JP5462103B2 - Coasting control device - Google Patents

Description

  The present invention relates to a coasting control device that disengages a clutch during traveling and returns an engine to an idle state to reduce fuel consumption, and relates to a coasting control device that does not give a sense of incongruity to clutch pedal operation during coasting control.

  In the vehicle, when the accelerator pedal is depressed when the clutch is disengaged, the accelerator is opened and the engine is so-called empty, and the engine speed settles at the engine speed corresponding to the accelerator opening. At this time, the driving force generated by the engine and the engine internal resistance (friction) are balanced, and the engine output torque is zero. That is, the engine does not work at all with respect to the outside, and fuel is wasted. For example, if the engine speed is 2000 rpm, the driver can hear a loud engine sound, so that a considerable amount of fuel is consumed wastefully.

  The state in which the engine does not work to the outside is not limited to the idling when the clutch is disengaged, but also occurs while the vehicle is running. That is, the engine only rotates at an engine speed corresponding to the accelerator opening, as in the case of flying, and does not contribute to acceleration / deceleration of the vehicle. At this time, fuel is consumed only for rotating the engine, which is very wasteful.

  The present applicant performs coasting control (also referred to as fuel consumption traveling control) that disengages the clutch and returns the engine to an idle state to reduce fuel consumption when the engine is rotating but not working to the outside. A coasting control device was proposed (Patent Document 1).

JP 2006-342832 A JP-A-8-67175 JP 2001-304305 A

  In addition to the above-mentioned proposal, the applicant uses a coasting control determination map using the clutch rotational speed and the accelerator opening as an index, and the plot points of the clutch rotational speed and the accelerator opening are within the coasting controllable region, When the accelerator pedal operation speed is within a predetermined range and the plot point of the clutch rotational speed and the accelerator opening passes the coasting control threshold line in the direction of decreasing the accelerator opening, the clutch is disengaged and the engine rotational speed is decreased. The coasting control device is now proposed to start coasting control and terminate coasting control when the accelerator pedal operation speed is out of a predetermined range or the plot point is out of the coasting controllable region.

  According to this coasting control device, during traveling by coasting control, the clutch is disengaged by operating the actuator by electronic control (ECU control), not by clutch disengagement by manual operation of the driver stepping on the clutch pedal. If the driver steps on the clutch pedal to perform a shifting operation during this coasting control, then if the coasting control continues at that time even if the shifting operation is completed and the clutch pedal is released, the clutch is engaged. As a result, the driver feels uncomfortable. In particular, when the driver performs a downshift operation in anticipation of engine braking, if the coasting control continues, the engine brake does not work, and the sense of discomfort is significant.

  Accordingly, an object of the present invention is to provide a coasting control device that solves the above-described problems and does not give a sense of incongruity to clutch pedal operation during coasting control.

  In order to achieve the above object, the present invention provides a coasting control determination map referred to by a clutch rotational speed and an accelerator opening, and a plot point of the clutch rotational speed and the accelerator opening on the coasting control determination map is a coasting controllable region. When the accelerator pedal operation speed is within a predetermined range and the plot point of the clutch rotational speed and the accelerator opening passes the coasting control threshold line in the direction of decreasing the accelerator opening, the clutch is disengaged and the engine The coasting control is started while the coasting control is started by lowering the rotational speed, and the coasting control is terminated when the accelerator pedal operation speed is out of the predetermined range or when the plot point is out of the coasting controllable region. And a clutch disengagement control stop unit for stopping the clutch disengagement control executed by the coasting control execution unit when the clutch pedal is depressed.

  The present invention exhibits the following excellent effects.

  (1) There is no sense of incongruity in clutch pedal operation during coasting control.

It is a block block diagram of the coasting control apparatus of this invention. 1 is a block configuration diagram of a vehicle clutch system to which a coasting control device of the present invention is applied. It is a block diagram of the actuator which implement | achieves the clutch system of FIG. 1 is an input / output configuration diagram of a vehicle to which a coasting control device of the present invention is applied. It is an operation | movement conceptual diagram for demonstrating the outline of coasting control. It is a graph image figure of a coasting control determination map. It is a graph for demonstrating the fuel consumption reduction effect by coasting control. It is a graph of the accelerator opening actually measured in order to create a coasting control determination map, and clutch rotation speed. It is a flowchart which shows the procedure of the clutch disengagement control stop in the coasting control apparatus of this invention. It is a block diagram of an actuator showing a state where the clutch pedal is not depressed during coasting control. It is a block diagram of an actuator showing a state where a clutch pedal is depressed during coasting control.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the coasting control device 1 according to the present invention includes a coasting control determination map 2 referred to by the clutch rotational speed and the accelerator opening, and the clutch rotational speed and the accelerator opening to the coasting control determination map 2. The plot point is within the coasting controllable region, the accelerator pedal operation speed is within the predetermined range, and the plot point of the clutch rotation speed and accelerator opening has passed the coasting control threshold line in the direction of decreasing accelerator opening. The coasting control is started when the clutch is disengaged and the engine speed is decreased to start coasting control, and the accelerator pedal operation speed is out of the predetermined range or the plot point is out of the coasting controllable region. A control executor 3, and a clutch disengagement control stop unit 4 that suspends the clutch disengagement control executed by the coasting control executor 3 when the clutch pedal is depressed during coasting control; Provided.

  The coasting control determination map 2, coasting control execution unit 3, and clutch disengagement control stop unit 4 constituting the coasting control device 1 are preferably mounted on, for example, an ECU (not shown).

  Each part is demonstrated about the vehicle carrying the coasting control apparatus 1 of this invention.

  As shown in FIG. 2, the vehicle clutch system 101 on which the coasting control device 1 of the present invention is mounted is a system in which a manual type and an automatic type by ECU control are compatible. A clutch master cylinder 103 mechanically coupled to the clutch pedal 102 supplies operating oil to an intermediate cylinder (also referred to as a clutch-free operating cylinder or a switching cylinder) 104 in accordance with a depression / return operation of the clutch pedal 102 by a driver. It is like that. On the other hand, a clutch-free actuator unit 105 controlled by an ECU (not shown) supplies hydraulic oil to the intermediate cylinder 104 in response to a clutch disengagement / contact command. The intermediate cylinder 104 supplies operating oil to the clutch slave cylinder 106. The piston 107 of the clutch slave cylinder 106 is mechanically connected to the movable part of the clutch 108.

  As shown in FIG. 3, the actuator 110 includes a clutch-free actuator 111. The clutch free actuator 111 includes an intermediate cylinder 104 and a clutch free actuator unit 105. The clutch free actuator unit 105 includes a solenoid valve 112, a relief valve 113, and a hydraulic pump 114. The intermediate cylinder 104 includes a primary piston 116 and a secondary piston 117 arranged in series. Clutch master cylinder 103 is connected to the bottom side (right side in the figure) of primary piston 116. Further, in intermediate cylinder 104, hydraulic pump 114 of clutch-free actuator unit 105 is connected between primary piston 116 and secondary piston 117, and solenoid valve 112 and relief valve 113 of clutch-free actuator unit 105 are connected to primary piston 116. Connected between secondary pistons 117. A clutch slave cylinder 106 is connected to the head side (left side in the figure) of the secondary piston 117.

  In the case of the clutch disengagement by manual operation, when the clutch pedal 102 is depressed, the working oil in the clutch master cylinder 103 flows into the bottom side of the primary piston 116 and the primary piston 116 strokes toward the head side. When the primary piston 116 strokes to the head side, it is pushed by the primary piston 116 and the secondary piston 117 strokes to the head side. When the clutch pedal 102 is returned, the operating oil on the bottom side of the primary piston 116 flows into the clutch master cylinder 103, so that the primary piston 116 is returned to the bottom side.

  In the case of clutch disengagement by ECU control, when all the solenoid valves 112 are fully closed, the hydraulic pump 114 is driven to introduce (IN) operating oil between the primary piston 116 and the secondary piston 117 of the intermediate cylinder 104. The secondary piston 117 strokes toward the head side.

  In both cases of manual operation and ECU control, when the secondary piston 117 strokes toward the head, operating oil is supplied to the clutch slave cylinder 106 and the clutch is disengaged. When the clutch pedal 102 is depressed while the secondary piston 117 is stroked to the head side by ECU control, the operating oil between the primary piston 116 and the secondary piston 117 is discharged from the relief valve 113 to the tank.

  In ECU control, when the hydraulic pump 114 is stopped and one or more of the solenoid valves 112 are opened from the clutch disengaged state, the hydraulic oil between the primary piston 116 and the secondary piston 117 is discharged into the tank in the intermediate cylinder 104. (OUT), and the secondary piston 117 returns to the bottom side. At this time, the solenoid valve 112 is duty-controlled (pulse control that adjusts the time ratio between fully closed and fully opened), so that the operating oil in the intermediate cylinder 104 is discharged at a speed determined by the duty. Thereby, the return speed of the secondary piston 117, that is, the contact speed of the clutch can be arbitrarily controlled.

  With the above configuration, the clutch disengagement / engagement by manual operation and the clutch disengagement / engagement by ECU control are possible, respectively, and when the clutch pedal is depressed, the clutch is disengaged with priority.

  As shown in FIG. 4, the vehicle is provided with an ECU 121 that mainly controls a transmission and a clutch, and an ECM 122 that mainly controls an engine. The ECU 121 includes a shift knob switch, a transmission shift sensor, a select sensor, a neutral switch, a T / M rotation sensor, a vehicle speed sensor, an idle switch, a manual changeover switch, an accelerator operation amount sensor, a clutch pedal sensor, a parking brake switch, and a door switch. Each input signal line of the brake switch, half-clutch adjustment switch, clutch sensor, and hydraulic switch is connected. Further, the ECU 121 is connected with output signal lines of a motor of the hydraulic pump 114 of the clutch system 101, a solenoid valve 112, a slope start assisting valve, and a warning & meter. Although not shown, various input signal lines and output signal lines used for engine control are connected to the ECM 122. The ECM 122 can transmit each signal of the engine speed, the accelerator opening, and the engine speed change request to the ECU 121 via a CAN (Controller Area Network) transmission path.

  The clutch pedal sensor is installed in the clutch pedal or actuator pedal system, and detects the amount of displacement of the clutch pedal or detects that the clutch pedal is in a predetermined position. The clutch pedal is depressed from the output. Can be detected.

  The clutch rotational speed used in the present invention is the rotational speed on the driven side of the clutch, and is the same as the rotational speed of the input shaft of the transmission. The clutch rotational speed can be obtained from the input shaft rotational speed detected by an input shaft rotational speed sensor (not shown). Alternatively, the clutch rotational speed can be obtained from the vehicle speed detected by the vehicle speed sensor using the gear ratio of the current gear stage. The clutch rotational speed represents the engine rotational speed corresponding to the vehicle speed.

  Hereinafter, the operation of the coasting control device 1 of the present invention will be described.

  The operation concept of coasting control will be described with reference to FIG. The horizontal axis shows time and control flow, and the vertical axis shows engine speed. While the accelerator pedal 141 is largely depressed from the idling state and the accelerator opening degree continues to be 70%, the engine speed 142 increases and the vehicle is accelerated. Assume that a coasting control start condition described later is satisfied when the engine speed 142 is stabilized, the depression of the accelerator pedal 141 is reduced, and the accelerator opening is 35%. By starting coasting control, the clutch is controlled to be disengaged, and the engine speed 142 is controlled to the idle speed. The vehicle will run in coasting control. Thereafter, it is assumed that the accelerator pedal is no longer depressed and the accelerator opening becomes 0% or other coasting control end conditions are satisfied. When the coasting control ends, the engine is controlled to rotate and the clutch is controlled to contact. In this example, since the accelerator opening is 0%, the engine is braked and the vehicle is decelerated.

  If coasting control is not performed, the engine speed remains high as indicated by the broken line during the coasting control execution period, so that fuel is wasted, but coasting control is performed. Thus, during coasting control, the engine speed 142 becomes the idling speed and fuel is saved.

  FIG. 6 shows the coasting control determination map 2 as a graph image.

  The coasting control determination map 2 is a map in which the horizontal axis is the accelerator opening and the vertical axis is the clutch rotational speed. The coasting control determination map 2 can be divided into a minus region MA where the engine output torque is negative and a plus region PA where the engine output torque is positive. The minus region MA is a region where the engine friction is larger than the engine required torque and the engine output torque is negative. The positive region PA is a region where the engine output torque is positive because the engine required torque is larger than the engine friction. The engine output torque zero line ZL, which is the boundary between the minus area MA and the plus area PA, indicates that the engine does not work to the outside as described in the background art, and fuel is wasted.

  In the present embodiment, the coasting control threshold line TL is set slightly to the left of the engine output torque zero line ZL of the coasting control determination map 2 (on the side where the accelerator opening is small). In the coasting control determination map 2, a coasting controllable area CA having a finite width including the coasting control threshold line TL is set between the minus area MA and the plus area PA. In the coasting control determination map 2, a lower limit threshold line UL of the clutch rotational speed is set. The lower limit threshold line UL defines a lower limit threshold value of the clutch rotational speed regardless of the accelerator opening. The lower limit threshold line UL is set slightly above the clutch rotational speed in the idle state as shown in the figure.

The coasting control device 1 starts coasting control when all the following four coasting start conditions are satisfied.
(1) The accelerator pedal operating speed is within the threshold range. (2) In the coasting control determination map 2, the plot points of the clutch rotational speed and the accelerator opening pass the coasting control threshold line TL in the accelerator return direction. The plot point on the control determination map 2 is within the coasting controllable area CA. (4) In the coasting control determination map 2, the clutch rotational speed is equal to or greater than the lower limit threshold line UL.

The coasting control device 1 is configured to end coasting control when at least one of the following two coasting termination conditions is satisfied.
(1) The accelerator pedal operating speed is outside the threshold range. (2) The plot point on the coasting control determination map 2 is outside the coasting control possible area CA.

  The operation of the coasting control device 1 according to the coasting control determination map 2, the coasting start condition, and the coasting end condition will be described.

  The coasting control execution unit 3 constantly monitors the accelerator opening based on the accelerator pedal operation amount and the clutch rotational speed obtained from the input shaft rotational speed or the vehicle speed, and displays the accelerator opening on the coasting control determination map 2 of FIG. And plot the clutch rotation speed coordinate point. Coordinate points move over time. At this time, when the coordinate point exists in the coasting controllable area CA, the coasting control execution unit 3 determines whether or not to start coasting control. When the coordinate point does not exist in the coasting controllable area CA, the coasting control execution unit 3 does not determine whether to start coasting control.

  Next, when the coordinate point passes the coasting control threshold line TL in the direction in which the accelerator opening decreases, the coasting control execution unit 3 starts coasting control. That is, the coasting control device 1 controls the clutch to be disengaged and controls the control accelerator opening that the ECM 122 instructs the engine to correspond to the idle. As a result, the clutch is disengaged and the engine is in an idle state.

  As shown in FIG. 6 by the arrow indicating the moving direction of the coordinate point, the direction in which the accelerator opening decreases is the left direction in the figure. Even if the coordinate point passes the coasting control threshold line TL, if the movement direction of the coordinate point has a component in the right direction in the figure, the accelerator opening increases, so the coasting control execution unit 3 performs coasting control. Do not start.

  The coasting control execution unit 3 constantly monitors the accelerator opening and the clutch rotational speed even after starting coasting control, and plots the coordinate points of the accelerator opening and the clutch rotational speed on the coasting control determination map 2. When the coordinate point goes out of the coasting controllable area CA, the coasting control execution unit 3 ends the coasting control.

  With the above operation, when the accelerator pedal is operated to the depression side, coasting control is not started even if the coordinate point of the accelerator opening and the clutch rotational speed passes the coasting control threshold line TL, and the accelerator pedal is Since the coasting control is started when the coordinate point passes the coasting control threshold line TL only when operated on the return side, the driver does not feel uncomfortable.

  The coasting control execution unit 3 does not start coasting control when the coordinate point is below the lower limit threshold line UL (the clutch rotational speed is lower than the lower limit threshold). This is because even if the clutch is disengaged when the engine is in an idle state, many effects of suppressing fuel consumption cannot be expected. Therefore, coasting control execution unit 3 starts coasting control only when the coordinate point exists above the lower limit threshold line UL.

  The fuel consumption reduction effect by coasting control will be described with reference to FIG.

  First, it is assumed that coasting control is not performed. The engine speed changes in the range of 1600 to 1700 rpm from about 30 s to about 200 s, and decreases from about 1700 rpm to about 700 rpm (idle speed) between about 200 s and about 260 s. .

  The engine torque increases from about 30 s to about 100 s, but then starts to decrease and continues to decrease to about 150 s. The engine torque is about 0 Nm from about 150 s to about 160 s and increases between about 160 s and about 200 s, but becomes about 0 Nm at about 200 s. As a result, the period during which the engine torque is approximately 0 Nm is from about 150 s to about 160 s (ellipse B1), from about 200 s to about 210 s (ellipse B2), and from about 220 s to about 260 s (ellipse B3) is there.

  The fuel consumption (no vertical axis scale; for convenience, it is arranged so as to overlap with the engine torque) changes from about 50 s to about 200 s almost accompanying the transition of the engine torque. Even if the engine torque is approximately 0 Nm, the fuel consumption is not zero.

  Here, when coasting control is performed, the engine speed is controlled to the idle speed during a period in which the engine torque is approximately 0 Nm. The graph shows a line (thick solid line) of the engine speed during coasting control so as to be separated from a line (solid line) of the engine speed not performing coasting control. The coasting control was executed three times for ellipses B1, B2 and B3. The fuel consumption amount in the period when the coasting control is performed is lower than the fuel consumption amount when the coasting control is not performed, and it is understood that the fuel consumption is saved.

  Next, a specific setting example of the coasting control determination map 2 will be described.

  As shown in FIG. 8, in order to create the coasting control determination map 2, the characteristics of the accelerator opening and the clutch rotational speed are measured, the horizontal axis is the accelerator opening, and the vertical axis is the clutch rotational speed (= engine rotational speed). ; When the clutch is engaged). Thereby, the actually measured engine output torque zero line ZL can be drawn. The entire left side of the engine output torque zero line ZL is the minus region MA, and the entire right side is the plus region PA.

  A coasting control threshold line TL is defined and drawn slightly to the left of the engine output torque zero line ZL. A deceleration zero threshold line TLg is estimated and drawn slightly to the left of the coasting control threshold line TL. An acceleration zero threshold line TLk is estimated and drawn slightly to the right of the engine output torque zero line ZL. A region sandwiched between the deceleration zero threshold line TLg and the acceleration zero threshold line TLk is defined as a coasting controllable region CA. In this example, the lower limit threshold line UL is set to 880 rpm.

  The deceleration zero threshold line TLg and the acceleration zero threshold line TLk are set to such an extent that the driver is difficult to drive. However, since they are a human sense problem, they cannot be quantified by design, and are tuned with an actual vehicle. The coasting control threshold line TL is set at the center of the deceleration zero threshold line TLg and the acceleration zero threshold line TLk.

  The graph of FIG. 8 created as described above is appropriately digitized (discretized) and written into the storage element, whereby the coasting control determination map 2 that can be used for the arithmetic processing by the coasting control execution unit 3 is obtained.

  Next, the procedure for stopping the clutch disengagement control in the coasting control device 1 of the present invention will be described with reference to FIG.

  In step S91, the clutch disengagement control stop unit 4 determines whether coasting control is being performed. If YES, the process proceeds to step S92. If NO, the process ends.

  In step S92, the clutch disengagement control stop unit 4 determines whether or not the clutch pedal has been depressed. If YES, the process proceeds to step S93. If NO, the process ends.

  In step S93, the clutch disengagement control stop unit 4 stops the clutch disengagement control that is being performed by the coasting control execution unit 3 because the clutch pedal has been depressed during the coasting control. Specifically, the motor of the hydraulic pump 114 in FIG. 3 is stopped and the solenoid valve 112 is opened.

  When the clutch disengagement control is stopped by the clutch disengagement control stop unit 4, the coasting control execution unit 3 may end the coasting control and increase the engine speed from the idle speed to match the clutch speed. .

  The operation of the actuator according to the procedure of FIG. 9 is as follows.

  As shown in FIG. 10, when the clutch pedal is not depressed during coasting control, the motor of the hydraulic pump 114 is operated, so that the working oil in the tank is transferred from the hydraulic pump to the primary piston 116 of the intermediate cylinder 104. And the secondary piston 117. Since the secondary piston 117 strokes toward the head side (the left side in the figure) and supplies the working oil to the clutch slave cylinder 106, the clutch 108 is disengaged.

  As shown in FIG. 11, when the clutch pedal is depressed during coasting control, the clutch disengagement control is stopped and the motor of the hydraulic pump 114 is stopped, so that the primary piston 116 and the secondary piston of the intermediate cylinder 104 are stopped. The supply of the working oil between the pistons 117 is stopped, and at the same time, the solenoid valve 112 is opened, so that the working oil is discharged from between the primary piston 116 and the secondary piston 117 to the tank. As a result, the clutch disengagement control in coasting control is canceled. At this time, since the clutch pedal is stepped on, the operating oil from the clutch master cylinder 103 strokes the primary piston 116, and the secondary piston 117 is on the head side. The clutch 108 remains disengaged.

  Thereafter, when the clutch pedal is released, the operating oil is returned to the clutch master cylinder 103 from the bottom side (right side in the drawing) of the primary piston 116, and the primary piston 116 returns to the bottom side. At this time, since the operating oil is not supplied between the primary piston 116 and the secondary piston 117, the secondary piston 117 is accompanied by the negative pressure and returns to the bottom side. Therefore, the clutch 108 is in contact. Thus, when the driver steps on the clutch pedal to perform a shifting operation during coasting control, the clutch is engaged when the clutch pedal is released.

  As described above, according to the coasting control device 1 of the present invention, when the clutch pedal is depressed during coasting control, the clutch disengagement control stopping unit 4 performs the clutch disengagement control performed by the coasting control execution unit 3. Will stop, so when you release the clutch pedal, the clutch will come into contact. Therefore, after the driver depresses the clutch pedal to perform the shifting operation, when the shifting operation is completed and the clutch pedal is released, the coasting control has already ended and the clutch is engaged, There is no sense of discomfort.

1 coasting control device 2 coasting control determination map 3 coasting control execution unit 4 clutch disengagement control stop unit

Claims (1)

Coasting control determination map referred to by clutch rotational speed and accelerator opening,
The plot points of the clutch rotational speed and the accelerator opening on the coasting control determination map are within the coasting controllable region, the accelerator pedal operation speed is within a predetermined range, and the plotted points of the clutch rotational speed and the accelerator opening are When the coasting control threshold line passes in the direction of decreasing the accelerator opening, the clutch is disengaged and the engine speed is decreased to start coasting control, and the accelerator pedal operating speed is out of the specified range or the plot point is coasting Coasting control execution unit that terminates coasting control when it goes out of the controllable area;
A coasting control device, comprising: a clutch disengagement control stopping unit that discontinues the clutch disengagement control executed by the coasting control execution unit when the clutch pedal is depressed during coasting control.

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