JPH056437B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive control device for a DC motor.

Conventional control devices control the supply of current to a DC motor to rotate or slide a load that has resistance in the direction of rotation of the DC motor. The motor was driven to rotate in a predetermined rotation direction at a predetermined rotation angle.

However, in order to rotate the DC motor against the above load, there is a time delay for the DC motor to start rotating against the inertia and static friction of the drive system including the DC motor, and , due to the above-mentioned inertia when stopping after rotation, and due to overactuation occurring because the kinetic friction coefficient is smaller than the above-mentioned static friction coefficient, the minimum rotation angle of the DC motor for a given load is determined by itself, and therefore the above-mentioned The minimum operating amount of the load and the corresponding minimum energization time of the motor were determined.

For this reason, it is difficult to perform minute control of the load, and the responsiveness deteriorates.

The present invention solves the above-mentioned problems, and is directed to a DC motor 1 which drives a driven member 2 and which exerts a resistance force in the rotational direction when driving the driven member.
8, and a control means 1 for setting the position of the driven member by controlling energization to the DC motor.
4, the control means controls the current for driving the DC motor in the first rotational direction for a first energization time.
After driving the driven member in a first driving direction by applying current across Ta, the control device applies a current to drive the DC motor in a second rotational direction opposite to the first rotational direction. Second energization time
By applying current across Tb, the driven member is driven in a second driving direction opposite to the first driving direction, which is necessary to drive the motor by the minimum rotation angle based on the resistance force, etc. The equivalent current-carrying time To is shorter than the current-carrying time (however, To=Ta−
KTb, K is a coefficient based on the difference in the resistance force in the first rotation direction and the second rotation direction), so that the position of the driven member is changed in accordance with The gist of this paper is a drive control device for a DC motor.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

Reference numeral 2 designates a throttle valve as a driven member disposed in the intake passage 6 of the carburetor 4, whose rotation is controlled by an accelerator pedal (not shown) and which comes into contact with a lever 8 fixed to the throttle valve 2. An idle control device 12 having a plunger 10 controls the fully closed position at idle. 14 is an operating circuit of the idle control device 12.

The idle control device 12 includes a case 16 fixedly disposed on the carburetor 4, a DC motor 18 disposed in the case 16, a worm gear 20 formed on the rotating shaft of the DC motor 18, and a worm gear 20. A sliding shaft 24 having an engaging worm wheel 22, and a threaded portion 26 formed on the sliding shaft 24.
and the plunger 10 described above.

28 is a switch device for detecting the position of the end 30 of the sliding shaft 24, which includes a first fixed contact 32, a second fixed contact 34, and a movable contact 36 that is always elastically biased in the direction of the end 30. The sliding shaft 24 is configured such that the movable contact 36 and the first fixed contact 32 are in contact with each other at the left end position in the figure, and the movable contact 36 and the second fixed contact 34 are in contact with each other at the right end position in the figure. ing.

The operating circuit 14 as a control means includes an engine rotational speed detection device 40 (not shown), and an idle-up circuit that issues an instruction to open the throttle valve 2 to a predetermined opening depending on loads such as an electrical load and a cooler compressor load (not shown). switch 42, an idle detection switch 46 disposed at the tip 44 of the plunger 10 that detects the contact of the lever 8 and indicates that the throttle valve 2 is in the idle position, and detects the position of the sliding shaft 24. A signal from the switch device 28 controls the energization of the DC motor 18 to rotate the DC motor 18 in the forward direction or in the reverse direction. 48 is a power source.

The operation of the above embodiment will be explained below.

The illustrated state shows a normal idle operating state, and the throttle valve 2 is held by a switch 46 at the tip of the plunger 10.

When an electrical load due to the lighting of a headlight or a cooler compressor load due to cooler operation is applied, an idle up instruction signal is input from the idle up switch 42 to the operating circuit 14.
The idle up rotational speed during idling operation of the engine is set according to the electrical load, cooler compressor load, etc., and in order to obtain the idle up rotational speed, the throttle valve 2 is opened to a predetermined opening αo. The operation of circuit 14 will now be described.

First, based on the instruction signal of the idle up switch 42, the opening degree αo of the throttle valve 2 necessary to obtain a predetermined idle rotation speed is set, and the DC motor 18 is activated to obtain the opening degree αo.
The time period To is energized is determined.

When the time To is longer than the minimum energization time Tmin, the current is applied as is along the time To, but when it is smaller than the minimum energization time Tmin, the time Tmin
A sufficiently longer first time Ta is set, and the first time Ta
The DC motor 18 is rotated in the first rotational direction by supplying current along the time Ta. At this time, the throttle valve 2 has an angular velocity in the opening direction.
It is opened at Wa, and the opening angle αa becomes αa=Ta・Wa.

Next, after the first time Ta has elapsed, a current in the opposite direction is supplied during a second time Tb, which is shorter than the first time Ta, so that the DC motor 18 is rotated in the opposite direction to the first rotation direction. Rotation drive is performed in the rotation direction of 2. At this time, the throttle valve 2 moves at an angular velocity in the closing direction.
The closing angle αb at which the valve is closed at Wb and the opening angle αa is αb is αb = Tb·Wb. At this time, Wb is larger than Wa due to the influence of a closing spring (not shown) of the throttle valve 2, and has the relationship Wb=KWa, where K≧1.

Therefore, the opening angle αo of the throttle valve 2 is αo＝αa−αb =TaWa−TbWb = (Ta−KTb)Wa becomes.

FIG. 3 shows the change over time of the current supplied to the DC motor 18, with the 1st side showing the current that opens the throttle valve 2, and the 1st side showing the current that opens the throttle valve 2. Time t(1) indicates the start of the flow of current on the tenth side, _t2 indicates the stop of the current on the tenth side and the start of the flow of the current on the one side, and _t3 indicates the interruption of the current.
Here, Tb' indicates Tb'=K・Tb, that is, To=Ta−KTb.

Furthermore, a signal from a rotational speed detection device 40 is input to the operating circuit 14, and when the idle rotational speed of the engine does not reach the target value or exceeds the target value due to the opening operation of the throttle valve 2. When this happens, it is controlled to match the target value by the same operation as described above.

In the operating circuit 14, the switch device 28
The first fixed contact 32 indicates the left end position of the sliding shaft 24, and holds the sliding shaft 24 at the left end position when a failure of the rotational speed detection device 40 or the like occurs. In addition, the second fixed contact 34 indicates the rightward limit position of the sliding shaft 24 to prevent excessive operation.

As is clear from the above operation, the throttle valve 2
Even if the opening angle αo of the throttle valve 2 is smaller than the minimum rotation angle of the throttle valve 2, first, the current that drives the DC motor 18 in the forward rotation direction is applied for the first energization time Ta, and then the current that drives the DC motor 18 in the forward rotation direction is applied, and then the current By applying the current that drives the rotational direction along the second energization time Tb, the energization time To in the opening operation direction is set as To=Ta−KTb, where K≧1, and the angle is less than or equal to the minimum rotation angle. It is possible to obtain the opening angle of the throttle valve 2 by setting a corresponding time.

Furthermore, according to this embodiment, the throttle valve 2 has good responsiveness and minute angle control can be achieved without using a DC motor with excessive torque, resulting in the overall effect of being smaller and lighter.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the present invention;
FIG. 2 is a sectional view taken along the - arrow in FIG. 1, and FIG. 3 is an operational characteristic diagram of an embodiment of the present invention. 2: Throttle valve, 4: Carburetor, 8: Lever,
12: Idle control device, 14: Operating circuit.

Claims (1)

[Claims] 1. A DC motor 18 that drives the driven member 2 and applies a resistance force in the rotational direction when driving the driven member, and sets the position of the driven member by controlling energization to the DC motor. and a control means 14 for controlling the current for driving the DC motor in a first rotational direction.
After driving the driven member in the first driving direction by applying current for a current application time Ta,
The control device controls a second current to drive the DC motor in a second rotational direction opposite to the first rotational direction.
The driven member is driven in a second driving direction opposite to the first driving direction by energizing for the energizing time Tb, thereby driving the motor by the minimum rotation angle based on the resistance force, etc. The equivalent energizing time To is shorter than the energizing time required for
=Ta-KTb, K is a coefficient based on the difference in the resistance force in the first rotation direction and the second rotation direction). Features: DC motor drive control device.