JPS60172515A - Extruder - Google Patents

Abstract

PURPOSE:To prevent the wear of a screw while improving the production efficiency by bringing a single or a plurality of support rolls provided facing a feed roll into contact with the circumferential end of a spiral flight of the screw to rotate it at a circumferential velocity the same as that of the screw. CONSTITUTION:A support roll 12 has the circumferential surface 12a thereof brought into contact with the circumferential end 6a of the flight 6 of a screw 7. A gear 14 fitted into a sprine is meshed with a gear 13 mounted on the shaft 12b thereof and the rotating shaft 5 of the screw 7 to make the circumferential velocity of the flight 6 of the screw 7 invariably almost equal to that of the support roll 12. With such an arrangement, when a rubber slab is fed to the screw 7 with a feed roll 11 in the initial operation, the circumferential surface 12a of the support roll 12 is supported against a stress load due to the rubber being kept in contact with the circumferential end 6a of the flight 6 of the screw 7 to prevent the screw 7 from deflecting. Thus, there is no metallic contact between the screw 7 and a barrel 4. In addition, a high speed rotation of the screw 7 can heighten the rising speed in the initial operation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an extruder for a comb, and particularly to a structure near a feed roll arranged below a hopper mouth.

(Prior art) In general, in an extruder for combs, a rubber slab that has been heated and plasticized (heated) or a rubber slab that is not heated is fed from the upper hopper port, extruded by a screw using mechanical pressure, and decorated with decorative designs at the tip. Rubber of a desired cross section (for example, hollow comb products such as tubes and hoses, and rubber gaskets in the shape of 4S or window frames) is continuously formed through the die, making it easy to bite into the supplied rubber slab. In order to do this, the feed roll is disposed approximately directly below the popper opening so that its axis is approximately parallel to the rotational axis of the screw.

In addition, a plurality of pins are arranged on the inward surface of the barrel so as to protrude radially inward, and a plurality of pin rows are arranged at predetermined intervals in the longitudinal direction of the barrel. The discharge amount is 5θ~g based on the extrusion capacity for the extruder.
θ% also increases, and the extruder
%) is also known. This pin (q) extruder has a screw flight height higher than normal ones.In other words, it has a structure with a large valley depth.

By the way, when starting the extruder as described above, since there is no rubber between the extruder 4fi barrel and screw, the barrel temperature and screw temperature are set to higher temperatures than normal operating conditions. At the same time, to lower the viscosity of the comb supplied to the extruder, the comb is heated or warmed with a roll machine, and then the screw is rotated at low speed to pass it through the feed roll to the extruder. The gate between the barrel and screw is gradually filled with com. This is the difference between the feed roll and the screw.
The screw is subjected to a bending force +i by the comb slab inserted into the screw 111, and the screw receives twisting and twisting.Thl' (Il) of the screw The wear of the outer peripheral edge of the flight that occurs is prevented by absorbing one bite of the screw by a gap provided in advance between the outer peripheral edge of the flight and the inner peripheral surface of the barrel. .

As described above, since the screw is being rotated at a low speed in the initial stage of operation 1c, there is a turning point that reduces the production efficiency.

Incidentally, the space between the screw and the barrel is completely filled with rubber, and the rubber is in a compressed state of 1δ. The rubber received 4
Therefore, there is no metal contact between the barrel and the screw, and therefore there is no risk of wear on the outer periphery Q of the screw (flight).

However, the operating method of the extruder as described above is
In a pin (=J extruder), the screw and barrel may come into contact with each other until a certain amount of rubber slab has been supplied from the ho-noparo.

Namely, 1. Regarding the conventional extrusion machine and the pin-type extruder,
Comparing the flight heights of the J knee, the latter is generally higher than the 011. s ~ 7.3j times higher, and when comparing screws with the same diameter in terms of rotating shaft diameter, the diameter ratio of the 1 it 1 screw is higher than the latter /, /j ~ /,
, 2/times larger, and when comparing the rigidity of the screw with the diameter of the rotating shaft of the screw IJ unit, the latter is only 6F% of the bender's stiffness. Therefore, the latter is ri
Compared to IT people, they are subjected to the same stress load (!:,
, 2. /7~/, 7.2 times more screw deflection occurs, and in the case of the latter screw, in the early stage of operation, the hopper mouth (near q) contacts the inner peripheral surface of the barrel, causing local damage. As a result of repeated use, abrasive metal powder gets mixed into the product, resulting in a slight loss of quality and, when operated for a long period of time, a problem such as a drop in discharge capacity.

Therefore, in the case of the "Pinyi" extruder, the gap between the outer circumference 17ffij of the screw flight and the inner circumferential surface of the barrel is made larger than that of a normal extruder (for example,
7.2~,2. / 7 times), which would lead to another problem of lowering the extruder's discharge capacity.

(Objective of the Invention) The present invention aims to improve the raw PR efficiency in an extruder such as the above-mentioned one, and also suppresses melting between the inner circumferential surface of the barrel and the outer circumferential end of the helical flight of the screw. ,
The purpose is to actually prevent screw wear.

(Structure of the Invention) The present invention provides an extruder as described above, in which a single or plural support rolls are disposed in pairs between the feed rolls, and the support rolls contact the outer circumferential end of the spiral flight of the screw. It is characterized by rotating at an outer circumferential speed that is approximately the same as the outer circumferential speed of the screw.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

11. In Fig. 11 and Fig. 2, 1 is a pin-il J extruder, which is installed inside a barrel 4 in which a cylindrical first member 2 and a concave part 3 are connected, and a screw is attached to the outer periphery of a rotating shaft 5. A screw 7 formed with an M-shaped blade 6 is rotatably inserted through the first member 2, so that the plurality of pins 8 do not interfere with the scree 7 in the radial pronation direction on the inner peripheral surface of the first member 2. A plurality of pin rows (A in FIG. 1,
B)! R1 is being used. 9 is Lotu Knut.

Reference numeral 10 denotes a hopper mouth into which the comb slab is supplied, and a feed roll 11 is disposed below the hopper mouth.
A support roll 12 is disposed so as to be opposed to the roller 1 through a screw 7 and whose axis is substantially parallel to the screw 7.

The support roll 12 is in contact with its outer peripheral surface 12a or the outer peripheral end 6a of the flight A of the screw 7.

In addition, the first gear 16 and the second gear 14, which are connected to the rotary shaft 51 of the screw 7 and the spline 1, are attached to the support 12b.
The screws 7 are engaged with each other so that the outer circumference of the flight 6 of the screw 7 and the outer circumference of the support roll 12 are always at substantially the same speed, and the screw 7 is received by the comb slab passing through the gap S between the feed roll 11 and the screw 7. This is designed to prevent denting due to stress. If J notes feed roll 11 foot 11a + 1 piece fitted 3rd gear 15
The second gear 14i is also in mesh with the second gear 14i.

An undercut groove 16 is provided on the inner peripheral surface of the barrel 4 from a position near the feed roll 11.
The comb slab is attached to the screw 7 by the feed roll 11.
It makes it easy to bite into one. If the direction of the stress applied to the screw 7 changes in a complicated manner depending on the shape of the undercut groove 16 as the groove is filled with rubber due to the flights 6 of the screw 7, as shown in FIG. It is desirable to support the screw 7 with a plurality of support rolls 21,22.

As mentioned above, decay occurs when the comb slab is fed to the screw 7 by the feed roll 11 during the first stage of operation, and the flight 6 of the screw 7 responds to the stress load by the comb.
The outer circumferential end 6ai of the supporting roll 12 is always in contact with the outer circumferential surface 12a of the supporting roll 12 to support it and prevent the screw 7 from being bent. By rotating the screw 7 at a higher speed than in the extruder described above, the start-up speed at the initial stage of operation is faster, and production efficiency can be improved.

In particular, by suppressing wear, 1
This eliminates the possibility of metal powder getting mixed into the extruded product and resulting in a defective product, and the quality of the extruded product is stabilized. Further, it is possible to prevent the discharge amount from decreasing due to the progress of wear of the screw 7, and the production capacity from decreasing over time.

(Effects of the Invention) As described above, since the present invention suppresses the deflection of the screw at the initial stage of operation, it is possible to prevent thickening of the screw due to contact between the screw and the barrel. , above the number of revolutions of the screw JT-
It is possible to achieve the same level of production efficiency as above.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 shows a pin (q extrusion 1).
The overall configuration diagram of Figure 2 is similar to 1. of Figure 7. - A sectional view taken along the JJ line, FIG. 3 is a view similar to FIG. 2 regarding a modification. 1. Pinyq extruder, 4. Barrel, 6.
Flight, 6a...outer edge, 7...screw, 8...pin, 11...feed roll, 12...support f? j Roll, 12a...Outer peripheral surface, 21.22...Support roll Fig. 3

Claims (1)

[Claims] (1) Installed in the barrel inserted with a screw 7
j (- A feed roll is disposed below the hopper. 1. An extruder characterized in that the supporting roll contacts the outer circumferential end of the helical flight of the screw 1j and rotates at an outer circumferential speed substantially the same as the outer circumferential speed of the screw 1j.