JP2003003745A - Door opener - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a door opener, by which a door open-close unit is miniaturized and lightened and a door can be opened efficiently by only one of the operation of a touch switch and which is silent. SOLUTION: In the door opener 1 opening the rotary type door in which one end section is supported rotatably by a hinge, the door opener 1 has a motor 2 housed in a bottomed cylindrical housing 3, a screw shaft 4, to which the rotation of the motor 2 is transmitted, a nut 5 screwed to the screw shaft 4 and internally inserted into the housing 3, the first spring 6 housed between the nut 5 and the shoulder section 3a of the housing 3 and the second spring 7 housed between the bottom section 3b of the housing 3 and the motor 2, and the rotation of the motor 2 is converted into the linear motion of the nut 5. The nut 5 is formed to the housing 3 retractively and irrotationally and the screw shaft 4 is formed integrally with an output shaft for the motor 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric door opener for automatically opening a door of a kitchen sink, a refrigerator or the like by operating a touch switch.

[0002]

2. Description of the Related Art Generally, doors of kitchen sinks and storages, for example, refrigerator doors of refrigerators, are of a rotary type, one end of which is rotatably supported by a hinge on the front surface of the refrigerator body, especially in general households. This type is used. A gasket provided with a magnet that is attracted to the front surface of the refrigerator body is provided at the peripheral edge of the inner surface of the door in order to improve the sealing performance in the closed state. For this reason, a certain amount of operating force is required to open the door manually, which is a burden to children who are particularly weak and physically handicapped.

In order to reduce such a burden, a rack having a gear mechanism, a pinion and an extruding rod as an integral unit is used as a drive source of a motor, and the rotation of the motor is transmitted from the worm gear to the pinion and the rack via the gear mechanism. The door opening unit is designed to open the door by converting it to the linear motion of the push rod. In addition, an electric door opener is known, such as a door opening unit that uses a solenoid as a driving source and projects a push rod integrated with the solenoid to open the door. (Japanese Patent Laid-Open No. 2001-55863).

In the electric door opener using the above-mentioned motor as a drive source, a cam is integrally formed on the pinion, and the motor is repeatedly turned on and off by an origin switch which is turned on and off by the rotation of a lever rolling on the cam. . When the touch switch installed on the front surface of the door is turned on, the motor is energized, and the rotation of the worm gear provided on the motor shaft transmits the rotation to the pinion via the gear mechanism. A push-out rod is integrally formed with the rack meshed with the pinion, and the push-out rod is projected at a predetermined stroke to open the door. A return spring biased in a direction opposite to the protruding direction is locked to the push-out rod, and after the push-out rod is projected to the most distal end position, the tooth portion of the rack is disengaged from the pinion,
You can instantly return to the original retracted position.

Further, in the electric door opener using the solenoid as a driving source, the coil of the solenoid is wound around the outer circumference of the cylindrical bobbin, and the plunger made of magnetic material is axially movable in the inner circumference of the bobbin. Has been inserted into. A push rod made of a non-magnetic material is fixed to one end of this plunger. When the touch switch installed on the front of the door is turned on, the solenoid is energized and the plunger is sucked and moved against the return spring locked by the plunger. To be done. When the solenoid is cut off, the pushing force of the return spring allows the push rod to instantly return to its original retracted position.

[0006]

In the electric door opener described above, the motor type having the gear mechanism, the pinion, and the rack has a large number of parts and has a complicated structure, so that the operating speed of the pushing rod is increased. It was difficult to make it faster and there was a problem that it took time to open the door. Further, the solenoid type has a high operation speed, but has a limitation in the projection stroke and the projection output. In addition, the refrigerator has
An automatic closing mechanism as a half-door prevention mechanism is usually provided between the door and the refrigerator body, and when the door is opened by the push rod, the automatic closing mechanism causes the protrusion to a stroke exceeding the closing distance of the door. There is a need. Further, in a situation where the refrigerator tends to become larger and larger, it is necessary to increase the current capacity in order to increase the protruding stroke and the protruding output of the door opening unit, which makes it difficult to reduce the size. As we enter an aging society in the future,
There is a demand for a door opener that does not require a force to open the door and can be easily opened by simply pressing the touch switch even when both hands are closed and the door knob cannot be gripped.

The present invention has been made in view of the above circumstances. Even in the case of a large door such as a refrigerator, the door opening / closing unit can be downsized, and the door can be efficiently operated by one touch switch operation. The purpose is to provide a door opener that can be opened.

[0008]

[Means for Solving the Problems] In order to achieve the purpose,
According to a first aspect of the present invention, in a door opener for opening a rotary door whose one end is rotatably supported by a hinge, a cylindrical housing having a bottom and an inner surface inserted in the housing. A motor, a nut that is inserted into the housing, is non-rotatable, and is capable of advancing and retracting; a screw shaft that is screwed onto the nut and that is rotated by the driving force of the motor; A first spring that is biased by force, and a second spring that is biased between the motor and the bottom of the housing and housed therein, and these are arranged axially in series in the housing, The motor can be moved forward and backward, and the nut is moved forward and backward by the forward and reverse rotations of the motor.

As described above, since the motor is arranged in series and the rotation of the motor is converted into a linear motion by a sliding screw, it is possible to provide a door opener having a large protruding stroke while being quiet, lightweight and compact. Further, if the lead angle of the screw shaft is appropriately set according to the motor capacity, it is possible to obtain the optimum push output and push speed of the pusher, and there is no restriction on the mounting position of the door opener. Further, even if an external force such as an impact load is generated on the nut, the nut and the motor are elastically supported by the spring, so that they can be buffered.

According to the second aspect of the present invention, when the motor is set backward so that the switch is turned on and the reverse rotation is performed, the nut is set back and a large impact force is applied to the nut and the motor. In addition, overload of the motor can be prevented.

Further, as in the invention described in claim 3,
If the switch is composed of a contact provided on the bottom of the housing via an elastic member and a contact provided on the rear end of the motor, no impact force is generated on the switch.

The invention according to a fourth aspect is the first aspect.
The spring coefficient of the first spring is set to be smaller than that of the second spring, so that when the nut comes into contact with the door, the first spring urging the nut protrudes as the screw shaft rotates. Acts as a force to assist the driving force of the motor.

When the nut is made of injection-moldable synthetic resin as in the fifth aspect of the invention, the rotation resistance is small and the quietness is further increased even without lubrication.
It has mass productivity and low cost.

Further, as in the invention described in claim 6, by providing a controller for detecting the current flowing in the motor and controlling the driving of the motor, the motor is rotated forward and the door is opened during the opening operation. When a situation in which it cannot be performed occurs and a current equal to or greater than a preset threshold value flows, the motor is stopped, so that the motor is not overloaded.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a vertical sectional view of a door opener according to the present invention.

In FIG. 1, a door opener 1 is housed in a motor 2, a cylindrical housing 3 having a bottom, and a screw shaft 4 to which the rotation of the motor 2 is transmitted. The screw shaft 4 is screwed onto the screw shaft 4. A nut 5 inserted in the housing 3, a first spring 6 housed between the nut 5 and a shoulder 3a of the housing 3, and a second spring housed between the bottom 3b of the housing 3 and the motor 2. Equipped with 7. In addition,
The motor 2 is elastically supported by the second spring 7 so as to be retractable. A spiral thread groove 4a is formed on the outer circumference of the screw shaft 4, and is in sliding contact with the thread groove 5a formed on the inner circumference of the nut 5, whereby the rotation of the motor 2 is converted into a linear movement of the nut 5. The screw shaft 4 is made of stainless steel such as SUS304, and the nut 5 is self-lubricating, and has low friction and wear resistance PPS (polyphenylene sulfide).
Made of resin. Other than this, the nut 5 may be formed of a synthetic resin based on a polyimide-based or PTFE (polytetrafluoroethylene) -based resin. Since such a sliding screw mechanism is quiet, can be downsized, and has rust prevention properties, a high linear conversion mechanism can be obtained. Further, by appropriately setting the lead angle of the screw groove 4a according to the motor capacity, it is possible to obtain the optimum protrusion output and protrusion speed of the nut 5.

A stopper pin 5b is planted on the outer circumference of the nut 5, and is engaged with a slit 3c extending in the axial direction on the inner circumference of the housing 3. In this way, the nut 5 is configured to be movable back and forth with respect to the housing 3 and non-rotatable. 5c is a stopper attached to the tip opening of the nut 5,
Seal the inside of the hollow nut. On the other hand, since the screw shaft 4 is coupled to the output shaft 2a of the motor 2, the screw shaft 4 is configured to be integrally movable with the motor 2 and rotatable.

FIG. 1 shows a state in which the nut 5 is retracted to the rearmost portion (bottom dead center), and FIG. 2 is a partially enlarged view showing an engaged state between the screw groove 4a of the screw shaft 4 and the screw groove 5a of the nut 5. Is. The first spring 6 is biased and accommodated.
Further, since the second spring 7 is also biased and accommodated, the spring force w of the second spring 7 causes the motor 2 to be always in contact with the shoulder portion 3 a of the housing 3. The spring force W of the first spring 6 and the spring force w of the second spring 7 are set to have a relation of W> w. That is, first, the spring 6 is set to have a smaller spring coefficient than the second spring 7, and the nut 5
Is always applied with a preload W in the protruding direction. Due to this preload, the thread groove 5a is formed on the first flank f1 of the thread groove 4a.
The first flank surface F1 of the above contacts with a predetermined pressure. On the other hand, an axial clearance δ of about several tens of μm is provided between the second flank surface f2 of the thread groove 4a and the second flank surface F2 of the thread groove 5a.
Are formed.

Since the lead angles of the screw grooves 4a, 5a are formed at 5 ° or less, even if an axial force is applied to the nut 5, it cannot be converted into a force for rotating the screw shaft 4. That is, the nut 5 does not slide on the screw shaft 4. Therefore, the forward / backward movement of the nut 5 depends only on the rotation angle of the motor 2.

Next, as an opening unit for the refrigerator door,
The operation of the door opener will be explained. When a touch switch (not shown) is turned on and the screw shaft 4 starts to rotate due to energization of the motor 2, the nut 5 projects. At this time, the spring force W of the first spring 6 is supported by the screw shaft 4, and the first flank f1 of the screw groove 4a and the first flank F1 of the screw groove 5a are in contact with each other as shown in FIG. . Nut 5
Is abutted on a door (not shown), the nut 5 stops, and the first flank f1 of the thread groove 4a is rotated as the screw shaft 4 rotates.
And the first flank F1 of the thread groove 5a tend to separate from each other. At this time, the spring force W of the first spring 6 acts as a force for opening the door. Therefore, the motor 2 need not be a force, a small motor can be used, and a speed reducer can be eliminated, so that the door opening unit can be made lightweight and compact.

Since the door of the refrigerator is packed by magnetic force in order to enhance the hermeticity and an automatic closing mechanism is provided to prevent the half door, a large force is required at the initial stage of opening the door. As described above, in this initial stage, the door is opened by the spring force W of the first spring 6 (see FIG. 3).

Once the door is opened, the first spring 6
Is longer than the free length, the second flank surface f2 of the thread groove 4a and the second flank surface F2 of the thread groove 5a come into contact with each other, the nut 5 projects only by the rotation of the motor 2, and the door is opened. It will be opened (see Figure 4).

FIG. 4 shows the state in which the nut 5 is projected to the frontmost portion (top dead center). At this time, the stopper pin 5b planted in the nut 5 is formed in the slit 3c of the housing 3.
The nut 5 stops moving by contacting the end of the nut 5. on the other hand,
Since the screw shaft 4 is further rotated by the rotation of the motor 2, the motor 2 and the screw shaft 4 are united by the reaction force of the stopper pin 5b to compress the second spring 7 and move backward.

A contact 2b is provided at the rear end of the motor 2. A pin 9 is attached to the bottom portion 3b of the housing 3 so as to be able to move forward and backward through an elastic member 8 such as a spring. A contact 9a is provided at the tip of this pin 9,
The contact 9a and the contact 2b constitute a reversing switch SW. As described above, when the motor 2 moves backwards against the second spring 7, these contacts 2b and 9 are contacted.
a comes into contact, the reverse rotation switch SW is turned on, and the motor 2 starts reverse rotation. The nut 5 is retracted by the reverse rotation of the motor 2 and is retracted to the bottom dead center position shown in FIG.

When the door is suddenly closed while the motor 2 is rotating forward to open the door, or when external force is applied to prevent the door from opening, Even in such a case, as described above, the motor 2 moves backward, the reverse rotation switch SW is turned on, and the motor 2 starts reverse rotation. Therefore, the first spring 6 and the second spring 7 serve as buffer springs, and the nut 5 and the motor 2 are
Since a large impact force is not applied to the motor 2, overload of the motor 2 can be prevented. Furthermore, since the control circuit is provided so that the motor 2 is stopped when the current value of the motor 2 is detected and a current larger than a preset threshold value flows, the overload of the motor 2 is prevented, The durability can be improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments and is merely an example, and does not depart from the scope of the present invention. Of course, the present invention can be implemented in various forms, and the scope of the present invention is shown by the description of the scope of claims, and the equivalent meanings described in the scope of claims and all within the scope Including changes.

[0027]

As described in detail above, the door opener according to the present invention has the following special effects. Since the rotation of the motor is converted into a linear motion by the sliding screw mechanism, and the motor and the sliding screw are arranged in series, it is possible to provide a door opener with a large protruding stroke with a simple structure while being quiet, lightweight and compact. it can. Further, the spring for urging the nut is housed in the housing, and these spring forces are appropriately set according to the motor capacity, so that the optimum push output of the pusher can be obtained. Therefore, in a rotary door whose one end is rotatably supported by a hinge on the front surface of the body of a refrigerator or the like, the door opener may be mounted at any position on the door, and the mounting position is not restricted. Furthermore, even when the door is suddenly closed while the motor is rotating forward to open the door, or when external force is applied to prevent the door from opening, Since the nut and the motor are elastically supported by the spring, it is possible to buffer the impact force, and the reverse switch is automatically turned on when the motor retracts and the spring is compressed to rotate the motor in reverse. A large impact force is not applied to the sliding screw or the motor, an overload of the motor can be prevented, and a highly durable door opener can be provided.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an embodiment of a door opener according to the present invention.

FIG. 2 is a partially enlarged sectional view for explaining an engaged state of a screw groove.

FIG. 3 is a vertical cross-sectional view showing a nut midpoint of the door opener according to the present invention.

FIG. 4 is a vertical sectional view showing a nut top dead center of the door opener according to the present invention.

[Explanation of symbols]

1 ... Door opener 2 ... Motor 2b ... 3 ... Housing 3a ... shoulder 3b ... bottom 3c ... Slit 4 ... Screw shaft 4a ... Screw groove 5 ... Nut 5a .... Screw groove 5b ... ・ Stopper pin 5c ... ・ Stopper 6 ... the first spring 7-Second spring 8: Elastic member 9 ... pin 9a ... ・ Contact points f1 ... First flank F1 ... First flank f2 ... the second flank surface F2 ・ ・ ・ ・ Second flank W: Spring force w ・ ・ ・ Spring force δ: Axial clearance

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Claims (6)

[Claims] 1. A door opener for opening a rotatable door whose one end is rotatably supported by a hinge.
A bottomed cylindrical housing, a motor inserted in this housing, and inserted in the housing, not rotatable,
And a nut capable of advancing and retracting, a screw shaft screwed into the nut and rotated by a driving force of a motor, a first spring biasing the nut with a predetermined force in a protruding direction thereof, and the motor. A second spring biased between the bottoms of the housing and housed therein, the springs being arranged in series in the housing in the axial direction to allow the motor to move forward and backward and to rotate the motor forward and backward. A door opener characterized in that the nut is moved back and forth. 2. The door opener according to claim 1, wherein the door opener is set so as to be turned on when the motor moves backward and to be rotated in the reverse direction. 3. The door opener according to claim 2, wherein the switch comprises a contact provided on the bottom of the housing via an elastic member and a contact provided on a rear end of the motor. 4. The spring coefficient of the first spring is set to be smaller than that of the second spring.
The door opener according to any one of 1 to 3. 5. The door opener according to claim 1, wherein the nut is made of injection-moldable synthetic resin. 6. The door opener according to claim 1, further comprising a controller that detects a current flowing through the motor and controls driving of the motor.