JPH0349865Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in a water-cooled heater that is attached to an extrusion cylinder in a synthetic resin extrusion molding machine in order to prevent the extrusion cylinder from overheating.

Conventional water-cooled heaters of this type include
As described in Japanese Patent No. 30668, there is a heat transfer plate in which an open and meandering groove is provided in the plate surface, and a water cooling pipe is removably fitted into the groove.

This water-cooled heater has a problem in that the gap between the water-cooled pipe and the groove reduces the rate at which heat from the heat exchanger plate is transferred to the water-cooled pipe, thereby reducing the water-cooling effect accordingly.

Furthermore, as described in Japanese Utility Model Application Publication No. 57-39722, a cavity for passing a cooling pipe is provided in the mold body, and on the same side as the molding surface of the cavity,
In a heater with water cooling, the hollow part is made of a metal material with good thermal conductivity, and the inner peripheral surface has the same shape as the outer peripheral surface of the water cooling pipe. is provided within the wall thickness of the mold body, so the cavity cannot be provided in a meandering manner, nor can the water cooling pipe be formed in a meandering manner and removably passed through the cavity. Even if it were possible, it would require special technology and would be impractical. Furthermore, since the entire space between the water cooling pipe and the cavity is not filled with the heat transfer material, the water cooling effect becomes uneven. Further, there are other problems such as the work of replacing water cooling pipes and the work of arranging metal materials becomes complicated.

The present invention aims to provide a water-cooled heater that can solve the above-mentioned conventional problems.

Below, an embodiment of the present invention will be explained based on the drawings. 1 is a heat transfer material, which is a pair of semicircular shapes made of a material that easily conducts heat, such as aluminum, steel, boron, or iron. The plate pieces 2, 2 are pressed against each other in a cylindrical shape, and the entire inner wall thereof is molded so as to be in contact with the outer peripheral surface of an extrusion cylinder in a synthetic resin extrusion molding machine. 3, 3 are each plate piece 2, 2
Power supply connection ends 4, 4 are made to protrude from one end side of each plate piece 2, 2 using a heating wire such as a sheathed wire cast in a meandering manner within the thickness of the plate. Reference numerals 5 and 5 indicate grooves that are open to the outer surface of each of the plate pieces 2 and 2 and are provided in a meandering manner; 6 and 6 are water cooling pipes that are removably fitted along the respective grooves 5 and 5; An inlet 7 and an outlet 8 for water are made to protrude from the other end side of each plate piece 2,2. Reference numeral 9 denotes a heat-resistant filler filled between the water cooling pipe 6 and the groove 5, such as heat transfer cement, silicone, putty, sealing material, etc., as shown in the third figure. Various materials can be used that are solidified so as to fill the entire gap between them and that can be peeled off from the groove 5 when the water cooling pipe 6 is removed. Reference numeral 10 denotes a band that tightens the outer peripheral surfaces of the plate pieces 2, 2 which are cylindrically butted against each other.

Next, to explain how to use the water-cooled heater constructed as described above, the outer circumferential surface of the extruded cylinder is sandwiched between the plate pieces 2, 2, and the plate pieces 2, 2 are butted against each other in a cylindrical shape, and the outer circumferential surface is held by the band 10. Tighten to complete the heater installation.

Then, electricity is applied to the heating wires 3, 3, and the generated electric heat is transferred from the heat exchanger plate 1 to the extrusion cylinder to heat it,
Extrude. When the extrusion cylinder is overheated beyond a predetermined temperature, a temperature detection device is activated,
Water is passed through the water cooling pipes 6, 6 for cooling, and when the water is cooled to a predetermined temperature, a temperature detection device is activated to stop the water flow.

The present invention is not limited to the above-mentioned embodiment, but as shown in FIG. In some cases, a filler material 9 may be filled between the water cooling pipe 6 and the groove 5, and the shape and depth of the groove 5 may be arbitrarily changed.
Furthermore, as shown in Figure 6, the heating wires 3 may be disposed between the water cooling pipes 6 and cast into the heat exchanger plate 1, and the heat exchanger plate 1 may not be separated into semicircular shapes. The design may be changed as appropriate, such as integrally molded into a cylindrical shape or deformed to match the shape of the object to be heated.

In this invention, as mentioned above, since the space between the water-cooled pipe and the groove is filled with a filler, the heat of the heat exchanger plate is transmitted to the pipe wall of the water-cooled pipe through the filler.
Compared to a conventional water-cooled heater that is not filled with a filler, the rate at which heat from the heat exchanger plate is transmitted to the water-cooled pipe increases, making it possible to provide a water-cooled heater with an improved water-cooling effect. Moreover, the meandering water cooling pipe can be opened in the surface of the electric heating plate and stably held inside the meandering groove by the filling material. In addition, if water scale adheres to the inner wall of the water cooling pipe and reduces the water cooling function, or if the inlet or outlet of the water cooling pipe breaks and loses the water cooling function, scrape off the filler material with an appropriate tool. Then, remove the water cooling pipe from the groove of the heat exchanger plate, remove the filler remaining in the groove, fit the new water cooling pipe into the groove, and reinstall the filler between the water cooling pipe and the groove. By filling, the water cooling function can be restored, and the entire heater does not have to be replaced with a new heater, which is economical. It also has the advantage of simplifying the work of replacing water cooling pipes and filling the filler material. have

[Brief explanation of drawings]

Fig. 1 is a front view of a heater with water cooling according to the present invention, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, Fig. 3 is an enlarged sectional view of the main parts, and Fig. 4 is a view similar to Fig. 1. FIG. 5 is a sectional view showing another embodiment of the present invention, and FIG. 6 is a sectional view showing still another embodiment of the present invention. 1... Heat transfer plate, 2... Plate piece, 3... Heating wire, 4
...Power connection end, 5...Groove, 6...Water cooling pipe,
7...Inflow port, 8...Outflow port, 9...Filling material, 1
0...Band.

Claims (1)

[Scope of utility model registration request] A heating wire such as a sheathed wire is buried within the thickness of a heat transfer plate attached to an extrusion cylinder in a synthetic resin extrusion molding machine, and the heat transfer plate is provided with an open and meandering groove on the plate surface, In a water-cooled heater in which a water-cooled pipe is removably fitted along the groove, the entire gap between the water-cooled pipe and the groove is filled with a heat-resistant filler such as heat transfer cement, and after filling, the A water-cooled heater whose entire space is filled with a solidifying material.