Contact, manufacturing method of contact, circuit breaker, and switchgear

Abstract

The contact includes: a base metal (3) having a first surface (3a), a second surface facing a direction opposite to the first surface (3a) and parallel to the first surface (3a), and a third surface (3c) perpendicular to the first surface (3a) and the second surface; a contact point (4) fixed to the third surface (3c) of the base metal (3); and a conductive member (5) disposed between the base metal (3) and the contact point (4), having a hardness lower than that of the contact point and capable of plastic flow. The surface of the contact point (4) facing a direction opposite to the base metal (3) has two first sides parallel to the normal direction of the first surface (3a), and a first notch portion (41) extending along the first side is formed at at least a part of the first side.

Description

Technical Field

[0001] The present invention relates to a contact in which a contact point is joined to a base metal, a method for manufacturing the contact, a circuit breaker, and a switch. Background Art

[0002] In a circuit breaker and a switch, a contact for switching between cutting off and conducting an electric circuit is used. The contact includes a contact point and a base metal to which the contact point is joined. The contact point and the base metal are formed of different materials. The contact point is joined to the base metal by brazing, resistance welding, or riveting. In recent years, sometimes the contact point is joined to the base metal by ultrasonic bonding. In ultrasonic bonding, ultrasonic vibration is applied to the contact by a horn in contact with the contact while applying a pressure that causes the base metal and the contact point to be in close contact with each other. By ultrasonic bonding, it is possible to eliminate the softening of the base metal caused by heat and the disadvantages of brazing and resistance welding such as the need for a metal activator such as a flux. The technique disclosed in Patent Document 1 is as follows: a plurality of grooves are formed in parallel on the base metal or the contact point to suppress the deviation between the base metal and the contact and to improve the bonding strength in ultrasonic bonding.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 60-250891 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In a circuit breaker and a switch using a contact, if an arc is generated between the contact points when the circuit is cut off, the contact points are damaged, and the life of the circuit breaker and the switch may be shortened. As in the technique disclosed in Patent Document 1, if a plurality of grooves are formed in parallel on the base metal or the contact point, the electric field is concentrated at the front end of the groove, and an arc is likely to be generated. That is, when a plurality of grooves are formed in parallel on the base metal or the contact point, there is a problem that the life of the circuit breaker and the switch may be shortened.

[0008] Especially in the case of a circuit breaker or the like that is used for an operation that requires instantaneously cutting off a circuit when a large current flows, the contact damage caused by the arc generated at the time of cutting is very large. Therefore, it is preferable that the surface of the contact point before cutting has as little damage or notch as possible. After being assembled as a contact in a state where the contact point has knurling, when an overcurrent flows and a cutting operation is performed, sometimes the electric field on the contact point side is concentrated at the front end of the groove formed by the knurling and an arc is ejected, and significant consumption occurs centering on this portion. As a result, the life becomes short, and thus the life of the contact may be shortened.

[0009] The present invention has been completed in view of the above circumstances, and an object thereof is to obtain a contact that can suppress the displacement between the base metal and the contact point in ultrasonic bonding and can achieve a long service life of a circuit breaker and a switch.

[0010] Means for Solving the Problem

[0011] In order to solve the above problems and achieve the object, the present invention is characterized by comprising: a base metal having a first surface, a second surface facing in a direction opposite to the first surface and parallel to the first surface, and a third surface perpendicular to the first surface and the second surface; a contact point fixed to the third surface of the base metal; and a conductive member provided between the base metal and the contact point, having a hardness lower than that of the contact point and capable of plastic flow. The surface of the contact point facing in a direction opposite to the base metal has two first sides parallel to the normal direction of the first surface, and a first notch portion extending along the first side is formed in at least a part of the first side.

[0012] Effects of the Invention

[0013] According to the present invention, the following effects are achieved: a contact that can suppress the displacement between the base metal and the contact point in ultrasonic bonding and can achieve a long service life of a circuit breaker and a switch can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a diagram showing a schematic structure of an energized part of a circuit breaker or a switch using the contact of Embodiment 1 of the present invention.

[0015] Figure 2 It is a side view of the contact of Embodiment 1.

[0016] Figure 3 It is along Figure 2 A view of the contact observed along the arrow III shown.

[0017] Figure 4 It is along Figure 2 A view of the contact observed along the arrow IV shown.

[0018] Figure 5 It is along Figure 3 A cross-sectional view taken along the line V-V shown.

[0019] Figure 6 It is a side view of the contact of Modification 1 of Embodiment 1.

[0020] Figure 7 It is along Figure 6 A view of the contact observed along the arrow VII shown.

[0021] Figure 8 It is along Figure 6View of the contact observed along the arrow VIII shown.

[0022] Figure 9 is a cross-sectional view along Figure 7 the IX-IX line shown.

[0023] Figure 10 is a view showing the schematic structure of the contact of Modification 2 of Embodiment 1, and is a view corresponding to the view of the contact observed along the arrow VII shown. Figure 6 along the arrow VII shown.

[0024] Figure 11 is a side view of the contact of Modification 3 of Embodiment 1.

[0025] Figure 12 is along Figure 11 the view of the contact observed along the arrow XII shown.

[0026] Figure 13 is along Figure 11 the cross-sectional view along the XIII-XIII line shown.

[0027] Figure 14 is a side view of the contact of Modification 4 of Embodiment 1.

[0028] Figure 15 is along Figure 14 the view of the contact observed along the arrow XV shown.

[0029] Figure 16 is along Figure 14 the cross-sectional view along the XVI-XVI line shown.

[0030] Figure 17 is a side view of the contact of Modification 5 of Embodiment 1.

[0031] Figure 18 is along Figure 17 the cross-sectional view along the XVIII-XVIII line shown.

[0032] Figure 19 is along Figure 18 the view of the contact observed along the arrow IXX shown.

[0033] Figure 20 is a front view showing the schematic structure of the manufacturing apparatus of the contact of Embodiment 1.

[0034] Figure 21 is a side view showing the schematic structure of the manufacturing apparatus of the contact of Embodiment 1.

[0035] Figure 22 is a view showing the flowchart of the manufacturing method of the contact of Embodiment 1.

[0036] Figure 23 It is a side view of the contact of Modification 6 of Embodiment 1.

[0037] Figure 24 It is a view Figure 23 observing the contact along the arrow XXIV shown.

[0038] Figure 25 It is a view Figure 23 observing the contact along the arrow XXV shown.

[0039] Figure 26 It is a side view of the contact of Modification 7 of Embodiment 1.

[0040] Figure 27 It is a view Figure 26 observing the contact along the arrow XXVII shown.

[0041] Figure 28 It is a view Figure 26 observing the contact along the arrow XXVIII shown. Detailed Embodiment

[0042] Hereinafter, the contact, the manufacturing method of the contact, the circuit breaker, and the switch of the embodiment of the present invention will be described in detail based on the drawings. In addition, the present invention is not limited to this embodiment.

[0043] Embodiment 1

[0044] Figure 1 It is a view showing a schematic structure of the energization part of a circuit breaker or a switch using the contact of Embodiment 1 of the present invention. For parts other than the energization part in the circuit breaker or the switch, a known structure can be used, so the illustration is omitted.

[0045] Figure 1 The contact 1 shown is mainly used for a low-voltage circuit breaker. In the following description, the case of being used for a low-voltage circuit breaker will be described, but it can also be used for a high-voltage circuit breaker or a switch.

[0046] The contact 1 for the energization part of the circuit breaker is roughly classified into two types: a fixed contact fixed to the frame of the circuit breaker, that is, the contact 1a, and a movable contact, that is, the contact 1b. The contact 1b is connected to the peeling mechanism 2. When a current exceeding the design value flows between the contacts 1a and 1b, the contact 1b is actuated by the peeling mechanism 2 and is physically peeled from the contact 1a, and the current is cut off.

[0047] The contact 1 includes a contact point 4 and a base metal 3. In Figure 1In the example shown, one contact 1 is provided on each of the movable side and the fixed side, but the number can be appropriately changed according to the voltage and current that must be cut off. For example, the structure may be such that there is one contact 1 on the fixed side and two or more contacts 1 on the movable side. It may also be that there is one contact 1 on the movable side and two or more contacts 1 on the fixed side. The contact 1 can be used either on the movable side or on the fixed side.

[0048] Figure 2 It is a side view of the contact of Embodiment 1. Figure 3 It is along Figure 2 A view of the contact observed along the arrow III shown. Figure 4 It is along Figure 2 A view of the contact observed along the arrow IV shown. Figure 5 It is along Figure 3 A cross-sectional view along the V-V line shown.

[0049] The base metal 3 has a first surface 3a, a second surface 3b facing in the direction opposite to the first surface 3a and parallel to the first surface 3a, and a third surface 3c perpendicular to the first surface 3a and the second surface 3b. The first surface 3a and the second surface 3b are surfaces parallel to the direction in which the base metal 3 overlaps with the contact 4 and extending from the contact 4 toward the peeling mechanism 2.

[0050] The contact 4 is joined and fixed to the third surface 3c of the base metal 3. The contact 4 and the base metal 3 are generally made of different metals. At the interface between the contact 4 and the base metal 3, there is an intermediate metal 5 having a hardness lower than that of the contact 4 and capable of plastic flow. The intermediate metal 5 is a conductive member.

[0051] The surface of the contact 4 facing in the direction opposite to the base metal 3 has a rectangular shape, and has two first sides 4a parallel to the normal direction of the first surface 3a and two second sides 4b connecting the ends of the two first sides 4a to each other. The first side 4a is the short side of the rectangle, and the second side 4b is the long side of the rectangle.

[0052] A first cutout portion, i.e., a cutout portion 41, extending along the first side 4a is formed in the first side 4a. The cutout portion 41 can be formed on both of the two first sides 4a or only on one of the first sides 4a. No irregularities other than the cutout portion 41 are formed on the surface of the contact 4 facing the side opposite to the base metal 3.

[0053] The interval, i.e., the width, between the first surface 3a and the second surface 3b of the base metal 3 is designated as t. The maximum length of the base metal 3 parallel to the second side 4b of the contact 4 is designated as L. The maximum length of the contact 4 along the first side 4a is designated as a. The maximum length of the contact 4 along the second side 4b is designated as b. The length of the contact 4 along the direction in which the base metal 3 and the contact 4 overlap is designated as c. The maximum length of the notch 41 along the first side 4a is designated as a 1 The maximum length of the notch 41 along the second side 4b is designated as b 1 The length of the notch 41 along the direction in which the base metal 3 and the contact 4 overlap is designated as c 1 .

[0054] In this case, it is set that a 1 ≤ a, b 1 < 0.5b, c 1 < c. In order to stably fix the base metal 3 during pressurization when applying ultrasonic vibration, it is preferable that a 1 , b 1 , c 1 are respectively equal between the notches 41 formed on the two first sides 4a. However, since the optimum values of a 1 , b 1 , c 1 are determined according to the shape of the contact 4, it is not necessary to make the respective dimensions consistent between the notches 41

[0055] It is preferable that the contact area between the contact 4 of the fixed-side contact 1a and the contact 4 of the movable-side contact 1b is large, so the smaller the notch 41 provided on the contact 4, the better. The maximum length b of the notch 41 1 has a great influence on the size of the contact area between the contacts 4, so it is desirable to minimize it. As an example, in the case where the maximum length a of the contact 4 is 5 mm, the width t of the base metal 3 is 5 mm, the maximum length b is 8 mm, and the length c is 3 mm, it is set that a 1 ≤ 5 mm, b 1 < 4 mm, c 1 < 3 mm

[0056] In addition, in the example shown in Figures 2 to 4 , the notch 41 formed on the first side 4a is formed symmetrically about the center line 50 of the first side 4a. In addition, as shown in Figure 5 , the notch 41 is formed by a surface parallel to the first side 4a and a surface parallel to the third surface 3c, and the surface parallel to the first side 4a and the surface parallel to the third surface 3c are perpendicular. The notch 41 being such a shape means that the shape of the notch 41 is a rectangular shape

[0057] In addition, the shape of the base metal 3 is not limited to a quadrangular prism shape, and may be a cylindrical shape, an elliptical cylindrical shape, a polygonal prism shape, or a shape formed by combining these shapes. The contact 4 has a quadrangular prism shape, but may also have a cylindrical shape, and the corners may be chamfered. Further, the surface of the contact 4 on the side opposite to the base metal 3 may be arc-shaped, for example, an arc surface or a spherical surface. Alternatively, it may be a shape formed by combining these shapes.

[0058] Figure 6 It is a side view of the contact of Modification 1 of Embodiment 1. Figure 7 It is along Figure 6 a view of the contact observed along the arrow VII shown in Figure 8 It is along Figure 6 a view of the contact observed along the arrow VIII shown in Figure 9 It is along Figure 7 a cross-sectional view taken along the line IX-IX shown in. In the contact 1 of Modification 1, a cutout portion 41 is formed in a chamfered shape in which the first side 4a is chamfered. More specifically, it is a flat chamfer shape.

[0059] As Figure 6 shown, if the chamfer angle of the cutout portion 41 is set to θ 1 , then it is set such that 0° < θ 1 < 90°. In order to stably fix the base metal 3 during pressurization when applying ultrasonic vibration, it is preferable that θ 1 is equal between the cutout portions 41 formed on the two first sides 4a. However, since the optimum values of a 1 , b 1 , and c 1 are determined according to the shape of the contact 4, it is not necessary for the respective θ 1 to be the same between the cutout portions 41. Further, a cutout portion 41 having a chamfered shape may be formed on one first side 4a, and a cutout portion 41 having a rectangular shape may be formed on the other first side 4a.

[0060] Figure 10 It is a diagram showing a schematic structure of the contact of Modification 2 of Embodiment 1, and is a diagram corresponding to a view of the contact observed along the arrow VII shown in Figure 6 . In the contact 1 of Modification 2, a cutout portion 41 is formed over the entire region of the first side 4a of the contact 4. The shape of the cutout portion 41 may be a rectangular shape or a chamfered shape.

[0061] Figure 11 It is a side view of the contact of Modification 3 of Embodiment 1. Figure 12 It is along Figure 11 a view of the contact observed along the arrow XII shown in Figure 13 It is along Figure 11Cross-sectional view taken along line XIII-XIII as shown.

[0062] In the contact 1 of Modification 3, in addition to the first side 4a of the contact point 4, a second cutout portion, i.e., the cutout portion 43, is formed along the second side 4b on the second side 4b. The cutout portion 43 is formed in a chamfered shape that chamfers the second side 4b. More specifically, it is a flat chamfer shape. The cutout portion 43 can be formed on both of the two second sides 4b or only on one of the second sides 4b. No irregularities other than the cutout portions 41 and 43 are formed on the surface of the contact point 4 on the side opposite to the base metal 3.

[0063] In addition, let the maximum length of the cutout portion 43 along the first side 4a be a 3 . Let the maximum length of the cutout portion 43 along the second side 4b be b 3 . Let the chamfer angle of the cutout portion 43 be θ 3 . It is set to a 3 <0.5a, b 3 ≤b, 0°<θ 3 <90°. For example, when the width t of the base metal 3 is set to 5 mm, the maximum length b is set to 8 mm, and the length c is set to 3 mm, it is set to a 3 <2.5 mm, b 3 ≤8 mm, 0°<θ 3 <90°. In order to stably fix the base metal 3 during pressurization when applying ultrasonic vibration, it is preferable that a 3 , b 3 , θ 3 are respectively equal between the cutout portions 43 formed on the two second sides 4b. However, since the optimal values of a 3 , b 3 , θ 3 are determined according to the shape of the contact point 4, it is not necessary to make the respective a 3 , b 3 , θ 3 consistent between the cutout portions 43. In addition, a cutout portion 43 having a chamfered shape can be formed on one of the second sides 4b, and a cutout portion 43 having a rectangular shape can be formed on the other second side 4b.

[0064] Figure 14 is a side view of the contact of Modification 4 of Embodiment 1. Figure 15 is along Figure 14 a view of the contact point observed along the arrow XV as shown. Figure 16 is along Figure 14 a cross-sectional view taken along line XVI-XVI as shown. In the contact 1 of Modification 4, the cutout portion 43 is formed over the entire area of the second side 4b of the contact point 4. The shape of the cutout portion 43 can be Figures 14 to 16The chamfered shape shown may also be a rectangular shape. Additionally, a notch 41 may be formed over the entire area of the first side 4a of the contact 4.

[0065] Figure 17 It is a side view of the contact of Modification 5 of Embodiment 1. Figure 18 It is along Figure 17 The cross-sectional view taken along line XVIII-XVIII shown. Figure 19 It is along Figure 18 The view of observing the contact along the arrow IXX shown.

[0066] In the contact 1 of Modification 5, recesses 31 are formed in the first surface 3a and the second surface 3b of the base metal 3. Let the maximum length of the base metal 3 along the direction in which the base metal 3 overlaps the contact 4 be W. Let the distance between the bottom surface of the recess 31 formed in the first surface 3a of the base metal 3 and the bottom surface of the recess 31 formed in the second surface 3b be t1. Let the maximum length of the recess 31 along the second side 4b be L1. Let the maximum length of the recess 31 along the direction in which the base metal 3 overlaps the contact 4 be W1. It is set that t1 < 0.5t, b ≤ L1 < L, and W1 < W. Additionally, by setting b < L, the base metal 3 can be fixed more stably. The recess 31 formed in the first surface 3a and the recess 31 formed in the second surface 3b may be of the same shape or different shapes.

[0067] Next, the manufacturing method of the contact 1 will be described and the structure of the manufacturing apparatus will be described. Figure 20 It is a front view showing the schematic structure of the manufacturing apparatus for the contact of Embodiment 1. Figure 21 It is a side view showing the schematic structure of the manufacturing apparatus for the contact of Embodiment 1. Figure 22 It is a diagram of a flowchart showing the manufacturing method of the contact of Embodiment 1.

[0068] First, the base metal 3 that has been shaped using press working, cutting, forging, etc. is fixed to the fixed table 6 of the bonding apparatus 7 as the manufacturing apparatus. In this process, the base metal 3 is inserted and set between the movable part 6a and the fixed part 6b provided in the fixed table 6 (step S1). Next, the movable part 6a is moved, and the base metal 3 is clamped by the movable part 6a and the fixed part 6b to fix it (step S2).

[0069] The movable part 6a can be moved by screws, pneumatic mechanisms, hydraulic mechanisms, etc., and can apply pressure to the base metal 3. The fixed part 6b is fixed to the bonding apparatus 7. The movable part 6a is arranged so as to be able to pressurize the base metal 3 directly below the bonding part of the base metal 3 and the contact 4.

[0070] As Figures 17 to 19When the concave portion 31 is formed in the base metal 3 as in the contact 1 of the modified example 5 shown, the base metal 3 can be fixed more firmly by previously forming convex portions that fit into the concave portion 31 on the movable portion 6a and the fixed portion 6b. Alternatively, it may be structured such that the base metal 3 is sandwiched between the movable portion 6a and the fixed portion 6b in which convex portions are formed without previously forming the concave portion 31 in the base metal 3, and as a result, the concave portion 31 is formed in the base metal 3. In addition, the bonding device 7 may include a plurality of movable portions 6a, and the base metal 3 is fixed by sandwiching it with the plurality of movable portions 6a.

[0071] Next, the contact 4 is provided on the third surface 3c of the base metal 3 (step S3). The contact 4 is provided with the surface on which the intermediate metal 5 is formed facing the third surface 3c. Alternatively, the intermediate metal 5 may be formed on the third surface 3c of the base metal 3.

[0072] Next, the contact 4 is pressed toward the base metal 3 by the pressing tool 8 of the bonding device 7, and ultrasonic vibration is applied to bond the contact 4 to the base metal 3 (step S4). When the contact 4 is pressed and ultrasonic vibration is applied, the interfaces at the joint portion between the base metal 3 and the contact 4 rub against each other, the oxide film is broken, and the interfaces are mixed, thereby bonding the two.

[0073] By adopting such a manufacturing method, the contact 4 can be bonded to the base metal 3 without using a metal activator such as a flux or a solder, and it is possible to achieve a reduction in manufacturing cost, material cost, and an improvement in conductivity due to the abolition of the cleaning process and the like.

[0074] In ultrasonic bonding, since vibrations with a minute amplitude of 20 kHz or more are applied, the contact 4 tilts during the bonding process, or positional deviation is likely to occur. In order to suppress the tilt and positional deviation of the contact 4, sometimes a plurality of grooves are formed side by side in the contact 4 and the base metal 3 by knurling or the like. However, when a plurality of grooves are formed side by side in the contact 4 and the base metal 3, the electric field concentrates at the front end of the grooves and an arc is likely to occur. Since an arc is likely to occur, the lifespan of the circuit breaker and switchgear using the contact 1 may be shortened due to a temperature rise during energization or the like. In addition, the grooves required for bonding such as knurling may become the starting point of breakage, and the rigidity of the contact 4 itself may be reduced.

[0075] On the other hand, in the present Embodiment 1, a convex portion that fits into the cutout portions 41 and 43 formed in the contact point 4 is formed at a portion of the pressing tool 8 that comes into contact with the contact point 4. When pressing and applying ultrasonic vibration, by fitting the convex portion of the pressing tool 8 into the cutout portions 41 and 43 formed in the contact point 4, it is possible to suppress the inclination or positional deviation of the contact point 4. That is, it is possible to suppress the inclination or positional deviation of the contact point 4 without providing knurling, chevron, or other shapes on the contact point 4 and the base metal 3. Therefore, it is possible to suppress the generation of arcs in the circuit breaker and switch using the contact 1, suppress the temperature rise during energization, and suppress the reduction in the rigidity of the contact point 4 itself, thereby enabling the circuit breaker and switch to have a longer service life.

[0076] In addition, in the case of using the contact point 4 in which only the cutout portion 41 is formed, a convex portion that fits into the cutout portion 41 may be formed in the pressing tool 8. Further, the cutout portions 41 and 43 may not be formed in the contact point 4 before being joined to the base metal 3, and instead, as a result of pressing the contact point 4 with the pressing tool 8 and applying ultrasonic vibration, the shape of the convex portion of the pressing tool 8 is transferred and the cutout portions 41 and 43 are formed.

[0077] In addition, by making the width t of the base metal 3 larger than the maximum length of the first side 4a of the contact point 4, it is also possible to suppress the inclination and positional deviation of the contact point 4. However, by imposing dimensional restrictions, the design freedom of the contact 1 is reduced, or the contact 1 becomes larger. On the other hand, in the present embodiment, it is possible to suppress the inclination and positional deviation of the contact point 4 without imposing dimensional restrictions, and therefore it is possible to suppress the reduction in the design freedom of the contact 1 or the enlargement of the contact 1.

[0078] In addition, if the cutout portion 41 is formed symmetrically about the center line 50 of the first side 4a, when the convex portion is fitted into the cutout portion 41 and pressed with the pressing tool 8, it is less likely for the contact point 4 to incline.

[0079] When the shapes of the cutout portions 41 and 43 are rectangular shapes, the convex portion of the pressing tool 8 enters deeper, and therefore it is possible to more reliably suppress the inclination and positional deviation of the contact point 4. When the shapes of the cutout portions 41 and 43 are chamfered shapes, it is possible to suppress the machining amount required for forming the cutout portions 41 and 43 and achieve cost reduction in manufacturing.

[0080] In addition, when the cutouts 41 and 43 are formed over the entire area of the first side 4a or the second side 4b, the contact points can be pressed over the entire sides, so it is more difficult for the contacts 4 to tilt. When the cutouts 41 and 43 are formed over the entire area of the first side 4a or the second side 4b, generation of burrs can be suppressed as compared with the case where the cutouts 41 and 43 are formed in a part of the first side 4a or the second side 4b. In addition, by forming the cutout 43 on the basis of the cutout 41, tilting and positional deviation are less likely to occur in the contacts 4 as compared with the case where only the convex portion is inserted into the cutout 41.

[0081] In addition, the contact 4 is preferably formed of a sintered material of silver and tungsten, tungsten carbide, or graphite, or a sintered material formed by combining at least two of silver, tungsten, tungsten carbide, and graphite, using a metal with higher hardness. In addition, the base metal 3 is preferably formed of electrolytic copper or oxygen-free copper. The intermediate metal 5 is preferably silver. The intermediate metal 5 can be formed in advance on the contact 4 by a vacuum evaporation method, a plating method, or the like. In addition, the intermediate metal 5 can be formed in advance on the base metal 3 by a vacuum evaporation method, a plating method, or the like. In addition, the intermediate metal 5 can also be formed on the surface on the base metal 3 side of the contact 4 by separation based on the difference in specific gravity within the structural material during the manufacture of the contact 4.

[0082] Since a sintered metal material with high hardness is used for the contact 4, when the contact 1 is used to cut off the current, the loss of the contact 4 can be suppressed to the minimum. Since silver used in the intermediate metal 5 and electrolytic copper or oxygen-free copper used in the base metal 3 are metals that easily plastically flow, when the two are joined by ultrasonic bonding, the two plastically flow. As a result, not only is it easy to break the oxides on the interface, but also by mixing the two on the interface, the bonding strength can be improved.

[0083] Since there is no solder on the contact 1, a metal activating material such as a flux is not required during bonding. Not only are the manufacturing and material costs reduced, but also even when the temperature of the contact 1 rises to a temperature equivalent to soldering or the contact 1 is exposed to an environment with a temperature equivalent to soldering during current cutoff, etc., the solder will not melt and flow out, and the heat resistance as an electrical contact can be improved. Moreover, since silver used in the intermediate metal 5 and electrolytic copper or oxygen-free copper used in the base metal 3 are metals that easily plastically flow, when the two are joined by ultrasonic bonding, the two plastically flow. As a result, not only is it easy to break the oxides on the interface, but also by mixing the two on the interface, the bonding strength can be improved.

[0084] Figure 23 It is a side view of the contact of Modification 6 of Embodiment 1. Figure 24 It is along Figure 23 The figure observing the contact along the arrow XXIV shown. Figure 25 It is alongFigure 23 View of the contact observed in the direction of arrow XXV shown in the figure.

[0085] In the contact 4 of Modification 6, cutout portions 41 are formed at both ends of the first side 4a. It can be said that cutout portions 41 are formed at the four corner portions of the quadrilateral formed by the first side 4a and the second side 4b. The length a of the cutout portion 41 1 , b 1 , c 1 can be appropriately changed according to the shape and size of the contact 4. In addition, the lengths a 1 , b 1 , c 1 of the respective cutout portions 41 may all be the same or different.

[0086] In the contact 4, a cutout portion 43 that chamfers the second side 4b is formed over the entire region of the second side 4b. The length a 3 , angle θ 3 can be arbitrarily set.

[0087] By forming the cutout portions 41 at both ends of the first side 4a, if a convex portion that fits into the cutout portion 41 is formed on the pressing tool 8, the convex portion can be fitted into the cutout portion 41 at both ends of the first side 4a, that is, at the four corner portions of the quadrilateral formed by the first side 4a and the second side 4b, to fix the contact 4. Thereby, it is possible to more reliably suppress the inclination and positional deviation of the contact 4 when the contact 4 is ultrasonically joined to the base metal 3.

[0088] In addition, since it is only necessary to form the cutout portions 41 at the four corner portions, the size of the cutout portion 41 can be further reduced. Thereby, it is possible to suppress a decrease in the volume of the contact 4 caused by the formation of the cutout portion 41, and when the contact 1 is used as a contact of a circuit breaker or a switch, it is possible to obtain the effects of suppressing the temperature rise during energization and suppressing the reduction in the rigidity of the contact 4.

[0089] In addition, if the cutout portions 41 are provided at the four corner portions, the above effects can be obtained, so it is not necessary to form the cutout portion 43.

[0090] Figure 26 is a side view of the contact of Modification 7 of Embodiment 1. Figure 27 is along Figure 26 View of the contact observed in the direction of arrow XXVII shown in the figure. Figure 28 is along Figure 26 View of the contact observed in the direction of arrow XXVIII shown in the figure.

[0091] In the contact 4 of Modification 7, a length b 1 , angle θ 1The cutout portion 41 having a chamfered shape. In addition, a length a is formed over the entire area of the second side 4b 3 and an angle θ 3 of the cutout portion 43 having a chamfered shape. At this time, the angle θ 1 and the angle θ 3 may be the same or different. The length b of the cutout portion 41 1 and the angle θ 1 and the length a of the cutout portion 43 3 and the angle θ 3 can be appropriately changed according to the shape and size of the contact 4.

[0092] By forming the cutout portions 41 and 43 over the entire area of the first side 4a and the entire area of the second side 4b, if convex portions that fit into the cutout portions 41 and 43 are formed on the pressing tool 8, the convex portions can be fitted into the cutout portions 41 and 43 to fix the contact 4. Thereby, it is possible to more reliably suppress the inclination and positional deviation of the contact 4 when the contact 4 is ultrasonically joined to the base metal 3.

[0093] In addition, if it is within the range where the positional deviation of the contact 4 can be suppressed by the convex portions formed on the pressing tool 8, it is preferable to minimize the angles θ 1 and θ 3 of the chamfered shapes of the cutout portions 41 and 43 and make the sizes of the cutout portions 41 and 43 smaller. Thereby, it is possible to suppress the reduction in the volume of the contact 4 caused by the provision of the cutout portion 41, and when the contact 1 is used as the contact of a circuit breaker or a switch, it is possible to more reliably obtain the effects of suppressing the temperature rise during energization and suppressing the reduction in the rigidity of the contact.

[0094] The structure shown in the above embodiment represents an example of the content of the present invention, and it may be combined with other known technologies, and within the scope not departing from the gist of the present invention, a part of the structure may also be omitted or changed.

[0095] Explanation of reference numerals

[0096] 1, 1a, 1b Contacts; 2 Stripping mechanism; 3 Base metal; 3a First surface; 3b Second surface; 3c Third surface; 4 Contact; 4a First side; 4b Second side; 5 Intermediate metal; 6 Fixed table; 6a Movable part; 6b Fixed part; 7 Joining device; 8 Pressing tool; 41, 43 Cutout portions.

Claims

1. A contact, characterized in that, it includes: a base metal having a first surface, a second surface facing in a direction opposite to the first surface and parallel to the first surface, and a third surface perpendicular to the first surface and the second surface; a contact fixed to the third surface of the base metal; and a conductive member disposed between the base metal and the contact, having a hardness lower than that of the contact and capable of plastic flow, a surface of the contact facing in a direction opposite to the base metal has two first sides parallel to the normal direction of the first surface, the contact has a second side connecting the ends of the two first sides to each other, a first notch extending along the first side is formed in at least a part of the first side, and a recess is formed in the first surface, and a length of the recess along the second side is longer than a length of the second side.

2. The contact according to claim 1, characterized in that, a second notch extending along the second side is formed in at least a part of the second side.

3. The contact according to claim 2, characterized in that, the second notch is formed over the entire region of the second side.

4. The contact according to claim 2 or 3, characterized in that, the second notch has a chamfered shape.

5. The contact according to any one of claims 1 to 3, characterized in that, a maximum length of the contact along the first side is equal to or greater than a width of a portion of the base metal in contact with the conductive member.

6. The contact according to any one of claims 1 to 3, characterized in that, the conductive member is disposed so as to be exposed between the base metal and the contact.

7. The contact according to any one of claims 1 to 3, characterized in that, the first notch is formed symmetrically about a central portion of the first side.

8. The contact according to any one of claims 1 to 3, characterized in that, when viewed in the direction along the normal direction, at least one of the first notches has a rectangular shape.

9. The contact according to any one of claims 1 to 3, characterized in that, when viewed in the direction along the normal direction, at least one of the first notches has a chamfered shape.

10. The contact according to any one of claims 1 to 3, characterized in that, the first notch is formed over the entire region of the first side.

11. The contact according to any one of claims 1 to 3, characterized in that, the first notch is formed at both end portions of the first side.

12. The contact according to any one of claims 1 to 3, characterized in that, the contact is a sintered material of silver and tungsten, tungsten carbide or graphite, or a sintered material formed by combining at least two of silver, tungsten, tungsten carbide and graphite, the base metal is electrolytic copper or oxygen-free copper, and silver is used as the intermediate metal.

13. A method for manufacturing a contact, the contact being the contact according to any one of claims 1 to 12, characterized in that, the base metal is fixed by clamping the first surface and the second surface, the contact is disposed on the third surface, Press the contact toward the base metal side and apply ultrasonic vibration.

14. The method for manufacturing a contact according to claim 13, wherein, the first notch is formed in the contact before pressing the contact toward the base metal side, and a pressing-side convex portion that fits into the first notch is formed in a pressing tool for pressing the contact toward the base metal side.

15. A method for manufacturing a contact, the contact comprising: a base metal having a first surface, a second surface facing in a direction opposite to the first surface and parallel to the first surface, and a third surface perpendicular to the first surface and the second surface ； a contact fixed to the third surface of the base metal; and a conductive member disposed between the base metal and the contact, having a hardness lower than that of the contact and capable of plastic flow, wherein a surface of the contact facing in a direction opposite to the base metal has two first sides parallel to the normal direction of the first surface, and a first notch extending along at least a part of the first side is formed in at least a part of the first side. The method is characterized in that the base metal is fixed by sandwiching the first surface and the second surface, the contact is disposed on the third surface, the contact is pressed toward the base metal side, and ultrasonic vibration is applied, the first notch is formed in a shape transferred from a convex portion of a pressing tool that presses the contact toward the base metal side.

16. A method for manufacturing a contact, the contact comprising: a base metal having a first surface, a second surface facing in a direction opposite to the first surface and parallel to the first surface, and a third surface perpendicular to the first surface and the second surface ； a contact fixed to the third surface of the base metal; and a conductive member disposed between the base metal and the contact, having a hardness lower than that of the contact and capable of plastic flow, wherein a surface of the contact facing in a direction opposite to the base metal has two first sides parallel to the normal direction of the first surface, the contact has a second side connecting the ends of the two first sides to each other, and a first notch extending along at least a part of the first side is formed in at least a part of the first side. The method is characterized in that the base metal is fixed by sandwiching the first surface and the second surface, the contact is disposed on the third surface, the contact is pressed toward the base metal side, and ultrasonic vibration is applied, depressions are formed in the first surface and the second surface of the base metal, and a base-metal-side convex portion that fits into the depressions is formed in a fixing table for fixing the base metal by sandwiching the first surface and the second surface.

17. A method for manufacturing a contact, the contact comprising: a base metal having a first surface, a second surface facing in a direction opposite to the first surface and parallel to the first surface, and a third surface perpendicular to the first surface and the second surface ； a contact fixed to the third surface of the base metal; and a conductive member disposed between the base metal and the contact, having a hardness lower than that of the contact and capable of plastic flow, a surface of the contact facing a direction opposite to that of the base metal having two first sides parallel to the normal direction of the first surface, the contact having a second side connecting the ends of the two first sides to each other, and a first notch portion extending along the first side being formed at at least a part of the first side, characterized in that the base metal is fixed by sandwiching the first surface and the second surface, the contact is disposed on the third surface, the contact is pressed toward the base metal side, and ultrasonic vibration is applied. On a fixing table that sandwiches and fixes the base metal by sandwiching the first surface and the second surface, base metal side convex portions are formed on the surface in contact with the first surface and the surface in contact with the second surface. By sandwiching the first surface and the second surface by the fixing table, recesses into which the base metal side convex portions are inserted are formed on the first surface and the second surface.

18. A circuit breaker characterized in that it includes the contact according to any one of claims 1 to 12.

19. A switch characterized in that it includes the contact according to any one of claims 1 to 12.

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