JP2005262893A - Lifting/lowering device for vehicle monitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lifting/lowering device for a vehicle monitor capable of making a gradual stop at a monitor lifting stop position and a monitor lowering stop position. <P>SOLUTION: This lifting/lowering device for the vehicle monitor includes a driving motor 1 with a rotary shaft, a lifting/lowering mechanism rotated by the driving motor 1 and lifting/lowering the vehicle monitor 2, stop position detecting sensors 22, 23 respectively provided at the lifting stop position and the lowering stop position of the vehicle monitor, and a control circuit 11 controlling the driving motor 1. The rotary shaft is provided with a reflection members with a plurality of reflection surfaces in the rotating direction to generate a detection pulse for detecting a rotational frequency. The reflection member is provided with a photo sensor 10 facing the reflection faces to detect the presence or absence of reflected light. The control circuit 11 is provided with a count circuit counting the detection pulse obtained by the photo sensor 10, and a deceleration control circuit 12 decelerating the rotational frequency of the driving motor 1 at a prescribed position before the stop position based on the count result of the count circuit. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an improvement of a lifting device for a vehicle monitor.

  Recently, a type of vehicle has been developed in which a vehicle monitor is stored in the instrument panel at the front of the vehicle, and the vehicle monitor is raised as necessary to expose it to the front of the instrument panel. It is being done.

  The vehicle monitor elevating device includes a drive motor having a rotating shaft, an elevating mechanism that is rotated by the drive motor to elevate the vehicle monitor, and an upward stop position and a downward stop position of the vehicle monitor, respectively. A stop position detection sensor provided; and a control circuit for controlling the drive motor, wherein the rotary shaft has a plurality of reflecting surfaces in the rotation direction in order to generate detection pulses for detecting the number of rotations. It is known that a reflective member is provided, and the reflective member is provided with a photosensor that detects the presence or absence of reflected light facing the reflective surface.

In addition, the thing of the structure which performs the deceleration control of a drive motor and stops a drive target object is also known (patent document etc. 1).
JP-A-10-302377

  By the way, in this conventional vehicle monitor raising / lowering device, the drive motor is turned off after detecting the raising / lowering stop position or the lowering / stopping position of the monitor. Sometimes, there is a problem that stress is suddenly applied to the case and instrument panel of the vehicle monitor.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an elevating device for a vehicle monitor capable of gently stopping the monitor at the ascending stop position and the descending stop position. It is in.

  The vehicle monitor lifting device according to claim 1 is a drive motor having a rotating shaft, a lifting mechanism that is rotated by the drive motor to lift the vehicle monitor, and an upward stop position and a downward stop of the vehicle monitor. A stop position detection sensor provided at each position and a control circuit for controlling the drive motor, and a plurality of rotation pulses are generated in the rotation direction to generate detection pulses for detecting the number of rotations on the rotation shaft. A reflective member having a reflective surface is provided, and the reflective member is provided with a photosensor that detects the presence or absence of reflected light facing the reflective surface, and the control circuit has a detection pulse obtained by the photosensor. And a deceleration control circuit that decelerates the rotational speed of the drive motor at a predetermined position before the stop position based on the count result of the count circuit. Wherein the bets are provided.

  According to the present invention, since the vehicle monitor is decelerated from the predetermined position before the stop position to the stop position, the raising and lowering speed of the vehicle monitor is decelerated and stopped at the stop position. Further, it is possible to prevent a sudden stress from being applied to the case of the vehicle monitor or the instrument panel when the vehicle is stopped, and a high-class feeling can be realized.

  Furthermore, since the number of detection pulses is counted to identify a predetermined position before the stop position and the deceleration control is started from this predetermined position, the stop by the deceleration can be stably performed. .

  In addition, there is a configuration in which the number of detection pulses is counted using an optical mechanism that detects the idling of a drive motor such as a reflection member or a photosensor that exists in the past, and deceleration control is performed from a predetermined position to a stop position. Since it is adopted, a new mechanical mechanism is not required for the deceleration control, the deceleration control can be performed by software, and the vehicle can be stopped gently without a significant increase in cost.

  Embodiments of a lifting device for a vehicle monitor according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic view showing an example of a lifting device for a vehicle monitor according to the present invention. In FIG. 1, 1 is a drive motor, 2 is a monitor, 3 is a mounting table for the monitor 2, and 4 is its A threaded rod 5 having a lifting screw 4a for moving the mounting table 3 up and down is a guide rod for guiding the mounting table 3 in the vertical direction.

  The mounting table 3, the threaded rod 4, and the guide rod 5 constitute a lifting mechanism of the monitor 2, and the monitor 2 is stored in the lower part of the instrument panel when not in use. The mounting table 3 is formed with a screw 3a that is screwed with the lifting screw 4a. The drive motor 1 has a rotating shaft 6, and an output gear 7 and a reflecting member 8 are fixed to the rotating shaft 6. A driven gear 9 is integrally provided on the threaded rod 4, and the driven gear 9 is engaged with the output gear 7.

  When the drive motor 1 is driven to rotate, the rotation is transmitted to the threaded rod 4 via the output gear 7 and the driven gear 9, and the mounting table 3 is moved up and down as indicated by the arrow by the rotation of the threaded rod 4. The

  Reflecting surfaces 8 a and non-reflecting surfaces 8 b are alternately formed on the outer peripheral surface of the reflecting member 8 at equal angles, and the photosensor 10 shown in FIG. 2 faces the outer peripheral surface of the reflecting member 8. This photosensor 10 is composed of a light emitting element 10a and a light receiving element 10b, and based on the change in the amount of reflected light based on the fact that the reflecting surface 8a and the non-reflecting surface 8b of the reflecting member 8 cross the photosensor 10 alternately. 10b outputs the detection pulse P shown in FIG. In FIG. 2, Vcc is a power supply voltage.

  The drive motor 1 is controlled by a control circuit 11 shown in FIG. 3, and this control circuit 11 is a main CPU 12, voltage dividing circuits 13, 14, 15, a constant voltage circuit 16, a motor drive circuit 17, and a switch input circuit 18. , 19, an oscillation circuit 20, and a reset circuit 21.

  The switch input circuit 18 receives detection signals from an ascending stop position detection switch 22 that defines the ascending stop position of the monitor 2 and a descending stop position detection switch 23 that defines a descending stop position. The switch input circuit 19 receives a lift signal from the lift switch circuit 24 of the monitor 2. The lift switch circuit 24 is turned on / off by turning on / off a lift button (not shown).

  The main CPU 12 includes an A / D conversion circuit terminal 12a, a first A / D conversion input terminal 12b, a power supply terminal 12c, a voltage reference terminal Vref, a second A / D conversion input terminal 12d, a PWM signal output terminal 12e, and a rotation direction. It has a control signal output terminal 12f, a detection pulse input terminal 12g, a first switch input terminal 12h, a second switch input terminal 12i, a lift switch signal input terminal 12j, and a reset signal input terminal 12k.

  An ACC voltage is applied to the voltage dividing circuit 13, an ignition voltage IGN is applied to the voltage dividing circuit 14, and a battery voltage BAT is applied to the voltage dividing circuit 15, the constant voltage circuit 16, and the motor drive circuit 17. The voltage dividing circuit 13 is connected to the A / D conversion circuit input terminal 12a, the voltage dividing circuit 14 is connected to the first A / D conversion input terminal 12b, and the constant voltage circuit 16 includes a power supply terminal 12c and a voltage reference terminal Vref. The voltage dividing circuit 15 is connected to the second A / D conversion input terminal 12d, and the motor driving circuit 17 is connected to the PWM signal output terminal 12e and the rotation direction control signal output terminal 12f. The emitter of the light receiving element 10b is connected to the detection pulse input terminal 12g.

  Here, the main CPU 12 also has a function as a deceleration control circuit, and includes a calculation unit 25, a voltage correction parameter table 26, a slow control parameter table 27, a count circuit 28, and an A / D conversion circuit 35. The calculation unit 25 includes a voltage correction circuit 29, a duty ratio determination circuit 30, an output determination circuit 31, a slow control circuit 32, a slow determination circuit 33, and an operation end determination circuit 34.

  The A / D conversion circuit 35 converts the analog power supply voltage into a digital signal and outputs the digital signal to the voltage correction circuit 29. The voltage correction circuit 29 detects voltage fluctuation, performs voltage correction with reference to the voltage correction parameter table 26, and outputs the correction voltage to the duty ratio determination circuit 30.

  The light receiving element 10 b of the photosensor 10 outputs a detection pulse P toward the count circuit 28, and the count circuit 28 outputs a count result toward the slow determination circuit 33 and the operation end determination circuit 34. The slow determination circuit 33 determines whether or not the number of the detection pulses P has reached a predetermined number. Since there is a certain proportional relationship between the number of detection pulses and the rising / lowering stroke of the monitor 2, whether or not the monitor 2 has reached a predetermined position before the ascending stop position and a predetermined position before the descending stop position. This can be determined by counting the number of detection pulses P.

  When the number of the detection pulses P reaches a predetermined value, the slow control circuit 32 refers to the slow control parameter table 27 and outputs the slow control information to the duty ratio determination circuit 30.

  The duty ratio determination circuit 30 determines the duty ratio based on the slow control information and the correction voltage, and outputs the duty ratio toward the output determination circuit 31. The output determination circuit 31 outputs the PWM signal PM to the motor drive circuit 17, and the motor drive circuit 17 detects whether the monitor 2 is moving up from the predetermined position to the lift stop position based on the rotation direction control signal. During this time, the rotational speed of the drive motor 1 is controlled to be decelerated based on the PWM signal PM, and when the monitor 2 is descending, the rotational speed of the drive motor 1 is decelerated from the predetermined position to the descending stop position based on the PWM signal PM Control.

  Then, when the ascending stop position detecting switch 22 or the descending stop position detecting switch 23 is turned on, the arithmetic unit 25 outputs an ascending stop position signal or a descending stop position signal to the output determining circuit 31 by the operation end determining circuit 34. Thereby, the drive of the drive motor 1 is stopped.

  FIG. 5 is a timing chart for explaining the drive timing of the drive motor 1. The drive motor 1 is rotated by a PWM signal having a constant duty ratio from the start (down) of the monitor 2 until reaching a predetermined position. During this time, a detection pulse P with a constant pulse width is output, and when it reaches a predetermined position (deceleration start position), the duty ratio is decreased and the rotational speed of the drive motor 1 is decelerated. The pulse width of the pulse P is increased.

  It should be noted that it is desirable that the deceleration speed when the monitor 2 is raised and the deceleration speed when the monitor 2 is lowered can be changed. This is because the lowering should be gentler considering the weight of the monitor 2.

It is a schematic diagram which shows an example of the raising / lowering apparatus of the monitor for vehicles concerning this invention. It is a schematic diagram which shows the relationship between the reflective member shown in FIG. 1, and a photosensor. It is a control circuit diagram of the raising / lowering apparatus of the monitor for vehicles concerning this invention. FIG. 4 is a control circuit diagram of the main CPU shown in FIG. 3. It is a timing chart for demonstrating the drive timing of the drive motor concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Drive circuit 2 ... Vehicle monitor 10 ... Photo sensor 11 ... Control circuit 12 ... Main CPU (Deceleration control circuit)

Claims (1)

  A drive motor having a rotating shaft; a lift mechanism that is rotated by the drive motor to raise and lower the vehicle monitor; a stop position detection sensor provided at each of the ascending stop position and the descending stop position of the vehicle monitor; A control circuit for controlling the drive motor, and the rotating shaft is provided with a reflecting member having a plurality of reflecting surfaces in the rotating direction in order to generate a detection pulse for detecting the number of rotations. Is provided with a photosensor for detecting the presence or absence of reflected light facing the reflection surface, the control circuit counting a detection pulse obtained by the photosensor, and the count result of the count circuit And a deceleration control circuit for decelerating the rotational speed of the drive motor at a predetermined position before the stop position. Nita of the lifting device.

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