Engine system

Abstract

An engine system is provided with: an engine; the throttle valve is arranged on an air inlet pipe of the engine; an oil tank for storing lubricating oil for the engine; an oil pipe that causes the oil to flow from the oil tank to the engine and causes blow-by gas to flow from the engine to the oil tank; a first blow-by gas pipe that causes the blow-by gas to flow from the tank to the intake pipe downstream of the throttle valve; the pressure sensor is used for detecting the pressure in the oil tank; and a notification control device that, when the amount of deviation of the pressure in the tank detected by the pressure sensor from a normal pressure is equal to or greater than a threshold value, performs notification processing for notifying a user of the occurrence of an abnormality in at least one of the oil pipe and the first blow-by gas pipe.

Description

Technical Field

[0001] This invention relates to an engine system. Background Technology

[0002] The oil tank storing the engine's lubricating oil is connected to the engine via an oil pipe and is also connected to a part of the intake manifold downstream of the throttle valve via a gas leakage pipe (see, for example, Japanese Patent Application Publication No. 2016-196864). Summary of the Invention

[0003] If an abnormality occurs in the oil piping or the gas leakage piping, and the engine continues to be driven, the leaking gas may continue to be released into the atmosphere.

[0004] Therefore, the object of the present invention is to provide an engine system capable of notifying the user of abnormalities in oil piping or leaking gas piping.

[0005] The above objectives can be achieved by an engine system with the following structure:

[0006] engine;

[0007] A throttle valve is installed in the intake manifold of the engine;

[0008] The fuel tank stores the lubricating oil for the engine;

[0009] Oil piping allows oil to flow from the fuel tank to the engine, and allows leaking gas to flow from the engine to the fuel tank;

[0010] The first leaking gas piping allows the leaking gas to flow from the oil tank to the intake pipe on a downstream side than the throttle valve.

[0011] A pressure sensor detects the pressure inside the oil tank; and

[0012] The notification control device, when the pressure in the oil tank detected by the pressure sensor deviates from the normal pressure by a threshold amount, performs a notification process to notify the user that at least one of the oil piping and the first leaking gas piping has an anomaly.

[0013] The engine system also features:

[0014] The compressor of the turbocharger is located in the intake pipe, and is positioned upstream of the throttle valve; and

[0015] The second leaking gas piping, when the engine is operating in a pressurized region, directs the leaking gas from the fuel tank to the intake manifold further upstream than the compressor.

[0016] When the deviation exceeds the threshold, the notification control device performs notification processing to notify the user that at least one of the oil piping, the first leaking gas piping, and the second leaking gas piping has an anomaly.

[0017] According to the present invention, an engine system is provided that can notify the user of abnormalities in oil piping or leaking gas piping. Attached Figure Description

[0018] Hereinafter, with reference to the accompanying drawings, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described, in which the same reference numerals denote the same elements, and wherein:

[0019] Figure 1 This is a schematic structural diagram of the engine system of the first embodiment.

[0020] Figure 2 This is a flowchart illustrating exception notification control.

[0021] Figure 3 It is a time series diagram showing the shift in tank pressure under abnormal conditions.

[0022] Figure 4 This is a schematic structural diagram of the engine system in the second embodiment. Detailed Implementation

[0023] Example 1

[0024] Figure 1 This is a schematic structural diagram of the engine system according to the first embodiment. The engine system is, for example, mounted in a vehicle. The engine system includes an engine 1, a fuel tank 10, an electronic control unit (ECU) 20, and a display 30. The engine 1 is an inline engine, but is not limited to this. Furthermore, the engine 1 is a gasoline engine, but it can also be a diesel engine.

[0025] An intake pipe 4 is connected to the engine 1. A throttle valve 6 and an intake manifold 2 are installed on the intake pipe 4 from the upstream side to the downstream side. The intake manifold 2 is connected to the intake port of the engine 1. In addition, an exhaust pipe is connected to the engine 1.

[0026] The upstream side of the throttle valve 6, which connects to the intake pipe 4, is connected to the fresh air inlet pipe 16 of the engine 1. When the pressure inside the engine 1 becomes below atmospheric pressure, fresh air is introduced into the engine 1 through the fresh air inlet pipe 16, thereby preventing the engine 1 from becoming negatively pressured.

[0027] ECU20 is configured around a computer that includes volatile or non-volatile memory such as a central processing unit (CPU), random access memory (RAM), or read-only memory (ROM). ECU20 is an example of a notification control device.

[0028] An ignition switch 21, a pressure sensor 22, an intake pressure sensor 23, and a display 30 are connected to the ECU 20. The ignition switch 21 detects the on / off state of ignition. The pressure sensor 22 detects the pressure within the gas-filled space of the fuel tank 10, i.e., the tank pressure. The intake pressure sensor 23 detects the intake pressure within the intake manifold 2. The ECU 20 adjusts the opening of the throttle valve 6 according to the driving state of the engine 1. The display 30 is, for example, located on the vehicle's dashboard.

[0029] The oil tank 10 is a dry sump tank for storing lubricating oil for the engine 1. The oil tank 10 is connected to the engine 1 via an oil pipe 10a. Oil used in the engine 1 flows into the oil tank 10 via the oil pipe 10a by driving the cleaning pump P1. Also, leaking gases generated within the engine 1 flow into the oil tank 10 via the oil pipe 10a. The cleaning pump P1 is a mechanical pump driven by the rotation of the crankshaft 1a of the engine 1. The oil stored in the oil tank 10 is pumped to various lubrication points of the engine 1 by the oil supply pump P2 located in the engine 1.

[0030] The lower part of the fuel tank 10 stores the fuel separated from the leaked gas. The leaked gas remains in the upper part of the fuel tank 10. A leaked gas pipe 15 is provided, connecting the upper part of the fuel tank 10 to the intake manifold 2. The leaked gas pipe 15 is an example of a first leaked gas pipe. A check valve 14 is provided on the leaked gas pipe 15. The check valve 14 allows gas to flow from the fuel tank 10 to the intake manifold 2, but restricts the flow of gas from the intake manifold 2 to the fuel tank 10.

[0031] During engine 1 operation, the pressure inside fuel tank 10 is higher than the pressure inside intake manifold 2. As a result, check valve 14 opens, and leaking gas from fuel tank 10 is supplied to combustion in engine 1 via leaking gas piping 15.

[0032] Thus, the oil used in the engine 1 is recovered through the cleaning pump P1, oil pipe 10a, and oil tank 10. Furthermore, the blow-by gas generated within the engine 1 is returned to the engine 1 through the cleaning pump P1, oil pipe 10a, oil tank 10, and blow-by gas pipe 15. Therefore, these mechanisms are used to achieve oil recovery and blow-by gas return. Additionally, the ECU 20 can estimate the flow rate of the blow-by gas flowing in the blow-by gas pipe 15 based on the pressure difference detected by the pressure sensor 22 and the intake air pressure sensor 23.

[0033] Anomaly Notification Control

[0034] Figure 2 This is a flowchart illustrating the abnormal notification control. This flowchart is executed repeatedly during ignition. ECU 20 determines whether the deviation of the tank pressure detected by pressure sensor 22 from the normal pressure exceeds a threshold (S1). The deviation is the value obtained by subtracting the tank pressure detected by pressure sensor 22 from the normal pressure. The normal pressure is the minimum tank pressure obtainable when driving engine 1, provided there are no holes or detachments in oil line 10a or leaky gas line 15, and is higher than atmospheric pressure. The threshold is the pressure that drops from the normal pressure when a hole is formed in oil line 10a or leaky gas line 15, or when oil line 10a or leaky gas line 15 is detached. If S1 is negative, this control ends.

[0035] If the condition in S1 is true, it is assumed that the pressure inside the tank has dropped to near atmospheric pressure due to a hole being formed in at least one of the oil pipe 10a and the leaking gas pipe 15. Alternatively, it is assumed that the pressure inside the tank has dropped to near atmospheric pressure due to at least one of the oil pipe 10a and the leaking gas pipe 15 becoming detached. In this case, the leaking gas in the fuel tank 10 is released into the atmosphere. Therefore, the ECU 20 performs an abnormality notification process (S2) to notify the user that at least one of the oil pipe 10a and the leaking gas pipe 15 is abnormal. The ECU 20 may notify the user, for example, by displaying this information on the display 30, or by using a malfunction indicator light (MIL) or a speaker.

[0036] Figure 3 This is a time-series diagram showing the pressure shift inside the tank under abnormal conditions. For example, if a hole is formed in the leaking gas pipe 15, the pressure inside the tank gradually decreases relative to the normal pressure (time t1). If the deviation of the tank pressure from the normal pressure gradually increases and the deviation exceeds a threshold, the aforementioned abnormal notification process is executed (time t2). This notification prompts the user to stop engine 1 and perform an inspection. By stopping engine 1, the release of leaking gas into the atmosphere can be suppressed.

[0037] Example 2

[0038] Figure 4 This is a schematic structural diagram of the engine system according to the second embodiment. In the engine system of the second embodiment, the engine 1 has a turbocharger. Therefore, a compressor 5 with the turbocharger is installed on the intake manifold 4, upstream of the throttle valve 6. Furthermore, a leaky gas pipe 13 is provided, connecting the upper part of the fuel tank 10 to the upstream side of the intake manifold 4, above the compressor 5. The leaky gas pipe 13 is an example of a second leaky gas pipe. A check valve 12 is provided on the leaky gas pipe 13. The check valve 12 allows gas to flow from the fuel tank 10 to the upstream side of the intake manifold 4 above the compressor 5, but restricts gas flow from the upstream side of the intake manifold 4 above the compressor 5 back to the fuel tank 10. Furthermore, a fresh air inlet pipe 16a connects the upstream side of the intake manifold 4 above the compressor 5 to the engine 1.

[0039] During natural aspiration, the pressure inside the fuel tank 10 is higher than the pressure inside the intake manifold 2. Consequently, the check valve 14 opens, and leaked gas from the fuel tank 10 is supplied to the combustion chamber of the engine 1 via the leaked gas pipe 15. During turbocharging, the pressure inside the fuel tank 10 is higher than the pressure upstream of the compressor 5. Consequently, the check valve 12 opens, and leaked gas from the fuel tank 10 is supplied to the combustion chamber of the engine 1 via the leaked gas pipe 13.

[0040] If the tank pressure detected by pressure sensor 22 is lower than the normal range, ECU 20a performs an anomaly notification processing. The anomaly notification processing involves notifying the user that at least one of the oil line 10a, the leaking gas line 15, and the leaking gas line 13 has an anomaly.

[0041] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific embodiments described above. Various modifications and alterations can be made within the scope of the spirit of the present invention as set forth in the claims.

Claims

1. An engine system, characterized in that, have: engine; A throttle valve, which is located in the intake manifold of the engine; A fuel tank that stores lubricating oil for the engine; Oil piping that allows oil to flow from the fuel tank to the engine, and allows leaking gas to flow from the engine to the fuel tank; The first leaking gas piping, which allows the leaking gas to flow from the oil tank to the intake pipe on a downstream side than the throttle valve; A pressure sensor detects the pressure inside the oil tank; and The notification control device performs a notification process to notify the user of an anomaly in at least one of the oil piping and the first leaking gas piping when the pressure in the oil tank, as detected by the pressure sensor, deviates from the normal pressure by a threshold amount.

2. The engine system according to claim 1, characterized in that, It also has: The compressor of the turbocharger is located in the intake manifold and is positioned upstream of the throttle valve; and The second leaking gas piping, when the engine is operating in a pressurized region, allows the leaking gas to flow from the fuel tank to the intake manifold further upstream than the compressor. When the deviation exceeds the threshold, the notification control device performs notification processing to notify the user that at least one of the oil piping, the first leaking gas piping, and the second leaking gas piping has an anomaly.

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