JPH04272014A - Screw type quantitative feeding device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw type quantitative feeding apparatus among loss-in-weight type quantitative feeding apparatuses.

0002

2. Description of the Related Art A conventional screw-type quantitative feeding device is constructed as shown in FIGS. 2 and 3.

[0003] All the loads of the hopper 1 into which the raw material is charged, the screw feeder 2 that cuts the raw material from the hopper 1, and the drive device 3 of the screw feeder 2 are weighed by a weighing machine (not shown). The drive device 3 is operated so that the amount of weight change per unit time of the weighing machine approaches the target weight value.

[0004] The screw feeder 2 is composed of a first screw 2a and a second screw 2b arranged in parallel, and the first and second screws 2a, 2b are connected to gears 3a, 3b, a chain 4 and 3c, they are driven by a single drive unit 3 in the same direction and at the same speed.

[0005]

[Problems to be Solved by the Invention] In this way, when raw material is cut out from the hopper 1 by the first and second screws 2a and 2b arranged in parallel,
, the pulsation of the raw material to be cut out during one rotation of the second screws 2a, 2b is reduced compared to the case of one screw.

However, even if two screws are used, a certain amount of the pulsation remains, so especially when the target flow rate is small, this pulsation has a large effect on constant flow control, and it is necessary to further reduce the pulsation. It is desired to do so.

[0007] An object of the present invention is to provide a screw type quantitative feeding device that can further reduce pulsation per revolution of the screw.

[0008]

[Means for Solving the Problems] The screw-type quantitative feeding device of the present invention uses a weighing machine to weigh a hopper, a screw feeder for cutting raw materials from this hopper, and a driving device for the screw feeder, while the unit time of the weighing machine is In a screw-type quantitative feeding device that operates the drive device so that the amount of weight change per unit approaches a target weight value, a first screw and a second screw are provided as the screw feeder for cutting raw materials from the hopper, and the drive device The device is characterized in that it includes a first motor that drives the first screw and a second motor that drives the second screw.

[0009]

[Operation] According to this configuration, since the first screw is driven by the first motor and the second screw is driven by the second motor, the position between the first screw and the second screw is It is also possible to control the phase difference and reduce pulsation.

0010

[Embodiment] An embodiment of the present invention will be described below with reference to FIG. Components having the same functions as in FIGS. 2 and 3 showing the conventional example will be described with the same reference numerals.

FIG. 1 shows a screw type constant flow device of the present invention. The first screw 2a that cuts out the raw material from the hopper 1 is driven by a first motor 3a, and the second screw 2b that is arranged in parallel with the first screw 2a and cuts out the raw material from the hopper 1 is driven by a second motor 3b. being driven. The rotation speed of the first motor 3a changes depending on the frequency of the output signal of the first converter 5a. The rotational speed of the second motor 3b changes depending on the frequency of the output signal of the second converter 5b. Frequency of output signal of first converter 5a and second converter 5b
The frequency of the output signal is controlled by the control section 6 as follows.

The weighing machine 7 includes a hopper 1, first and second screws 2a and 2b, and first and second motors 3.
All loads a and 3b are weighed. The control unit 6 determines the frequency of the output signal of the first converter 5a and the frequency of the output signal of the second converter 5b so that the amount of weight change per unit time of the weighing machine 7 approaches the target weight value, and The frequency of the output signal of the first converter 5a or the second converter 5b is modified in accordance with the pulsating component that can be detected from the amount of weight change per unit time of the weighing machine 7, so that the detected pulsating component is reduced. So, 1st,
The phase difference between the second screws 2a and 2b is changed.

In this way, the first and second screws 2a
, 2b can be controlled by the control unit 8, the pulsation that occurs can be reduced more than in conventional devices, and especially constant flow control when the target flow value is small. This system can be expected to improve.

The first and second screws 2a of the above embodiment
, 2b, by making one screw smaller than the other, coarse feeding and fine feeding can be switched and used in one device.

[0015]

As described above, according to the present invention, a first screw and a second screw are provided as a screw feeder for cutting raw materials from a hopper, and a first motor for driving the first screw and a first motor for driving the first screw are provided. Since a second motor is provided to drive the second screw, it is also possible to control the phase difference between the first screw and the second screw. This device can further reduce the pulsations that occur compared to existing devices.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a screw type quantitative feeding device of the present invention.

FIG. 2 is a rear view of the main parts of a conventional screw-type quantitative feeding device.

FIG. 3 is a configuration diagram of a drive system of a conventional screw type quantitative feeding device.

[Explanation of symbols]

1 Hopper 2a First screw 2b Second screw 3a First motor 3b Second motor 5a First converter 5b Second converter 6 Control section 7 Weighing machine

Claims (1)

[Claims] Claim 1: While weighing a hopper, a screw feeder for cutting raw material from this hopper, and a driving device for the screw feeder using a weighing machine, the driving device is operated so that the amount of weight change per unit time of the weighing machine approaches a target weight value. In the screw type quantitative feeding device that operates the device,
A first screw and a second screw are provided as the screw feeder for cutting raw materials from the hopper,
A screw-type fixed-quantity feeding device comprising a first motor that drives a first screw and a second motor that drives a second screw as the driving device.