Electric door closer

Abstract

To provide an electric door closer superior in coping force to a power failure.SOLUTION: A main shaft 4 that rotates in conjunction with opening and closing of the door, an electric drive unit 10 that drives the main shaft 4, a control unit 11 that controls the electric drive unit 10, a self-closing unit 6 for power failure that applies a closing force to the main shaft 4, and a battery 12 that supplies power to the control unit 11 at the time of power failure, the self-closing unit 6 includes a spring 30 that generates a closing force, a power storage unit that stores power in the spring 30 by a door opening operation and applies the closing force of the spring 30 to the main shaft, and a switching unit that can switch between a connected state in which the spring 30 and the power storage unit are connected and the power storage unit and the spring 30 are interlocked when the door is opened and closed, and a retracted state in which the spring 30 and the power storage unit are separated and the power storage unit and the spring 30 are not interlocked when the door is opened and closed, when a power failure occurs, the switching unit is not set to the connected state immediately, but is set to the connected state after a delay.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electric door closer that electrically closes a door. [Background technology]

[0002] The applicant has already proposed a device that uses commercial power as a power source to open and close doors electrically, as in Patent Document 1 below. However, if a power outage occurs and the door is no longer able to open and close automatically, it is possible that a door that has been manually opened may remain open. In addition, there are long-lasting power outages and short power outages that are restored within a few minutes, known as momentary power outages. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6947681 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide an electric door closer that is highly adaptable to power outages. [Means for solving the problem]

[0005] The electric door closer of the present invention is an electric door closer that electrically closes a door and comprises: a main shaft that rotates in conjunction with the opening and closing of the door; an electric drive unit that drives the main shaft; a control unit that controls the electric drive unit; a self-closing unit for use in the event of a power outage that applies a closing force to the main shaft; and a battery that supplies power to the control unit in the event of a power outage; the self-closing unit comprises: a spring that generates a closing force; an energy storage unit that stores energy in the spring through the door-opening operation and applies the closing force of the spring to the main shaft; and a switching unit that can switch between a connected state in which the spring and the energy storage unit are connected and the energy storage unit and the spring work together when the door is opened or closed, and a retracted state in which the spring and the energy storage unit are separated and the energy storage unit and the spring do not work together when the door is opened or closed; the control unit sets the switching unit to the retracted state when power is applied, and when a power outage occurs, the control unit does not immediately set the switching unit to the connected state but sets it to the connected state after a delay.

[0006] According to this configuration, when the switching unit is in the retracted state, the electric door closer is in the electric mode, and the door is closed by the electric drive unit. When the switching unit changes from the retracted state to the connected state, the electric door closer transitions from the electric mode to the manual mode. In the manual mode, the electric drive unit does not drive the main shaft, and the door is manually opened, and the opened door is closed by the automatic closing unit.

[0007] When power is on, which is the normal state, the control unit controls the electric drive unit using commercial power. The electric drive unit applies a closing force to the main shaft, automatically closing the door. When power is on, the switching unit is in a retracted state. In other words, the spring and the energy storage unit are separated, and the energy storage unit and the spring do not work together when the door opens or closes. Therefore, the energy storage unit does not apply a closing force to the main shaft and does not interfere with the operation of the electric drive unit. When a power outage occurs, power supply from the commercial power source is stopped and power is supplied to the control unit from the battery. The control unit switches the switching unit from the retracted state to the connected state, but does not switch immediately after the power outage, but delays the switch. In other words, when a power outage occurs, the electric door closer does not immediately switch from electric mode to manual mode, but rather the transition is delayed.

[0008] In the event of a momentary power outage, the switching unit does not switch to the connected state but remains in the retracted state. Therefore, even if a momentary power outage occurs, the operation of the electric door closer is not affected, and the electric door closer maintains its electric mode. The control unit uses battery power to control the electric drive unit to close the door electrically. When power is restored after a momentary power outage, the door will close electrically, just as it did before the power outage. The user can use the electric door closer as usual after power is restored without being particularly aware of the momentary power outage. On the other hand, in the event of a prolonged power outage that lasts longer than a momentary power outage, the switching unit switches from the retracted state to the connected state. When the switching unit switches to the connected state, the spring and the energy storage unit are connected, and the spring and the energy storage unit interact with the opening and closing of the door. When the door is manually opened during a power outage, the energy storage unit stores energy in the spring to generate a closing force. Therefore, a manually opened door will automatically close due to the closing force of the spring. Note that the control unit may control the electric drive unit to automatically open the door in addition to automatically closing it.

[0009] In particular, it is preferable that the switching unit maintains the standby state while receiving power and switches from the standby state to the connected state when the power supply is stopped, and that the control unit supplies power to the switching unit when power is supplied and until the battery is depleted during a power outage, and stops supplying power to the switching unit when the battery is depleted during a power outage. With this configuration, the switching unit is maintained in the standby state during a power outage until the battery is depleted. Since the control is to use up the battery, the switching unit can be easily controlled. Furthermore, by increasing the battery capacity, it is possible to easily handle power outages longer than momentary power outages, such as power outages of ten minutes or several tens of minutes. If the power outage is restored before the battery is depleted, the user can continue to use the electric door closer as usual after the power outage is restored. On the other hand, in the case of a long power outage in which the battery runs out, the control unit stops supplying power to the switching unit as soon as the battery runs out. The switching unit switches to the connected state, and the electric door closer transitions to manual mode.

[0010] Furthermore, it is preferable that the switching unit compresses the spring with electromagnetic force to place the spring in the retracted state, and releases the compressed state to place the spring in the connected state. With this configuration, while the control unit is supplying power to the switching unit, the electromagnetic force can easily maintain the spring in the compressed state. When a power outage occurs and the battery runs out, the control unit stops supplying power to the switching unit, and the electromagnetic force no longer acts, so the spring force can easily transition from the retracted state to the connected state.

[0011] Furthermore, it is preferable that the control unit keeps the switching unit in the standby state when power is supplied and until a predetermined time has elapsed since the power outage, and then switches the switching unit to the connected state once the predetermined time has elapsed since the power outage. With this configuration, the predetermined time can be set to, for example, a time longer than the duration of a momentary power outage. When a power outage occurs, the control unit measures the time since the power outage occurred. For example, if the predetermined time since the power outage is five minutes, the control unit switches the switching unit from the standby state to the connected state once five minutes have elapsed since the power outage. The electric door closer will switch from electric mode to manual mode five minutes after the power outage. The user can easily determine the timing to switch to manual mode based on the time.

[0012] Furthermore, it is preferable that the control unit keeps the switching unit in the standby state when power is supplied and during a power outage until the battery voltage drops to a predetermined value, and then, during a power outage, puts the switching unit into the connected state when the battery voltage drops to the predetermined value. According to this configuration, when the battery voltage drops to the predetermined value after a power outage, the electric door closer automatically transitions from electric mode to manual mode. Even during a power outage, the door continues to be closed electrically using battery power, but if this is done frequently, the battery voltage will drop quickly and the transition to manual mode will also be quick. Conversely, if the door is closed electrically infrequently after a power outage, the battery voltage will drop slowly and the transition to manual mode will also be slow. Therefore, if the door is closed infrequently after a power outage, the electric door closer can withstand a relatively long power outage and maintain the electric mode.

[0013] Furthermore, it is preferable that the control unit keeps the switching unit in the retracted state when power is supplied and during a power outage until the number of times the door has been closed by the electric drive unit reaches a predetermined number, and then, during a power outage, puts the switching unit in the connected state once the number of times the door has been closed by the electric drive unit reaches the predetermined number. According to this configuration, when a power outage occurs, the control unit counts the number of times the door has been closed by the electric drive unit. Then, when the number of times the door has been closed by the electric drive unit reaches the predetermined number, the electric door closer automatically transitions from the electric mode to the manual mode. The user can determine the timing to transition to the manual mode based on the number of times the door has been closed after the power outage.

[0014] The electric drive unit preferably includes a motor and a rotation transmission unit that transmits the motor's rotation to the main shaft, and the rotation transmission unit is preferably configured to be reversible from the main shaft. With this configuration, the rotation transmission unit does not have a self-locking feature. Therefore, when the door is closed by the closing force of the spring in manual mode, the rotation is transmitted to the rotation transmission unit via the main shaft, and the rotation transmission unit rotates together with the main shaft. Therefore, the resistance in the rotation transmission unit acts as a rotational load on the main shaft, providing a cushioning effect when the door is closed.

[0015] Furthermore, the switching unit preferably includes first and second engagement portions engageable with each other, a stopper movable between a first position in which the first and second engagement portions are kept engaged and a second position in which the first and second engagement portions are disengaged and biased toward the second position, and an electromagnetic member that applies an electromagnetic force to the stopper to hold the stopper at the first position in the electric mode, wherein the first and second engagement portions maintain engagement in the electric mode, thereby maintaining the spring in a compressed state, and the first and second engagement portions disengage in the manual mode, thereby releasing the compressed state of the spring. According to this configuration, in the electric mode, the electromagnetic member applies an electromagnetic force to the stopper, so that the stopper is held in the first position, the first and second engagement portions are kept engaged, and the spring is kept compressed. When the mode is switched to the manual mode, the electromagnetic force of the electromagnetic member no longer acts on the stopper, the stopper moves to the second position, the first and second engagement portions are disengaged, and the compressed state of the spring is released. In this way, by using a mechanism for engaging and disengaging the first and second engagement portions, the spring can be easily switched between the retracted state and the connected state.

[0016] It is also preferable to have a position adjustment unit that adjusts the distance between the main shaft and the retracted spring. The door opening angle at which the door is fully opened varies depending on the conditions of the location where the door is installed. For example, in some locations, the door can only open approximately 100 degrees, while in other locations, the door can open up to approximately 150 degrees. Thus, the door's openable angle depends on the installation location. In the electric mode, the door opening angle at which the door is most open is called the "powered door opening angle." In installation locations where the door's openable angle is small, the powered door opening angle is small. On the other hand, in installation locations where the door's openable angle is large, the powered door opening angle is generally large. By having a position adjustment unit that adjusts the distance between the main shaft and the retracted spring, the distance between the main shaft and the retracted spring can be shortened when the powered door opening angle is small, and the distance between the main shaft and the retracted spring can be lengthened when the powered door opening angle is large. This increases the versatility of the electric door closer.

[0017] Preferably, the switching unit includes an auxiliary drive unit that moves the spring, and when switching to the manual mode during a power outage, the control unit operates the auxiliary drive unit using battery power to move the spring from the retracted state position to the connected state position. With this configuration, the spring can be reliably moved by the auxiliary drive unit. [Effects of the Invention]

[0018] As described above, since the automatic closing unit is provided, in the event of a power outage, the automatic closing unit can switch from electric mode to manual mode and automatically close the door. Furthermore, since the automatic closing unit does not immediately switch from electric mode to manual mode when a power outage occurs, in the case of a short power outage such as a momentary power outage, the automatic closing unit maintains the electric mode without switching from electric mode to manual mode. Therefore, after the power outage is restored, the door can be closed in the electric mode as usual without requiring any special operation. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic cross-sectional view showing the fully closed state of the electric door closer in the first embodiment of the present invention in an electric mode. [Figure 2] Enlarged view of the main part of Figure 1. [Figure 3] 4 is a schematic cross-sectional view showing the electric door closer in a state immediately after switching to a manual mode. FIG. [Figure 4] 4 is a schematic cross-sectional view showing the electric door closer in a state immediately after switching to a manual mode. FIG. [Figure 5] FIG. 4 is a schematic cross-sectional view showing the electric door closer in a state where the door is manually opened in a manual mode. [Figure 6] FIG. 4 is a schematic cross-sectional view showing the electric door closer in a state where the door is closed in a manual mode. [Figure 7] 10 is a schematic cross-sectional view of the electric door closer showing a state in which the door is manually opened when power is restored. FIG. [Figure 8]FIG. 6 is a schematic cross-sectional view showing a fully closed state of an electric door closer in an electric mode according to a second embodiment of the present invention. [Figure 9] 4 is a schematic cross-sectional view showing the electric door closer in a state immediately after switching to a manual mode. FIG. [Figure 10] 4 is a schematic cross-sectional view showing the electric door closer in a state immediately after switching to a manual mode. FIG. [Figure 11] FIG. 4 is a schematic cross-sectional view showing the electric door closer in a state where the door is manually opened in a manual mode. [Figure 12] FIG. 10 is a schematic cross-sectional view showing a fully closed state of an electric door closer in an electric mode according to a third embodiment of the present invention. [Figure 13] (a) is an enlarged view of the main part of Figure 12, and (b) is a cross-sectional view taken along the line AA in (a). [Figure 14] 1A and 1B are cross-sectional views showing the components of the electric door closer, in which FIG. 1A shows the separated state and FIG. 1B shows the joined state. [Figure 15] 4 is a schematic cross-sectional view showing the electric door closer in a state immediately after switching to a manual mode. FIG. [Figure 16] 4 is a schematic cross-sectional view showing the electric door closer in a state immediately after switching to a manual mode. FIG. [Figure 17] 10 is a schematic cross-sectional view of the electric door closer showing a state in which the door is being manually opened in manual mode. FIG. [Figure 18] 10 is a schematic cross-sectional view of the electric door closer showing a state in which the door is manually opened when power is restored. FIG. [Figure 19] 10 is a schematic cross-sectional view of the electric door closer showing a state in which the door is manually opened when power is restored. FIG. [Figure 20] FIG. 10 is a schematic cross-sectional view of an electric door closer according to a fourth embodiment of the present invention, seen from the front in a fully closed state in an electric mode. [Figure 21] FIG. 4 is a schematic cross-sectional view of the electric door closer in a fully closed state in the electric mode, as viewed from above. [Figure 22] FIG. 2 is a schematic cross-sectional view showing the main parts of the electric door closer, seen from the front just after switching to the manual mode. [Figure 23] FIG. 2 is a schematic cross-sectional view showing the main parts of the electric door closer in manual mode as viewed from the front. [Figure 24] FIG. 2 is a schematic cross-sectional view showing the main parts of the electric door closer, viewed from the front when the door is manually opened after power is restored. [Figure 25] FIG. 2 is a schematic cross-sectional view showing the main parts of the electric door closer, viewed from the front when the door is manually opened after power is restored. [Figure 26] 5A and 5B are diagrams showing a first support member of the electric door closer, in which FIG. 5A is a front view and FIG. 5B is a cross-sectional view taken along the line BB. [Figure 27] 4A and 4B are diagrams showing a second support member of the electric door closer, in which (a) is a front view and (b) is a cross-sectional view taken along line CC. [Figure 28] FIG. 2 is a schematic diagram showing the main parts of the electric door closer from the front. [Figure 29] FIG. 2 is a schematic diagram showing the main parts of the electric door closer from the front. [Figure 30] 28, (b) is an EE cross-sectional view of FIG. 29, and (c) is an FF cross-sectional view of FIG. 29. [Figure 31] (a) and (b) are schematic diagrams showing the main parts of the electric door closer from the front. [Figure 32] FIG. 11 is a schematic cross-sectional view of an electric door closer according to a fifth embodiment of the present invention, seen from above in a fully closed state in an electric mode. DETAILED DESCRIPTION OF THE INVENTION

[0020] An electric door closer according to a first embodiment of the present invention will be described below with reference to Figs. 1 to 7. The electric door closer of this embodiment has an electric mode and a manual mode. In the electric mode, the door is opened and closed electrically. In the manual mode, the door is opened manually, and then closed by the force of a spring 30, which will be described later.

[0021] The left-right direction is the direction perpendicular to the door's pivot axis (hinge), connecting the end of the door closest to the pivot axis and the end of the door farthest from the pivot axis. The axial direction of the door's pivot axis is the up-down direction, and the direction normal to the door surface is the front-to-back direction.

[0022] The door is rotatably attached to the door frame via hinges. The door rotates horizontally around a vertical axis. Figure 1 shows the overall configuration of an electric door closer. The electric door closer comprises a main body 1 attached to the door, a link mechanism connecting the main body 1 to the door frame, and a power supply device (not shown) that supplies commercial power to the main body 1. The main body 1 is attached to the upper front of the door, near the hinge, via a mounting plate (not shown). A cover 8 is placed over the main body 1. Removing the cover 8 exposes a frame 7. The link mechanism comprises an arm 2 and a bracket 3. The bracket 3 is attached to the upper frame of the door frame.

[0023] <Main unit 1> The main body 1 is equipped with a main shaft 4 that rotates around an axis in the vertical direction as the door rotates. The main body 1 has a rectangular parallelepiped shape that is long in the left-right direction. The main body 1 is equipped with an electric unit 5 and a self-closing unit 6. Both the electric unit 5 and the self-closing unit 6 have shapes that are long in the left-right direction. The electric unit 5 and the self-closing unit 6 are arranged side by side, one above the other. That is, the electric unit 5 and the self-closing unit 6 are lined up in the axial direction of the main shaft 4. The electric unit 5 is located above the self-closing unit 6. However, they may be arranged upside down, or the self-closing unit 6 may be located above the electric unit 5. The cover 8 covers both the electric unit 5 and the self-closing unit 6 together.

[0024] The main body 1 has a frame 7. An electric unit 5 and a self-closing unit 6 are attached to the frame 7. A main shaft 4 is journaled on the frame 7. The upper end of the main shaft 4 protrudes upward from the frame 7. One end of the arm 2 is connected to the upper end of the main shaft 4. The main shaft 4 passes vertically through the electric unit 5, extends to the self-closing unit 6, and reaches the lower end of the frame 7. The main shaft 4 has an upper part corresponding to the electric unit 5 and a lower part corresponding to the self-closing unit 6. The upper and lower parts of the main shaft 4 may be formed integrally, or the main shaft 4 may be configured as two separate parts, upper and lower.

[0025] The electric unit 5 includes an electric drive unit 10 that electrically rotates the main shaft 4 to open and close the door, and a control unit 11 that controls the electric drive unit 10. The control unit 11 may be disposed in another part other than the electric unit 5, such as the self-closing unit 6, or may be disposed in a part other than the main body 1.

[0026] <Electric drive unit 10> The electric drive unit 10 includes a motor 13, which is a drive source that drives the main shaft 4, and a rotation transmission unit that transmits the rotation of the motor 13 to the main shaft 4. The motor 13 is, for example, a brushless DC motor. The motor 13 has a left-right axis. The motor 13 is disposed facing the main shaft 4. The rotation transmission unit reduces the speed of the rotation of the motor 13 and converts the direction of the rotation axis from left-right to up-down before transmitting the rotation to the main shaft 4. The rotation transmission unit includes a reduction gear unit 15 located on the left side of the motor 13, a torque limiter 16, and a bevel gear train. The left side is the side closer to the main shaft 4, and the right side is the side farther from the main shaft 4. The rotation of the motor 13 is reduced in speed by the reduction gear unit 15 and transmitted to a first output shaft 17. The bevel gear train converts the direction of the rotation axis of the motor 13 from left-right to up-down. The bevel gear train has a first bevel gear 18 that rotates integrally with the main shaft 4, and a second bevel gear 19 that meshes with the first bevel gear 18 and rotates about an axis in the left-right direction. The second bevel gear 19 is attached to a second output shaft 20. The second output shaft 20 is coaxial with the first output shaft 17, and a torque limiter 16 is disposed between the second output shaft 20 and the first output shaft 17.

[0027] <Control unit 11 and battery 12> The control unit 11 drives and controls the motor 13, and also controls switching from the electric mode to the manual mode in the event of a power outage. In the electric mode, the electric drive unit 10 electrically opens and closes the door. In the manual mode, the door is opened manually, and the automatic closing unit 6 closes the door. In the electric mode, the automatic closing unit 6 does not operate, and in the manual mode, the electric drive unit 10 does not operate. The automatic closing unit 6 applies a closing force to the main shaft 4 only when the electric drive unit 10 does not drive the main shaft 4.

[0028] The control unit 11 is disposed, for example, on the opposite side of the spindle 4 with respect to the electric drive unit 10. When energized, the control unit 11 is supplied with power from a commercial power source. When energized, the control unit 11 is supplied with power from a power supply device (not shown). The power supply device converts AC power to DC power. The power supply device receives AC 100V AC power from the commercial power source, converts it to DC 12V, and outputs it. When energized, the control unit 11 receives power converted to DC power by the power supply device.

[0029] The main body 1 is equipped with a battery 12 as an emergency power source that supplies power to the control unit 11 in the event of a power outage. The battery 12 may be located anywhere in the main body 1, but in this embodiment, it is located in the motorized unit 5. Note that the battery 12 may be located not in the main body 1 but in a power supply device, for example. The battery 12 is preferably a secondary battery, such as a nickel-metal hydride battery of AA or AAA size. For example, multiple batteries 12 are arranged side by side, front to back. The number and capacity of the batteries 12 may vary. For example, the batteries 12 are arranged so that their axes are vertical. The battery 12 is charged when power is applied. Therefore, the battery 12 is normally fully charged. In the event of a power outage, power is supplied from the battery 12 to the control unit 11. The control unit 11 boosts the DC power supplied from the battery 12 to, for example, DC 12 V, and uses the boosted power to control the motor 13 and the solenoid 40 and auxiliary motor 60, which will be described later.

[0030] <Self-closing part 6> The self-closing unit 6 applies a closing force to the main shaft 4 in place of the electric drive unit 10 when the electric drive unit 10 does not drive the main shaft 4. In the electric mode, the electric drive unit 10 drives the main shaft 4 to open and close the door, but in the manual mode, the self-closing unit 6 applies a closing force to the main shaft 4 to close the door. The self-closing unit 6 is connected to the main shaft 4 in the manual mode. When the door is manually opened, the self-closing unit 6 stores a closing force and closes the door using the closing force (stored force). In the electric mode, the electric drive unit 10 drives the main shaft 4, so the self-closing unit 6 is separated from the main shaft 4 and is configured not to store a closing force when the door is opened. Specifically, the self-closing unit 6 includes a spring 30, a storage unit, and a switching unit. The spring 30 generates a closing force. The storage unit stores energy in the spring 30 during the door-opening operation and applies the closing force of the stored spring 30 to the main shaft 4. The switching unit is configured to be switchable between a retracted state and a connected state. In the retracted state, the spring 30 and the energy storage unit are separated. Therefore, in the retracted state, the energy storage unit and the spring 30 do not move together when the door opens or closes. In the connected state, the spring 30 and the energy storage unit are connected. Therefore, in the connected state, the energy storage unit and the spring 30 move together when the door opens or closes.

[0031] In this embodiment, the switching unit maintains the spring 30 in a compressed state to place the spring 30 in a retracted state, and releases the compressed state to place the spring 30 in a connected state. The switching unit includes a first engagement portion and a second engagement portion, a stopper, an electromagnetic member, and a biasing portion. The first engagement portion and the second engagement portion are engageable with each other. The stopper is movable between a first position, in which the first engagement portion and the second engagement portion are maintained engaged, and a second position, in which the first engagement portion and the second engagement portion are disengaged. The biasing portion biases the stopper toward the second position. In the electric mode, the electromagnetic member applies an electromagnetic force to the stopper to hold the stopper in the first position. When the first engagement portion and the second engagement portion are maintained engaged, the spring 30 is maintained in a compressed state, and when the first engagement portion and the second engagement portion are disengaged, the compressed state of the spring 30 is released. This is described in detail below.

[0032] In this embodiment, the energy accumulator rod 51 and pinion gear 50, which will be described later, constitute the energy accumulator portion. The solenoid 40, switching box 43, regulating ball 44, stopper pin 46, urging spring 47, locking claw 35, and regulating shaft 33, which will be described later, constitute the switching portion. The regulating ball 44 is the first engaging portion, and the locking groove 46a of the stopper pin 46 is the second engaging portion. The switching box 43 is the stopper. The solenoid 40 is an electromagnetic member, and an internal spring (not shown) built into the solenoid 40 is the urging portion.

[0033] The spring 30 is a compression coil spring. The number of springs 30 can be any number; in this embodiment, there is one, but there may be two or more. The axial direction of the spring 30 is the left-right direction, which is perpendicular to the main shaft 4. The spring 30 is disposed between a first spring retainer 31 and a second spring retainer 32. The first spring retainer 31 is disposed relatively far from the main shaft 4, and the second spring retainer 32 is disposed relatively close to the main shaft 4. The first spring retainer 31 is disposed on the right side, and the second spring retainer 32 is disposed on the left side. The first spring retainer 31 is fixed to the frame 7. The second spring retainer 32 is not fixed to the frame 7 and is movable relative to the frame 7. The second spring retainer 32 moves left-right to approach and move away from the first spring retainer 31.

[0034] A restricting shaft 33 is fixed to the second spring bearing 32. The restricting shaft 33 extends to the right from the second spring bearing 32 and passes through the radially inner side of the spring 30. The restricting shaft 33 passes through the first spring bearing 31 and extends to the right of the first spring bearing 31. The restricting shaft 33 is slidable in the left-right direction relative to the first spring bearing 31.

[0035] As shown in FIG. 2 , the regulating shaft 33 has a number of locking teeth 34. The locking teeth 34 face upward. The locking teeth 34 are formed on a portion of the regulating shaft 33 to the right of the first spring retainer 31. A claw portion 36 of a locking pawl 35 locks with the locking teeth 34. The locking pawl 35 is disposed above the regulating shaft 33. The claw portion 36 is provided on a lower portion of the locking pawl 35. The locking pawl 35 is rotatably mounted on a support shaft 37. The locking pawl 35 has an locking position in which the locking teeth 34 are locked to prevent the regulating shaft 33 from moving leftward, a first unlocking position in which the locking teeth 34 are not locked to allow the regulating shaft 33 to move leftward, and a second unlocking position in which the locking teeth 34 are not locked to allow the regulating shaft 33 to move rightward. The first non-locking position is a position in which the locking claw 35 has rotated clockwise in the figure relative to the locking position. The second non-locking position is a position in which the locking claw 35 has rotated counterclockwise in the figure relative to the locking position. In other words, the rotation direction of the locking claw 35 is opposite between the first non-locking position and the second non-locking position relative to the locking position. The support shaft 37 is fixed to the frame 7. The support shaft 37 is disposed above the regulating shaft 33. The support shaft 37 has an axis in the front-to-rear direction. The locking claw 35 is provided with a biasing spring (not shown) and is biased clockwise in the figure by the biasing spring.

[0036] A solenoid 40 is fixed to the frame 7. The solenoid 40 includes a solenoid body 41 and a plunger 42 (movable iron core) extending to the right from the solenoid body 41. The plunger 42 moves forward and backward relative to the solenoid body 41. The solenoid 40 also includes a built-in spring (not shown) that biases the plunger 42 in a direction to retract it into the solenoid body 41. Power is supplied to the solenoid 40 from the control unit 11. When power is supplied to the solenoid 40, the solenoid 40 uses electromagnetic force to retract the plunger 42 to the left against the biasing force of the built-in spring. On the other hand, when the power supply to the solenoid 40 is stopped, the electromagnetic force no longer acts on the solenoid 40, and the biasing force of the built-in spring causes the plunger 42 to protrude to the right.

[0037] A switching box 43 is attached to the tip (right end) of the plunger 42. A ball accommodating portion 45 that accommodates a plurality of regulating balls 44 is provided inside the switching box 43. The inner wall of the ball accommodating portion 45 is provided with a small diameter portion 45a and a large diameter portion 45b that has a larger diameter than the small diameter portion 45a. The small diameter portion 45a is located to the right of the large diameter portion 45b.

[0038] A stopper pin 46 penetrates the ball accommodating portion 45 of the switching box 43 in the left-right direction. The stopper pin 46 has an axis in the left-right direction. The stopper pin 46 is biased to the left by a biasing spring 47. The tip of the stopper pin 46 abuts against the upper part of the locking claw 35 from the right side. The biasing spring 47 is disposed between the stopper pin 46 and the frame 7. The stopper pin 46 is movable in the left-right direction relative to the switching box 43. A locking groove 46a is formed on the outer peripheral surface of the stopper pin 46. The regulating ball 44 can engage with the locking groove 46a.

[0039] When the plunger 42 retracts to the left, the switching box 43 moves to the left accordingly. When the plunger 42 retracts to the left, the switching box 43 is in the first position. When the switching box 43 is in the first position, the regulating ball 44 is located in the small diameter portion 45a of the ball accommodating portion 45, and the regulating ball 44 engages with the locking groove 46a of the stopper pin 46. The engagement of the regulating ball 44 with the locking groove 46a prevents the stopper pin 46 from moving left and right. The position of the stopper pin 46 at this time is referred to as the stop position. On the other hand, when the plunger 42 protrudes to the right, the switching box 43 also moves to the right accordingly. When the plunger 42 protrudes to the right, the switching box 43 is in the second position. When the switching box 43 is located in the second position, the restriction ball 44 escapes from the small diameter portion 45a and can enter the large diameter portion 45b, and the restriction ball 44 disengages radially outward from the locking groove 46a of the stopper pin 46. When the restriction ball 44 disengages from the locking groove 46a, the restriction state of the stopper pin 46 by the restriction ball 44 is released, and the stopper pin 46 becomes movable in the left-right direction.

[0040] The control unit 11 keeps the electric door closer in the electric mode when power is supplied. In the event of a power outage, the control unit 11 transitions the electric door closer from the electric mode to the manual mode. However, the control unit 11 does not immediately transition the electric door closer to the manual mode even when a power outage occurs, but delays the transition to the manual mode and then transitions to the manual mode. That is, the control unit 11 places the switching unit in a retracted state when power is supplied. The control unit 11 continues to supply power to the solenoid 40 of the switching unit when power is supplied. The switching unit maintains the retracted state while receiving power from the control unit 11. Therefore, the switching unit is held in the retracted state when power is supplied. In the event of a power outage, the control unit 11 does not immediately transition the switching unit to a connected state, but instead delays the switching using the battery 12 and then transitions to a connected state. In the event of a power outage, the control unit 11 continues to supply power to the solenoid 40 of the switching unit until the battery 12 is depleted. When battery 12 is depleted and its remaining charge becomes low, control unit 11 is unable to boost the power to a constant voltage, for example, 12 V. When battery 12's remaining charge becomes low, control unit 11 is no longer able to supply constant voltage power to solenoid 40 of the switching unit, and the supply of constant voltage power to the switching unit is stopped. In this way, when the power supply from control unit 11 is stopped, the switching unit switches from the retracted state to the connected state.

[0041] In the electric mode, power is supplied from the control unit 11 to the solenoid 40. As shown in FIGS. 1 and 2, the solenoid 40 is in the ON state, the plunger 42 is retracted to the left, and the switching box 43 is moved to the left. The restricting ball 44 is located in the small-diameter portion 45a of the ball receiving portion 45 and engaged with the locking groove 46a of the stopper pin 46. Therefore, the stopper pin 46 is held in a stopped position and cannot move to the right. Because the tip of the stopper pin 46 abuts against the locking pawl 35, the locking pawl 35 cannot rotate clockwise and is in a locked position. Meanwhile, the spring 30 is in a compressed state, pushing the second spring retainer 32 to the left, and a biasing force to the left also acts on the restricting shaft 33. Because the locking tooth 34 of the restricting shaft 33 is engaged with the pawl portion 36 of the locking pawl 35, the restricting shaft 33 cannot move to the left. Because the restricting shaft 33 is attempting to move to the left, the locking claw 35 is attempting to rotate clockwise, but the clockwise rotation of the locking claw 35 is prevented by the stopper pin 46. In other words, the leftward movement of the second spring holder 32 and the restricting shaft 33 is prevented by the locking claw 35 and the stopper pin 46.

[0042] When a power outage occurs, the control unit 11 boosts the power of the battery 12 and supplies it to the solenoid 40. Even when a power outage occurs, the control unit 11 does not immediately switch to manual mode. Therefore, the control unit 11 continues to drive and control the electric drive unit 10 to open and close the door. As the electric drive unit 10 operates to open and close the door, the remaining charge of the battery 12 gradually decreases. Even when the electric drive unit 10 does not open or close the door, the remaining charge of the battery 12 gradually decreases as power continues to be supplied to the solenoid 40. Then, when the remaining charge of the battery 12 runs out, that is, when the control unit 11 can no longer boost the power, the control unit 11 stops supplying power to the solenoid 40. As a result, the electric door closer switches from electric mode to manual mode.

[0043] When switching from the electric mode to the manual mode, as shown in FIG. 3, the solenoid 40 is turned off, the plunger 42 protrudes to the right, and the switching box 43 also moves to the right. The restricting ball 44 is located in the large-diameter portion 45b of the ball accommodating portion 45 and is disengaged from the locking groove 46a of the stopper pin 46. This allows the stopper pin 46 to move to the right, causing the locking pawl 35 to rotate clockwise and assume the first unlocked position. The stopper pin 46 is then pushed by the locking pawl 35 and moves to the right. As the locking pawl 35 rotates clockwise and assumes the first restricted position, the claw portion 36 of the locking pawl 35 disengages from the locking tooth 34 of the restricting shaft 33, and the restricting shaft 33 and the second spring retainer 32 move to the left. FIG. 3 shows the restricting shaft 33 and the second spring retainer 32 in the middle of moving to the left.

[0044] Meanwhile, a pinion gear 50 is provided on the lower part of the main shaft 4. The pinion gear 50 rotates integrally with the main shaft 4. The pinion gear 50 may be formed integrally with the lower part of the main shaft 4, or may be formed separately and attached to the lower part of the main shaft 4. A rack 52 of a charging rod 51 meshes with the pinion gear 50. The charging rod 51 has an abutment head 53 at its right end. The abutment head 53 is located on the right side of the main shaft 4. When the main shaft 4 rotates, the charging rod 51 moves left and right. Figure 1 shows the closed door state, in which the charging rod 51 is located on the left side. When the main shaft 4 rotates in conjunction with the door-opening operation, the charging rod 51 moves to the right.

[0045] When the door is opened electrically, the contact head 53 moves to the position shown by the two-dot chain line in Fig. 1. That is, in the electric mode, when the door is opened and closed, the contact head 53 moves back and forth between the closed position shown by the solid line in Fig. 1 and the open position shown by the two-dot chain line. In the electric mode shown in Fig. 1, the contact head 53 does not contact the second spring retainer 32. The second spring retainer 32 is positioned so that it does not contact the contact head 53 when it is in the open position, and a gap is provided between the contact head 53 in the open position and the second spring retainer 32.

[0046] When the door is in the manual mode, as shown in Fig. 3, the second spring retainer 32 moves to the left and eventually comes into contact with the contact head 53 located in the closed position as shown in Fig. 4. When the second spring retainer 32 is in contact with the contact head 53 in the closed position, the spring 30 may be in a free length or in a compressed state. The amount of compression of the spring 30 from the state in which the second spring retainer 32 is in contact with the contact head 53 in the fully closed state to the state in which the spring 30 is compressed in the electric mode as shown in Fig. 1 is greater than the amount of left-right movement of the contact head 53 associated with the door opening and closing operation (the left-right distance between the closed and open positions).

[0047] 5 shows the state when the door is manually opened in manual mode. When the main shaft 4 rotates with the door opening operation, the pinion gear 50 rotates integrally with the main shaft 4, and the energy storage rod 51 moves to the right. The movement of the energy storage rod 51 to the right compresses the spring 30, and a closing force is stored. Pushed by the energy storage rod 51, the second spring retainer 32 and the restriction shaft 33 move to the right. At that time, the locking claw 35 is pushed by the restriction shaft 33 and rotates counterclockwise to assume the second unlocking position.

[0048] Then, when the manual door opening operation is completed, the door can be automatically closed by the closing force of the spring 30, as shown in Figure 6. That is, the spring 30 pushes and moves the energy storage rod 51 to the left via the second spring retainer 32, causing the main shaft 4 to rotate. The restriction shaft 33 also moves to the left, but the locking claw 35 is pushed by the restriction shaft 33 and rotates clockwise to assume the first unlocking position.

[0049] When the power outage ends and power is restored, power is again supplied from the control unit 11 to the solenoid 40. The battery 12 is charged as power is restored. When power is restored, the plunger 42 of the solenoid 40 retracts to the left, moving the switching box 43 to the left, as shown in Figure 7. The restricting ball 44 is positioned in the small-diameter portion 45a of the ball accommodating portion 45 and engages with the locking groove 46a of the stopper pin 46. Therefore, the stopper pin 46 cannot move to the right and is stopped. In this state, the door is manually opened. The door is opened to a larger opening angle than when the door is opened electrically. In other words, the door is manually opened to a larger opening angle than the power-on door opening angle, which is the maximum opening angle of the door in the electric mode. Figure 7 shows the door being opened manually. By manually opening the door, the energy storage rod 51 moves the second spring retainer 32 to the right, and the restricting shaft 33 also moves to the right. The locking pawl 35 is pushed by the regulating shaft 33 and rotates counterclockwise to a second unlocked position, allowing the regulating shaft 33 to move to the right. When the door is manually opened to an opening angle greater than that when the door is opened electrically, the locking pawl 35 is in an locked position in which the claw portion 36 is locked with the leftmost locking tooth 34 of the regulating shaft 33, as shown in Figure 1, and the regulating shaft 33 is held in that position. The contact head 53 in the open position when the door is electrically operated is shown by a two-dot chain line in Figure 1, but the second spring retainer 32 is held in a state separated to the right of the contact head 53 in the open position when the door is electrically operated.

[0050] Thereafter, the door is electrically closed. The motor 13 is operated to rotate the main shaft 4, and the energy storage rod 51 moves to the left, but because the locking claw 35 prevents the movement of the regulating shaft 33, the second spring retainer 32 does not move to the left, and the energy storage rod 51 moves to the left away from the second spring retainer 32, resulting in the fully closed state shown in Fig. 1. Immediately after power is restored, the door may be opened by the motor 13, not manually, to a larger opening angle than when the door is electrically opened and closed in the electric mode.

[0051] As described above, in the electric mode, which is the normal state, the self-closing unit 6 does not function and does not apply a closing force to the spindle 4. Therefore, in the electric mode, the self-closing unit 6 does not affect the drive of the spindle 4 by the electric drive unit 10, and the electric drive unit 10 electrically opens and closes the door regardless of the presence of the self-closing unit 6. When a power outage occurs and the mode is switched from the electric mode to the manual mode, the self-closing unit 6 begins to function. When the mode is switched to the manual mode, the power supply to the solenoid 40 is stopped, so the solenoid 40 is turned off and the switching box 43 moves to the right. Therefore, there is no need to separately move the switching box 43 to the right. Furthermore, when the mode is switched to the manual mode and the power supply is stopped, the switching box 43 can be instantly moved to the right. Furthermore, the compressed state of the spring 30 can be used to quickly move the second spring retainer 32 to the left and make it contact with the contact head 53. In other words, the spring 30 can be connected to the energy storage unit.

[0052] Furthermore, in manual mode, when the door is manually opened, the spring 30 stores a closing force and applies the stored closing force to the main shaft 4, but the rotation transmission unit does not have self-locking properties. Therefore, as the door closes, rotation is transmitted from the main shaft 4, which is the output side, to the rotation transmission unit. Therefore, the resistance generated when the rotation transmission unit rotates becomes a rotational load and is applied to the main shaft 4. Although the automatic closing unit 6 does not have a hydraulic buffer mechanism, the rotational load of the rotation transmission unit acts on the main shaft 4, preventing the door from closing suddenly. In other words, a buffer effect can be applied to the door closing operation by the automatic closing unit 6. Then, when power is restored, power supply to the solenoid 40 is resumed, and the solenoid 40 automatically switches to the ON state.

[0053] When a power outage occurs, the control unit 11 switches the switching unit of the automatic closing unit 6 from the retracted state to the connected state, but does not switch immediately, maintaining the retracted state until the battery 12 is depleted. Therefore, if the power outage is a momentary power outage, the switching unit does not switch to the connected state and maintains the retracted state. Therefore, even if a momentary power outage occurs, there is no change in the operation of the electric door closer, and the door will close electrically just as it did before the power outage, even after the momentary power outage. The user can use the electric door closer as usual immediately after power is restored, without being particularly aware that there was a momentary power outage. Furthermore, there is no need to perform any special operations after power is restored.

[0054] On the other hand, in the event of a prolonged power outage, the battery 12 will run down, the control unit 11 will stop supplying power to the solenoid 40, and the switching unit will transition from the retracted state to the connected state. When the switching unit transitions to the connected state, the spring 30 and the energy storage unit will connect, and the spring 30 and the energy storage unit will operate in conjunction with the opening and closing of the door. When the door is manually opened during a power outage, the energy storage unit will store energy in the spring 30 to generate a closing force. Therefore, a manually opened door will automatically close due to the closing force of the spring 30.

[0055] In the event of a power outage, the control unit 11 continues to supply power to the solenoid 40 until the battery 12 is depleted. This makes it easy to control the solenoid 40, and the configuration of the control unit 11 can be simple. Furthermore, by incorporating a large-capacity battery, it is possible to easily handle long-term power outages, for example, power outages of several tens of minutes. Furthermore, when the battery runs out and the control unit 11 stops supplying power to the solenoid 40, the electromagnetic force no longer acts, and the force of the spring 30 allows the solenoid 40 to easily transition from the retracted state to the connected state.

[0056] In this embodiment, the control unit 11 continues to supply power to the solenoid 40 after a power outage until the battery 12 is completely depleted. However, instead of completely depleting the battery 12, the control unit 11 may stop supplying power to the solenoid 40 and transition to manual mode while leaving enough charge in the battery 12 to allow for voltage boosting. That is, the control unit 11 may transition to manual mode even when power supply to the solenoid 40 is still possible. The control unit 11 monitors the voltage of the battery 12, and in the event of a power outage, continues supplying power to the solenoid 40 until the voltage of the battery 12 drops to a predetermined value. Then, the control unit 11 may stop supplying power to the solenoid 40 when the voltage of the battery 12 drops to the predetermined value. In this way, control may be exercised to transition from electric mode to manual mode based on the voltage value of the battery 12.

[0057] The transition to manual mode may also be based on the time since the power outage. The control unit 11 measures the time since the power outage. The control unit 11 may maintain the switching unit in a retracted state until a predetermined time has elapsed since the power outage, and then switch the switching unit to a connected state after the predetermined time has elapsed. In this case, the power supply to the solenoid 40 is stopped after the predetermined time has elapsed, regardless of the remaining charge of the battery 12, i.e., even if the battery 12 is nearly fully charged. Since the system automatically switches to manual mode after the predetermined time has elapsed regardless of the number of times the door is opened and closed after the power outage, the user only needs to be aware of the time that has elapsed since the power outage. In addition, in buildings with multiple doors, the number of times each door is opened and closed after the power outage may vary from door to door. Even in such cases, the electric door closers of all doors can be switched to manual mode after a predetermined time has elapsed since the power outage. Conversely, the time until switching to manual mode can be set to be different for each door. The time until switching to manual mode may also be adjustable or changeable by the user.

[0058] Furthermore, the electric door closer may be configured to transition to manual mode depending on the number of times the door is closed after a power outage. When a power outage occurs, the control unit 11 counts the number of times the door is closed by the electric drive unit 10. Then, when the number of times the door is closed by the electric drive unit 10 reaches a predetermined number, the control unit 11 stops supplying power to the solenoid 40, and the electric door closer transitions from electric mode to manual mode. In this case, the user can determine the timing to transition to manual mode based on the number of times the door is closed after a power outage.

[0059] Next, an electric door closer according to a second embodiment of the present invention will be described. Note that detailed description of the same configuration as in the first embodiment will be omitted. Figures 8 to 11 show the electric door closer of this embodiment. The electric door closer of this embodiment differs from that of the first embodiment mainly in the switching unit of the automatic closing unit 6.

[0060] The self-closing unit 6 includes an auxiliary motor 60. The control unit 11 controls the auxiliary motor 60. When switching from the electric mode to the manual mode, the auxiliary motor 60 moves the spring 30 from a standby position (a retracted position) to a connected position (a connected position), and when switching from the manual mode to the electric mode, the auxiliary motor 60 returns the spring 30 from the connected position to the standby position. The auxiliary motor 60 is fixed to the frame 7. The auxiliary motor 60 has an axis in the left-right direction. The auxiliary motor 60 has a screw shaft 61 extending toward the left. The screw shaft 61 penetrates the first spring holder 31 in the left-right direction. The first spring holder 31 has a female screw portion 62 that screws onto the screw shaft 61. That is, in this embodiment, the first spring holder 31 is not fixed to the frame 7 but is provided so as to be movable in the left-right direction. The screw shaft 61 and the female screw portion 62 of the first spring holder 31 form a screw feed mechanism. In this embodiment, the auxiliary motor 60, the screw shaft 61, and the female screw portion 62 of the first spring holder 31 constitute a switching unit and also constitute an auxiliary drive unit that moves the spring 30. It is preferable that a sensor be provided to detect the left-right position of the first spring holder 31, and that the control unit 11 control the auxiliary motor 60 based on the output of the sensor.

[0061] The auxiliary motor 60 moves the first spring retainer 31, thereby moving the spring 30 and the second spring retainer 32. The auxiliary motor 60 moves the first spring retainer 31 between an energized position (shown by a solid line in FIG. 8 and a two-dot chain line in FIG. 11 ) and a power-off position (shown by a two-dot chain line in FIG. 8 and a solid line in FIG. 11 ). The first spring retainer 31 is located in the energized position in the electric mode and in the power-off position in the manual mode. When switching from the electric mode to the manual mode, the first spring retainer 31 moves from the energized position to the power-off position, and the spring 30 moves from the standby position to the connected position. When the spring 30 is located in the standby position, the second spring retainer 32 is separated to the right from the contact head 53. Even when the door is opened or closed in the electric mode and the contact head 53 moves left or right, the contact head 53 does not contact the second spring retainer 32. When the spring 30 is in the connected position, the second spring retainer 32 is in contact with the contact head 53. Therefore, when the door is opened or closed in the manual mode, the contact head 53 and the second spring retainer 32 move left and right while maintaining their contact state.

[0062] In FIG. 8, the spring 30 is in a free length state. However, the spring 30 may also be in a slightly compressed state. For example, a limiting rod may be provided to limit the distance between the first spring retainer 31 and the second spring retainer 32 so that it does not exceed a predetermined distance and to allow the second spring retainer 32 to move to the right, thereby placing the spring 30 in a slightly compressed state. In this embodiment, the spring 30 is in a free length state in FIG. 8. In the electric mode, the second spring retainer 32 is spaced to the right from the contact head 53, and the spring 30, the first spring retainer 31, and the second spring retainer 32 are in a separated state, spaced to the right from the contact head 53. Even when the door is fully open, the contact head 53 does not contact the second spring retainer 32.

[0063] FIG. 9 shows the state immediately after transitioning from electric mode to manual mode. When a power outage occurs, the control unit 11 maintains the electric mode until a predetermined time has elapsed since the power outage. Then, once the predetermined time has elapsed since the power outage, the control unit 11 activates the auxiliary motor 60 to transition to manual mode. The control unit 11 rotates the auxiliary motor 60 in a first direction using power from the battery 12. When the auxiliary motor 60 activates and the screw shaft 61 rotates in the first direction, the first spring retainer 31 moves to the left, and the first spring retainer 31 pushes the spring 30 to the left, causing the second spring retainer 32 to move leftward in conjunction with the first spring retainer 31. Then, as shown in FIG. 10, the second spring retainer 32 abuts against the abutment head 53, and the control unit 11 stops the auxiliary motor 60.

[0064] Figure 11 shows the state in which the door is being manually opened from this state. As the energy storage rod 51 moves to the right, the second spring retainer 32 is pushed by the abutment head 53 and moves to the right, compressing the spring 30. A force in the right direction acts on the first spring retainer 31 from the spring 30, but due to the self-locking nature of the screw feed mechanism, the first spring retainer 31 does not move to the right and remains in that position. Therefore, in manual mode, the automatic closing unit 6 automatically closes the manually opened door.

[0065] When power is restored, the control unit 11 uses normal commercial power to rotate the auxiliary motor 60 in a second direction opposite to the first direction, moving the first spring retainer 31 from the power failure position to the powered position. When the first spring retainer 31 returns to the powered position, the second spring retainer 32 moves away from the contact head 53, and the spring 30 separates from the energy storage rod 51 to the right and returns to the standby position.

[0066] As described above, this embodiment is provided with the auxiliary motor 60 for the manual mode. Therefore, the auxiliary motor 60 can move the spring 30 accurately and reliably.

[0067] It should be noted that a position adjustment unit may be provided for adjusting the standby position of the spring 30 in the left-right direction. By adjusting the standby position of the spring 30 in the left-right direction, the spring 30 in the standby position can be moved closer to or further away from the spindle 4, and the distance between the contact head 53 and the second spring bearing 32 can be adjusted. This makes it possible to adjust the standby position of the spring 30 depending on where the door is installed, and easily accommodate cases where the door can be opened or closed at a large or small angle.

[0068] In addition, in this embodiment, the control unit 11 activates the auxiliary motor 60 and transitions to manual mode as time passes after the power outage occurs, but it may also activate the auxiliary motor 60 and transition to manual mode when the voltage value of the battery 12 drops to a predetermined value, or it may transition to manual mode based on the number of times the door is closed after the power outage.

[0069] Next, an electric door closer according to a third embodiment of the present invention will be described. Note that detailed description of the same configuration as in the first embodiment will be omitted. Figures 12 to 19 show the electric door closer of this embodiment. The electric door closer of this embodiment differs from that of the first embodiment mainly in the switching part of the self-closing part 6. In this embodiment, an electromagnet 72, a separation spring 73, a regulating body 74, and a regulating ball 44, which will be described later, make up the switching part. The regulating ball 44 is the first engaging part, and the locking groove 33a of the regulating shaft 33 is the second engaging part. The regulating body 74 is a stopper. The electromagnet 72 is an electromagnetic member, and the separation spring 73 is a biasing part.

[0070] The first spring bearing 31 is fixed to the frame 7. The first spring bearing 31 has a bearing portion 31a that bears the spring 30 and a guide tube portion 31b that protrudes to the right from the bearing portion 31a. The bearing portion 31a may have any shape, but in this embodiment, it has a rectangular shape when viewed from the left and right, as shown in FIG. 13(b). The guide tube portion 31b is cylindrical. The guide tube portion 31b may be formed integrally with the bearing portion 31a, or may be formed separately from the bearing portion 31a and fixed to the bearing portion 31a by screws or the like. The guide tube portion 31b is coaxial with the regulating shaft 33. The regulating shaft 33 is inserted through the first spring bearing 31. As shown in FIG. 13(a), the guide tube portion 31b has a plurality of horizontal holes 31c that penetrate radially. Regulating balls 44 fit into the horizontal holes 31c. A plurality of regulating balls 44 are provided. Preferably, each horizontal hole 31c is provided with one restriction ball 44. The restriction ball 44 is movable in the horizontal hole 31c in the radial direction of the guide tube portion 31b.

[0071] A locking groove 33a is formed on the outer peripheral surface of the restriction shaft 33. A restriction ball 44 can be engaged with the locking groove 33a. Both left and right side surfaces of the locking groove 33a are inclined, and the width of the locking groove 33a increases radially outward. By providing the inclined surfaces in the locking groove 33a, when the restriction shaft 33 moves left and right, the inclined surfaces of the locking groove 33a can push the restriction ball 44 radially outward of the restriction shaft 33.

[0072] A support stay 70 is attached to the frame 7. The support stay 70 is disposed a predetermined distance to the right of the first spring bearing 31. A support hole 71 is formed in the center of the support stay 70. The support hole 71 passes through the support stay 70 in the left-right direction. The right end of the regulating shaft 33 is inserted into the support hole 71. The regulating shaft 33 is guided by the support hole 71. The regulating shaft 33 is supported by the first spring bearing 31 and the support stay 70 so as to be slidable.

[0073] An electromagnet 72 is attached to the left surface of the support stay 70. As shown in FIG. 13(b), a plurality of electromagnets 72 are provided. Specifically, the electromagnets 72 are arranged at equal intervals around the support hole 71. The number of electromagnets 72 is arbitrary, but in this embodiment there are three. Separation springs 73 are arranged between the electromagnets 72. The separation springs 73 are compression coil springs with an axis in the left-right direction. The separation springs 73 are also arranged at equal intervals around the support hole 71, and in this embodiment there are three.

[0074] A regulating body 74 is disposed on the left side of the electromagnet 72. The regulating body 74 is disposed between the receiving portion 31a of the first spring bearing 31 and the electromagnet 72, and is movable in the left-right direction in the section between the receiving portion 31a of the first spring bearing 31 and the electromagnet 72. The guide tube portion 31b of the first spring bearing 31 extends to the electromagnet 72. The guide tube portion 31b penetrates the regulating body 74 in the left-right direction. The regulating body 74 slides in the left-right direction while being guided by the outer peripheral surface of the guide tube portion 31b. When the regulating body 74 moves, the regulating body 74 slides on the outer peripheral surface of the guide tube portion 31b. The outer shape of the regulating body 74 is arbitrary, but in this embodiment, it is circular as shown in FIG. 13(b). That is, the regulating body 74 is cylindrical.

[0075] The inner peripheral surface of the regulating body 74 is provided with a regulating portion 75 having a constant diameter and a relief portion 76 having a larger diameter than the regulating portion 75. The relief portion 76 is provided on the right side of the regulating portion 75. The relief portion 76 is a groove recessed radially outward from the regulating portion 75. The regulating ball 44 can engage with the relief portion 76. It is preferable that an inclined surface 77 be provided on the wall surface of the relief portion 76 on the regulating portion 75 side, the diameter of which increases as it moves away from the regulating portion 75 to the right.

[0076] As shown in FIG. 14 , the regulating body 74 is preferably configured from two left and right members. That is, the regulating body 74 preferably includes a first member 78 and a second member 79 configured separately from each other. The first member 78 is provided with a recess 76, and the second member 79 is provided with a regulating portion 75. In this embodiment, the first member 78 is provided with a right-hand portion of the recess 76 excluding the inclined surface 77, and the second member 79 is provided with the regulating portion 75 and the inclined surface 77 of the recess 76. The first member 78 and the second member 79 are fixed to each other with screws, for example, to form an integrated unit. By configuring the regulating body 74 from two members in this way, the regulating portion 75 and the recess 76 can be easily machined.

[0077] The regulating body 74 is made of a ferromagnetic material. The repulsion spring 73 is disposed between the regulating body 74 and the support stay 70 and biases the regulating body 74 to the left. In the electric mode, the electromagnet 72 attracts the regulating body 74 against the biasing force of the repulsion spring 73. The position of the regulating body 74 when attracted to the electromagnet 72 is the first position. When switching to the manual mode, power supply to the electromagnet 72 is stopped, so that the electromagnet 72 releases the attraction of the regulating body 74, and the regulating body 74 moves away from the electromagnet 72 to the left due to the biasing force of the repulsion spring 73. The regulating body 74 is pushed by the repulsion spring 73 and moves until it abuts against the receiving portion 31a of the first spring bearing 31. The position of the regulating body 74 at this time is the second position.

[0078] 12 and 13(a) show the state of the electric mode. In the electric mode, the electromagnet 72 attracts and holds the regulating body 74. The regulating ball 44 is in a state in which it partially protrudes radially inward from the horizontal hole 31c of the guide tube portion 31b and is engaged with the locking groove 33a of the regulating shaft 33. The approximately hemispherical portion of the regulating ball 44 is located in the horizontal hole 31c of the guide tube portion 31b, and the remaining approximately hemispherical portion is engaged with the locking groove 33a. The regulating portion 75 of the regulating body 74 is located radially outward of the regulating ball 44 and restricts the regulating ball 44 from moving radially outward. Therefore, the engagement state between the regulating ball 44 and the locking groove 33a is maintained, the regulating shaft 33 cannot move to the left, and the spring 30 is maintained in a compressed state.

[0079] When the door is opened in the electric mode, the contact head 53 moves to the position shown by the two-dot chain line in Fig. 12. That is, in the electric mode, as the door is opened and closed, the contact head 53 moves back and forth between the closed position shown by the solid line in Fig. 12 and the open position shown by the two-dot chain line. In the electric mode shown in Fig. 12, the contact head 53 does not contact the second spring retainer 32. The second spring retainer 32 is positioned so that it does not contact the contact head 53 located in the open position, and a gap is provided between the contact head 53 in the open position and the second spring retainer 32.

[0080] When a power outage occurs, the control unit 11 switches to the manual mode after a delay. The control unit 11 controls the switch to the manual mode based on the above-mentioned factors: when the battery 12 runs out, the voltage value of the battery 12, the time elapsed since the power outage, the number of times the door is electrically closed after the power outage, etc. When the manual mode is activated, the electromagnet 72 releases the regulating body 74, as shown in FIG. 15 . The regulating body 74 is pushed by the retracting spring 73 to move leftward and abuts against the receiving portion 31a of the first spring receiving portion 31, stopping there. When the recess 76 of the regulating body 74 faces the radially outer side of the regulating ball 44, the regulating ball 44 moves radially outward of the guide tube portion 31b, disengages from the locking groove 33a, and fits into the recess 76. When the regulating ball 44 disengages from the locking groove 33a, the regulating state of the regulating shaft 33 is released, and the regulating shaft 33 becomes movable. The spring 30 moves the regulating shaft 33 to the left together with the second spring retainer 32. Then, as shown in Figure 16, the second spring retainer 32 abuts against the abutment head 53, which is located in the closed position. The regulating ball 44 is in a state in which it partially protrudes radially outward from the horizontal hole 31c of the guide tube portion 31b and engages with the recess 76 of the regulating body 74. That is, the approximately hemispherical portion of the regulating ball 44 is located in the horizontal hole 31c of the guide tube portion 31b, and the remaining approximately hemispherical portion engages with the recess 76.

[0081] Figure 17 shows the door being manually opened in manual mode. The door opening operation moves the energy storage rod 51 to the right. The second spring retainer 32 and the regulating shaft 33 are pushed by the energy storage rod 51 and move to the right, compressing the spring 30 and storing closing force. Because the regulating ball 44 is in a state where it is avoided by the recess 76 of the regulating body 74, the regulating shaft 33 can move to the right. The manually opened door is then automatically closed by the spring 30.

[0082] When the power supply is resumed, the control unit 11 resumes the power supply to the electromagnet 72. When the power supply is resumed in the closed door state as shown in FIG. 16 , the electromagnet 72 magnetically attracts the regulating body 74, which has moved away to the left. The regulating body 74 attempts to move to the right due to the magnetic force of the electromagnet 72, but the regulating ball 44, which partially protrudes radially outward from the horizontal hole 31c of the guide tube portion 31b, engages with the recess 76 of the regulating body 74. The regulating ball 44 is restricted from moving radially inward of the regulating shaft 33 by the outer circumferential surface of the regulating shaft 33. Therefore, the regulating ball 44 remains engaged with the recess 76, the regulating body 74 cannot move to the right, and the regulating body 74 remains separated from the electromagnet 72.

[0083] After the power supply is resumed, the door is manually opened wide. As shown in FIG. 18 , the door is manually opened until the locking groove 33a of the regulating shaft 33 reaches the position of the regulating ball 44. At this time, the abutment head 53 is positioned further to the right than the position when the door is opened to the predetermined opening angle in the electric mode. When the locking groove 33a of the regulating shaft 33 reaches a position facing the regulating ball 44, the regulating ball 44 can move radially inward. As described above, the power supply to the electromagnet 72 is resumed by the resumption of the power supply, and the regulating body 74 attempts to move to the right due to the magnetic force of the electromagnet 72. Therefore, the regulating ball 44, which is engaged with the recess 76, is pushed out by the regulating body 74 and moves radially inward of the regulating shaft 33, and disengages from the recess 76. In particular, when the wall surface on the left side of the escape portion 76 is an inclined surface 77, the inclined surface 77 pushes the regulating ball 44 to the right, thereby applying a force to the regulating ball 44 in the radial direction inward of the regulating shaft 33, and the regulating ball 44 can be smoothly moved radially inward of the regulating shaft 33.

[0084] As the regulating ball 44 disengages from the recess 76, the regulating body 74 can move to the right, and as shown in FIG. 19, the electromagnet 72 attracts the regulating body 74 against the biasing force of the separation spring 73. Meanwhile, the regulating ball 44 engages with the locking groove 33a of the regulating shaft 33, and the regulating portion 75 of the regulating body 74 faces the regulating ball 44, preventing the regulating ball 44 from moving radially outward from the regulating shaft 33. Therefore, the engagement between the regulating ball 44 and the locking groove 33a is maintained, the regulating shaft 33 cannot move to the left, and the spring 30 is held in a compressed state. The door is then electrically closed.

[0085] In this manner, in this embodiment, when switching from the electric mode to the manual mode after a power outage, the control unit 11 stops the power supply to the electromagnet 72. This allows the compressed state of the spring 30 to be instantly released, and the second spring holder 32 can be brought into contact with the contact head 53.

[0086] In the above embodiment, the energy storage unit includes the rack 52 and the pinion gear 50, but instead of these, a cam may be provided.

[0087] Next, an electric door closer according to a fourth embodiment of the present invention will be described. Detailed descriptions of components similar to those of the first embodiment will be omitted. Figures 20 to 31 show the electric door closer of this embodiment. Figures 22 to 25 omit the illustration of the motorized unit 5 and show only the self-closing unit 6. The electric door closer of this embodiment differs from that of the first embodiment mainly in the switching unit and the energy storage unit of the self-closing unit 6. In this embodiment, the energy storage unit uses a cam 80 instead of the rack-and-pinion type described above. The switching unit is mainly composed of a regulating plate 86, an engaging roller 88, a regulating roller 89, a regulating pin 100, an auxiliary spring 99, an adsorption plate 102, and an electromagnet 72, which will be described later. The engaging roller 88 is the first engaging unit, and the engaging recess 87 of the regulating plate 86 is the second engaging unit. The regulating roller 89 is the stopper. The electromagnet 72 is an electromagnetic member. In this embodiment, the spring 30 biases the regulating roller 89 toward the second position.

[0088] Figures 20 and 21 show the fully closed state in the electric mode. The cam 80 is provided on the main shaft 4 and rotates integrally with the main shaft 4. The cam 80 may be configured as an integral part of the main shaft 4 or may be configured as a separate component, i.e., a separate part. A slide plate 81 is provided near the main shaft 4. The slide plate 81 is plate-shaped with its thickness direction in the vertical direction. A pair of slide plates 81 are provided, one above the other. The cam 80 is disposed between the pair of upper and lower slide plates 81. The slide plate 81 is movable in the left-right direction relative to the frame 7. A slide hole 82 is formed in the slide plate 81, penetrating it in the vertical direction. The slide hole 82 is elongated in the left-right direction. The main shaft 4 passes through the slide hole 82.

[0089] Guide rollers 83a, 83b, 83c, and 83d are rotatably supported on the upper and lower slide plates 81. The guide rollers 83a, 83b, 83c, and 83d rotate in contact with the inner surface of the frame 7. A total of four guide rollers 83a, 83b, 83c, and 83d are provided, spaced apart in the front, back, left, and right directions. The guide rollers 83a, 83b, 83c, and 83d are disposed between the upper and lower slide plates 81 and near the four corners of the slide plate 81. The guide rollers 83a, 83b, 83c, and 83d have axes extending in the vertical direction. The guide rollers 83a, 83b, 83c, and 83d rotate or slide in contact with the inner surface of the frame 7, causing the slide plate 81 to slide left and right. Of the four guide rollers 83a, 83b, 83c, and 83d, the guide roller 83a on the right side and in front is a cam follower and abuts against the cam 80. When the cam 80 rotates together with the main shaft 4 during door opening, the guide roller 83a as a cam follower is pushed and moved to the right by the cam 80, and the slide plate 81 moves to the right. However, the guide roller 83a as a cam follower may be separated from the cam 80 to the right.

[0090] The spring 30 is disposed between a first spring bearing 31 and a second spring bearing 32. The first spring bearing 31 is disposed to the right of the second spring bearing 32 and is fixed to the frame 7. A restricting shaft 33 is inserted through the radially inner side of the spring 30. The restricting shaft 33 has an axis along the left-right direction. A male thread is formed on the left end of the restricting shaft 33, and the second spring bearing 32 is threadedly engaged with the male thread. By rotating the second spring bearing 32 around the axis of the restricting shaft 33, the second spring bearing 32 can be moved left and right along the restricting shaft 33. In other words, the second spring bearing 32 can be moved toward or away from the first spring bearing 31, thereby adjusting the spring force of the spring 30. The second spring bearing 32 functions as a spring adjustment unit for adjusting the spring force of the spring 30. A large number of holes are formed radially on the outer circumferential surface of the second spring bearing 32, and the second spring bearing 32 can be rotated by inserting a tool into these holes.

[0091] An abutment head 53 is provided on the left end of the regulating shaft 33. The abutment head 53 faces the right side of the slide plate 81 at a distance. In the manual mode, the abutment head 53 moves to the left and abuts against the slide plate 81, but in the electric mode, the slide plate 81 does not abut against the abutment head 53 when the door is opened or closed automatically. At the energized door opening angle, a predetermined gap is secured between the slide plate 81 and the abutment head 53.

[0092] The regulating shaft 33 penetrates the first spring bearing 31 in the left-right direction and protrudes a predetermined distance to the right of the first spring bearing 31. A holder 85 is fixed to the right end of the regulating shaft 33. A pair of upper and lower regulating plates 86 are fixed to the holder 85 at their left ends. The regulating plates 86 are plate-shaped with their thicknesses measured in the vertical direction. The pair of upper and lower regulating plates 86 are fixed to the upper and lower surfaces of the holder 85, respectively. The pair of upper and lower regulating plates 86 are formed to be symmetrical with each other and have the same shape. An engaging recess 87 is formed on each of the opposing surfaces of the pair of upper and lower regulating plates 86. The upper part of Figure 20 shows the regulating plate 86 as viewed from the back. The engaging recess 87 extends in the front-rear direction. The engaging recess 87 is provided on the lower surface of the upper regulating plate 86 and on the upper surface of the lower regulating plate 86 so as to face each other. The right end of each regulating plate 86 is a free end.

[0093] A damper is provided to interfere with the movement of the regulating shaft 33 by the spring 30. The damper is an air damper. A damper body 110 is attached to the first spring bearing 31. The damper body 110 extends toward the left from the first spring bearing 31. A pair of front and rear damper bodies 110 are arranged, located in front of and behind the spring 30. A fitting hole 111 that opens to the right is formed in the damper body 110. A piston shaft 112 is slidably fitted into this fitting hole 111. A pair of front and rear piston shafts 112 are provided corresponding to the damper bodies 110. The piston shaft 112 penetrates the first spring bearing 31 in the left-right direction. The right end of the piston shaft 112 is fixed to the holder 85. When the piston shaft 112 moves to the left, the air flow resistance of the fitting hole 111 acts as a buffer force on the piston shaft 112.

[0094] A pair of upper and lower engagement rollers 88 are disposed between the pair of upper and lower regulating plates 86. The engagement rollers 88 engage with the engagement recesses 87. The engagement rollers 88 are disposed so that their axes are aligned in the front-to-rear direction. The axes of the upper and lower engagement rollers 88 are parallel to each other, spaced apart vertically, and positioned at the same position in the left-to-right direction. Only the upper part of the upper engagement roller 88 engages with the engagement recess 87 of the upper regulating plate 86, while only the lower part of the lower engagement roller 88 engages with the engagement recess 87 of the lower regulating plate 86. The engagement recesses 87 are disposed at positions where the engagement rollers 88 engage when the door is opened beyond the energized door-opening angle. The depth of the engagement recesses 87 is smaller than the radius of the engagement rollers 88. Two pairs of upper and lower engagement rollers 88 are disposed spaced apart vertically. In other words, a total of four engagement rollers 88 are provided.

[0095] A regulating roller 89 is disposed between the pair of upper and lower engaging rollers 88. Two regulating rollers 89 are provided in total, one at the front and one at the back. The regulating roller 89 is disposed in a position slightly off-center to the right relative to the pair of upper and lower engaging rollers 88. The axis of the regulating roller 89 is located to the right of the axis of the engaging roller 88. In this embodiment, the regulating roller 89 has a smaller diameter than the engaging roller 88, and is longer in the axial direction (front-rear direction) than the engaging roller 88.

[0096] The engagement roller 88 and the regulating roller 89 are supported at their opposite ends by a first support member 91 and a second support member 92, respectively. The first support member 91 and the second support member 92 are disposed between the upper and lower regulating plates 86. The first support member 91 and the second support member 92 are movable in the left-right direction relative to the upper and lower regulating plates 86. FIG. 26 shows the first support member 91. The first support member 91 is block-shaped and has a front-to-back symmetrical shape. Support grooves are formed on the front and rear surfaces of the first support member 91 for movably supporting the engagement roller 88 and the regulating roller 89, respectively. More specifically, lateral support grooves 93, which are elongated in the left-to-right direction, are formed in the center of the front and rear surfaces of the first support member 91. The lateral support grooves 93 are support grooves that support the regulating roller 89. One end of the regulating roller 89 engages with the lateral support groove 93 in the axial direction of the regulating roller 89, i.e., in the front-to-back direction. The regulating roller 89 is guided by the lateral support groove 93 and is movable in the left-right direction.

[0097] Vertical support grooves 94 are formed above and below the left portion of the lateral support groove 93. The vertical support grooves 94 are support grooves for supporting the engagement roller 88. The upper and lower vertical support grooves 94 are arranged symmetrically relative to each other. The vertical support grooves 94 extend in the vertical direction. The upper vertical support groove 94 reaches the upper surface of the first support member 91 and opens on the upper surface, while the lower vertical support groove 94 reaches the lower surface of the first support member 91 and opens on the lower surface. One end of the engagement roller 88 engages with the vertical support groove 94 in the front-to-rear direction. The engagement roller 88 is guided by the vertical support groove 94 and can move in the vertical direction. The vertical support groove 94 is shallower than the lateral support groove 93.

[0098] FIG. 27 shows the second support member 92. A pair of second support members 92 are provided, one in front and one in back, and are arranged symmetrically in the front-to-back direction. Similar lateral support grooves 93 and vertical support grooves 94 are also formed on one side of the second support member 92. The lateral support groove 93 and vertical support groove 94 are formed on the rear surface of the front second support member 92, and on the front surface of the rear second support member 92. The other end of the regulating roller 89 engages with and is supported in the lateral support groove 94 of the second support member 92, and the other end of the engaging roller 88 engages with and is supported in the vertical support groove 94 of the second support member 92. The first support member 91 is arranged in the middle in the front-to-back direction, and the front and rear second support members 92 are arranged a predetermined distance in front of and behind the first support member 91, respectively. A first set of upper and lower pair of engagement rollers 88 and regulating rollers 89 is disposed between the first support member 91 and the front second support member 92, and a second set of upper and lower pair of engagement rollers 88 and regulating rollers 89 is disposed between the first support member 91 and the rear second support member 92. Both front and rear ends of the engagement rollers 88 and regulating rollers 89 are supported by the first support member 91 and the second support member 92. The engagement rollers 88 are movable in the up and down direction, and the regulating rollers 89 are movable in the left and right direction.

[0099] In addition, in Figure 26, the engagement rollers 88 and the regulating rollers 89 in the electric mode are indicated by two-dot chain lines, and in Figure 27, the engagement rollers 88 and the regulating rollers 89 in the manual mode are indicated by two-dot chain lines. In the electric mode, the regulating roller 89 is moved close to the dead point and is located near the left end of the lateral support groove 93, and the upper and lower engagement rollers 88 are moved upward and downward, respectively. The position of the regulating roller 89 at this time is the first position. In the manual mode, the regulating roller 89 is moved to the right, and the upper and lower engagement rollers 88 are moved downward and upward, respectively. The position of the regulating roller 89 at this time is the second position.

[0100] The first support member 91 and the front and rear second support members 92 are fixed to an inner frame 95. The inner frame 95 is made up of multiple members that are connected together to form a framework. The inner frame 95 is configured so that its position can be adjusted left and right relative to the frame 7, and the mechanism for adjusting this position (position adjustment unit) will be described later. The inner frame 95 is long in the left and right direction, and the first support member 91 and the second support member 92 are attached to the left side of the inner frame 95.

[0101] 30, an adjustment shaft 120 passes through the first support member 91 in the left-right direction. The adjustment shaft 120 extends in the left-right direction. The adjustment shaft 120 protrudes from the first support member 91 to the left and right. A male thread is formed on the left end of the adjustment shaft 120, and an adjustment nut 121 is threadedly engaged with this male thread. Similar to the outer peripheral surface of the second spring bearing 32 described above, a large number of holes are formed radially on the outer peripheral surface of the adjustment nut 121, and a tool can be inserted into these holes to rotate the adjustment nut 121.

[0102] It is preferable to provide a window in the frame 7 that exposes the adjusting nut 121 so that a tool can be inserted through the window into the hole in the adjusting nut 121. As described above, the frame 7 is exposed when the cover 8 is removed. With the cover 8 removed, a tool can be inserted through the window into the hole in the adjusting nut 121 to rotate the adjusting nut 121.

[0103] The inner frame 95 is provided with a left end plate 96 at its left end. The adjusting nut 121 is located between the left end plate 96 and the first support member 91. When the adjusting nut 121 is rotated in a first direction as if screwing it in and moved to the right, the adjusting nut 121 slides on the left end surface of the first support member 91 and pushes the first support member 91 to the right. Conversely, when the adjusting nut 121 is rotated in a second direction as if loosening it and moved to the left, the adjusting nut 121 slides on the right end surface of the left end plate 96 and pushes the left end plate 96 to the left.

[0104] The right end of the adjustment shaft 120 is fixed to a bridge 122. The bridge 122 is long in the front-rear direction and is fixed to the frame 7. Therefore, by rotating the adjustment nut 121, the position of the inner frame 95 can be adjusted in the left-right direction relative to the frame 7. In this embodiment, the adjustment shaft 120 and the adjustment nut 121 form a position adjustment unit, which is a screw feed mechanism. This position adjustment unit will be described in more detail below.

[0105] The inner frame 95 extends to the right of the bridge 122, bypassing the bridge 122 up and down. An electromagnet 72 is attached to the right part of the inner frame 95, which is located to the right of the bridge 122. Power is supplied to the electromagnet 72 from the control unit 11. The attracting surface of the electromagnet 72 is provided at the right end and faces right. The attracting direction of the electromagnet 72 faces left.

[0106] The inner frame 95 is provided with a right end plate 97 at its right end. The right end plate 97 is spaced a predetermined distance to the right of the electromagnet 72. The left end surface of the right end plate 97 faces an attraction plate 102, which will be described later. A countersunk hole 98 is formed in the left end surface of the right end plate 97. The countersunk holes 98 are provided in multiple locations. The right end of an auxiliary spring 99 fits into the countersunk hole 98.

[0107] Meanwhile, a regulating pin 100 is disposed on the right side of the regulating roller 89. The left end surface of the regulating pin 100 abuts against the regulating roller 89. The regulating pin 100 extends in the left-right direction. The center of the regulating roller 89 is located on an extension of the axis of the regulating pin 100. A pair of regulating pins 100, one in front and one in back, is provided corresponding to the regulating roller 89. The regulating pins 100 are attached to a connecting member 101. The connecting member 101 is inserted through a bridge 122 in the left-right direction and is slidable in the left-right direction relative to the bridge 122. The connecting member 101 extends to the right, bypassing the front and rear of the electromagnet 72. An attraction plate 102 is attached to the right end of the connecting member 101. The attraction plate 102 is made of a ferromagnetic material. When the electromagnet 72 is energized, the attraction plate 102 is attracted to the attraction surface of the electromagnet 72 and comes into close contact with the electromagnet 72. The suction plate 102 is disposed between the electromagnet 72 and the right end plate 97 of the inner frame 95. The auxiliary spring 99 described above is disposed between the suction plate 102 and the inner frame 95. The auxiliary spring 99 pushes the suction plate 102 to the left. Therefore, in the electric mode, both the electromagnetic force of the electromagnet 72 and the spring force of the auxiliary spring 99 act on the suction plate 102, and both act on the suction plate 102 in the leftward direction. In the manual mode, the electromagnetic force of the electromagnet 72 does not act, and only the spring force of the auxiliary spring 99 acts on the suction plate 102.

[0108] In the electric mode, a leftward force is applied to the regulating pin 100 by the electromagnetic force of the electromagnet 72 acting on the suction plate 102 and the spring force of the auxiliary spring 99, causing the regulating pin 100 to push the regulating roller 89 to the left. The regulating roller 89 pushes the upper engagement roller 88 upward and pushes the lower engagement roller 88 downward. As a result, the upper and lower engagement rollers 88 engage with the engagement recesses 87 of the upper and lower regulating plates 86, respectively. Meanwhile, the spring force of the compressed spring 30 acts on the regulating plate 86, and the regulating plate 86 is pushed to the right by the spring 30. The spring force of the spring 30 acts on the upper and lower engagement rollers 88 via the engagement recesses 87, pushing the upper and lower engagement rollers 88 toward the regulating roller 89. That is, the spring force of the spring 30 acts on the upper engagement roller 88 as a force pushing down the upper engagement roller 88, and also acts on the lower engagement roller 88 as a force pushing up the lower engagement roller 88. The force acting on the upper and lower engagement rollers 88 from the spring 30 acts on the regulation roller 89 as a force tending to move the regulation roller 89 to the right.

[0109] In this way, a rightward force is applied to the regulating roller 89 from the spring 30 via the engagement recess 87 and engagement roller 88, while a leftward force is applied from the electromagnet 72 and auxiliary spring 99 via the regulating pin 100. In the electric mode, the leftward force from the electromagnet 72 and auxiliary spring 99 is greater than the rightward force from the spring 30. Therefore, as shown in Figures 20, 21 and 28, the regulating roller 89 presses the upper and lower engagement rollers 88 up and down to engage with the engagement recess 87.

[0110] Figure 22 shows the state immediately after transition to the manual mode. Figure 29 also shows the state in the manual mode. In the manual mode, the electromagnetic force of the electromagnet 72 no longer acts, so the balance of forces between the left and right is reversed. In other words, the leftward force exerted by the auxiliary spring 99 alone becomes smaller than the rightward force exerted by the spring 30. As a result, the restriction roller 89 moves to the right as if being pushed by the upper and lower engagement rollers 88, and the engagement rollers 88 disengage from the engagement recesses 87, thereby releasing the engagement between the engagement rollers 88 and the engagement recesses 87.

[0111] When the engaging roller 88 disengages from the engaging recess 87, the spring force of the spring 30 moves the regulating plate 86 to the left. Then, as shown in Figure 23, the contact head 53 comes into contact with the upper and lower slide plates 81. The provision of a damper reduces the impact when the contact head 53 comes into contact with the slide plates 81.

[0112] In the manual mode, the door can be opened manually and closed by the closing force of the spring 30. After that, when the power outage is resolved and power is restored, the door is manually opened wide. FIG. 24 shows the state during manual door opening. As the door opens, the regulating plate 86 moves to the right, and the engaging recess 87 approaches the engaging roller 88. As shown in FIG. 25, the engaging recess 88 moves to a position facing the waiting engaging roller 88. When the engaging recess 87 faces the engaging roller 88, the engaging roller 88 can engage with the engaging recess 87. This allows the regulating roller 89 to move leftward, and the attraction plate 102 can also move leftward. Therefore, the electromagnet 72 attracts the attraction plate 102 and moves it leftward. The regulating roller 89 is in the energized position (first position) as shown in FIG. 20, and the engagement roller 88 remains engaged with the engaging recess 87. Since the auxiliary spring 99 presses the suction plate 102 to the left, even if the suction plate 102 is separated from the suction surface of the electromagnet 72, the suction plate 102 can move smoothly and surely to the left, and the electromagnet 72 can suction and hold the suction plate.

[0113] In this manner, in this embodiment, the retracted state and the connected state are switched depending on the balance of the left-right force acting on the engagement roller 88. The balance of forces is switched by turning on and off the electromagnet 72. Note that the electromagnetic force of the electromagnet 72 may be increased and the auxiliary spring 99 may be omitted.

[0114] FIG. 31 shows the details of the position adjustment performed by the position adjustment unit. When the adjustment nut 121 is rotated in the tightening direction (first direction) from the state shown in FIG. 31(a) to move the adjustment nut 121 to the right relative to the adjustment shaft 120, the inner frame 95 moves to the right relative to the adjustment shaft 120, the adjustment nut 121, and the bridge 122, as shown in FIG. 31(b). In other words, the inner frame 95 moves to the right relative to the frame 7. The inner frame 95 can move to the right until the right end plate 97 abuts against the frame 7, as shown in FIG. 31(b). The distance between the right end plate 97 and the frame 7 in the state shown in FIG. 31(a) is the adjustment allowance. When the inner plate 95 moves to the right relative to the frame 7, the first support member 91 and the second support member 92 fixed to the inner plate 95 also move to the right, and the engagement roller 88, the regulating roller 89, the regulating pin 100, the electromagnet 72, the suction plate 102, and the like also move to the right together. Therefore, the position of the engagement recess 87 that engages with the engagement roller 88 in the electric mode also moves to the right. The position of the regulating plate 86 moves to the right, and the holder 85, the regulating shaft 33, and the second spring bearing 32 also move to the right. As the second spring bearing 32 moves to the right, the abutment head 53 also moves to the right, and the distance between it and the slide plate 81 increases. In other words, the distance between the main shaft 4 and the spring 30 increases.

[0115] Conversely, when the adjustment nut 121 is rotated in the second direction, the inner frame 95 moves leftward relative to the frame 7 as shown in FIG. 31(a), and the regulating plate 86 and the abutment head 53 also move leftward, shortening the distance between the abutment head 53 and the slide plate 81 and reducing the distance between the main shaft 4 and the spring 30. In this way, the position adjustment unit can adjust the left-right position at which the engagement recess 87 and the engagement roller 88 can engage with each other vertically when manually opening the door as shown in FIG. 25. The door's openable angle varies depending on the installation location. Some installation locations have a large openable angle, while others have a small openable angle. In an installation location where the openable angle is large, the inner frame 95 is moved rightward as shown in FIG. 31(b), shifting the position at which the engagement recess 87 and the engagement roller 88 engage to the right. Conversely, in an installation location where the openable angle is small, the inner frame 95 is moved leftward as shown in FIG. 31(a), shifting the position at which the engagement recess 87 and the engagement roller 88 engage to the left. By providing a position adjustment unit in this way, the versatility of the electric door closer is increased, and there is no need to prepare many different types of electric door closers depending on the installation location.

[0116] By rotating the second spring retainer 32 in a tightening direction (first direction), the second spring retainer 32 moves to the right, thereby increasing the distance between the main shaft 4 and the spring 30. Conversely, by rotating the second spring retainer 32 in a loosening direction (second direction), the second spring retainer 32 moves to the left, thereby reducing the distance between the main shaft 4 and the spring 30. In other words, the second spring retainer 32 functions as a spring adjustment unit for adjusting the spring force of the spring 30, and also functions as a position adjustment unit.

[0117] Next, an electric door closer according to a fifth embodiment of the present invention will be described. Detailed description of the same configuration as in the above-described fourth embodiment will be omitted. Fig. 32 shows the electric door closer of this embodiment. Fig. 32 is a view corresponding to Fig. 21. In the electric door closer of this embodiment, the abutment head 53 and the slide plate 81 are integrally configured. Therefore, in the electric mode as shown in Fig. 32, the guide roller 83a serving as a cam follower is separated to the right from the cam 80. In the manual mode, when the compressed state of the spring 30 is released, the slide plate 81 moves to the left and the guide roller 83a serving as a cam follower abuts against the cam 80. In this way, the slide plate 81 may be integrally configured with the second spring bearing 32.

[0118] In the above embodiment, the electric door closer electrically opens and closes the door, but it may also be possible to electrically perform only the door closing operation. [Explanation of symbols]

[0119] 1 Main unit 2 Arms 3 Bracket 4 spindle 5 Electric part 6 Self-closing part 7 frames 8 Cover 10 Electric drive unit 11 Control section 12 batteries 13 Motor 15 Reduction gear section (rotation transmission section) 16 Torque limiter (rotation transmission part) 17 First output shaft (rotation transmission part) 18 First bevel gear (rotation transmission part) 19 Second bevel gear (rotation transmission part) 20 Second output shaft (rotation transmission part) 30 springs 31 First spring holder 31a Receiving part 31b Guide tube 31c horizontal hole 32 Second spring holder 33 Regulating shaft (switching part) 33a Locking groove 34 Locking teeth 35 Locking claw (switching part) 36 Claw 37 Spindle 40 Solenoid (switching part, electromagnetic component) 41 Solenoid body 42 Plunger 43 Switching box (switching part, stopper) 44 Regulating ball (switching portion, first engagement portion) 45 Ball storage section 45a Small diameter section 45b Large diameter part 46 Stopper pin (switching part) 46a Locking groove (second engagement part) 47 Spring (switching part) 50 Pinion gear (energy storage part) 51 Energy storage rod (energy storage part) 52 racks 53 Contact head 60 Auxiliary motor (auxiliary drive unit) 61 Screw shaft (auxiliary drive unit) 62 Female thread part (auxiliary drive part) 70 Support stay 71 Support hole 72 Electromagnet (switching part, electromagnetic component) 73 Separation spring (switching part, biasing part) 74 Regulator (switching part, stopper) 75 Regulatory Department 76 Relief 77 Slope 78 First member 79 Second member 80 Cam (energy storage unit) 81 Slide Plate 82 Slide hole 83a Guide roller (cam follower, energy storage part) 83b Guide roller 83c Guide roller 83d Guide roller 85 Holder 86 Regulatory Plate 87 Engagement recess (second engagement portion) 88 Engagement roller (first engagement portion) 89 Regulating roller (stopper) 91 first support member 92 second support member 93 Lateral support groove 94 Vertical support groove 95 inner frame 96 Left end plate 97 Right end plate 98 Counterbore 99 Auxiliary spring 100 Regulatory pin 101 Connecting member 102 Adsorption plate 110 Damper body 111 Fitting hole 112 Piston shaft 120 Adjustment axis (position adjustment part) 121 Adjustment nut (position adjustment part) 122 Bridge

Claims

1. An electric door closer that electrically closes a door, The main shaft rotates in conjunction with the opening and closing of the door, an electric drive unit that drives the spindle; a control unit that controls the electric drive unit; A self-closing unit for power outages that applies a closing force to the main shaft; a battery that supplies power to the control unit during a power outage, The self-closing section is A spring that generates a closing force; a spring energy storage unit that stores energy in the spring by the door opening operation and applies the closing force of the spring to the main shaft; a switching unit that can switch between a connected state in which the spring and the energy storage unit are connected and the energy storage unit and the spring work together when the door is opened or closed, and a retracted state in which the spring and the energy storage unit are separated and the energy storage unit and the spring do not work together when the door is opened or closed, The control unit sets the switching unit to a retracted state when energized, and when a power outage occurs, the control unit does not immediately set the switching unit to a connected state but sets the switching unit to a connected state after a delay.

2. the switching unit maintains the standby state while receiving power supply, and switches from the standby state to the connected state when the power supply is stopped; 2. The electric door closer according to claim 1, wherein the control unit supplies power to the switching unit when power is on and until the battery is depleted during a power outage, and stops supplying power to the switching unit when the battery is depleted during a power outage.

3. 3. The electric door closer according to claim 2, wherein the switching unit compresses the spring with an electromagnetic force to bring the spring into the retracted state, and releases the compressed state of the spring to bring the spring into the connected state.

4. 2. The electric door closer according to claim 1, wherein the control unit keeps the switching unit in a retracted state when power is applied and until a predetermined time has elapsed since the power outage, and keeps the switching unit in a connected state after the predetermined time has elapsed since the power outage.

5. 2. The electric door closer of claim 1, wherein the control unit keeps the switching unit in a standby state when power is applied and during a power outage until the battery voltage drops to a predetermined value, and when the battery voltage drops to the predetermined value during a power outage, the control unit keeps the switching unit in a connected state.

6. 2. The electric door closer of claim 1, wherein the control unit keeps the switching unit in a retracted state when power is applied and during a power outage until the number of times the door has been closed by the electric drive unit reaches a predetermined number, and when the number of times the door has been closed by the electric drive unit reaches a predetermined number during a power outage, the control unit keeps the switching unit in a connected state.

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