JPS6260293B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an electromagnetic clutch for a vehicle, and in particular, it performs direct connection control in each situation depending on the engine speed, and when the transmission is in neutral, the clutch is directly connected at a predetermined engine speed. The present invention relates to a control device for an electromagnetic clutch for a vehicle, which controls the clutch so that it does not occur.

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. is excited, and by concentrating magnetic lines of force in the gap between it and the driven member, the engine's power is transmitted to the input side of the transmission, and the clutch current and time are cut off to release the constraint caused by the lines of magnetic force in the gap. The power transmission is cut off, and the clutch current is changed to cause slippage between the drive member and the driven member.
This slippage is used to start the vehicle without the need for clutch pedal operation, which facilitates driving operations, and is already known as a publicly known technique.

This electromagnetic clutch is combined with a transmission and used in automatic transmissions, etc., but in order to be used in a vehicle, it must be controlled optimally depending on the usage situation. There is a vehicle speed sensor that detects the speed of the vehicle and uses this as one of the control decisions. This vehicle speed sensor detects a predetermined speed and outputs a signal, performs slip control from a stopped state to a predetermined speed, and can control the electromagnetic clutch to a directly engaged state when a steady running speed is reached.
Furthermore, in order to prevent the engine from stopping when the speed drops below a predetermined speed, the electromagnetic clutch is controlled to open when the speed is below a predetermined speed.

Conventionally, this vehicle speed sensor has been built into a speedometer, so an accident such as a breakage of the speedometer cable causes the vehicle speed sensor to lose its function. If the vehicle speed sensor loses its function and is no longer able to detect the vehicle speed, when the accelerator is released due to deceleration, etc., the clutch control current will not flow and the engine and axle will be released, resulting in a state in which the engine brake will not work. Furthermore, even if the vehicle speed sensor is operating normally, the range in which the engine brake operates is limited depending on the vehicle speed, and the engine brake cannot be operated depending on the gear ratio of each gear of the transmission.

For this reason, a configuration has been devised in which the engine speed is detected and the clutch is directly engaged or released when the engine speed reaches a set value. However, with this configuration, when the idle speed is increased by pulling the clutch yoke, the clutch may be inadvertently connected directly, which is dangerous. This required changing the set rotation speed. Furthermore, when the transmission is in neutral, if the clutch is directly engaged at a predetermined engine speed or higher, the clutch may jump out during shifting, which is dangerous.

In view of the above-mentioned drawbacks, the present invention provides an electromagnetic clutch for a vehicle, which determines whether to directly engage the clutch based on the engine speed, and which does not directly engage the clutch when the transmission is in a neutral state at a predetermined engine speed or higher. The present invention provides a control device for the following.

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 FIGS. 1 and 2, the electromagnetic powder clutch assembled into a transaxle type transmission will be explained in detail. Reference numeral 1 is an electromagnetic powder clutch, 2 is a four-speed forward transmission, 3 is a final reduction gear.

In the electromagnetic powder clutch 1, a drive member 8 containing a built-in coil 7 is integrally coupled to a crankshaft 5 from the engine via a drive plate 6 within a clutch case with a sealed structure, and a drive member 10 is connected to an input shaft 9 of a transmission 2. The drive member 8 is spline-fitted to be integrated in the rotational direction and closely fitted to the drive member 8 via a gap 11, and electromagnetic powder from the powder chamber 12 is collected in the gap 11. Further, a cap 13 is integrally connected to the drive member 8, and its cylindrical end is loosely fitted onto the input shaft 9, and a slip ring 14 is attached thereto. Lead wire X is connected between
As shown in detail in FIG.
7 and is in sliding contact to supply power to the coil 7.

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.
The two adjacent driven gears 23 and 24 are connected to the output shaft 22 by a synchronization mechanism 27, and the driven gears 25 and 26 are connected to the output shaft 22 by another synchronization mechanism 28. Furthermore, a gear mechanism 29 for reverse movement is provided between these input and output shafts 9 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. The speed is obtained, and each speed change is 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.

The control system of the clutch is shown in FIG. 3, and consists of a control device 38 that controls the clutch current according to the running condition of the vehicle, and various signal sources that detect operating conditions.The input side of the control device 38 is An accelerator switch 39 that is turned off when starting the vehicle and a neutral switch 40 that is turned on when the vehicle is in neutral are connected. Further, the voltage of a battery 41 is applied to the control device 38 via a key switch 42, and the ignition coil 4 is connected to the key switch 42.
The primary side negative terminal of the ignition coil 43 is connected to the control device 38 in order to detect the ignition pulse, and the negative terminal is grounded via the breaker 44. There is. The output of the control device 38 is connected to a conductor 15 leading to the brush 16.

FIG. 4 shows the inside of the control device 38, in which the accelerator switch 39 is connected to the accelerator detection circuit 4.
The ignition coil 43 is connected to the pulse wave generating circuit 45 and the clutch direct connection circuit 46, and the neutral switch 40 is connected to the clutch direct connection circuit 46. The outputs of the accelerator detection circuit 44 and the pulse wave generation circuit 45 are input to an AND gate 47.
7 and the respective outputs of the clutch direct connection circuit 46 are input to an OR gate 48. 49 is a transistor for switching, and the output of the OR gate 48 is connected to the base of the transistor 49. One end of the coil 7 is connected to the collector. Further, a commutation circuit 50 consisting of a diode and a resistor is connected to both ends of the coil 7.

FIG. 5 shows the output characteristics of the accelerator detection circuit 44. When the accelerator is released and the pedal is not depressed, a low level signal is output, and when the accelerator is depressed, a high level signal is output. Each high or low level is artificially output.

FIG. 6 shows the output characteristics of the pulse wave generation circuit 45. The circuit 45 houses a differential circuit, a waveform shaping circuit, a one-shot multivibrator, etc., and the ignition coil 43 generates a spark for ignition. One pulse wave is generated each time the pulse wave is performed, and the pulse width of the pulse wave is set to a predetermined value in advance. Therefore, as shown in the figure, the interval between pulse waves becomes narrower in proportion to the engine speed, and as the engine speed increases, the frequency of the pulse waves increases in proportion to it.

FIG. 7 shows the output characteristics of the clutch direct connection circuit 46. This circuit outputs either a high level or a low level, but the output characteristics differ when the rotational speed is high and when the rotational speed is low. The switching speed is different; when the rotation speed is N ₁ , it switches from low level to high level, and when the rotation speed is N ₂ , it switches from high level to low level, and the rotation speed is N ₂ <N. ₁ relationship. Furthermore, when the neutral switch 40 is turned on, a low level output can be made regardless of the engine speed.

FIG. 8 is an electric circuit diagram specifically showing the inside of the clutch direct connection circuit 46, in which the accelerator switch 39 is connected to an OR gate 51, and the output of the OR gate 51 and the neutral switch 40 are connected to each other.
is connected to the AND gate 52, and a positive voltage is applied to the accelerator switch 39 and the neutral switch 40 via resistors R ₁ and R ₂ . The ignition coil 43 includes a waveform shaping circuit 5.
The output of the AND gate 52 and the output of the waveform shaping circuit 54 are connected to an AND gate 53, and the output of the AND gate 53 is connected to a monostable multi-circuit 55 consisting of transistors, operational amplifiers, etc.
It is connected to the. The output of the monostable multicircuit 55 is connected to an integrating circuit 56 via a transistor Tr ₃ , and the output of the integrating circuit 56 is connected to a comparator 57 . The output of this comparator 57 is output to the OR gate 48 as the output of the clutch direct connection circuit 46, but the output of the comparator 57 is also connected to the OR gate 51, and the output of the comparator 57 is connected to the resistor _R3.
~ Voltage divider circuit 58 consisting of _{R 5} and transistor Tr ₄
The output of the voltage dividing circuit 58 is connected to the comparator 57.

Next, the operation of this example will be explained.

When the accelerator is depressed from the vehicle stopped state in FIG. b in Fig. 9
As shown, a current that is somewhat proportional to the rotational speed is supplied to the coil 7. Therefore, the electromagnetic powder clutch 1 performs a sliding operation, and the vehicle is gradually accelerated. When the engine speed reaches _N1 , the clutch direct connection circuit 46 outputs a high level signal to the OR gate 48 to keep the transistor 49 on. Therefore, as shown by c in FIG. 9, the rated current Im flows through the coil 7, and the electromagnetic powder clutch 1 is brought into a directly connected state. Next, the engine speed gradually decreases, and as shown in the figure, the engine speed decreases.
Even if N becomes less than ₁ , the clutch is kept in the directly engaged state and the engine brake continues to work, reducing the rotation speed.
When the voltage reaches _N2 , the clutch direct connection circuit 46 outputs a low level signal (at this time, the accelerator detection circuit 44 is at low level and the AND gate 47 is outputting a low level signal). By turning it off, no current is allowed to flow through the coil 7, and the electromagnetic powder clutch 1 is opened, as shown in FIG. 9e. As mentioned above, the control circuit 38 is
The control cycle is repeated in the order of →b→c→d→e.

Next, the operation of the clutch direct connection circuit 46 shown in FIG. 8 will be explained. When the transmission 2 is engaged with any gear stage, the neutral switch 40
is off, a high level signal is applied to the AND gate 52, and the AND gate 52 can output the signal from the OR gate 51 as is. When the accelerator pedal is stepped on, the accelerator switch 39 is turned off and outputs a high level signal to the AND gate 52 via the OR gate 51, causing the AND gate 52 to output a high level signal. The waveform shaping circuit 54 is connected to the ignition coil 4
Since the ignition pulse wave from 3 is shaped and a pulse wave having the same frequency as the ignition pulse wave is sent to the AND gate 53, when the accelerator switch 39 turns off, the AND gate 53
sends the pulse wave of the waveform shaping circuit 54 to the monostable multi-circuit 55, and the monostable multi-circuit 55 is operated by the pulse wave. In this way, the monostable multi-circuit 55 operates, generates a pulse wave with a predetermined pulse width, turns on and off the transistor Tr ₃ , and reverses the polarity of the pulse wave. transistor
The pulse wave from Tr ₃ is integrated and smoothed by an integrating circuit 56 and input to a comparator 57. Since the set voltage from the voltage dividing circuit 58 is applied to one end of the comparator 57 (the transistor Tr ₄ is on, the divided voltage is formed by R ₃ , R ₄ , and R ₅ ). When the voltage of the integrating circuit 56 becomes higher than this set voltage (that is, when the engine speed reaches the set speed _N1 ), the comparator 57 outputs a high level signal to directly connect the clutch. The output of this comparator 57 is also transmitted to the OR gate 51, which transmits a high level signal to the AND gate 52, causing it to perform the same operation as holding the AND gate 53, and at the same time
Tr ₄ is turned off to lower the set voltage output by voltage divider circuit 58 (voltage divider circuit 58 divides the voltage by resistors R ₃ and R ₄ ). Therefore, comparator 57 outputs a high level. (The voltage set by the voltage dividing circuit 58 corresponds to the engine speed _N2 .) The comparator 57 outputs a low level signal. When output, a low level output is made to the AND gate 52 via the OR gate 51, and at the same time, the transistor Tr ₄ is turned on to wait for the next operation. This series of operations results in the characteristic curve shown in FIG. Further, when any gear of each gear of the transmission 2 is set to neutral without meshing, the neutral switch 40 is turned on and a low level signal is applied to the AND gate 52, which operates the accelerator switch 39. Outputs low level regardless of. Therefore, the AND gate 53 outputs a low level regardless of the output of the waveform shaping circuit 54 (that is, the engine speed), and the clutch direct connection circuit 46 does not output a high level signal for direct clutch connection.

Since the present invention is configured as described above, it is possible to output a signal for directly connecting the clutch based on the engine speed and accelerator operation.
Engine braking can be effectively applied to each gear of the transmission, and the clutch is not directly engaged when the transmission is in neutral, thereby preventing danger.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an electromagnetic powder clutch embodying the present invention, Fig. 2 is a sectional view taken along the Z-Z line in Fig. 1, and Fig. 3 is a clutch control showing an embodiment of the present invention. Fig. 4 is an electric circuit diagram of the control device, Fig. 5, Fig. 6, and Fig. 7 are characteristic curve diagrams showing the output characteristic curves of the members constituting the control device, and Fig. 8 is a diagram of the clutch. FIG. 9 is an electric circuit diagram showing a specific configuration of the direct connection circuit, and is a graph showing the relationship between engine rotation speed and coil current. 1... Electromagnetic powder clutch, 4... Clutch case, 5... Crankshaft, 6... Drive plate, 7... Coil, 8... Drive member, 9...
...Transmission input shaft, 10...Driven member, 11
...Gap.

Claims (1)

[Claims] 1. A crankshaft is coupled to a drive member containing a coil, a driven member of a transmission input shaft is closely fitted to the drive member via a gap, and a clutch current from a control device is supplied to the coil; In a vehicle electromagnetic clutch that transmits power by integrally restraining the drive and driven member using electromagnetic force, the engine's ignition pulse is input, the engine rotation speed is detected, and the clutch is engaged at a predetermined rotation speed. A vehicle characterized by having a clutch direct coupling means for controlling the clutch to be directly coupled, and a neutral detecting means for detecting the neutral of the transmission and controlling the clutch so that the clutch is not directly engaged at a predetermined engine speed or higher when in neutral. Control device for electromagnetic clutch.