JPS62168366A - Molding die for molding junction of heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a molding die for molding a connection portion for connecting a protruding terminal of a ceramic heater to an external wiring.

[Background technology]

Ceramic heaters with excellent corrosion resistance are used for heating developer solutions in developing devices. This heater has a heating element enclosed within the ceramic outer wall and functions as a heater.

This ceramic heater reaches a high temperature during firing, so resin-coated terminals cannot be used to protect the wiring, so the uncoated terminals connected to the heating element protrude.
This terminal must be connected to the external wiring from the power supply.

This connection part is preferably molded with an elastomer such as rubber in order to ensure reliable connection and to insulate it from the outside.

To do this, a ceramic heater is placed inside the mold and the connection portion is filled with molding material, but recesses are formed in the upper and lower molds to accommodate the external wiring. There is a need. However, if the external wiring is accommodated in the recess of one mold and then matched with the other mold, the external wiring will be sandwiched between the upper and lower molds in areas other than the recess, which may cause disconnection.

The present invention has been made in consideration of the above-mentioned fact, and an object of the present invention is to obtain a molding die that does not cause wire breakage even when the wire connection portion is integrally molded with an elastomer such as rubber.

C. Overview and operation of the invention] The molding die according to the present invention is a molding die having an upper die and a lower die for molding a connection portion for connecting a protruding terminal of a ceramic heater and an external wiring. , recesses for accommodating external wiring are formed in the upper and lower molds, and one of these recesses has a depth that accommodates most of the external wiring.

Therefore, when the upper and lower molding molds are joined together, the external wiring, which has already been largely accommodated in one mold, will not be pinched anywhere other than the recess, and there will be no possibility of disconnection of the external wiring. do not have.

[Embodiments of the invention]

FIG. 1.2 shows a mold according to an embodiment of the invention. This mold has an upper mold 10 and a lower mold 12, and a ceramic heater I4 is arranged between these to perform molding.

The protruding terminal 16 protruding from the ceramic heater 14 is connected to the conductive wire 18A of the external wiring 18 at a connection part 20, and this connection part 20 is placed in the cavity 22 formed by the upper mold 10 and the lower mold 12. It has become so. An injection port 24 is formed in the upper mold 10 so as to communicate with the cavity 22, so that a molten elastomer such as rubber can be filled from a mold pump (not shown).

A heater placement portion 26 is formed adjacent to the cavity 22 by the upper mold 10 and the lower mold 12. A partition wall 28 is provided between the heater placement portion 26 and the cavity 22, and a gap 3o is formed between the partition wall 28 and the outer periphery of the ceramic heater 14.
2 and the heater arrangement section 26 are communicated with each other.

As shown in Figure 3, the external arrangement &! 1l18 is inserted into the recesses 32.34 formed in the upper mold 10 and the lower mold 12,
This arrangement is such that when the upper mold 10 and the lower mold 12 are placed one on top of the other, they are sandwiched between them.

Here, the recess 34 is formed deeper than the recess 32,
Most (80% or more) of the external wiring A18 is accommodated in the recess 34. Therefore, even if the upper mold 10 and the lower mold 12 are matched with each other while the external wiring is inserted into the recess 34, the external wiring 18 will not be caught in the joining surface of the upper mold 10 and the lower mold 12. It is configured so that it does not.

For this reason, as shown in FIG. 2, the joint surfaces 36 between the upper mold 10 and the lower mold 12 are in a misaligned state after the third slope, and the ceramic heater 14 is in a state of misalignment in the vicinity of the heater placement portion 26. The shaft center portion can be used as the contact surface of the upper die 10 and the lower die 12. In the present invention, the joining surface 36 is not limited to such an inclined portion 38, but can also be changed into a stepped shape.

In this embodiment configured as described above, the external wiring 18 is connected to the protruding terminal 16 of the ceramic heater 14 using a crimp terminal or the like through the connection part 20, and the ceramic heater 14 to which the external wiring 18 is connected is connected to the protruding terminal 16 of the ceramic heater 14 in the heater arrangement part. Attach to 26. Here, the external arrangement 1118 is received within the recess 34 and joins the upper mold 10 and the lower mold 12. As a result, the connection portion 20 of the ceramic heater 14 is placed into the cavity 22 as shown in FIG.

In this case, since most of the external wiring 18 is already accommodated in the recess 34, the external wiring 18 is connected to the upper mold 10 and the lower mold 12.
It is possible to prevent the external wiring 18 from being accidentally pinched by a portion other than the recessed portions 32 and 34 between the external wirings 18 and 34, thereby preventing the external wiring 18 from being disconnected.

If the elastomer 40 is filled through the injection port 24, the connection portion 20 is integrally formed with the elastomer 40 together with a part of the coating of the external wiring 18 and a part of the ceramic heater 14, as shown in FIG. It is fixed and becomes insulated.

In this case, if the pressure of the molding material injected into the cavity 22 is high, it may cause internal pressure to be generated in the ceramic heater 14 and destroy the ceramic flange 14A, or it may become a force that pushes out the valve wiring 18. Tensile force is applied to the protruding terminals 16 and the crimp terminals 20, causing wire breakage. In this embodiment, since the cavity 30 is provided, a part of the mold material is absorbed into the cavity 30.
It escapes to the heater arrangement section 26 through the. Therefore, the pressure increase in the cavity 22 is suppressed to a predetermined value, and the ceramic flange 14A is prevented from breaking. At the same time, the tensile force acting on the connection portion 20, that is, the protruding terminal 16
Since the force that separates the external wiring 18 is also weaker, the connection part 2
There is no breakage at 0.

Moreover, this mold pressure acts as a force that presses the ceramic heater 14 in the left direction in FIG.
If the ceramic heater 14 is not supported by the upper mold, the mounting flange 14A formed at the middle part of the ceramic heater 14 may be destroyed. 10 and the lower mold 12, there is no risk of the mounting flange portion 14A being destroyed.

Note that these explanations are for injection molding and rim molding, but compression molding can also be handled in the same way, although the injection port 24 is not required.

In the above embodiment, the cavity 30 is provided between the cavity 22 and the heater arrangement part 26, but the cavity 30 is formed by providing holes in other parts of the upper mold 10 and the lower mold 12 to communicate the cavity 22 with the outside. It is also possible to assign a similar role.

〔Effect of the invention〕

As explained above, the present invention provides a mold having an upper mold and a lower mold for molding a connection part for connecting a protruding terminal of a ceramic heater and an external wiring, the mold having an upper mold and a lower mold. In addition, one of these recesses is deep enough to accommodate most of the external wiring, so that the external wiring is not sandwiched between the molds. It has no good effect.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a molded state showing an embodiment of a mold for a heater connection part according to the present invention, FIG. 2 is a side view showing a joined state of the molds, and FIG. 3 is a separated state of the molds. The second shown
FIG. 4 is a side view corresponding to the right side view in the figure, and a front view showing the ceramic heater after molding. IO... Upper mold, 12... Lower mold, 14... Ceramic heater, 16... Protruding terminal, 18... External wiring, 20... Connection part, 22... Cavity, 30 ...Gap, 32.34, Recess, 40, Elastomer.

Claims (1)

[Claims] (1) A mold having an upper mold and a lower mold for molding a connection part that connects a protruding terminal of a ceramic heater and an external wiring, and the upper mold and the lower mold accommodate the external wiring. 1. A mold for a heater connection part, characterized in that one of the recesses is deep enough to accommodate most of the external wiring.