JP2018178764A - Oil cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil cooling device capable of improving fuel efficiency while suppressing unnecessary pressure loss due to an oil cooler.SOLUTION: An oil cooling device 100 controls the amount of oil to be divided into an oil cooler passage 106 and a bypass passage 107 on the basis of an engine speed under the consideration of relationships between pressure loss and heat radiation in an oil cooler 104 and the engine speed. Specifically, when the engine speed is a threshold value Th1 or more, the amount of the oil to flow to the oil cooler 104 is kept the same or further reduced and the amount of the oil to flow to the bypass passage 107 is kept the same or further increased, as or than when the engine speed is lower than the threshold value Th1. This suppresses pressure loss due to the oil cooler 104 in a high-engine-speed region where the pressure loss in the oil cooler 104 is on the increase rather than the heat radiation in the oil cooler 104.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle oil cooling device.

  As an oil cooling device of a vehicle, there is one described in Patent Document 1. Patent Document 1 describes a hydraulic control device having an oil pump, an oil cooler, and a bypass passage that bypasses the oil cooler. In Patent Document 1, when the oil pressure of the oil supplied to the oil cooler is too high, the cooler bypass valve is opened to drain the oil so that the oil cooler does not have an excessive oil pressure.

Unexamined-Japanese-Patent No. 2006-29981

  By the way, when the oil is cooled by the oil cooler, a pressure loss occurs because the oil passes through the oil cooler. When pressure loss occurs, the working volume of the pump increases to compensate for the pressure loss. Since the pump is driven by the engine, as a result, if the pressure loss is large, the fuel consumption will be deteriorated.

  The present invention has been made in consideration of the above points, and provides an oil cooling device capable of suppressing unnecessary pressure loss due to an oil cooler and improving fuel efficiency.

One aspect of the oil cooling device of the present invention is
An oil cooler to cool the oil,
A bypass passage bypassing the oil cooler;
A valve that diverts the oil into an oil cooler passage leading to the oil cooler and the bypass passage;
A control unit that controls a diversion operation by the valve;
Equipped with
The control unit controls the diversion by the valve based on the engine speed.

  According to the present invention, since diversion is controlled by the valve that diverts oil to the oil cooler passage and the bypass passage leading to the oil cooler based on the engine speed, unnecessary pressure loss due to the oil cooler is suppressed, and fuel consumption is reduced. It is possible to realize an oil cooling device that can improve the

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a diagram for explaining the principle of the embodiment, and FIG. 1A is a diagram showing the relationship between pressure loss in the oil cooler and the engine speed, and FIG. 1B is a diagram showing the relationship between the heat release amount in the oil cooler and the engine speed Figure shown Schematic which shows the principal part structure of the oil cooling device of embodiment Flow chart showing control procedure of diversion by control unit

  First, prior to describing a specific embodiment, the principle of the embodiment will be described.

  The inventor of the present invention investigated the relationship between the pressure loss and the heat release amount in the oil cooler, and the engine speed. Here, since the oil pump is driven by the engine, the flow rate of oil corresponds to the engine speed. FIG. 1A shows the relationship between the pressure loss in the oil cooler and the engine speed. FIG. 1B shows the relationship between the amount of heat release in the oil cooler and the engine speed. As can be seen from FIG. 1A, the rate of increase in pressure loss in the oil cooler increases as the engine speed increases. On the other hand, the rate of increase of the amount of heat release in the oil cooler decreases (that is, increases gradually) as the engine speed increases.

  Focusing on this point, in the present embodiment, the amount of oil divided into the oil cooler passage and the bypass passage is controlled based on the engine speed. In particular, when the engine rotational speed is equal to or higher than the predetermined threshold Th1, the flow rate of oil flowing through the oil cooler is maintained or reduced and the flow rate of oil flowing through the bypass passage is reduced compared to when the engine rotational speed is less than the threshold Th1. Control to maintain or increase. As a result, the pressure loss due to the oil cooler can be suppressed in the region where the increase in the pressure loss of the oil cooler is larger than the increase in the amount of heat release of the oil cooler and the engine rotational speed is high.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a schematic view showing the main configuration of the oil cooling device according to the embodiment. The oil cooling device 100 pumps the oil in the oil pan 101 to an engine (not shown) by the pump 102. The pump 102 is driven by the crankshaft of the engine.

  The oil discharged by the pump 102 enters the valve inlet of a valve 103 which is a diverting valve such as a three-way valve. An oil cooler passage 106 connected to the oil cooler 104 is connected to one outlet of the valve 103, and a bypass passage 107 bypassing the oil cooler 104 is connected to the other outlet of the valve 103. The oil cooler 104 is, for example, a water-cooled oil cooler in which cooling water is circulated around the flow path.

  The diversion by the valve 103 is controlled based on the control signal from the control unit 105. Based on the control signal, the valve 103 can discharge the oil from only one of the two outlets, or can discharge the oil from both of the two outlets. In practice, the control unit 105 is embodied by an ECU (Engine Control Unit) of a vehicle.

  The oil passing through the oil cooler 104 and the oil passing through the bypass passage 107 are supplied to the engine.

  Further, the oil cooling device 100 includes an oil temperature sensor 108 and an oil pressure sensor 109, and the output of these sensors is input to the control unit 105. Further, information on the engine speed is also input to the control unit 105. The control unit 105 controls the valve 103 based on the detected oil temperature, oil pressure, and engine rotational speed.

  In the example of FIG. 2, the oil temperature sensor 108 and the hydraulic pressure sensor 109 are disposed downstream of the oil cooler 104, but they may be disposed upstream of the oil cooler 104. Further, in the example of FIG. 2, a three-way valve is provided at a branch point between the oil cooler passage 106 connected to the oil cooler 104 and the bypass passage 107, but the valve is not limited thereto. The oil cooler passage 106 or the bypass passage 107 The amount of oil flowing to the oil cooler 104 and the amount flowing to the bypass passage 107 can be controlled by providing an open / close valve in any of the above.

  Next, characteristic operations of the oil cooling device 100 according to the present embodiment will be described with reference to FIG.

  If the control unit 105 of the oil cooling device 100 determines that the engine has been started in step S11, the control unit 105 proceeds to step S12. In step S12, the control unit 105 determines whether the oil temperature is equal to or less than the first temperature Th0 based on the detection result of the oil temperature sensor 108. If the oil temperature is equal to or less than the first temperature Th0 At step S13, the valve 103 is controlled so that the bypass passage 107 is opened and the oil cooler passage 106 is closed. That is, when the oil temperature is equal to or lower than the first temperature Th0, the oil is not supplied to the oil cooler 104, and the oil is not cooled.

  Eventually, when the oil temperature rises and the oil temperature exceeds the first temperature Th0 in step S12, the control unit 105 moves from step S12 to step S14, and based on the oil temperature and the oil pressure, the bypass passage 107 and the oil Control the diversion to the cooler passage 106. Specifically, oil cooling is performed by diverting the oil not only to the bypass passage 107 but also to the oil cooler passage 106. For example, the control unit 105 increases the amount of oil supplied to the oil cooler passage 106 as the oil temperature is higher than the target oil temperature, and increases the amount of oil supplied to the bypass passage 107 as the hydraulic pressure is smaller than the target hydraulic pressure.

  Next, in step S15, the control unit 105 determines whether the engine speed is equal to or more than a predetermined threshold Th1. If the engine rotation number is less than the threshold, the process returns to step S14. On the other hand, when the engine speed becomes equal to or higher than the predetermined threshold value Th1, the control unit 105 proceeds to step S16 to maintain or reduce the flow rate of oil flowed to the oil cooler passage 106 and flowed oil flowed to the bypass passage 107. Maintain or increase That is, the higher the engine speed, the greater the total oil flow rate of the oil cooler passage 106 and the bypass passage 107, but the oil flow rate supplied to the oil cooler passage 106 in the region where the engine speed is greater than the threshold Th1. Do not increase. As a result, as can be understood from FIG. 1, it is possible to avoid the situation where only the pressure loss increases although the increase in the heat release amount can not be expected. After performing the process of step S16, the control unit 105 returns to the process of step S14 again.

  As described above, according to the present embodiment, the oil cooler passage 106 and the bypass passage are determined based on the engine rotational speed, taking into consideration the relationship between the pressure loss and the heat release amount in the oil cooler and the engine rotational speed. The amount of oil diverted to 107 was controlled. In particular, when the engine rotational speed is equal to or higher than the predetermined threshold Th1, the flow rate of the oil to be flowed to the oil cooler 104 is maintained or reduced compared to when the engine rotational speed is less than the threshold Th1. Control to maintain or increase the flow rate. As a result, the pressure loss due to the oil cooler 104 can be suppressed in a region where the increase in the pressure loss of the oil cooler 104 is larger than the increase in the heat release amount of the oil cooler 104 and the engine rotational speed is high. Therefore, the unnecessary oil pressure loss by oil cooler 104 can be controlled, and as a result, oil cooling device 100 which can improve fuel consumption can be realized.

  The above-described embodiment is merely an example of embodying the present invention, and the technical scope of the present invention should not be interpreted in a limited manner by these. That is, the present invention can be implemented in various forms without departing from the scope of the present invention or the main features thereof.

  The present invention is broadly applicable to an oil cooler having an oil cooler passage and a bypass passage that bypasses the oil cooler passage.

Reference Signs List 100 oil cooler 101 oil pan 102 pump 103 valve 104 oil cooler 105 control unit 106 oil cooler passage 107 bypass passage 108 oil temperature sensor 109 oil pressure sensor

Claims (2)

An oil cooler to cool the oil,
A bypass passage bypassing the oil cooler;
A valve that diverts the oil into an oil cooler passage leading to the oil cooler and the bypass passage;
A control unit that controls a diversion operation by the valve;
Equipped with
The control unit controls the diversion by the valve based on an engine speed.
Oil cooler. The control unit maintains or reduces the flow rate of the oil to be supplied to the oil cooler when the engine rotational speed becomes equal to or higher than a predetermined threshold, as compared to when the engine rotational speed is lower than the predetermined threshold, Maintain or increase the flow rate of oil
The oil cooling device according to claim 1.

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