JP5961987B2 - Electric pump discharge flow rate control device - Google Patents

Description

  The present invention relates to a discharge flow rate control device for an electric pump used for appropriately supplying cooling oil including lubrication to a starting clutch of a transmission.

  The transmission has a starting clutch that is fastened to control power transmission at each gear position. This starting clutch requires acceleration by accelerator operation or repeats low-speed running while switching the gear speed on a curved uphill road. In addition, the load increases as the clutch transmission torque increases or repeatedly changes, and the amount of heat generation increases.

  When the amount of heat generated by the starting clutch increases, or when the starting clutch rises in temperature, the clutch needs to be cooled so as not to cause problems such as burning of the clutch.

  When the oil discharged from the electric oil pump is used for this cooling, for example, as described in Patent Document 1, when the cooling is necessary due to the temperature rise of the clutch, the electric oil pump is temporarily used to increase the oil pump discharge flow rate. It is normal to set the rotation speed of the high.

  That is, the rotational speed of the electric oil pump is controlled, and the discharge flow rate is made as required according to the above-described clutch heat generation amount and clutch temperature, thereby solving the problem related to overheating of the clutch.

JP 2007-198438 A

  However, with the conventional technology that achieves the target discharge flow rate by controlling the rotational speed of the pump, the pump achieves the target discharge flow rate by reducing the volumetric efficiency when the pump sucks air due to a sudden increase in the target discharge flow rate, etc. However, this causes a problem that the clutch is undercooled.

However, when controlling the rotational speed of the electric pump, it is expected that the pump volumetric efficiency will decrease due to air suction, etc. If the pump rotational speed is increased in advance and used for discharge flow rate control, it will be due to air suction, etc. When the pump volumetric efficiency is not lowered, the pump discharge flow rate is too high, and the power consumption of the electric pump is increased unnecessarily, leading to a deterioration in power consumption.
Further, the countermeasure further increases the strength requirement of the electric pump, and the pump sliding resistance increases due to the increase in pump sliding resistance, which inevitably causes a cost disadvantage.

  On the other hand, when the electric pump is driven by a DC motor that responds to a constant electric power to achieve a target discharge flow rate, an inverter is not necessary for controlling the pump, which is advantageous in terms of cost. There is a concept of realizing a target discharge flow rate using a drive type electric pump.

According to the present invention, when a DC motor drive type electric pump is used based on such a concept, the pump discharge flow rate is compensated even when this type of electric pump has a reduced pump volumetric efficiency due to air suction or the like, and the above-mentioned An object of the present invention is to provide a pump discharge flow rate control device that does not cause various problems.
In addition, in the present invention, since the reduction in pump volume efficiency due to the suction of air, which is the cause of the above problems, appears as a change in pump rotation speed due to a decrease in pump driving load, It is an object of the present invention to provide a discharge flow rate control device for an electric pump that does not cause the above-mentioned problems by correcting the constant power based on the above and making it possible to compensate the target discharge flow rate.

To this end, the electric pump discharge flow rate control device according to the present invention is configured as follows.
First, an electric pump as a premise of the present invention will be described. As described above, this is an electric pump that is driven by a DC motor that responds to a constant power to achieve a target discharge flow rate. The target discharge flow rate is realized by controlling the driving of the DC motor so as to realize the corresponding target pump driving torque and the pump rotation speed at which the target pump driving torque can be obtained with the constant power . Is.

  The pump discharge flow rate control device of the present invention is provided with the following target pump rotation speed calculation means, pump rotation speed information detection means, pump rotation speed deviation calculation means, and pump drive power correction for the above-described electric pump. And a configuration provided with means.

The target pump rotational speed calculation means is configured to generate a target pump driving torque based on the target pump driving torque when the target discharge flow rate becomes unrealizable due to a pump driving torque change and a pump rotational speed change during pump driving by the DC motor with the constant power. The target pump rotational speed of the electric pump for compensating the target discharge flow rate is calculated,
The pump rotation speed information detecting means detects pump rotation speed information related to the actual pump rotation speed of the electric pump.

The pump rotation speed deviation calculating means calculates the pump rotation speed deviation of the actual pump rotation speed with respect to the target pump rotation speed based on the signals from the target pump rotation speed calculation means and the pump rotation speed information detection means,
Pump driving power correcting means, the constant power on the basis of the calculated pump speed deviation, the actual pump speed is corrected so that toward the target pump speed with the pump driving torque is restored to the target pump driving torque Is.

In the discharge flow control device of the electric pump according to the present invention,
When the target discharge flow rate becomes unrealizable due to pump drive torque change and pump rotation speed change during pump drive by DC motor with constant power, the electric pump for compensating the target discharge flow rate based on the target pump drive torque The target pump rotation speed is calculated, and the pump drive torque returns to the target pump drive torque based on the pump rotation speed deviation of the actual pump rotation speed with respect to the target pump rotation speed, and the actual pump rotation speed is directed toward the target pump rotation speed. In order to correct the constant power used to drive the electric pump,
If the target discharge flow rate cannot be realized due to a decrease in pump volumetric efficiency due to air suction, etc., the target discharge flow rate is compensated for the actual pump rotation speed that changes according to the decrease in pump driving force accompanying the decrease in pump volumetric efficiency. The constant pump driving power is corrected so that the pump driving torque is returned to the target pump driving torque .

With the correction of the constant pump driving power, the pump discharge flow rate change due to the pump rotation speed deviation can be offset to compensate the target discharge flow rate,
As in the case sucked pump rapid increase of the target discharge flow rate of the air, when the pump is reduced volumetric efficiency, Ri by the compensation of the target discharge flow rate, the adverse effect given function can not be obtained, such as cooling Can be avoided .

In addition, in anticipation of a decrease in pump volume efficiency, the above-mentioned effects can be obtained without depending on measures to constantly increase the constant pump drive power accordingly.
In the case where the pump volumetric efficiency is not lowered, the pump discharge flow rate is too high, and the electric pump does not consume power unnecessarily, and there is no problem of deteriorating power consumption.

  Furthermore, there is no need to increase the strength of the electric pump as in the case where measures are taken to constantly increase the constant pump driving power, and the pump driving power is increased by increasing the pump sliding resistance due to the high strength of the electric pump. It does not cause a cost penalty.

It is a block diagram classified by function which shows the discharge flow rate control apparatus of the electric pump which becomes one Example of this invention. FIG. 2 is a functional block diagram illustrating a voltage correction amount determination unit in the pump discharge flow rate control device of FIG. A pump that realizes a pump operating point that is a combination of the pump rotating speed, the pump driving torque, and the pump rotating speed and the pump driving torque used to explain the pump operating point obtained by the target operating point calculation unit in FIG. It is a characteristic diagram which shows the relationship with drive electric power. FIG. 2 is a characteristic diagram showing that the relationship between the pump rotation speed of the electric oil pump and the pump driving torque in FIG. 1 varies depending on the oil temperature. FIG. 3 is a map diagram showing a map used when a voltage correction amount is obtained by a voltage correction amount calculation unit in FIG. 3 is a flowchart showing a control program when the pump discharge flow rate control device shown in FIGS. 1 and 2 is configured by a microcomputer. It is a time chart which shows the operation | movement by the conventional pump discharge flow control apparatus. FIG. 3 is a time chart showing an operation by the pump discharge flow rate control device shown in FIGS.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
<Configuration of Example>
FIG. 1 is a functional block diagram showing a discharge flow rate control device for an electric pump according to an embodiment of the present invention. This discharge flow rate control device includes lubrication for a start clutch (not shown) in a transmission 1. It is assumed that the electric oil pump 2 (corresponding to the electric pump in the present invention) for appropriately supplying cooling oil as needed is controlled in discharge flow rate.
The electric oil pump 2 is a so-called inverter-less motor-driven pump that is driven by a DC motor that responds to a constant electric power to achieve a target discharge flow rate.

  The start clutch (not shown) in the transmission 1 is a clutch that is fastened to control power transmission at each shift stage. This start clutch is requested to accelerate by an accelerator operation or while changing the shift stage on a curved uphill road. When the low-speed traveling is repeated, the load increases as the clutch transmission torque increases or repeatedly changes, and the heat generation amount increases.

When the heat generation amount of the starting clutch increases or the temperature of the starting clutch rises as a result, the clutch is cooled so as not to cause problems such as burning of the clutch. There is a need.
In this case, the electric oil pump 2 is operated to supply the discharge oil from now to the starting clutch, and at the same time, the electric oil pump 2 is fixed so that the discharge flow rate corresponds to the amount of oil required for cooling of the starting clutch. The drive is controlled by the direct current power.

  Therefore, the discharge flow rate control device for the electric oil pump 2 shown in FIG. 1 includes an oil pump operation necessity determination unit 10, a voltage correction amount determination unit 20, and a pump rotation speed sensor 30 that detects the rotation speed Nop of the electric oil pump 2. (Corresponding to the pump rotation speed information detecting means in the present invention) and the pump drive power correction unit 40, which will be described in detail below.

  The oil pump operation necessity determination unit 10 is based on the oil temperature TEMPoil of the transmission 1, the input torque Tcin of the starting clutch, the clutch slip amount ΔNcl that is the differential rotation of the starting clutch, the road surface gradient θ, and the temperature TEMPcl of the starting clutch. It is checked whether or not the starting clutch should be cooled to determine whether or not the electric oil pump 2 should be operated.

If the clutch temperature TEMPcl or the oil temperature TEMPoil is a high temperature that requires cooling of the starting clutch, the starting clutch should be cooled. Therefore, in order to command the operation of the electric oil pump 2, the oil pump operation necessity determination unit 10 sets the oil pump operation necessity signal Sop to Sop = ON.
If the clutch temperature TEMPcl or the oil temperature TEMPoil is low enough not to require cooling of the starting clutch, it is not necessary to cool the starting clutch. The section 10 sets the oil pump operation necessity signal Sop to Sop = OFF.

The oil pump operation necessity determination unit 10 further predicts from the clutch input torque Tcin, the clutch slip amount ΔNcl, and the road surface gradient θ whether or not the starting clutch will soon reach a high temperature that requires cooling,
The start clutch should be cooled under conditions where the start clutch is expected to reach a high temperature that needs to be cooled soon, so the oil pump operation necessity signal Sop is set to Sop to command the operation of the electric oil pump 2. = ON and none,
Under conditions where it is predicted that the starting clutch will not reach the high temperature that needs to be cooled in the near future, it is not necessary to cool the starting clutch. The reject signal Sop is set to Sop = OFF.

  Whether the oil pump operation necessity determination unit 10 should cool the start clutch based on any one of the oil temperature TEMPoil, the clutch input torque Tcin, the clutch slip amount ΔNcl, the road surface gradient θ, and the start clutch temperature TEMPcl. It may be determined whether or not the electric oil pump 2 should be operated, or the determination may be performed by combining any of these input information.

  The electric oil pump 2 is controlled to be activated or deactivated by the above-described oil pump activation necessity signal Sop. The electric oil pump 2 is activated when Sop = ON and deactivated when Sop = OFF.

  When the electric oil pump 2 is unable to achieve the target discharge flow rate due to the volumetric efficiency of the electric oil pump 2 being reduced due to air suction or the like, the voltage correction amount determining unit 20 is required to compensate for the target discharge flow rate. The voltage correction amount ΔVe for realizing the power correction amount is obtained, and details will be described later with reference to FIG.

  The pump drive power correction unit 40 converts the power of a DC power source (not shown) into a predetermined voltage by a DC / DC converter to form a pump drive power Pw_1, which is supplied to the electric oil pump 2 to drive the pump 2 In this case, the pump drive power correction unit 40 corrects the voltage of the pump drive power Pw_1 by the voltage correction amount ΔVe obtained by the determination unit 20, and the supply power Pw_1 to the electric oil pump 2 is corrected by the voltage correction amount ΔVe. Correct by.

  The voltage correction amount determination unit 20 will be described in detail with reference to FIG. 2. The voltage correction amount determination unit 20 includes a target operating point calculation unit 21, a subtractor 22, a voltage correction amount calculation unit 23, and a voltage correction amount selection. It consists of part 24.

  The target operating point calculation unit 21 calculates the target pump discharge flow rate from the pre-correction pump supply power Pw_0 before correction by the pump drive power correction unit 40 in FIG. 1 and the oil temperature TEMPoil of the oil supplied by the electric oil pump 2. The target operating point (combination of pump rotational speed Nop and pump driving torque Top) of the electric oil pump 2 that realizes the above is calculated, and the target pump discharge flow rate is realized from the pump target operating point under the driving with the constant power. For the target pump speed tNop.

  Here, the above-mentioned pump supply power Pw_0 before correction is the initial required power of the electric oil pump 2 set in the pump drive power correction unit 40 in FIG. 1, and is determined by system requirements such as fuel consumption requirements and auxiliary machinery operating states. However, it is not determined by the request from the electric oil pump 2.

  Next, the target operating point of the electric oil pump 2 (a combination of the pump rotation speed Nop and the pump driving torque Top) will be supplemented.

In the electric oil pump 2, the discharge flow rate Qop is determined according to the oil temperature TEMPoil and the pump rotation speed Nop, and the pump discharge circuit load (pump drive torque Top) is determined according to the discharge flow rate Qop.
When the electric oil pump 2 is driven by constant DC power (current is determined if the voltage is determined) as described above, the operating point of the electric oil pump 2 (a combination of the pump rotation speed Nop and the pump driving torque Top) is the oil temperature TEMPoil Each is determined as described below based on the example of FIG.

  Fig. 3 shows the combination of the rotational speed Nop and drive torque Top of the electric oil pump 2 (pump operating point) and the pump drive required to realize these pump operating points when the oil temperature TEMPoil is a certain value. The relationship with electric power (equal pump drive power lines are indicated by thick broken lines) is shown on the two-dimensional coordinates of the pump rotation speed Nop and the pump drive torque Top.

The relationship between the pump rotation speed Nop (discharge flow rate Qop) and the pump drive torque Top (pump discharge circuit load) depends on the oil temperature TEMPoil (oil viscosity) even under the same pump rotation speed Nop (discharge flow rate Qop). Since the pump discharge circuit load (pump drive torque Top) is different, it varies depending on the oil temperature TEMPoil as shown by the thin solid line in FIG.
Therefore, a characteristic diagram as shown in FIG. 3 exists for each oil temperature TEMPoil, and the operating point of the electric oil pump 2 (a combination of the pump rotation speed Nop and the pump driving torque Top) differs for each oil temperature TEMPoil.

At the pump operating point A1 in FIG. 3, when the electric oil pump 2 in which the target pump discharge flow rate is realized with constant power supply is being operated, when the volume efficiency of the pump 2 is reduced due to air suction or the like,
The pump discharge flow rate is reduced by the amount of efficiency reduction of the pump volume, and the pump discharge circuit load (pump drive load) is reduced. As a result, the pump operating point changes from A1 to the same pump drive power line, for example, A2 Move to (low load, high rotation side).

  By the way, in order to compensate the target pump discharge flow rate, the pump discharge flow rate must be the same pump discharge circuit load (pump drive load) as that at the operation point A1, that is, the amount that causes the same pump drive torque Top as the operation point A1. There is.

Therefore, the target operating point of the electric oil pump 2 that realizes the target pump discharge flow rate is the same as the operating point A1, the pump driving torque Top is the operating point A1, as shown by A3 in FIG. The target operating point A3 is higher than the operating point A2, and this target operating point A3 can be realized by increasing the pump driving power indicated by ΔPw in FIG.
In this embodiment, the increase ΔPw of the pump driving power is realized by the voltage correction ΔVe of the pump driving power Pw_1 described above with respect to the pump driving power correction unit 40 in FIG. Calculate as follows.

That is, the target operating point calculation unit 21 in FIG. 2 further calculates the target pump rotation speed tNop illustrated in FIG. 3 at the target operating point A3 from the target operating point A3 determined as described above.
Therefore, the target operating point calculation unit 21 corresponds to the target pump rotation speed calculation means in the present invention.

In the subtractor 22, from the actual pump rotation speed Nop (in the case of FIG. 3, the pump rotation speed at the operating point A2) that has been increased due to a decrease in volumetric efficiency due to air suction or the like, the target pump rotation speed tNop (in the case of FIG. 3) By subtracting the pump rotational speed at the operating point A3), the pump rotational speed deviation, which is the amount of change in the pump rotational speed required to achieve the target operating point A3 by matching the actual pump rotational speed Nop with the target pump rotational speed tNop. Find ΔNop (see Figure 3).
Accordingly, the subtractor 22 corresponds to the pump rotation speed deviation calculating means in the present invention.

Based on the map illustrated in FIG. 5 for the current oil temperature from the pump rotation speed deviation ΔNop and the oil temperature TEMPoil, the voltage correction amount calculation unit 23 calculates the target operating point (A3 in FIG. 3) to achieve the target pump discharge flow rate. The voltage correction amount ΔVe_0, which is the power correction amount for enabling the transition to (1), is obtained.
Therefore, the voltage correction amount calculation unit 23 corresponds to the pump drive power correction means in the present invention.

As shown in FIG. 5, the voltage correction amount ΔVe_0 is set so as to increase as the pump rotation speed deviation ΔNop increases.
The reason is that as the pump rotational speed deviation ΔNop is larger, the pump volumetric efficiency decreases more and the pump rotational speed is higher, so that it is necessary to correct the pump rotational speed to be higher.

The voltage correction amount ΔVe_0 is not shown, but is set to increase as the oil temperature TEMPoil decreases.
The reason is that the lower the oil temperature TEMPoil, the higher the discharge circuit load as described above with reference to FIG. 4 and the higher the pump driving torque.

  The voltage correction amount selection unit 24 determines whether the oil pump operation necessity signal Sop = ON (signal indicating the operation request of the electric oil pump 2) or the oil pump operation necessity signal Sop = OFF (no operation of the electric oil pump 2 is required). The voltage correction amount ΔVe_0 or the voltage correction prohibition command ΔVe = 0 from the calculation unit 23 is output to the pump drive power correction unit 40 in FIG. 1 as the final voltage correction amount ΔVe.

That is, if Sop = ON, the voltage correction amount selection unit 24 directs the voltage correction amount ΔVe_0 from the calculation unit 23 to the pump drive power correction unit 40 in FIG. 1 as the final voltage correction amount ΔVe,
If Sop = OFF, the voltage correction prohibition command ΔVe = 0 is sent to the pump drive power correction unit 40 of FIG. 1 as the final voltage correction amount ΔVe.

  As described above, the pump drive power correction unit 40 converts the power of a DC power source (not shown) into a predetermined voltage by a DC / DC converter to obtain the pump drive power Pw_1 of the electric oil pump 2. At this time, the pump drive power The voltage of Pw_1 is corrected by the voltage correction amount ΔVe obtained by the determination unit 20, and the supply power Pw_1 to the electric oil pump 2 is corrected by the voltage correction amount ΔVe.

By correcting the power (voltage), for example, the operating point of the electric oil pump 2 that has moved from A1 to A2 in Fig. 3 (with reduced discharge flow rate) due to air suction, etc., is compensated for the target discharge flow rate indicated by A3 in the same figure. To the target pump operating point for
Even when the pump volumetric efficiency is reduced due to air suction or the like, the electric oil pump 2 can compensate for the target discharge flow rate, and it is possible to avoid insufficient cooling of the starting clutch in the transmission 1.

  When the pump drive power correction unit 40 corrects the voltage of the pump drive power Pw_1 by the voltage correction amount ΔVe, the target corresponding to the target pump discharge flow rate obtained from the target operating point (A3 in FIG. 3) of the electric oil pump 2 The constant power for driving the pump may be corrected until the pump driving torque Top_1 is realized.

<Oil pump discharge flow control>
The discharge flow rate control of the constant DC power drive type oil pump 2 according to the above embodiment will be described below based on the flowchart of FIG.
In step S11, the oil temperature TEMPoil of the transmission 1, which is input information, the input torque Tcin of the starting clutch, the slip amount ΔNcl of the starting clutch, the road surface gradient θ, and the temperature TEMPcl of the starting clutch are read.

In the next step S12, whether the electric oil pump 2 is necessary or not is determined based on the above input information in the same manner as the oil pump operation necessity determining unit 10 in FIG. 1, and the start clutch is already at a high temperature. If the electric oil pump 2 should be operated for cooling it, the oil pump operation necessity signal Sop is set to Sop = ON, and the start clutch need not be cooled at this time. If so, the oil pump operation necessity signal Sop is set to Sop = OFF.
In step S12, the oil pump operation necessity signal Sop, which is the determination result, is checked for ON / OFF.

  If it is determined in step S12 that Sop = ON (operation of the electric oil pump 2 is required), in step S13, the oil temperature TEMPoil and the correction are performed in the same manner as performed in the target operating point calculation unit 21 in FIG. The target operating point (A3 in the case of Fig. 3) of the electric oil pump 2 that achieves the target pump discharge flow rate is calculated from the pre-supplied power Pw_0, and the target pump discharge flow rate is driven from this pump target operating point under constant power drive. The target pump rotational speed tNop for realizing is obtained.

  In the next step S14, it is possible to shift to the target operating point (A3 in FIG. 3) that realizes the target pump discharge flow rate by the same calculation as that performed by the subtractor 22 and the voltage correction amount calculation unit 23 of FIG. A voltage correction amount ΔVe_0, which is a power correction amount for achieving the above, is obtained.

That is, first, the actual pump rotational speed Nop (in FIG. 3, the pump rotational speed at the operating point A2) is subtracted from the target pump rotational speed tNop (in FIG. 3, the pump rotational speed at the operating point A3). A pump rotational speed deviation ΔNop (see FIG. 3), which is a pump rotational speed change amount necessary for realizing the target operating point A3 by matching the rotational speed Nop with the target pump rotational speed tNop, is obtained.
Next, based on the map illustrated in Fig. 5 for the current oil temperature from the pump rotational speed deviation ΔNop and oil temperature TEMPoil, transition to the target operating point (A3 in Fig. 3) that realizes the target pump discharge flow rate A voltage correction amount ΔVe_0, which is a power correction amount for enabling the above, is obtained.

In the next step S15, the voltage Ve for realizing the corrected supply power Pw_1 is set to the initial required voltage Ve_0 and the voltage correction amount ΔVe_0 in the same manner as performed by the pump drive power correction unit 40 of FIG. Command the electric oil pump 2 by summing up.
As described above, the initial required voltage Ve_0 is determined by the system requirements such as the fuel consumption requirement and the auxiliary machinery operating state as the initial required power of the electric oil pump 2, and is not determined by the request from the electric oil pump 2.

  If it is determined in step S12 that Sop = OFF (operation of the electric oil pump 2 is not required), in step S16, the same as that performed by the voltage correction amount selection unit 24 in FIG. 2, that is, Sop = in step S12 = In response to the OFF determination, the voltage correction amount ΔVe = 0 is set, and based on this, the voltage Ve for realizing the corrected supply power Pw_1 is obtained by Ve = Ve_0 + ΔVe = Ve_0 and commanded to the electric oil pump 2.

<Effect of Example>
The effect of the discharge flow rate control of the above embodiment will be described below.
Prior to this description, the voltage Ve of the pump driving power is not corrected by the voltage correction amount ΔVe_0 obtained by the calculation unit 23 in FIG. 2 (the constant pump driving power is not corrected), that is, this voltage Ve is set to the initial required voltage. The operation and problems when the electric oil pump 2 is driven while maintaining Ve_0 (conventional) will be described based on the time chart of FIG.

FIG. 7 shows that the starting clutch starts to be engaged at the instant t1, the clutch input torque Tcin rises as illustrated, and the clutch output rotational speed Ncout increases from 0 toward the clutch input rotational speed Ncin as illustrated.
At the instant t2 due to the heat generated by the starting clutch, it is necessary to cool the starting clutch (operation of the electric oil pump 2), and the oil pump operation necessity signal Sop is switched from OFF to ON,
Cooling of the starting clutch by the oil discharged from the electric oil pump 2 instantly eliminates cooling of the starting clutch (operation of the electric oil pump 2) and the oil pump operation necessity signal Sop has switched from ON to OFF. It is an operation | movement time chart in the case.

During the operation of the electric oil pump 2 in response to Sop = ON at the instant t2 to t3 in FIG. 7, the electric oil pump 2 is driven by a constant electric power with the voltage Ve equal to Ve = Ve_0 without correcting the voltage Ve of the pump driving electric power. If
If the electric oil pump 2 does not suck in air (the volumetric efficiency is not reduced), the pump rotation speed Nop is the speed specified by the broken line in FIG. 7, and the pump discharge flow rate Q is also broken in FIG. As shown, the target flow rate Q1 is as intended without any excess or deficiency in cooling the starting clutch.

Therefore, since the predetermined amount of oil necessary for cooling the clutch is directed from the electric oil pump 2 to the starting clutch, the starting clutch can be cooled as intended,
The starting clutch temperature TEMPcl can be made lower than the guaranteed temperature TEMPcl_s as shown by the broken line in FIG.

However, when the electric oil pump 2 sucks air due to a sudden increase in the target discharge flow rate and the volumetric efficiency is lowered, the electric oil pump 2 is lowered to the extent that the discharge flow rate Q is indicated by a solid line due to the decrease in volumetric efficiency. The target discharge flow rate Q1 cannot be realized.
At this time, the pump rotation speed Nop is increased as indicated by the solid line, but the increase in the pump rotation speed Nop is caused by a decrease in volumetric efficiency due to air suction, and causes an increase in the pump discharge flow rate Q. Not a thing.
For this reason, the start clutch falls under cooling, and the start clutch temperature TEMPcl exceeds the guaranteed temperature TEMPcl_s as shown by the solid line in FIG.

In the discharge flow rate control of the electric oil pump 2 according to the above-described embodiment, the above problem can be solved as follows.
FIG. 8 shows an operation time chart when the electric oil pump 2 sucks air under the same conditions as FIG.

The operation of the electric oil pump 2 in response to the oil pump operation necessity signal Sop = ON at the instant t2 to t3 is performed at a constant voltage Ve (constant power) indicated by a solid line in FIG.
In this embodiment, the target pump discharge flow rate calculated by the calculation unit 23 in FIG. 2 as the pump operating point has moved from A1 to A2 as described above with reference to FIG. 3 due to air suction (decrease in pump volumetric efficiency). A voltage Ve (= Ve_0 + ΔVe_0) higher than the initial required voltage Ve_0 by the voltage correction amount ΔVe_0 for realizing the target pump operating point A3 for compensation is set as the pump driving voltage.

That is, the electric oil pump 2 is driven by the voltage Ve (= Ve_0 + ΔVe_0) indicated by the solid line in FIG. 8 that is higher than the conventional pump drive voltage Ve_0 (drive power) indicated by the broken line in FIG. 8 by ΔVe_0.
As a result, the pump rotation speed Nop is increased from the conventional level indicated by the broken line in FIG. 8 to the target pump rotation speed tNop (see FIG. 3) indicated by the solid line by the voltage increase ΔVe_0 (power increase). Conventionally, the air level has been lowered to the broken line level (same as the solid line level in FIG. 7) due to air suction, but in this embodiment, it can be maintained at the solid line level (same as the broken line level in FIG. 7) Q1.

  For this reason, the starting clutch temperature TEMPcl can be lowered from the broken line level (same as indicated by the solid line in FIG. 7) to the solid line level (same as indicated by the broken line in FIG. 7) to be below the guaranteed temperature TEMPcl_s. The problem relating to insufficient cooling of the starting clutch when air is sucked, as described above with respect to 7, can be solved.

In order to achieve this effect, the driving power (driving voltage Ve) of the electric oil pump 2 is not always increased from the initial required voltage Ve_0 by the amount ΔVe_0 of the pump volume efficiency reduction due to air suction or the like. Only when the volumetric efficiency is lowered, the drive voltage Ve (pump drive power) of the electric oil pump 2 is raised by the pump volumetric efficiency drop ΔVe_0.
If the pump volumetric efficiency is not reduced due to air suction, etc., the pump discharge flow rate is too high, and the electric oil pump 2 does not consume power unnecessarily. Absent.

  Furthermore, the strength of the electric pump does not increase as in the case of adopting measures to constantly increase the drive voltage Ve (pump drive power) of the electric oil pump 2, and the pump sliding resistance due to the high strength of the electric pump. This increases the pump drive power and does not cause a cost penalty.

  Further, the pump discharge flow rate control of the present embodiment is a pump discharge flow rate control when the electric oil pump 2 is an electric pump driven by a DC motor using a constant power as an energy source, so that the electric oil pump is driven. An inverter is not required for control, and the cost can be reduced accordingly.

  In addition, in the present embodiment, the power increase correction for increasing the pump drive voltage Ve by the voltage correction amount ΔVe_0 from the initial required voltage Ve_0, the oil pump operation necessity signal Sop is Sop = ON (operation of the electric oil pump 2 Therefore, it is possible to avoid the foolishness that the power increase correction is performed in vain.

Then, when determining the target pump rotation speed tNop necessary for determining the voltage correction amount ΔVe_0 to achieve the target pump discharge flow rate under the drive with the constant power (target operating point calculation unit 21),
The target operating point (A3 in the case of Fig. 3) of the electric oil pump 2 that achieves the target pump discharge flow rate is calculated from the oil temperature TEMPoil and the uncorrected supply power Pw_0, and from this pump target operating point, as described above with reference to Fig. 3 To find the target pump speed tNop,
The voltage correction amount ΔVe_0 is determined according to the parameters related to the decrease in volumetric efficiency due to air suction, etc., and this voltage correction amount ΔVe_0 can accurately compensate for the decrease in pump discharge flow rate due to the decrease in volumetric efficiency. As a result, the above-described effects can be made more remarkable.

As described above, when the pump drive power correction unit 40 in FIG. 1 corrects the voltage of the pump drive power Pw_1 by the voltage correction amount ΔVe, the target obtained from the target operating point of the electric oil pump 2 (A3 in FIG. 3). Even when correcting the constant power for driving the pump until the target pump driving torque Top_1 corresponding to the pump discharge flow rate is realized,
The voltage correction amount ΔVe_0 accurately compensates for a decrease in pump discharge flow rate due to a decrease in volumetric efficiency without excess or deficiency, so that the above effect can be made remarkable.

<Other examples>
In the above embodiment, the electric oil pump 2 is described as being for cooling the starting clutch in the transmission 1, but the electric oil pump 2 is for cooling other clutches in the transmission 1. It may be for cooling an arbitrary object, not limited to a transmission.
Moreover, the electric pump which is the target of the discharge flow rate control is not limited to the electric oil pump, and may discharge liquid other than oil.

1 Transmission
2 Electric oil pump (electric pump)
10 Oil pump operation necessity judgment part
20 Voltage correction amount determination
21 Target operating point calculator (Target pump rotation speed calculation means)
22 Subtractor (pump rotation speed deviation calculation means)
23 Voltage correction amount calculation unit (pump drive power correction means)
24 Voltage correction amount selector
30 Pump rotation speed sensor (Pump rotation speed information detection means)
40 Pump drive power correction unit

Claims (4)

An electric pump that is driven by a DC motor that responds to a constant power and realizes a target discharge flow rate, the target pump drive torque corresponding to the target discharge flow rate, and the target pump drive torque based on the constant power In the electric pump that realizes the target discharge flow rate by controlling the driving of the DC motor to realize the pump rotation speed that can be obtained ,
In order to compensate the target discharge flow rate based on the target pump drive torque when the target discharge flow rate becomes unrealizable due to a change in pump drive torque and a change in pump rotation speed while the pump is driven by the DC motor at the constant power. Target pump rotation speed calculating means for calculating the target pump rotation speed of the electric pump;
Pump rotation speed information detecting means for detecting pump rotation speed information related to the actual pump rotation speed of the electric pump;
Based on signals from these means, pump rotation speed deviation calculating means for calculating a pump rotation speed deviation of the actual pump rotation speed with respect to the target pump rotation speed;
The constant power based on the pump rotational speed deviation computed by said means, a pump driving power correcting means for actual pump rotational speed is corrected so that toward the target pump rotational speed together with the pump driving torque is restored to the target pump driving torque And a discharge flow rate control device for an electric pump. The discharge flow control device of the electric pump according to claim 1, wherein the discharge liquid of the electric pump is used for cooling.
The pump drive power correction means determines whether or not the electric pump needs to be operated based on the actual temperature and / or temperature change requirements of the object to be cooled, and corrects the constant power when the electric pump does not need to be operated. A discharge flow rate control device for an electric pump, which is prohibited. In the discharge flow control device of the electric pump according to claim 1 or 2,
The target pump rotation speed calculation means obtains an electric pump target operating point for realizing a target pump discharge flow rate from the pump driving power before the correction is performed and the temperature of the liquid supplied by the electric pump, A discharge flow rate control device for an electric pump, characterized in that the target pump rotation speed is obtained from the electric pump target operating point. In the discharge flow rate control device of the electric pump according to claim 3,
The pump drive power correcting means corrects the constant power until a target pump drive torque corresponding to a target pump discharge flow rate obtained from the electric pump target operating point is realized. Pump discharge flow control device.

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