JPH0599163A - Oil pressure control device for variable capacity vane pump - Google Patents

Abstract

PURPOSE:To provide an oil pressure control device for an electric control variable capacity vane pump which improves control stability at a high gain. CONSTITUTION:An oil pressure control device for a variable capacity vane pump comprises a variable capacity vane pump to generate a delivery flow rate responding to a control oil pressure and feed it to an oil pressure circuit, an oil pressure sensor to detect a delivery oil pressure, a computing means to compute a control amount through which a deviation between a target oil pressure and a delivery oil pressure is reduced to zero, and an electromagnetic control valve to control a control oil pressure according to the computed result of the computing means. A resistance varying means to vary circuit resistance of the oil pressure circuit is provided. When the variable capacity vane pump is operated at a given gain, the resistance varying means forms an object to be controlled instead of the electromagnetic valve. Preferably, the given gain is a gain equivalent to that when a ratio of a change in a delivery oil pressure to the change in a control amount of the variable capacity vane pump exceeds a given ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control device for a variable displacement vane pump mounted on an automatic transmission of a vehicle, and more particularly,
The present invention relates to a hydraulic control device for an electronically controlled variable displacement vane pump.

[0002]

2. Description of the Related Art As a hydraulic control apparatus of a conventional variable capacity vane pump, for example as described in the real Hei 3-8687 discloses detects the discharge pressure P _O of the vane pump in a hydraulic sensor, and the detected value A so-called electronic control (hereinafter abbreviated as electronic control) that electrically controls the control hydraulic pressure P _C by calculating a control amount such that the deviation from the target value (target hydraulic pressure P _M ) is always zero. Variable displacement vane pumps are known.

[0003]

However, the "electrically controlled" variable displacement vane pump has the characteristic as shown in FIG. 7, that is, the characteristic that the discharge hydraulic pressure greatly changes with a slight change in the control amount as the rotation speed increases (gain characteristic). There is also
Similarly, the smaller the load consumption flow rate, the larger the discharge hydraulic pressure changes even with a slight change in the control amount, and there is a problem to be solved especially in terms of control stability at high gain.

Therefore, when the pump discharge control is performed in a state where the pump rotational speed is high, the discharge hydraulic pressure greatly changes in accordance with the change in the control amount, which makes it difficult to match the discharge hydraulic pressure with the target hydraulic pressure. There are challenges. Therefore, an object of the present invention is to provide a hydraulic control device for an "electrically controlled" variable displacement vane pump, which has improved control stability at high gain.

[0005]

The hydraulic control system for a variable displacement vane pump according to the present invention has a variable capacity for generating a discharge flow rate according to a control hydraulic pressure and supplying it to a hydraulic circuit as shown in the principle diagram of FIG. A vane pump, a hydraulic pressure sensor that detects the discharge hydraulic pressure, a calculation unit that calculates a control amount that makes the deviation between the target hydraulic pressure and the discharge hydraulic pressure zero, and an electromagnetic control valve that operates the control hydraulic pressure according to the calculation result of the calculation unit. When,
In a hydraulic control device for a variable displacement vane pump, the variable resistance vane pump is provided with variable resistance means for varying the circuit resistance of the hydraulic circuit, and when the variable displacement vane pump operates at a predetermined gain, the variable resistance vane pump replaces the electromagnetic control valve. Preferably, the predetermined gain is a gain corresponding to a case where the rate of change of the discharge hydraulic pressure with respect to the change of the control amount of the variable displacement vane pump is larger than a predetermined rate. More preferably, the resistance varying means varies the flow path resistance of the lubricating oil system of the hydraulic circuit.

[0006]

In the present invention, when the vane pump operates with a predetermined gain (preferably high gain), the flow path resistance of the hydraulic circuit (preferably the lubricating oil system) is variably controlled. For example, when the pump discharge pressure control is performed in a state where the pump rotation speed is high, the discharge hydraulic pressure changes significantly (high gain) with a change in the control amount, and the discharge hydraulic pressure changes with respect to the target hydraulic control operation amount change ( In this case, it becomes difficult to adjust the proper hydraulic pressure required for the shift operation. That is, although the controllability deteriorates, in such a case, by using the "flow path resistance control", the merit (responsiveness) can be utilized to bring the pressure close to the target hydraulic pressure quickly.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 2 to 6 are views showing an embodiment of the hydraulic control device for the "electrically controlled" variable displacement vane pump according to the present invention. In FIG. 2, reference numeral 20 denotes a variable displacement vane pump. The variable displacement vane pump 20 adjusts the amount of eccentricity between the cam ring and the rotor by the movement of the control piston 20a, and has a size according to the amount of eccentricity, the number of revolutions and the discharge flow rate. Discharge hydraulic pressure P _O (corresponding to the line pressure) is generated.
The control piston 20a moves so that the magnitude of the control hydraulic pressure P _C and the urging force of the spring 20b are always balanced, and the control hydraulic pressure P _C regulates the discharge hydraulic pressure P _O by the first solenoid valve (electromagnetic control valve) 21. Given. First solenoid valve 21
Changes its on / off duty according to a predetermined control signal S _P (in the case of a duty valve) or changes the current value proportionally (in the case of a pressure control proportional valve,
Hereinafter, the proportional valve) and the control oil pressure P _C are regulated.

Reference numeral 22 is an engine for rotationally driving the variable displacement pump 20, and the rotational speed N _P of the engine 22 (that is, the rotational speed of the variable displacement vane pump 20) is detected by the rotational speed detecting means 23. Reference numeral 24 denotes a hydraulic pressure sensor that detects the discharge hydraulic pressure P _O , and the hydraulic pressure sensor 24 outputs a hydraulic pressure signal P _L that indicates the magnitude of the discharge hydraulic pressure P _O. 25 is the second
The second solenoid valve 25 is inserted into an oil passage 26 that connects the discharge port 20c of the variable displacement vane pump 20 and a lubricating system (not shown) (for lubricating each part of the automatic transmission). .. The second solenoid valve 25 changes its on / off duty (in the case of a duty valve) or changes its current value proportionally (in the case of a proportional valve) according to a predetermined control signal S _F , and the oil passage 26 Is controlled to control the flow rate of the lubricating oil flowing from the discharge port 20c of the variable displacement vane pump 20 to the lubricating system (not shown).
That is, the second solenoid valve 25 functions as a resistance varying unit that varies the flow path resistance of the lubricating system according to the control signal S _F.

Reference numeral 27 is an orifice, 28 is a controller, and the controller (calculation means) 28 is an optimum gear ratio according to the traveling state when the present invention is applied to, for example, an automatic transmission (hereinafter referred to as A / T). Is determined, and "gear shift control" for achieving the gear ratio is executed, and the discharge hydraulic pressure P
“Eccentricity amount control” and “flow path resistance control” for controlling the discharge hydraulic pressure P _O of the variable displacement vane pump 20 are executed based on the deviation between the _O and the target hydraulic pressure P _M , the engine speed N _{P, and the} like.

The "eccentricity amount control" and the "flow passage resistance control" are both controls for eliminating the deviation between the discharge hydraulic pressure P _O and the target hydraulic pressure P _M , but the former is the control hydraulic pressure P _C. While the control signal S _P for operating is generated, the latter is the amount of lubricating oil flowing through the oil passage 26 (for example, when applied to A / T).
The difference is that a control signal S _F for operating is generated.
That is, in the eccentricity control, the eccentricity of the variable displacement vane pump 20 (more precisely, the stroke amount of the control piston 20a) is controlled, but in the flow path resistance control, the lubricating oil flow rate is controlled.

FIG. 3 is a main part flowchart of a processing program executed by the controller 28, which is a program including "eccentricity amount control" and "flow path resistance control". This program consists of a decision block B ₁ and a control block B ₂ , and the decision block B ₁ performs "eccentricity control based on the engine speed N _P and the deviation ε between the discharge hydraulic pressure P _O and the target hydraulic pressure P _M. "And" flow path resistance control "are individually executed or simultaneously executed, and the control block B ₂ executes one of the three controls (control A, control B, control C) according to the judgment result. Run.

Here, the determination condition of the embodiment is that the engine
Number of rotations N_PIs a low standard speed N_LOWGreater than or equal to (No.
Judgment condition of 1: step 30), engine speed N_P
Is a high standard speed N_HiIs less than (the second judgment article
Case: Step 31), the absolute value of the deviation ε (| ε |) is low
Deviation reference value ε₁Is larger than (the third judgment
Condition: Step 32), the absolute value of deviation ε (| ε |) is high.
Deviation reference value for rotation ε ₂Is smaller than (the fourth judgment
There are four fixed conditions: step 33).

When the first determination condition 30 is NO and the third determination condition 32 is YES, the control A is executed, the first determination condition 30 is YES, the second determination condition 31 is NO, and the fourth determination condition is NO. If the determination condition 33 of is YES, the control C
If both the first determination condition 30 and the second determination condition 31 are YES, or if the first determination condition 30 and the third determination condition 32 are both NO, or When the determination condition 30 is YES and the second determination condition 31 and the fourth determination condition 33 are both NO, the control B is executed.

That is, is the rotation speed N of the vane pump.
This is a case where _P is in a predetermined low rotation range equal to or lower than N _LOW and the vane pump is operating at “low gain”. In this case, the deviation between the target hydraulic pressure P _M and the discharge hydraulic pressure P _O (more accurately, When the absolute value | ε |) of the deviation ε is equal to or larger than the predetermined value (ε ₁ ), the “eccentricity amount control” and the “flow path resistance control” are used together.
Is when the rotation speed (N _P ) of the vane pump is in a predetermined high rotation range of N _Hi or more and the vane pump is operating at “high gain”. In this case, the target hydraulic pressure P _M and the discharge hydraulic pressure are Deviation from P _O (more precisely, absolute value of deviation ε | ε |)
When is less than or equal to the predetermined value (ε ₂ ), the “flow path resistance control” is independently executed (in other words, the “eccentricity amount control” is stopped).
Is when the rotation speed (N _P ) of the vane pump is in the middle rotation range of N _LOW or more and N _Hi or less, and the vane pump is operating at “medium gain”. In this case, “ "Eccentricity control" is executed independently. If the absolute value of deviation | ε | is less than or equal to ε ₁ even if the vane pump is operating at “low gain” below N _LOW , or if the vane pump is operating at “high gain” above N _Hi. If the absolute value of the deviation | ε | is not less than ε ₂ , the "eccentricity amount control" is independently executed.

Considering the case where the pump discharge pressure control is performed at a high pump rotation speed, in this case, in particular, when the deviation between the target oil pressure P _M and the discharge oil pressure P _O is small, the electric vane pump is used. However, since the discharge hydraulic pressure changes greatly with the change in the control amount, it becomes difficult to match the discharge hydraulic pressure with the target hydraulic pressure, and the control accuracy deteriorates. In view of this, in the present embodiment, when the gain of the vane pump is high, the flow path resistance control is performed instead of the eccentricity control to solve the above-mentioned inconvenience and improve the control accuracy.

That is, when the deviation is large in the low speed range (), since the gain is low, the response is emphasized and the "eccentricity amount control" and the "flow path resistance control" are used together, while the high speed range is high. When the deviation is small in (), since the gain is high, the "flow path resistance control" is executed solely with an emphasis on stability. However, if the deviation is small even at low gain in the low speed range, the responsiveness does not deteriorate so much, so "eccentricity control" is executed independently. If it is larger, execute "Eccentricity control" to reduce the deviation by ε.
After suppressing to ₂ or less, shift to independent execution of "flow path resistance control". Alternatively, when the medium gain is in the medium speed range, the "eccentricity amount control" is independently executed regardless of the magnitude of the deviation.

The principle of "flow path resistance control" can be explained, for example, by the thickness of the hose connected to the tap of the water supply. That is, the tap of the water supply corresponds to the discharge port of the vane pump 20, and the thickness of the hose corresponds to the opening degree of the second solenoid valve 25. Connecting a thin hose increases the water pressure at the faucet (equivalent to the discharge hydraulic pressure), and connecting a thick hose decreases it. Such a change in water pressure (change in discharge hydraulic pressure) depends on a change in the inner diameter of the hose if the water supply pressure (correlation with the internal pressure of the vane pump 20, the number of revolutions and the eccentricity) of the water supply is constant, There is no time lag between the change in inner diameter and the change in water pressure. Therefore, by using the "flow path resistance control" and the "eccentricity amount control" together, it is possible to improve the responsiveness of the vane pump in the low rotation range.

Further, when the water supply pressure of the water supply is considerably high, that is, when the pump rotation speed is considerably high, the water pressure changes greatly even if the faucet is slightly opened and closed (the pump gain is high). Becomes extremely difficult. In such a case, it is effective to change the thickness of the hose while keeping the opening of the faucet constant.
Therefore, according to the present embodiment, as described in relation to the water supply and the hose, the eccentricity amount control (corresponding to the operation of the water supply pressure) for operating the movement itself of the vane pump 20,
The flow path resistance control (corresponding to the inner diameter operation of the hose) that controls the discharge flow rate without being involved in the movement of the vane pump 20 is appropriately selected according to the gain determined from the rotational speed N _{P of the} pump and the like. Therefore, it is possible to achieve an excellent effect that it is possible to improve the response in the low rotation speed range and the stability in the high rotation speed range.

In the embodiment, the responsiveness in the low speed range and the stability in the high speed range are both improved, but the present invention is not limited to this. For example, in a sports car with a high normal speed range. Alternatively, a control mode (mainly executing eccentricity amount control and flow path resistance control) may be performed with a focus on improving stability. Further, in the embodiment, the gain determination is performed based on the pump rotation speed N _P , but the present invention is not limited to this. For example, the discharge hydraulic pressure P and the discharge flow rate Q are read, and the flow rate is determined based on these P and Q. The road resistance R may be calculated (R = P / Q), and the first determination condition 30 and the second determination condition 31 may be set as follows.

First determination condition 30 → It is determined whether or not the value of the flow path resistance R is greater than or equal to the reference flow path resistance value R ₁ . Second determination condition 31 → It is determined whether or not the value of the flow path resistance R is greater than or equal to the reference flow path resistance value R ₂ . According to this condition setting, a high gain is determined when R ≧ R ₁ and R ≦ R ₂ are not satisfied, a low gain is determined when R ≧ R ₁ is not satisfied, and further, R ≧ R ₁ and R ≦ R ₂ are determined. In the case of, the medium gain is determined.

Here, in the eccentricity control, the pressure operation amount ΔQ _P of the control oil pressure P _C is calculated according to the functional expression shown in the following expression (1), and the control signal S _P having a magnitude corresponding to the calculation result is generated. To do. ΔQ _P = f (ε) (1) Further, in the flow path resistance control, the flow rate operation amount ΔQ _F of the hydraulic oil is calculated according to the functional expression shown in the following expression (2), and the magnitude according to the calculation result is calculated. Control signal S _F is generated.

ΔQ _F = f (ε) (2) In any case, the manipulated variable ΔQ _P or ΔQ _F that can direct the discharge hydraulic pressure P _O at that time to the target hydraulic pressure P _M can be obtained. FIG. 4 shows an example in which ΔQ _P and ΔQ _F are obtained from a map. That is, in step 40, the pump rotation speed N _P is read, the deviation ε between the discharge oil pressure P _O and the target oil pressure P _M is obtained, and in step 41 a predetermined map is searched by N _P and ε.

FIG. 5 is an example of a map, in which three zones A1, A2 and A3 are set in a two-dimensional map in which the vertical axis is ε and the horizontal axis is N _P. When N _P and ε exist in the zone A1, a value obtained by multiplying ε by k is substituted for ΔQ _P in step 42, and a value obtained by multiplying ε by m is substituted for ΔQ _F at step 43. That is, in this case, both the eccentricity amount control and the flow path resistance control are executed. If N _P and ε exist in zone A2, ΔQ _{P is set} to ε in step 44.
The value multiplied by k is substituted, and ΔQ _F
Substitute 0 for. That is, in this case, only the eccentricity amount control is executed. Furthermore, when N _P and ε exist in the zone A3, 0 is substituted for ΔQ _P in step 46, and a value obtained by multiplying ε by n is substituted for ΔQ _F in step 47. That is, in this case, only the flow path resistance control is executed.

The shape of the map and the sizes of the coefficients k, m and n can be changed.
The control characteristics can be freely changed by simply changing the setting. Cause
FIG. 6 is a diagram showing another example of the map, and FIG.
Is N _P6 (b) shows an example in which the zone is divided by
This is an example of separate parts.

[0025]

According to the present invention, the resistance varying means for varying the flow path resistance of the hydraulic circuit is provided, and when the variable displacement vane pump operates at a predetermined gain, the resistance varying means is the control target. It is possible to provide a hydraulic control device for an "electrically controlled" variable displacement vane pump with improved control stability in gain.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of an embodiment.

FIG. 3 is a control flow diagram of an embodiment.

FIG. 4 is a pressure operation amount ΔQ _P and a flow rate operation amount Δ of one embodiment.
It is a calculation flow diagram for obtaining the Q _F from the map.

FIG. 5 is a map diagram of an example.

FIG. 6 is another map diagram of an example.

FIG. 7 is a discharge flow rate-discharge pressure characteristic diagram of an electrically controlled variable displacement vane pump.

[Explanation of symbols]

P _C : Control oil pressure P _O : Discharge oil pressure 20: Variable capacity vane pump 28: Controller (calculation means) 21: First solenoid valve (solenoid control valve) 24: Oil pressure sensor 25: Second solenoid valve (resistance variable means)

Claims (3)

[Claims] 1. A variable displacement vane pump that generates a discharge flow rate according to a control hydraulic pressure and supplies it to a hydraulic circuit, a hydraulic pressure sensor that detects the discharge hydraulic pressure, and a control amount that makes a deviation between a target hydraulic pressure and the discharge hydraulic pressure zero. In a hydraulic control device for a variable displacement vane pump, comprising: an arithmetic means for performing an arithmetic operation; and an electromagnetic control valve for operating the control hydraulic pressure according to the arithmetic result of the arithmetic means, a variable resistance for varying a flow path resistance of the hydraulic circuit. Means for controlling the variable displacement vane pump in place of the electromagnetic control valve when the variable displacement vane pump operates at a predetermined gain. 2. The variable gain according to claim 1, wherein the predetermined gain is a gain corresponding to a case where the ratio of change in the discharge hydraulic pressure to the change in the control amount of the variable displacement vane pump is larger than a predetermined ratio. Hydraulic controller for capacity vane pump. 3. The hydraulic control device for a variable displacement vane pump according to claim 1, wherein the resistance varying means varies the flow path resistance of the lubricating oil system of the hydraulic circuit.