Opening / closing device

Abstract

To provide an opening / closing device capable of effectively preventing closing operation from being unable to be completed due to malfunction even if the device is a load sensing type opening / closing device in which a system can be constructed at low cost.SOLUTION: The opening / closing device includes an opening / closing body that performs an opening operation or a closing operation by sliding an end portion in the closing direction, obstacle determination means that estimates and determines the presence of an object on the side in the closing direction of the end portion in the closing direction by a load sensing method, and reverse control means that stops the closing operation and then performs a reverse lifting operation when the obstacle determination means estimates and determines the presence of the object. The reverse control means performs the reverse lifting operation at a distance smaller than the distance at which the end portion in the closing direction is lowered during the total time of a processing time required for the estimation and determination and a processing time required for stopping the closing operation.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an opening and closing device that uses a load sensing method to estimate and determine the presence of an object on the side in the closing direction of an opening and closing body, and more particularly to an opening and closing device that is suitable as a shutter device. [Background technology]

[0002] Conventionally, this type of opening and closing device has a seat plate sensing unit at the closing end of the opening and closing body for contact detection of objects on the closing side of the opening and closing body, or a photoelectric sensor for non-contact detection of objects, and when the seat plate sensing unit detects contact with an obstacle or the photoelectric sensor detects an obstacle or the like non-contact during the closing operation of the opening and closing body, the opening and closing body is reversed and raised a predetermined amount. Also, there is a load-sensing opening and closing device that, instead of actually sensing an object, estimates that a load is applied to the drive motor by monitoring the motor current of the motor, which is the drive mechanism for closing the opening and closing body, or by monitoring the rotation speed of a rotating member linked to the motor rotation using a Hall sensor, and based on this, determines that an object is present and performs a reverse upward operation (Patent Document 1).The load-sensing method makes it possible to use the component configuration that is originally equipped in the opening and closing device, and does not require additional components such as a seat plate sensor (seat plate switch) or a photoelectric sensor, making it possible to build a system at low cost. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-76269 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a switchgear that actually detects an object, the possibility of a malfunction causing a reversal and upward movement is extremely low, but in the case of a load-sensing switchgear, a malfunction may occur. When used in cold regions, the opening and closing body may become difficult to move due to freezing, and the opening and closing body may also become difficult to move due to aging and other factors other than freezing. In such cases, the load increases, which may result in a false determination that an object is present when in fact there is no object, resulting in an unnecessary reversal and upward movement.

[0005] In such a case, the operator who has confirmed that the object is not present will naturally operate the operating means (close button, etc.) of the opening and closing device to start the closing operation again, but this causes a troublesome problem. That is, if the amount of downward movement of the opening and closing body until the closing operation is stopped because it is determined that the load has increased balances with the amount of movement of the reversing and rising operation, even if it is lowered again, it will stop at the same position and then reverse and rise, and this state will be repeated, resulting in a problem that the closing operation will never be completed. Incidentally, with an opening and closing device that actually detects an object, there is no risk of such a problem occurring, since erroneous judgment and the resulting malfunction are almost unthinkable except for defects in the detection system.

[0006] The present invention aims to address such problems. That is, it is an object of the present invention to provide a switching device that can effectively prevent the closing operation from being unable to be completed due to a malfunction, while being based on a load sensing switching device that allows a system to be constructed at low cost. [Means for solving the problem]

[0007] In order to achieve this object, the technical means according to the present invention comprises at least the following configuration.

[0008] In an opening and closing device comprising an opening / closing body which performs an opening or closing operation by sliding a closing direction end, an obstacle determination means which uses a load sensing method to estimate the presence of an object on the closing direction side of the closing direction end, and an inversion control means which stops the closing operation when the obstacle determination means estimates the presence of an object and then performs a reverse and upward operation, the inversion control means is characterized in that it performs the reverse and upward operation a distance which is smaller than the distance which the closing direction end has descended during the total time required for the processing time for the estimation determination and the processing time required for stopping the closing operation. Effect of the Invention

[0009] By virtue of these characteristics, the present invention provides the following advantageous effects. While being premised on a load sensing type opening and closing device that enables a system to be constructed at low cost, it is possible to effectively prevent the closing operation from being unable to be completed due to a malfunction. [Brief description of the drawings]

[0010] [Figure 1] 1 is a front view showing an example of an opening / closing device according to an embodiment of the present invention, illustrating a state in which an opening / closing body is opened and closed. [Diagram 2] 2 is an explanatory diagram showing a hardware configuration and functional blocks of a control unit of a switching device according to an embodiment of the present invention. FIG. [Diagram 3] 4 is a flowchart showing a control operation of the opening and closing device according to the embodiment of the present invention. [Figure 4] 10 is a flowchart showing a control operation of a switching device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Overall configuration of switchgear) Fig. 1 is a front view showing an example of an opening / closing device according to an embodiment of the present invention, showing the opening and closing of an opening / closing body. Fig. 1(a) shows the opening / closing body in a completely closed state, Fig. 1(b) shows the opening / closing body in a completely open state, and Fig. 1(c) shows the opening / closing body in a closing operation.

[0012] The opening / closing device 1 of the embodiment of the present invention is applied to the shutter of a garage attached to a house, and is particularly effective when applied to a configuration in which the opening / closing body is wound up on a winding shaft and stored (such as a shutter device, etc.) as shown in Figure 1, but it can also be applied to a configuration in which the opening / closing body is stored on the opening side without being wound up on a winding shaft (such as an overhead door device, etc.).

[0013] Examples of the form of the opening / closing body include a sheet-like body, a net-like body, a plurality of slats or pipes, or a panel arranged in the opening / closing direction, and further, a form in which the aforementioned sheet-like body, net-like body, slats, pipes, and panels are appropriately combined.

[0014] The stop command and close command for the opening / closing body may be signals issued by, for example, an operating switch or a remote control, and in a particularly preferred embodiment with good operability, the stop command and close command are signals issued by pressing a push button switch.

[0015] In this embodiment, the "thickness direction of the opening / closing body" refers to the thickness direction of the opening / closing body in the closed state. The "width direction of the opening / closing body" refers to a direction perpendicular to the opening / closing direction of the opening / closing body, and not the thickness direction of the opening / closing body. The "opening / closing body opening / closing direction" refers to the direction in which the opening / closing body slides to open or close an opening or space.

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1, this opening / closing device 1 comprises an opening / closing body 10 that opens and closes by sliding a closing direction end 11, and a guide rail 20 that surrounds an end of the opening / closing body 10 in the width direction (left and right direction in Fig. 1) and guides it in the opening and closing direction, and a winding device (not shown) that winds and unwinds the opening / closing body 10 to perform opening and closing operations is provided in a storage case 12. Also stored in the storage case 12 are electrical components such as a control unit 50 including a control board 13 that drives and controls the opening / closing device. In addition, the opening / closing device 1 also comprises an operating unit 14, but in Fig. 1, the operating unit 14 is depicted diagrammatically and is actually disposed at an appropriate position inside or outside the garage.

[0017] The opening / closing body 10 has a main body formed by connecting a plurality of so-called slats, which are formed by bending a horizontally elongated, approximately rectangular metal plate, so that the slats can rotate between adjacent slats above and below, and the lower end of the main body of the opening / closing body 10 is the closing direction end 11.

[0018] The guide rail 20 is a member having an approximately C-shaped cross section that surrounds the widthwise end of the opening / closing body 10, and is arranged between the contact object (e.g., a floor surface, the ground, a frame member, etc.) against which the opening / closing body 10 sits and a winding device (not shown).

[0019] The winding device (not shown) is provided with a storage case 12 having an opening on the lower side for allowing the opening / closing body 10 to appear and disappear, and is equipped with a winding shaft that winds up and pays out the opening / closing body 10, an opening / closing body drive unit 105 (not shown) that drives, rotates, and brakes the winding shaft, and a control unit 50 including a control board 13 that controls the opening / closing body drive unit 105 (not shown) to open or close the opening / closing body 10.

[0020] The opening / closing body drive unit 105 (not shown) includes a DC or AC electric motor that serves as a drive source for opening or closing the opening / closing body 10, and a power transmission mechanism (specifically, gears or the like) that adjusts the rotational force of the electric motor to an appropriate rotation speed and torque and transmits it to the winding shaft. In addition, the electric motor is provided with a current detection unit 106 (not shown) that detects the current flowing through the motor.

[0021] The control unit 50 is a control circuit that electronically processes the electric signal input from the operation unit 14 and the output signal from the current detection unit 106 (not shown) and the Hall sensor 107 (not shown) based on a program, and supplies control power according to the processing result to the opening / closing body drive unit 105 (not shown) to rotate the opening / closing body drive unit 105 (not shown) forward, reverse, stop, etc. In addition, the control unit 50 also performs a process of estimating the presence of an object and a control related to a reverse lift operation, which will be described later, that is performed when the estimation is made. This control unit 50 is preferably configured with a programmed logic circuit used in, for example, a microcomputer or a programmable controller so that the circuit configuration and set values ​​can be easily changed according to the site situation, etc., but it is also possible to use a circuit using a relay circuit or other electronic circuit.

[0022] The operation unit 14 is a switch box having three switches: an open switch, a stop switch, and a close switch, and is electrically wired so that the contact signals of each of the switches are input to the control unit 50.

[0023] (Configuration of control unit 50) FIG. 2 is an explanatory diagram showing a control unit of an opening and closing device according to an embodiment of the present invention, where FIG. 2(a) shows the hardware configuration of the control unit and FIG. 2(b) shows the functional blocks performed by a control board in the control unit.

[0024] First, the hardware configuration of the switching device control unit will be described with reference to Fig. 2(a). The CPU 101 comprehensively controls each component of the switching device 1. The CPU 101 executes a control program, for example, to cause a computer to realize the functions according to the present invention, and specifically, as described above, is configured by a programmed logic circuit used in a microcomputer, a programmable controller, or the like.

[0025] The ROM 102 stores control programs, etc. The RAM 103 serves to temporarily store various setting input conditions by an operator, and also temporarily stores other information required for control.

[0026] The operation switches 104 are three switches, an open switch, a stop switch, and a close switch, which are provided in a switch box (not shown). Operation inputs from these switches are transmitted to the CPU 101.

[0027] The opening / closing body drive unit 105 is a DC or AC electric motor, which opens or closes the opening / closing body 10. This electric motor is provided with a current detection unit 106 that detects a current flowing through the motor. The current detection unit 106 is for detecting a large current when a high torque is required to operate the opening / closing body 10. When the current detection unit 106 detects a large current that exceeds a predetermined time, which is a threshold value, the CPU 101 estimates that a load is applied to the opening / closing body and that an object is present. However, since a peak current several times the rated current flows when the motor is started, the CPU 101 is programmed not to execute this estimation process immediately after the motor is started.

[0028] The Hall sensor 107 generates pulses in response to the rotation of a rotating member that is linked to the motor rotation. The CPU 101 counts the generated pulses to calculate the distance that the closing direction end 11 has moved downward from the upper limit, and obtains the current position P0 of the closing direction end 11. In Fig. 1, the current position P0 of the closing direction end 11, which will move downward as the opening / closing body 10 closes, is obtained from the upper limit position P1 in Fig. 1(b).

[0029] Next, the function of the control unit 50 (control board 13) will be described with reference to Fig. 2(b). The end position detection means F1 calculates the current position P0 of the closing direction end 11 by counting the number of output pulses from the Hall sensor 107 from when the closing direction end 11 is located at the upper limit position P1.

[0030] The obstacle determination means F2, when a large current exceeding a threshold value is detected by the current detection unit 106 and this detection continues for a predetermined time, determines that an object that can become an obstacle is present since the opening / closing body 10 is continuously under load. The obstacle determination means F2 can also be configured to determine that an object that can become an obstacle is present since the operation of the opening / closing body 10 is slowed down and some kind of load is applied when the interval between pulses output from the Hall sensor 107 becomes large beyond a threshold value and this state continues for a predetermined time. Alternatively, a comprehensive determination may be made using both the output of the current detection unit 106 and the output of the Hall sensor 107.

[0031] The reverse lift amount calculation means F3 calculates the operation time T2 for the reverse lift operation of the closing direction end 11 based on the current position P0 of the closing direction end 11 calculated by the end position detection means F1, using (Equation 1). (Formula 1) T2=(P0-P1) / (P2-P1)×(T1+T0) Here, P0, P1, and P2 are the current, upper, and lower limit positions of the closing direction end 11 (see also FIG. 1), T1 is the processing time required to determine the presence of an object (obstacle), and T0 is the time required to stop the closing direction end 11 after it is determined that there is an object (obstacle), which is usually about 2 seconds. Note that the reverse upward movement at this time is performed at the same speed as the downward movement.

[0032] As can be seen from the above (Equation 1), while the denominator is a fixed value of "P2-P1," the numerator "P0-P1" becomes larger as the closing direction end 11 approaches the lower limit. On the other hand, "T1+T0" can also be considered to be a substantially fixed value, so the operation time T2 for the reversing and ascending operation is small if the closing direction end 11 is near the upper limit, but becomes gradually larger as the closing direction end 11 approaches the lower limit. However, whether the closing direction end 11 is near the upper limit or the lower limit, the numerator is smaller in value than the denominator, so the amount of movement during the reversing and ascending operation is smaller than the amount of descent until the end of the movement due to the determination that there is an object (obstacle) immediately ahead.

[0033] The reason for this control can be explained as follows. Even if a person gets caught in the shutter, it is relatively easy to escape at the upper limit of the shutter. In contrast, it is difficult to escape near the lower limit of the shutter. For this reason, the closer to the lower limit of the shutter, the longer the time for the closing direction end 11 to rise, and the greater the amount of rise. In addition to ensuring a higher level of safety, the following effect can also be expected. That is, near the upper limit of the shutter, the amount of reverse rise is smaller than the amount of descent just before the stop time due to load detection, so this makes it possible to greatly improve the problem of the conventional technology in which the shutter descends, stops, and then reverses and rises again, resulting in repeated up and down movements.

[0034] Moreover, the contents of the calculation process by the reverse rise amount calculation means F3 can also be realized by obtaining the rising speed V during reverse rise by the following (Equation 2). (Formula 2) V=(P0-P1) / (P2-P1)×V0 Here, P0, P1, and P2 are the current, upper and lower limit positions of the closing direction end 11 (see also FIG. 1), and V0 is a speed that is the reference for the reverse ascent speed, which may be the same value as the descent speed of the closing direction end 11, but may also be based on a value different from the descent speed. Note that the reverse ascent operation at this time is fixed at the time required to stop the closing direction end 11 after it is determined that there is an object (obstacle), and specifically, in this embodiment, it is fixed at about 2 seconds.

[0035] Even when controlled in this way, the closer to the lower limit of the shutter, the faster the lifting speed of the closing direction end 11 becomes, and as a result, the amount of lift of the closing direction end 11 becomes larger, so that a higher level of safety is ensured. Also, the problem of repeated up and down movements, which was a problem with the conventional technology, can be greatly improved.

[0036] The reversal control means F4 generates an operation control signal for reversing and raising the closing direction end 11 in accordance with the operation time T2 or the operation speed V calculated by the reversal and raising amount calculation means F3.

[0037] (Example of control operation of switching device) 3 is a flowchart showing a control operation of a switching device according to an embodiment of the present invention, an example of the control operation of the switching device will be described with reference to FIG.

[0038] In step S101, when the close switch of the operating unit 14 is operated, the closing operation of the opening / closing body 10, that is, the lowering operation of the closing direction end 11, is started.

[0039] As mentioned above, when the motor starts, a peak current several times the rated current flows. Therefore, if the load sensing method is used to estimate and determine that an object is present in the closing direction, it will be erroneously determined that an object is present. Therefore, the function of the obstacle determination means F2 is programmed to be enabled in step S102 after waiting a certain period of time after the close switch is pressed.

[0040] After the function of the obstacle determination means F2 is enabled, the current position P0 of the closing direction end 11 is constantly (or periodically) calculated by the end position detection means F1 (step S103). Specifically, the end position detection means F1 calculates the current position P0 of the closing direction end 11 by counting the number of output pulses from the Hall sensor 107 from when the closing direction end 11 is located at the upper limit position P1.

[0041] In step S104, if the current position P0 of the closing direction end 11 coincides with the lower limit position P2, the closing operation of the opening / closing body 10 is terminated, and the opening / closing body 10 stops at the lower limit (step S107).

[0042] If it is determined in step S104 that the lower limit has not been reached, and if the obstacle determination means F2 estimates and determines in step S105 that an object (obstacle) is present, the process proceeds to the next step. At this time, there are cases where an object actually exists beyond the closing direction end 11, and cases where the movement of the opening / closing body 10 has become poor due to freezing or aging, but no object actually exists. In either case, the process is the same.

[0043] In step S106, the CPU 101 stops the closing direction end 11, and then immediately reverses the upward movement of the closing direction end 11 and stops it in accordance with a command to perform an upward movement for T2 seconds, which is the condition calculated by the reversal upward movement amount calculation means F3.

[0044] If the operator confirms that no object (obstacle) actually exists, the process returns to step S101, and the operator operates the close switch of the operation unit 14 again.

[0045] As already explained, the amount of movement when reversing and ascending is smaller than the amount of descent until the stop following the determination that an object (obstacle) is immediately before, so even if the events of stopping the closing operation, reversing and ascending, and then starting the closing operation again are repeated, the closing operation of the opening / closing body 10 will proceed reliably. In addition to the control of the amount of reverse and ascending movement, the time lag between pressing the close switch in step S101 and starting the obstacle determination function in step S102 also contributes to the reliable progress of the closing operation.

[0046] From the above, in this embodiment, the problem that the conventional device had, that the emergency stop during descent and the reversal rise are repeated and the closing operation can never be completed, can be solved, and the closing operation can be completed reliably. In addition, since the amount of reversal rise is large near the lower limit of the shutter where escape becomes difficult, a higher level of safety is ensured.

[0047] (Another example of switchgear control operation) 4 is a flowchart showing a control operation of a switching device according to another embodiment of the present invention, An example of the control operation of a switching device according to another embodiment will be described with reference to FIG.

[0048] In step S201, when the close switch of the operating unit 14 is operated, the closing operation of the opening / closing body 10, that is, the lowering operation of the closing direction end 11, is started.

[0049] As mentioned above, when the motor starts, a peak current several times the rated current flows. Therefore, if the load sensing method is used to estimate and determine that an object is present in the closing direction, it will be erroneously determined that an object is present. Therefore, the function of the obstacle determination means F2 is programmed to be enabled in step S202 after waiting a certain period of time after the close switch is pressed.

[0050] After the function of the obstacle determination means F2 is enabled, the current position P0 of the closing direction end 11 is constantly (or periodically) calculated by the end position detection means F1 (step S203). Specifically, the end position detection means F1 calculates the current position P0 of the closing direction end 11 by counting the number of output pulses from the Hall sensor 107 from when the closing direction end 11 is located at the upper limit position P1.

[0051] In step S204, if the current position P0 of the closing direction end 11 coincides with the lower limit position P2, the closing operation of the opening / closing body 10 is terminated, and the opening / closing body 10 stops at the lower limit (step S207).

[0052] If it is determined in step S204 that the lower limit has not been reached, and if the obstacle determination means F2 estimates and determines in step S205 that an object (obstacle) is present, the process proceeds to the next step. At this time, there are cases where an object actually exists beyond the closing direction end 11, and cases where the movement of the opening / closing body 10 has become poor due to freezing or aging, but no object actually exists, and the process is the same in either case.

[0053] In step S206, the CPU 101 stops the closing direction end portion 11, and then immediately reverses the upward movement of the closing direction end portion 11 for 2 seconds and stops it, in accordance with a command to perform an upward movement at a speed V, which is a condition calculated by the reversal upward movement amount calculation means F3.

[0054] If the operator confirms that no object (obstacle) actually exists, the process returns to step S201 and the operator operates the close switch of the operation unit 14 again.

[0055] As already explained, the amount of movement when reversing and ascending is smaller than the amount of descent until the stop following the determination that an object (obstacle) is immediately before, so even if the events of stopping the closing operation, reversing and ascending, and then starting the closing operation again are repeated, the closing operation of the opening / closing body 10 will proceed reliably. In addition to the control of the amount of reverse and ascending movement, the time lag between pressing the close switch in step S201 and starting the obstacle determination function in step S202 also contributes to the reliable progress of the closing operation.

[0056] From the above, in another embodiment, the problem that the conventional device had, that the emergency stop during descent and the reversal and ascent are repeated and the closing operation cannot be completed no matter how long it takes, is solved, and it becomes possible to complete the closing operation reliably. Also, since the amount of reversal and ascent is large near the lower limit of the shutter where escape becomes difficult, a higher level of safety is ensured.

[0057] The opening and closing device according to the embodiment of the present invention has been described in detail with reference to the drawings, and its configuration has been described above. However, the specific configuration is not limited to these embodiments, and can be appropriately changed within the scope of the present invention. For example, in the embodiment, the amount of reverse rise is increased as the shutter approaches the lower limit, but as long as the amount of reverse rise is set not to be greater than the amount of descent when an emergency stop is made due to load detection, the desired object can be achieved even if the amount of reverse rise is constant regardless of the height position. In that case, from the viewpoint of ensuring safety, a large amount of reverse rise when the shutter is close to the lower limit should be used as the standard. However, it should be prepared for the additional time required to complete the closing operation. In addition, as a middle mode between the mode in which the amount of reverse rise is continuously changed in a stepless manner and the mode in which the amount of reverse rise is constant, the technical idea of ​​the present invention also includes a mode in which the amount of reverse rise is changed in multiple steps.

[0058] <Summary> As described above, the above embodiment discloses the following inventions. (1) A switching device comprising an opening / closing body that performs an opening or closing operation by sliding a closing direction end, an obstacle determination means that uses a load sensing method to estimate the presence of an object on the closing direction side of said closing direction end, and a reversal control means that stops the closing operation when said obstacle determination means estimates the presence of an object and then performs a reversal and lifting operation, characterized in that said reversal control means performs the reversal and lifting operation a distance smaller than the distance that said closing direction end has descended during the total time required for the processing time for the estimation determination and the processing time required for the closing operation stop (see Figs. 3 and 4). (2) The opening and closing device described in (1) (see Figures 3 and 4) is characterized in that it is provided with an end position detection means for detecting the position of the closing direction end, and the reversal control means is set so that the distance moved by the reversal and upward movement is greater when the closing direction end is located near the lower limit position compared to when the closing direction end is located near the upper limit position, depending on the position of the closing direction end detected by the end position detection means. (3) The opening and closing device according to (1) or (2) (see FIG. 3), wherein the reverse control means adjusts and controls the time for performing the reverse and ascending operation while keeping the reverse and ascending operation speed substantially fixed. (4) The opening and closing device according to (1) or (2) (see FIG. 4), wherein the reverse control means adjusts and controls the reverse and ascending operation speed while keeping the time for which the reverse and ascending operation is performed substantially fixed. (5) The opening and closing device described in any one of (1) to (4) (see Figures 3 and 4), wherein the obstacle determination means is configured so that its function is activated with a delay after the start of the closing operation of the opening and closing body. [Explanation of symbols]

[0059] 1: Switchgear 10: Opening and closing body 11: Closing direction end 12: Storage case 13: Control board 14:Operation section 20: Guide rail 50: Control unit 101:CPU 102:ROM 103:RAM 104: Operation switch 105: Opening and closing body drive unit 106: Current detection unit 107: Hall sensor F1: End position detection means F2: Obstacle determination means F3: Reversal rise amount calculation means F4: Inversion control means

Claims

1. An opening and closing device including an opening and closing body that performs an opening or closing operation by sliding a closing direction end, an obstacle determination means that uses a load sensing method to estimate and determine that an object is present on the closing direction side of the closing direction end, and a reversal control means that stops the closing operation when the obstacle determination means estimates and determines that an object is present, and then performs a reversal and lifting operation, The reversal control means causes the closing direction end portion to perform a reversal and raising operation by a distance smaller than a distance that the closing direction end portion has lowered during a total time required for processing the estimation determination and a processing time required for stopping the closing operation. An opening and closing device characterized by:

2. an end position detection means for detecting the position of the closing direction end, The reverse control means is set so that the distance moved by the reverse upward movement is larger when the closing direction end is located near a lower limit position compared to when the closing direction end is located near an upper limit position, depending on the position of the closing direction end detected by the end position detection means. The opening and closing device according to claim 1 .

3. The reverse control means adjusts and controls the time for which the reverse lifting operation is performed while keeping the reverse lifting operation speed substantially fixed. The opening and closing device according to claim 2 .

4. The reverse control means adjusts and controls the reverse and lifting operation speed while keeping the time for which the reverse and lifting operation is performed substantially fixed. The opening and closing device according to claim 2 .

5. The obstacle determining means is configured to activate its function with a delay after the start of the closing operation of the opening / closing body. The opening and closing device according to any one of claims 1 to 4.

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