JP5462091B2 - Coasting control device - Google Patents

Description

  The present invention relates to a coasting control device that disengages a clutch during traveling in an automatic transmission type vehicle to return the engine to an idle state and suppresses fuel consumption, and can prevent engine overrun at high speed traveling, and reduce vehicle speed. The present invention relates to a coasting control device that can sometimes shift down quickly.

  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.

  When the coasting control is started, the clutch is disengaged and the engine speed decreases. When coasting control ends, the engine speed is increased to the clutch speed, which is the engine speed corresponding to the vehicle speed, and the clutch is engaged.

  By the way, in an automatic transmission type vehicle in which the target gear stage is automatically set according to the shift map referred to by the vehicle speed and the accelerator opening, and the transmission is controlled by switching the transmission with an actuator, the clutch is set when the new target gear stage is set. The control is performed so that the clutch is engaged after the switch is turned off and the shift is switched.

  If two different controls for engaging and disengaging the clutch are executed simultaneously in parallel, such as coasting control and shift control, an irregular state can occur. For example, if the gear shift control shifts to a lower gear than the current gear during coasting control when the vehicle speed is high, the coasting control ends and the clutch is engaged. When the engine speed is returned to the vehicle speed at the original gear stage from the idle speed, the load-side speed is increased due to the downshift with respect to the engine speed, so the clutch is engaged. In some cases, the engine rotated by the load may overrun beyond the rated speed, or the tire may not be able to rotate following the vehicle speed and may be locked. Alternatively, if the engine speed is returned to the vehicle speed at the gear stage after the downshift from the idle speed before the coasting control is finished and the clutch is to be engaged, the target engine speed is If the engine speed exceeds the rated speed, the engine will be overrun by the control when the engine speed is increased as intended.

  Therefore, a solution is conceivable in which the coasting control is prioritized over the shift control and the shift control is prohibited during the coasting control.

  However, when coasting control is continued for a long time, the vehicle speed may decrease considerably while the plot points of the coasting control determination map remain within the coasting controllable region. In this case, the vehicle alone improves the fuel consumption and causes no problem, but the distance between the vehicles opens due to the difference in vehicle speed from the preceding vehicle. When the preceding vehicle accelerates, the distance between the vehicles opens even more. On the other hand, the space between the following vehicles is clogged. At this time, if the driver depresses the accelerator pedal, the coasting control is terminated and the clutch is engaged, but the vehicle speed is considerably reduced, so the current gear stage at the start of the coasting control remains at the gear stage. Vehicle acceleration slows down. As a result, the traffic flow is delayed, causing traffic jams.

  In addition, as described above, when the vehicle speed is considerably reduced during coasting control, coasting control ends when the driver depresses the accelerator pedal. When the control sequence is performed, the time from the time when the accelerator pedal is depressed to the time when the clutch is engaged after shifting becomes longer, and during that time, the driver feels idle. A long feeling of idling during a downshift is a problem because it is very uncomfortable for the driver of an automatic transmission vehicle.

  Accordingly, an object of the present invention is to provide a coasting control device that solves the above-described problems, can prevent engine overrun during high-speed traveling, and can quickly shift down when the vehicle speed decreases.

  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 by reducing the number of revolutions, and the coasting control is terminated when the accelerator pedal operation speed is out of the predetermined range or the plot point is outside the coasting controllable region, and the vehicle speed and the accelerator. Set the gear map defined by the shift map referenced by the opening and the plot points of the vehicle speed and accelerator opening to the shift map as the target gear, When the clutch rotational speed exceeds a predetermined value during coasting control, and shift switching from the current gear stage to the target gear stage, and when the clutch rotational speed exceeds a predetermined value during coasting control, And an arbitration unit that permits shift switching by the shift control unit when the clutch rotational speed is less than or equal to a predetermined value.

  When the arbitration unit permits shift switching during coasting control, the shift control unit may perform shift switching while the coasting control execution unit is disengaged.

  The present invention exhibits the following excellent effects.

  (1) Engine overrun at high speed can be prevented.

  (2) When the vehicle speed decreases, it is possible to shift down quickly.

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 which mediates the speed change control during coasting control in the coasting control apparatus of this invention. It is a graph image figure of coasting control determination map which shows that the vehicle speed falls, while the plot point of coasting control determination map maintains the coasting control possible area | region during coasting control. 7 is a graph showing changes in vehicle speed and clutch and shift control timing when shift switching is performed simultaneously with the end of coasting control. 6 is a graph showing changes in vehicle speed and timing of clutch and shift control when shift switching is performed 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. The control execution unit 3, the shift map 4 referred to by the vehicle speed and the accelerator opening, and the gear stage defined by the plot points of the vehicle speed and the accelerator opening to the shift map 4 are used as the target gear. When the clutch rotational speed exceeds a predetermined value during coasting control and the shift control unit 5 that engages the clutch, the clutch is disengaged and the shift is switched from the current gear stage to the target gear stage. An arbitration unit 6 that prohibits shift switching by the shift control unit 5 and permits shift switching by the shift control unit 5 when the clutch rotational speed is a predetermined value or less.

  The coasting control determination map 2, the coasting control execution unit 3, the shift map 4, the shift control unit 5, and the arbitration unit 6 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. In the intermediate cylinder 104, a primary piston 116 and a secondary piston 117 are arranged in series, and when the primary piston 116 is stroked by the operating oil from the clutch master cylinder 103, the secondary piston 117 is stroked with it. . The intermediate cylinder 104 is configured such that the secondary piston 117 is stroked by the operating oil from the clutch-free actuator unit 105. Operating oil is supplied to the clutch slave cylinder 106 in accordance with the stroke of the secondary piston 117. With this configuration, when manual operation is performed, clutch disengagement / engagement is preferentially performed according to manual operation, and when manual operation is not performed, clutch disengagement / engagement according to ECU control is performed.

  The coasting control device 1 of the present invention can also be applied to an automatic clutch system without a manual type.

  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, a parking brake switch, a door switch, a brake switch, a half-clutch adjustment switch, Input signal lines for the accelerator operation amount sensor, the clutch sensor, and the hydraulic switch are connected. The ECU 121 is connected with output signal lines of a shift actuator, 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 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 shift control performed by the shift control unit 5 in FIG. 1 will be described.

  The shift map 4 can be imaged as a two-dimensional graph with the vehicle speed and accelerator opening as axes. A plurality of gear speed regions are defined in the shift map 4. The shift control unit 5 refers to the gear stage by the shift map 4. That is, the gear stage at the plot point of the vehicle speed and the accelerator opening is read and set as the target gear stage. Here, since the vehicle speed is decreasing, the shift-down shift map 4 is referred to.

  The shift control unit 5 performs a shift when the current gear stage recognized by the ECU 121 and the target gear stage obtained from the shift map 4 are different. The gear shifting procedure is such that the clutch is disengaged by the clutch system of FIG. 2 and the shift actuator switches the current gear to the target gear and then the clutch is engaged.

  Shift switching is achieved by the shift control unit 5 outputting a control signal to the shift actuator, and the shift actuator moving the gear of the transmission. However, the mechanism of the shift actuator is well known in the art and will not be described. To do.

  In the coasting control device 1 of the present invention, there is a case where a shift is executed during coasting control. In this case, since the clutch is already controlled to be disengaged by the coasting control execution unit 3, the shift control unit 5 performs only shift switching and ends the shift. After the shift switching by the shift control unit 5, when the coasting control is finished, the coasting control execution unit 3 controls the clutch to be in contact.

  Next, in the coasting control device 1 of the present invention, a procedure in which the arbitrating unit 6 arbitrates coasting control and shift control will be described with reference to FIG.

  In step S <b> 1, the arbitration unit 6 determines whether the coasting control by the coasting control execution unit 3 is currently being performed. In the case of NO, since the coasting control execution unit 3 is not executing coasting control, the process proceeds to step S2. In step S <b> 2, the arbitration unit 6 permits shift switching by the shift control unit 5.

  If the determination in step S1 is YES, since the coasting control execution unit 3 is executing coasting control, the process proceeds to step S3.

  In step S3, the arbitrating unit 6 determines that the accelerator opening (accelerator pedal operation amount) Acc is smaller than a predetermined value Th1, and the clutch rotational speed (vehicle speed equivalent engine rotational speed) Ver is a predetermined value Th2. Determine if smaller. If YES, the clutch rotational speed Ver is smaller than the predetermined value Th2, which means that the vehicle speed is decreasing. At the same time, since the accelerator opening Acc is smaller than the predetermined value Th1, it can be confirmed that the accelerator pedal is not depressed. In this case, the process proceeds to step S4.

  In step S4, the arbitration unit 6 permits shift switching by the shift control unit 5 because the vehicle speed decreases and the clutch rotational speed Ver is smaller than the predetermined value Th2 even during coasting control.

  If the determination in step S3 is NO, the accelerator opening degree Acc is equal to or greater than the predetermined value Th1, or the clutch rotational speed Ver is equal to or greater than the predetermined value Th2, and the vehicle speed is high or the accelerator pedal is depressed. Will be. In this case, the process proceeds to step S5.

  In step S5, the arbitrating unit 6 is in coasting control, the vehicle speed is high, and the clutch rotational speed Ver is equal to or greater than the predetermined value Th2, and therefore shift switching by the shift control unit 5 is prohibited.

  Next, in what vehicle state the coasting control device 1 of the present invention is effective will be described together with the actual vehicle operation.

  As shown in FIG. 10, it is assumed that the coasting control is started when all the four coasting start conditions described above are satisfied at the plot point p1 of the accelerator opening to the coasting control determination map 2 and the clutch rotational speed. Thereafter, with the passage of time, the vehicle speed gradually decreased, and in parallel with this, the accelerator opening gradually decreased. Therefore, the plot point was almost the coasting control threshold line TL (or the engine output torque zero line ZL; FIG. 6). ) To the plot point p2. At this time, the locus Tr of the plot points has never been outside the coasting controllable area CA. If the operating speed of the accelerator pedal has never been outside the threshold range during this time, neither of the two coasting end conditions described above is satisfied, and therefore coasting control is continued for a long time. Thereafter, if the plot point moves substantially along the coasting control threshold line TL and draws a locus like a broken line, the coasting control is further continued. Theoretically, it can continue until the clutch rotational speed reaches the idle rotational speed, but it is preferable to end coasting control below the lower limit threshold line UL.

  Here, the vehicle speed was high at the point of the plot point p1 where the coasting control was started, whereas the vehicle speed was considerably lowered when the vehicle moved to the plot point p2. If the current gear stage is the fourth speed when the coasting control is started, the current gear stage remains at the fourth speed even at the plot point p2. In the shift map 4, when the vehicle speed is lowered, the gear region where the plot points of the vehicle speed and the accelerator opening are entered is, for example, the second gear region. Therefore, the shift control unit 5 sets the target gear stage to the second speed. At this time, if the clutch rotational speed exceeds a predetermined value, the arbitration unit 6 prohibits shift switching by the shift control unit 5, but if the clutch rotational speed is equal to or less than the predetermined value, the arbitration unit 6 Shift switching by 5 is permitted.

  The clutch rotational speed here is used as a quantity for determining whether the vehicle speed is high or low. If the current gear stage is a high gear stage such as 3-5, the clutch speed is low even at the same vehicle speed, and if the current gear stage is a low gear stage such as 1st or 2nd speed, the same vehicle speed But the clutch speed is high. Therefore, in order to determine the vehicle speed strictly, it is preferable to set a predetermined value to be compared with the clutch rotational speed for each gear stage. However, since the object of the present invention is to prevent engine overrun and eliminate idling feeling, the clutch rotational speed corresponding to an appropriate vehicle speed at a certain appropriate gear may be set to a predetermined value.

  FIG. 11 shows the change in vehicle speed and the timing of clutch and shift control when shift switching is performed simultaneously with the end of coasting control. As the coasting control end operation, it is inefficient that the coasting control execution unit 3 performs the clutch engagement and immediately after that, the shift control unit 5 performs the clutch disengagement in the shift control. The clutch engagement in the operation is omitted and the clutch disengagement in the shift control is omitted, and the shift switching is performed as soon as the coasting control end condition is satisfied.

  As shown in the figure, the clutch is disengaged during coasting control, and the vehicle speed gradually decreases with the current gear stage remaining at the fourth speed.

  Assuming that the coasting control end condition is satisfied by depressing the accelerator pedal, the shift to the second speed is performed after the coasting control end condition is satisfied. After the shift switching period, the clutch is engaged and the vehicle speed starts to increase after the clutch engagement period. A combination of the shift switching period and the clutch engagement period is the idle running period.

  FIG. 12 shows the change in vehicle speed and the timing of clutch and shift control when shift switching is performed during coasting control. Here, before the coasting control end condition is satisfied, if the target gear stage according to the shift map 4 is different from the current gear stage, the shift is switched immediately.

  As shown in the drawing, the clutch is disengaged during coasting control, and the vehicle speed gradually decreases while the current gear stage remains at the fourth speed. During the coasting control, the arbitration unit 6 permits shift switching when the clutch rotational speed becomes a predetermined value or less. If the target gear stage according to the shift map 4 is the second speed, the shift control unit 5 performs the shift switching to the second speed while the clutch is disengaged.

  Assuming that the coasting control end condition is satisfied by depressing the accelerator pedal, after the coasting control end condition is satisfied, the clutch is engaged and the vehicle speed starts to increase after the clutch engagement period. Only the clutch engagement period is the idle period.

  As described above, according to the coasting control device 1 of the present invention, when the clutch rotational speed becomes low during coasting control, the shift to the target gear stage set in the shift map 4 is performed even during coasting control. Switching is performed. At this time, when the driver steps on the accelerator pedal, the clutch engagement is immediately started, so the idling period is shortened. As a result, when the distance between the preceding vehicle and the preceding vehicle is increased, acceleration is performed quickly, and it is prevented that the traffic flow is delayed.

  On the other hand, even during the same coasting control, shift switching is prohibited when the clutch rotational speed is high as indicated by the plot point p1 in FIG. 10, and therefore engine overrun due to shift down can be prevented.

1 coasting control device 2 coasting control determination map 3 coasting control execution unit 4 shift map 5 shift control unit 6 arbitration unit

Claims (2)

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 shift map referred to by vehicle speed and accelerator opening;
Set the gear stage defined by the plot points of the vehicle speed and accelerator opening to the shift map as the target gear stage, disengage the clutch, switch the shift from the current gear stage to the target gear stage, and engage the clutch A shift control unit;
During coasting control, when the clutch rotational speed exceeds a predetermined value, shift switching by the shift control unit is prohibited, and when the clutch rotational speed is less than a predetermined value, shift switching by the shift control unit is permitted. A coasting control device comprising an arbitration unit.   2. The shift control unit according to claim 1, wherein when the arbitration unit permits shift switching during coasting control, the shift control unit performs shift switching while the clutch is disengaged by the coasting control execution unit. The coasting control device described.

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