KR20020022963A - A tact switch assembly - Google Patents

Abstract

PURPOSE: A tact switch assembly is provided to achieve an improved productivity and reduce manufacturing cost by integrating a tact switch and button into a housing. CONSTITUTION: A tact switch assembly(20) comprises a housing(21) fixed to a circuit board, a button(22) disposed in the housing, and a tact switch(23) operating by the button. The housing includes a main body(21a) where the button is arranged to move forward and backward; a cover(21g) mounted to the main body, and which has the tact switch arranged inside the cover; and a mounting element for mounting the main body and the cover. The cover includes a hook(21i) fixed to a circuit board(12); and a pair of terminals(23e) for connecting the tact switch to the circuit board when the housing is fixed through the hook.

Description

Tact switch assembly

The present invention relates to a tact switch assembly for use in electronic products, and more particularly, to a tact switch assembly having a tact switch electrically connected to a circuit board and a button for operating the tact switch.

In general, a control panel of various electronic products is provided with a circuit board on which an electric circuit is printed, and a tact switch assembly for directly controlling each driving element by being electrically connected to the circuit board.

A tact switch assembly used in such a conventional electronic product includes a tact switch electrically connected to a circuit board, and a housing having a button for operating the tact switch. The tact switch is separately assembled on a printed circuit board so as to be driven by the push of a button. And the housing is usually fixed to the circuit board or the control panel, the button is provided in the axial direction to move forward and backward. At this time, the operation button is restored and supported by the elastic member, the front end is arranged to maintain a constant distance from the tact switch.

Therefore, when the user presses the button, the tip of the button presses the tact switch while compressing the elastic member, so that the function set on the circuit board is selected or programmed. When the button is released, the button is restored to its initial state by the elastic restoring force of the elastic member.

However, in the conventional tact switch assembly, the housing having the tact switch and the button for driving the tact switch is composed of separate parts, and after the tact switch is separately assembled on the circuit board, the housing is fixed to the circuit board or the control panel again. Must be assembled That is, due to the dualization of parts, not only the assembly process of the conventional tact switch assembly is complicated but also the manufacturing cost increases.

The present invention is to solve this problem, an object of the present invention is to configure the tact switch directly inside the housing with a button to unify the parts, thereby improving the assembly productivity and at the same time reduce the manufacturing cost of the tact switch assembly To provide.

1 shows a control panel of a microwave oven to which the present invention is applied.

Figure 2 is an exploded perspective view showing a tact switch assembly according to the present invention.

FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2 and illustrates the internal structure of the tact switch according to the present invention.

Figure 4 is a perspective view showing a part of the mounting structure of the tact switch according to the present invention.

5 is a cross-sectional view showing an operating state of the tact switch assembly according to the present invention.

* Description of the symbols for the main parts of the drawings *

10. Control panel 12. Circuit board 20. Tact switch assembly

21. Housing 21a. Body 21e. Upper cover

21g.Lower cover 21i.Hanging hook 23.Tact switch

23 a.movable contact 23b.support 23c.fixed contact

23e .. Terminal 26. Mounting means 26a. Mounting pole

26b.26c..Mounting hole 26d..Mounting projection

The present invention for achieving this object is;

A tact switch assembly having a housing fixed to a circuit board, a button disposed on the housing, and a tact switch operated by the button,

The housing is configured to include a body in which the button is arranged to move forward and backward, a cover mounted to the body and having a tact switch therein, and mounting means for mounting the body and the cover.

In addition, the cover is characterized in that it comprises a hook hook to be fitted to the circuit board and fixed, and a pair of terminals for connecting the tact switch to the circuit board when the housing is fixed through the hook hook.

In addition, the tact switch is provided to protrude in the recess formed in the cover and is provided with a fixed contact connected to any one of the terminals, symmetrically provided on both sides of the recess with respect to the fixed contact, and the support portion connected to any one of the terminals; The edge is connected and supported by the support and the center portion is configured to have a movable contact that is energized with the fixed contact while being deformed according to the pressing action of the button.

In addition, the mounting means includes a mounting hole perforated in the thickness direction formed in the body, a mounting pole provided in the cover so that the tip is exposed to the outside through the mounting hole, and a mounting protrusion formed by plastic deformation of the tip of the mounting pole. It is a configuration characterized in that.

According to such a configuration, the tact switch and the button for operating the same are integrally configured in the housing, that is, the parts are united, thereby improving assembly productivity and reducing manufacturing costs.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings, a case in which the tact switch assembly according to the present invention is applied to a control panel of a microwave. Brief description of the accompanying drawings, Figure 1 is an exploded perspective view showing a control panel of a microwave oven to which the present invention is applied, Figures 2 to 4 are a perspective view and a cross-sectional view showing a tact switch assembly according to the present invention.

In general, a microwave oven radiates a high frequency of 2450 MHz in a magnetron into a cooking chamber to repeatedly convert a molecular array of moisture contained in the food, thereby cooking food by frictional heat between molecules.

The microwave oven to which the present invention having such a function is applied forms a cabinet, and the cooking compartment and the electrical equipment compartment are partitioned therein, one side of the cabinet is hinged to one side of the cabinet to open and close the cooking compartment, and the electrical equipment compartment front side. Have a control panel placed on it.

In the electrical equipment room, a magnetron that oscillates high frequency and radiates to a cooking chamber, a high voltage transformer that applies a high voltage to the magnetron, a cooling fan for cooling an electric component that generates heat, and the like are disposed.

As shown in FIG. 1, the control panel 10 includes a display unit 11 on which a cooking stroke is displayed, a circuit board 12 on which a cooking stroke of a microwave is programmed, and an electrical circuit to the circuit board 12. The tact switch assembly 20 and the auxiliary button 13 and the auxiliary knob 14 for directly operating the tact switch assembly 20 to control the respective driving elements are provided.

2 and 3, the tact switch assembly 20 according to the present invention may include a housing 21 coupled to a circuit board 12 and a predetermined width in the axial direction in the center of the housing 21. The button 22 arrange | positioned, and the tact switch 23 built in the housing 21, and a contact are temporarily turned on by the push action of the button 22 are provided.

As described above, a series of strokes are programmed in the circuit board 12 to electrically control each driving element according to the selected cooking stroke, and the terminal 24e and the tact of the time setting device 24, which will be described later, will be described later. The first connector 12a and the second connector 12b to which the terminal 23e of the switch 23 side is electrically connected, the fastener 12c to which the engaging hook 12c is fitted, and the like are formed.

The housing 21 covers a body 21a having a coupling portion 21b to which the button 22 is fitted and coupled, an upper cover 21e covering the upper portion of the body 21a, and a lower portion of the body 21a. A lower cover 21g coupled to the tact switch 23, and mounting means 26 for sequentially mounting the upper cover 21e and the body 21a and the lower cover 21g in sequence. Injection molding is made of plastics.

Body 21a is provided with a coupling portion 21b having an engaging tool 21c formed in the axial direction so that the engaging jaw 22b of the button 22 to be described later is loosely coupled to the upper surface. In addition, the body 21 is additionally provided with a time adjusting device 24 for setting the driving time of the microwave oven. The time control device 24 is called an encoder in the microwave oven, and an annular recessed recess 21d is formed in the outer periphery of the coupling portion 21b for installation thereof. An annular contact plate 24d is inserted into the bottom of the recess 21d so that the contact is turned on and off, and the dial knob 24a is rotatably disposed on the outer circumference of the engaging portion 21b. The contact plate 24d is electrically connected to the circuit board 12 through the terminal 24e provided to extend to the side of the body 21a. In addition, the dial knob 24a is formed in a cylindrical shape so that one end of the button 22 penetrates, and a contact piece 24c on the bottom thereof rubs against the contact plate 24d according to the rotational movement so that the on / off is repeated. Is provided. Accordingly, when the dial knob 24a is rotated, the on / off operation of the contact piece 24c and the contact plate 24d is repeatedly performed, thereby setting the driving time of the microwave oven. Reference numeral `` 25 '' denotes a click device consisting of a sphere 25a and a coil spring 25b, and the gear portion 25a is provided on the outer circumference of the dial knob 24a by the elastic force of the coil spring 25b. It is in constant friction with 24b. Accordingly, when the dial knob 24a is rotated, a click sound is generated and the degree of rotation thereof can be easily felt by the user.

The button 22 installed in the body 21a has an auxiliary button assembly 22c extending through the upper cover 21e and extended to the outside, and a pair of engaging jaws (22c) to be assembled while being elastically deformed to the coupler 21c. 22b) and a pressing portion 22d extending from the tip of the elastic coupling portion 22a so as to operate the tact switch 23 according to the pressing action of the button 22. . The auxiliary button assembly 22c is provided to extend coaxially at one end of the button 22, and the chamfer 22e is formed at the outer circumference so that the auxiliary button 13 (see FIG. 1) is assembled directly. In addition, the elastic fastening part 22a is provided at the other end of the button 22. The coil spring type elastic member 22f is disposed on the outer circumference so that the elastic fastening part 22a is elastically supported in the restoring direction while being assembled to the coupling hole 21c. . Further, the pressing portion 22d extends coaxially between the pair of locking jaws 22b and is disposed adjacent to the center of the movable contact 23a of the tact switch 23, the tip of which is described later.

The upper cover 21e is formed in a rectangular plate shape to cover the upper portion of the body 21a, and the through-hole 21f so that the dial knob 24a and the auxiliary button assembly 22c of the button 22 penetrate and extend outwardly. ) Is provided.

The lower cover 21g is also made of a rectangular body to cover the lower portion of the body 21a, and four locking hooks 21i are formed integrally with two symmetrically on both sides. This locking hook 21i is for firmly fixing to the circuit board 12.

The recess 21h recessed concave is provided in the upper part of the lower cover 21g, and the tact switch 23 is provided here. The tact switch 23 is a kind of switching means in which energization is temporarily determined according to the pressing action of the button 22. The tact switch 23 includes a fixed contact 23c and a movable contact 23a made of metal. The fixed contact 23c is insert-molded to protrude upward from the center of the recess 21h of the lower cover 21g, and the movable contact 23a has its own elastic restoring force and is normally spaced apart from the fixed contact 23c. The dome is formed in a dome shape in which the central portion is convexly protruded upward to maintain a shorted state and a flange 23b is formed at an edge thereof. This movable contact 23a is supported by the supporting part 23d which is insert-molded to protrude on both sides of the edge of the recess 21h. A pair of terminals 23e protruding outward from the lower cover 21g are inserted, and the fixed contact 23c is electrically connected to any one of them, and the movable contact 23a is supported on the other. The supporting part 23d to support is electrically connected. In addition, the terminal 23e is bent and extended in the downward direction of the lower cover 21g, so that in the process of assembling the housing 21 to the circuit board 12, this is also the first connector 12a of the circuit board 12. It is inserted into and electrically connected.

On the other hand, the mounting means 26, as described above, by mounting the upper cover (21e), the body (21a) and the lower cover (21g) in order to unite the parts, the lower part where the tact switch 23 is built Four mounting poles 26a, which are provided to extend upwardly to have a predetermined length at the corners of the cover 21g, and corresponding body 21a and upper cover 21e to allow the mounting poles 26a to pass therethrough. Four mounting holes 26b and 26c respectively drilled in the thickness direction at the corners of the " At this time, the length of the mounting pole 26a is slightly longer than the sum of the thicknesses of the upper cover 21e and the body 21a, and the tip of the mounting pole 26a penetrates the mounting holes 26b and 26c simultaneously. It is preferable that the configuration so as to slightly project out of the upper cover (21e). This is to form a hemispherical mounting protrusion 26d by applying heat to the tip of the mounting pole 26a to plastic deformation, which will be described in detail in the assembling process described later.

Next, the assembly process of the tact switch assembly according to the present invention configured as described above and the effects thereof will be described.

First, when the elastic member 22f is inserted into the elastic fastening portion 22a of the button 22 and then inserted into the coupling hole 21c, the locking jaw 22b enters while being elastically deformed, thereby causing the button 22 to enter the housing. It is assembled to the body 21a of the 21 so that a predetermined width advance movement is possible. At this time, the pressing part 22d of the button 22 penetrates through the body 21a and protrudes downward.

In this state, if the top cover 21 is covered after the dial knob 24a and the click device 25 are installed on the outer circumference of the engaging portion 21b, the auxiliary button assembly 22c and the dial knob 24a of the button 22 are covered. One end of) is projected outward through the through hole 21f. As such, when the upper cover 21e is coupled to the upper portion of the body 21a constituting the housing 21, the mounting holes 26b and 26c respectively formed therein communicate with each other.

Then, after the movable contact 23a is placed on the recess 21h of the lower cover 21g in which the fixed contact 23c is inserted, the mounting contacts 26a and 26c are applied to the four mounting poles 26a. When the body 21a and the upper cover 21e are inserted in sequence, the tip of the mounting pole 26a extends outward from the upper cover 21e and the upper cover 21e and the body 21a and the lower cover 21g are formed. It is assembled.

Subsequently, as shown in FIG. 4, heat is applied to the tip of the mounting pole 26a ("A" portion shown in FIG. 4) exposed to the outside through the body 21a and the upper cover 21e, In other words, if the hemispherical mounting protrusion 26d is formed by plastic deformation, the upper cover 21e, the body 21a and the lower cover 21g are integrally and firmly assembled through the mounting pole 26a. At this time, the movable contact 23a embedded in the lower cover 21e is kept short-circuited at a predetermined interval from the fixed contact 23c, and the pressing portion 22d of the button 22 is connected to the movable contact 23a. It is located adjacent to the center.

As a result, the tact switch 23 having the movable contact 23a and the fixed contact 23c is installed in the lower cover 21g, which is mounted on the body 21a having the button 22, thereby providing the tact switch 23 and The button 22 is configured in one housing 21, thereby uniting the parts.

Meanwhile, when the tact switch assembly 20 assembled as described above is fitted to the circuit board 12 through the hook hook 21i, the tact switch 23 side terminal 23e and the time setting device 24 side terminal ( 24e) is connected to the circuit board 12. That is, when the engaging hook 21i extending to the lower cover 21g is inserted into the fixture 12c of the circuit board 12, the terminal 23e of the tact switch 23 side is the first of the circuit board 12. It is inserted and connected to the connector 12a, and the terminal 24e on the time setting device 24 side is also connected to the second connector 12b of the circuit board 12 at the same time. As a result, the tact switch assembly 20 in which the button 22 and the tact switch 23 are integrated can be more easily assembled and installed on the circuit board 12.

Next, the operation of the tact switch assembly 20 configured as described above will be described through an example in which the control panel 10 of the microwave oven is mounted.

First, an auxiliary knob 14 (refer to FIG. 1) is installed on a dial knob 24a extending outside the upper cover 21e so that a user can use the tact switch assembly 20 more easily, and the button 22 The auxiliary button 13 (see Fig. 1) is assembled to the auxiliary button assembly 22c.

If you want to use such a microwave, first put the food in the cooking chamber and close the door. When the user rotates the auxiliary knob 14, the dial knob 24a rotates integrally, and the on / off contact change of the contact piece 24c and the contact plate 24d of the time setting device 24 is repeatedly performed. In the circuit board 12, the phenomenon is detected through the terminal 24e and the cooking time is set, which is displayed on the display unit 11.

In this way, after setting the cooking time, when the user pushes the auxiliary button 13 down in the direction of the arrow “D”, as shown in FIG. 5, the button 22 is lowered and its pressing part 22d is tacted. The movable contact 23a of the switch 23 is pushed. At this time, the movable contact 23a is temporarily energized with the fixed contact 23c while elastically deforming. This temporary energization phenomenon is sensed by the circuit board 12 through the terminal 23e, thereby driving the magnetron embedded in the electrical equipment room for a set time to cook the food.

At this time, since the button 22 is elastically supported in the direction restored through the elastic member 22f, the user's hand is released from the auxiliary button 13 and the button 22 is restored and at the same time the movable contact 23a. ) Is also restored to its elastic restoring force and maintained in its initial state.

As described in detail above, according to the tact switch assembly according to the present invention, the tact switch is arranged in the housing so as to move forward and backward, and at the same time the tact switch operating according to the pressing action of the button is integrally formed, and the housing is a circuit board. The tact switch is also electrically connected to the circuit board during assembly. Accordingly, the assembly productivity is improved due to the unification of the parts of the button and the tact switch, and there is an effect of reducing the manufacturing cost.

Claims (4)

A tact switch assembly comprising a housing fixed to a circuit board, a button disposed on the housing, and a tact switch operated by the button, The housing 21, A body 21a on which the button 22 is disposed to move forward and backward, a cover 21g mounted to the body 21a and having the tact switch 23 therein; and the body 21a and the cover. And a mounting means (26) for mounting (21g). The method of claim 1, The cover 21g, A catching hook 21i inserted into and fixed to the circuit board 12; And a pair of terminals (23e) for connecting the tact switch (23) to the circuit board (12) when the housing (21) is fixed through the locking hook (21i). Assembly. The method of claim 2, The tact switch 23, A fixed contact 23c provided to protrude into a recess 21h formed in the cover 21g and connected to any one of the terminals 23e; A support portion 23d provided symmetrically on both sides of the recess 21h with respect to the fixed contact 23c and connected to any one of the terminals 23e; An edge is connected and supported by the supporting part 23d, and a center part has a movable contact 23a that is energized with the fixed contact 23c while being elastically deformed according to the pressing action of the button 22. Switch assembly. The method of claim 1, The mounting means 26, A mounting hole 26b bored in the thickness direction formed in the body 21a, A mounting pole 26a provided in the cover 21g to penetrate the mounting hole 26b so that the tip thereof is exposed to the outside of the body 21a; And a mounting protrusion (26d) formed by plastically deforming the tip of the mounting pole (26a).