JPH0716022Y2 - Water cooling device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Purpose of the Invention (1) Field of Industrial Application The present invention relates to a water cooling device for an internal combustion engine, and more particularly to an improvement of its bypass circuit.

(2) Conventional Technology Conventionally, the cooling water from the discharge port of the water pump is returned to the suction port of the water pump through a water jacket and a radiator formed in the engine body formed by polymerizing and binding a cylinder head to the upper part of the cylinder block. An internal combustion engine comprising a circuit and a bypass circuit for returning the cooling water from the outlet of the water jacket to the suction port of the water pump through a bypass passage outside the engine body and a bypass communication passage inside the engine body branched from the radiator circuit. The water cooling system of the engine is, for example,
As disclosed in Japanese Laid-Open Patent Publication No.-40818, the publicly known one is such that hot water can be supplied to a heat riser in an intake manifold by utilizing a bypass circuit, and a bypass communication path in the bypass circuit is provided. Since it has a structure that traverses the inside of the engine body without largely bypassing the outer end of the engine body, there are advantages such as shortening the passage length of the bypass circuit and simplifying the configuration of the external piping in the bypass circuit. is there.

(3) Problems to be Solved by the Invention However, in the above-mentioned known art, the inlet passage formed on one side of the engine body, the outlet passage formed on the other side of the engine body, and the inlet and outlet passages thereof. Since the bypass communication passage is constituted by a relatively long intermediate communication passage formed by partially hollowing out the cylinder head so as to communicate the inner ends of each other, the formation of the long intermediate communication passage is It is necessary to specially use a sand core having a shape corresponding to the path simultaneously with the casting and molding of the cylinder head. Therefore, the casting process is relatively complicated and the cost is high. Exists in the hollow part of the cylinder head and is not exposed to the outside, so even if there is sand remaining, sand sticking, burrs, etc., it is difficult to post-process and it is difficult to visually inspect. There is a problem It was

The present invention has been proposed in view of the above, and an intermediate communication passage, which is a main part of the bypass communication passage to be formed in the engine body, can be easily formed in the engine body, and post-processing after formation can be performed. Another object of the present invention is to provide a water cooling device for an internal combustion engine, which is easy to perform visual inspection.

B. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above-mentioned object, the invention of Claim 1 superposes the cooling water from the discharge port of the water pump and the cylinder head on the upper part of the cylinder block by polymerization bonding. A water jacket formed in the engine body and a radiator circuit for returning to the suction port of a water pump through a radiator, and a cooling water from the outlet of the water jacket, a bypass passage and an engine outside the engine body branched from the radiator circuit. In a water cooling device for an internal combustion engine, comprising a bypass circuit for returning the water to a suction port of a water pump through a bypass communication passage in the main body, the bypass communication passage is formed at one side of the engine body. An inlet passage for opening the outer end to the outer surface of the engine, an outlet passage formed on the other side of the engine body for opening the outer end to the outer surface of the other side, and the cylinder head and the cylinder. And an intermediate communication passage that extends along the mating surface with the inner block and communicates the inner ends of the inlet and outlet passages with each other, and the intermediate communication passage bypasses the combustion chamber of the engine body. In addition to the above-mentioned features, the bypass passage is provided with a heat riser for heating intake air flowing in the intake manifold. It is characterized by that.

(2) Operation According to the above-mentioned structure of the invention of each claim, among the bypass circuits branched from the radiator circuit, the main part of the bypass communication passage to be formed in the engine main body is formed to bypass the combustion chamber. The relatively long intermediate communication passage is formed by a relatively simple casting process that does not require a sand core, or by a relatively simple process in which the cylinder block and the head are separated and their mating surfaces are exposed to the outside. It can be easily and accurately formed by machining, and after the formation, the intermediate communication passage is widely opened to the outside through the exposed mating surface, so maintenance such as post-processing and visual inspection is easy. Is.

Further, in particular, according to the above configuration of the invention as defined in claim 2, a part of the bypass circuit (that is, the bypass communication passage) for circulating the hot water to the intake air heating heat riser in the intake manifold largely bypasses the outer end of the engine body. Since the structure crosses the inside of the engine body without doing so, the bypass passage for the heat riser can be shortened and the configuration of the external piping can be simplified.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings.
1 and 2 show the entire water cooling system of the internal combustion engine.
The engine body E of the four-cylinder internal combustion engine is composed of a cylinder block 1 and a cylinder head 2 which is superposed and bonded on the deck surface of the upper end portion thereof via a gasket as usual. A water jacket Jw for cooling the heating portion is formed in the engine body E, and the water jacket Jw is the third
As shown in the figure, a cylinder block 1 is provided with a block-side water jacket 5 provided so as to surround a cylinder 3 formed therein, and a cylinder head 2 is provided so as to surround a combustion chamber 4 formed therein. The block side water jacket 5 comprises a head side water jacket 6
And the head side water jacket 6 communicate with each other.

An inlet 7 is opened at the bottom of the water jacket Jw on one side of the cylinder block 1, and an outlet 8 of the water jacket Jw is opened on the other side of the cylinder head 2 so that the inlet 7 is at a low temperature. The outlet 8 is connected to the lower tank 11 of the radiator R via a water passage 9, and the outlet 8 is connected to the upper tank 12 of the radiator R via a high temperature water passage 10. The inlet 7 is opened at the bottom of the water jacket Jw so that the water in the water jacket Jw does not stagnant.

At the connection between the inlet 7 and the low temperature water passage 9, a water pump P
Is provided, and a thermo valve V is provided on the suction side of the water pump P.
Are placed close to each other. The housing PH of the water pump P and the housing VH of the thermo valve V are integrally formed and supported on one side wall of the cylinder block 1. The thermo valve V is a main valve 15 that connects the low temperature water passage 9 and the suction port 13 of the water pump P at a preset temperature.
Have. Water pump P, water jacket Jw, hot water passage 1
The radiator circuit Cr is constituted by 0, the radiator R, the low temperature water passage 9 and the thermo valve V.

The intake manifold In integrally connected to the cylinder head 2 has a bypass passage 17 having a heat riser 18 for raising the temperature of intake air flowing in the intake manifold In.
Is formed, the inflow port 19 of the bypass passage 17 is communicated with the outlet 8 of the water jacket Jw, and the outflow port 20 thereof is
A bypass communication passage 21 formed in the engine body E, which will be described in detail later.
Also, it is communicated with the suction port 13 of the water pump P via the auxiliary valve 16 of the thermo valve V. When the engine temperature is low, the auxiliary valve 16 of the thermo valve V is opened, and a part of the cooling water flowing from the water pump P through the water jacket Jw of the engine body E and heated up is transferred to the heat riser 18 in the middle of the bypass passage 17. After flowing and heating the intake air in the intake manifold In, it is sucked into the suction port 13 of the water pump P through the bypass communication passage 21.

The water pump P, the water jacket Jw, the bypass passage 17 and the bypass communication passage 21 form a bypass circuit Cb.

A heater circuit Ch having a heater 22 is connected between the outlet 8 of the water jacket Jw and the suction port 13 of the water pump P, and the high-temperature cooling water flowing in the water jacket Jw flows through the heater circuit Ch and is heated. After warming 22, it is returned to the water pump P.

1 and 2, the main valve 15 of the thermo-valve V is closed and the sub-valve 16 of the thermo valve V is opened and discharged from the discharge port 14 of the water pump P at a low temperature such as in the initial stage of starting the internal combustion engine. The cooling water is the block side water jacket 5 of the engine body E.
To the head side water jacket 6 and then from its outlet 8 to the bypass passage, that is, the hot water riser passage 17 and the heater circuit 23 to heat the heat riser 18 and the heater 22.

When the engine warms up and the temperature is high, the main valve 15 opens and the sub valve 16 closes, and the cooling water from the water pump P has a radiator R from the outlet 8 of the water jacket Jw to the radiator circuit. Circulates through Cr, engine body E
To cool. The circulation of the cooling water to the heater circuit Ch is continuously performed.

The cooling water circulation operation described above is commonly performed in this type of water cooling device.

Next, a specific configuration of the bypass communication passage 21 formed in the engine body E and connecting the bypass passage 17 and the suction port 13 of the water pump P will be described mainly with reference to FIGS. The bypass communication passage 21 is formed in one side portion Ea of the engine body E (that is, one side portion of the cylinder head 2) and has an inlet passage 21 ₁ having an outer end opened to the outer surface thereof and the other side portion of the engine body E. Eb
An outlet passage 21 ₃ formed in (that is, the other side of the cylinder block 1) and having an outer end opened to the outer surface thereof, and a cylinder head 2 for communicating between the inner ends of the inlet and outlet passages 21 ₁ and 21 _3. It is composed of an intermediate communication passage 21 ₂ formed along the mating surface with the cylinder block 1.

The inlet passage 21 ₁ is formed by two straight passages 21 ₁ -1,21 ₁ -2 that are open at the outer surface and the lower surface of one side of the cylinder head 2 and intersect with each other.
1 ₃ is also formed by two straight passages 21 ₃ -1,21 ₃ -2 opened respectively to the other side outer side surface and the deck surface of the cylinder block 1 intersecting each other. Since the inlet and outlet passages 21 ₁ and 21 ₂ are linear and the outer ends thereof are open to the outer surface of the cylinder block 1 or the cylinder head 2, they can be easily formed by machining, casting or the like. You can

The intermediate communication passage 21 ₂ is a block side water passage groove 21 ₂ -1 having a semicircular cross section formed on the deck surface of the cylinder block 1 (that is, a mating surface with the cylinder head 2) and the lower surface of the cylinder head 2. (i.e. the mating surface of the cylinder block 1) is constructed by polymerizing the same cross-section semi-circular head-side water passage grooves 21 _2-2 formed mutually in the head-side water passage grooves 21 _2-2
Is formed in a plane arc shape so as to bypass the combustion chamber 4 of the engine body E, and the block side water passage groove 21 ₂ -1 is also flat so as to correspond to the head side water passage groove 21 ₂ -2. It is formed in an arc shape. Both ends of the intermediate communication passage 21 ₂ are communicated with the inlet and the mating surface side open ends of the outlet passages 21 ₁ , 21 ₃ .

As described above, when the cooling water flows through the bypass circuit Cb in order to circulate the hot water to the intake air heating heat riser 18 in the intake manifold In, the cooling water that has passed through the bypass passage 17 will be the bypass communication passage in the engine body E. 3rd in 21
It flows as shown by the arrow A in the figure and reaches the suction port 13 of the water pump P.

Meanwhile bypass circuit of Cb, intermediate communication passage 21 ₂ in particular so as to form the main part of the bypass communication passage 21 to be formed in the engine body E bypassing the combustion chamber 4 extends relatively long, the cylinder block 1 as described above And the water flow grooves 21 ₂ -1,21 ₂ -2 that are recessed in the mating surface between the heads 2,
As an intermediate communication passage 21 _2, a relatively simple cast that does not require a sand core or the cylinder block 1 and the head 1
Costs can be saved by accurately and easily forming by relatively simple machining performed with the mating surfaces separated from each other and exposing the mating surfaces to the outside. Moreover the intermediate communication passage 21 ₂ after its formation, it is possible to widely open to the outside through the mating surface was exposed state, it is possible to perform maintenance such post processing or visual inspection extremely easy.

In the present invention, the intermediate communication passage 21 ₂ may be formed by only the block-side water passage grooves 21 ₂ -1 or head side water passage grooves 21 _2-2.

C. Effect of the Invention As described above, according to the invention of each claim, among the bypass circuits branched from the radiator circuit, the main portion of the bypass communication passage to be formed in the engine body is formed to bypass the combustion chamber. Since the intermediate communication passage extending relatively long is formed by the water passage groove formed in the mating surface between the cylinder block and the head, the intermediate communication passage is formed by a relatively simple casting that does not require a sand core. The molding can be performed accurately and easily by a relatively simple machining process in which the cylinder block and the head are separated from each other and their mating surfaces are exposed to the outside, which contributes to cost reduction. Further, after the formation, the intermediate communication passage can be widely opened to the outside through the exposed mating surface, so that maintenance such as post-processing and visual inspection can be performed. It can be done to ease.

Further, in particular, according to the invention of claim 2, a part of a bypass circuit (that is, a bypass communication passage) for circulating hot water in the intake air heating heat riser in the intake manifold does not largely bypass the outer end of the engine body. Since the structure traverses the inside of the engine body, the heat riser bypass passage can be shortened and the configuration of the external piping can be simplified.

[Brief description of drawings]

The drawings show one embodiment of the present invention. Fig. 1 is a schematic plan view showing a water cooling system of an internal combustion engine, Fig. 2 is a schematic side view thereof, and Fig. 3 is a line III-III in Fig. 1. FIG. 4 is a plan view of the cylinder block taken along line IV-IV in FIG. 3, and FIG. 5 is a bottom view of the cylinder head taken along line VV in FIG. E …… Engine body, In …… Intake manifold, Jw…
... water jacket, P ... water pump, R ... radiator 1 ... cylinder block, 2 ... cylinder head, 13 ...
… Suction port, 14 …… Discharge port, 17 …… Bypass passage, 21 ……
Bypass communication passage, 21 ₁ …… Inlet passage, 21 ₂ …… Intermediate communication passage, 21 ₃ …… Outlet passage, 21 ₂ -1 …… Water passage, 21 ₂ -2 …… Water passage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toshihiro Oikawa 4-1 Chuo, Wako City, Saitama Prefecture Honda R & D Co., Ltd. (72) Creator Naoki Hotta 1-4-1 Wako, Saitama Prefecture Incorporated in Honda R & D Co., Ltd. (56) Bibliography Sho 62-156126 (JP, U) Shokoku 60-34741 (JP, Y2)

Claims (2)

[Scope of utility model registration request] 1. Water formed by cooling water from a discharge port (14) of a water pump (P) in an engine body (E) formed by polymerizing and binding a cylinder head (1) to an upper portion of a cylinder block (1). A radiator circuit (Cr) that returns to the suction port (13) of the water pump (P) through the jacket (Jw) and radiator (R),
The cooling water from the outlet of the water jacket (Jw) is connected to the bypass passage (17) outside the engine body (E) branched from the radiator circuit (Cr) and the bypass communication passage (21) inside the engine body (E). In a water cooling device for an internal combustion engine, which comprises a bypass circuit (Cb) that recirculates to a suction port (13) of a water pump (P) through a bypass passage (21) of the engine body (E). An inlet passage (21 ₁ ) formed in the side portion (Ea) and having an outer end opened to the outer surface of the one side portion (Ea), and the other side portion (E) of the engine body (E).
b) the formed an outlet passage (21 ₃₎ to open the outer end to said other side (Eb) outer surface, and extends so that the cylinder head (2) along the mating surface between the cylinder block (1) An intermediate communication passage (21 ₂ ) which connects the inner ends of the inlet and outlet passages (21 ₁ , 21 ₃ ) to each other, and the intermediate communication passage (21 ₂ )
Is formed by water passages (21 ₂ , -1,21 ₂ , -2) which are formed in the mating surface and bypass the combustion chamber (4) of the engine body (E). Water cooling device for internal combustion engine. 2. The internal combustion engine according to claim 1, wherein the bypass passage (17) is provided with a heat riser (18) for heating intake air flowing in the intake manifold (In). Water cooling device.