JPH07754Y2 - Drum brake push-up device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a lifting device for a drum brake.

[Conventional technology]

As is well known, a drum brake refers to a friction brake that applies a brake to the drum by winding a band around the drum or pressing a brake shoe, but these bands and brake shoes are used to activate the brake shoe. A thruster (push-up machine) is attached to the shoe via a brake lever (for example, Jikkaku Sho 41-944).
(See No. 9 and Japanese Utility Model Publication No. 44-439).

[Problems to be solved by the device]

By the way, recently, a crane provided with such a drum brake has been increased in size, and accordingly, it is necessary to increase the capacity of the drum brake. Therefore, a large capacity thruster is required to increase the thrust force of the thruster. However, the large-capacity thruster is a bespoke product, resulting in an extremely high cost.

Therefore, it is conceivable to adopt two standard (commercial) thrusters. That is, as shown in FIG. 4, two thrusters 1a and 1b having the same capacity are arranged side by side, and the thruster rods 2a and 2b of these thrusters 1a and 1b are connected to both ends of one horizontal intermediate lever 3. However, a device in which the intermediate lever 3 is connected to one intermediate rod 5 via the pin 4 and the intermediate rod 5 is connected to the intermediate brake levers 6, 6 is conceivable. Reference numeral 7 is a frame of the crane or the brake device, and will be simply referred to as a frame hereinafter.

However, in such a connecting device, if one thruster malfunctions, a component force other than the upward pushing force is generated on the intermediate rod, and other normal thrusters and the entire connecting device may be damaged.

[Means for Solving the Problems]

Therefore, the present invention has been devised in order to eliminate such inconvenience, and its gist is to connect a brake lever pivotally supported by a frame to a band or a brake shoe for braking a drum, In a drum brake in which a lever is operated by a push-up machine, the push-up machine is
Two pushers having the same capacity are installed side by side to increase the capacity. The tips of the rods of these pushers are connected to both ends of a horizontal intermediate lever, and the pusher is pushed up to the center of the intermediate lever. A guide cylinder along the direction is provided, and a center pole that penetrates the guide cylinder and the central portion of the intermediate lever and guides those members slidably is erected on the frame, and the intermediate lever is connected to the intermediate rod. A lifting device for a drum brake, characterized in that it is connected to the brake lever via the above.

〔Example〕

The structure of the present invention, together with its operation, will be described in detail with reference to an embodiment shown in the accompanying drawings.

FIG. 1 is a side view of an embodiment of the present invention, and FIG. 2 is A of FIG.
~ A side view from the arrow A, Fig. 3 is a side view from the arrow B in Fig. 2, and elements common to the conventional example shown in Fig. 4 are denoted by the same reference numerals.

The band brake of this embodiment is conveniently applied to a container crane installed on a wharf or the like.

The band brake of this embodiment is shown in FIG.
A band 11 is wound around the bracket 11, one end of the band 11 is fixed to a bracket 12 attached to the frame 7, and the other end is connected to a brake lever 13. The base of the brake lever 13 is pivotally supported by the bracket 12, and the other end of the band 11 is connected near the pivot.

Further, the coil spring 14 always acts in the middle of the brake lever 13 to apply a pressing force to the brake lever 13 and
Tighten band 11 to. That is, as shown in FIG. 2 and FIG. 3, the coil spring 14 has upper and lower spring supports.
The spring bearings 15 and 16 are retained by 15, 16 and are fitted into a spring mounting rod 17 pivotally supported by the frame 7. The lower spring support 16 is brought into contact with the brake lever 13 to push down the brake lever 13.

Further, a link 18 is connected to the free end of the brake lever 13, and the intermediate brake lever 6, 6 composed of two levers is pin-connected to the link 18.

Therefore, if the intermediate brake lever 6 is pushed up by a push-up machine described later, the brake lever 13 is lifted against the spring force of the coil spring 14, so that the band 11 is loosened and the brake is released.

Here, in this embodiment, the intermediate brake lever 6 is composed of two push-up machines (also referred to as thrusters, which are also referred to as thrusters, hydraulic pressure, pneumatic cylinders, etc.) of the same capacity via the following coupling device. ) It is operated by 1a and 1b. That is, in FIG. 1, two thrusters 1
a, 1b are installed side by side on the frame 7, and these thrusters 1a, 1b
The thruster rods 2a and 2b are connected to each other via the both end pins 3a and 3b of one horizontal intermediate lever 3, and the intermediate lever 3 is further connected with a turnbuckle 19 through a pair of pins 4a and 4b. The two intermediate rods 5a, 5b are connected to each other, and these intermediate rods 5a, 5b are connected to the above-mentioned intermediate brake levers 6, 6 to form a connecting device.

Then, in such a connecting device, a pipe-shaped center pole 20 erected on the frame 7 penetrates through the central portion of the intermediate lever 3 described above. That is, the intermediate lever 3
The upper oilless bush 21a is embedded in the center of the, and the guide tube 22 is hung downward from the center of the intermediate lever 3,
A lower oilless bush 21b is provided at the lower end of the guide cylinder 22, and the center portion of the intermediate lever 3 and the guide cylinder 22 are slidably guided by the center pole 20. Therefore, when the two thrusters 1a and 1b operate, the thruster rods 2a and 2b
Is lifted and the intermediate lever 3 is pushed up together with the guide cylinder 22 by being guided by the center pole 20 via the upper and lower oilless bushes 21a and 21b.

Next, the operation of this embodiment will be described. The lengths of the respective intermediate rods 5a and 5b are adjusted by the tongue buckle 19 so as to be equal. Therefore, to release the drum brake, energize each thruster 1a, 1b, and thruster rods 2a, 2b
Pushes up the intermediate lever 3 in a horizontal state as shown by the chain double-dashed line in FIG. 1, so that the intermediate rods 5a and 5b are pulled up. As a result, through the intermediate brake lever 6, the brake lever
13 is lifted against the spring force of the coil spring 14, and the band
11 is loosened. However, when one of the thrusters 1a and 1b malfunctions, the intermediate lever 3 tends to be tilted and lifted up. In other words, the intermediate lever 3
Generates upward pushing force and other component force,
Since this component force is corrected and absorbed by the guide cylinder 22 and the center pole 20, the intermediate lever 3 is raised in the horizontal state. Therefore, twisting due to malfunction of one thruster does not reach other normal thrusters,
No eccentric load is generated in the connecting portion of each member.

[Effect of device]

According to the present invention, since two pushers having the same capacity are used for the push-up machine for the drum brake, the push-up machine having the same capacity can be used, and the push-up machine can be applied to the large-sized drum brake. As a result, it is possible to make the push-up machine inexpensive as a whole despite the large capacity.

In particular, even if one of the two push-up machines arranged in parallel causes a malfunction, the guide lever provided on the intermediate lever is guided by the center pole to raise the intermediate lever. It is possible to prevent damage without damaging the machine or the entire device.

Furthermore, since the guide cylinder provided on the intermediate lever is guided by the vertically installed center pole, the guide sliding area becomes large, and the horizontal state of the intermediate lever can be maintained well.
Moreover, even if two push-up machines for increasing the capacity are provided, the reliability of the drum brake is not impaired.

In addition, even if the guide cylinder or the center pole member is arranged at the center of the intermediate lever, the guide cylinder and the center pole are along the rod of the push-up machine, so that a so-called dead space can be used.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention, and FIG. 2 is A of FIG.
~ A side view from the arrow A, Fig. 3 is a side view from the arrow B of Fig. 2,
The figure is a side view of a conventional example. 1a, 1b …… Thruster, 2a, 2b …… Thruster rod, 3
...... Intermediate lever, 10 …… Drum, 11 …… Band, 13 ……
Brake lever, 20 …… Center pole.

Claims (1)

[Scope of utility model registration request] 1. A drum brake in which a brake lever pivotally supported by a frame is connected to a band or a brake shoe for braking a drum, and the brake lever is operated by a push-up machine, wherein the push-up machines are two units having the same capacity. The above-mentioned push-up machines are installed side by side to increase the capacity, the ends of the rods of these push-up machines are connected to both ends of a horizontal intermediate lever, and the guide tube along the push-up direction of the above-mentioned push-up machine is provided at the center of the intermediate lever. A center pole that penetrates the guide cylinder and the central portion of the intermediate lever and guides these members slidably is provided upright on the frame, and the intermediate lever is provided with the brake lever through the intermediate rod. A push-up device for a drum brake, which is characterized by being connected to.