JPH03329Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a strand breakage detection device. More specifically, the present invention relates to a strand breakage detection device used to detect strand breakage particularly in the production of synthetic resin pellets using the cold strand cutting method, which is easy to handle and has high detection sensitivity. , and is characterized by a simple structure.

[Prior Art] Generally, thermoplastic molding materials are manufactured in the form of pellets to facilitate handling and feeding of the materials to molding machines. Pellet manufacturing methods can be divided into cold cut method and hot cut method.

The cold cut method is a method in which a sheet-like or strand-like molded product extruded from an extruder is cooled with water or air, and then cut. This is a method of cutting.

In the above-mentioned cold cutting method, in order to cool the extruded strands in the shape of udon noodles, a large number of strands coming out of the die are suspended and moved through a cooling device, but during this time, one of the strands is cut. Sometimes. This phenomenon is
The frequency of occurrence varies depending on the type of molten resin, presence or absence of filler, non-uniformity of composition, presence of air bubbles and foreign objects, etc., but when one strand breaks and hangs down,
This can entrain other strands and form large clumps of resin that accumulate at the exit of the die, eventually requiring the molding operation to be stopped. Therefore, if a strand breaks, it is necessary to immediately detect and deal with the breakage.

Conventionally, there is no means to automatically detect such strand breakage, so workers in the manufacturing process must monitor it themselves. Therefore, in addition to requiring manpower, unforeseen situations may occur due to inadvertent oversight.

[Problems to be Solved by the Invention] The present invention has been made in order to solve the above-mentioned conventional problems.

That is, an object of the present invention is to provide a strand breakage detection device that instantly and reliably detects strand breakage.

Another object of the present invention is to provide a strand breakage detection device that has the above-mentioned functions, has a simple structure, and is easy to handle.

[Means for Solving the Problems] The strand breakage detection device of the present invention includes: a receiver containing cooling water; a support member that supports the receiver; and an upward force on the support member to place the receiver in a predetermined position. A biasing member to hold; a detection rod that is attached to the support member and moves according to the vertical movement of the receiving tank; a water level detection switch provided on the upper side of the detection rod; a weight detection switch provided on the lower side of the detection rod; It consists of a water supply system that is activated by the water level detection switch and supplies water to the tank; and an alarm device that is activated by the weight detection switch.

[Function] In the strand breakage detection device of the present invention having the above configuration, when the broken strand falls onto the receiving tank, the receiving tank moves downward due to the weight of the strand. As this tank descends,
A detection rod attached to a support member supporting the receiving tank also lowers to activate a weight detection switch. Activation of this switch activates an alarm system, which immediately notifies the operator of strand breakage. On the other hand, the receiving tank is always filled with a certain amount of cooling water, which cools the strands that have fallen onto the receiving tank and prevents them from sticking to the receiving tank. Furthermore, when the amount of cooling water decreases due to evaporation or the like, the weight of the water tank decreases, and the water level detection switch is activated to automatically open the water supply system valve and supply water to the water tank.

[Example] The strand breakage detection device of the present invention will be described in more detail below with reference to Examples.

First, the outline of the method for producing pellets by the cold strand cutting method will be briefly explained with reference to the process diagram shown in FIG.

The synthetic resin material is first transferred from the hopper 1 to the extruder 2.
is supplied to The resin material is heated and kneaded in an extruder 2 and extruded from a die 3 into a large number of strands 4 having a diameter of about 2 to 3 mm. Next, this strand 4 is introduced into a cooling tank 5, cooled and solidified, and then cut into a predetermined length with a cutter 6 to obtain a synthetic resin pellet 7 as a product.

In the above process, all of the many strands 4 extruded from the die 3 are normally introduced into the cooling device 5, but due to non-uniform composition, air bubbles, foreign matter, etc., some of the strands may It may break and sag. If you leave this,
The root of the broken strand 8 touches other normal strands, winds them up and cuts them, forming a lump and falling downward, eventually leading to a situation where the operation has to be stopped.

The strand breakage detection device of the present invention is used to prevent such situations by receiving and detecting the broken strand 8 from below and immediately notifying the operator. .

The strand breakage detection device of the present invention will be described in detail below with reference to the illustrated embodiments.

FIG. 1 shows a first embodiment of the strand breakage detection device of the present invention. Strand breakage detection device 11
A receiver tank 13 containing cooling water 12; a support member 14 that supports the receiver tank 13; and a biasing member 1 that urges the support member 14 upward to hold the receiver tank 13 in a predetermined position.
5; Detection rod 16 attached to the support member 14 and moved according to the vertical movement of the receiving tank 13; Water level detection switch 17 provided on the upper side of the detection rod 16; Weight detection switch 18 provided on the lower side of the detection rod 16; It consists of a water supply system 19 which is activated by the water level detection switch 17 and supplies water to the receiving tank 13; and an alarm device 20 which is activated by the weight detection switch 18.

The receiving tank 13 containing the cooling water 12 is usually in the shape of a quadrilateral or circular tray, and its shape
The material etc. are not particularly limited. Further, the cooling water 12 in the receiving tank 13 cools the cut strands and prevents the resin material from sticking to the receiving tank 13. Even if the cooling water evaporates to a certain extent or the receiving tank 13 is slightly tilted, the amount of the cooling water 12 remains unchanged.
It is sufficient that the entire bottom surface of the container is covered with water, and a depth of 1 cm is usually sufficient.

In this embodiment, the support member 14 is the support column 21
and a pair of spring pins 22. The support column 21 is vertically attached to the center of the bottom surface of the receiving tank 13, and the spring pin 22 is adapted to hang the lower end of the biasing member 15.

The biasing member 15 is for biasing the support member 14 upward to hold the receiving tank 13 in a predetermined position.
In this embodiment, it consists of a pair of tension coil springs, each of which is tensioned between the spring pin 2 and the inner wall at the center of the upper surface of the casing 23. The biasing member 15 may be any member as long as it elastically supports the receiving tank 13 upward, and may be made of rubber or other elastic members.Also, the biasing member 15 may be configured to support the support member 14 from below with a compression spring. It's okay.

A detection rod 16 extending laterally is attached to the support column 21 of the support member 14.
The vertical movement due to the weight change of the receiving tank 13 is detected by the water level detection switch 17 and the weight detection switch 18.
It is something that can be conveyed to people. That is, the water level detection switch 17 is placed above the detection rod 16, and the water level detection switch 17 is placed above the detection rod 16.
A weight detection switch 18 is provided below. The water level detection switch 17 and the weight detection switch 18 can be supported by appropriate supports, and the interval between the water level detection switch 17 and the weight detection switch 18 can be set arbitrarily. The appropriate spacing varies depending on the modulus of elasticity of the biasing member 15, but by adjusting this spacing, the weight to be applied to the switch can be changed. Normally, the appropriate amount of weight change for the switch to operate is about 50g.

On the other hand, when the amount of cooling water 12 in the receiving tank 13 decreases, the receiving tank 13 becomes lighter, so that the receiving tank 13 is lifted by the support member 14 according to the tensile force of the biasing member 15. Therefore, the detection rod 16 comes into contact with the water level detection switch 17, and the switch is turned on. When the water level detection switch 17 is turned on, the valve 24 of the water supply system 19
(e.g., a solenoid valve) is activated to start supplying water. When the cooling water 12 in the receiving tank 13 reaches a predetermined amount, the receiving tank 1 becomes heavier and lowers, and the detection rod 16 also lowers, so the water level detection switch 17 is turned off and the valve 24 of the water supply system 19 is closed.

Furthermore, when the strand breaks and the strand hangs down onto the receiver tank 13, the weight of the receiver tank 13 increases, so the receiver tank 13 descends against the supporting force of the biasing member 15, and the detection rod 16 detects the weight. switch 18
, the weight detection switch 18 is turned on and the alarm device 20 is activated.

These switches 17 and 18 may have any structure and are not particularly limited, and may be, for example, ordinary micro switches or proximity switches. Further, the alarm device 20 is
Appropriate equipment such as a bell, buzzer, or lamp may be used. Further, the alarm device 20 includes a strand breakage detection device 11.
Although it is installed inside the casing 23 of
The weight detection switch 18 and the alarm device 20 can also be electrically connected.

In addition, the reference numeral 25 is a stopper for preventing the column 21 from descending excessively, the reference numeral 26 is a water connection port, the reference numeral 27 is a power plug, and the reference numeral 28 is a caster for moving the detection device.

FIG. 3 shows a second embodiment of the strand breakage detection device of the present invention. This strand breakage detection device 1
In No. 1, a diamond-shaped link mechanism is used as the support member 14, and the sliding portions when the receiving tank 13 moves up and down are only the shaft portions of the links.
3, the frictional resistance of vertical movement is small, and detection sensitivity and reliability can be increased. In addition, the biasing member 1
A zero point adjustment screw 29 is provided at the upper end of 5. Furthermore, in this embodiment, instead of the casters 28 in the first embodiment, a bracket 28a is attached to the cooling tank 5, and the detection device 11 is slidably mounted on the bracket 28a.

Furthermore, FIG. 4 shows a third embodiment of the present invention.
In this embodiment, for example, the receiving tank 13 is connected to the dotted line 30
When the link 31 and 32 are slightly lowered to the position shown in FIG. Therefore, as the points of force c and d fall, points e and f move largely around the fulcrums a and b, and the detection rod 16 comes into contact with the switch 18, thereby increasing the detection sensitivity. Also, code 3
3 indicates a water tap and 34 indicates an AC power source.

In addition, in the second example and the third example,
Members similar to those in the first embodiment are indicated by corresponding symbols, and have similar functions.

[Effects of the invention] As described above, the strand breakage detection device of the invention has a simple structure and is easy to manufacture and handle, yet it reliably detects broken and dangling strands and issues an alarm. This is useful for practical purposes.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view of a strand breakage detection device according to a first embodiment of the present invention, FIG. 2 is a pellet manufacturing process diagram, FIG. 3 is a schematic vertical cross-sectional view of a second embodiment, and FIG. The figure is a schematic longitudinal sectional view of the third embodiment. 11... Strand breakage detection device, 12... Cooling water, 13... Receiving tank, 14... Support member, 15...
...Biasing member, 16...Detection rod, 17...Water level detection switch, 18...Weight detection switch, 19...
Water supply system, 20...Alarm device.

Claims (1)

[Claims for Utility Model Registration] (1) A receiver tank containing cooling water; a support member that supports the receiver tank; a biasing member that urges the support member upward to hold the receiver tank in a predetermined position; a detection rod that is attached to the member and moves according to the vertical movement of the receiver;
a water level detection switch provided on the upper side of the detection rod; a weight detection switch provided on the lower side of the detection rod; a water supply system operated by the water level detection switch to supply water to the water tank; Strand breakage detection device consisting of an activated alarm device. (2) The strand breakage detection device according to claim 1, wherein the biasing member is a coil spring. (3) The strand breakage detection device according to claim 1 or 2, wherein the water level detection switch and the weight detection switch are micro switches.