JP2514794B2 - Automatic clutch control system for vehicles - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a control device for an automatic clutch which is provided in a drive system of a vehicle and electronically controls a clutch torque, and more particularly to a clutch disengagement control during sudden deceleration. The applicant of the present application has already proposed a large number of automatic clutches for vehicles of this type, for example, those intended for electromagnetic clutches. Most of them are transient conditions such as starting
In the steady state after the clutch is directly connected, the clutch torque is optimally controlled in relation to the operation of the accelerator pedal or shift lever, the running condition, the engine state, etc., and further in combination with the manual transmission or the belt type continuously variable transmission. This is to perform suitable control. Particularly in recent years, electronic control of not only the engine but also the clutch of the drive system, the transmission and the like has been advanced, and even automatic clutches tend to be controlled more finely.

[Prior art]

Conventionally, regarding the clutch control of the above-mentioned vehicle automatic clutch, there is, for example, the prior art of Japanese Patent Laid-Open No. 60-161224, in which the clutch torque is increased in proportion to the engine speed and the throttle opening at the time of start, and the set vehicle speed is set. When it reaches, the clutch is completely engaged by the direct connection current. Then, at the time of deceleration, it is shown that the engine is stopped by releasing the clutch at a speed equal to or lower than the set vehicle speed.

[Problems to be Solved by the Invention]

The clutch disengagement control of the above prior art, particularly during deceleration, is normally performed in the case of normal braking or coasting, and there is no problem.
However, when the vehicle decelerates rapidly due to sudden braking, etc., the speed of change of the vehicle speed is very large, and the input cycle of the vehicle speed pulse becomes longer as the speed is slower and it takes longer to detect the vehicle speed. There is a risk that the operation of releasing the clutch will be delayed, the engine speed will drop, and engine stalling will occur. Especially when the road surface frictional resistance such as on a snowy road is small,
This tendency is remarkable because the vehicle speed suddenly becomes zero due to the early locking of the tires. Therefore, it is conceivable to increase the clutch release vehicle speed during deceleration to give a margin to the clutch release, but if this is done, the effect of engine braking will be cut off at a relatively high vehicle speed,
There is a problem that the engine braking performance deteriorates. The present invention has been made in view of the above circumstances, and is an automatic clutch for a vehicle that ensures sufficient engine braking performance during normal deceleration and prevents the engine speed from dropping during sudden deceleration. The purpose is to provide a control device.

[Means for solving problems]

As a means for achieving this object, the present invention is a control device for an automatic clutch for a vehicle combined with a continuously variable transmission, in which the clutch is directly connected and the accelerator is released during traveling at a set vehicle speed or higher. In a vehicle automatic clutch control device having a clutch torque control means for releasing the clutch when the vehicle speed falls below the set vehicle speed during deceleration, the clutch torque control means is provided with A deceleration determination unit for forcibly releasing the clutch at the time of deceleration is provided, and the rapid deceleration determination unit detects the deceleration of the engine rotation speed and the engine rotation speed based on the engine rotation speed signal, and decelerates the engine rotation speed. Is above the set value, and when the engine speed is below the set value set to a value higher than the idle speed, it is determined that the vehicle is decelerating suddenly. Characterized by forcibly released clutch.

[Action]

Based on the above configuration, at the time of normal deceleration, the clutch engagement mode is set up to the clutch release vehicle speed, and the engine braking is sufficiently applied. On the other hand, if the engine speed deceleration and the engine speed setting value are judged to be a sudden deceleration, the clutch is forcibly released by the hydraulic pressure switching signal or current cut in the clutch engagement mode, and the engine speed drops. Will not occur. In this way, according to the present invention, it is possible to satisfy both the engine braking performance during normal deceleration and the prevention of engine speed drop during sudden deceleration.

【Example】

Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 1, an overall structure of a drive system in which an electromagnetic clutch is combined with a belt type continuously variable transmission will be described. The engine 1 is connected to a continuously variable transmission 4 via an electromagnetic clutch 2 and a forward / reverse switching device 3, and is connected to the continuously variable transmission 4 via a set of a reduction gear 5, an output shaft 6, a differential gear 7 and an axle 8. To the drive shaft 9. The electromagnetic clutch 2 has a drive member 2a on an engine crankshaft 10 and a driven member 2b having a clutch coil 2c on an input shaft 11. Then, by the clutch current flowing through the clutch coil 2c, electromagnetic powder is coupled and accumulated in the gap between the members 2a and 2b in a chain shape, and the coupling force by this causes the clutch disconnection and the clutch torque to be variably controlled. The forward / reverse switching device 3 is configured to be in a synchronous mesh type between the input shaft 11 and the transmission main shaft 12 by a gear, a hub, and a sleeve, and has at least a forward position where the input shaft 11 is directly connected to the main shaft 12 and an input shaft. And a retracted position where the rotation of 11 is reversed and transmitted to the main shaft 12. The continuously variable transmission 4 includes a main shaft 12 and an auxiliary shaft arranged in parallel with the main shaft 12.
The main shaft 12 is provided with a primary pulley 14 having a hydraulic cylinder 14a and a variable pulley distance, and the auxiliary shaft 13 is similarly provided with a secondary pulley 15 having a hydraulic cylinder 15a. A drive belt 16 is wound around both pulleys 14 and 15, and both cylinders 14a and 15a are configured in a hydraulic control circuit 17. Then, a line pressure corresponding to the transmitted torque is supplied to both cylinders 14a and 15a to apply a pulley pressing force, and the primary pressure changes the ratio of the winding diameter of the drive belt 16 to the pulleys 14 and 15 to continuously change the speed. Is configured to control. Next, an electronic control system of the electromagnetic clutch 2 and the continuously variable transmission 4 will be described. Engine speed sensor for engine 1
19, rotation speed sensors 21 and 22 for the primary pulley and the secondary pulley of the continuously variable transmission 4 and sensors 23 and 24 for detecting the operating states of the air conditioner and the choke. The shift lever 25 of the operation system is mechanically coupled to the forward / reverse switching device 3 and includes a shift position sensor 26 for detecting each range of reverse (R), drive (D) and sporty drive (Ds). Have. Further, the accelerator pedal 27 has an accelerator switch 28 for detecting the accelerator pedal depression state, and a throttle opening sensor 29 on the throttle valve side. Various signals of the switches and sensors are input to the electronic control unit 20 and processed by software using a microcomputer or the like. Then, the electromagnetic clutch control signal output from the electronic control unit 20 is input to the electromagnetic clutch 2 and the shift control signal and the line pressure control signal are input to the hydraulic control circuit 17 of the continuously variable transmission 4 to perform each control operation. ing. Referring to FIG. 2, the electromagnetic clutch control system of the control unit 20 will be mainly described. First, the primary pulley rotation speeds Np of the sensors 21, 22, and 29,
The signals of the secondary pulley rotation speed Ns and the throttle opening θ are input to the speed change control unit 30, and control signals corresponding to the speed change di / dt are output. The signals of the engine speed Ne of the sensor 19, the throttle opening θ, and the actual gear ratio i (Ns / Np) are input to the line pressure control unit 31 and a control signal corresponding to the target line pressure is output. Then, these control signals are input to the continuously variable transmission 4 to control the line pressure to a predetermined value and to control the shift. The electromagnetic clutch control system includes a reverse excitation mode determination unit 32 to which the signals of the engine speed Ne and the travel range of R, D, and Ds of the shift position sensor 26 are input. For example, when Ne <300 rpm, or when parking ( In the case of the P) and neutral (N) ranges, the mode is determined to be the reverse excitation mode, and the output determination unit 33 supplies a small current in a direction opposite to the normal direction. Then, the electromagnetic clutch 2 is completely released except the residual magnetism. Also, the judgment output signal of the reverse excitation mode judgment unit 32, the accelerator switch
28 stepping signal and secondary pulley speed sensor 22
The driving mode determination unit 34 receives the vehicle speed V signal, and determines a running state such as starting. Current setting section 3 for drag mode and direct connection mode
Enter 5,36,37. The start mode current setting unit 35 sets the start characteristics individually in relation to the engine speed Ne and the like in the case of the normal start or the start using the air conditioner and the choke. Then, the starting characteristic is corrected by each running range of the throttle opening θ and the vehicle speed V, R, D, Ds, and the clutch current is set. The drag mode current setting unit 36 determines a minute drag current when the accelerator is released at a low vehicle speed in each range of R, D, Ds,
A drag torque is generated in the electromagnetic clutch 2 so that the belt and the drive system are squeezed together to smoothly start the vehicle. Further, in this mode, the current is set to zero until just before the vehicle is stopped after the clutch in the D range is released to ensure coasting. The direct-coupling mode current setting unit 37 determines the direct-coupling current according to the relationship between the vehicle speed V and the throttle opening θ in each range of R, D, and Ds, completely engages the electromagnetic clutch 2, and saves power in the engaged state. . The output signals of the current setting units 35, 36, 37 are input to the output determination unit 33, and the clutch current is determined according to the instruction, and the map of each mode is as shown in FIG. The signals from the throttle opening sensor 29 and the accelerator switch 28 are input to the throttle valve opening setting unit 38,
The throttle actuator 18 is operated according to the deviation between the two to set the opening of a throttle valve (not shown). An example of clutch release control during sudden deceleration in the electromagnetic clutch control system will be described with reference to FIG. First, the engine speed signal of the engine speed sensor 19
It has a deceleration detection unit 40 to which Ne inputs, where deceleration G
(= −dNe / dt) is calculated and compared with a predetermined deceleration setting value G ₁ , and when G ≧ G ₁ , a determination signal is output. Also,
In the case of sudden deceleration, the engine speed starts to drop, and even if the clutch is disengaged when the engine speed becomes equal to or less than the idling speed nId, the engine speed must be determined. Therefore, the engine speed determination unit 41 is provided, a set value n ₁ higher than the idle speed nId is set, and a determination signal is output when Ne ≦ n ₁ . These engine rotation speed deceleration determination result and engine rotation speed determination result are input to the rapid deceleration determination unit 42, and when G ≧ G ₁ and Ne ≦ n ₁ , it is determined that there is rapid deceleration. On the other hand, the direct mode current setting unit 37, the direct mode current determination unit 37a, the determination result and, for example, the current setting unit 37b, and an output unit for setting a plurality of direct current I _L by a throttle opening degree θ for various signal inputs Has 37c. Then, the direct connection current of the current setting unit 37b is cut by the output signal of the rapid deceleration determination unit 42. Next, the operation of the control device thus configured will be described. First, at the time of normal deceleration, the direct connection mode is switched to the drag mode at the vehicle speeds V ₄ and V ₂ set in the energization mode determination unit 34, and a zero current or a drag current is generated, and the electromagnetic clutch 2 is released. At this time, especially in the Ds range, the clutch release vehicle speed V ₂ is low, so that the engine braking is sufficiently effective. On the other hand, during rapid deceleration, the rapid deceleration determination unit 42 makes a rapid deceleration determination based on the outputs of the deceleration detection unit 40 and the engine speed determination unit 41. The operation of the deceleration detector 40 will be described below with reference to the flowchart of FIG. That is, an interrupt is made at regular intervals to enter the timer interrupt routine. Then, the deceleration G is obtained by subtracting the current engine speed Ne ₂ from the engine speed Ne ₁ at the time of the previous interruption. The current engine speed Ne ₂ is stored in Ne ₁ to prepare for the next interrupt. When the deceleration G thus calculated is larger than the set value G _1, it is determined that the deceleration of the engine speed is large. Deceleration G ≧ G _{1 of the} above engine speed and engine speed
With the judgment result of Ne ≦ n ₁ , it will be judged as a sudden deceleration,
This determination signal is input to the current setting unit 37b in the direct connection mode. At this time, when the energization mode determination unit 34 has switched to the direct coupling mode and the current setting unit 37b causes the direct coupling current to flow and the clutch is engaged, the direct coupling current is forcibly cut off and the electromagnetic clutch 2 is operated. To release. As a result, the engine 1 is separated, and a drop in engine speed due to an overload on the wheel side is avoided. Then, when the vehicle speed reaches the set vehicle speed V ₄ or V ₃ due to the decrease in the vehicle speed, the energization mode determination unit 34 switches from the direct connection mode to the drag mode and continues the clutch release. At this point, the compulsory electromagnetic clutch release control associated with the sudden deceleration described above is released and the steady control is resumed. Therefore,
When the vehicle is stopped, a drag torque is generated in the clutch 2 and the accelerator is depressed to shift to the start mode. Although one embodiment of the present invention has been described above, the present invention is not limited to this. That is, in the embodiment, the element of the engine speed is not used for the mode switching by the energization mode determination, but when this engine speed is also used for the mode switching, the mode is switched by the energization mode determination during deceleration to control the clutch release. You can also Further, it can be applied to various automatic clutches other than the electromagnetic clutch.

【The invention's effect】

As described above, according to the present invention, when the vehicle is decelerated, the clutch is basically released when the vehicle speed becomes lower than the set vehicle speed. Even when the engine has a speed change characteristic in which the engine speed is gradually changed to a low speed steplessly and the engine speed is kept substantially constant, the clutch can be released accurately and a good driving feeling can be obtained. In particular, even if the engine speed deceleration is equal to or higher than the set value and the engine speed is equal to or lower than the set value set to a value higher than the idling speed, the rapid deceleration determination unit rapidly decelerates even if the vehicle speed is equal to or higher than the set vehicle speed. Since it is determined that it is time and the clutch is forcibly released, it is possible to prevent the engine speed from dropping and the engine stall due to the sudden deceleration of the vehicle. Here, the rapid deceleration determination unit determines the rapid deceleration time on the condition of the deceleration of the engine rotation speed and the degree of decrease of the engine rotation speed, so the determination is quick and highly accurate, and the wheel lock is performed. Even in the case of occurrence of the engine, it is possible to reliably prevent the engine speed from dropping and stall due to the sudden deceleration. In addition, the rapid deceleration determination unit determines whether the clutch is decelerated during normal deceleration where the engine speed deceleration is smaller than the set value, or when the vehicle runs at high speed when the engine speed exceeds the set value higher than the idling speed. Since the vehicle is not forcibly released, the engine brake can be reliably operated during normal deceleration of the vehicle or during rapid deceleration during high-speed traveling, which is safe.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a control device of the present invention, FIG. 2 is a block diagram of an entire electronic control system, FIG. 3 is a map diagram of each mode, and FIG. Figure, fifth
The figure is a flow chart. 2 ... Electromagnetic clutch, 37 ... Direct connection mode current setting section, 37
b ... current setting section, 40 ... deceleration detecting section, 41 ... engine speed determining section, 42 ... sudden deceleration determining section.

Claims (1)

(57) [Claims] 1. A controller for an automatic clutch for a vehicle combined with a continuously variable transmission, wherein the clutch is directly connected during traveling at a speed higher than a set vehicle speed, and is below the set vehicle speed when decelerating the vehicle with the accelerator released. In the vehicle automatic clutch control device having the clutch torque control means for disengaging the clutch, the clutch torque control means forcibly engages the clutch during sudden deceleration during traveling at a set vehicle speed or more where the clutch is directly connected. A rapid deceleration determination unit that releases the engine rapidly, the rapid deceleration determination unit detects deceleration of the engine speed and the engine speed based on the engine speed signal,
When the deceleration of the engine speed becomes equal to or higher than the set value and the engine speed becomes equal to or lower than the set value set higher than the idle speed, it is determined that the vehicle is in rapid deceleration and the clutch is forcibly released. A vehicle automatic clutch control device characterized by the above.