JPH058722Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a drive control device for an electric vehicle motor, and more particularly to a drive control device for an electric vehicle motor equipped with an accelerator through which an operator commands the drive.

[Prior Art] Generally, in an electric vehicle such as an electric wheelchair, an accelerator circuit unit that commands driving and a drive control circuit unit for a motor are separately installed for convenience of operation by an operator. On the other hand, as a result of such separate equipment, the ground line of the accelerator circuit section is more likely to be disconnected or have poor contact due to incoming vibrations.

This conventional example is shown in FIG. In FIG. 2, reference numeral 102 indicates an accelerator circuit section (hereinafter referred to as "accelerator"), numeral 104 indicates a drive control circuit section, and numeral 106 detachably connects the accelerator 102 and drive control circuit section 104. Figure 3 shows a coupler as a possible cord connection means.

Among these, the accelerator 102 is configured by connecting in series a semi-fixed resistor 8 for protection and an accelerator 10 consisting of a variable resistor. Semi-fixed resistance 8
As shown in the figure, one end is configured to receive V _CC power from the drive control circuit section 104 through a power line L _V formed through the first coupler 6A of the coupler 106. .

Further, the accelerator signal taken out from the lever (movable contact piece) of the accelerator 10 is supplied to the drive control circuit section 104 by the accelerator signal line _LA formed via the second coupler 6B of the coupler 106. It is designed so that Furthermore, the other end of the accelerator 10 is connected to the ground within the drive control circuit section 104 via a ground line L _E configured via the third coupler 6C of the coupler 106.

The drive control circuit section 104 includes the control signal forming means 1
2. Switching means 14, temperature sensor circuit 11
6. Motor protection circuit 18 and V _CC power supply circuit 20
It is composed of. Of these, the control signal forming means 12 is composed of a comparator 22 and a sawtooth oscillator 24. The accelerator signal L _ACC is applied to the non-inverting input terminal of the comparator 22, and the sawtooth signal V _OSC is applied to the inverting input terminal. Therefore, the output of the comparator 22 becomes a logic H level when the accelerator signal V _ACC exceeds the sawtooth signal L _OSC , and becomes a logic L level in the opposite case.
This is outputted to the switching means 14 as a pulsed control signal V _C .

The switching means 14 is constructed with an NPN type switching transistor 26 as a main part. A control signal V _C from the comparator 22 is applied to the base of the transistor 26 . The collector of this transistor 26 is connected to the emitter via a motor 28 for driving the electric vehicle, a switch 30, and a battery 32 of the electric vehicle, thereby forming a motor circuit. For this reason,
The transistor 26 is turned on only while the control signal V _C is at logic H level, and the battery 32 is connected to the motor 2.
8 is energized, and the motor 28 rotates.

On the other hand, the temperature sensor circuit 116 consists of a thermistor 34 having a negative characteristic and a resistor 36 connected in series, and this is inserted between the V _CC power supply and the ground. Of these, the thermistor 34 is the transistor 2
6, and outputs the detection signal V _D divided by the resistor 36 to the motor protection circuit 18 at the next stage. This allows the temperature change of the transistor 26 to be detected.

The motor protection circuit 18 includes a comparator 38 that receives the detection signal V _D as an input signal at its inverting input terminal, and resistors 40 and 42 for setting a reference potential connected between the V _CC power supply and ground. has been done. The potential at the midpoint between the resistors 40 and 42 is the reference potential.
The signal V _S is connected to the non-inverting input terminal of the comparator 38 . Further, the output terminal of the comparator 38 is connected to the base of the transistor 26 via a diode 44.

Therefore, as the current of the motor 28 increases, the temperature of the transistor 26 increases. If this temperature rise is below the allowable value, the output of the comparator 38 becomes a logic H level because the reference potential V _S is predetermined so that the detection signal V _D is lower than the reference potential V _S. , does not involve the transistor 26 in any way. However, if the temperature of the transistor 26 rises abnormally and exceeds a set value due to, for example, an overload condition of the motor 28, the thermistor 34
resistance value decreases. Then, the detection signal V _D exceeds the reference potential V _S , and the output of the comparator 38 becomes logic L.
level. Accordingly, transistor 26 is forced to an "off" state and motor 28 is stopped. This avoids situations such as burnout of the windings of the motor 28 and thermal destruction of the transistor 26.

Here, the V _CC power supply circuit 20 is configured with a three-terminal regulator 46 as a main part.

[Problem that the invention attempts to solve]

However, in the above conventional example, among the earth lines L _E extending from the accelerator 10, for example,
If _one point A or _two points A are disconnected, a situation will occur in which the V _CC voltage becomes the accelerator signal V _ACC as it is, regardless of the position of the lever of the accelerator 10. When this situation occurs, transistor 26
This caused a serious problem in that the electric vehicle remained "on" and the electric vehicle could no longer be controlled, resulting in a so-called runaway condition.

This runaway state occurs in the third coupler 6C of the coupler 6.
The same problem occurs when a contact failure occurs due to vibration or the like.

[Purpose of invention]

The present invention is a drive control device for an electric vehicle motor that improves the disadvantages of the conventional example and makes it possible to effectively avoid runaway of the electric vehicle that occurs due to disconnection of the ground line in the accelerator circuit. Its purpose is to provide.

[Means for solving problems]

In this invention, a predetermined power supply V _CC and earth line L _E
and a switching means 14 for controlling the energization circuit of the motor 28 on and off in accordance with the output of the accelerator circuit section 2, which is connected between the accelerator circuit section 2 and outputs an accelerator signal having a value corresponding to the operation amount. drive control circuit section 4;
and the accelerator circuit section 2.
It has a coupler 6 equipped with A to 6D. The drive control circuit section 4 includes a temperature sensor circuit 16 that detects the temperature rise of the circuit elements of the switching means 14 and outputs an electric signal of a value corresponding to the temperature rise, and a temperature sensor circuit 16 that controls the temperature sensor circuit 16 to a predetermined level. Switching means 1 is activated when detecting
The motor protection circuit 18 is provided with a motor protection circuit 18 that controls the motor 4 to turn off. The temperature sensor circuit 16 includes a coupler 6
and is grounded via the ground side terminal P of the accelerator circuit section 2. This aims to achieve the above-mentioned purpose.

[Example of idea]

An embodiment of the present invention will be described below with reference to FIG.

Here, the same reference numerals are used for the same components as in the conventional example described above.

In FIG. 1, L _AD indicates an additional line newly provided in this embodiment. This additional line
L _AD is transmitted through the fourth coupler 6D of the coupler 6,
The ground side terminal P of the accelerator 2, which is the connection point between the accelerator 10 and the earth line L _E , is connected to the ground terminal of the temperature sensor circuit 16 of the drive control circuit section 4. That is, temperature sensor circuit 1
The ground for the V _CC power supply of 6 is the additional line L _AD ,
This will be done via the connection point P and the earth line L _E.

The other configurations are the same as those in FIG. 2, which shows the prior art example described above.

Next, the operation of this embodiment will be explained.

First, turn on the switch 30 and press the accelerator 10.
By operating the lever, the motor 28 can be driven at an appropriate speed by the control signal forming means 12 and the switching means 14. Further, when the motor current exceeds a set value, the temperature sensor circuit 16 and the motor protection circuit 18 are activated, and as in the conventional example described above, it is possible to avoid situations such as burnout of various parts.

Here, disconnection of each line, etc. will be explained.
First, even if a disconnection or the like occurs in the power supply line L _V , the accelerator signal V _CC is not output because the V _CC power is not supplied. Therefore, the electric vehicle will not be running. The same applies to the case of disconnection of the accelerator signal line _LA .

On the other hand, if a disconnection occurs in the earth line L _E or a contact failure occurs in the third coupler 6C, the V _CC voltage is applied to the comparator 22 and its output becomes a logic H level. However, the ground circuit of the temperature sensor circuit 16 is also opened, and the motor protection circuit 1
The output of the comparator 38 of No. 8 is always at the logic L level. As a result, the transistor 26 of the switching means 14 is also forcibly turned off, the rotation of the motor 28 is stopped, and a runaway state can be reliably avoided.

Furthermore, if a disconnection occurs in the additional line L _AD or a contact failure occurs in the fourth coupler 6D, the output of the comparator 38 becomes the logic L level and the rotation of the motor 28 is stopped, as described above. .

Even if the above-mentioned four modes of disconnection, etc. occur together, the effect is the same.

In this way, in this embodiment, the temperature sensor circuit 16
It has a simple configuration in which an additional line L _AD is added between the and the accelerator 10. And the existing temperature sensor circuit 16 and motor protection circuit 18
In addition to the original temperature detection function, the earth line L _E
It also has a function to prevent the vehicle from running out of control in the event of a wire breakage. Therefore, it can be implemented extremely easily and inexpensively on existing electric vehicles.

[Effect of idea]

Since the present invention is configured and functions as described above,
According to this, if a disconnection accident occurs in the ground line in the accelerator circuit, the electric vehicle motor will be immediately controlled to stop due to the action of the temperature sensor circuit and the motor protection circuit. It is possible to provide an unprecedented and practical drive control device for an electric vehicle motor that can effectively avoid runaway.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing one embodiment of the present invention;
The figure is a circuit diagram showing a conventional example. 2... Accelerator as an accelerator circuit section,
4...Drive control circuit section, 6...Coupler, 6A to 6D...Coupler, 14...Switching means, 1
6...Temperature sensor circuit, 18...Motor protection circuit, 28...Motor, L _E ...Earth line, P
...Ground side terminal, V _CC ...Specified power supply.

Claims (1)

[Claims for Utility Model Registration] An accelerator circuit unit 2 that is connected between a predetermined power supply V _CC and an earth line L _E and outputs an accelerator signal with a value corresponding to the amount of operation; A drive control circuit section 4 equipped with a switching means 14 for controlling the energization circuit of the motor 28 on and off accordingly, and a plurality of couplers 6A to 6 that connect the drive control circuit section 4 and the accelerator circuit section 2.
a temperature sensor circuit 16, which has a coupler 6 equipped with D, and in which the drive control circuit section 4 detects a temperature rise of a circuit element of the switching means 14 and outputs an electric signal having a value corresponding to the temperature rise; When the temperature sensor circuit 16 detects a temperature at a predetermined level, the switching means 14 is activated.
A drive control device for an electric vehicle motor, comprising: a motor protection circuit 18 for turning off the temperature sensor circuit 16; A drive control device for an electric vehicle motor, characterized by: