JPH07276452A - Melting and kneading screw in which surface temperature can be measured - Google Patents

Abstract

PURPOSE: To provide the subject melting/kneading screw high in coaxiality, low in cost and easy to deal with the trouble of a temp. sensor. CONSTITUTION: A melting/kneading screw 4 capable of measuring its surface temp. in a molding machine is constituted of a head 9, a main body portion 10 and a base portion 11. The main body portion 10 consisting of a plurality of cylindrical segments 17 is externally fitted to the shaft lever 12 of the head 9 and the rear end of the shaft lever 12 is screwed in the base portion 11 to integrally assemble the screw 4. Each segment 17 has a temp. sensor 7 in the vicinity of the outer peripheral surface thereof and the lead wire 22 is led out to the outside through the guide passage 14 formed to the shaft lever 12. The temp. sensor 7 is mounted on the segment 17 in parallel to the outer peripheral surface thereof according to circumstances.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw for melting and kneading a resin inside a heating cylinder of a molding machine such as an injection molding machine and an extrusion molding machine, and capable of measuring the temperature of the screw surface. Regarding screws.

[0002]

2. Description of the Related Art A molding machine such as an injection molding machine or an extrusion molding machine (referred to as a molding machine) has an injection unit, and a resin as a molding material is melted inside a cylinder assembly 1 (FIG. 6) provided in the injection unit. Kneaded. Cylinder assembly 1
In the above, the heating cylinder 2, the heater 3 for heating wound around the surface of the heating cylinder 2, and the screw 4 (screw 4) for melting and kneading are installed inside. Reference numeral 5 is an injection nozzle (the injection molding machine is shown). Further, the screw 4 is usually a precision grinding / polishing work of tool steel as a whole.

The melting and kneading of the resin is performed by the action of compression and kneading by the heater 3 and the screw 4 mounted on the heating cylinder 2. At this time, the temperature of the molten resin and the molten resin are received in the heating cylinder 2. It is important how much the total amount of heat is, and if the temperature is low and the amount of heat is insufficient, the resin will not be sufficiently melted and kneaded, and a satisfactory molded product cannot be obtained. On the contrary, when the temperature is higher than necessary and the amount of heat becomes excessive, the molten resin begins to deteriorate and decompose inside the heating cylinder 2, and the molded product is colored and decomposed gas is mixed, so that the molded product also becomes defective.

Therefore, as shown in FIG. 6, the heater 3 is divided into a plurality of parts in order to precisely control the internal temperature of the heating cylinder 2, and a plurality of temperature sensors 6 such as thermocouples are embedded in the thick portion of the heating cylinder 2. Then, the temperature information inside the cylinder obtained from this is processed by the control device provided in the molding machine to finely control the temperature of each heater 3.

By the way, the surface temperature of the screw 4 is scarcely measured, although the quality of the molten resin may change on the surface of the screw 4. Moreover, when measuring the surface temperature of the screw 4, as shown in FIG.
The temperature information obtained is not accurate because it is attached to the hole 8 formed in the thick portion of the screw 4 in the radial direction. That is, the hole 8 formed in the radial direction has a large temperature gradient from the inner surface side to the surface side, and the temperature sensor 7 is affected by heat conduction due to this temperature gradient.

In addition to that, when a radial hole 8 is formed in the screw 4 or a temperature sensor 7 is welded to this hole, the integrally formed screw 4 which is long in the axial direction is deformed by processing stress or thermal stress. It is easy, and the coaxiality (the degree of coincidence with the regular screw axis) may be greatly changed. Moreover, if even one of the temperature sensors 7 of the screw 4 formed in this way fails, the repair,
The replacement work is very difficult.

Further, the screw 4 having such a structure and capable of measuring the surface temperature is expensive, and it is extremely difficult to provide all the screws of various types and standards which are normally used with the surface temperature measuring function. It will be expensive.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a screw for melting and kneading, which has a high degree of coaxiality, is inexpensive, and is capable of measuring a surface temperature which can easily cope with a failure of a temperature sensor.

[0009]

The present invention relates to a screw for melting and kneading in a molding machine, the screw being capable of measuring the surface temperature. The screw is composed of a head, a main body and a base. The head has a shaft rod whose axis coincides with the screw axis. The shaft rod is formed with a guide path for a lead wire in the axial direction and a screw portion on the base side.

The main body is constructed as a set of a plurality of tubular segments, each of which is formed by axially dividing a tubular body having a flight on its outer peripheral surface and having a through hole in the axial direction. A temperature sensor is embedded in each segment close to the outer peripheral surface between the flights. A female screw hole into which the screw portion of the shaft rod is screwed is formed in the base portion.

The segments are sequentially inserted into the shaft rod of the head, and the screw portion of the shaft rod is screwed into the female screw hole of the base portion, so that the head, the main body portion and the base portion are aligned with each other along the screw axis and integrally assembled. To be The lead wire of each temperature sensor is led to the outside from the base portion through the guide path of the rod.

It is preferable that the temperature sensor is arranged in a groove formed on the outer peripheral surface between the flights substantially parallel to the outer peripheral surface and fixed by silver sticking.

[0013]

[Operation] The structure consisting of a head with an axial rod, a body and a base made up of multiple cylindrical segments makes it possible to attach a temperature sensor to the screw for melting and kneading without changing the coaxiality. To The configuration in which the main body is made up of a plurality of tubular segments enables repair by exchanging each segment and deformation into a screw having another performance / standard by exchanging the segment.

[0014]

EXAMPLE FIG. 2 shows a melting / kneading screw 4 (hereinafter referred to as screw 4) in an injection molding machine as an example of a molding machine. The intermediate portion in the direction of the screw axis a is omitted. The screw 4 is entirely made of tool steel and includes a head 9, a main body 10 and a base 11. As shown in FIG. 1, the head 9 is a disk that constitutes the front end of the screw 4, and a shaft rod 12 is integrally fixed from the center to the rear of the disk. The shaft rod 12 is a round bar, the axis line of which coincides with the screw axis line a, and the threaded portion 13 is formed at the rear end portion. In addition, as shown in a cross section in FIG.
2 is a guideway 1 which is groove-shaped in the longitudinal direction across the center of the cross section.
4 and key groove 15 are engraved up to the position of the screw portion 13.

The body 10 is a tubular body having a flight 16 on the outer peripheral surface as a whole, but is formed of a plurality of segments 17 divided in the direction of the screw axis a (FIGS. 1 and 3). . Each segment 17 has a through hole 18 in the axial direction, and a key groove 19 in the screw axis line a direction is formed in the through hole 18. Through hole 18
The diameter of the shaft rod 12 is substantially equal to the outer diameter of the shaft rod 12 so that the shaft rod 12 can be fitted without backlash.

Each segment 17 has a through hole 18 in the front surface.
From the through hole 18 to the outer peripheral surface and a mounting groove 20 for the key formed in the radial direction from the through hole 18 in the front surface.
However, the mounting groove 2 connected to the mounting groove 20 on the outer peripheral surface
1 is formed. The mounting groove 21 is formed in the screw axis a direction at a position between the flights 16 in the main body 10 and is a little deeper than the thickness of the temperature sensor 7 arranged therein.

Then, the mounting groove 21 of each segment 17
A temperature sensor 7 such as a thermocouple is arranged in the and is fixed by silver sticking. In this case, the temperature sensor 7 is laid on the bottom surface of the mounting groove 21 and arranged parallel to the outer peripheral surface.
Further, since the depth of the mounting groove 21 is slightly deeper than the thickness of the temperature sensor 7, the temperature sensor 7 is embedded close to the outer peripheral surface of each segment 17. The lead wire 22 of the temperature sensor 7 is fitted into the mounting groove 20 and guided to the through hole 18.

The base 11 has a female screw hole 23 at the center of the front surface.
(FIG. 2) is engraved, and a lead-out groove 24 of the lead wire 22 is formed along the female screw hole 23 to the rear of the female screw hole 23, and the rear end is open to the outside. Code 25
Is for obtaining a rotational force from the screw sleeve of the injection unit at the spline portion.

The end faces (front face, rear face) of each segment 17 and the through holes, the diameter of the shaft rod 12 and the linearity in the direction of the axis a are precisely machined. Since each segment 17 has a structure in which the length is relatively small with respect to the diameter and has high rigidity, it is less likely to be deformed by mechanical processing or thermal processing such as silver sticking.

In the screw 4 composed of the above-mentioned members, the segments 17 are successively fitted and inserted into the shaft rod 12 of the head 9, and the key 26 (FIG. 4) is used to insert the key groove 15 of the shaft rod 12 and the through hole of each segment 17. After the rotation of each segment with respect to the shaft rod 12 is blocked by fitting over the fitting groove 19 in, the screw portion 13 of the shaft rod 12 is screwed into the female screw hole 23 of the base portion 11 to be integrally assembled. At this time, each temperature sensor 7
Lead wire 22 from the mounting groove 20 to the guide path 14 of the shaft rod 12.
And each segment 17 is mounted. The lead wire 22 is finally exposed to the outside through a lead-out groove 24 at the rear part and connected to a device such as a telemeter connected to a control device. Further, by accurately fitting each segment 17 to the shaft rod 12, the head 9, the main body portion 10 and the base portion 1 are
1 is aligned along the screw axis a.

The screw 4 thus constructed is used inside the heating cylinder 2 of the injection molding machine, and the plurality of temperature sensors 7 mounted on the screw 4 allow the screw 4 to be installed.
The surface temperature of can be detected. In this case, since each temperature sensor 7 is attached to the outer peripheral surface of the screw 4 so as to crawl (parallel to the outer peripheral surface), the temperature gradient is larger than that in the case where the temperature sensor 7 is mounted in the conventional radial mounting hole. Hardly affected by.

If any of the plurality of temperature sensors 7 is found to be malfunctioning, the segment to which the temperature sensor 7 is attached is removed and repaired. Alternatively, the entire segment 17 may be replaced. Further, the screws 4 having different flight pitches and flight groove depths can be obtained by exchanging the segments 17.

Although the above is an example of the injection molding machine, the present invention can be applied to other molding machines such as an extrusion molding machine that use a screw for melting and kneading. Further, the present invention is not limited to the illustrated specific configuration. For example, the guide rod 14 for guiding the lead wire 22 of the temperature sensor 7 through the shaft rod 12 has a pipe structure.
Sometimes.

[0024]

EFFECTS OF THE INVENTION In the melting / kneading screw capable of measuring the surface temperature, it is extremely easy to replace and repair a plurality of temperature sensors. Since unnecessary stress is not applied in the processing and assembling steps, it is possible to obtain a melting / kneading screw capable of highly coaxial surface measurement.
Since the temperature sensor is arranged close to the outer peripheral surface of the screw, the screw surface temperature can be accurately grasped. In this case, if the temperature sensor is arranged parallel to the outer peripheral surface of the segment, the screw surface temperature can be detected more accurately. By combining various segments with different flight pitch and flight groove depth,
Various types of screws with different performances and specifications can be obtained at a relatively low cost.

[Brief description of drawings]

FIG. 1 is a front view (partially sectional view) of a screw that is disassembled and shown.

FIG. 2 is a front view of a screw.

FIG. 3 is a perspective view of a segment.

FIG. 4 is a sectional view of a shaft rod portion.

FIG. 5 is a front view of a screw (conventional example).

FIG. 6 is a front view (partial cross section) of the cylinder assembly.

[Explanation of symbols]

 1 Cylinder Assembly 2 Heating Cylinder 3 Heater 4 Screw 5 Injection Nozzle 6 Temperature Sensor (Cylinder) 7 Temperature Sensor (Screw) 8 Radial Hole 9 Head 10 Main Body 11 Base 12 Shaft Rod 13 Screw Part 14 Guideway 15 Key Groove 16 Flight 17 Segment 18 Through hole 19 Fitting groove 20 Mounting groove 21 Mounting groove 22 Lead wire 23 Female screw part 24 Outlet groove 25 Spline 26 Key

 ─────────────────────────────────────────────────── ─── Continuation of front page (71) Applicant 590000422 Minnesota Mining and Manufacturing Company Minnesota, USA 55144-1000, St. Paul, 3M Center (No address) (71) Applicant 000002174 Sekisui Chemical Co., Ltd. Osaka Prefecture 2-4-4 Nishitenma, Kita-ku, Osaka (71) Applicant 000003001 Teijin Limited 1-6-7 Minamihonmachi, Chuo-ku, Osaka-shi, Osaka (71) Applicant 000003458 Toshiba Machine Co., Ltd. 4 Ginza, Chuo-ku, Tokyo 2-11 (71) Applicant 000222587 Toyo Kikai Kinzoku Co., Ltd. 1-523 No. 523 Nishinoyama, Fukusato, Futami-cho, Akashi-shi, Hyogo (71) Applicant 000003193 Toppan Printing Co., Ltd. 1-5, Taito, Taito-ku, Tokyo No. 1 (71) Applicant 000003159 Toray Industries, Inc. Chuo-ku, Tokyo Nihonbashi Muromachi 2-2-1 (71) Applicant 000227054 Nissei Jushi Kogyo Co., Ltd. 2110 Nanjo, Sakagi-cho, Hanashina-gun, Nagano Prefecture (71) Applicant 390008235 FANUC Co., Ltd. 3580 Kobaba, Oshino-mura, Oshino-mura, Minamitsuru-gun, Yamanashi Prefecture Local (71) Applicant 390006323 Polyplastics Co., Ltd. 2-33-1 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka Prefecture (71) Applicant 000005887 Mitsui Petrochemical Co., Ltd. 3-5-3 Kasumigaseki, Chiyoda-ku, Tokyo ( 71) Applicant 390022655 Munekata Co., Ltd. 1-30 Tsujiko, Takatsuki City, Osaka Prefecture (71) Applicant 000010076 Yamaha Motor Co., Ltd. 2500, Shinkai, Iwata-shi, Shizuoka Prefecture (72) Wataru Shiraishi, Oshino Village, Minamitsuru-gun, Yamanashi Prefecture Ninbozo Kobaba 3580 FANUC Co., Ltd. (72) Inventor Hidetoshi Yokoi 7-22-1 Roppongi, Minato-ku, Tokyo Tokyo Institute of Industrial Science

Claims (2)

[Claims] 1. A screw for melting and kneading in a molding machine, comprising a head, a main body and a base, the head having an axial rod whose axis coincides with the screw axis, and the axial rod has an axial direction. The lead wire is provided with a guide path, and the base part is provided with a threaded part.The main body part has an axially divided cylindrical body with flights on its outer peripheral surface, and the body part is penetrated in the axial direction. It is configured as a set of a plurality of cylindrical segments having holes,
A temperature sensor is embedded in each segment in the vicinity of the outer peripheral surface between flights, and a female screw hole is formed in the base at which the threaded portion of the shaft rod is screwed, and the segment is attached to the shaft rod of the head. The head, the main body and the base are aligned and assembled integrally by screwing the shaft rod into the female screw hole of the base, and the lead wire of each temperature sensor is attached to the shaft rod. A melting / kneading screw capable of measuring the surface temperature, characterized in that the screw is led to the outside from the base via the guide path. 2. The melting / kneading according to claim 1, wherein the temperature sensor is arranged in a groove formed on the outer peripheral surface of the segment substantially parallel to the outer peripheral surface and fixed by silver sticking. Screw for.