boundary 114.

In manufacturing these water-cooled engines having different mounting heights of a pump chamber 101a of a water pump case 101, conventionally, a thermostat case 10 is used.
2 are prepared from a plurality of types having different heights. For a water-cooled engine having a low mounting height of the pump chamber 101a shown in FIG. 5, a low-profile thermostat case 102e is used, and a pump chamber shown in FIG. For a water-cooled engine having a high mounting height 101a, a tall thermostat case 102
The height of the bypass outlet 102a with respect to the bypass inlet 101b is adjusted using f.

[0004]

The above prior art has the following problems. << 1 >> In each thermostat case 102e, 102f,
A complex structure cannot be adopted. As shown in FIGS. 5 and 6, each thermostat case 102e
Since 102f has a single structure that cannot be divided, a simple structure is inevitable due to the necessity of die cutting during the forming process.
A complicated structure cannot be adopted for each of the thermostat cases 102e and 102f. For this reason, a thermostat of a bottom bypass type cannot be used. This is because when a bottom bypass type thermostat is used, a valve seat for a bottom bypass valve is required in each of the thermostat cases 102e and 102f, which results in a complicated structure.

<< 2 >> Each thermostat case 102e
When the 102f has a divided structure, component costs increase and component management tends to be complicated. When each of the thermostat cases 102e and 102f has a divided structure,
Since the die can be easily removed at the time of molding each divided part, a complicated structure can be adopted. However, if different types of divided parts are used for different engines having different mounting heights of the pump chamber 101a of the water pump case 101, the number of parts increases. For example, if each of the thermostat cases 102e and 102f has a two-part structure and different kinds of divided parts are used for each of two types of engines, a total of four kinds of divided parts are required. For this reason, the component cost increases and the component management tends to become complicated.

An object of the present invention is to solve the above problems.
An object of the present invention is to provide a method for manufacturing a water-cooled engine.

[0007]

The structure of the first aspect of the present invention is as follows. As shown in FIGS. 1 and 3, a water pump case 1, a thermostat case 2, and a bypass pipe 3 are provided.
The thermostat case 2 includes a pump chamber 1a and a bypass inlet 1b, and includes a bypass outlet 2a and a mounting flange 2g.
In the method for manufacturing a water-cooled engine which is attached to the cylinder head 6 with the attachment flange 2g and communicates the bypass outlet 2a and the bypass inlet 1b with the bypass pipe 3, the pump chamber 1a of the water pump case 1 is attached. In manufacturing a plurality of types of water-cooled engines having different heights, a single type of thermostat accommodating portion 2b having the bypass outlet 2a and a plurality of types of mounting flange portions 2c and 2d are prepared. Part 2
Each of c and 2d includes the mounting flange 2g and has a different height from each other. For a water-cooled engine in which the mounting height of the pump chamber 1a of the water pump case 1 is low, a short mounting flange is used. For a water-cooled engine in which the mounting height of the pump chamber 1a of the water pump case 1 is high, a tall mounting flange portion 2d and the thermostat housing are used. Part 2
b. A method for manufacturing a water-cooled engine, comprising using a high-profile thermostat case 2f in combination with b.

[0008]

Operation and Effect of the Invention The first aspect of the invention has the following operation and effects. << 1 >> A complex structure can be used for each of the thermostat cases 2e and 2f. As shown in FIG. 1 or FIG. 3, since each of the thermostat cases 2e and 2f has a divided structure, there are the following advantages. Even if a complicated structure is adopted, since the die can be easily removed at the time of molding each divided part, a complicated structure can be employed for each of the thermostat cases 2e and 2f. Therefore, for example, a thermostat of a bottom bypass type can be used.

<2> Component costs can be reduced, and component management is simplified. Water pump case 1
Since the same type of thermostat accommodating portion 2b is shared by a plurality of types of water-cooled engines having different mounting heights of the pump chambers 1a, there are the following advantages. For example, each of the thermostat cases 2e and 2f has a two-part structure, and the mounting height of the pump chamber 1a of the water pump case 1 is different.
When the same type of thermostat accommodating portion 2b is shared by the different types of engines, only three types of divided parts are required. For this reason, component costs can be kept low and component management is simplified.

[0010]

Embodiments of the present invention will be described with reference to the drawings. 1 to 4 are diagrams for explaining an embodiment of the present invention. This embodiment relates to a method for manufacturing a vertical multi-cylinder water-cooled diesel engine.

The structure of the engine shown in FIG. 1 is as follows. This engine is of a type in which the mounting height position of the pump chamber 1a of the water pump case 1 is low. In this embodiment, the mounting height of the pump chamber 1a is determined with the boundary 14 between the cylinder block 5 and the cylinder head 6 as a reference position, and the center 1 of the pump chamber 1a from this reference position.
Determined by the position up to c. This engine includes a cylinder block 5, a cylinder head 6, an oil pan 7, and a gear case 8. The cylinder block 5 includes a cylinder 9 and a crankcase 10. The cylinder head 6 is assembled on the upper part of the cylinder block 5. The oil pan 7 is attached to a lower part of the cylinder block 5. The gear case 8 is assembled to a front part of the cylinder block 5.

The structure of the water cooling device for this engine is as follows. The water cooling device includes a radiator 11, a water pump case 1, a cooling fan 12, a thermostat case 2, a bypass pipe 3, and a cooling water outlet pipe 13. The radiator 11 is arranged in front of the engine. The water pump case 1 includes a pump chamber 1a, a bypass inlet 1b, and a cooling water introduction part 1c, and is assembled to a front part of the gear case 8. The pump chamber 1a is arranged at the same height as the boundary 14 between the cylinder block 5 and the cylinder head 6. The bypass inlet 1b is led upward at an upper part of the pump chamber 1a. The cooling water introduction part 1d is led obliquely downward from the pump chamber 1a.
An input shaft 15 is inserted into the center 1c of the pump chamber 1a,
An input pulley 16 is fixed to the input shaft 15. The input pulley 16 is linked with a drive pulley 18 fixed to a crankshaft 17 by a belt (not shown).

The cooling fan 12 is arranged between the engine and the radiator 11, and is fixed to the input pulley 16. The thermostat case 2 has a bypass outlet 2a.
And a mounting flange 2g. The mounting flange 2g is assembled to the head jacket outlet 6a of the cylinder head 6. The bypass pipe 3 is a flexible rubber pipe, and connects the bypass outlet 2a and the bypass inlet 1b. The cooling water outlet pipe 13 is mounted on the upper part of the thermostat case 2. The cooling water outlet pipe 13 and the radiator 11 are connected by a radiator pipe (not shown).

The function of this water cooling device is as follows.
During the warm-up operation of the engine, the cooling water in the cylinder jacket (not shown) in the cylinder 9 passes through the head jacket (not shown) in the cylinder head 6 and passes through the thermostat case 2.
To the pump chamber 1a of the water pump case 1 via the bypass pipe 3, and returns to the cylinder jacket. After the warm-up operation of the engine, the cooling water in the cylinder jacket is introduced into the thermostat case 2 through the head jacket, is introduced into the radiator 11 through the cooling water outlet pipe 13 and the radiator pipe, and is passed through another radiator pipe. The cooling water is introduced into the pump chamber 1a from the cooling water introduction section 1c of the water pump case 1, and returns to the cylinder jacket. The radiator 11 is a cooling fan 1
It is cooled by the cooling air generated in Step 2.

The configurations of the thermostat case 2 and the thermostat 29 are as follows. As shown in FIG. 2, the thermostat case 2 has a two-part structure including a thermostat housing 2b and a mounting flange 2c. FIG.
As shown in (E), the thermostat housing 2b is a die-cast product and includes a thermostat chamber 19, a bypass outlet passage 20, a partition wall 21, a bypass outlet 2a, a thermostat mounting seat 22, and a bypass valve seat 23. ing. The thermostat chamber 19 and the bypass outlet passage 20 are partitioned by a partition wall 21. Bypass outlet 2a
Is horizontally protruded from the lateral side of the thermostat housing 2b and communicates with the bypass outlet passage 20. The thermostat mounting seat 22 is provided around the upper opening of the thermostat chamber 19. The bypass valve seat 23 is provided at a lower central portion of the thermostat chamber 19.

As shown in FIG. 2 (E), the mounting flange 2c is also a die-cast product, and has a mounting flange 2g, a cooling water inlet 25, a cooling water introducing passage 26, and a reversing passage 27.
And a partition wall 28. The cooling water inlet 25 is
It is opened at the center of the mounting flange 2g. The cooling water introduction passage 26 is led upward from the cooling water introduction port 25. The cooling water introduction passage 26 and the reversing passage 27 are partitioned by a partition wall 28. The thermostat 29 is of a bottom bypass type, and includes a flange 30, a main valve 31, a temperature detector 32, and a bypass valve 33.

The assembling structure of the thermostat case 2 and the thermostat 29 is as follows. The thermostat 29 has its flange 30 attached to the thermostat housing 2.
The thermostat mounting seat 22 of FIG. The flange 30 of the thermostat 29 is connected to the thermostat housing 2.
b and the cooling water outlet pipe 13 to be fixed. The thermostat 29 is housed in the thermostat chamber 19, and its bypass valve 33 faces the bypass valve seat 23.
As shown in FIG. 2D, an adhesive 34 is applied to the upper surface of the mounting flange 2c, and the adhesive 34 is applied to the thermostat housing 2b.
2 (E), and assembled with mounting bolts 35 as shown in FIG. 2 (E). In this assembled state, the cooling water introduction passage 26 of the mounting flange portion 2c communicates with the thermostat chamber 19. The reversing passage 27 is connected to the bypass valve seat 2.
3 and the bypass outlet passage 20 respectively.

The functions of the thermostat case 2 and the thermostat 29 are as follows. As shown in FIG. 2E, during the warm-up operation of the engine, the main valve 31 of the thermostat 29 is closed and the bypass valve 33 is open. Therefore, the cooling water flows from the head jacket to the cooling water introduction passage 26, the thermostat chamber 19,
After passing through the reversing passage 27 and the bypass outlet passage 20 in order, it is led out from the bypass outlet 2a. Since the bypass outlet 2a is led out horizontally, it is difficult for the bypass pipe 3 to have a large upward convex curve, and it is difficult for air to accumulate in the bypass pipe 3. When the temperature of the cooling water rises and the main valve 31 is opened, much of the cooling water is led out of the cooling water outlet pipe 13 through the cooling water introduction passage 26 and the thermostat chamber 19 in this order from the head jacket. When the main valve 31 is fully opened and the bypass valve 33 is fully closed, the flowing water from the bypass outlet 2a stops.

The engine shown in FIG. 3 is of the type in which the mounting height of the pump chamber 1a of the water pump case 1 is high. In this engine, the center 1c of the pump chamber 1a of the water pump case 1 is located higher than the boundary 14 between the cylinder block 5 and the cylinder head 6. This engine is for mounting on a tractor. To avoid interference with the front wheels (not shown),
A vertically long radiator 11 is used. Therefore, the center of the radiator 11 is at a high position, and the position of the input pulley 16 for driving the cooling fan 12 needs to be high. As a result, the mounting height of the pump chamber 1a is also high. For this reason, in the engine of FIG. 4, as compared with the engine of FIG.
d is tall. The thermostat housing 2b is
The same engine as in FIG. 1 is used. The other structure of the water cooling device is substantially the same as that of the engine of FIG. 1, and in FIGS. 3 and 4, the same elements as those of the engine of FIG. 1 are denoted by the same reference numerals.

Pump chamber 1a of water pump case 1
The manufacturing of the water-cooled engines of FIGS. 1 and 3 having different mounting heights is performed as follows. A single type of thermostat housing 2b shown in FIGS. 2 and 4 and two types of mounting flanges 2c and 2d shown in FIGS. 2 and 4 are prepared. The mounting flange 2c shown in FIG. 2 and the mounting flange 2d shown in FIG.
2 is shorter and FIG. 4 is taller. As for the water-cooled engine of FIG. 1 in which the mounting height of the pump chamber 1a of the water pump case 1 is low, as shown in FIG. 2, a low-profile thermostat case 2e combining a short mounting flange portion 2c and a thermostat housing portion 2b. Is used. This low-profile thermostat case 2e
Then, the thermostat 29 and the cooling water outlet pipe 13 are assembled, and the low-profile thermostat case 2e is assembled to the cylinder head 6. The bypass pipe 3 connects the bypass outlet 2 a of the thermostat housing 2 b and the bypass inlet 1 b of the water pump case 1.
Also, the cooling water outlet pipe 13 and the radiator 11 are communicated by a radiator pipe, and the other radiator pipes
The radiator 11 communicates with the cooling water inlet 1d of the water pump case 1.

On the other hand, for the water-cooled engine of FIG. 3 in which the mounting height of the water pump 1 is high, as shown in FIG.
Tall mounting flange 2d and thermostat housing 2
and a high-profile thermostat case 2f in combination with b. The thermostat 29 and the cooling water outlet pipe 13 are assembled to the tall thermostat case 2f, and the tall thermostat case 2f is assembled to the cylinder head 6. The bypass pipe 3 connects the bypass outlet 2 a of the thermostat housing 2 b and the bypass inlet 1 b of the water pump case 1. Also, a cooling water outlet pipe 13 and a radiator 11 are connected by a radiator pipe.
And radiator 1 with another radiator pipe.
1 and the cooling water inlet 1d of the water pump case 1 are communicated.

The advantages of this manufacturing method are as follows.
As shown in FIG. 1 or FIG. 3, since each of the thermostat cases 2e and 2f has a divided structure, there are the following advantages. Even if a complicated structure is employed, the die can be easily removed at the time of molding each divided part, so that a complicated structure can be employed. Therefore, a thermostat 29 of a bottom bypass type can be used.

Each of the thermostat cases 2e and 2f has a two-part structure, and the pump chamber 1 of the water pump 1
For two types of engines having different mounting heights a, the same type of thermostat accommodating case 2b is commonly used.
Only the kind of divided parts is needed. For this reason, component costs can be kept low and component management is simplified.

[Brief description of the drawings]

FIG. 1 is a front view of a water-cooled engine obtained by a manufacturing method according to an embodiment of the present invention, wherein a mounting height of a pump chamber is low.

2A and 2B are diagrams illustrating a thermostat case used for the water-cooled engine in FIG. 1; FIG. 2A is a plan view, and FIG.
2C is a front view, FIG. 2C is a side view, FIG. 3D is a plan view of a mounting flange portion, and FIG. 2E is a sectional view taken along line EE of FIG. 2B.

FIG. 3 is a front view of a water-cooled engine obtained by a manufacturing method according to an embodiment of the present invention, wherein a mounting height of a pump chamber is high.

4A and 4B are diagrams illustrating a thermostat case used for the water-cooled engine of FIG. 3, wherein FIG. 4A is a front view and FIG.
4C is a side view, FIG. 4C is a plan view of a mounting flange portion, FIG.
FIG. 4D is a sectional view taken along line DD of FIG.

FIG. 5 is a front view of a water-cooled engine obtained by a manufacturing method according to the related art, in which a mounting height of a pump chamber is low.

FIG. 6 is a front view of a water-cooled engine obtained by a manufacturing method according to the related art, in which a mounting height of a pump chamber is high.

[Explanation of symbols]

1 ... water pump case, 1a ... pump room, 1b ...
Bypass outlet, 2 ... Thermostat case, 2a ... Bypass outlet, 2b ... Thermostat storage part, 2c-2d ...
Mounting flange, 2e ... Low-profile thermostat case, 2
f: High-profile thermostat case, 2g: Mounting flange,
3 ... Bypass pipe.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidemasa Tsuji 3-8 Chikushinmachi, Sakai City, Osaka Inside Kubota Sakai Coastal Plant (72) Inventor Hideyuki Koyama 3-8 Chikushinmachi, Sakai City, Osaka Prefecture Inside Kubota Sakai Rinkai Plant (72) Inventor Kazuhiro Higuchi 3-8 Chikushinmachi, Sakai City, Osaka Prefecture Inside Kubota Sakai Rinkai Plant

Claims (1)

[Claims] A water pump case (1), a thermostat case (2) and a bypass pipe (3) are provided, and the water pump case (1) has a pump chamber (1).
a) and a bypass inlet (1b), the thermostat case (2) includes a bypass outlet (2a) and a mounting flange (2g), and is attached to the cylinder head (6) at the mounting flange (2g); Bypass pipe (3)
The bypass outlet (2a) and the bypass inlet (1b)
In the method of manufacturing a water-cooled engine, a plurality of types of water-cooled engines having different mounting heights of a pump chamber (1a) of a water pump case (1) are manufactured by using a single type provided with the bypass outlet (2a). And a plurality of types of mounting flanges (2c) and (2d) are prepared. Each of the plurality of types of mounting flanges (2c) and (2d) is provided with the mounting flange (2g). Prepare and use different heights from each other,
For a water-cooled engine having a low mounting height of the pump chamber (1a) of the water pump case (1), a short mounting flange portion (2c) and the thermostat housing portion (2b).
And a pump chamber (1) of a water pump case (1) using a low-profile thermostat case (2e)
The water-cooled engine having a high mounting height a) uses a high-profile thermostat case (2f) combining a tall mounting flange portion (2d) and the thermostat housing portion (2b). Engine manufacturing method.