JP2557689Y2 - Switch circuit in drive unit - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a switch circuit in a driving device, and particularly requires less circuit components, and reduces the durable load of a motor, a first PTC element, and a second PTC element. The present invention relates to a switch circuit in a driving device that can perform the driving.

2. Description of the Related Art A driving device generally includes a power supply, a motor connected to the power supply via a switch, and a moving body which is linked to the motor via a driving force transmission mechanism and moves by driving the motor. . When the switch is operated to energize the motor, the motor is driven, and the driving force of the motor is transmitted to the moving body via the driving force transmission mechanism, and the moving body moves. Then, at a predetermined stop position,
By operating the switch to cut off the power supply to the motor, the driving of the motor is stopped, and the moving body stops at a predetermined stop position.

The driving device described above is used in various devices. For example, electric retractable door mirrors in automobiles, power windows, power antennas, retractable lamps, power seats, and sliding devices in other fields,
Widely used for rotating devices, opening and closing devices, etc.

Many of such driving devices are provided with a switch circuit that stops the moving body at a predetermined stop position and cuts off the current to the motor.

Examples of the switch circuit in the above-mentioned driving device include a microfilm disclosed in Japanese Utility Model Application No. Sho 62-54803 (Japanese Utility Model Application Laid-Open No. 63-164392), Japanese Patent Application Laid-Open No. 1-158803, and Japanese Utility Model Application No. 60-53.
No. 65 (No. 61-122134) is described in the microfilm.

When the object to be moved is locked during forward or reverse rotation of the motor (21), the first switch circuit rapidly increases the motor current, and the positive-characteristic thermistor (33) or (34) generates heat to reduce the resistance value. The current increases sharply, and the supply current to the motor (21) decreases, thereby preventing the motor (21) from being damaged.

When the extension or contraction of the rod antenna (10) is locked, the second switch circuit rapidly increases the motor current, and accordingly, the voltage across the PTC (24) increases to reach a predetermined threshold, At this moment, the logic circuit (AND gate (2
0) and a flip-flop (21) and an AND gate (22) operate the motor stopping means (transistor (23)) to stop the motor (M).

In the third switch circuit, a rotation position detection circuit of the mirror housing (12) is constituted by a contact holder (21), a brush (22) for energization, a disk (23), a conduction pattern, and the like. When the switch (4) is turned on, the relay (3) is excited, the relay contacts (3a-3b) are turned on, the motor (5) rotates forward or reverse, and the mirror housing (12) is moved to the retracted position. Or, it rotates to the set position. When the mirror housing (12) rotates to a position just before the storage position or the set position, the control unit (2) (mirror housing rotation position detection circuit) is operated, and the relay (3) is activated.
Is demagnetized, the relay contacts (3a-3b) are turned off,
The motor (5) stops and the mirror housing (12) is retracted or set.

[Problem to be Solved by the Invention] However, the first switch circuit uses the motor (21) by increasing the resistance value of the positive characteristic thermistor (33) or (34).
Since the current supplied to the positive temperature coefficient thermistor (33) or (34) is reduced, a current still flows through the motor (21) and the positive temperature coefficient thermistor (33) or (34). 21) and PTC thermistor (33) or (3)
4) The endurance load is large.

In addition, the second switch circuit requires a logic circuit that operates the transistor (23) due to an increase in the voltage between both ends of the PTC (24), and thus has a problem that there are many circuit components.

Further, the third switch circuit includes a control unit (2) (mirror housing rotation position detection circuit) for stopping the mirror housing (12) at the storage position or the set position, and a relay (3) and a relay contact (3a-3b). )
And an overcurrent protection circuit (7) for preventing the motor (5) from burning when an external current is applied to the mirror housing (12) during rotation of the mirror housing (12) and an overcurrent occurs. Since they are required separately, there are problems such as a large number of circuit components. In addition, in the latter switch circuit, the relay contacts (3a-3b) of the relay (3) are not turned off even if the overcurrent protection circuit (7) is activated when an overcurrent occurs, so that the overcurrent protection circuit ( 7), a current always flows, and there is a problem in durability of the overcurrent protection circuit (7).

An object of the present invention is to provide a switch circuit in a drive device that requires less circuit components and can reduce the durable load on the motor and the first and second PTC elements.

[Means for Solving the Problems] The present invention relates to an overcurrent generated when a moving body is physically stopped by a stopper or some other cause and an overload is applied to a motor. A first PTC element and a second PTC element whose resistance value rapidly increases when a certain temperature range is reached and performs a switching action, wherein the first PTC element is connected in series between the switch and the motor in a mutually parallel state; And the first
A 2PTC element, a first diode and a second diode connected in series to the first PTC element and the second PTC element, respectively, and having different current flowing directions, and demagnetizing by a switching operation of the first PTC element or the second PTC element. A relay coil of a relay circuit, the relay coil being connected in series with the first PTC element and the second PTC element and the first diode and the second diode, and connected in parallel with the motor; The motor and the second motor
1 PTC element and a relay contact of a relay circuit that cuts off current to the second PTC element, which is connected in parallel with the relay coil, and the motor and the first PTC element and
A relay contact of a 2PTC element and a relay circuit connected in series with the first diode and the second diode; and a starting capacitor for starting the motor and exciting the relay coil, wherein the relay coil and the first PTC A starting capacitor connected in series with the element, the second PTC element, the first diode and the second diode, and connected in parallel with the relay contact and the motor; and a relay self-holding for maintaining an excitation state of the relay coil. Resistance, connected in series with the relay contact and the relay coil, the first PTC element and the second PTC element, the first diode and the second diode, and in parallel with the motor and the starting capacitor. And a connected self-holding resistor.

[Operation] According to the present invention, when the moving body is stopped by the above configuration, an overload is applied to the motor and an overcurrent occurs, and the overcurrent causes the first PTC element or the second PTC element to perform a switching operation. In conjunction therewith, the relay contacts of the relay circuit operate to cut off the power supply to the motor.

As described above, the present invention operates the relay contact of the relay circuit by the switching operation of the first PTC element or the second PTC element to cut off the power supply to the motor and the first PTC element and the second PTC element. 21) and the first thermistor (33) or (34) with a current still flowing
In comparison with the switch circuit of the above, it is possible to reduce the durable load of the motor and the first PTC element and the second PTC element,
The logic circuit operates due to the increase in the voltage between both ends of the PTC (24), and the number of circuit components is reduced as compared with the conventional second switch circuit that stops the motor (M) by operating the transistor (23).

In addition, in the present invention, the moving body is stopped by the operation of the first PTC element or the second PTC element and the relay contact of the relay circuit at a predetermined position and in an abnormal state (when an external force is applied). A single circuit (first PTC element) has a function to stop the motor at a predetermined position and a function to prevent the motor from burning due to an overcurrent caused by an external force applied to the moving object while the moving object is moving. And a second PTC element and a relay circuit), so that the control unit (2) (mirror housing rotation position detection circuit) for stopping the mirror housing (12) at the retracted position or the set position, and the relay (3) and relay contacts (3a-3b) and the mirror housing (1) during rotation of the mirror housing (12).
2) Compared with the conventional latter switch circuit, which requires an overcurrent protection circuit (7) for preventing burnout of the motor (5) when an external current is applied and an overcurrent occurs, and which requires a separate circuit. The number of circuit components is reduced.

Further, when an overcurrent occurs, the first PTC element or the second PTC
1st PTC by operation of TC element and relay contact of relay circuit
The power to the element and the second PTC element is completely cut off,
Since the current does not completely flow through the TC element and the second PTC element, when the overcurrent occurs, the first PTC element is compared with the former switch circuit in which the overcurrent flows through the overcurrent protection circuit (7). In addition, the durability load of the second PTC element can be reduced.

In addition, since the operation and self-holding of the relay circuit need only be performed by the starting capacitor and the relay self-holding resistor, a simple circuit configuration is sufficient and the cost is low.

[Embodiment] Hereinafter, an embodiment of a switch circuit in the drive device of the present invention will be described with reference to the accompanying drawings.

This example is an example applied to an electric retractable door mirror of an automobile.

In the figure, reference numeral 1 denotes a mirror base fixed to a vehicle body.

Reference numeral 2 denotes a shaft holder in which a hollow shaft 3 is integrally implanted. The shaft holder 2 is fixed to the mirror base 1. The shaft 3 is provided with a chamfer 4 for stopping rotation, and an engaging groove 5 is provided at an upper end of the shaft 3 in a circumferential direction. A pair of arc-shaped grooves 6 are provided on the fixed surface on the upper surface of the shaft holder 2 along the arc trajectory of the ball 12 incorporated in the mirror assembly 7 when the mirror assembly 7 described later is rotated.

As shown in FIG. 6, the arc-shaped groove 6 has step portions 60 and 61 having a height H cut at right angles at both ends thereof. The positions of the step portions 60 and 61 at both ends are determined based on a use position of the mirror assembly 7 described later (a state in which the mirror assembly 7 protrudes laterally from the vehicle body as shown by a solid line in FIG. 2) and a storage position ( (A state in which the mirror assembly 7 is tilted rearward along the vehicle body, as shown by a one-dot chain line in FIG. 2).

Note that the bottom surface of the above-described arc-shaped groove 6 may be smooth, and may have a gently upward convex shape as shown by a two-dot chain line.

Reference numeral 7 denotes a mirror assembly as a moving body. The mirror assembly 7 includes a unit bracket 8 rotatably supported by the shaft 3, a mirror housing 9 and a power unit 10 fixed to the unit bracket 8.
Attached to this power unit 10 so that it can tilt up, down, left and right,
And a mirror 11 disposed at a front opening of the mirror housing 9.

A hemispherical concave portion is provided at a position facing the arc-shaped groove 6 of the shaft holder 2 in the rotation surface of the lower surface of the unit bracket 8, and the ball 12 is rollably fitted into the concave portion.

When the ball 12 hits the step 60 on the use position side as shown by a solid line in FIG. 6, the mirror assembly 7 is at the use position. When the ball 12 hits the step 61 on the storage position side as shown by the one-dot chain line in FIG. 6, the mirror assembly 7 is located at the storage position. Further, as shown by a two-dot chain line in FIG. 6, when the ball 12 rides up from the arc-shaped groove 6 in the direction of arrow A and is positioned on the fixed surface of the shaft holder 2, the mirror assembly 7 is manually operated. Alternatively, it is in a state of being tilted forward along the vehicle body as indicated by a two-dot chain line in FIG.

Steps 60 and 61 at both ends of the arc-shaped groove 6 and the ball 12
Constitutes a stopper for physically and forcibly stopping the mirror assembly 7 as a moving body at a predetermined stop position. The step portions 60 and 61 of the arc-shaped groove 6 are also provided.
The height H and the ball 12 are stoppers that cannot be run by the torque of the motor 13 described later, but can be run by manual or shock-absorbing rotation.

Reference numerals 22 and 23 denote protrusions projecting from the fixed surface on the upper surface of the shaft holder 2 and semicircular grooves provided on the rotation surface on the lower surface of the unit bracket 8, respectively.
23 is slidably fitted.

Reference numeral 13 denotes a motor built in the mirror assembly 7,
The motor 13 is mounted on a plate 14 fixed to the unit bracket 8. The motor 13 is electrically connected to the battery 31 via a switch circuit according to the present invention described later.

Reference numeral 15 denotes a clutch mechanism mounted on the shaft 3. The clutch mechanism 15 manually rotates the mirror assembly 7, or rotates the mirror assembly 7 to buffer the mirror assembly 7 when something hits the mirror assembly 7. For example, the edge between the moving-side mirror assembly 7, the motor 13, and a speed reduction mechanism 24 described later, and the fixed-side mirror base 1, the shaft holder 2, and the shaft 3 are cut off. The clutch mechanism 15 includes a push nut 16 fitted to the shaft 3 in order from the top, a compression spring 17,
Clutch gear 19, clutch holder 20, and washer 18
And 21.

The clutch gear 19 is rotatable with respect to the shaft 3, and has a locking groove on the lower surface. The clutch holder 20 is fixed to the shaft 3 and has a locking claw on the upper surface. The push nut 16 is mounted on the shaft 3
And the compression spring 17 is compressed. Due to the elastic force of the compression spring 17, the locking claw on the upper surface of the clutch holder 20 is locked in the locking groove on the lower surface of the clutch gear 19, and the clutch gear 19 and the clutch holder 20 are connected. is there. In addition, the elastic force of the compression spring 17 urges the shaft holder 2 upward through the shaft 3 (inversely, the unit bracket 8 downward through the clutch mechanism 15). The ball 12 is pressed against the bottom of the arc-shaped groove 6 of the shaft holder 2.

Reference numeral 24 denotes a reduction mechanism as a driving force transmission mechanism disposed between the clutch mechanism 15 and the motor 13. The reduction mechanism 24 includes a first worm 25 attached to an output shaft of the motor 13, and a first worm 25. First worm wheel meshed with
26, a second worm 27 in which one end of a rotating shaft is axially movably and non-rotatably mounted in a central through hole of the first worm wheel 26 by a D-cut surface, and the second worm
27 and a second worm wheel 28 meshed with
Motor side gear 29 fixed coaxially to worm wheel 28
The idle gear 30 is interposed between the gear 29 on the motor side and the clutch gear 19. That is, the idle gear 30 meshes with the gear 29 on the motor side and the clutch gear 19.

The speed reduction mechanism 24 includes the unit bracket 8 and the plate 14 fixed to the unit bracket 8.
And a support 32 attached to the plate 14 with a screw 33.

The shaft 3, the motor 13, the latch mechanism 15, the reduction mechanism 24, and the like are provided with a gear case 44 provided on the unit bracket 8 and a lid 45 fitted and attached to an upper opening of the gear case 44. And more covered.

Hereinafter, the operation of the electric retractable door mirror configured as described above will be described.

First, the motor 13 is driven. Then, the motor 13
Is transmitted to the idle gear 30 via the two-stage worm gear and the gear 29 on the motor side. here,
Since the clutch gear 19 and the clutch holder 20 are in a spliced state, the clutch gear 19 is in a fixed state. As a result, the idle gear 30 revolves while rotating around the clutch gear 19. As the idle gear 30 revolves, the mirror assembly 7 rotates by an angle θ with respect to the shaft 3 of the mirror base 1, and the mirror assembly 7 moves from the use position to the storage position or from the storage position to the use position. Rotationally displaces. At this time, the ball 12 on the mirror assembly 7 or the unit bracket 8 rolls along the arc-shaped groove 6 on the mirror base 1 or the shaft holder 2 in the direction of arrow B or C. And the above-mentioned ball 12 is a step of the arc-shaped groove 6.
When it hits 60 or 61, the switch circuit of the present invention described later is operated, the driving of the motor 13 is stopped, and the mirror assembly 7 is stopped at a predetermined stop position, that is, a use position or a storage position.

Also, when an obstacle or the like hits the mirror assembly 7 with a force greater than the elastic force of the compression spring 17 in a state where the mirror assembly 7 is in the use position, or when the mirror assembly 7 is moved in and out of the garage, the mirror assembly 7 is manually moved. When the clutch spring 19 is rotated with a force larger than the elastic force of the compression spring 17, the clutch gear 19 of the clutch mechanism 15 and the clutch holder 20 are disconnected, and the clutch gear 19 rotates with respect to the shaft 3, and the mirror assembly 7 is accordingly rotated. Rotates from the use position to the storage position, or from the storage position to the use position,
In addition, the angle φ is tilted forward from the use position.

FIG. 1 is an electric circuit diagram showing an embodiment of a switch circuit in the drive device of the present invention.

In the figure, reference numeral 31 denotes a battery as a power supply, and this battery 31 is a normal DC 12 V battery mounted on an automobile.

Reference numeral 37 denotes a switch disposed in the driver's seat. This switch 37 is a switch for switching the polarity. In this example, a three-position changeover switch linked to two movable contacts is used. This switch 37 is connected to the first movable contact 371 and the first movable contact 372 which are linked to each other, and the first common contact COM1 and the second common contact COMCO.
M2 and a first terminal connected to the positive terminal of the battery 31, respectively.
The positive contact A1 and the second positive contact A2, and the negative
First and second contacts B1 and B2 respectively connected to the poles
And a first middle contact C1 and a second middle contact C2.
In this switch 37, the movable contacts 371 and 372 normally contact the middle contacts C1 and C2.

Reference numeral 13 denotes the motor, and the motor 13 is connected to the switch 37 in series. That is, one terminal of the motor 13 is connected to the first common contact COM1 of the switch 37, and the other terminal of the motor 13 is connected to the second common contact COM2 of the switch 37.

Reference numerals 38 and 39 denote a first PTC element and a second PTC element utilizing resistance temperature characteristics. The PTC elements 38 and 39 exhibit switching characteristics in which the resistance value changes rapidly in a certain temperature range. Company Raychem product name PolySwitch) is used. These PTC elements 38 and 39
The mirror assembly 7 as a moving body is physically and forcibly stopped by stoppers (steps 60, 61 and the ball 12) or the like, and an overcurrent generated when the motor 13 is overloaded causes an internal current. When the temperature rises and reaches a certain temperature range, the internal resistance value sharply increases and a switching operation is performed.

41 and 42 are a first diode and a second diode for selecting a PTC element by selecting a current flow.
The first diode 41 and the second diode 42 are connected to the first
The first PTC element 38 and the second PTC element 39 are connected in series, respectively, and these are connected in series between the motor 13 and the switch 37 in an anti-parallel state. That is, the cathode of the first diode 41 is connected to the second common contact COM2 of the switch 37, and the anode of the first diode 41 is connected to the second common contact.
One terminal of one PTC element 38 is connected to the other terminal of the first PTC element 38 and the other terminal of the motor 13.
Further, one terminal of the second PTC element 39 is connected to the switch 37.
The other terminal of the second PTC element 39 is connected to the anode of the second diode 42, and the cathode of the second diode 42 is connected to the other terminal of the motor 13.

40 is a relay circuit, this relay circuit 40 is a normally open relay
400, a relay coil 401, a common contact COM, an A contact, and a B contact. The common contact COM is connected to a first common contact COM1 of the switch 37, and the B contact is connected to one terminal of the motor 13. One terminal of the relay coil 401 is connected to the relay 4 via a capacitor 46.
00 common contact COM1 and the first common contact COM1 of the switch 37
And the other terminal of the relay coil 401 is connected to the first PTC element 38 and the second diode 42 and the motor 13
And between them.

Reference numeral 48 denotes a resistor. One terminal of the resistor 48 is connected between the relay coil 401 and the capacitor 46, and the other terminal of the resistor 48 is connected between the B contact of the relay 400 and the motor 13. .

 Next, the operation of the above-described electric circuit will be described.

First, the switch 37 is operated to bring the movable contacts 371 and 372 into contact with the positive contact A1 and the negative contact B2, respectively. Then, a current flows momentarily from the capacitor 46 to the relay coil 401, and the relay coil 401 is excited, and accordingly, the relay 400 switches from the A contact to the B contact. As a result, the current from the battery 31 flows in the direction of the solid line arrow from the relay 400 → the motor 13 → the first PTC element 38 → the first diode 41, so that the motor 13 rotates (forward rotation). On the other hand, a part of the current in the direction of the solid line arrow flows from the relay 400 → the resistor 48 → the relay coil 401 → the first PTC element 38 → the first diode 41, so that the contact state of the relay 400 with the B contact is self-held. . By the rotational force of the motor 13, the mirror assembly 7 is rotated from the use position to the storage position, for example, as described above. When the mirror assembly 7 reaches the storage position, which is a predetermined stop position, the stopper operates, that is, the moving-side ball 12 hits the step 61 of the fixed-side arc-shaped groove 6, and the mirror assembly 7 It is physically and forcibly stopped at the storage position, which is a predetermined stop position. At this time, an overload is applied to the motor 13, and an overcurrent flows in the electric circuit. Due to this overcurrent, the first PTC element 38
When the internal temperature rises and reaches a certain temperature range, the first PTC
The internal resistance of the element 38 rapidly increases, and the first PTC element 38 performs a stoppering operation. Then, the relay coil 401
Is cut off, the relay 400 self-returns, switches from the B contact to the A contact, and the power supply to the motor 13 is cut off. As a result, the rotation (drive) of the motor 13 stops, and the mirror assembly 7 stops completely at the storage position. Therefore, the operation of the switch 37 is stopped, and the movable contacts 371 and 372 are automatically returned to the middle contacts C1 and C2.

Next, the switch 37 is operated to bring the movable contacts 371 and 372 into contact with the negative contact B1 and the positive contact A2, respectively. Then, a current flows momentarily from the second PTC element 39 and the second diode 42 to the capacitor 46 via the relay coil 401, and the relay coil 401 is excited, and accordingly, the relay 400 switches from the A contact to the B contact. As a result, the current from the battery 31 flows from the second PTC element 39, the second diode 42, the motor 13, and the relay 400 in the direction of the dashed line arrow, so that the motor 13 rotates (reverse rotation). On the other hand,
A part of the current in the direction of the dashed-dotted arrow flows from the second PTC element 39, the second diode 42, the relay coil 401, the resistor 48, and the relay 400, so that the contact state of the relay 400 with the B contact is maintained. By the rotational force of the motor 13, as described above, the mirror assembly 7 is rotated, for example, from the storage position to the use position. Then, when the mirror assembly 7 reaches the use position, which is a predetermined stop position, the stopper operates, that is, the moving-side ball 12 hits the step 60 of the fixed-side arc-shaped groove 6, and the mirror assembly 7 It is physically and forcibly stopped at a use position which is a predetermined stop position. At this time, an overload is applied to the motor 13, and an overcurrent flows in the electric circuit. This overcurrent causes the second PTC element 39
When the internal temperature rises and reaches a certain temperature range, the second PTC
The internal resistance of the element 39 rapidly increases, and the second PTC element 39 performs a switching operation. Then, energization of the relay coil 401 is interrupted, the relay 400 self-returns, switches from the B contact to the A contact, and the energization to the motor 13 is interrupted.
As a result, the rotation (drive) of the motor 13 stops, and the mirror assembly 7 stops completely at the use position. Therefore, the operation of the switch 37 is stopped, and the movable contacts 371 and 3
72 is automatically returned to the middle contacts C1 and C2.

As described above, the switch circuit of the present invention in this embodiment performs the switching operation by the first PTC element 38 and the second PTC element 39 whose resistance value rapidly increases with the temperature rise. The number of circuit components is reduced as compared with the case of performing the above. Moreover, since the switching operation described above is performed instantaneously,
Burnout of the motor 13 can be reliably prevented.

In addition, the switch circuit of the present invention in the above-described embodiment includes a mirror assembly 7 as a moving body,
Since the drive of the motor 13 is stopped after being physically and forcibly stopped at 0,61, there is no backlash in the gear group of the reduction mechanism 24 as the drive force transmission mechanism. As a result, the predetermined stop position without the mirror assembly 7
That is, it can be stopped at the use position or the storage position. Moreover, if the rotating mirror assembly 7 is physically and forcibly stopped for any reason at a position other than the predetermined stop position, the mirror assembly 7 is moved to that position by the above-described switch circuit of the present invention. The motor 13 is stopped when the rotating mirror assembly 7 is physically and forcibly stopped at a position other than the predetermined stop position.
This eliminates the need for a clutch mechanism or the like for preventing burnout of the vehicle. As a result, it is sufficient if the driving force of the motor 13 is slightly greater than the rotational resistance of the mirror assembly 7, that is, the resistance of the ball 12 rolling in the arc-shaped groove 6. Therefore,
The motor 13 and the speed reduction mechanism 24 can be reduced in size and capacity. Further, the clutch torque of the buffering clutch mechanism 15 can be increased separately from the torque of the motor 13, so that the mirror assembly 7 can be held without play, and as a result, the image reflected on the mirror 11 is blurred. There is no danger.

In particular, the switch circuit of the present invention in this embodiment is:
With two PTC elements 38 and 39 in parallel, switch 37
When the mirror assembly 7 is rotated in one direction and then the mirror assembly 7 is rotated in the opposite direction, one of the PTC elements 38 or 39 is connected. Although the PTC element 39 or 38 has a high resistance value as the temperature rises, the other PTC element 39 or 38 is in a low resistance state at room temperature, so that the motor 13 is driven to instantaneously move the mirror assembly 7 in the reverse direction. Can be rotated. Thus, with the other PTC element 39 or 38,
In one of the PTC elements 38 or 39, it is possible to increase the time until the internal temperature decreases and the switching operation becomes possible again.

Moreover, since the two PTC elements 38 and 39 are connected to the relay circuit 40 that cuts off the power supply to the PTC elements 38 and 39 in conjunction with the switching operation of the PTC elements 38 and 39, the PTC element 38 When the switching operation of the PTC element 38 or 39 is performed, the relay circuit 40 is turned off and the power supply to the PTC element 38 or 39 can be cut off.
Endurance load can be reduced.

In the above embodiment, the steps 60 and 61 of the arc-shaped groove 6 and the ball 12 are used as the stoppers, but other techniques may be used.

Further, in the above-described embodiment, the electric retractable door mirror for a vehicle has been described. However, it can be used as a switch circuit of another driving device.

Further, instead of the switch 37 in the above embodiment,
An operation holding type switch may be used.

[Effects of the Invention] As is apparent from the above description, the switch circuit in the drive device of the present invention operates the motor, the first PTC element, and the second PTC element by operating the relay contact of the relay circuit by the switching operation of the first PTC element or the first PTC element. Since the power supply to the element is cut off, the number of circuit components is reduced as compared with the conventional switch circuit, and the motor, the first PTC element and the
The durability load of the 2PTC element can be reduced.

[Brief description of the drawings]

The accompanying drawings show an embodiment of the switch circuit in the driving device according to the present invention, FIG. 1 is an electric circuit diagram of the switch circuit of the present invention, and FIGS. 2 to 6 show an automobile equipped with the switch circuit of the present invention. 2 is a partially cutaway plan view, FIG. 3 is a cross-sectional view of an assembled state of a motor, a driving force transmission mechanism and a moving body, FIG. 4 is an exploded perspective view of the same, and FIG. 5 is a view taken in the direction of the arrow V in FIG. 4, and FIG. 6 is a development view taken along the line VI-VI in FIG. 1 ... Mirror base, 2 ... Shaft holder, 3 ...
Shaft, 6: arc-shaped groove, 7: mirror assembly (moving body), 8: unit bracket, 12: ball (stopper), 13: motor, 15: clutch mechanism, 24
…… Deceleration mechanism (driving force transmission mechanism), 31 …… Battery (power supply), 37… Switch, 38 and 39… PTC element, 4
0 ... timer circuit, 41 and 42 ... diode, 60 and 61 ... step (stopper).

Claims (1)

(57) [Scope of request for utility model registration] A power supply, a motor connected to the power supply via a switch, a moving body linked to the motor via a driving force transmitting mechanism, and moving by driving the motor, and moving the moving body to a predetermined position. In a driving device having a stopper for stopping, the temperature rises due to an overcurrent generated when the moving body is physically stopped due to the stopper or any cause and the motor is overloaded. When the temperature reaches a certain temperature range, the resistance value rapidly increases and the 1st P that performs switching action
A TC element and a second PTC element, the first PTC being connected in series between the switch and the motor in a mutually parallel state;
An element and a second PTC element; a first diode and a second diode connected in series to the first PTC element and the second PTC element, each having a different current flowing direction; and a switching operation of the first PTC element or the second PTC element. A relay coil of a relay circuit degaussed by
A relay coil of a relay circuit connected in series with the 1PTC element and the second PTC element and the first diode and the second diode, and connected in parallel with the motor;
A relay contact of a relay circuit that cuts off current supply to the TC element and the second PTC element, is connected in parallel with the relay coil, and includes the motor and the first PTC element and the second PTC element.
A relay contact of a relay circuit connected in series with the TC element and the first diode and the second diode; and a starting capacitor for starting the motor and exciting the relay coil, wherein the relay coil and the first PTC A starting capacitor connected in series with the element, the second PTC element, the first diode and the second diode, and connected in parallel with the relay contact and the motor; and a relay self-holding for maintaining an excitation state of the relay coil. Resistance, connected in series with the relay contact and the relay coil, the first PTC element and the second PTC element, the first diode and the second diode, and in parallel with the motor and the starting capacitor. A relay for self-holding a relay connected to the switch. Circuit.