JPH11117742A - Bypass passage structure in water-cooled device in engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve manufacturing performance and productivity by connecting and fixing a cover of a water pump to a gear case connected to an engine main body, and a passage part composed of recessed grooves on the connecting surface of the gear case and the water pump as a bypass passage. SOLUTION: In a water-cooled device for an engine provided with a cooling water passage and a bypass passage 6, a cover 9 for a water pump 4 is connected and fixed to a gear case 8 connected to an engine main body 7, and a passage composed of recessed grooves 8A, 9A is arranged on a connecting surface of the gear case 8 and the cover 9 for the water pump 4 as a bypass passage 6. A cooling water passage part 17 is formed in the cover 9 for pouring cooling water which flows from a radiator side to an engine side. The cooling water passage part 17 is partitioned into a flow-in side 19 and a flow-out side 20 by a diaphragm 18 interposed and fixed between an opening surface side of the cover 9 and a gear case 8 wall on which the cover 9 is installed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling water bypass passage structure in a water cooling device for an engine, and more particularly to a technique for forming a cooling water bypass passage.

[0002]

2. Description of the Related Art Conventionally, the following structure is known as a water cooling device for an engine (see Japanese Utility Model Laid-Open No. 5-47358). That is, the water cooling system of the engine is of an inlet control circuit type, and the cylinder jacket of the engine is connected to the cylinder jacket through a head jacket, a radiator, a thermostat, and a water pump in this order while being circulated. The housing of the thermostat is fixed to the front surface of the cylinder block of the engine, and the head jacket communicates with the stat outlet side chamber of the thermostat via a bypass passage.

In this prior art, the bypass passage is formed so as to pass through the inside of the wall of the cylinder head and the inside of the wall of the cylinder block in order, so as to reach the cylinder head via the cylinder block. Has become.

[0004]

However, in the above-described conventional water cooling device for an engine, the bypass passage is constituted by a passage portion formed integrally with the cylinder head and the cylinder block, respectively. There is a problem that the structures of the cylinder head and the cylinder block are complicated, their formability is inferior, and the productivity and productivity are reduced.

As a conventional general bypass passage, there is known a separate bypass passage structure in which a bypass passage is constituted by a hose or the like. And the like, and there is a problem that the workability is poor. Further, in a configuration in which a bypass passage is formed by a hose or the like, a large space is required as the bypass passage on the end face side of the engine body, and the width of the engine body in the front-rear direction (crankshaft axial direction) is increased. There is a problem that it becomes large.

In view of the above-mentioned conventional problems, the present invention aims to improve the productivity and productivity by improving the structure of forming a bypass passage in a water cooling device of an engine, and to reduce the number of parts and to manufacture the engine. It is an object of the present invention to improve workability, downsize the engine, and the like.

[0007]

For this purpose, the invention according to claim 1 includes a cooling water circulation path from the engine to the engine again through the thermostat, the radiator and the water pump, and a bypass path for bypassing the radiator. In the water cooling device for an engine, the cover of the water pump is fixedly connected to the gear case connected to the engine body, while the connection surface between the gear case and the cover of the water pump is integrally formed on the connection surface between them. A passage portion comprising a concave groove is provided, and the passage portion is configured as the bypass passage.

According to a second aspect of the present invention, the thermostat is mounted inside a cover of the water pump.
The outlet for the bypass passage of the cover communicates with the inflow side of the bypass passage of the thermostat, and the outlet of the passage communicating with the engine-side cooling water passage of the gear case communicates with the inflow side of the bypass passage. It is characterized by.

The operation of the present invention will be described. Claim 1
In the invention according to the invention, the cooling water on the discharge side of the water pump flows in from the inflow side of the bypass passage via the cylinder block and the cylinder head, passes through the bypass passage,
It flows out of the outflow side and reaches, for example, a thermostat housing.

The bypass passage structure in the water cooling system for an engine having such a configuration can be formed simply by providing concave grooves in the gear case and the cover of the water pump. Furthermore, in the configuration in which the bypass passage is formed on the joint surface between the gear case and the cover of the water pump, the space to be secured on the end face side of the engine body as the bypass passage is smaller than the space for laying out the bypass passage made of a hose or the like. Is done.

In the invention according to claim 2, the communication structure between the bypass passage, the thermostat and the engine-side cooling water passage becomes easy.

[0012]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. First, the outline of the present invention will be described with reference to FIGS. That is, as shown in FIG. 4, the radiator 3, the thermostat 2,
FIG. 5 shows a water cooling system for an engine including a cooling water path 5 that reaches the engine 1 again through the water pump 4 and a bypass path 6 that bypasses the radiator 3 and flows the outlet water of the engine 1 to the thermostat 2. As described above, the cover 9 of the water pump 4 is fixedly connected to the gear case 8 connected to the engine body 7, while the connecting surface of the gear case 8 and the cover 9 of the water pump 4 is integrally formed on the connecting surface of the two. Molded concave groove 8A,
A passage portion made of 9A is provided, and the passage portion is configured as the bypass passage.

1 to 3 show the water pump 4 described above.
1 is a front view, a rear view, and a sectional view taken along the line AOA in FIG. 1 showing a specific configuration of the cover 9 of FIG. In these figures, for example, a cover 9 of an aluminum water pump is integrally formed with a boss 10 in the left region of each of the left and right regions of FIG. The bearing 12 of the pump rotation drive shaft 11 is supported.

At the outer end of the pump rotation drive shaft 11,
A pump driving pulley 13 is connected, and an impeller 14 is connected to the inner end. A mounting flange 15 is integrally formed around the cover 9, and a plurality of bolt insertion holes 16 are formed in the mounting flange 15. Further, a cooling water passage 17 through which cooling water flows in from the radiator 3 side and flows out to the engine 1 side is formed in the cover 9.

The cooling water passage 17 is formed on the inlet side 19 by a partition plate 18 interposed and fixed between the open side of the cover 9 and the wall of the gear case 8 to which the cover 9 is attached.
The cooling water from the radiator 3 flows in from the inflow side 19 and the opening 18 formed at a position corresponding to the center of the impeller 14 of the partition plate 18.
A flows out of the outflow side 20 made of A and reaches the engine 1 side.

On the other hand, the concave groove 9A is integrally formed around the right region of the right and left regions of the cover 9 in FIG. This concave groove 9A is formed in a substantially semicircular cross section. And, as described above, a passage portion composed of concave grooves 8A and 9A integrally formed on the joint surface between the gear case 8 and the cover 9 of the water pump is provided on the joint surface between the two, and this passage portion is bypassed. It is configured as a passage 6.

The thermostat 2 is mounted inside the cover 9 of the water pump 4 and communicates with the bypass passage outlet 6A of the cover 9 and the inflow side of the bypass passage of the thermostat 2 to cool the gear case 8 on the engine side. The outlet of the passage communicating with the water passage and the inflow side 6B of the bypass passage 6 are communicated. Therefore, the cooling water flows from the water pump 4 through the cylinder block and the cylinder head from the inflow side 6B of the bypass passage 6, passes through the bypass passage 6, flows out of the outflow side 6A, and reaches the thermostat 2 side. Is again discharged by the water pump 4 and circulates to the engine 1 side.

According to the bypass passage structure in the water cooling system for an engine having the above-described structure, the connecting surface between the gear case 8 and the cover 9 of the water pump 4 is formed with the concave grooves 8A and 9A integrally formed on the connecting surface of the two. As a result of providing the passage portion and configuring the passage portion as the bypass passage 6, the structure of the cylinder head and the cylinder block is complicated as in the case where the bypass passage is constituted by a passage portion integrally formed with the cylinder head and the cylinder block. Instead, it is only necessary to form the grooves 8A, 9A in the gear case 8 and the cover 9 of the water pump 4, which is advantageous in terms of moldability, manufacturability and productivity.

In addition, the number of parts can be reduced as compared with a separate bypass passage structure in which a bypass passage is constituted by a hose or the like as a conventional general bypass passage. There is no inferiority. Further, in the configuration in which the bypass passage 6 is formed on the joint surface between the gear case 8 and the cover 9 of the water pump 4, the space secured on the end face side of the engine body 7 as the bypass passage is to lay out the bypass passage made of a hose or the like. Space is reduced.

As a result, the width of the engine body 7 in the front-rear direction (crankshaft axis direction) can be reduced, which contributes to downsizing of the engine body 7.

[0021]

As described above, according to the first aspect of the present invention, the passage portion formed of the groove formed integrally with the coupling surface between the gear case and the cover of the water pump is formed on the coupling surface of the two. Is provided, and this passage portion is configured as a bypass passage, so that productivity and productivity are improved, the number of parts is reduced, and workability related to production is improved.
Engine size can be reduced.

According to the second aspect of the invention, the communication structure between the bypass passage, the thermostat and the engine-side cooling water passage becomes easy, and the effect of the first aspect of the invention can be more effectively exhibited.

[Brief description of the drawings]

FIG. 1 is a plan view of a water pump cover illustrating an embodiment of a bypass passage structure in a water cooling device for an engine of the present invention.

FIG. 2 is a rear view thereof.

FIG. 3 is a sectional view taken along the line AOA in FIG.

FIG. 4 is a schematic view showing a water cooling device for an engine for explaining the outline of the present invention;

FIG. 5 is a schematic view showing a bypass passage structure for explaining an outline of the present invention.

[Explanation of symbols]

 Reference Signs List 1 engine 2 thermostat 3 radiator 4 water pump 5 cooling water circulation path 6 bypass passage 7 engine body 8 gear case 9 cover 8A, 9A concave groove

Claims (2)

[Claims] 1. A water cooling system for an engine, comprising: a cooling water circulation path from the engine to the engine again through a radiator and a water pump; and a bypass passage for bypassing the radiator. While the cover of the water pump is fixedly coupled to the gear pump, the coupling surface of the gear case and the cover of the water pump is provided with a passage portion formed of a concave groove integrally formed on the mutual coupling surface, and the passage portion is A cooling water bypass passage structure in an engine water cooling device, wherein the cooling water bypass passage structure is configured as the bypass passage. 2. A thermostat provided on the engine inlet side of the cooling water passage is mounted inside a cover of the water pump, and communicates with a bypass passage outlet of the cover and an inflow side of the bypass passage of the thermostat. 2. The cooling water bypass passage structure in a water cooling system for an engine according to claim 1, wherein an outlet of a passage portion communicating with the engine-side cooling water passage of the gear case communicates with an inflow side of the bypass passage.