JP2016156459A - Creep traveling form setting method for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a creep traveling form setting method for a vehicle which can improve the durability of a clutch by determining whether or not a vehicle is a creep-travelable vehicle in which the clutch is brought into the full-connected state, in the vehicle which travels by transmitting the power of an internal combustion engine to wheels via the clutch, avoiding that the creep-travelable vehicle creep-travels by bringing a clutch into a semi-connection state even if the clutch is brought into a full-connection state, and reducing the wear of the clutch.SOLUTION: When a reference creep speed Vc at creep traveling is set, a diameter of a wheel is set as D, a gear ratio of a final gear is set as GR, a minimum rotation number of an internal combustion engine 10 is set as Ne, and Nc which is calculated by a formula of Nc=Ne×D×GR is set as a reference rotation number, a connection state of a clutch at the creep traveling is set into a semi-connection state when [Nc/Vc] is equal to or larger than a determination threshold, and when [Nc/Vc] is smaller than the determination threshold, the connection state of the clutch at the creep traveling is set into a full-connection state.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a creep travel configuration setting method for a vehicle that travels by transmitting power of an internal combustion engine to wheels via a clutch, a transmission, and a final gear (differential gear).

  Generally, a vehicle including an internal combustion engine such as a diesel engine travels by transmitting engine power to wheels via a transmission. Usually, a clutch is disposed between the engine and the transmission, and the power transmission between the engine and the transmission is controlled by switching the connection / disconnection state of the clutch.

  This clutch is provided with a disk at each of the end of the input shaft on the engine side and the end of the output shaft on the transmission side provided inside, and friction generated by contact between the disks (contact state of the clutch). Power is transmitted from the engine to the transmission. There are two types of clutches: wet clutches that contain lubricating oil for lubricating and cooling the disks, and dry clutches that do not contain lubricating oil.

  When a wet clutch is used for this clutch, the engine power is transmitted to the transmission via the lubricating oil even when the clutch discs are separated by separating the disks inside the clutch, and the transmission of the power is performed. Since it cannot be completely shut off, if the shift lever is not input to the P range or N range and the transmission gear stage in the transmission is engaged, the vehicle will There is a creep phenomenon that travels at a slow speed.

  Using this creep phenomenon, creep driving is performed in which the driver moves the vehicle at a slow speed while adjusting the amount of depression of the brake pedal. In this creep driving, the power transmitted from the engine to the transmission is increased to some extent. For this purpose, a half-contact state in which a part of the disks inside the clutch are in contact with each other, that is, a half-clutch is used.

  In this connection, a creep control device for a starting clutch of a vehicle having a manual transmission, which can be selected from a fully connected state where the clutch is completely connected, a half clutch state where the clutch is slid, and a disconnected state where the clutch is disconnected. This transmission control unit gears the transmission when the vehicle brake is on and the clutch is disengaged, and switches the clutch from the disengaged state to the half-clutch state after gearing is complete. A start clutch creep control device has been proposed in which the clutch is switched from a half-clutch state to a fully connected state after the vehicle is started with the brake turned off (see, for example, Patent Document 1).

  However, when the vehicle is creeping, the vehicle speed is generally controlled by controlling the slip amount in the clutch. However, if the clutch is kept in a half-clutch state for a long time with relatively large power, the clutch slips due to slipping. Wears, and there is a problem that the durability of the clutch is lowered.

JP 2005-289219 A

  On the engine side, the inventor has determined that the engine speed is the idling speed and the minimum engine speed is determined. The engine speed is the engine speed that enables the creep speed, which is the vehicle speed in creep travel. When the number is large, it is preferable to run with a half-clutch. On the other hand, when the minimum engine speed is smaller than the engine speed that enables the creep speed, the engine is not fully connected but fully connected. It is preferable to drive while changing the engine speed on the side. Therefore, if creep travel can be performed in a fully connected state, a vehicle that travels with the clutch fully connected during creep travel of the vehicle eliminates the semi-contact state in creep travel and reduces clutch wear and clutch durability. The knowledge that can be avoided.

  On the other hand, with respect to the engine speed, the vehicle speed is determined for each type of vehicle according to the diameter of the tire mounted on the wheel and the gear ratio (difference ratio) of the final gear (differential gear). Therefore, even if the creep speed, which is the vehicle speed in creep driving, is set on the engine side, the number of revolutions at which idling can be performed is determined. Therefore, depending on the type of vehicle, the clutch can be fully engaged and the vehicle can run at the creep speed. There are cases where the vehicle becomes a vehicle and where the vehicle cannot run at the creep speed even when the clutch is fully engaged.

  Therefore, during this creep travel, it is determined whether creep travel is performed at the creep speed with the clutch half-connected, or creep travel without slip with the clutch fully engaged, and creep travel is performed for each type of vehicle. It is necessary to set the operation of the clutch in the engine, but the determination of which one to use is made by using “Nc / Vc” which is the ratio of the rotational speed Nc of the output shaft to the creep vehicle speed Vc according to the differential ratio and the tire size. Thus, the knowledge that it can be easily determined was obtained.

  The present invention has been made in view of the above, and an object of the present invention is to completely connect the clutch in a vehicle that travels by transmitting the power of the internal combustion engine to the wheels via the clutch, transmission, and final gear. By determining whether or not the vehicle is capable of creeping the vehicle in a state, it is possible to prevent a vehicle that can be creeped even if the clutch is in a fully engaged state from creeping with the clutch in a semi-connected state Thus, an object of the present invention is to provide a vehicle creep travel configuration setting method that can reduce clutch wear due to slip in a half-clutch state and improve the durability of the clutch.

  In order to achieve the above object, a creep travel mode setting method for a vehicle according to the present invention includes creep travel for a vehicle traveling by transmitting the power of an internal combustion engine to wheels via a clutch, transmission, and final gear. In the creep travel mode setting method of the vehicle for setting the engagement state of the clutch at the time, a reference creep speed Vc during creep travel is set, the wheel diameter is D, the gear ratio of the final gear is GR, and the internal combustion engine When “Nc / Vc” is equal to or greater than a predetermined determination threshold when the minimum engine speed is Ne and Nc calculated by Nc = Ne × D × GR is a reference speed, The clutch engagement state during creep travel is set to a semi-connected state, and when “Nc / Vc” is less than the determination threshold, the vehicle The clutch is set to be in a fully connected state during travel.

  According to the creep travel mode setting method for a vehicle of the present invention, it is determined whether or not the vehicle is capable of creeping the vehicle with the clutch in the fully connected state, so that the creep is performed even when the clutch is in the fully connected state. It is possible to avoid creeping travel of a travelable vehicle with the clutch in a semi-connected state, reduce clutch wear due to slip in the semi-connected state, and improve the durability of the clutch.

It is a figure which shows an example of a structure of the vehicle to which the creep running form setting method of the vehicle of embodiment which concerns on this invention is applied.

  Hereinafter, a creep driving mode setting method for a vehicle according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, in the configuration shown in FIG. 1, the clutch 11 is configured as a dual clutch including two clutches 11a and 11b. However, the clutch 11 may be configured as a single clutch including one clutch. If the clutch used is a clutch that can be in a semi-connected state, such as a wet clutch, the present invention can be applied, and the effects of the present invention described later can be achieved.

  As shown in FIG. 1, a vehicle to which a vehicle creep travel configuration setting method according to an embodiment of the present invention is applied is, in order from an engine (internal combustion engine) 10, a clutch 11, a transmission 12, and a final gear (differential gear: A differential gear (not shown) and wheels (not shown) are arranged, and the vehicle travels by transmitting the power of the engine 10 to the wheels via the clutch 11, the transmission 12, and the final gear.

  Here, a power transmission path when the power of the engine 10 is transmitted to the final gear and the wheels via the dual clutch 11 and the transmission 12 will be described. Each connection / disconnection state of the first clutch 11a and the second clutch 11b can be switched according to the operating state of the engine 10. However, when the dual clutch 11 is switched from the disconnection state to the connection state, the engine 10 is usually connected. Is transmitted to the final gear and the wheels via the first clutch 11a, the counter shaft 12a, and the main shaft 12b. However, when a direct-coupled gear stage is used as the transmission gear stage of the transmission 12, the first clutch 11a is brought into a contact state, and the power of the engine 10 is transmitted to the first clutch 11a and the main shaft 12b without passing through the counter shaft 12a. To the final gear and wheels.

  In FIG. 1, the torque converter 14 is disposed between the engine 10 and the dual clutch 11, but the present invention can also be applied to a case where the torque converter 14 is not provided. There is an effect.

  In the creep travel mode setting method for a vehicle according to the embodiment of the present invention, creep is applied to a vehicle that travels by transmitting the power of the engine 10 to the wheels via the clutch 11, the transmission 12, and the final gear. This is a creep travel configuration setting method for a vehicle in which the connection state of the clutch 11 during travel is set.

  In this method, the reference creep speed Vc during creep driving is set, the wheel diameter is D, the gear ratio of the final gear is GR, the minimum engine speed of the engine 10 is Ne, and Nc = Ne × D × GR. When “Nc / Vc” is equal to or greater than a predetermined determination threshold value R1 when Nc is set as a reference rotational speed, the setting of the clutch 11 to be in a semi-connected state during creep traveling of the vehicle is performed. When “Nc / Vc” is less than the determination threshold value R1, a setting is made in which the connection state of the clutch 11 during the creep running of the vehicle is set to the complete connection state. Here, the determination threshold value R1 is set to an appropriate value in advance through experiments or the like.

  When the calculated ratio “Nc / Vc” is equal to or higher than a determination threshold value R1 set in advance based on the creep speed Vc, the clutch 11 (11a, 11b) is in a fully engaged state, and the vehicle is in a creeping state. It is determined that the traveling speed exceeds the upper limit value (for example, 5 km / h) of the creep speed region and the vehicle cannot travel at a low speed, and the clutch 11 (11a, 11b) during creep traveling is in a semi-connected state. Set to.

  On the other hand, when the calculated ratio “Nc / Vc” is less than the above-described determination threshold value R1, even when the clutch 11 (11a, 11b) is in the fully engaged state, the traveling speed during creep traveling of the vehicle is within the creep speed region. It is determined that the vehicle can be traveled at a low speed without exceeding the upper limit value, and the clutch 11 (11a, 11b) during creep travel is set to a fully connected state.

  According to the creep travel mode setting method for a vehicle having the above-described configuration, the clutch 11 is determined by determining whether or not the vehicle is capable of creeping the vehicle with the clutch 11 (11a, 11b) in a fully connected state. (11a, 11b) Even if the vehicle is capable of creeping even if it is in the fully connected state, the clutch 11 (11a) is prevented from creeping with the clutch 11 (11a, 11b) in the semi-connected state and slipping in the semi-connected state. 11b) and the durability of the clutch 11 (11a, 11b) can be improved.

10 Engine (Internal combustion engine)
11 Dual clutch 11a First clutch 11b Second clutch 12 Transmission 12a Counter shaft 12b Main shaft 14 Torque converter

Claims (1)

In a vehicle creep traveling mode setting method for setting a connection state of the clutch during creep traveling, for a vehicle traveling by transmitting power of an internal combustion engine to wheels via a clutch, transmission, and final gear,
Set the reference creep speed Vc during creep running,
When the wheel diameter is D, the gear ratio of the final gear is GR, the minimum engine speed of the internal combustion engine is Ne, and Nc calculated by Nc = Ne × D × GR is the reference speed, “Nc When “/ Vc” is equal to or greater than a preset determination threshold, the clutch is connected in a semi-connected state during creeping of the vehicle, and “Nc / Vc” is less than the determination threshold. When the vehicle is creeping, the vehicle creeping travel mode setting method is characterized in that the clutch is connected in a fully engaged state.

Images