JPH0218356Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake device that applies braking to a rotating body rotating at high speed and under high load, such as a wire winding device of a hydraulic crane.

In general, a hydraulic crane suspends a heavy object using a wire, winds the wire using a wire winding device, and moves the heavy object while controlling unwinding. For this reason, a brake device is attached to the wire winding device so that the kinetic energy when the wire winding device stops rotating and the inertial energy generated in the wire winding device are absorbed by the braking action of the brake device. It is configured.

In the above-mentioned braking device, a band assembly consisting of a lining and a band is wound around the braking surface of the brake drum, and the band assembly is tightened by a braking force applying mechanism such as a cam, a link, or a hydraulic device, and the lining is applied to the brake. A shoe assembly consisting of a band brake device, a lining and a shoe that provides braking action by pressing against a surface is attached to the anchor bolt in an expandable and retractable manner, and the shoe assembly is applied with the same braking force applying mechanism as described above. Drum brake devices and the like are used that provide a braking action by tightening and pressing a lining against a braking surface.

BACKGROUND ART Conventionally, as this type of brake device, an internal retraction type band brake device shown in FIGS. 1 to 4 has been known.

In FIG. 1, 1 is a drum used for a wire winding device, and this drum 1 includes a brake drum 2,
A wire winding drum 3 coaxially and integrally formed with the brake drum 2, and a rotation mechanism (not shown)
The ratchet pawl 4 engages with the drum 1 to rotate the drum 1, and a wire (not shown) is wound around the wire winding drum 3.

Next, as shown in FIGS. 2 to 4, the brake drum 2 is formed into a cylindrical shape, and its outer peripheral surface serves as a brake surface 5, and each side surface 2A, 2B of the brake drum 2 has a large number of Heat dissipation fins 6 and 7 are provided radially, respectively, to dissipate heat generated during braking operation. Further, the inner surface 2C of the brake drum 2, which faces the brake surface 5, serves as a clutch surface, and the brake drum 2 has a hollow cylindrical shape.

Reference numeral 8 indicates a band assembly, and the band assembly 8 includes a fixed band 9 and a movable band 10.
, a connecting bolt 11 connecting each band 9, 10, linings 12, 12 fixed to the inner peripheral surface of the fixed band 9, linings 13, 13 fixed to the inner peripheral surface of the movable band 10. It consists of One end of the fixed band 9 is rotatably fixed to a fixed machine frame 15 of the wire winding device via a pin 14, and the other end of the movable band 10 is a connecting hole 16 connected to a braking force applying mechanism. There is.

The brake device according to the prior art is constructed as described above, and the drum 1 is rotated at high speed in the direction of arrow A by a rotating mechanism that engages with the ratchet pawl 4, and the wire is wound on the wire winding drum 3, and the wire is wound on the wire winding drum 3. It has been returned. In this state, in order to apply a braking action to the drum 1 and stop the rotation of the wire winding device,
The braking force applying mechanism connected to the connecting hole 16 is activated to pull the movable band in the direction of arrow B. As a result, the fixed band 9 connected to the movable band 10 via the connecting bolt 11 is also pulled in the same direction, and the linings 12, 13 and the brake surface 5 of the brake drum 2 are frictionally engaged to provide a braking action.

At this time, the kinetic energy of the drum 1 absorbed by the frictional engagement between the linings 12, 13 and the braking surface 5 is converted into heat, and this heat is transferred from the heat radiation fins 6, 7 and each part of the drum 1. However, most of the remaining heat is accumulated in the drum 1, in particular in the brake drum 2 and in the linings 12, 13, increasing the temperature of the braking surface 5 and the linings 12, 13.

By the way, in general, in a brake device, the wear of the brake surface 5 of the brake drum 2 made of a metal body tends to increase as the temperature increases, and also on the linings 12, 13 side, if the brake surface 5 becomes high temperature, the linings 12, 13, Alumina, chromium oxide, quartz, etc. as friction coefficient improvers contained in 13 precipitate and float up, resulting in a state of grinding wear between the brake surface 5 and the linings 12 and 13.
It is known that linear roots are generated on the brake surface 5, leading to abnormal wear. Furthermore, when the friction coefficient improver falls off from the linings 12 and 13,
Three-dimensional grinding wear occurs due to the linings 12, 13, the brake surface 5, and these precipitated particles, and abnormal wear progresses further.

However, in the brake device according to the prior art described above, the heat dissipation fins 6 provided radially,
Since the structure is such that heat is released only from the drum 7, the heat cannot be dissipated sufficiently, and when the drum 1 rotates under a high load or rotates at high speed, the temperature of the brake surface 5 becomes high, and the abnormal wear described above progresses. It has the disadvantage of being easy to do. Furthermore, when the brake surface 5 becomes high in temperature, particles of the friction coefficient improver and the like that fall off from the linings 12 and 13 have the disadvantage that abnormal wear of the brake surface 5 further progresses. On the other hand, if the brake surface 5 becomes high in temperature, the lining 1
2 and 13 are thermally degraded, the friction coefficient decreases, and the braking performance becomes unstable. Moreover, when the brake surface 5 becomes high temperature, the brake drum 2 is thermally deformed and the brake surface 5 and the linings 12, 13
There is a disadvantage that the contact is uneven, the surface pressure increases, and only a portion becomes high temperature, which further progresses abnormal wear. Furthermore, in order to suppress wear on the brake drum 2 and linings 12 and 13, it is necessary to use the brake equipment at a lower performance than its original performance, or to use a brake equipment larger than its rated value. This has the disadvantage that not only is the weight large, but the brake device is unable to perform its original function.

The purpose of the present invention is to improve the drawbacks of the prior art described above, and by lowering the saturation temperature of the brake surface and removing wear particles generated on the brake surface, the present invention improves the brake drum,
To provide a brake device capable of preventing abnormal wear of both linings.

In order to achieve the above object, the present invention provides a brake drum that is formed into a cylindrical body and has either an inner or outer surface serving as a brake surface, and a brake drum that presses the brake surface of the brake drum into contact with the brake drum. A brake device comprising: a lining that applies braking to the brake; and a heat dissipation fin provided on the brake drum and located on at least one side in the width direction of the brake surface to dissipate heat generated during braking. A large number of small-diameter air passages are bored in the brake drum, one end of each air passage is opened at predetermined intervals around the entire circumference of the brake surface, and the other end of each air passage is opened at predetermined intervals around the entire circumference of the brake surface. The heat dissipating fins are characterized by openings on a surface different from the brake surface through which cooling air can be introduced.

With this configuration, cooling air is generated from the heat dissipation fins while the brake drum is rotating, and is ejected onto the brake surface via this cooling air.
This cooling air enhances the cooling effect of the brake surface, and when the brake surface becomes hot, particles of the friction coefficient improver that precipitate from the lining are discharged through the air passage, reliably preventing abnormal wear. sell.

Hereinafter, the present invention will be described along with the embodiments shown in FIGS. 5 to 8. The same components as those of the prior art described above will be denoted by the same reference numerals, and the explanation thereof will be omitted.

First, FIGS. 5 to 7 show a first embodiment of the present invention, in which 21A, 21B, and 21C (referred to as 21 as a whole) are formed in the axial direction on the brake surface 5 of the brake drum 2. A large number of holes 21 are formed at predetermined intervals in the rotational direction of the brake surface 5, as shown in FIG. Also, 2
2A, 22B, 22C (referred to as 22 as a whole)
6 are air passages having small diameter holes bored in the brake drum corresponding to the respective holes 21, and as shown in FIG. 21A and 21B, and the other end is the side surface 2A of the brake drum 2.
It is open to On the other hand, one end of the air passage 22C is open to the hole 21C, and the other end is open to the side surface 2B.

Although the present embodiment is constructed as described above, its braking operation is not particularly different from that of the prior art.

However, in this embodiment, a large number of holes 21 are formed in the brake surface 5, and the brake drum 2
Since an air passage 22 is formed for each hole 21 with one end opening into each hole 21 and the other end opening into the side surface 2A or 2B, when the brake drum 2 rotates in the direction of arrow A in the figure, Cooling air is generated by the radiation fins 6 and 7 provided on each side surface 2A and 2B, and this cooling air is passed through the air passage 22 to the hole 21.
to the brake surface 5. Thereby, the brake surface 5 is constantly exposed to the cooling air and is cooled. Moreover, the cooling air blows out from inside the brake drum 2 as shown by arrow C in FIG. 7, and this cooling air flows along the brake surface 5 in the opposite direction to the rotational direction A of the brake drum 2. , it is possible to remove a large amount of heat from the brake surface 5 and further enhance the cooling effect.

On the other hand, when the brake surface 5 becomes hot, the friction coefficient improver that precipitates from the linings 12 and 13 remains in the holes 21 and further falls through the air passage 22, and can be discharged from the side surfaces 2A and 2B. As a result, it is possible to prevent the above-mentioned abnormal wear, and also to remove wear powder from the linings 12 and 13.

Next, FIG. 8 shows a second embodiment of the present invention,
In this embodiment, a large number of holes 21 are formed in the brake surface 5, as in the previous embodiment. However, 22′
Reference numerals A, 22'B, and 22'C (referred to as 22' as a whole) indicate air passages of this embodiment. One end of each air passage 22' is opened to the hole 21, and the other end is opened to the inner surface of the brake drum 2. The reason is that it is configured to open at 2C.

With this configuration as well, the same effects as described above can be achieved.

In each of the above-described embodiments, an internal compression type band brake device was described as the brake device, but it goes without saying that the present invention may also be applied to a drum brake device. Alternatively, an expansion type brake device may be used in which the inner surface of the brake drum is used as a braking surface and a band assembly or a shoe assembly is pressed against the inner surface to provide a braking action. Further, in the first embodiment, the air passage was described as being open on both sides of the brake drum, but it may be open only on one side. Furthermore, the air passage may be opened directly into the brake surface without forming holes in the brake surface.

As described in detail above, the brake device according to the present invention has a large number of small-diameter air passages bored on the brake surface to send cooling air generated by heat radiation fins,
Furthermore, since the friction coefficient improver and wear powder can be discharged through the air passage, the following effects can be achieved.

The amount of wear on both the brake surface and the lining is reduced, extending the life of the brake device.

Since the friction coefficient improver that precipitates at high temperatures can be discharged, abnormal wear such as three-way grinding wear can be prevented.

Since thermal deformation of the brake drum is eliminated, uneven contact of the lining against the brake surface can be prevented, and the cause of abnormal wear can be eliminated.

Thermal deterioration of the lining can be prevented, the friction coefficient can be adjusted to the designed value, and stable braking performance can be exhibited.

Since the brake device can exert the braking force according to the rated value, the brake drum, lining, etc. can be made smaller than the current ones.

[Brief explanation of the drawing]

1 to 4 show a conventional brake device, in which FIG. 1 is an external perspective view of a drum consisting of a brake drum and a wire winding drum, FIG. 2 is a front view of the brake drum, and FIG. 3 is a front view of the brake drum. is a cross-sectional view in the direction indicated by the - arrow in FIG. 2, FIG. 4 is a cross-sectional view in the direction indicated by the - arrow in FIG. 5 is a sectional view similar to FIG. 4, FIG. 6 is a plan view taken along the - arrow direction line in FIG. 5, and FIG.
8 is a sectional view in the direction indicated by the - arrow in the figure, and FIG. 8 is a sectional view similar to FIG. 4 showing a second embodiment of the brake device according to the present invention. 1...Drum, 2...Brake drum, 5...
Brake surface, 8...Band assembly, 9,1
0... Band, 12, 13... Lining, 21
...hole, 22, 22'...air passage.

Claims (1)

[Scope of utility model registration request] A brake drum formed into a cylindrical body and having either an inner or outer surface serving as a braking surface; a lining that applies braking to the brake by pressing against the braking surface of the brake drum; In order to radiate the generated heat, the brake device includes a heat radiating fin located on at least one side of the brake surface in the width direction and provided on the brake drum, wherein the brake drum is provided with a large number of small diameter air passages. the braking surface, wherein one end of each of the air passages is opened at predetermined intervals over the entire circumference of the braking surface, and the other end of each of the air passages is capable of introducing cooling air from the heat dissipation fins; A brake device characterized by having an opening on a different surface.