Oil level detection device

Abstract

To provide an oil level detection device capable of improving detection accuracy of an oil level.SOLUTION: An oil level detection device includes: an oil pump for discharging oil from a storage section; a detection section that detects that an oil level in the storage section is located at a predetermined position; and a control section that increases a discharge amount of the oil pump in accordance with a load status of an internal combustion engine.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an oil level detection device. [Background technology]

[0002] 2. Description of the Related Art There is known a technique for detecting an oil level in an internal combustion engine (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-38041 A Summary of the Invention [Problem to be solved by the invention]

[0004] An oil level switch is provided in the oil pan. The oil level switch detects when the oil level (oil level) has dropped to a certain position. The position of the oil level changes depending on the discharge volume of the oil pump. As the discharge volume decreases, the oil level position becomes less likely to drop. It is difficult for the oil level switch to detect a drop in the oil level. Therefore, the objective of the present invention is to provide an oil level detection device that can improve the accuracy of detecting the oil level. [Means for solving the problem]

[0005] The above objective can be achieved by an oil level detection device comprising an oil pump that discharges oil from a reservoir, a detection unit that detects when the oil level in the reservoir is at a predetermined position, and a control unit that increases the discharge amount of the oil pump to a predetermined amount depending on the load condition of the internal combustion engine. Effect of the Invention

[0006] It is possible to provide an oil level detection device capable of improving the accuracy of detecting the oil level. [Brief description of the drawings]

[0007] [Figure 1] 1(a) and 1(b) are schematic views illustrating an oil level detection device according to an embodiment. [Diagram 2] 2(a) and 2(b) are schematic views illustrating an oil level detection device according to an embodiment. [Diagram 3] FIG. 3 is a flowchart illustrating a process according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The oil level detection device of the present embodiment will be described below with reference to the drawings. However, the dimensions and ratios of each part in the drawings may not be illustrated to be completely consistent with the actual ones. Also, some details may be omitted in the drawings.

[0009] 1(a) to 2(b) are schematic diagrams illustrating an oil level detection device 100 according to an embodiment. Figures 1(a) and 2(a) show a state in which the internal combustion engine is stopped, and Figures 1(b) and 2(b) show a state in which the internal combustion engine is operating.

[0010] As shown in FIGS. 1(a) to 2(b), an oil level detection device 100 has an oil pan 10 (storage section), an oil level switch 12 (detection section), an oil pump 14, and an ECU (Electronic Control Unit) 20 (control section).

[0011] The oil pan 10 is attached to, for example, a crankcase of an internal combustion engine. Oil 15 is stored in the oil pan 10. The liquid level of the oil 15 is an oil level 16.

[0012] The positions of the oil level 16 in Figures 1(a), 1(b), 2(a) and 2(b) are designated as L1, L2, L3 and L4, respectively. With respect to the bottom surface of the oil pan 10 as the reference, position L2 is lower than position L1. Position L3 is higher than position L1. Position L4 is lower than position L3 and higher than position L2.

[0013] An oil passage 17 is connected to the oil pump 14. An end of the oil passage 17 is submerged in the oil 15. The oil pump 14 pumps up oil from the oil pan 10. The oil flows through the oil passage 17 and is supplied to components of the internal combustion engine. The oil drops from the components into the oil pan 10 and is pumped up again by the oil pump 14. The oil pump 14 can change the amount of oil discharged.

[0014] The oil level switch 12 is provided inside the oil pan 10. When the oil level 16 is above the oil level switch 12, the oil level switch 12 does not issue an alarm. The oil level switch 12 detects when the oil level 16 reaches the position of the oil level switch 12 and issues an alarm. The rotation speed sensor 18 detects the rotation speed of the internal combustion engine.

[0015] The ECU 20 is electrically connected to the oil level switch 12, the oil pump 14, and the rotation speed sensor 18. The ECU 20 acquires the position of the oil level 16 detected by the oil level switch 12, and acquires the rotation speed of the internal combustion engine detected by the rotation speed sensor 18. The ECU 20 changes the amount of oil discharged by the oil pump 14 by controlling the rotation speed of the oil pump 14 according to the load condition of the internal combustion engine. The load condition refers to operating conditions such as the rotation speed, oil temperature, water temperature, and intake load rate of the internal combustion engine.

[0016] As shown in the examples of Figures 1(a) and 1(b) and the examples of Figures 2(a) and 2(b), the oil level 16 while the internal combustion engine is operating is lower than the oil level 16 while the internal combustion engine is stopped. As the internal combustion engine operates, the oil pump 14 is driven to pump out oil 15, causing the oil level 16 to drop.

[0017] The oil level detection device 100 detects a drop in the oil level and notifies the vehicle user. For example, it is desired to detect that the oil level 16 while the engine is stopped is below position L1 in FIG. 1(a). Meanwhile, the oil level detection device 100 operates while the internal combustion engine is in operation. Therefore, as in the examples of FIG. 1(a) and FIG. 1(b), it is sufficient that the oil level 16, which is below position L1 while the internal combustion engine is stopped, drops to the position of the oil level switch 12 while the internal combustion engine is in operation.

[0018] FIG. 3 is a flow chart illustrating the process in the embodiment. The internal combustion engine starts (step S10). The rotation speed sensor 18 detects the rotation speed, and the ECU 20 acquires the rotation speed R of the internal combustion engine (step S12). The ECU 20 judges whether the rotation speed R of the internal combustion engine is equal to or lower than a predetermined rotation speed Rth (step S14). If the judgment is negative (No), the process ends. If the judgment is positive (Yes), the ECU 20 increases the amount of oil discharged by the oil pump 14 to a predetermined amount, for example, sets the discharge amount to a maximum value (step S16). It is judged whether the oil level 16 after the operation of the oil pump 14 has reached the position of the oil level switch 12 (step S18). If the judgment is negative, the process ends. If the judgment is positive, the oil level switch 12 outputs a warning (step S20). The warning is given by, for example, a sound or a lamp. After step S20, the process ends.

[0019] According to this embodiment, the ECU 20 increases the discharge amount of the oil pump 14 (step S16). When the oil pump 14 is driven, the oil level 16 of the oil 15 drops. The oil level detection device 100 can accurately detect that the oil level 16 is below the position L1 and issue a warning.

[0020] In the example of FIG. 1(a), the oil level 16 before discharge is at position L1. The discharge amount of the oil pump 14 increases to a maximum value (step S16). As shown in FIG. 1(b), the oil level 16 after discharge is at position L2, and drops to the position of the oil level switch 12. The oil level switch 12 detects the oil level 16 and outputs a warning (step S20). In this way, the oil level detection device 100 can detect that the oil level 16 is below position L1.

[0021] In the example of Fig. 2(a), the oil level 16 before discharge is at position L3, which is higher than position L1. As shown in Fig. 2(b), the oil level 16 after discharge is at position L4, and does not reach the oil level switch 12. The oil level switch 12 does not detect the oil level 16, and does not issue a warning (No in step S18).

[0022] The position of the oil level 16 during operation of the internal combustion engine depends on the engine speed. For example, when the engine speed R is higher than a threshold value Rth, the oil level 16 during operation may reach the position of the oil level switch 12 even though the oil level 16 at the time of stopping is higher than the position L1. The ECU 20 changes the discharge amount of the oil pump 14 according to the engine speed R of the internal combustion engine. When the engine speed R is higher than Rth, the discharge amount is not increased. The oil level 16 does not reach the position of the oil level switch 12. When the engine speed R is equal to or lower than Rth, the discharge amount is increased and set to, for example, a maximum value. The oil level 16 reaches the position of the oil level switch 12. The detection accuracy of the oil level 16 is improved. The ECU 20 may change the discharge amount according to the load conditions, such as the engine speed R, oil temperature, water temperature, and intake load rate.

[0023] The position of the oil level switch 12 and the discharge rate of the oil pump 14 are determined according to the position of the oil level 16 to be detected. It is sufficient that the position of the oil level 16 when stopped is equal to or lower than L1, and that the position of the oil level 16 when the discharge rate is increased is at the height of the oil level switch 12.

[0024] The ECU 20 increases the discharge amount at least once during the period from after the internal combustion engine is started (step S10) until it is stopped. It is possible to detect whether the oil level 16 at the time of stopping is at position L1. The discharge amount during the increase may be, for example, the maximum discharge amount possible for the oil pump 14, or may be less than the maximum discharge amount.

[0025] Although a preferred embodiment of the present invention has been described in detail above, the present invention is not limited to such a specific embodiment, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0026] 10 oil pan, 12 oil level switch, 14 oil pump, 15 oil, 16 oil level, 17 oil passage, 18 rotation speed sensor, 20 ECU, 100 oil level detection device

Claims

[Claim 1] an oil pump that discharges oil from the reservoir; A detection unit that detects whether the oil level in the reservoir is at a predetermined position; a control unit that increases the discharge amount of the oil pump to a predetermined amount in accordance with the load condition of the internal combustion engine.

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