JP5217834B2 - Traction drive vehicle with different braking assistance when towing and when not towing - Google Patents

Description

  The present invention relates to a traction drive vehicle configured to be able to travel while towing a towed vehicle, and particularly relates to making the braking performance of a traction drive vehicle different depending on a traction state.

In a vehicle such as a lorry in which the traveling mass of the vehicle changes greatly according to the cargo loading state, the braking effectiveness when the vehicle is braked varies considerably depending on the loading load. Regarding the control of braking in accordance with the load of the vehicle, the following Patent Document 1 discloses a master cylinder pressure at which a brake assist for assisting a braking operation by a driver by a power unit called a booster is started. It is described that when the vehicle is in a fixed volume state, it is lower than when the vehicle is in a lightly loaded state. Japanese Patent Application Laid-Open No. 2004-228561 describes that the increase speed of the braking force by the brake assist is variably controlled so as to increase when it is large according to the load amount of the vehicle. Patent Document 3 below describes that the automatic brake operation start timing is variably controlled in accordance with the load of the vehicle so as to be earlier when the load is large.
JP2002-2466 JP-A-11-217064 JP 10-307999 A

  A towing drive vehicle that travels by towing a towed vehicle has been conventionally designed to operate by towing a towed vehicle as its basic operation mode, and its braking means also has its own traveling mass. It is designed to generate the necessary braking force for the maximum travel mass, which is the sum of the travel mass of the towed vehicle and the travel mass based on the load weight scheduled to be loaded on the towed vehicle.

  However, even a traction drive vehicle sometimes has to travel without towing a towed vehicle. In such a case, a traction drive vehicle designed as an operation mode only when traveling by pulling a conventional towed vehicle has a problem that the braking device is too effective and is difficult to drive. This is particularly noticeable during emergency braking in which the brake pedal is depressed rapidly or in high deceleration braking in which the brake pedal is depressed deeply.

  The present invention pays attention to the above-mentioned problems in the traction drive vehicle, and an object thereof is to provide an improved traction drive vehicle in this regard.

In order to solve the above-mentioned problems, the present invention comprises a driving means for driving a wheel by a prime mover, and a braking means for assisting a driver's braking operation to brake the rotation of the wheel, and pulls the towed vehicle. In the traction drive vehicle adapted to be able to travel, the braking means pulls a towed vehicle loaded with a predetermined maximum load and provides a braking force required when the traction drive vehicle travels. It is designed to assist the driver's braking operation so that it can be obtained, and when the traction drive vehicle travels without towing the towed vehicle, the driver's braking operation can be performed only by the traction drive vehicle. To assist to the extent suitable for the braking of the driver, to assist the same braking operation of the driver when towing the towed vehicle and towed without the towed vehicle It is characterized by becoming It is intended to propose a that traction drive vehicles.

  The assistance includes non-traction emergency braking assistance that assists the driver's braking operation when the driver depresses the brake pedal at a brake pedal depression speed that is equal to or higher than a predetermined brake pedal depression speed when not towing, and driving when towing. An emergency braking assist during towing that assists the driver's braking operation when the driver depresses the brake pedal at a brake pedal depression speed equal to or higher than a predetermined brake pedal depression speed may be included.

  The assistance includes non-traction high deceleration assistance that assists the braking operation of the driver when the driver depresses the brake pedal to a depth that is greater than or equal to a predetermined brake pedal depression depth during non-traction, Occasionally, a high deceleration assist during towing that assists the driver's braking operation when the driver depresses the brake pedal to a depth that is greater than or equal to a predetermined brake pedal depression depth may be included.

  Further, even in the case of deviation, the assist may include a boost failure assist that assists the driver's braking operation when a fault occurs in the booster of the braking means.

  Furthermore, the assist may include an additional assist that is added only when towing, not when not towing.

  Each assist during the non-traction may be performed when the vehicle speed is equal to or higher than a predetermined value determined for the non-traction, and each assist during the towing is performed when the vehicle speed is the towing. It may be performed when it is equal to or greater than a predetermined value defined for

  As described above, the driving means for driving the wheels by the prime mover and the braking means for assisting the driver's braking operation to brake the rotation of the wheels can be used to tow the towed vehicle. In the towing drive vehicle, the braking means assists the driver for the same braking operation when towing the towed vehicle and towing the vehicle without the towed vehicle. If the traction drive vehicle brake means, the braking means of the traction drive vehicle can obtain the braking force required when the traction drive vehicle travels by towing the towed vehicle loaded with the planned maximum load. Even if it is designed to assist the driver's braking operation, the driver's braking operation is suitable for braking the running mass of only the traction drive vehicle when the traction drive vehicle travels without towing the towed vehicle. To subsidize to a certain extent Come, traction drive vehicle even when traveling without having to tow a towed vehicle, it is possible to comfort the braking feeling of the driver.

  In addition to the above-mentioned assistance, when the driver depresses the brake pedal at a brake pedal depressing speed equal to or higher than a predetermined brake pedal depressing speed when not towing, the non-traction emergency braking assist that assists the driver's braking operation, and the driver when towing If it includes emergency braking assistance during towing that assists the braking operation of the driver when the brake pedal is depressed at a brake pedal depression speed that is equal to or higher than the predetermined brake pedal depression speed, During emergency braking in which the difference in braking effect with respect to the depression of the brake pedal becomes particularly significant, it is possible to appropriately assist the braking with respect to the driver's operation of depressing the brake pedal with respect to when the vehicle is not towed and towed.

  In addition, when the driver depresses the brake pedal to a depth that is greater than or equal to a predetermined brake pedal depressing depth when not towing, non-traction high deceleration assist that assists the driver's braking operation, and when towing If the driver includes high-speed deceleration assistance that assists the driver's braking operation when the brake pedal is depressed to a depth that is greater than or equal to the predetermined brake pedal depression depth, During high deceleration braking where the difference in braking effect with respect to depression of the brake pedal becomes particularly noticeable depending on the time, braking assistance for the brake pedal depression operation of the driver is properly performed for each of when not towing and towing be able to.

  Also, in the case of deviation, if the assist includes a boost failure assist that assists the driver's braking operation when a defect occurs in the booster of the braking means, the booster of the braking means When a defect occurs, it is possible to respond appropriately.

  Further, if the assist has an additional assist that is added only during towing, not during non-traction, a large difference in braking force between non-traction and during towing can be easily filled.

  Each assist at the time of non-towing is performed when the vehicle speed is equal to or higher than a predetermined value determined for non-towing, and each assist at the time of towing is performed when the vehicle speed is towing. If it is to be performed when the value is equal to or greater than a predetermined value, the assist control is performed for each of the non-traction time and the non-traction time, regardless of whether it is non-traction or traction. The lower limit of the vehicle speed to be activated is set appropriately, and when the vehicle speed is very small, the driver's brake operation is reflected in the braking as it is to enable delicate braking adjustment, and the vehicle speed at which the assist control is activated is clarified. The assist control performance can be clearly set.

  FIG. 1 is a schematic side view showing two typical configurations of a tow vehicle (trailer) composed of a combination of a tow drive vehicle and a towed vehicle. Of these, in the towing vehicle shown in FIG. A, the towing drive vehicle 10 does not have a cargo loading portion, the towed vehicle 12 does not have a front wheel, and the towed vehicle has a load and a pulling force at its front end. It is towed by the traction drive vehicle while being supported by the traction drive vehicle via a pivotal coupling device 14 capable of transmitting both of them. On the other hand, in the towing vehicle shown in FIG. B, the towing drive vehicle 16 has a cargo compartment 18 in which a certain amount of cargo can be loaded, and the towed vehicle 20 has front and rear wheels. The load is supported by its own front and rear wheels, and is pulled by a traction drive vehicle via a pivotal coupling device 22 that can transmit only the traction force. . Here, the traction force transmitted by the pivotal coupling devices 14 and 22 is a positive traction force that acts when the traction drive vehicle pulls the towed vehicle, and a traction force that acts when the traction drive vehicle brakes the towed vehicle. It shall mean both negative traction forces.

  The types of towing vehicles shown in FIGS. A and B are used depending on the type of cargo to be loaded. In either case, the driving force for driving the towing vehicle and the braking force for braking the towing vehicle are traction driving. Only generated in the car. The pushing force of the wheel against the road surface necessary to transmit the driving force and the braking force between the wheel and the road surface is determined by the weight of the traction driving vehicle and the load of the towed vehicle in the case of the towing vehicle of FIG. Is covered by the pressing force exerted on the traction drive vehicle through the front end of the towed vehicle. In the traction vehicle of the type shown in FIG. B, the weight of the traction drive vehicle and the cargo compartment 18 of the traction drive vehicle are loaded. It is covered by the load capacity.

  In this type of vehicle, the driving means for driving the wheels by the prime mover and the braking means for assisting the driver's braking operation in variously controlled degrees to brake the rotation of the wheels are provided in this technical field. Since they are well known to those skilled in the art, a detailed description of these driving means and braking means will be omitted to avoid redundancy of the specification.

  FIG. 2 is a diagram illustrating a traction drive vehicle according to the present invention, which is different in assisting the driver for the same braking operation when traction is performed by towing a towed vehicle and when the vehicle is not towed without a towed vehicle. It is a flowchart which shows the aspect which controls a braking means so that it may perform about one embodiment. The control according to this flowchart is provided with an appropriate sensor for detecting whether or not the towed vehicle is connected to the towing drive vehicle, and such a sensor, a vehicle speed sensor and a brake pedal that are normally equipped on this type of vehicle. It can be executed by using a stroke sensor, a longitudinal acceleration sensor, and an electronic control device, and by causing the microcomputer of the electronic control device to perform appropriate calculations and control instructions based on signals from these sensors. It may be repeated with a period of several tens of milliseconds during operation.

  When the control is started, it is determined in step 10 whether or not the towing drive vehicle is towing the towed vehicle. If the answer is no (N), the control proceeds to step 20, and it is determined whether or not the vehicle speed V is equal to or higher than a certain predetermined relatively low lower limit value Vo determined for non-traction. When the answer is no, i.e. when the traction drive vehicle is stopped or traveling at a very low speed, even if the driver depresses the brake pedal, it is assisted according to the invention. At this time, this control is finished. In addition, when the vehicle stops in the middle of an uphill, the control that automatically assists the driver to depress the brake pedal to prevent the vehicle from moving backward is a control different from the present invention. It is not involved. If the answer to step 20 is yes (Y), control continues to step 30.

  In step 30, it is determined whether or not the brake pedal depression speed Rbp is equal to or greater than a predetermined limit value Ro indicating that the driver is seeking emergency braking. If the answer is yes, control proceeds to step 40, where emergency braking assistance during non-traction is performed for the driver's brake pedal depression operation.

If the answer to step 30 is no, the control proceeds to step 50 where the brake pedal depression depth Dbp is equal to or greater than a predetermined limit value Do indicating that the driver is about to decelerate the vehicle. It is determined whether or not. If the answer is no, the control of this time is completed. If the answer is yes, the control proceeds to step 60, and the driver is forced to accelerate at a high speed when the brake pedal is not depressed. Is called. At this time, the control further proceeds to step 70.
It is determined whether there is no failure in the booster of the braking means. This may be determined, for example, by the fact that the vehicle is not decelerated corresponding to the high deceleration assist at the time of non-traction performed at step 60. If the answer is no, the control is terminated at this time, but if the answer is yes, the control proceeds to step 80, where an appropriate braking assist is provided for the failure of the booster. Note that the difference in braking effect with respect to the depression of the brake pedal between when not towing and when towing is particularly noticeable during emergency braking and during high deceleration control. In this embodiment, the answer to step 50 is no. No control is performed to distinguish between non-traction and non-traction at the time of, but when the answer to step 50 is no, braking assistance during normal braking, which is neither emergency braking nor high deceleration braking, It may be performed in a non-traction mode different from that at the time of traction.

  When the answer to step 10 is yes, that is, when the towing drive vehicle is towing the towed vehicle, the control proceeds to step 90.

  In step 90, it is determined whether or not the vehicle speed V is equal to or higher than a predetermined relatively low lower limit value Vt determined for towing. The value of Vt may be the same as the value of Vo determined for non-traction, but may be somewhat smaller than the value of Vo. If the answer is no, that is, if the towing drive vehicle that is towing the towed vehicle is stopped or traveling at an extremely low speed, it is assumed that the driver has depressed the brake pedal. However, since it is not necessary to assist it according to the present invention, the control is terminated at this time. Also in this case, when the vehicle stops in the middle of the uphill, the control that automatically assists the driver to depress the brake pedal to prevent the vehicle from moving backward is a control different from the present invention. The present invention is not involved. If the answer to step 90 is yes, control proceeds to step 100.

  In step 100, it is determined whether or not the brake pedal depression speed Rbp is equal to or greater than a predetermined limit value Rt indicating that the driver is seeking emergency braking. Again, the value of Rt may be the same as the value of Ro determined for non-traction, but may be somewhat smaller than the value of Ro. If the answer is yes, control proceeds to step 110, where emergency braking assistance during towing is performed for the driver's brake pedal depression operation. As a matter of course, the emergency braking assistance at the time of towing is stronger than the emergency braking assistance at the time of non-towing, which is performed in Step 40, for the same brake depression speed. Furthermore, in the illustrated embodiment, in addition to this, braking assistance for applying braking force is also performed. The degree of addition of this braking force may be appropriately determined.

If the answer to step 100 is no, the control proceeds to step 120 where the brake pedal depression depth Dbp is equal to or greater than a predetermined limit value Dt indicating that the driver is about to decelerate the vehicle. It is determined whether or not. Again, the value of Dt may be the same as the value of Do determined for non-traction, but may be somewhat smaller than the value of Do. If the answer is no, the control of this time is completed. If the answer is yes, the control proceeds to step 130, and a high deceleration assist at the time of towing is performed for the driver's brake pedal depression operation. . As a matter of course, this high deceleration assist during towing is also made stronger against the same brake depression depth than the non-traction high deceleration assist performed at step 60. Further, in the illustrated embodiment, in addition to this, braking assistance for applying braking force is performed. The degree of addition of this braking force may be determined appropriately. At this time, the control further proceeds to step 140.
It is determined whether there is no failure in the booster of the braking means. This may be determined, for example, by the fact that there is no deceleration corresponding to the high deceleration assist + braking force applied at the time of towing performed in step 130 in the vehicle. If the answer is no, the control is terminated at this time, but if the answer is yes, the control proceeds to step 150, and an appropriate braking assist for the failure of the booster is performed. Also in this case, the difference in braking effect with respect to the depression of the brake pedal between when not towing and when towing is particularly noticeable during emergency braking and during high deceleration braking. When the answer is no, no control is performed to distinguish between non-traction and non-traction, but when the answer to step 120 is no, it is for emergency braking that is neither emergency braking nor high deceleration braking. The braking assistance may be performed in a mode at the time of traction different from that at the time of non-traction.

  While the present invention has been described in detail with respect to one embodiment thereof, it will be apparent to those skilled in the art that various modifications can be made within the scope of the present invention.

The schematic side view which shows two typical structures of the tow vehicle (trailer) which consists of a combination of a tow drive vehicle and a towed vehicle. The flowchart which shows the control aspect of the braking means which performs different assistance with respect to the same braking operation of a driver | operator by the time of towing | pulling and the time of non-traction | pulling in the towing drive vehicle by this invention about one embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Towing drive vehicle, 12 ... Towed vehicle, 14 ... Pivoting connection device, 16 ... Towing driving vehicle, 18 ... Cargo compartment, 20 ... Towed vehicle, 22 ... Pivoting connection device

Claims (6)

A traction drive comprising driving means for driving the wheels by a prime mover and braking means for assisting the driver's braking operation to brake the rotation of the wheels so that the towed vehicle can be towed The braking means assists the driver's braking operation so that the driver can obtain the necessary braking force when the towing drive vehicle travels by towing the towed vehicle loaded with the planned maximum load. When the towing drive vehicle travels without towing the towed vehicle, the towed vehicle is subsidized to assist the driver's braking operation to the extent suitable for braking the running mass of only the towed driving vehicle. in time tow running towing cars and the time of non-towing running without the towed vehicle, being adapted to perform different assisting for the same brake operation by the driver, the assistance at the time of non-towing operation The brake pedal depressing speed Emergency braking assistance when not towing when the brake pedal depressing speed is equal to or higher than a certain brake pedal depression speed and braking assistance when not towing when not, including the brake pedal depression speed of the driver as a predetermined brake pedal A towing drive vehicle characterized by including emergency braking assistance during towing when the speed is greater than the stepping speed and braking assistance during towing when it is not . For assistance when the brake pedal depression speed when not towing is not equal to or greater than the predetermined brake pedal depression speed, when the driver depresses the brake pedal to a depth that is greater than or equal to the predetermined brake pedal depression depth when not towing Non-traction high-speed deceleration assistance that assists the driver's braking operation is included, and assistance when the brake pedal depressing speed during towing is not equal to or higher than the predetermined brake pedal depressing speed includes that the driver traction drive vehicle according to claim 1, characterized in that it includes a high deceleration auxiliary urging during towing for assisting a braking operation of a driver when depresses the brake pedal to pedal depth or more brake pedal depression depth. The high-speed deceleration assist at the time of non-traction or attraction includes a boost failure assist that assists the driver's braking operation when a defect occurs in the booster of the braking means. The traction drive vehicle according to 2.   The traction drive vehicle according to any one of claims 1 to 3, wherein the assist includes an additional assist that is added only when towing, not when not towing.   5. The traction according to claim 1, wherein each assist in the non-traction is performed when a vehicle speed is equal to or higher than a predetermined value determined for the non-traction. 5. Driving car.   The traction drive vehicle according to any one of claims 1 to 4, wherein each of the assists at the time of towing is performed when a vehicle speed is equal to or higher than a predetermined value determined for towing. .

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