JP6315433B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a control device that controls output torque of a power source in a vehicle that supplies torque output from the power source to an axle via a drive system.

  An internal combustion engine, which is a universal automobile power source, is mounted on a frame via a vibration isolation member using an elastic material. When the internal combustion engine is displaced by a certain amount or more with respect to the frame, the stopper comes into contact with the internal combustion engine to prevent further displacement (for example, refer to the following patent document).

JP 2006-160992 A

  A situation where the driver is not stepping on the accelerator pedal and the power source is not inputting positive torque to the drive system (typically due to negative torque transmitted from the axle side, such as during fuel cut of the internal combustion engine) When the driver depresses the accelerator pedal under the output shaft of the power source (the situation in which the rotation of the crankshaft in the case of an internal combustion engine is maintained), first the drive system is increased as the output torque of the power source increases. The backlash of the gears such as backlash is clogged, and then the output torque of the power source is transmitted to the axle via the drive system.

  In the process of backlash of the drive system immediately after the output torque of the power source begins to increase, a large mechanical load does not act on the power source from the drive system. Torque in the reverse rotation direction is applied to the power source as a reaction of the source inputting torque to the drive system. If the reaction torque is instantaneously large, the internal combustion engine may be relatively displaced with respect to the frame, and an impact may occur due to the contact of the stopper, which may cause the passenger to feel uncomfortable.

  The present invention made in view of the above is intended to alleviate or eliminate the problem that an impact is generated when the power source is displaced relative to the vehicle when the output torque of the power source is increased.

In order to solve the above-described problems, the present invention increases or decreases the output torque of the power source in a vehicle that supplies the torque output from the power source to the axle via the drive system in accordance with the accelerator operation amount by the driver. The power source is supported on the frame of the vehicle via an elastic member, and when the power source is displaced relative to the frame by a certain amount or more, the stopper is configured to restrict further displacement. When an accelerator operation requiring an increase in the output torque of the power source is performed in a situation where the engine does not input a positive torque to the drive system, the power source inputs a positive torque to the drive system. When there is a risk that the power source may be displaced more than a certain amount with respect to the frame due to the reaction received in step 1, a delay period for delaying the increase in the output torque of the power source with respect to the change in the accelerator operation amount Therefore, during the delay period, control is performed so as not to output a large torque that causes the power source to be displaced more than a certain amount with respect to the frame. The upper limit value of the output torque of the power source during the delay period is set to If the road surface is a downward slope, the vehicle control device is configured such that the higher the slope is, the higher the slope is, and the higher the slope is, the lower the slope is .

When the power source is an internal combustion engine, the upper limit value of the output torque of the internal combustion engine during the delay period can be set higher as the temperature of the internal combustion engine is lower.

  According to the present invention, when the output torque of the power source is increased, the problem that the power source is displaced relative to the vehicle and an impact is generated can be alleviated or eliminated.

The figure which shows schematic structure of the internal combustion engine and control apparatus in one Embodiment of this invention. The figure which shows typically the mount structure to the flame | frame of the internal combustion engine of the embodiment. The timing diagram which shows the pattern of the control which the control apparatus of the embodiment implements.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of a vehicle internal combustion engine 9 as a power source of the vehicle according to the present embodiment. The internal combustion engine 9 in the present embodiment is a spark ignition type four-stroke engine, and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode. The ignition coil is integrally incorporated in a coil case together with an igniter that is a semiconductor switching element.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  Torque output from the internal combustion engine 9 is transmitted to the vehicle axle (not shown) and then to the drive wheels via the drive systems 5 and 6. The drive system includes, for example, a torque converter 5 and a transmission 6 (a forward / reverse switching device using a planetary gear mechanism and a continuously variable transmission or a stepped automatic transmission), and a differential gear (not shown) directly connected to an axle. including. As shown in FIG. 2, the internal combustion engine 9 and the drive systems 5 and 6 are mounted on a vehicle frame (subframe, cross member or suspension member) 7.

  A vibration isolating member 8 using an elastic material is interposed between the internal combustion engine 9 and the frame 7. The vibration isolator 8 is made of an elastic body such as rubber in which a buffer liquid such as ethylene glycol is enclosed.

  The internal combustion engine 9 is provided with a mounting bracket 91, which is attached to the upper end portion of the vibration isolating member 8. The outer periphery of the portion of the bracket 91 protruding toward the frame 7 is covered with a covering material using an elastic material such as rubber. The lower end portion of the vibration isolation member 8 is attached to a support member 71 fixed to the frame 7.

  Further, a member 72 serving as a metal stopper, for example, is fixed to the support member 71. The stopper member 72 has an arch shape and is positioned so as to straddle the bracket 91.

  When the internal combustion engine 9 is displaced relative to the frame 7, the vibration isolation member 8 is elastically deformed. When the displacement amount of the internal combustion engine 9 with respect to the frame 7 exceeds a certain value, the bracket 91 on the internal combustion engine 9 side (the portion covered with the covering material) abuts against the stopper member 72 on the frame 7 side, and more than that of the internal combustion engine 9. The displacement of is suppressed.

  An ECU (Electronic Control Unit) 0 that is a control device of the present embodiment is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like.

  The input interface includes a vehicle speed signal a output from a vehicle speed sensor that measures the actual vehicle speed of the vehicle, a crank angle signal b output from an engine rotation sensor that measures the rotation angle and engine speed of the crankshaft, and depression of the accelerator pedal. Accelerator opening signal c output from a sensor that measures the amount as an accelerator opening (so-called demand load), intake air temperature / intake pressure that measures intake air temperature and intake air pressure in intake passage 3 (especially surge tank 33) An intake air temperature / intake pressure signal d output from the sensor, an acceleration signal e output from an acceleration sensor that measures vehicle acceleration and road surface inclination, and a cooling water temperature signal output from a sensor that measures the cooling water temperature of the internal combustion engine 9 f, shift range signal output from a sensor (or shift position switch) to know the range of the shift lever , The oil temperature signal h or the like to be output from the sensor for measuring the temperature of the working fluid used in the torque converter 5 and transmission 6 (also a lubricating oil) is input.

  From the output interface, an ignition signal i for the igniter of the spark plug 12, a fuel injection signal j for the injector 11, an opening operation signal k for the throttle valve 32, and a gear ratio control signal l for the transmission 6. Etc. are output.

  The processor of the ECU 0 interprets and executes a program stored in advance in the memory, calculates operation parameters, and controls the operation of the internal combustion engine 9. The ECU 0 acquires various information a, b, c, d, e, f, g, and h necessary for operation control of the internal combustion engine 9 through the input interface, knows the engine speed, and is filled in the cylinder 1. Estimate the amount of intake air. Various operating parameters such as required fuel injection amount, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, ignition timing, gear ratio, etc. To decide. The ECU 0 applies various control signals i, j, k, and l corresponding to the operation parameters via the output interface.

  The ECU 0 performs a fuel cut that temporarily stops fuel injection from the injector 11 in accordance with the driving situation of the vehicle. That is, the fuel cut is started when the accelerator pedal depression amount is 0 or less than a threshold value close to 0 and the engine speed is equal to or higher than the fuel cut permission speed. When one of the conditions such as the accelerator pedal depression amount exceeding the threshold value or the engine speed decreasing to the fuel cut return speed is satisfied, the fuel cut is finished and the fuel injection is restarted.

  As a general rule, the opening degree of the throttle valve 32 controlled by the ECU 0 is determined according to the accelerator operation amount by the driver, that is, the depression amount (change amount) of the accelerator pedal. However, when the amount of depression of the accelerator pedal increases in a situation where the internal combustion engine 9 is not inputting positive torque to the drive systems 5 and 6, the throttle valve 32 responds to changes in the amount of depression of the accelerator pedal. A delay period is provided to delay the increase in the opening degree.

  The situation in which the internal combustion engine 9 is not inputting positive torque to the drive systems 5 and 6 is that the output torque of the internal combustion engine 9 is small (the fuel injection amount is small or zero) and the output shaft of the internal combustion engine 9 This refers to a situation in which no torque is input from a certain crankshaft to the drive trains 5 and 6, and this is typically the case when a fuel cut is being performed. At this time, the rotation of the crankshaft of the internal combustion engine 9 is maintained by receiving torque input from the axle via the drive systems 5 and 6.

  As already described, when the driver depresses the accelerator pedal during the fuel cut, the fuel cut end condition is satisfied by the increase of the depression amount, and the fuel supply to the cylinder 1 is resumed. At that time, the throttle valve 32 is not enlarged according to the amount of depression of the accelerator pedal as in the normal time, but as shown in FIG. 3, at the time immediately after the time T when the fuel cut end condition is satisfied. Regardless of the depression amount of the pedal, the opening degree of the throttle valve 32 is suppressed to the upper limit value L or less. This period is the delay period described above. By suppressing the opening degree of the throttle valve 32 to the upper limit value L or less, the intake air amount and the fuel injection amount charged in the cylinder 1 are also suppressed, and the output torque of the internal combustion engine 9 is suppressed.

  The upper limit T is the engine speed when the output torque of the internal combustion engine 9 is increased in response to the accelerator operation by the driver, the transmission gear ratio (or shift position) of the transmission 6, and the temperature of the internal combustion engine 9. It is determined according to the inclination of the road surface where the vehicle is located, the travel distance of the vehicle, and the like.

  This upper limit value T ranges from a negative value (that is, a state where torque is transmitted from the torque converter 5 to the crankshaft) from the crankshaft of the internal combustion engine 9 to a positive value (ie, from the crankshaft to the torque converter 5). Is a condition in which the torque is transmitted). Alternatively, the upper limit value L is determined by the internal combustion engine 9 being displaced with respect to the frame 7 by the reaction torque that the crankshaft receives from the drive systems 5 and 6 when backlash of the gears of the drive systems 5 and 6 is clogged. The value immediately before the bracket 91 abuts against the stopper 72.

  The temperature of the internal combustion engine 9 is addressed to this by, for example, the cooling water temperature of the internal combustion engine 9 detected via a water temperature sensor or the temperature of the working fluid used in the drive systems 5 and 6 detected via an oil temperature sensor. . The temperature of the internal combustion engine 9 suggests a mechanical loss (friction loss) inside the internal combustion engine 9. The lower the temperature of the internal combustion engine 9, the higher the viscosity of the lubricating oil that lubricates each part of the internal combustion engine 9, and the greater the mechanical loss. Therefore, the torque transmitted from the crankshaft to the drive systems 5 and 6 becomes small for the same throttle valve 32 opening (intake amount and fuel injection amount). Accordingly, the lower the temperature of the internal combustion engine 9, the higher the upper limit value L.

  The inclination of the road surface on which the vehicle is located is determined from the actual vehicle speed detected via the vehicle speed sensor and the acceleration detected via the acceleration sensor. The road surface has a downward slope, and the larger the slope, the more difficult the backlash of the drive systems 5 and 6 becomes clogged even if the output torque of the internal combustion engine 9 is increased, so the upper limit value L becomes higher. On the contrary, the road surface has an upward slope, and the larger the slope is, the more easily the backlash of the drive systems 5 and 6 is clogged, so the upper limit L is lower.

  The travel distance of the vehicle is, for example, the cumulative travel distance from the time of shipment or the previous inspection (maintenance), and can be obtained from an odometer or trip meter mounted on the vehicle, and the vehicle speed detected through the vehicle speed sensor. Can also be calculated by time integration. Since the degree of secular change of the vibration isolating member 8 increases as the traveling distance of the vehicle increases, the upper limit value L decreases.

  In the memory of the ECU 0, the engine speed when the output torque of the internal combustion engine 9 is to be increased, the transmission gear ratio (or shift position) of the transmission 6, the temperature of the internal combustion engine 9, and the vehicle are located in advance. Stored is map data that defines the relationship between the slope of the road surface, the travel distance of the vehicle, and the upper limit L corresponding thereto. When the torque input from the internal combustion engine 9 to the drive systems 5 and 6 is switched from negative to positive, such as when the fuel cut condition is satisfied, the ECU 0 determines the engine speed, the gear ratio (or shift position), the internal combustion engine 9 The map is searched using the temperature of the vehicle, the slope of the road surface, the travel distance, etc. as keys, and the upper limit L is obtained. Then, at the time of the delay period immediately after the trigger, the opening of the throttle valve 32 is suppressed to the upper limit value L or less even if the amount of depression of the accelerator pedal is large. The length of the delay period may be appropriately determined experimentally.

  In the present embodiment, the output torque of the power source 9 in the vehicle that supplies the torque output from the power source 9 to the axle via the drive systems 5 and 6 is increased or decreased according to the accelerator operation amount by the driver. In the situation where the power source 9 does not input a positive torque to the drive systems 5 and 6 and an accelerator operation that requires an increase in the output torque of the power source 9 is performed, the mechanical loss of the power source 9 is affected. , The condition L at which the power source 9 inputs a positive torque to the drive systems 5 and 6 is known, and the change in the accelerator operation amount is obtained. On the other hand, a delay period for delaying an increase in output torque of the power source 9 is provided, and control is performed so that the power source 9 does not output a large torque exceeding the condition L during the delay period. 0 Configuration was.

  Moreover, in this embodiment, the output torque of the power source 9 in the vehicle that supplies the torque output from the power source 9 to the axle via the drive systems 5 and 6 is increased or decreased according to the accelerator operation amount by the driver. The power source 9 is supported by the vehicle frame 7 via the elastic member 8, and the stopper 72 restricts further displacement when the power source 9 is displaced relative to the frame 7 by a certain amount or more. In the situation where the power source 9 does not input a positive torque to the drive systems 5 and 6 and an accelerator operation for requesting an increase in the output torque of the power source 9 is performed, the power source 9 When there is a possibility that the power source 9 is displaced by a certain amount or more with respect to the frame 7 due to the reaction received by inputting positive torque to the drive systems 5 and 6, the power source 9 output To constitute a control apparatus 0 for a vehicle and providing a delay period to delay the increase in torque. During the delay period, control is performed so as not to output such a large torque that the power source 9 is displaced with respect to the frame 7 by a certain amount or more (so that the bracket 91 comes into contact with the stopper 72).

  According to the present embodiment, when the output torque of the power source 9 is increased immediately after the end of the fuel cut or the like, the problem that the power source 9 is displaced relative to the vehicle and an impact is generated at the stopper 72 portion is alleviated. Can be resolved. In particular, since the mechanical loss of the power source 9 itself changes depending on the temperature of the power source 9, the torque transmitted from the power source 9 to the drive systems 5 and 6 changes. However, the upper limit value L should be determined taking this into consideration. Therefore, immediately before the backlash of the drive systems 5 and 6 is clogged, the output torque of the power source 9 is quickly raised, and the output torque is limited appropriately when the backlash of the drive systems 5 and 6 is clogged. It is possible to suppress the impact. As long as the bracket 91 does not collide with the stopper 72, it is allowed to increase the output torque of the power source 9, so that the acceleration response is not impaired.

  The present invention is not limited to the embodiment described in detail above. For example, in the above embodiment, the output torque of the internal combustion engine 9 as the power source is suppressed by determining the upper limit value L with respect to the opening of the throttle valve 32 and suppressing the opening of the throttle valve 32. In addition to or instead of this, an upper limit value may be set for the fuel injection amount from the injector 11 and the number of combustions in each cylinder 1 to suppress the fuel injection amount or the number of combustions. The suppression of the number of times of combustion is so-called combustion thinning (in a part of the cycle that sequentially visits each cylinder 1, fuel is not intentionally injected and fuel combustion in the expansion stroke is not generated).

  The power source 9 is not limited to an internal combustion engine. In the case of a hybrid vehicle or an electric vehicle, an electric motor is used as the power source 9, but the technical idea of the present invention can naturally be applied to this as well. In this case, an upper limit is set on the applied current or applied voltage to the electric motor as the power source 9 and the output torque of the electric motor 9 is suppressed.

  Other specific configurations of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to control of output torque of a power source of a vehicle.

0 ... Control unit (ECU)
DESCRIPTION OF SYMBOLS 11 ... Injector 32 ... Throttle valve 5, 6 ... Drive system (torque converter, transmission)
9 ... Power source (internal combustion engine)
f ... Cooling water temperature signal h ... Working fluid temperature signal

Claims (2)

In the vehicle that supplies the torque output from the power source to the axle via the drive system, the output torque of the power source in the vehicle is increased or decreased according to the accelerator operation amount by the driver,
The power source is supported on the frame of the vehicle via an elastic member, and when the power source is displaced relative to the frame by a certain amount or more, the stopper is configured to restrict further displacement.
In the case where an accelerator operation is performed that requires an increase in the output torque of the power source in a situation where the power source does not input positive torque to the drive system,
When there is a risk that the power source may be displaced more than a certain amount relative to the frame due to the reaction that the power source receives by inputting positive torque to the drive system, the output torque of the power source A delay period for delaying the increase is provided, and during the delay period, control is performed so as not to output a large torque such that the power source is displaced more than a certain amount with respect to the frame.
The upper limit value of the output torque of the power source during the delay period is set higher as the slope is larger if the road surface on which the vehicle is located is larger, and the slope is larger if the road surface is ascending. A control device for a vehicle that is set so low. The vehicle control device according to claim 1, wherein the power source is an internal combustion engine, and the upper limit value of the output torque of the internal combustion engine during the delay period is set higher as the temperature of the internal combustion engine is lower .

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