JPH049985B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a damper that uses a motor as a driving source to open and close a butthole, for example, to open and close a cold air intake of a refrigerator. Relating to a method of detecting by change.

Prior Art The applicant of the patent has already proposed the basic structure of this motor type damper device in Utility Application No. 60-088082. In this technique, the opening and closing positions of the baffle 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 motor-type damper 1 is assembled by a driver 5 including a buttful 3 built into a frame 2 and a motor 4 for driving the buttful 3. ing. The baffle 3 is for opening and closing the opening 2a of the frame 2, and 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 urged in the direction of closing the opening 2a by a spring 8 attached to the frame 2, and its maximum opening angle is regulated by a stopper 9 attached to the frame 2. ing.

On the other hand, the motor 4 is integrally attached to the other surface of the frame 2 together with the base plate 10 and the gear case 11. A pinion 12 on the output side of the motor 4 protrudes from the base plate 10 and meshes with large teeth of a composite gear 13 inside the gear case 11. 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. Composite gear 13,
14 and the gear 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 a shaft 20 integral with the gear 16.
It is rotatably supported between the base plate 10 and the base plate 10.

The gears 15 and 16 mesh with each other at a gear ratio of 1:1, and integrally form a plate cam 21 and an end cam 22, respectively. One plate cam 21 forms a high part and a low part with a center angle of 180 degrees, and the switch lever 2 is formed at the outer peripheral part of these parts.
It touches one end of 3. 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 held against the circumferential surface of the plate cam 21 by a spring 25. It is biased in the direction of contact and holds the magnet 26 at its tip. This magnet 26 corresponds to a reed switch 27 fixed inside the gear case 11. Note that this reed switch 27 is connected to the printed circuit board 2.
It is fixed to motor 4 by soldering.
It is connected to the connector 30 by a lead wire 29 together with a lead wire 33 .

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, and the spindle 31 is formed at these end faces. It touches one end. This spindle 31 is for opening and closing the buttful 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 come into contact with the recessed part of Batsuful 3.

Now, suppose that Batsuful 3 is located at opening 2 as shown in Figure 5.
Assume that a is in a closed state. When a start command is given to the motor 4 in this state, the rotational force of the motor 4 is transmitted to the pinion 12, the composite gears 13, 14, and the gears 15, 16 while being decelerated. In the initial state of rotation, the switch lever 23 is in contact with the upper part of the plate cam 21, and the reed switch 27 is set in the on state. However, plate cam 21
When the reed switch 2 rotates 180 degrees, the switch lever 23 falls into the lower part of the plate cam 21.
7 is turned off, the motor 4 immediately stops,
It becomes locked. During this time, the end cam 22 similarly rotates 180 degrees, contacts the spindle 31 from the lower part to the higher part, pushes the spindle 31 to the left in FIG. 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 buffle 3 is set to the closed state.

As described above, in the conventional device, in order to confirm the locked state of the motor 4, that is, the open/closed state of the buffer 3, the plate cam 21, the switch lever 23, the spring 25, the magnet 26, the reed switch 27, and its printed circuit board 28 are used. etc. become essential, the number of parts increases, and the assembly process becomes complicated. This is the technical problem of the conventional example.

OBJECT OF THE INVENTION Therefore, 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 buttful 3 with a simple structure.

SUMMARY OF THE INVENTION Accordingly, the present invention focuses 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, so that the position of the buffle 3 can be detected.

Structure of the Invention FIGS. 1 and 2 show a driving section 5 of the present invention. As is clear from the figure, in this drive unit 5, the plate cam 21, switch lever 23, spring 26, magnet 26, reed switch 27 and printed circuit board 28 are omitted, and accordingly, the gear 15 is eliminated. Composite gear 14
is directly meshed with the gear 16 through small teeth.
Corresponding to this, the gear case 11 has also become smaller. In the present invention, a fixed stopper 34 is fixed to the base plate 10, and two stopper pins 35 and 36 are integrally connected in the diametrical direction at a position where the fixed stopper 34 touches the boss of the gear 16. It is provided.

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.

Effect of the Invention The control circuit 37 rotates the motor 4 in a predetermined direction upon receiving the start command. This direction is
For DC motors or stepping motors, this can be set on the control circuit 37 side. During this time, similarly to the conventional example, the spindle 31 is moved by the end cam 22.
move from the lower part to the higher part, and open Batsuful 3. On the other hand, since the end cam 22 rotates 180 degrees, it replaces one stopper pin 35.
The other stopper pin 36 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, comparator 39
compares the reference current value set by the setting device 40 at the other input terminal with the current at the time of motor lock, generates an output when the magnitude relationship changes, and sends it to the control circuit 37. 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 buffle 3 can be determined based on these two conditions. This can be confirmed objectively. Note that the change in motor current varies depending on the type of motor, so it is hard to say exactly, but for example, in a brushless style DC motor, it will be 2 to 2.5 times the normal current, and in a brushed DC motor, it will be 2 to 2.5 times the normal current. of the current of about 5
Changes to about twice as much.

Thereafter, when operating the baffle 3 in the closing direction, the motor 4 rotates in the opposite direction. Then, it is confirmed that the rotation in the opposite direction and that the stopper pin 35 has hit the fixed stopper 34, thereby confirming that the baffle 3 is in the closed state.

Note that in this embodiment, the motor 4 is
Since the direction of rotation changes as the end cam 22 is opened and closed, a half circumferential portion of the end cam 22 is not substantially in operation. Of course, this end cam 22 is
If the type is such that it rotates 360 degrees as the Batsuful 3 is opened and closed, the end cam 22 will be formed as a slope with the same inclination starting from a certain point and continuing over the entire 360 degree circumference, and in that case, Either one of the stopper pins 35, 36 becomes unnecessary.

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

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,
This means that the direction of rotation cannot be set in advance. However, when the Batsuful 3 opens and closes, the spring 8
Since the load on the motor 4 changes depending on the elasticity of the spindle 31 and whether the spindle 31 moves up or down the slope of the end cam 22, the AC motor The direction of rotation can be confirmed.

Further, in the above embodiment, the control circuit 37, the comparator 39, etc. are configured as dedicated circuits, but these 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, when the baffle is opened or closed, the motor is locked, 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 drawings]

FIG. 1 is a partially cutaway side view of the drive unit according to the present invention, and FIG. 2 is a plan view with the main plate removed.
Figure 3 is a block diagram of the control section, Figure 4 is a front view of the motor damper, Figure 5 is a partially cutaway side view, and Figure 6 is a plan view of the drive unit with the main plate removed. be. DESCRIPTION OF SYMBOLS 1... Motor type damper device, 3... Buzzful, 4... Motor, 5... Drive unit, 22... End face cam, 34... Fixed stopper, 35, 36... Stopper pin, 37... Control circuit, 38 ... Current detector, 39 ... Comparator, 40 ... Setting device.

Claims (1)

[Claims] 1. A motor damper equipped with a motor and a baffle driven by the motor, the motor being configured to lock when the buffle is in at least one of open and closed positions,
A method for detecting the position of a motor-type damper, characterized in that the position of the buffle is detected by detecting a change in current when the motor is locked.