Elevator apparatus
In an elevator apparatus, a brake device stops a car from running. The brake device can adjust the magnitude of part of a total braking force generated at a time of emergency braking of the car. As an example of the brake device, the brake device has a nonadjustable brake portion for immediately generating a braking force without making an adjustment thereof at the time of emergency braking of the car, and an adjustable brake portion for generating a braking force while making an adjustment thereof at the time of emergency braking of the car.
1. An elevator apparatus, comprising:
a car; and
a brake device configured to stop the car, and to adjust a magnitude of part of a total braking force generated at a time of braking of the car, the brake device including
a first brake portion configured to generate a braking force immediately without making an adjustment of the braking force, and
a second brake portion configured to generate a braking force while making an adjustment to the braking force, the second brake portion including
a second brake shoe that is brought into contact with and away from a brake rotational body,
a second braking spring for pressing the second brake shoe against the brake rotational body,
a second brake coil for generating an electromagnetic force for opening the second brake shoe away from the brake rotational body against the second braking spring,
a brake control portion for controlling the electromagnetic force generated by the second brake coil,
a brake control switch provided between the second brake coil and a power supply, and
a forcible braking switch configured to invalidate any adjustment of the braking force to forcibly generate the total braking force of the second brake portion, the forcible braking switch provided between the second brake coil and the power supply and connected in series to the brake control switch.
2. The elevator apparatus according to claim 1 , wherein the first brake portion has a braking force that can stop the car even when the braking force of the second brake portion remains canceled.
3. The elevator apparatus according to claim 1 , wherein the first brake portion includes a first brake shoe that is brought into contact with and away from the brake rotational body that is rotated as the car runs, a first braking spring for pressing the first brake shoe against the brake rotational body, and a first brake coil for generating an electromagnetic force for opening the first brake shoe away from the brake rotational body against the first braking spring.
4. The elevator apparatus according to claim 1 , wherein the forcible braking switch is opened and closed in response to an external signal.
5. The elevator apparatus according to claim 1 , further comprising:
an actuation command generating portion configured to generate a brake actuation command; and
a timer circuit configured to output a command to a timer switch after a lapse of a predetermined time from a time when the brake actuation command is received, the timer switch is connected in series to the brake control switch and is opened in response to the command from the timer circuit.
6. The elevator apparatus according to claim 5 , wherein the second brake portion further includes
a current limiter for limiting a current flowing through the second brake coil, the current limiter is connected between the timer switch and the power supply.
7. The elevator apparatus according to claim 5 , wherein the brake control switch is responsive to the brake actuation command without the use of the brake control portion.
8. The elevator apparatus according to claim 5 , further comprising:
an adjustment switch configured to control the current supplied to the second brake coil, the brake actuation command from the actuation command generating portion is input to the brake control portion, such that the brake control portion monitors a deceleration of the car, and controls an open/close state of the adjustment switch for controlling the deceleration of the car.
9. An elevator apparatus, comprising:
a car; and
a brake device configured to stop the car, and to adjust a magnitude of part of a total braking force generated at a time of braking of the car, the brake device including
a first brake portion configured to generate a braking force immediately without making an adjustment of the braking force, and
a second brake portion configured to generate a braking force while making an adjustment to the braking force, the second brake portion including
a second brake shoe that is brought into contact with and away from a brake rotational body,
a second braking spring for pressing the second brake shoe against the brake rotational body,
a second brake coil for generating an electromagnetic force for opening the second brake shoe away from the brake rotational body against the second braking spring, and a brake control portion for controlling the electromagnetic force generated by the second brake coil, and
a third brake coil for generating an electromagnetic force for opening the second brake shoe away from the brake rotational body against the second braking spring, and the third brake coil is immediately stopped from being supplied with a current.
10. The elevator apparatus according to claim 9 , wherein the second brake portion further comprises:
a brake control switch provided between the second brake coil and a power supply, and
a forcible braking switch configured to invalidate any adjustment of the braking force to forcibly generate the total braking force of the second brake portion, the forcible braking switch provided between the second brake coil and the power supply and connected in series to the brake control switch.
11. The elevator apparatus according to claim 9 , wherein the first brake portion has a braking force that can stop the car even when the braking force of the second brake portion remains canceled.
12. The elevator apparatus according to claim 9 , wherein the first brake portion includes a first brake shoe that is brought into contact with and away from the brake rotational body that is rotated as the car runs, a first braking spring for pressing the first brake shoe against the brake rotational body, and a first brake coil for generating an electromagnetic force for opening the first brake shoe away from the brake rotational body against the first braking spring.
13. The elevator apparatus according to claim 12 , wherein the first and second braking springs are disposed so that the first and second braking springs correspond to positions of the first and second brake coils, respectively.
14. The elevator apparatus according to claim 9 , wherein the second brake portion further comprises:
a forcible braking switch for invalidating the adjustment of the braking force at the time of braking to forcibly generate a total braking force of the second brake portion.
15. The elevator apparatus according to claim 14 , wherein the forcible braking switch is provided between the second brake coil and a power supply and connected in series to the second brake switch, and is opened in response to an external signal.
16. The elevator apparatus according to claim 9 , wherein the second brake portion further comprises:
a current limiter for limiting a current flowing through the second brake coil, the current limiter is connected between the second break coil and the power supply.
17. The elevator apparatus according to claim 9 , wherein the second brake portion further comprises:
a third braking spring for pressing the second brake shoe against the brake rotational body, the third braking spring corresponding to the third brake coil.