JPS6035113A - Engine cooling apparatus - Google Patents

Abstract

PURPOSE:To cool each cylinder to an optimum temp. by installing a coolant injection means for each cylinder and controlling each injection means according to the operation state, in the apparatus for cooling an engine by utilizing the evaporation heat due to the vaporization of the coolant. CONSTITUTION:In a cylinder-quantity control engine in which supply of mixed gas into the 4th-6th cylinders 54-56 is suspended in a low-load low-speed operation range, one edge of a coolant injection pipe 15 installed into a cylinder head 4 is connected to a coolant supply passage 12 connected to the discharge side of a pump 11 for feeding the pressurized coolant. The injection pipe 15 is equipped with injecton ports 16... opposed to the upper position of the peripheral wall 5a of the combustion chamber of each cylinder 51-56, and a cut-off valve 17 for the supplied coolant is installed at the center part. Therefore, the supply of coolant into the cylinders 54-56 can be cut-off by closing the cut-off valve 17 during partial cylinder operation. The coolant after injection is introduced into a steam turbine 20 and a radiator 21 through a recovery passage 19 and then recovered into a tank 9.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine cooling device that cools an engine using the heat of vaporization caused by evaporation of a refrigerant.

(Prior art) Engine cooling is generally done by providing a water jacket around the combustion chamber in the cylinder block and cylinder head, and circulating cooling water through the jacket to remove the heat generated in the combustion chamber. This is done by absorbing heat and dissipating this heat into the atmosphere through a radiator. However, such a cooling method requires a large amount of water, which makes it difficult to use an internal engine.

Further, when starting an engine in a cold state, the combustion chamber is surrounded by cooling water, so it takes time to warm up the engine to the optimum temperature.

On the other hand, as disclosed in, for example, JP-A-56-1-13312@ and JP-A-56-115812, there are cooling systems that use the heat of vaporization of water to cool the engine. There is. These can be effectively cooled with a small amount of cooling water by providing thin grooves on the cylinder peripheral wall and vaporizing water using capillary action, or by injecting cooling water into the upper part of each cylinder that serves the engine. A valve is provided to inject cooling water onto the peripheral wall of the combustion chamber in order to efficiently cool the combustion chamber by absorbing the heat of vaporization of the same water.

However, the methods shown in the above publications do not allow uniform cooling even though the heat load of each cylinder is different, for example, the heat dissipation conditions are different between the cylinder located in the center and the cylinders located at both ends. Therefore, there is a dynamic point in which it is not possible to optimally control the combustion chamber circumferential wall adjustment for all cylinders.

This is particularly a problem in the case of a so-called number-of-cylinders control engine, in which the operation of a specific cylinder is stopped and the number of cylinders is reduced when the load is low in a multi-cylinder engine. In other words, in this J: Una engine, if the dormant cylinders are cooled in the same way as the operating cylinders during cylinder reduction operation, it will become supercooled, and when the engine is operated again, combustion will not resume properly, resulting in problems such as incomplete fuel combustion. arise.

(Object of the Invention) The present invention deals with the above-mentioned problems regarding engine cooling.In a cooling method that utilizes the heat of vaporization of a refrigerant, each cylinder is cooled to an optimum temperature depending on the operating condition. . The purpose of this is to efficiently cool the engine without causing overcooling or insufficient cooling of some cylinders.

-3- (Structure of invention) The present invention is configured as follows to achieve the above object.

That is, as shown in FIG. 1, the refrigerant supply control means A receives a signal from the operating state detection means B that detects the operating state of each cylinder, and injects the refrigerant injection means G...C provided in each cylinder, respectively.
The refrigerant injection supply is controlled for each cylinder.

The operating state detection means B detects the peripheral wall temperature of the combustion chamber, which differs depending on the arrangement of each cylinder or the difference in combustion state, or controls the number of cylinders 1. In the case of an engine, it is detected whether a specific cylinder is in operation or at rest. The refrigerant supply means A controls the refrigerant injection means C to inject, inject, or stop the respective refrigerant injection means C, depending on the detected state of each cylinder. Note that refrigerant injection control for each cylinder can be performed for each cylinder individually, or in the case of an engine with cylinder number control. There are cases where control is performed for the II.

(Embodiment) -4- Hereinafter, an embodiment in which the present invention is applied to a cylinder number controlled engine will be described.

FIG. 2 is a system diagram showing an embodiment of the present invention. Here, the drawing on the right side of the figure is a partial plan view of the drawing on the left side of the figure, and the engine 1 indicated by the chain line is the same as the engine 1 on the left side of the figure. As shown in the figure, an engine 1 has pistons 2...
2. It has six cylinders 51 to 56 formed by the cylinder block 3 and the cylinder head 4, and has a cooling device 6 for cooling the engine 1, etc., and operates the number of operating cylinders of the engine 1. It has a cylinder number control III equipment 7 that performs increase/decrease control according to the state, and a control circuit 8 for the cooling device 6 and the cylinder number control device 7.

The cooling device 6 includes a pump 11 for pumping refrigerant provided at the outlet 10 of the tank 9 as a refrigerant supply system, a refrigerant supply passage 12 connected to the discharge side of the pump 11, and a refrigerant supply passage 12 connected to the discharge side of the pump 11. The refrigerant supply passage 1 has a bypass valve 14 that controls opening and closing of the bypass passage 13 provided therein.
2 is connected to one end of a refrigerant injection pipe 15 provided in the cylinder head 4 of the engine 1. This injection pipe 15 includes combustion chamber peripheral walls 5a and 5a in each cylinder 51 to 56.
... 16 are provided at the lower positions of the pipes 5a, and a refrigerant supply cutoff valve 17 is provided in the center of the pipe 15, and the three cylinders 54 located on the right side of the figure It is possible to cut off the refrigerant supply to ~56. Further, as a refrigerant recovery system, a refrigerant recovery passage 19 is led out from the side wall of the cylinder block 3 to the space 18 around each of the cylinders 51 to 56 in the cylinder block 3 and the cylinder head 4, and is connected to the steam turbine 2.
0 and the radiator 21 to the tank 9. Note that the steam turbine 20 has a radiator 21 with a cold fIJ.
! A fan 22 that sends I is driven.

On the other hand, the cylinder number control device 7 is provided on one side of the engine 1, and connects the downstream side of the throttle valve of the intake pipe 25, which is provided with the fuel r1 injection valve 23 and the throttle valve 24 from the upstream side, by a partition wall 26. The passage is branched into two passages 271 and 272, and one branch passage 272 is provided with a shutter valve 28. and close the shutter valve 28.
An actuator 29 for detecting the rotation speed of the engine 1, an intake negative pressure sensor 30 for detecting the intake negative pressure on the downstream side of the throttle valve, and a rotation speed sensor 31 for detecting the rotation speed of the engine 1 are provided in the intake pipe 25. Here, the branch passage 272 provided with the shutter valve 28 is historically branched into three passages, and the branch passage 272 is divided into three passages, which are connected to three cylinders 54 to 54 located downstream of the cutoff valve 17 of the refrigerant injection pipe 15 in the cooling device 6. 56
The combustion chambers are connected to each other. In addition, the other branch passage 27
1 is further branched into three passages, each communicating with the combustion chambers of cylinders 51-53. The control circuit 8 receives the signal S1 from the intake negative pressure sensor 30 and the rotation speed sensor 3.
1, the peripheral wall 5 of the combustion chamber of one of the cylinders 54 to 56 whose intake passage is equipped with a shutter valve 28.
A receives the signals from the temperature sensor 32 which is attached to the peripheral wall 5a and detects the temperature of the peripheral wall 5a, and receives these signals 8.
Based on signals S1 to S3, control signals S4 and S5 are sent to the air conditioner 29 in the cylinder number control device 7 and the refrigerant supply cutoff valve 17 in the cooling system H6, respectively.

Next, the configuration of the control circuit 8 will be explained. As shown in FIG. 3, the control circuit 8 includes: - a first comparator 33 into which a signal 81 from the intake negative pressure sensor 30 is input; and a second comparator 33 into which a signal S2 from the rotation speed sensor 31 is input. 34 and the output signal 86. of both comparators 33.371. An AND circuit 35 to which Sy is input, a first driver 36 to which output signal S8 of the AND circuit 35 is input, and a temperature sensor 32.
a third comparator 37 to which the signal S3 from the comparator 37 is input; an OR circuit 38 to which the output signal S9 of the comparator 37 and the output signal S8 of the AND circuit 35 are input; and an output signal S10 of the OR circuit 38. and a second driver 39 into which is input the first driver. Control signals QSn and S5 are output from the second drivers 36 and 39 to the actuator 29 and the refrigerant supply cutoff valve 17, respectively.

Here, each of the comparators 33. Input on '34.37 -8- The signal St from each sensor 30.31.32.

82.33 have been converted into voltage levels, respectively, and are reference voltage values ej, e2 . e3, and when each input signal level is smaller than each set reference value, each comparator 3
3.34.37 output signal 86. Sy and Sq become Todorbel. Also number 1. The second drivers 36, 39 receive respective input signals S8. When S1o is at the '1-1' level, the signals S4 and S5 are output to 1, the actuator 29 is operated so that the shutter valve 28 is closed, and the refrigerant supply valve 17 is also closed.

Next, the operation of the above embodiment will be explained.

First, when the operating range of the engine 1 is in a high load or high speed range, the signal S1 from the intake negative pressure sensor 30 indicating the intake negative pressure value downstream of the throttle valve 24 in the intake passage indicates the intake air corresponding to the reference value e1. It is larger than the negative pressure value (atmospheric pressure side), or the signal S2 from the rotation speed sensor 31 indicating the engine rotation speed is higher than the rotation speed corresponding to the reference value e2.

Therefore, −〇 − the first . Output signal 86 of the second comparator 33.3/I, Sy
At least one of them is at the "L" level. Therefore, the AND circuit 35 to which both signals @ S 6 and S y are input
The output signal S8 also becomes the "L" level. In other words, at high speeds or high loads as shown by area x in Figure 4, the AN
I') The output signal S8 of the circuit 35 becomes l L 97 level. Therefore, in this case, since the control signal 84 is not output from the first driver 36, the actuator 29 that drives the shutter valve 28 in the closing direction cannot operate when the signal S4 is received, and the shutter valve 28 is kept in the open state. Ru. This allows air and fuel to flow through all cylinders 51 to 56.
is supplied to the engine 1, and the engine 1 enters an all-cylinder operation state. At this time, since the cylinder 56 equipped with the temperature sensor 32 also operates, the temperature of the peripheral wall of the combustion chamber of the cylinder 56 indicated by the signal S3 from the sensor 32 is higher than the temperature corresponding to the reference value 03 of the third comparator 37. Therefore, the output signal 89 of the comparator 37 is
Therefore, the output signal S10 of the OR circuit 38 to which the output signal S9 of the third comparator 37 and the output signal S8 of the AND circuit 35 are input also becomes the level "[". The second driver 39 does not output the control signal S5. Therefore, the refrigerant supply cutoff valve 17 provided in the refrigerant injection pipe 15 in the cooling device 6 is in an open state.

By the way, the liquid refrigerant stored in the tank 9 of the cold 1816 is sent to the refrigerant injection pipe 15 in the engine 1 through the refrigerant supply passage 12 by the pump 11. This moment,
A separately controlled bypass valve 14 adjusts the supply amount to the appropriate amount required for cooling. In this way, the injection pipe 15
Since the refrigerant supply cutoff valve 17 is in the open state as described above, the refrigerant sent to the cylinders 51 to 56 flows through all the nozzles 16...16 provided at the upper part of each cylinder 51 to 56, respectively, to the surrounding walls 5a and 56 of the combustion chambers.
...It is injected towards 5a. Then, the injected refrigerant cools all the cylinders 51 to 56 by removing heat from the combustion chamber surrounding walls 5a...5a which are heated to high temperatures, and
It vaporizes itself into high-temperature, high-pressure steam.

After that, this steam flows into the cylinder block 3 and the cylinder 11.
- From the space 1B around each cylinder 51 to 56 in the fern head 1, the refrigerant passes through the refrigerant recovery passage 19 to the radiator 21, where it is cooled and condensed and returned to the tank 9. Here, a steam turbine 20 is installed in the refrigerant recovery passage 19, and the refrigerant that has turned into high-temperature and high-pressure steam drives this, thereby consuming energy and reducing the condensability of the refrigerant in the radiator 21. In addition, since the fan 22 that sends cooling air to the radiator 21 through the turbine 20 is driven, the refrigerant is more reliably condensed.

However, when the operating range of the engine 1 is in the low load/low speed range y shown in FIG. 4, the signal S1 from the intake negative pressure sensor 30 and the signal Fr 82 from the rotation speed sensor 31 are
1st in the control circuit 8. Setting reference value e1 of the second comparator 33.34. Since it becomes less than e2, the output signal S8 of the AND circuit 35 becomes as shown in FIG.
7i J: Sea urchin II Hu level. Accordingly, the first driver 36 outputs a control signal qS-12-4 as shown in FIG. 5(b), and the shutter valve 28 is closed via the actuator 29. As a result, the 4th to 6th cylinders 5
The supply of the air-fuel mixture to the cylinders 4 to 56 is stopped, and the engine 1 enters a reduced-cylinder operation state.

At this point, the output signal S8 of the AND circuit 35 is OR
Since the output signal J'131o of the OR circuit 38 is input to one input gate of the circuit VfI38, the output signal J'131o of the OR circuit 38 is related to the output level of the third comparator 37, which is input to the other input gate. ° level.

Therefore, as shown in FIG. 5(C), the second driver 3
9 outputs a control signal S5, and the refrigerant injection pipe 1
The refrigerant supply cutoff valve 17 provided at 5 is closed. As a result, the refrigerant sent by the pump 11 to the injection pipe 15 via the refrigerant supply passage 12 is transferred to the cylinder 5, which has stopped operating due to cylinder reduction operation, since the cutoff valve 17 is closed.
~56 will not be supplied, and the body stop cylinders 54~5 will not be supplied.
Supply of unnecessary refrigerant to the cylinders 54 to 6 and the associated cylinders 54 to 6.
56 proper cooling of 1 Jl is prevented. Here, this operation of cutting off the refrigerant supply is performed at the same time as the start of cylinder reduction operation-13- as shown in FIG. Therefore, during cylinder reduction operation, body 11
The temperature of the combustion chamber surrounding wall of cylinders 54 to 56 is shown in Figure 5(d).
), it gradually decreases.

Furthermore, the case of returning from the reduced-cylinder operating state to the full-cylinder operating state will be explained.

When the operating range of the engine 1 returns to the high-speed or high-load operating range indicated by region x in FIG. 4, the control circuit 8 (
As shown in FIG. 5(a), the output signal S8 of the dielectric ΔND circuit 35 becomes the "L" level again, and the output of the control signal S4 from the first driver 36 receiving the signal 88 is stopped. , the shutter valve 28 is opened. At this time, the engine 1 is supplied with air-fuel mixture to all cylinders 51 to 56, and returns to the all-cylinder operating state.

By the way, as mentioned above, the temperature of the peripheral wall of the combustion chamber of the cylinders 54 to 56 which are inactive during cylinder reduction operation gradually decreases at the same time as the cylinders are inactive, and becomes lower than the temperature corresponding to the reference value e3. If refrigerant is supplied to a cylinder in such a temperature state at the same time as it is restarted, it will take a long time for the peripheral wall temperature to reach the most suitable temperature for the cylinder, and during this time, incomplete combustion of fuel, etc. cause problems. However, the control circuit E3 in this case performs the following J:
It's working fine. That is, the output signal S9 of the third comparator 37 shown in FIG.
Since the signal S3 from QS is kept at the 'l-1' level until it exceeds the temperature corresponding to the reference value e3, the output signal S10 of the OR circuit 38 to which this signal QS9 is input is also held at the ']-bi level. .

Therefore, the control signal S5 continues to be output from the second driver 39, and the refrigerant supply cutoff valve 17 remains closed.

In other words, even if all the operating conditions are restored, refrigerant is not immediately supplied to the cylinders 54 to 56 that were inactive until then.
The temperature of the peripheral walls of the combustion chambers of the cylinders 54 to 56 is quickly raised, and incomplete combustion due to overcooling is prevented. Then, as shown in FIG. 5(d), the temperature sensor 3
When the signal S3 from 2 exceeds the temperature corresponding to the reference value e3, the output signal @ S to of the OR circuit 38 becomes "L"
level, and as shown in Figure 5 (C), the second do 1
5 - The output of the control signal S5 from the liver 39 is stopped and the refrigerant supply cutoff valve 17 is opened. From this, refrigerant is again supplied to the cylinders 54 to 56, which have resumed operation due to the return to all-cylinder operation.

Although this embodiment shows a cooling method for an engine with a controlled number of cylinders, in a general engine, a temperature sensor is provided for each cylinder, and the injection amount, injection, and stop of refrigerant are controlled for each cylinder. By providing an injection control valve to perform this, it is also possible to perform cooling control according to the temperature of each cylinder.

Further, the turbine 20 in this embodiment has a cooling fan 2
It can also be used to drive other auxiliary equipment.

Furthermore, not only water but also fuel can be used as a refrigerant. In this case, the fuel system and the cooling system can be shared and covered, and the vaporized fuel easily mixes with air, resulting in improved combustibility.

(Effects of the Invention) As described above, according to the present invention, in a cooling device that cools an engine using the heat of vaporization of a refrigerant, a refrigerant injection means is provided for each cylinder to control the operating state. Since the configuration is such that the injection and supply of refrigerant is controlled for each cylinder, each cylinder is efficiently and optimally cooled according to its respective state. In particular, when the present invention is applied to an engine with a controlled number of cylinders, overcooling of a dormant cylinder is prevented, and when the cylinder is restarted, combustion is started smoothly without incomplete combustion of fuel. become.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of the present invention, Fig. 2 is a system diagram showing an embodiment of the invention, Fig. 3 is a circuit diagram showing the configuration of a control circuit in the embodiment, and Fig. 4 is a system diagram showing an embodiment of the invention. FIG. 5, which is an explanatory diagram of the cylinder number control region, is a time chart diagram showing the operation of this embodiment. A... Refrigerant supply means, B... Operating state detection means, C
... Refrigerant injection means, 6 ... Cooling device, 8 ... Control circuit, 15 ... Refrigerant injection pipe, 16 ... Spout, 1
7... Refrigerant supply cutoff valve, 32... Temperature sensor 1
7 - Figure 1

Claims (1)

[Claims] (1) A cooling device that cools an engine by evaporation of refrigerant injected and supplied to a peripheral wall of a combustion chamber, comprising a refrigerant injection means provided in each cylinder, an operating state detection means for detecting an operating state of each cylinder, A cooling device for an engine, comprising a refrigerant supply control means for controlling injection and supply of refrigerant by the refrigerant injection means for each cylinder in response to an output from the operating state detection means.