JPH04110245A - Controller for motor-driven type accommodation door mirror - Google Patents

Abstract

PURPOSE:To prevent the burning of a motor and an electrical installation parts by installing a relay contact inserted into the driving circuit for an electric motor, relay circuit for operating the relay contact, overcurrent detecting sensor, overcurrent operation circuit, and a delaying circuit connected between the overcurrent operation circuit and a relay circuit. CONSTITUTION:When a door mirror contacts a stopper not shown on the figure or the turn of the door mirror is obstructed by a certain external trouble, the electric current value increases as shown by i3. Accordingly, the following relation: R1.-i2>VBE of a transistor Q2 is established, and the transistor Q2 is turned ON, and the output of IC1 becomes of H level. When the output exceeds the IC input wave form curve 1/2 Vcc at the time t3 IC1 is turned ON. At the time t4 in delay by time tw2 from the time t3 the output of IC2 becomes of H level, and the output is transmitted to the base of a transistor Q4 through a fixed resistance R4 and the transistor Q4 is turned ON. Through the turning ON of the transistor Q4 a relay A/2 operates, and contact points a1 and a2 are switched to turning-ON side. Accordingly, the electric conduction for a motor M is cut off and the motor M stops.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for controlling a motor for rotating an electrically retractable door mirror to open and close it.

[Conventional technology]

The door mirrors are installed flush against the sides of the vehicle, so
There is no risk of collision with external obstacles, and the vehicle may get in the way, for example, when driving into a garage.

Electrically retractable door mirrors are used to solve these problems.

A mirror base 2 is fixed to a door portion 1 of a vehicle body.

The mirror housing 3 has the following features with respect to the mirror base 2:
It is rotatably supported on a shaft 4.

A motor M is mounted on the mirror housing 3,
An attempt is made to rotate said shaft 4 via gear means 5.

However, since the shaft is fixed to the mirror base 2, the mirror housing 3 is equipped with a motor M and rotates to open and close as shown by the arcuate arrow.

3' drawn with a chain line indicates a retracted position in which the mirror housing sink is rotated in the closing direction.

3 drawn with a solid line indicates a normal posture (functioning as a door mirror) in which the mirror is rotated in the opening direction.

FIG. 5 is a circuit diagram showing a conventional example of a control device for a motor M that drives the door mirror to open and close.

BT is a battery, SW+ is a manual operation switch with 2 circuits and 2 contacts, DI + D2 is a diode, and LSWl.

LSW2 is a limit switch.

The motor M rotates in a direction to open the door mirror when the X terminal side is at 10, and in a direction to close the door mirror when the X terminal side is at 10.

It is now assumed that the door mirror is in an intermediate state between open and closed. Therefore, the NC contact side of the limit switch L SW + is conductive.

In this state, operate switch SWI to connect contact S and s2.
, when the contacts S4 and S5 are electrically connected, the motor M is energized in the opening direction and rotates.

This allows the door mirror (not shown) to turn in the opening direction mj
When the stroke end is reached, the limit switch LS
W2 is activated and switched to the No contact side, the current is cut off and the motor M is stopped.

Next, in this state (door mirror open position), switch SW
When I is operated to connect the contacts sl and s3 and the contacts s4 and s6, the motor M is energized in the closing direction and rotates.

When the door mirror rotates in the closing direction and reaches the end of its stroke, the limit switch LSW is activated and switched to the No contact side, cutting off the current and stopping the motor M.

Furthermore, in this state (door mirror closed position), switch S
By operating W, the contacts s1 and s2, and the contacts s4 and s5
When each of them is made conductive, the motor M is energized and rotates in the opening direction.

C Problems to be Solved by the Invention] In the conventional control device shown in FIG. 5, when the manual operation switch SWl is operated to rotate the motor M, either the limit switch LSW or LSW2 is activated. The motor M continues to be energized until.

For this reason, when the door mirror is rotating, if it is blocked by an external obstacle before it reaches the end of its rotation stroke and the limit switch is switched, or if the door mirror becomes unable to rotate due to ice, etc. If the manual operation switch SW is operated while the motor M is not rotating, the motor M will be energized and burnt out while being unable to rotate.

Furthermore, there is a risk that not only the motor M but also the diode DD2 and the limit switches LSWI and LSW2 will be burnt out.

The present invention was made in view of the above-mentioned circumstances, and even if the rotation of the door mirror is prevented by an external obstacle or ice formation, the motor for driving the door mirror opening/closing and other electrical components may be burnt out. The purpose of the present invention is to provide an electric retractable door mirror control device.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a control device for an electric motor that rotates door mirrors to open and close by switching the direction of energization by a polarity changeover switch between forward and reverse directions, which is inserted into the drive circuit of the electric motor. a relay contact, a circuit for activating the relay contact, an overcurrent detection sensor provided in the drive circuit, and an overcurrent activation circuit that is activated by receiving the output signal of the overcurrent detection sensor. and a delay circuit connected between the overcurrent activation circuit and the relay circuit, and a one-way power supply circuit connected between the delay circuit and the polarity changeover switch. It is characterized by

[Effect]

According to the above configuration, when the rotation of the door mirror is blocked and an excessive current flows, the overcurrent detection sensor activates the relay means via the overcurrent activation circuit to cut off the motor flow, thereby preventing burnout. be done.

Furthermore, since a delay circuit is provided between the overcurrent activation circuit and the relay means, the relay is not activated too sensitively.

Generally, when a DC motor is started under load, it instantaneously consumes a large amount of current, but due to the action of the delay circuit described above,
The relay is automatically controlled so that the large current at startup does not activate the relay and cut off the motor.

〔Example〕

FIG. 1 is a circuit diagram showing one embodiment of a control device according to the present invention.

The motor M for opening/closing the door mirror (not shown), the battery BT, and the manual operation switch SW are similar to the conventional example (fifth
The components are the same or similar to those in Figure).

A relay contact 12 is inserted and connected in a motor drive circuit that connects a polarity changeover switch circuit 11 constituted by the above switch SWI and a motor M.

Reference numeral 13 denotes a relay circuit consisting of a two-circuit second contact relay A/2 for operating the relay contact 12, a transistor Q4, and a fixed resistor R4.

An overcurrent detection sensor 14 made of a fixed resistor R1 is inserted and connected in the drive circuit of the motor M, and generates a voltage proportional to the current value between points 69 and e at both ends thereof.

The above generated voltage is input to an overcurrent activation circuit 15 made up of transistors Q++, transistors Qz and transistors Q3.

A delay circuit 16 is connected between the overcurrent activation circuit 15 and the relay circuit 13 described above.

'CI+IC2 is an IC whose output becomes H level when the level of the input signal becomes 172 or more of the power supply voltage Vcc.

CI and C2 are capacitors, and RZ+Rat R4 is a fixed resistor.

FIG. 2 is a chart showing the current characteristics of the motor M, and the horizontal axis is the time axis.

The vertical axis represents the current value, and in this Figure 2, the current value i
and the fixed resistance R1, that is, the two points d shown in FIG.
, e.

Time t. When the switch is turned on, a relatively large starting current i1 flows during the time tw (indicated by the initial operation period I).
Instantly transistor Q1. Slightly exceeds the VBE of Q2.

After the above-mentioned initial operation period (2) passes, a steady operation period (2) begins after time t1, in which a steady current i2 smaller than the VBE of the transistor QQ2 flows.

When the door mirror (not shown) is restrained by an external force and the motor M is prevented from rotating at time t2, the mechanical stop period (■) is entered and the current i3 increases rapidly, causing the aforementioned transistor Q+,
It far exceeds the VBE of Q2.

This overcurrent i3 continues until the fault is eliminated, or until catastrophic damage occurs due to secondary or tertiary faults, or until the power supply circuit is opened (in this embodiment, the automatically actuates the relay contacts to open the power circuit).

The delay time width tw2 of the delay circuit 16 is equal to the time t.
Compared to wl, t W2>> t Wl ・+ ++ +・
+ (1).

The current value iI, 12+'13 shown in FIG. 2, the fixed resistor R1 shown in FIG. 1, and the transistor Q + + Q
The relationship with VIIE in 21Q3 is Rloi + > Q+ + Q2 (7) VBERl
・i2>Q+, VBE of Q2 R1・i3>Q+, VBE of Q2.

17 is a unidirectional power supply circuit made up of diodes D1 to D4.

Next, the operation of this embodiment having the above-mentioned configuration will be explained. First, to briefly describe the overall operation, this embodiment does not have a limit switch as in the conventional example,
When the door mirror reaches the end of its rotational stroke and comes into contact with the stopper and is prevented from rotating, the control mechanism is activated to cut off the power to the motor M, as will be described later, and the motor M is stopped.

Even when the door mirror is prevented from rotating due to an external factor, the control mechanism similarly operates to cut off the power supply and prevent secondary damage from occurring.

When the door mirror (not shown) is in the closed position,5 To open it, operate the switch SWj and connect the contacts S1 and s2. contact! ! 4+ Makes s5 conductive.

With this operation, the motor M is energized in the opening direction.

In this state, the (+) of the battery BT is the diode [)2
The signal is transmitted to the (+) power supply terminal of DIN CI r I C2 through , and is transmitted to one side terminal of relay A/2.

The (-) terminals of IC and IC2, one side terminal of fixed resistor R2 + capacitor C1, and the emitter of transistor Q4 are connected to (-) terminal of battery BT via diode D3.
Conducted to the terminal and becomes operational.

The current in the motor M changes as shown at l++ 12 in FIG. 2, creating a potential difference between points d and e in FIG.

The above potential difference is O
Let it be N.

As a result, the voltage of the battery BT is transmitted to the input of the IC.

When (+) is not transmitted to the input of the IC, the fixed resistor R2 is grounded to GND (L level or (-)
(also called capacitor C)
This is the discharge resistor of No. 1.

■With the human power of 01, like the hill record (+)', lt rank (
When Vcc (also called H level) is transmitted, V
cc) l/2 Vcc makes its output 1-Level. The holding time of this H level is the time width t mentioned above.
wI, which is the delay time tw2 as shown in equation (1) above.
Since it is much shorter than , the output of IC2 is kept at L level.

In this way, transistor Q4 remains OFF and relay A/2 is not activated. Therefore, relay contact 1
2 is on the <NC side in the figure, and the motor M continues to rotate.

After the initial operating period I, the stationary period H begins, and the current reaches a constant value of 1.
It becomes 2.

Since this is the VBE of R1 and transistor Q2, transistor Q2 is turned off, the input of the IC becomes L level, and the output of IC2 maintains L level. Therefore, relay A/2 does not operate, and motor M continues to rotate.

If the door mirror (not shown) rotates to the stroke end and comes into contact with stopper j (not shown in Figure 1) and is prevented from rotating,
Alternatively, if rotation is prevented by some external obstacle, the current value increases as shown at 13 in FIG. Therefore, R1.12>VBE of transistor Q2, transistor Q2 is ONL, and the output of IC becomes H level.

This state continues until the contact a1 switches to the contact No side.

The operation when the output of the IC becomes H level as described above will now be described with reference to FIG.

At time t3, when the input waveform curve of the IC exceeds 1/2 Vcc, the IC turns ON.

After a delay time twz from time t3, the output of IC2 becomes H level at time t4, which is transmitted to the base of transistor Q4 via fixed resistor R4, turning on transistor Q4.

When transistor Q4 is turned on, relay A/2 is activated, and both contacts al and a2 are switched to the NC side. As a result, the motor M is de-energized and stops.

When the motor M is de-energized, 2 at both ends of the fixed resistor R1
The potential difference between points d and e disappears, and transistor Q2 becomes O again.
Becomes FF. Therefore, the V supplied to the input of the ICI
Although cc is cut off, the output of IC+ remains at H level until capacitor C1 is discharged and its potential becomes 1/2 Vcc, and at time t5, the output of IC+ becomes L level.

When transistor Q2 turns OFF, the output of IC2 also becomes L level after some time, but contact a2 of relay A/2 becomes N.
Since it has been switched to the C side, relay A/2 maintains its operating state. In this state, turn off the manual operation switch SW.
It continues until

Next, the operation when closing the door mirror from the open position will be described.

Operate the manual operation switch SW, and connect the contacts sI and s3.
, when the contacts s4 and s6 are made conductive, the motor M
is energized in the closing direction and starts rotating, and a potential difference opposite to that during the opening operation described above is generated at points d and e at both ends of the fixed resistor R1.

At the same time, the (+) voltage of the battery BT is transmitted via the diode D to the circuit on the (+) terminal side of rC, IC2.

The (-) terminal side of ICIC2 is connected to the (=) terminal of battery BT via diode D4 and becomes operable.

As mentioned above, since point e has a higher potential than point d, transistor Q1 is turned on, transistor Q3 is turned on, and the IC
, the H level is transmitted to the inputs of.

The time width of the H level at this time is the aforementioned twl, which is shorter than the delay time tW2, so the relay A/2 does not operate and the motor M continues to rotate. The subsequent operation is similar to the opening operation described above.

To summarize the above-mentioned operations related to this embodiment, the motor M for driving the door mirror opening/closing can be arbitrarily rotated in the opening and closing directions by manual operation of the switch SW.

When the rotation of the door mirror is blocked by a stopper or an external obstacle, the energization of the motor M is delayed for a delay time tW.
2, the motor is automatically stopped, thereby preventing damage to the motor and other secondary damage.

〔Effect of the invention〕

The polarity changeover switch changes the direction of current flow; positive,
When the present invention is applied to a control device for an electric motor that rotates the door mirror in reverse and opens and closes it, when the rotation of the door mirror is blocked by an external obstacle, the power to the motor is automatically cut off, causing damage to the motor and other problems. Secondary damage to electrical components is prevented.

[Brief explanation of drawings]

FIG. 1 shows one example of an electric retractable door mirror control device according to the present invention.
FIG. 2 is a circuit diagram showing an example. FIG. 2 and FIG. 3 are diagrams for explaining the functions and effects of the above embodiment, respectively. FIG. 4 and FIG. 5 are explanatory diagrams of the prior art, respectively. DESCRIPTION OF SYMBOLS 11... Polarity changeover switch circuit, 12... Relay contact, 13... Relay circuit, 14... Overcurrent detection sensor, 15... Overcurrent activation circuit, 16... Delay circuit,
17・One-way power supply circuit, R+, R2, R3, R4・
・Fixed resistance, c,, c2... Capacitor, Q+ + Q
2! Q3t Qa...transistor, M/motor,
BT...Battery, Al1/Relay, 81~s6/Contact, al+ 82...Contact. Figure 2 Patent Applicant Ichikoh Industries Co., Ltd. Representative Patent Attorney Tadashi Akimoto Figure 3 Figure Figure

Claims (1)

[Scope of Claims] 1. In a control device for an electric motor that rotates a door mirror by switching the direction of energization between forward and reverse by a polarity changeover switch to open and close a door mirror, a relay contact inserted in a drive circuit of the electric motor; a relay circuit that activates the relay contact; an overcurrent detection sensor provided in the drive circuit; an overcurrent activation circuit that is activated by receiving an output signal from the overcurrent detection sensor; and an overcurrent activation circuit. An electric retractable door mirror control comprising: a delay circuit connected between the relay circuit; and a one-way power supply circuit connected between the delay circuit and the polarity changeover switch. Device.