JPH0625478Y2 - Fall prevention mechanism in lifting device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a fall prevention mechanism of a carrier in a simple lifting device used for elevating and lowering materials at a construction site, etc. The present invention relates to an improvement for preventing the fall.

[Conventional technology]

A self-propelled simple lifting device used at a construction site, etc. is a motor attached to a carry device, which is provided with a carry device that can be moved up and down through rollers engaged with a pair of left and right vertically installed guide rails. The pinion gear driven by the gear is engaged with a rack standing upright in parallel with the guide rail, and the rotary drive of the pinion gear engaged with the rack allows the carrier to be moved up and down along the guide rail. . A governor brake is generally used as a fall-prevention mechanism of this type of lifting device, but this is to obtain a braking force by pressing a shoe connected to a rotating shaft against a drum by centrifugal force. The governor brake is attached to the carrier side, and a pinion gear that pivotally supports one end of its rotation shaft is meshed with the rack. In the event of an accident in which the rack of the drive side pinion gear is disengaged and the rack is disengaged and the carrier drops at an abnormal speed, the governor brake side pinion gear meshes with the rack. The rotary shaft is rotated at a high speed, and the centrifugal force applied to the shoe activates a brake to lock the rotation of the rotary shaft so that the carrier can be stopped.

[Problems to be solved by the device]

However, in the governor brake used in the conventional fall prevention mechanism as described above, the brake is adjusted so that it operates when the drop speed of the carrier reaches 2-3 times the steady operation speed. This adjustment is difficult because the drop speed of the carrier depends on the load amount of the carrier, and the operation timing of the brake is uncertain, and the drop speed of the carrier is 2 to 3 of the steady operation speed.
Since it takes time to double the number of times, when an accident occurs in a relatively low place, the transport device crashes before the brake is actuated, and the function of preventing fall cannot be reliably obtained.

The present invention is an attempt to improve the above-mentioned problems in order to solve the above problems, and an object of the present invention is to promptly and surely perform a brake operation in the event of an accident and improve its safety. The specific means and actions are as follows.

[Means for Solving the Problems]

A rotating shaft driven by a pinion gear meshing with the rack is provided, and a braking plate is slidably fitted only on the rotating shaft in the axial direction. The movable disk is pivotally supported on the rotary shaft, the fixed disk is fixed to the rotary shaft, and the movable disk is screwed movably with respect to the rotary shaft. While being provided so as to rotate synchronously, the movable disk is moved to the braking plate side through its screwing action by a rotating shaft whose rotational speed increases when an accident occurs, and the both disks are pressed against the braking plate.

[Action]

Since the movable disk is provided so as to rotate synchronously with the rotating shaft that is driven and driven by the motor to move the carrier up and down, the movable disk does not move and the brake is not applied.

On the other hand, when an accident occurs, the rotation speed of the rotating shaft becomes higher than the rotation speed of the moving disk, so that the moving disk moves to the braking plate side through its screwing action, and both disks are pressed against the braking plate to rotate the rotating shaft. Brakes on
It is possible to prevent the carrier from falling.

〔Example〕

Specific embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 5 are drawings showing a first embodiment of the present invention, in which 1 is a lifting device, 2 is a carrier constituting the lifting device 1, and 3 and 3 are guide rails, respectively. . The guide rails 3 and 3 are formed in a long shape by using a pair of left and right channel rods having a U-shaped cross section, and are vertically set up with an appropriate interval. A rack 4 is erected parallel to the guide rails 3 and 3 between the guide rails 3 and 3, and one side surface of the rack 4 has a tooth portion 4'which can be meshed with pinion gears 11 and 15 which will be described later. It is formed along the direction.
Further, the carrier 2 is formed in a box shape with side plates surrounding the periphery, and a plurality of rollers 5 and 5 are axially supported in opposed relation on the left and right sides of the back surface thereof. By engaging the rollers 5 and 5 with the guide rails 3 and 3, the carrier 2 can be vertically moved along the guide rails 3 and 3. A base 6 extends downward from the lower portion of the carrier 2, and a motor 7 and a speed reducer 8 for lifting and lowering are fixed to the base 6. Motor 7
The output shaft of is connected to the speed reducer 8 via the coupling 9, and the drive shaft 10 is projected from the speed reducer 7 toward the back side of the carrier 2, and the rack is provided at the end of the drive shaft 10. The pin-on gear 11 that meshes with the tooth portion 4'of 4 is fixed. The motor 7 rotates the pin-on gear 11 to raise and lower the carrier 2. A screw brake 12 is attached to the base 6. The rotary shaft 13 of the screw brake 12 is rotatably supported by bearings 14 and 14, and the pinion gear 1 is attached to one end of the rotary shaft 13.
5, the pinion gear 15 is engaged with the tooth portion 4'of the rack 4, and is provided so as to rotate the rotary shaft 13 following the elevation of the carrier 2. Rotating shaft 1
A brake plate 16 is loosely fitted to the shaft 3, and a fixed disk 17 and a movable disk 18 are axially supported on both sides of the brake plate 16 with the brake plate 16 interposed therebetween. The braking plate 16 has an insertion hole 19 through which the rotary shaft 13 is inserted and has a diameter slightly larger than that of the rotary shaft 13, and a cutout portion 20 is formed at a side end portion of the base plate 6 side. By engaging with a rotation restricting piece 21 protruding from the base 6, it is provided slidably only in the axial direction of the rotary shaft 13. The fixed disk 17 is fixed to the rotary shaft 13, and a pad 22 made of a friction material is attached to the inner end surface facing the braking plate 16, while the movable disk 18 rotates a female screw hole 18 'engraved in the center thereof. Male screw part 13 'engraved on the shaft 13
A pad 22 formed of a friction material is attached to the inner end surface facing the braking plate 16 in the same manner as the fixed disk 17 while being screwed into the shaft so as to be movable in the axial direction. Further, the gear 2 is provided on the outer peripheral portion of the movable disk 18.
3 is engraved, the gear 23 is a reduction gear 24 and a gear 25,
It is connected to the output shaft of the motor 7 through a gear mechanism composed of 26 and 27. The movable disk 18 is provided so as to rotate in synchronization with the rotary shaft 13 by the rotational force transmitted from the motor 7 via the gear mechanism during steady operation, while the rotational speed of the rotary shaft 13 increases when a drop accident occurs. Male screw portion 13 'for female screw hole 18'
The movable disc 18 is relatively moved in the direction of the fixed disc 17 by the screwing action of the above so that a state where both discs 17 and 18 are pressed against the braking plate 16 is provided.

FIG. 6 is a drawing showing the second embodiment, in which the rotary shaft 13
The brake plate 16 'which is loosely fitted in is formed in a disk shape, and a tightening band 29 is wound around the outer peripheral surface of the brake plate 16' via a lining 28. Both ends of the tightening band 29 are fastened by bolts 31 having a spring 30 interposed therebetween, and the elastic force of the spring 30 is changed by the forward / backward operation of the bolt 31, so that the tightening force of the tightening band 29 on the braking plate 16 'can be adjusted. In addition, both ends of the tightening band 29 are extended in parallel toward the base 6 side and are engaged with the rotation restricting pieces 21 protruding from the base 6.

Next, the operation will be described.

During the steady operation shown in FIG. 3, the pin 7 of the drive shaft 10 is rotated by the driving force of the motor 7, and the pin 4 is engaged with the rack 4 to move the carrier 2 up and down at a steady speed. can get. When the carrier 2 moves up and down in this manner, the rotation shaft 13 is rotated by the pinion gear 15 of the screw brake 12 meshed with the rack 4.
The movable disk 18 screwed into the male screw portion 13 'of the rotary shaft 13 is driven by the rotational force transmitted from the motor 7 via the gear mechanism.
Since the movable disk 18 is rotated integrally with the male screw portion 13 ', the movable disk 18 is rotated integrally with the male screw portion 13' without moving on the male screw portion 13 '.
Held in a position away from. The rotating shaft 13 rotates in the opposite direction when the carrier 2 is raised and lowered, but since the motor 7 is rotated in the opposite direction when the carrier 2 is raised, the rotary shaft 13 is raised and lowered. Even in this case, the rotary shaft 13 and the movable disk 18 can be rotated synchronously. On the other hand, in such a steady operation, when the pin 2 of the drive shaft 10 is damaged and the carrier 2 is no longer supported and an accident occurs such that the carrier 2 drops, the rack 4
The rotational speed of the rotary shaft 13 driven by the pinion gear 15 meshing with the rotary disk 13 becomes higher than the rotational speed of the movable disk 18, and the male screw portion 13 ′ has the female screw hole 1 of the movable disk 18.
By rotating in 8 ', the movable disk 18 moves to the side of the braking plate 16 as shown in FIG. 5, and is pressed by the braking plate 16, and the braking plate 16 is pressed to the side of the fixed disk 17. Moved and fixed disk 1
Pressed by 7. When the disks 17 and 18 are pressed against the braking plate 16 via the pads 22 in this manner, the rotation of the braking plate 16 is restricted by the rotation restricting piece 21, so that the rotation shaft 13 is braked. As a result, the rotation of the pinion gear 15 meshing with the rack 4 is stopped, and the action of stopping the carrier 2 is obtained.

Further, in the second embodiment, the tightening force of the spring 30 of the tightening band 29 against the braking plate 16 'is adjusted to be slightly weakened by the forward / backward movement of the bolt 31, so that the above-described braking is performed. When both discs 17 and 18 are pressed against both sides of the plate 16 ′, it is possible to obtain a state in which a so-called semi-brake in which the braking plate 16 ′ rotates while sliding on the tightening band 29 can be obtained during the brake operation. The effect of gently lowering is obtained.

In the present invention, it is possible to provide a sensor mechanism that stops the motor 7 by detecting the brake operation when the brake is operated.

[Effect of device]

The present invention is configured as described above, and as described above, the movable disk that is screwed to the rotary shaft of the screw brake is provided so as to always rotate synchronously with the rotary shaft, while the rotation speed increases when an accident occurs. By moving the movable disc to the braking plate side through its screwing action by the shaft and pressing both discs against the braking plate to obtain the braking action, the braking action at the time of an accident can be promptly and reliably performed. It has become possible to prevent the carrier from falling and improve its safety.

[Brief description of drawings]

1 to 5 are drawings showing a first embodiment of the present invention, in which FIG. 1 is an overall plan view of a lifting device according to the present invention, FIG. 2 is a rear view of the same, and FIG. FIG. 4 is an enlarged side view of essential parts, FIG. 4 is a sectional view taken along the line AA of FIG. 1, and FIG. FIG. 6 is a drawing showing the second embodiment,
FIG. 5 is a sectional view similar to FIG. 4. 1 ... Lifting device, 2 ... Carrier, 3 ... Guide rail, 4
... rack, 4 '... teeth, 5 ... roller, 6 ... base, 7 ... motor, 8 ... reducer, 9 ... coupling, 10 ... drive shaft, 11 ... pinion gear, 12 ……
Screw brake, 13 ... Rotating shaft, 13 '... Male screw part,
14 ... Bearing, 15 ... Pinion gear, 16, 16 '
...... Brake plate, 17 ...... Fixed disk, 18 ...... Movable disk, 18 '...... Female screw part, 19 ...... Insertion hole, 2
0 ... Notch, 21 ... Rotation restriction piece, 22 ... Pad, 23 ... Gear, 24 ... Reduction gear, 25, 26, 27
...... Gear, 28 ...... Lining, 29 ...... Tightening band, 3
0 ... spring, 31 ... bolt.

Claims (1)

[Scope of utility model registration request] 1. A pinion gear rotatably driven by a motor.
To the lifting device that engages the rack with the rack to lift the carrier.
And driven by a pinion gear that meshes separately with the rack
A rotating shaft that rotates is provided, and a braking plate is attached to the rotating shaft.
It is slidable only in the line direction and is rotated together
There is a braking plate on the shaft and a fixed disk and a movable disk.
If the fixed disk is fixed to the rotary shaft by supporting the disk
In both cases, the movable disc is screwed so that it can move freely around the rotary shaft.
The movable disk is always rotated by the above motor.
It is installed so that it rotates synchronously with the shaft, but it rotates when an accident occurs.
The movable disk is screwed by the rotating shaft which becomes higher in number.
To the braking plate side through the
In the lifting device that is installed so that both disks are pressed against
A falling prevention mechanism.