ATF-temperature adjustment device for vehicle

Abstract

To provide an ATF temperature adjustment device for a vehicle that advances the start of adjustment, elongates a work time, and suppresses engine fuel consumption when adjusting ATF oil quantity.SOLUTION: An ATF temperature adjustment device 12 for a vehicle performs control for switching a flow passage of engine cooling water We to a bypass flow passage 56 which does not go through an ATF warmer 50 when adjusting an ATF oil quantity, performs control for switching the flow passage of the engine cooling water We to the ATF warmer 50 (a cooling flow passage 54b) when an engine water temperature Tw is higher than a prescribed warmup determination temperature Ts, and performs control for switching the flow passage of the engine cooling water We to the bypass flow passage 56 when an ATF oil temperature To is equal to or higher than a prescribed lower limit temperature Tu. With this constitution, an ATF can be quickly warmed up to the prescribed lower limit temperature Tu. After the ATF is warmed up, a work time for oil quantity adjustment is elongated and an engine 20 is warmed up more quickly, thus suppressing the engine fuel consumption.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an ATF temperature control device for a vehicle. [Background technology]

[0002] In a vehicle equipped with an automatic transmission (AT), a technology has been disclosed for improving fuel economy by warming up the automatic transmission, i.e., by quickly warming up the automatic transmission fluid (ATF) in the automatic transmission and accelerating the start of lock-up control of the automatic transmission. For example, Patent Document 1 discloses an ATF temperature adjustment device for a vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-283872 A

[0004] Patent Document 1 discloses an ATF temperature adjustment device that has an ATF warmer that exchanges heat between engine coolant and the ATF of an automatic transmission, circulates coolant warmed by the engine through the ATF warmer, and uses the heat of the coolant to warm the ATF of the automatic transmission, thereby warming up the automatic transmission.

[0005] In addition, the temperature adjustment of the ATF of an automatic transmission is also performed in the ATF oil amount adjustment of the automatic transmission, which is a vehicle maintenance work. The ATF is stored in a transmission oil pan provided at the bottom of the housing of the automatic transmission. The ATF oil amount adjustment is usually performed while the engine is running, but particular attention is required to manage the oil temperature, and it needs to be performed when the ATF oil temperature is within a predetermined range between a lower limit temperature and an upper limit temperature. Therefore, when adjusting the oil amount, it is desirable to quickly warm the ATF to the predetermined lower limit temperature and, after warming, to lengthen the time during which the ATF is within the predetermined range between the lower limit temperature and the upper limit temperature, i.e., the operation time for adjusting the oil amount. Summary of the Invention [Problem to be solved by the invention]

[0006] By the way, when adjusting the amount of ATF, in the conventional temperature adjustment of ATF using an ATF warmer, the ATF is quickly heated to the predetermined lower limit temperature at which the amount of ATF can be adjusted, but the engine coolant is difficult to warm up due to heat exchange with the ATF. Therefore, the engine warms up slowly, and the friction of the engine increases until the engine warms up, resulting in a problem of increased engine fuel consumption during the oil amount adjustment.

[0007] The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide an ATF temperature adjustment device for a vehicle which, in adjusting the ATF temperature when adjusting the amount of ATF oil, quickly warms the ATF to the specified lower limit temperature at which oil amount adjustment can be performed, and after warming up, extends the time that the ATF remains within the range between the specified lower limit temperature and upper limit temperature, i.e., the working time for adjusting the amount of ATF oil, and hastens the warm-up of the engine to suppress the amount of engine fuel consumption. [Means for solving the problem]

[0008] The gist of the first invention is an ATF temperature control device for a vehicle including (a) an engine, an automatic transmission, an ATF warmer, a cooling flow path through which engine coolant circulates between the engine and the ATF warmer, a bypass flow path through which the engine coolant bypasses the ATF warmer, and a switching valve for switching a portion of the cooling flow path to the bypass flow path, (b) when adjusting the amount of ATF oil, the device switches a portion of the cooling flow path to the bypass flow path, and when the temperature of the engine coolant is higher than a predetermined warm-up judgment temperature, the device switches the flow path of the engine coolant from the bypass flow path to a portion of the cooling flow path, and further when the ATF oil temperature is higher than a predetermined lower limit temperature, the device performs control to switch a portion of the cooling flow path to the bypass flow path. Effect of the Invention

[0009] According to the first invention, when adjusting the amount of oil in the ATF, a part of the cooling passage is switched to the bypass passage, and when the temperature of the engine cooling water is higher than the predetermined warm-up judgment temperature, the passage of the engine cooling water is switched from the bypass passage to a part of the cooling passage, and when the oil temperature of the ATF is equal to or higher than the predetermined lower limit temperature, a part of the cooling passage is switched to the bypass passage. As a result, heat exchange between the engine cooling water and the ATF is started after the temperature of the engine cooling water exceeds the predetermined warm-up judgment temperature at which it can be determined that the engine has reached a predetermined warm-up state. Therefore, friction in the engine is suppressed by accelerating the warm-up of the engine, and the engine fuel consumption is suppressed. Then, the engine cooling water is heated to a state where the temperature difference is large and exceeds the predetermined warm-up judgment temperature, and heat exchange is started, so that the amount of heat exchanged is large and the ATF is heated quickly. Furthermore, since heat exchange is stopped after the ATF is heated to above the predetermined lower limit temperature at which oil amount adjustment can be performed, the time during which the ATF is within the range between the predetermined lower limit temperature and upper limit temperature can be extended after the ATF is heated. Therefore, in ATF temperature adjustment when adjusting the oil amount of the ATF, it is possible to provide an ATF temperature adjustment device for a vehicle that quickly warms the ATF to the predetermined lower limit temperature at which oil amount adjustment can be performed, and extends the time during which the ATF is within the range between the predetermined lower limit temperature and upper limit temperature after it has been warmed up, i.e., the operation time for oil amount adjustment, while also hastening the warm-up of the engine, thereby suppressing engine fuel consumption. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a cooling system for an engine and an automatic transmission of a vehicle to which the present invention is applied, and is also a diagram illustrating main parts of the control functions and control systems for various controls in the vehicle. [Diagram 2] 4A and 4B are time charts illustrating the control operation of ATF temperature adjustment when adjusting the amount of ATF oil in the ATF temperature adjustment device of FIG. 1, where (a) is a diagram illustrating a conventional example and (b) is a diagram illustrating the present embodiment. [Diagram 3]3 is a flowchart illustrating a main part of the control operation of the ATF temperature regulator of FIG. 1, and is a flowchart illustrating the control operation corresponding to the time chart of FIG. 2(b). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. EXAMPLES

[0012] FIG. 1 is a diagram illustrating the schematic configuration of a cooling system for an engine 20 and an automatic transmission 40 of a vehicle 10 to which an ATF temperature adjustment device 12 of the present invention is applied, and is also a diagram illustrating the control functions and main parts of the control system for various controls in the vehicle 10.

[0013] The engine 20 is a known internal combustion engine such as a gasoline engine, a diesel engine, etc. The output of the engine 20 is controlled by an engine control device 22 provided in the vehicle 10 being controlled by an electronic control device 70 described later.

[0014] The automatic transmission 40 is controlled by an electronic control device 70 (described later) and a hydraulic control device 42 provided in the vehicle 10, and shifts gears according to the accelerator opening, vehicle speed, etc. The automatic transmission 40 is, for example, a known planetary gear type multi-speed transmission in which a plurality of gears with different gear ratios are selectively established, or a known continuously variable transmission in which the gear ratio can be changed continuously and steplessly.

[0015] The automatic transmission 40 stores the ATF in an oil pan located below the automatic transmission 40. The ATF is circulated between the automatic transmission 40 and an ATF warmer 50 (described later) via an ATF oil passage 44 by an ATF circulation mechanism (not shown) provided in the automatic transmission 40.

[0016] The vehicle 10 is equipped with a water pump 24, a radiator 26, engine water flow paths 28 (28a, 28b), an ATF temperature regulator 12 (described later), and the like for circulating the engine cooling water We. The engine cooling water We is circulated by the water pump 24 driven by the power of the engine 20. In Fig. 1, the arrows shown in each of the engine water flow paths 28 (28a, 28b) indicate the direction in which the engine cooling water We flows. For example, the engine cooling water We that has passed through the engine 20 from the water pump 24 passes through the engine water flow path 28a, via the radiator 26, and through the engine water flow path 28b, before circulating back to the water pump 24.

[0017] The ATF temperature regulator 12 includes a cooling passage 54 (54a, 54b, 54c), a bypass passage 56, a switching valve 52, an ATF warmer 50 that exchanges heat between the engine coolant We and the ATF, an electronic control device 70 (described later), and an ATF oil temperature sensor 82. The cooling passage 54 is a passage through which the engine coolant We circulates to the ATF warmer 50, and the arrows shown in each of the cooling passages 54 (54a, 54b, 54c) indicate the direction in which the engine coolant We flows. For example, the engine coolant We that has passed through the water pump 24 and the engine 20 passes through the cooling passage 54a, passes through the switching valve 52 and either the cooling passage 54b or the bypass passage 56, and circulates from the cooling passage 54c back to the engine water passage 28b. Engine cooling water We circulates through the ATF warmer 50 via a cooling passage 54b, and ATF circulates through the ATF oil passage 44, and heat exchange occurs between the engine cooling water We and the ATF within the ATF warmer 50. Also, a bypass passage 56 is a passage that bypasses the engine cooling water We without passing it through the ATF warmer 50, and a changeover valve 52 switches the passage for the engine cooling water We between the ATF warmer 50 (cooling passage 54b) and the bypass passage 56.

[0018] The vehicle 10 further includes an ATF oil amount adjustment work instruction device 84 that allows the worker to set the start of the ATF oil amount adjustment work, and an oil level indicator 86 that notifies the worker that the ATF oil temperature To, which is the temperature of the ATF, is within a predetermined range between a lower limit temperature Tu and an upper limit temperature Tv, which will be described later.

[0019] The electronic control device 70 includes a so-called microcomputer. The electronic control device 70 outputs an engine control command signal Se to the engine control device 22 for controlling the engine 20, a hydraulic control signal Sp to the hydraulic control device 42 for controlling the automatic transmission 40, a switching control command signal Swr to the switching valve 52 for selecting whether the flow path of the engine cooling water We should be the ATF warmer 50 (cooling flow path 54b) or the bypass flow path 56, and an indicator command signal Omi to control the oil level indicator 86 to be turned on or off.

[0020] The electronic control device 70 is supplied with an engine water temperature Tw, which is the temperature of the engine coolant We, from an engine water temperature sensor 80, and an ATF oil temperature To, which is the temperature of the ATF, from an ATF oil temperature sensor 82. The electronic control device 70 is also supplied with a signal Omm, which sets an instruction to start an ATF oil amount adjustment work, from an ATF oil amount adjustment work instructing device 84.

[0021] Fig. 2 is a time chart for explaining the control operation of ATF temperature adjustment when adjusting the amount of ATF oil by ATF temperature adjustment device 12. Fig. 2(a) shows a case where the present invention is not applied (conventional example), and Fig. 2(b) shows a case where the present invention is applied (this embodiment).

[0022] In FIG. 2A, when the ATF oil amount adjustment is started, the flow path of the engine cooling water We is switched to the ATF warmer 50 (cooling flow path 54b) by the switching valve 52, and in a state in which heat exchange between the engine cooling water We and the ATF is performed, the engine water temperature Tw and the ATF oil temperature To rise from the environmental temperature Ta. At time t01 when the ATF oil temperature To rises to or above a predetermined lower limit temperature Tu at which the oil amount adjustment can be performed, the switching valve 52 switches the flow path of the engine cooling water We to the bypass flow path 56, and the heat exchange between the engine cooling water We and the ATF is stopped. The oil amount adjustment time TW1 is from time t01 to time t02 at which the ATF oil temperature To exceeds a predetermined upper limit temperature Tv due to an oil temperature rise in the automatic transmission 40. Here, at time t01 at which the oil amount adjustment can be performed, the engine water temperature Tw is below a predetermined warm-up determination temperature Ts at which it can be determined that the engine 20 has reached a predetermined warm-up state, and the warm-up of the engine 20 is insufficient. In the conventional example, there was a problem that the friction of the engine 20 increased until the engine reached a predetermined warm-up state, resulting in increased engine fuel consumption during oil amount adjustment.

[0023] 4B, when the ATF oil amount adjustment is started, the flow path of the engine coolant We is switched to the bypass flow path 56 by the switching valve 52, and in a state where the heat exchange between the engine coolant We and the ATF is stopped, first, only warming up of the engine 20 is performed. At a time t10 when the engine water temperature Tw rises from the ambient temperature Ta and exceeds a predetermined warm-up determination temperature Ts at which it can be determined that the engine 20 has reached a predetermined warm-up state, the switching valve 52 switches the flow path of the engine coolant We to the ATF warmer 50 (cooling flow path 54b), and heat exchange between the engine coolant We and the ATF is started. Next, at a time t11 when the ATF oil temperature To becomes equal to or higher than a predetermined lower limit temperature Tu at which the oil amount adjustment can be performed, the switching valve 52 switches the flow path of the engine coolant We to the bypass flow path 56, and heat exchange between the engine coolant We and the ATF is stopped. The oil amount adjustment time TW2 is from time t11 to time t12 when the ATF oil temperature To exceeds a predetermined upper limit temperature Tv due to the oil temperature rise in the automatic transmission 40. At time t10, heat exchange between the engine coolant We and the ATF starts in a state where the engine water temperature Tw is sufficiently warmed up beyond the predetermined warm-up judgment temperature Ts and there is a large temperature difference, so the amount of heat exchanged is larger than in the case of FIG. 2(a) and the temperature rise of the ATF oil temperature To is more rapid than in the case of FIG. 2(a). Therefore, the time until t11 is equivalent to the time until t01 in FIG. 2(a). In addition, the state where the heat exchange between the engine coolant We and the ATF is stopped is the same as in FIG. 2(a), so the oil amount adjustment time TW2 is also equivalent to the oil amount adjustment time TW1. As a result, in adjusting the ATF temperature when adjusting the amount of ATF oil, the ATF is quickly warmed up to a predetermined lower limit temperature Tu at which oil amount adjustment can be performed, and after being warmed up, the time that the ATF is within the range between the predetermined lower limit temperature Tu and upper limit temperature Tv, i.e., the oil amount adjustment work time, is lengthened, and the warm-up of the engine 20 is also accelerated, thereby suppressing engine fuel consumption.

[0024] Fig. 3 is a flowchart for explaining the main parts of the control operation of ATF temperature adjustment when adjusting the amount of ATF oil by ATF temperature regulator 12, and is a flowchart for explaining the control operation corresponding to the time chart of Fig. 2(b) described above. In Fig. 3, each step of the flowchart corresponds to a function of electronic control unit 70.

[0025] First, in step (hereinafter, step will be omitted) S10, it is determined whether or not an oil amount adjustment work start instruction has been set from the ATF oil amount adjustment work instructing device 84. If the determination in S10 is negative, this routine is terminated. Next, if the determination in S10 is positive, in S20, a switching control command signal Swr is sent to the switching valve 52, the flow path of the engine cooling water We is switched to the bypass flow path 56, and heat exchange between the engine cooling water We and the ATF is stopped. Next, in S30, it is determined whether or not the engine water temperature Tw has exceeded a predetermined warm-up determination temperature Ts at which it can be determined that the engine 20 has reached a predetermined warm-up state. If the determination in S30 is negative, the determination in S30 is repeated. If the determination in S30 is positive, then in S40, a switching control command signal Swr is sent to the switching valve 52, the flow path of the engine cooling water We is switched to the ATF warmer 50 (cooling flow path 54b), and heat exchange between the engine cooling water We and the ATF is started. This state is shown at time t10 in FIG. 2B. Then, in S50, it is determined whether the ATF oil temperature To is equal to or higher than a predetermined lower limit temperature Tu at which oil amount adjustment can be performed. If the determination in S50 is negative, then the determination in S50 is repeated. If the determination in S50 is positive, then in S60, an indicator command signal Omi is sent to the oil level indicator 86, and the oil level indicator 86 is turned on to notify the operator that the ATF oil temperature is within the range between the predetermined lower limit temperature Tu and upper limit temperature Tv. This state is shown at time t11 in FIG. 2B. Next, in S70, a switching control command signal Swr is sent to the switching valve 52, the flow path of the engine coolant We is switched to the bypass flow path 56, and heat exchange between the engine coolant We and the ATF is stopped. Next, in S80, it is determined whether the ATF oil temperature To has exceeded a predetermined upper limit temperature Tv at which oil amount adjustment can be performed. If the determination in S80 is negative, the determination in S80 is repeated.If the determination in S80 is positive, in S90, a switching control command signal Swr is sent to the switching valve 52, the flow path of the engine cooling water We is switched to the ATF warmer 50 (cooling flow path 54b), heat exchange between the engine cooling water We and the ATF is started, and further in S100, an indicator command signal Omi is sent to the oil level indicator 86, the oil level indicator 86 is turned off, and this routine is terminated. This state is shown at time t12 in FIG. 2(b).

[0026] As described above, according to this embodiment, when adjusting the amount of ATF oil, the flow path of the engine cooling water We is switched to the bypass flow path 56, and when the engine water temperature Tw is higher than a predetermined warm-up determination temperature Ts, the flow path of the engine cooling water We is switched to the ATF warmer 50 (cooling flow path 54b), and when the ATF oil temperature To is equal to or higher than a predetermined lower limit temperature Tu, the flow path of the engine cooling water We is switched to the bypass flow path 56. This makes it possible to provide an ATF temperature regulator 12 for a vehicle that, in adjusting the ATF oil amount, quickly warms the ATF to a predetermined lower limit temperature Tu at which oil amount adjustment can be performed, and, after warming up, lengthens the time that the ATF is within the range between the predetermined lower limit temperature Tu and upper limit temperature Tv, i.e., the operation time of oil amount adjustment, and hastens the warm-up of the engine 20 to suppress engine fuel consumption.

[0027] Although the embodiment of the present invention has been described in detail above with reference to the drawings, the present invention can be applied to other embodiments.

[0028] For example, in the above-described embodiment, the vehicle 10 is engine-driven, but the present invention is not limited to this. For example, the present invention can be applied to a hybrid electric vehicle equipped with an engine and an electric motor as a power source.

[0029] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various modified and improved forms based on the knowledge of those skilled in the art. [Explanation of symbols]

[0030] 10: Vehicle 12: ATF temperature control device 20: Engine 40: Automatic transmission 50: ATF warmer 52: Switching valve 54: Cooling flow path 54b: Cooling flow path (part of the cooling flow path) 56: Bypass flow path 70: Electronic control device We: Engine coolant Ts: Warm-up judgment temperature Tu: Lower limit temperature

Claims

[Claim 1] An ATF temperature adjustment device for a vehicle including an engine, an automatic transmission, an ATF warmer, a cooling passage through which engine coolant flows between the engine and the ATF warmer, a bypass passage through which the engine coolant bypasses the ATF warmer, and a changeover valve for switching a part of the cooling passage to the bypass passage, When adjusting the amount of ATF oil, a portion of the cooling flow path is switched to the bypass flow path, and when the temperature of the engine cooling water is higher than a predetermined warm-up judgment temperature, the flow path of the engine cooling water is switched from the bypass flow path to a portion of the cooling flow path, and further when the oil temperature of the ATF is equal to or higher than a predetermined lower limit temperature, the device performs control to switch a portion of the cooling flow path to the bypass flow path.

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