JPS6322194B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that evenly and easily removes slack that occurs in a screen net (woven net, hereinafter simply referred to as the net) attached to a sieving machine, and restores the tension state. It is particularly effective for sieving machines that use fine mesh.

Generally, the net of a sieving machine is subjected to an equally large load due to the weight of the material to be supplied and the motion of the machine, and the stress and strain on the wires that make up the screen are extremely high.
As a result, permanent strain occurs in the entire net, leaving the net in a so-called slack state, but in the past it has been considered extremely difficult to restore this to its original uniform tension state.
Originally, the screen of the sieving machine was tensioned as strongly as possible.
It is well known that the most efficient method of use is to apply the mechanical motion directly to the net, but as the net gradually loosens, the mechanical motion cannot be faithfully transmitted to the net, and the net will not be able to reach the specified level. Since the particles no longer move, the flow of the supplies becomes unstable and the sieving efficiency decreases, eventually making the sieving function completely impossible. If operation continues in this state, the net will eventually become fatigued and damaged.

The present invention was made with the intention of correcting the loosening of the mesh in such a sieving machine, and includes flexible beams that are adjacent to the surface of the mesh attached to the sieve frame and have supporting points between opposing members of the frame. Then, a screw device (jacket) installed at the fulcrum part to match the distance between both fulcrums of the beam,
Alternatively, there is a net tensioning device that uses a boosting mechanism such as a pneumatic device to shorten the beam, flexing it in an arch shape and pressing it against the net surface to remove slack in the net and apply tension. It is a sieving machine.

Next, an embodiment of the present invention will be explained with drawings.
is a perspective view of one unit of the sieve frame, where 1 is the mesh and 2 is the sieve frame.
1 is a sieve frame, 3 is a flexible beam (hereinafter simply referred to as a beam)
This is an example in which two sets are arranged directly under the network 1. Of the two fulcrums of each beam, one end is a pin fulcrum 4 fixed to the frame 2, and the other end is a pin fulcrum, but a movable fulcrum 6 that can be moved slightly by a screw device 5 allows the beam 3 to be compressed in the longitudinal direction. Configure it as follows.

FIG. 1 shows a sieving machine in which several tiers of such units of sieve frames are stacked one on top of the other, and a predetermined movement is performed by a movement generating device, which will be described later. The raw materials supplied from the supply port 7 on the top stage are sieved by a screen, and substances larger than the screen are discharged as products on the screen through the discharge port 8, while fine materials that have passed through the screen fall to the bottom of the frame and are discharged. 9 and are discharged to the outside. Generally, a single screen is a unit that separates supplied materials into two types, large and small, in what is called a single stage. When unit sieve frames are stacked in several stages as in the sieving machine shown in Figure 1, the mesh size of each stage is determined depending on the throughput of material, particle size composition, separation accuracy, etc., and the product on the screen of each stage is By devising the path for introducing the product under the mesh, separation of two types, two types, two types, three types, three stages, etc. can be performed, but the present invention can be applied to any of these cases.

Next, as shown in FIGS. 3 to 7, the beam 3 is a leaf spring with a constant width and a thin thickness, and if the movable fulcrum 6 is moved toward the opposite fulcrum 4 by the screw device 5, the beam 3 The beam is compressed and bent upward in an arch shape, gradually coming into contact with the net surface from the highest point in the center of the beam, allowing for smooth removal of slack and at the same time applying tension. Generally, the slackness of the netting is greater at the central portion of the netting that is farther away from the peripheral attachment portions, so the arch-like deformation of the beam 3 is well adapted to such slackening of the netting and can correct the slackness. The amount of tension depends on the amount of push-up. This situation is very similar to the relationship between the bones of a bat umbrella and the fabric when it is unfolded.

Regarding the number and arrangement of the beams 3, placing one set in the center of the sieve frame 2 can achieve the purpose, but if the slack of the mesh is the same, it is better to install two sets of beams as shown in the figure than one set. This is advantageous because the push-up height of the surface is low, and the deformation and inclination of the net surface are accordingly reduced, so that the flow of materials is not affected. Note that the beams 3 can be arranged to intersect with each other if necessary. Also, although the beam 3 is normally placed below the net, it can also be placed above and used by pushing down the net 1.

The shape of the beam 3 may be selected as appropriate depending on the situation, such as a constant width and thickness, a variable width and thickness, a pipe or an inverted U-shaped cross section. Next, when the beam 3 is compressed at both fulcrums and bent into an arch shape, the shape of the beam should be
Carefully examine dimensions, materials, etc. Also, in order to ensure that the beam always bends upward in a certain direction during compression, the beam should be slightly warped in its free state, or the pin fulcrum 6 should be slightly eccentric to the direction of movement of the screw shaft to generate a moment at the beginning of compression. Let them do it.

The material of the beam 3 can be appropriately selected from ordinary spring materials that can withstand large elastic deformations, as well as bamboo, reinforced wood, synthetic resin, carbon fiber, and the like.

Next, FIG. 5 is a detailed view of the vicinity of the movable fulcrum, in which the movable fulcrum 6 is fixed to one end of the screw shaft 11 of the screw device 5. The eye at the end of the beam 3 is supported by a pin 10 on a U-shaped fulcrum metal fitting 6. The screw device 5 is a kind of small jack, and as is clear from the figure, it has a built-in rotary nut 12 that engages with a screw shaft 11. When the screw device 5 is rotated, the screw shaft 11 is guided by a key 13 and moves without rotating. Therefore, the distance between both supporting points of the beam 3 is shortened and compressed. 14 is a lock nut that prevents the screw shaft 11 from loosening. On the other hand, the other end of the beam 3 is a pin fulcrum fixed to the frame 2 as shown in FIGS. 6 and 7, and the eye of the end of the beam 3 is supported by a pin 10 on the U-shaped metal fitting 4.

Next, the support method for both ends of the beam 3 is, in addition to the pin fulcrum that allows both ends to rotate and does not bear a moment as in this example, or the so-called material mechanics, in which both ends are firmly restrained with metal fittings so as to not allow rotation and to withstand moments. It is also possible to fix both ends, or to use one end as a pin fulcrum and the other end as a fixed fulcrum.

Now, in the explanation so far, the screw device has been described as a boosting mechanism for compressing the beam, but it is not necessarily necessary; for example, the piston rod of an air cylinder can be replaced with the screw shaft 11, or the screw device can be used with pneumatic pressure. It is also possible to use a combination of devices in which a pinion is provided at the end of the rotating nut 12 of the screw device 5, while a rack is provided on the piston rod of the air cylinder to rotate the engaging screw shaft 11.

Next, in the sieve vibration generating device of FIG. By driving the vertical shaft 19 having a vertical axis, the sieve frame 2 can be rotated to perform sieving. 20 and 21 are upper and lower counterweights, respectively.

The sieving machine in this example is a so-called shifter that performs a low-speed rotating motion, but the present invention also includes various types of vibrating sieves that move at a high speed,
It is an effective and appropriate tensioning device for various sieving machines with similar sieving surfaces.

The present invention relates to the above-mentioned configuration, and when the screen of the sieving machine is relatively tense, the amount of deflection of the adjacent beams is reduced to allow the beams to come into light contact with the screen surface and face with a weak supporting force. . As the slack of the net gradually increases during use, by turning the rotary nut of the screw device and moving the movable fulcrum, the arch-shaped deformation of the beam is increased and the supporting force is strengthened. In this way, by pressing the center part of the net upward or downward, the slack of the net can be uniformly and reliably eliminated, and the net can be easily corrected into a taut state. In particular, by adjusting the distance between the supporting points with a screw device depending on the degree of slack in the net, it is possible to finely adjust the tension to be uniform throughout the net, and this invention has quick and accurate effects. be.

[Brief explanation of the drawing]

Figure 1 is a side view of a sieving machine embodying the present invention, Figure 2 is a perspective view of the same sieve frame, Figure 3 is a sectional view thereof, Figure 4 is a sectional view of its side, and Figure 5 is a cross section near the movable fulcrum. FIG. 6 is a sectional view of the vicinity of the fixed fulcrum, and FIG. 7 is a plan view thereof. 1... Net, 2... Sieve frame, 3... Flexible beam, 4
...Fixed fulcrum (metal fittings), 5...Screw device, 6...
... Movable fulcrum (metal fittings), 7 ... Supply port, 8 ... Discharge port on the screen, 9 ... Discharge port under the screen, 10 ... Pin, 11 ... Screw shaft, 12 ... Rotating nut, 13
... Key, 14 ... Lock nut, 15 ... Electric motor, 16 ... V-belt, 17 ... Flexible link, 1
8...Foundation frame, 19...Vertical axis, 20...Balance weight (top), 21...Balance weight (bottom).

Claims (1)

[Claims] 1. Arranging flexible beams each having a fulcrum between opposing members of the sieve frame to which the screen net is attached,
By shortening the distance between the two supporting points using a boosting mechanism such as a screw device or pneumatic device installed at the supporting point, the beam is bent in an arch shape and pressed against the screen surface, removing the slack. A sieving machine equipped with a screen tensioning device that simultaneously applies tension to the screen.