JPS6232633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Objective) The method of the present invention involves fitting a piezoelectric element unit into a unit fitting groove provided in a metal frame, and using the elasticity of a metal stator whose outer periphery is in elastic contact with the unit fitting groove, The piezoelectric element unit with an insulating gap therebetween is pressed against a pressure receiving protrusion provided at one end of the unit insertion groove to maintain the unit form, and then the entire circumference of the piezoelectric element unit including the insulating gap is covered with resin. At the same time, the piezoelectric element unit is surrounded and fixed to a metal frame using the same resin, and a part of the shaft-like protrusion of the piezoelectric element unit that is pressed into contact with the hammer that slides in the hammer sliding groove by the pressure elasticity of the impact spring is removed from the insulating coating using the resin. The purpose of this method is to form the piezoelectric element unit into a unit fitting groove without applying an insulating coating to the piezoelectric element unit in advance to maintain its shape. This method simultaneously fixes the resin to the metal mold by press-fitting the resin into the mold once.

(Prior art) The front and rear pads of the piezoelectric element unit are pressed from the front and back by a pair of restraining molds that can freely move forward and backward to maintain the unit form, and the piezoelectric element is sandwiched between the piezoelectric elements in the unit. The upper and lower parts of the high-voltage terminal, except for a part of the high-voltage terminal that protrudes from the inserted electrode to the outside, are housed in a cavity of an injection molded metal, and the molten resin is press-fitted into the cavity. Accordingly, a method for manufacturing a piezoelectric body for piezoelectric ignition in which a piezoelectric element is coated with a resin is disclosed in Japanese Patent Laid-Open No. 89691/1989. However, since the above-mentioned conventional technology is based on the premise of using a pair of holding dies, a piezoelectric without resin coating is placed in the unit insertion groove formed in a metal frame configured such that the holding dies cannot be used. Even if the element unit is inserted, the shape of the unit cannot be maintained, and it is inserted into the unit insertion groove of the metal frame after being coated with resin, so it is difficult to fix the resin piezoelectric element unit with the metal frame. This method has disadvantages such as requiring a separate invention from the above-mentioned molding.

(Configuration of the method of the present invention) The method of the present invention differs from the conventional method described above,
The metal frame 11 is provided with a hammer sliding groove 13 and a unit fitting groove 12 formed in an extension shape by the hammer sliding groove 13. A pressure receiving protrusion 14 is formed at one end of the fitting groove 12, and a shaft corresponding to the hammer striking force is provided at the front part. protrusion 4
The piezoelectric elements 2, 2a are inserted between the front pad 3 that protrudes and the rear pad 5 that contacts the pressure receiving projection 14, and the electrode 6 is interposed between the piezoelectric elements to connect the high voltage terminal 7 to the outside. The protruding piezoelectric element unit 1 is installed in the unit fitting groove 12, and a metal stator 8 made of a plate spring is fitted into the shaft-like protrusion 4 of the front pad 3.
Due to the elastic contact of the outer periphery of the piezoelectric element unit 1 with the groove edge of the unit insertion groove 12, the metal stator 8 elastically forces the piezoelectric element unit 1 into pressure contact with the pressure receiving protrusion 14 to maintain the unit shape. An insulating interval S is created between the groove edge of the unit fitting groove 12 and the piezoelectric element unit 1, excluding the contact area between the hole edge and the metal stator 8 and the contact area of the rear pad 5 with the pressure receiving protrusion 14.
and the rear edge of the pressure receiving projection 14, and the unit fitting groove 1 is in contact with the shaft-shaped projection 4.
A mold 24 enclosing a part of the lengthwise direction within the metal frame 2 and a part of the tip of the high voltage terminal 7 is applied to both sides of the metal frame 11, and molten resin is press-fitted into the cavity of the mold. After cooling the piezoelectric element unit 1 inside the cavity, the resin surrounds the entire circumference including the insulation interval S except for a part of the shaft-like protrusion 4, etc., and
The present invention also relates to a method for manufacturing a piezoelectric body for piezoelectric ignition, characterized in that the piezoelectric element unit 1 is fixed to a metal frame 11 via the resin. In order to explain the method of the present invention in more detail, examples of the method of the present invention will be described in the next section.

(Example) Reference numeral 1 in the figure is a piezoelectric unit, in which a front part 3 with a protruding shaft-like protrusion 4 is applied to the front part of the cylindrical piezoelectric elements 2, 2a, and a rear part 5 is applied to the rear part of the piezoelectric element 2, 2a. An electrode plate 6 is interposed between the elements 2 and 2a to connect the high voltage terminal 7.
A metal stator 8 made of a plate spring is loosely fitted into a shaft-like projection 4 of the front pad 3.

Reference numeral 11 denotes a metal frame made of a metal plate of a constant thickness, and has a hammer sliding groove 13 and a unit fitting groove 12 suitable for loosely fitting the entire length of the piezoelectric unit 1 into the frame.
A pressure receiving protrusion 14 is formed at one end of the hammer sliding groove 13, and engaging recesses 15, 15 are provided at the groove edge of the groove 12 near the hammer sliding groove 13. Further, a spring hooking projection 16 is provided at one end of the hammer sliding groove 13.

In the piezoelectric unit 1 assembled as described above, the edges on both sides of the outer periphery of the metal stator 8 are engaged in the engagement recesses 15, and the rear end surface of the rear pad 5 is brought into contact with the pressure receiving protrusion 14 due to its elasticity. Fit the unit into the unit fitting groove 12 of the metal frame 11 as shown in FIG. That is, the piezoelectric unit 1 maintains its unit form by being pushed in the direction of the pressure-receiving protrusion 14 as a whole by the elasticity of the metal stator 8 made of plate spring, and the engagement between the contact portion to the pressure-receiving protrusion 14 and the metal stator 8 An insulating interval S is created between the outer periphery excluding the portions that fit into the recesses 15, 15 and the groove edge of the unit fitting groove 12. The high voltage terminal 7 protrudes at right angles to one side surface 11a of the metal frame 11.

21 and 22 are one side surface 11a and the other side surface 11b of the metal frame 11, as shown by the two-dot chain line in FIG.
A neck portion 21a that fits into the unit fitting groove 12 of the molds 21 and 22 and tightly surrounds the outer periphery of the shaft-like protrusion 4 of the front pad 3. , 22a (see FIG. 3) are provided. Further, the mold 22 is formed with a cylindrical portion 23 that surrounds the outer periphery of the high voltage terminal 7 at intervals, and another mold 24 is fitted into the cylindrical portion 23 to tightly fit the terminal 7 into the center. match. A mold 24 is placed in the cylindrical part 23.
can also be provided integrally.

The cavity 25 formed by the molds 21 and 22 has groove edges of the unit fitting groove 12 on one side 11a and the other side 11b of the metal frame 11, and the shaft-like projection 4 of the front pad 3. The outer periphery of the piezoelectric unit 1 excluding a part of the tip, the outer periphery of the metal stator 8, and the above-mentioned insulation interval S are accommodated. Also mold 2
A cavity 26 is formed of two cylindrical portions 23 and a mold 24 and communicates with the cavity 25. The mold 24 surrounds the outer periphery of the high voltage terminal 7.

Therefore, when the molten resin is press-fitted into the cavities 25 and 26 and cooled, the resin coating 1 is formed as shown in FIGS. 2 and 3 according to the inner shape of each cavity. This coating 17 is connected and integrated at the part that fills the insulation gap S, and is also connected to the groove edges on both sides of the unit fitting groove 12 of the metal frame 11, so the piezoelectric unit 1 is fixed using the metal frame 11 as a carrier.
The hammer force applied to the shaft-shaped protrusion 4 of the front pad 3 distorts the piezoelectric elements 2, 2a, so that a high voltage can be extracted from the high-voltage terminal 7.

The hammer 18 has sliding grooves 19, 19 in the axial direction separated by 180 degrees on the outer periphery of the hammer sliding groove 13.
is fitted into the edge of the hole, and the impact spring 20 is further hung between the spring hooking protrusion 16 and the hammer 18. The hammer 18 may be inserted at any time before or after the resin coating 17 is formed.

(Function) As clarified by the explanation of the structure and the embodiments, the method of the present invention is to provide a piezoelectric material for piezoelectric ignition by forming a unit fitting groove 12 and a hammer sliding groove 13 in an extended shape to form a metal frame used for piezoelectric ignition. The piezoelectric element unit 1 includes a metal stator 8 made of a sheet spring fitted into a shaft-like protrusion 4 corresponding to a hammer of a front pad 3. Temporary installation is carried out by fitting the metal stator 8 into the unit fitting groove 12, elastically engaging the outer periphery of the metal stator 8 with the unit fitting groove 12, and fixing it against the rear pad 5 and the pressure receiving protrusion 14 of the groove 12 to maintain the unit form. alms,
After that, synthetic resin press-fit molds 21 and 22 corresponding to both end surfaces of the metal frame 11 and the above-mentioned shaft-like projections are applied,
A piezoelectric element unit 1 including a metal stator 8 and a unit fitting groove are placed in the mold cavity, and molten resin is press-fitted into the mold cavity and cooled to produce a piezoelectric element corresponding to the groove edge of the unit fitting groove. The outer periphery of the element unit including the insulation interval S is covered with resin, and at the same time it is fixed to the metal frame 11 with the same resin.

(Effects) The method of the present invention does not involve covering the entire piezoelectric element unit with resin;
Of course, the part of the outer periphery of the metal stator 8 that is in elastic contact with the unit insertion groove and the part of the rear pad 5 that is in pressure contact with the pressure receiving protrusion are left in elastic contact or pressure contact, so that the metal Regarding the manufacture of a piezoelectric body for piezoelectric ignition using the frame 11 as a substrate, the conventional intermediate step of applying resin coating to the piezoelectric element unit is completely omitted, and this has the effect of making mass production possible.

[Brief explanation of the drawing]

FIG. 1 is a front view showing how the piezoelectric element unit 1 and the metal frame 11 are fitted into the unit fitting groove 12, and FIG. 2 is a longitudinal side view of the piezoelectric element unit 1.
FIG. 3 is a partially cutaway longitudinal sectional plan view showing the press contact of the mold to both sides of the metal frame 11, FIG. 4 is a partially cutaway side view of a piezoelectric body for piezoelectric ignition manufactured according to the present invention, and FIG. FIG. 4 is a front view taken longitudinally at the high voltage terminal 7 in FIG. 4;

Claims (1)

[Claims] 1. A hammer sliding groove 13 and a unit fitting groove 12 extending from the hammer sliding groove 13 are provided in the metal frame 11, and a pressure receiving projection 14 is formed at one end of the fitting groove 12, and the front part is adapted to receive hammer pressure. The piezoelectric elements 2, 2a are inserted between the front part 3 from which the shaft-shaped projection 4 is projected and the rear part 5 which contacts the pressure-receiving projection 14, and the electrode 6 is interposed between the piezoelectric elements to form a high-voltage terminal. A piezoelectric element unit 1 with a piezoelectric element 7 protruding outside is installed in the unit fitting groove 12, and a metal stator 8 made of a plate spring is fitted into the shaft-shaped projection 4 of the front pad 3.
Due to the elastic contact of the outer periphery of the piezoelectric element unit 1 with the groove edge of the unit insertion groove 12, the metal stator 8 elastically forces the piezoelectric element unit 1 into pressure contact with the pressure receiving protrusion 14 to maintain the unit shape. An insulating interval S is created between the groove edge of the unit fitting groove 12 and the piezoelectric element unit 1, excluding the contact area between the hole edge and the metal stator 8 and the contact area of the rear pad 5 with the pressure receiving protrusion 14.
and the rear edge of the pressure receiving projection 14, and the unit fitting groove 1 is in contact with the shaft-shaped projection 4.
A mold 24 enclosing a part of the lengthwise direction within the metal frame 2 and a part of the tip of the high voltage terminal 7 is applied to both sides of the metal frame 11, and molten resin is press-fitted into the cavity of the mold. After cooling, the entire circumference of the piezoelectric element unit 1 inside the cavity, including the insulation interval S except for a part of the shaft-like protrusion 4, is surrounded by the resin, and the piezoelectric element unit 1 is surrounded by the metal frame 11. A method for producing a piezoelectric material for piezoelectric ignition, characterized in that the piezoelectric material is fixed to a material via the resin.