JPS612675A - Tension generator for wire - Google Patents

Abstract

PURPOSE:To apply an arbitrary tension onto a wire taken-up onto a winding drum by installing a tension drum equipped with a brake part into the fore-stage of the winding drum and applying an arbitrary damping force onto the tension drum in the brake part. CONSTITUTION:A wire 5 supplied from a storing bobbin 6 is wound in plural turns onto the groove 3a formed onto both tension drums 3 and 3 and wound onto a winding drum 2. A back tension T1 is applied in this state, suppressing the mutual slide between the wire 5 and the tension drum 3 and the revolution of the tension drum, and the wire 5 is pulled by a tension T2, and when T1 and T2 are balanced, the equation T2/T1=e<mutheta> is established. If each value of mu, theta, and T1 exists so that the necessary tension T2 can be obtained when the wire 5 is taken-up onto the winding drum 2, the wire can be firmly wound onto the winding drum 2 by controlling the damping force in a brake part 4. In the above, mu is the friction factor between the wire and the tension drum, theta is the turning angle of the wire with respect to the winding drum, and e is the base of natural logarithm.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a tension generator that applies a predetermined tension to a filament such as a wire rope when the filament is wound around a winding drum of a winch or the like. be.

[Problems to be solved by this invention]

Wire ropes for high-lift cranes, which are often used in recent years, are
The length of the strip is extremely long, so when it is wound onto the drum of a winch installed on a crane, it is inevitably wound in multiple layers. This number of layers may reach around 10 layers in some cases.

In addition, wire rope has elasticity not only in the longitudinal direction but also in the diametrical direction, so the more multi-layered it is, the more tension it must be applied to when winding it into the winding drum. As a result, it is wrapped in a baggy state,
If a large tension is suddenly applied to the wire rope, it will be forced into the lower layer at the winding point.

When this sinking or so-called depression occurs, the wire rope does not unravel smoothly from the winding drum and does not slip out, but the wire lobes are damaged early due to abnormal friction with each other.

At the same time, it also promotes harmful deformation, shortens the life of the wire rope, and becomes a serious problem from a safety standpoint.

In order to prevent shortening of the wire rope's service life due to shortening of the wire rope and early damage, it is common sense to wind the wire rope while applying tension when winding it around the winding drum. good.

In this way, it is possible to wind the rope firmly against the winding drum without leaving any gaps between the ropes, thereby preventing the rope from falling.

However, conventionally, there is no effective or easy method for applying tension to wire ropes, and therefore, wire ropes are generally wound into a winding drum without generating tension as described below.

■ Wrap a rag around a wire rope, squeeze the rope to obtain braking force, and rely on this to generate tension before winding it into the winding drum.

■ Once the tension is applied, albeit imperfectly, by means of (■), the rope is wound around the winding drum, and then tension is applied to the wire rope using a weight, and the weight is raised and lowered repeatedly to move the wire against the winding drum. Tighten the rope.

However, (2) is not preferable because sufficient tension cannot be obtained and the wire rope is strained, which tends to untwist the wire rope, which has a negative effect on the quality of the wire rope. isn't it.

In addition, since the weight is suspended in a position where there is still a possibility that the rope may fall, the rope may fall. In order to wind the entire length of the wire rope into the winding drum under conditions where sufficient tension is evenly applied, a special working yard is required, which is not a sufficient condition in reality.

On the other hand, when winding the wire rope into the winding drum, for example, 10
When applying a ton of tension - do not apply it all at once, but first
Winding υ and unwinding are performed with a tension of tons.

Next, the film is wound and rewound with a tension of 3 tons.

In this way, it is common to gradually apply a load of 5 tons, 7 tons, and finally a tension of 10 tons.

There has also been a desire for a device that can easily perform such tasks.

[Purpose of the invention]

The present invention was devised in view of the above-mentioned circumstances, and its purpose is to be able to apply arbitrary tension when winding the filament around the winding drum, thereby reliably preventing the filament from falling to the lower layer. The object of the present invention is to provide a tension generating device that can perform the following tasks.

[Structure of the invention]

According to this invention, a tension drum is provided at the front stage of the winding drum, and a braking section is attached to this tension drum.

Then, the filament is wound around the tension drum multiple times and then wrapped around the winding drum, and the braking section applies a desired braking force to the tension drum, thereby applying tension to the filament wound around the winding drum. It is something.

〔Example〕

The present invention will be explained below with reference to illustrative embodiments.

The tension generator 1 is installed in the front stage of a winding drum 2 of a crane, etc., and includes two tension drums 3 installed in parallel, and a friction brake or an electric control installed on the tension drums 3. It consists of a braking unit 4 such as a brake using power. (See FIGS. 1 and 2) The tension drum 3 is provided with a plurality of grooves 3a on its circumferential surface, around which filaments 5 such as wire ropes are wound.

With this configuration, the filament 5 from the storage frame 6 is passed around the grooves 3a of the binocular drums 3, 3 several times, and then transferred to the winding drum 2.
is wrapped around.

In this state, a back tension T is applied to prevent mutual sliding between the filament 5 and the tension drum 3, as well as rotation of the tension drum.
, and T are balanced, the following equation holds.

T.

Here, T1 is the pack tension (Ky).

T2 is the magnitude of the fore-tension (Kp), μ is the friction coefficient between the filament and the tension drum, θ is the rotation angle (rad) of the filament with respect to the winding drum, and e is the base of the natural logarithm. At this time, T2 is an order of magnitude larger than T.

When winding the filament 5 onto the winding drum 2, if μ, θ, and T1 exist such that the required T2 is obtained, the filament will move against the winding M2 by adjusting the braking force of the braking unit 40. It is tightly rolled up to form a thick layer.

Note that the braking section 4 is not limited to the one in this embodiment, and may be provided on both sides of the tension drum 3. In this way, it is possible to apply an arbitrary braking force of 4° by appropriately equipping each braking section.

Further, the number of tension drums 3 is not limited to two arranged in parallel as in this embodiment, but may be one.

〔Effect of the invention〕

The present invention has such a configuration and has the following effects.

By providing a tension drum with a braking unit attached to the front stage of the winding drum, it is possible to apply any amount of braking force to the tension drum. It is given as tension.

As a result, a winding layer is formed in which the filament is tightly wound around the winding drum, so even when a large lifting load is suddenly applied, the filament does not fall down, and wear and tear on the filament is significantly reduced. This makes it possible to improve safety during use of cranes, etc.

Furthermore, since the magnitude of the winding tension on the winding drum can be adjusted as desired, it is easy to gradually increase the magnitude of the winding load.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the tension generating device of the present invention, and FIG. 2 is a front view thereof. 1... Tension generator, 2... Winding drum, 3... Tension drum, 3a... Groove, 4... Braking part, 5...
String, 6... Preservation winding frame.

Claims (1)

[Claims] It is provided with a tension drum which is provided in front of the winding drum around which the filament is wound, and which winds the filament a plurality of times, and a braking part provided on the tension drum, and the braking part acts as a brake on the tension drum. 1. A device for generating tension on a filament, characterized in that it is configured to be able to apply tension to the filament wound around a winding drum using power and frictional resistance between the tension drum and the filament.