JPS60157485A - Emergency brake gear for lifting machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a machine that is equipped with an elevating body that can be raised and lowered along a vertical structure such as a mast or a tower, such as an elevating crane or an elevating type high-altitude work machine. This invention relates to an emergency brake system that operates to prevent a body from freely descending due to some kind of accident.

Conventional emergency braking devices for lifting machines are equipped with a rotating brake that rotates in conjunction with the lifting of the lifting body when the lifting body attempts to freely descend due to, for example, a break in the lowering wire or a malfunction of the normally used brake device. The weight block detects an increase in body rotation and speed and engages a ratchet fixed to the elevating body with a pawl on the rotary body, or by cam engagement. The structure is configured to stop the rotation of the elevator and stop the descent of the elevating body.

However, according to this conventional configuration, since the elevating body is stopped by the engagement between the pawl and the ratchet, that is, by the metal touch,
For machines such as cranes and high-altitude working machines where the operator works while riding on an elevating body, the V given to the operator is
The impact was large, and the teeth of the pawls and ratchets were chipped, making them impossible to reuse and requiring parts to be replaced each time the emergency brake was activated. In addition, this type of conventional emergency braking device is
1.Since the structure is such that the wind and cam are moved by an angle and distance corresponding to the free descent speed of the descending object, in the event of an accident where the ascending and descending object descends at a speed near the limit for the emergency brake system to operate, Since the wind and the cam rotate while colliding with the teeth of the ratchet at the tip, there is a risk that the tip of the pawl or the like will be damaged and the ratchet will no longer function as an emergency braking device.

In view of the above-described points, an object of the present invention is to provide an emergency brake device for a lifting machine that has a small impact when the emergency brake is activated, can be reused, and is highly reliable.

To achieve this objective, the emergency brake device for lifting machinery of the present invention includes a free-fall detection system using a pawl and a ratchet operated by a centrifugal force-sensitive weight block, a power transmission mechanism, and a band having a brake drum integrated with the ratchet. In order to clarify the operating limits of the emergency braking device, the wind is normally locked to the locking part of the weight block, and due to the increase in centrifugal force during free descent, When the weight block moves to a certain extent, the pawl is released from the weight block, and the pawl is actuated by the force of the biasing spring attached to the pawl to engage the ratchet, and the brake drum integrated with the ratchet is activated. is characterized in that it is configured so that it rotates while rubbing against the brake band and is stopped by the frictional force.

The details of the present invention will be explained below with reference to embodiments shown in the drawings. FIG. 1 shows a scaffolding device for working on a building exterior wall that employs an emergency brake device according to the present invention, and is a device that has already been developed by the present inventors. In FIG. 1, 1 is a rail installed on the ground 3 near a building 2, 4 is a traveling truck that can run along the rail 1, 5 is a mast mounted on the traveling truck 4, and 6 is the mast 5. An elevating frame 8 is attached to the elevating frame 7 so that it can be raised and lowered and is lowered by an elevating device 7, and 8 is a workbench that is attached to the elevating frame 7 so that it can protrude in a horizontal direction that is approximately perpendicular to the installation direction of the rail 1. .

This scaffolding device eliminates the need to construct scaffolding across the entire exterior wall of a building as in the past, reducing the labor and time required for assembly and disassembly, as well as reducing security, sunlight obstruction, and privacy issues. In addition, by operating the operating device by the worker on the workbench 8 to operate the travel motor 9, the lifting motor 10, and the workbench moving motor 11, it is possible to move horizontally instead of vertically. Because it can be moved freely, it can be easily moved to the desired location compared to conventional construction scaffolding, aerial work equipment, or gondolas.
Efficiency is improved, there is no need for scaffolding, and workability is good.Furthermore, as shown in FIG. As shown in ゛, the lifting frame 6 is raised and lowered with the workbench 8 retracted, and when the protruding portion 2A is at a height where it does not get in the way, the workbench 8 is protruded to the position shown by the solid line. This has the advantage that the personnel can work in close proximity to the outer wall 2B.

The elevating device 7 for elevating and lowering the elevating frame 6 includes two roller chains 13 and 14 attached to the mast 5 by being stretched between the projecting frame 12 provided at the top of the mast 5 and the traveling truck 4. , these roller chains 13.
sprockets 15 and 16 meshing with each other are provided on the output shaft, and a reduction gear a is installed on the elevating frame 6.
17. Electric motor 10 for lifting and lowering with 10a and sprockets meshing with each of the roller chains 13 and 14, respectively.
an emergency brake device 19 according to the present invention having a 18 and can be attached to the lifting frame 6; and as shown in FIG. 15.16 and sprocket) 17, '18 are provided respectively between tin rocket 15.16 and sprocket 17.1
It consists of a set of two idlers 20, 21, and 22 that secure the engagement range with the eight roller chains 13, 14. In this embodiment, most of the roller chains 13 (for example, 9
As shown in FIG. 1, the other roller chain 14 is compressed against the protruding frame 12 so that a load of
It hangs down through 23. Note that 24 is a generator that supplies power to each of the motors 9 to 11 via a control panel 25 that is a group of switches controlled by an operating device.

Next, details of the emergency brake device 19 according to the present invention will be explained with reference to FIGS. 3 and 4. 26 is a rotating shaft supported by bearings 27 and 28 attached to the lifting frame 6, and having the sprockets 17 and 18 fixed to one end;
A rotary disk 29 is fixed concentrically to the rotary shaft 26. 3
Reference numeral 0 denotes an arc-shaped weight block which is rotatably attached to the rotary disk 29 around a pin 31, and a rectangular locking portion 30a for locking a claw 46, which will be described later, is formed near the pin 31. . 32 hangs both ends on a stop pin 34 fixed to the tip of the weight block 30 and a stop pin 35 fixed to the rotary disk 29 to press the tip of the weight block 30 against a pin 33 fixed to the rotary disk 29. By this,
This is a stationary spring that prevents the weight block 30 from moving due to gravity as the rotary disk 29 rotates.

36 is a brake drum attached to the rotary shaft 26 via a bearing 37, and 38 is a brake band, one end of which is fixed to the elevating frame 6 with a pin 39, and the other end with a threaded rod 40 attached. For installation, the rod 40 is fixed to the lifting frame 6 by inserting it into the hole 42 of the frame 41, and for installation, a compression spring 44 is interposed between the adjustment screw 43 screwed into the threaded rod 40 and the frame 41. Accordingly, the brake drum 36 can be tightened via the lining 38a stretched over the brake band 38.

45 is a ratchet fixed to the brake drum 36 so as to rotate with the drum 36; 46 is a ratchet rotatable on the rotary plate 2-9 so as to be interposed between the ratchet 45 and the weight block 30; A pawl 49 fixedly attached to a shaft 47 extending through the shaft 47 with a screw 48 is a biasing spring that biases the pawl in the direction of engagement with the ratchet (in the direction of arrow 50). Reference numeral 52 denotes a lever for returning the wind 46 to its original position after activation of the emergency brake device, and the lever is provided on a portion of the shaft 47 that protrudes outside the device so that it can be easily operated by hand.

In this emergency brake device, the spring force of the compression spring 44 is adjusted by the adjustment screw 43 to tighten the brake band 38 against the brake drum 36, so that the frictional force caused by the force is greater than the maximum load including the own weight of the lifting frame 6 (for example, 1
(approximately 50 to 180%). In the normal state, one end of the wind 46 is locked to a locking portion 30a formed on the weight block 30 by the force of the biasing spring 49, and the engaging portion with the ratchet 45 is connected to the ratchet 45.
Even if the lifting frame 6 moves up and down at a normal speed (for example, 3 m 7 minutes) and the rotary plate 29 rotates in the direction of the arrow 51, the centrifugal force acting on the weight block 30 is small. , the tip of the weight block 30 remains pressed against the pin 33 by the force of the stationary spring 32.

If the brake device or deceleration device 10a of the lifting motor 10 breaks down or the roller chain 713 is cut off, the lifting frame 6 begins to freely descend and the rotary plate 2
9 gradually increases, and the centrifugal force acting on the weight block 30 increases, the weight block 30 rotates around the pin 31 against the force of the stationary spring 32, causing the lift frame 6 to rotate. When the descending speed reaches a limit speed (for example, 20 m/min) determined by the spring force of the stationary spring 32 and the degree of engagement between the locking portion 30a of the weight block 30 and the pawl 46 (for example, 20 m/min), the speed shown in FIG. The weight block 30 moves as shown by the two-dot chain line, the wind 46 is released from the locking portion 30a, and the wind engages the ratchet 45 due to the force of the biasing spring 49. Therefore, the rotation of the rotary disk 29 is controlled by the pawl 46.
, is transmitted to the brake drum 36 via the ratchet 45, and the brake drum 36 rotates while rubbing against the lining 38a of the brake band 38. This frictional force causes the brake drum 36 and the rotating shaft rotating integrally with the brake drum 36 to rotate. The rotational speed of 26 gradually decreases and stops. Therefore, the elevating frame 6 stops smoothly without suddenly stopping, and the impact is alleviated.

Even if for some reason it falls at a speed close to the limit speed, as long as the pawl 46 is engaged with the locking portion 30a, the pawl 46 will not engage with the ratchet 45.
Unlike in the past, the pawl and ratchet do not collide and get damaged at half-way speeds, and the pawl 46 always engages with the ratchet 45 once the limit speed is exceeded, so operation is ensured. In addition, this emergency brake device can be used any number of times because the lifting frame is stopped freely by friction between the brake drum 36 and the lining 38a.

Further, in this embodiment, since the lever 52 is provided, after the emergency brake device is activated and the repair is completed, the pawl 46 can be returned to its original position simply by operating the lever 52. There is no need to disassemble the device.

Although the present invention has been described above with reference to examples, the present invention can be applied to any machine such as an elevating crane in which an elevating body moves up and down on a mast or the like. It can also be applied to those used.

As described above, according to the present invention, since the band brake device is used to stop the free descent of the elevating body by frictional force, the impact is small and damage to pawls, ratchets, etc. is prevented. Reuse becomes possible. Furthermore, since the impact when the emergency brake is activated is alleviated, safety is improved in the case of a machine where an operator rides and works. In addition, due to the structure in which the claw is locked with the locking part of the weight block,
The emergency brake operates reliably when the critical speed is reached, and the pawl and ratchet do not collide when the speed is below the critical speed, preventing accidents where the pawl or ratchet breaks near the critical speed, which is the case with conventional brakes. can do. Also,
Since the device of the present invention is constructed relatively easily by combining parts that have been used in the past, it is possible to realize a highly reliable device. −

[Brief explanation of the drawing]

Fig. 1 is a side view showing a scaffolding device to which an emergency braking device according to the present invention is applied, Fig. 2 is a rear view of its elevating frame portion, and Fig. 3 is an emergency braking device according to the present invention used in the scaffolding device. FIG. 4 is a sectional view showing one embodiment of the third embodiment.
It is an AA sectional view of the figure. 5... Mast, 6... Lifting frame, 19... Emergency brake device, 26... Rotating shaft, 29... Rotating disk, 3°... Weight block, 32... Stationary spring,
36... Brake drum, 38... Brake band, 38a... Lining, 45... Ratchet, 4
6...Claw, 49...Biasing spring, 52...Lever Patent applicant Hitachi Construction Machinery Co., Ltd. Agent Patent attorney Masami Akiki Agent Patent attorney Masaru Wakata

Claims (1)

[Scope of Claims] 1. An emergency brake device for a lifting machine that is activated and stopped when a vertical structure such as a mast is ascending or descending due to an obstacle in its physical strength. a weight block attached to a rotating body that rotates in conjunction with the vertical movement of the rotating body; a stationary spring that prevents the weight block from rotating due to gravity as the rotating body rotates; and a stationary spring that is concentric with the rotating body. A brake drum provided on the lift body is equipped with a brake band attached to the frame of the elevating body to stop the descent of the R bulge, and a band brake device is tightened with force, and the brake drum is connected to the drum. A ratchet fixed concentrically, a pawl attached to the rotating body so as to be interposed between the ratchet and the weight block, and an urging force that biases the pawl in a direction to engage the ratchet. a spring, and normally a part of the pawl is locked to a locking part formed on the weight block by the force of the biasing spring, and the engaging part with the ratchet is in a disengaged state with the ratchet. When the elevating body is held in place, and the elevating body freely descends, the steel block operates against the force of the stationary spring, and the pawl is released from the latch by the latch portion, and the force of the biasing spring releases the latch. An emergency brake device for a lifting machine, characterized in that a pawl is configured to engage with the ratchet. 2. The emergency brake device for a lifting machine according to claim 1, characterized in that an operating means for returning the pawl to its original position after the emergency brake device is activated is provided outside the device that can be manually operated. .