JPH0684648U - Contact device - Google Patents

Abstract

(57) [Summary] [Purpose] Prevent contact failure and chattering and improve the reliability of the contact device. A contact rubber member 10 in which concentric annular and circular first and second movable contacts 17 and 18 are formed on the lower end surfaces of the first and second contact portions 13 and 16, respectively, is provided. Substrate 110 on which non-conducting fixed contacts 111 and 112 of
Mounted on the top, the surface of the first movable contact 17 is a conical surface having a point P1 on the central axis C as an apex and a vertex angle of ∠α. When the pressing portion 11 is pressed in the X direction shown by the arrow, the second bulging portion 14 is deformed, and the lower end portion of the first contact portion 13 is curved outward accordingly. After contacting the first fixed contact 111 in a substantially parallel manner, the second movable contact 18 contacts the second fixed contact 112.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a contact device used in electronic devices such as electronic musical instruments, office automation equipment, and precision control devices such as cameras, and more particularly, a contact device provided with a contact rubber member that is deformed by being pressed and driven by an actuator of its operator. Regarding

[0002]

[Prior art]

 As this type of conventional contact device, for example, there is one as shown in FIGS. 10 (a), 10 (b) and 10 (c).

A contact rubber member 40 shown in FIG. 10 (a) is integrally formed of an elastic material such as rubber, and is pressed by an actuator (not shown) in the arrow X direction by an actuator, and the pressing portion 41. A dome-shaped first bulging portion 42 that expands outward from the lower end portion of 41, a first contact portion 43 that is continuous therebelow, and a second bulging portion from the first contact portion 43. 44, a base portion 45 continuous through 44, a second contact portion 46 that converges and hangs downward from the lower end portion of the pressing portion 41, and a conductive ink is printed on the lower end surface of the first contact portion 43. Alternatively, an annular first movable contact 47 formed by coating or fusion of conductive rubber chips, and a second movable contact 48 concentric with the first movable contact 47 formed on the lower surface of the second contact portion 46. Consists of.

The contact rubber member 40 having such a structure forms non-conductive first and second fixed contacts 141 and 142 corresponding to the first and second movable contacts 47 and 48. By being mounted on the fixed substrate 140, and the pressing portion 41 is pressed in the X direction shown by the arrow, first, the second bulging portion 44 is deformed and the first contact portion 43 is lowered, and the first contact portion 43 is lowered. After the moving contact 47 pressure-bonds the non-conducting first fixed contact 141 to turn on the first contact of the first makeup, the first bulging portion 42 is deformed and the second contact portion 46 descends. Then, the second movable contact 48 is pressed against the non-conducting second fixed contact 142 to turn on the second contact of the second make.

Further, the contact rubber member 40 ′ shown in FIG. 10B has a pressing portion 41 ′, a first bulging portion 42 ′ and a base portion 45 which are similar to those shown in FIG. 10A. ′, The second movable contact 47 ′ having an annular shape is formed on the lower end surface of the second contact portion 43 ′ that converges and hangs down from the pressing portion 41 ′. The first movable contact 48 'having a concentric circular shape is formed on the lower surface of the first contact portion 46' formed through the second bulge portion 44 'from the ′, and the pressing portion 41 ′ is pressed. First, the first movable contact 48 'conducts the first fixed contact 142' on the fixed substrate 140 ', and then the second movable contact 47' conducts the second fixed contact 141 '. Has become.

Thus, for example, when the above contact device is used for a keyboard device of an electronic musical instrument, the first contact (lower contact) is turned on and then the second contact (upper contact) is turned on. It is possible to detect the time difference at the time, and the pressing speed of the operator, which is inversely proportional to the time difference, is obtained by the table conversion means or the calculation means, and it becomes possible to perform the touch control according to the pressing speed. Also, when the above contact device is used in an autofocus camera, etc., when the shutter button is pressed a little, the first contact is turned on to enable the operation of focusing, and when it is pressed more than that, the second contact is turned on. Allows the shutter to be released.

Further, the contact rubber member 40 ″ shown in FIG. 10 (c) is different from the one dome / two-make type shown in FIGS. 10 (a) and 10 (b), and has a pressing portion 41 ″ and a bulging portion. This is a one-dome one-make consisting of 42 ", base portion 45", contact portion 46 ", and movable contact 48". By pressing, the movable contact 48 "conducts the fixed contact 142" of the fixed substrate 140 ". The contact is turned on.

In these conventional contact devices, the surfaces of the circular movable contacts 48, 48 ′ and 48 ″ and the annular movable contacts 37, 37 ′ and 37 ″ are both flat and fixed. , 140 ', 140 ", respectively.

[0009]

[Problems to be solved by the device]

 However, in such a conventional contact device as shown in FIGS. 10 (a) and 10 (b), since the surface of the movable contact of the contact rubber member is formed parallel to the surface of the fixed contact, Depending on the shape of the rubber member, when the annular movable contact is pressed against the fixed contact, the contact surface may be inclined with respect to the fixed contact surface.

This phenomenon occurs especially when the shape of the contact rubber member is set so that a large load is generated before the annular movable contact comes into contact with the fixed contact in order to improve the touch feeling of the operator. The tendency becomes greater.

FIGS. 11A and 11B show the pressed state of the contact rubber member shown in FIGS. 10A and 10B, respectively. In FIG. 11A, when the pressing portion 41 is pressed down, first, the second bulging portion 44 elastically deforms to generate a load (reaction force), and accordingly, the lower end surface of the first contact portion 43 is generated. Falls while tilting, and the first movable contact 47 tilts from the horizontal plane and comes into contact with the first fixed contact 141.

Further, in FIG. 11B, when the pressing portion 41 ′ is pressed, the first bulging portion 42 ′ is elastically deformed, and the first contact portion 46 ′ is lowered to move the first contact portion 46 ′. After press-contacting the fixed contact 142 'of the second contact portion 42', the second bulge portion 44 'is elastically deformed and the lower end surface of the second contact portion 43' is inclined and lowered, so that the annular second movable contact 47 'is brought into the horizontal plane. And contacts the second fixed contact 141 '. This state is shown in FIG.

As described above, in both cases (a) and (b), the annular movable contact comes into contact with the fixed contact in the horizontal state in a tilted state, and the contact area is insufficient to easily cause poor contact. Also, chattering may occur.

Further, the circular movable contacts 48, 48 ′, 48 ″ formed in the center of the contact rubber members 40, 40 ′, 40 ″ shown in (a), (b) and (c) of FIG. When the pressing portions 41, 41 ′ and 41 ″ are vertically pressed, they are lowered while maintaining a substantially horizontal state, but when they are pressed obliquely, they may tilt from the horizontal and contact the fixed contacts.

In particular, when the circular movable contact is formed by printing conductive ink instead of fusing the conductive chips, it is difficult for ink to adhere to the peripheral portion of the lower end surface of the contact portion, and the movable contact is If the surface is slightly inclined, there is a problem that contact failure occurs as shown in FIG. 11 (c). The present invention has been made in view of the above points, and an object thereof is to prevent contact failure and chattering from occurring and improve reliability of contacts.

[0016]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention integrally forms a dome-shaped bulging portion having a pressing portion at the top and a contact portion having a movable contact forming at least an annular portion on the lower surface by an elastic material. In a contact device having a contact rubber member and a horizontal fixed substrate on which the contact rubber member is mounted and which forms a fixed contact corresponding to the movable contact, the movable contact is formed into a conical surface shape, It is intended to provide a contact device in which a contact surface of a movable contact is parallel to a surface of the fixed contact when the movable contact comes into contact with the fixed contact.

Further, a contact rubber member in which a dome-shaped bulging portion having a pressing portion at the top and a contact portion forming a circular movable contact on the lower surface are integrally formed by an elastic material, and the contact rubber member. In a contact device having a fixed board on which a fixed contact corresponding to the movable contact is mounted, the movable contact forming surface of the contact portion is formed into a convex curved surface, and the movable contact is formed up to the peripheral portion thereof. Equipment is also provided.

[0018]

[Action]

 By configuring the contact device according to the present invention as described above, in the case where the annular movable contact of the contact rubber member is formed in the shape of a conical surface in advance, the contact surface is fixed by pressing the pressing portion. The contact area with the fixed contact and the contact pressure per unit area increase, and reliable contact without contact failure or chattering is possible.

Further, in the case where the circular movable contact forming surface of the contact rubber member is formed into a convex curved surface, even when the movable contact contacts the fixed contact with a slight inclination from the horizontal, a sufficient contact area between both contacts is provided. As a result, poor contact and chattering are less likely to occur, and contact reliability is improved.

[0020]

【Example】

 An embodiment of the present invention will be specifically described below with reference to the drawings. 1 is a sectional view showing a first embodiment of the present invention, FIG. 2 is a sectional view showing a contact conduction state thereof, and FIG. 3 is a plan view showing an example of a fixed contact.

As shown in FIG. 1, the contact rubber member 10 includes a thick cylindrical pressing portion 11 and a dome-shaped first bulging portion that expands outward from the lower end of the pressing portion 11. Part 12, a first contact part 13 continuous therebelow, a second bulge part 14 expanding outward from the first contact part 13, and a base continuous with the second bulge part 14. The portion 15 and the second contact portion 16 that converges and hangs downward from the lower end portion of the pressing portion 11 are integrally formed by an elastic material such as rubber, and the lower end surface of the first contact portion 13 is made of conductive rubber. A ring-shaped first movable contact 17 made of a chip such as the above is fused to a circular second fixed contact 18 made of the same material on the lower end surface of the second contact portion 16, and the first and second The movable contacts 17 and 18 are concentric. The contacts 17 and 18 may be formed by printing or applying conductive ink, or by inserting the portions into an ink fountain and attaching the same, as described in the prior art.

Then, the lower end surface of the first contact portion 13 forms a conical surface having a point P1 on the central axis C of the contact rubber member 10 as an apex and an apex angle of ∠α. The angle β formed with the horizontal plane of the first movable contact 17 formed on the lower end surface of 13 is set to β = (180 ° −α) / 2. The value of ∠β needs to be changed depending on the height of the contact rubber member 10 in the natural state from the bottom surface of the first movable contact 17, the shape and thickness of the second bulging portion 14, the material of the elastic material, and the like. However, in the case of the one used in the experiment, the best result was obtained at about 20 degrees.

The contact rubber member 10 having the above-described configuration is a horizontal rubber member having non-conductive first and second fixed contacts 111 and 112 corresponding to the first and second movable contacts 17 and 18, respectively. Is mounted on a fixed substrate (hereinafter, simply referred to as “substrate”) 110.

FIG. 3A shows an example of a specific shape of the first and second fixed contacts 111 and 112 formed on the substrate 110. The first and second fixed contacts 111 and 112 are shown in FIG. The patterns are formed in a plurality of sets (two sets in FIG. 3 (a)) having different diameters in a substantially concentric shape, and the pattern of the semi-arcuate first fixed contact 111 is formed on the outside and the circle is formed on the inside. Each pattern of second fixed contacts 112 of the shape is provided. The first fixed contact 111 is composed of an outermost pattern 111a and an inner pattern 111b which are insulated from each other. The second fixed contact 112 is composed of one pattern 112a and the other pattern 112b which are insulated from each other.

In contrast to these two fixed contact patterns, as shown in FIG. 3B, the movable contact pattern has a circular outer pattern 121 and a circular arc-shaped outer pattern 121 centering on the zigzag portion on the fixed contact. Inner pattern 122. FIG. 3B is an end view. The three-dimensional shape of the outer movable contact may be formed by slightly recessing the ring-shaped portion other than the pattern 121 from the pattern 121, or may be formed on the same surface as the pattern and the other ring-shaped portion, and ink may be applied only to the pattern 121. You may apply. If the lead wire 112c from the inner zigzag portion of the second fixed setting is an insulating resist, the movable contact outer pattern 121 may have a perfect annular shape. The movable contact and the fixed contact thus configured are turned on and off with a time difference between the inner and outer comrades, respectively.

By the way, when the pressing portion 11 of the contact rubber member 10 is pushed in the X direction shown by the arrow from the state shown in FIG. 1, the second bulging portion 14 elastically deforms, and accordingly the lower end of the first contact portion 13 The side curves outward. As a result, as shown by the solid line in FIG. 2, the surface of the first movable contact 17 is brought into a substantially horizontal state and pressed against the first fixed contact 111, so that the first fixed contact 111 becomes conductive. At this time, the contact area of both movable and fixed contacts is maximized, and contact failure and chattering can be drastically reduced.

When the pressing portion 11 is further pressed from this state, the first bulging portion 12 elastically deforms as shown by an imaginary line in FIG. 2, whereby the second contact portion 16 descends, and the second contact portion 16 descends. The movable contact 18 is pressed into contact with the second fixed contact 112 substantially in parallel, and the second fixed contact 112 is brought into conduction. As a result, both the first and second movable contact surfaces become horizontal surfaces to ensure contact with the first and second fixed contacts 111 and 112.

Next, FIG. 4 is a sectional view showing a second embodiment of the present invention, and FIG. 5 is a sectional view showing its contact conduction state.

As shown in FIG. 4, the contact rubber member 20 of the second embodiment has a pressing portion 21 similar to the first embodiment and a dome that expands outward from the lower end of the pressing portion 21. -Shaped first bulging portion 22, a base portion 25 that is continuous therebelow, a second contact portion 23 that hangs inward from the lower end portion of the pressing portion 21, and further inside from the second contact portion 23. The second bulging portion 24 that rises up to the bottom and the first contact portion 26 that hangs inside the second bulging portion 24 are integrally molded by an elastic material, and the lower end surface of the first contact portion 26 is formed. A circular first movable contact 28 is formed, and a second movable contact 27 concentric with the first movable contact 28 is formed on the lower end surface of the second contact portion 23.

Then, the lower end surface of the second contact portion 23 forms a conical surface (inverse conical surface) having a point P2 on the central axis C ′ of the contact rubber member 20 as an apex and a vertex angle of ∠γ. , The angle δ between the second movable contact 27 formed on the lower end surface of the second contact portion 23 and the horizontal plane is set to δ = (180 ° −γ) / 2. The value of ∠δ is also changed by each element as in the case of the first embodiment.

The contact rubber member 20 having such a configuration has a horizontal surface formed with the non-conductive first and second fixed contacts 122 and 121 corresponding to the first and second movable contacts 28 and 27. It is mounted on the substrate 120 of. The specific shapes of the first and second fixed contacts 122 and 121 are the same as those shown in FIG. 3, but the inner pattern 112 is the first fixed contact pair and the outer pattern 111 is the second. It is applied to each fixed contact pair.

When the pressing portion 21 is pushed down in the X direction shown by the arrow in the state as shown in FIG. 4 with the above-mentioned configuration, the first bulging portion 22 is elastically deformed and the first and second contact portions 26. , 23 are both lowered, the first movable contact 28 is brought into pressure contact with the first fixed contact 122, and the first fixed contact 122 is brought into conduction. When the pressing portion 21 continues to be pressed, the second bulging portion 24 elastically deforms, the inner peripheral side of the second contact portion 23 is lifted accordingly, and the surface of the second movable contact 27 is substantially horizontal. Then, the second fixed contact 121 is brought into contact with the second fixed contact 121, and the second fixed contact 121 becomes conductive as shown in FIG.

In the above first and second embodiments, the case where the present invention is applied to the contact device having the contact rubber member of the one dome and the two make has been described, but the present invention has three contact points or more. The present invention can also be applied to a contact device having a dome multi-make contact rubber member. Further, in the first and second embodiments, the surface of the outer movable contact is a conical surface, but a part of the spherical surface may be omitted or another similar curved surface may be used. That is, in the first aspect, the conical surface shape includes these similar curved surfaces.

Further, FIG. 6 is a sectional view showing a third embodiment of the present invention, and FIG. 7 is a sectional view showing its contact conduction state. As shown in FIG. 6, the contact rubber member 30 of the third embodiment has a cylindrical pressing portion 31, a dome-shaped bulging portion 32 bulging outward from the lower end of the pressing portion 31, and a bulging portion. A base portion 35 continuing to the lower portion of the portion 32, a contact portion 36 that hangs from the lower end portion of the pressing portion 31 and has a lower end surface 36a formed in a spherical shape around a point P3 on the central axis C ″, and The end surface 36a includes a movable contact 38 having conductive ink applied thereto in the same manner as described above.

The contact rubber member 30 configured as described above is mounted on the substrate 130 on which the non-conductive fixed contact 132 corresponding to the movable contact 38 is formed. Then, when the pressing portion 31 is pushed down by an actuator (not shown), the bulging portion 32 elastically deforms and the contact portion 36 descends, and the movable contact 38 is pressed against the fixed contact 132 and fixed contact 132. Becomes conductive.

At this time, even if the pressing portion 31 is obliquely pressed as shown by the arrow X ′ in FIG. 7 and the contact portion 36 is grounded in the inclined state, the surface of the movable contact 38 becomes spherical. In addition, since the contact surface is slightly deformed into a flat surface by being pressed against the surface of the substrate, the contact area with the fixed contact 142 is enlarged, and the possibility of contact failure or chattering is drastically reduced.

FIGS. 8 (a) and 8 (b) show only a main part of a modified example in which the shape of the movable contact surface of the third embodiment is changed, and FIG. 8 (a) shows the contact portion 36 '. An annular flat surface portion 36b 'is formed on the peripheral edge portion of the spherical lower end surface 36a' to facilitate the attachment of printing ink to the peripheral edge portion, (b) is a plan view of the lower end surface 36a "of the contact portion 36". The peripheral portion 36b ″ has a rounded shape and is appropriately rounded.

By doing so, even when the pressing portion 31 of the contact rubber member 30 is pushed down obliquely, as shown in FIGS. 9A and 9B, the movable contact point deformed into a planar shape by pressure contact. 38 ', 38 "can contact the fixed contacts 132', 132" formed on the substrates 130 ', 130 "in a large area, and contact failure and chattering can be prevented.

In the third embodiment and its application example described above, the invention is applied to the contact device having the contact rubber member of one dome and one make, but the invention is not limited thereto. Instead, it can be implemented on the movable contact at the center of the contact rubber member with one dome and many make-up without any trouble. Also, the movable contact surface is not a perfect spherical shape, and it does not matter if an arbitrary convex curved surface is formed. Further, the contact device according to the present invention extends to not only a key switch of an electronic musical instrument, but also a switch device of an electronic device such as a camera and an OA device that can be variously selected or controlled by a delicate touch.

[0040]

[Effect of device]

 As described above, in the contact device according to the present invention in which the annular movable contact is formed in the shape of a conical surface, the contact portion having the movable contact formed on the lower end surface is deformed by the pressing of the contact rubber member. The movable contact comes into contact with the fixed contact substantially in parallel to each other, and the contact areas of both contacts are increased, so that contact failure and chattering can be prevented, and the reliability of the contact device can be improved.

Further, in the case where the movable contact forming surface of the contact portion formed with the circular movable contact is formed into a convex curved surface and the movable contact is formed up to the peripheral portion, the contact rubber member is pressed obliquely and the contact portion is Even if it contacts the fixed contact at an angle, a sufficient contact area can be secured between the fixed contact and the fixed contact, and in this case too, contact failure and chattering are prevented, and the contact device reliability is improved. It becomes possible to improve.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a contact conduction state of the same.

FIG. 3 is a plan view similarly illustrating the fixed contact and the movable contact.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a sectional view showing a contact conduction state of the same.

FIG. 6 is a sectional view showing a third embodiment of the present invention.

FIG. 7 is a sectional view showing the contact conduction state of the same.

FIG. 8 is a sectional view showing, in an enlarged manner, only a main part of a modified example of the third embodiment.

FIG. 9 is a sectional view showing the contact conduction state of the same.

FIG. 10 is a cross-sectional view illustrating a conventional contact device.

FIG. 11 is a sectional view showing the contact conduction state of the same.

[Explanation of symbols]

10, 20, 30 ... Contact rubber members 11, 21, 31
... pressing portion, 12, 22 ... first bulging portion, 13, 26 ... first contact portion, 14, 24 ... second bulging portion, 16, 23 ...
2nd contact part, 17, 28 ... 1st movable contact, 18, 2
7 ... 2nd movable contact, 32 ... bulging part, 36, 36 ', 3
6 ″ ... contact part, 38, 38 ′, 38 ″ ... movable contact, 11
0, 120, 130 ... Substrate, 111, 122 ... First fixed contact, 112, 121 ... Second fixed contact, 132 ... Fixed contact

Claims (2)

[Scope of utility model registration request] 1. A contact rubber member in which a dome-shaped bulging portion having a pressing portion at the top and a contact portion having a movable contact forming at least an annular portion on the lower surface are integrally formed of an elastic material, In a contact device having a horizontal fixed substrate on which the contact rubber member is mounted and a fixed contact corresponding to the movable contact is formed, the movable contact is formed in a conical surface shape, and the movable contact contacts the fixed contact. The contact device is characterized in that its contact surface is parallel to the surface of the fixed contact when the contact device is operated. 2. A contact rubber member in which a dome-shaped bulging portion having a pressing portion on the top and a contact portion having a circular movable contact formed on the lower surface are integrally formed of an elastic material, and the contact rubber member is mounted. A contact device having a fixed substrate on which a fixed contact corresponding to the movable contact is formed, wherein the movable contact forming surface of the contact portion is formed into a convex curved surface, and the movable contact is formed up to the peripheral portion thereof. Contact device.