WO2004060517A1

WO2004060517A1 - Motor driven toy

Info

Publication number: WO2004060517A1
Application number: PCT/JP2002/013841
Authority: WO
Inventors: Youichi Maeda
Original assignee: Nikko Co., Ltd.
Priority date: 2002-12-27
Filing date: 2002-12-27
Publication date: 2004-07-22

Abstract

A motor driven toy comprising a drive shaft, a motor for rotating the drive shaft, and a motor control circuit for driving the motor. The motor driven toy further comprising a motor current detecting circuit connected with the motor control circuit and detecting an overcurrent being generated upon locking of the drive shaft, and a timer circuit connected with the motor current detecting circuit and delivering a drive stop signal to the motor control circuit upon elapsing a specified time after measuring the generating time of an overcurrent.

Description

Specification

Motor drive toy Technical field

The present invention relates to a motor-driven toy that travels or navigates by driving a motor, and prevents occurrence of an overcurrent when the motor squeezes due to an obstacle.

When a motorized automobile toy as shown in Fig. 4 travels on a road surface with poor running ability such as grassland or wasteland, the wheel may get stuck in the gap etc. and the wheel may be locked. In addition, the wheel may be locked by pressing the vehicle body or the wheel with a hand or foot. In such a case, if the motor is driven in the ON state even though the wheel is locked and can not rotate, an excessive current is generated in the motor and the control element of the motor, and the motor or Joule heat causes The control element may be heated and damaged. In particular, in the case where these toy vehicles are operated by radio steering using electromagnetic waves, infrared radiation, etc., when the occurrence of an accident is not in the vicinity of the operator, it takes time-consuming motors or control elements to eliminate the cause of the obstacle. It can not be broken forever.

Such an accident does not necessarily occur only with an automobile toy, and a similar accident also occurs with, for example, a ship toy Skrieu shown in FIG. For example, when algae is tangled in the screw, the rotation of the screw is stopped and the motor is locked, an overcurrent flows, and the motor or the controller is damaged.

Several measures have been proposed against the occurrence of over current due to motor lock due to such a motor load factor.

Japanese Patent Laid-Open Publication No. Hei 8-2 2 7 2 4 1 detects an increase in the steering motor drive current due to an obstacle in steering operation of the radio control vehicle and not in the steering wheel. There is disclosed a configuration in which the drive current is dropped based on the judgment. Here, There is disclosed a step of detecting the presence or absence of an overcurrent detection signal of a current sensor, and, if detected, reducing the drive current if the elapsed time is longer than a predetermined time.

Further, in Japanese Patent Laid-Open No. 9-5650, a voltage monitoring element detects an overcurrent generated at both ends of a current detection resistor to start a timer. An over-current control method for determining inrush current and lock current is disclosed. Detects over current, starts timer, and detects again after set time to distinguish between lock current and inrush current. Furthermore, in addition to the failure to be controlled such as a motor lock in JP-A-200 0 2 3 3 4 5 ^ ^ ^, even if it is a failure such as a runaway of the control unit, overcurrent protection control is performed. The circuit is disclosed. The latch unit holds the overcurrent signal output. After the power supply voltage drops below a predetermined voltage, monitor the elapsed time after inputting the latch signal, and send a reset signal after a predetermined time has elapsed.

However, in the conventional overcurrent protection circuit, since timer 1 is used to measure the state of overcurrent only at the start of overcurrent and after a specific time, changes such as overcurrent reduction or recovery during timer measurement can be made. Had the problem that it could not cope.

In addition, in order to measure the overcurrent using timer one, a dedicated component is often required. In addition, control is not necessarily realized with an inexpensive circuit configuration, such as using a dedicated central processing processor.

Therefore, the object of the present invention is to prevent the occurrence of overcurrent when the motor is locked due to a failure, and to cope with the case where the overcurrent condition during timer 1 measurement is stopped, and also only the highly versatile parts. It is to provide a motor drive toy that can be configured with Disclosure of the Invention In order to solve the above-mentioned problems, according to the invention of claim 1, according to the present invention, a motor drive toy comprises a drive shaft, an electric motor for rotating the drive shaft, and a motor control circuit for driving the electric motor. In the motor drive toy provided with, the drive shaft is locked by being connected to the motor control circuit And a motor current detection circuit that detects an overcurrent that is generated, and a timer circuit that is connected to the motor current detection circuit and measures the occurrence time of the overcurrent and sends a drive stop signal to the motor control circuit after a specific time has elapsed. And Such a configuration prevents the occurrence of overcurrent when the motor is locked due to a failure, and is configured with only versatile parts that cope with the case where the overcurrent condition is under measurement during timer measurement. it can. According to a second aspect of the present invention, the motor current detection circuit includes a comparator for comparing the potential of the motor current source for supplying current to the motor provided in the motor control circuit with a predetermined reference potential. It features. With this configuration, the magnitude of the overcurrent can be realized by adjusting the reference potential.

According to a third aspect of the present invention, the timer circuit includes an integration circuit that integrates the output signal of the comparator. It is possible to respond when the overcurrent condition during timer measurement stops.

The invention according to claim 4 of the present invention is characterized in that the timer circuit is connected to the motor control circuit via the latch circuit. With this configuration, the over-current signal can be latched even if the over-current is stopped halfway through the over-current.

In the invention of claim 5 according to the present invention, the drive shaft is provided with a traveling wheel at the end of the shaft to constitute a traveling toy. The present invention can be applied to so-called car-type toys. The invention according to claim 6 of the present invention is characterized in that the drive shaft is provided with a screw at the end of the shaft to constitute a marine toy. The present invention can be applied to so-called ship-type toys.

• The invention according to claim 7 of the present invention is characterized in that the motor control circuit further comprises a radio control reception unit for receiving a motor drive control signal, and a demodulation unit for demodulating a reception signal. . Brief description of the drawings

FIG. 1 is a circuit block diagram showing an embodiment of a mobile drive toy according to the present invention; Fig. 2 is a detailed circuit diagram showing an embodiment of the motor drive toy according to the present invention, Fig. 3 is a time chart showing the operation of the embodiment of the motor drive toy according to the present invention, and Fig. 4 is a motor according to the present invention. FIG. 5 is a block diagram of an automobile toy (a) and a boat-type toy (b) showing an embodiment of a motorized toy according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Other details, advantages and features of the present invention are revealed by the examples described below with reference to the attached drawings.

FIG. 1 is a circuit block diagram showing an embodiment of a motor drive toy according to the present invention, and FIG. 2 shows a detailed circuit diagram. First, the overall configuration will be described using FIG.

The motor drive toy 1 has a motor control circuit 2 for controlling the motor and a motor detection circuit 4 and is connected by two signal lines 6 and 8.

The motor control circuit 2 is a circuit that controls the increase or decrease of the current or voltage and the polarity to control start, acceleration, deceleration, stop, and reverse of the motor. Connected to the motor lock detection circuit 4, the signal line for the motor lock detection circuit 4 to detect the current value is 6, and the motor lock detection circuit 4 feeds back the detected result. There are 8 signal lines.

The motor lock detection circuit 4 includes a motor current detection circuit 10 and a timer circuit 12 and is connected via a signal line 14.

The motor current detection circuit 10 is a circuit that detects whether or not a current exceeding a predetermined current flows in via the signal line 6. When a current exceeding a predetermined current flows in, the overcurrent detection signal is sent to the timer circuit 12 via the signal line 14. The timer 1 circuit 12 starts counting the timer upon arrival of the overcurrent detection signal transmitted from the motor current detection circuit 10. After the start, when the timer is continuously counted and the predetermined time is exceeded, the motor lock detection signal is generated. Occurs The motor clock detection signal is transmitted to the motor control circuit 2 through the signal line 8. When the motor control circuit 2 detects the motor clock detection signal, it stops the drive current of the motor to prevent the inflow of the overcurrent.

Next, FIG. 2 shows a detailed circuit diagram showing an embodiment of the mobile driving toy according to the present invention. In the detailed circuit diagram, a power supply unit is shown in addition to the motor control circuit 2, the motor current detection circuit 10, and the timer circuit 12.

The power supply section is wired so that 5 V, which is a standard voltage, is supplied to each circuit by a three-terminal regulator IC 2 and a smoothing circuit consisting of an electrolytic capacitor and a capacitor. The detailed circuit of the motor control circuit 2 is shown. TR 1 is a transistor that performs rotation Z stop control and current limitation of the motor M 1 that drives the motor drive toy, and controls the current flowing to the motor M 1 that drives the motor drive toy by ONZOFF of the transistor TR 1. Do. The base of the transistor TR 1 is further connected to the diode D 1 of the timer circuit 12 via the transistor TR 2. The emitter of the transistor TR 1 is input to the comparator CMP 1 of the motor current detection circuit 10. In this transistor TR1, current flows from the motor M1 directly through the emitter. When the transistor TR 2 receives an L signal at the base, the transistor TR 2 is turned off, the base of the transistor TR 1 becomes an L signal, the transistor TR 1 is turned off, and the current does not flow to Ml and stops. . The collector of TR 2 is connected to the power supply circuit of the main port, but is omitted in the drawing.

Next, a detailed circuit of the motor current detection circuit 10 is shown. The comparator CMP 1 is for detecting the current flowing to the motor M 1 that drives the motor driving toy, and detects the voltage generated across the resistor R 3 when the current flows to the resistor R 3. The detection voltage is determined by the reference voltage applied to the-input terminal of the comparator CMP 1 and is a voltage obtained by dividing the 5 V voltage generated by the 3-terminal regulator IC 2 with the variable resistor VR 1 and the resistor R 1 As the reference voltage. Here, the set value of the reference voltage is adjusted and set by the variable resistor VR1 so as to be an appropriate value below the maximum rating of the drive element. Comparator CM P The output of 1 is determined by comparing the voltage of the + input terminal of CMP 1 with the reference voltage, and outputs the Hi level if the voltage of the + input terminal is higher than the reference voltage, and the voltage of the + input terminal is If it is lower than the voltage, it outputs Lo level. The + input terminal of this CMP 1 is a voltage obtained by converting the current value flowing to the motor M1 driving the motor drive toy into a voltage. The output of CMP 1 is input to the resistor R 4 of the timer circuit 12.

Furthermore, a detailed circuit of the timer circuit 12 is shown. The timer circuit 12 is composed of a comparator CMP 2 which operates largely as a timer circuit, and a latch circuit. The comparator CMP 2 is connected via an integration circuit composed of CMP 1, a resistor R 4 and an electrolytic capacity C 5. That is, it is for calculating time by being integrated by the integration circuit, and comparing the integrated voltage with the second reference potential. The voltage obtained by dividing the voltage of 5 V generated by 3-terminal regulator I C 2 by resistors R 2 and R 5 is used as the reference voltage. Here, the setting value of the reference voltage is set to be an appropriate value to detect the integrated voltage. The output of CMP 2 is determined by comparing the voltage at the + input terminal of CMP 2 with the reference voltage, and outputs the Hi level if the voltage at the + input terminal is higher than the reference voltage. If the terminal voltage is lower than the reference voltage, it outputs the Lo level. The output of the comparator CMP 2 indicates that the excess current is output beyond the set time of the timer. The output of comparator CMP2 is input to the latch circuit through diode D3.

In the latch circuit, when the output of CMP 2 is H i, the transistor TR 4 is turned on, and current flows in the diode D 1 so that the base of the transistor TR 2 becomes L o, so the transistor TR 2 is turned off. Therefore, the transistor TR 1 is also turned off. This is only when the output of CMP 2 is Hi, and when the output of CMP 2 is Lo, transistor TR4 is off, so transistor TR 2 is on and transistor TR 1 is also on. is there. In the latch circuit, although the connection is omitted for the diode D2, the diode is provided to connect a plurality of motors such as a reversing motor or a motor for turning, but in the drawing, The tip is omitted Is described.

Therefore, the operation of the detailed circuit showing the embodiment of the motor drive toy according to the present invention configured as described above will be described below with reference to FIG. 2 and FIG. Here, as shown in Figure 2, the emitter of transistor TR 1 is VA, the contact point of resistor R 4 and electrolytic capacitor C 5 is VB. The output of comparator CMP 2 is VC, the output of diode D 3 is VD, transistor TR4 Let the collector be VE. Let the drive current of the motor be Im.

There are three modes of operation, and a normal current flows and it is a normal mode with no problem in motor drive. In addition, this switching mode does not take a long time such as when the motor starts up or when switching back and forth between motor and so on when the overcurrent flows. Furthermore, it is a lock mode in which the overcurrent does not flow due to the lock of the tire, etc. These are described below as the normal mode, the switching mode, the mouth, and the hook mode, respectively.

First, the normal mode will be described. The output voltage of the driving mode VA is a voltage generated across the resistor R3. Since the transistor TR1 is ON, a current within a preset current value range flows into the + input terminal of the comparator CMP1. VA generates only a voltage that does not exceed the reference potential. The comparator CMP I is therefore low with the input OFF. Since the output VB of the comparator CMP 1 is L 0, the comparator CMP 2 including the integrating circuit into which this output flows is also OFF, and the output VC of the comparator CMP 2 is L o. Therefore, the latch circuit is not set, VD maintains Lo, the transistor TR4 is OFF, and V E maintains the H i state. Therefore, both the transistors TR 2 and TR 1 are in the ON state. For this reason, current continues to flow also in the motor Ml.

Next, the switching mode will be described. While the current of the motor M1 is the same as the normal time, it is identical to the normal mode. In this state, when an overcurrent flows, VA, which is the voltage across the resistor R3, exceeds the reference voltage VTA input to the − terminal of the comparator CMP 1. Then, the comparator CMP 1 is turned ON, so its output becomes H i and starts charging the electrolytic capacity C 5 of the integration circuit (A to B of VB). However, the over current If the overcurrent is stopped at point B, that is, the time shorter than the preset time, the output of the comparator CMP 1 drops to Lo. Since the output of the comparator CMP 1 is input through the integration circuit, the output VC of the comparator CMP 2 is not changed, and the VD remains at L 0 without the input of the set signal. The transistor TR4 to which the VD is input to the base remains OFF, VE maintains H i, and the transistors TR 2 and TR 1 remain ON.

Furthermore, the lock mode will be described. The output of the comparator CMP 1 becomes H i and is the same as in the switching mode until it starts charging the electrolytic capacity C 5 of the integration circuit. In the lock mode, the overcurrent continues to flow, and the charged voltage VB exceeds the reference voltage VTB input to one terminal of the comparator CMP 2, so the output VC of the comparator CMP 2 Is Hi. When the output VC becomes Hi, the voltage of VD rises and the latch circuit is set. Therefore, the transistor TR4 is turned on. As a result, the voltage of VE, which is the collector of the transistor TR4, changes to L o, so the transistors TR 2 and TR 1 are turned off, and the overcurrent is stopped.

Further, FIG. 4 is a flowchart showing the operation of the embodiment of the motor drive toy according to the present invention.

First, it is detected that the comparator CMP 1 for detecting an overcurrent exceeds the set value of the drive current VTA which is the reference potential (A1). This is to detect the presence or absence of an overcurrent. Next, the timer operation starts when the output of the comparator CMP 1 charges the integration circuit (A4). This is to measure the time during which the overcurrent flows, and to determine whether it is a switching current or an overcurrent due to a tire lock or the like.

Here, it is determined whether or not the output of comparator CMP 1 is reduced by the completion of charging in order to measure whether or not the overcurrent continues to flow for a predetermined time or more (A 6) ₀

Therefore, if the overcurrent continues to flow for more than a predetermined time, comparator C MP 2 detects that the integral output exceeds the set value of VT B which is the reference potential (A 8).

By exceeding the set value of V TB which is this reference potential, the latch circuit is set (A 10).

Therefore, the motor drive current is stopped by the set latch circuit output (A12).

On the other hand, if the output of the comparator CMP 1 is lowered by the completion of charging in A6, it is in the switching state and is a temporary overcurrent, so the normal operation continues.

According to the configuration and operation of the present invention as described above, the occurrence of overcurrent when the motor is locked due to a failure can be prevented, and it is possible to cope with the case where the overcurrent state during timer measurement is stopped. It is possible to provide a motor drive toy that can be configured with only high parts. In addition, since the timer circuit uses the integration circuit, there is no possibility that it will be counted when the overcurrent is stopped halfway, so that the lock state can be detected with certainty.

Furthermore, since the parts to be used can be configured with inexpensive general-purpose products such as an operational amplifier, a transistor, and a three-terminal diode, it is possible to realize a motor toy that prevents the occurrence of overcurrent at low cost.

In addition, a variable resistor is used to adjust the value of overcurrent and the time between timers, and the value of overcurrent and timer time can be freely changed.

The present invention is not limited to the above embodiment, and modifications and improvements as long as the object of the present invention can be achieved are included in the present invention.

Claims

The scope of the claims

1. In a motor drive toy including a drive shaft, an electric motor for rotating the drive shaft, and a motor control circuit for driving the motor, the drive shaft is connected with the motor control circuit to generate an overrun. Motor drive comprising a motor current detection circuit for detecting a current, and a timer circuit connected to the motor current detection circuit to measure an occurrence time of an overcurrent and send out a drive stop signal to the motor control circuit after a specific time has elapsed. toy.

2. The motor current detection circuit is provided with a comparator that compares the potential of the motor current source for supplying current to the motor provided in the motor control circuit with a predetermined reference potential. A motor drive toy.

3. The motor drive toy according to claim 1 or 2, wherein the timer circuit includes an integration circuit that integrates the output signal of the comparator.

4. The motor drive toy according to any one of claims 1 to 3, wherein the timer circuit is connected to the motor control circuit via a latch circuit.

5. The motor driven toy according to any one of claims 1 to 4, wherein the driving shaft is provided with a traveling wheel at the end of the shaft to constitute a traveling toy.

6. The motor drive toy according to any one of claims 1 to 4, characterized in that the drive shaft is provided with a screw on its tip to constitute a marine toy.

7. The motor drive toy according to any one of claims 1 to 6, wherein the motor control circuit further comprises: a wireless control receiving unit that receives a motor drive control signal; and a demodulation unit that demodulates the received signal. .