JPH10203761A - Braking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equalize pressing force of a braking member of a brake shoe by displacing one support point member of bath support point members at both ends selectively as a support point in accordance with the direction of load which acts on a brake drum at the time of braking by the brake shoe. SOLUTION: Two pairs of support point rods 21 to 24 as support point members extended up to the inside of a traction sieve 4 which is a brake drum in parallel with a rotor shaft 3 are fixed to a bearing base 5. A pair of brake shoes 25, 26 which can reciprocate in the radial direction of the traction sieve 4 are arranged between these support point rods 21, 22 and a friction face 4a and between the support point rods 23, 24 and the friction face 4a. These brake shoes 25, 26 can displace one pair of two pairs of support point rods 21 to 24 as support points selectively in accordance with the direction of load which acts on the traction sieve 4 at the time of braking. Consequently, the pressing force of braking members 27, 28 of the brake shoes 25, 26 is equalized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake device used for, for example, an elevator hoist, and more particularly to an inner drum brake.

[0002]

2. Description of the Related Art FIG. 11 is a side view showing an example of a conventional elevator hoist. In the figure, a motor 2 is fixed on a base 1. On the rotor shaft 3 of the motor 2,
A cylindrical traction sheave 4 is fixed. In addition, a bearing base 5 that rotatably holds the tip of the rotor shaft 3 is provided on the base 1.

FIG. 12 is a block diagram showing a conventional brake device for an elevator hoisting machine similar to that disclosed in Japanese Patent Publication No. 47-2330, and FIG.
This corresponds to a sectional view taken along the line I. In the figure, a pair of fulcrums 6 a and 6 b extending parallel to the rotor shaft 3 are fixed to the bearing base 5. Inside the traction sheave 4, a pair of brake shoes 7 that rotate about fulcrums 6a and 6b are provided.
a, 7b are attached. To these brake shoes 7a, 7b, brake members 8a, 8b that are in contact with and separate from the friction surface 4a, which is the inner peripheral surface of the traction sheave 4, are fixed, respectively.

The fulcrums 6a, 6 of the brake shoes 7a, 7b
Pressing means 9 is provided between the ends opposite to b to press the braking members 8a and 8b evenly against the friction surface 4a.
As the pressing means 9, for example, an actuator such as a hydraulic cylinder or an elastic body such as a spring is used. Illustration of the means for releasing the braking force is omitted.

[0005] Generally, a brake device as shown in FIG. 12 is called a leading trailing type drum brake. During braking by such a brake device, a load due to a load difference between the car side and the counterweight side acts on the traction sheave 4 via a main rope (not shown) wound around the traction sheave 4. .

FIG. 13 is an explanatory view showing a frictional force between the braking members 8a and 8b and the friction surface 4a when a load is applied to the traction sheave 4 of FIG. 12 in a counterclockwise direction (L direction).
FIG. 14 is an explanatory diagram when a clockwise (R direction) load is applied. The pressing force of the pressing means 9 is F, the braking material 8 is
a, 8b, P, Q, friction coefficient μ, friction force μ
P and μQ are shown. For example, in FIGS. 13A and 13B, the forces P and Q of the braking members 8a and 8b pressing the friction surface 4a are given as follows from the balance of moments around the fulcrums 6a and 6b.

P =】 A / (B-μC)｝ F Q = ｛A / (B + μC)｝ F = ｛(B-μC) / (B +
μC)｝ P <P

[0008] From the above equation, in FIG.
The pressing force Q of the braking member 8b is applied with a load in the direction in which a enters the braking member 8b from the fulcrum 6b side of the brake shoe 7b.
Is (B−μC) / (B + μC) times the pressing force P of the braking member 8a on which the load acts in the direction in which the friction surface 4a enters from the force point side of the brake shoe 7a. 2
The sum of the braking forces generated by the two brake shoes 7a and 7b is constant regardless of the direction of the load, but the braking force of each of the brake shoes 7a and 7b differs depending on the direction of the load. That is, when a load acts in a direction in which the friction surface 4a enters the braking members 8a, 8b from the fulcrums 6a, 6b of the brake shoes 7a, 7b, the braking torque is such that the friction surface 4a is on the force point side of the brake shoes 7a, 7b. Smaller than the braking torque when a load acts in the direction of intrusion from the vehicle.

Next, FIG. 15 is a configuration diagram showing another example of a conventional brake device for an elevator hoist. In the figure, a pair of brake shoes 11a and 11b
It is attached to the bearing stand 5 (FIG. 11) via a and 12b. These brake shoes 11a and 11b are attached in the same direction in the circumferential direction of the traction sheave 4. Each brake shoe 11a, 11b
, Brake materials 13a and 13b are fixed. Pressing means 15a and 15b are provided between a pair of holding portions 14a and 14b fixed to the bearing base 5 and ends of the brake shoes 11a and 11b opposite to the fulcrums 12a and 12b.

[0010] Generally, a brake device as shown in FIG. 15 is called a two-reading type drum brake. FIG. 16 is an explanatory view showing a balanced state of the force when the traction sheave 4 of FIG. 15 tries to rotate in the counterclockwise direction (L direction), and FIG. 17 is a view in the case of the clockwise direction (R direction). Two braking members 12a and 12b in FIG.
Have the same value and are given by the above equation for obtaining P. In addition, the two braking materials 1 shown in FIG.
The pressing forces Q of 2a and 12b also have the same value, and both are given by the above equation for obtaining Q. That is, the overall braking force differs depending on the direction in which the load acts, and the braking force when the load acts in the direction in which the friction surface 4a enters the braking materials 13a, 13b from the fulcrums 12a, 12b of the brake shoes 11a, 11b. , The friction surface 4a is the brake shoe 11a, 1
The braking force is smaller than the braking force when a load acts in the direction of entering the braking members 13a and 13b from the force point side of 1b.

[0011]

In the conventional brake device for an elevator hoist constructed as described above,
The pressing force of the braking material varies depending on the direction in which the load acts.
On the other hand, in a normal elevator hoist, the load acting direction changes depending on whether or not the weight of passengers in the car exceeds half of the car capacity. It is rare for passengers to get in more than half.

Therefore, in the conventional leading trailing drum brake as shown in FIG. 12, one of the brake shoes is often pressed with a larger force than the other, and the brake material of one of the brake shoes is used. However, there is a problem that the friction coefficient of the other brake shoe is not stable, as well as the wear is rapid. Further, since the braking force generated by one brake shoe is smaller than the braking force generated by the other brake shoe, the overall braking force is reduced. In order to avoid this, it is necessary to increase the pressing force of the brake shoe, and the area of the brake material is enlarged with the increase of the pressing force, and the pressing device is enlarged, so that the entire device is enlarged. There was also a problem.

Further, in the conventional two-leading drum brake as shown in FIG. 15, it is necessary to secure a sufficient braking force even in the direction in which the pressing force of the braking material decreases, so that the pressing force of the pressing means is required. It is necessary to increase the braking material area as the pressing force increases,
Increasing the size of the pressing means causes a problem that the entire device is increased in size.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and can equalize the pressing force of the brake material of the brake shoe regardless of the direction of the load acting. It is an object of the present invention to obtain a brake device that can efficiently use a braking material and can reduce the size of the whole.

[0015]

According to a first aspect of the present invention, there is provided a brake device comprising: a cylindrical brake drum having a friction surface on an inner peripheral surface; A plurality of brake shoes provided on the inside of each of the brake shoes, a braking member provided on each of these brake shoes and coming into contact with and separating from the friction surface, and engaging at both ends of each of the brake shoes, respectively; A plurality of fulcrum members, and a plurality of pressing means provided at both ends of each brake shoe to press the brake shoe in a direction in which the braking material comes into contact with the friction surface, and the braking material is moved from the friction surface against these pressing means. Release means for releasing the brake shoe, and the brake shoe can be selectively displaced using one of the fulcrum members at both ends as a fulcrum according to the direction of the load acting on the brake drum during braking. It is those that are made by.

According to a second aspect of the present invention, there is provided a brake device comprising:
A pair of brake shoes are provided, and a common pressing means is arranged between the opposing ends.

The brake device according to the third aspect of the present invention has
A pair of brake shoes are provided, and a common fulcrum member is disposed between the opposing ends.

According to a fourth aspect of the present invention, there is provided a brake device comprising:
A pair of brake shoes, wherein the release means is connected to a plurality of release fulcrum members provided at both ends of the brake shoes, and to the release fulcrum members in a rotatable and slidable manner. It has a pair of brake release arms rotatable with respect to the rotation axis.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a configuration diagram showing a brake device of an elevator hoist according to a first embodiment of the present invention, FIG. 2 is a configuration diagram showing a release device of FIG. 1 removed, and FIG.
FIG. 4 is a cross-sectional view taken along line II-III of FIG. 1 and FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 1.

In the figure, the tip of the rotor shaft 3 of the motor 2 (FIG. 11) is rotatably held by a bearing base 5. A traction sheave 4 as a brake drum is fixed to an intermediate portion of the rotor shaft 3. A main rope (not shown) for suspending a car (not shown) and a counterweight (not shown) is wound around the outer periphery of the traction sheave 4. In addition, a friction surface 4 a is formed on the inner peripheral surface of the traction sheave 4.

Two pairs (four) of fulcrum rods 21 to 24 as fulcrum members extending to the inside of the traction sheave 4 in parallel with the rotor shaft 3 are fixed to the bearing base 5. Between the fulcrum rods 21 and 22 and the friction surface 4a and between the fulcrum rods 23 and 24 and the friction surface 4a, a pair of brake shoes 2 reciprocally movable in the radial direction of the traction sheave 4.
5, 26 are arranged. These brake shoes 2
Grooves 25a, 25b, 26a, and 26b that engage with the fulcrum rods 21 to 24 are formed on both ends of the support rods 5 and 26, respectively.
Further, braking members 27, 28 which come into contact with and separate from the friction surface 4a are fixed to the brake shoes 25, 26.

The bearing base 5 has two holding portions 29 and 3 extending parallel to the rotor shaft 3 and inside the traction sheave 4.
0 is fixed. Between these holding portions 29, 30 and both ends of the brake shoes 25, 26, a braking material 27,
Four pressing means 31 to 3 for pressing the pressing member 28 against the friction surface 4a
4 are provided. As the pressing means 31 to 34, for example, an elastic body such as a spring is used.

The brake members 27 and 28 are separated from the friction surface 4a by the brake release magnet 35. The brake release magnet 35 includes a pair of brake release arms 3.
6, 37 are rotatably connected. The brake release arms 36 and 37 are rotatable with respect to the rotor shaft 3. Each of the brake shoes 25, 26 is provided with two release fulcrum members 38, each of which is rotatably and slidably connected to brake release arms 36, 37. The brake release magnet 35, the brake release arms 36 and 37, and the release fulcrum member 38 constitute release means 39.

Next, the operation will be described. As shown in FIG. 5, when the load acts in the counterclockwise direction (L direction) in the figure, the brake shoe 25 uses the fulcrum rod 21 as a fulcrum, and a gap ε occurs between the fulcrum rod 22 and the brake shoe 25. . The brake shoe 26 has a fulcrum rod 23 as a fulcrum, and the fulcrum rod 24 and the brake shoe 26.
And a gap ε is generated. Then, the pressing members 32 and 34 arranged diagonally dispose the braking members 27 and 28 respectively on the friction surfaces 4.
Press on a.

Further, as shown in FIG. 6, when the acting direction of the load is clockwise (R direction) in the figure, the brake shoe 25 has the fulcrum rod 22 as a fulcrum and the brake shoe 25 is located between the fulcrum rod 21 and the brake shoe 25. A gap ε occurs. The brake shoe 26 has the fulcrum rod 24 as a fulcrum, and a gap ε is generated between the fulcrum rod 23 and the brake shoe 26.
Then, the pressing means 31, 33 press the brake members 27, 28 against the friction surface 4a, respectively.

In such a brake device, the brake shoe 25,
Since the frictional surface 4a has a force point on the entry side of the friction surface 26 and a fulcrum on the escape side, the value of the pressing force P of the braking members 27, 28 is P = ｛A /
(B−μC)｝ F. Therefore, the pressing means 31 to 34
Even if the pressing force is the same, a larger braking force can be obtained than in the conventional example, and the whole can be downsized. Further, only the braking members 27, 28 on one side are not worn, and the braking members 27, 28 can be used efficiently. Further, since the pressing force of the braking members 27 and 28 is not too small, the friction coefficient is stabilized.

When the braking force is released, the brake release magnet 35 is excited and the brake release arm 3 is released.
6 and 37 are rotated, and the release fulcrum member 38 is drawn. As a result, the brake shoes 25 and 26 move toward the rotor shaft 3 from the state of FIG. 2 until ε / 2 disappears, the brake members 27 and 28 are separated from the friction surface 4a, and the brake is released.

At this time, the brake release arms 36, 37
Since the brake shoes 25 and 26 are rotatable and slidable via the release fulcrum member 38, machining errors and mounting errors may occur in the elongated holes of the release fulcrum member 38 and the brake shoe release arms 36 and 37. In some cases, the fulcrum rod 21
Even if there is a dimensional error or mounting error of ~ 24, the gap ε is released to the point where the gap ε comes into close contact without being restrained by interference.

Embodiment 2 7 is a configuration diagram showing a brake device for an elevator hoist according to a second embodiment of the present invention, FIG. 8 is a sectional view taken along line VIII-VIII of FIG. 7, and FIG. 9 is a sectional view taken along line IX-IX of FIG. 7, the illustration of the release means is omitted. In the first embodiment, four pressing means 31 to 34 are used. However, in the second embodiment,
Two pressing means 41 and 42 are used. As a result, the number of components is reduced, and the size of the apparatus can be reduced.

Embodiment 3 FIG. 10 is a configuration diagram showing a brake device of an elevator hoist according to a third embodiment of the present invention, and illustration of a release unit is omitted. In the first embodiment, four fulcrum rods 21 to 24 are used, but in the third embodiment, two fulcrum members 43 and 44 are used.
You are using Accordingly, the fulcrum strength can be improved without increasing the size of the device.

The pressing means is not limited to an elastic body, a hydraulic cylinder or the like, but may press the brake shoe by rotating a cam, for example. Further, in the above example, a gearless hoist was shown, but the brake device of the present invention can be applied to, for example, a worm gear hoist, a helical gear hoist, and the like.

Further, in the above example, the brake shoe is rotatable with respect to the fulcrum, but may be slidably engaged. Furthermore, for example, when the fulcrum is moved together with the brake shoe to release the brake, a gap is not necessarily provided between the fulcrum and the brake shoe.

Although two brake shoes are provided in the above example, three or more brake shoes may be provided. Furthermore, in the above example, the fulcrum of the brake shoe was attached to the bearing stand,
Any portion that does not move when the motor rotates or the brake is released may be attached to another portion. Furthermore, in the above example, the brake device of the elevator hoist has been described, but the present invention can be applied to the brake devices of other devices.

[0034]

As described above, in the brake device according to the first aspect of the present invention, the fulcrum members are provided at both ends of the brake shoes, and the brake shoes are arranged at both ends according to the direction of the load acting on the brake drum during braking. One of the fulcrum members is selectively displaced as a fulcrum, so that, regardless of the load acting direction, the fulcrum must have a fulcrum on the ingress side of the friction surface against the brake shoe and a fulcrum on the escape side. Therefore, the pressing force of the brake material of the brake shoe can be made uniform irrespective of the direction of the acting load, so that the brake material can be used efficiently and the whole can be downsized.

In the brake device according to the second aspect of the present invention, since the pressing means for the two brake shoes is common, the number of components can be reduced and the device can be downsized.

In the brake device according to the third aspect of the present invention, since the fulcrum member of the two brake shoes is shared, the fulcrum strength can be improved without increasing the size of the device.

In the brake device according to the fourth aspect of the present invention, the brake release arm is rotatably and slidably connected to the release fulcrum members provided at both ends of the brake shoe. Even if there is a machining error, the brake can be released more reliably.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a brake device of an elevator hoist according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a state in which release means of FIG. 1 is removed.

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is an explanatory view showing a state when a counterclockwise load acts on the traction sheave of FIG. 1;

FIG. 6 is an explanatory diagram showing a state when a clockwise load acts on the traction sheave of FIG. 1;

FIG. 7 is a configuration diagram illustrating a brake device of an elevator hoist according to a second embodiment of the present invention.

FIG. 8 is a sectional view taken along line VIII-VIII of FIG. 7;

FIG. 9 is a sectional view taken along line IX-IX of FIG. 7;

FIG. 10 is a configuration diagram showing a brake device for an elevator hoist according to a third embodiment of the present invention.

FIG. 11 is a side view showing an example of a conventional elevator hoist.

FIG. 12 is a configuration diagram illustrating an example of a conventional brake device of an elevator hoist.

FIG. 13 is an explanatory diagram showing a state when a counterclockwise load acts on the traction sheave of FIG. 12;

FIG. 14 is an explanatory diagram showing a state when a clockwise load acts on the traction sheave of FIG. 12;

FIG. 15 is a configuration diagram showing another example of a conventional brake device for an elevator hoist.

FIG. 16 is an explanatory diagram showing a balanced state of forces when the traction sheave of FIG. 15 is about to rotate in a counterclockwise direction.

FIG. 17 is an explanatory view showing a balanced state of force when the traction sheave of FIG. 15 is about to rotate clockwise.

[Explanation of symbols]

3 rotor shaft (rotating shaft), 4 traction sheave (brake drum), 4a friction surface, 21 to 24 fulcrum rod (fulcrum member), 25, 26 brake shoe, 27, 2
8 braking material, 31-34, 41, 42 pressing means, 3
6, 37 brake release arm, 38 release fulcrum member,
39 release means, 43, 44 fulcrum members.

Claims (4)

[Claims] 1. A cylindrical brake drum having a friction surface on an inner peripheral surface; a plurality of brake shoes provided inside the brake drum so as to be reciprocally movable in a direction of coming into contact with and separating from the friction surface; A brake member provided on each of the brake shoes and coming into contact with and separating from the friction surface; a plurality of fulcrum members engaging with both ends of each of the brake shoes and serving as a fulcrum of the operation of the brake shoes; A plurality of pressing means respectively provided at both ends of the brake means for pressing the brake shoe in a direction in which the braking material comes into contact with the friction surface; and releasing means for separating the braking material from the friction surface against these pressing means. The brake shoe can be selectively displaced with one of the fulcrum members at both ends as a fulcrum according to the direction of the load acting on the brake drum during braking. Brake system, characterized in that it it. 2. The brake device according to claim 1, further comprising a pair of brake shoes, wherein a common pressing means is disposed between the opposing ends. 3. The brake device according to claim 1, further comprising a pair of brake shoes, wherein a common fulcrum member is disposed between the opposing ends. 4. A brake shoe comprising a pair of brake shoes, wherein the release means comprises a plurality of release fulcrum members provided at both ends of the brake shoe, and the release fulcrum members are rotatable and slidable. The brake device according to any one of claims 1 to 3, further comprising a pair of brake release arms connected to each other and rotatable with respect to a rotation axis of the brake drum.