JP2008067428A - Method of controlling forward/reverse rotation drive circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To change over forward and reverse rotations of a motor as quickly as possible in a forward/reverse rotation drive circuit using relays. <P>SOLUTION: A pair of relays is connected to a motor. From the timing T1 when an ascending command signal to one relay in an excited state is changed over from ON to OFF, a descending command signal to the other relay is changed over from OFF to ON prior to the lapse of the time lag Toff of the relay. The contact point of the other relay is changed over before the contact point of the relay in the excited state is actually changed over by the time lag, so that the motor is decelerated by braking and put into a descending command state after the lapse of the time lag to quickly start reverse rotation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control method for a forward / reverse rotation drive circuit that switches forward / reverse rotation of a motor by exciting / de-energizing forward and reverse relays.

  2. Description of the Related Art Conventionally, there is a drive circuit that rotates a motor forward and reverse by switching alternately using two relays in a drive circuit that rotates an electric motor forward and reverse, and an example thereof is used for a power window device for an automobile. Is shown in FIG. A first output terminal O1 and a second output terminal O2 for outputting a command signal to the power element are provided in the CPU 1 that controls the raising and lowering of the window in response to an input of an operation switch (not shown). Each signal of high or low level is output, and the motor 2 rotates forward and backward by a combination of high and low of these command signals.

  A first transistor Q1 that is turned on by the output of the high level signal is connected to the first output terminal O1, and a second transistor Q2 that is turned on by the output of the high level signal is connected to the second output terminal O2. Also, the first relay RL1 is excited when the first transistor Q1 is turned on, the second relay RL2 is excited when the second transistor Q2 is turned on, and the motor 2 is connected via the relays RL1 and RL2. Yes.

  The relays RL1 and RL2 may have a known structure having two position selection contacts S1 and S2 corresponding to the coils L1 and L2, respectively. In the figure, the coil L1 of the first relay RL1 is connected between the constant voltage terminal Vc and the first transistor Q1, the normally open contact S1a of the corresponding first contact S1 is connected to the drive voltage terminal Vm, and the normally closed contact. S1b is grounded, and the movable contact S1c is connected to one of both terminals of the motor 2. Similarly, the coil L2 of the second relay RL2 is connected between the constant voltage terminal Vc and the second transistor Q2, the normally open contact S2a of the corresponding second contact S2 is connected to the drive voltage terminal Vm, and the normally closed contact S2b is grounded and the movable contact S2c is connected to the other terminal of the motor 2. Note that free-wheeling diodes D1 and D2 are connected to the coils L1 and L2, respectively. (For example, see Patent Document 1)

  In the forward / reverse rotation drive circuit as described above, for example, the forward rotation of the motor 2 will be described as the upward side of the window, and the reverse rotation will be described as the downward side of the window. In the case of normal rotation, an ON signal is output from the first output terminal O1 to the first transistor Q1 with respect to the state shown in the figure, and the state is until the timing T1 in FIG. That is, the first contact S1 is in the voltage Vm supply state, the second contact S2 is in the ground state, the current flows from the first contact S1 to the second contact S2 via the motor 2, and the motor 2 rotates forward. .

  When the motor 2 is reversely rotated by operating an operation switch (not shown), an off signal (low) is output from the first output terminal O1 (timing T1). At this time, the coil L1 of the first relay RL1 switches from the excited state to the non-excited state. However, since the current due to the electromotive force generated in the coil L1 flows through the return diode D1, the movable contact S1c is actually the normally closed contact. A relatively long time lag (Toff) occurs before switching to the S1b side. When excitation is performed from the non-excited state, there is no long time lag as described above, but the idle time (Ton) of the movable contact S1c is substantially required.

Since the time lag Toff is known in advance according to the type of the relay, when the motor 2 is rotated in reverse, a predetermined time (Toff-Ton) from the timing T1 at which the rising command signal from the first output terminal O1 is turned off is turned on. ) By outputting a descending command (ON) signal for exciting the coil L2 of the second relay RL2 from the second output terminal O2 at the elapsed timing T2, the normally closed contact S1b side of the movable contact S1c of the first relay RL1 The movable contact S2c of the second relay RL2 is switched in accordance with the operation timing of switching to, so that the rotation direction of the motor 2 is switched.
JP-A-8-303111

  However, in the forward / reverse rotation drive circuit disclosed in the above-mentioned document 1 using the energization switching type relay to the coil, when one relay (forward relay) is switched from the excited state to the non-excited state. The contact (S1) cannot be switched until the operation time (time lag Toff) elapses for the reason described above, and after the contact (S1) is switched, as shown in FIG. When switching the relay (reverse relay) from the non-excited state to the excited state, it takes a free running time (Ton), and after the contact (S2) is switched, the rotational speed of the motor 2 gradually decreases and reverses. Since the time Tr3 until the rotational speed is gradually increased through the time until the predetermined reverse speed is reached is also necessary, the reverse speed is actually reversed at the set speed from when the forward rotation command signal is commanded (T1). Time Tr2 until the jar there is a problem that becomes longer. In particular, when applied as a method for controlling a device that performs a reversal operation when sandwiched, such as a power window device, reversal as soon as possible is desired.

  In order to solve such a problem and realize the switching of the forward / reverse rotation of the motor as early as possible in the forward / reverse rotation drive circuit using the relay, in the present invention, the forward / reverse command signal is transmitted. One of a forward / reverse command signal output means for selectively outputting, a forward excitation relay excited by the forward command signal, a reverse excitation relay excited by the reverse command signal, and both excitation relays A forward / reverse rotation drive circuit control method having a motor provided to rotate forward / reversely according to one excitation state, wherein either the forward / reverse command signal is output by the forward / reverse command signal output means. Is output before the time lag elapses until the excitation relay contact switches from the excited state to the non-excited state. It was.

  In particular, the forward rotation command signal and the reverse rotation command signal may be output simultaneously, and the motor is a drive source for an actuator that opens and closes an automobile window, and the forward rotation command signal and the reverse rotation command signal are The window may be controlled to open and close.

  Thus, according to the present invention, when a non-excitation command signal is output to one relay coil in order to switch one relay coil from excitation to non-excitation, the contact is actually switched from the excitation state to the non-excitation state. Since the excitation command signal for the other relay is output before the time lag until switching, the control is performed to reversely rotate the motor from the time of switching the contact of the other relay that switches from non-excitation with almost no time lag to the excited state. Can move. In order for the motor to shift from normal rotation to reverse rotation, the rotation speed during normal rotation starts from 0 rotation and then reverse rotation starts. Therefore, it takes a certain amount of time (braking from the predetermined normal rotation speed to zero rotation). In the meantime, the relay contact that switches from the excited state to the non-excited state due to the time lag can actually be switched. Reverse rotation switching can be performed.

  In particular, a control program can be easily assembled by outputting a normal rotation command signal and a reverse rotation command signal simultaneously. In addition, by applying to a power window device of an automobile, a reverse rotation operation at the time of pinching can be quickly performed, which is preferable.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a view corresponding to FIG. 3 showing the control procedure according to the present invention. Note that the forward / reverse rotation drive circuit to which the present invention is applied may be the same as the circuit of FIG. 2 shown in the background art, and therefore, when applied to the circuit of FIG. As an example applied to the opening (lowering) and closing (upward) of a window in a power window device of an automobile as follows.

  In FIG. 1, a rising command signal for closing a window (not shown) is output from the first output terminal O1 of the CPU 1 as the forward / reverse rotation command signal output means (ON), and no lowering command signal is output from the second output terminal O2. In the case of (OFF), since the coil L1 of the first relay RL1 in FIG. 2 is excited and the coil L2 of the second relay RL2 is in a non-excited state, the movable contact S1c of the first relay RL1 is shown in FIG. As indicated by the dotted line, the switching is made to the normally open contact S1a side, the current flows from the first relay RL1 to the second relay RL2 via the motor 2, and the motor 2 is at a predetermined positive rotational speed (+ N). It rotates forward.

  For example, when operating the operation switch (not shown) or pinching detection processing, when reverse rotation is performed from the normal rotation state, the output of the ascending command signal from the first output terminal O1 is stopped (off), and the output from the second output terminal O2 is stopped. Outputs a descent command signal (ON). These off / on timings are simultaneously performed at timing T1 in the illustrated example.

  When the current supply to the excited coil L1 is stopped by turning off the ascending command signal, the current flows to the coil L1 via the return diode D1 as described above, so that the movable contact S1c is immediately moved to the normally closed contact S1b side. Without being switched, the output state of the first contact S1 continues for the operating time (Toff) when the drive voltage Vm is supplied.

  Here, in the illustrated example, the ON output by the lowering command signal is performed at the same time that the rising command signal is turned OFF, so the output of the second contact S2 is supplied with the drive voltage Vm after the idle running time Ton has elapsed from the ground state. Switch to state. Since the idle time Ton when the relay is excited from the non-excited state is shorter than the operation time Toff, the second contact S2 is turned on before the first contact S1 is actually turned off, and both the contacts S1 and S2 are turned on. At the same time, the drive voltage Vm is applied.

  As described above, when the second contact S2 is actually switched after the lowering command signal is turned on (after T1 to Ton), the timing at which the first contact S1 is actually switched after the rising command signal is turned off. In the period up to T2, both contacts S1 and S2 are both connected to the power supply terminal Vm, and a closed circuit is formed between both terminals of the motor 2, so that a regenerative braking force acts on the motor 2. . As a result, the motor 2 is rapidly decelerated, and if the timing T2 is matched with the time when the motor 2 is stopped (0 rotation), the two relays RL1 and RL2 are in the reverse rotation driving state due to the switching of the first contact S1, Thereafter, a reverse rotation current is supplied to the motor 2, and the reverse rotation speed (−N) is reached after a predetermined time.

  Thus, the required time Tr1 from when the ascending command signal is turned off until when the motor 2 actually switches from forward rotation to reverse rotation is as shown in the figure, and is according to the conventional method described in the background art. It can be made shorter than the required time Tr2. In the illustrated example, the ON output by the descending command signal is performed at the same time as turning off the ascending command signal. However, it may not be performed at the same time and may be within the time lag Toff from the timing T1.

  As a result, even when a relay having a time lag Toff is used for the forward / reverse rotation drive circuit of the motor before the contact is actually switched when the coil is switched from excitation to de-excitation, the control method of the present invention is used. Thus, the time until the motor actually rotates in the reverse direction can be shortened, and the rotation direction of the motor during the reverse rotation can be quickly switched.

  The forward / reverse rotation drive circuit to which the present invention is applicable is not limited to the illustrated circuit (FIG. 2), and the forward / reverse rotation of the motor is switched by switching between excitation and non-excitation of the relay. Any circuit may be used.

  The control method of the forward / reverse rotation drive circuit according to the present invention is such that the excitation command signal for the other relay is passed before the time lag from when the command signal of one relay is changed from the excited state to the non-excited state until the contact is actually switched. Is useful for a forward / reverse rotational drive circuit for forward / reverse rotation of a motor connected to the relay, which has the effect of quickly switching the motor whose rotation direction is switched according to the switching of the relay. is there.

It is a time chart which shows the control point based on this invention. It is a circuit diagram which shows an example of a normal / reverse rotation drive circuit. It is a time chart which shows the conventional rotation switching point.

Explanation of symbols

1 CPU
2 Motor RL1, RL2 relay

Claims (3)

Forward / reverse command signal output means for selectively outputting forward and reverse command signals, forward rotation excitation relay excited by the forward rotation command signal, reverse rotation excitation relay excited by the reverse rotation command signal, A control method of a forward / reverse rotation drive circuit having a motor provided to rotate forward / reversely depending on the excitation state of either one of the two excitation relays,
When either one of the forward rotation and reverse rotation command signals is output by the forward / reverse rotation command signal output means, the other of the forward rotation and reverse rotation command signals is changed from the excitation state to the non-excitation state. A control method for a forward / reverse rotation drive circuit, wherein the output is made before the elapse of a time lag until switching.   2. The forward / reverse rotation drive circuit control method according to claim 1, wherein the forward rotation command signal and the reverse rotation command signal are simultaneously output. The motor is a drive source of an actuator for opening and closing a window of an automobile;
3. The forward / reverse rotation drive circuit control method according to claim 1, wherein the forward rotation command signal and the reverse rotation command signal control the opening / closing of the window.

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