JP2005083239A - Cooling device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve optimum temperature control of an internal combustion engine and a reduction of product costs by controlling a supply flow rate of cooling water to a cylinder head and a cylinder block according to the operation state of the engine without using a plurality of water pumps. <P>SOLUTION: At a branching part between a head side supply passage 9 for supplying the cooling water to a head side jacket 1 from the water pump 4 and a block side supply passage 10 for supplying the cooling water to a block side jacket 2 from the pump 4, a distribution control valve 11 is disposed for controlling distribution of the cooling water to the both passages. The water pump 4 and the distribution control valve 11 are controlled according to the water temperature of the head side jacket 1 and the block side jacket 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The invention of this application relates to a cooling device that cools a cylinder head and a cylinder block of an internal combustion engine according to an operating state of the engine.

  As a cooling device for an internal combustion engine, a first circulation system that supplies cooling water from the cylinder block to the water jacket and a second circulation system that supplies cooling liquid from the cylinder head to the water jacket are provided. The cooling water is pumped by a main water pump driven by an engine, and the cooling water is pumped by a second water pump by a motor-driven sub water pump (see Patent Document 1). .

In this cooling device, the sub water pump is turned on / off in accordance with the operating state of the engine, thereby improving the cooling efficiency of the internal combustion engine.
Japanese Patent Publication No. 5-9615

  However, this conventional cooling device has a problem that the product cost increases because a sub-water pump must be provided in addition to the main water pump.

  Accordingly, the invention of this application enables optimal temperature control and product cost of an internal combustion engine by controlling the supply flow rate of cooling water to the cylinder head and the cylinder block according to the operating state of the engine without using a plurality of water pumps. It is an object of the present invention to provide a cooling device for an internal combustion engine that can reduce the amount of the internal combustion engine.

  As means for solving the above-mentioned problems, the invention of this application includes a water pump for pumping cooling water from the radiator side, and a head side supply passage for supplying cooling water from the water pump to the inlet of the cylinder head side water jacket. And a block-side supply passage for supplying cooling water from the water pump to the inlet of the cylinder block-side water jacket, and a head-side supply passage and a block-side supply. A distribution control valve for controlling the distribution of cooling water to the passage, a return passage connecting the outlet of the cylinder head side water jacket and the outlet of the cylinder block side water jacket to the inlet side of the radiator, and the cylinder block side of the return passage And the confluence on the cylinder head side and the cylinder block side wall A check valve that is disposed between the outlets of the rotor jacket and allows only the flow of the cooling water to the radiator side, a head water temperature detecting means for detecting the temperature of the cooling water in the cylinder head, and the cooling in the cylinder block Block water temperature detecting means for detecting the temperature of the water, and controlling the distribution control valve based on at least detection values of the head water temperature detecting means and the block water temperature detecting means.

  In the case of this invention, since the distribution control valve is controlled according to each water temperature of the cylinder head and the cylinder block, for example, the supply flow rate of cooling water to the cylinder head side water jacket is supplied to the cylinder block side water jacket according to each water temperature. It is possible to increase the flow rate more than the flow rate, or to increase or decrease the supply flow rate for both water jackets in the same manner.

  According to a second aspect of the present invention, the water pump may be driven by an electric motor, and the electric motor may be controlled based on at least detection values of the head water temperature detecting means and the block water temperature detecting means.

  In this case, since the discharge flow rate of the water pump itself can be controlled by the control of the electric motor corresponding to each water temperature, the supply flow rate to each water jacket can be more optimally controlled by one water pump.

  According to a third aspect of the present invention, when the detected values of the head water temperature detecting means and the block water temperature detecting means are not more than a set value that does not require cooling of the internal combustion engine, the water pump is rotated at an extremely low speed. It is desirable to drive with

  In this case, even when the water temperature in the water jacket is a low temperature below the set value, the flow of the cooling water does not stop completely, so the cooling water temperature in the water jacket must always be accurately detected by each water temperature detection means. Can do.

  In the invention of this application, since the distribution control valve is controlled in accordance with each water temperature of the cylinder head and the cylinder block, the flow rate of the cooling water supplied to the cylinder head and the cylinder block can be set to the operating state of the engine without using a plurality of water pumps. It is possible to control optimally according to.

  Next, an embodiment of the invention of this application will be described with reference to the drawings.

  FIG. 1 shows the overall configuration of a cooling device for an internal combustion engine according to the present invention. In FIG. 1, reference numerals 1 and 2 denote cylinder head side water jackets (hereinafter referred to as “head side jackets”) in the engine block. ), A cylinder block side water jacket (hereinafter referred to as “block side jacket”), 3 is a radiator that radiates the heat of the cooling water heated in the engine, and 4 is for pumping the cooling water. It is a water pump.

  As shown in FIG. 2, the water pump 4 has a well-known structure in which the blade 6 is rotated by rotation of the drive shaft 5 and the cooling water on the outlet 3b side of the radiator 3 is pumped to the discharge passage 7 side. The drive shaft 5 of the pump 4 is rotated by an electric motor 8.

  Further, from the discharge passage 7, a head side supply passage 9 communicating with the inlet 1 a of the head side jacket 1 and a block side supply passage 10 communicating with the inlet 2 a of the block side jacket 2 are branched. A distribution control valve 11 (to be described later) is arranged at the branch portions 9 and 10.

  The head side jacket 1 and the block side jacket 2 are independent from each other, and the cooling water is separately circulated and supplied through the supply passages 9 and 10.

  Further, the outlets 1b and 2b of the jackets 1 and 2 and the inlet 3a side of the radiator 3 are connected by a return passage 12, and the cylinder head side passage portion and the cylinder block side passage portion of the return passage 12 are connected. A check valve 15 is interposed between the junction 14 and the outlet 2 b of the block side jacket 2. The check valve 15 allows only the flow in the direction in which the cooling water in the block side jacket 2 is returned to the radiator 3, and prevents the cooling water from flowing from the head side jacket 1 to the block side jacket 2.

  The head side jacket 1 and the block side jacket 2 are provided with temperature sensors 16 and 17 (head water temperature detecting means and block water temperature detecting means), respectively, and these detected temperature signals are input to the controller 18. ing. The controller 18 receives signals from the temperature sensors 16 and 17 as well as a load and rotation speed signal of the internal combustion engine, and controls the electric motor 8 and the distribution control valve 11 in accordance with the operating state of the internal combustion engine. Yes. However, the basic control of the electric motor 8 and the distribution control valve 11 is based on the water temperature of both jackets 1 and 2.

  In this embodiment, the distribution control valve 11 is constituted by a rotary valve as shown in FIG. 3, and the discharge passage 7, the head side supply passage 9, and the block side supply passage 10 are communicated with the valve body 19. 3 openings 20a, 20b, and 20c that are electrically connected to each other are provided.

  In this distribution control valve 11, the valve element 19 can be controlled to be switched to the three positions shown in FIGS. 3A, 3B, and 3C. The first control shown in FIG. At the position, the opening 20a communicates with the discharge passage 7 and the head-side supply passage 9 in a slightly opened state, and at the same time, the opening 20b communicates with the passage 10 with the block-side supply passage 10 in a slightly opened state. Therefore, in this first position, the discharge passage 7 is connected to both the supply passages 9 and 10 in a state where the area is greatly reduced.

  On the other hand, in the second position shown in FIG. 3B, the openings 20c and 20a communicate with the discharge passage 7 and the head side supply passage 9 in the fully opened state, and at the same time, the opening 20b passes through the block side supply passage 10. It communicates with the passage 10 in a substantially half-open state. Therefore, in this second position, the discharge passage 7 is connected to the head side supply passage 9 in a fully open state and is connected to the block side supply passage 10 in a half open state.

  In the third position shown in FIG. 3C, the openings 20c, 20a, and 20b communicate with the discharge passage 7, the head-side supply passage 9, and the block-side supply passage 10 in the fully opened state. As a result, the discharge passage 7 is connected to both the supply passages 9 and 10 in a fully opened state.

  A bypass passage 22 is connected to the suction passage 21 that connects the water pump 4 and the outlet 3 b of the radiator 3, with one end communicating with the vicinity of the inlet 3 a of the radiator 3 in the return passage 12. An opening / closing valve 23 that opens the passage only at a set low temperature is interposed in a connection portion with the suction passage 21. The on-off valve 23 may open the passage 22 by a command from the controller 18 when the value detected by the temperature sensors 16 and 17 is not more than a set value that does not require cooling of the internal combustion engine.

  In addition, a heater pipe 24 is branched and connected in the middle of the return passage 12 toward the radiator 3 so that heat heated by the heat of the internal combustion engine is used for heating or the like.

  Hereinafter, specific control of the electric motor 8 and the distribution control valve 11 by the controller 18 and the state of each part at that time will be described.

  For example, when the value detected by both the temperature sensors 16 and 17 is equal to or less than a set value that does not require cooling of the jackets 1 and 2, such as when the internal combustion engine is cold started, a very small amount of cooling water is sent out. Further, the electric motor 8 (water pump 4) is rotated at a very low speed, and the valve body 19 of the distribution control valve 11 is displaced to the first position shown in FIG. As a result, only a very small amount of cooling water flows through the jackets 1 and 2, so that the amount of heat taken by the engine block by the cooling water is reduced. Therefore, the internal combustion engine warms up quickly and the operation of the internal combustion engine is stabilized.

  At this time, since a very small amount of cooling water flows in both jackets 1 and 2, the detection of water temperature due to variations in temperature in jackets 1 and 2 hardly occurs. Therefore, even in such an engine operating state, it is possible to accurately detect a water temperature change in each of the jackets 1 and 2.

  When the detected values detected by the two temperature sensors 16 and 17 are high temperature values that do not satisfy the set threshold values, such as when the internal combustion engine is operated in a medium / low speed rotation range, the engine rotation speed is increased. The electric motor 8 (water pump 4) is rotated so as to discharge the corresponding cooling water, and the valve body 19 of the distribution control valve 11 is displaced to the second position shown in FIG. Thereby, the cooling water is distributed to the head-side jacket 1 and the block-side jacket 2 at a ratio of about 2 to 1, and the discharge flow rate of the water pump 4 increases according to the engine speed.

  Further, when the detected values detected by the two temperature sensors 16 and 17 are high-temperature values that are equal to or higher than the set threshold values, such as when the internal combustion engine is operated in a high-speed rotation range, cooling according to the engine rotation speed is performed. The electric motor 8 (water pump 4) is rotated so as to discharge water, and the valve body 19 of the distribution control valve 11 is displaced to the second position shown in FIG. Thereby, the cooling water is distributed to the head side jacket 1 and the block side jacket 2 at substantially the same rate, and the discharge flow rate of the water pump 4 increases in accordance with the engine speed.

  In the case of this cooling device, cooling water can be efficiently supplied to the head-side jacket 1 and the block-side jacket 2 in accordance with the operating state of the engine, and the cooling water discharged from one water pump 4 is distributed. 11 is appropriately distributed to both jackets 1 and 2, so that the product cost is greatly reduced compared to the conventional one in which the cooling water supply flow rate to both jackets is controlled by two water pumps, respectively. be able to.

  Further, in this cooling device, the water pump 4 is driven by the electric motor 8, and the cooling water supply flow rate to each of the jackets 1 and 2 is minute under the condition that the cooling water temperature is sufficiently low such as during cold start. As a result, the engine block can be quickly heated, and the amount of work unnecessary for the water pump 4 can be eliminated to improve the efficiency of energy utilization.

  That is, when the rotational speed of the water pump 4 is simply increased according to the engine rotational speed, the total flow rate of the cooling water supplied to both the jackets 1 and 2 is as shown by the broken line in FIG. However, there is no need to cool the engine block at cold start, etc., and the required flow rate of cooling water is as shown by the solid line in FIG. 4, and the area between the broken line and the implementation line in the figure (shown with diagonal lines) Area) becomes a waste work area. In the cooling device of this embodiment, the energy utilization efficiency is increased by eliminating this useless work area.

  The embodiment of the invention of this application is not limited to that described above. For example, when the detected values by the temperature sensors 16 and 17 are not more than a set value that does not require cooling of the jackets 1 and 2. In addition, by controlling the distribution control valve 11 so as to switch the communication between the head side supply passage 9 and the block side supply passage 10 with respect to the discharge passage 7 at predetermined time intervals, a minute flow of cooling water in both jackets 1 and 2 is achieved. You may make it produce. Further, the distribution control valve 11 has a cooling water supply flow rate to the head side jacket 1 when the detected value by the temperature sensors 16 and 17 is larger than a set value that does not require cooling of the jackets 1 and 2. Control may be performed so that the flow rate is always larger than the supply flow rate.

  Next, inventions other than the invention described in the claims that can be grasped from the description of the embodiment described above will be described together with the effects thereof.

  (A) When the detected values of the head water temperature detecting means and the block water temperature detecting means are not more than a set value that does not require cooling of the internal combustion engine, the distribution control valve controls the head side supply passage and the block side supply passage. 4. The cooling apparatus for an internal combustion engine according to claim 3, wherein the cooling water supply to the engine is switched every predetermined time.

  In this case, when the water temperature in the water jacket is a low temperature below the set value, both supply passages communicate with the water pump alternately every predetermined time, so each water jacket can be rotated even if the rotation of the water pump is further reduced. A moderate flow of cooling water can be created inside.

  (B) A bypass passage communicating the inlet side and the outlet side of the radiator is provided, and the detected values of the head water temperature detecting means and the block water temperature detecting means are not more than a set value that does not require cooling of the internal combustion engine. 4. The internal combustion engine cooling device according to claim 3, wherein an opening / closing valve is provided that opens the passage only when

  In this case, when the water temperature in the water jacket becomes a low temperature below the set value, the bypass passage is opened by the on-off valve, and the cooling water is returned to the water pump without passing through the radiator. For this reason, since the cooling water is not radiated by the radiator, the temperature rises efficiently due to the explosion of the engine.

  (C) When the detected values of the head water temperature detecting means and the block water temperature detecting means are larger than a set value that does not require cooling of the internal combustion engine, the supply flow rate of cooling water to the cylinder head side water jacket is The cooling apparatus for an internal combustion engine according to any one of claims 1 to 3, wherein the distribution control valve is controlled so as to be always larger than a supply flow rate to the engine.

  In this case, it is possible to more efficiently cool the cylinder head portion that is likely to be hotter due to the explosion of the engine.

The circuit block diagram which shows one Embodiment of invention of this application. Sectional drawing of the water pump which shows the embodiment. The typical expanded sectional view which shows the action | operation of the distribution control valve of the embodiment. The figure which showed the engine speed-flow rate characteristic of the embodiment with the comparative example.

Explanation of symbols

1. Head side jacket (cylinder head side water jacket)
2. Block side jacket (cylinder block side water jacket)
DESCRIPTION OF SYMBOLS 3 ... Radiator 4 ... Water pump 8 ... Electric motor 9 ... Head side supply passage 10 ... Block side supply passage 11 ... Distribution control valve 12 ... Return passage 15 ... Check valve 16 ... Temperature sensor (head water temperature detection means)
17 ... Temperature sensor (block water temperature detection means)

Claims (3)

A cooling device that controls the supply flow rate of cooling water to the cylinder head and the cylinder block according to the operating state of the internal combustion engine,
A water pump for pumping cooling water from the radiator side;
A head-side supply passage for supplying cooling water from the water pump to the inlet of the cylinder head-side water jacket;
A block side supply passage for supplying cooling water from the water pump to the inlet of the cylinder block side water jacket;
A distribution control valve disposed at a branch portion of the head side supply passage and the block side supply passage, and for controlling distribution of cooling water to the head side supply passage and the block side supply passage;
A return passage connecting the outlet of the cylinder head side water jacket and the outlet of the cylinder block side water jacket to the inlet side of the radiator;
A check valve that is arranged between the confluence of the cylinder block side and the cylinder head side of the return passage and the outlet of the water jacket on the cylinder block side and allows only the flow in the direction of returning the cooling water to the radiator side,
Head water temperature detecting means for detecting the temperature of the cooling water in the cylinder head;
Block water temperature detecting means for detecting the temperature of the cooling water in the cylinder block,
A cooling apparatus for an internal combustion engine, wherein the distribution control valve is controlled based on at least detection values of the head water temperature detecting means and the block water temperature detecting means.   2. The cooling apparatus for an internal combustion engine according to claim 1, wherein the water pump is driven by an electric motor, and the electric motor is controlled based on at least detection values of the head water temperature detecting means and the block water temperature detecting means. . The water pump is driven at an extremely low rotation when the detected values of the head water temperature detecting means and the block water temperature detecting means are not more than a set value that does not require cooling of the internal combustion engine. The internal combustion engine cooling device according to 2.

Images