JP4422499B2 - Electric pump control device - Google Patents

Description

  The present invention relates to a control device that controls the operation of an electric pump that delivers coolant for an in-vehicle unit.

  There is a cooling system that cools in-vehicle units such as a transaxle unit, an automatic transmission unit, and a continuously variable transmission unit by circulating a coolant. Some cooling systems of this type employ an electric pump as a pump for delivering a coolant. In this case, the electric pump, for example, sucks the coolant in the in-vehicle unit and sends it out to the radiator. And the cooling fluid cooled with the radiator returns in the in-vehicle unit (cooling piping), and the in-vehicle unit is cooled.

JP 2000-18377 A

  However, in such a cooling system, the operation sound of the electric pump may be audibly noticeable, and the occupant may feel uncomfortable as if some sort of abnormality occurred. Conventionally, in such a case, in order to lower the sound pressure level in the passenger compartment of the operating sound of the electric pump, measures such as providing an insulator or a soundproof wall have been taken. There has been a problem of increasing labor and manufacturing costs.

  In addition, although there exists a technique disclosed by the said patent document 1 as a technique of reducing the noise of the electric oil pump for automatic transmissions, this is not what assumed the electric pump for cooling fluid.

An electric pump control device according to the present invention is an electric pump control device that controls the operation of an electric pump that sends out coolant for an in-vehicle unit , and controls the start and stop of the electric pump , and the electric pump By driving the electric pump based on a predetermined parameter corresponding to the magnitude of noise other than the operation sound of the motor, the operation sound of the electric pump is configured to be masked by the noise , and the electric pump is started The parameter threshold value is different from the parameter threshold value to be stopped.

  In the electric pump control device according to the present invention, it is preferable to variably control the flow rate of the electric pump.

  In the electric pump control apparatus according to the present invention, it is preferable that the parameter is a vehicle speed.

  Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an example of a configuration of a main part of a cooling system 10 for an in-vehicle unit including a control device 18 for an electric pump 16 according to an embodiment of the present invention.

  In the example of FIG. 1, the cooling system 10 includes a radiator 14 that cools a cooling liquid (for example, ATF, antifreeze liquid, etc.) for an in-vehicle unit (for example, a transaxle unit, an automatic transmission unit, a continuously variable transmission unit, etc.) The electric pump 16 that sucks the coolant from the in-vehicle unit 12 and sends it to the radiator 14 and the control device 18 that controls the operation of the motor 16 are provided. It is configured to circulate in the closed cooling pipe 20. The electric pump 16 includes a pump (for example, a gear pump) 22 and an electric motor (for example, a DC motor) 24. In addition, the arrangement | sequence order of the vehicle-mounted unit 12, the electric pump 16, and the radiator 14 is not limited to the example of FIG.

  The control device (e.g., ECU) 18 operates the electric pump 16 based on a predetermined parameter (e.g., vehicle speed) so that the operation sound of the electric pump 16 is masked by noise other than the operation sound of the electric pump 16. To control. Hereinafter, control examples of the electric pump 16 by the control device 18 will be described with reference to FIGS.

  FIG. 2 shows a sound pressure in a specific audible frequency band (a band in which the operation sound of the electric pump 16 is large) of road noise and other noises in the vehicle interior and operation sound of the electric pump 16, and a control example of the electric pump 16 in this case. The horizontal axis represents the vehicle speed V [km / h], and the vertical axis represents the sound pressure [dB] in the passenger compartment.

  When the sound pressure of the operation sound of the electric pump 16 is lower than the sound pressure of the noise, the operation sound of the electric pump 16 is masked by the noise. Here, as shown in FIG. 2, the sound pressure of background noise or other background noise increases as the vehicle speed V increases, whereas the sound pressure of the operating sound of the electric pump 16 is substantially constant regardless of the vehicle speed V. It is. Therefore, the control device 18 acquires the vehicle speed V as a parameter, and the electric pump is used only when the vehicle speed V is equal to or higher than the threshold vehicle speed Vth0 at which the sound pressure of the electric pump 16 and the sound pressure of the noise are equal. 16 is driven (ON), otherwise, the electric pump 16 is not driven (OFF). By doing so, the electric pump 16 is driven only in a state where the operation sound is masked by the noise, and it becomes difficult for the passenger in the vehicle compartment to recognize the operation sound of the electric pump 16 audibly.

  FIG. 3 is a diagram schematically showing another example (upper stage) of road noise and other noises in the passenger compartment and the sound pressure of the operating sound of the electric pump 16, and a control example (lower stage) of the electric pump 16 in that case. In the upper graph, the horizontal axis represents the vehicle speed V [km / h], and the vertical axis represents the sound pressure [dB] in the passenger compartment.

  As shown in the upper part of FIG. 3, some electric pumps 16 have a loud operating sound only when they are activated. In this case, the control device 18 determines that the vehicle speed V is equal to the first threshold vehicle speed Vth1 (that is, the sound pressure of the operating sound when the electric pump 16 is started) when the vehicle speed is increased (that is, when the electric pump 16 is started). The electric pump 16 is turned on when the vehicle speed is equal to or higher than the vehicle speed at which the sound pressure of the noise becomes equal, hereinafter referred to as the vehicle speed threshold value at the time of acceleration, and on the other hand, at the time of deceleration (ie, when the electric pump 16 is stopped) ), The vehicle speed V is referred to as a second threshold vehicle speed Vth2 (that is, the vehicle speed at which the sound pressure of the operating sound and the sound pressure of the noise other than when the electric pump 16 is activated are equal, hereinafter referred to as the vehicle speed threshold at the time of deceleration, The electric pump 16 is turned off while Vth2 ≠ Vth1, Vth2 <Vth1) or higher. By doing so, it is possible to obtain a masking effect due to the noise even for the electric pump 16 in which the operation sound becomes loud at the time of activation.

  FIG. 4 is a diagram schematically showing road noise and other noises in the vehicle interior, the sound pressure of the operating sound of the variable flow electric pump 16, and the discharge flow rate in that case, and the horizontal axis represents the vehicle speed V [km / h]. ], The vertical axis represents the sound pressure [dB] in the passenger compartment.

  When the electric pump 16 is a variable flow pump, the operation sound of the electric pump 16 also changes according to the discharge flow rate. Therefore, when the electric pump 16 is a variable flow pump, the sound pressure of the operation sound of the electric pump 16 is changed by changing the discharge amount of the electric pump 16 within a range that can be masked by noise according to the vehicle speed V. It can be lower than the sound pressure. For example, the example of FIG. 4 shows control in which the discharge amount of the electric pump is increased stepwise as the vehicle speed V increases. The control device 18 switches the discharge flow rate (Q1, Q2, Q3) at each vehicle speed threshold value (Vth3, Vth4, Vth5). When performing such control, it is possible to obtain a masking effect due to noises other than the operation sound of the electric pump 16, and further, cooling liquid is discharged even in a region where the vehicle speed V is relatively low, so that the cooling capacity is increased. There is a merit. The discharge amount of the electric pump 16 can be variably controlled by changing the drive voltage applied to the electric motor 24, for example. Further, instead of switching the flow rate to multiple stages as shown in FIG. 4, variable control (continuous variable control) may be performed in a stepless manner.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the example of FIG. 3, the case where the threshold vehicle speed Vth1 at the time of acceleration is higher than the threshold vehicle speed Vth at the time of deceleration is shown. However, for example, since the electric pump 16 is momentarily disconnected, In such a case, the threshold vehicle speed Vth2 during deceleration (when the electric pump 16 is stopped) is set higher than the threshold vehicle speed Vth1 during acceleration (when the electric pump 16 is started). Is preferred. That is, the operating sound of the electric pump 16 for some reason at the time of starting or stopping can be obtained by making the threshold value of the parameter that is the starting / stopping source different between when the electric pump 16 is started and when it is stopped. The masking effect can be obtained more reliably even when the value of the mask increases.

  In the examples of FIGS. 2 to 4, the vehicle speed information is used as a parameter for controlling the operation of the electric pump 16, but information indicating the rotation speed of the engine or the vehicle drive motor may be used instead. Further, in the case of a so-called hybrid vehicle equipped with both an engine and a vehicle drive motor, ON / OFF of the electric pump 16 may be controlled using information indicating the operation / stop of the engine. In this case, the electric pump 16 is turned on when the engine is operating, and the electric pump 16 is turned off when the engine is stopped. By doing so, the operation sound of the electric pump 16 is masked by the noise generated by the operation of the engine (that is, the rotation operation at the idling speed or higher).

It is a figure which shows one structural example of the principal part of the cooling system for vehicle-mounted units containing the control apparatus of the electric pump concerning embodiment of this invention. It is a figure which shows typically the example of 1 control of the electric pump by the noise in a vehicle interior, the sound pressure of the operating sound of an electric pump, and the control apparatus of the electric pump concerning embodiment of this invention. It is a figure which shows typically the noise in a vehicle interior, the sound pressure of the operating sound of an electric pump, and another control example of the electric pump by the control apparatus of the electric pump concerning embodiment of this invention. It is a figure which shows typically the noise in a vehicle interior, the sound pressure of the operating sound of an electric pump, and another control example of the electric pump by the control apparatus of the electric pump concerning embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Cooling system, 12 Car-mounted unit, 14 Radiator, 16 Electric pump, 18 Control apparatus, 20 Cooling piping, 22 Pump, 24 Electric motor.

Claims (2)

A control device for an electric pump that controls the operation of an electric pump that sends out coolant for an in-vehicle unit,
Control the start and stop of the electric pump,
And by driving the electric pump based on a predetermined parameter corresponding to the magnitude of noise other than the operating sound of the electric pump, the operating sound of the electric pump is masked by the noise ,
And the threshold value of the parameter which starts an electric pump differs from the threshold value of the parameter which stops , The control apparatus of the electric pump characterized by the above-mentioned. The electric pump control device according to claim 1, wherein the parameter is a vehicle speed.

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