JPH0528665Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a keyboard switch, which is a single switch in which a plurality of key tops are incorporated into a keyboard arranged on an operation panel, and particularly to a mechanical contact type keyboard switch. In general, mechanical contact type keyboard switches include switches with a click action and switches without a click action, but the present invention relates to a keyboard switch that can have both types with the same structure. [Prior art] Conventional mechanical contact type keyboard switches with a click action often used a dome-shaped disc spring made of metal or rubber (Japanese Patent Application Laid-open No. 40925/1983). . In addition, for those without click action, when the key stem descends, there is a direct method in which the key stem directly presses the contact part, or an indirect method in which the key stem presses the pusher, and the pusher presses the contact part. It was common. Therefore, the structures with a click action and those without a click action are completely different. Therefore, in the past, keyboard switches with a click action and keyboard switches without a click action were designed with different structures and used different parts, so they could not be used in common. Two types of production lines were also required: one with click action and one without. In particular, keyboard switches with click action have the following problems. The conventional example shown in FIG. 9 is an example in which a metal dome-shaped spring is used for the pressing portion. A key top 1 is arranged at the upper end of the key stem 2 arranged in the upper holder 3a, and the key stem 2
A coil spring 4 is disposed on the bottom surface of the coil spring 4, and a slider 5 is disposed in the guide 3c at the lower end of the coil spring 4. Inside the lower holder 3b, a fixed contact 9 is disposed on the bottom surface, a movable contact plate 8 is disposed on the upper side facing it, and a dome-shaped metal spring 6 is disposed on the dome-shaped spring receiver 7 further above. In addition, the slider 5 is in contact with the upper surface of the dome-shaped metal spring 6. In this way, the conventional click-action keyboard switch using the dome-shaped metal spring 6 provides a click feeling by causing the dome-shaped metal spring 6 to be pressed from above and reversely displaced due to a jumping phenomenon, and also to provide a click-action keyboard switch using a movable contact. The plate 8 and the dome-shaped metal spring suddenly come into contact and act to press the movable contact plate 8 against the fixed contact 9. Here, since both the dome-shaped metal spring 6 and the movable contact plate 8 are metal springs, natural vibration occurs when they make contact, and a chattering phenomenon occurs in which the movable contact turns ON multiple times with one press on the fixed contact. This method not only lacks reliability but also has the problem of producing too high an impact sound. Moreover, after about 200,000 to 300,000 uses, metal fatigue occurred and the product became unusable, resulting in a short lifespan. Next, in order to solve the above-mentioned problem, it is known that the dome-shaped metal spring is replaced with a dome-shaped rubber spring 12, as shown in FIG. However, the dome part of the dome-shaped rubber spring,
If the rubber film cannot be made very thick and the switch is operated many times, the repeated loads will cause the material to become fatigued and deformed, leaving the dome-shaped spring in a state where it does not recover, resulting in chattering, instantaneous disconnections, etc. This had the problem of causing contact malfunctions. Moreover, the number of times of use is 100,000 times or less, which also poses a problem in terms of lifespan.
With this structure of a keyboard switch with an action, it was impossible to create a keyboard switch without an action, and no such keyboard switch existed. [Purpose of the invention] The present invention replaces the conventional dome-shaped metal spring with an S-shaped leaf spring to achieve long life and reliable ON/OFF operation without chattering or momentary interruption. Aims to provide high quality keyboard switches. [Structure of the invention] In order to achieve the above object, the present invention includes a key stem disposed in an upper holder so as to be slidable in the vertical direction, a coil spring disposed inside the key stem, and a lower end of the coil spring. In the keyboard switch, the keyboard switch is composed of a pressing part disposed in the lower holder, and a contact part having a movable contact and a fixed contact disposed in the lower holder. an elastic member, and the engaging part is fitted into the engaging groove in the holder such that the center part of the S-shaped metal elastic member is located closer to the key stem than the engaging part in a no-load state. This is the configuration of the keyboard switch. Preferably, the S-shaped metal elastic member has a ring portion and a pair of curved portions extending diagonally downward at the center thereof. Further, it is preferable that the S-shaped elastic metal member is integrally formed by press-molding a part of the S-shaped elastic metal member so that a protrusion protrudes downward from the center of the S-shaped elastic metal member. Further, it is preferable to form a plurality of rising pieces upward from a ring portion formed at the center of the S-shaped metal elastic member. Further, it is preferable to fix damper rubber to the upper surface of the S-shaped metal elastic member. Further, it is preferable that the cross-sectional shape of the upper and lower holders is rectangular, and that the engagement grooves are formed at diagonally even portions. Furthermore, by forming a bent part in the curved part of the S-shaped metal elastic member and changing the bending angle of the bent part, the dimensions from the upper surface of the engaging part to the upper surface of the central part can be changed, and the engaging part can be formed in the engaging groove. It is preferable to fit the two. [Function] In the present invention, since the pressing part is constituted by an S-shaped elastic metal member, the size of the cutout between both ends of the S-shaped elastic metal member and/or the curved portion of the S-shaped elastic metal member may be reduced. Whether a click action is generated or not depends on the size of the bending angle and/or the size of the distance from the protrusion of the S-shaped metal elastic member to the cushion rubber. That is, if one or more of the following conditions is met: the cutout size is large, the bending angle is small, or the distance from the protrusion to the cushion rubber is large, the cushion is equipped with a click action. [Embodiment] The shapes and functions of the components of a keyboard switch with a click action (hereinafter referred to as an action switch) and a keyboard switch without a click action switch (hereinafter referred to as a non-action switch) are almost the same. The action switch will be explained below. Fig. 1 is a plan view of the switch body of the action switch of the present invention with the key top removed, and Fig. 2 shows the internal section taken along line X-X in Fig. FIG. FIG. 3 is a sectional view of the upper holder and key stem taken along line Y--Y in FIG. 1. 4 is a partially cutaway plan view of the lower holder excluding the cushion rubber, and FIG. 5 is a plan view of the cushion rubber covering the contact portion of FIG. 4. The action switch of this invention has 1 key top.
0, a key stem 20, a holder 30, a coil spring 40, a pressing part 50, and a contact part 60. (The non-action switch also has the same configuration.) Each component will be explained in detail below. As shown in FIG. 2, the holder 30 is composed of an upper holder 31 and a lower holder 32, forming an envelope of the action switch. The connection structure of the upper and lower holders is such that the pillars 33 placed at the four corners of the lower holder 32 fit into the through holes 34 drilled in the upper holder 31, and the parts that protrude from the upper holder 31 are heat-swaged. holder 31,
32 are integrated. The holder 30 is formed by molding a plastic such as polybutylene terephthalate. The upper holder 31 has a structure in which a cylinder 31b for guiding the key stem 20 is disposed in the center of a housing 31a having a substantially square cross section. Therefore, the upper surface of the upper holder 31 has a key stem through hole 35.
is drilled. Further, as shown in FIG. 2, step portions are provided near the lower ends of opposing corners on the line X-X in FIG. 1 of the housing 31a, and the protrusion 32a of the lower holder is fitted into the step portions, Engagement grooves 36, 36 are formed into which engagement portions of an S-shaped spring, which will be described later, are fitted. Further, as shown in FIG. 3, a guide groove 37 is provided at the upper corner of the upper holder along Y-Y line in FIG. 1, and the guide portion 22 of the key swim 20 is slidably fitted therein. Furthermore, inside the upper holder 31, the cylinder 3
1b extends, and the sub-guide portion 23 of the key stem 20
A notch groove 38 for guiding the key stem 20 and a guide groove 37 for guiding the guide portion 22 of the key stem 20 are formed. Next, the key stem 20 is composed of a cylindrical key stem main body 21, as shown in FIG. 3, and a guide portion 22, which is integrally provided in a convex manner in the direction of the X--X line in FIG. The key stem body 21 is provided with a mounting hole 24 for fitting and mounting the key top 10 thereon. Further, near the lower end of the key stem body 21, a ring-shaped groove 25 is formed into which the coil spring 40 is fitted. Furthermore, a protrusion is provided on the outer circumference of the key stem body 21 along the line X-X in FIG.
is formed. The key stem 20 is formed by molding of a self-lubricating and slippery plastic such as acetal resin or nylon resin. Next, the coil spring 40 is a compression spring made of an elastic material such as stainless steel or phosphor bronze. The upper end of the coil spring 40 is fitted into the ring-shaped groove 25 of the key stem, and the lower end is attached to contact the pressing part 50. In addition, the operating force for pressing the key switch is generally 30
There are various types ranging from ~500g, and users can request light or heavy weights depending on their preference. In this case, since the spring constant is changed by changing the wire diameter of the coil spring, it is possible to deal with various operating forces without changing the shape and length. In other words, to increase the operating force, the wire diameter of the coil spring must be increased and the spring constant must be increased. Furthermore, if it is desired to reduce the operating force, this can be achieved by reducing the wire diameter of the coil spring. Furthermore, the spring constant can also be changed by changing the material of the coil spring, so this problem can be solved. Next, the pressing part 50 has a structure in which an S-shaped metal elastic member is fitted into a holder, and as an example, as shown in the plan view of FIG. It consists of an S-shaped leaf spring 51 and a damper rubber 52 fixed to its upper surface. The S-shaped leaf spring 51 has upper and lower curved parts 53a, 5
3b is integrally continuous with a ring portion 54 provided at the center. Engaging portions 55 are provided at the ends of the upper and lower curved portions 53a and 53b. The dimension between the engaging parts at both ends is called the cutting length L, and in the case of an action type, it is longer than that of a non-action type. By making it longer, it increases the amount of deflection when attached to the holder and strengthens its springiness. The engaging portion 55 is connected to the curved portion 53
It is formed wider than the width of a and 53b. The engaging portion 55 fits into the engaging groove 36 formed in the holder 30 with a clearance of about 0.1 to 0.3 mm in the vertical direction. Further, the upper and lower curved parts 53a and 53b are bent downward at an intermediate position to form a bent part 56, and the engaging part 55 is positioned below the central ring part 54 to return after being reversely displaced. I have good sex.
The dimension from this engaging part 55 to the ring part 54 is H
The H dimension of an action switch is smaller than that of a non-action switch, and has stronger springiness. Next, the ring part 54 has a central side 54a forming part of an S-shape and a perpendicular side 54b perpendicular to the central side 54a, and the intersection of these sides, that is, the central part of the ring part 54, is circular and is pushed downward. The protrusion 57 is integrally formed by press molding. Note that the protrusion 57 is not made by press molding a part of the ring part 54, but by forming the protrusion 57 separately.
It is also possible to form it by fixing it to the center of 4. The dimension from the tip of this protrusion 57 to a cushion rubber to be described later is set larger than that of a non-action type, and the structure is such that the S-shaped plate spring is pressed until it is completely reversed and displaced. Further, the inner edge of the ring portion 54 is provided with a ring portion 54.
A rising piece 58 is integrally formed higher up by press molding. The upright pieces 58 have a trapezoidal shape with a wide upper part, and are formed in plural numbers inside the ring portion, all of which are located so as to contact the inside diameter of the coil spring 40 and are slightly inclined inward. That is,
The inner circumference of the lower end of the coil spring 40 is
The coil spring 40 is fitted into the coil spring 40 to maintain its position. In this embodiment, a case has been described in which a leaf spring is used as the metal elastic material, but it is also possible to use square or round springs other than leaf springs. Next, the damper rubber 52 is fixed to the upper surface of the S-shaped leaf spring 51. The fixing method may be to use an adhesive or the like, but in this embodiment, the rising piece 5
8 and fixed. In this embodiment, the damper rubber 52 is disposed on the ring portion 54 and a portion of the curved portions 53a and 53b in the vicinity thereof.
If it is present on the entire upper surface of the S-shaped leaf spring, it will be more effective in suppressing the natural vibration of the S-shaped leaf spring 51. Further, the coil spring 40 has a damper rubber 5
2, this prevents the coil spring 40 and the S-shaped leaf spring 51 from directly colliding with each other when the S-shaped leaf spring 51 returns, thereby preventing the generation of metallic sounds. However, if you prefer a high-pitched metallic sound when clicking, an embodiment in which the damper rubber 52 is omitted is also possible. The method for attaching the S-shaped leaf spring 51 to the upper holder 31 configured as described above is as follows.
is placed upside down, and the key stem 20 is fitted into the guide groove 37 of the upper holder 31 with the guide portion 22 positioned. Next, attach the coil spring 41 to the key stem 20.
After installing the coil spring 4 into the ring-shaped groove 25 of
The upright piece 58 of the S-shaped leaf spring 51 is placed so as to fit on the inner periphery of the end of the S-shaped plate spring 51, and the engaging portion 55 is positioned on the engaging groove 36. And the center ring part 5
The engaging part 55 is pushed into the engaging groove 36 while pressing so that the engaging part 4 is above the engaging part 55. Next, as shown in FIGS. 2 and 4, the lower holder 32 is a housing whose upper surface is approximately square, and an octagonal recess 39 is formed inside the housing, and the upper holder 32 A pillar portion 33 is formed to be fitted with and thermally caulked. Further, a contact portion 60 is provided in the recess 39 . The contact portion 60 includes a fixed contact 61 disposed on the bottom surface of the recess 39, a movable contact 62 disposed above the fixed contact 61, and a cushion rubber 63 disposed above the movable contact 61. It consists of The fixed contact 61 has a plurality of protrusions 6 whose surfaces are plated with gold at positions facing a movable contact plate 70 which will be described later.
4, and a conductive member 66 connected to the contact plate 65. The fixed contact plate 65 is embedded and fixed in the bottom surface of the recess 39. The fixed contact plate 65 also includes a conductive member 6 embedded in the bottom of the lower holder 32.
6, and its end extends outward from the lower holder 32 to form a positive terminal 67. Next, the movable contact 62 is fixed to the upper surface of a ring-shaped spacer portion 68 that is provided on the bottom of the lower holder 32 so as to be spaced apart from the fixed contact 61 by a certain distance. The movable contact 62 is formed by punching a plate spring material, for example, a phosphor bronze plate, and has a shape including a ring-shaped contact holder 69 and a plurality of movable contact plates 70 extending inward from the contact holder 69. , consists of tongue-shaped connecting portions 71 protruding from both left and right inner sides of the contact holding portion 69. The reason why a plurality of movable contact plates 70 are provided is to ensure that any movable contact plate 70 is turned on even if the key stem is pushed not from directly above but from either direction. Therefore, if there are three movable contact plates 70 divided by 120 degrees, the above effect can be achieved, but in order to further improve reliability and extend the service life, in this embodiment, four movable contact plates 70 are used. was installed. Further, the tongue-shaped connecting portions 71 provided on the left and right inner sides of the movable contact plate holding portion 69 are welded and fixed to a conductive connecting plate 72 provided below. The connection plate 72 is connected by a conductive member 66a buried in the bottom surface of the lower holder 32, and its end is extended outward from the lower holder 32 to connect to the negative terminal 7.
3. The movable contact 62 is made of a leaf spring material as described above, but if a material clad with silver or gold, which has good conductivity, is used on the fixed contact side of the movable contact 62, it will improve conductivity and reduce chattering. More preferred. It is also possible to use thick plating instead of cladding. Next, as shown in FIG. 5, the cushion rubber 63 has the same octagonal shape as the recess 37 of the lower holder 32 so that it fits properly into the recess 37 of the lower holder 32. It prevents
Any rubber-like material can be used, but neoprene rubber is preferred from the viewpoint of longevity and return force. Furthermore, since the cushion rubber 63 is in contact with the movable contact 62, when the cushion rubber 63 is pressed and deformed by the aforementioned pressing section 50, the movable contact plate 70 bends downward and comes into contact with the fixed contact 61. It is configured as follows. Next, the configuration of the non-action switch will be explained below. The non-action switch is composed of a key top 10, a key stem 20, a holder 30, a coil spring 40, a pressing part 50, and a contact part 60, which is the same as the action switch. Among these components, the key top 10, key stem 20, holder 30, and contact portion 60 are completely the same as those of the action switch, so their explanation will be omitted. Therefore, since the shapes can be said to be almost the same, the same machine can be used for the process of supplying and assembling the parts by an automatic assembly machine. Next, the S-shaped leaf spring 51 of the pressing portion 50 is composed of a curved portion 53a, a ring portion 54, and an engaging portion.
have the same shape. Only the engaging part 55 is different from the action switch, and its length is 0.05 to 0.1 on one side.
It is formed mm shorter. Both engaging portions 55, 55
The length between the two is called the cutting length L, as shown in Figure 6.
This cutting length is 0.1 to 0.2 mm shorter than the action switch to weaken the spring properties. Next, the bending angle of the bending part 57 of the curved part 53a is increased by the action switch, and as shown in FIG. 8, the dimension from the upper surface of the engaging part 55 to the upper surface of the central ring part 54 is called the H dimension It is 0.3 to 1.0 mm larger than an action switch, has weaker spring properties, and has a large stroke point at the point of reverse displacement. For example, the H dimension of an action switch is 0.05 to 0.25 mm, while the H dimension of a non-action switch is 0.75 to 0.9 mm. However, this value also changes depending on the material and plate thickness. Further, the damper rubber 52 may not be provided. The reason is that since it is a non-action, there is no jumping phenomenon of the leaf spring, and the coil spring 40 and the pressing part 50 are always in contact with each other, so if they are pressed normally, there will be no contact noise between the two, and the S This is because the natural vibration of the letter-shaped plate spring does not occur. However, if the load is suddenly reduced to zero after pressing the key top 10, for example, when the key top is flicked, the coil spring 40 and the S-shaped leaf spring 51 may vibrate, producing a contact sound or causing the natural vibration of the leaf spring. may also occur.
Therefore, it is preferable that the non-action switch also be provided with the damper rubber 52. The method of mounting this S-shaped leaf spring 51 is also the same as that of an action switch, so the explanation will be omitted. In this way, the coil spring 40 and the S-shaped leaf spring 5
By changing the spring characteristics of No. 1, the point at which the S-shaped leaf spring 51 is reversely displaced is set at a position with a long stroke, and the pressing portion 50 is moved toward the contact portion 60.
is pressed to form the ON state at the position before the reverse displacement, and during the stroke where the key stem 20 is not reversely displaced by further pressing, the tip of the guide portion 22 of the key stem 20 comes into contact with the bottom surface of the lower holder and does not move any further. . In other words, it is configured to have a push-off load. Therefore, even if the S-shaped leaf spring 51 has the property of being reversely displaced, it will not be reversely displaced during the stroke of the non-action switch.
Since it acts as a simple leaf spring material, it is constructed so that no click action occurs. In other words, whether it becomes a click action or a non-action is determined if any one of the following four factor conditions is met.

〔effect〕

As explained above, the present invention provides a keyboard switch comprising a key stem, a coil spring disposed on the key stem, a pressing section having an elastic member disposed at the lower end of the coil spring, and a contact section. However, since an S-shaped leaf spring having a protrusion on the lower center side is used, a keyboard switch with a click action and a keyboard switch without a click action can be formed with substantially the same parts and substantially the same structure. I can do it. Therefore, parts can be used, and both keyboard switches can be manufactured on the same production line.
The automatic assembly of the keyboard switch becomes easy, which has a great effect on reducing costs. In addition, in order to make the elastic member as long as possible within the narrow holder by using a metal spring material, S
Since the shape prevents metal fatigue from concentrating in one place, it has the effect of providing a keyboard switch with a long life and high reliability. Furthermore, its durability is guaranteed to last over ¹⁰⁷ times. In addition, since the protruding part is integrally press-formed on the lower side of the center of the S-shaped leaf spring, the process of forming and attaching the protruding part separately can be omitted, simplifying the structure, preventing failures, and ensuring reliability. This has the effect of providing a keyboard switch with high performance. Furthermore, since a plurality of rising pieces are formed upward from the ring part of the S-shaped leaf spring and an upper protrusion is provided, the lower end of the coil spring can be fitted into the upper protrusion. It becomes possible to determine the position properly. Therefore, since the keyboard is always pressed from above the center, chattering is unlikely to occur, and a highly reliable keyboard switch that can be turned on and off reliably can be provided. Furthermore, since the damper rubber is fixed to the upper surface of the S-shaped leaf spring, it is possible to prevent the metal impact noise generated when clicking, and also has the effect of suppressing the natural vibration of the S-shaped leaf spring and preventing chattering. In addition, the engaging parts are provided at both ends of the S-shaped leaf spring, and the engaging parts are placed in the engaging groove of the holder so that the center part of the S-shaped leaf spring is above the engaging part, so that the click actuator can be easily moved. This has the effect that it is possible to generate a shock. Furthermore, by providing a bent part on the upper and lower curved parts of the S-shaped leaf spring, and by changing the bending angle of this bent part, the S-shaped spring of the same shape can be used to create a keyboard switch with a click action and a keyboard switch without a click action. It has the effect of being able to be used for both.

[Brief explanation of drawings]

1 is a plan view of the keyboard switch of the present invention, FIG. 2 is a longitudinal sectional view taken along the line X-X in FIG. 1, and FIG. FIG. 4 is a partially cutaway plan view excluding the cushion rubber of the lower holder;
6 is a plan view of the cushion rubber, FIG. 6 is a plan view of the S-shaped leaf spring, FIG. 7 is a side view of the S-shaped leaf spring with click action, and FIG. is a side view of an S-shaped leaf spring without click action, and FIGS. 9 and 10 are
1 is a cross-sectional view of a conventional keyboard switch;
FIG. 1 is a graph showing the relationship between the pressing load and stroke of a keyboard switch with a click action, and FIG. 12 is a graph showing the relationship between the pressing load and stroke of a keyboard switch without a click action. 10...Key top, 20...Key stem, 3
0...Holder, 31...Upper holder, 32...
Lower holder, 40... Koine spring, 50... Pressing part, 51... S-shaped leaf spring, 52... Damper rubber, 53... Curved part, 54... Ring part, 55...
...Engagement part, 56...Bending part, 57...Protrusion part, 5
8... Standing piece, 60... Contact part.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A key stem disposed slidably in the vertical direction within the upper holder, a coil spring disposed inside the key stem, and a coil spring disposed at the lower end of the coil spring. A keyboard switch comprising a pressing part and a contact part having a movable contact and a fixed contact arranged in a lower holder, wherein the pressing part has an S-shaped metal elastic member with engaging parts arranged at both ends. , the engaging portion is placed in the engaging groove in the holder,
A keyboard switch characterized in that the S-shaped metal elastic member is fitted so that its center portion is located closer to the key stem than the engaging portion in an unloaded state. (2) The keyboard switch according to claim 1, wherein the S-shaped metal elastic member is integrally provided with a ring portion and a pair of curved portions extending diagonally downward at the center thereof. (3) Utility model registration claim 1, in which the S-shaped elastic metal member is integrally formed by press-molding a part of the S-shaped elastic metal member so that a protrusion protrudes downward from the center of the S-shaped elastic metal member. The keyboard switch according to item 1 or 2. (4) The keyboard switch according to claim 2, wherein a plurality of rising pieces are formed upwardly from a ring portion formed at the center of the S-shaped metal elastic member. (5) The keyboard switch according to claim 1, wherein a damper rubber is fixed to the upper surface of the S-shaped metal elastic member. (6) The keyboard switch according to claim 1, wherein the upper and lower holders have a rectangular cross-sectional shape, and the engaging grooves are formed on diagonal joints. (7) By forming a bent part in the curved part of the S-shaped elastic metal member and changing the bending angle of the bent part, the dimensions between the upper surface of the engaging part and the upper surface of the central part can be changed to form the engaging groove. A keyboard switch according to claim 2 or 6 of the utility model registration claim in which the engaging portion is fitted.