JPH10122274A - Centrifugal internal expanding brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the extend of braking performance by way of antilocking in this centrifugal internal expanding brake. SOLUTION: In this centrifugal internal expanding brake 1 where a rotator 3 is set up on the inside of a fixed drum 2, setting up a pair of brake shoes 6 in this rotator 3, and these paired brake shoes 6 come into slidingly contact with the fixed drum 2 against a spring 7 by a rotation of this rotator 3 for the sake of braking, each anchor pin 5 is installed in a central part halving each individual brake shoe 6, and the spring 7, energizing the brake shoes 6 in the non-braking direction, is installed in space between both ends being opposed, and further the anchor pins 5 are set up in respective opposed positions, and thus each of these brake shoes 6 is made up to be shiftable only in a direction (x) connecting the paired anchor pins 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal in-branch braking device for braking a brake shoe by sliding a brake shoe against a fixed drum by centrifugal force.

[0002]

2. Description of the Related Art In a centrifugal force internal braking device, for example, a rotating body 101 is disposed inside a fixed drum 100 as shown in FIG.
And the trailing shoe 103 is the end 102
a and 103a are provided with the anchor pins 104 and 105 as fulcrums, and the other ends 102b and 103b are attached to the springs 106 and 103b.
Is always provided in a non-braking direction. For example, when the rotating body 101 rotates in the direction of the arrow, the leading shoe 102 opens outward against the spring 106 with the anchor pin 104 as a fulcrum, and slides against the fixed drum 100 to apply braking when the rotating body 101 rotates in the direction of the arrow. . On the other hand, when braking is performed when the rotating body 101 rotates in the reverse direction, the trailing shoe 103 opens outward against the spring 106 with the anchor pin 105 as a fulcrum, and slides on the fixed drum 100 to brake.

[0003]

Such a centrifugal force-increasing braking device can provide a large braking force and can achieve the same braking performance at the time of forward / reverse rotation, but the locking toughness is not stable. For example, when used in a descent device that evacuates in the event of a fire, care must be taken to prevent self-locking.

That is, as shown in FIG. 2, for example, a resultant force of a central force P acting on the leading shoe surface and a tangential force Q acting on the leading shoe surface acts on a point K,
Assuming that the self-induction coefficient at that time is λ, self-locking is performed as follows: λ = Mq / Mp = μ (rC-IB) / IA> 1.

Here, Mq = moment on the anchor pin due to Q Mp = moment against the anchor pin due to P μ = coefficient of friction of the braking sliding surface b = brake lining width r = radius of fixed drum l = position of anchor pin

[0006]

The present invention has been made in view of such circumstances, and has as its object to provide a centrifugal in-branch braking device in which braking performance is stabilized by anti-locking.

[0008]

In order to solve the above-mentioned problems and to achieve the object, according to the first aspect of the present invention, a rotating body is disposed inside a fixed drum, and a pair of brake shoes is provided on the rotating body. In a centrifugal force expanding braking device that brakes by sliding against the fixed drum against the spring by the rotation of the rotating body, the pair of brake shoes is provided at a central portion where each of the brake shoes is divided into two. An anchor pin is provided, and a spring for urging the brake shoe in the non-braking direction is provided between both opposing ends, and the anchor pins are disposed at opposing positions, and each brake shoe is provided with the pair of anchor pins. It is characterized in that it is configured to be movable only in the connecting direction. At the time of braking, the pair of brake shoes move only in the direction connecting the pair of anchor pins and slide against the fixed drum to brake, and the brakes rotate around the anchor pins and do not brake, so there is no self-locking and anti-locking. This stabilizes the braking performance.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the centrifugal in-branch braking system according to the present invention will be described below. FIG. 1 is a plan view of a centrifugal in-branch braking device.

The in-centrifugal braking device 1 is used, for example, in a descending device that evacuates in the event of a fire. A rotating body 3 is disposed inside a fixed drum 2. The rotating body 3 has a rotating shaft 4
And an anchor pin 5 provided symmetrically with respect to the rotation shaft 4. Further, a pair of brake shoes 6 are arranged on the rotating body 3. A central portion 6a that divides each brake shoe 6 into two portions has an inner concave portion 6b that engages with the rotating shaft 4, and an outer concave portion 6c that engages with the anchor pin 5.
Are formed, the inner concave portion 6b is provided on the rotation shaft 4, and the outer concave portion 6c is formed.
Is engaged with the anchor pin 5 and is movable only in the direction x connecting the pair of anchor pins 5, and the movement is restricted in the direction y orthogonal to the direction x connecting the pair of anchor pins 5. A spring 7 for urging the brake shoes 6 in the non-braking direction is provided between the opposite ends 6d of the respective brake shoes 6.

[0011] The pair of brake shoes 6 includes the rotating body 3.
Due to the centrifugal force caused by the rotation of, the spring moves outward against the spring 7 and slides on the fixed drum 2 to apply braking. The inner concave portion 6b of each brake shoe 6 is provided on the rotating shaft 4 and the outer concave portion 6b.
Since c is engaged with the anchor pin 5, the brake shoe 6 moves only in the direction x connecting the pair of anchor pins 5 to brake. In this way, at the time of braking, the pair of brake shoes move only in the direction connecting the pair of anchor pins, slide and contact the fixed drum to brake, and do not brake by rotating with the anchor pin as a fulcrum, so there is no self-locking, Anti-locking stabilizes braking performance.

That is, in FIG. 1, for example, the resultant force of a central force P acting on the left brake shoe surface and a tangential force Q acting on the brake shoe surface acts on the point K, and the self-induction coefficient at that time is λ. Λ = Mq / Mp.

Where Mq = Q is the moment with respect to the anchor pin, and Mp = P is the moment with respect to the anchor pin.

[0014]

Here, since the anchor pin portion has a non-rotating structure only by guiding the brake shoe, it can be dynamically treated as Mq = Ql ₁ = 0, so that anti-locking is performed with λ = Mq / Mp = 0 <1. It is.

[0016]

As described above, according to the first aspect of the present invention, at the time of braking, the pair of brake shoes move only in the direction connecting the pair of anchor pins and slide against the fixed drum to perform braking, so that the anchor pins are moved. Since the fulcrum does not rotate and brake, there is no self-locking, and anti-locking stabilizes the braking performance.

[Brief description of the drawings]

1 is a plan view of a centrifugal in-branch braking device.

FIG. 2 is a plan view of the conventional centrifugal in-branch braking device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Centrifugal force internal expansion device 2 Fixed drum 3 Rotating body 5 Anchor pin 6 Brake shoe 7 Spring

Claims (1)

[Claims] A rotating body is arranged inside a fixed drum, and a pair of brake shoes are arranged on the rotating body. The pair of brake shoes slide on the fixed drum against a spring by rotation of the rotating body. In a centrifugal in-branch braking device that brakes in contact with each other, an anchor pin is provided at a central portion that divides each of the brake shoes into two, and a spring that biases the brake shoes in a non-braking direction is provided between opposing ends. Further, the anchor pin is disposed at an opposing position, and each brake shoe is configured to be movable only in a direction connecting the pair of anchor pins.