JPS621191Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a band brake device used for a hoisting drum of a crane, etc.

In a hoisting drum of a crane, the drum shaft is often bent by the hoisting load, and the drum shaft center moves in the radial direction. Among conventional band brake devices, a general brake device exclusively for positive brakes is known in which the brake band can follow the movement of the drum axis as described above. In such a brake device, the moving point side of the brake band is fixed in position by the cylinders of both the positive and negative brake mechanisms attached to the fixed part, so it cannot follow the movement of the drum axis. For this reason, there was a problem in that a gap was formed in a portion between the brake band and the brake drum, resulting in poor brake effectiveness.

Therefore, the present invention aims to provide a band braking device that is equipped with both positive and negative braking mechanisms and can follow the movement of the drum axis on both the dead center side and moving point side of the brake band. .

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a brake drum, 2 is a brake band wrapped around the drum 1, and brackets 5 and 6 are fixed to both ends 3 and 4 of the band 2 on the dead center side and moving point side, respectively. . One end of each of the rod-shaped first link 7 and the frame-shaped second link 8 is attached to the dead point side bracket 5 by a common pin 9.
The first link 7 is pivotally connected to be rotatable about an axis parallel to the drum axis, and the other end of the first link 7 is pivotally connected to a fixed part 11 via an anchor pin 10 parallel to the pin 9. Both positive and negative brake mechanisms 12 and 13, which will be described later, are installed between the second link 8 and the moving point side bracket 6, and the movement of the second link 8 is controlled by the brake mechanism 12 and 13 through the brake mechanisms 12 and 13. The signal is transmitted to the end 4 on the moving point side.

Therefore, when using this brake device, the dead center side end 3 of the brake band 2 is connected to the anchor pin 10.
The end 4 on the moving point side rotates around .
Since it can rotate around the pin 9, which is a movable fulcrum, both ends 3 and 4 on the dead center side and the moving point side can fully follow the movement of the drum axis O, so that the brake is always good. The effect can be maintained.

Both positive and negative brake mechanisms 12,
13 will be explained in detail with reference to FIG. 2 and subsequent figures.

The moving point side bracket 6 is fixed to the band moving point side end 4 with bolts 14 and pins 15. A first hydraulic cylinder 16 for a positive brake is fixed to this bracket 6, and its piston rod 17 is screwed and fixed to an end plate 18 of the second link 8. Therefore, the first cylinder 16
Due to the extension operation of the piston rod 17, the second
When a pressing force is applied to the link 8 and the reaction force is applied from the cylinder 16 to the bracket 6,
The moving point side end 4 moves to the dead center side, and the drum tightening force (braking force) by the brake band 2 is applied. Reference numerals 19 and 19 indicate return springs for the first cylinder 16, which are tensioned between the end plate 18 of the second link 8 and the mounting pin 15 of the bracket 6.

Reference numeral 20 denotes a second hydraulic cylinder for negative brake, which is fixed to the end of the second link 8 on the dead center side. The piston rod 21 of the cylinder 20 is formed to be long, and its middle portion is connected to the projecting piece 23 of the bracket 6 via a cylindrical movable spring seat 22 with a flang.
In addition, the tip end is connected to the end plate 18 via the fixed spring seat 24.
are supported so as to be slidable in the axial direction. The movable spring seat 22 is fitted onto the rod 21, and is prevented from moving in the axial direction from the intermediate portion of the rod toward the dead center side by nuts 25 and 26. A push spring 27 is wound between the movable and fixed spring seats 22 and 24 of the rod 21, and the push spring 27 constantly presses the rod 21 toward the dead center side.
Therefore, unless pressure oil is supplied to the second cylinder 20, the flange 22a of the movable spring seat 22 will not touch the bracket 6.
The rod comes into contact with the protruding piece 23, and the rod pressing force by the push spring 27 is applied to the bracket 6 via the flange 22a and the protruding piece 23, thereby pushing the end 4 on the side of the band moving point toward the dead center side. Braking force will be applied. In other words, a negative braking action is exerted by the spring force. Note that 28 is a stopper fixed to the rod 21, and the stopper 28 restricts the movement stroke of the rod 21 toward the moving point.

In such a configuration, if you want to release both the positive and negative brakes,
Pressure oil is supplied only to the second hydraulic cylinder 20. In this way, the rod 21 moves to the moving point side and compresses the push spring 27, so the spring force of the push spring 27 does not act on the moving point side end 4 of the band 2, and therefore the negative brake is released. state (see Figure 4).

In the above state, if pressure oil is supplied to the first hydraulic cylinder 16, the band moving point side end 4
moves to the dead center side and the positive brake is applied (see Figure 5).

Furthermore, when the pressure oil in the second hydraulic cylinder 20 is released in the positive brake released state, the end 4 on the moving point side is pushed toward the dead center by the spring force of the push spring 27.
The negative brake action state shown in FIG. 2 is reached.

In the above embodiment, the spring force of the push spring 27 is transmitted from the rod 21 to the bracket 6 by the flange 22a of the movable spring seat 22 and the projecting piece 23 of the moving point side bracket 6. The configuration of the protrusions on the rod side and the bracket side for transmitting the spring force can be changed as appropriate when implementing the present invention.

As described above, according to the present invention, both ends of the brake band on the dead center side and on the dynamic point side can follow the movement of the drum axis while having both positive and negative brakes. The desired braking performance can be reliably maintained even in crane hoisting drums and the like where the drum axis tends to shift.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is an overall front view, Fig. 2 is an enlarged sectional view of main parts, Fig. 3 is a sectional view taken along the line shown in Fig. 2, and Fig. 4 is a positive and negative view. FIG. 2 is a view corresponding to FIG. 2 showing both brakes released, and FIG. 5 is a view corresponding to FIG. 2 showing a positive brake applied state. 1... Brake drum, 2... Brake band, 3... End of the band on the dead center side, 4... End on the co-moving point side, 5... Bracket on the dead center side, 6... Bracket on the moving point side, 7...First link, 8...Second link, 10...Anchor pin, 11...Fixing part, 1
2... Positive brake mechanism, 13... Negative brake mechanism, 16... Hydraulic cylinder for positive brake, 17... Piston rod, 2
0...Hydraulic cylinder for negative brake, 21
...the same rod, 22...a spring seat as a protruding piece on the rod side, 23...a protruding piece on the bracket side, 27...a push spring.

Claims (1)

[Scope of utility model registration request] A bracket is fixed to both ends of the brake band wrapped around the brake drum, on the dead center side and moving point side, and both the first and second links are rotated on the dead center side bracket around axes parallel to the drum axis. A band brake device that is pivotably connected to the first link and connects the first link to a fixed part via an anchor pin, and incorporates both positive and negative brake mechanisms between the second link and the moving point side bracket. The positive brake mechanism is configured by connecting a piston rod of a positive brake cylinder fixed to the movable point side bracket to the second link, and the negative brake mechanism is configured by connecting the piston rod of a positive brake cylinder fixed to the moving point side bracket to the second link. A pressure spring is wound around the piston rod of the negative brake cylinder to always press the rod toward the dead center side, and a protrusion is attached to both the rod and the bracket to transmit the rod pressing force from the pressure spring to the moving point side bracket. A band brake device characterized in that it is configured by being provided facing each other.