Elevator control method and elevator

Abstract

Provided is an elevator control method that allows a door 10 of an elevator 1 to safely close by self-closing force without stopping midway. According to the present invention, an elevator control method for when a door 10 of an elevator 1 closes by self-closing force involves performing dynamic brake control when the door 10 closes by self-closing force such that a dynamic brake (DB) is activated (ON) when the speed (V) of the door 10 is at least a prescribed threshold value (Vref) and the dynamic brake (DB) is released (OFF) when the speed (V) of the door 10 is below the prescribed threshold value (Vref).

Description

Elevator control method and elevator

[0001] The present invention relates to an elevator control method and an elevator.

[0002] For example, in the event of a power outage, elevator doors may close by themselves. In this case, it is desirable to close the doors slowly in order to close them safely.

[0003] One example of such technology is disclosed in Patent Document 1. The abstract of Patent Document 1 states, "We provide an elevator door control device that can safely close elevator doors in the event of a power outage and prevent rescue workers from being overwhelmed. The elevator door control device of this invention includes a door dynamic brake control circuit (15) that, when a power outage occurs with the elevator doors in an intermediate position, performs dynamic brake control of the door motor (2) until full door closure is detected, and releases the dynamic brake control when full door closure is detected."

[0004] Regarding the dynamic brake, FIG. 1 and paragraph 0020 of Patent Document 1 state that the short circuit (13) has a function of short-circuiting, for example, the phases of the door motor (2). Furthermore, paragraph 0030 of Patent Document 1 states that when the door dynamic brake control circuit (15) receives a dynamic brake drive command signal from the door control circuit (6), it operates the short circuit (13) to short-circuit the phases of the door motor (2), thereby starting dynamic brake control of the door motor 2.

[0005] Furthermore, paragraph 0020 of Patent Document 1 states that, for example, if the charge of the smoothing electrolytic capacitor (4) can become zero in a short time, the short-circuit circuit (13) may be configured with only one element that short-circuits between the busbars of the converter circuit (3) rather than between the motor phases.

[0006] International Publication No. 2020 / 110176

[0007] According to the technology described in Patent Document 1, when an elevator door closes by its own closing force, dynamic brake control is performed using a short circuit (13), so that the door can be closed at a slow speed.

[0008] However, the technology described in Patent Document 1 has a problem in that dynamic brake control may cause the door to stop midway before it is completely closed.

[0009] The problem to be solved by the present invention is to provide an elevator control method and an elevator that can safely close elevator doors without stopping midway when the elevator doors close by self-closing force.

[0010] In order to solve the above-mentioned problems, the elevator control method of the present invention is an elevator control method for when an elevator door closes by a self-closing force, characterized in that when the door closes by the self-closing force, a dynamic brake is activated if the door speed is equal to or greater than a predetermined threshold, and the dynamic brake is released if the door speed is less than the predetermined threshold, performing dynamic brake control.

[0011] Furthermore, the elevator of the present invention is an elevator having a door, a motor for driving the door, and a control unit for controlling the motor, wherein the control unit performs dynamic brake control such that, when the door is closing by self-closing force, the control unit activates a dynamic brake if the speed of the door is equal to or greater than a predetermined threshold, and releases the dynamic brake if the speed of the door is less than the predetermined threshold.

[0012] According to the present invention, an elevator control method and an elevator can be realized that can safely close elevator doors by self-closing force without stopping midway.

[0013] Problems, means for solving the problems, and effects other than those described above will be made clear in the claims and examples.

[0014] A functional block diagram of an elevator of an embodiment. A circuit diagram explaining operation in normal mode in an elevator of an embodiment. A circuit diagram explaining operation in dynamic brake mode in an elevator of an embodiment. A timing chart explaining operation of dynamic brake control in an elevator of an embodiment. A flowchart explaining operation in an elevator of an embodiment.

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing and embodiment, the same or similar components are designated by the same reference numerals, and redundant explanations will be omitted.

[0016] FIG. 1 is a functional block diagram of an elevator according to an embodiment of the present invention.

[0017] The elevator 1 of this embodiment has a door 10, a motor 20 that drives the door 10, wiring 22 connected to the motor 20, an inverter 30 that supplies power to the motor 20 via the wiring 22, a DC power supply 40, a smoothing capacitor 41, and a control unit 50.

[0018] The door 10 has a door drive mechanism 11 that opens and closes the door 10 using power from a motor 20 .

[0019] The motor 20 has an encoder 21 such as a rotary encoder, and a signal from the encoder 21 is input to the control unit 50 .

[0020] The inverter 30 has a switching element 31. The inverter 30 converts DC power input from a DC power supply 40 via a smoothing capacitor 41 into AC power and outputs the AC power to the motor 20. The on and off of the switching element 31 is controlled by a control unit 50.

[0021] The control unit 50 controls the inverter 30 to thereby control the motor 20 .

[0022] Furthermore, in this embodiment, dynamic braking is realized by the control unit 50 controlling the switching element 31 of the inverter 30 that supplies power to the motor 20 for driving the door 10. In other words, the dynamic braking function is realized by the inverter 30. This makes it possible to realize dynamic braking at low cost without the need to separately provide a short circuit for realizing dynamic braking. A specific control method will be described later.

[0023] FIG. 2 is a circuit diagram illustrating the operation of the elevator in the normal mode according to the embodiment.

[0024] As an example of the inverter 30, a three-phase inverter in which an upper arm 32 and a lower arm 33 are configured by switching elements 31 will be used for explanation.

[0025] 2 shows an example of the path of the current i during normal mode operation. The normal mode operation is the same as that of a general inverter, so a detailed description thereof will be omitted.

[0026] FIG. 3 is a circuit diagram illustrating the operation of the dynamic brake mode in the elevator of the embodiment.

[0027] When dynamic braking is activated using the inverter 30 as in this embodiment, the control unit 50 turns on all phases of the switching elements 31 of the lower arm 33 and turns off all phases of the switching elements 31 of the upper arm 32. This shorts the phases of the wiring 22 connected to the motor 20, activating the dynamic brake. Figure 3 shows an example of the path of the current i when operation in the dynamic braking mode is being performed.

[0028] In addition, a typical dynamic brake has an additional resistive element in the short circuit, and the resistive element consumes energy.

[0029] In contrast, when dynamic braking is implemented using inverter 30 when elevator door 10 closes by self-closing force, as in this embodiment, no additional resistance element is provided. The reason for this is that when elevator door 10 closes by self-closing force, not much energy is generated, and motor 20 has winding resistance, so if dynamic braking is used only when door 10 closes by self-closing force, no additional resistance element is required. Therefore, by using dynamic braking using inverter 30 only when elevator door 10 closes by self-closing force, dynamic braking can be implemented at low cost without the need for a short circuit or a separate resistance element.

[0030] FIG. 4 is a timing chart illustrating the operation of the dynamic brake control in the elevator of the embodiment.

[0031] 4, the horizontal axis represents time t, and the vertical axis represents door speed V and the ON / OFF state of the dynamic brake (DB). A threshold value Vref represents a predetermined threshold value for door speed V.

[0032] The control unit 50 performs dynamic brake control by activating (ON) the dynamic brake (DB) when the speed of the door 10 (door speed V) is equal to or greater than a predetermined threshold (threshold Vref) when the door 10 is closing by its own closing force, and by releasing (OFF) the dynamic brake (DB) when the speed of the door 10 (door speed V) is smaller than the predetermined threshold (threshold Vref).

[0033] This allows the door 10 to be closed safely at a low speed and prevents the door 10 from stopping midway.

[0034] Furthermore, if the dynamic brake control is continued even after the door 10 is completely closed, there is a problem that the dynamic brake will be activated when opening the door 10 from the outside for rescue purposes, making it difficult to open the door 10.

[0035] Therefore, it is desirable that the control unit 50 releases the dynamic brake control after the door 10 is completely closed. As a result, after the door 10 is completely closed, the dynamic brake will not be activated when the door 10 is opened from the outside for rescue, making it easier to open the door 10.

[0036] However, the present invention is not limited to this, and the dynamic brake control may be continued even after the door 10 is completely closed. Even in this case, if the door is opened slowly at a door speed V equal to or less than the threshold value Vref, the dynamic brake will not be activated, and the door 10 can be opened.

[0037] The control unit 50 can obtain the door speed V using the signal from the encoder 21 .

[0038] The threshold value Vref is preferably set to, for example, about 0.1 m / s, but is not limited to this.

[0039] 5 is a flowchart illustrating the operation of the elevator of the embodiment. Note that this flowchart is an example, and processing may be performed according to another flowchart.

[0040] The control unit 50 determines whether the door 10 is in a state where it can be closed by its own closing force, such as when a power outage occurs (S1). If the answer is No in S1, the process returns to S1.

[0041] If the answer is Yes in S1, the control unit 50 determines whether the door speed V is equal to or greater than a predetermined threshold value Vref (S2).

[0042] If the answer is Yes in S2, the control unit 50 activates the dynamic brake as the dynamic brake control and performs the dynamic brake mode control shown in Fig. 3 (S3). If the answer is No in S2, the control unit 50 releases the dynamic brake as the dynamic brake control and performs the normal mode control shown in Fig. 2 (S4). Then, under the state of S3 or S4, the door 10 closes by its own closing force (S5).

[0043] The control unit 50 determines whether the door 10 is completely closed, i.e., whether the door is fully closed (S6). If the answer is No in S6, the process returns to S1. If the answer is Yes in S6, the process ends and the dynamic brake control is released.

[0044] In this embodiment, the dynamic braking function is realized by the inverter 30, but this is not limiting. For example, the dynamic braking may be realized by a short circuit (not shown) that short-circuits between phases of the motor 20 that drives the door 10. Alternatively, the dynamic braking may be realized by a short circuit (not shown) that short-circuits the DC input to the inverter 30 that supplies power to the motor 20 that drives the door 10. In either case, the short circuit is provided outside the inverter 30. The short circuit is controlled by the control unit 50. If the dynamic braking is to be activated only when the elevator door 10 closes due to a self-closing force, an additional resistive element does not need to be provided in the short circuit.

[0045] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations described in the embodiments, and various modifications are possible within the scope of the technical concept of the present invention. In addition, some or all of the configurations described in the embodiments may be combined and applied.

[0046] 1: Elevator 10: Door 11: Door drive mechanism 20: Motor 21: Encoder 22: Wiring 30: Inverter 31: Switching element 32: Upper arm 33: Lower arm 40: DC power supply 41: Smoothing capacitor 50: Control unit i: Current V: Door speed Vref: Threshold value DB: Dynamic brake t: Time

Claims

1. An elevator control method when an elevator door closes by self-closing force, characterized by performing dynamic brake control such that, when the door closes by self-closing force, the door speed is equal to or greater than a predetermined threshold, and the dynamic brake is released when the door speed is less than the predetermined threshold.

2. The elevator control method according to claim 1, wherein the dynamic brake control is released after the doors are completely closed.

3. An elevator control method according to claim 1, characterized in that the dynamic brake is realized by controlling a switching element of an inverter that supplies power to a motor for driving the door.

4. An elevator control method according to claim 3, characterized in that the dynamic brake is activated by turning on all phases of the switching elements of the lower arm of the inverter and turning off all phases of the switching elements of the upper arm.

5. An elevator control method according to claim 1, wherein the dynamic brake is realized by a short circuit that short-circuits between phases of the motor for driving the door.

6. An elevator control method according to claim 5, wherein the short circuit is provided outside an inverter that supplies power to the motor.

7. An elevator control method according to claim 1, characterized in that the dynamic brake is realized by a short circuit that short-circuits the DC input to an inverter that supplies power to a motor for driving the door.

8. The elevator control method according to claim 7, wherein the short circuit is provided outside the inverter.

9. An elevator having a door, a motor for driving the door, and a control unit for controlling the motor, wherein the control unit performs dynamic brake control such that when the door closes by its self-closing force, the control unit activates a dynamic brake if the speed of the door is equal to or greater than a predetermined threshold, and releases the dynamic brake if the speed of the door is less than the predetermined threshold.

10. An elevator control method when elevator doors close by self-closing force, characterized in that a dynamic brake is activated by controlling a switching element of an inverter that supplies power to a motor for driving the doors.

11. An elevator control method according to claim 10, characterized in that the dynamic brake is activated by turning on all phases of the switching elements of the lower arm of the inverter and turning off all phases of the switching elements of the upper arm.

12. An elevator having a door, a motor that drives the door, an inverter that supplies power to the motor, and a control unit that controls the motor by controlling the inverter, wherein the control unit activates a dynamic brake by controlling a switching element of the inverter when the door closes by self-closing force.

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