JPS5814727A - Driving method of conveyor in continuous molding machine for plate-shaped article - Google Patents

Abstract

PURPOSE:To make parallel conveyors run at the same speed when plate-shaped article is molded continuously by charging raw material between two endless conveyors running in the same direction by driving one of them by a main driving gear and the other by an auxiliary driving gear that revolves holding a fixed torque. CONSTITUTION:Expandable synthetic resin original liquid 12 is discharged from an injector 21 onto the upper surface of the base material 11 on the lower side charged continuously, filler 13 is scattered nearly equally on this upper surface from a feeder 22, then expandable synthetic resin original liquid 14 is charged from an injector 23 onto said filler 13, it is covered with upper base material 15 and introduced into the facing surfaces between the lower 25 and the upper conveyor 26 to obtain plate-shaped foamed object 10 continuously by integral expansion molding of a fixed thickness. In this case, the lower conveyor 25 is driven by a main driving gear and the upper conveyor 26 is driven by an auxiliary driving gear that revolves holding a constant torque.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for driving a conveyor in a continuous forming machine for plate-shaped products.

For example, when a polyurethane foam resin is interposed together with a desired filler between two continuously supplied base materials to continuously form a plate-shaped foam molded product of a predetermined thickness, two endless conveyors running in the same direction are placed relative to each other. So-called double conveyor devices installed facing the same direction are often used. This double conveyor device is configured to carry out a predetermined foam molding by squeezing the raw material on its opposing surfaces, but the two conveyors must run at the same speed. For example, when two conveyors are driven by separate drive devices, it is necessary to precisely match the rotational speed of each drive device, but this requires equipment such as a control device, reducer, and transmission. , the structure is complicated and it is not economical. On the other hand, when two conveyors are run simultaneously by a single drive device, it is natural that the drive pulley or sprocket diameter of each conveyor must be designed with extremely high precision to a predetermined diameter. If there is a slight difference in the tension of the belt or chain, slippage, etc., will inevitably occur, and this will accumulate during long-term operation and cause unforeseen problems in product manufacturing or equipment. .

As a means to solve this problem, a drive device for a platform conveyor equipped with a front free mechanism is currently used.

Alternatively, a method has been proposed in which a driving device is provided only on one belt conveyor, and the other belt conveyor is driven by contact resistance interposed between the belt surfaces without a driving device. However, these methods are not necessarily fully applicable to, for example, polyurethane resin foam molded products. However, in the former case, there is a risk that a slight slip may occur at the moment the front free mechanism is activated, and this occurs alternately between the two conveyors, and in the latter case, shearing force acts in the direction of travel of the foam, and eventually Also has an unfavorable effect on foam molded products.

In view of these points, this invention proposes an extremely advantageous method especially for foam molding such as polyurethane resin. It is characterized in that the conveyor is run by an auxiliary drive device that rotates the other conveyor while maintaining a constant torque. This will be explained in detail below.

Figure 1 of the attached drawings schematically shows the entire apparatus for continuously forming plate-shaped foam molded products using a double conveyor apparatus.
11 is a lower side base material made of kraft paper, a plastic plate, a metal plate, etc.; 12 is a thermosetting foamed synthetic resin stock solution such as polyurethane resin, and the components are separated into two or three parts in advance, and these components are separated into two or three parts; Those that cause a foaming and hardening reaction by mixing the components,
13 is a reinforcing filler such as perlite, shirasu balloon, glass wool, etc., 14 is a foamed synthetic resin stock solution similar to the foamed synthetic resin stock solution in 12 above, 15 is the above-described downward side base material 125 is a lower mold conveyor, and 26 is an upper mold conveyor. Each mold conveyor is shown. As shown in the figure, this device discharges a foamed synthetic resin stock solution 12 from an injector 21 onto the upper surface of a lower side base material 11 that is continuously supplied, and spreads a filler 13 almost uniformly on this upper surface from a feeder 22. Next, the foamed synthetic resin stock solution 14 is supplied onto the filler 13 by the injection machine 23, and the upper surface side base material 15 is coated with this, and the foamed synthetic resin stock solution 14 is introduced into the opposing surfaces of the lower mold conveyor 25 and the upper mold conveyor 26 to a predetermined thickness. A plate-shaped foam molded product 10 is continuously obtained by integrally foaming molding.

FIG. 2 is a partially enlarged side view showing the drive structure of the double conveyor device according to an embodiment of the present invention. That is, in this invention, the lower mold conveyor 25 is driven by a main drive device including a motor 30, and the other upper mold conveyor 26 is driven by an auxiliary drive device such as a torque motor 32 that rotates while maintaining a constant torque. be done. In the figure, numerals 31 and 33 represent drive pulleys or sprockets connected to each drive device.

An electric motor, generally referred to as a torque motor, generates a constant torque in response to an applied voltage and rotates by an angle corresponding to the torque, so its rotational speed is basically unrelated to the torque. In the embodiment, the above-described raw material for foam molding is introduced into the opposing surfaces of the lower mold conveyor 25 and the upper mold conveyor 26, and the contact resistance between this raw material and the upper mold conveyor 26 is controlled by a constant torque. The aim of the present invention is to understand this torque and run the upper conveyor auxiliary based on this torque.

The torque of the upper mold conveyor 26 when raw material is introduced onto opposing surfaces of both conveyors can be measured by the graph shown in FIG. In the figure, the vertical axis shows the current value measured by the ammeter 35 of the drive motor 30 on the main drive side, and the horizontal axis shows the value of the current measured by the torque motor 32 on the auxiliary drive side.
is the value of the voltage measured by the voltmeter 36. In the figure, the lowest point P of the current on the main drive side represents the point where the circumferential speeds of the torque motor 32 and the main drive motor 30 match. Therefore, it is sufficient to set the torque of the torque motor 32 at this position, but it is actually desirable to set the torque of the torque motor 32 at a position Q slightly before this position.

At the lowest point P, when the current on the main drive side changes due to some reason, the peripheral speed of the torque motor 32 increases, the main drive side lags behind this, and the direction of the load on the product changes. This is because there are concerns.

As the auxiliary drive device, in addition to a commercially available torque motor, an electromagnetically coupled continuously variable transmission modified to have low torque characteristics can be used.

As described above, according to the present invention, one conveyor is driven by a main drive device, and the other conveyor is driven by an auxiliary drive device that rotates while maintaining a constant torque. The driving conveyor can run at the same speed as the main driving conveyor while always maintaining a constant contact resistance with the material interposed between both conveyors. Therefore, the load on the material introduced to the opposing surfaces between both conveyors is always constant, and for example, it is possible to prevent unexpected effects on the material during foam molding.

Further, in this invention, it is possible to use general and versatile parts such as an l-lux motor, so there is a great advantage in terms of design and economy.

Note that the present invention is extremely effective not only for belt conveyors driven by pulleys but also for chain-driven slat conveyors.

[Brief explanation of the drawing]

Is Figure 1 a double conveyor device? Fig. 2 is an enlarged side view showing the driving device portion of the double conveyor device of Fig. 1, which shows an embodiment of the present invention. Figure, Figure 3d
It is a graph showing the relationship between the main drive motor and the auxiliary drive motor. DESCRIPTION OF SYMBOLS 10... Plate foam molded product, 25... Lower die conveyor, 26... Upper die conveyor, 30... Main drive motor, 31... Torque motor. (8) Figure

Claims (1)

[Claims] When continuously forming a predetermined plate-shaped product by supplying raw materials to opposing surfaces of two endless conveyors running in the same direction, one conveyor is run by the main drive device, and the other conveyor is driven by a constant torque. A method for driving a conveyor in a continuous molding machine for plate-shaped products, characterized in that the conveyor is driven by an auxiliary drive device that holds and rotates the conveyor.