JPS6361749B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sensor-added heat cartridge for heating a hot runner mold nozzle.

The gate part of a hot runner mold is located at the boundary between the cooled part and the heated part, and incorrect heat management in this part will not only impair the quality of the molded product but also determine whether or not the molding itself can be completed. It is considered the most important part. Therefore, several proposals have been made regarding structures for heating and controlling the temperature of the jacket whose tip is located at the center of the gate.

In the conventional device shown in FIG. 1, a cartridge heat source 11 with a sensor is inserted into a jacket 10. 12 is an outer cylinder, and a material passage is formed between the outer cylinder 12 and the jacket. When the cartridge heat source 11 and temperature sensor T are configured separately from the jacket in this way, the problem arises that the heat of the heater 11 disposed inside the cartridge is difficult to be transmitted to the tip of the jacket 10, and the temperature at the tip of the jacket cannot be detected. arise. When trying to maintain the tip of the jacket 10, which dissipates the most heat, at a desired temperature,
It becomes necessary to raise the temperature of other parts higher than necessary, which may not only cause decomposition of the material resin or other changes in quality, but also cause the gate hole to close due to resin leakage from the gate hole, or to lower the temperature at the tip to an appropriate temperature. Since it was difficult to maintain the material, there was a problem that the material near the gate hole was likely to solidify. In the conventional example shown in FIG. 2, two types of heaters _H1 and _H2 are installed in the jacket 10 for the purpose of preventing material solidification and material leakage especially near the gate hole.
A portion of the H ₂ is exposed at the tip of the jacket 10 so that the material in that portion can be directly heated only when necessary. The energization of the heater _H1 that heats the entire jacket 10 is controlled based on the voltage detected by a sensor T attached to the inner wall of the jacket tube. Note that the temperature of heater _H2 is not controlled.

Although the conventional device shown in FIG. 1 allows the cartridge 11 to be replaced, there is a problem in that the tip of the jacket 10 cannot be heated sufficiently. Second
The device shown in the figure has the problem that the temperature at the tip cannot be controlled and that if a problem occurs with the sensor or heater, the entire jacket must be replaced. In short, with conventional devices, it has been impossible to sufficiently heat the tip of the jacket and control the temperature.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sensor-added heat cartridge that can solve the above-mentioned problems.

In order to achieve the above object, the sensor-added heat cartridge according to the present invention is a sensor-added heat cartridge for heating a hot runner mold nozzle. A heater wire that reaches the lower end from one side of a pair of holes, each having a center and passing through vertically symmetrically with the central axis, is pulled out from the other side to the upper end, and has a power supply terminal on the upper side, and a central axis of the cylinder. a second plane perpendicular to the first plane including
a sensor in which a lead wire is led to the upper end from a pair of holes having respective centers on the plane of the heater wire and are vertically penetrated symmetrically to the central axis, and a temperature detecting section is positioned across the lower side of the heater wire; A heat-resistant and insulating fixing member that protrudes from the center of the lower end to support the main body and seals the lower end of the main body.

If the cartridge having the above structure is inserted into a jacket having a hole in the center and a small hole in the center of the lower end of the hole to receive the sensor, the sensor can detect the temperature at the tip of the jacket. All problems can be solved and the objectives of the invention can be fully achieved.

The present invention will be described in more detail below with reference to the drawings and the like.

FIG. 3 is a perspective view showing an embodiment of the cartridge according to the present invention, FIG. 4 is a front view and a cross-sectional view with the lower end partially cut away, and FIG. 5 is a side view and a cross-sectional view. The cartridge body 1 is made of molded alumina porcelain or the like, and has heater holes 2a, 2b and sensor lead holes 3a, 3b extending vertically therethrough. A plane including the centers of the holes 2a and 2b and a plane including the centers of the holes 3a and 3b are perpendicular to each other at the central axis position of the cartridge body. The heater 4 is inserted from the bottom, and both ends reach the top and are connected to the heater leads 8,8. Leads 6, 6 of sensor 5
The heater 4 is also inserted from below and pulled out upward so as to straddle the horizontal portion of the heater 4. The positional relationship between the heater 4 and the sensor lead 6 in the cartridge body 1 is shown in FIG. After the heater 4 and sensor lead 6 are inserted in this manner, the tip of the sensor is fixed with a heat-resistant and insulating fixing member, and the lower end is sealed. As this fixing member, alumina (Al ₂ O ₃ ) powder mixed with a heat-resistant adhesive can be used. The tip end is shaped like a cone to fit into the jacket 10 shown in FIG. Note that in order to facilitate the molding of the fixing member, holes 2a,
It is preferable to seal alumina (Al ₂ O ₃ ) powder in 2b. The upper end of the cartridge body 1 is similarly sealed using alumina powder kneaded with adhesive.

An example of the use of the cartridge configured as described above will be explained with reference to FIG. 7. Jacket 1
0 is provided with a hole that can receive the cartridge main body 1, and a small hole that receives the sensor 5 is provided at the lower end of the hole. Therefore, the main body of the cartridge 1 is brought into close contact with the inner wall of the jacket 10, and the sensor 5 is also housed in close contact with the center of the front end of the jacket. 12 is an outer cylinder, and this outer cylinder 12
A material passageway is formed between the inner periphery of the jacket and the jacket.

As mentioned above, since the sensor can accurately detect the temperature of the tip of the jacket, which is the gate part, it is possible to accurately control the temperature of the gate part. Next, in the present invention, since the heater wire is housed in a U-shaped cartridge, the amount of heat generated at the tip where a lot of heat is dissipated is increased, which prevents the temperature from dropping at the tip and makes the temperature distribution uniform. can do. Maintenance is also easy because if the heater or sensor malfunctions, the cartridge can be replaced.

[Brief explanation of drawings]

FIGS. 1 and 2 are views showing conventional examples of a heating device for a hot runner mold nozzle, and are partially cut away to show the internal structure. FIG. 3 is a perspective view showing an embodiment of the cartridge according to the present invention, FIG. 4 is a front view and a cross-sectional view of the cartridge, and FIG. 5 is a side view and a cross-sectional view of the cartridge. is shown with the lower end cut away. FIG. 6 is a perspective view for explaining the arrangement of the heater and sensor in the cartridge, and FIG. 7 is a sectional view for explaining an example of use. 1... Cartridge body, 2a, 2b... Hole for heater, 3a, 3b... Hole for sensor lead, 4...
... Heater wire, 5 ... Sensor, 6 ... Sensor lead, 7 ... Heat-resistant fixing member, 8 ... Heater lead, 10 ... Jacket, 12 ... Outer cylinder.

Claims (1)

[Scope of Claims] 1. A sensor-added heat cartridge for heating a hot runner mold nozzle, which includes a porcelain cartridge main body cylinder and a first plane that includes the central axis of the cylinder, and is symmetrical to the central axis. The first plane includes a heater wire that reaches a lower end from one side of a pair of holes that are vertically penetrated through the cylinder, and is pulled out from the other side to the upper end and has a power supply terminal on the upper side, and a central axis of the cylinder. A lead wire is guided to the upper end through a pair of holes that are respectively centered on a second plane orthogonal to the heater wire and penetrate vertically symmetrically with the center axis, and a temperature detection section is positioned across the lower side of the heater wire. A cartridge for applying heat to a sensor, comprising a sensor and a heat-resistant and insulating fixing member that supports the sensor in a protruding state from the center of the lower end and seals the lower end of the main body. 2. The cartridge is used by being inserted into the center hole of the jacket, and a small hole for receiving the sensor is provided at the lower end of the center hole of the jacket, and the sensor inserted into the small hole causes the jacket to 2. The sensor-added heat cartridge according to claim 1, which is capable of detecting the temperature at the tip of the cartridge.