JP7804474B2 - vehicle - Google Patents

Description

The present invention relates to a vehicle.

In recent years, in light of climate-related disasters, there has been growing interest in electric vehicles equipped with motors as drive sources and hybrid electric vehicles equipped with engines and motors as drive sources in order to reduce _{CO2 emissions} . Furthermore, automatic transmissions that convert torque from a drive source mounted on a vehicle and automatically shift gears have become widely adopted. With the aim of increasing the power output of the drive source and improving the quality of automatic transmissions, automatic transmissions are required to shift gears more frequently, which tends to increase the amount of heat generated by automatic transmissions. For this reason, a technology has been disclosed for suppressing the rise in oil temperature of automatic transmission fluid (hereinafter sometimes referred to as "ATF").

Patent Document 1 discloses an automatic transmission oil temperature control device that can appropriately suppress excessive oil temperature rise (overshoot) during high-load operation. The temperature control device includes a heat exchanger that exchanges heat between the automatic transmission oil and engine coolant, and a switching valve that switches whether the automatic transmission oil is circulated through the heat exchanger based on the temperature and load of the automatic transmission oil.

JP 2017-48893 A

However, when the above-mentioned switching valve is operated in an environment with low background noise, such as when the vehicle is stopped or traveling at low speeds, the operating noise of the switching valve resonates inside the vehicle, posing a problem of reducing the marketability of the vehicle. In particular, when an electric vehicle or hybrid electric vehicle is traveling at low speeds while the motor is powered, there is no engine noise and road noise is low, making the operating noise of the switching valve more noticeable. This type of operating noise of the switching valve not only reduces the marketability of the vehicle, but may also lead vehicle users to mistakenly believe that a malfunction has occurred.

The present invention was made in consideration of the above-mentioned problems, and aims to provide a vehicle that can reduce noise generated when a valve used to cool automatic transmission oil is operating.

(1) The present invention relates to a vehicle having a coolant flow path through which coolant flows and a heat exchanger that exchanges heat between the coolant and automatic transmission fluid, wherein the coolant flow path has an ATF flow path that is connected to the heat exchanger and flows the coolant through the heat exchanger, the ATF flow path is provided with a valve that can be switched between a closed state that closes the ATF flow path and an open state that opens the ATF flow path, and the vehicle has a control device that switches the valve to the closed state or the open state when predetermined conditions are met, and the control device switches the valve to the closed state or the open state when the predetermined conditions are met and the proximity notification system is activated.

The invention (1) provides a vehicle that can reduce noise generated when a valve used to cool automatic transmission oil is operating.

(2) The vehicle described in (1), wherein the valve is a normally open type, and the control device prohibits the valve from switching to the closed state from after the vehicle is started until the approach notification system is activated, and switches the valve to the closed state when the approach notification system is activated.

The invention (2) provides a vehicle that can reduce noise generated when the valves are operated during vehicle startup.

(3) A vehicle described in (1) or (2), wherein the control device issues a switch request to switch the valve from the closed state to the open state when the temperature of the automatic transmission oil is equal to or higher than a predetermined temperature, and when the valve is in the closed state and the temperature of the automatic transmission oil becomes equal to or higher than the predetermined temperature after the vehicle has stopped, switches the valve to the open state when the approach notification system is activated.

The invention (3) provides a vehicle that can reduce noise during valve operation when the temperature of the automatic transmission oil reaches a predetermined temperature or higher after the vehicle has stopped.

(4) A vehicle described in any one of (1) to (3), in which, when the predetermined condition is met, the operating sound of the approach notification system is increased compared to when the predetermined condition is not met.

Invention (4) makes it possible to further reduce noise generated when the valve used to cool automatic transmission oil is operating.

(5) A vehicle as described in (4), in which, if the predetermined condition is met before the approach notification system is activated, the operating sound of the approach notification system is increased.

Invention (5) makes it possible to further reduce noise generated when the valve used to cool automatic transmission oil is operating.

(6) A vehicle as described in (4) or (5), in which an increase in the operating sound of the approach warning system is prohibited if the predetermined condition is not met while the approach warning system is operating.

The invention (6) can prevent unnecessary increases in the operating noise of the approach notification system.

1 is a block diagram showing the configuration of a refrigerant circuit according to an embodiment of the present invention. FIG. 10 is a diagram showing the relationship between the vehicle speed and load of the vehicle, the FDU oil temperature, and the FSV operation according to one embodiment of the present invention. FIG. 2 is a flow diagram illustrating the control logic of a valve according to an embodiment of the present invention. 4 is a graph showing the relationship between the vehicle speed, AVAS output, and solenoid valve permission flag of a vehicle according to an embodiment of the present invention.

One embodiment of the present invention will be described below with reference to the drawings. The present invention is not limited to the description of the following embodiment.

The vehicle according to this embodiment has a coolant flow path through which coolant for cooling the drive source flows, and a heat exchanger that exchanges heat between the coolant and the ATF. The vehicle according to this embodiment may be equipped with an electric motor 20 described below as a drive source, or may be equipped with an internal combustion engine and an electric motor 20 as drive sources.

Figure 1 is a block diagram showing the configuration of a refrigerant circuit 1 provided in a vehicle according to one embodiment of the present invention. As shown in Figure 1, the refrigerant circuit 1 according to this embodiment is mounted on a vehicle V and includes an internal combustion engine ICE, a control unit (ECU) 10, an electric motor 20, a generator 30, a transmission 40, a power conversion device 50, a temperature control circuit 60, an FDU (front drive unit) 70, and an AVAS (Acoustic Vehicle Alerting System) 80.

The electric motor 20 is a rotating electric machine that outputs power to drive the vehicle V using electricity stored in a power storage device (not shown) mounted on the vehicle V or electricity generated by the generator 30. The electric motor 20 is provided with a temperature sensor 20a that detects the temperature of the electric motor 20. The temperature sensor 20a outputs the detected temperature value of the electric motor 20 to the control device 10.

The generator 30 is a rotating electric machine that generates electricity using the power of the internal combustion engine ICE, charges the aforementioned power storage device, or supplies power to the electric motor 20.

The transmission 40 is a device that reduces the speed of the power output from the electric motor 20 and transmits it to the drive wheels, and is, for example, a gear-type power transmission device.

The power conversion device 50 converts the power output from the aforementioned power storage device from DC to AC, and boosts the voltage of the power output from the aforementioned power storage device as needed. The power conversion device 50 is provided with a temperature sensor 50a that detects the temperature of the power conversion device 50. The temperature sensor 50a outputs the detected value of the temperature of the power conversion device 50 to the control device 10.

The FDU (front drive unit) 70 is a unit that includes an electric motor 20, a generator 30, and a transmission 40. The electric motor 20, generator 30, and transmission 40 that make up the FDU 70 are circulated with the automatic transmission fluid (ATF), which will be described later, to lubricate the gears and cool the equipment.

The temperature control circuit 60 has an ATF oil passage 61 through which ATF (Automatic Transmission Fluid) circulates and regulates the temperature of the electric motor 20, generator 30, and transmission 40, a coolant passage 62 through which coolant circulates and regulates the temperature of the power conversion device 50, and a heat exchanger 63 that exchanges heat between the ATF and the coolant. ATF is an oil that can lubricate and regulate the temperature of the electric motor 20, generator 30, and transmission 40.

The ATF oil passage 61 is provided with a first pump 611 and a storage section 612. The first pump 611 is a mechanical pump driven by the power of the internal combustion engine ICE and the rotational force of an axle (not shown) of the vehicle V. The first pump 611 is configured so that its rotation speed can be adjusted by adjusting the power supplied to it, and its discharge capacity can be changed continuously. The storage section 612 stores the ATF circulating through the ATF oil passage 61. The storage section 612 is, for example, an oil pan provided at the bottom of a housing (not shown) that houses the electric motor 20, generator 30, and transmission 40. The ATF oil passage 61 has a branch section 613. The ATF oil passage 61 includes a pressure passage 610a, which is provided with a first pump 611 and has an upstream end connected to a reservoir 612, passes through the first pump 611, and has a downstream end connected to a branch 613; a first branch passage 610b1, which is provided with an electric motor 20 and a generator 30 and has an upstream end connected to the branch 613, passes through the electric motor 20 and the generator 30, and has a downstream end connected to the reservoir 612; and a second branch passage 610b2, which is provided with a transmission 40 and has an upstream end connected to the branch 613, passes through the transmission 40, and has a downstream end connected to the reservoir 612. In the ATF oil passage 61, the heat exchanger 63 is located upstream of the electric motor 20 and the generator 30 in the first branch passage 610b1.

The coolant flow path 62 is provided with a second pump 621 and a radiator 622. The second pump 621 is, for example, an electric pump driven by electricity stored in the aforementioned power storage device. The radiator 622 is located at the front of the vehicle V and is a heat dissipation device that cools the coolant using the wind generated when the vehicle V is moving.

The cooling water flow path 62 has a branching section 624 and a merging section 625. The cooling water flow path is provided with a second pump 621 and a radiator 622, in that order from the upstream side, and has a pressure flow path 620a whose upstream end connects to the merging section 625, passes through the second pump 621 and the radiator 622, and whose downstream end connects to the branching section 624. The cooling water is pressure-fed by the second pump 621 through the pressure flow path 620a and is cooled by the radiator 622.

The coolant flow path 62 further includes a branch flow path 620b1, which is provided with a power conversion device 50 and has its upstream end connected to a branch 624, passes through the power conversion device 50, and connects to a junction 625 at its downstream end; and an ATF flow path 620b2, which is provided with a heat exchanger 63 and has its upstream end connected to the branch 624, passes through the heat exchanger 63, and connects to a junction 625 at its downstream end. A flow shut valve 626, which can be switched between a closed state that closes the ATF flow path 620b2 and an open state that opens the ATF flow path 620b2, is provided upstream of the heat exchanger 63 in the ATF flow path 620b2.

The flow shut valve 626 is, for example, a normally open solenoid valve that is in an open state that opens the ATF flow path 620b2 when not energized. The normally open flow shut valve 626 can be switched to a closed state that closes the ATF flow path 620b2 when energized. The flow shut valve 626 can be switched between a closed state and an open state in response to a command from the control device 10. The flow shut valve 626 may be a normally closed solenoid valve, but is preferably a normally open type from the perspective of preventing sticking, etc. Below, the flow shut valve 626 will be described as a normally open solenoid valve.

The flow shut valve 626 has a valve portion that opens and closes the flow path, and a drive portion that drives the valve portion. The valve portion is composed of a valve element, a valve seat, etc. When the flow shut valve 626 is switched from a closed state to an open state, the valve element comes into contact with the components that make up the flow path, generating valve operating noise. When the flow shut valve 626 is switched from an open state to a closed state, valve operating noise is generated in the drive portion. For example, if the valve element and the components that make up the flow path are made of a resin such as fluororesin, and the drive portion is made of a metal, the operating noise when the flow shut valve 626 is switched from an open state to a closed state is louder than the operating noise when it is switched from a closed state to an open state.

The coolant pumped by the second pump 621 in the pressure flow path 620a and cooled by the radiator 622 branches into branch flow path 620b1 and ATF flow path 620b2 at branch point 624. The coolant flowing through branch flow path 620b1 cools the power conversion device 50 and merges with ATF flow path 620b2 and pressure flow path 620a at junction point 625. The coolant flowing through ATF flow path 620b2 cools the ATF by exchanging heat with the ATF in heat exchanger 63, and merges with branch flow path 620b1 and pressure flow path 620a at junction point 625. The coolant that flowed through branch flow path 620b1 and ATF flow path 620b2 is supplied again to the second pump 621 through pressure flow path 620a, and the coolant circulates through the coolant flow path 62.

The AVAS (Vehicle Approach Alert System) 80 is a system that emits an operating sound (warning sound), such as a simulated engine sound, from a speaker to alert pedestrians and others around the vehicle of an approaching vehicle while the vehicle is running on the electric motor 20. The AVAS 80 is controlled by the control device 10 to emit an operating sound, for example, when the vehicle starts running on the electric motor 20 and travels at a speed below a predetermined speed (e.g., 25 km/h), when the vehicle is decelerated and travels at a speed below a predetermined speed (e.g., 25 km/h), or when the vehicle is put into parking range (reverse).

The vehicle according to this embodiment further includes a rotation sensor capable of detecting the engine speed, which is the rotation speed of the torque converter input shaft, a vehicle speed sensor that detects the vehicle speed, a sensor that detects the air conditioning air volume, and the like.

The control device 10 controls the internal combustion engine ICE, the power conversion device 50, the second pump 621, and the flow shut valve 626. Furthermore, the control device 10 adjusts the power supply to the second pump 621 and controls the opening and closing of the flow shut valve 626 based on the detection results of the above sensors. The control device 10 also controls the generation of operating sounds by the AVAS 80. Below, details of the control of the second pump 621, the flow shut valve 626, and the AVAS 80 performed by the control device 10 are described.

The control device 10 issues a switching request to switch between a closed state and an open state, closing the flow shut valve 626 when the oil temperature falls below a predetermined oil temperature at which fuel economy benefits are achieved through reduced ATF friction, and opening the flow shut valve 626 when the oil temperature exceeds a predetermined oil temperature determined by the drive source cooling request. The control device 10 controls the flow shut valve 626 to switch when the above-mentioned predetermined conditions are met, and also when the condition that AVAS 80 is operating is met. This allows the operating sound of the flow shut valve 626 to be masked by the operating sound of AVAS 80, thereby reducing noise caused by the flow shut valve 626.

Figure 2 shows an example of the relationship between vehicle speed, load on the drive source including the electric motor 20, oil temperature of the FDU 70, and operation of the flow shut valve 626 when the vehicle is traveling at low speed. First, immediately after starting the drive source (IG on), the oil temperature of the FDU 70 is low. Therefore, it is necessary to raise the oil temperature of the ATF. If the flow shut valve 626 is a normally open type, the flow shut valve 626 is in an open state before startup, so it is preferable to switch the flow shut valve 626 from an open state to a closed state soon after startup. At this time, it is preferable that the operating sound of the flow shut valve 626 be masked by the operating sound of the AVAS 80.

Next, during low-speed driving, such as in urban areas, the FDU oil temperature is still in the low-oil-temperature/heat-accumulation period. Because low load continues during this period, flow shut valve 626 remains closed. Next, during high-speed driving, such as suburban/high-speed driving (in the case of a hybrid vehicle, driving is performed using the internal combustion engine), and immediately after high-speed driving, the optimum temperature/cooling/heat-up switching period occurs. During this period, a cooling request (switching request) is made if the ATF oil temperature exceeds a predetermined temperature, and a heating request (switching request) is made if the ATF oil temperature falls below the predetermined temperature, and flow shut valve 626 switches between the closed and open states as appropriate. Next, when the vehicle stops or drives at low speed after high load, the FDU 70 may receive heat due to a rise in the temperature of the drive source, such as the internal combustion engine, even though the load is low, and the ATF oil temperature may rise (dashed line in Figure 2). At this time, a request may be made to switch the flow shut valve 626 from a closed state to an open state, and in this case too, it is preferable that the operating sound of the flow shut valve 626 be masked by the operating sound of the AVAS 80.

Next, an example of a control routine of the control device 10 that masks the operating sound of the flow shut valve 626 with the operating sound of the AVAS 80 will be described using the flow diagram in Figure 3.

The control routine shown in Figure 3 detects the vehicle speed (Vsp) and parking shift range after the vehicle starts, and if certain requirements are met, causes the AVAS 80 to emit an operating sound. Then, while the AVAS 80 is operating, the flow shut valve 626 is switched from a closed state to an open state (step S1).

Next, the control routine determines whether the vehicle remains stopped (step S2). If the vehicle remains stopped, the routine proceeds to step S7, where operation (switching) of the flow shut valve 626 is prohibited. If the vehicle does not remain stopped, the routine proceeds to step S3.

Next, the control routine detects the FDU oil temperature (step S3) and determines whether or not there is a request to switch the flow shut valve 626 (step S4). If there is a request to switch the flow shut valve 626, the routine proceeds to step S5. If there is no request to switch the flow shut valve 626, the routine proceeds to step S3.

Next, the control routine determines whether AVAS 80 is operating (step S5). If AVAS 80 is operating, the process proceeds to step S6, where operation (switching) of flow shut valve 626 is permitted. If AVAS 80 is not operating, the process proceeds to step S7, where operation (switching) of flow shut valve 626 is prohibited.

The above control routine may be executed only when the vehicle speed is below a predetermined speed (e.g., 25 km/h). This is because if the vehicle speed exceeds the predetermined speed (e.g., 25 km/h), the AVAS 80 will not operate and the operating noise of the flow shut valve 626 will not be a problem.

In the above control routine, it is preferable that the sound pressure (dB) of the operating sound emitted from AVAS 80 when a request to switch flow shut valve 626 is made higher than usual. This improves the masking effect of AVAS 80 on the operating sound of flow shut valve 626.

In the above control routine, if a request to switch the flow shut valve 626 occurs before the AVAS 80 operates, it is preferable to increase the sound pressure (dB) of the AVAS 80's operating noise when the AVAS 80 operates. This can further improve the masking effect of the AVAS 80 on the operating noise of the flow shut valve 626.

In the above control routine, if there is no request to switch the flow shut valve 626 while the AVAS 80 is operating, it is preferable to prohibit an increase in the sound pressure (dB) of the operating noise of the AVAS 80. This prevents unnecessary increases in the operating noise of the AVAS 80.

Next, using Figure 4, we will explain the relationship between vehicle speed, AVAS output, and the solenoid valve enable flag issued by the above control routine.

The vertical axis of each graph in Figure 4 represents, from top to bottom, vehicle speed, AVAS output, and solenoid valve enable flag. The horizontal axis of each graph represents elapsed time.

As shown in Figure 4, after time T0 when the vehicle starts moving, vehicle speed Vsp increases, which in turn increases AVAS output and the operating noise of AVAS 80. At time T11, after AVAS output reaches a predetermined threshold, a permission flag is issued to switch the solenoid valve (flow shut valve) from an open state to a closed state. The permission flag remains in effect until time T12, when vehicle speed Vsp exceeds a predetermined vehicle speed (25 km/h).

Next, after time T2, when the vehicle speed Vsp falls below a predetermined speed (25 km/h), the AVAS output rises accordingly. At time T21, after the AVAS output reaches a predetermined threshold, a solenoid valve permission flag is set to permit switching of the solenoid valve (flow shut valve). The solenoid valve permission flag remains set until time T3, when the vehicle speed Vsp exceeds the predetermined speed (25 km/h). Similarly, after time T4, when the vehicle speed Vsp falls below the predetermined speed (25 km/h), the solenoid valve permission flag is set at time T41, after the AVAS output reaches the predetermined threshold, and remains set until time T5.

The times h1, h2, and h3 during which the solenoid valve permission flag is activated are shorter than the time during which vehicle speed Vsp is below a predetermined vehicle speed, and the solenoid valve permission flag is activated after the AVAS output reaches a predetermined threshold. As a result, the flow shut valve 626 is switched while the operating noise of AVAS 80 is increased, allowing AVAS 80 to effectively mask the operating noise of the flow shut valve 626.

10 ECU (control unit)
62 Cooling water flow path 620b2 ATF flow path 626 Flow shut valve (valve)
63 Heat exchanger 80 AVAS (Approach Alert System)
V vehicle

Claims (6)

a cooling water flow path through which cooling water flows;
A vehicle having a heat exchanger that exchanges heat between the cooling water and the automatic transmission oil,
the coolant flow path has an ATF flow path connected to the heat exchange device and allowing the coolant to flow through the heat exchange device;
a valve that can be switched between a closed state that closes the ATF flow path and an open state that opens the ATF flow path is provided in the ATF flow path,
a control device that switches the valve to the closed state or the open state when a predetermined condition is satisfied;
The control device switches the valve to the closed state or the open state when the predetermined condition is met and an approach notification system is activated. the valve is normally open;
2. The vehicle according to claim 1, wherein the control device prohibits the valve from being switched to the closed state after the vehicle is started and until the approach notification system is activated, and switches the valve to the closed state when the approach notification system is activated. The control device
When the temperature of the automatic transmission fluid is equal to or higher than a predetermined temperature, a switching request is made to switch the valve from the closed state to the open state,
3. The vehicle according to claim 1, wherein if the valve is in the closed state, and if the vehicle does not remain stopped after stopping, and if the oil temperature of the automatic transmission oil reaches or exceeds a predetermined temperature, the valve is switched to the open state when the approach notification system is activated. A vehicle as described in any one of claims 1 to 3, wherein when the predetermined condition is met, the operating sound of the approach warning system is increased compared to when the predetermined condition is not met. The vehicle of claim 4, wherein if the predetermined condition is met before the approach warning system is activated, the operating sound of the approach warning system is increased. A vehicle as described in claim 4 or 5, wherein an increase in the operating sound of the approach warning system is prohibited if the predetermined condition is not met while the approach warning system is operating.