JPS6321437B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drive device for each DC motor in a ground moving object such as an automatic guided vehicle, which uses a plurality of DC motors as a drive source.

[Conventional technology and its problems]

DC motors are generally used as drive motors for automatic guided vehicles that use batteries as a power source due to their good braking performance, but in the case of a single DC motor, the left and right running wheels can be controlled simultaneously. The power transmission device for this is complicated and expensive, and in the case of multiple DC motors, the circuit configuration is changed by mechanically switching the contacts, making the device complicated.

[Means for solving problems]

The present invention is configured to alternately turn on and off the armatures and field coils of a plurality of DC motors in a ground moving object such as an automatic guided vehicle using three transistors, thereby performing power running and regenerative motion with constant torque. ,
Furthermore, the present invention provides a drive device for multiple DC motors suitable for wheel-in drive.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

In Figure 1, 1 is the body of the automatic guided vehicle, and 2 is 1
3 and 4 are two running wheels that can rotate freely, and each running wheel is connected to an individual DC motor M.
1 and M2 via reduction gears 5 and 6. In the embodiment shown in FIG. 2, 7 and 8 are positive and negative electric lines connected to the battery E. Power transistors TR1, TR2, and TR3 connected in series are connected to this electric line, and a power diode D is connected to each transistor.
1, D2, and D3 are connected in antiparallel. Here, the transistor TR1 on the positive current path side and the intermediate transistor
The first connection point connecting TR3 is designated as A, and the second connection point connecting transistor TR2 on the negative current path side and intermediate transistor TR3 is designated as B. The first DC motor M1 has a series field coil FS1 and a shunt field coil FP1, and includes an armature and a series field coil FS1 connected thereto.
The outer ends of the shunt field coil FP1 are connected to the positive current path 7 and the first connection point A, and the shunt field coil FP1 is connected to the first connection point A and the negative current path 8. The second DC motor M2 has a series field coil.
FS2 and a shunt field coil FP2, each outer side of the armature and the series-wound field coil FS2 connected thereto is connected to the negative current circuit 8 and the second connection point B, and the shunt-wound field coil
Connect FP2 to the second connection point B and the positive current path.

One embodiment of the device of the present invention has the above configuration,
Due to the following action, the first electric motor M1 and the second electric motor M2
control the speed and direction of rotation.

(1) Action of each transistor Transistor TR1 supplies power to the armature of second motor M2 and series field coil FS2, and in this case, transistor TR2 supplies power to the armature of second motor M2 and series field coil FS2.
It performs on/off control alternately and acts as a chopper for the shunt field coil FP2 of the second motor.

Similarly, the transistor TR2 is connected to the first motor M2.
power is supplied to the armature and the series field coil FS1, and in this case, the transistor TR1 is
It is controlled on and off alternately with TR2 and acts as a chopper for the shunt field coil FP1 of the first motor.

Transistor TR3 connected between transistors TR1 and TR2 is controlled on/off in conjunction with TR1 and TR2.

(2) When driving and controlling only the first motor M1 alone Turn on the transistor TR2, turn on and off the transistors TR1 and TR3 alternately, and control the speed of the first motor M1 by the chopper.

(3) When driving and controlling only the second electric motor M2 alone The transistor TR1 is turned on, and the speed of the second electric motor M2 by the chopper is controlled by the transistors TR2 and TR3.

(4) When controlling the drive of the first and second electric motors M1 and M2 at the same time If the same amount of load is applied to the first electric motor M1 and the second electric motor M2, both can be driven by simply controlling the transistor TR3 on and off. The speed of the electric motor can be controlled at a constant speed.

If you want to obtain the speed difference between the two motors when the loads on the two motors are different, use a transistor.
TR1 and TR2 are controlled on and off alternately to check whether the load on the first motor M1 is heavy or whether the first motor M
1 (this means M1>M2), increase the on time of transistor TR2,
On the other hand, if the load on the second motor M2 is heavy or if you want to make the second motor M2 faster, the transistor TR
Increase the on time of 1.

In this way, transistors TR1 and TR2 are controlled on and off alternately, and during that time the transistor
TR3 continues to operate as a chopper, controlling the input power to both motors and controlling both motors to a predetermined speed.

With the above (1) to (4), power running and regenerative operation can be performed without mechanically switching the contacts. Note that the on-period T1 of transistors TR1 and TR2,
Duty ratio determined by T2 (T2 - T1) - (T1 +
By controlling T2), complementary operation of the two DC motors can be realized.

In either case, diodes D1 to D3 create a circuit that releases the energy stored in the armature coil and field coil at the moment the transistor is turned off, ensuring continuity and smoothing of the current, and also serves as a circuit during dynamic braking. It becomes a discharge circuit element and a feedback circuit for regenerative power during regenerative braking.

The above describes one embodiment of the present invention regarding an automatic guided vehicle equipped with a compound motor; however, the present invention is not limited to this embodiment, and the design can be changed within the gist of the invention. It can be widely applied to terrestrial vehicles such as electric vehicles.

[Effects of the present invention]

According to the present invention, since the armatures and field coils of multiple electric motors are alternately controlled in a chopper manner, the number of control parts is small and the configuration is simple. Complementary operation of multiple electric motors is realized by controlling the duty ratio of transistors. It has a certain effect.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an automatic guided vehicle, and FIG. 2 is a wiring diagram showing an embodiment of the present invention. Note that ES is a battery, 7 and 8 are positive and negative electric circuits, and TR
1, TR2, TR3 are transistors, D1, D2,
D3 is a diode, A is a first coupling point, B is a second coupling point, M1 is a first motor, FP1 is its field coil, M2 is a second motor, and FP2 is its field coil.

Claims (1)

[Claims] 1 Connect three transistors directly to the positive and negative circuits connected to the battery, connect a diode to each transistor in antiparallel, and connect the first connecting point connecting the transistor on the positive circuit side and the intermediate transistor to the first node in the positive circuit. The armature of the second DC motor is connected to the second connection point connecting the transistor on the negative current path side and the intermediate transistor, and the armature of the second DC motor is connected to the negative current path, and the field coil of the first DC motor is connected to the first Connect the connecting point to the negative current path, and connect the field coil of the second DC motor to the second connecting point and the positive current path to operate both motors at the same speed, or increase the speed of one motor and increase the speed of the other motor. A drive device for multiple electric motors, characterized in that the speed of the motor can be lowered.