vehicle

Abstract

The present invention aims to provide a vehicle capable of reducing the noise generated by a valve used to cool automatic transmission oil during operation. To address the aforementioned issues, the vehicle includes a cooling water flow path for circulating cooling water used to cool a drive source of the vehicle; a heat exchange device for exchanging heat between the cooling water and the automatic transmission oil; the cooling water flow path includes an automatic transmission fluid (ATF) flow path connected to the heat exchange device for circulating the cooling water to the heat exchange device; a valve is provided in the ATF flow path that is switchable between a closed state (closing the ATF flow path) and an open state (opening the ATF flow path); and a control device that switches the valve between a closed state and an open state when specific conditions are met. The control device switches the valve between a closed state and an open state when the specific conditions are met and when background noise exceeds a specific threshold.

Description

Technical Field

[0001] The present invention relates to a vehicle. Background Art

[0002] Automatic transmissions are now widely used, converting torque from a drive source such as an engine or motor mounted on a vehicle to automatically shift gears. In recent years, to achieve higher output from the drive source and improve the quality of automatic transmissions, automatic transmissions have been frequently shifting gears, leading to an increase in the amount of heat generated by the automatic transmission. Therefore, a technology has been developed to suppress the temperature increase of automatic transmission fluid (ATF).

[0003] Patent Document 1 discloses an automatic transmission oil temperature control device that can appropriately suppress excessive oil temperature increases (overshoot) during high-load operation. The temperature control device includes a heat exchanger for performing heat exchange 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.

[0004] [Prior technical literature]

[0005] (Patent Document)

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-48893 Summary of the Invention

[0007] [Problems to be solved by the invention]

[0008] However, there is a problem that when the switching valve is operated in an environment with low background noise, such as when the vehicle is parked or traveling at low speed, the operating sound of the switching valve becomes noise that resonates in the vehicle, thereby reducing the marketability of the vehicle.

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a vehicle capable of reducing noise generated when a valve used for cooling automatic transmission oil is operated.

[0010] [Technical means to solve the problem]

[0011] (1) The present invention relates to a vehicle comprising: a cooling water flow path for circulating cooling water for cooling a driving source of the vehicle; and a heat exchange device for performing heat exchange between the cooling water and automatic transmission oil; and the cooling water flow path has an ATF flow path, the ATF flow path being connected to the heat exchange device and allowing the cooling water to flow to the heat exchange device, the ATF flow path being provided with a valve capable of switching between a closed state for closing the ATF flow path and an open state for opening the ATF flow path, and the vehicle having a control device for switching the valve to the closed state or the open state in response to a switching request when a specific condition is satisfied; the control device switches the valve to the closed state or the open state when the specific condition is satisfied and a background noise condition is satisfied that the background noise is above a specific threshold.

[0012] According to the invention of (1), since the valve used for cooling the automatic transmission oil is opened or closed when the background noise is equal to or higher than a specific threshold, a vehicle can be provided that can reduce the noise during valve operation.

[0013] (2) The vehicle according to (1), wherein the control device switches the valve to the closed state or the open state when a specific time has passed while the specific condition is satisfied and the background noise condition is not satisfied.

[0014] According to the invention of (2), since the valve is switched when a specific time has passed even when the background noise condition is not satisfied, the vehicle performance when the cooling water is used for control is ensured.

[0015] (3) The vehicle according to (1), wherein a pump device for pressurizing the cooling water is provided on the cooling water flow path, the valve is provided on the downstream side of the pump device, and when the valve is switched from the closed state to the open state, the control device opens the valve after reducing the rotation speed of the pump device.

[0016] According to the invention of (3), since the valve is opened in a state where the operating force of the valve is reduced by reducing the water pressure of the pump device, the operating sound when the valve is opened can be reduced.

[0017] (4) The vehicle according to (1), wherein a pump device for pressurizing the cooling water is provided on the cooling water flow path, the valve is provided on the downstream side of the pump device, and when the valve is switched from the open state to the closed state, the control device closes the valve after increasing the rotation speed of the pump device.

[0018] According to the invention of (4), since the valve is closed in a state where the operating force of the valve is reduced by utilizing the increase in water pressure of the pump device, the operating sound when the valve is closed can be reduced.

[0019] (5) The vehicle according to (1), wherein the background noise condition is a condition that the vehicle speed is equal to or greater than a specific threshold value.

[0020] According to the invention of (5), a vehicle can be provided that can reduce the noise generated when the valve is in operation.

[0021] (6) The vehicle according to (1), wherein the background noise condition is a condition that the engine speed is equal to or greater than a specific threshold.

[0022] According to the invention of (6), a vehicle can be provided that can reduce the noise generated when the valve is in operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a block diagram showing the structure of a refrigerant circuit according to one embodiment of the present invention.

[0024] Figure 2 This is a flowchart showing the control logic of the valve according to one embodiment of the present invention.

[0025] Figure 3 This is a timing chart showing an example of applying the control logic of one embodiment of the present invention to a vehicle.

[0026] Figure 4 This is a graph showing the vibration reduction effect of the valve according to one embodiment of the present invention. DETAILED DESCRIPTION

[0027] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the content of the present invention is not limited to the description of the following embodiment.

[0028] The vehicle of this embodiment includes a cooling water flow channel for circulating cooling water for cooling the drive source, and a heat exchange device for exchanging heat between the cooling water and the ATF. The vehicle of this embodiment may include an internal combustion engine as the drive source, a motor as the drive source, or both an internal combustion engine and a motor as the drive source. The following description of the vehicle of this embodiment uses a vehicle including an internal combustion engine (engine) as an example.

[0029] Figure 1This is a block diagram illustrating the structure of a refrigerant circuit 1 included in a vehicle according to one embodiment of the present invention. The refrigerant circuit 1 includes cooling water flow paths L11, L12, L13, and L14, ATF flow paths L21 and L22, a radiator 30, an electric water pump (EWP) 40 as a pump device, a heat exchange device 60 (ATFC), and an ECU 70 as a control device. The refrigerant circuit 1 is configured to exchange heat generated by an engine (ENG) 10, which serves as a drive source, with cooling water flowing through the cooling water flow paths, thereby cooling the engine 10. Furthermore, the cooling water is configured to flow through the heat exchange device 60, thereby also exchanging heat with the ATF, the hydraulic fluid of the automatic transmission (T / F) 20.

[0030] Cooling water flow paths L11, L12, L13, and L14 are configured to allow cooling water to flow. Cooling water flow path L11 is provided with an EWP 40, a pump device capable of pumping cooling water. Cooling water flow path L12 is located downstream of EWP 40 and communicates with the cooling water flow path of engine 10. Cooling water flow path L13, serving as an ATF flow path, is located downstream of EWP 40 and branches off from cooling water flow path L12 at a branch point J1. The downstream side of cooling water flow path L12 and the upstream side of cooling water flow path L11 are connected to the radiator 30.

[0031] A check valve 50 is provided in the cooling water flow channel L13, which serves as the ATF flow channel. The check valve 50 can switch between a closed state, which closes the cooling water flow channel L13, and an open state, which opens the ATF flow channel. The downstream end of the cooling water flow channel L13 is connected to the upstream end of the cooling water flow channel provided within the heat exchange device 60. The upstream end of the cooling water flow channel L14 is connected to the downstream end of the cooling water flow channel provided within the heat exchange device 60. The cooling water flow channel L14 merges with the cooling water flow channel L12 at a confluence point J2.

[0032] Automatic transmission 20 is composed of a torque converter for transmitting the rotational output of engine 10 to a transmission gear mechanism, a hydraulic control device, and other components. The hydraulic control device can lock the torque converter or set the input-to-output speed ratio of the transmission gear mechanism to a desired number of speed steps by engaging or releasing hydraulically controlled friction engagement elements (clutches, etc.) provided within the torque converter and transmission gear mechanism using specific combinations.

[0033] ATF flow paths L21 and L22 are oil passages through which ATF can flow, and each includes an oil pump (not shown) capable of pressurizing the ATF. The ATF in the automatic transmission 20 can flow to the heat exchange device 60 via the ATF flow path L21. After undergoing heat exchange in the heat exchange device 60, the ATF is returned to the automatic transmission 20 via the ATF flow path L22. This allows heat exchange between the ATF and the cooling water flowing through the heat exchange device 60.

[0034] The radiator 30 is composed of fins, cooling pipes, etc. The radiator 30 performs heat exchange between cooling water and the atmosphere to cool the cooling water.

[0035] The EWP 40 is provided in the cooling water flow path L11 and pumps the cooling water circulating in the refrigerant circuit 1. The EWP 40 is an electric water pump whose rotation speed is adjusted by adjusting the power supplied to the EWP 40, and whose discharge capacity can be varied in an indefinite number of steps.

[0036] The stop valve 50 is, for example, a normally open solenoid valve. When de-energized, it is in an open state, opening the cooling water flow channel L13. When energized, the stop valve 50 switches to a closed state, closing the cooling water flow channel L13. The stop valve 50 can switch between the closed and open states based on commands from the control unit. While the stop valve 50 is described below as a normally open solenoid valve, it may also be a normally closed solenoid valve.

[0037] The stop valve 50 includes a valve portion that opens or closes the flow path, and a drive portion that drives the valve portion. The valve portion is composed of a valve body, a valve seat, and other components. When the stop valve 50 is switched from a closed state to an open state, the valve body contacts the components that constitute the flow path, thereby generating a valve operating sound. When the stop valve 50 is switched from an open state to a closed state, a valve operating sound is generated in the drive portion. For example, when the valve body and the components that constitute the flow path are made of a resin such as fluororesin, and the drive portion is made of metal, the operating sound when the stop valve 50 is switched from an open state to a closed state is louder than the operating sound when the stop valve 50 is switched from a closed state to an open state.

[0038] A flow path through which cooling water and ATF flow is provided inside the heat exchange device 60 , and the cooling water flowing in from the cooling water flow path L13 and the ATF flowing in from the ATF flow path L21 perform heat exchange.

[0039] In the vehicle of this embodiment, in addition to the above-mentioned components, there are also provided a temperature sensor capable of detecting the oil temperature of the working oil of the oil pressure control device, namely the ATF, a rotation sensor capable of detecting the rotation speed of the input shaft of the torque converter, namely the engine speed, a vehicle speed sensor for detecting the vehicle speed, a sensor for detecting the air volume of the air conditioner, etc.

[0040] The ECU 70 is an engine control unit (ECU) serving as a control device. Based on the detection results of the aforementioned sensors, the ECU 70 adjusts the power supply to the EWP 40 and controls the opening and closing of the stop valve 50. The details of the control of the EWP 40 and the stop valve 50 by the ECU 70 will be described below.

[0041] ECU 70 requests a switch between the closed and open states, closing stop valve 50 when the oil temperature falls below a specific temperature at which the fuel saving effect of ATF friction reduction is achieved, and opening stop valve 50 when the oil temperature exceeds a specific temperature determined by the drive source cooling request. ECU 70 controls the switch of stop valve 50 when the above-mentioned specific conditions are met and, in addition, the background noise condition, that the background noise exceeds a specific threshold, is met. This reduces noise by masking the operating sound of stop valve 50 with the background noise.

[0042] In addition to the above, when the normally open check valve 50 is open, the combined spring force and water pressure become greater than the residual magnetic force, causing the valve body to operate. Therefore, the ECU 70 preferably controls the EWP 40 to reduce its rotational speed (water pressure) and control the check valve 50 to open while suppressing the operating force of the valve body. Similarly, when the check valve 50 is closed, the electromagnetic attraction generated by energizing the coil becomes greater than the combined spring force and water pressure, causing the valve body to operate. Therefore, the ECU 70 preferably controls the EWP 40 to increase its rotational speed (water pressure) and control the check valve 50 to close while suppressing the operating force of the valve body. This control can reduce the operating sound of the check valve 50. Furthermore, when a normally closed solenoid valve is used as the check valve 50, the ECU 70 controls the EWP 40 to increase its rotational speed (water pressure) when the check valve 50 is open and to reduce its rotational speed (water pressure) when the check valve 50 is closed, thereby achieving similar effects.

[0043] Figure 4 The graph compares the vibration of the mounting portion of the check valve 50 when control is performed to reduce the water pressure of the EWP 40 when the normally open check valve 50 is open and to increase the water pressure of the EWP 40 when the check valve 50 is closed, and when such control is not performed. Figure 4 The vertical axis represents vibration (G). Figure 4 The two bar graphs on the left side of represent the vibration when the check valve 50 is open. When the check valve 50 is open, the water pressure of the EWP 40 is reduced, thereby reducing the vibration by about 27%. Figure 4 The two bar graphs on the right side of represent vibrations when the stop valve 50 is closed. When the stop valve 50 is closed, the water pressure of the EWP 40 is increased, thereby reducing the vibrations by approximately 25%.

[0044] Below, reference Figure 2 An example of a control routine 100 of the ECU 70 from when a valve closing request as a switching request is issued to when the stop valve 50 is closed when a specific condition is satisfied will be described.

[0045] exist Figure 2 In the control routine 100 shown, when a request to close the stop valve 50 is received, a timer is first started (step S1). Next, a determination is made as to whether the vehicle is starting (step S2). If the vehicle is starting, the process proceeds to step S8, where closing of the stop valve 50 is permitted. If the vehicle is not starting, a determination is made as to whether the air conditioning air volume is below Wp (step S3). Steps S3 through S5 determine whether background noise conditions are met.

[0046] If it is determined in step S3 that the air conditioning air volume exceeds Wp, the process proceeds to step S8 to allow closing of the stop valve 50. If it is determined to be below Wp, it is determined whether the ENG (engine) speed is below Np (step S4).

[0047] If it is determined in step S4 that the ENG speed exceeds Np, the process proceeds to step S8 to allow closing of the stop valve 50. If it is determined to be below Np, it is determined whether the vehicle speed is above Vp (step S5).

[0048] If the vehicle speed is determined to be Vp or higher in step S5, the process proceeds to step S8 to allow closing of the stop valve 50. If the vehicle speed is determined to be lower than Vp, it is determined whether the timer started in step S1 has exceeded time Tp (step S6).

[0049] If it is determined in step S6 that the timer elapsed time has exceeded time Tp, an EWP Duty MAX instruction is issued to increase the speed of the EWP 40 (step S7), and then the process proceeds to step S8 to allow closing of the stop valve 50. If it is determined in step S6 that time Tp has not elapsed, the process returns to step S3.

[0050] The above is a description of the control routine 100 from the issuance of a valve closing request as a switching request to the closing of the stop valve. Regarding the control routine when a valve opening request is issued as a switching request, the control routine is the same as when a valve closing request is issued, except that a step of reducing the rotation speed of the EWP 40 is executed instead of step S7.

[0051] Figure 3 1 is a timing chart showing the operation status of the stop valve 50 controlled by the ECU 70 to which the control routine 100 of the present embodiment is applied. Figure 3The vertical axis represents, from top to bottom, the vehicle speed, the ATF oil temperature, the switching request, the elapsed time of the timer, the valve closing permission / prohibition control routine 100, the rotation speed of the EWP 40, the operating condition C1 of the stop valve 50 of the present embodiment, and the operating condition C2 of the conventional stop valve, respectively. Figure 4 The horizontal axis represents the time T0 to T9 from T0 to T9.

[0052] Below, use Figure 3 The operation state C1 of the stop valve 50 of this embodiment will be described. In the conventional operation state C2 of the stop valve, the stop valve is operated only in response to a switching request.

[0053] At time T1, the ATF oil temperature exceeds a specific oil temperature To, prompting a request to switch check valve 50 from closed to open. At this point, the vehicle speed is above a specific speed Vp, thus satisfying background noise conditions. Therefore, opening of check valve 50 is permitted, and control is performed to open check valve 50.

[0054] Next, at time T3, the ATF oil temperature falls below a predetermined temperature Tc, prompting a request to switch the check valve 50 from open to closed. At this point, since the vehicle speed is below Vp, the background noise condition is not met, prohibiting closing of the check valve 50 and starting a timer.

[0055] Next, at time T4, since the ATF oil temperature is still lower than the oil temperature Tc and the vehicle speed is Vp or higher, the background noise condition is satisfied, and closing of the stop valve 50 is permitted, and control to close the stop valve 50 is performed.

[0056] Next, at time T5, the ATF oil temperature exceeds a specific oil temperature To, prompting a request to switch check valve 50 from closed to open. At this point, since the vehicle speed is above a specific speed Vp, the background noise condition is satisfied, allowing the check valve 50 to be opened. Control is then performed to open the check valve 50.

[0057] Next, at time T7, the ATF oil temperature falls below a predetermined temperature Tc, prompting a request to switch the check valve 50 from open to closed. At this point, since the vehicle speed is below Vp, the background noise condition is not met, prohibiting closing of the check valve 50 and starting a timer.

[0058] Next, at time T8, the timer elapses beyond time Tp, and control is performed to increase the speed of the EWP. Subsequently, at time T9, the speed of the EWP reaches a specific speed or higher, allowing closing of the stop valve 50, and control is performed to close the stop valve 50.

[0059] When using the above Figure 3In the description, the control routine 100 of the ECU 70 determines whether the vehicle speed is Vp or more (equivalent to Vp) as a background noise condition. Figure 2 However, a determination equivalent to step S3 or step S4 may be performed instead of or in addition to the above.

[0060] While preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate.

[0061] In the above embodiment, Figure 2 In the description above, the control routine 100 of the ECU 70 includes steps S3, S4, and S5 for determining background noise conditions. However, this is not limiting. The step of determining background noise conditions may be at least one of steps S3, S4, and S5. Furthermore, when multiple steps for determining background noise conditions are provided, the order of the steps is not particularly limited.

[0062] Reference numerals

[0063] 10 ENG (drive source)

[0064] 40 EWP (Pump unit)

[0065] 50 Check valve

[0066] 60 ATFC (heat exchange device)

[0067] 70 ECU (control unit)

[0068] L11, L12, L13, L14 cooling water channels

Claims

1. A vehicle comprising: A cooling water flow channel for circulating cooling water for cooling the driving source of the vehicle; and, a heat exchange device for performing heat exchange between the aforementioned cooling water and the automatic transmission oil; and, The cooling water flow channel includes an ATF flow channel, which is connected to the heat exchange device and allows the cooling water to flow to the heat exchange device. The ATF flow passage is provided with a valve that can switch between a closed state for closing the ATF flow passage and an open state for opening the ATF flow passage. The vehicle includes a control device that switches the valve to the closed state or the open state in response to a switching request when a specific condition is satisfied; The control device switches the valve to the closed state or the open state when the specific condition is satisfied and the background noise condition that the background noise is greater than a specific threshold is satisfied.

2. The vehicle according to claim 1, wherein The control device switches the valve to the closed state or the open state when a specific time period has elapsed while the specific condition is satisfied and the background noise condition is not satisfied.

3. The vehicle according to claim 1, wherein: A pump device for pressurizing the cooling water is provided on the cooling water flow channel. The valve is arranged on the downstream side of the pump device. When switching the valve from the closed state to the open state, the control device opens the valve after reducing the rotation speed of the pump device.

4. The vehicle according to claim 1, wherein A pump device for pressurizing the cooling water is provided on the cooling water flow channel. The valve is arranged on the downstream side of the pump device. When switching the valve from the open state to the closed state, the control device increases the rotation speed of the pump device and then closes the valve.

5. The vehicle according to claim 1, wherein The aforementioned background noise condition is a condition where the vehicle speed is above a specific threshold.

6. The vehicle according to claim 1, wherein The aforementioned background noise condition is a condition where the engine speed is equal to or higher than a specific threshold.

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