JPH05107271A - Motor rotational speed display device for electric vehicle - Google Patents

Abstract

PURPOSE:To provide a motor rotational speed display device which enables the checking of ON or OFF state of an energization circuit. CONSTITUTION:A cross coil type analog indicator is provided to generate a driving force for driving a pointer 2 according to the rotational speed of a motor for generating a driving force of an electric vehicle and a hair spring which makes the pointer 2 return to a specified position when a current to a cross coil of the indicator is cut to hold the pointer 2 at the specified position securely in contact with a stopper 103. The stopper 103 is set at a position as given by advancing the pointer 2 by a specified angle alpha from the position (free zero position) to which the pointer is returned with the hair spring when the current to the cross coil is cut and a power source OFF graduation 104 is provided at the position on a dial disc 1. Then, a revolutions 0 graduation is provided at the position as determined by advancing the pointer 2 by a specified angle beta from the position of the stopper 103. When the rotational speed is zero with a motor energization circuit ON, the current is supplied to the cross coil to turn the pointer 2 to the position indicating 0 in the number of revolution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor rotation speed display device for an electric vehicle.

[0002]

2. Description of the Related Art Conventionally, there is a rotational speed display device for displaying the rotational speed of an internal combustion engine provided in a vehicle, and an occupant refers to the display of the rotational speed display device to appropriately rotate the internal combustion engine. It can be driven within several ranges.
The rotation speed display device includes, for example, Japanese Patent Laid-Open No. 2-2
The cross-coil type analog indicating instrument shown in Japanese Patent No. 22840 can be adopted. The indicating instrument will be described with reference to FIGS. 3, 6, and 7.

FIG. 3 shows a main part of an analog indicating instrument, which has a pair of coils 3 and 4 as shown in the figure. These coils 3 and 4 are wound so as to cross each other in a cross shape. A disk 5 made of a permanent magnet is rotatably supported by a rotary shaft 6 in the coils 3 and 4.
The outer peripheral portion is magnetized so that N poles and S poles alternate in the circumferential direction, and a predetermined magnetic force is generated in a direction determined by the magnetization characteristic. Reference numeral 2 is a pointer, which includes a support portion 201 and a boss portion 202, and is fixed to the rotating shaft 6 by the boss portion 202. A hair spring (returning means) that generates a returning force for holding the pointer 2 at a predetermined position is fixed to the rotating shaft 6. In the above structure, when current is supplied to each of the coils 3 and 4, a magnetic force (driving force) is generated in the coils 3 and 4, and this magnetic force acts on the disc 5 to reach a portion balanced with the urging force of the hair spring. 5 rotates together with the rotating shaft 6, and the pointer 2 swings. When the current to the coils 3 and 4 is cut off, the pointer 2 is returned to a predetermined position by the hair spring.

FIG. 6 is a diagram showing the relationship between the waveform of the current supplied to the coils 3 and 4 and the indicated deflection angle of the pointer 2. As shown in the figure, the SIN wave current 301 supplied to the coil 3 and the coil 4 are shown. The indicated deflection angle of the pointer 2 is determined according to the COS wave current 302 supplied to the.

FIG. 7 is a view showing a display portion visually recognized by an occupant. The indicator is composed of a dial 1 including a scale 101 and numerals 102, and a pointer 2. Stopper 103
Is provided in order to ensure that the indication of the pointer 2 when the current to the coils 3 and 4 is cut off is zero. In other words, the hair spring returns the pointer to a predetermined position (hereinafter referred to as the "free zero point") when the current to the coils 3 and 4 is cut off, but it is free from the influence of friction of the bearing of the rotating shaft. Since the zero point varies, the stopper 103 is provided at a position where the pointer 2 is swung by a predetermined angle α from the free zero point, and the pointer 2 is brought into contact with the stopper 103 by the biasing force (returning force) of the hair spring when the coil current is cut off. Thus, the pointer 2 is configured to surely indicate 0.

[0006]

By the way, when the internal combustion engine goes into an idle state after starting, the engine speed display device displays the idle speed, so that it is possible to confirm that the engine is ready to be driven. Even if the motor, which is power, does not have an idling state and the drive circuit is turned on by turning on the energizing circuit to the motor, the motor is stopped when the vehicle is stopped and the rotation speed display device is displayed. The pointer of 0 remains indicating 0, and it cannot be recognized whether the energizing circuit to the motor is on or off. Therefore, in the electric vehicle, it is necessary to add another display device so that the ON / OFF state of the energizing circuit for the motor can be confirmed, which causes problems such as an increase in cost and an increase in the number of assembling steps.

In view of the above problems, it is an object of the present invention to make it possible to easily confirm the turning-on of power to the motor energizing circuit with a rotation speed display device.

[0008]

In order to achieve the above object, the present invention provides pointer driving means for driving a pointer by generating a driving force according to the rotation speed of a motor which is a power source of an electric vehicle. And a return means for applying a return force in a direction opposite to the drive force of the pointer drive means to the pointer, and the pointer indicates the scale of the display board at a position where the drive force and the return force are balanced. Is displayed, and when the pointer driving means does not generate a driving force, the speed display device holds the pointer at a predetermined position by bringing the pointer into contact with the stopper by the restoring force of the restoring means. The pointer driving means generates a driving force for driving the pointer by a predetermined amount from the position of the stopper when the energizing circuit to the motor is closed and the rotation speed of the motor is 0, Is the above It is to adopt a configuration in which the scale of zero velocity quantitative driving position.

[0009]

When the motor energizing circuit is powered on and the rotation speed display device functions, the pointer drive means drives the pointer from the position of the stopper by a predetermined amount, and when the rotation speed is 0, the scale of rotation speed 0 is surely set. To instruct.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotation speed display device according to the present invention will be described below with reference to the drawings as an embodiment adapted to a motor rotation speed display device of an electric vehicle.

FIG. 1 is a diagram showing a display portion of an embodiment of the device of the present invention, and FIG. 2 is a diagram showing the relationship between the coil current and the indicated deflection angle, which corresponds to FIGS. 6 and 7 showing the prior art. The same reference numerals are given to the parts and the description thereof will be omitted. Further, in the present embodiment, the pointer driving mechanism of the pointer driving means is shown in FIG.
The conventional cross-coil type analog indicating instrument shown in Fig. 3 is adopted.

In the present embodiment, as shown in FIG. 1, as in the prior art, a predetermined angle α from the point of free zero of the hair spring.
Although the stopper 103 is arranged at a position where the pointer is advanced, the position of the stopper 103 indicates that the power supply to the motor energization circuit is in the OFF state, and the position of the stopper 103 is further predetermined. It is characterized by displaying that the power supply to the motor energizing circuit is ON and the number of revolutions is 0 at a position where the pointer is advanced by the angle β.

FIG. 4 is a block diagram of a meter driving section for driving the above-mentioned cross-coil type analog indicating instrument, in which a pulse-shaped rotation signal having a frequency corresponding to the rotation speed of the motor is inputted from a terminal 70. This signal is shaped by the waveform shaping circuit 10 and converted into a voltage signal indicating the magnitude of the rotation speed by the frequency-voltage conversion circuit 20. The waveform distribution circuits 30 and 40 determine the SIN wave current component and the COS wave current component in accordance with the magnitude of the voltage signal, and drive both coils 3 and 4 through the output circuits 50 and 60. Here, when the voltage is applied to the power supply terminal 80 and the motor is stopped and the rotation signal is not input to the signal input terminal 70, the pointer 2 has the above-described rotation speed of 0.
Is driven up to the scale.

FIG. 5 shows a schematic structure of a motor energizing circuit and a power supply circuit to the meter drive section. 90 is a battery for supplying power to the vehicle driving motor 94, and 91 is a potentiometer 92. It is a switch that opens and closes an energization path from the battery 90. 93 is a movable contact of the potentiometer 92, which moves in conjunction with the accelerator pedal of the vehicle,
Increase or decrease the amount of electricity to the motor. Also, 95 is the menu of FIG.
A battery that supplies power to the motor drive unit, 96 is a switch that opens and closes an energization path to the terminal 80 of the meter drive unit, and both switches 91 and 96 are for switching the key switch 97 to the motor start position. It will be closed in conjunction with the closing. Here, the key switch 97 has an ON position, an accessory position (ACC), and an OFF position in the same manner as the key switch of the internal combustion engine in addition to the start position (ST) described above. Both switches 91 and 96 are closed when the switch is returned to the ON position after the switch is turned into the negative position.

Therefore, according to this embodiment, with the switch 91 closed and the energizing circuit for the motor 94 is formed,
Further, when the motor 94 is not energized, the pointer is driven to the scale of the rotational speed of 0 as described above.

Therefore, the ON / OFF state of the motor energizing circuit can be confirmed by the rotation speed display device, and it is not necessary to provide another display device, which is structurally advantageous. Further, since the cross-coil type analog indicating instrument which has been conventionally used can be adopted as it is, it does not require a dedicated display device and is versatile.

[0017]

As described above, according to the rotation speed display device of the present invention, the ON state of the power supply to the motor energizing circuit can be surely confirmed, and a simple structure is achieved without using a dedicated display device. Power ON / OFF when the electric vehicle is stopped
The condition can be easily confirmed.

[Brief description of drawings]

FIG. 1 is a plan view showing a display section of an embodiment of a rotation speed display device of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a current supplied to a cross coil and a pointer deflection angle in the above embodiment.

FIG. 3 is a schematic view showing a cross-coil type analog indicating instrument adopted in the above embodiment.

FIG. 4 is a circuit configuration diagram of a meter driving unit of the above embodiment.

FIG. 5 is a schematic configuration diagram of a motor energizing circuit and a power supply circuit to a meter driving unit of the above embodiment.

FIG. 6 is a plan view showing a display unit of a conventional rotation speed display device.

FIG. 7 is a characteristic diagram showing a relationship between a current supplied to a conventional cross coil and a pointer deflection angle.

[Explanation of symbols]

 1 dial 103 stopper 104 power OFF scale 2 pointers 3,4 a pair of crossed coils 5 disk made of permanent magnets 6 rotary shaft 90,95 battery 91,96 switch 92 potentiometer 94 motor 97 key switch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kurahashi 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (2)

[Claims] 1. A pointer driving means for driving a pointer by generating a driving force according to a rotation speed of a motor which is a power source of an electric vehicle, and a restoring force in a direction opposite to the driving force of the pointer driving means. A pointer for indicating the scale of the display panel at a position where the driving force and the restoring force are balanced and the speed is displayed, and the pointer driving means generates the driving force. When not, in the speed display device for holding the pointer at a predetermined position by bringing the pointer into contact with the stopper by the restoring force of the restoring means, the pointer driving means is configured such that the energizing circuit to the motor is closed. In this state, and when the rotation speed of the motor is 0, a driving force for driving the pointer by a predetermined amount is generated from the position of the stopper, and a scale of 0 speed is provided at the position where the pointer is driven by the predetermined amount. Special Speed display device according to. 2. The rotation speed display device according to claim 1, wherein the pointer driving means includes a cross coil type analog indicator.