NL8104610A - CONTROL SYSTEM FOR AN ELECTROMAGNETIC CLUTCH USED IN A VEHICLE. - Google Patents

Description

Control system for an electromagnetic clutch used in an automobile.

The invention relates to a system for controlling an electromagnetic clutch, which can be used efficiently in automobiles, and more particularly to a system for an electromagnetic powder clutch, whereby the shock can be reduced when changing the transmission ratio .

The electromagnetic powder clutch includes an annular drive member attached to the crankshaft of an engine as well as a magnetizing coil disposed in this drive member, driven by the drive input shaft of the transmission, which has a small gap relative to the drive member , and a sliding lever to change the relative position of the transmission elements in the transmission. The slide lever is provided with a switch for the magnetizing coil, which is actuated by operating the slide lever. When the slide lever is moved in such a way that the transmission elements enter into an interlocking position, the switch is closed so that an electric current flows through the magnetizing coil to magnetize the actuator.

20 When the accelerator pedal is pressed, the current supplied to the coil will increase. The magnetic powder will collect in the slit space between the drive member and the driven member, thereby establishing a connection between this drive member and the driven member. The current flowing through the magnetizing coil will gradually increase as the accelerator pedal is pressed more or less, while the coupling between the driving member and the driven member will show a certain slip.

Furthermore, the system is designed such that during the period a small coupling current will flow in which the clutch is turned on again after an operation to change the speed 8104610 * -2- so that the power is coupled into a partially engaged condition is transmitted, thereby damping shock caused by sudden clutch engagement. The circuit in which the coupling coil 5 is accommodated is switched on and off by operating the slide lever. The clutch tone is controlled by operating a shifting switch to cause the clutch to slip. In Fig. 7, the reference letter A indicates the engaged state of the coupling, in which a coupling current flows, whereby a fully engaged condition of the coupling is effected. When the shift lever is operated at the beginning of the change of transmission ratio, the clutch coil chain is broken as indicated by B and the clutch will be disengaged.

15 When the sliding lever is released again after the driver's ratio change is completed, the clutch coil will cause a smaller clutch current In than the current and flow as indicated by C and causing the clutch to be in a partially coupled state is maintained, that is, in a slipping state, so that the shock qp caused by clutch coupling can be reduced in this manner. The control period t ^ for the state during adjustment in which the clutch is partially coupled is shorter than the period t2 when decelerating. After the period t ^ or 25 t2 the current flows as indicated by D or E in Fig. 7, so that the coupling is then fully engaged. The period during which the clutch is partially engaged as a result of the current In is determined by operating the shifting switch, which is closed during the depressing of the shifting pedal. Thus, under the condition of a heavy load during acceleration, the period of partial engagement is shortened to reduce slipping of the clutch, and this period is extended during deceleration.

That is, with a classic system 35, when the accelerator pedal is not depressed for a long period of time, the clutch will be in a partial engagement state, so that by engaging the clutch during deceleration no shock will be caused. But. when the speed change operation is performed frequently or quickly, the shifting switch will close despite the deceleration. In such a state, the period of partial engagement ^ S ^ .z. equal to t ^, which will cause a strong impact shock that will make the passenger feel unpleasant.

When the accelerator pedal is depressed further, although the vehicle is in a deceleration gear, with the depressing action only slightly, the vehicle body will be subjected to a strong shock, when the shifting switch is closed and the clutch is suddenly engaged.

The invention has the main object of providing a control system for an electromagnetic coupling which operates in such a way that the period of partial engagement of the coupling is varied in dependence on the negative pressure, which is in the suction pipe of the motor 20 is present during the change of the transmission ratio, so that the notch dioclet of the coupling can be reduced in this way.

In accordance with the invention, there is provided a system for controlling an electro-magnetic coupling of a vehicle-mounted internal combustion engine equipped with a drive member mounted to a crankshaft of the internal combustion engine, as well as a magnetizing coil arranged in this drive member, of which a driven member is placed next to the driving member, of a gearbox mounted on the driven member with a number of transmission elements which can be mutually mutually positionable in several stages, and a sliding lever angle. to operate the gearbox, and characterized by a first detection element which appeals to the actuation of the shift lever to output an output signal of changing the mutual position of the transmission elements by a second detection element cp 8104G1 0 -4- a negative pressure in the suction pipe of the engine with internal appeals to combustion to output a corresponding output signal; by outputting a first control circuit which responds to the output signals from the first detection lane and the second detection element 5 for an period of time determined by the output signal of the second detection element; through a first gate circuit, which addresses the output of the first control circuit to output an output; and by a switch which responds to the output signal of the first gate circuit to cause current to flow through the magnetizing coil.

The invention will now be explained in more detail with reference to the figures.

FIG. 1 is a cross-sectional view of an electromagnetic transfer coupling controlled by the control system of the present invention; Fig. 2 shows a section according to the line II-II of Fig. 1; Fig. 3 shows an electronic circuit of the control system; FIG. 4 is a sectional view illustrating an embodiment of a negative pressure sensor; FIG. 5 is a sectional view of the receptacle of FIG. 4; FIG. 6 shows a number of time frames showing the variation of signals occurring at certain points in the diagram of FIG. 3; and FIG. 7 is a graphical representation illustrating the variation of the coupling current.

In FIGS. 1 and 2, 1 indicates an electromagnetic powder clutch, 2 indicates a four-speed gearbox, and 3 indicates a final reduction stage.

The electromagnetic powder clutch 1 is mounted in a clutch box and contains a drive plate 6 attached to the end of a crankshaft 5 8104610-5 * * of an internal combustion engine, and a drive ring attached to this drive plate 6 in a ring-shaped manner. part 8, a dental meshing coil 7 arranged in the driving part 8, and a driven member 10, which is connected by means of a band effected by sliding ribs to an input shaft of the gearbox 2, and which is connected by means of a spatial space 11 of the actuator 8 is separated. In a powder chamber 12 there is magnetically powdered material, so that the spatial space 11 can be filled with this powder. A cap 13 is attached to the driver 8. This cap 13 has a cylindrical portion which extends coaxially with the input shaft 9 and on which slip rings 14 are mounted. The slip rings 14 are just connected to the actuator 8 by means of a wire X. A number of brushes 16, which press against the slat rings 14 under pressure, are supported in a holder 17 and are connected by means of a wire Y to a control means to be described.

In such a construction, the driving plate 6 and the driving member 8 rotate together with the crankshaft 5, the magnetic powder contained in the powder chamber 12 in the sealed state being driven by the centrifugal force on the inner surface of the driving member 8. When the magnetizing coil 7 is energized by the currents supplied through the wire Y, the brushes 16, the slip rings 14 and the wire X, the actuator 8 is magnetized so that, as shown by the arrows in FIG.

1, a magnetic flux through the driven member 10 will radiate. This means that the powder in the gap-shaped space 11 will be contracted by this magnetic flux, so that the power of the motor will be transferred via the coupling cp to the input shaft 9.

In the gearbox 2, the driving gears 18 to 21 for the first to fourth gears are mounted as one unit on the input shaft 9. The driving gears 18 to 21 engage respectively in driven gears 23 to 26. These driven gears 23 to 26 are rotatable mounted on the output shaft 22 running parallel to the input shaft 9. Each driven gear 23 and 24 is arranged such that it can be brought into engagement with the output shaft 22 by operating a synchronization mechanism 27 and each driven gear 25 and 26 can be actuated in a sufficiently known manner by means of a synchronous mechanism 28 are engaged with the output shaft 22. Furthermore, a driven gear wheel 29 for reverse gear is provided. Thus, by operating the gearbox sliding lever (not shown), the driven gear 23 can be coupled to the output shaft 22 by means of the syndircmesh mechanism 27, the output shaft 22 being set in first gear 10 so that it is driven by the output shaft 9 transmitted power qpthis way is greatly reduced? while the second, third and fourth gears or gear ratios can be obtained in the same manner.

Furthermore, on one end of the output shaft 22, an out-of-gear gear 30 is arranged, which engages in an annular gear wheel 32 of a differential 31 of the final reduction stage 3. The output power of the output shaft 22 of the gearbox 2 is transferred directly from the annular gearwheel 32 via a housing 33, a star-shaped part 34 and a pinion 35 to a conical gearwheel 36 and from there via the wheel shafts 37 to the driving wheels.

In the control circuit according to FIG. 3, the input signals are formed by a gear change signal a, which is generated during actuation of the slide, as well as by a gear signal b which arises when the negative pressure in the suction line decreases, and by a carriage speed -ity signal c, which is generated when the speed of the car exceeds a predetermined value. From these signals a, b, c, a clutch control signal is derived. The transfer-change signal a is applied via an inverter stage 40 to the base of a transistor 41, the emitter of which is earthed and the collector of which is connected to a charging circuit 44, which consists of a resistor 42 and a capacitor 43. The accelerating signal b is applied via an inverter stage 45 to a standard voltage circuit 49, which consists of resistors 46, 47 and 48. The output signals from the load circuit 44 and the standard voltage circuit 49 are applied to the inputs of a comparator 50. The output of comparator 50 is connected to an AND gate 51 and to an inverting AND pointer 52. The car speed signal c is applied to the other input of AND gate 51. The other input 5 of the inverting AND gate 52 is supplied with an output signal from the oscillating circuit 53, which consists of inverter stages and resistors, etc. The outputs of the AND gate 51 and the inverting AND gate 52 are connected to an inverting AND gate 54, the output of which is again connected to an AND poart 55. The transfer change signal a is applied to the other input of AND gate 55, while the output of AND gate 55 is connected to the base of a transistor 56. The emitter of transistor 55 is grounded and the collector is connected to one end of coil 7. Furthermore, the two ends of the coil 7 are connected to an on-circuit circuit 57, which consists of a diode and a resistor.

Fig. 4 shows an exemplary embodiment of the acceleration detection element, for which use is made of a vacuum switch <73 on a suction line 72 of a motor 71.

This vacuum switch 73 is operated by the negative pressure of the air-fuel mixture supplied by a carburettor 70. Reference numeral 74 designates an exhaust pipe from the engine 71. In Fig. 5, the interior of the vacuum switch 73 is illustrated. The switch 73 has a cylindrical hollow body 75, which is distributed in an airtight manner by means of a maribron 76 in a pressure chamber 77 and a switching chamber 78. The pressure chamber 77 communicates with the suction line 72 and the switch chamber 78 communicates with the outside air. Furthermore, the pressure chamber 77 is provided with a helical spring 79 which acts on an operating part 80 fixed to the meirforane 76, while the switching chamber 78 is provided with a micro switch 81, which is actuated by the valve 76.

When the negative pressure in the suction line 72 is low (when the accelerator pedal is depressed), the difference between the pressure in the pressure chamber 77 and in the shift chamber 78 is small. As a result, the operating member 80 will pass through in such a manner

V

the helical spring 79 is actuated, the microswitch 81 is depressed and turned on. When the negative pressure is high (when the accelerator pedal is released again), the pressure difference will be large, so that the diaphragm 76 is bent back against the action of the helical spring 79, thereby disabling the microswitch 81. The acceleration is then interpreted by the position of the micro switch 81. The output signal from the microswitch 81 is applied to the input b of Fig. 3.

The operation of the system will now be described with reference to the time cranes according to Fig. 6.

The transmission change signal a will have a low level during the time the shift lever for the gearbox is actuated; the acceleration signal b will only reach a high level when the microswitch 81 is actuated when the negative pressure in the suction line is low; and the car speed signal c will only have a high level when the car speed is above a predetermined speed of, for example, 15 km / h side.

20 Shifting into a different gear at a speed greater than the predetermined car speed, with the accelerator pedal depressed and the negative pressure being low.

Here, the level of the transmission change signal a will change from high to low and a high level will be inverted by the inverting stage 25, thereby turning on the transistor 41. As a result, the capacitor 43 of the charging circuit 44 is discharged and the level of the output signal from the charging circuit 44 is reduced to zero, the signal being fed to comparator 50 at this level. The high level acceleration signal b is inverted at a low level by the inverter stage 45 and is applied to the resistor 46 so that the terminal voltage of the resistor 48 will be reduced thereby. The reduced signal bj_ will serve as a standard voltage for comparator 50. By the comparator 50, the signals b 'and d are compared with each other, and a high level signal is output when the signal 8104610 -9-b * is higher than the signal d. When the high level signal e is applied to the AND gate 51, the AND gate 51 outputs a high level signal £, and the level of the carriage speed signal c is also high. Since the signal e from the high-level comparator 50 and the pulse-shaped signal f are supplied to the inverting AND gate 52 from the oscillator circuit 53, pulses i are delivered through this gate and are inverted into the pulses f. Thus, only when the signals £ and i have a high level, the inverting AND gate 54 produces a low level signal £ which is passed to the AND gate 55. During this time, as long as the other input of the AND gate $ eai transmission change signal a with a low level is applied, the level of the output of the AND gate 55 will be low, so that the transistor 56 is turned off. is wrong. After the gear shifting has ended, the level of the change signal a will change from low to high, so that AND gate 55 will output high-level signals k, which will be output with the high level of the signal j, and which turns the transistor 56 on and off. Thus, an electric current with a certain scratch velocity will flow through the coil 7. This means that a coupling current will flow through the coil 7, which small value will then be a current with a permissible value, and as a result of which a partial engagement of the coupling will be caused. Due to the electromagnetic powder coupling 1, the power of the motor will therefore be transferred while slipping. When the level changes the transfer change signal a from low to high, the output signal of the inverter stage 40 turns off the transistor 41, so that the capacitor 43 is charged again through the resistor 42. As a result, the signal d from the load circuit 44 will increase parabolically. When the voltage of the signal d exceeds that of the signal d 'from the standard voltage circuit 49, the level of the output signal e from the comparator 50 will change to a low level as indicated by m in Fig. 6. Thus, the level of the output signal £ from AND gate 51 becomes low; the level of the output 8104610-10-i signal _j_ from the inverting AND gate 54 becomes high; so that a high output will be output from the AND gate 55, since ec eaa transmission change signal a is present, whereby the transistor 56 is switched on and through which a current 5 with a permissible value will flow through the coil 7 , which will result in complete encapsulation of the electromagnetic powder coupling 1.

Switching the gear at a speed higher than the predetermined speed, the accelerator pedal not being depressed and the negative pressure being high.

Since the acceleration signal b has a low level when the accelerator pedal is not depressed, a high-level signal is applied from the inverter stage 45 to the resistor 46, so that the standard voltage circuit 49 uses a standard voltage circuit 49 to the signal 46. comparator 50 is supplied, which has a higher level than the signal bj, which is generated when the accelerator pedal is pressed. Thus, when the level of the transmission change signal a changes from low to high and the voltage of the output signal d from the charge circuit 44 increases gradually, there will be a change in the output signal e of the comparator 50 from a high level to a low level at the point n, where the two signals b 'and d coincide at the same level. In this case, the point n occurs later than the point m, in which the levels of the signals 25 d and b 'coincide during the pressing of the accelerator pedal. This means that the period of the high level of the signal e is now longer. As a result, the interval between the completion of shifting to another gear and the decrease of the output signal e has lengthened. During this interval, AND gate 55 generates pulses, causing the period of partial engagement of the coupling is made longer. The variation in the signals from the output of the comparator 50 are indicated by the dotted lines in the signals c [, i, j, k, Ic in Fig. 6.

Due to the construction of the invention described above, the period during which the clutch is partially engaged can be varied in dependence on the acceleration gear of the vehicle during gear shifting, so that the engagement shock caused by the clutch is damped.

»8104610

Claims (5)

1. System for controlling an electromagnetic clutch for a vehicle-mounted internal combustion engine having a driving means mounted on a crankshaft of said engine with internal combustion, as well as adjacent to said drive actuated member, a gearbox mounted on the actuating member with a number of transmission elements, the mutual position of which can be changed in a plurality of stages, and a sliding-lift mechanism to operate said gearbox, characterized in that the system further from a first detection element is that it is operative to actuate said shift lever to output a transmission change output signal; as well as a second detection element which responds to the vacuum 15 in the suction pipe of the engine with the internal combustion in order to supply the relevant output signals? from a first control circuit which addresses the output signals of the first detection element and the second detection element to output an output signal for a period determined by the output signal from the second detection means; of a first gate circuit which addresses the output signal of the first control circuit to output an output signal? and a switching means which is responsive to the output of the first gate circuit to cause a current to flow through the magnetizing gate. 2. System for controlling an electromagnetic coupling of an internal combustion engine according to claim 1, characterized in that it further comprises an oscillator circuit for supplying an alternating train and a second gate circuit which is connected to the output of the said switches are tripped by said oscillator circuit to control the first gate circuit and allow the current flowing through said magnetizing coil to decrease. System for controlling an electromagnetic coupling of an internal combustion engine according to claim 1, characterized in that the first control circuit comprises an 8104610 * t -13 charging circuit, a standard voltage circuit, and a comparator for outputting the output signals. comparing the charging circuit and the standard voltage circuit to output an output signal for a period determined by the level of the output signal from said standard voltage circuit. System for controlling an electromagnetic clutch of an internal combustion engine according to claim 1, characterized in that the former gate chain is switched such that it is actuated when the carriage speed 10 exceeds a predetermined speed. 5. System substantially as described in the description and / or depicted in the figures. 8104610