JPH0727213Y2 - Abnormality processing device for turbo heater system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an abnormality processing device for a turbo heater system that directly or indirectly uses high-temperature gas from a turbo heater as a heating heat source.

[Conventional technology]

Conventionally, particularly in a cold region or the like, under a use condition in which the vehicle is frequently stopped and operated after a cold start, the engine does not warm up easily, and only a general hot water heating device using engine cooling water as a heat source is used. It was completely inadequate in heating the passenger compartment quickly.

Therefore, in order to solve this problem, the present applicant has developed a turbo heater system capable of early heating of a vehicle compartment by directly or indirectly utilizing high-temperature gas generated by a turbo heater as a heat source for heating (Japanese Patent Application No. Sho. 63-25757, Japanese Patent Application 63-384
No. 90, see Japanese Patent Application No. 63-15753). This is because an exhaust turbine of a turbo heater is arranged in a bypass passage that bypasses a control valve provided in the exhaust passage, and the control valve is fully closed to allow exhaust gas to flow through the bypass passage to the exhaust turbine. The high temperature gas is generated by an air temperature raising blower that is driven and rotates integrally with the air temperature raising blower, and the high temperature gas is used as a heat source for early heating of the interior of the vehicle.

With this series of proposed techniques, the problem of the conventional early heating has been solved extremely well.

[Problems to be solved by the device]

However, the introduction of the turbo heater system has caused new problems such as damage due to over rotation of the turbo heater. That is, the turbo heater is considerably smaller than a turbocharger for supercharging that is generally used, and is set to operate most effectively at low speed operation. Therefore, for example, when the control valve in the exhaust passage becomes inoperable with the valve fully closed, the entire amount of exhaust gas is still supplied to the exhaust turbine of the turbo heater even in the medium / high speed range. Therefore, the turbo heater overruns beyond its capability, which not only deteriorates fuel efficiency extremely, but may damage the turbo heater. Note that problems such as overruns also exist in turbochargers, so
Various technologies have been proposed to solve and solve this problem
61-87928, JP-A-61-190124, etc.), these abnormality processing devices assume that the turbocharger generates a high supercharging pressure. Directly or indirectly detect and determine whether there is an abnormality.

However, although the turbo heater is very similar in appearance to the turbo charger, it is completely different in its purpose and function and effect. In other words, a turbocharger is a compressor that is as efficient as possible to obtain high supercharging.
Although it uses an impeller and is intended for so-called adiabatic compression (although the supercharged air is warming up), the turbo heater has nothing to do with the efficiency of the blower impeller. The purpose is to raise the air temperature by stirring a large amount. Further, although the turbo heater generates a slight discharge pressure, its supercharging pressure is equal to zero as compared with the turbo charger.

As described above, it is meaningless and practically impossible to determine whether or not the turbo heater is abnormal based on the boost pressure. A reasonable, accurate and reliable method is to make a determination based on the flow rate of the exhaust gas that drives the exhaust turbine of the turbo heater, which corresponds to the degree of air agitation.

As can be easily understood from such a point, the abnormality processing technique of the above-mentioned conventional publication based on the supercharging pressure of the turbocharger cannot be immediately applied to the turbo heater.

In view of the above points, the present invention appropriately determines the abnormality of the turbo heater based on the characteristics of the turbo heater that essentially raises the temperature of the air, by the flow rate of the exhaust gas that drives the exhaust turbine of the turbo heater or the parameter that represents this exhaust flow rate. It is an object of the present invention to provide an abnormality processing device for a turbo heater system that can be processed.

[Means for Solving the Problems]

FIG. 1 is a block diagram showing the principle of the present invention. According to the abnormality processing device of the turbo heater system according to the present invention,
A control valve is arranged in the exhaust passage, and an exhaust passage upstream of the control valve is branched to form a bypass passage leading to the exhaust passage downstream of the control valve, and an exhaust turbine of the turbo heater is provided in the bypass passage. In a turbo heater system in which high temperature gas discharged from a blower of a turbo heater is used as a heat source for heating, the flow rate of the exhaust gas that drives the exhaust turbine or a value of a parameter that can represent this exhaust gas flow rate is detected. State detecting means, operating state detecting means for detecting the engine operating state, basic exhaust flow rate state calculating means for calculating the basic exhaust flow rate state corresponding to this engine operating state, detected exhaust flow rate state and this basic exhaust flow rate state And a comparison means for comparing the above and outputting a signal indicating an abnormality of the system. .

[Action]

According to the present invention, the flow rate of the exhaust gas that drives the exhaust turbine of the turbo heater or the value of a parameter that can represent it is detected, and this exhaust flow rate state is compared with the basic exhaust flow rate state corresponding to the engine operating state. Abnormal processing is performed. That is, appropriate abnormality processing that matches the characteristics of the turbo heater is performed, and the durability and reliability of the turbo heater system are improved.

〔Example〕

 The present invention will be described below with reference to illustrated embodiments.

FIG. 2 is an overall schematic view of a first embodiment of an abnormality processing device for a turbo heater system according to the present invention, in which 1 is an engine, 2 is an intake passage, 3 is an exhaust passage, 4 is a turbo heater, An air cleaner 5 is attached to the inlet of the intake passage 2.

The turbo heater 4 includes a turbine 7 and a blower 8 which are connected to each other via a rotary shaft 6. A control valve A is arranged in the exhaust passage 3, and a bypass passage 9 that connects the exhaust passage 3 upstream of the control valve A and the exhaust passage 3 downstream of the control valve A is connected to the exhaust passage 3. The exhaust turbine 7 of the turbo heater 4 is arranged in the bypass passage 9, and the exhaust turbine 7 is rotationally driven by the exhaust gas flowing in the bypass passage 9. On the other hand, the air intake passage 10 of the blower 8 of the turbo heater 4 is connected to the air cleaner 5 via the auxiliary intake passage 11 arranged so as to surround the exhaust passage 3,
The discharge passage 12 is connected to the intake passage 2.

The turbo heater 4 is considerably smaller than a turbocharger for supercharging that is generally used, and its sole purpose is to raise the air temperature as described above, and it is most efficient during idling operation or low speed operation. Well set to stir the air.

The control valve A is connected to a corresponding negative pressure diaphragm device 16, and the negative pressure chamber 19 of the negative pressure diaphragm device 16 is connected to a negative pressure source via an electromagnetic switching valve A ₀ that can communicate with the atmosphere. When the negative pressure chamber 19 is opened to the atmosphere by the switching action of the electromagnetic switching valve A _0, the control valve A is closed, and when the negative pressure chamber 19 is connected to the negative pressure source, the control valve A is fully opened.

A heater 23 for utilizing engine heat generation is arranged in the passenger compartment 14. Cooling water whose temperature has been raised in the engine 1 is supplied to the engine heat generating heater 23 through a cooling water supply conduit 24, and cooling water whose temperature has dropped due to heat being released into the passenger compartment 14 is a cooling water return conduit. twenty five
It is returned to the engine 1 via.

The electronic control unit 51 is composed of a digital computer, and has a ROM (read-on memory) 53 and a RAM (random access memory) 5 interconnected by a bidirectional bus 52.
4, CPU (microprocessor) 55, input port 56 and output port 57. The starter switch 27 for driving the starter motor is connected to the input port 56,
Further, a water temperature sensor 26 for detecting the cooling water temperature is connected via an A / D converter. On the other hand, an electromagnetic switching valve A ₀ is connected to the output port 57.

An example of the operation of the warm-up heating control of the turbo heater system configured as above will be described with reference to the flowchart of FIG. First, at step 301, it is judged if the starter switch 27 is ON. If the starter switch 27 is ON, proceed to step 303 and step 303
Then, it is judged from the output signal of the water temperature sensor 26 whether or not the cooling water temperature T has become higher than the preset temperature T ₀ . T ₀ ＞
If it is T, the routine proceeds to step 305, where the control valve A is closed. When the control valve A is closed, all the exhaust gas discharged from the engine 1 is sent into the bypass passage 9, and the turbo heater 4 is immediately driven to rotate. When the turbo heater 4 starts rotating, the high temperature air heated by the blower 8 is discharged to the discharge passage 12 of the blower 8, so that the high temperature air is supplied into the engine cylinder through the intake passage 2. When the engine starts rotating in this way, hot air is immediately supplied to the cylinder, so that the engine speed immediately rises and the engine is warmed up early. As a result, the engine cooling water temperature rises quickly, and as a result, the heating of the vehicle compartment by the engine heat generation utilizing heater 23 is favorably performed after the engine starts, for example, early after the cold start.

If it becomes TT ₀ (step 303), step 307
Then, the control valve A is opened. When the control valve A is opened, exhaust gas is no longer supplied into the bypass passage 9, and the turbo heater 4 is stopped. That is,
If the cooling water temperature T becomes equal to or higher than the set temperature T ₀ , the heating of the vehicle interior by the engine heat generation utilizing heater 23 is already at a sufficient level, and therefore it is necessary to supply the hot air by the turbo heater 4 to the engine 1 any more. It's none other than nothing.

With the above operation, when the engine 1 is driven by the starter motor, high-temperature air is immediately supplied to the cylinder, so that a good start of the engine can be ensured, and the rise of the engine speed is accelerated, so that the cooling water temperature is increased. It is possible to rapidly raise the temperature and, therefore, quickly heat the passenger compartment. Further, it is possible to suppress the production or emission of unburned hydrocarbons. Further, like the cooling water, the temperature of the lubricating oil rapidly rises, and as a result, the lubricity of each part of the engine 1 and the turbo heater bearing is improved, so that the durability of the engine 1 and the turbo heater 4 can be enhanced.

However, as described above, the overrun of the turbo heater 4 caused by the case where the control valve A is in the stick state with the valve fully closed causes various inconveniences and problems. Therefore, such an abnormality is appropriately processed. There is a need.

The characteristic part of the present embodiment for solving this will be described below in the second section.
As will be described with reference to the drawings, a flow rate sensor 28 that directly detects the flow rate of the exhaust gas that drives the exhaust turbine 7 of the turbo heater 4 in the bypass passage 9 is provided, and the input port 56 of the electronic control unit 51 is provided with an A / Connected via a D converter. The fuel injection device 29 is connected to the output port 57.
Then, the exhaust gas flow rate in the maximum operating state where the turbo heater 4 does not overrun, that is, the upper limit value of the exhaust flow rate is determined in advance, and the actual exhaust flow rate detected during the operation of the turbo heater 4 is compared with this upper limit value. By doing so, it is possible to perform the abnormality detection of the turbo heater with high reliability based on the characteristics of the turbo heater extremely easily. Moreover, based on this abnormality detection, the fuel supply amount to the engine is promptly limited, for example, cut through the fuel injection device 29, so that the progress of the abnormal state can be safely and reliably avoided.

In the first embodiment described above, the exhaust gas flow rate is directly detected and the presence / absence of abnormality of the turbo heater system is determined based on this, but in the second embodiment described below, this exhaust gas flow rate can be represented. Make a decision based on the parameters.

FIG. 4 is a schematic view of the essential portions of a second embodiment of an abnormality processing device for a turbo heater system according to the present invention, and the description of the same parts as those in the first embodiment will be omitted.

The magnitude of the flow rate of the exhaust gas that drives the exhaust turbine 7 of the turbo heater 4 is closely related to the valve opening degree of the control valve A provided in the exhaust passage 3, and the abnormality of the turbo heater 4, especially overrun, is caused by the control valve A. This can mainly occur when the valve opening is not sufficient when the valve should be opened. Therefore, the theoretical valve opening of the control valve A corresponding to the engine operating state is compared with the actual valve opening, and if the latter actual valve opening is smaller than the former, the turbo heater 4 is inevitably overrun. Therefore, it is a characteristic part of the present embodiment that the abnormality of the turbo heater is not accurately detected based on these comparisons.

That is, referring to the abnormality processing control flowchart of FIG. 5, for example, the engine speed and the load are detected as the engine operating state (step 501), and based on these, the theoretical valve opening θ ₀ (request opening) of the control valve A is detected. Is calculated (step 503). The engine speed and the load are detected by an engine speed sensor 30 and a load sensor 31 (Fig. 4), respectively. The obtained required opening degree of the control valve A has a characteristic as shown in FIG. 6, for example. In this figure, the fuel injection amount is used as the load.

On the other hand, the actual valve opening θ (deg) of the control valve A is detected by the position sensor 32 (step 505).

Then, these are compared (step 507), and if θ <θ ₀ , the control valve A is not at the opening that should be opened, that is, the valve is in an insufficient / improper opening state. The risk of overrun of the heater 4 is extremely high. Therefore, for example, the fuel injection amount is promptly limited (step 509).

As described above, the region in which the turbo heater 4 is operated (control valve A fully closed) and the region in which the turbo heater 4 is not operated (control valve A fully open) are clarified, and the actual valve opening of the control valve A is applied to this, whereby the turbo heater Since it was decided to determine the abnormality of No. 4, not only when the control valve A is in the stick state with the valve fully closed, but also when the control valve A is caused by a deposit or the like.
Even in the case where the valve opening direction is slightly deviated from the regular valve opening degree, the turbo heater abnormality can be reliably detected. Since the fuel injection amount is limited at the time of this abnormality, it is possible to avoid situations such as engine destruction that accompany deterioration of fuel efficiency and progress of the abnormality, and maintenance can be performed at an early stage because the abnormality can be detected before it becomes important. It becomes possible to improve the durability and the like of the turbo heater system.

Similarly to the second embodiment, the third embodiment described below also makes a determination based on a parameter that can represent the exhaust flow rate.

FIG. 7 is a schematic view of a main part of a third embodiment of the abnormality processing device for a turbo heater system according to the present invention, and the description of the same parts as those in the first embodiment will be omitted.

As described above, the magnitude of the flow rate of the exhaust gas that drives the exhaust turbine 7 of the turbo heater 4 is closely related to the opening degree of the valve of the control valve A. However, the control valve A is in the worst state, for example, the stick state in the fully closed state. In such a case, the exhaust flow rate is closely related to the exhaust pressure in the exhaust passage 3 on the upstream side of the control valve A. That is, there may be an exhaust pressure value corresponding to the exhaust flow rate when the turbo heater 4 overruns. Therefore, this is compared with the actual exhaust pressure detected as the upper limit value, and when the actual exhaust pressure exceeds this upper limit value, the overrun of the turbo heater 4 is inevitable, and therefore the turbo heater 4 is based on these comparisons. It is a characteristic part of the present embodiment that the abnormality of (2) is not accurately detected.

That is, referring to FIG. 7, an exhaust pressure sensor 33 for measuring the exhaust pressure in the exhaust passage 3 on the upstream side of the control valve A is provided, and the exhaust pressure sensor 33 has a predetermined limit value. By appropriately comparing with this, it is possible to detect the abnormality of the turbo heater with high reliability based on the characteristics of the turbo heater very easily. Then, based on this, by restricting the fuel injection amount, abnormal progress can be avoided.

Alternatively, since the exhaust pressure is mainly obtained by two parameters of the opening degree of the control valve A and the engine operating state, simply the engine speed, these correlations are mapped and the upper limit of the exhaust pressure in each rotational state is set in advance. It may be calculated and the actual exhaust pressure and its comparison may be used as the criterion for abnormality detection. In this case, more reliable abnormality detection can be performed.

Similarly to the second and third embodiments, the fourth embodiment described below also makes a determination based on a parameter that can represent the exhaust flow rate.

FIG. 8 is a schematic view of the essential portions of a fourth embodiment of an abnormality processing device for a turbo heater system according to the present invention, and the description of the same parts as those in the first embodiment will be omitted.

As described above, the turbo heater 4 overruns when the flow rate of the exhaust gas that drives the exhaust turbine 7 of the turbo heater 4 exceeds the limit, but the exhaust flow rate and the rotary shaft 6 that integrally connects the exhaust turbine 7 and the blower 8 It is closely related to the rotation speed of. Therefore, when the turbo heater 4 overruns, the upper limit rotational speed of the rotary shaft 6 is determined, and the actual rotational speed of the rotary shaft 6 is compared with this upper limit value, and the actual rotational speed exceeds the upper limit value. In this case, the turbo heater 4 is inevitably overrun. Therefore, it is a characteristic part of the present embodiment that the abnormality of the turbo heater 4 is not accurately detected based on these comparisons.

That is, referring to FIG. 8, a rotation speed sensor 34 for detecting the rotation speed of the rotary shaft 6 of the turbo heater 4 is provided, and by comparing it with a predetermined limit value which is determined in advance, as appropriate. The abnormality of the turbo heater can be detected extremely simply and with high reliability based on the characteristics of the turbo heater. Particularly in the case of the present embodiment, unlike the second and third embodiments, which tend to be premised on the engine operating state in which the engine speed has risen to some extent with respect to the abnormality processing of the turbo heater, the turbo is irrelevant regardless of the engine operating state. The heater abnormality can be processed. That is, in a case where air cannot be supplied to the blower 8 of the turbo heater 4 in the engine low speed region for some reason, the load of the blower 8 of the turbo heater 4 is rapidly removed and the rotation of the exhaust turbine 7 is reduced. Abnormal rise (overrun)
However, the turbo heater 4 may be destroyed, but since the rotation speed of the rotary shaft 6 of the turbo heater 4 is used as the criterion for the abnormality determination, such an abnormal situation can be prevented safely, reliably and in advance. Moreover, since complicated control is not required at all and heat damage from the engine is not particularly caused, there is no need to bother correcting the temperature of the sensors.

Note that it is preferable to set the upper limit rotation speed of the rotary shaft 6 of the turbo heater 4 to be lower than the rotation speed at which it actually overruns in consideration of the system operation delay.

As can be understood from the drawings showing the four embodiments of the abnormality processing device for the turbo heater system according to the present invention described above, the mounting position of the control valve A is not specified in these devices. As shown in FIG. 9, a control valve A is provided on the upstream side of the main muffler 36 far downstream of the exhaust passage.
Is preferably arranged so that the hot exhaust gas does not hit the control valve A directly. That is, in order to drive the exhaust turbine 7 of the turbo heater 4 efficiently, it is necessary to supply high-energy exhaust gas to the exhaust turbine 7. Therefore, it is preferable to arrange the turbo heater 4 as close to the engine as possible. Similarly, if the control valve A is arranged near the engine, the durability and reliability of its constituent parts and the actuator (diaphragm device 16) for driving it will be lacking. Therefore, it is preferable to arrange the control valve A on the downstream side of the exhaust passage 3 as much as possible as shown in FIG. The sub muffler 37 is located upstream of the control valve A. Since the control valve A is set apart from the engine 1 in this way, the control valve A is not exposed to high heat, the control valve A can be formed of an inexpensive material, and when the control valve A is closed. Since the hermeticity can be improved, the output of the turbo heater 4 can be improved.

By the way, in implementing the second and third embodiments, the position sensor is protected by protecting the control valve A from heat damage in this way.
Similarly, 32 (FIG. 4) and exhaust pressure sensor 33 (FIG. 7) can be protected from heat damage, so that their reliability and durability can be improved.

[Effect of device]

As described above, according to the present invention, based on the characteristics of the turbo heater, an abnormality such as an overrun of the turbo heater can be accurately, reliably and appropriately processed, and the durability and reliability of the entire turbo heater system are improved. Can be achieved.

[Brief description of drawings]

FIG. 1 is a block diagram showing the principle of the present invention, FIG. 2 is an overall schematic diagram of a first embodiment of an abnormality processing device for a turbo heater system according to the present invention, and FIG. 3 is a warm-up / heating control flowchart diagram, FIG. 4 is a schematic view of a main part of the second embodiment, FIG. 5 is a flow chart of abnormality processing control, FIG. 6 is a view showing a required opening characteristic of a control valve, and FIG. 7 is a third embodiment. FIG. 8 is a schematic view of a main part of the fourth embodiment, and FIG. 9 is a view showing an embodiment in which a control valve is provided at a distance from the engine. 1 ... Engine, 2 ... Intake passage, 3 ... Exhaust passage, 4 ... Turbo heater, 6 ... Rotating shaft, 7 ... Exhaust turbine, 8 ... Blower, 9 ... Bypass passage, A ... Control valve, 26 ... Water temperature sensor,
30 ... Engine speed sensor, 31 ... Load sensor, 32 ... Position sensor, 33 ... Exhaust pressure sensor, 34 ... Rotation speed sensor, 36 ... Main muffler.

Claims (1)

[Scope of utility model registration request] 1. An exhaust turbine of a turbo heater, wherein a control valve is arranged in an exhaust passage, and an exhaust passage upstream of the control valve is branched to form a bypass passage leading to an exhaust passage downstream of the control valve. In a turbo heater system that is arranged in the bypass passage and uses the high temperature gas discharged from the blower of the turbo heater as a heat source for heating, the flow rate of the exhaust gas that drives the exhaust turbine or the value of a parameter that can represent this exhaust flow rate. Exhaust gas flow state detecting means, an operating state detecting means for detecting the engine operating state, a basic exhaust flow rate state calculating means for calculating a basic exhaust flow state corresponding to the engine operating state, and a detected exhaust flow state And a comparison means for comparing the basic exhaust flow rate state and outputting a signal indicating a system abnormality. Abnormality processing apparatus turbo heater system.