JP2010156380A - Controller of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller of a vehicle, reducing a load on a lockup clutch while preventing a sense of incongruity from being given to the driver. <P>SOLUTION: When the lockup clutch 65 is controlled in a flex lockup state, a drive force variation amount ΔF, which is the difference between a present drive force F and a drive force F_est obtained when the lockup clutch 65 is disengaged, is calculated (step S14). Since the lockup clutch 65 is disengaged (step S18) when the drive force variation amount ΔF is within a predetermined drive force threshold F_tv (determined in step S15), a load on the lockup clutch 65 is reduced while preventing a sense of incongruity from being provided to the driver with less variation of a vehicle 10 when the lockup clutch 65 is disengaged. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle control device that controls a vehicle including a torque converter with a lockup mechanism.

  In general, an automatic transmission mounted on a vehicle includes a torque converter and a transmission mechanism. The speed change mechanism selectively switches the power transmission path of the speed change gear mechanism by engagement and release of a plurality of friction engagement elements such as a clutch and a brake, so that a predetermined speed is achieved. Further, as a speed change mechanism, there is a continuously variable transmission (CVT) that does not have a step in the speed change and sets the speed change ratio steplessly. Some continuously variable transmissions are designed to change gears by changing the gear ratio stepwise.

On the other hand, the torque converter uses a fluid such as oil (operating oil) to transmit power transmitted from a power source (for example, an engine or an electric motor) to the shaft of the transmission mechanism.
For example, a torque converter includes a donut-shaped container (hereinafter referred to as a housing) filled with oil, a pump impeller that transmits power from an engine, a turbine runner that transmits power to a transmission mechanism, and a torque increasing action. And a stator for performing.

  The pump impeller is connected to a crankshaft that is an output shaft of the engine, and rotates integrally with the crankshaft. The turbine runner is connected to an input shaft that is an input shaft of the speed change mechanism, and rotates integrally with the input shaft. The pump impeller and the turbine runner are disposed to face each other, and a stator is provided between the pump impeller and the turbine runner.

  The engine rotates the pump impeller via the crankshaft. The pump impeller flows into the turbine runner by being rotated by the engine. The turbine runner is rotated by the oil flowing out from the pump impeller, thereby rotating the input shaft. The stator controls the direction of oil flowing from the pump impeller toward the turbine runner.

  With such a configuration, the torque converter receives engine power, increases torque, and transmits the torque to the transmission mechanism. However, since such a torque converter transmits rotation via a fluid, the rotational speed on the input side is set to 100 on the output side due to friction between oil, the pump impeller and the turbine runner, transmission loss, and the like. % Can not communicate.

  For this reason, the torque converter includes a lock-up clutch that is a friction engagement element between the crankshaft and the input shaft, and by fastening the lock-up clutch, the input side of the torque converter, that is, the crankshaft and the torque converter The output side, that is, the input shaft is directly connected so that they can be rotated together.

  A vehicle equipped with such a torque converter with a lock-up mechanism sets in advance a lockup clutch engagement and disengagement state as a characteristic map using a travel state such as a throttle opening and a vehicle speed as parameters, and based on this characteristic map. Thus, the state of engagement or disengagement of the lockup clutch suitable for the traveling state is determined.

  For example, when the vehicle is running at a high load and low vehicle speed, that is, when the throttle opening is large and the vehicle speed is small, a torque increasing action of the torque converter or a shock absorbing action during a shift operation is required. It is completely opened to a so-called converter state. On the other hand, when the vehicle is running at a low load and high vehicle speed, that is, when the throttle opening is small and the vehicle speed is large, the torque increasing action of the torque converter and the shock absorbing action during the shifting operation are not so required. In order to improve the power transmission efficiency of the torque converter and improve the fuel efficiency of the engine, the lockup clutch is completely engaged and is in a so-called lockup state.

  In the above characteristic map, the vehicle is flex-locked in which the lock-up clutch is slipped in addition to the converter region in which the lock-up clutch is released and the lock-up operation region in which the lock-up clutch is completely engaged. An up-acting area may be provided. In this flex lockup operation region, slip control is performed to maintain the slip amount of the lockup clutch at a predetermined target slip amount in order to absorb vibration while ensuring good fuel efficiency.

  By the way, a vehicle having a flex lockup operation region in such a characteristic map has an accelerator opening in the flex lockup operation region when the vehicle moves to a gentle climbing slope in the flex lockup operation region. If it is increased, a load is applied to the lock-up clutch during slip control.

On the other hand, when the vehicle approaches the uphill road with the lock-up clutch engaged, the lock-up clutch is released regardless of the throttle opening when the amount of increase in the throttle opening exceeds the criterion value. Thus, there has been proposed a lockup clutch engagement force control device capable of releasing the lockup clutch even when the throttle opening is small (see, for example, Patent Document 1).
JP-A-11-182670

  However, in such a conventional control device, when driving uphill, the engagement of the lockup clutch is released according to the amount of increase in the throttle opening. There was a problem that the driver suddenly changed and the engine speed increased, which could cause the driver to feel uncomfortable. Further, in such a control device, if the increase amount of the throttle opening for releasing the engagement of the lockup clutch is increased, there is a problem that an excessive load is applied to the lockup clutch.

  The present invention has been made to solve such a conventional problem, and is capable of reducing the load on the lock-up clutch while preventing the driver from feeling uncomfortable when the lock-up clutch is released. It is an object to provide an apparatus.

  In order to solve the above problems, a vehicle control apparatus according to the present invention is (1) provided between a power source and a transmission mechanism, and the power of the power source is supplied to the transmission mechanism via a fluid or a lock-up clutch. In a vehicle control device including a torque converter for transmitting the vehicle, vehicle state detection means for detecting the state of the vehicle, a lockup state for fastening the lockup clutch, a converter state for releasing the lockup clutch, A lock-up clutch control means for controlling the lock-up clutch in any state of a flex lock-up state in which the lock-up clutch is slid, and a current travel path is an uphill road based on the detected state of the vehicle An uphill traveling determination means for determining whether or not the current driving force is determined based on the detected state of the vehicle Present driving force calculating means to be output, releasing driving force calculating means for calculating driving force when the lockup clutch is released, and driving force when the current driving force and converter state are set Driving force change amount calculating means for calculating a driving force change amount that is a difference between the lockup clutch control means and the lockup clutch control means when controlling the lockup clutch to the flex lockup state. When the travel path is determined to be an uphill road, and the amount of change in the driving force is within a predetermined driving force threshold, the lockup clutch is released, and the converter state is entered. It has a configuration.

  With this configuration, when the lockup clutch is controlled to be in the flex lockup state, the current driving force and the driving force when the lockup clutch is released even if the load of the lockup clutch increases due to uphill running Because the lockup clutch is released when the amount of change in the driving force, which is the difference between the two, is within a predetermined driving force threshold value, there is little fluctuation in the vehicle when the lockup clutch is released, and the driver feels uncomfortable. It is possible to reduce the load on the lockup clutch while preventing this.

In the vehicle control apparatus according to the present invention, for example, the uphill traveling determination unit estimates the road surface gradient of the traveling road from the estimated acceleration and the actual acceleration of the vehicle, and compares it with a preset gradient threshold value. By doing so, it can be determined whether or not it is an uphill road.
In addition, the current driving force calculation means can calculate the current driving force from the current engine speed, the current turbine speed, and the current engine torque.

Further, the release driving force calculation means has a release engine speed calculation means for calculating an engine speed at release when the lockup clutch is released, and releases from the accelerator opening and the turbine speed based on the engine torque characteristics. And calculating the driving force when the lock-up clutch is released from the engine torque at the time of release, the engine speed at the time of release, and the current turbine speed. .
Further, the release engine speed calculation means can calculate the engine speed at release from the engine torque and the turbine speed based on the torque converter characteristics.

  Furthermore, the vehicle control apparatus according to the present invention provides an engine rotation which is a difference between the current engine speed and the engine speed when the converter state is established, instead of the driving force change amount calculating means. A rotation speed change amount calculating means for calculating a number change amount, wherein the lockup clutch control means performs transition determination to the converter state based on the rotation speed change amount instead of the driving force change amount; When the rotational speed change amount is within a predetermined rotational speed threshold value, the lock-up clutch can be released to shift to the converter state.

Further, the vehicle control device according to the present invention includes both the driving force change amount calculating means and the rotation speed change amount calculating means, and the lockup clutch control means determines whether or not to shift to the converter state. Based on both the driving force change amount and the rotational speed change amount, the driving force is within a predetermined driving force threshold value, and the rotational speed change amount is a predetermined rotational speed threshold value. If it is within the range, the lock-up clutch can be released to shift to the converter state.
Furthermore, the vehicle control apparatus according to the present invention can calculate the gradient threshold value, the driving force threshold value, and the rotation speed threshold value according to a traveling state of the vehicle.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus of the vehicle which can reduce the load of a lockup clutch can be provided, preventing discomfort to a driver at the time of releasing of a lockup clutch.

Embodiments of the present invention will be described below with reference to the drawings.
First, the configuration will be described.
FIG. 1 is a schematic block configuration diagram of a vehicle including a control device according to an embodiment of the present invention. FIG. 2 is a schematic block diagram showing the configuration of the transmission in the embodiment of the present invention.

  As shown in FIG. 1, a vehicle 10 according to the present embodiment includes an engine 20 as a power source, a transmission 30 that transmits power generated in the engine 20 and changes a gear ratio according to a traveling state of the vehicle 10. The differential mechanism 40 that distributes the power transmitted from the transmission 30 to the drive shafts 51L and 51R as drive shafts, and the drive wheels 52L and 52R that are rotated by the power transmitted from the drive shafts 51L and 51R and drive the vehicle 10. And.

  The vehicle 10 also includes an ECU (Electronic Control Unit) 100 as a vehicle electronic control device for controlling the entire vehicle 10 and a hydraulic control device 120 that controls the transmission 30 with hydraulic pressure. Further, the vehicle 10 includes a crank sensor 131, a drive shaft rotational speed sensor 132, a shift sensor 141, an accelerator sensor 142, a foot brake sensor (hereinafter referred to as “FB sensor”) 143, a parking brake sensor (hereinafter, referred to as “brake sensor”). 144 (referred to as “PKB sensor”), a throttle sensor 145, an engine torque sensor 146, an intake air amount sensor 151, an intake air temperature sensor 152, a cooling water temperature sensor 153, and other various sensors (not shown). The various sensors are configured to output detected detection signals to the ECU 100.

  The engine 20 is constituted by a known power device that outputs power by burning a mixture of hydrocarbon fuel such as gasoline or light oil and air in a combustion chamber of a cylinder (not shown). The engine 20 intermittently repeats intake, combustion, and exhaust of the air-fuel mixture in the combustion chamber to reciprocate the piston in the cylinder, and rotates the crankshaft 21 (see FIG. 2) connected to the piston so that power can be transmitted. As a result, torque is transmitted to the transmission 30. The fuel used for the engine 20 may be an alcohol fuel containing alcohol such as ethanol.

  The transmission 30 receives the torque output from the engine 20 via the crankshaft 21, changes the gear ratio according to the traveling state of the vehicle 10, and outputs it to the differential mechanism 40 by final gear. . Details of the transmission 30 will be described later.

  The differential mechanism 40 allows a difference in rotational speed between the drive wheel 52L and the drive wheel 52R when traveling on a curve or the like. The differential mechanism 40 distributes the torque input by the final gear to the drive shafts 51L and 51R and outputs it. Note that the differential mechanism 40 may be capable of taking a differential lock state in which the drive shafts 51L and 51R have the same rotation and do not allow a difference in rotational speed between the drive wheels 52L and the drive wheels 52R.

  The drive wheels 52L, 52R include, for example, metal wheels attached to the drive shafts 51L, 51R, and, for example, resin tires attached so as to cover the outer periphery of the wheels. The drive wheels 52L and 52R are rotated by the torque transmitted by the drive shafts 51L and 51R, and drive the vehicle 10 by the frictional action between the tire and the road surface.

  The ECU 100 includes a CPU (Central Processing Unit) 100a as a central processing unit, a ROM (Read Only Memory) 100b for storing fixed data, a RAM (Random Access Memory) 100c for temporarily storing data, and rewritable. An EEPROM (Electrically Erasable and Programmable Read Only Memory) 100d and an input / output interface circuit (I / F) 100e, each of which is a non-volatile memory, control the vehicle 10.

Further, as will be described later, the ECU 100 is connected to a crank sensor 131, a drive shaft rotational speed sensor 132, an input shaft rotational speed sensor 133, an accelerator sensor 142, an engine torque sensor 146, and the like. The ECU 100 detects the engine speed Ne, the vehicle speed V (travel speed of the vehicle 10), the turbine speed Nt (output shaft speed of the torque converter 60), the accelerator opening degree Ac, the engine based on the detection signals output from these sensors. Torque Te or the like is detected. Further, the actual acceleration αr of the vehicle 10 is also detected from the rate of change in the rotational speed of the drive shaft 51L (or 51R) represented by the detection signal output from the drive shaft rotational speed sensor 132.
Further, the ECU 100 controls the hydraulic control device 120 to control the hydraulic pressure of each part of the transmission 30.

  Further, in the ROM 100b of the ECU 100, there are a throttle opening control map, a shift diagram, a lockup control map, an engagement table for realizing each shift stage, specification values of the vehicle 10, a program for executing vehicle control, and the like. It is remembered.

  FIG. 3 is a map showing an example of a throttle opening degree control map in the embodiment of the present invention.

  As shown in FIG. 3, the throttle opening degree control map is a map for obtaining the throttle opening degree θth based on the accelerator opening degree Ac. Further, the throttle opening degree control map may have a plurality of modes, and the modes may be switched according to the traveling state, the traveling path, and the like. The ECU 100 may automatically switch the mode selection in the throttle opening control map according to the traveling state, the traveling path, or the like, or may be switched according to the selection by the driver.

  FIG. 4 is a map showing an example of a shift map in the embodiment of the present invention.

  As shown in FIG. 4, the shift diagram is a map for determining a gear position based on the vehicle speed V and the throttle opening θth. For example, when the vehicle speed V increases at the same throttle opening θth and shifts to the vehicle speed V high throttle opening θth low region (lower right region in FIG. 4) exceeding the solid line shown in FIG. Upshift to a gear position corresponding to On the other hand, when the vehicle speed V decreases at the same throttle opening degree θth and shifts to a region where the vehicle speed V is low and the throttle opening degree θth is higher than the dotted line shown in FIG. Downshift to the corresponding gear position. Similarly, when the throttle opening degree θth increases at the same vehicle speed V and shifts to the vehicle speed V low throttle opening degree θth high region (upper left region in FIG. 4) beyond the dotted line shown in FIG. Downshift to a gear position corresponding to the region.

  FIG. 5 is a map showing an example of the lock-up control map in the embodiment of the present invention.

  As shown in FIG. 5, the lockup control map is a map for determining the lockup state of the torque converter 60 (see FIG. 2) based on the vehicle speed V and the accelerator opening degree Ac. For example, in a region where the vehicle speed V is large and the accelerator opening degree Ac is small, a lock-up operation region is entered, and the ECU 100 places the torque converter 60 in a lock-up state. Further, in a region where the vehicle speed V is small and the accelerator opening degree Ac is large, the converter region is established, and the ECU 100 is in a converter state in which the lock-up of the torque converter 60 is completely released. Further, when the region corresponding to the vehicle speed V and the accelerator opening degree Ac becomes the flex lock-up operation region among these, the ECU 100 sets the torque converter 60 in the flex lock-up state, that is, a predetermined slip rate. In this state, the lockup is engaged.

  FIG. 6 is an engagement table showing the engagement states of the friction engagement elements that realize the respective shift speeds according to the embodiment of the present invention.

  As shown in FIG. 6, the engagement table that realizes each shift stage is an engagement of each friction engagement element (clutch, brake, one-way clutch) of the transmission mechanism 70 described later in order to realize each shift stage. And release. For example, when realizing the first speed (1st), the ECU 100 engages the clutch C1 and the one-way clutches F3 and F4. Further, when realizing the fifth speed (5th), the ECU 100 engages the clutches C2 and C3 and the brake B1. Note that the ECU 100 engages the clutch C4 and the brake B4 in addition to the engagement of the clutch C1 and the one-way clutches F3 and F4 when applying the engine brake at the first speed (1st). Further, when realizing the fifth speed (5th), the ECU 100 also engages the clutch C1 and the brake B3, but the engagement of the clutch C1 and the brake B3 is not involved in power transmission.

  The specification values of the vehicle 10 include vehicle dimensions such as full width and total height, vehicle weight, total engine displacement, minimum turning radius, tire diameter of the vehicle 10 (the diameters of the drive wheels 52L and 52R), and the speed change mechanism 70. Gear ratio etc. are included.

Further, the ROM 100b of the ECU 100 includes a gradient threshold value θgrad_tv for determining whether or not the road is an uphill road, a driving force threshold value F_tv for determining a change amount of the driving force, and a change amount of the engine speed. A rotational speed threshold value Ne_tv, an engine torque characteristic map, and a torque converter characteristic map for determination are stored.
The gradient threshold value θgrad_tv, the driving force threshold value F_tv, and the rotation speed threshold value Ne_tv may be calculated according to the traveling state of the vehicle 10.

  The engine torque characteristic map is a map obtained by combining the engine characteristic and the torque converter characteristic, and is a map showing the engine torque Te based on the turbine speed Nt according to the throttle opening θth. When the turbine speed Nt and the throttle opening θth are determined, the engine speed Ne, the engine torque Te, and the turbine torque Tt when the torque converter 60 (see FIG. 2) balances are uniquely determined. It is a map. That is, this engine torque characteristic map is a characteristic map that represents a balance point between torque and rotation derived by combining the engine torque characteristic and the torque converter characteristic. At the same time as the engine torque Te, the engine rotational speed Ne and the turbine torque Tt. Can be obtained directly.

  Similar to the engine torque characteristic map, the torque converter characteristic map is a map obtained by combining the engine characteristic and the torque converter characteristic, and indicates the engine speed Ne based on the turbine speed Nt according to the engine torque Te. It is a map.

  The hydraulic control device 120 includes transmission solenoids ST1 to ST4, SR, linear solenoids SLT, SLU, SL1, and SL2 as electromagnetic valves controlled by the ECU 100. The hydraulic control device 120 is controlled by the ECU 100 to switch the hydraulic circuit and control the hydraulic pressure by the solenoid valves, and operate each part of the transmission 30. The function of each solenoid valve of the hydraulic control device 120 will be described later.

  The crank sensor 131 is controlled by the ECU 100 to detect the rotational speed of the crankshaft 21 and output the detected detection signal to the ECU 100. Further, the ECU 100 is configured to acquire the rotational speed of the crankshaft 21 represented by the detection signal output from the crank sensor 131 as the engine rotational speed Ne.

  The drive shaft rotational speed sensor 132 is controlled by the ECU 100 to detect the rotational speed of the drive shaft 51L (or 51R) and to output a detection signal representing the rotational speed of the drive shaft 51L (or 51R) to the ECU 100. It has become. Further, the ECU 100 is configured to calculate the vehicle speed V based on the detection signal output from the drive shaft rotational speed sensor 132.

  The shift sensor 141 is controlled by the ECU 100 to detect which of the plurality of switching positions the shift lever 211 is in, and outputs a detection signal indicating the switching position of the shift lever 211 to the ECU 100. It has become. In addition, the ECU 100 acquires the switching position of the shift lever 211 represented by the detection signal output from the shift sensor 141 as the shift position.

  The accelerator sensor 142 is controlled by the ECU 100 to detect an amount of depression (hereinafter referred to as a stroke) by which the accelerator pedal 212 is depressed, and outputs a detected detection signal to the ECU 100. Further, the ECU 100 calculates the accelerator opening degree Ac from the stroke of the accelerator pedal 212 represented by the detection signal output from the accelerator sensor 142.

  The FB sensor 143 is controlled by the ECU 100 to detect an amount of depression (hereinafter referred to as a stroke) by which the foot brake pedal 213 is depressed, and outputs the detected detection signal to the ECU 100. Further, the ECU 100 calculates the foot brake pedal force Bf from the stroke of the foot brake pedal 213 represented by the detection signal output from the FB sensor 143.

  The FB sensor 143 sets a predetermined threshold value for the stroke of the foot brake pedal 213, not the foot brake pedal force Bf representing the stroke of the foot brake pedal 213. A foot brake on / off signal may be output depending on whether or not the threshold value is exceeded. Further, the FB sensor 143 may detect the hydraulic pressure of a brake cylinder provided in the drive wheels 52L and 52R and output a detection signal indicating the hydraulic pressure of the brake cylinder to the ECU 100. Also in this case, the FB sensor 143 provides a predetermined threshold value for the hydraulic pressure of the brake cylinder, and outputs a foot brake on / off signal depending on whether or not the hydraulic pressure of the brake cylinder exceeds this threshold value. Good.

The PKB sensor 144 is controlled by the ECU 100 to detect an operation amount of the parking brake lever 214 and outputs a detected detection signal to the ECU 100. In addition, the ECU 100 is configured to acquire the operation amount of the parking brake lever 214 represented by the detection signal output from the PKB sensor 144 as the parking brake operation amount Pb.
When the parking brake mechanism is a pedal type instead of a lever type, the PKB sensor 144 detects the parking brake pedal stroke, and outputs a detection signal indicating the parking brake pedal stroke to the ECU 100. Good.

The throttle sensor 145 is controlled by the ECU 100 to detect the opening degree of a throttle valve that is driven by a throttle actuator (not shown), and outputs the detected detection signal to the ECU 100. In addition, the ECU 100 is configured to acquire the throttle valve opening represented by the detection signal output from the throttle sensor 145 as the throttle opening θth.
Further, the ECU 100 may directly use the control value set by the throttle opening control map (see FIG. 3) as the throttle opening θth without using the detection signal output from the throttle sensor 145 for the throttle opening θth. it can.

  The engine torque sensor 146 is controlled by the ECU 100 to detect the torque of the engine 20 and output the detected detection signal to the ECU 100. Further, the ECU 100 acquires the torque represented by the detection signal output from the engine torque sensor 146 as the engine torque Te.

  The intake air amount sensor 151 is controlled by the ECU 100 to detect the amount of air drawn from an intake valve (not shown) of the engine 20 and output the detected detection signal to the ECU 100. Further, the ECU 100 acquires the intake air amount of the engine 20 from the detection signal output from the intake air amount sensor 151.

  The intake air temperature sensor 152 is controlled by the ECU 100 to detect the temperature of air sucked from the intake valve of the engine 20 and output the detected detection signal to the ECU 100. The ECU 100 acquires the intake air temperature of the engine 20 from the detection signal output from the intake air temperature sensor 152.

  Cooling water temperature sensor 153 is controlled by ECU 100 to detect the temperature of cooling water for cooling a cylinder (not shown) of engine 20 (hereinafter simply referred to as cooling water for engine 20), and the detected signal is sent to ECU 100. It is designed to output. Further, the ECU 100 acquires the temperature of the cooling water of the engine 20 from the detection signal output from the cooling water temperature sensor 153.

  Next, a detailed configuration of the transmission 30 will be described.

  As shown in FIG. 2, the transmission 30 receives torque from the engine 20 and outputs it via oil, and the rotation speed of an input shaft 71 as an input shaft and the rotation of an output shaft 72 as an output shaft. And a speed reduction gear mechanism 90 that receives torque from the speed change mechanism 70 and increases the driving force while reducing the rotational speed, and outputs it to the differential mechanism 40.

  The torque converter 60 is disposed between the engine 20 and the transmission mechanism 70, and changes the direction of oil flow, a pump impeller 61 that inputs torque from the engine 20, a turbine runner 62 that outputs torque to the transmission mechanism 70, and the oil flow. A stator 64 and a lockup clutch 65 that directly connects the pump impeller 61 and the turbine runner 62 are provided, and torque is transmitted via oil.

The pump impeller 61 is connected to the crankshaft 21 of the engine 20. Further, the pump impeller 61 is rotated integrally with the crankshaft 21 by the torque of the engine 20.
The turbine runner 62 is connected to the input shaft 71 of the transmission mechanism 70 via the turbine shaft 67. The turbine runner 62 is rotated by the flow of oil pushed out by the rotation of the pump impeller 61, and outputs the rotation of the crankshaft 21 of the engine 20 to the transmission mechanism 70 via the input shaft 71.

The stator 64 is rotatably supported by the non-rotating member via the one-way clutch 63. The stator 64 flows out of the turbine runner 62 and again changes the direction of oil flowing into the pump impeller 61 to change the force to further rotate the pump impeller 61. The stator 64 is prevented from rotating by the one-way clutch 63, and changes the direction in which the oil flows.
Further, the stator 64 is configured to prevent idling and reverse torque acting on the turbine runner 62 when the pump impeller 61 and the turbine runner 62 rotate at substantially the same speed.

The lockup clutch 65 is directly connected between the pump impeller 61 and the turbine runner 62, and mechanically directly transmits the rotation of the crankshaft 21 of the engine 20 to the input shaft 71 of the transmission mechanism 70.
Here, the torque converter 60 transmits rotation between the pump impeller 61 and the turbine runner 62 via oil. Therefore, the rotation of the pump impeller 61 cannot be transmitted 100% to the turbine runner 62. Therefore, when the rotational speed of the pump impeller 61 and the turbine runner 62 approaches, the lockup clutch 65 is operated and the pump impeller 61 and the turbine runner 62 are mechanically directly connected to each other. The transmission efficiency of rotation to 70 is increased, and the fuel efficiency is improved.

Further, the lock-up clutch 65 can realize a flex lock-up that causes the slip-up to slip at a predetermined slip rate. It should be noted that the lock-up clutch 65 is in a converter state with the lock-up clutch 65 released, in a lock-up state with the lock-up clutch 65 engaged, or in a flex lock-up state with the lock-up clutch 65 slipped. Is selected by the CPU 100a of the ECU 100 according to the traveling state of the vehicle 10, specifically, the vehicle speed and the accelerator opening, based on the lock-up control map (see FIG. 5) stored in the ROM 100b of the ECU 100. It has become so.
Further, the pump impeller 61 is provided with a mechanical oil pump 66 that generates a hydraulic pressure for shifting the transmission mechanism 70 and a hydraulic pressure for supplying oil to each part.

  The transmission mechanism 70 includes a double pinion type first planetary gear device 73, and a single pinion type second planetary gear device 74 and a third planetary gear device 75. The sun gear S1 of the first planetary gear unit 73 is selectively connected to the input shaft 71 via the clutch C3 and is selectively connected to the housing 31 via the one-way clutch F2 and the brake B3. Further, the one-way clutch F2 prevents the input shaft 71 from rotating in the opposite direction (hereinafter referred to as the reverse direction).

  The carrier CA1 of the first planetary gear device 73 is selectively connected to the housing 31 via the brake B1. The carrier CA1 is always prevented from rotating in the reverse direction by a one-way clutch F1 provided in parallel with the brake B1.

  The ring gear R1 of the first planetary gear device 73 is connected to the ring gear R2 of the second planetary gear device 74, and is selectively connected to the housing 31 via the brake B2. The sun gear S2 of the second planetary gear device 74 is connected to the sun gear S3 of the third planetary gear device 75, and is selectively connected to the input shaft 71 via the clutch C4. The sun gear S2 is selectively coupled to the input shaft 71 via the one-way clutch F4 and the clutch C1, and is prevented from rotating in the reverse direction.

  The carrier CA2 of the second planetary gear unit 74 is connected to the ring gear R3 of the third planetary gear unit 75, is selectively connected to the input shaft 71 via the clutch C2, and is connected to the housing 31 via the brake B4. Are selectively connected to each other. The carrier CA2 is prevented from rotating in the reverse direction by a one-way clutch F3 provided in parallel with the brake B4. Further, the carrier CA3 of the third planetary gear device 75 is connected to the output shaft 72.

  The clutches C1 to C4, the one-way clutches F1 to F4, and the brakes B1 to B4 (hereinafter simply referred to as the clutch C and the brake B unless otherwise specified) are hydraulic pressures controlled by hydraulic actuators such as multi-plate clutches and brakes. It is comprised by the type | formula friction engagement apparatus. In addition, the clutch C and the brake B are switched according to the excitation and non-excitation of the transmission solenoids ST1 to ST4, SR and the linear solenoids SLU, SLT, SL1, SL2 of the hydraulic control device 120 and the operating state of a manual valve (not shown). In response to this, either the engaged state or the released state is taken.

Here, the function of each solenoid valve of the hydraulic control device 120 will be described.
The transmission solenoid ST1 operates at the time of shifting from the first speed to the second speed. Further, the transmission solenoid ST1 switches the oil path of the linear solenoid SL1 pressure. The transmission solenoid ST2 operates when shifting from the 2nd speed to the 3rd speed and when shifting from the 5th speed to the 6th speed.

The transmission solenoid ST3 is operated at the time of shifting from the third speed to the fourth speed. The transmission solenoid ST4 is operated at the time of shifting from the fourth speed to the fifth speed. Further, the transmission solenoid ST4 switches the oil path of the linear solenoid SL1 pressure.
The transmission solenoid SR switches the clutch C4 and the brake B1.

The linear solenoid SLT performs control of line pressure, which is the original pressure of oil supplied to each part, and back pressure control of an accumulator (not shown). The linear solenoid SLU controls the lockup mechanism.
The linear solenoid SL1 performs pressure control of the clutch C and back pressure control of the accumulator. The linear solenoid SL2 performs pressure control of the brake B.

  As described above, the speed change mechanism 70 generates friction by the oil pressure with the line pressure as the original pressure in accordance with the operating states of the transmission solenoids ST1 to ST4, SR and the linear solenoids SLT, SLU, SL1, SL2 of the hydraulic control device 120. The engaging elements (clutch C and brake B) are selectively engaged or released. The speed change mechanism 70 constitutes a gear position corresponding to the combination of engagement and release of these friction engagement elements (clutch C and brake B), and changes the ratio of the rotational speeds of the input shaft 71 and the output shaft 72. It has become.

  The speed change mechanism 70 according to the present embodiment is configured to take any one of six forward speeds and one reverse speed constituted by first to sixth speeds.

  Further, the transmission 30 is provided with an input shaft rotational speed sensor 133 and an output shaft rotational speed sensor 134.

The input shaft rotational speed sensor 133 is controlled by the ECU 100 to detect the rotational speed of the input shaft 71 and output the detected detection signal to the ECU 100. Further, the ECU 100 acquires the rotation speed of the input shaft 71 represented by the detection signal output from the input shaft rotation speed sensor 133 as the input shaft rotation speed Nm.
Since the input shaft 71 is connected to the turbine shaft 67 of the torque converter 60 and has the same rotational speed as the turbine shaft 67, the input shaft rotational speed detected by the input shaft rotational speed sensor 133 will be described below. Nm is the turbine speed Nt.

  The output shaft rotational speed sensor 134 is controlled by the ECU 100 to detect the rotational speed of the output shaft 72 and output the detected detection signal to the ECU 100. Further, the ECU 100 acquires the rotation speed of the output shaft 72 represented by the detection signal output from the output shaft rotation speed sensor 134 as the output shaft rotation speed Nc.

The hydraulic control device 120 is provided with an oil temperature sensor 154.
The oil temperature sensor 154 is controlled by the ECU 100 to detect the temperature of oil in the hydraulic circuit in the transmission 30 and the hydraulic control device 120 (hereinafter simply referred to as oil temperature or oil temperature), and the detected detection signal Is output to the ECU 100. Further, the ECU 100 is configured to acquire the oil temperature from the detection signal output from the oil temperature sensor 154.

  Hereinafter, the characteristic structure of the vehicle 10 provided with the control apparatus in embodiment of this invention is demonstrated. FIG. 7 is a functional block diagram showing a main part of the control function provided in the vehicle in the embodiment of the present invention.

  As shown in FIG. 7, the vehicle 10 includes a vehicle state detection unit 310, a lockup clutch control unit 320, an uphill traveling determination unit 330, a current driving force calculation unit 340, a release driving force calculation unit 350, and a drive A force change amount calculation unit 360 and a rotation speed change amount calculation unit 370 are provided.

  The vehicle state detection unit 310 detects the state of the vehicle 10. The vehicle state detection unit 310 includes, for example, a crank sensor 131, a drive shaft rotation speed sensor 132, an input shaft rotation speed sensor 133, an accelerator sensor 142, and an engine torque sensor 146.

  The lockup clutch control means 320 is in any one of a lockup state in which the lockup clutch 65 is engaged, a converter state in which the lockup clutch 65 is released, and a flex lockup state in which the lockup clutch 65 is slid. The lockup clutch 65 is controlled.

  Further, the lockup clutch control means 320 determines that the travel path of the vehicle 10 is an uphill road while controlling the lockup clutch 65 to the flex lockup state, and the driving force change amount is a predetermined driving force. When the engine speed is within the threshold value and the engine speed change amount is within a predetermined engine speed threshold value, the lockup clutch 65 is released and the converter state is entered.

  Further, the lock-up clutch control means 320 determines whether or not to change to the converter state when the driving force change amount is within a predetermined driving force threshold value or the engine speed changing amount is a predetermined rotation number. The driving force change amount is within a predetermined driving force threshold value or the rotational speed change amount is within a predetermined rotational speed threshold value. In this case, the lock-up clutch 65 can be released to shift to the converter state. Further, the lockup clutch control means 320 may calculate the driving force threshold value and the rotation speed threshold value according to the traveling state of the vehicle 10.

The uphill traveling determination means 330 determines whether or not the current traveling road is an uphill road based on the detected state of the vehicle 10.
Further, the uphill traveling determination unit 330 estimates the road surface gradient of the traveling road from the estimated acceleration and the actual acceleration of the vehicle 10, and compares it with a preset gradient threshold value to determine whether the road is an uphill road. Is supposed to do. Further, the uphill traveling determination unit 330 may calculate the gradient threshold value according to the traveling state of the vehicle 10.

The current driving force calculation means 340 calculates the current driving force based on the detected state of the vehicle 10.
Further, the current driving force calculation means 340 calculates the current driving force from the current engine speed, the current turbine speed, and the current engine torque.

The disengagement driving force calculating means 350 calculates the driving force when the converter is in the state of releasing the lockup clutch.
Further, the release driving force calculating means 350 calculates the engine speed at release when the lockup clutch 65 is released, and calculates the engine torque at release from the accelerator opening and the turbine speed based on the engine torque characteristics. The driving force when the lockup clutch 65 is released is calculated from the engine torque at the time of release, the engine speed at the time of release, and the current turbine speed. Further, the release drive force calculation means 350 calculates the engine speed at release from the engine torque and the turbine speed based on the torque converter characteristics.

The driving force change amount calculation unit 360 calculates a driving force change amount that is a difference between the calculated current driving force and the driving force in the case of the converter state.
The rotational speed change amount calculation means 370 calculates the rotational speed change amount that is the difference between the current engine speed and the engine speed when the converter is in the converter state.

  Here, the lockup clutch control means 320, the uphill traveling determination means 330, the current driving force calculation means 340, the release driving force calculation means 350, the driving force change amount calculation means 360, and the rotation speed change amount calculation means 370 are realized by the ECU 100. It has come to be.

Next, the operation will be described.
FIG. 8 is a flowchart showing a vehicle control process in the embodiment of the present invention.

  The flowchart shown in FIG. 8 represents the execution contents of a vehicle control process program executed by the CPU 100a of the ECU 100 using the RAM 100c as a work area. The vehicle control processing program is stored in the ROM 100b of the ECU 100. In addition, the vehicle control process is executed at predetermined time intervals by the CPU 100a of the ECU 100.

  As shown in FIG. 8, first, the CPU 100a of the ECU 100 detects the traveling state of the vehicle 10 (step S11). Here, the CPU 100a of the ECU 100 detects the engine speed Ne, the vehicle speed V, the actual acceleration αr, the turbine speed Nt, the accelerator opening degree Ac, and the engine torque Te.

  Specifically, the CPU 100a of the ECU 100 detects the engine speed Ne, the vehicle speed based on detection signals output from the crank sensor 131, the drive shaft speed sensor 132, the input shaft speed sensor 133, the accelerator sensor 142, and the engine torque sensor 146. V, turbine rotational speed Nt, accelerator opening degree Ac, and engine torque Te are detected. Further, the actual acceleration αr of the vehicle 10 is also detected from the rate of change in the rotational speed of the drive shaft 51L (or 51R) represented by the detection signal output from the drive shaft rotational speed sensor 132.

  Further, the CPU 100a of the ECU 100 obtains the throttle opening degree θth from the accelerator opening degree Ac based on the throttle opening degree control map (see FIG. 3) stored in the ROM 100b. Next, the CPU 100a of the ECU 100 determines the turbine torque Tt from the engine speed Ne, the turbine speed Nt, the engine torque Te, and the throttle opening θth based on the engine torque characteristic map stored in the ROM 100b. Next, the CPU 100a of the ECU 100 obtains the driving force F from the turbine torque Tt, the current gear position, and the specification values stored in the ROM 100b. Specifically, the driving force is obtained by the following equation (1).

Driving force F = Engine torque Te * Transmission gear ratio
* Final gear ratio / tire radius (1)
Further, the CPU 100a of the ECU 100 obtains a reference acceleration αb (acceleration obtained when traveling on a flat road) from the driving force F, the vehicle speed V, and the specification values, the reference acceleration αb, the actual acceleration αr, and the gravitational acceleration g. To obtain an estimated gradient θgrad of the current travel path. Specifically, the reference acceleration αb is obtained by the following equation (2), and the estimated gradient θgrad is obtained by the following equation (3).

Reference acceleration αb = (driving force F−rolling resistance Fr−air resistance Fl−turning resistance Fk)
/ Vehicle mass M (2)
M · g · sin θgrad = M · αb−M · αr to sinθgrad = (αb−αr) / g
Therefore,
θgrad = arcsin (αb−αr) / g (3)
Here, the vehicle mass M may use the vehicle weight as it is based on the specification value, but a more accurate value can be obtained in consideration of the number of passengers, the remaining amount of fuel, and the like in the vehicle weight.

  Further, the CPU 100a of the ECU 100 obtains the estimated engine torque Te_est when the lock-up of the torque converter 60 is released from the accelerator opening degree Ac and the torque rotational speed Nt based on the engine torque characteristic map stored in the ROM 100b. . Next, the CPU 100a of the ECU 100 obtains the estimated engine speed Ne_est from the engine torque Te and the turbine speed Nt based on the torque converter characteristic map stored in the ROM 100b.

  Next, the CPU 100a of the ECU 100 obtains the estimated turbine torque Tt_est from the turbine speed Nt, the estimated engine torque Te_est, the estimated engine speed Ne_est, and the throttle opening θth based on the engine torque characteristic map stored in the ROM 100b. Estimated driving force F_est is obtained.

  The above calculation by the CPU 100a of the ECU 100 is performed using the RAM 100c as a work area, and the engine speed Ne, the vehicle speed V, the accelerator opening degree Ac, the driving force F, the estimated gradient θgrad, and the estimated engine speed, which are detection results and calculation results. Ne_est and estimated driving force F_est are each stored in the RAM 100c.

  Next, the CPU 100a of the ECU 100 determines whether or not the current travel path is an uphill road, and ends the vehicle control process if the current travel path is not an uphill road (step S12). Specifically, the CPU 100a of the ECU 100 determines whether or not the calculated estimated gradient θgrad is greater than or equal to the gradient threshold θgrad_tv stored in the ROM 100b, and the estimated gradient θgrad_est is greater than or equal to the gradient threshold θgrad_tv. In some cases, it is determined that the current travel path is an uphill road, and if the estimated gradient θgrad_est is less than the gradient threshold θgrad_tv, it is determined that the current travel path is not an uphill road.

  When the CPU 100a of the ECU 100 determines that the current traveling road is an uphill road (YES in step S12), the CPU 100a determines whether or not the torque converter 60 is controlled to the flex lockup state, and the flex lock is determined. If it is not controlled to the up state, the vehicle control process is terminated (step S13). Specifically, the CPU 100a of the ECU 100 determines whether the region corresponding to the vehicle speed V and the accelerator opening degree Ac is in the flex lockup operation region based on the lockup control map (see FIG. 5) stored in the ROM 100b. Determine whether or not.

  When the CPU 100a of the ECU 100 determines that the torque converter 60 is controlled to be in the flex lockup state (YES in step S13), the driving force change amount ΔF when the flex lockup of the torque converter 60 is released is determined. Is calculated (step S14). Specifically, the CPU 100a of the ECU 100 calculates a difference (ΔF = F_est−F) between the calculated current driving force F and the estimated driving force F_est when the flex lockup is released. The CPU 100a of the ECU 100 stores the calculated driving force change amount ΔF in the RAM 100c.

  Next, the CPU 100a of the ECU 100 determines whether or not the driving force change amount ΔF is within the driving force threshold value F_tv. If the driving force change amount ΔF is not within the driving force threshold value F_tv, the vehicle The control process is terminated (step S15). Specifically, the calculated driving force change amount ΔF is compared with the driving force threshold value F_tv stored in the ROM 100b, and the driving force change amount ΔF is within the driving force threshold value F_tv (| ΔF | It is determined whether or not ≦ F_tv).

  When the CPU 100a of the ECU 100 determines that the driving force change amount ΔF is within the driving force threshold value F_tv (determined as YES in step S15), the rotational speed change when the flex lockup of the torque converter 60 is released is determined. The amount ΔNe is calculated (step S16). Specifically, the CPU 100a of the ECU 100 calculates the difference (ΔNe = N_est−Ne) between the calculated current engine speed Ne and the engine speed Ne_est when the flex lockup is released. The CPU 100a of the ECU 100 stores the calculated rotation speed change amount ΔNe in the RAM 100c.

  Next, the CPU 100a of the ECU 100 determines whether or not the rotational speed change amount ΔNe is within the rotational speed threshold value Ne_tv. If the rotational speed change amount ΔNe is not within the rotational speed threshold value Ne_tv, the vehicle The control process is terminated (step S17). Specifically, the calculated rotation speed change amount ΔNe is compared with the rotation speed threshold value Ne_tv stored in the ROM 100b, so that the rotation speed change amount ΔNe is within the rotation speed threshold value Ne_tv (| ΔNe | It is determined whether or not ≦ Ne_tv).

  When the CPU 100a of the ECU 100 determines that the rotational speed change amount ΔNe is within the rotational speed threshold value Ne_tv (determined as YES in step S17), the flex lockup of the torque converter 60 is canceled and the vehicle control is performed. The process ends (step S18). Specifically, the CPU 100a of the ECU 100 controls the linear solenoid SLU of the hydraulic control device 120 to release the lockup clutch 65 of the torque converter 60.

  In the present embodiment, the CPU 100a of the ECU 100 makes a lockup release determination and releases the lockup clutch 65 only when the torque converter 60 is controlled to be in the flex lockup state. Even when the torque converter 60 is controlled to be in the lock-up state, the lock-up release determination may be performed and the lock-up clutch 65 may be released.

  As described above, when the lockup clutch 65 is controlled to the flex lockup state when the lockup clutch 65 is controlled to be in the flex lockup state, the vehicle control apparatus in the present embodiment can When the driving force change amount ΔF, which is the difference between the driving force F and the driving force F_est when the lock-up clutch 65 is released, is within a predetermined driving force threshold F_tv, the lock-up clutch 65 is Since the release is performed, when the lock-up clutch 65 is released, the load of the lock-up clutch 65 can be reduced while the fluctuation of the vehicle 10 is small and the driver feels uncomfortable.

  In the present embodiment, the case of the vehicle 10 using the engine 20 that uses gasoline as fuel as a power source has been described. However, the present invention is not limited to this, and an electric vehicle that uses a motor as a power source and hydrogen as fuel. A hydrogen vehicle using an engine as a power source, or a hybrid vehicle using both an engine and a motor may be used. In this case, the same effect as that of the vehicle control device described above can be obtained.

  The embodiment disclosed this time is illustrative in all respects and is not limited to this embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

  As described above, the vehicle control device according to the present invention has the effect of reducing the load on the lock-up clutch while preventing the driver from feeling uncomfortable when the lock-up clutch is released. This is useful as a vehicle control device for controlling a vehicle including a torque converter with an up mechanism.

It is a schematic block block diagram of the vehicle provided with the control apparatus which concerns on embodiment of this invention. It is a schematic block block diagram showing the structure of the transmission in embodiment of this invention. It is a map which shows an example of the throttle opening control map in embodiment of this invention. It is a map which shows an example of the shift map in embodiment of this invention. It is a map which shows an example of the lockup control map in embodiment of this invention. It is an engagement table | surface which shows the engagement state of the friction engagement element which implement | achieves each gear stage in embodiment of this invention. It is a functional block diagram which shows the principal part of the control function with which the vehicle in embodiment of this invention was equipped. It is a flowchart which shows the vehicle control process in embodiment of this invention.

Explanation of symbols

10 vehicle 20 engine (power source)
21 Crankshaft 30 Transmission 40 Differential mechanism 51L, 51R Drive shaft 52L, 52R Drive wheel 60 Torque converter 61 Pump impeller 62 Turbine runner 63 One-way clutch 64 Stator 65 Lock-up clutch 67 Turbine shaft 70 Transmission mechanism 71 Input shaft 72 Output shaft 73 First planetary gear device 74 Second planetary gear device 75 Third planetary gear device 90 Reduction gear mechanism 100 ECU (lock-up clutch control means, uphill traveling determination means, current driving force calculation means, release driving force calculation means, driving force change Quantity calculation means)
120 Hydraulic Control Device 131 Crank Sensor (Vehicle State Detection Means)
132 Drive shaft rotational speed sensor (vehicle state detection means)
133 Input shaft rotation speed sensor (vehicle state detection means)
134 Output shaft rotational speed sensor 142 Accelerator sensor (vehicle state detection means)
143 Foot brake sensor (FB sensor)
144 Parking brake sensor (PKB sensor)
145 Throttle sensor 146 Engine torque sensor (vehicle state detection means)
212 Accelerator pedal 213 Foot brake pedal

Claims (1)

In a vehicle control device including a torque converter that is provided between a power source and a speed change mechanism and transmits power of the power source to the speed change mechanism via a fluid or a lock-up clutch.
Vehicle state detection means for detecting the state of the vehicle;
A lock that controls the lock-up clutch in any one of a lock-up state in which the lock-up clutch is engaged, a converter state in which the lock-up clutch is released, and a flex lock-up state in which the lock-up clutch is slid An up clutch control means;
Uphill traveling determination means for determining whether or not the current traveling road is an uphill road based on the detected state of the vehicle;
Current driving force calculating means for calculating a current driving force based on the detected state of the vehicle;
A release driving force calculating means for calculating a driving force when the converter is in a state of releasing the lock-up clutch;
A driving force change amount calculating means for calculating a driving force change amount that is a difference between the current driving force and the driving force in the case of the converter state;
The lockup clutch control means determines that the traveling road is an uphill road while controlling the lockup clutch to the flex lockup state, and the driving force change amount is a predetermined driving force threshold value. If it is within the range, the lock-up clutch is released, and the vehicle control device shifts to the converter state.