JPS60157924A - Clutch torque control device for electromagnetic clutch for car - Google Patents

Abstract

PURPOSE:To increase stall rotation and obtain an engine output torque nearly equal to that when an air conditioner is not yet in use by converting the characteristic of clutch torque while said air conditioner is in use, to that whose increasing rate is low. CONSTITUTION:An input terminal 60 for an ignition pulse, which detects the rotation of engine, and an air conditioner switch 50, which detects whether an air conditioner is in use or not, constitute a part of a circuit for a clutch coil 15, through a control unit 51. The unit 51 has a wave form shaping circuit 52 for the ignition pulse signal and a saw tooth wave generating circuit 53, which are connected to the inversion side inpt of a comparator 54. The output side of the comparator 54 is connected to an AND gate circuit 57, and to the clutch coil 15 through a driving transistor 58. When the air conditioner is in use, the switch 50 is on, the reference voltage becomes lower due to a voltage dividing circuit 55 and a resistor 56, and a current for clutch is also controlled low, resulting in a clutch torque with a characteristic of low increasing rate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch torque control device for a vehicle electromagnetic clutch installed in a transmission system from an engine. This relates to clutch torque control at the time of starting with use.

Regarding the clutch torque control of this type of electromagnetic clutch, many proposals have been made by the applicant of the present invention, for example, in the special publication 1987-87720@.

On the other hand, in recent years, a transmission system that combines this electromagnetic clutch with a belt-type continuously variable transmission has been proposed, and even in vehicles with such a transmission system, by electrically controlling the clutch torque of the electromagnetic clutch, This has advantages such as eliminating the need for clutch pedal operation.

By the way, a belt-type continuously variable transmission has a completely different structure from a normal manual transmission, and utilizes the performance of an electromagnetic clutch that can be electrically controlled to overcome this structural difficulty. It is hoped that the problem will be resolved as a whole. Here, one of the drawbacks of the continuously variable transmission is that the belt starting torque is large, and in order to deal with this, there is a method such as, for example, generating drag torque in the clutch before starting the vehicle.

Therefore, when the air conditioner is used when starting, a compressor load is added to the engine, and a portion of the engine power is consumed by the continuously variable transmission due to the drag torque of the clutch mentioned above, so the decrease in engine output torque is compared. It's a big target. To explain this concretely in Fig. 4, the engine output torque characteristic surface mTHz when the air conditioner is not in use decreases to TE2 when the air conditioner is in use.
On the other hand, if the clutch torque characteristic curve at the time of starting is set to a substantially quadratic curve proportional to the engine rotation like TCI, the stall point where both curves coincide will shift from Pl to P2, and at this stall point The engine output torque decreases from T1 to T2. For this reason, when the air conditioner is in use, not only does the engine output per liter decrease, but the clutch becomes engaged at low engine speeds, causing problems such as slow start.

In view of this problem when starting when using an air conditioner, the present invention is designed to improve starting performance by changing the characteristics of the clutch torque in response to a decrease in engine output torque due to the use of an air conditioner. An object of the present invention is to provide a clutch torque control device for an electromagnetic clutch for a vehicle.

For this purpose, the configuration of the present invention takes advantage of the fact that the stall rotation should be increased in response to the decrease in engine output torque due to the use of the air conditioner, and the characteristics of the clutch torque when the air conditioner is used are adjusted to increase the rate of increase. The main idea is to increase the stall rotation by changing the torque to a lower one to obtain an engine output torque that is approximately the same as when the air conditioner is not in use.

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. In FIG. 1, as an example of a continuously variable transmission to which the present invention is applied, a continuously variable transmission 3! with an electromagnetic powder type clutch is shown. To explain about Tsuki, the symbol @1 is an electromagnetic powder type clutch, and 2 is a continuously variable transmission. The final reduction unit 5 has a transmission configuration.The electromagnetic powder type clutch 1 is housed in one side of the clutch housing 6, and the other side of the clutch housing 6 and the main case 7 are connected thereto.
Further, a switching section 3. of the continuously variable transmission 2 is provided inside a side case 8 which is joined to the opposite side of the main case 7 from the clutch housing 6. A pulley ratio changing section 4J3J and a final reduction section 5 are attached to each other.

The electromagnetic powder clutch 1 is connected to the crankshaft 10 from the engine.
A ring-shaped drive member 12 is coupled to the drive plate 11 via a drive plate 11, and a disk-shaped driven member 14 is integrally spline-coupled to the transmission input shaft 13 in the rotational direction. A coil 15 is built into the outer peripheral side of the driven member 14, and a gap 1G with a long circumference is formed between both members 12.14, and this gillep 16 communicates with the powder chamber 17 containing electromagnetic powder inside. are doing. In addition, a power supply brush 19 is in sliding contact with a slip ring 18 at the hub portion of the driven member 14 equipped with a coil 15, passes through the inside of the driven member 14 from the slip ring 18, and is connected to the coil 15 to form a clutch current circuit. has been done.

In this way, when the clutch current is applied to the coil 15, the drive and driven member 12.1 are connected through the gap 16.
4, electromagnetic powder is combined and accumulated in the gap 16 in a chain shape, and the resulting binding force causes the driven member 14 to slide and integrally connect to the drive member 12, resulting in a clutch connected state. . On the other hand, when the clutch current is cut, the drive by electromagnetic powder and the coupling force between the driven members 12 and 14 are lost, resulting in a clutch disconnected state.

In this case, the clutch current is controlled by the continuously variable transmission 2.
J, which is performed in conjunction with the operation of the switching unit 3, and P(
Parking) or N to neutral) D for forward movement from range
(drive), Ds (sporty drive) or reverse R (reverse) range automatically clutch 1.
acts as a rear guard, eliminating the need for clutch pedal operation.

Next, in the continuously variable transmission 2, the switching section 3 is provided between the input 4613 from the clutch 1, etc., and the main shaft 20 disposed coaxially therewith. That is, a reverse drive gear 21 that also serves as a forward engaged side is integrally formed on the input shaft 13, and a reverse driven gear 22 on the reverse engaged side is rotatably fitted to the main shaft 20. Gears 21 and 22 are meshed with each other via a counter gear 1724° supported by a shaft 23 and an idler gear 2G supported by a shaft 25. A switching device 4i27 is provided between the main @J20 and the gear 21. Here, the above gears 21.24.2 that are meshing
6.22 connects the coil 15 of the clutch 1 to the driven member 14 on the right side, and the inertia mass of this part is relatively low when the clutch is disengaged, so that the switching mechanism 27
The sleeve 29 that fits into the A-button 28 of the main shaft 20 is attached to each gear 2
1.22 for interlocking connection.

As a result, in the neutral position of the P or N range, the switching mechanism 2
The sleeve 29 of No. 1 is fitted only with the hub 28, and the main shaft 20
is disconnected 1111 from the input shaft 13. Next, when the sleeve 29 is meshed with the gear 21 side via the synchronizing mechanism 30, the main shaft 20 is directly connected to the input @13, and the input @13 is directly connected to the input @13.
) The camera enters the forward state of S range. On the other hand, when the sleeve 29 is reversely engaged with the gear A722 side via the synchronizing mechanism 31, the input shaft 13 is connected to the main shaft 20 via the gears j-/21, 24, 213, 22, and the engine power is decelerated and reversed. Then the vehicle enters the R range reverse mode.

In the boolean ratio converter 4, a sub-shaft 35 is arranged parallel to the main shaft 20, and a main pulley 36. A sub pulley 37 is provided, and both pulleys 36.
An endless drive belt 34 is looped between the pulleys 3G and 37. Both the pulleys 3G and 37 are divided into two parts, one half of the pulleys 36a and 37a, and the other half of the 361), 37b has variable boob spacing,
l' 5 movable, movable side boob half 3C11
), 371) are equipped with hydraulic servo devices 38, 39 which also serve as pistons (= i Forced.

Further, as a hydraulic control system, an A-il pump 41 as an operating source is installed adjacent to the main pulley 36. This A-il pump 41 is a gear A7 bomb for high pressure, and the pump drive shaft 4
2 is the main pulley 36. It penetrates through the main shaft 20J and the input shaft 13 and is directly connected to the crankshaft 10, so that hydraulic pressure is generated during engine operation. The hydraulic pressure of this oil pump 41 is controlled to control each hydraulic servo device 38.3.
9, the pulley spacing between the main pulley 36 and the sub pulley 37 is reversed, and the pulley 36 of the drive belt 34
．． 37, the pulley ratio at J3 is converted steplessly, and the steplessly variable power is output to the subshaft 35.

The final reduction unit 5 has a minimum boolean ratio on the high-speed stage side of the boolean converting unit 4 that is very small, for example, 0.5, so that the secondary shaft 35
In view of the fact that the number of rotations is high, an output shaft 44 is connected to the subshaft 35 via a set of intermediate reduction gears 43 . Then, the final gear 4G meshes with the drive gear 45 of this output shaft 44, and the differential m #R4 is output from the final gear ψ4G.
7 to the axles 48 and 49 of the left and right drive wheels.

The clutch torque control system of the electromagnetic powder clutch 1 combined with the continuously variable speed m2 is disclosed in Japanese Patent Application Laid-Open No. 56-13143.
There is a publication published in October, which discloses that the clutch torque is controlled so as to increase in proportion to the engine rotation. To explain only the control system of the present application in FIG. 2, the input terminal 6 for the ignition pulse signal that detects the engine rotation.
0, and an air conditioner switch 50 that detects whether or not the air conditioner is being used, and these are configured as a circuit in the clutch coil 15 via a control unit 51.

The control units 1 to 51 have a waveform shaping circuit 52 for the ignition pulse signal, and a waveform shaping circuit 52 for controlling the ignition pulse signal. It has a sawtooth wave destination circuit 53 that generates this sawtooth wave, and this circuit 53 is connected to the inverting side input of the comparator 54. A voltage dividing circuit 55 for determining m*lightning voltage is connected to the non-inverting side input of the comparator 54, and an air conditioner switch 50 is connected to the middle of this voltage dividing circuit 55 via a resistor 5G. The output side of the comparator 54 is connected to an AND gate 57 along with various control signals, and further connected to the clutch coil 15 via a driving transistor 58.

The operation of the device configured in this way will be explained using FIG. 3. The ignition pulse signal Δ is
3 and becomes a sawtooth wave B which is input to the comparator 54. On the other hand, when the air conditioner is not in use, the air conditioner switch 50 is turned off and the level of the reference voltage C1 is set high by the voltage dividing circuit 55, thereby outputting a signal with a duty ratio such as D1 having a long on time. So when I started,
When a control signal of 1 level corresponding to the depression of the accelerator is input to the AND gate 57, the above-mentioned duty signal is input as is to the transistor 58, causing an on/off operation).
As a result, the clutch current ICx of the clutch coil 15 is controlled to be high, and the clutch current IC
It becomes a characteristic like To i.

On the other hand, when using the air conditioner, the air conditioner switch 5
When 0 is turned on, the voltage dividing circuit 55 and resistor 56 reduce the base tF-voltage to 01. Therefore, the duty signal from the comparator 54 has a short A2 time as shown in D2, and as a result, the clutch current IC2 is also controlled to be low, and the clutch torque has a characteristic with a low rate of increase as shown by the curve TC2 in FIG. becomes.

Therefore, when starting the vehicle using the air conditioner, the clutch torque of the electromagnetic powder clutch 1 is changed to the characteristic of the curve TCz,
Based on this, the engine speed at the stall point P2'', which coincides with the characteristic curve TE2 of the engine output 1 to lux, which is reduced due to the compressor load or the like, is set to be high.

As a result, when the clutch is engaged, it is possible to generate an engine output torque that is substantially the same as when the air conditioner is not used, and thus, when the air conditioner is used, the starting characteristics are the same as when the air conditioner is not used.

Here, in the actual flow example described above, a reduction in engine output when an air conditioner is used has been described, but the same can be said about control when the idle speed is set high when a choke is used. That is, when starting at high idle using a choke, the clutch current rises rapidly in response to the high idle rotation, causing the vehicle to jump out. Therefore, as a preventive measure, as in the above embodiment, by changing the clutch torque increase rate to a lower characteristic and setting the stall rotation even higher, it is possible to perform a smooth start despite the high idle rotation. It becomes possible.

As for the control unit 51, it is of course possible to perform similar operations using software using a microcomputer.

As is clear from the above embodiments, according to the present invention, in an electromagnetic clutch combined with a continuously variable transmission, the clutch torque increases at a low rate in response to a decrease in engine output when starting with the use of an air conditioner. Since the clutch is engaged with engine output torque that is approximately the same as when the air conditioner is not used, the sluggish start caused by the decrease in engine output torque is eliminated, improving starting performance. In addition, since the upper limit rate of clutch torque is low, the engine speed can be increased easily. Since the duty ratio of the duty signal that controls the clutch current is changed, control is easy and the characteristics can be arbitrarily determined.

[Brief explanation of drawings]

Fig. M1 is a sectional view showing an example of an electromagnetic clutch to which the present invention is applied, Fig. 2 is a circuit diagram showing an embodiment of the device according to the present invention, Fig. 3 is a waveform diagram of each part, and Fig. 4 is a sectional view showing an example of an electromagnetic clutch to which the present invention is applied. The figure is a diagram showing engine output and clutch torque characteristics. DESCRIPTION OF SYMBOLS 1... Electromagnetic powder type clutch, 15... Clutch 1~LUK, 50... Air conditioner switch, 51... Control unit, 52... Waveform shaping circuit, 53... Sawtooth wave generation 1 circuit, 54... Comparator, 55... Voltage dividing circuit, 5
6...Resistor, 57...AND gate, 58...Transistor, 6o...Ignition pulse signal input terminal.

Claims (1)

[Claims] An electromagnetic clutch for a vehicle that controls the clutch torque to increase in proportion to the engine rotation when starting, has a means for detecting the use of an air conditioner, and when starting with the use of an air conditioner, the clutch is activated by Iz@ from the means. Clutch torque I of a heavy-duty electromagnetic clutch characterized by changing the torque to a characteristic with a low rate of increase
III control device.