CN1411005A - Variable resistor - Google Patents

Abstract

The object of the invention is to provide a variable resistor not affected by resin powder produced between a substrate and a rotating shaft. To achieve the object, the variable resistor is constituted so that its resistance value may be adjusted by sliding the contact pieces 35a and 35b of a slider 35 on a collector and a resistor concentrically provided on the surface of the substrate 10. In the center hole 11a of the substrate 10, a recessed section 11b having a stepped surface 11c is formed, and, on the rotating shaft 30, a stepped surface 33 is formed correspondingly to the stepped surface 11c of the recessed section 11b. The stepped surfaces 11c and 33 are brought into contact with each other. When the rotating shaft 30 is rotated, the resin powder is generated by frictional. However, the resin powder is not scattered on the surface of the substrate 10.

Description

Variable resistance

Technical field

The present invention relates to a kind of variable resistance.Particularly relate to a kind ofly, regulate the variable resistance of resistance value by making the sliding contact that is installed on the rotatable rotary axle in resistive element on the substrate and the slip on the collector body.

Background technology

As traditional rotating type adjustable resistor that is provided with sliding contact, known has, and opens among the 2000-138109 disclosed a kind of the spy.Shown in Fig. 7～10, this variable resistance has centre bore (dead eye) 101 on the substrate 100 that is made of synthetic resin, and is embedded with the 1st and the 2nd terminal 112,113.End 112a, the 113a of terminal 112,113 protrudes from the side of substrate 100, and the other end 112b, 113b expose above substrate 100.On substrate 100, form concentrically ringed circular collector body 104 and roughly circular resistive element 105.Collector body 104 is connected with the other end 112b of terminal 112, and by by being connected with the other end 113b of terminal 113 with the electrode that both ends 105a drew 106 on the mutual opposite of resistive element.

The rotating shaft 107 that is made of synthetic resin of the sliding contact that is made of electric conducting material having of can rotating freely is installed in the centre bore (dead eye) 101 of substrate 100, the sliding contact 108 that is made of electric conducting material is installed on rotating shaft 107, and this sliding contact 108 has the contact pin 108b in the contact pin 108a of sliding contact on the resistor 105 and sliding contact on current-collector 104.Regulate resistance value between terminal 112 and 113 by the position of contact pin 108a and 108b.

And, the lid 109 that is made of synthetic resin is installed on substrate 100, as shown in figure 11, on this lid 109, form by the fastening hook 109a on the dorsal edge that is fastened on substrate 100.That is, when using as shown in figure 12 121,122 pairs of lids 109 of mould to carry out resin forming, the 121a of pin portion that fastens hook 109a and be by mould 121 is formed, and then forms opening 109b by the vestige of extracting of the 121a of pin portion.Fig. 7 (a) has provided the diagram of 6 opening 109a.

Summary of the invention

Yet, in the variable resistance shown in Fig. 7～10, in the centre bore 107a of rotating shaft 107, insert the axostylus axostyle of not representing among the figure, give rotating shaft 107 with revolving force by this axostylus axostyle.The rotation number of rotating shaft can reach millions of times in the variable resistance.The surperficial sliding contact mutually (the represented position of symbol A among Fig. 8) of the flange part 107b of rotating shaft 107 and substrate 100 can produce toner.On the collector body 104 and resistive element 105 near the toner that produces may be attached to, form the obstacle that contacts of contact pin 108a and 108b, cause the decline of rotational life.

Shown in Fig. 7～12, owing to will form the vestige opening 109b that obtains fastening hook 109a and the 121a of pin portion is extracted inevitably, so fine foreign matter such as dust just enters from this opening 109b easily and covers 109 inside, thereby the contact obstacle or the short circuit of sliding contact 108 may take place, cause the decline of rotational life.

And during mounting cover 109, lid 109 has the possibility that irregular inclination takes place on substrate 100.For example cover 109 when tilting along as shown in figure 10 arrow Y directions, the top of lid 109 will produce pressure to the contact pin 108a of sliding contact 108, will cause contact pin 108a distortion etc.

And then, in Figure 13, because in described variable resistance, because the rotation number of rotating shaft 107 can reach millions of times, thus with regard to the bearing that requires rotating shaft 107 and be mated enough intensity is arranged, to bear the eccentric or inhomogeneous impact that is brought of axostylus axostyle.That is to say that it is big to wish that the effective aperture portion C of bearing 101 is tried one's best, it is thick that the wall thickness B of rotating shaft 107 tries one's best.

Therefore, in traditional variable resistance, the necessary amount in order to ensure the effective aperture portion C of dead eye 101 just needs substrate 100 to have certain thickness, like this, just be difficult to realize thin typeization, and, the maximization of axostylus axostyle, though the anti-rotation fracture strength to himself can obtain to improve, but owing to must guarantee that the wall thickness B of rotating shaft 107 has enough thickness, so the maximization of axostylus axostyle (centre bore) just makes the volume of variable resistance self increase.The requirement of the miniaturization of this and electronic unit runs in the opposite direction, and makes the enforcement of the miniaturization difficulty that becomes.

In other words, in order to make substrate 100 thin typeizations, the effective diameter portion C is diminished, or make wall thickness B attenuation for axostylus axostyle is maximized, these all can cause the intensity decreases of bearing portions, cause problems such as being easy to wearing and tearing.

And then, shown in Fig. 7～9, collector body 104 be coated by the coating of good conductors such as argentiferous, burn till and on substrate 100, form, and have physical engagement intensity with the regulation of the other end 112b of another terminal 112.But this joint belongs between the sinter of metal material 112 and coating, and promptly the joint between the dissimilar substances may not obtain enough intensity.Like this, terminal is cut off or load during bending machining or the stress that forms owing to the difference of the thermal coefficient of expansion between substrate 100 and the collector body 104, just may cause peeling off of described joint, make reliability decrease as electronic unit.And, because the sulfuration of silver also can make contact resistance increase, thereby cause the decline of product quality.

And, owing to being the collector body 104 that on substrate 100, applying coating and sintering is formed,, cause cost to rise so equipment and operation are increased.

In view of the above problems, the objective of the invention is to, a kind of variable resistance is provided, can avoid between substrate that constitutes by resin material respectively and rotating shaft, taking place the harmful effect of toner.

The present invention also aims to, a kind of variable resistance is provided, do not form unnecessary connecting covering, thereby can prevent the intrusion of fine foreign matter to the peristome of variable resistance inside.

The present invention also aims to, a kind of variable resistance is provided, when assembling is covered for substrate, can avoid the distortion of the sliding contact of internal part.

The present invention also aims to, a kind of variable resistance is provided, can strengthen the bearing portions of rotating shaft, and can improve durability, can realize the thin typeization of substrate and the big footpathization of rotating shaft (the thin axiation of rotating shaft) simultaneously.

The present invention also aims to, a kind of variable resistance is provided, the connection reliability height and the cost of terminal and collector body can reduce.

In order to achieve the above object, variable resistance of the present invention, on the substrate that constitutes by resin, its each terminal is set with one heart constitutes resistive element and the collector body that is electrically connected, and the rotating shaft that is made of resin material is installed on described substrate, the sliding contact that can slide on resistive element and collector body is being installed on the described rotating shaft, it is characterized in that: on described substrate, form and to rotate the centre bore that described rotating shaft is installed freely, and on described substrate, be formed on the concentric circles with this centre bore and form continuous recess by jump face and this centre bore, on described rotating shaft, form with the jump of described recess in the face of to the jump face, the jump face of described rotating shaft and the jump face of described recess are in contact with one another.

In variable resistance of the present invention, substrate and rotating shaft that each free resin constitutes contact by the jump face that forms on the recess jump face that forms on the substrate center hole and rotating shaft, and rotating shaft rotates under this contact condition.Though can produce toner between the jump face that is in contact with one another, this generation place is limited to the inner peripheral surface in substrate center hole, toner can not disperse to the surface of substrate.So, on the collector body of substrate surface setting and resistive element, just can not adhere to toner, thereby can prevent the obstacle that contacts with sliding contact and the reduction of rotational life.

Particularly, it is desirable to, described sliding contact is installed in the flange part that is protruded by the rotating shaft outer peripheral face, and between the surface of this flange part and substrate, forms the space.Can prevent the generation of substrate surface toner so really.

And described centre bore can also be formed in the circular lug boss of substrate back protrusion, thereby the intensity of the bearing portions of the axostylus axostyle that inserts in the rotating shaft is enhanced.And then, it is desirable to, circular lug boss can be entrenched in the hole portion of printed base plate.The height of variable resistance is reduced, and make circular lug boss can access the support of printed base plate.Simultaneously, can play of the effect of decision variable resistance with respect to the position of substrate.

Variable resistance among the present invention, have following feature: described substrate is covered by the lid of described resin material, form the 1st buckling parts in the side of described substrate, on the tabs of the described side that is arranged on described lid, be formed with the 2nd buckling parts that the 1st buckling parts with described substrate is interlocked, near this tabs, the peristome that does not exist the inside with variable resistance to connect.

Particularly, the inside of the variable resistance of indication in this specification is meant substrate surface and covers formed space between the lid of this substrate.

In the variable resistance among the present invention,,, promptly can stop the intrusion of small foreign matter on the tabs of lid so can guarantee to cover inner dust tightness because there is not the peristome that connects to the inside of variable resistance in the 2nd buckling parts that forms near tabs.

Particularly, the 2nd buckling parts is the through hole that forms on the tabs direction, so extract and residual vestige near the pin portion that designs on by mould with regard to can not stay the resin forming at lid the time tabs.And described through hole is by the described lid of resin forming the time, forms by using the movable member of can be from the side freely advancing and retreat to the mould side wall portion of a side.

Variable resistance of the present invention also has following feature: described substrate is covered by the lid of described resin material, form the 1st buckling parts in the side of described substrate, on the tabs of the side of described lid setting, form and to connect the through hole of this tabs at thickness direction as the 2nd buckling parts that is interlocked with described the 1st buckling parts, described through hole is by the described lid of resin forming the time, forms by using the movable member of can be from the side freely advancing and retreat to the mould side wall portion of a side.

The effect that illustrates in the effect of this variable resistance and the variable resistance of the invention described above is basic identical.

Variable resistance among the present invention, also has following feature: on the substrate that constitutes by resin, be provided with one heart with each terminal and constitute resistive element that is electrically connected and the collector body that is positioned at this resistive element inboard, and, the rotating shaft that has sliding contact is installed on described substrate, the 1st contact pin of this sliding contact is on resistive element, the 2nd contact pin can be slided on collector body separately, described substrate is covered by the lid of described resin material, side at described substrate forms the 1st and the 2nd tabs that is positioned at described substrate side surfaces, forming the 2nd buckling parts that is interlocked with the 1st buckling parts that on described substrate side surfaces, forms on the 1st tabs, and on the 2nd buckling parts, not forming buckling parts, the 2nd tabs of described lid is set at than the position of the 1st tabs of covering further from the 1st contact pin of the described sliding contact when assembling initial setting.

In variable resistance of the present invention, will cover for the substrate pressurization, the 2nd buckling parts that forms the 1st tabs and the 1st buckling parts that forms in substrate side surfaces are interlocked, this fastens needs certain fastening power.On the other hand, the 2nd tabs does not then need the power that fastens especially just can place the side of substrate.At this moment, if the relative substrate of supposition lid forms certain inclination, owing to the 2nd tabs that does not need the power of fastening can at first tilt with the state that avales, so if be provided with the 2nd tabs to such an extent that leave the position of the 1st contact pin that is positioned at the outside, then lid just can not make the 1st contact pin distortion.And, because the 2nd contact pin is positioned at inner side, so, also can not deform even be stamped some inclinations.

In variable resistance of the present invention, if near the 1st tabs, there is not the peristome that connects to the inside of variable resistance in the 2nd buckling parts that forms on described the 1st tabs, variable resistance in inventing with the above-mentioned the 1st, the 2nd is same, can prevent the intrusion of small foreign matter.And, described the 2nd buckling parts peristome is the through hole that its thickness direction forms in described the 1st tabs upper edge, described through hole is by the described lid of resin forming the time, forms by using the movable member of can be from the side freely advancing and retreat to the mould side wall portion of a side.

Variable resistance among the present invention, also have following feature: the approximate centre portion at described substrate is formed with the dead eye that rotation described rotating shaft freely is installed, and is formed with the circular lug boss that is in the protrusion of concentric circles position with described dead eye simultaneously at the back side of substrate.

In variable resistance of the present invention, also has following feature: rotating shaft is rotated with sliding contact by the axostylus axostyle that is inserted in the described rotating hole, be provided with the lug boss that is in the protrusion of concentric circles position with described dead eye at the back side of described substrate, the bearing of the inner peripheral surface of this lug boss as described axostylus axostyle.

In the variable resistance of the 1st and the 2nd invention, axostylus axostyle in order to make the rotating shaft rotation in the insertion rotating shaft, the centre bore that its rotation not only is rotated axle supports, and the circular lug boss that also is set at substrate back supports, so can increase the intensity of the bearing portions of axostylus axostyle.Like this, thin-walled property of the thin typeization of substrate, axostylus axostyle (rotating shaft) etc. just becomes possibility.

Particularly, preferably make the circular lug boss that is arranged on substrate back have identical internal diameter with the centre bore of rotating shaft, and then, it is desirable to, circular lug boss can be entrenched in the hole portion on the printed base plate that variable resistance is installed.Height in the time of can reaching the installation that is accompanied by the substrate thin typeization like this reduces, and circular lug boss can access the support of printed base plate.And, can play of the effect of decision variable resistance with respect to the position of substrate.

Variable resistance among the present invention, also have following feature: described terminal is made of the 1st terminal and the 2nd terminal, described collector body is by forming one with described the 1st terminal, circular or roughly circular metal forming material constitutes, and expose on the surface of described substrate, the length of prolonging face by making described collector body and resistive element can corresponding described sliding contact position of rotation change, and adjust resistance value between described the 1st terminal and the 2nd terminal.

In variable resistance of the present invention, the 1st terminal and collector body are made of a metal forming material, do not have the bonding part.Therefore, even terminal is subjected to the effect of load, or collector body is subjected to the effect of thermal stress, the decline of the electrical characteristics between the 1st terminal and the collector body can not take place yet or move bad, problem such as can not work.And, because collector body and terminal are disposed as one, can carry out the cut-out of metal material and the insertion of synthetic resin (substrate), there is no need to adopt the operation of glue applying coating, sintering to form.

Particularly, be preferably in the conductivity lubricating layer is set on the described collector body.When collector body is metal material,, is provided with lubricating layer and can makes these wearing and tearing reduce, increase the service life by the slip meeting enhance faster wear of sliding contact.And, if this conductivity lubricating layer uses and the same material of described resistive element, then can adopt with the same operation of resistive element and apply (for example silk screen printing).

Also have, it is desirable to, the width dimensions of described conductivity lubricating layer is equal to or less than the width dimensions of collector body.Like this, lubricating layer only forms on collector body, just can not be subjected to the caused stress of difference owing to thermal coefficient of expansion between metal material (collector body) and the resin material (substrate), thereby can prevent lubricating layer generation crackle.

Description of drawings

Fig. 1 is the variable resistance of the present invention the 1st embodiment, (A) is vertical view, (B) is side view.

Fig. 2 is that expression is installed in profile on the printed base plate to described variable resistance.

Fig. 3 is the vertical view of the described variable resistance substrate of expression.

Fig. 4 is the vertical view of the described substrate die completed state of expression.

Fig. 5 is the stereogram of the lid of expression variable resistance.

Fig. 6 is the profile of fastening structure one example of described variable resistance of expression and lid.

Fig. 7 is the traditional variable resistance of expression, (A) is vertical view, (B) is side view.

Fig. 8 is the profile of expression variable resistance shown in Figure 7.

Fig. 9 is the vertical view of expression variable resistance substrate shown in Figure 7.

Figure 10 is the profile of expression variable resistance shown in Figure 7.

Figure 11 is the profile of the buckling structure of expression variable resistance shown in Figure 7.

Figure 12 is expression when this of variable resistance shown in Figure 7 carried out resin forming, the profile of mould therefor.

Figure 13 is the profile of expression variable resistance shown in Figure 7.

Figure 14 is the variable resistance of the present invention the 2nd embodiment, (A) is vertical view, (B) is side view.

Figure 15 is the profile of the described variable resistance of expression.

Figure 16 is the vertical view of the described variable resistance substrate of expression.

Figure 17 is the vertical view of the described substrate die completed state of expression.

Figure 18 is the stereogram of the lid of expression variable resistance.

Figure 19 is the profile of fastening structure one example of described variable resistance of expression and lid.

Figure 20 is expression when described lid carried out resin forming, the profile of mould therefor.

Figure 21 is the buckling parts of the 2nd routine middle cover one side of expression fastening structure, (A) is vertical view, (B) is side view.

Figure 22 is the buckling parts of substrate one side in the 2nd example of expression fastening structure, (A) is vertical view, (B) is side view.

Figure 23 is the buckling parts of the 3rd routine middle cover one side of expression fastening structure, (A) is vertical view, (B) is side view.

Figure 24 is the buckling parts of substrate one side in the 3rd example of expression fastening structure, (A) is vertical view, (B) is side view.

Figure 25 is the variable resistance of third embodiment of the invention, (A) is vertical view, (B) is side view.

Figure 26 is illustrated in described variable resistance is installed on the printed base plate, and inserts the profile of the state of axostylus axostyle.

Figure 27 is the vertical view of the described variable resistance substrate of expression.

Figure 28 is the vertical view of the described substrate mold forming state of expression.

Figure 29 is the stereogram of the lid of expression variable resistance.

Figure 30 is the profile of fastening structure one example of described variable resistance of expression and lid.

Figure 31 is the variable resistance of fourth embodiment of the invention, (A) is vertical view, (B) is side view.

Figure 32 is the profile that the described variable resistance of expression is installed on printed base plate.

Figure 33 is the vertical view of the described variable resistance substrate of expression.

Figure 34 is the vertical view of the described substrate mold forming state of expression.

Figure 35 is the stereogram of the lid of expression variable resistance.

Figure 36 is the profile of fastening structure one example of described variable resistance of expression and lid.

Figure 37 is the vertical view of substrate of the variable resistance of expression fifth embodiment of the invention.

Figure 38 is the width dimensions relation of expression collector body and lubricating layer.Symbol description:

The 10-substrate, the circular lug boss of 11-, 11a-centre bore, 11b-recess, 11c-jump face, 12, the 13-terminal, the 12b-collector body, 15-resistive element, 30-rotating shaft, 31-centre bore, 32-flange part, 33-jump face, 35-sliding contact, 45-printed base plate, 46-hole portion, C-gap.

Embodiment

Be elaborated below in conjunction with the execution mode of accompanying drawing to variable resistance among the present invention.

At first, in conjunction with Fig. 1～4, the formation of variable resistance among the present invention is illustrated.

This variable resistance is made of synthetic resin substrate 10, synthetic resin lid 20 and the synthetic resin rotating shaft 30 that is provided with sliding contact 35.Rear side protrusion at substrate 10 is provided with lug boss 11, is formed with centre bore 11a, and is embedded with terminal 12,13.The end 12a of terminal 12 protrudes from the side of substrate 10, and central portion exposes the surface of substrate 10 as circular collector body 12b.The end 13a of terminal 13 protrudes from the side of substrate 10, and the other end 13b exposes the surface of substrate 10.

As shown in Figure 4, described terminal the 12, the 13rd is die-cut into the regulation shape by the ring-shaped material 40 of growing size, inserts mould (not shown) shaping substrate 10.Behind this resin forming, on the surface of substrate 10, form obtain by the coating of electroconductive resin material almost be circular resistive element 15, the both ends 15a of the mutual subtend of resistive element 15 is connected with the other end 13b of described terminal 13.Collector body 12b is provided with conductivity lubricating layer 14.The resin that this lubricating layer 14 is close with the resinous principle with resistive element 15 is as its main component.Or lubricating layer 14 adopts same electroconductive resin with resistive element 15, and applies equally with resistive element 15.

Collector body 12b (lubricating layer 14) and resistive element 15 are arranged at the surface of substrate 10 with one heart, and collector body 12b is positioned at the inboard of resistive element 15.

Rotating shaft 30 has centre bore 31, around flange part 32 sliding contact 35 is installed, and among the centre bore 11a of installation base plate 10, can freely rotates.Sliding contact 35 is made of conductive metal material, is included in the 1st contact pin 35a of the brush shape that can slide that is the elasticity crimped status on the resistive element 15 and is brush shape the 1 two contact pin 35b that can slide of elasticity crimped status on collector body 12b (lubricating layer 14).

And then, form recess 11b in the first half of the centre bore 11a of described substrate 10.The recess 11b of this substrate 10 and the centre bore 11a of substrate 10 are positioned on the concentric circles, and centre bore 11a and jump face 11c are continuous.Shown in Fig. 1 (A), the part of the circular port of the centre bore 31 of rotating shaft 30 is made buried shape, and the centre bore 31 of rotating shaft 30 has identical internal diameter with the centre bore 11a of substrate 10.

As shown in Figure 2, when rotating shaft 30 was installed in the centre bore 31 of substrate 10, the jump face 33 of rotating shaft 30 was connected with the recess 11b jump face 11c of substrate 10.Form clearance C between the flange part 32 of rotating shaft 30 and the surface of substrate 10.

Lid 20 has the centre bore 21 of decision rotating shaft 30 upper positions, is installed on the substrate 10 in the mode that sucks.In detail, as shown in Figure 6, side at substrate 10, form the fastening lug boss 10a that upside tilts, at the 1st tabs 22 places that the side surface part of covering 20 is provided with, thickness direction along tabs 22 is formed with the through hole 20a that is interlocked with lug boss 10a, and through hole 20a is installed in lug boss 10a in the mode that sucks.And then, on lid 20, be formed with the 2nd tabs 23 of the side 10c that is positioned at substrate 10.For fear of the interference of terminal 12,13, the 2nd tabs 23 forms the broach shapes, only is that face contacts and is not fastening with side 10c.

The resistor of forming by above structure, in the hole of printed base plate 45 shown in dotted lines in Figure 2 one 46, the chimeric lug boss 11 that substrate 10 is arranged, and, in the mode of soldering terminal 12,13 is installed in the bonding land, position, plane of printed base plate 45 (not shown).In order to make rotating shaft 30 and sliding contact 35 rotations, in centre bore 31,11a, insert the operation axostylus axostyle of not representing among the figure.The insertion portion of this axostylus axostyle forms the shape that is interlocked with centre bore 11a, drive by the rotation of any direction to the left and right, make rotating shaft 30 and the rotation of sliding contact 35 one, according to contact pin 35a, 35b variation, adjust the resistance value between the terminal 12,13 for the contact position of resistive element 15 and collector body 12b.

In the variable resistance of present embodiment, when by axostylus axostyle rotating shaft being rotated driving, maximum frictional force occurs in jump face 33, the 11c that is in contact with one another.Generate toner herein.But this generation place is the medial surface at centre bore 11a, so toner can not disperse to substrate surface.Therefore, just can not adhere to toner above collector body 12b (lubricating layer 14), the resistive element 15 etc., thereby prevent the obstacle that contacts with sliding contact 35, and the decline of rotational life.Simultaneously, owing to be formed with clearance C between the surface of the flange part 32 of rotating shaft 30 and substrate 10, the result can guarantee to prevent the generation of these resin dust.

Axostylus axostyle is supported by the inner peripheral surface (centre bore 11a) of the circular lug boss 11 that is provided with on the centre bore 31 of rotating shaft 30 and the substrate, can make the intensity increase of bearing portions, the durability raising.And, can make substrate 10 slimmings, the projection of only outstanding lug boss 11.

Because described circular lug boss 11 is to be embedded in the hole portion 46 of printed base plate 45, reduces so can reach the height of variable resistance when mounted, and can make the intensity of lug boss 11 improve.And play for of the effect of decision variable resistance with respect to the position of printed base plate.

Variable resistance of the present invention is not limited to described embodiment, in the scope of its theme, certainly does various changes.

The following describes the 2nd embodiment of variable resistance among the present invention, at first its structure is illustrated in conjunction with Figure 14～Figure 17.

This variable resistance is made of the lid 220 of the substrate 210 of synthetic resin, synthetic resin and the rotating shaft 230 that is provided with the synthetic resin of sliding contact 235.Substrate 210 is formed with centre bore 211, and has secretly set terminal 212,213.The end 212a of terminal 212 protrudes from the side of substrate 210, and central portion exposes the surface of substrate 210 as circular collector body 212b.The end 213a of terminal 213 protrudes from the side of substrate 210, and the other end 213b exposes the surface of substrate 210.

As shown in figure 17, described terminal the 212, the 213rd is die-cut into the regulation shape by the ring-shaped material 240 of growing size, inserts the mould (not shown) again and is shaped to substrate 210.Behind this resin forming, on the surface of substrate 210, form obtain by the coating of electroconductive resin material almost be circular resistive element 215, the both ends 215a of the mutual subtend of resistive element 215 is connected with the other end 213b of described terminal 213.Be provided with conductivity lubricating layer 214 at collector body 212b.The resin that this lubricating layer 214 is close with the resinous principle with resistive element 215 is as its main component.Or lubricating layer 214 adopts same electroconductive resin with resistive element 215, and applies equally with resistive element 215.

Collector body 212b (lubricating layer 214) and the resistive element 215 concentric surfaces that are arranged at substrate 210, collector body 212b is positioned at the inboard of resistive element 215.

Rotating shaft 230 has centre bore 231, around flange part 232 sliding contact 235 is installed, and is installed in the centre bore 211 of substrate 210, can freely rotate.Sliding contact 235 is made of conductive metal material, be included in and be the elasticity crimped status on the resistive element 215, the 1st contact pin 235a of the brush shape that can slide and is the elasticity crimped status, the 2nd contact pin 235b of the brush shape that can slide on collector body 212b (lubricating layer 214).

Shown in Fig. 7 (A), the part of the circular port of the centre bore 230a of rotating shaft 230 is made buried shape.Insert the operation axostylus axostyle that does not show among the figure among the centre bore 230a, rotation by an assorted left and right sides any direction drives, make rotating shaft 230 and the rotation of sliding contact 235 one, according to contact pin 235a, 235b variation, adjust the resistance value between the terminal 212,213 for the contact position of resistive element 215 and collector body 212b.

Lid 220 has the centre bore 221 of decision rotating shaft 230 upper positions, is installed on the substrate 210 in the mode that sucks.Suction is meant that the elasticity by resin etc. makes two joint portions force chimeric combinations.With other combination, for example the weldering is sticking, welding, soldering etc. are compared owing to do not need special processing, so have assembling simple, be suitable for producing in batches, low cost and other advantages.

In detail, as shown in figure 19, side at substrate 210, upside forms the fastening lug boss 210a of inclination, at the 1st tabs 222 places that the side surface part of covering 220 is provided with, thickness direction along tabs 222 is formed with the through hole 220a that is interlocked with lug boss 210a, and through hole 220a is installed in lug boss 210a in the mode that sucks.As shown in figure 20, this through hole 220a, when being to use 251,252 pairs on mould lid 220 to carry out resin forming, the movable pin parts 253 that can freely advance and retreat in mould 251 1 side settings are formed by the vestige of extracting of these pin parts 253.

As shown in figure 16,4 places that fasten the recess 210b that sink slightly with lug boss 210a on the side of substrate 210 form, the 1st tabs 222 keep corresponding with this recess 210b and with suction in conjunction with necessary flexible state under form.Like this because through hole formed by the pin parts 253 that can advance and retreat from a side, so just can be at the surface of lid 220 formation pin parts 121a as shown in figure 12 extract vestige peristome 109b (with reference to Fig. 7 (A)).Therefore, small foreign matter just can not take place do not enter and cover 220 interior phenomenons, the following degradation to contact obstacle, short circuit and the rotational life of sliding contact 235 that can avoid causing thus.

And then, on lid 220, be formed with the 2nd tabs 223 that is positioned at substrate 210 side 210c.For fear of the interference of terminal 212,213, the 2nd tabs 223 forms the broach shapes, only is that face contacts and is not fastening with side 210c.As shown in figure 15, by being contacted by the surface with substrate 210, jump face 225 constitutes the location.

Also have,, except the 1st example as shown in figure 19, can also adopt the 2nd example shown in Figure 21,22, the 3rd example shown in Figure 23,24 about the structure of substrate 210 with the suction fastening of lid 220.Certainly, also can adopt above-mentioned structure in addition.

The 2nd example has, and formed shallow recess 220d on the 1st tabs 222 as shown in figure 21 goes up the fastening structure that the low fastening that forms combines with lug boss 210d with as shown in figure 22 recess 210b.The 3rd example has, and formed rectangle bulge 220e on the 1st tabs 222 as shown in figure 23 goes up the fastening structure that the jump face 210e that forms combines with as shown in figure 24 recess 210b.

Described sliding contact 235 as shown in figure 16, is set to such an extent that the 1st contact pin 235a of sliding contact contacts for resistive element 215 at position A at the initial stage of assembling, and the 2nd contact pin 235b of sliding contact contacts for collector body 212b (lubricating layer 214) at position B.In Figure 15, also represented this initial setting state.The 1st tabs 222 of lid 220 is arranged on the nearer position of the 1st contact pin 235a apart from sliding contact, and the 2nd tabs 223 of lid 220 is arranged on the side of the 2nd contact pin 235b of sliding contact.That is to say that when the initial setting of assembling, the 2nd tabs 223 of sliding contact is provided with than the 1st tabs 222 of the sliding contact farther position of position A apart from the 1st contact pin 235a of sliding contact.

In the variable resistance of present embodiment, to cover 220 when being installed on the substrate 210, from the top of lid it is exerted pressure, the tendency that lid 220 may avale in the 2nd tabs 223 1 sides that not are not interlocked with the side 210c of substrate 210, even cover 220 inclination having taken place, also is the direction inclination along arrow Y shown in Figure 15.This incline direction is to leave to cover 220 top-direction for the 1st contact pin 235a that is positioned at the outside, therefore can not cause the distortion of the 1st contact pin 235a.And, because the 2nd contact pin 235b is positioned at the inboard,, can not cause distortion to it so some inclinations have taken place even cover 220 directions along arrow Y yet.

The following describes the 3rd embodiment of variable resistance among the present invention, at first its structure is illustrated in conjunction with Figure 25～Figure 28.

This variable resistance is made of the lid 320 of the substrate 310 of synthetic resin, synthetic resin and the rotating shaft 330 that is provided with the synthetic resin of sliding contact 335.Substrate 310 is formed with centre bore (dead eye) 311a, and is embedded with terminal 312,313.The end 312a of terminal 312 protrudes from the side of substrate 310, and central portion exposes the surface of substrate 310 as circular collector body 312b.The end 313a of terminal 313 protrudes from the side of substrate 310, and the other end 313b exposes the surface of substrate 310.

As shown in figure 28, described terminal the 312, the 313rd is die-cut into the regulation shape by the ring-shaped material 340 of growing size, inserts the mould (not shown) again and is shaped to substrate 310.Behind this resin forming, on the surface of substrate 310, form obtain by the coating of electroconductive resin material almost be circular resistive element 315, the both ends 315a of the mutual subtend of resistive element 315 is connected with the other end 313b of described terminal 313.Collector body 312b is provided with conductivity lubricating layer 314.The resin that this lubricating layer 314 is close with the resinous principle with resistive element 315 is as its main component.Or lubricating layer 314 adopts same electroconductive resin with resistive element 315, and applies equally with resistive element 315.

Collector body 312b (lubricating layer 314) and the resistive element 315 concentric surfaces that are arranged at substrate 310, collector body 312b is positioned at the inboard of resistive element 315.

Rotating shaft 330 has centre bore 331, around flange part 332 sliding contact 335 is installed, and in the centre bore 311 of installation base plate 310, can freely rotates.Sliding contact 335 is made of conductive metal material, be included in the 1st contact pin 335a of the brush shape that can slide that is the elasticity crimped status on the resistive element 315 and on collector body 312b (lubricating layer 314), be the 2nd contact pin 335b of the brush shape that can slide of elasticity crimped status.

And then, be provided with the circular lug boss 311b of protrusion in the back side of described substrate 310 side.This lug boss 311b and dead eye 311a and have identical internal diameter with the centre bore 311 of rotating shaft 330 on concentric circles.And shown in Figure 25 (A), the part of the circular port of the centre bore 311 of rotating shaft 330 is buried state.

As shown in figure 26, in the hole portion 346 of the printed base plate 345 of variable resistance, the chimeric lug boss 311 that substrate 310 is arranged, and, with the mode actual installation of soldering terminal 312,313 is arranged in the bonding land, position, plane of printed base plate 45 (not shown).In order to make rotating shaft 330 and sliding contact 335 rotations, in centre bore 331,311a, insert the operation axostylus axostyle of not representing among the figure 350, the insertion portion of this axostylus axostyle forms the shape that is interlocked with centre bore 331, under the state that inserts, supported by the inner peripheral surface 311c of centre bore 331 and described lug boss 311b.By any direction rotating driveshaft bar 350 to the left and right, make rotating shaft 330 and the rotation of sliding contact 335 one, according to contact pin 335a, 335b variation, adjust the resistance value between the terminal 312,313 for the contact position of resistive element 315 and collector body 312b.

Lid 320 has the centre bore 321 of decision rotating shaft 330 upper positions, and is installed on the substrate 310 in the mode that sucks.In detail, as shown in figure 30, upside in the side of substrate 310 forms the fastening lug boss 310a of inclination, the 1st tabs 322 places that are provided with in the side of lid 320, thickness direction along tabs 322 is formed with the through hole 320a that is interlocked with lug boss 310a, and through hole 320a is installed on the lug boss 310a in the mode that sucks.And then, on lid 320, be formed with the 2nd tabs 323 of the side 310c that is positioned at substrate 310.For fear of the interference of terminal 312,313, the 2nd tabs 323 forms the broach shapes, only is that face contacts and is not fastening with side 310c.

In variable resistance of the present invention, axostylus axostyle 350 is supported by the centre bore 331 of rotating shaft 330 and the inner peripheral surface 311c that is arranged on the lug boss 311b on the substrate 310, and the intensity of bearing portions is increased, and durability improves.And, can make substrate 310 slimmings, and only give prominence to the projection of lug boss 311.The wall thickness of rotating shaft 330 can attenuation, and the wall thickness B of attenuation as shown in figure 26.Because the wall thickness of rotating shaft 330 can attenuation, centre bore 331 just can maximize, and this diameter that just means axostylus axostyle 350 increases, thereby makes its anti-rotation fracture strength raising.

Described circular lug boss 311b can be entrenched in the hole portion 346 of printed base plate 345.The height of variable resistance is reduced, and the intensity of circular lug boss 311b is improved.And, also play of the effect of decision variable resistance with respect to the position on the substrate.

The following describes the 4th embodiment of variable resistance among the present invention, at first its structure is illustrated in conjunction with Figure 31～Figure 36.

This variable resistance is made of the lid 420 of the substrate 410 of synthetic resin, synthetic resin and the rotating shaft 430 that is provided with the synthetic resin of sliding contact 435.Substrate 410 is formed with centre bore (dead eye) 411, and is embedded with terminal 412,413.

End 412a, the 412a of the 1st terminal 412 protrudes from the side of substrate 410, and central portion exposes the surface of substrate 410 as circular collector body 412b.The end 412a of the 1st terminal 412 and collector body 412b are formed by a metal material one cutting, and the end 413a of the 2nd terminal 413 protrudes from the side of substrate 410, and the other end 413b exposes the surface of substrate 410.

As shown in figure 34, described terminal the 412, the 413rd, the ring-shaped material 440 very long by size is die-cut into the regulation shape, inserts the mould (not shown) again and is shaped to substrate 410.Behind this resin forming, on the surface of substrate 410, form obtain by the coating of electroconductive resin material almost be circular resistive element 415, the both ends 415a of the mutual subtend of resistive element 415 is connected with the other end 413b of described terminal 413.Collector body 412b and the resistive element 415 concentric surfaces that are arranged at substrate 410, collector body 412b is positioned at the inboard of resistive element 415.

Rotating shaft 430 has centre bore 431, around flange part 432 sliding contact 435 is installed, and in the centre bore 411 of installation base plate 410, can freely rotates.Sliding contact 435 is made of conductive metal material, is included in the 1st contact pin 435a of the brush shape that can slide that is the elasticity crimped status on the resistive element 415 and is the 2nd contact pin 435b of the brush shape that can slide of elasticity crimped status on collector body 412b.

Shown in Figure 31 (A), the part of the circular port of the centre bore 430a of rotating shaft 430 is made buried shape.Insert the operation axostylus axostyle that does not show among the figure among the centre bore 430a, drive by the rotation of any direction to the left and right, make rotating shaft 430 and the rotation of sliding contact 435 one, according to contact pin 435a, 435b variation, adjust the resistance value between the terminal 414,413 for the contact position of resistive element 415 and collector body 412b.

Lid 420 has the centre bore 421 of decision rotating shaft 430 upper positions, is installed on the substrate 410 in the mode that sucks.In detail, as shown in figure 36, upside in the side of substrate 410 forms the fastening lug boss 410a of inclination, the 1st tabs 422 places that are provided with in the side of lid 420, thickness direction along tabs 422 is formed with the through hole 420a that is interlocked with lug boss 410a, and through hole 420a is installed on the lug boss 410a in the mode that sucks.And then, on lid 420, be formed with the 2nd tabs 423 of the side 410c that is positioned at substrate 410.For fear of the interference of terminal 412,413, the 2nd tabs 423 forms the broach shapes, only is that face contacts and is not fastening with side 410c.

In the variable resistance of the 1st embodiment, collector body 412b and the 1st terminal 412 are integrally formed by a metal material institute, do not have the coupling part between collector body 412b and the 1st terminal 412.Therefore, even terminal 412 is subjected to the effect of load, or collector body 412b is subjected to the effect of thermal stress, the decline of the electrical characteristics between terminal 412 and the collector body 412b can not take place yet or move bad, problem such as can not work.And, on substrate 410, collector body is set, there is no need to adopt the operation of glue applying coating, sintering to form, can reduce manufacturing cost.And then, because do not use the glue coating of argentiferous, so can not take place to cause the phenomenon that resistance increases owing to the sulfuration of silver yet.

The 5th embodiment below in conjunction with variable resistance among Figure 31, the 38 couples of the present invention is illustrated.Have essentially identical structure among this variable resistance and described the 1st embodiment, its difference is that as shown in figure 37, collector body 412b is provided with lubricating layer 414.This lubricating layer 414 uses can reduce and the carbon of the frictional resistance of sliding contact 435 or the graphite material as main component, with the akin resin of the resinous principle of resistive element 415 be main component.Perhaps also can be that lubricating layer 414 is a same material with resistive element 415.If lubricating layer 414 adopts same material with resistive element 415, then can carry out coating processing such as silk screen printing to the two, can increase work efficiency.

In the present embodiment, if on collector body 412b, be provided with lubricating layer 414, the wearing and tearing between itself and the sliding contact 435 are reduced greatly, thereby can prolong the life-span of collector body 412b.In order to improve sliding, except such lubricating layer is set, it is also conceivable that to make contact pin 435a, 435b respectively and the surface treatment that reduces of the frictional resistance between resistive element 415 and the collector body 412b.Yet, carry out different processing for two places (contact pin 435a, 435b) of parts of sliding contact 435, can cause the rising of manufacturing cost, this is undesirable.In this 5th embodiment, so that the inexpensive method of lubricating layer 414 to be set, can prolong the life-span of collector body 412b on collector body 412b, make itself and resistive element 415 much at one.

As shown in figure 38, preferably be decorated with the width dimensions of the lubricating layer 414 of oblique line and compare with the width dimensions of collector body 412b, identical or less.In other words, wish that lubricating layer 414 does not surmount collector body 412b and covers on the substrate 410.Because metal material (collector body 412b) is different with the thermal coefficient of expansion of resin material (substrate 410),, then lubricating layer 414 is cracked owing to thermal stress if lubricating layer 414 is crossed over collector body 412b and substrate 410 simultaneously and formed.So,, just the generation of crackle on the lubricating layer 414, the undesirable situations such as harmful effect of butt strip 435b can be able to be prevented trouble before it happens by satisfying the condition of B≤A.

The action effect of lubricating layer 414 is set, suitable equally for the collector body 104 of variable resistance shown in Fig. 7～9 of conventional case, prove effective equally.

Variable resistance of the present invention is not limited to described embodiment, can carry out all changes in the scope that it is mainly conceived.Particularly, collector body can not be circular completely, also can be the slightly circular of part shortcoming.

By above explanation as can be known, according to the present invention, the rotation because the recess jump face that forms on the jump face that forms on the rotating shaft and inner peripheral surface at the centre bore of substrate contacts, so the toner that takes place at this contact site just can not disperse to the surface of substrate, can prevent the obstacle that contacts of sliding contact and collector body and resistive element, thereby improve the rotational life of sliding contact.

In addition, on the circular lug boss that substrate back protrudes, form described centre bore, can increase the intensity of the bearing portions of the axostylus axostyle that inserts in the rotating shaft.And then, circular lug boss is embedded in the hole portion of printed base plate, show that in actual installation the height that can make variable resistance reduces, and, printed base plate has strengthening action to circular lug boss, and, play of the effect of decision variable resistance with respect to the position of substrate.

According to the present invention,,, promptly can prevent the intrusion of small foreign matter so can guarantee to cover the dustproof of inside owing to penetrate into the peristome of variable resistance inside with near the buckling parts that forms in the substrate side surfaces portion's existence tabs that fastens.Can solve the problem of contact obstacle, short circuit and the rotational life weak point etc. of sliding contact thus.

According to the present invention,, can not cause that by this inclination the 1st contact pin of the sliding contact of distortion exerts an influence to the substrate mounting cover time to being positioned at the easy of the outside even inclination has taken place yet.Therefore can obtain the high variable resistance of contact reliability.

In described invention, because the fastening of substrate and lid has adopted suction, compare with alternate manner, do not need special processing, have and assemble simply, be suitable for batch process, low cost and other advantages.

According to the present invention, the axostylus axostyle owing to inserting in the centre bore of rotating shaft is not only supported by this centre bore, but also is supported by the circular lug boss in the setting of the back side of substrate, so can strengthen the intensity of bearing portions, improves its durability.And also owing to can reach the thin typeization of substrate, the thin-walled property of rotating shaft, the big footpathization of axostylus axostyle etc. are so can improve the rotation fracture strength of axostylus axostyle.

In addition, if make circular lug boss have the internal diameter identical, then can use axostylus axostyle basically with coherent diameter with the centre bore of rotating shaft in the substrate back setting.And then, as circular lug boss being embedded in the hole portion of printed base plate, then when actual installation, can making highly and reduce, and, lug boss there is strengthening action, and plays of the effect of decision variable resistance with respect to the position of substrate.

According to the present invention, because collector body and the 1st terminal are integrally formed and the surface of exposing substrate, so the contact reliability height of collector body and the 1st terminal does not need by other operation collector body to be formed on the substrate, so can make variable resistance with cheap price.And then, because do not use the glue coating of argentiferous, so can not take place to cause the phenomenon that resistance increases owing to the sulfuration of silver yet.

And, in the present invention,, can prolong the life-span of collector body on described collector body by the conduction lubricating layer is set.And then if this lubricating layer and resistive element are same materials, then lubricating layer and resistive element can be formed by same operation.And, identical or hour when the width dimensions of lubricating layer is compared with the width dimensions of collector body, then can avoid because the influence of thermal stress causes the crackle generation of lubricating layer.

Claims (20)

1. variable resistance, on the substrate that constitutes by resin, be provided with one heart with each terminal and constitute resistive element and the collector body that is electrically connected, and the rotating shaft that is made of resin material is installed on described substrate, the sliding contact that can slide on resistive element and collector body is being installed on the described rotating shaft, it is characterized in that: on described substrate, form and to rotate the centre bore that described rotating shaft is installed freely, and on described substrate, be formed on the concentric circles with this centre bore and form continuous recess by jump face and this centre bore, on described rotating shaft, form with the jump of described recess in the face of to the jump face, the jump face of described rotating shaft and the jump face of described recess are in contact with one another.

2. variable resistance according to claim 1 is characterized in that: described sliding contact is installed in from the flange part of described rotating shaft outer peripheral face protrusion, is formed with the gap between the surface of this flange part and described substrate.

3. variable resistance according to claim 1 is characterized in that: described centre bore is formed on from the circular protuberance that protrude at the back side of described substrate.

4. variable resistance according to claim 3 is characterized in that: described circular protuberance is entrenched in the hole portion of printed base plate.

5. variable resistance according to claim 1, it is characterized in that: described substrate is covered by the lid of described resin material, form the 1st buckling parts in the side of described substrate, on the tabs that is arranged on the side of described lid, the 2nd buckling parts of the lid that the 1st buckling parts of formation and described substrate is interlocked, near the projection tab of described lid, there is not the peristome that connects to variable resistance inside.

6. variable resistance according to claim 5 is characterized in that: described the 2nd buckling parts is formed in the through hole on the described tabs thickness direction.

7. variable resistance according to claim 6 is characterized in that: described through hole is by the described lid of resin forming the time, forms by using the movable member of can be from the side freely advancing and retreat to the mould side wall portion of a side.

8. variable resistance according to claim 1, it is characterized in that: described substrate is covered by the lid of described resin material, form the 1st buckling parts in the side of described substrate, on the tabs of the side of described lid setting, form and to connect the through hole of this tabs at thickness direction as the 2nd buckling parts that is interlocked with described the 1st buckling parts, described through hole is by the described lid of resin forming the time, forms by using the movable member of can be from the side freely advancing and retreat to the mould side wall portion of a side.

9. variable resistance, on the substrate that constitutes by resin, be provided with one heart with each terminal and constitute resistive element that is electrically connected and the collector body that is positioned at this resistive element inboard, and, the rotating shaft that has sliding contact is installed on described substrate, the 1st contact pin of this sliding contact is on resistive element, the 2nd contact pin can be slided on collector body separately, it is characterized in that: described substrate is covered by the lid of described resin material, side at described substrate forms the 1st and the 2nd tabs that is positioned at described substrate side surfaces, forming the 2nd buckling parts that is interlocked with the 1st buckling parts that on described substrate side surfaces, forms on the 1st tabs, and on the 2nd buckling parts, not forming buckling parts, the 2nd tabs of described lid is set at than the position of the 1st tabs of covering further from the 1st contact pin of the described sliding contact when assembling initial setting.

10. variable resistance according to claim 9 is characterized in that: be formed on the 2nd buckling parts on the 1st tabs, do not have the peristome that connects to the inside of variable resistance near the 1st buckling parts.

11. variable resistance according to claim 10 is characterized in that: the peristome of described the 2nd buckling parts is the through hole that its thickness direction forms in described the 1st tabs upper edge.

12. variable resistance according to claim 11 is characterized in that: described through hole is by the described lid of resin forming the time, forms by using the movable member of can be from the side freely advancing and retreat to the mould side wall portion of a side.

13. variable resistance according to claim 1, it is characterized in that: the approximate centre portion at described substrate is formed with the dead eye that rotation described rotating shaft freely is installed, and is formed with the circular lug boss that is in the protrusion of concentric circles position with described dead eye simultaneously at the back side of substrate.

14. variable resistance according to claim 1, it is characterized in that: rotating shaft is rotated with sliding contact by the axostylus axostyle that is inserted in the described rotating hole, be provided with the lug boss that is in the protrusion of concentric circles position with described dead eye at the back side of described substrate, the bearing of the inner peripheral surface of this lug boss as described axostylus axostyle.

15. variable resistance according to claim 13 is characterized in that: described circular lug boss has identical internal diameter with the centre bore of described rotating shaft.

16. variable resistance according to claim 13 is characterized in that: described circular lug boss is embedded in the hole portion of printed base plate.

17. variable resistance according to claim 1, it is characterized in that: described terminal is made of the 1st terminal and the 2nd terminal, described collector body is by forming one with described the 1st terminal, circular or roughly circular metal forming material constitutes, and expose on the surface of described substrate, the length of prolonging face by making described collector body and resistive element can corresponding described sliding contact position of rotation change, and adjust resistance value between described the 1st terminal and the 2nd terminal.

18. variable resistance according to claim 17 is characterized in that: on described collector body, be provided with the conductivity lubricating layer.

19. variable resistance according to claim 18 is characterized in that: described conductivity lubricating layer and described resistive element are same material.

20. variable resistance according to claim 18 is characterized in that: the width dimensions of described conductivity lubricating layer is equal to or less than the width dimensions of collector body.

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