Hydraulic control device for internal combustion engines

Abstract

The objective is to provide a hydraulic control device for an internal combustion engine that can prevent abnormal noises and suppress deterioration of fuel efficiency and exhaust emissions. [Solution] A hydraulic control device for an internal combustion engine comprising: a first oil passage for supplying oil from an oil pump to a component; a second oil passage connected to the first oil passage for supplying the oil from the oil pump to a chain tensioner; a control valve provided in the first oil passage on the component side of the position where the second oil passage is connected; and a control unit for controlling the opening degree of the control valve.

Description

Technical Field

[0001] The present invention relates to a hydraulic control device for an internal combustion engine.

Background Art

[0002] Techniques have been developed that enable oil to be supplied to components such as a tensioner by an oil pump and the hydraulic pressure to be adjusted (for example, Patent Document 1, etc.).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Noise occurs due to air being mixed into the chain tensioner. By increasing the hydraulic pressure, the entry of air can be suppressed. However, the fuel consumption and exhaust deteriorate due to the increase in hydraulic pressure. Therefore, an object is to provide a hydraulic control device for an internal combustion engine that can prevent noise and suppress deterioration of fuel consumption and exhaust.

Means for Solving the Problems

[0005] The above object can be achieved by a hydraulic control device for an internal combustion engine, comprising a first oil passage for supplying oil from an oil pump to components, a second oil passage connected to the first oil passage for supplying the oil from the oil pump to a chain tensioner, an adjustment valve provided on the component side of the first oil passage at a position where the second oil passage is connected, and a control unit for controlling the opening degree of the adjustment valve.

Effects of the Invention

[0006] It is possible to provide a hydraulic control device for an internal combustion engine that can prevent noise and suppress deterioration of fuel consumption and exhaust. [Brief explanation of the drawing]

[0007] [Figure 1] Figures 1(a) and 1(b) are schematic diagrams illustrating a hydraulic control device according to an embodiment. [Figure 2] Figure 2 is a flowchart illustrating the process in the embodiment. [Modes for carrying out the invention]

[0008] The hydraulic control device for an internal combustion engine according to an embodiment will be described below with reference to the drawings. Figures 1(a) and 1(b) are schematic diagrams illustrating the hydraulic control device 100 according to the embodiment. The hydraulic control device 100 includes an oil passage 10 (first oil passage), an oil passage 12 (second oil passage), an oil pump 14, a control valve 16, and an ECU (Electronic Control Unit) 20. The hydraulic control device 100 is installed, for example, in a hybrid vehicle.

[0009] Oil passage 10 is connected between the oil pump 14 and component 22. Oil passage 12 branches off from oil passage 10 and is connected to the chain tensioner 24. A control valve 16 is provided in oil passage 10 at a position closer to component 22 than the connection point of oil passage 12. The control valve 16 is an openable and closable valve mechanism, such as a butterfly valve or a globe valve. Figure 1(a) shows the control valve 16 in a fully open state. Figure 1(b) shows the control valve 16 in a more closed state than in Figure 1(a).

[0010] Component 22 is, for example, a part of an internal combustion engine such as a piston. The chain tensioner 24 contacts a chain (not shown) and adjusts the slack in the chain.

[0011] The ECU20 includes a processing unit such as a CPU (Central Processing Unit), and storage devices such as RAM (Random Access Memory) and ROM (Read Only Memory). The ECU20 performs various controls by executing programs stored in the ROM and other storage devices. The ECU20 controls the oil pump 14 to increase and decrease the amount of oil discharged. The ECU20 functions as a control unit that adjusts the opening degree of the regulating valve 16.

[0012] The oil pump 14 draws oil from an oil pan (not shown) and supplies it to the oil passage 10. The oil flows through the oil passage 10 and is supplied to components 22, for example, from an oil jet (not shown). A portion of the oil is supplied to the chain tensioner 24 through the oil passage 12.

[0013] For example, when the vehicle is running on the motor (EV mode), the internal combustion engine stops. While the internal combustion engine is stopped, the drive system may rotate in reverse due to inertia. This reverse rotation may cause oil to leak from the chain tensioner 24, potentially allowing air to enter the system. This can result in abnormal noise when the internal combustion engine is restarted. Increasing the discharge volume of the oil pump 14 can raise the oil pressure and prevent this abnormal noise. However, this can lead to a decrease in fuel efficiency and exhaust emissions due to the excess oil flow. In this embodiment, the oil flow rate is controlled by opening and closing the control valve 16, rather than by increasing the discharge volume of the oil pump 14, to prevent abnormal noise.

[0014] Figure 2 is a flowchart illustrating the process in the embodiment. The ECU 20 determines whether or not the internal combustion engine has restarted (step S10). If the determination is negative (No), the process ends. If the determination is positive (Yes), the ECU 20 reduces the opening of the control valve 16 (step S12, Figure 1(b)).

[0015] The ECU 20 determines whether time T0 has elapsed since the opening degree was reduced (step S14). If the determination is negative, step S14 is repeated. If the determination is positive, the ECU 20 increases the opening degree of the control valve 16 (step S16, Figure 1(a)). After step S16, the process ends.

[0016] According to an embodiment, the ECU 20 controls the opening degree of the regulating valve 16. As shown in FIG. 1(b), when the internal combustion engine is restarted, the ECU 20 reduces the opening degree of the regulating valve 16. The amount of oil flowing through the oil passage 10 decreases, and the amount of oil flowing through the oil passage 12 increases. The amount of oil supplied to the chain tensioner 24 increases, and the oil pressure rises. Air can escape, preventing abnormal noises.

[0017] After the elapse of time T0, the ECU 20 increases the opening degree of the regulating valve 16, for example, to full opening. The amount of oil supplied to the component 22 increases. The chain tensioner 24 is subjected to an oil pressure such that the oil does not run out.

[0018] As shown in FIGS. 1(a) and 1(b), the ECU 20 changes the opening degree of the regulating valve 16, but does not change the discharge amount of the oil pump 14. That is, the discharge amount is substantially constant. Since the discharge amount is not increased, deterioration of fuel consumption and exhaust can be suppressed. By opening and closing the regulating valve 16, the ratio of the amount of oil to the component 22 and the ratio of the amount of oil to the chain tensioner 24 may be changed within a constant discharge amount.

[0019] According to conditions such as air temperature, oil temperature, and EV driving time, time T0 may be set to an appropriate value. When abnormal noises occur, vibrations of a predetermined frequency or higher may occur. The opening degree of the regulating valve 16 may be reduced according to the frequency of vibration of the head cover or the like.

[0020] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

Description of Reference Numerals

[0021] 10, 12 oil passages, 14 oil pump, 16 regulating valve, 20 ECU, 22 component, 24 chain tensioner, 100 hydraulic control device

Claims

[Claim 1] A first oil passage for supplying oil from the oil pump to the parts, A second oil passage connected to the first oil passage for supplying the oil from the oil pump to the chain tensioner, A control valve provided in the first oil passage on the side of the component that is connected to the second oil passage, A hydraulic control device for an internal combustion engine, comprising a control unit for controlling the opening degree of the aforementioned adjustment valve.

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