JPS62295730A - Automatic clutch control device for automobile - Google Patents

Abstract

PURPOSE:To improve starting performance by obtaining clutch torque based on a clutch control element at a stall condition during clutch engagement, and by obtaining engine torque based on engine load and revolving speed whereby making stall revolving speed changeable based on both torque. CONSTITUTION:During an engine operation, change in revolving speed DELTANe is obtained by an engine revolving speed change detecting section 43 based on engine revolving speed Ne for inputting said change DELTANe together with engine revolving speed Ne and car speed V into a stall condition judging section 44. In this state, in case of Ne>0, V>0 and DELTANe=0, the case is judged to be in a stall condition. And at the time of judgment made as a stall condition, clutch torque Tc is computed by a clutch torque computing section 45 based on clutch current Ic at that time for obtaining engine torque Te based on a throttle opening theta and revolving speed Ne. Then, a predetermined correction value is obtained by a stall revolving speed judging section 47 based on both torque Tc and Te, thereby having a correction section 50 correct the clutch current in accordance with said correction value.

Description

[Detailed description of the invention]

3. Detailed Description of the Invention (Industrial Field of Application 1) The present invention relates to an automatic clutch control device installed in the drive system of a vehicle to electronically control the clutch torque. The applicant has already proposed a number of automatic clutches of this type for vehicles, for example those in which an electromagnetic clutch is used as a counter current. Operates the accelerator pedal and shift lever in a steady state after direct connection.Clutch torque is optimally controlled in relation to driving conditions, engine status, etc., and in combination with a manual transmission or belt-type continuously variable transmission, 1 In particular, in recent years, electronic control of not only engines but also drivetrain clutches, transmissions, etc. has progressed, and there is a trend toward even more fine-grained control of automatic clutches. be.

[Prior Art] Conventionally, clutch torque control in the start mode in the automatic clutch for a vehicle has been disclosed in, for example, Japanese Patent Laid-Open No. 60-16.
There is a prior art disclosed in Japanese Patent No. 1224, in which the clutch torque at the time of starting is determined as a function of the engine rotation speed, and it is shown that the clutch torque increases in proportion to the engine rotation speed. Problems to be Solved by the Invention) According to the control of the above-mentioned prior art, a stall point A where clutch torque Tc and engine torque 1°e match is determined as shown in FIG. 7 in the clutch engagement process, and this stall point After this point, the engine speed Ne becomes constant at the stall speed NS, and the clutch becomes directly connected at point B, which coincides with the clutch-driven side rotation loss NC. Therefore, the stall rotational speed Ns in this case is determined each time by the balance between both torques Te and Tc. There is no way to deal with variations in torque characteristics, changes over time, or decreases in engine torque at high altitudes. For this reason, the rotational speed NS in the stall state changes, making it impossible to always maintain optimal starting performance. In particular, when the engine torque Te decreases at high altitudes as shown by the broken line in Figure 7, the rotational speed Ns- at the stall point A- also decreases, and the engine rotational speed Ne is suppressed to this rotational speed NS-, resulting in a slow start. etc. are invited. The present invention has been made in view of these points, and provides a control device for an IT dual-use automatic clutch that constantizes the stall rotational speed at the time of starting to ensure optimal starting performance at all times. The purpose is to [Means for Solving the Problems] In order to achieve the above object, the present invention detects a stall state in the clutch engagement process in a start control system that controls clutch torque as a function of engine rotation speed,
The clutch torque is determined from the clutch control element in the stall state, and at the same time, the engine torque is determined from the relationship between the engine load and the rotation speed at this time, and the stall rotation speed is changed based on the relationship between both torques. . [Function] Based on the above configuration, it is determined whether the stall rotation speed is normal from the relationship between the clutch torque and engine torque in the stall state during start control, and if the engine torque is larger, the increase rate of the clutch torque is determined. By decreasing the clutch torque to increase the stall rotation speed, and conversely correcting the clutch torque if it is larger, the normal stall rotation speed can be obtained. In this way, in the present invention, it is possible to make the stall rotational speed constant at the time of starting, thereby absorbing variations in characteristics, changes over time, etc. (Example) Hereinafter, an example of the present invention will be described based on the drawings. In FIG. , the electromagnetic powder type clutch 22 is connected to the continuously variable transmission 4 via the forward/reverse switching gear 3, and from the continuously variable transmission 4, one set of transmission gears 5.output shaft 6.differential gear 7 is connected.
and is configured to transmit power to a drive shaft 9 via an axle 8. The electromagnetic clutch 2 includes a drive member 2a fixed to a crankshaft 10 of an engine, and a driven member 2b provided with a clutch coil 2C on an input shaft 11. The clutch current flowing through the clutch coil 2C connects electromagnetic powder in a chain shape to the gap between the two members 2a and 2b to form a chain of 4J, and the resulting coupling force variably controls the clutch contact pressure and clutch torque. front/rear) IL switching device 3 is connected to the input shaft 11 and the transmission main shaft 12.
The input shaft 11 is connected to the main @ 12 by gears, hubs, and sleeves.
It has a forward position where it is directly connected to the main shaft 12, and a retracted position where the rotation of the input shaft 11 is transmitted to the main shaft 12 by one reverse rotation. The continuously variable transmission 4 includes a main shaft 12 and a DI parallel to the main shaft 12.
@13, and a primary pulley 14 with variable pulley spacing, which is equipped with a hydraulic cylinder 14a on the main shaft 12;
3 is similarly provided with a secondary pulley 15 equipped with a hydraulic cylinder 15a. Further, a drive belt 16 is wound around both pulleys 14 and 15, and both cylinders 14a,
15a is configured as a hydraulic control circuit 17. Then, line pressure corresponding to the transmitted torque is supplied to both cylinders 14a and 15a to apply a boolean pressing force, and the primary pressure causes the drive belt 16 to wrap around the pulley 14.15 steplessly by changing the diameter ratio. It is configured to change gears to πi'l ill. Next, the electronic control i of the electromagnetic powder clutch 2 and the continuously variable transmission 4 is
The 2a system will be explained. Engine speed sensor 19 for engine 1. Rotation speed sensors 21 and 22 for the primary and secondary boosters of the continuously variable transmission 4 include sensors 23 and 24 for detecting operating conditions of the air conditioner and choke. In addition, the shift lever 25 of the operation system is connected to the forward/reverse switching device 3.
It is mechanically connected to reverse (R), drive (
D) and a shift position sensor 26 for detecting each range of sporty drive (Ds). Further, the accelerator pedal 27 has an accelerator switch 28 for detecting the accelerator depression state, and a throttle interval sensor 29 for rotating the throttle. The various signals from the switches and sensors are input to the electronic control unit 20 and processed by software using a microcomputer or the like. Then, the clutch control signal output from the electronic control unit 2o is sent to the electromagnetic clutch 2,
A shift control signal and a line pressure control signal are input to a hydraulic control circuit 17 of the continuously variable transmission 4 to perform each braking operation. In FIG. 2, the electromagnetic clutch t1112 (1 system) of the control unit 20 will be mainly explained. The signal is input to the shift speed control section 30, which outputs a control signal according to the shift method rgdi/dt.
Engine rotation speed Ne of sensor 19, throttle distance θ,
The signal of the actual gear ratio i<Ns/No) is sent to the line pressure control section 3.
1 and outputs a control signal according to the target line pressure. These control units input data to the continuously variable transmission lever 4 to control the line pressure to a predetermined level and to control the speed change. In the fδ magnetic clutch control system, the engine speed Ne
and a reverse excitation mode determination unit 32 to which signals of the R, D, and DS travel ranges of the shift position sensor 26 are input.
), the reverse excitation mode is determined in the case of the neutral (N) range, and the output determination section 33 causes a minute current to flow in the opposite direction to the normal one. Then, the residual magnetism of the electric powder type clutch 2 is removed and the clutch is completely released. Also, the determination output signal q of this floating tin E-do determination section 32. It has an energization mode determination section 34 that receives the depression signal of the accelerator switch 28 and the vehicle speed V signal of the secondary brake rotation speed sensor 22, and determines the running state such as starting, and this determination signal is used to determine whether the starting mode, drag mode, or Input to each current setting section 35.36°37 in direct connection mode. The starting mode current setting unit 35 separately sets starting characteristics in relation to the engine rotation speed Nc and the like in the case of normal starting or starting using an air conditioner or a choke. Then, the throttle distance θ and the vehicle speed V. The clutch current is set by correcting the starting characteristics according to each driving range of R, D, and DS. The drag mode current setting unit 36 determines a slight drag current when the accelerator is released at low vehicle speed in each of the R, D, and DS ranges, and generates drag torque in the electromagnetic powder clutch 2 to prevent play in the belt and drive system. Fill the space and start smoothly. In this mode, the snow current is set until just before the vehicle stops after the clutch is released in the D range to ensure coasting performance. The direct-coupling mode current setting unit 37 determines the direct-coupling current based on the relationship between the vehicle speed V and the throttle opening θ in each of the R, D, and DS ranges, fully engages the electromagnetic powder clutch 2, and saves power in the engaged state. I do. The output signals of these current setting units 35, 36, and 37 are input to the output determining unit 33, and the clutch current is determined according to the instructions thereof, and the map of each mode is as shown in FIG. In the electromagnetic clutch control system described above, an embodiment of start control will be described with reference to FIG. The starting mode current setting section 35 determines the energization mode. Engine speed Ne, throttle distance θ, vehicle speed V. It has a starting mode determining unit 40 that determines the starting mode by inputting each of the driving ranges R, D, and DS (M), and based on the determination result, the clutch current lc is determined by the current setting unit 41, and the clutch current lc is determined by the output unit 42. The current setting unit 41 determines the clutch current IC in proportion to the engine speed Ne by Ic = t'(Ne).In addition, regarding the stall speed control, the engine speed N
O has an engine rotation speed change detection section 43 that inputs this change ΔNe and the engine rotation speed Ne. The vehicle speed ■ is input to the stall state determination section 44, and Ne
,■〉0. When ΔNe=O, it is determined that the state is low. The determination signal from the stall state determination section 44 is input to the clutch torque calculation section 45 and the engine torque search section 4G, and the clutch torque calculation section 45 uses the clutch current IC in the stall state from the clutch current IC in the stall state as shown in FIG. The clutch torque TC is determined using the torque characteristics, and the engine torque search unit 4
In step 6, the normal engine speed Te is determined using the torque characteristic shown in FIG. These torques TC, To are determined by the stall rotation speed determining section 4.
7, and if Tc=Te, it is determined that the stall rotation speed NS is normal. On the other hand, when Te>TC, the stall low determination unit 48. It has a stall height determination section 49 in the case of Te<Tc, and the stall low determination section 48 determines the correction value C,
Based on the deviation or ratio of both torques Te and Tc, C is determined as C1, and the stall height determination section 49 similarly sets a correction value c>
1. This correction value C is input to the correction section 5.0 on the output side of the current setting section 41, and the clutch current 1c is corrected by lc=f(Ne).C. Next, the operation of the control device configured in this way is explained in the sixth section.
This will be explained with reference to the characteristics of the figure. First, when the accelerator is depressed in a low speed range including when the vehicle is stopped, the start mode determination section 40 determines the start mode, and the drag mode is switched to the start mode. Therefore, the current setting section 41
Then, the clutch current 1 according to the upper limit of the engine speed Ne
When c is set and flows to the clutch 2, clutch torque is generated and the clutch is engaged. In this engagement process, the sixth
As shown in the figure, the actual engine torque Tp and clutch torque TO match at the stall point A, and become constant at the stall rotational speed Ns at this time. Then, the stall state determining section 44 determines this state, and the clutch torque TO and the normal engine torque Te at this time are determined from the map, and the stall rotation speed determining section 47 determines the clutch torque TO and the normal engine torque Te. In other words, if Tl)=T(3, Te-=Tc is determined to be the normal stall rotation speed. On the other hand, if Tp<Te as shown in Figure 6, the normal stall point is reached. Since the balance is maintained at the stall point A', which is lower than A, inevitably Te>Tc, it is determined that the stall is low, and a correction value of c<1 is input to the correction unit 50.Therefore, the clutch current 1
c' is corrected to a characteristic with a small rate of increase, and is balanced at the stall point ALL on this characteristic, thus increasing the stall rotational speed to a normal value. On the other hand, when Tp>Te, Te<l”
C, it is determined that the stall is high, and the clutch current is corrected with a correction value of C>1, so that the clutch current has a characteristic with a large rate of increase. Therefore, the stall rotational speed is lowered and the deviation is similarly corrected. Although one embodiment of the present invention has been described above, the present invention is not limited to this, and correction may be made using a variable stall control method. Also, for automatic clutches other than electromagnetic clutches)
Can be used for B.

【Effect of the invention】

As described above, according to the present invention, the stall rotation speed is always the normal value in the start control, so variations in torque characteristics, secular changes, etc. are absorbed, and deterioration of start performance at high altitudes etc. is prevented. becomes possible. Since the normal engine torque and clutch torque in an actual stall state are compared, the stall rotation speed can be appropriately determined. Furthermore, the rate of increase in clutch torque can be accurately corrected based on the deviation between both torques.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram showing an embodiment of the control device of the present invention, Fig. 2 is an overall block diagram of the electronic control system, Fig. 3 is a map diagram of each mode, and Fig. 4 is a block diagram of the main parts. 5(2) and (b) are diagrams showing each torque map, and FIG. 6(2) shows each torque map.
), ■) are the starting characteristic diagrams, Figure 7 (c). ■) is a conventional characteristic diagram. 2...ff [powder type clutch, 20... Electronic control unit, 35... Starting mode current setting section, 40... Starting mode determining section, 41... Current setting section, 44... Stall Condition determination unit, 45...Clutch torque output unit,
46... Engine torque search section, 47... Stall rotation speed determination section, 50... Correction section. Patent Applicant Fuji Heavy Industries Co., Ltd. Agent Patent Attorney Nobu Kobashi Ukiyo Patent Attorney Susumu Murai■ Joji → Sahojisape

Claims (1)

[Claims] In a start control system that controls clutch torque as a function of engine speed, a stall state in the clutch engagement process is detected, the clutch torque is determined from the clutch control element in the stall state, and at the same time, A vehicle automatic clutch control device that determines engine torque from the relationship between the engine load and engine speed, and changes the stall speed based on the relationship between both torques.