JP2016008657A - Apparatus and method for controlling start of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a shock caused when a vehicle is put in gear at startup, in a multi-stage transmission having main and auxiliary transmission parts.SOLUTION: A transmission (3) comprises a main transmission part (20), a range part (21) and a splitter part (22). When a vehicle starts by using a high-speed gear of the range part (21), the transmission (3) performs start preparation control for shifting the range part (21) to a low-speed gear before gear engagement in the main transmission part (20) and shifting the range part (21) to the high-speed gear after the gear engagement in the main transmission part (20).

Description

  The present invention relates to a vehicle start control device and a start control method including a transmission having a main transmission unit and a sub-transmission unit.

  A large vehicle such as a tractor that pulls a trailer is provided with a multi-stage transmission capable of 12-speed or 16-speed. The multi-stage transmission generally includes a main transmission section having three or four-stage transmission gears, and a range-type sub-transmission section having a low speed gear and a high speed gear for expanding the gear ratio range of the main transmission section ( And a splitter type sub-transmission unit (hereinafter referred to as a splitter unit) that subdivides each gear ratio of the main transmission unit.

  In a vehicle having such a multi-stage transmission, it is necessary to perform many operations such as downshifting or upshifting in order to specify the gear stage at the time of starting (hereinafter referred to as starting stage) by the driver's operation. Was annoying.

  Therefore, for example, the setting value of the start stage is set in advance when the trailer is connected and when the trailer is not connected, and the controller automatically selects the start stage only by setting the change lever to the D position. Is disclosed (see Patent Document 1).

JP 2001-280466 A

  In general, it is preferable that there is a rotational speed difference between the input side and the output side when gears are engaged (geared) in a transmission. In the case of putting gears, the shock at the time of putting gears becomes larger when the gears are put in the high speed stage where the gears are rotating at a high speed even if the rotational speed difference is the same.

  In Patent Document 1 described above, when starting in a trailer disconnected state, a high speed gear is selected in the range portion. However, if the main transmission portion is geared in this state, a relatively large shock occurs, which is inconvenient for the driver. May give a pleasant feeling.

  The present invention has been made to solve such a problem, and an object of the present invention is to reduce a gear-set shock at the start of a vehicle in a multi-stage transmission having a main transmission unit and an auxiliary transmission unit. An object of the present invention is to provide a vehicle start control device and a start control method.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

  (1) A vehicle start control device according to this application example includes a main transmission unit having a plurality of transmission gears, and a sub-transmission unit having a high-speed gear and a low-speed gear that expand the range of the gear ratio of the main transmission unit. When starting using the transmission and the high-speed gear of the sub-transmission unit, the sub-transmission unit is switched to a low-speed gear before putting the gear in the main transmission unit, and after the start gear is put in the main transmission unit A start control unit that performs start preparation control for switching the auxiliary transmission unit to a high-speed gear.

  (2) In the vehicle start control device according to this application example, when the start control unit starts using the high speed gear of the auxiliary transmission unit as the start preparation control, the vehicle stops and the main shift The sub-transmission unit may be switched to a low speed gear when the unit becomes neutral.

  (3) In the vehicle start control device according to this application example, the start control unit may perform the start preparation control only when the vehicle stops and the brake pedal is released for a predetermined time or more. .

  (4) In the vehicle start control device according to this application example, the vehicle including the transmission may be a tractor capable of pulling a trailer.

  (5) A vehicle start control method according to this application example includes a main transmission unit having a plurality of transmission gears, and a sub-transmission unit having a high-speed gear and a low-speed gear that expand the range of the gear ratio of the main transmission unit. A start control method for a vehicle including a transmission, wherein when the vehicle starts using a high-speed gear of the sub-transmission unit, low-speed gear switching that switches the sub-transmission unit to a low-speed gear before gearing in the main transmission unit And a high-speed gear switching step of switching the sub-transmission unit to a high-speed gear after the start gear in the main transmission unit is engaged.

  (6) In the vehicle start control method according to this application example, the low-speed gear switching step may switch the sub-transmission unit to a low-speed gear when the vehicle stops and the main transmission unit becomes neutral. .

  (7) In the vehicle start control method according to this application example, the low speed gear switching step may be performed when the vehicle stops and the brake pedal is released for a predetermined time or more.

  According to the present invention using the above means, in a multi-stage transmission having a main transmission unit and a sub-transmission unit, it is possible to reduce a gearing shock when the vehicle starts.

It is a schematic block diagram which shows the drive system of the vehicle provided with the vehicle start control apparatus in one Embodiment of this invention. It is a related figure of each gear stage and each gear of a transmission. 4 is a time chart showing various driving states when the ECU of the vehicle start control device according to the embodiment of the present invention executes start preparation control.

  Hereinafter, an embodiment of a vehicle start control device embodying the present invention will be described.

  FIG. 1 is an overall configuration diagram showing a drive system of a vehicle provided with a start control device of the present embodiment, and the configuration of the present embodiment will be described below based on the same diagram.

  The vehicle in this embodiment is a tractor that can pull a trailer, and a diesel engine (hereinafter referred to as an engine) 1 is mounted as a power source for traveling. An output shaft 1 a of the engine 1 is connected to an input shaft 3 a of a multi-stage transmission (hereinafter simply referred to as a transmission) 3 via a clutch device 2, and the rotation of the engine 1 is transmitted to the transmission 3 when the clutch device 2 is connected. It has come to be.

  The transmission 3 is, for example, a multi-stage transmission having 12 forward speeds and 2 reverse speeds. As described below, the transmission 3 and the connection / disconnection operation of the clutch device 2 associated with the shift are automated. Automated Manual Transmission).

  The clutch device 2 is configured as a friction clutch that is connected to the flywheel 4 by press-contacting the clutch plate 5 with a pressure spring 6 and is disconnected by separating the clutch plate 5 from the flywheel 4. An air cylinder 8 is connected to the clutch plate 5 via an outer lever 7, and an air tank 11 filled with compressed air is connected to the air cylinder 8 via an air passage 10 in which an electromagnetic valve 9 is interposed.

  When the electromagnetic valve 9 is opened, compressed air is supplied from the air tank 11 to the air cylinder 8 through the air passage 10. Then, the air cylinder 8 is actuated to separate the clutch plate 5 from the flywheel 4 via the outer lever 7. As a result, the clutch device 2 is switched from the connected state to the disconnected state. On the other hand, when the solenoid valve 9 is closed, the air cylinder 8 is not operated due to the supply stop of the compressed air. Therefore, the clutch plate 5 is pressed against the flywheel 4 by the pressure spring 6. As a result, the clutch device 2 is switched from the disconnected state to the connected state. As described above, the air cylinder 8 is operated in accordance with the opening and closing of the electromagnetic valve 9 so that the clutch device 2 can be automatically connected and disconnected.

  The transmission 3 mainly includes a main transmission unit 20 and two sub transmission units, a range type sub transmission unit (hereinafter referred to as a range unit) 21 and a splitter type sub transmission unit (hereinafter referred to as a splitter unit) 22.

  Specifically, the main transmission unit 20 is composed of a gear group having three forward speeds of a low speed gear (Low), a medium speed gear (Middle), and a high speed gear (High) in order from the low speed stage and a reverse gear for reverse movement (Reverse). .

  The range unit 21 is provided on the output side of the main transmission unit 20 and has a gear group including two stages of a low speed gear (Low) and a high speed gear (High). The range unit 21 expands the range toward the low speed side and the high speed side with respect to the gear ratio of the main transmission unit 20 by switching these two gears. In addition, the gear group of the range part 21 consists of planetary gears, for example.

  The splitter unit 22 is provided on the input side from the main transmission unit 20 and has a gear group including two stages of a low speed gear (Low) and a high speed gear (High). The splitter unit 22 subdivides the gear ratio of the main transmission unit 20 into the low speed side and the high speed side by switching these two gears.

  As shown in FIG. 2, the transmission 3 can switch the gear position from the first speed (1st) to the 12th speed (12th) by combining the gears of the main transmission unit 20, the range unit 21, and the splitter unit 22. is there. Although not shown, when the vehicle is moved backward, the main transmission unit 20 selects a reverse gear, and the range unit 21 selects a low-speed gear. In the splitter unit 22, the low-speed gear and the high-speed gear can be selected to reverse the speed in two stages, low speed and high speed.

  Further, the transmission 3 is provided with a gear shift unit 23 for switching the gear position. Although not shown, the gear shift unit 23 incorporates a plurality of air cylinders and a plurality of solenoid valves for operating the air cylinders. Each air cylinder of the gear shift unit 23 is connected to a shift rod or a shift piston corresponding to each gear of the main transmission unit 20, the range unit 21, and the splitter unit 22. The gear shift unit 23 is connected to the air tank 11 via the air passage 12, and compressed air from the air tank 11 is supplied to a corresponding air cylinder in accordance with opening / closing of each electromagnetic valve. And by operating an air cylinder and operating a corresponding shift rod or shift piston, gearing of each part is performed according to the said operation.

  Also, in the vehicle, an input / output device (not shown), a storage device (ROM, RAM, etc.) used for storing control programs and control maps, an ECU (control unit) equipped with a central processing unit (CPU), a timer counter, etc. (Unit) 30 is installed, and comprehensive control of the engine 1, the clutch device 2, and the transmission 3 is performed.

  On the input side of the ECU 30, an engine rotation speed sensor 31 that detects the rotation speed of the engine 1, a clutch rotation speed sensor 32 that detects the rotation speed (clutch rotation speed) of the input shaft 3a of the transmission 3, and a driver's seat are provided. A lever position sensor 33 for detecting the switching position of the change lever 13, an accelerator sensor 34 for detecting an operation amount (accelerator opening) of the accelerator pedal 14, and an output shaft rotational speed (vehicle speed) provided on the output shaft 3b of the transmission 3. Sensors such as a vehicle speed sensor 35 for detecting the operation of the brake pedal 15, a brake switch 36 for detecting the operation of the brake pedal 15, and a clutch stroke sensor 37 for detecting the clutch stroke of the clutch device 2 are connected.

  Further, the electromagnetic valve 9 of the clutch device 2 and the electromagnetic valves of the gear shift unit 23 are connected to the output side of the ECU 30, and the fuel injection valve of the engine 1 is connected, although not shown. . Note that an ECU dedicated to engine control may be provided separately from the ECU 30, for example, without comprehensive control by the single ECU 30 as described above.

  For example, the ECU 30 calculates the fuel injection amount to each cylinder of the engine 1 from a map (not shown) based on the engine rotation speed detected by the engine rotation speed sensor 31 and the accelerator opening detected by the accelerator sensor 34. The fuel injection timing is calculated from a map (not shown) based on the engine speed and the fuel injection amount. Based on these calculated values, the engine 1 is operated while driving the fuel injection valves of the respective cylinders.

  The ECU 30 executes the automatic transmission mode when the lever position sensor 33 detects that the change lever 13 is switched to the D (drive) range. Specifically, the ECU 30 calculates a target gear position from a shift map (not shown) based on the accelerator opening detected by the accelerator sensor 34 and the vehicle speed detected by the vehicle speed sensor 35. Then, while opening and closing the electromagnetic valve 9 of the clutch device 2 and connecting and disconnecting the clutch device 2 with the air cylinder 8, the predetermined electromagnetic valve of the gear shift unit 23 is opened and closed and the corresponding shift rod or shift piston is opened with the air cylinder. By operating, the main transmission unit 20, the range unit 21, and the splitter unit 22 are geared to the gear corresponding to the target shift stage. Thus, the ECU 30 automatically causes the vehicle to travel at an appropriate gear position.

  The shift position that can be selected by the change lever 13 includes a P (parking) range selected during parking, an N (neutral) range in which the gear of the main transmission 20 of the transmission 3 is neutral, and a D selected during forward travel. There are a (drive) range, an R (reverse) range that is selected during reverse travel, an M (manual) range that allows manual shift-up or shift-down.

  On the other hand, when starting the vehicle from the stopped state, the ECU 30 executes start control for starting by selecting an appropriate start stage (start control unit).

  The ECU 30 determines the target start stage based on a map based on conditions such as trailer connection or disconnection, vehicle weight, and road surface gradient. Alternatively, although not shown, a start stage selection switch that allows the driver to select the start stage is provided in the vehicle, and the ECU 30 sets the shift stage selected by the start stage selection switch as the target start stage.

  In particular, when starting using the high speed gear of the range unit 21 in the start control, the ECU 30 switches to the low speed gear in the range unit 21 (low speed gear switching step) before engaging the gear in the main transmission unit 20. After the gear is engaged, the range portion 21 is switched to a high-speed gear (high-speed gear switching step) and start preparation control is performed.

  That is, in the present embodiment, the start preparation control is performed when the start stage is 7th speed or higher using the high speed gear in the range unit 21 as shown in FIG. Specifically, the ECU 30 sets the gear of the main transmission unit 20 to neutral and temporarily sets the range unit 21 when the vehicle stops (vehicle speed 0) and the driver sets the change lever 13 to the N range. Switch to a low gear. Then, after the driver switches the change lever 13 to the D range for starting, the main transmission unit 20 puts a gear into the gear corresponding to the starting stage, and then switches the range unit 21 to the high speed gear.

  The ECU 30 performs the above-described start preparation control only in a situation where a shock when the gear is engaged is particularly affected, for example, when the brake pedal 15 and a parking brake (not shown) are continuously released (brake OFF) for a predetermined time or more when the vehicle is stopped. Is preferably performed. By providing such a condition, when a sufficient braking force is applied to the vehicle or when the stop time of the vehicle is short, the vehicle starts quickly without switching the gear of the range unit 21 before starting. Can be prioritized.

  Here, referring to FIG. 3, various operation states when the ECU 30 executes the start preparation control are shown in a time chart, and the operation of the start control device and the start control method according to the present embodiment and The effect will be described. In FIG. 3, as various operating states, the shift position detected by the lever position sensor 33, the clutch stroke detected by the clutch stroke sensor 37, the gear state of the main transmission unit 20, the gear state of the range unit 21, and the clutch rotation speed The clutch rotation speed detected by the sensor 32 is shown.

  The time chart of FIG. 3 starts from the time when the vehicle stops, and the vehicle is in a trailer disconnected state, stops at the seventh speed, and the starting stage is also the seventh speed. When the transmission 3 is in the seventh speed, as shown in FIG. 2, the main transmission unit 20 selects the low-speed gear, the range unit 21 selects the high-speed gear, and the splitter unit 22 selects the low-speed gear.

  As shown in FIG. 3, when the driver switches the change lever from the D range to the N range at time t1 after the vehicle stops, the ECU 30 first switches the main transmission 20 from the low speed gear at time t2 immediately thereafter. Switch to neutral. Since the ECU 30 is set to the seventh speed using the high speed gear of the range unit 21 as the target start stage, the range unit 21 is moved from the high speed gear as the start preparation control at the time t3 when the main transmission unit 20 becomes neutral. Switch to low gear.

  The clutch device 2 is in the form of maintaining the connected state during the N range, and therefore the ECU 30 places the clutch device 2 in the connected state at the subsequent time t4. When the clutch device 2 is in the connected state, the clutch rotational speed increases to about the idle rotational speed of the engine 1. Since the main transmission unit 20 is neutral, the rotation of the engine 1 is not transmitted to the output side of the transmission 3.

  At time t6, when the driver switches the change lever from the N range to the D range for starting, the ECU 30 brings the clutch device 2 into a disconnected state. When the clutch device 2 is completely disconnected at time t7, the clutch rotational speed gradually decreases. The ECU 30 gears the main transmission 20 from the neutral to the low speed gear at time t8 before the clutch rotational speed becomes zero. At this time, the clutch rotational speed is 0 or more, that is, the input side of the transmission 3 rotates and the output side stops and a rotational speed difference is generated, so that the main transmission unit 20 can smoothly put gears. It is.

  Further, as shown by a broken line in FIG. 3, if the main transmission unit 20 is geared in a state where the range unit 21 is maintained at a high speed gear from the stop of the vehicle to the start of the vehicle, a large shock may occur. On the other hand, in the present embodiment, when the gear is engaged in the main transmission unit 20 at time t8, the range unit 21 is switched to the low speed gear, so that the gear engagement shock in the main transmission unit 20 is the range. This is more reliably reduced than when the portion 21 is a high-speed gear.

  Next, the ECU 30 switches the range unit 21 from the low-speed gear to the high-speed gear at the time t9 after completing the gear setting of the main transmission unit 20, thereby setting the gear stage of the transmission 3 to the seventh speed that is the target start stage. Since the range unit 21 is composed of planetary gears, the range unit 21 can be easily switched even if there is no difference in rotational speed, and almost no shock is generated.

  And start preparation control is also complete | finished at the time t10 when switching to the high speed gear of the range part 21 is complete | finished, and a vehicle can start.

  As described above, when the ECU 30 starts using the high speed gear of the range unit 21, the range unit 21 is switched to the low speed gear before the main transmission unit 20 is geared, and after the main transmission unit 20 is geared. By switching the range unit 21 to the high speed gear, it is possible to smoothly put gears using the difference in rotation speed, and to suppress a shock at the time of gearing to a minimum.

  Further, the ECU 30 switches the range unit 21 to the low speed gear at a time point (t3) when the vehicle stops and the main transmission unit 20 becomes neutral, so that the change lever 13 is switched to the D range. The period until the vehicle is ready to start can be shortened to a minimum, and the start delay can be suppressed.

  In particular, when the trailer is not towed, the start control device and the start control method according to the present embodiment are applied to a tractor that often starts using the high-speed gear of the range unit 21, thereby driving by a shock at the time of start. The discomfort of the person can be greatly improved.

  This is the end of the description of the vehicle start control device and the start control method according to the present invention, but the embodiment is not limited to the above embodiment.

  In the above-described embodiment, the tractor that can pull the trailer is described as an example of a vehicle that can obtain particularly advantageous effects as described above. However, the vehicle to which the present invention can be applied is not limited to this, and a multi-stage transmission is possible. It can also be applied to other large trucks and passenger cars having

  Moreover, in the said embodiment, although the engine 1 is a diesel engine, an engine is not restricted to this, For example, a gasoline engine may be sufficient.

  In the above-described embodiment, the transmission 3 includes the main transmission unit 20 and the two sub-transmission units, the range-type sub-transmission unit 21 and the splitter-type sub-transmission unit 22. The present invention can also be applied to a transmission having only a range-type sub-transmission unit, and in this case, the same effect can be achieved.

DESCRIPTION OF SYMBOLS 1 Engine 2 Clutch apparatus 3 Multistage transmission 20 Main transmission part 21 Range part 22 Splitter part 23 Gear shift unit 30 ECU (start control part)

Claims (7)

A transmission including a main transmission unit having a plurality of transmission gears, and a sub-transmission unit having a high speed gear and a low speed gear for expanding a range of a gear ratio of the main transmission unit;
When starting using the high-speed gear of the sub-transmission unit, the sub-transmission unit is switched to a low-speed gear before gearing in the main transmission unit, and the sub-transmission unit is switched on after starting the gear in the main transmission unit. A start control unit that performs start preparation control for switching to a high-speed gear;
A vehicle start control device.   The start control unit, when starting using the high speed gear of the auxiliary transmission unit as the start preparation control, sets the auxiliary transmission unit to the low speed gear when the vehicle stops and the main transmission unit becomes neutral. The vehicle start control device according to claim 1, wherein   The vehicle start control device according to claim 1, wherein the start control unit performs the start preparation control only when the vehicle stops and the brake pedal is released for a predetermined time or more.   The vehicle start control device according to any one of claims 1 to 3, wherein the vehicle including the transmission is a tractor capable of pulling a trailer. A vehicle start control method including a transmission including a main transmission unit having a plurality of transmission gears, and a sub-transmission unit having a high-speed gear and a low-speed gear for expanding a gear ratio range of the main transmission unit,
When starting using the high speed gear of the auxiliary transmission unit,
A low-speed gear switching step for switching the sub-transmission unit to a low-speed gear before gearing in the main transmission unit;
A high-speed gear switching step of switching the sub-transmission unit to a high-speed gear after gearing of the starting stage in the main transmission unit;
A vehicle start control method.   6. The vehicle start control method according to claim 5, wherein the low-speed gear switching step switches the sub-transmission unit to a low-speed gear when the vehicle stops and the main transmission unit becomes neutral.   The vehicle start control method according to claim 5 or 6, wherein the low-speed gear switching step is performed when the vehicle stops and the brake pedal is released for a predetermined time or more.

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