JPH022508Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is based on a material pressing method in which the material is sandwiched between a pair of rollers including a drive roller and the material is fed by the rotation of the drive roller. The present invention relates to a material feeding device characterized in that the pressing force is automatically changed.

In order to correctly feed a predetermined length, conventional material feed rollers either increase the friction coefficient or pressing force on the roller surface to reduce slippage between the material and the roller, or install multiple sets of drive rollers, or move the material to the front stage. Methods such as installing a device to pull it out from the reel and leave it slack are used, but the latter two cases are costly,
Due to space issues, it is difficult to use this method in lightweight and simple devices. Also, even if the frictional force on the roller surface is increased, in the case of fixed-size feed, the length is determined by the rotation angle x radius, so materials whose radius changes, that is, materials that are easily deformed or easily abraded, are not allowed. However, since it would be a problem if the coefficient of friction changes even with a small amount of wear, the materials and roller surfaces that can be used are quite limited. Therefore, slip prevention is inevitably dependent on the pressing force, which may be achieved by fixing the shafts of both rollers or by intervening a spring.
With fixed shafts, when the material being fed between the two rollers is drawn in, the pressing force is obtained by deforming the material or a part of the roller, and the dimensions of the material being fed (wire diameter, plate When the roller thickness (thickness, etc.) changes, it is necessary to change the roller or readjust the distance between the shafts. A type in which a spring is interposed between both roller shafts and a pressing force is applied by this elastic force can cope with changes in the dimensions of the material, and is the most desirable type among conventional types. However, the reaction force that the roller receives when the material is drawn into the roller (the force that prevents the material from being drawn in) is complex, and is caused by a combination of factors such as reel friction, vibration, and pulsating motion when the material is loosened. Since the pressing force is constant even with the spring-mediated roller, slipping occurs when the roller cannot withstand the local peak of the reaction force. In addition, when the pressing force of the spring is made strong and able to withstand any reaction force, other factors such as increasing the power of the feed motor, damage to the material being fed, etc.
In many cases, disadvantages such as wear and tear on equipment suddenly increase.

This invention was made for the purpose of improving the above-mentioned drawbacks of conventional rollers.In addition to the pressing force exerted by the elastic force of the spring, the roller of this invention is also subjected to the load when the roller pulls in the material. The present invention provides a material feeding device equipped with a mechanism in which the pressing force has a self-increasing function depending on the magnitude of the reaction force.

One embodiment of this invention, a roller for feeding a fixed length of wire rod, will be described with reference to the drawings. FIG. 1 is a sectional view showing the main structure. The rotation of the pulse motor 1 is transmitted to a drive shaft 5 via a timing pulley 2, a timing belt 3, and a timing pulley 4, and a drive roller attached to the other end of the drive shaft 5. Rotate 6.
The wire 20 held between the drive roller 6 and the idle roller 7 is sent out by the rotation of the drive roller 6, and the pressing force at that time is backed up through the wire 20 as the idle roller 7 rotates with respect to the fixed shaft 8. A bearing may be interposed between the fixed shaft 8 and the idle roller 7, but the idle roller 7
If the bearing is made of polyacetal resin or the like having a low coefficient of friction, it is often possible to omit the bearing as in this embodiment. The drive shaft 5 has an arm 11 that is swingable within a certain range about a fixed shaft 10 that is fixed to a frame 9 that is an extension of the axial center of the pulse motor 1 with its axial center substantially coinciding with the axial center of the pulse motor 1.
The arm 11 and the fixed shaft 8 are connected to each other by a spring 12, and this elastic force is applied to the wire 20 via the drive shaft 5 and the drive roller 6. This is a constant pressing force, which is defined as F ₁ .

Next, the self-increasing mechanism of the pressing force, which is a feature of the present invention, will be explained. Figure 2 shows arm 11 in Figure 1.
If the axial center of the fixed shaft 10, which is the center of oscillation of the This is what I did. Let A be the center of the drive roller 6, B be the contact point between the drive roller 6 and the wire, and θ be the angle that OB makes with the direction of the load (reaction force) on the wire 20. The drive roller 6 is swingably mounted on a part of a circular orbit with a radius OA centered at a point O, and in FIG. 2, the drive roller 6 is rotated counterclockwise to feed the wire 20 upward.
The load when drawing the wire 20 is applied in the direction opposite to the movement of the wire 20, and this is designated as L. Due to this L, the driving roller 6 pushes the wire rod 20 with a pressing force
F ₂ is F ₂ = L・tanθ, and when θ is small, the influence of load fluctuation is small, and when θ is large, the influence becomes large, so 0°<
It is designed by finding the appropriate value of θ where θ<90°. When the total pressing force is F, F is the sum of _F2 and the pressing force _F1 biased by the elastic force of the spring 12, that is, F= _F1 + _F2 . When the type of wire changes and the diameter changes, the position of the drive roller changes and θ also changes, but since the OB is long enough to accommodate the increase or decrease in the wire diameter, the same device can be applied to a considerable range of material sizes.

Although the present invention has the above-mentioned configuration, the pressing force changes depending on the size of the load, and as the load L increases, the pressing force also increases, so the constant pressing force due to the elastic force of the spring is The roller and material can be set to a low value so that they do not slip when there is no load, and wire rods that are easily deformed by lateral loads are not crushed more than necessary, and when a load is applied while feeding the material, it can be pushed immediately in response to this. By increasing the pressure and preventing slippage, we can always stably supply materials of the specified size.
Although it is a simple mechanism, it is highly effective.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the main structure of the present invention, Figure 2
The figure is an explanatory diagram showing the relationship between the swing center of the arm, the drive roller, the idle roller, and the wire rod in order to explain the self-increasing effect of the pressing force. 1... Pulse motor, 2, 4... Timing pulley, 3... Timing belt, 5... Drive shaft,
6... Drive roller, 7... Idle roller, 8,
10...Fixed shaft, 9...Frame, 11...Arm, 12...Spring, 13...Bearing.

Claims (1)

[Scope of utility model registration request] An arm is attached to a frame so as to be able to swing freely around a rotational fulcrum, a drive roller is attached to the arm and driven to rotate, and the outer circumferential surface of the arm is disposed opposite to the outer circumferential surface of the drive roller and is rotatable. an idle roller, and a spring that biases the drive roller toward the idle roller, and a contact point where the material to be fed out is sandwiched between the outer circumferential surface of the drive roller and the outer circumferential surface of the idle roller comes into contact with the drive roller. The extended line is on the material supply side, which is bisected by an extended line extending through the center of the drive roller and a straight line extending through the contact point at right angles to the extended line; With respect to a straight line, the arm is rotated to a position where the angle between the straight line and the straight line connecting the rotation fulcrum of the arm and the contact point is an acute angle in an area that is the side to which the center of the drive roller belongs. A material feeding device characterized in that a fulcrum is arranged.