JPH02107827A - Control device of automatic clutch for vehicle - Google Patents

Abstract

PURPOSE:To improve efficiently the startability and the accelerationability in the case of the lower of the output of an engine at the high ground, etc., by correcting the characteristics of the clutch torque to be reduced in response to an amount of the lower of the atmospheric pressure when the atmospheric pressure detected by an atmospheric pressure sensor lowers at the time of starting at the high ground, etc. CONSTITUTION:At the time of starting at the high ground, the engine torque also lowers in response to the lower of the atmospheric pressure, and the atmospheric pressure P detected by an atmospheric pressure sensor 40 is input to a correction factor computing unit 41 so as to compute the correction factor K with K - P/760 in relation of the atmospheric pressure P and the 760 mmHg of the atmospheric pressure at the flat ground. And a current correcting unit 42 is provided at the output side of a starting mode current setting unit 35, and Ic X K of the correction is performed against the clutch current Ic output from the starting mode current setting unit 35. Thereby, the clutch torque characteristics is controlled to be reduced in response to an amount of the lower of the atmospheric pressure, and the clutch torque coincides with the stall engine speed as same as that of the flat ground can be obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an automatic clutch control device installed in a vehicle drive system that electronically controls clutch torque. The present invention relates to correction of the starting characteristics of the vehicle.

[Conventional technology]

Many automatic clutches for vehicles of this type, such as electromagnetic clutches, have already been proposed by the applicant. Most of these involve operating the accelerator pedal and shift lever in transient states such as when starting, and in steady states after direct clutch engagement.

The clutch torque is optimally controlled in relation to driving conditions, engine status, etc., and furthermore, in combination with a manual transmission or a belt-type continuously variable transmission, appropriate control is performed.

Particularly in recent years, electronic control of not only engines but also drive system clutches, transmissions, etc. has progressed, and there is a trend toward even more fine-grained control of automatic clutches.

Conventionally, regarding start control using the automatic clutch, there is a prior art, for example, in Japanese Patent Application Laid-Open No. 131430/1983, which shows that the clutch torque is controlled to be gradually increased and engaged when starting. . The characteristics of the clutch torque Tc and the engine torque Te in this case are as shown in Fig. 5, and the stall rotation speed N at the stall point P where the clutch torque Tc and the engine torque To match.
s is optimally set in consideration of starting performance, acceleration performance, etc.

[Problem to be solved by the invention]

By the way, the clutch torque characteristic and the stall rotation speed Ns in the start control of the prior art are generally set in relation to the engine torque characteristic on flat ground. Therefore, when the atmospheric pressure decreases at high altitudes and the engine torque decreases as shown by the broken line in FIG. 5, the stall point and stall rotational speed inevitably decrease as shown by P'N's. Therefore, the clutch engages when both the engine speed and the torque are low, resulting in problems such as a reduction in the half-clutch region, resulting in poor starting performance, and a reduction in engine speed growth, resulting in poor acceleration.

For this reason, when starting at a high altitude, etc., it is desirable to correct the clutch torque characteristics in accordance with the engine torque characteristics in this case to optimize the stall rotational speed. In addition, although the above-mentioned prior art shows that the stall rotation speed at the time of starting is changed, the stall rotation speed is set to be extremely low in order to make it impossible to start in the high speed gear. It has nothing to do with countermeasures.

The present invention has been made in view of the above points, and its object is to provide an automatic clutch for a vehicle that can effectively improve starting performance and acceleration performance when engine output decreases at high altitudes, etc. The purpose of this invention is to provide a control device for

[Means to solve the problem]

In order to achieve the above object, the control device of the present invention detects atmospheric pressure in a control system that variably controls clutch torque to gradually increase at least when the accelerator is pressed to start, and sets the stall rotation speed to a predetermined stall speed. The vehicle is equipped with an atmospheric pressure sensor, and when the atmospheric pressure measured by the atmospheric pressure sensor decreases when starting at a high altitude or the like, the clutch torque characteristics are corrected to decrease in accordance with the decrease in atmospheric pressure.

[For production]

Based on the above configuration, when starting at a high altitude, etc., the engine torque also decreases as the atmospheric pressure decreases, and in this case, the clutch torque characteristics are corrected to decrease according to the decrease in atmospheric pressure, so that the clutch The engine torque increases and decreases more slowly than on flat ground, but the stall rotational speed is approximately the same as on flat ground, and the starting performance is the same as on flat ground.
You will begin to gain acceleration.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Referring to FIG. 1, the overall configuration of a drive system that combines an electromagnetic clutch and a belt-type continuously variable transmission will be described. The engine 1 is connected to a continuously variable transmission 4 via an electromagnetic powder clutch 22 and a forward/reverse switching device 3. Output shaft 6. Differential gear 7
The power is transmitted to the drive wheels 9 via the axle 8 .

The electromagnetic powder clutch 2 has a drive member 2a on the engine crankshaft 10, and a driven member 2b on the input shaft 11 with a clutch coil 2C. Then, due to the clutch current flowing through the clutch coil 2C, both members 2a,
Electromagnetic particles are combined and accumulated in a chain in the gap between the parts 2b, and the resulting binding force variably controls clutch engagement and clutch torque.

The forward/reverse switching device 3 is configured in a synchronous meshing type with gears, hubs, and sleeves between the input shaft 11 and the main shaft 12 of the transmission, and has at least a forward position where the human power shaft 1 is directly connected to the main shaft 12, and an input position. It has a retreat position where the rotation of the shaft 11 is reversed and transmitted to the main shaft I2.

The continuously variable transmission 4 has a main shaft 12 and a subshaft 13 arranged parallel to the main shaft 12. The main shaft 12 is provided with a primary pulley 14 with a variable boob interval and equipped with a hydraulic cylinder 14a.
A secondary pulley 15 is similarly provided with a hydraulic cylinder 15a. Further, a drive belt 16 is wound around both pulleys 14 and 15, and both cylinders 14a and 15a are connected to each other.
is configured in the hydraulic control circuit 17. Then, a line pressure corresponding to the transmission torque is supplied to both cylinders 14a and 15a to apply a bobbin pressing force, and the primary pressure is used to push the brilliance bobbin 14 of the drive belt 16. The winding around the secondary pulley 15 is configured to change the ratio of diameters to perform stepless speed change control.

Next, the electronic control system of the electromagnetic powder clutch 2 and the continuously variable transmission 4 will be explained. Engine speed sensor 19 for engine l. Rotation speed sensors 21 and 22 for the primary pulley and secondary pulley of the continuously variable transmission 4 include sensors 23 and 24 for detecting operating conditions of the air conditioner and choke. Further, the shift lever 25 of the operating system is mechanically connected to the forward/reverse switching device 3, and is set to reverse (R), drive (D).
, and has a shift position sensor 2B that detects each range of sporty drive (Ds). Furthermore, accelerator pedal 2
7 has an accelerator switch 28 for detecting the accelerator depression state, and a throttle opening sensor 2 on the throttle valve side.
It has 9.

The various signals from the switches and sensors are input manually 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 20 is input to the electromagnetic powder clutch 2, and the shift control signal and line pressure control signal are input to the hydraulic control circuit 17 of the continuously variable transmission number to perform each control operation. It has become.

In FIG. 2, the electromagnetic clutch control system of the control unit 20 will be mainly explained.

First, the signals of the primary pulley rotation speed Np, secondary pulley rotation speed Ns, shift positions R, D, Ds, and throttle opening θ from the sensors 21, 22, 28, and 29 are input to the shift speed control section 30, and A control signal corresponding to the speed di/dt is output. Also, the engine rotation speed Ne and the throttle opening degree θ of the sensor 19.

The signal of the actual speed ratio I (Ns/Np) is input to the line pressure control section 31, which outputs a control signal according to the target line pressure. These control signals are input to the continuously variable transmission 4 to control the line pressure to a predetermined level and to control the speed change.

The electromagnetic clutch control system includes a reverse excitation mode determination unit 32 in which parking (P) and neutral (N) signals other than engine speed Ne and R, D, and Ds of the shift position sensor 26 are manually operated. e < 30Orp
In the case of m, or in the case of P or N range, it is determined to be the reverse excitation mode, and the output determination section 33 causes a small current to flow in the opposite direction to the normal one. Then, the residual magnetism of the electromagnetic powder clutch 2 is removed and it is completely released.

Also, the determination output signal of this reverse excitation mode determination section 32.

It has an energization mode determination unit 34 that receives the depression signal of the accelerator switch 28 and the vehicle speed V signal of the secondary pulley rotation speed sensor 22, and determines the driving state such as starting, and this determination signal is used to determine whether the driving mode is start mode, drag mode, or direct connection. Manually input each mode's current setting section 85.36°37.

The starting mode current setting unit 35 separately sets starting characteristics in relation to the engine rotation speed Ne, etc. in the case of normal starting or starting using an air conditioner or a choke. Then, throttle opening θ and 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 reduce play in the belt and drive system. to ensure a smooth start. In this mode, the current is set to zero 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 range of R, D, and Ds, 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, 38, 37 are input manually 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 above electromagnetic clutch control system, we will discuss correction measures for start control at high altitudes, etc.

First, an atmospheric pressure sensor 40 is provided.
The atmospheric pressure P is manually input to the correction factor calculating section 41, and the correction factor K is calculated from the relationship between the atmospheric pressure P and the atmospheric pressure of 760 mm11 g on a flat ground using K - P /760. Further, a current correction section 42 is provided on the output side of the starting mode current setting section 35, and is configured to correct Ic XK for the clutch current 1c output from the starting mode current setting section 35.

Next, the operation of the control device having such a configuration will be described using the flowchart of FIG. 4 and the characteristic diagram of FIG. 5.

First, when the accelerator 27 is pressed to start, the energizing mode determining section 34 selects the starting mode current setting section 35, and the starting mode current setting section 35 applies the clutch current 1e to the electromagnetic powder clutch 2 via the output determining section 33. The flow is variably controlled so that it gradually rises. Therefore, a torque corresponding to the clutch current is generated in the electromagnetic powder clutch 2, and the vehicle is engaged through a half-clutch state to start the vehicle.

At this time, the atmospheric pressure is detected by the atmospheric pressure sensor 40, and the correction factor K is calculated according to this atmospheric pressure as shown in the flowchart of FIG. Therefore, in the case of flat ground, the correction factor becomes -1, the clutch current 1c of the start mode current setting section 35 flows as it is, and the characteristic of the latch torque Tc is as shown by the solid line in FIG. 5, and the predetermined stall rotational speed Ns
get.

On the other hand, in a low-pressure state on a highland or flatland, the engine torque Te decreases as shown by the broken line in FIG. 5 due to a decrease in atmospheric pressure. Then, in response to the decrease in engine torque, the correction factor K becomes less than 1, and the current correction unit 42 adjusts Ic
The clutch current is uniformly reduced and corrected by K. Therefore, the clutch torque Tc has a characteristic of gradually increasing as shown by the broken line in Fig. 5, and the stall point with the decreasing engine torque Te becomes P', and the stall rotational speed becomes equal to the stall rotational speed Ns on flat ground. Become Roma-. In this way, even at high altitudes, the same half-clutch area as on flat land is obtained, and the clutch is engaged.

Note that the present invention can also be applied to automatic clutches using hydraulic pressure or the like other than electromagnetic powder type clutches.

〔Effect of the invention〕

As described above, according to the present invention, when the engine torque decreases at high altitudes in automatic clutch start control, the clutch torque characteristics are gently corrected.
Since the half-clutch area and stall rotation speed are the same as on flat ground, it is possible to obtain the same good starting performance and acceleration as on flat ground.

Furthermore, since the correction is controlled using a correction factor based on the atmospheric pressure measured by the atmospheric pressure sensor and the atmospheric pressure on the ground, control is easy9.
Corrections can always be made in accordance with the drop in atmospheric pressure.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an example of an automatic clutch to which the present invention is applied, FIG. 2 is a block diagram of a control system, FIG. 3 is a diagram showing clutch operation modes, FIG. 4 is a flowchart of the operation, FIG. 5 is a characteristic diagram of engine torque and clutch torque. 2... Electromagnetic powder clutch, 20... Electronic control unit, 34... Energization mode determination section, 35... Starting mode current setting section, 40... Atmospheric pressure sensor, 41... Correction factor Calculation section, 42...Current correction section Patent applicant Fuji Heavy Industries Co., Ltd. agent Patent attorney Shin Kobashi Slag amount Patent attorney Susumu Murai

Claims (2)

[Claims] (1) The control system that variably controls the clutch torque to gradually increase at least when the accelerator is pressed to start, and sets it to a predetermined stall rotation speed, has an atmospheric pressure sensor that detects atmospheric pressure, and is equipped with an atmospheric pressure sensor to detect atmospheric pressure. A control device for an automatic clutch for a vehicle, characterized in that when the atmospheric pressure measured by the atmospheric pressure sensor decreases at the time of starting, the characteristic of the clutch torque is corrected to decrease in accordance with the decrease in atmospheric pressure. (2) The control device for an automatic clutch for a vehicle according to claim 1, wherein the reduction correction amount is a ratio between the atmospheric pressure measured by the atmospheric pressure sensor and the atmospheric pressure on a flat ground.