JPS6350217B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a control device for an electromagnetic clutch for a vehicle, and more particularly to a control device for an electromagnetic clutch for a vehicle that can control clutch current so that set clutch torque characteristics are not affected by disturbances.

[Conventional technology]

In an electromagnetic clutch for a vehicle, the driven member on the input side of the transmission is closely fitted to the drive member on the crankshaft side, which has a built-in coil, through an extremely small gap, and the clutch current is passed through the coil to connect the drive member to the drive member. The clutch current is cut off to release the constraint by the magnetic lines of force in the gear and the power is transmitted. cut off the
Furthermore, the clutch current is changed to cause slippage between the drive member and the driven member, and this slippage is used to start the vehicle without the need for clutch pedal operation, thereby facilitating driving operation.
This is already known as shown in Japanese Patent Application Laid-Open No. 53-52849 and Japanese Patent Application Laid-Open No. 53-102448.

[Problem to be solved by the invention]

The clutch torque of this electromagnetic clutch for vehicles is controlled by changing the cycle of the voltage applied to the coil.
It was intended to obtain predetermined characteristics. However, since the cycle of the voltage applied to the coil is simply changed, if the voltage (generally the battery) fluctuates, the clutch torque also fluctuates, making it impossible to obtain the set characteristics. Furthermore, if the electrical resistance of the coil changes due to temperature changes due to clutch slippage, etc. (even if the applied voltage is constant), the clutch current will fluctuate and the clutch torque will also fluctuate. As described above, open loop control is susceptible to disturbances such as voltage and temperature, making it difficult to obtain preset characteristics. In view of the above-mentioned drawbacks, the present invention detects changes in the clutch current, compares the detected value with a set value determined by the engine speed and gear position, and corrects the clutch current to maintain a constant clutch torque. The present invention provides a control device for an electromagnetic clutch for a vehicle that can obtain the following characteristics.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a control device in which a crankshaft is coupled to a drive member containing a coil through a drive plate, a driven member of a transmission input shaft is closely fitted to the drive member, and a control device is provided. An electromagnetic clutch for a vehicle transmits power by supplying a clutch current from the coil to the coil and integrally restraining the drive and driven member by electromagnetic force. It is equipped with means for detecting the gear position and means for detecting the clutch current flowing through the coil, and the detected clutch current is compared with a value preset based on the engine speed and the gear position to correct the clutch current. , is configured to maintain the set clutch torque characteristics.

【Example】

An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the present invention will be explained by embodying an electromagnetic powder clutch, which is a type of electromagnetic clutch. In Figures 1 and 2, the electromagnetic powder clutch assembled into the transaxle type transmission will be explained in detail. Reference numeral 1 is the electromagnetic powder clutch, 2 is the 4-speed forward transmission, and 3 is the electromagnetic powder clutch. is the final gearbox. In the electromagnetic powder clutch 1, a drive member 8 containing a built-in coil 7 is integrally connected to a crankshaft 5 from the engine via a drive plate 6 within a clutch case 4 having a sealed structure. 10 are spline-fitted so as to be integrated in the rotational direction, and are closely fitted to the drive member 8 via a gap 11, and electromagnetic powder from the powder chamber 12 is accumulated in this gap 11. Further, a cap 13 is integrally connected to the drive member 8, and a cylindrical end portion of the cap 13 is loosely fitted onto the input shaft 9, and a slip ring 14 is inserted therein.
is attached, and a lead wire X is connected between the slip ring 14 and the drive member 8, and the slip ring 14 has a brush 16 connected to the lead wire Y, as detailed in FIG. It is held by a holder 17 and is in sliding contact with the coil 7 to supply power. With this configuration, the drive plate 6 and the drive member 8 rotate together with the crankshaft 5, and the electromagnetic powder sealed in the powder chamber 12 is appropriately gathered toward the inner peripheral surface of the drive member 8 by centrifugal force. There is. Therefore, from the lead wire Y to the brush 16,
When power is supplied to the coil 7 via the slip ring 14 and the lead wire X, the excitation of the drive member 8 generates lines of magnetic force around the driven member 10 as shown by the arrow, so that electromagnetic particles accumulate in the gap 11. The drive member 8 and the driven member 10 are integrated, and the engine power of the crankshaft 5 is transmitted to the input shaft 9. Next, in the transmission 2, first to fourth speed drive gears 18 to 21 are integrally provided to an input shaft 9 from the clutch 1, and an output shaft 22 is arranged parallel to the input shaft 9. There is a driven gear 23 that constantly meshes with each of the above gears 18 to 21.
26 are rotatably fitted, and adjacent 2
The driven gears 23 and 24 are connected to the output shaft 22 by a synchronization mechanism 27, the driven gears 25 and 26 are connected to the output shaft 22 by another synchronization mechanism 28, and these input and output shafts 9, A gear mechanism 29 for reversing is provided between 22 and 22 . In this way, by operating the change lever and integrally coupling the driven gear 23 to the output shaft 22 by the synchronizer 27, the power of the input shaft 9 is decelerated most by the gears 18 and 23, and is taken out to the output shaft 22 to reach the first speed. is obtained, and subsequent gear changes are performed in the same manner. Further, an output gear 30 is provided at the end of the output shaft 22.
is provided and meshes with the ring gear 32 in the differential device 31 of the final reduction gear 3, so that the power of the output shaft 22 of the transmission 2 is immediately transferred from the ring gear 32 to the side gear via the case 33, spider 34, and pinion 35. 36 and further transmitted to the drive wheels via the axle 37. FIG. 3 is a block diagram showing the control system of this embodiment. An ignition pulse a that is proportional to the engine speed and a gear position signal b that detects the gear position of the transmission 2 are input to the target setting section 40. The output of the target setting section 40 is input to the control section 42 via the comparison point 41, and the output of this control section 42 controls the clutch current 4.
3 is controlled. This clutch current 43 is detected by a detection section 44, and its detection output is obtained at a comparison point 4.
1 is entered. FIG. 4 shows a more specific electric circuit in FIG. 3, showing the ignition pulse a and the gear position signal b.
is input to the function generator 45, and the function generator 5
The output of is input to one end of the comparator 46. The output of the comparator 46 is input to one end of an AND gate 47, and the output of the AND gate 47 is input to the base of a transistor 49 via a resistor 48. The emitter of the transistor 49 is grounded via a resistor 50 with a minute resistance value, the coil 7 is connected to the collector, and a commutation circuit 52 consisting of a diode and a resistor is connected to both ends of the coil 7. . An amplifier 53 is connected between the emitter of this transistor 49 and a resistor 50, and the output of this amplifier 53 is input to the other end of the comparator 46. The other end of the AND gate 47 receives a speed change signal c.
is input, and this shift signal c is provided at a shift lever or the like of the transmission 2, and becomes a low level when a shift operation is performed. Next, the operation of this embodiment will be explained. In FIG. 3, when the ignition pulse a and the gear position signal b are input, the target setting section 40 transmits a preset target value to the control section 42, and causes the clutch current 43 to flow by a predetermined value to generate clutch torque. let This clutch current 43 is
4 is detected, inputted to a comparison point 41, and the signal from the target setting section 40 is corrected to control the clutch current 43 so as to always obtain a predetermined characteristic without being fluctuated by disturbance. In the specific electric circuit shown in FIG. 4, the relationship between the engine speed and the optimum clutch current, which is predetermined from the vehicle starting characteristics by the function generator 45, is approximated by the ignition pulse a and the gear position signal b. The function signal is output to a comparator 46, and when this signal is larger than the output from the amplifier 53, the comparator 46 outputs a high level signal to the AND gate 47. When the speed change signal c is at a high level, the AND gate 47 outputs a high level signal and applies it to the base of the transistor 49 via the resistor 48 to turn on the transistor 49. Therefore, the voltage from the battery flows through the coil 7, the transistor 49, and the resistor 50 in this order, thereby connecting the electromagnetic powder clutch 1 with a predetermined torque. The current flowing through the coil 7 appears as a voltage at the terminal of the resistor 50, and this terminal voltage is amplified by the amplifier 53 and fed back to the comparator 46 to monitor whether an appropriate current is flowing. The current is controlled so that the set current always flows. The operation of the control system using this comparator 46 is shown in FIG. 5. The comparator 46 has the relay characteristics shown in the figure, and in the range i(t)>h/2, the output is always m(t). = M, and i(t) < 0, i(t)
>−h/2 also, m(t)=M. Here, i(t) is the clutch current, m(t) is the comparator 4
6, h is the fluctuation range of the clutch current. Also, in the range i(t)<-h/2, m(t)=0, i
Even if (t)>0 and i(t)<h/2, m(t)=0
It is. Further, the transfer function of the coil 7 of the electromagnetic powder clutch 1 is K/(1+ST), and from this, the change in the clutch current io(t) flowing through the coil 7 is as shown in FIG. Here function generator 4
When the output from 5 is (t)=Io (constant), the clutch current io(t) is controlled to vary within the range h of change in relay characteristics around Io. The output of this function generator 45 has different characteristics depending on the gear position signal b, and even at the same engine speed, it can be set to either a low gear (low second) or a high gear (third top). Therefore, the characteristics controlling the clutch current are changed, and as a result, the clutch torque that the electromagnetic powder clutch 1 can transmit is changed. The characteristics of the function generator 45 due to this change in gear position are shown in FIG.

【Effect of the invention】

Since the present invention is configured as described above, it is possible to detect fluctuations in the clutch current due to disturbance and compare it with a preset value, so that the clutch torque to be transmitted can always be maintained at the set value, thereby achieving desired starting characteristics. can be obtained. Furthermore, since the variation range of the clutch current can be limited, the clutch torque variation can be reduced compared to conventional control methods.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of an electromagnetic powder clutch that is an embodiment of the present invention, Fig. 2 is a sectional view taken along the Z-Z line in Fig. 1, and Fig. 3 is a block diagram showing the control system. , Fig. 4 is a specific electric circuit diagram of the same as above, Fig. 5 is an explanatory diagram showing the action of the comparator, Fig. 6 is a graph showing changes in clutch current, and Fig. 7 is a change in control characteristics depending on gear stage. This is a graph showing. 1... Electromagnetic powder clutch, 5... Crankshaft,
6... Drive plate, 7... Coil, 10...
...Driven member, 11...Gap, a...Ignition pulse, b...Shift stage signal.

Claims (1)

[Claims] 1. The crankshaft is coupled to a drive member containing a coil through a drive plate, and a driven member of a transmission input shaft is closely fitted to the drive member, and a clutch current from a control device is supplied to the coil. , an electromagnetic clutch for a vehicle that transmits power by integrally restraining a drive and a driven member using electromagnetic force, which includes a means for detecting engine rotation speed, a means for detecting a gear position of a transmission, and a coil. and means for detecting a clutch current flowing through the clutch, and compares the detected clutch current with a preset value based on the engine speed and gear position to correct the clutch current and maintain the set clutch torque characteristic. A control device for an electromagnetic clutch for a vehicle, which is characterized by: