JP3539218B2 - Operation control device for combustion type heater - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an operation control device for a combustion heater, and more particularly to an operation control device for a combustion heater that heats engine cooling water of an internal combustion engine in order to promote warm-up of the internal combustion engine.
[0002]
[Prior art]
2. Description of the Related Art In an internal combustion engine, in order to improve fuel efficiency by stabilizing combustion and reducing friction, it is necessary to promote warm-up especially in cold weather.
[0003]
Therefore, there is known a technology in which a combustion heater is provided separately from the internal combustion engine body, and warm-up is promoted by using combustion heat generated by the combustion heater. In general, a combustion heater uses the combustion heat not only for improving engine warm-up, but also for heating a vehicle compartment.
[0004]
As such a technique, for example, there is a combustion heater described in Japanese Utility Model Laid-Open No. 60-152152. In the technique described in this publication, when the temperature of the engine cooling water reaches a certain fixed temperature, the engine warm-up is determined to be sufficient and the combustion type heater is stopped.
[0005]
[Problems to be solved by the invention]
However, in this technique, since the criterion for stopping the operation of the combustion-type heater is set at the fixed predetermined temperature of the engine cooling water, when the temperature of the engine cooling water reaches the predetermined temperature, the combustion-type heater is controlled regardless of the level of the outside air temperature. Stops its operation. However, even when the outside air temperature is low and the heating of the vehicle interior is desired to be still effective by utilizing the combustion heat of the combustion type heater, the combustion type heater does not operate depending on the setting of the predetermined temperature, and the combustion is stopped. There is a possibility that the combustion heat generated by the type heater cannot be effectively used as heating of the vehicle interior.
[0006]
On the other hand, if the outside air temperature is high, the temperature of the engine cooling water increases accordingly. For this reason, when the vehicle interior heater is not used at room temperature, the operation time of the combustion heater for warming the engine cooling water and warming up the engine can be relatively short, but even in this case, the operation of the combustion heater is not required. Since the criterion for stopping is the predetermined temperature of the engine cooling water, if the set value of the predetermined temperature is high, the combustion heater operates until the temperature of the engine cooling water reaches the predetermined temperature. However, at this time, assuming that the internal combustion engine has already warmed up and the temperature of the engine cooling water has reached a temperature at which engine friction is reduced, operating the combustion heater in spite of that, the combustion heater continues wasteful combustion. Will be.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and operates a combustion heater capable of reliably heating a vehicle compartment when the outside air temperature is low and eliminating waste of combustion of the combustion heater. It is a technical object to provide a control device.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, an operation control device for a combustion heater according to the present invention has the following configuration.
[0009]
(1) A combustion-type heater that heats the engine cooling water to warm up the engine and to use it as a heat source for the vehicle interior heater, and stops operation when the temperature of the engine cooling water becomes higher than a predetermined value due to this heating. In the operation control device, the predetermined value related to the engine cooling water based on the operation stop reference of the combustion type heater is switched based on the outside air temperature, and the predetermined value related to the engine cooling water when the outside air temperature is higher than a specific temperature is: , Characterized in that the temperature is lower than that when the outside air temperature is equal to or lower than the specific temperature.
[0010]
Here, (1) "specific temperature" refers to, for example, an outside temperature at which a driver or a passenger does not feel cold even if the heater for the passenger compartment is not activated. Rather, it is not necessary to determine whether to operate the combustion heater based on a predetermined value relating to the engine coolant temperature to be switched based on the outside air temperature. However, when the outside air temperature is higher than the specific temperature, the outside air temperature is relatively high, and if the combustion type heater is activated at this time, the engine cooling water reaches a temperature at which the engine friction can be reduced. The time to reach is short.
[0011]
(2) "Switching the predetermined value related to the engine cooling water based on the combustion heater stop criteria based on the outside air temperature" means that the switching of the predetermined value related to the temperature of the engine cooling water is continuous compared to the outside air temperature. Although it may be appropriate, it is preferable to determine the predetermined value based on whether the outside air temperature is higher than the specific temperature. For example, the predetermined values relating to the engine cooling water when the outside air temperature is higher than a specific temperature and when it is not higher are set to T1 and T2, respectively. However, the predetermined value T1 is a temperature sufficient to reduce engine friction when the engine cooling water reaches that temperature, and T2 is a temperature sufficient for the vehicle interior heater to function using the combustion heat of the engine cooling water as a heat source. I will say that.
[0012]
In this mode (1), the predetermined value relating to the temperature of the engine cooling water based on the operation stop reference of the combustion type heater is switched based on the outside temperature, and the engine cooling when the outside temperature is higher than the specific temperature is performed. It is characterized in that the predetermined value relating to the temperature of water is made smaller than that when the outside air temperature is equal to or lower than a specific temperature.
[0013]
That is, the operation stop of the combustion type heater when the outside air temperature is higher than the specific temperature is performed in a state where the temperature of the engine cooling water is lower than the operation stop of the combustion type heater when the outside air temperature is the specific temperature or lower. As a result, when the outside air temperature is high, the combustion type heater stops its operation relatively quickly. Moreover, if the predetermined value relating to the engine cooling water, which is a criterion for stopping the operation of the combustion type heater, is set to a temperature sufficient to reduce engine friction when the engine cooling water reaches that temperature, the level of the outside air temperature can be increased or decreased. Regardless, the combustion of the combustion type heater can be prevented from being wasted while ensuring warm-up of the engine. Therefore, it is possible to improve the fuel efficiency of the internal combustion engine with the combustion heater.
[0014]
Further, since the predetermined value relating to the engine cooling water changes in accordance with the outside air temperature, the combustion type heater does not operate even if it is desired to use the combustion heat of the combustion type heater to still heat the vehicle interior. Since such a situation does not occur, the output of the combustion type heater can be adjusted when the temperature is higher when the temperature is higher. Therefore, there is no possibility that the vehicle heater becomes ineffective as in the conventional techniques.
[0015]
(2) In the above (1), an outside air temperature determining means for determining whether or not the outside air temperature is higher than the specific temperature, and a predetermined value related to the engine cooling water based on a determination result by the outside air temperature determining means. And a combustion type heater for controlling the operation of the combustion type heater based on whether the temperature TW of the engine cooling water is equal to or lower than a predetermined value TT switched by the cooling water predetermined value switching unit. Operation control executing means.
[0016]
The "outside air temperature determination means", the "cooling water predetermined value switching means" and the "combustion heater operation control execution means" are a computer for controlling the entire internal combustion engine, that is, an ECU (engine control unit). CPU (Central Processing Unit).
[0017]
In the item (2), the effect described in the above (1) can be embodied since the device includes the outside air temperature determination unit, the cooling water predetermined value switching unit, and the operation control execution unit of the combustion type heater.
[0018]
(3) In the above (1) or (2), the combustion heater includes an air supply path for supplying combustion air to the combustion chamber, and a combustion gas discharge for discharging combustion gas generated in the combustion chamber from the combustion chamber. A combustion path, and the combustion type heater is installed in the intake passage of the internal combustion engine via the air supply path and the combustion gas exhaust path. May be characterized by being located upstream of the supercharger provided in the.
[0019]
In the item (3), since the combustion heater is located upstream of the supercharger, both the air supply passage and the combustion gas discharge passage of the combustion heater are located upstream of the supercharger. Therefore, even if the intake pressure at the portion of the intake passage downstream of the turbocharger installation location rises with the operation of the supercharger, the increased pressure is increased by the intake passage upstream of the supercharger. There is no effect on the connection between the air supply passage and the intake passage and the combustion gas discharge passage. Therefore, no backflow occurs in the combustion heater.
Further, in the intake passage, there is no supercharger between the connection point with the air supply path and the connection point with the combustion gas discharge path. Therefore, no excessive pressure is generated between the air supply passage and the combustion gas discharge passage connected to the intake passage. For this reason, the air velocity in the combustion type heater main body connected to the intake passage via the air supply passage and the combustion gas discharge passage does not become excessive. Therefore, since strong ventilation is not generated in the combustion chamber main body to such an extent that the combustion type heater cannot be ignited, the combustion type heater can be reliably ignited.
[0020]
(4) In the above (3), the combustion gas discharge passage may have a cooling device for cooling the combustion gas emitted from the combustion type heater. Here, as the cooling device, for example, an exhaust gas cooler is suitable.
[0021]
In this mode (4), since the combustion gas emitted from the combustion heater is cooled by the cooling device, even if the combustion gas enters the intake passage, it does not cause heat damage to the intake system structure.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<First Embodiment>
First Embodiment A first embodiment of the present invention will be described with reference to FIGS.
(Engine 1)
The engine 1 as an internal combustion engine is a water-cooled type, and has an engine body 3 having a water jacket containing engine cooling water, an intake device 5 for sending air necessary for combustion into a plurality of cylinders (not shown) of the engine body 3, The vehicle includes an exhaust device 7 that emits exhaust gas after combustion of the air-fuel mixture into the atmosphere, and a vehicle interior heater 9 that warms the interior of a vehicle equipped with the engine 1.
(Suction device 5)
The intake device 5 starts with an air cleaner 13 that takes in fresh air into a cylinder and ends with an intake port (not shown) of the engine body 3. In the meantime, the compressor 15a of the turbocharger 15, which is a supercharger, an intercooler 19, and an intake manifold 21 for distributing the air-fuel mixture that has passed through the intercooler 19 to each of the cylinders are provided.
[0023]
The components of the intake device 5 are connected by a plurality of connecting pipes described below that belong to the intake pipe 23.
(Intake pipe 23)
The intake pipe 23 composed of a plurality of connection pipes is connected to the downstream connection pipe 27 which is in a pressurized state by forcibly pushing the intake air coming into the intake device 5 from the air cleaner 13 and the upstream which is not so with the compressor 15a as a boundary. It can be roughly divided into the side connection pipe 25.
(Upstream connecting pipe 25)
The upstream connecting pipe 25 is a rod-shaped connecting pipe that connects the air cleaner 13 and the compressor 15a and extends in the left-right direction in FIG.
(Outside air temperature sensor 32)
An outside air temperature sensor 32 is attached to a location near the downstream side of the air cleaner 13 in the upstream connection pipe 25. However, the outside air temperature sensor 32 may be provided upstream of the air cleaner 13. Outside air entering the main pipe 29 from the air cleaner 13 is fresh air for the engine 1 and the combustion heater 17, and the temperature To is detected by the outside air temperature sensor 32. The outside air temperature sensor 32 is electrically connected to the ECU 46, and the detected value To of the outside air temperature sensor 32 is temporarily stored as an electric signal in a RAM (random access memory) (not shown) of the ECU 46, and is called up as needed. It is.
(Downstream connecting pipe 27)
The downstream connecting pipe 27 is an L-shaped main pipe 29 extending vertically in FIG. 1 connecting the compressor 15 a and the intake manifold 21, and a heater as a branch pipe connected to the main pipe 29 in a bypass shape. And a branch pipe 31.
(Branch 31 for heater)
The heater branch pipe 31 includes a combustion type heater 17 in the middle thereof, and connects an upstream end of the combustion type heater 17 with the main pipe 29 and supplies air to the combustion type heater 17. A downstream end of the heater 17 and the main pipe 29 are connected to each other, and a combustion gas discharge path 35 for discharging combustion gas from the combustion heater 17 to the main pipe 29 is provided. The connection points C1 and C2 between the air supply path 33, the combustion gas discharge path 35, and the main pipe 29 are located upstream of the main pipe 29 at the connection point C1 relative to the connection point C2. (Air supply path 33)
A valve device 44 is provided in the air supply passage 33 connecting the upstream end of the combustion heater 17 and the main pipe 29 near the combustion heater 17.
(Valve device 44)
As shown in FIG. 2, the valve device 44 is provided with a valve body 44a for opening and closing the air supply passage 33, a drive motor 44b for driving the valve body 44a to open and close, and between the drive motor 44b and the valve body 44a. The drive motor 44b includes an opening / closing mechanism 44c, and its operation is controlled by a computer (not shown) of the ECU 46 (see FIG. 1) that controls the entire engine 1. The valve device 44 also operates to close the valve body 44a even when the main flow pipe 29 is throttled by an intake throttle valve 70 described later in order to actively stop driving the engine 1.
(Combustion gas discharge path 35)
An exhaust gas cooler 84 as a cooling device is mounted near the combustion heater 17 in the combustion gas discharge passage 35 connecting the downstream end of the combustion heater 17 and the main flow pipe 29.
(Exhaust gas cooler 84)
The exhaust gas cooler 84 cools the combustion gas emitted from the combustion heater 17.
(Parts around connection points C1 and C2)
An intercooler 19 is provided between the connection point C1 and the compressor 15a, and an intake throttle valve 70 is provided between the connection point C1 and the connection point C2 in the main pipe 29.
(Intercooler 19)
The intercooler 19 cools air downstream of the installation location of the compressor 15a, which is received by the combustion heater 17 and the compressor 15a, which warms the intake air for promoting warm-up of the engine 1 and improving startability.
(Intake throttle valve 70)
The operation of the intake throttle valve 70 is controlled by the CPU of the ECU 46. The intake throttle valve 70 throttles the main pipe 29 when the engine 1 is in a predetermined stop state and the combustion heater 17 needs to be operated. However, the intake throttle valve 70 can be opened after the engine 1 is started. Here, "when the engine 1 is in a predetermined stop state" refers to a stop state before the engine 1 starts operating. Specifically, although the engine 1 is not yet in the cranking state, the driver Actuates the switch of the electric system and is in a state where the combustion type heater can be driven. Note that "when the engine 1 is in a predetermined stopped state" is simply referred to as "the engine 1 is in a stopped state" unless otherwise specified.
[0024]
Then, the output of the engine 1 can be controlled by the intake throttle valve 70. Further, the throttle control of the intake throttle valve 70 is performed during the operation of the engine 1, so that the engine 1 is used to stop the engine 1 positively.
[0025]
The intake air passing through the main pipe 29 is divided into the intake air branched to the branch pipe 31 for the heater at the connection point C1 and the intake air flowing downstream without branching. Then, the intake air branched into the branch pipe 31 for the heater passes through the air supply path 33 having the valve device 44, the combustion type heater 17, and the combustion gas discharge path 35 having the exhaust gas cooler 84, and is connected at the connection point C 2. Returning to the main flow pipe 29, it merges with the unbranched intake air. As a result, the temperature of the intake air entering the engine body 3 is increased.
(Exhaust device 7)
The exhaust device 7 is a catalytic converter that purifies exhaust gas from the exhaust manifold 37, the turbine 15 b of the turbocharger 15, and the exhaust gas from the exhaust port (not shown) of the engine body 3 to the muffler 41 at the end. 39 is provided on the exhaust pipe 42.
(EGR device 88)
The engine body 3 is provided with an EGR device 88 as an exhaust gas recirculation device that returns a part of the exhaust gas to the intake system. The EGR device 88 includes an EGR passage 90 that connects the exhaust manifold 37 of the exhaust pipe 42 and the intake manifold 21 of the intake pipe 23 to a cylinder (not shown) of the engine body 3 in a bypass shape. Further, the EGR passage 90 is provided with an EGR valve 92 for controlling the amount of gas flowing therethrough. The EGR valve 92 is electrically connected to the CPU of the ECU 46, and basically opens when the engine 1 is sufficiently warmed up, in which the EGR device 88 functions as an original exhaust gas recirculation device. Is a switchable valve that opens when the engine 1 is stopped and the combustion heater 17 needs to be operated. Further, the EGR valve 92 is connected to a pressure control valve (not shown) for negatively controlling the EGR valve 92, such as a duty VSV. When a drive pulse signal having a duty ratio corresponding to the ratio of the fully open time and the fully closed time of the EGR valve 92, in other words, a duty ratio corresponding to the open ratio of the EGR valve 92, is input from the CPU, the pressure control valve The EGR valve 92 is driven according to the following.
[0026]
As described above, when the EGR device 88 is opened when the engine 1 is stopped and the combustion type heater 17 needs to be operated, the combustion gas discharged from the combustion type heater 17 is supplied through the EGR passage 90 to the intake pipe. 23 to the exhaust pipe 42.
[0027]
In other words, the description of the EGR passage 90 can be said as follows. That is, the EGR passage 90 bypasses the main flow pipe 29 of the intake pipe 23 at a location downstream of the location where the combustion heater 17 is installed and the exhaust pipe 42 at a location upstream of the location where the catalytic converter 39 is installed with respect to the cylinder. It is a passage connected in a shape.
(Combustion heater 17)
The operation of the combustion heater 17 is controlled such that the combustion heater 17 is driven not only when the engine 1 is in a predetermined stop state but also when the engine 1 is in a predetermined operation state. “When the engine 1 is in a predetermined operating state” means that the engine 1 is operating or the engine 1 is operating in a cold state at a temperature of about −10 ° C. to 15 ° C. or in an extremely cold state at a temperature of −10 ° C. or less. After the engine is started, when the calorific value of the engine 1 itself is small (for example, when fuel consumption is small), when the calorific value of the engine 1 itself is small, and the amount of heat received by the cooling water is small, and furthermore, the normal temperature higher than 15 ° C. The time when the cooling water temperature is low immediately after the start of the engine 1 and the time when the engine 1 is present under such conditions are also "when it is necessary to operate the combustion heater 17". It is the CPU of the ECU 46 that determines when it is necessary to operate the combustion heater 17, and when the CPU determines that it is necessary to operate the combustion heater 17, the combustion heater 17 is activated. The combustion gas comes out from there.
[0028]
For convenience, the condition under which the combustion heater 17 operates when the engine 1 is stopped in a predetermined state is referred to as "the preheating condition of the combustion heater is satisfied while the engine is stopped". The operation of the combustion heater 17 when the preheating condition of the combustion heater 17 is satisfied is referred to as execution of preheating of the combustion heater. However, the fact that the preheating condition of the combustion type heater 17 is satisfied does not mean that the combustion type heater 17 immediately starts combustion, but the combustion type heater 17 described later in the stopped state of the engine 1 shown in FIG. Only after the operation start control is performed, the combustion heater 17 operates.
[0029]
Next, the structure of the combustion heater 17 is schematically shown.
[0030]
The combustion heater 17 is operated when the engine 1 is in a predetermined operating state to increase the temperature of the engine cooling water, and is thus connected to the water jacket containing the engine cooling water. Therefore, the combustion type heater 17 includes a cooling water passage 17a through which the engine cooling water passes. The cooling water passage 17a is heated by the combustion gas flowing through the combustion chamber 17d, which is a heat source.
(Combustion chamber 17d)
The combustion chamber 17d has a combustion cylinder 17b disposed therein, and the combustion cylinder 17b is covered with a cylindrical partition wall 17c. By covering the combustion cylinder 17b with the partition wall 17c, the combustion chamber 17d is defined in the case body 43a of the combustion chamber main body 43, and the cooling water passage 17a is formed between the inner surface of the case body 43a and the outer surface of the partition wall 17c. I do.
[0031]
The combustion chamber 17d also functions as an air passage in the heater. Therefore, the combustion chamber 17d is connected to the air supply passage 33 and the combustion gas discharge passage 35 of the combustion type heater 17 through the air supply port 17d. ₁ And exhaust outlet 17d _Two Connected. Then, as described above, when the intake air branches off from the main flow pipe 29 and passes through the heater branch pipe 31, as shown by the solid arrow in FIG. 2, the air supply path 33, the combustion chamber 17d, and the combustion gas discharge path 35 are moved. Via this, the intake air containing the combustion gas returns to the main flow pipe 29. Since the intake air is heated by the combustion heat of the combustion gas, the heated intake air is exhausted from the combustion chamber main body 43 until the heated intake air is discharged from the combustion chamber main body 43 via the path indicated by the solid arrow. The cooling water flowing through the cooling water passage 17a as a heat medium is warmed. Therefore, the combustion chamber 17d can be said to be a heat exchange passage.
(Combustion cylinder 17b)
Combustion fuel is supplied to the combustion cylinder 17b by a fuel supply pipe 17e as a fuel supply passage. When the combustion fuel is supplied from here to the combustion chamber 17d, the fuel is vaporized in the combustion chamber main body 43. . Then, the vaporized fuel is ignited by an ignition device (not shown), and the vaporized fuel burns.
(Cooling water passage 17a)
On the other hand, the cooling water passage 17a has a cooling water inlet 17a1 and a cooling water outlet 17a2, and the cooling water inlet 17a1 is, as can be seen from FIG. It is connected to the outlet via a water pipe W1.
[0032]
The cooling water discharge port 17a2 is connected to the vehicle interior heater 9 via a water pipe W2. The cabin heater 9 is connected to a cooling water inlet of the water jacket of the engine body 3 via a water pipe W3.
[0033]
Therefore, the cooling water of the water jacket reaches the combustion heater 17 via the water pipe W1 and is warmed there, and thereafter, from the combustion heater 17 to the vehicle heater 9 via the water pipe W2, the cooling water for the vehicle cabin. Heat is exchanged as a heat medium of the heater 9 to emit warm air into the vehicle interior. The cooling water whose temperature has been lowered by the heat exchange returns to the water jacket via the water pipe W3. In this manner, the cooling water circulates between the engine main body 3, the combustion type heater 17, and the vehicle interior heater 9 via the water pipes W1 to W3.
[0034]
A water temperature sensor 40 that is electrically connected to the ECU 46 is attached to a connection point of the water pipe W1 with the water jacket. Water temperature sensor 40 detects the temperature TW of the engine cooling water contained in the water jacket, and sends the detection result to ECU 46 as an electric signal. The electric signal sent from the water temperature sensor 40 is temporarily stored in the RAM of the ECU 46 and called up as needed. Further, the RAM stores a predetermined value TT relating to the engine cooling water as a reference for stopping the operation of the combustion type heater 17. The predetermined value TT is a value that is switched based on the outside air temperature To, and the value when the outside air temperature To measured by the outside air temperature sensor 32 is higher than the normal temperature that means the specific temperature T is when the outside air temperature To is equal to or lower than the normal temperature. Set smaller than the value of. Specifically, if the value when the outside air temperature To measured by the outside air temperature sensor 32 is higher than the normal temperature meaning the specific temperature T is T1, T1 is, for example, 60 ° C. Assuming that the time when the temperature To is equal to or lower than the normal temperature is T2, T2 is, for example, 85 ° C. Then, the predetermined value TT is compared with the temperature TW of the engine cooling water contained in the water jacket detected by the water temperature sensor 40. When the temperature TW of the engine cooling water becomes higher than the predetermined value TT, the combustion type is stopped. The operation of the heater 17 is controlled. This control will be described in detail in the description of the operation control execution routine of the combustion type heater.
(Other components of the combustion heater 17)
In addition, the combustion chamber main body 43 is further provided with a blower fan 45 to suitably operate the combustion type heater 17, so that a flame F is generated in the combustion chamber 17d.
(Other)
The air supply passage 33 and the combustion gas discharge passage 35 are tributary pipes of the main flow pipe 29 belonging to the intake pipe 23. Is regarded as a component of the combustion type heater 17.
[0035]
Next, an operation control execution routine of the combustion heater 17 will be described with reference to FIG. This routine is for operating the combustion type heater 17 for warming up the engine when the engine 1 is started, and includes the following steps S101 to S106. A flowchart comprising the steps constituting this routine is stored in the ROM of the ECU 46. The processing in each step of each flowchart is entirely performed by the CPU of the ECU 46.
[0036]
Note that the symbol S is used, and for example, if it is step 101, it is abbreviated as S101.
[0037]
First, in S101, it is determined whether or not the outside air temperature detected by the outside air temperature sensor 32 is higher than a normal temperature T which is a specific temperature. If an affirmative determination is made in S101, the process proceeds to S102, and if a negative determination is made, the process proceeds to S103. As described above, in S101, it is determined whether or not the outside air temperature To is higher than the normal temperature T, so that this can be referred to as outside air temperature determination means.
[0038]
In S102, the predetermined value TT relating to the engine cooling water as a reference for stopping the operation of the combustion heater 17 is set to T1 (60 ° C.).
[0039]
In S103, the predetermined value TT relating to the engine cooling water as a reference for stopping the operation of the combustion heater 17 is set to T2 (85 ° C.).
[0040]
Since S102 and S103 switch the predetermined value TT relating to the engine cooling water based on the determination result of the outside air temperature determination unit S101, they can be referred to as cooling water predetermined value switching means.
[0041]
In S104, whether the temperature TW of the engine cooling water contained in the water jacket detected by the water temperature sensor 40 is equal to or lower than the predetermined value TT related to S102 and S103, in other words, whether the temperature TW of the engine cooling water is higher than the predetermined value TT. Is determined. If the determination is affirmative, the process proceeds to S105, where the combustion type heater 17 is turned on. If the determination is negative, the process proceeds to S106, where the combustion type heater 17 is turned off.
[0042]
In S104 to S106, the operation control of the combustion type heater 17 is executed based on whether the temperature TW of the engine cooling water is equal to or less than the predetermined value TT switched by the predetermined cooling water value switching means S102 and S103. S106 can be referred to as operation control execution means of the combustion type heater.
[0043]
The outside air temperature determining means, the cooling water predetermined value switching means and the operation control execution means of the combustion type heater comprise steps constituting an operation control execution routine of the combustion type heater. Are all performed by the CPU of the ECU 46, the outside air temperature determination means, the cooling water predetermined value switching means, and the operation control execution means of the combustion type heater are the CPU, and can be said to be the ECU 46 including the CPU. Since the operation of the combustion heater 17 is controlled by the operation control execution routine of the combustion heater, the ECU 46 including this routine in the ROM can be regarded as the operation control device of the combustion heater 17.
<Operation and Effect of First Embodiment>
Next, the path from the air cleaner 13 to the air entering the intake device 5 to the exhaust device 7 when the combustion heater 17 operates when the engine 1 is in a predetermined stop state will be described.
{Circle around (1)} The air that has entered the upstream connection pipe 25 of the intake pipe 23 from the air cleaner 13 originally travels to the intake throttle valve 70 of the main pipe 29 via the compressor 15 a and the intercooler 19 of the turbocharger 15. Since the intake throttle valve 70 is closed as described above, the air flows from the connection point C1 to the air supply path 33.
(2) The air that has entered the air supply passage 33 passes through the valve device 44 and is then sent into the combustion chamber main body 43 of the combustion heater 17.
(3) The air entering the combustion chamber main body 43 is provided as combustion air for combustion fuel sent from the fuel supply pipe 17e in the combustion chamber 17d of the combustion chamber main body 43, and after combustion, becomes combustion gas and discharges combustion gas. Exit at Road 35.
{Circle around (4)} The combustion gas that has exited the combustion gas discharge passage 35 enters the main pipe 29 from the connection point C2 of the main pipe 29 via the exhaust gas cooler 84.
(5) The combustion gas entering the main pipe 29 does not enter the cylinder of the engine body 3 because the intake port and / or exhaust port is closed while the engine 1 is stopped, and the intake manifold 21 and the exhaust manifold 37 Via the EGR passage 90 connecting the exhaust gas to the catalytic converter 39 in the exhaust pipe 42, where the catalytic converter 39 is warmed.
[0044]
As described above, the engine 1 is provided with the EGR device 88 including the EGR passage 90 and the EGR valve 92, which originally function to recirculate the exhaust gas of the engine 1 from the exhaust pipe 42 to the intake pipe 23. When the combustion type heater 17 needs to be operated in the stopped state, the combustion gas emitted by the combustion type heater 17 is sent from the intake pipe 23 to the exhaust pipe 42 via the EGR passage 90, so that the intake port of the engine 1 And / or even when the engine 1 whose exhaust port is still closed is in a stopped state, the combustion gas of the combustion heater 17 flows to the catalytic converter 39 of the exhaust pipe 42 using the EGR passage 90. Thus, when the engine 1 operates, the catalytic converter 39 can be raised to a temperature at which it can already function sufficiently effectively. Therefore, after the start of the engine 1, the purification performance of the catalytic converter 39 can be sufficiently improved. In addition, since the existing EGR passage is used, the structure is simple and the cost can be reduced.
[0045]
Further, even when the engine 1 is stopped, since the hot combustion gas of the combustion heater 17 flows to the catalytic converter 39 of the exhaust pipe 42 via the EGR passage 90, when the engine 1 enters the operating state from the stopped state, The catalytic converter 39 is already at a temperature at which it can function satisfactorily. Therefore, after the start of the engine 1, the purification of the exhaust gas emitted from the engine body 3 can be processed extremely effectively. In addition, the combustion gas emitted from the combustion heater 17 can be purified by the catalytic converter 39 both before and after the start of the engine 1.
[0046]
Further, when the combustion heater 17 is operated to emit combustion gas from the combustion heater 17, the combustion gas reaches the main pipe 29 through the combustion gas discharge path 35, and at this time, the main pipe 29 is throttled by the intake throttle valve 70. Therefore, the intake throttle valve 70 blocks the main flow pipe 29 of the intake pipe 23. Therefore, the combustion gas of the combustion heater 17 does not flow from the combustion gas discharge path 35 side of the main pipe 29 toward the air supply path 33 side. Since the EGR valve 92 of the EGR passage 90 is open at this time, all the combustion gas of the combustion heater 17 flows through the EGR passage 90 to the exhaust pipe 42. Therefore, the catalytic converter 39 provided in the exhaust pipe 42 can be efficiently warmed in advance.
[0047]
Further, the compressor 15a of the turbocharger 15 and the intercooler 19 are not provided downstream from the connection point C2 between the main pipe 29 and the combustion gas discharge passage 35 in the intake pipe 23. Therefore, the combustion gas emitted from the combustion heater 17 reaches the main pipe 29 via the connection point C2 to the combustion gas discharge path 35, and does not hit the compressor 15a or the intercooler 19. Therefore, the heat of the combustion gas does not disperse in the main pipe 29. Therefore, it is possible to allow a large amount of combustion gas to reach the exhaust pipe 42 through the EGR passage 90, so that the catalytic converter 39 in the exhaust pipe 42 can be sufficiently warmed.
[0048]
Next, a case where the engine 1 is operated will be described.
[0049]
In the operating state of the engine 1, the intake throttle valve 70 is fully open, but the EGR valve 92 and the valve body 44a of the valve device 44 may be fully open or fully closed.
[0050]
What is important is that, in this embodiment, the predetermined value TT relating to the temperature TW of the engine cooling water based on the operation stop reference of the combustion type heater 17 is switched based on the outside air temperature To. Since T1 (60 ° C.), which is the predetermined value TT when To is higher than the normal temperature which is the specific temperature, is smaller than T2 (85 ° C.) which is the predetermined value TT when the outside air temperature TW is equal to or lower than the normal temperature. The operation stop of the combustion type heater 17 when the temperature To is higher than the normal temperature is performed in a state where the temperature TW of the engine cooling water is lower than the operation stop of the combustion type heater 17 when the outside temperature To is equal to or lower than the specific temperature. That is. As a result, when the outside air temperature TW is high, the combustion type heater 17 stops its operation relatively quickly. In addition, if the engine cooling water reaches a predetermined value TT (including both T1 and T2) relating to the engine cooling water as a criterion for stopping the operation of the combustion type heater 17, the engine friction becomes sufficient to reduce engine friction. If the temperature is set, the combustion of the combustion heater 17 can be prevented from being wasted while ensuring engine warm-up regardless of the level of the outside air temperature. Therefore, the fuel efficiency of the engine 1 can be improved.
Further, since the predetermined value TT relating to the engine cooling water is switched to T1 or T2 in accordance with the outside air temperature TW, even if it is desired to use the combustion heat of the combustion type heater 17 to heat the vehicle interior still, Since the heater 17 does not stop operating, the output of the combustion heater 17 can be adjusted to be colder when the temperature is cold and higher when the temperature is higher. Therefore, there is no possibility that the vehicle heater becomes ineffective as in the conventional techniques.
[0051]
Further, the combustion type heater 17 is connected in a bypass manner to the intake passage 29 in the order of the air supply passage 33, the combustion chamber main body 43, and the combustion gas discharge passage 35. The compressor 15a and the intercooler 19 of the turbocharger 15 are not interposed between the connection point C1 and the connection point C2 with the combustion gas discharge path 35. That is, the combustion heater 17 is disposed downstream of the installation location of the compressor 15a. Therefore, an excessive pressure difference does not occur between the side of the air supply passage 33 around the combustion chamber main body 43 of the combustion type heater 17 and the side of the combustion gas discharge passage 35. Therefore, the air velocity in the combustion chamber main body 43 connected to the main pipe 29 via the air supply passage 33 and the combustion gas discharge passage 35 does not become excessive. Therefore, there is no fear that the ventilation which is so strong that the combustion type heater 17 cannot be ignited in the combustion chamber main body 43, so that the combustion type heater 17 can be reliably ignited.
[0052]
Furthermore, since there is no compressor 15a in the main flow pipe 29 between the connection point C1 with the air supply path 33 and the connection point C2 with the combustion gas discharge path 35, the compressor 15a does not operate in this part. For this reason,
Only the pressure on the connection point C2 side between C1 and the connection point C2 does not increase, and the pressure on the connection point C1 side does not decrease in comparison with the pressure. Therefore, backflow does not occur in the combustion chamber 17d of the combustion type heater 17 connected to the main pipe 29 via the air supply passage 33 and the combustion gas discharge passage 35. Therefore, there is no occurrence of a flashback phenomenon in which the direction of the flame of the combustion heater 17 is directed toward the air supply passage 33, and as a result, a sufficient amount of heat is obtained from the combustion heater 17 when the engine 1 is warmed up.
[0053]
Since the air supply passage 33 and the combustion gas discharge passage 35 of the combustion heater 17 are open to the main pipe 29 and are not directly open to the atmosphere, a noise reduction effect can be expected.
[0054]
Further, during the operation of the engine 1, when the main flow pipe 29 is throttled by the intake throttle valve 70 in order to actively stop the driving of the engine 1, as described in the section of the valve device 44, the air supply passage 33 Actuates the valve device 44 to close the air supply passage 33 by the valve body 44a. Therefore, the intake air flowing through the intake pipe 23 via the heater branch pipe 31 has no escape place. Further, since the main flow pipe 29 is restricted by the intake throttle valve 70 as described above, air may pass therethrough. Can not. Therefore, the intake air flowing through the entire intake pipe 23 is completely shielded. Therefore, the driving of the engine 1 using the intake throttle valve 70 can be stopped.
[0055]
Then, the amount of air flowing through the air supply passage 33 of the combustion heater 17 can be adjusted by the valve device 44. Therefore, if the amount of air flowing through the air supply passage 33 is reduced by the above adjustment sufficiently to be ignitable or set to 0 (zero) at least when the combustion type heater 17 is operated, the strong ventilation that cannot be ignited causes combustion. There is no danger of occurring inside the heater 17. Therefore, since strong wind does not occur in the air flow passage 33, the ignition of the combustion heater 17 can be reliably performed at once. In addition, since ignition is reliable, not only generation of white smoke can be prevented, but also generation of unpleasant odor caused by generation of unburned hydrocarbons can be sufficiently prevented.
[0056]
Further, since the combustion gas enters the main pipe 29 from the connection point C2 of the main pipe 29 via the exhaust gas cooler 84, even if the combustion gas enters the main pipe 29, it may cause heat damage to the intake system structure such as the intake manifold 21. Absent.
[0057]
In addition, since the warm-up is promoted by using the combustion gas of the combustion type heater 17 which has almost no smoke, in other words, does not contain carbon, the carbon does not adhere to the inner wall surface of the cylinder. An improvement in durability can also be expected.
<Second embodiment>
A second embodiment will be described with reference to FIGS.
[0058]
The second embodiment is different from the first embodiment in that (1) the branch pipes 31 for the heater are connected by the upstream connecting pipe 25 instead of the main pipe 29, and (2). A branch pipe 95 extending downstream of the intake throttle valve 70 in the main pipe 29 is provided in the middle of the combustion gas discharge path 35. (3) A three-way valve 97 is provided at a branch point of the branch pipe 95 in the combustion gas discharge path 35. Since only the provision of (4) the valve device 44 is omitted, the same reference numerals are given to the other same parts, and the description is omitted. Further, the same applies to the operation control execution routine of the combustion type heater 17, so that the description thereof will be omitted.
[0059]
As shown in FIG. 4, by connecting the heater branch pipes 31 with the upstream connecting pipe 25, the heater branch pipe 31 including the combustion type heater 17, the air supply path 33, and the combustion gas discharge path 35 becomes It becomes a U-shaped bypass passage located upstream of the compressor 15a. Therefore, the downstream connection pipe 27 described in the first embodiment is only the main flow pipe 29 having an L shape in the second embodiment. Connection points where the air supply passage 33 and the combustion gas discharge passage 35 of the heater branch pipe 31 are connected to the upstream connection pipe 25 are indicated by reference numerals C1 and C2, respectively.
[0060]
Further, since the branch pipe 95 that branches from the combustion gas discharge passage 35 extends downstream of the intake throttle valve 70, the distal end of the branch pipe 95 downstream of the compressor 15 a and the intercooler 19 installed upstream of the intake throttle valve 70. Will be located. Therefore, when the combustion heater 17 is operated to burn the fuel for combustion when it is necessary to operate the combustion heater 17, the combustion gas emitted at that time passes through the branch pipe 95 to the intercooler in the intake pipe 23. It is led downstream from the 19 installation locations. Therefore, it can be said that the branch pipe 95 is an introduction pipe (introduction path) for guiding the combustion gas of the combustion type heater 17 downstream of the compressor 15 a and the intercooler 19.
[0061]
On the other hand, the three-way valve 97 has a configuration as shown in FIG.
[0062]
The three-way valve 97 is connected to a first port 97a, which is one of the ports, by an exhaust outlet 17d of the combustion heater 17. _Two One of the remaining two ports 97b is connected to the combustion gas discharge path 35, and the other third port 97c is connected to the branch pipe 95. That is, the three-way valve 97 is located between the combustion heater 17, the combustion gas discharge path 35, and the branch pipe 95. In the case body 97a of the three-way valve 97, a valve body 98 which is moved in the longitudinal direction of the case body 97a by the operation of a diaphragm (not shown) is provided. The valve body 98 has two of the three ports, ie, the first port 97a and the second port 97b, or the first port 97b, depending on the position of the valve body 98 in the case body 37a. The port 97a communicates with the third port 97c. In this case, when the first port 97a and the second port 97b communicate with each other, the third port 97c closes, and the first port 97a communicates with the third port 97c. The second port 97b is closed.
[0063]
Specifically, when the engine 1 is stopped and the combustion type heater 17 needs to be operated, the valve body 98 moves so that the first port 97a and the third port 97c communicate with each other. In this case, when the combustion type heater 17 burns, the combustion gas emitted at that time passes through the branch pipe 95-the main flow pipe 29-the EGR passage 90 and reaches the catalytic converter 39 of the exhaust pipe 42. It functions effectively before the start of 1.
<Operation and effect of second embodiment>
In the second embodiment, the following operation and effect can be obtained.
[0064]
First, the operation and effect when the engine 1 is in a stopped state will be described.
[0065]
When the combustion type heater 17 operates, the air that has entered the intake device 5 from the air cleaner 13 follows the following path and reaches the exhaust device 7.
{Circle around (1)} The air that has entered the upstream connection pipe 25 of the intake pipe 23 from the air cleaner 13 originally travels to the intake throttle valve 70 of the main pipe 29 via the compressor 15 a and the intercooler 19 of the turbocharger 15. Since the intake throttle valve 70 is closed as described above, it flows to the air supply passage 33 at the connection point C1.
(2) The air that has entered the air supply passage 33 is sent to the combustion chamber main body 43 of the combustion heater 17.
(3) The air entering the combustion chamber main body 43 is provided as combustion air for combustion fuel sent from the fuel supply pipe 17e in the combustion chamber 17d of the combustion chamber main body 43, and after combustion, becomes combustion gas and discharges combustion gas. The path 35 goes to a three-way valve 97 provided at a branch point of the branch pipe 95.
(4) Since the three-way valve 97 is in the state of S206 in the flowchart at this time, the combustion gas advances through the branch pipe 95 and enters the main flow pipe 29 downstream of the intake throttle valve 70.
(5) The combustion gas entering the main pipe 29 enters the EGR passage 90 via the intake manifold 21 because the engine 1 is stopped and the intake port and / or exhaust port is closed. At this time, since the EGR valve 92 is open, it reaches the exhaust manifold 37 via the EGR passage 90 and finally enters the exhaust pipe 42. Thereafter, the flow reaches the catalytic converter 39 of the exhaust pipe 42, and the catalytic converter 39 is warmed.
[0066]
Also in the case of the second embodiment, the combustion gas emitted by the combustion heater 17 is sent from the intake pipe 23 to the exhaust pipe 42 via the EGR passage 90, similarly to the first embodiment, so that the engine 1 Even when the engine 1 in which the intake port and / or the exhaust port is still closed is in a stopped state, the combustion gas of the combustion heater 17 flows to the exhaust pipe 42 via the EGR passage 90. For this reason, even if the combustion heater 17 is operated when the engine 1 is stopped and the combustion gas is discharged therefrom, the combustion gas from the combustion heater 17 does not fill the intake pipe 23. Therefore, the heat generated by the combustion gas of the combustion heater 17 does not affect the intake system structure. In addition, similarly to the first embodiment, it is possible to preheat the catalytic converter 39 before the start of the engine 1 or to purify the exhaust gas emitted from the engine body 3 after the start of the engine 1. An effect such as extremely effective processing can be obtained.
[0067]
When the engine 1 is in a predetermined stop state and it is necessary to operate the combustion type heater 17, the combustion gas of the combustion type heater 17 is supplied by the branch pipe 95 from the installation location of the compressor 15 a and the intercooler 19 in the intake pipe 23. When the combustion heater 17 is operated to emit combustion gas, the combustion gas is guided by the branch pipe 95 downstream of the intake pipe 23 at a location where the compressor 15 a is installed or / and at a location where the intercooler 19 is installed. Be frightened. Therefore, since the combustion gas avoids and does not hit the compressor 15a and the intercooler 19, the heat of the combustion gas does not disperse in the intake passage. Therefore, a large amount of combustion gas is allowed to reach the exhaust pipe 42 via the EGR passage 90, and the catalytic converter 39 located there can be sufficiently warmed.
[0068]
In addition, the branch pipe 95 guides the combustion gas from the combustion heater 17 downstream of the intake pipe 23 from the place where the compressor 15 a and the intercooler 19 are installed, so that the flow of the combustion gas in the combustion gas discharge passage 35 is substantially reduced. If the combustion gas does not flow into the upstream connection pipe 25 from the connection point C2 of the combustion gas discharge path 35 with the upstream connection pipe 25, the same situation occurs. Therefore, in the intake pipe 23, the combustion gas of the combustion heater 17 does not flow from the connection point C2 to the combustion gas discharge path 35 toward the connection point C1 to the air supply path 33. That is, no backflow occurs. Also in this case, since the EGR valve 92 of the EGR passage 90 is open, all the combustion gas of the combustion heater 17 flows to the exhaust pipe 42 via the EGR passage 90. Therefore, the catalytic converter 39 provided in the exhaust pipe 42 can be efficiently warmed in advance. Next, a case where the engine 1 is operated will be described.
[0069]
While the engine 1 is not sufficiently warmed up, the EGR valve 92 is closed and the three-way valve 97 is opened so that the combustion gas of the combustion heater 17 flows to the branch pipe 95 side. By doing so, the high-temperature combustion gas of the combustion heater 17 enters the cylinder of the engine body 3, so that the warm-up of the engine 1 proceeds.
[0070]
When the engine 1 is sufficiently warmed up, the EGR valve 92 is opened, and the three-way valve 97 is opened so that the combustion gas of the combustion heater 17 flows to the combustion gas discharge path 35 (broken line in FIG. 5). Arrow)). This is because the warm-up of the engine 1 is sufficient to execute the original exhaust gas recirculation of the EGR device 88, and the high-temperature combustion gas generated by the combustion heater 17 despite the warm-up of the engine 1 is sufficient. Need not be sent directly to the engine body 3.
[0071]
Further, the essential function of the EGR passage 90 serving as the exhaust gas recirculation passage works not when the engine 1 is started at a low temperature, but after the internal combustion engine warms up to some extent. Therefore, since the EGR valve 92 opens and the EGR passage 90 fulfills its original function after the catalytic converter 39 of the internal combustion engine has sufficiently warmed up, the EGR passage 90 is used for increasing the temperature of the catalytic converter 39. This is a very preferable mode because there is no problem and the existing equipment is used.
[0072]
【The invention's effect】
As described above, according to the present invention, it is possible to reliably heat the vehicle compartment when the outside air temperature is low, and to eliminate waste in the combustion of the combustion heater.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a first embodiment of a combustion heater operation control device according to the present invention.
FIG. 2 is a schematic sectional view of a combustion type heater.
FIG. 3 is an operation control execution routine of the combustion type heater according to the first embodiment.
FIG. 4 is a schematic configuration diagram of a second embodiment of a combustion heater operation control device according to the present invention.
FIG. 5 is a schematic explanatory view of a valve device that is a three-way valve.
[Explanation of symbols]
1. Engine (internal combustion engine)
3. Engine body
5. Intake device
7 Exhaust device
9 ... Heater for vehicle compartment
13 ... Air cleaner
15. Turbocharger (supercharger)
15a ... Compressor
15b: Turbocharger turbine
17. Combustion heater
17a: Cooling water passage of combustion type heater
17a ₁ … Cooling water inlet
17a _Two … Cooling water outlet
17b ... combustion cylinder
17c ... cylindrical partition
17d ... combustion chamber
17d ₁ ... Air supply port
17d _Two … Exhaust outlet
17e ... fuel supply pipe
19. Intercooler
21 ... intake manifold
23 ... intake pipe
25 ... upstream connecting pipe
27… Downstream connecting pipe
29… Main pipe (intake passage)
31 ... Branch for heater
32 ... Outside air temperature sensor
33 ... Air supply path
35 ... Combustion gas discharge path
37 ... Exhaust manifold
39 ... catalytic converter
40 ... Water temperature sensor
41 ... Muffler
42 ... exhaust pipe
43… Combustion chamber body
43a ... Case body
44 ... Valve device
44a ... valve body
44b Drive motor
44c: Opening / closing mechanism
45… Blower fan
46 .ECU (outside air temperature determination means, cooling water predetermined value switching means, combustion heater control execution means, combustion heater operation control device)
70 ... intake throttle valve
84 ... Exhaust gas cooler (cooling device)
88 ... EGR device
90 ... EGR passage
92 ... EGR valve
95 ... Branch pipe
97… Three-way valve
C1: Connection point between the air supply passage 33 and the main flow pipe 29 or the upstream connection pipe 25
C2: connection point between the combustion gas discharge path 35 and the main pipe 29 or the upstream connection pipe 25
To… Outside temperature
T: room temperature (specific temperature)
TT: Predetermined temperature (predetermined value based on criteria for stopping operation of combustion type heater)
T1 is one of the predetermined temperatures TT and is a predetermined value relating to engine cooling water when the outside air temperature To is equal to or higher than the specific temperature T
T2: one of the predetermined temperatures TT, a predetermined value relating to the engine cooling water when the outside air temperature To is lower than the specific temperature T
TW: temperature of engine cooling water
W1 ... Water pipeline
W2 ... 〃
W3 ... 〃

Claims (4)

Operation control of a combustion type heater that heats the engine cooling water to warm up the engine and to use it as a heat source for the vehicle interior heater, and stops the operation when the temperature of the engine cooling water becomes higher than a predetermined value due to this heating. In the device,
Switching a predetermined value relating to the engine cooling water based on the operation stop reference of the combustion type heater based on the outside air temperature,
An operation control device for a combustion-type heater, wherein a predetermined value related to the engine cooling water when the outside air temperature is higher than a specified temperature is smaller than that when the outside air temperature is equal to or lower than the specified temperature. Outside air temperature determination means for determining whether the outside air temperature is higher than the specific temperature,
Cooling water predetermined value switching means for switching a predetermined value related to the engine cooling water based on a determination result by the outside air temperature determination means;
Control execution means for a combustion-type heater that executes operation control of the combustion-type heater based on whether the temperature of the engine cooling water is equal to or less than a predetermined value switched by the cooling water predetermined value switching means,
The operation control device for a combustion-type heater according to claim 1, further comprising: The combustion type heater has an air supply path for supplying combustion air to the combustion chamber,
A combustion gas discharge path for discharging combustion gas generated in the combustion chamber from the combustion chamber,
Installing the combustion heater in the intake passage of the internal combustion engine via the air supply path and the combustion gas discharge path,
The internal combustion engine having a combustion type heater according to claim 1 or 2, wherein, in the intake passage, a location where the combustion type heater is installed is upstream of a supercharger provided on the intake path. . The operation control device for a combustion-type heater according to claim 3, wherein the combustion gas discharge path includes a cooling device that cools combustion gas emitted from the combustion-type heater.

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