JPH04272016A - Screw type feed device - Google Patents

Abstract

PURPOSE:To provide a screw type feed device with a first and a second screws arranged in parallel. CONSTITUTION:A first screw 2a and a second screw 2b to cut out material from a hopper are provided, a first motor 3A to drive the first screw 2a and a second motor 3B to drive the second screw 2b are provided, and a control part 6 to control a drive signal to the second motor 3B is provided so that a phase difference between a detected phase value of a first rotation phase detector 7a to detect a rotation phase of the first screw 2a and a detected phase value of a second rotation phase detector 7b to detect a rotation phase of the second screw 2b approaches a set phase difference. It is possible to reduce pulsation by making a rotation phase difference of the first screw 2a against the first screw as the set phase difference given to the control part 6.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw type feeding device.

0002

2. Description of the Related Art A conventional screw type feeding device is constructed as shown in FIGS. 2 and 3. This screw type feeding device is a loss-in-weight type quantitative feeding device, and all the loads of the hopper 1 into which the raw material is input, the screw feeder 2 that cuts the raw material from this hopper 1, and the drive device 3 of the screw feeder 2 are calculated. The weight is weighed by a heavy machine (not shown), and the drive device 3 is operated so that the amount of weight change per unit time of the weigh machine approaches the target weight value.

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.

0004

[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.

[0006] 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.

[0007]

[Means for Solving the Problems] The screw type feeding device of the present invention is provided with a first screw and a second screw for cutting raw material from a hopper, and a first motor that drives the first screw and a second motor that drives the first screw. A second motor for driving the screw is provided, a first rotational phase detector is provided for detecting the rotational phase of the first screw, and a second rotational phase detector is provided for detecting the rotational phase of the second screw. , a control unit is provided for controlling the drive signal to the second motor so that the phase difference between the detected phase value of the first rotational phase detector and the detected phase value of the second rotational phase detector approaches a set phase difference. It is characterized by:

[0008]

[Operation] According to this configuration, the first screw is driven by the first motor, the second screw is driven by the second motor, and if an appropriate phase difference is set in the control section, the second screw is driven by the second motor. The drive of the second motor is controlled so that the detected phase value of the rotational phase detector is a set phase difference than the detected phase value of the first rotational phase detector, and the pulsation is suppressed by the set phase difference. Can be reduced.

[0009]

[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 first motor 3A is operated at a rotation speed determined by the output signal of the motor controller 5. Second
An output signal from the motor controller 5 is applied as a drive signal to the motor 3B via the control section 6. The control section 6 is connected to first and second rotational phase detectors 7a, 7b and a phase difference setting section 8. First rotational phase detector 7
a is attached to the first screw 2a to detect the rotational phase of the first screw 2a, and a second rotational phase detector 7b is attached to the second screw 2b to detect the rotational phase of the second screw 2b. Detecting phase. Control unit 6
is set so that the difference between the detection values of the first and second rotational phase detectors 7a and 7b becomes the phase difference set in the phase difference setting section 8.
The second motor 2a is operated by outputting the output signal of the motor controller 5 with a delay.

With this configuration, the rotation of the second screw 2a relative to the first screw 2a can be controlled by changing the phase difference set in the phase difference setting section 8 during operation according to the properties of the raw material to be handled. The phase can be changed, and pulsation of the discharged raw material can be reduced.

Note that by changing the frequency of the output signal of the motor controller 5, the first and second motors 3A
, 3B can be varied. In addition, in the loss-in weight type constant flow supply device, the hopper 1 and the first and second
screws 2a, 2b, first and second motors 3A, 3
While measuring the load of B with a weighing machine, the frequency of the output signal of the motor controller 5 is controlled so that the decrease weight value per unit time of the weight value of the weighing machine approaches the set value, and By automatically controlling the set value of the phase difference setting unit 8 so that the pulsation component determined from the decreasing change becomes small, constant flow rate supply without pulsation can be realized.

In the above embodiment, the first and second motors 2a
, 2b is supplied from the motor controller 5, but even if the drive sources are supplied from separate signal sources, the control unit 6 controls the drive of the second screw based on the detected values of the first and second rotational phase detectors 7a and 7b. The rotation phase of 2a can be changed.

[0014]

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. A second motor is provided to drive the second screw, and the phase difference between the first screw and the second screw is controlled by the control unit, so they are not operated at the same speed and with a constant phase difference as in the conventional case. 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 feeding device of the present invention.

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

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

[Explanation of symbols]

1 Hopper 2a First screw 2b Second screw 3A 1st motor 3B Second motor 6 Control section 7a First rotational phase detector 7b Second rotational phase detector 8 Phase difference setting section

Claims (1)

[Claims] Claim 1: A first screw and a second screw are provided for cutting raw material from a hopper, a first motor that drives the first screw, a second motor that drives the second screw, and a first screw that cuts raw material from a hopper. A first rotational phase detector is provided to detect the rotational phase of the screw, a second rotational phase detector is provided to detect the rotational phase of the second screw, and the detected phase value of the first rotational phase detector and A screw-type feeding device provided with a control unit that controls a drive signal to a second motor so that a phase difference between detected phase values of a second rotational phase detector approaches a set phase difference.