JPS60110423A - Extrusion heating molding machine - Google Patents

Abstract

PURPOSE:To contrive uniform heating and temperature rise of raw materials, by turning a screw of an extruder and a sharing mandrel of a heater by the same electric motor. CONSTITUTION:Both a screw 13 and a sharing mandrel 12 are connected mechanically by a driving shaft 23a of the same electric motor 23 with each other, and when the electric motor 23 is driven, raw materials are carried to a heater 2 by plasticizing the raw materials through turning of a screw 3 and heating and a temperature rise of the raw materials are done by turning the sharing mandrel 12. A rotary speed of the screw 3 is varied by a variation of viscosity of the raw materials during operation of the titled molding machine. In this instance, as the rotary speed of the sharing mandrel 12 is varied according to the variation of the rotary speed of the screw 3, heating through the sharing mandrel is adjusted naturally, harmony is kept between an extruder 1 and the heater 2 and uniform molding terms can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an extrusion heating molding machine used in the field of molding of rubber, plastics, etc. One type of extrusion force molding machine is known as an extrusion heat molding machine having a configuration including an extrusion device having a screw and a heating device having a shearing mandrel. This extrusion thermoforming machine usually uses unvulcanized rubber or thermosetting resin as a raw material, compresses and plasticizes the raw material by rotating a screw, and supplies it to a heating device.The supplied raw material is shared by the heating device. The rotation of the mandrel applies mechanical shear to the cylinder wall, and the frictional heat generated at this time heats the raw material to the temperature required for vulcanization or hardening, and then extrudes the raw material to form it. It is something to do.

[Prior Art] Conventional extrusion thermoforming machines have a structure in which the screw of the extrusion device and the shearing mandrel of the heating device are rotated by separate electric motors, which causes the following problems. That is, the amount of raw material supplied from the extrusion device to the heating device varies considerably depending on the viscosity and temperature of the material used. For example, when the viscosity of the raw material is low, the resistance of the screw decreases, so the rotational speed of the screw increases, resulting in an excessive amount of raw material being supplied from the extrusion device into the heating device. In this case, since the rotation of the shearing mandrel is kept constant, the heating by the heating device is not sufficient, and the temperature of the extruded product extruded by the heating device is low. This makes it difficult to perform appropriate vulcanization or hardening. As a result, there was a problem that the performance of the completed product deteriorated. On the other hand, if the amount supplied from the extrusion device to the heating device is too small, the temperature of the raw material in the heating device will rise excessively because there is too little raw material, and a vulcanization reaction will occur in the heating device. However, there were problems such as the raw material becoming vulcanized in the heating device, making it impossible to mold it.

Furthermore, in the conventional method in which the screw and the shearing mandrel are rotated by separate electric motors, a corresponding amount of space is required, and this method is disadvantageous. Furthermore, the electric motors had to be operated separately, making the operation complicated.

[Purpose of the invention] The present invention has been made in view of the above-mentioned prior art.

An object of the present invention is to provide an extrusion thermoforming machine that can uniformly heat and raise the temperature of raw materials.

[Structure of the Invention] The extrusion thermoforming machine of the present invention includes an extrusion device that plasticizes a raw material by rotation of a screw, and a heating device that heats the raw material supplied from the extrusion device by rotation of a shearing mandrel. The thermoforming machine is characterized in that the screw of the extrusion device and the shearing mandrel of the heating device are rotated by the same electric motor.

The main components of the extrusion thermoforming machine of the present invention are an extrusion device that plasticizes the raw material and extrudes it to the heating device, and a heating device that heats the raw material extruded from the extrusion device to a predetermined temperature and extrudes it. . As raw materials, unvulcanized rubber, anti-sand plastic, etc. can be used.

The extrusion device has a screw. This screw is usually rotatably housed within a cylinder.

The screw has a shaft and grooves provided at a predetermined pitch around the shaft. When the shaft is rotated to turn the screw, the raw material inside the cylinder is plasticized and transported forward. This screw is similar to the screw used in ordinary extrusion molding machines, and generally L/D
It has a length of 10 to 20, and by changing the pitch or depth of the screw-shaped grooves provided on its surface, a compression ratio of about 1.2 to 2.0 is provided. It is now possible to pressurize the raw material and supply it to the heating device. Further, as the screw, a vent type screw for discharging moisture, air, etc. contained in the raw material may be used.

The heating device has a shearing mandrel.

The shearing mandrel is normally rotatably housed within a cylinder communicating with the cylinder housing the screw. In this case, the shearing mandrel is usually rotatably housed with respect to the inner wall of the cylinder so as to have a clearance equivalent to 5 to 20% of the outer diameter of the shearing mandrel. When this shearing mandrel rotates, mechanical shearing force acts on the raw material filled in the clearance,
The friction generated at this time generates heat in the raw material and raises the temperature to the required temperature. The raw materials whose temperature has been raised in this manner are sequentially shaped and extruded from the machine by a die, and then kept at a temperature for a predetermined period of time by a heat insulating means such as hot air to complete vulcanization.

Now, in the extrusion thermoforming machine of the present invention, the screw of the extrusion device and the shearing mandrel of the heating device are rotated by the same electric motor. As the electric motor, a series-wound motor, a shunt-wound motor, a compound-wound motor with characteristics intermediate between the series-wound and shunt-wound motors, an induction motor, etc. can be used.

In this case, it is desirable to add a control mechanism for controlling the appropriate rotational speed. A configuration in which the screw and the shearing mandrel are rotated by the same electric motor means that both the screw and the shearing mandrel are mechanically connected to the drive shaft of the same electric motor, and when the electric motor is driven, the screw and the shearing mandrel rotate together. It is. A power transmission mechanism may be used for mechanical connection.

As the power transmission mechanism, at least one of a transmission device such as a pulley, a belt, or a chain, a speed reduction device, etc. can be used. In particular, it is desirable to provide a transmission between the sharing mandrel and the electric motor. This is to change the rotational speed ratio between the screw and the shearing mandrel depending on the properties of the raw material. For example, when the extrusion temperature of the raw material is increased, the transmission is operated to increase the rotational speed of the shearing mandrel to promote heat generation due to shearing. Conversely, if it is desired to lower the extrusion temperature, the rotation speed of the shearing mandrel is lowered to control heat generation due to shearing. Therefore, it is desirable that the transmission be able to be adjusted steplessly. Normally, if the outer diameters of the screw and shearing drill are about the same, the number of revolutions of the screw is 20~? O
rpm, the number of revolutions of the shearing mandrel is 40 to 12
It is preferable to use approximately 0 rpm. Note that the axis of the shearing mandrel and the axis of the screw may be oriented parallel to each other, or may be oriented in directions that intersect with each other depending on the case.

Now, in the above-mentioned extrusion heat molding machine, when the electric motor is driven, the screw rotates to plasticize the raw material and transport it to the heating device, and the shearing mandrel of the heating device rotates to heat and heat the raw material. It will be done.

The heated raw material is extruded out of the machine from the tip of the shearing mandrel. During operation of an extrusion heating molding machine, the rotational speed of the screw may fluctuate due to changes in the viscosity of the raw materials. This is because the negative flange torque applied to the motor changes depending on the viscosity of the raw material, and the rotational speed of the motor changes. In this case, the rotational speed of the shearing mandrel rotated by the electric motor also varies accordingly. Therefore, the heating by the shearing mandrel is also naturally adjusted. That is, in the extrusion heat molding machine of the present invention, even if the viscosity of the raw material changes and the rotational speed of the electric motor changes, the extrusion device and the heating device can maintain harmony and uniform molding conditions can be maintained. I'll keep it.

[Effects of the Invention] As described above, according to the present invention, even when the rotational speed of the screw fluctuates, the temperature of the raw material can be raised uniformly.

Furthermore, the present invention, in which the screw and the sharing mandrel are rotated by the same electric motor, is more economical and requires less space than the conventional structure in which the screw and the sharing mandrel are rotated by separate electric motors. Furthermore, there is no need to worry about operating separate electric motors.

[Example] The drawing is an example of the present invention. The main components of the extrusion thermoforming machine of this example are an extrusion device 1 and a heating device 2.

The extrusion device 1 includes a screw 3, a cylinder 4 that rotatably accommodates the screw 3, a rotating shaft 5 that rotates the screw 3, and a feed roller 6. The rotation axis δ is rotatably supported by bearings 8 and 9.

9- A warm water channel 10 is formed inside the cylinder 7.

The heating device 2 includes a shearing mandrel 12, a cylinder 13 that rotatably houses the shearing mandrel 12, and a rotating shaft 15 that rotates the shearing mandrel 12.

The cylinder 13 communicates with the cylinder 4 via the passage 11. The rotating shaft 16 is rotatably supported by bearings 16, 17, 18.

A warm water channel 21 is formed inside the cylinder 13 .

Further, a rectifying ring 22 is provided at the front of the cylinder 13.

Now, in this example, the rotating shaft 15 that rotates the sharing mandrel 12 and the rotating shaft 5 that rotates the screw 3
Both are configured to be rotated by an electric motor 23.

That is, the screw 3 is configured to be rotated by an electric motor 23, and a joint 24 is provided on the drive shaft 23a of the electric motor 23, a reduction gear 25 is provided in front of the joint 24, and a pulley 10-26 connected to the reduction gear 25 is provided. Furthermore, a pulley 27 is provided at the base end of the rotating shaft 5 that rotates the screw 3, and the pulley 27 and the pulley 26
A timing belt 28 is stretched between the two, and the rotation of the electric motor 23 is thereby transmitted to the screw 3.

On the other hand, the sharing mandrel 12 is configured to be rotated by an electric motor 23, and a pulley 29 is provided on a drive shaft 23a of the electric motor 23, and a belt 30 and a pulley 31 are further provided to transmit the rotation of the pulley 29. Further, a continuously variable transmission 32 is provided at the front of the pulley 31, and the continuously variable transmission 3
A deceleration device 33 is provided at the other end of 2. And reduction gear 3
A timing belt 36 is stretched between a pulley 34 connected to the motor 3 and a pulley 35 provided on the rotating shaft 16, and the rotation of the electric motor 23 is transmitted to the sharing mandrel 12.

In the extrusion heating molding machine configured as described above, the electric motor 23
When energized and driven, the screw 3 of the extrusion device 1 rotates, and the shearing mandrel 12 of the heating device 2 also rotates. In -11-, when unvulcanized rubber is charged as a raw material into the extrusion device 1, this unvulcanized rubber is plasticized as the screw 3 rotates and is transported to the front of the extrusion device 1. Furthermore, passage 11
is supplied into the cylinder 13 of the heating device 2 through. Then, the plasticized unvulcanized rubber is stirred with the wall surface of the cylinder 13 by the rotation of the shearing mandrel 12. At this time, shear force acts on the unvulcanized rubber between the wall surface of the cylinder 13 and the shearing mandrel 12, generating frictional heat, and as a result, the unvulcanized rubber reaches the temperature required for vulcanization. The temperature is raised.

Then, the heated unvulcanized rubber is extruded from the rectifying ring 22 into a predetermined shape through an orifice 40 provided in an extrusion die, and is kept warm for a predetermined period of time by a heat insulating means such as hot air (not shown) to be vulcanized.

Incidentally, even if the viscosity of the unvulcanized rubber that has been plasticized by the screw 3 increases considerably and the negative torque applied to the electric motor 23 increases and the rotational speed of the electric motor 23 decreases, the rotational speed of the electric motor 23 decreases. As the rotational speed of the sharing man 12-drel 12 decreases, the rotational speed of the sharing man 12-drel 12 also decreases. That is, as the amount of raw material fed into the heating device 2 by the screw 3 decreases, the rotational speed of the shearing mandrel 12 also decreases accordingly. Therefore, the temperature of the extruded product extruded from the heating device 2 can be ensured appropriately.

In this example, since a continuously variable transmission device 32 is provided between the sharing mandrel 12 and the electric motor 23,
By appropriately operating the continuously variable transmission device 32, the extrusion temperature of unvulcanized rubber can be set regardless of the extrusion amount. That is, when the heat generation of the rubber in the heating device 2 is small, the continuously variable transmission device 32 is operated to increase the rotational speed of the shearing mandrel 12. Conversely, if the rubber in the heating device 2 generates too much heat, the continuously variable transmission 32 is operated to reduce the rotational speed of the shearing mandrel 12 to control the heat generation.

[Brief explanation of the drawing]

The figure shows one embodiment of the present invention, and is a plan view of an extrusion heating molding machine showing a main part in cross section. In the figure, l is an extrusion device, 2 is a heating device, 3 is a screw,
12 is a sharing mandrel, 23 is an electric motor, 24 is a joint, 25 is a reduction gear, 32 is a continuously variable transmission, and 33 is a reduction gear. Patent applicant: Toyoda Gosei Co., Ltd. Agent Patent attorney: Hirotoshi Okawa Patent attorney: Jodo Fujitani Patent attorney: Akio Maruyama 14-

Claims (2)

[Claims] (1) An extrusion thermoforming machine including an extrusion device that plasticizes the raw material by rotation of a screw, and a heating device that heats the raw material supplied from the extrusion device by rotation of a shearing mandrel, the screw of the extrusion device; And an extrusion thermoforming machine characterized in that the sharing mandrels of the heating device are configured to be rotated by the same electric motor. (2) The extrusion heating molding machine according to claim 1, wherein the sharing mandrel has a transmission device between it and the electric motor.