JP2012193690A - System for utilizing waste heat for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for utilizing waste heat for an automobile including a Rankine circuit, in which an expansion unit and a pump that directly transmits the operation of the expansion unit to an internal combustion engine via an on/off clutch and feeds a working fluid are coaxially and integrally arranged, and in which even when abnormality occurs in the on/of clutch, over-rotation of the pump and the expansion unit can be prevented, and the pump and the expansion unit are prevented from becoming an unnecessary load for the internal combustion engine.SOLUTION: The system is configured in such a manner that, when an abnormality detection means (54) detects occurrence of operational abnormality in the on/off clutch (48) with respect to a connection control instruction and a disconnection control instruction on the on/off clutch by a control means (60), the system limits the flow of a working fluid to the expansion unit (42) by limiting means (36, 38).

Description

  The present invention relates to a waste heat utilization system for automobiles, and more particularly, to a technology for assisting a driving force of an internal combustion engine by collecting waste heat of an internal combustion engine of a vehicle.

In this type of automobile waste heat utilization system, an evaporator that heats and evaporates the working fluid by the waste heat of the internal combustion engine is expanded in the refrigerant circulation path as the working fluid, and the working fluid that passes through the evaporator is expanded. An expander that generates a rotational driving force, a power transmission device to which the rotational driving force generated by the expander is transmitted, a condenser that condenses the working fluid that passes through the expander, and a working fluid that passes through the condenser Is provided with a Rankine circuit in which pumps for supplying the gas to the evaporator are sequentially disposed.
In such an automotive waste heat utilization system, for example, a pump, an expander, and a generator / motor as a driven transmission device are arranged on the same axis, and the generator / motor is operated when the expander is operated by a Rankine circuit. A waste heat utilization apparatus having a configuration in which the pump functions as a generator and rotates the pump is known (Patent Document 1).

By the way, in the waste heat utilization apparatus with such a configuration, when an abnormality occurs in the generator during the operation of the expander by the Rankine circuit, normally, the power generation by the generator is stopped so that the expander is in a no-load state. Yes. However, when the expander is in a no-load state, the expander is accelerated beyond the allowable rotational speed, and the expander generates noise and vibration or is not preferable.
Therefore, in the above waste heat utilization device, for example, the flow of the working fluid flowing into the expander when the expander is abnormal is stopped, while the working fluid is allowed to flow through the expander bypass flow path to prevent the expander from being accelerated. I am trying so.

JP 2006-170185 A

On the other hand, in recent years, a waste heat utilization system for automobiles in which the power transmission device is an internal combustion engine has also been developed, and in this configuration, the operation of the expander by the Rankine circuit is directly applied to the internal combustion engine via the connection / disconnection clutch. This is transmitted to assist the driving of the internal combustion engine. That is, by controlling the connection / disconnection of the connection / disconnection clutch, the driving force generated by the expander is appropriately used as the driving force of the internal combustion engine.
In the waste heat utilization system having such a configuration, when an abnormality occurs in the operation of the connecting / disconnecting clutch, for example, when the connecting / disconnecting clutch is unintentionally disconnected from the connected state, the driving force generated by the expander is If the expander cannot be properly used as the driving force of the engine and the expander overrotates and causes the same problem as described above, or the disconnection clutch remains disconnected, the expander remains in the internal combustion engine. This is an undesirable load.

In particular, recently, a waste heat utilization system in which a pump for delivering the working fluid and an expander are integrally arranged on the same axis has been developed. In such a waste heat utilization system, the pump also rotates together with the expander. For this reason, there is a problem that excessive rotation of the expander is promoted, or that the pump together with the expander becomes an unnecessary load on the internal combustion engine.
In this regard, the above-mentioned Patent Document 1 does not mention anything about the response at the time of abnormality of the connecting / disconnecting clutch in the configuration in which the operation of the expander is directly transmitted to the internal combustion engine via the connecting / disconnecting clutch. There is no suggestion to prevent the expander from becoming an unnecessary load on the internal combustion engine.

  The present invention has been made in view of such problems, and is an automotive waste heat utilization system having a Rankine circuit, in which the operation of the expander is directly transmitted to the internal combustion engine via the connection / disconnection clutch. The pump that pumps fluid and the expander are integrated on the same axis and can prevent over-rotation of the pump and the expander even when the connection / disconnection clutch is abnormal. An object of the present invention is to provide a waste heat utilization system for automobiles that can prevent a heavy load.

  In order to achieve the above-mentioned object, the waste heat utilization system for automobiles according to claim 1 passes through an evaporator that heats and evaporates the working fluid by the waste heat of the internal combustion engine in the circulation path of the working fluid. An automobile having a Rankine circuit in which an expander for expanding the working fluid, a condenser for condensing the working fluid via the expander, and a pump for sending the working fluid via the condenser to the evaporator are sequentially provided. Waste heat utilization system, wherein the expander and the pump are coaxially configured integrally as a fluid machine, and the rotary shaft of the fluid machine and the rotary shaft of the internal combustion engine are connected via a connection / disconnection clutch A transmission means; a control means for performing connection control and disconnection control of the connection / disconnection clutch; and a restriction means provided in the circulation path for restricting the flow of the working fluid to the expander. By the control means An abnormality detecting means for detecting the occurrence of an abnormal operation of the connection / disconnection clutch in response to the connection control command and the disconnection control command of the connection / disconnection clutch, wherein the abnormality detection means detects an abnormal operation of the connection / disconnection clutch; And restricting the flow of the working fluid to the expander.

According to a second aspect of the present invention, there is provided a waste heat utilization system for automobiles according to the first aspect, wherein the restriction means is bypass means for bypassing the flow of the working fluid to the expander, and the abnormality detecting means operates the connection / disconnection clutch. When an abnormality is detected, the flow of the working fluid is bypassed by the bypass means.
According to a third aspect of the present invention, there is provided a waste heat utilization system for automobiles according to the first or second aspect, wherein the restriction means is a shut-off means for stopping a flow of a working fluid to the expander, and the control is performed by the abnormality detection means. When an operation abnormality of the connection / disconnection clutch is detected in response to a connection control command of the connection / disconnection clutch by the means, the flow of the working fluid is stopped by the interruption means.

  According to a fourth aspect of the present invention, there is provided a waste heat utilization system for automobiles according to any one of the first to third aspects, wherein the connection / disconnection clutch is an electromagnetic clutch and is connected / disconnected by receiving power supply. An ammeter for measuring a current supplied to the clutch, wherein the abnormality detecting means is the ammeter, and the limiting means is configured to respond to a connection control command and a disconnection control command of the connection / disconnection clutch by the control means. When an abnormality is detected in the current measured by the ammeter, the flow of the working fluid to the expander is limited.

  According to the waste heat utilization system for automobiles of claim 1, the waste heat utilization system for automobiles having a Rankine circuit, wherein the expander and the pump are coaxially configured as a fluid machine, and the fluid machine is rotated. When the shaft and the rotating shaft of the internal combustion engine are connected by the transmission means via the connection / disconnection clutch, the connection / disconnection clutch operation control error and the connection / disconnection control command by the control means have occurred. When the abnormality is detected by the abnormality detection means, the flow of the working fluid to the expander is restricted by the restriction means, so that the connection / disconnection clutch is connected even though the connection / disconnection clutch command is issued by the control means. Is not normally connected and operated, the flow of the working fluid to the expander is restricted, and the expander and the poker are caused by the expander idling without assisting the driving force of the internal combustion engine. Can prevent over-rotation of up to prevent noise and vibration due to excessive rotation of the expander and the pump, it is possible to prevent failure of the expander and the pump.

  In addition, when the connection / disengagement clutch command is controlled by the control means and the connection / disconnection clutch does not normally disconnect, the flow of the working fluid to the expander is restricted and the internal combustion engine forcibly operates. It is possible to reduce the work amount of the expander that is caused to reduce an unnecessary load on the internal combustion engine, and it is possible to suppress fuel consumption in the internal combustion engine and prevent deterioration of fuel consumption in the vehicle.

According to the waste heat utilization system for automobiles of the second aspect, since the restricting means is a bypass means for bypassing the flow of the working fluid to the expander, the connection / disconnection clutch connection control command is issued by the control means. When the connection / disconnection clutch is not normally connected and operated, the high-pressure pressure of the working fluid on the upstream side of the expander can be released to the downstream side by bypassing the flow of the working fluid by the bypass means, and the expander can be satisfactorily And over-rotation of the pump can be prevented.
In addition, when the connection / disengagement clutch command is controlled by the control means, but the connection / disconnection clutch does not normally disconnect, the bypass means bypasses the flow of the working fluid, so that the internal combustion engine is not required. Load can be reduced.

According to the waste heat utilization system for automobiles of the third aspect, the restricting means is a shut-off means for stopping the flow of the working fluid to the expander. Therefore, even though the connection / disconnection clutch command is issued by the control means. When the connection / disconnection clutch is not normally connected and operated, the flow of the working fluid to the expander is stopped by the shut-off means, so that the over-rotation of the expander and the pump can be well prevented.
According to the automobile waste heat utilization system of claim 4, when an abnormality is detected in the current measured by the ammeter with respect to the connection / disconnection control command and the disconnection control command of the connection / disconnection clutch by the control means, the operation to the expander is detected. Since the flow of the fluid is restricted, it is possible to detect an abnormal operation of the connection / disconnection clutch with a simple configuration, and it is possible to simplify the waste heat utilization system for automobiles.

It is a figure which shows typically the waste heat utilization system for motor vehicles based on 1st Example of this invention. It is a flowchart which shows the control routine of the connection / disconnection clutch abnormality process control which concerns on 1st Example of this invention. It is a figure which shows typically the waste heat utilization system for motor vehicles based on 2nd Example of this invention. It is a flowchart which shows the control routine of the connection / disconnection clutch abnormality process control which concerns on 2nd Example of this invention. It is a figure which shows typically the waste heat utilization system for motor vehicles based on 3rd Example of this invention. It is a flowchart which shows the control routine of the connection / disconnection clutch abnormality process control which concerns on 3rd Example of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the first embodiment will be described.
FIG. 1 is a diagram schematically showing an automotive waste heat utilization system according to a first embodiment of the present invention.
The waste heat utilization system 1 is mounted on, for example, a vehicle and includes an engine (internal combustion engine) 10, a coolant circuit 20, and a Rankine circuit 30.
The engine 10 is a driving source that applies driving force to the vehicle, and a pulley 12 is provided at the tip of a main shaft 11 that extends from the crankshaft of the engine 10. Further, the engine 10 is provided with an engine rotation speed sensor 16 for detecting the rotation speed of the main shaft 11, that is, the engine rotation speed Ne.

The cooling water circuit 20 is arranged in order in the cooling water circulation path 22 communicated with the cooling water passage of the engine 10 as viewed in the flow direction of the cooling water, a Rankine evaporator 24, a radiator (not shown), a thermostat, a water pump, etc. Is installed to form a closed circuit, and the engine 10 is cooled.
The Rankine circuit 30 supplies a rotational driving force to the working fluid circulation path 32 by the expansion of the working fluid that is heated by the Rankine evaporator 24 and the Rankine evaporator 24 in an overheated state in order in the flow direction of the working fluid. The expander 42 to be generated, the Rankine condenser (condenser) 34, the pump 44 for circulating the working fluid, and the like are interposed to form a closed circuit. The Rankine evaporator 24 and the cooling water circulating through the cooling water circuit 20 The waste heat of the engine 10 is recovered by performing heat exchange between them.

By the way, the expander 42 and the pump 44 of the Rankine circuit 30 are integrally configured as a fluid machine 40. That is, the expander 42 and the pump 44 are integrally configured as a fluid machine 40 that is rotated by the same rotation shaft 45. The fluid machine 40 is provided with a rotating shaft 45, that is, an expander rotation speed sensor 43 that detects an expander rotation speed Ni of the expander 42.
Here, the expander 42 is, for example, a scroll type expander, and the pump 44 is, for example, a variable displacement pump capable of increasing a low-pressure working fluid to a high pressure. Details of these are known, The description is omitted here.

A pulley 46 is provided at the tip of the rotating shaft 45 of the fluid machine 40, and the pulley 46 and the pulley 12 on the engine 10 side are connected by an endless belt 14 (transmission means).
The pulley 46 is internally provided with a connection / disconnection clutch 48 for connecting and disconnecting the pulley 46 and the rotary shaft 45, whereby the pulley 46 and the expander 42 and the pump 44 are rotated synchronously with the pulley 12 and the engine 10. Alternatively, the pulley 46 and thus the expander 42 and the pump 44 can be released from the pulley 12 and thus the engine 10.
The connection / disconnection clutch 48 is composed of, for example, an electromagnetic clutch, and a battery 50 is connected to an electromagnetic coil (not shown) of the connection / disconnection clutch 48 including the electromagnetic clutch via a relay switch 49. An electronic control unit (ECU) (control means) 60 is electrically connected. An ammeter (abnormality detection means) 54 is provided on the power line 52 connecting the relay switch 49 and the battery 50.

In the Rankine circuit 30, an electromagnetic on-off valve (shut-off valve) (shut-off means, limit means) 36 is interposed on the upstream side of the expander 42 as viewed in the direction of the working fluid flow in the circulation path 32. Thus, it is possible to switch between circulation and blocking of the working fluid flowing through the circulation path 32 toward the expander 42.
Further, in the Rankine circuit 30, a bypass flow path 37 that bypasses the expander 42 is provided between the upstream portion and the downstream portion of the circulation path 32 relative to the expander 42. An electromagnetic on-off valve (bypass valve) (bypass means, limiting means) 38 having the same function as that of the electromagnetic on-off valve 36 is interposed. As a result, the working fluid flowing through the circulation path 32 can flow to the expander 42, or the expander 42 can be bypassed and short-circuited.

The ECU 60 is a control device composed of a CPU, a memory, and the like. Various sensors such as the engine rotation speed sensor 16, the expander rotation speed sensor 43, and the ammeter 54 are electrically connected to the input side of the ECU 60. Devices such as the electromagnetic on-off valve 36, the electromagnetic on-off valve 38, and the relay switch 49 of the connection / disconnection clutch 48 are electrically connected to the output side.
Then, the ECU 60 issues a command to connect the connecting / disconnecting clutch 48 when the expander 42 can assist the engine 10 and to disconnect the connecting / disconnecting clutch 48 when it cannot assist.

Further, the ECU 60 determines the connection / disconnection clutch 48 based on the current value information detected by the ammeter 54 in response to the control command for the connection / disconnection clutch 48 from the ECU 60 and information on the expander rotational speed Nex and the engine rotational speed Ne. An abnormal operation is determined, and the electromagnetic on-off valve 36 and the electromagnetic on-off valve 38 are controlled to open and close.
Hereinafter, the operation contents of the automobile waste heat utilization system according to the present invention configured as described above, that is, the abnormality process control contents of the connection / disconnection clutch 48 will be described.
FIG. 2 shows a flowchart showing a control routine of connection / disconnection clutch abnormality processing control according to the first embodiment, which will be described based on the flowchart.

In step S10, it is determined whether or not the expander 42 can assist the engine 10. If the determination result is true (Yes) and the assist by the expander 42 is possible, the process proceeds to step S12.
In step S12, a control command is issued to the relay switch 49, and control is performed such that, for example, a pilot current is supplied to connect the connection / disconnection clutch 48.
In step S14, it is determined whether or not the ammeter 54 detects a current I greater than a predetermined current value I0 (for example, 0 amperes), that is, greater than the predetermined current value I0 from the battery 50 to the electromagnetic coil of the connection / disconnection clutch 48. It is determined whether or not the current I is flowing. When the determination result is true (Yes) and the current I measured by the ammeter 54 is larger than the predetermined current value I 0, power is normally supplied to the connection / disconnection clutch 48 in response to a control command from the ECU 60. The process proceeds to step S16.

In step S16, it is further determined whether or not the corrected engine rotational speed ρNe and the expander rotational speed Nex are equal. If the determination result is true (Yes) and the corrected engine rotational speed ρNe and the expander rotational speed Nex are equal to each other, the connecting / disconnecting clutch 48 is normally operated and connected, and the engine 10 and the fluid machine 40 and thus the expander are connected. 42 can be regarded as rotating synchronously, and the process proceeds to step S18.
In step S18, the electromagnetic on-off valve 36 is controlled to open. In step S20, the electromagnetic on-off valve 38 is controlled to be closed. That is, the working fluid is allowed to flow through the expander 42 as a normal state.

If the determination result in step S14 is false (No) and the current I measured by the ammeter 54 is equal to or less than the predetermined current value I0, or the determination result in step S16 is false (No) and the corrected engine speed ρNe If the expander rotation speed Nex is different from the expander rotation speed Nex and is higher than the corrected engine rotation speed ρNe, it can be determined that the connection / disconnection clutch 48 is not normally connected and is abnormal. The process proceeds to step S22.
In step S22, the electromagnetic on-off valve 36 is controlled to close. In step S24, the electromagnetic on-off valve 38 is controlled to open, and the upstream portion and the downstream portion of the expander 42 in the circulation path 32 are short-circuited. That is, the working fluid flows around the expander 42 and does not flow into the expander 42.

  In this way, the expander 42 assists the driving force of the engine 10 when the connection / disconnection clutch 48 is not normally connected despite the control command from the ECU 60 to connect the connection / disconnection clutch 48. In particular, in the fluid machine 40, the pump 44 rotates together with the expander 42, so that the working fluid is maintained at a high pressure on the upstream side of the expander 42, and the expander 42 and the pump 44 continue to rotate excessively. However, the high pressure of the working fluid upstream of the expander 42 can be released downstream without flowing the working fluid through the expander 42, and the expander 42 and the pump 44 are over-rotated. Is prevented. As a result, noise and vibration due to excessive rotation of the expander 42 and the pump 44 can be prevented, and failure of the expander 42 and the pump 44 can be prevented.

On the other hand, if the determination result in step S10 is false (No) and the expander 42 cannot assist the engine 10, the process proceeds to step S26, and the connecting / disconnecting clutch 48 is supplied without supplying pilot current to the relay switch 49. A control command is issued to disconnect
In step S28, whether or not the current I detected by the ammeter 54 is equal to or less than a predetermined current value I0 (for example, 0 amperes), that is, the current I flowing from the battery 50 to the electromagnetic coil of the connection / disconnection clutch 48 is the predetermined current value I0. It is determined whether or not: When the determination result is true (Yes) and the current I measured by the ammeter 54 is equal to or less than the predetermined current value I0, no electric power is supplied to the connection / disconnection clutch 48 in response to a control command from the ECU 60, and the operation is normal. That is, the connection / disconnection clutch 48 can be regarded as being disconnected, and the process proceeds to step S30.

In step S30, it is further determined whether or not the corrected engine rotational speed ρNe and the expander rotational speed Nex are equal. If the determination result is false (No), the corrected engine rotational speed ρNe and the expander rotational speed Nex are different and the expander rotational speed Nex is equal to or less than the corrected engine rotational speed ρNe, the connecting / disconnecting clutch 48 is normally operated and disconnected. The process proceeds to step S18.
When the determination result of step S28 is false (No) and the current I measured by the ammeter 54 is larger than the predetermined current value I0, or when the determination result of step S30 is true (Yes) and the corrected engine rotational speed ρNe is expanded. When the engine rotational speed Nex is equal and the engine 10 and the fluid machine 40 and thus the expander 42 are rotating synchronously, the connection / disconnection clutch 48 is not operating normally and is connected. It can be determined that the condition is abnormal and the process proceeds to step S32.

In step S32, the electromagnetic on-off valve 38 is controlled to open, and the upstream portion and the downstream portion of the expander 42 in the circulation path 32 are short-circuited. That is, the working fluid flows around the expander 42. The electromagnetic opening / closing valve 36 is kept open.
In this way, if the connection / disconnection clutch 48 does not operate normally and is in the connected state despite the control command from the ECU 60 to disconnect the connection / disconnection clutch 48, the expander 42 is forced to Although it is rotated synchronously with the engine 10, it becomes an unnecessary load on the engine 10, but the work of the expander 42 that is forced to operate by reducing the amount of working fluid flowing through the expander 42. The amount can be reduced, and the load on the engine 10 can be reduced.

  As described above, in the automobile waste heat utilization system according to the present invention, the connection / disconnection clutch 48 is normally connected despite the control command from the ECU 60 to connect the connection / disconnection clutch 48 built in the pulley 46. When not operating, the electromagnetic on-off valve 36 is closed to stop the flow of the working fluid to the expander 42, and the electromagnetic on-off valve 38 is opened to short-circuit the circulation path 32 so that the working fluid is supplied to the expander 42. Since the flow is bypassed, over-rotation of the expander 42 and the pump 44 can be prevented, noise and vibration due to the over-rotation of the expander 42 and the pump 44 are prevented, and failure of the expander 42 and the pump 44 is prevented. can do.

  Further, when the connection / disconnection clutch 48 is not normally disconnected even though a control command is issued from the ECU 60 to disconnect the connection / disconnection clutch 48 built in the pulley 46, the electromagnetic on-off valve 38 is controlled to open and the circulation path is controlled. 32 is short-circuited, and the working fluid is allowed to flow around the expander 42, so that the amount of working fluid flowing through the expander 42 is reduced and the work of the expander 42 that is forced to be operated by the engine 10 is reduced. It is possible to reduce the size, and the unnecessary load on the engine 10 can be reduced. Thereby, the fuel consumption in the engine 10 can be suppressed, and the deterioration of the fuel consumption in the vehicle can be prevented.

Further, here, based on the current I detected by the ammeter 54 in step S14 or step S28, and further in step S16 or step S30, based on the comparison between the engine rotational speed Ne and the expander rotational speed Nex, the connecting / disconnecting clutch 48 is provided. Therefore, even when the abnormal operation of the connection / disconnection clutch 48 is in the power supply system between the battery 50 and the connection / disconnection clutch 48, there is a problem with the connection / disconnection clutch 48 itself. Even in some cases, it is possible to reliably perform the abnormal processing of the connection / disconnection clutch 48.
Here, the abnormal operation of the connection / disconnection clutch 48 is determined based on the comparison between the current I measured by the ammeter 54 and the engine rotational speed Ne and the expander rotational speed Nex as described above. An abnormal operation of the connection / disconnection clutch 48 may be determined based only on the current I measured by the ammeter 54. Alternatively, the operation abnormality of the connection / disconnection clutch 48 may be determined based only on the comparison between the engine rotation speed Ne and the expander rotation speed Nex. In this way, it is possible to determine the operation abnormality of the connection / disengagement clutch 48 with a simple configuration, and to simplify the waste heat utilization system for automobiles.

Next, a second embodiment will be described.
The second embodiment is different from the system configuration of FIG. 1 of the first embodiment in that the ammeter 54 is replaced with a voltmeter (abnormality detection means) 55, and here, a difference from the first embodiment. Only will be described.
As shown in FIG. 3, in the second embodiment of the present invention, the automobile waste heat utilization system is configured such that a voltmeter 55 is provided on a power line 52 connecting a relay switch 49 and a battery 50.
In the automobile waste heat utilization system configured as described above, the ECU 60 corrects the voltage value information detected by the voltmeter 55 in response to the control command for the connection / disconnection clutch 48 from the ECU 60 and the expander rotational speed Nex. Based on the coincidence with the engine rotational speed ρNe, an operation abnormality of the connection / disconnection clutch 48 is determined, and the electromagnetic on / off valve 36 and the electromagnetic on / off valve 38 are controlled to open / close.

That is, FIG. 4 shows a flowchart similar to FIG. 2 showing the control routine of the connection / disconnection clutch abnormality process control according to the second embodiment, but in step S14 ′, the voltmeter 55 uses the predetermined voltage value E0 ( For example, it is determined whether or not a voltage E greater than 0 volts is detected, that is, whether or not a voltage E greater than a predetermined voltage value E0 is applied from the battery 50 to the electromagnetic coil of the connection / disconnection clutch 48. When the determination result is true (Yes) and the voltage E measured by the voltmeter 55 is larger than the predetermined voltage value E0, the electric power is normally supplied to the connection / disconnection clutch 48 in response to the control command from the ECU 60. The process proceeds to step S16.
On the other hand, when the determination result in step S14 ′ is false (No) and the voltage E measured by the voltmeter 55 is equal to or less than the predetermined voltage value E0, the connecting / disconnecting clutch 48 is not operating normally and an abnormality occurs. It can be determined that it is in progress, and the process proceeds to step S22.

In step S28 ′, whether or not the voltage E of the predetermined voltage value E0 or less (for example, 0 volts) is detected by the voltmeter 55, that is, the voltage E applied from the battery 50 to the electromagnetic coil of the connection / disconnection clutch 48 is determined. Is less than or equal to a predetermined voltage value E0. When the determination result is true (Yes) and the voltage E measured by the voltmeter 55 is equal to or less than the predetermined voltage value E0, power is not supplied to the connection / disconnection clutch 48 in response to a control command from the ECU 60, and is normal. That is, it can be regarded as a disconnected state, and the process proceeds to step S30.
On the other hand, when the determination result in step S28 'is false (No) and the voltage E measured by the voltmeter 55 is larger than the predetermined voltage value E0, the connecting / disconnecting clutch 48 is not operating normally, that is, it is not connected. The state can be determined, and the process proceeds to step S32.

As described above, even if the operation abnormality of the connection / disengagement clutch 48 is determined based on the voltage E detected by the voltmeter 55, the same effect as in the first embodiment can be obtained.
According to FIG. 4, also in the second embodiment, the abnormal operation of the connection / disconnection clutch 48 is determined based on the comparison between the voltage E detected by the voltmeter 55 and the corrected engine rotational speed ρNe and the expander rotational speed Nex. Although the determination is made, the operation abnormality of the connection / disconnection clutch 48 may be determined based only on the voltage E detected by the voltmeter 55. Thereby, simplification of the waste heat utilization system for automobiles can be achieved.

Next, a third embodiment will be described.
The third embodiment differs from the system configuration of FIG. 1 of the first embodiment in that a pressure gauge (abnormality detection means) 33 and a pressure gauge (abnormality detection means) 35 for measuring the pressure of the working fluid are provided. Only the parts different from the first embodiment will be described here.
As shown in FIG. 5, in the third embodiment of the present invention, the waste heat utilization system for automobiles includes, for example, a pressure gauge 33 that detects the pressure of the working fluid flowing in the upstream portion of the Rankine condenser 34 in the circulation path 32. The pressure gauge 35 is configured to detect the pressure of the working fluid flowing through the downstream portion of the Rankine condenser 34.
In the automobile waste heat utilization system configured as described above, the ECU 60 controls the working fluid flowing through the upstream portion of the Rankine condenser 34 detected by the pressure gauge 33 in response to the control command for the connection / disconnection clutch 48 from the ECU 60. The flow rate of the working fluid can be estimated from the differential pressure (pressure loss) between the pressure and the pressure of the working fluid flowing through the downstream portion of the Rankine condenser 34 detected by the pressure gauge 35. Therefore, based on the estimated flow rate of the working fluid, the operation abnormality of the connection / disconnection clutch 48 is determined, and the electromagnetic on / off valve 36 and the electromagnetic on / off valve 38 are controlled to open / close.

  That is, FIG. 6 shows a flowchart similar to FIG. 2 showing the control routine of the connection / disconnection clutch abnormality processing control according to the third embodiment. However, in step S16 ′, the pressure detected by the pressure gauge 33 and It is determined whether or not the flow rate Q of the working fluid estimated from the pressure difference from the pressure detected by the pressure gauge 35 is equal to or less than a predetermined flow rate Q0. Here, the predetermined flow rate Q0 is a value determined according to the engine speed Ne, for example. When it is determined that the flow rate Q of the working fluid estimated with the determination result being true (Yes) is equal to or less than the predetermined flow rate Q0, it is considered that the connection / disconnection clutch 48 is normally connected to the control command from the ECU 60. The process proceeds to step S18.

On the other hand, if it is determined that the flow rate Q of the working fluid estimated as the determination result is false (No) is greater than the predetermined flow rate Q0, the connecting / disconnecting clutch 48 is not normally operated in response to the control command from the ECU 60. Therefore, it can be determined that it has been cut, and the process proceeds to step S22.
In step S30 ′, it is determined whether or not the estimated flow rate Q of the working fluid is smaller than a predetermined flow rate Q0. When it is determined that the flow rate Q of the working fluid estimated as the determination result is true (Yes) is smaller than the predetermined flow rate Q0, the connecting / disconnecting clutch 48 is normally operated in response to the control command from the ECU 60, that is, It can be regarded as a disconnected state, and the process proceeds to step S18.
On the other hand, when the flow rate Q of the working fluid estimated as false (No) in step S30 ′ is greater than or equal to the predetermined flow rate Q0, it is determined that the connection / disconnection clutch 48 is not operating normally and is connected. The process proceeds to step S32.

As described above, even if the abnormal operation of the connection / disengagement clutch 48 is determined based on the estimated flow rate Q of the working fluid, the same effect as in the first embodiment can be obtained.
According to FIG. 6, in the second embodiment as well, the abnormal operation of the connection / disconnection clutch 48 is determined based on the current I detected by the ammeter 54 and the estimated flow rate Q of the working fluid. The abnormal operation of the connection / disconnection clutch 48 may be determined based only on the estimated flow rate Q of the working fluid.
In the third embodiment, the connection / disconnection clutch 48 is operated based on the voltage E detected by the voltmeter 55 as in the second embodiment, instead of the current I detected by the ammeter 54. You may make it determine abnormality.

Here, the flow rate of the working fluid is estimated from the differential pressure between the pressure detected by the pressure gauge 33 and the pressure detected by the pressure gauge 35, but the flow meter is connected to the circulation path 32 of the Rankine circuit 30. The flow rate of the working fluid may be directly detected by a flow meter.
Although the description of the embodiment of the present invention has been completed above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, in the first to third examples, the electromagnetic on-off valve (shutoff valve) 36 and the electromagnetic on-off valve (bypass valve) 38 are provided, and the electromagnetic on-off valve 36 and the electromagnetic on-off valve 38 are controlled to open / close. For example, in the case where the connection / disconnection clutch 48 does not operate normally even though a control command is issued from the ECU 60 to connect the connection / disconnection clutch 48, the electromagnetic on-off valve (shutoff valve) 36 and the electromagnetic Only one of the on-off valve (bypass valve) 38 may be controlled.

In the above embodiment, the electromagnetic on-off valve (shutoff valve) 36 and the electromagnetic on-off valve (bypass valve) 38 are provided. Only the valve 38 may be controlled to open and close.
In the above embodiment, the Rankine circuit 30 recovers the waste heat of the engine 10 by exchanging heat with the cooling water circulating through the cooling water circuit 20 via the Rankine condenser 34. Instead of or together with this, the waste heat of the engine 10 may be recovered by exchanging heat with the exhaust gas flowing through the exhaust passage of the engine 10, for example.

1 Waste heat utilization system 10 Engine 12 Pulley (transmission means)
14 Belt (Transmission means)
16 Engine speed sensor 20 Cooling water circuit 30 Rankine circuit 33, 35 Pressure gauge (abnormality detection means)
36 Electromagnetic on-off valve (shutoff valve) (shutoff means, limiting means)
37 Bypass flow path 38 Electromagnetic switching valve (bypass valve) (bypass means, limiting means)
40 Fluid Machine 42 Expander 43 Expander Rotational Speed Sensor 44 Pump 46 Pulley (Transmission Means)
48 Connection / disconnection clutch 49 Relay switch 50 Battery 54 Ammeter (Abnormality detection means)
55 Voltmeter (Abnormality detection means)
60 ECU (control means)

Claims (4)

An evaporator that heats and evaporates the working fluid by waste heat of the internal combustion engine, an expander that expands the working fluid that passes through the evaporator, and a condensation that condenses the working fluid that passes through the expander A waste heat utilization system for automobiles having a Rankine circuit in which a pump for sending a working fluid passing through the condenser to the evaporator is sequentially disposed,
The expander and the pump are coaxially configured integrally as a fluid machine,
Transmission means for connecting the rotating shaft of the fluid machine and the rotating shaft of the internal combustion engine via a connection / disconnection clutch;
Control means for performing connection control and disconnection control of the connection / disconnection clutch;
A restriction means provided in the circulation path and restricting the flow of the working fluid to the expander;
The restricting means includes an abnormality detecting means for detecting that the connection / disconnection clutch operating control command and the disconnection control command by the control means are abnormal, and the abnormality detecting means detects the disconnection clutch. A waste heat utilization system for automobiles that restricts the flow of the working fluid to the expander when an abnormal operation of the contact clutch is detected.   The restricting means is a bypass means for bypassing the flow of the working fluid to the expander, and when the abnormality detecting means detects an operation abnormality of the connection / disconnection clutch, the bypass means bypasses the flow of the working fluid. The waste heat utilization system for automobiles according to claim 1, wherein:   The restricting means is a shut-off means for stopping the flow of the working fluid to the expander, and the abnormality detecting means causes the connection / disconnection clutch operating abnormality to be controlled by the abnormality detecting means by the control means. 3. The automobile waste heat utilization system according to claim 1, wherein the flow of the working fluid is stopped by the shut-off means when detected. The connecting / disconnecting clutch is an electromagnetic clutch that operates by connecting / disconnecting electric power, and includes an ammeter that measures a current supplied to the connecting / disconnecting clutch,
The abnormality detection means is the ammeter,
The restricting means restricts the flow of the working fluid to the expander when an abnormality is detected in the current measured by the ammeter with respect to the connection control command and the disconnection control command of the connection / disconnection clutch by the control means. The waste heat utilization system for automobiles according to any one of claims 1 to 3, characterized by:

Images