JPS58196332A - Electromagnetic driving device - Google Patents

Abstract

PURPOSE:To prevent dangers caused by generation of heat or reckless driving of an output shaft by detecting the time required for that the exciting current of a clutch coil amounts to the regulation value to detect a clutch gap. CONSTITUTION:A control circuit 15 is adapted to excite a clutch coil 6 through a driver 17, start a timer 16 and stop exciting when a time T1 of the timer 16 passes. Subsequently, the control circuit 15 resets the timer 16 to be restarted, again excites theclutch coil 6 when the timer 16 counts up a time T2 when there is no clutch coil current flowing through D2, R1 of a fly wheel circuit, and resets the timer 16 to start. After that, when an output signal Vb of a comparator 20 is inverted from L to H, a result value of the time 16 is input. If the result value is below a preset time T, a gap is judged to be normal, and if it is above T, the gap is judged to be small.

Description

[Detailed Description of the Invention] The present invention enables constant high-speed operation by energizing the built-in clutch coil to fully press and secure the clutch friction member provided on the motor shaft side and the clutch lining provided on the output shaft side. The present invention relates to an electromagnetic drive device having an electromagnetic clutch mechanism that transmits the rotational force of a motor to an output shaft, and in which a wear amount of the clutch lining is detected.

Conventionally, a drive device having the above-mentioned electromagnetic clutch mechanism has been used, for example, for driving a sewing machine, and when the wear of the clutch lining accelerates and the coupling member carrying the clutch lining comes into contact with the clutch friction member,
The speed of the output shaft may become unstable, or the metal may come into contact with metal at the pressure welding portion, resulting in meshing and speed control, and in some cases, the output shaft rotates at high speed and cannot stop, which is dangerous. In addition, as mentioned above, the temperature rises significantly due to metal-to-metal contact, which is dangerous.On the other hand, the clutch friction member may be damaged due to metal-to-metal contact, which may require repair, which is a problem for after-sales service. There was also a problem.

However, the current situation is that no measures have been taken to address the above drawbacks.

The present invention aims to provide a safe electromagnetic drive device by detecting the above-mentioned wear margin before metals come into contact with each other, eliminating the above-mentioned dangers or problems.

FIG. 1 shows the entire configuration of an electromagnetic clutch motor. A flywheel 1 is fixed to a motor shaft 2 and constantly rotates at high speed. Magnetic metal, c! The clutch friction member 3 , designated by ll, is fixed to the flywheel 1 and forms a magnetic circuit shown by broken lines between the clutch fixed iron core 4 and the clutch connecting member 5 , which is a magnetic metal element. Excitation produces a magnetic flux φA. The clutch lining 7 is usually made of cork, and is adhered and supported on the clutch connecting member 6. The clutch connecting member 6 is freely movable in the entire thrust direction on a spline shaft 9 fixed to the output shaft 8, while being completely fixed in the rotational direction.

Brake coils 10. Brake fixed core 11. Brake friction member 12
．． Brake lining 13. A brake mechanism called the brake coupling member 14 is arranged, and the excitation of the brake coil 10 generates a magnetic flux φB as shown by the broken line.

The operation configured as described above is performed as follows.

When the clutch coil 6 is excited, magnetic flux φ.

occurs, the clutch connecting member 6 moves toward the clutch friction member 3 which is constantly rotating at high speed, the clutch lining 7 is pressed into engagement, and the rotational force of the clutch friction member 3 is transferred to the clutch connecting member 6. It is transmitted to the output shaft 8 via the spline shaft 9, and the output shaft 8 is rapidly accelerated.

On the other hand, when the speed increases higher than the set speed, the brake coil 1o is excited, a magnetic flux φ8 is generated as shown by the broken line, and the brake connecting member 14 moves toward the brake friction member 12 and is pressed into engagement with the surface of the brake lining 13. The stationary force thereof is transmitted to the output shaft 8 via the spline shaft 9,
The output shaft 8 is decelerated.

In this way, a predetermined speed can be obtained, but in normal stable operating conditions, the excitation force of the clutch coil 6 is fully adjusted,
Therefore, by adjusting the magnetic flux φA' (r) and adjusting the pressure contact force on the surface of the clutch lining 7 to generate an appropriate force V, the operation is performed such that a constant speed is maintained.

As mentioned above, since the speed of the clutch lining 7 is controlled while constantly sliding on its surface, wear is inevitably accelerated, and eventually the height GC of the clutch lining 7 from the end surface of the clutch connecting member 6 decreases. 0, the clutch friction member 3 and the clutch connecting member 6 become straight and shiny, and as mentioned above, there is no heat generation at all, creating a dangerous situation, and due to their engagement, high-speed operation becomes unstoppable. There was a risk of an abnormal situation.

According to the present invention, a predetermined amount of wear of the clutch lining 7 is detected before the abnormal state occurs, and the dangerous state is prevented.

Here, wear of the brake lining 13 is accelerated as well, but there is no danger because the other brake friction member 12 with which it is press-fitted is always stationary, or it is usually not possible to operate at intermediate speeds as described above. Since this is mainly carried out only on the clutch side, the clutch lining 7 wears out more quickly than the clutch lining 7. However, the object of the present invention can also be achieved by a method that completely detects only the specified wear amount of the clutch lining 7. , see below for examples in Figure 2~
This will be explained using FIG.

In FIG. 2, 16 is a control circuit, which is composed of a logic IC circuit centered on a microcomputer.

Reference numeral 16 denotes a timer, which is comprised of a timer IC that counts a reference clock.When the start command from the control circuit 16 goes low, it is reset and starts counting, and the result is output as a digital value.

17 is a driver for driving the clutch coil 6 built into the motor 18, 19 is a current measuring circuit, and 2o is a comparator.

FIG. 3 shows an example of a configuration in which the above-mentioned configuration is further embodied, and in particular, the control circuit 16 and timer 16 are configured by a 1-chip microcomputer 21 (hereinafter referred to as microcomputer).

Furthermore, FIG. 4 shows a time chart of the operation.

In FIG. 3, (-vDD indicates the DC power supply voltage for driving the clutch coil 6, 10V, 0 indicates the full DC stabilized power supply voltage for driving the IC circuit, and 21 indicates the DC power supply voltage for driving the IC circuit. IC1 is an inverter IC that drives the clutch coil 6 by switching the transistor TR1i through the diode D1i.
The artificial resistor R1 is a flywheel circuit for suppressing the abnormal voltage generated at the collector when the transistor TR1 is turned off and protecting the transistor.

A resistor R2 connected to the emitter of the transistor TR1
The voltage across the transistor TR1 changes in proportion to the current flowing through the clutch coil 6 when the transistor TR1 is turned on. The current measuring circuit 19 is constituted by the resistor R2, the resistors R3, R4, R5, and the OP amplifier IC IC2, and the signal representing the coil current is amplified to a required level and a signal Va is output.

In addition, i resistors R6, R7, R8, variable resistors vR1, and op
The amplifier IC C3 constitutes the comparator 2°, and when the signal Va reaches the voltage vc set in cv stages at the variable resistor vR1, the output vb of the IC3 is inverted.

The clutch gap Gc detection operation from the end of the clutch connecting member 5 configured as described above is as follows.

First, the control circuit 16 excites the clutch coil 6 through the driver 17, starts the timer 16, and stops the excitation when the timer 16 indicates that time T1 has elapsed. This time T1 is set as the time required for the clutch lining 7 to come into contact with the clutch friction member 3.

Next, the control circuit 15 completely resets and restarts the timer 16, and controls D2 of the flywheel circuit.
, R1i, when the timer 16 has not timed the time T2 during which the clutch coil current no longer flows, the clutch coil 6 is energized again and the timer 16 is reset and started.

Continuing from the above, the control circuit 16 controls the comparator 2o.
starts detecting the output signal vb of
When the result value of the timer 16 changes from "H" to "H", the result value of the timer 16 is read, and if the result value is below the set time T12J, it is "normal" (Fig. If so, it is determined that the cap is small (curve n in Figure 4).

The principle of detecting the gap described above is based on f/(m.

That is, the inductance L of the clutch coil 6 changes in proportion to the permeance P of its magnetic circuit, and the permeance P changes greatly in accordance with changes in the distance of the gap section unless there is magnetic saturation in the iron core. That is, as the gap becomes smaller tL, the permeance P becomes thicker and the inductance L changes so as to become larger. On the other hand, the time constant τ, which is a guideline for 9 hours of rise of the excitation current of the clutch coil 6, is expressed as τ=L/R, and since the series resistance R in this equation is constant, τ is proportional to the inductance L Vc. Then you can say. .

Therefore, if the clutch gap CC to be detected is set in advance with all the jigs and set so that the signal Va after the elapse of time T matches the reference voltage Vc, wear will be accelerated during normal use. It becomes possible to detect that the specified value has been reached.

FIG. 5 is a flowchart showing the entire operation of the Ail microcomputer 21 mentioned above. 22, clutch lining 7
The suction pulse signal '4 of the dummy clutch coil 6 is moved so that it comes into contact with the clutch friction member 3.
After outputting data for a time T, the motor waits for a time T2 at the moat where the current in the clutch coil 6 becomes almost zero.

23, in order to actually measure Mi, + ae clutch gap Gc, the mi clutch coil 6 is magnetized, the VC timer 16 is completely reset and started, and the comparator 2 is
Wait until the 0 output signal changes from "L" to "Hn."

At step 24, the timer 16 is completely stopped, the sound is read as a result, and if the result T3 is less than or equal to T, it is determined to be normal, otherwise it is determined that the gear is small, and subsequent processing is performed such that all operations are stopped.

1.1 Here, when the clutch coil 6 is energized for the time T1 or T5, a phenomenon occurs in which the output shaft slightly rotates, but as a countermeasure to this, the brake coil 1o is turned off during the measurement of the clutch gap GO. The present invention can be realized even more effectively by using an excitation method.

Further, normally the wear of the lining does not occur suddenly, so the determination is made once immediately after the power is turned on, and thereafter the control circuit 16 controls the clutch coil 6f! via the driver 17 regardless of the timer 16. : It can be said that the method of driving is one effective means for realizing the present invention.

As described above, the present invention provides a so-called dummy section in which the clutch coil is excited for a time T1 and then waits for a time T2, and after initializing the magnetic circuit, the gap Gc is The change in permeance due to the change is regarded as a change in the inductance/s of all the coils, and therefore, the time T3 until the clutch coil current reaches the specified value is detected by r, j...
■It detects the canog GO, and can completely prevent dangers caused by heat generation or runaway of the output shaft, unlike conventional methods.
This is advantageous in service as it can detect the surface of the clutch friction member before it is damaged, and has a great effect in that it can be provided at low cost with a simple circuit configuration.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the electromagnetic clutch motor, Fig. 2 is a book diagram of the electromagnetic drive device of the present invention, Fig. 3 is a circuit diagram of the wear detection means used in the device, and Fig. 4 is the operation of the circuit. The explanatory diagram, FIG. 6, is an explanatory diagram of the operation of the wear detection. 2... Motor shaft, 3... Clutch friction member, 4... Fixed iron core, 6... Clutch connecting member, 6... Clutch Coil, 7...
...Clutch lining, 8...Output shaft,
16...Control circuit, 16...Timer, 17...Driver, 18...Motor, 19...Current measurement circuit, 20.・・・・・・
Comparator. Name of agent: Patent attorney [Toshio Nakao and 1 other person IK2]
Figure 3 Figure 41! i

Claims (1)

[Claims] A motor that constantly operates at high speed, a clutch friction member made of magnetic metal disposed on a part of the motor, and a clutch connecting member disposed on an output shaft and supporting a clutch lining at a position facing the clutch friction member. and,
A fixed iron core arranged with an appropriate gap between the clutch friction member and the fixed iron core, a coil arranged in the center of the fixed iron core so as to form a magnetic path between the clutch friction member and the fixed iron core, and this coil. a control means for fully energizing the coil so as to press and engage the clutch friction member, the clutch connecting member, and the entire clutch lining by energizing the coil so as to transmit the rotational force of the monitor to the output shaft, and the clutch lining. a wear detection means for detecting a wear allowance of the coil; the wear detection means includes a driver for exciting the coil; a timer for starting the excitation and measuring time from the point in time; It consists of a current measuring means for measuring the current value to the coil, and a comparator that compares the current measurement value with a specified current value during this time, and stops the timer when the output of this comparator is reversed. When the elapsed time measured by the timer reaches a set value or more, the entire amount of wear of the clutch lining exceeding a specified amount is detected.