JPS6383571A - Position sensing method of motor type damper - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention uses a motor as a driving source to open and close a baffle.
For example, the present invention relates to a damper for opening and closing a cold air intake of a refrigerator, and particularly relates to a method of detecting the opening/closing position of a baffle based on changes in motor current.

The applicant of the prior art patent has already proposed the basic structure of this motor-type damper device as U.S. Pat. No. 60-088082. In that technology, the open and close positions of the puffful are detected by a combination of a cam driven by a motor and a reed switch.

First, the configuration of this conventional device will be explained in detail with reference to the drawings, and its technical problems will be clarified.

As shown in FIGS. 4 to 6, the motorized damper 1 is assembled by a baffle 3 built into a frame 2 and a drive unit 5 including a motor 4 for driving the baffle 3. . The above Puffful 3 is
It is for opening and closing the opening 2a of the frame 2,
It is rotatably supported by a lower fulcrum shaft 6 on one side of the frame 2 with respect to a bearing 7 . This baffle 3 is always biased in the direction of closing the opening 2a by a radius spring 8 attached to the frame 2, and its maximum opening angle is determined by a stopper 9 attached to the frame 2.
regulated by.

On the other hand, the motor 4 includes a main plate 10 and a gear case 11.
At the same time, it is integrally attached to the other surface of the frame 2. The output side pinion 12 of the motor 4 protrudes from the main plate 10 and is connected to the composite gear 1 inside the gear case 11.
It meshes with the big teeth of number 3. This composite gear 13 meshes with large teeth of a composite gear 14 with small teeth, and this composite gear 14 meshes with a gear 15 with small teeth, and finally transmits rotation to a gear 16. The compound gears 13, 14 and the gears 15 constitute a reduction gear train, and these and other gears 16 are connected to the gear case 11 by pins 17, 18, 19 fixed to the gear case 11, or by shafts 20 integral with the gears 16. It is rotatably supported between the base plate 10 and the base plate 10.

The gears 15, 16 mesh with each other at a gear ratio of 1:1, and the plate cams 21, 16, 15, 16, 16, 15, 16, and 15 mesh with each other at a gear ratio of 1:1, respectively. The end cam 22 is integrally formed. One of the plate cams 21 has a high part and a low part formed at a central angle of 180 degrees, and their outer peripheral parts are in contact with one end of the switch lever 23. The switch lever 23 has a substantially L-shape as a whole, is rotatably supported by a support shaft 24 inside the gear case 11, and is always supported by a spring 25 to keep the plate cam 21
The magnet 26 is biased in a direction in contact with the circumferential surface of the magnet 26, and holds the magnet 26 at its tip. And this magnet 26
corresponds to the reed switch 27 fixed inside the gear case 11.

Note that this reed switch 27 is fixed to a printed circuit board 28 by soldering, and is connected to a connector 30 by a lead wire 29 together with a lead wire 33 of the motor 4.

Further, the end face cam 22 forms an upwardly inclined end face at a rotation angle of 180 degrees, and forms a downwardly inclined end face at the remaining center angle of 180 degrees. It touches one end. This spindle 31 is for opening and closing the baffle 3, and is supported slidably in the axial direction by a guide cylinder 32 formed by a part of the gear case 11, and is a part that protrudes to the outside. It is in a state where it can touch the recessed part of Puffful 3.

Assume now that the baffle 3 is in a state where the opening 2a is closed as shown in FIG. When a start command is given to the motor 4 in this state, the rotational force of the motor 4 is
In the initial state of 0 rotation, which is transmitted while being decelerated to the compound gears 13.14 and 15.16, the switch lever 23 is in contact with the upper part of the temporary cam 21, and the reed switch 27 is set to the on state. ing. However, temporary cam 2
1 rotates 180 degrees and the switch lever 23 falls into the lower part of the temporary cam 21, so the reed switch 27 is turned off and the motor 4 immediately stops and becomes locked. During this time, the end cam 22 similarly contacts the 180-degree rotating spindle 31 from the lower part to the higher part, and pushes the spindle 31 leftward in FIG. 5, thereby causing the baffle 3 to resist the spring 8. Leave it open. In this way, the baffle 3 is set to the open state, but when the motor 4 receives a start command again after this, the baffle 3 is set to the open state.
is set to the closed state.

In this way, in the conventional one, the locked state of the motor 4,
In other words, in order to confirm the open/closed state of the baffle 3, the temporary cam 21, switch lever 23, spring 25, magnet 26, reed switch 27, and its printed circuit board 28 are essential, and the number of parts increases and the assembly is difficult. The work will also be complicated. This is the technical problem of the conventional example.

OBJECT OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned technical problem, that is, to reduce the number of parts and make it possible to detect the open/closed position of the buff full 3 with a simple structure.

SUMMARY OF THE INVENTION Therefore, the present invention makes it possible to detect the position of the baffle 3 by focusing on the change in motor current due to an increase in the load on the motor 4 when the baffle 3 is in an open or closed state.

Structure of the Invention FIGS. 1 and 2 show the drive unit 5 of the invention.
As is clear from the figure, in this drive section 5, the temporary cam 21
, switch lever 23, spring 26, magnet 2
6. Since the reed switch 27 and the printed circuit board 28 are omitted, and the gear 15 is also eliminated, the composite gear 14 directly meshes with the gear 16 with small teeth. Corresponding to this, the gear case 11 has also become smaller.

In the present invention, the stopper 3 is fixed to the base plate 10.
4 is fixed, and two stopper pins 35 and 36 are integrally provided in the diametrical direction at a position where the boss of the gear 16 contacts the fixed stopper 34.

On the other hand, the motor 4 is constituted by a DC motor or a stepping motor, and is connected to a control circuit 37 as shown in FIG. A current detector 38 is provided in the power supply path. This current detector 38 is connected to one input of a comparator 39, which is connected at its other input to a reference current value setter 40, and whose output is connected to the reference current value setter 40. It is also connected to a control circuit 37.

- The action control circuit 37 of the invention rotates the motor 4 in a predetermined direction upon receiving the activation command. This direction can be set on the control circuit 37 side in the case of a DC motor or a stepping motor. During this time, the spindle 3
1 moves from the lower part to the higher part of the end face cam 22 to open the baffle 3. On the other hand, the end cam 22 is 18
Since the rotation is 0 degrees, the other stopper pin 36 instead of one stopper pin 35 hits the fixed stopper 34 and stops there. As a result, the motor 4 becomes locked and its load increases rapidly, causing a sudden large change in motor current. This condition is detected by current detector 38 and applied to one input of comparator 39. Therefore, the comparator 39 compares the reference current value set by the setting device 40 at the other input end with the current at the time of motor lock, and generates an output when the magnitude relationship changes, and outputs an output to the control circuit 37. Send it in. At this time, the locked state of the motor can be confirmed, and since the rotational direction of the motor 4, that is, the direction of opening or closing of the baffle 3, is set in advance, the open or closed state of the baffle 3 can be determined from these two conditions. This can be confirmed objectively. Note that the change in motor current varies depending on the type of motor, so it cannot be said exactly, but for example, in a brushless style DC motor, the current will be 2 to 2.5 times the normal current, and in a brushed DC motor, the current will be 2 to 2.5 times the normal current. The current changes to about 5 times the normal wind current.

Thereafter, when operating the baffle 3 in the closing direction, the motor 4 rotates in the opposite direction. Then, due to this rotation in the opposite direction, the stopper pin 35 is fixed to the fixed stopper 3.
4 is confirmed, thereby confirming that the baffle 3 is closed.

In this embodiment, since the motor 4 changes its rotational direction according to the opening and closing of the baffle 3, the end cam 22
Of course, if the end cam 22 is of a type that rotates 360 degrees as the baffle 3 opens and closes, the end cam 22 will be at the same inclination from a certain point. It is formed as a continuous slope with the same inclination over the entire circumference of 360 degrees, and in this case, either one of the stopper pins 35 and 36 becomes unnecessary.

Modification of the Invention In the above embodiment, the fixed stopper 34 is provided at the end cam 22.
Although the load on the motor 4 is changed by the contact relationship of the stopper pins 35 and 36 with respect to the stopper pins 35 and 36, such a contact portion may be related to the opening/closing operation of the puffful 3 itself. That is, when the baffle 3 closes and is pressed against the opening 2a, or when the baffle 3 opens and contacts the stopper 9, the motor load increases rapidly, so the current of the motor 4 also increases at this time. . Therefore, the position of at least one of the baffles 3 can be detected based on the current change at this time.

Further, in the above embodiment, since a DC motor or a stepping motor is used as the motor 4, the direction of rotation thereof can be set in advance in the control circuit 37. However, in the case of an AC motor, the direction of rotation can be set in advance. It turns out you can't do it. However, when the baffle 3 opens and closes,
Since the load on the motor 4 changes depending on the elasticity of the spring 8 and whether the spindle 31 ascends or descends the slope of the end cam 22, the magnitude of the current value due to the change in load changes. You can check the rotation direction of the AC motor.

Further, in the above embodiment, the control circuit 37, the comparator 39, etc. are configured as dedicated circuits, but they can be configured as part of a microcomputer for motor control, and the problem can also be solved in the field of programming.

Effects of the Invention In the present invention, the motor is locked when the baffle is opened or closed, and the open or closed position of the baffle can be electrically detected from the change in motor current when the baffle is locked. can be omitted, the drive unit is simplified, and its assembly and adjustment are also simpler than conventional ones.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of the drive unit according to the present invention, Fig. 2 is a plan view with the main plate removed, Fig. 3 is a block diagram of the control section, and Fig. 4 is a front view of the motor-type damper. figure,
FIG. 5 is a partially cutaway side view, and FIG. 6 is a plan view of the drive unit with the base plate removed. l...morph type damper device, 3...baffle, 4...
Motor, 5... Drive unit, 22... End cam, 34... Fixed stopper, 35. 36... Stopper pin, 37... Control circuit, 38... Current detector, 39... Comparator, 40...
・Setting device. Figure 1 Figure 2 Figure 3 Figure 4 JJ σ

Claims (1)

[Claims] In a motor-type damper equipped with a motor and a baffle driven by the motor, the motor is configured to be locked when the baffle is in at least one of the open and closed positions, and the current change when the motor is locked is A method for detecting the position of a motor-type damper, characterized in that the position of the baffle is detected by detecting the position of the baffle.