JPH09137726A - Cooling device for multiple cylinder engine with suspending cylinder mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately retain balance of temperature difference between a suspending cylindrical part and a moving cylindrical part, by controlling a cooling water supplying directional control valve so that cooling water accompanying the change-over of a cylinder during the operation of the whole cylinders of a water-cooled multiple cylinder engine and cylinder suspending operation, can be supplied after lapse of the predetermined delay from the change-over operation of the cylinders. SOLUTION: Directional control valves 15a, 15b are closed during the suspending cylinder operation of a water-cooled V8 type engine 11, hereby, most water is returned to a cooling water introducing passage 14 by being passed through circulating flow passage 17a, 17b and a part of cooling water is delivered to a first cooling water passage A by being passed through supply increasing passages 16a, 16b so that the supply of cooling water to the passage A can be increased. At this time, during a change-over period from a cylinder operating condition to a cylinder suspending condition and vice versa, the directional control valves 15a, 15b are controlled to be changed over having time difference that a certain extent is delayed after lapse of the predetermined time than the change-over of the cylinder operating condition. Hereby, balance of temperature difference between a suspended cylindrical part and a moving cylindrical part is sufficed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a multi-cylinder engine with a cylinder deactivation mechanism, which is capable of deactivating some of the cylinders in accordance with operating conditions.

[0002]

2. Description of the Related Art Conventionally, a multi-cylinder engine with a cylinder deactivation mechanism has been adopted which is designed to improve fuel efficiency by appropriately suspending operation of up to half of all cylinders during light load operation. ing. For example, in the water-cooled V-type 8-cylinder engine 11 as shown in FIG. 11, when all cylinders are in operation, the cylinders are operated in the order of 1-2-7-3-4-5-6-8. However, when the four cylinders are deactivated, the cylinders 2 and 3 and the cylinders 5 and 8 are deactivated. In addition, when the cylinders 2, 3, 5 and 8 are stopped,
For example, the cylinder is deactivated by stopping the fuel supply and the ignition to the cylinder to be deactivated.

Therefore, when the cylinder is deactivated, the cylinders 1 and 7 at both ends of the engine 11 on one side of the column 11a are operating, and the cylinders 4 and 6 on the inside of the engine 11 are operating on the other side of the column 11b. Cylinder to be used (hereinafter referred to as "moving cylinder" if necessary)
That is) and the cylinder to be deactivated is adjacent to each other. By the way, generally, as a water-cooled cooling device for a multi-cylinder engine with a cylinder deactivation mechanism, cooling water passing through a radiator 12 is circulated by a water pump 13 in all cylinders, so that all cylinders are operated and some cylinders are deactivated. Instead, all the cylinders are cooled.

In such a configuration in which each cylinder is cooled even when the cylinder is deactivated, the temperature of the entire cooling water does not rise and the temperature of the cooling water decreases when the cylinder is deactivated. A vehicle that uses the heating system will not be able to obtain sufficient heating during light load operation. Therefore, for example, as disclosed in Japanese Utility Model Publication No. 2-5059, at the same time as the cylinder deactivation switching during light load operation, the circulation of cooling water to the cylinder deactivation portion is stopped,
It has been proposed to circulate the cooling water only in the moving cylinder part to reduce the temperature drop of the entire cooling water.

[0005]

However, in such a conventional multi-cylinder engine with a water-cooled cylinder deactivation mechanism, not only the cylinders that are deactivated at the time of cylinder deactivation are immediately stopped, but also the moving cylinders. Since the cylinders that are operating are constantly cooled, the temperature difference between the idle cylinder portion and the moving cylinder portion is large, and the difference in temperature difference is uneven, as indicated by the solid and dotted lines in FIG. .

As described above, if the temperature difference between the idle cylinder part and the moving cylinder part becomes large and the temperature balance between them is not properly maintained, the gap between the cylinder block and the piston becomes large at the time of overcooling and abnormal noise is generated. However, as described above in Japanese Utility Model Publication No. 2-5059, only the all-cylinder operation can be performed because it may cause creaking with the piston due to increased friction when overheated. If the cooling water supply on the cylinder deactivation side is immediately switched when switching between the cylinder deactivation operation and the cylinder deactivation operation, the problem cannot be solved.

The present invention was devised in view of the above problems, and supplies the cooling water accompanying the switching of the cylinders of the water-cooled multi-cylinder engine between the all-cylinder operation and the cylinder deactivation operation. By carefully controlling the opening and closing timing of the cooling water supply switching control valve, such as after a lapse of a predetermined delay time after switching, the temperature difference between the idle cylinder part and the moving cylinder part can be properly maintained. An object of the present invention is to provide a cooling device for a multi-cylinder engine with a cylinder deactivation mechanism.

[0008]

Therefore, the cooling device for an engine with a cylinder deactivation mechanism of the present invention is a multi-cylinder engine with a cylinder deactivation mechanism in which a part of cylinders can be deactivated in accordance with an operating state. A first cooling water passage that cools a first cylinder group that is always operating, a second cooling water passage that cools a second cylinder group that is switched to active or inactive according to the operating state of the engine, and the second cylinder group Switching control valve that stops or suppresses the circulation of the cooling water to the second cooling water passage when the operation of the second cylinder group is stopped, and the switching control valve after a lapse of a predetermined delay time from the switching of the second cylinder group to the suspension or the operation. And a control means for switching control of the.

At this time, it is preferable that the delay time is set in accordance with the engine load state and the water temperature state, and the deactivation switching delay time when deactivating the second cylinder group is deactivated. It is preferable that the setting is made to be longer than the operation switching delay time when switching the two cylinder group to the operating state. Furthermore, when the second cylinder group is deactivated, the switching control valve is used to increase the amount of water supplied to the first cooling water passage for cooling the first cylinder group from the second cooling water passage to the first cooling water passage. It is also possible to provide a supply passage for supplying cooling water to the cooling water passage.

Further, the control means may be configured to open and close the switching control valve at a predetermined timing when the second cylinder group is deactivated.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 10 show one embodiment of a cooling device for a multi-cylinder engine with a cylinder deactivation mechanism according to the present invention. 1 is a configuration diagram showing a connection configuration between each cylinder of the engine and each cooling water passage, FIG. 2 is a block diagram showing a control configuration of the present device, and FIG. 3 is a graph showing a switching timing of the switching control valve at the time of switching the cylinder deactivation. FIG. 4 is a comparative diagram showing the temperature change between the moving cylinder portion and the cylinder-removing portion when the cylinder is stopped, and FIG. 5 is a flowchart explaining the operation when switching from the moving-cylinder state to the cylinder-stopping state,
6 is a map diagram relating to the flow chart of FIG. 5, FIG. 7 is a flow chart explaining the operation at the time of switching from the cylinder deactivation state to the moving cylinder state, FIG. 8 is a map diagram relating to the flow chart of FIG. A flow chart for explaining the operation at the time of switching from the moving cylinder state to the deactivated cylinder state according to the embodiment of
FIG. 10 is a map diagram related to the flowchart of FIG. 9, and the same reference numerals in each figure indicate almost the same parts.

In FIG. 1, reference numeral 11 denotes a water-cooled V8 type multi-cylinder engine.
3, 5, 7 are arranged in order, and the cylinders 2, 4, 6, 8 are arranged in order in the other side row 11b. A multi-cylinder engine with a cylinder deactivation mechanism is configured by being divided into one cylinder group 1, 7, 4, 6 and a second cylinder group 3, 8, 5, 2 which is stopped during cylinder deactivation.

Then, a cooling unit such as a water jacket for the cylinders 1 and 7 on the one side 11a which is constantly operated (hereinafter, referred to as "cooling") via a water pump 13 provided in a cooling water introduction passage 14 connected to the radiator 12. Section means a thing such as a water jacket) and the first cooling water passage A communicating with the cooling section for the cylinders 4 and 6 on the other side 11b.
Are formed.

The first cooling water passage A on the downstream side of the water pump 13 is branched to communicate with the cooling section for the cylinder 3 on the one side 11a and the cooling section for the cylinder 8 on the other side 11b. A second cooling water passage B1 and a second cooling water passage B2 connected to the cooling portion for the cylinder 5 on the one side 11a and the cooling portion for the cylinder 2 on the other side 11b are formed. Then, electromagnetic switching control valves 15a and 15b are provided in the second cooling water passage B1 and the second cooling water passage B2, respectively. And
When the switching control valves 15a and 15b are opened (the operation valve body 1 shown
5 is in a horizontal state), that is, when the passages are formed during operation of all cylinders, the second cooling water passages B1 and B2 are in communication with each other, while the switching control valves 15a and 15b are closed (operation valves shown in the figure). (When the body 15 is in the vertical state), that is, when the passage is formed when switching the cylinders, the communication between the second cooling water passages B1 and B2 is closed and the second cooling water passage on the upstream side of the switching control valve is switched to the switching control valve 15a. , 15b is connected to the side passage.

In this side passage, the switching control valve 15a,
Passage 16 for increasing supply, which communicates with the first cooling water passage A from 15b
a, 16b and a return passage 17a returning to the cooling water introduction passage 14,
17b is provided, and one switching control valve 15
A bypass passage 18 that communicates from a to the upstream side of the other switching control valve 15b is provided. In this case,
Bypass passage 18 on the side of switching control valve 15a and passage 1 for increasing pay
The relationship between the thickness of 6a and the thickness of the return passage 17a is as follows.
8, the increase passage 16a is thicker, and the return passage 17a is thicker than the increase passage 16a.

Also on the side of the switching control valve 15b, the return passage 17b is set to be thicker than the supply passage 16b. By the way, the second cooling water passage is
In the illustrated V8 cylinder engine, the cylinders 3 and 8 are deactivated in the first stage, and the cylinders 2 and 5 are deactivated in the second stage. Therefore, the cooling water system is divided into two parts. In a multi-cylinder engine with a cylinder deactivation mechanism having only one stage, only one second cooling water passage and one switching control valve are required.

Then, each cylinder 1, 3 on the one side 11a
5, 7 and the cooling water outlet passages 19 led out from the respective cylinders 2, 4, 6, 8 on the other side 11b are joined together and connected to the radiator 12. In the figure, 20 is a thermostat provided in the cooling water introduction passage 14,
Is a bypass path connecting the cooling water outlet path 19 and the cooling water inlet path 14.

With the above construction, the first
Cooling water is sent through the cooling water passage A as shown by the arrow a to cool the cylinders 1 and 7 and the cylinders 4 and 6, and at the same time, both of the switching control valves 15a and 15b are in the open state (the actuation valve body 15
Is in a horizontal state), the cooling water flowing through the second cold water passage B1 as shown by the arrow b1 cools the cylinders 3 and 8 and flows through the second cooling water passage B2 as shown by the arrow b2. Cooling water cools the cylinders 5 and 2.

When the switching control valves 15a and 15b are switched to the closed state (the operating valve body 15 is in the vertical state), most of the water is returned to the cooling water introducing passage 14 through the reflux passages 17a and 17b. At the same time, a part of the cooling water is sent to the first cooling water passage A through the supply passages 16a and 16b, and the supply of the cooling water to the first cooling water passage A is increased.

Further, the cooling water on the side of the switching control valve 15a is sent from the bypass passage 18 to the side of the second cooling water passage B2 to adjust the balance of the water flow when the first stage switching and the second stage switching are performed. I have to. Furthermore, the cooling water outlet 1
A water temperature sensor 21 is provided in the vicinity of the confluence portion of 9, but a plurality of water temperature sensors 21 may be appropriately provided at other portions of the cooling water passage.

Then, according to the temperature information extracted from the water temperature sensor 21 and the detection result of the operating state detecting means 22 for detecting the engine operating state from the engine load and the engine speed, the engine is judged to be in the all-cylinder operating state. Valve control means 23 is provided for switching control of the switching control valves 15a and 15b in response to a cylinder switching signal from the cylinder deactivation control means 24 for switching to the partial cylinder deactivation state.

That is, as shown in the block diagram of FIG. 2, in response to the cylinder switching signal from the cylinder deactivation control means 24 and the temperature information of the water temperature sensor 21, a control signal from the valve control means 23 to the switching control valves 15a and 15b. Is sent to switch between the first cooling water passage A and the second cooling water passages B1 and B2. Hereinafter, the state of the cooling water control in the cooling water system will be described based on the control by the valve control means 23.

First, when the cylinder operating state of the engine is switched to the cylinder deactivated state and when the cylinder deactivated state is switched to the cylinder operating state, the switching control valves 15a and 15b are switched from the cylinder operating state switching of the engine. Also, the switching is performed with a certain time delay after the elapse of a predetermined time. This will be described with reference to FIG. 3. When switching the engine from the cylinder operating state (operating state) to the cylinder deactivated state, switching is performed by applying a delay (delay) of 30 to 60 seconds to the switching control valves 15a and 15b, and When switching the engine from the cylinder deactivated state to the cylinder operating state, the switching control valves 15a and 15b are delayed by 5 to 10 seconds for switching.

That is, as shown in FIG. 5, in the switching mode from the cylinder operating state to the cylinder deactivated state, after the switching is started, in step c1, the engine load (average volume in the last 30 seconds is calculated according to the map M1 shown in FIG. 6). Efficiency) and a delay of 30 to 60 seconds depending on the current water temperature level, and in step c2, the switching control valves 15a and 15b are used to increase the passage 1
The increased amount of cooling water is sent to the moving cylinders (cylinders 1, 7, 4, 6) by being sent to the first cooling water passage A via 6a and 16b.

Further, in the switching mode from the cylinder deactivated state to the cylinder operating state as shown in FIG. 7, after the switching start, at step d1, the engine load (average volume efficiency of the past 30 seconds in the past 30 seconds is determined by the map M2 shown in FIG. ) And a delay of about 5 to 10 seconds depending on the current water temperature, and step d2
Then, from the switching control valves 15a, 15b to the increase passage 16a,
The increased amount of cooling water to the moving cylinders (cylinders No. 1, 7, 4, 6) being sent to the first cooling water passage A via 16b is stopped.

In this way, when switching from the cylinder operating state to the cylinder deactivated state, the water supply is stopped after a predetermined time has elapsed from the switching time, that is, after the temperature of the cylinder deactivated portion has been lowered to some extent. Moreover, in the moving cylinder part, the amount of water supplied to the moving cylinder part is increased when the temperature of the moving cylinder part rises, so the temperature difference between the idle cylinder part and the moving cylinder part at the time of operation switching is balanced. Can be kept properly.

Also, when switching from the cylinder deactivated state to the cylinder operating state, the cooling water passage is switched after a lapse of a predetermined time from the time of switching the operation to start the water supply to the cylinder deactivated portion and the moving cylinder portion. Since the increased water supply to the cylinder is stopped, the balance of the temperature difference between the idle cylinder part and the moving cylinder part at the time of operation switching can be appropriately maintained in this case as well. Therefore, as clear from the comparison between the graph of FIG. 4 according to the present embodiment and the graph of FIG. 12 according to the conventional example, in the present embodiment, the difference in temperature difference between the idle cylinder part and the moving cylinder part is reduced, In addition, the cylinder blocks are in a well-balanced state, which prevents thermal distortion and deformation of the cylinder block, eliminates creaking with the piston due to increased friction, or the generation of impact noise with the piston due to the formation of gaps This has the effect of contributing to the performance improvement of the multi-cylinder engine with a mechanism and also of being able to greatly contribute to the reduction of fuel consumption.

Further, as described above and as can be seen from FIG. 3, a predetermined delay time (closed delay time) when the second cylinder group, that is, the cylinder deactivation section is switched from the operation to the deactivation is 30.
It is set to -60 seconds, and the predetermined delay time (open delay time) when switching from rest to operation is set to 5 to 10 seconds. The delay time is set longer than the open delay time (delay time when switching from the cylinder deactivated state to the cylinder operating state) because the transition of the temperature change in the cylinder deactivated portion when switching to the cylinder deactivated state. However, it takes longer than the transition of the temperature change at the time of switching to the cylinder operating state.By performing such careful control, the temperature difference between the cylinder deactivation section and the moving cylinder section can be maintained and the cylinder deactivation There is an effect that can contribute to the performance improvement of the multi-cylinder engine with a mechanism.

Further, in a multi-cylinder engine in which the cylinders are close to each other, such as a Siamese type engine, the second cooling water passages B1 and B are provided when the second cylinder group is deactivated.
The switching control valves 15a and 15b are controlled so as to switch the water supply to the water supply 2 to the water supply and the water supply stop by a predetermined tamming. This will be described with reference to FIGS. 9 and 10. In the switching mode from the cylinder operating state to the cylinder deactivated state, the map M1 shown in FIG.
A delay is applied according to the engine load and the water temperature depending on the value, and the amount of water supplied to the moving cylinder portion is increased at step e2. At this time, at step e3, according to the duty classification divided into several stages according to the map M3 shown in FIG. As shown by the dotted line E in FIG. 3, the water supply to the cylinder deactivation side is intermittently executed.

That is, the cooling water is supplied at a timing of about 3 seconds in 10 seconds in a large duty state where the engine load is high and the water temperature is high, and the cooling water is supplied at a timing of about 2 seconds in 10 seconds in a duty state. However, when the engine load is small and the water temperature is low and the duty is small, 1 in 10 seconds
The switching control valves 15a and 15b are controlled to be opened / closed so that the cooling water is supplied at a timing of about a second.

As described above, in an engine in which the moving cylinder portion and the cylinder deactivation portion are close to each other, the temperature of the cylinder deactivation portion rises even when the cylinder is deactivated. The cooling water is intermittently supplied so that the temperature of the cylinder deactivation portion during the cylinder deactivation does not rise more than necessary.

[0032]

As described in detail above, claim 1 of the present invention
According to the cooling device for an engine with a cylinder deactivation mechanism described above, in a multi-cylinder engine with a cylinder deactivation mechanism in which some cylinders can be deactivated in accordance with an operating state, the first cylinder group that is always operating is cooled. A first cooling water passage, a second cooling water passage for cooling the second cylinder group which is switched to be operated or stopped in accordance with the operating state of the engine, and to the second cooling water passage when the operation of the second cylinder group is stopped. A switching control valve for stopping or suppressing the circulation of the cooling water, and a control means for controlling the switching of the switching control valve after a lapse of a predetermined delay time from the switching of the second cylinder group to the pause or the operation. Therefore, even if the second cylinder group is deactivated or the operation is switched, the supply of the cooling water to the second cylinder group is not immediately stopped or started, but is stopped or started with a slightly delayed time difference. , Switching to a cylinder suspension In rapidly perform cooling of the second cylinder group, upon switching to the all-cylinder operating state it will be performed by delaying the cooling of the second cylinder group.

Therefore, the cylinder block is not partially and unevenly overheated or overcooled, the temperature difference between the idle cylinder part and the moving cylinder part is well balanced, and the friction between the cylinder block and the piston is increased. There is an advantage that the fuel consumption can be prevented and the fuel consumption can be reduced. According to the cooling device for an engine with a cylinder deactivation mechanism according to claim 2 of the present invention, since the delay time is set according to the engine load state and the water temperature state, each cylinder group is overheated or overcooled. There is an advantage that the cooling water can be appropriately supplied according to the change in the state of the cooling water so as not to be caused.

According to the third aspect of the present invention, there is provided the cooling system for an engine with a cylinder deactivation mechanism, wherein the switching delay time at the time of switching the second cylinder group to the deactivated state is set to the second cylinder group. Since it is set to be longer than the operation switching delay time when switching to the operating state, the temperature decrease time of the cylinder deactivation part when switching to the cylinder deactivating state and the time when switching to the all cylinders operating state By stopping and starting the supply of the cooling water so as to match the difference between the rising time of the temperature of the idle cylinder part and the rising time, the balance of the temperature difference between the idle cylinder part and the moving cylinder part can always be kept good. There are advantages.

According to a fourth aspect of the present invention, there is provided a cooling device for an engine with a cylinder deactivation mechanism, wherein when the cylinder deactivation of the second cylinder group is performed, the first cooling water passage for cooling the first cylinder group is introduced. Since a supply passage for supplying cooling water from the second cooling water passage to the first cooling water passage through the switching control valve is provided so as to increase the supply water of the By increasing the amount of water supplied to the moving cylinder to prevent the moving cylinder from being overheated, there is an advantage that it can help maintain an appropriate balance of the temperature difference between the idle cylinder and the moving cylinder.

According to a fifth aspect of the present invention, there is provided an engine cooling device with a cylinder deactivation mechanism, wherein the control means opens and closes the switching control valve at a predetermined timing when the cylinder of the second cylinder group is deactivated. Since it is configured to operate, it is possible to properly maintain the balance of the temperature difference between the idle cylinder part and the moving cylinder part by preventing the idle cylinder part from being overheated due to the influence of the moving cylinder part even when the cylinder is idle. There are advantages.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a cooling device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a control configuration according to an embodiment of the present invention.

FIG. 3 is a switching timing chart of the switching control valve between a cylinder deactivated state and a moving cylinder state according to the embodiment of the present invention.

FIG. 4 is a comparison diagram of temperature changes between a moving cylinder part and a cylinder-free part when the cylinder is stopped according to an embodiment of the present invention.

FIG. 5 is a flow chart illustrating an operation at the time of switching from the moving cylinder state to the deactivated cylinder state according to the embodiment of the present invention.

FIG. 6 is a map diagram related to the flowchart of FIG.

FIG. 7 is a flowchart illustrating an operation at the time of switching from the cylinder-inactive state to the moving-cylinder state according to the embodiment of the present invention.

8 is a map diagram relating to the flowchart of FIG. 7. FIG.

FIG. 9 is a flowchart illustrating an operation at the time of switching from the moving cylinder state to the deactivated cylinder state according to another embodiment of the present invention.

FIG. 10 is a map diagram relating to the flowchart of FIG.

FIG. 11 is a schematic plan view showing a cylinder arrangement of a conventional general water-cooled V8 engine.

FIG. 12 is a comparison diagram of temperature changes between a moving cylinder portion and a cylinder-removing portion when switching cylinders according to a conventional example.

[Explanation of symbols]

 1 to 8 cylinders 11 water-cooled V8 engine 11a V8 one-sided cylinder row 11b V8 engine other-sided cylinder row 12 radiator 13 water pump 14 cooling water introduction path 15 actuating valve body 15a, 15b switching control valve 16a, 16b Supply passage 17a, 17b Recirculation passage 18 Bypass passage 19 Cooling water outlet 19a Bypass passage 20 Thermostat 21 Water temperature sensor 22 Operating state detecting means 23 Valve control means 24 Cylinder control means A 1st cooling water passage B1, B2 2nd Cooling water passage M1, M2, M3 map a, b1, b2 Cooling water flow direction

Claims (5)

[Claims] 1. A multi-cylinder engine with a cylinder deactivation mechanism, wherein a part of cylinders can be deactivated in accordance with an operating state, a first cooling water passage for cooling a constantly operating first cylinder group, and an engine A second cooling water passage that cools the second cylinder group that is switched to active or inactive according to the operating state, and stops or suppresses the circulation of cooling water to the second cooling water passage when the operation of the second cylinder group is stopped. And a control means for controlling the switching of the switching control valve after a lapse of a predetermined delay time from the switching of the second cylinder group to rest or operation. Cooling system for multi-cylinder engine with mechanism. 2. The cooling device for a multi-cylinder engine with a cylinder deactivation mechanism according to claim 1, wherein the delay time is set according to an engine load state and a water temperature state. 3. The idle switching delay time when switching the second cylinder group to the idle state is set to be longer than the operation switching delay time when switching the second cylinder group to the operating state. The cooling device for a multi-cylinder engine with a cylinder deactivation mechanism according to claim 1, wherein: 4. When the second cylinder group is deactivated, the switching control valve is used to increase the amount of water supplied to the first cooling water passage for cooling the first cylinder group from the second cooling water passage. The first
2. The cooling device for a multi-cylinder engine with a cylinder deactivation mechanism according to claim 1, further comprising: a supply passage for supplying cooling water to the cooling water passage. 5. The cylinder according to claim 1, wherein the control means is configured to open / close the switching control valve at a predetermined timing when the cylinder of the second cylinder group is cylinder-free. Cooling system for multi-cylinder engine with mechanism.