JPH0773799B2 - Granular or powder material pressure molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides a predetermined shape by passing a granular or powdery material between pressure-forming rolls arranged to face each other. The present invention relates to a pressure molding device for molding.

<Prior Art> A granular or powdery material is supplied from a hopper between a pair of rolls whose outer peripheral surfaces are opposed to each other, and a pressing force applied between both rolls forms a mold formed on the outer peripheral surface of the rolls. There is known a pressure-molding apparatus which is capable of obtaining a molded product having a predetermined shape. As a means for applying a pressing force applied between both rolls in such a pressure molding apparatus, for example, as disclosed in Japanese Patent Publication No. 50-38230,
A coil spring is known.

<Problems to be Solved by the Invention> Such a roll pressing device using a coil spring has the following problems.

A. When starting from the state where the pressure forming rolls are in contact with each other, if the initial pressing force acting on the roll is too strong, the roll is difficult to open when passing the material between the rolls, and therefore the predetermined forming thickness is The initial start-up time until the product is obtained tends to be long, and the operating rate of the pressure molding device tends to decrease. Further, if the initial pressing force is too weak, the material will spill from between the rolls without being molded. The ratio of the initial pressing force to the product molding pressing force for obtaining the product is preferably about 1:30, but it is difficult to obtain such a pressing force change with the pressing force of the coil spring.

B. Coil springs inevitably generate vibrations due to changes in pushing force, and if hunting occurs when the roll is open or in the open state, the forming thickness, forming density, forming strength, etc. tend to be unstable. .

The present invention has been devised to improve such inconvenience, and its main purpose is to improve the granularity or granularity improved so as to achieve the reduction of the initial rise time and the stabilization of the product molding pressing force. An object of the present invention is to provide a pressure molding device for powdery materials.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, the object of the present invention is to provide a granular or powdery material, which is supplied between the molding rolls opposed to each other, with an initial pressing force and a product This is achieved by providing a pressure molding apparatus configured to be able to mold into a predetermined shape by applying a two-stage pressing force, which is the molding pressing force, to a molding roll.

<Operation> According to such a configuration, at the start of pressure molding, the appropriate initial pressing force generated by the initial pressing device is applied to the forming rolls facing each other, so that the material at the initial stage of supply falls off. The pressure contact state between the rolls is maintained so that nothing happens. Then, as the pressure reaction force of the material exceeds the initial pressing force as the supply amount of the material increases, the interval between the forming rolls is opened in a short time, and the initial pressing force and the supply amount of the material are proportional to each other. The material is hardened. Further, when the roll interval reaches a dimension that can obtain the product thickness, high molding stability can be obtained by applying a pressing force capable of obtaining the desired molding strength and molding density to the molding roll by the product molding pressing device. .

<Examples> The configuration of the present invention will be described in detail below based on specific examples shown in the accompanying drawings.

FIG. 1 shows the entire pressure molding apparatus constructed according to the present invention. A material storage hopper 3, a material supply device 4, two forming rolls 5a and 5b, and a roll pressing device 6 are provided on a frame 2 of the pressure forming device 1.

The material storage hopper 3 has a funnel-shaped cross section, a material input port 7 is provided on the upper side, and a material discharge port 8 is provided on the lower side. The material discharge port 8 is opened between the two forming rolls 5a and 5b. is doing.

The material supply device 4 has a feed screw 10 driven by an electric motor 9 with a speed reducer, and is rotated by the rotation of the feed screw 10 having its tip inserted into the material discharge port 8 of the material storage hopper 3 from above. The granular or powder material stored in the material storage hopper 3 is fed between the two forming rolls 5a and 5b.

The two forming rolls 5a and 5b extend horizontally with their axes parallel to each other. One of these 5a is rotatably supported by a bearing box 11 fixed to the frame 2, and the other 5b is in a direction orthogonal to the axis of the roll, in other words, for one roll 5a. It is rotatably supported by a movable bearing box 12 which is supported by the frame 2 so as to be movable in the contacting and separating directions.

The roll pressing device 6 is connected to the movable bearing box 12. The roll pressing device 6 is composed of a cylinder device that generates thrust by fluid pressure. As shown in FIGS. 2 and 3, the roll pressing device 6 is a high output main cylinder directly attached to the frame 2 as a product forming pressing device. 13 and a load receiving member 15 connected to the ram end of the main cylinder 13 via a load cell 14.
It is composed of a small output sub-cylinder 16 as an initial pressing device mounted on the upper side. Both cylinders 13 and 16
Are both configured to generate thrust along the moving direction of the movable bearing box 12. The tip of the piston rod 17 of the sub cylinder 16 can come into contact with the side surface of the movable bearing box 12. When the piston rod 17 of the sub cylinder 16 is extended, the movable bearing box 12 and the load receiving member 15 A predetermined gap G1 is opened between them.

Next, the operation procedure of the above embodiment will be described.

When starting the pressure molding, the main cylinder 13 is fully pushed out, and then the sub cylinder 16 is extended to move the movable bearing box.
12 is extruded and the outer peripheral surfaces of the two forming rolls 5a and 5b are brought into contact with each other. At this time, the movable bearing box 12 and the load receiving member 15
A predetermined gap Gl, which is equal to the product molding thickness, is opened between and (the state of FIG. 2).

From this state, the forming rolls 5a and 5b are rotationally driven while feeding the material (such as pulverized coal having a grain size of 0.3 mm or less) between the two forming rollers 5a and 5b. Then both forming rolls
Since the gap between 5a and 5b is practically zero, the material accumulates in the valleys between the forming rolls, and the reaction force exerted on the rolls when the gap passes between the forming rolls 5a and 5b passes through the movable bearing box. It is transmitted to the sub cylinder 16 via 12. At this time, the molding pressure of the material and the gap G2 between both molding rolls 5a and 5b are determined according to the balance between the reaction force exerted by the material on the molding roll and the thrust of the sub-cylinder 16, and the material is molded into a substantially flat plate shape. It

Then, when the forming reaction force of the material exceeds the thrust of the sub-cylinder 16 in accordance with the increase of the supply amount of the material, the movable bearing box 12 moves and the forming roll reaches a position where the movable bearing box 12 and the load receiving member 15 contact each other. The space between 5a and 5b opens. In this way, when the gap G2 between the two forming rolls 5a and 5b reaches a dimension at which the product thickness can be obtained, from that time point, the movable bearing box 12 is moved from the other roll 5b.
Also, the main cylinder 13 receives the molding pressure acting on the load receiving member 15.

Here, by setting the thrust of the sub-cylinder 16 to the extent that the material can be appropriately hardened in the initial stage of molding, the roll gap is started from 0 and the product thickness is reached in a relatively short time. can do. Further, by appropriately setting the thrust of the main cylinder 13 according to the required molding strength and molding density, it is possible to obtain a stable molding thickness according to the properties of the material.

[Effects of the Invention] As described above, according to the present invention, the material is pressed with an initial pressing force significantly lower than the pressing force generated by the product molding pressing device from the start of pressure molding to the product molding thickness. Therefore, the gap between the forming rolls can be opened smoothly in a short time. Therefore, it is possible to significantly reduce the initial start-up time until the product molding thickness is reached, which is very effective in increasing the actual operating rate of the pressure molding device. Also, in the product molding state,
Since it is possible to exert a stable pressing force on the forming roll, which is sufficient for forming the product, it is possible to exert an extremely large effect in enhancing the stability of the product thickness, strength and density. Moreover, since the pressing force can be set appropriately, it is possible to deal with a wide range of changes in the properties of the material.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a pressure molding apparatus according to the present invention, FIG. 2 is an enlarged view of a main part showing a molding start state, and FIG. 3 is a product molding state. It is a principal part enlarged view similar to FIG. 1 ... Pressure molding device, 2 ... frame 3 ... Material storage hopper, ... Material supply device 5a ・ 5b ... Molding roll 6 ... Roll pressing device, 7 ... Material input port 8 ... Material discharge port , 9 ...... Motor with reduction gear 10 ...... Feed screw, 11 ...... Bearing box 12 ...... Movable bearing box, 13 ...... Main cylinder 14 ...... Load cell, 15 ...... Load receiving member 16 ...... Sub cylinder, 17 ... … Piston rod

Claims (1)

[Claims] 1. Granules or powder for forming a predetermined shape by supplying granular or granular material stored in a hopper between forming rolls arranged facing each other and applying a pressing force to the forming rolls. In a pressure molding apparatus for sheet material, the distance between the molding rolls is from a state in which they are in contact with each other, until a distance at which a predetermined product thickness is obtained,
An initial pressing device for applying an appropriately set initial pressing force to the forming roll, and an interval between the forming rolls that can obtain the product thickness, a product forming pressing force higher than the initial pressing force is applied to the forming roll. And a device for molding and molding a product for applying to a granular material or a powdery material.