JP4028496B2 - Idle stop control device - Google Patents

Description

  The present invention relates to an idle stop control device that idles an engine when a running vehicle stops.

  Conventionally, as an idle stop control device, an idle stop with an electric oil pump provided with a special device such as an electric sub oil pump as a means of securing hydraulic pressure such as a forward clutch pressure and a pulley pressure of an automatic transmission when the idle stop is released. Control devices were common. However, such an idle stop control device has problems such as an increase in weight and cost and an increase in power consumption. For this reason, recently, there has been proposed an electric oil pump-less idle stop control device that performs hydraulic control using a main pump as a hydraulic pressure supply source without providing a special device (see, for example, Patent Document 1).

JP 2002-257220 A

  By the way, in a system having a V-belt type continuously variable transmission, for example, a V-belt is stretched between a primary pulley connected to the engine side and a secondary pulley connected to the axle side, and the groove width of the primary pulley is hydraulically set. In order to variably control, there are the following configurations.

  That is, for example, as shown in FIG. 2, the primary pulley 1 is supplied with hydraulic pressure to a fixed pulley 1a that rotates integrally with an output shaft (not shown) of a torque converter (not shown) and a cylinder chamber 1b that faces the fixed pulley 1a. Thus, a V-shaped pulley groove is formed with the movable pulley 1c that can be displaced in the axial direction. The secondary pulley 2 is urged in a direction to reduce the width of the pulley groove by a return spring 2b facing the fixed pulley 2a that rotates integrally with an output shaft (not shown) toward the axle, and on the back surface. A V-shaped pulley groove is formed by a movable pulley 2d which is supplied with hydraulic pressure to the cylinder chamber 2c and can be displaced in the axial direction. A transmission mechanism (V-belt type continuously variable transmission) 4 is configured by passing the V-belt 3 over the pulley grooves of the pulleys 1 and 2. Further, the line pressure PL is controlled by the shift control valve 6 sliding in the case 6 a, and the controlled hydraulic pressure is supplied to the cylinder chamber 1 b of the primary pulley 1 through the oil passage 5.

  When controlling the hydraulic pressure supplied to the cylinder chamber 1b of the primary pulley 1, the displacement of the movable pulley 1c of the primary pulley 1 due to the movement of the step motor 7 to the HI side or the LOW side is fed back. Therefore, the step motor 7 here is connected to the tip of the spool 6b slidably housed in the case 6a of the speed change control valve 6 and the feedback member 1d that moves together with the movable pulley 1c of the primary pulley 1. A shift link 8 is provided. A spring 6c is interposed between the case 6a and the rear end of the spool 6b.

  When the step motor 7 having such a configuration is driven to move the step position, the speed change link 8 is displaced, and the spool 6b slides in the case 6a in accordance with the displacement, so that the line pressure supplied to the speed change control valve 6 is increased. PL is regulated and the hydraulic pressure is supplied to the cylinder chamber 1 b of the primary pulley 1 through the oil passage 5. On the other hand, the line pressure PL is supplied to the cylinder chamber 2c of the secondary pulley 2, and the clamping pressure with respect to the V belt 3 is controlled. Accordingly, when the driving force is transmitted according to the contact friction force between the V belt 3 and each of the pulleys 1 and 2, the movable pulley 1c is displaced according to the control of the hydraulic pressure supplied to the cylinder chamber 1b of the primary pulley 1. Thus, the groove width of the primary pulley 1 is variably controlled to obtain a predetermined gear ratio.

  In the system configured as described above, when the step position of the step motor 7 is moved to the HI side as indicated by an arrow in FIG. 2, the hydraulic pressure supplied to the cylinder 1 b chamber of the primary pulley 1 increases, and the primary pulley 1 The groove width becomes smaller. In this case, the V belt 3 has a larger contact radius on the primary pulley 1 side and a smaller contact radius on the secondary pulley 2 side, so that the gear ratio of the transmission mechanism unit 4 is directed toward the HI side (high speed stage side). On the other hand, when the step position of the step motor 7 is moved to the LOW side as indicated by the arrow in FIG. 2, the hydraulic pressure supplied into the cylinder chamber 1b of the primary pulley 1 decreases, and the groove width of the primary pulley 1 increases. . In this case, since the V belt 3 has a smaller contact radius on the primary pulley 1 side and a larger contact radius on the secondary pulley 2 side, the gear ratio of the transmission mechanism unit 4 is directed to the LOW side (low speed stage side).

  When the system is normal, as shown in FIG. 3A, the hydraulic pressure is supplied from the line pressure PL to the primary pulley 1 (not shown here) via the oil passage 5 as indicated by an arrow α in the figure. Thus, the lowest LOW position of the step motor 7 (not shown here) corresponds to the lowest LOW position of the movable pulley 1c of the primary pulley 1. Further, in this system, when the vehicle stops suddenly, the step position of the step motor 7 is rapidly moved to the maximum LOW position, and the hydraulic oil supplied to the cylinder 1b chamber of the primary pulley 1 is drained so that the speed change ratio of the speed change mechanism 4 is as fast as possible. It tries to become the lowest LOW.

  However, when the conventional electric oil pumpless idle stop control device is applied to the above-described system having the V-belt continuously variable transmission, the shift mechanism 4 (not shown here) has finished shifting to the lowest LOW. If the vehicle stops before the operation, the position of the movable pulley 1c of the primary pulley 1 deviates from the lowest position as illustrated in FIG. 3B, but the spool 6b of the speed change control valve 6 is in the cylinder chamber 1b of the primary pulley 1. The hydraulic pressure supplied to is maintained at the drain position. For this reason, the hydraulic pressure supplied to the cylinder chamber 1b of the primary pulley 1 remains the drain as shown by the arrow β in FIG.

  When the idle stop is permitted in such a state, as illustrated in FIG. 3C, the step position of the step motor 7 is moved to the HI side, and as shown by the arrow γ in FIG. Even if the pressure PL is supplied to the oil passage 5, when the engine is restarted after the idle stop is released, the hydraulic pressure of the primary pulley 1 remains at zero, or the rise of the oil is delayed or the rise is delayed. In such a situation, since the hydraulic pressure applied to the primary pulley 1 at the time of starting is low, there is a problem that the V-belt 3 slides on the pulley groove.

SUMMARY OF THE INVENTION An object of the present invention is to provide an idle stop control device that advantageously solves the above problems. The idle stop control device of the present invention is connected to a primary pulley connected to a prime mover side and an axle side. Used in a vehicle having a belt-type continuously variable transmission that hangs a belt between a secondary pulley and hydraulically controls a groove width of the primary pulley with a main pump as a hydraulic supply source, and when the vehicle is stopped In an idle stop control device that idles a prime mover, a detecting means for detecting a hydraulic pressure for controlling a groove width of the primary pulley, and determining whether or not the hydraulic pressure is less than a preset required pressure, the hydraulic pressure is Idle stop prohibiting means for prohibiting idle stop of the prime mover when it is determined that the required pressure is not reached. It is characterized in that to obtain.

  According to the idle stop control device of the present invention, the detecting means detects the hydraulic pressure that controls the groove width of the primary pulley, and the idle stop prohibiting means determines whether the hydraulic pressure detected by the detecting means is less than a preset required pressure. As a result, when it is determined that the required pressure is not reached, idle stop of the prime mover is prohibited. Accordingly, even when the gear ratio of the belt type continuously variable transmission does not return to the lowest level when the vehicle is stopped, idle stop is prohibited when the hydraulic pressure is less than the required pressure. Insufficient hydraulic pressure for controlling the groove width can be avoided. From this, it is possible to prevent the belt stretched around the pulley from slipping on the pulley groove due to the lack of necessary pressure.

  Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings. FIG. 1 is a flowchart showing a processing procedure of idle stop permission / inhibition control executed by an idle stop control device according to an embodiment of the idle stop control device of the present invention. FIG. 2 is a schematic diagram showing a hydraulic circuit around a primary pulley that is an object of idle stop permission / prohibition control by the idle stop control device of the present embodiment.

  The idle stop control device of the present embodiment spans a V-belt 3 between a primary pulley 1 connected to an engine (primary motor) side (not shown) and a secondary pulley 2 connected to an axle side (not shown). This is used in a vehicle (not shown) having a speed change mechanism (V-belt type continuously variable transmission) 4 that variably controls the groove width of the motor.

The idle stop control device includes a pulley pressure sensor (not shown) as detection means and idle stop prohibiting means. The pulley pressure sensor here detects the hydraulic pressure (hereinafter referred to as primary pulley pressure P _PRI ) of the cylinder chamber 1b that controls the groove width of the primary pulley 1. The idle stop prohibiting means here determines whether or not the primary pulley pressure P _PRI detected by the pulley pressure sensor is less than a preset required pressure, and the primary pulley pressure P _PRI is determined as the primary pulley required pressure P _PRI. When it is judged that _NEED is not met, engine idle stop is prohibited. Here, a controller (not shown) provided in the vehicle functions as idle stop prohibiting means.

The schematic diagram shown in FIG. 2 of the hydraulic circuit around the primary pulley 1 in the present embodiment has already been outlined in [Problems to be Solved by the Invention], and therefore, redundant description is omitted here. In the example, an oil passage 9 that connects the cylinder chamber 1b of the primary pulley 1 and the pulley pressure sensor is provided so that the pulley pressure sensor (not shown) can detect the primary pulley pressure _PPRI .

In this idle stop control device, a controller (not shown) provided in the vehicle performs the process of the idle stop permission / inhibition control flowchart shown in FIG. For this reason, the controller includes an energization / non-energization signal from an idle stop switch (not shown), a vehicle speed signal from a vehicle speed sensor (not shown), and an ON / OFF from a brake switch (not shown). A signal, a steering angle signal from a steering angle sensor, a selection range signal from a range sensor (not shown), a primary pulley pressure P _PRI signal from a pulley pressure sensor (not shown), and a pulley sensor (not shown). ) From the movable pulley position (groove width of the primary pulley 1) signal.

  Next, the processing procedure of the flowchart of the idle stop permission / inhibition control shown in FIG. 1 will be described. In this flowchart, first, in step S1, it is determined whether or not the vehicle satisfies an idle stop permission condition. In this step S1, the idle stop switch is energized, the vehicle speed is 0, and the brake switch is turned on in order to determine whether or not the idle stop condition is satisfied, similar to the idle stop condition described in the above prior art document. , Whether the steering angle is 0, a range other than the R range is selected, or if the D range is selected, it is determined whether the temperature is within a predetermined temperature range. As a result, if it is determined that all these conditions are satisfied, the process proceeds to step S2. On the other hand, if it is determined that even one of these conditions is not satisfied, the idle stop permission / prohibition control is not performed, and the processing of this flowchart is terminated.

  In step S2, it is determined whether or not the pulley ratio (speed ratio of the speed change mechanism unit 4) is the lowest (speed ratio of the lowest speed). As a result, when it is determined that the pulley ratio is at the lowest level, the process proceeds to step S3, the idle stop is permitted, and the process of this flowchart is terminated. Thereby, the idle stop control device performs idle stop of the engine in a state where the pulley ratio is at the lowest level. On the other hand, if it is determined in step S2 that the pulley ratio is not the lowest, the process proceeds to step S4.

In step S4, it is determined whether or not the primary pulley pressure P _PRI is greater than the preset primary pulley required pressure P _NEED (P _PRI > P _NEED ). As a result, when it is determined that the primary pulley pressure P _PRI is larger than the primary pulley required pressure P _NEED , the process proceeds to the above-described step S3, and idle stop is permitted. On the other hand, if it is determined in step S4 that the primary pulley pressure P _PRI is not larger than the primary pulley required pressure P _NEED , the process proceeds to step S5, and idle stop is prohibited.

And it progresses to step S6 which continues from step S5, and moves the step position of the step motor 7 a little. That is, here, the step position of the current step motor 7 is slightly moved to the HI side so that the gear ratio of the transmission mechanism unit 4 is directed to the HI side (high speed stage side) (see FIG. 2). By this movement of the step motor 7, the spool 6b of the shift control valve 6 is also moved to the HI side (upper side in FIG. 2). As a result, the hydraulic pressure supplied to the cylinder chamber 1b of the primary pulley 1 increases and the primary pulley pressure P _PRI increases. When the process of step S6 is completed, the process returns to the previous step S4, and it is determined again whether the primary pulley pressure P _PRI is larger than the primary pulley required pressure P _NEED .

In this manner, the processes of step S4, step S5, and step S6 are sequentially repeated until it is determined in step S4 that the primary pulley pressure P _PRI is greater than the primary pulley required pressure P _NEED . In such a process, while the idle stop is prohibited, the step position of the step motor 7 is gradually increased so that the gear ratio of the transmission mechanism unit 4 is directed to the HI side until the primary pulley pressure P _PRI reaches the primary pulley required pressure P _NEED. Moved. When the primary pulley pressure P _PRI reaches the primary pulley necessary pressure P _NEED, it is determined in step S4 that the primary pulley pressure P _PRI is larger than the primary pulley necessary pressure P _NEED, and the process proceeds to the above step S3 to allow idle stop. .

According to the idle stop control device of the present embodiment having the above-described configuration, the pulley pressure sensor (detecting means) detects the primary pulley pressure P _PRI that controls the groove width of the primary pulley 1. Further, the controller (idle stop prohibiting means) determines whether or not the primary pulley pressure P _PRI detected by the pulley pressure sensor is less than the preset primary pulley required pressure P _NEED (step S4 in FIG. 1). As a result, when it is determined that the required pressure P _NEED is not _reached , engine idle stop is prohibited (step S5 in FIG. 1).

Accordingly, even when the gear ratio of the speed change mechanism unit 4 does not return to the lowest level when the vehicle is stopped, idle stop is prohibited when the primary pulley pressure P _PRI does not reach the required pressure P _NEED. The shortage of the required hydraulic pressure for controlling the groove width of the primary pulley 1 can be avoided. From this, it is possible to prevent the belt 3 stretched around the pulley from slipping due to the lack of necessary pressure.

Moreover, the speed change mechanism 4 in the idle stop control device of the present embodiment is variably controlled by the primary pulley pressure P _{PRI in which} the groove width of the primary pulley 1 is regulated via the speed change control valve 6 driven by the step motor 7. It is what is done. Then, the controller (idle stop prohibiting means) is configured to step the motor so that the gear ratio of the speed change mechanism unit 4 is directed toward the high speed stage until the primary pulley pressure P _PRI reaches the primary required pressure P _NEED while the idle stop is prohibited. 7 is moved little by little, and when the primary pulley pressure P _PRI reaches the primary required pressure P _NEED , the idle stop prohibition is canceled and the idle stop is permitted (steps S3, S4, S5 in FIG. 1). Step S6).

Therefore, according to the idle stop control device of the present embodiment, even if the idle stop is prohibited in step S5 in FIG. 1, the primary pulley pressure P _PRI is increased during the prohibition to increase the primary pulley pressure P _PRI to the required pressure P. _NEED can be reached, and as soon as the required pressure is reached, it is possible to lead to the permission of idling stop, and the above effect can be obtained more reliably.

  As mentioned above, although demonstrated based on the example of illustration, this invention is not limited to the above-mentioned example. For example, in the idle stop control device of the above embodiment, the idle stop permission condition is determined in step S1 of FIG. 1, but the idle stop permission condition is not limited to the condition in the above embodiment, and is changed as appropriate. Of course you can.

It is a flowchart which shows the process sequence of idle stop permission / inhibition control performed with the idle stop control apparatus which becomes one Example of the idle stop control apparatus of this invention. It is the schematic which shows the hydraulic circuit of the periphery of the primary pulley used as the object of the idle stop permission / inhibition control by the idle stop control apparatus of a present Example. In order to explain the problems of the conventional idle stop control device, the operation of the transmission mechanism for controlling the hydraulic pressure supplied to the primary pulley, the displacement of the movable pulley of the primary pulley and the step position of the step motor according to the operation It is explanatory drawing which illustrates a relationship, (a) is the state at the time of normal when both the displacement of the movable pulley of a primary pulley and the step position of a step motor become the lowest LOW, (b) is the speed change to the lowest LOW. (C) shows the state when the vehicle has stopped before the end and the primary pulley position has not fully returned to the LOW position, and (c) shows the release of the idle step when the step position of the step motor is shifted to the HI side while the idle step is permitted. The state at the time of subsequent engine restart is shown, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Primary pulley 1a, 2a Fixed pulley 1b, 2c Cylinder chamber 1c, 2d Movable pulley 2 Secondary pulley 2b Return spring 3 V belt 4 Transmission mechanism part (V belt type continuously variable transmission)
5, 9 Oil path 6 Shift control valve 6a Case 6b Spool 6c Spring 7 Step motor 8 Shift link PL Line pressure

Claims (2)

A belt type continuously variable transmission in which a belt is stretched between a primary pulley connected to the prime mover side and a secondary pulley connected to the axle side, and the groove width of the primary pulley is variably controlled by hydraulic pressure using a main pump as a hydraulic supply source. In an idle stop control device that is used in a vehicle having a machine and idles the prime mover when the vehicle is stopped,
Detecting means for detecting hydraulic pressure for controlling the groove width of the primary pulley;
An idle stop prohibiting means for determining whether or not the hydraulic pressure is less than a preset required pressure, and prohibiting an idle stop of the prime mover when the hydraulic pressure is determined to be less than the required pressure;
An idle stop control device comprising: In the belt-type continuously variable transmission, the groove width of the primary pulley is variably controlled by hydraulic pressure adjusted through a shift control valve driven by a step motor,
The idle stop prohibiting means sets the step position of the step motor so that the gear ratio of the belt-type continuously variable transmission is directed toward the high speed stage until the hydraulic pressure reaches the required pressure while the idle stop is prohibited. The idle stop control device according to claim 1, wherein the idle stop control is canceled when the hydraulic pressure reaches the required pressure by gradually moving.

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