JP2710494B2 - Control method of transport screw - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for controlling the rotation of a conveying screw used in a combination weighing machine.

[0002]

2. Description of the Related Art FIG. 2 is a side view showing a combination weighing machine, and FIG. 3 is a front view of the weighing machine. This combination weigher
A loading hopper 12 is provided at an uppermost portion of the apparatus housing 11, and a workpiece W is loaded. A plurality of conveying screws 14 are arranged below the input hopper 12. The transport screw 14 is provided in a mortar-shaped guide path 14b having an open top, and the workpiece W is rotated by a driving unit 14a provided at the base end of the transport screw 14.
Is transported from the lower position of the input hopper 12 on the base end side to the forward end of the transport screw 14 in the forward direction of the weighing machine. A cylindrical pool hopper 15 is provided at a position corresponding to the tip of the transport screw 14. A plurality of pool hoppers 15 are mounted on a bottom plate 15 a fixed to the housing 11. The pool hopper 15 has a work W
The bottom plate 15 a
By moving further forward, a predetermined amount of the work W is dropped downward.

A plurality of cylindrical weighing hoppers 17 are provided at the falling position of the work W. The weighing hoppers 17 are placed on respective independent bottom plates 18.
The bottom plate 18 is connected to a weighing load cell 18a provided inside the housing 11, and the weighing load cell 18a weighs the work W. Then, a desired measurement value can be obtained by combining the measurement values of the respective measurement hoppers 17. Only the designated measurement hopper 17 is moved forward of the bottom plate 18 by the extension of the cylinder 19, and the internal work W is dropped. . At a lower position of the weighing hopper 17, a flat plate-like collecting plate 22 is provided. A scraper 23 is provided on the collecting plate 22 for scraping the work W on the collecting plate 22 to the center. The work W collected by the scraper 23 is carried out to the next step via the collecting chute 22a.

[0004]

However, in the above-described conventional combination weighing machine, the rotation of the transport screw 14 only advances the work W in one direction, so that the following problems occur. The transport screw 14a is provided in a mortar-shaped guide path 14b having an open top, and the work W is transported by the transport screw 14a along the guide path 14b. In some cases, as shown in the partial front view of FIG.
The work W is transported by the conveying screw 14a and the guide path 14b.
It was easy to get caught in the middle. In this case, the transport screw 14a cannot rotate, and if the transport screw 14a is forcibly rotated, the transport screw 14a or the work W may be damaged.

The work W is transported by a transport screw 14a.
The workpiece W is supplied to the pool hopper 15 in synchronization with the rotation of the transport screw 14a.
When the predetermined amount of the work W is supplied to the pool hopper 15, the conveyance screw 14a is stopped to stop the supply. However, even after the conveyance screw 14a is stopped, the work W at the tip end falls into the pool hopper 15. There was a problem to do. As a result, the measured value of the work W becomes uneven, which causes a new problem that high-precision combination weighing cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and when intermittent conveyance is performed, the work can be prevented from dropping when the conveyance is stopped. An object of the present invention is to provide a control method of a transport screw that can be transported and can be transported easily without being caught by the transport screw when transporting a work.

[0007]

In order to achieve the above object, a method for controlling a conveying screw according to the present invention comprises the steps of: moving a conveying screw 14 provided in a guide path 14b to a driving screw provided at a base end of the conveying screw 14; A method of controlling a transport screw that transports a predetermined amount of a workpiece W from a base end to a distal end side of the guide path 14b by intermittently rotating the motor 14a, wherein the transport screw 14 is rotated forward by a predetermined amount. After transporting and stopping the workpiece W,
It is characterized in that the operation of rotating the transport screw 14 at least once in the reverse direction is continuously repeated.

[0008]

By the forward rotation of the transport screw 14 by the operation of the drive motor 14a, a predetermined amount of work W corresponding to the number of rotations is transported along the guide path 14b from the proximal end to the distal end of the transport screw 14. After the transport screw 14 has stopped after the predetermined rotation, the work W on the tip side of the guide path 14b is returned by reversely rotating at least once, so that the work W does not fall from the end position of the guide path 14b.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the flow of a workpiece W in the combination weighing machine shown in FIGS.
It is controlled by the amount of storage by the learning function. That is, at the time of the initial setting, the weighing value of the work W corresponding to the rotation amount of the drive motor 14a is stored, and the rotation amount of the drive motor 14a corresponds to each desired weighing value for combination weighing in each weighing hopper 17 portion. Is controlled.

FIG. 1 is a flowchart showing a method for controlling a conveying screw according to the present invention. The transport screw 14 is intermittently rotated by the intermittent operation of the drive motor 14a. First, the drive screw 14a is controlled to rotate the transport screw 14 in the forward direction by a predetermined amount (SP1). As a result, the transport screw 14 rotates in the forward direction, and the work W is taken out from the lower part of the input hopper 12, and is sequentially transported and supplied into the pool hopper 15 (SP2). After a predetermined rotation of the transport screw 14 by the learning function, the transport screw 14 stops (SP3). In this state, a predetermined amount of the work W is stored in the pool hopper 15. Thereafter, the workpiece W is transferred to the weighing hopper 17 and weighed.
It is combined with the work W in the other plurality of weighing hoppers 17 and discharged to a predetermined weight.

Next, the transport screw 14 rotates in a reverse direction by a predetermined rotation (for example, one rotation) (SP4).
Therefore, the work W returns by a predetermined amount in the direction opposite to the transport direction. Therefore, the transport screw 14 and the guide path 14b
The work W at the tip does not fall from the guide path 14b to the pool hopper 15 after the transport screw 14 stops. Therefore, the work W is transported only when the transport screw 14 rotates and is supplied to the pool hopper 15, and does not drop naturally into the pool hopper 15 when the transport screw 14 is stopped. Can be. The rotation of the transport screw 14 is controlled until the combination weighing machine stops every time the work W in the pool hopper 15 is supplied to the weighing hopper 17 (SP5).
During this period, it is operated intermittently.

Since the transport screw 14 rotates in a reverse direction after a predetermined number of forward rotations at each intermittent operation, even if the workpiece W has a property of being easily caught between the transport screw 14 and the guide path 14b. , Conveying screw 14
Can be released before it is excessively pinched in the reverse direction, so that stable operation can be performed without affecting continuous operation.

In the above embodiment, the control method of the present invention is applied to the intermittently operating conveying screw provided in the combination weighing machine. The control method of the present invention may be applied to a device provided with a screw, and in this case, the same operation and effect as the above-described embodiment can be obtained.

[0014]

According to the conveying screw control method of the present invention, the intermittently operating conveying screw can rotate a predetermined amount of work corresponding to the number of rotations in the forward rotation from the base end side of the conveying screw to the front end. The conveying screw is rotated at least once after stopping after the predetermined rotation, so that the work on the tip end side of the guide path is returned,
The work does not fall from the guide road end position. As a result, a constant amount of work can always be intermittently conveyed.
Further, by the reverse rotation operation of the transport screw, stable transport and supply can be performed without the work being pinched between the transport screw and the guide path.

[Brief description of the drawings]

FIG. 1 is an operation flowchart according to a transport screw control method according to the present invention.

FIG. 2 is a side view showing the combination weighing machine.

FIG. 3 is a front view of the weighing machine.

FIG. 4 is a partial front view of a transport screw.

[Explanation of symbols]

14: conveying screw, 14a: drive motor, 14b ...
Guide path, 15 ... Pool hopper, W ... Work.

Claims (1)

(57) [Claims] An intermittent rotation of a transport screw (14) provided in a guide path (14b) by a drive motor (14a) provided at a base end of the transport path allows the base of the guide path to be formed. A method of controlling a transport screw that transports a predetermined amount of a work (W) from an end side to a distal end side, comprising: rotating the transport screw forward by a predetermined amount to transport the work; stopping the transport screw; A method for controlling a transport screw, wherein an operation of making one rotation in a direction is continuously repeated.