Elevator brake control device

Abstract

There is a concern that the brake coil will not be able to handle the return current and the semiconductor switching elements that make up the switch may be destroyed. [Solution] An elevator brake control device controls the contact and separation of the brake shoe with the brake drum by controlling the current flowing through the brake coil, and is equipped with: a first discharge circuit in which the anode side of a first diode and one end of a first resistor are connected at a first connection point, the cathode side of the first diode is connected to the positive electrode side of the brake coil, and the other end of the first resistor is connected to the negative electrode side of the brake coil; a second discharge circuit in which the cathode side of a second diode and one end of a second resistor are connected at a second connection point, the other end of the second resistor is connected to the positive electrode side of the brake coil, and the anode side of the second diode is connected to the negative electrode side of the brake coil via a switch; and a connection determination unit that determines whether the first resistor and the second resistor are connected properly from the voltage values ​​of the first connection point and the second connection point, respectively.

Description

[Technical Field]

[0001] The present disclosure relates to a brake control device for an elevator. [Background technology]

[0002] In elevator brake control devices, two brake shoes are brought into contact with a brake drum to brake the rotation of the brake drum. In Patent Document 1, an adjustment resistor and a switch are connected in parallel to a base resistor. During an emergency stop, the adjustment resistor and base resistor are connected in series, which abruptly reduces the return current and causes the brake shoes to abruptly contact the brake drum. During a normal stop, the switch and base resistor are connected in series and the adjustment resistor is bypassed, which gradually reduces the return current and causes the brake shoes to gradually contact the brake drum. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-218880 Summary of the Invention [Problem to be solved by the invention]

[0004] The device described in Patent Document 1 cannot handle the reflux current if there is an abnormality in the base resistor, or in the contact between the base resistor and the adjustment resistor, or in the switch. In this case, there is a concern that the energy stored in the brake coil will have no way to escape and may destroy the semiconductor switching element that makes up the switch.

[0005] An object of the present disclosure is to provide an elevator brake control device that can detect an abnormality in the connection of a resistor through which a return current flows. [Means for solving the problem]

[0006] An elevator brake control device controls the contact and separation of a brake shoe with a brake drum by controlling the current flowing through a brake coil, and includes: a first discharge circuit in which an anode side of a first diode and one end of a first resistor are connected at a first connection point, a cathode side of the first diode is connected to the positive electrode side of the brake coil, and the other end of the first resistor is connected to the negative electrode side of the brake coil; a second discharge circuit in which a cathode side of a second diode and one end of a second resistor are connected at a second connection point, the other end of the second resistor is connected to the positive electrode side of the brake coil, and the anode side of the second diode is connected to the negative electrode side of the brake coil via a switch; and a connection determination unit that determines whether the first resistor and the second resistor are connected properly from the voltage values ​​of the first connection point and the second connection point, respectively. [Effects of the Invention]

[0007] This disclosure enables early detection of defects in resistors through which return current flows, thereby preventing energy stored in the brake coil from having an escape route and destroying the semiconductor switching elements that make up the switch. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall configuration diagram of an elevator in which a brake control device according to a first embodiment is used. [Figure 2] 2 is a circuit diagram showing ON / OFF of a switch and a current flow of the brake control device in the first embodiment. FIG. [Figure 3] 4 is a time chart showing the timing at which a connection check is performed in the brake control device in the first embodiment. [Figure 4] 4 is a diagram showing, in time series, changes in each switch of the brake control device in the first embodiment, the current flowing through the first brake coil, and the torque applied to the first brake shoe. FIG. [Figure 5] FIG. 3 is a circuit diagram for comparison of the brake control device in the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure will be described with reference to the accompanying drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and redundant explanations will be appropriately simplified or omitted.

[0010] Embodiment 1 FIG. 1 is a diagram showing the overall configuration of an elevator in which a brake control device according to a first embodiment is used.

[0011] 1, an elevator 200 is provided with a car 201 for passengers to ride in and a weight 202. The car 201 and the weight 202 are connected via a rope 203. The rope 203 is wound around a hoist 204.

[0012] In such an elevator 200, when the hoisting machine 204 rotates, the rope 203 moves. Due to this movement, the car 201 and the weight 202 rise and fall in opposite directions.

[0013] The brake control device 10 comprises a brake device 11 and a brake control unit 100. The brake device 11 is provided with a brake drum 12. The brake drum 12 is connected to a hoist 204. The brake drum 12 rotates following the rotation of the hoist 204. A first brake shoe 13a and a second brake shoe 13b are arranged on the outside of the outer circumferential surface of the brake drum 12. The first brake shoe 13a and the second brake shoe 13b are constantly biased in the direction of the brake drum 12 by a spring or the like.

[0014] A first brake coil 14a is provided corresponding to the first brake shoe 13a. When current is supplied to the first brake coil 14a, the first brake coil 14a generates a magnetic force on the first brake shoe 13a in the direction opposite to the direction of the brake drum 12. This causes the first brake shoe 13a to be separated from the brake drum 12. A second brake coil 14b is provided corresponding to the second brake shoe 13b. When current is supplied to the second brake coil 14b, the second brake coil 14b generates a magnetic force on the second brake shoe 13b in the direction opposite to the direction of the brake drum 12. This causes the second brake shoe 13b to be separated from the brake drum 12.

[0015] The negative electrode of the first brake coil 14a is connected to a first switch 15a and a second switch 16a, which are connected to ground. The positive electrode of the first brake coil 14a is connected to a third switch 17a, which is connected to a first power supply 18a. The first switch 15a, the second switch 16a, and the third switch 17a are semiconductor switching elements such as IGBTs, MOSFETs, and transistors.

[0016] A first resistor 19a and a first diode 20a are connected in series between the first switch 15a and the negative electrode of the first brake coil 14a and between the third switch 17a and the positive electrode of the first brake coil 14a. That is, the cathode of the first diode 20a is connected between the third switch 17a and the positive electrode of the first brake coil 14a. The anode of the first diode 20a is connected to one end of the first resistor 19a. The other end of the first resistor 19a is connected between the first switch 15a and the negative electrode of the first brake coil 14a. As a result, the first resistor 19a and the first diode 20a are connected in parallel to the first brake coil 14a.

[0017] A second diode 21a and a second resistor 22a are connected in series between the second switch 16a and the first switch 15a and between the third switch 17a and the positive electrode of the first brake coil 14a. That is, the anode of the second diode 21a is connected between the second switch 16a and the first switch 15a. The cathode of the second diode 21a is connected to one end of the second resistor 22a. The other end of the second resistor 22a is connected between the third switch 17a and the positive electrode of the first brake coil 14a. As a result, the second diode 21a and the second resistor 22a are connected in parallel to the first brake coil 14a.

[0018] The resistance value R1 of the first resistor 19a and the resistance value R2 of the second resistor 22a have the relationship R1>R2.

[0019] A third diode 23a is connected between the second switch 16a and ground and between the third switch 17a and the positive electrode of the first brake coil 14a. That is, the anode of the third diode 23a is connected between the second switch 16a and ground. The cathode of the third diode 23a is connected between the third switch 17a and the positive electrode of the first brake coil 14a. As a result, the third diode 23a is connected in parallel with the first brake coil 14a.

[0020] A first connection point 24a between the first resistor 19a and the first diode 20a is connected to ground via a third resistor 25a and a fourth resistor 26a.

[0021] A second connection point 27a between the second diode 21a and the second resistor 22a is connected to ground via a fifth resistor 28a and a sixth resistor 29a.

[0022] The brake control unit 100 includes a first switch control unit 101a, a second switch control unit 101b, a first connection determination unit 102a, and a second connection determination unit 102b.

[0023] The first switch control section 101a appropriately transmits ON / OFF signals to the first switch 15a, the second switch 16a, and the third switch 17a to control the conduction / non-conduction of these switches.

[0024] The first connection determination unit 102a is connected to a third connection point 30a between the third resistor 25a and the fourth resistor 26a. The first connection determination unit 102a receives a signal based on the voltage value appearing at the third connection point 30a, in this case a cut signal 1, and determines the connection on the circuit. Note that a comparator (not shown), for example, is used here.

[0025] The first connection determination unit 102a is connected to a fourth connection point 31a between the fifth resistor 28a and the sixth resistor 29a, and receives a signal based on the voltage value appearing at the fourth connection point 31a, in this case a cut signal 2, and determines the connection on the circuit.

[0026] Similarly, the negative electrode of the second brake coil 14b is connected to the fourth switch 15b and the fifth switch 16b, which are connected to ground. The positive electrode of the second brake coil 14b is connected to the sixth switch 17b, which is connected to the second power supply 18b. The fourth switch 15b, the fifth switch 16b, and the sixth switch 17b are semiconductor switching elements such as IGBTs, MOSFETs, and transistors.

[0027] A seventh resistor 19b and a fourth diode 20b are connected in series between the fourth switch 15b and the negative electrode of the second brake coil 14b and between the sixth switch 17b and the positive electrode of the second brake coil 14b. That is, the cathode of the fourth diode 20b is connected between the sixth switch 17b and the positive electrode of the second brake coil 14b. The anode of the fourth diode 20b is connected to one end of the seventh resistor 19b. The other end of the seventh resistor 19b is connected between the fourth switch 15b and the negative electrode of the second brake coil 14b. As a result, the seventh resistor 19b and the fourth diode 20b are connected in parallel to the second brake coil 14b.

[0028] A fifth diode 21b and an eighth resistor 22b are connected in series between the fifth switch 16b and the fourth switch 15b and between the sixth switch 17b and the positive electrode of the second brake coil 14b. That is, the anode of the fifth diode 21b is connected between the fifth switch 16b and the fourth switch 15b. The cathode of the fifth diode 21b is connected to one end of the eighth resistor 22b. The other end of the eighth resistor 22b is connected between the sixth switch 17b and the positive electrode of the second brake coil 14b. As a result, the fifth diode 21b and the eighth resistor 22b are connected in parallel to the second brake coil 14b.

[0029] The seventh resistor 19b has the same resistance value R1 as the first resistor 19a, and the eighth resistor 22b has the same resistance value R2 as the second resistor 22a.

[0030] A sixth diode 23b connects between the fifth switch 16b and ground and between the sixth switch 17b and the positive electrode of the second brake coil 14b. That is, the anode of the sixth diode 23b is connected between the fifth switch 16b and ground. The cathode of the sixth diode 23b is connected between the sixth switch 17b and the positive electrode of the second brake coil 14b. As a result, the sixth diode 23b is connected in parallel with the second brake coil 14b.

[0031] A fifth connection point 24b between the seventh resistor 19b and the fourth diode 20b is connected to ground via a ninth resistor 25b and a tenth resistor 26b.

[0032] A sixth connection point 27b between the fifth diode 21b and the eighth resistor 22b is connected to ground via an eleventh resistor 28b and a twelfth resistor 29b.

[0033] The second switch control section 101b appropriately transmits ON / OFF signals to the fourth switch 15b, the fifth switch 16b, and the sixth switch 17b to control the conduction / non-conduction of these switches.

[0034] The second connection determination unit 102b is connected to the seventh connection point 30b with the ninth resistor 25b and the tenth resistor 26b, and receives a signal based on the voltage value appearing at the seventh connection point 30b, in this case a cut signal 1, to determine the contact point on the circuit.

[0035] The second connection determination unit 102b is connected to an eighth connection point 31b with the eleventh resistor 28b and the twelfth resistor 29b, and receives a signal based on the voltage value appearing at the eighth connection point 31b, here a cut signal 2, to determine the contact point on the circuit.

[0036] Next, we will explain the operation of this brake control device 10. Note that since the operation on the first brake coil 14a side and the operation on the second brake coil 14b side are basically the same, only the operation on the first brake coil 14a side will be explained.

[0037] Fig. 2 is a circuit diagram showing the ON / OFF state of the switch and the current flow on the first brake coil 14a side. Note that the circuit on the first brake coil 14a side in Fig. 1 has been partially simplified, and the third resistor 25a, fourth resistor 26a, fifth resistor 28a, and sixth resistor 29a have been omitted.

[0038] FIG. 2A is a circuit diagram showing the operation during connection check. During the connection check, the first switch 15a and the second switch 16a are turned off, and the third switch 17a is always turned on.

[0039] As a result, a voltage is applied from the first power supply 18a via the second resistor 22a and the second connection point 27a. Then, the voltage is detected by the fifth resistor 28a and the sixth resistor 29a, and a cut signal 2 is input to the first connection determination unit 102a. Also, a voltage is applied from the first power supply 18a via the first brake coil 14a, the first resistor 19a, and the first connection point 24a. Then, a voltage is detected by the third resistor 25a and the fourth resistor 26a, and a cut signal 1 is input to the first connection determination unit 102a.

[0040] Naturally, if the first resistor 19a is defective, the first connection determining unit 102a does not receive the cut signal 1. Also, if the second resistor 22a is defective, the first connection determining unit 102a does not receive the cut signal 2. Therefore, if the first connection determining unit 102a receives the cut signal 1, it determines that the first resistor 19a is good, and if not, it determines that the first resistor 19a is bad. Similarly, if the cut signal 2 is received, it determines that the second resistor 22a is good, and if not, it determines that the second resistor 22a is bad.

[0041] FIG. 3 is a time chart showing the timing at which a connection check is performed. The vertical axis represents the rotational speed of the hoist 204. After departing from the stopping floor, the hoist 204 increases its rotational speed, then rotates at a constant speed, and as it approaches the destination floor, it slows down and stops. Following the operation of this hoist 204, the brake drum 12 also increases its rotational speed, rotates at a constant speed, descends, and stops.

[0042] The connection check is performed before the hoist 204 starts to rotate, i.e., before the brake drum 12 starts to rotate. It is also performed when the hoist 204 stops to rotate, i.e., after the brake drum 12 stops to rotate. The first connection determination unit 102a monitors the input of cut signal 1 and cut signal 2. If it determines that either signal is not input, it issues an alarm indicating a fault. Thereafter, the brake is not released. After receiving this alarm, the hoist 204 will no longer operate. The first connection determination unit 102a will not take any action even if cut signal 1 or cut signal 2 is detected or not detected except during a connection check.

[0043] FIG. 2(B) is a circuit diagram showing the operation when the brake is released. When the brake is released, the first switch 15a and the second switch 16a are always on, and the third switch 17a alternates between on and off.

[0044] Current flows from the first power supply 18a to the first brake coil 14a, the first switch 15a, and the second switch 16a. As a result, the first brake coil 14a applies a magnetic force to the first brake shoe 13a in the direction opposite to the direction of the brake drum 12. The first brake shoe 13a is then pulled away from the brake drum 12. In this state, the hoist 204 rotates, causing the car 201 to rise or fall. During this time, the third switch 17a repeatedly turns on and off to adjust the magnetic force applied to the first brake shoe 13a.

[0045] FIG. 2C is a circuit diagram showing the operation during normal shutdown. During normal shutdown, the first switch 15a is always on, and the second switch 16a and the third switch 17a are always off.

[0046] As a result, a reflux current flows through a second discharge circuit consisting of the negative electrode of the first brake coil 14a, the first switch 15a, the second diode 21a, the second resistor 22a, and the positive electrode of the first brake coil 14a, and eventually disappears. Figure 4 is a time series diagram showing the current flowing through each switch and the first brake coil 14a, and the change in torque applied to the first brake shoe 13a. Figure 4(a) shows the time series during a normal stop.

[0047] Here, at time t1, the second switch 16a and the third switch 17a are turned off, cutting off the current from the first power supply 18a. This reduces the current flowing through the first brake coil 14a. At the same time, the magnetic force acting on the first brake shoe 13a weakens. This causes the first brake shoe 13a to come into contact with and press against the brake drum 12, increasing torque. At time t2, the return current is discharged through the second resistor 22a, and the current flowing through the first brake coil 14a becomes zero.

[0048] FIG. 2(D) is a circuit diagram showing the operation during an emergency stop. In the event of an emergency stop, the first switch 15a, the second switch 16a, and the third switch 17a are all turned off.

[0049] As a result, a reflux current flows through the first discharge circuit, which is made up of the negative electrode of the first brake coil 14a, the first resistor 19a, the first diode 20a, and the positive electrode of the first brake coil 14a, and then eventually disappears. Figure 4(b) shows a time series during an emergency stop.

[0050] Here, at time t1, first switch 15a, second switch 16a, and third switch 17a are turned off, and the current from first power supply 18a is cut off, so that at time t3, the current flowing through first brake coil 14a becomes zero.

[0051] The resistance value R1 of the first resistor 19a is greater than the resistance value R2 of the second resistor 22a. Therefore, the time interval between t3 and t1 during an emergency stop in FIG. 4(b) is shorter than the time interval between t2 and t1 during a normal stop in FIG. 4(a). The discharge time of the brake coil is largely determined by the reflux resistance. Therefore, to discharge in a short time, a resistor with a larger resistance value must be connected. However, a short discharge time results in a correspondingly louder sound (falling sound) when the brakes are applied. Therefore, in an emergency, the resistance value of the first resistor 19a is made larger to prioritize discharge, even if it results in a louder sound. Note that emergency stops occur very rarely. Furthermore, the resistance value of the second resistor 22a is made smaller during normal operation to avoid discomfort to passengers due to the operating noise.

[0052] 5 is a circuit diagram in which the positions of the first resistor 19a and the first diode 20a are swapped for comparison with FIG. 2(A). That is, the anode of the first diode 20a1 is connected between the first switch 15a and the negative electrode of the first brake coil 14a. The cathode of the first diode 20a1 is connected to one end of the first resistor 19a1. The other end of the first resistor 19a1 is connected between the third switch 17a and the positive electrode of the first brake coil 14a.

[0053] In this circuit configuration, during a connection check, voltage is applied from the first power supply 18a via the first resistor 19a1 and the first connection point 24a. Also, voltage is applied via the first brake coil 14a, the first diode 20a1, and the first connection point 24a. Therefore, even if the first resistor 19a1 is disconnected, it would not be noticeable. Furthermore, during an emergency stop, an excessive voltage equal to the return current multiplied by the first resistance 19a1 is applied to the third resistor 25a and the fourth resistor 26a.

[0054] Taking these into consideration, the first diode 20a and the first resistor 19a are connected in the order shown in FIG.

[0055] In the first embodiment, by checking the connections, it is possible to detect defects in the resistors through which the return current flows at an early stage, and it is possible to prevent the energy accumulated in the brake coil from having nowhere to escape and destroying the semiconductor switching elements that make up the switches.

[0056] In addition, by checking the connection when the hoist is started and stopped, the number of checks increases, allowing for more detailed response.

[0057] In addition, the resistor that releases the return current during an emergency stop and the resistor that releases the return current during a normal stop are completely separate. After checking the connection, even if one resistor is found to be faulty, the other resistor may be able to handle the problem.

[0058] By separating the resistance during emergency stops from the resistance during normal stops, it is now possible to adjust the brake operation to suit the situation, with emphasis on stopping time during emergency stops and noise during normal stops.

[0059] Although the preferred embodiments have been described in detail above, the present invention is not limited to these embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the disclosure.

[0060] Furthermore, when the number, quantity, amount, range, etc. of each element is mentioned in the embodiments, the device of this disclosure is not limited to the mentioned number unless otherwise specified or clearly specified in principle. Furthermore, the structures, etc. described in the embodiments are not necessarily essential unless otherwise specified or clearly specified in principle. [Explanation of symbols]

[0061] 10 brake control device, 11 brake device, 12 brake drums, 13a first brake shoe, 13b second brake shoe, 14a first brake coil, 14b second brake coil, 15a first switch, 15b fourth switch, 16a second switch, 16b fifth switch, 17a third switch, 17b sixth switch, 18a first power supply, 18b second power supply, 19a 1st resistor, 19b 7th resistor, 20a first diode, 20b fourth diode, 21a second diode, 21b fifth diode, 22a 2nd resistor, 22b 8th resistor, 23a third diode, 23b sixth diode, 24a first connection point, 24b fifth connection point, 25a Third Resistance, 25b Ninth Resistance, 26a 4th resistance, 26b 10th resistance, 27a second connection point, 27b sixth connection point, 28a 5th Resistance, 28b 11th Resistance, 29a 6th Resistance, 29b 12th Resistance, 30a third connection point, 30b seventh connection point, 31a fourth connection point, 31b eighth connection point, 100 brake control unit, 101a: first switch control unit; 101b: second switch control unit; 102a: first connection determination unit; 102b: second connection determination unit; 200 elevator, 201 car, 202 weight, 203 rope, 204 Hoisting machine

Claims

1. In an elevator brake control device, the contact and separation of the brake shoes with the brake drum are controlled by controlling the current flowing through the brake coil. a first discharge circuit in which an anode side of a first diode and one end of a first resistor are connected at a first connection point, a cathode side of the first diode is connected to a positive electrode side of the brake coil, and the other end of the first resistor is connected to a negative electrode side of the brake coil; a second discharge circuit in which a cathode side of a second diode and one end of a second resistor are connected at a second connection point, the other end of the second resistor is connected to the positive electrode side of the brake coil, and the anode side of the second diode is connected to the negative electrode side of the brake coil via a switch; a connection determination unit that determines whether the connections of the first resistor and the second resistor are good or bad based on the voltage values ​​of the first connection point and the second connection point, respectively.

2. 2. The elevator brake control device according to claim 1, wherein the resistance value of the first resistor is greater than the resistance value of the second resistor.

3. 3. The elevator brake control device according to claim 1, wherein the connection determination unit performs the determination before the brake drum rotates.

4. 3. The elevator brake control device according to claim 1, wherein the connection determination unit makes the determination after the brake shoes come into contact with the brake drum and the rotation of the brake drum stops.

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