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US-12624667-B2 - Control device for hydrogen engine

US12624667B2US 12624667 B2US12624667 B2US 12624667B2US-12624667-B2

Abstract

The hydrogen engine includes a blow-by gas passage that recirculates the blow-by gas leaked from the combustion chamber to the crankcase from the crankcase to the intake passage. The threshold temperature is set in advance based on the temperature at which the water contained in the oil stored in the crankcase starts evaporation in the crankcase. The control device limits the output of the hydrogen engine from when the oil temperature, which is the temperature of the oil, exceeds the threshold temperature for a predetermined period of time.

Inventors

  • Ryu Hamaguchi

Assignees

  • TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date
20260512
Application Date
20241225
Priority Date
20240418

Claims (5)

  1. 1 . A control device for a hydrogen engine including a blow-by gas passage through which blow-by gas leaked from a combustion chamber into a crankcase is recirculated from the crankcase to an intake passage, wherein a threshold temperature is preset based on a temperature at which moisture contained in oil stored in the crankcase starts to evaporate in the crankcase, and the control device is configured to limit power of the hydrogen engine for a predetermined period from a time when an oil temperature of the oil exceeds the threshold temperature.
  2. 2 . The control device according to claim 1 , wherein: the hydrogen engine further includes a pressure sensor configured to detect a crankcase pressure in the crankcase; the control device is configured to limit the power of the hydrogen engine for the predetermined period when a logical product condition is satisfied, the logical product condition including a condition that the oil temperature exceeds the threshold temperature and a condition that the crankcase pressure detected by the pressure sensor exceeds a threshold pressure; and the threshold pressure is set to a value lower than a pressure at which the oil is jetted from the blow-by gas passage toward the intake passage.
  3. 3 . The control device according to claim 1 , wherein: the hydrogen engine further includes a pressure sensor configured to detect a crankcase pressure in the crankcase; the control device is configured to limit the power of the hydrogen engine for the predetermined period when the crankcase pressure exceeds a threshold pressure within a given period after the oil temperature has exceeded the threshold temperature; and the threshold pressure is set to a value lower than a pressure at which the oil is jetted from the blow-by gas passage toward the intake passage.
  4. 4 . The control device according to claim 1 , wherein: the hydrogen engine further includes a pressure sensor configured to detect a crankcase pressure in the crankcase; the control device is configured to limit the power of the hydrogen engine for the predetermined period when a logical product condition is satisfied for a first time during one trip that is a period from a start of the hydrogen engine to a stop of the hydrogen engine, the logical product condition including a condition that the oil temperature exceeds the threshold temperature and a condition that the crankcase pressure detected by the pressure sensor exceeds a threshold pressure; and the threshold pressure is set to a value lower than a pressure at which the oil is jetted from the blow-by gas passage toward the intake passage.
  5. 5 . The control device according to claim 1 , wherein the control device is configured to set an upper limit value for the power of the hydrogen engine and limit the power of the hydrogen engine to the upper limit value or less for the predetermined period from the time when the oil temperature exceeds the threshold temperature.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Japanese Patent Application No. 2024-067665 filed on Apr. 18, 2024, incorporated herein by reference in its entirety. BACKGROUND 1. Technical Field The present disclosure relates to a control device for a hydrogen engine. 2. Description of Related Art Japanese Unexamined Patent Application Publication No. 2013-100730 (JP 2013-100730 A) discloses a control device for an internal combustion engine. The internal combustion engine includes a pressure sensor that detects a pressure inside a crankcase. When the pressure detected by the pressure sensor is equal to or higher than a predetermined pressure, the control device performs a limiting process for limiting the power of the internal combustion engine. When the pressure detected by the pressure sensor is equal to or higher than the predetermined pressure, there is a high possibility that abnormal combustion such as pre-ignition has occurred. As the power of the internal combustion engine is smaller, the abnormal combustion is less likely to occur. Therefore, the control device can suppress the occurrence of the abnormal combustion through the limiting process. SUMMARY During operation of a hydrogen engine, blow-by gas may leak from a combustion chamber into a crankcase. Compared to a gasoline engine, the blow-by gas in the hydrogen engine contains more moisture. Due to a long cold operation time after the startup of the hydrogen engine, the moisture from the blow-by gas may accumulate in oil in the crankcase. When the oil temperature rises along with continuation of the engine operation from this state, the moisture accumulated in the oil due to the blow-by gas starts to evaporate. Therefore, the pressure inside the crankcase rises abruptly. In such a case, there is a possibility that the oil is jetted together with the blow-by gas toward an intake passage through a blow-by gas passage that recirculates the blow-by gas to the intake passage. Hereinafter, means for solving the above problem and its operations and effects will be described. An aspect of the present disclosure provides a control device for a hydrogen engine including a blow-by gas passage through which blow-by gas leaked from a combustion chamber into a crankcase is recirculated from the crankcase to an intake passage. A threshold temperature is preset based on a temperature at which moisture contained in oil stored in the crankcase starts to evaporate in the crankcase. The control device is configured to limit power of the hydrogen engine for a predetermined period from a time when an oil temperature of the oil exceeds the threshold temperature. With the above configuration, it is possible to suppress the jet of the oil toward the intake passage through the blow-by gas passage. BRIEF DESCRIPTION OF THE DRAWINGS Features, advantages, and technical and industrial significance of exemplary embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like signs denote like elements, and wherein: FIG. 1 is a schematic diagram illustrating a configuration of a hydrogen engine according to an embodiment; FIG. 2 shows a control device for controlling the hydrogen engine shown in FIG. 1; FIG. 3 is a flowchart illustrating a process according to the first embodiment; FIG. 4 is a time chart for explaining the operation according to the first embodiment; FIG. 5 is a flow chart showing a process according to the second embodiment; and FIG. 6 is a time chart for explaining the operation according to the second embodiment. DETAILED DESCRIPTION OF EMBODIMENTS First Embodiment Hereinafter, a hydrogen engine control device according to a first embodiment will be described with reference to the drawings. Configuration of the Hydrogen Engine 100 As shown in FIG. 1, the hydrogen engine 100 includes a cylinder block 16. The hydrogen engine 100 has a cylinder head 18 attached to the upper end of the cylinder block 16. The hydrogen engine 100 has a crankcase 12 attached to the lower end of the cylinder block 16. An upper portion of the cylinder head 18 is covered with a ventilation case 22. When fuel is burned in the combustion chamber 10 of the hydrogen engine 100, blow-by gas leaks from the combustion chamber 10 of the hydrogen engine 100 to the crankcase 12. The hydrogen engine 100 includes a blow-by gas reduction device for flowing blow-by gas leaked to the crankcase 12 to the intake system 14 of the hydrogen engine 100. FIG. 1 shows an intake passage 14a which is part of the intake system 14. The blow-by gas reduction device has a blow-by gas passage 20 for flowing the blow-by gas to the intake system 14 of the hydrogen engine 100. That is, the hydrogen-engine 100 includes the blow-by gas passage 20 that recirculates the blow-by gas leaked from the combustion chamber 10 to the crankcase 12 from the crankcase 12 to the intake passage 14a. The blow-by gas reduction device includes a PCV (Positiv