JPH0811508B2 - 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 torque control when shifting from a half-clutch state in a starting mode to a direct coupling mode. . 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 states such as when 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, in the above-mentioned vehicle automatic clutch, clutch torque control in a transitional state such as start-up has been disclosed in
There is the prior art of 60-161224. Here, in the start mode, the clutch torque is increased in proportion to the engine speed, and when the vehicle speed reaches a predetermined direct-coupling speed, the mode is switched to the direct-coupling mode and a predetermined torque is applied to completely engage the clutch. It is shown. In this case, if the vehicle is still in the half-clutch state when the directly connected vehicle speed is reached, a sudden engagement may occur at that directly connected vehicle speed, which may cause a shock. Therefore, for example, Japanese Patent Laid-Open No. 60-139540 discloses that a transition characteristic region is provided after the set vehicle speed in the start mode and the increase speed of the clutch torque is controlled to reduce the engagement shock.

[Problems to be Solved by the Invention]

The actual engagement of the clutch is determined by the balance between the output torque of the engine and the load torque of the vehicle when a certain clutch torque is applied. Therefore, it is impossible to appropriately change the engagement state of the clutch simply by increasing the clutch torque at a constant speed as in the above-mentioned prior art, and the engagement state of the clutch is changed according to each load state. The speed is different and the engagement shock cannot be reduced properly. Therefore, it is necessary to control the torque in consideration of the running state of the vehicle. Further, if a clutch torque that is excessively large compared to the engine torque is applied even after the clutch is engaged, the torque fluctuation of the engine may also be transmitted to cause vibration and noise. Therefore, it is desirable that the transmission torque of the clutch substantially corresponds to the net generated torque of the engine except for the torque fluctuation of the engine. The present invention has been made in view of such a point, and accurately reduces the engagement shock when shifting from the half clutch state to the clutch engagement, and transmits the torque fluctuation amount of the engine after the clutch engagement. An object of the present invention is to provide a control device for an automatic clutch for a vehicle, which is made difficult.

[Means for solving problems]

As a means for achieving this object, the present invention controls the increase of the clutch torque according to the increase of the engine speed at the start, and when the direct connection vehicle speed is reached, the direct connection torque is generated to directly engage the clutch to control the vehicle automatic clutch. In the device,
In the region between the set vehicle speed Va set below the direct-coupling vehicle speed and the direct-coupling vehicle speed, the clutch torque is increased by adding the torque correction amount that increases as an increasing function of the vehicle speed to the clutch torque that increases in accordance with the increase in the engine speed. It is characterized in that a starting torque setting means for increasing control is provided.

[Action]

In the present invention employing such means, the clutch torque at the start of the vehicle is controlled to increase only in accordance with the increase in the engine speed in the region up to the set vehicle speed, and in the region between the set vehicle speed and the directly connected vehicle speed. An increase control is performed by adding a torque correction amount that increases as an increasing function of the vehicle speed to the clutch torque that increases according to the engine speed, and the torque is held at the direct connection torque in a region exceeding the direct connection vehicle speed. Here, in the region between the set vehicle speed and the direct-coupling vehicle speed, the clutch torque is controlled to be gradually increased by adding the torque correction amount increasing as an increasing function of the vehicle speed to the clutch torque increasing according to the engine speed. Therefore, even when the engine speed is low and the load is high and the engine speed is high,
The clutch is smoothly engaged regardless of the change of the stall point, and the engagement shock is appropriately reduced. Further, after the clutch is engaged, the clutch torque gradually increases without suddenly increasing, so that an excessively large transmission torque is not generated and transmission of torque fluctuation of the engine is suppressed.

【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
Of the current setting unit 3 for the start mode, the drag mode, and the 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. An embodiment of the start control in the electromagnetic clutch control system will be described with reference to FIG. The start mode current setting unit 35 has a start current determination unit 40 to which signals of energization mode determination, engine speed Ne, vehicle speed V, and throttle opening θ are input, and when the energization mode determination is the start mode, the start mode current setting unit 35 changes depending on the vehicle speed. The starting current is determined by Va or more and less than Va. Then, according to the result of this determination, two kinds of current setting units 4
1, 42, and the current setting unit 41 sets the clutch current Ic when the vehicle speed is less than Va as shown in FIG.
Since it is set as an increasing function of, Ic = _K f (Ne). _K is a correction constant when using a choke or an air conditioner for normal starting. The current setting unit 42 controls the clutch current Ic at a vehicle speed of Va or higher to a current _K f proportional to the engine speed.
Iv = _K f (Ne)
Set with + Iv. Here, the correction unit Iv is shown in FIG.
As shown in, it is an increasing function of the vehicle speed V. Next, the operation of the control device thus configured will be described with reference to the starting characteristic of FIG. First, in the low vehicle speed region D _{1 where} V <Va, the starting current determination unit 40
The current setting section 41 is selected by, and therefore Ic = _K f (N
Due to e), the clutch torque increases in proportion to the engine speed. In the correction area D ₂ of reaching Va, the current setting unit 42 is selected, and the clutch torque increases by adding the correction amount proportional to the vehicle speed by Ic = _K f (Ne) + Iv, and the direct connection vehicle speed V ₃ or V After reaching ₄ , the energization mode determination unit 34 switches from the start mode to the direct coupling mode through the transient characteristic region D ₃ , and the direct coupling current I _L flows to give the direct coupling torque T _L. Therefore, when it is combined with a continuously variable transmission that automatically changes continuously according to the throttle opening as in the embodiment, a region where the gear ratio is large and the engine speed is relatively high when starting a high load. Therefore, the torque of the clutch 2 rises rapidly in proportion to the engine speed, and the half-clutch state does not continue until the set vehicle speed Va or later. Therefore, in the low vehicle speed region D ₁ , the clutch 2 smoothly engages in the range where slippage is minimal. On the other hand, when starting a low load with a small throttle opening,
Since the region where the gear ratio is small is taken, the engine speed is low, the rise of the clutch torque is small, and the half-clutch state may reach the region D ₂ . However, since the transmission torque in this case is small, even if there is some slippage, the heat generated by it is small and no trouble occurs. And the change of the clutch torque in the area D _{2 in} this case is
Since it is smaller than that in the transient characteristic region D _3, the clutch engagement is gradually shifted to alleviate the shock. Further, since the clutch torque is maintained at a relatively small value even after the engagement, the variation of the engine torque is not transmitted. Although one embodiment of the present invention has been described above, the present invention is not limited to this, and a correction amount other than the vehicle speed can be used according to the traveling state. It can also be applied to various automatic clutches other than the electromagnetic clutch.

【The invention's effect】

As described above, according to the present invention, in the region between the set vehicle speed and the directly connected vehicle speed, the clutch torque is increased by adding the torque correction amount increasing as an increasing function of the vehicle speed to the clutch torque increasing according to the engine speed. Since the increase control is performed gradually, the clutch smoothly engages regardless of the change of the stall point even when the engine speed is low and the load is high, and the engine speed is high. The engagement shock of the clutch can be appropriately reduced. Further, since the clutch torque gradually increases without rapidly increasing after the clutch is engaged, it is possible to suppress the transmission of the torque fluctuation of the engine without generating an excessive transmission torque.

[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
Figures (a) and (b) are respective characteristic diagrams, and Figure 6 is a starting characteristic diagram. 2 ... Electromagnetic clutch, 20 ... Electronic control unit, 35 ...
Start mode current setting unit, 40 ... Start current determination unit, 41, 42,
43: current setting section, 44: vehicle speed determination section.

Claims (1)

[Claims] 1. A controller for an automatic clutch for a vehicle, wherein a clutch torque is controlled to increase in response to an increase in engine speed when the vehicle starts, and a direct connection torque is generated when the vehicle speed reaches a direct connection vehicle speed to directly engage the clutch. In the region between the set vehicle speed Va and the direct-coupled vehicle speed set below, the clutch torque is controlled to increase by adding the torque correction amount that increases as an increasing function of the vehicle speed to the clutch torque that increases as the engine speed increases. A vehicle automatic clutch control device comprising a starting torque setting means.