Contact device and contact member

Abstract

An object of the present disclosure is to suppress contact welding while suppressing complication of the structure of the contact device.SOLUTION: The contact device 1 includes a first contact 110 and a second contact 120. The second contact 120 moves between a first position at which the second contact is in contact with the first contact 110 and a second position at which the second contact is not in contact with the first contact 110. The first contact 110 is made of copper or low-density copper which is a copper alloy containing copper as a main component and has a relative density of 80% or more and 95% or less.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a contact device and a contact member, and more particularly to a contact device including a contact member formed of copper or a copper alloy, and a contact member used in the contact device. [Background technology]

[0002] Patent Document 1 describes an electromagnetic relay designed to prevent contact welding. The electromagnetic relay includes a first fixed terminal, a second fixed terminal, a first movable contact piece, and a second movable contact piece. The first fixed terminal includes a first open / close fixed contact and a first energizing fixed contact. The second fixed terminal includes a second open / close fixed contact and a second energizing fixed contact. The first movable contact piece includes a pair of open / close movable contacts that can come into contact with the first open / close fixed contact and the second open / close fixed contact. The second movable contact piece includes a pair of energizing movable contacts that can come into contact with the first energizing fixed contact and the second energizing fixed contact. When the first movable contact piece and the second movable contact piece move in a contact direction, the pair of energizing movable contacts come into contact with the first open / close fixed contact and the second open / close fixed contact after the pair of open / close movable contacts come into contact with the first open / close fixed contact and the second open / close fixed contact. Furthermore, when the first movable contact piece and the second movable contact piece move in the opening direction from a state in which the pair of open / close movable contacts are in contact with the first open / close fixed contact and the second open / close fixed contact and the pair of energizing movable contacts are in contact with the first energizing fixed contact and the second energizing fixed contact, the pair of open / close movable contacts open from the first open / close fixed contact and the second open / close fixed contact after the pair of energizing movable contacts have opened from the first open / close fixed contact and the second open / close fixed contact. The electrical path between the pair of open / close movable contacts has higher electrical resistance than the electrical path between the pair of energizing movable contacts. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-29724 Summary of the Invention [Problem to be solved by the invention]

[0004] In a contact device such as the electromagnetic relay described in Patent Document 1, welding of the contacts can be suppressed solely by the structure of the contact device, but the structure of the contact device becomes complicated.

[0005] An object of the present disclosure is to suppress contact welding while suppressing the complexity of the structure of the contact device. [Means for solving the problem]

[0006] A contact device according to one aspect of the present disclosure includes a first contact and a second contact. The second contact moves between a first position in contact with the first contact and a second position in which it is not in contact with the first contact. The first contact is made of copper or a copper alloy containing copper as a main component, low-density copper, with a relative density of 80% or more and 95% or less.

[0007] A contact device according to one aspect of the present disclosure includes a first contact and a second contact. The second contact moves between a first position in contact with the first contact and a second position in not contacting the first contact. The second contact is made of copper or a copper alloy containing copper as a main component, low-density copper, with a relative density of 80% or more and 95% or less.

[0008] A contact member according to one embodiment of the present disclosure is used as the first contact or the second contact in a contact device having a first contact and a second contact. The second contact moves between a first position in contact with the first contact and a second position in not contacting the first contact. The contact member is made of copper or a copper alloy containing copper as its main component, low-density copper, with a relative density of 80% or more and 95% or less. [Effects of the Invention]

[0009] According to the present disclosure, there is an advantage that it is possible to suppress contact welding while suppressing the complexity of the structure of the contact device. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional image of a contact element according to an embodiment of the present disclosure, the cross-section of which was photographed using an optical microscope and has a relative density of 95%. [Figure 2] FIG. 2 is a cross-sectional image of a contact member according to an embodiment of the present disclosure, the cross-section of which is photographed using an optical microscope and has a relative density of 92%. [Figure 3] FIG. 3 is a cross-sectional image of a contact element according to an embodiment of the present disclosure, the cross-section of which is photographed using an optical microscope and has a relative density of 85%. [Figure 4] FIG. 4 is a cross-sectional image of a contact element according to an embodiment of the present disclosure, the cross-section of which was photographed using an optical microscope and has a relative density of 80%. [Figure 5] FIG. 5 is a cross-sectional image of a contact member of a comparative example, the cross-section of which was photographed using an optical microscope and had a relative density of 75%. [Figure 6] FIG. 6 is an explanatory diagram for explaining a heating method in the peel test of the contact member. [Figure 7] FIG. 7 is an explanatory diagram showing the temperature profile in the peel test. [Figure 8] FIG. 8 is an explanatory diagram showing a peeling device used in the peeling test. [Figure 9] FIG. 9 is a cross-sectional view of an electromagnetic relay including the contact member. [Figure 10] FIG. 10 is a cross-sectional view of the electromagnetic relay. DETAILED DESCRIPTION OF THE INVENTION

[0011] A contact device and a contact member according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. However, the embodiment described below is merely one of various embodiments of the present disclosure. The embodiment described below can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Furthermore, each diagram described in the embodiment described below is a schematic diagram, and the ratios of the sizes and thicknesses of the components in the diagram do not necessarily reflect the actual dimensional ratios.

[0012] (1) Implementation form The contact member 9 of this embodiment is a member used as the first contact 110 or the second contact 120 in a contact device 1 (see FIG. 9) that includes a first contact 110 and a second contact 120 that are configured to come into contact with and separate from each other. The first contact 110 is, for example, a fixed contact that is fixed in position within a case 13 of the contact device 1. The second contact 120 is, for example, a movable contact that is arranged within the case 13 of the contact device 1 so as to be movable relative to the first contact 110. The second contact 120 moves, for example, along one direction (the Z-axis direction) between a first position (see FIG. 10) where it comes into contact with the first contact 110 and a second position (see FIG. 9) where it does not come into contact with the first contact 110.

[0013] (1.1) Overview of contact components The contact member 9 of this embodiment is made of copper or low-density copper, which is a copper alloy containing copper as its main component.

[0014] In this disclosure, "copper alloy containing copper as the main component" means an alloy containing 99% or more copper and 1% or less of components other than copper. In this disclosure, "components other than copper" that may be contained in a copper alloy are components that make the electrical conductivity of a low-density copper copper alloy containing this component in a proportion of 1% or less 75% IACS or more. "% IACS" refers to the electrical conductivity of the internationally adopted pure standard annealed copper (resistivity: 1.7241 x 10 -8It is an index of electrical conductivity, with a conductivity of Ωm (Ω / cm) being 100%. The "components other than copper" contained in the copper alloy include, for example, at least one selected from the group consisting of Al2O3 (aluminum oxide), WC (tungsten carbide), W (tungsten), Cr (chromium), Zr (zirconium), Si (silicon), Mo (molybdenum), Ag (silver), and P (phosphorus).

[0015] In addition, in the present disclosure, "low-density copper" means copper or a copper alloy having a relative density of less than 100%. The "relative density" of the contact member 9 made of low-density copper is determined as the ratio of the density of the contact member 9 to the density of dense copper or a copper alloy having the same composition. Specifically, when the contact member 9 is made of copper, the "relative density" of the contact member 9 made of low-density copper is determined as the ratio of the density of C1020 (oxygen-free copper) (8.94 g / cm 3 ) of the contact member 9. In addition, when the contact member 9 is made of a copper alloy, the "relative density" of the contact member 9 made of low-density copper is determined as the ratio of the density of the contact member 9 to the theoretical value of the density of a copper alloy having the same composition as the contact member 9. As mentioned above, in the present disclosure, the copper alloy constituting the contact member 9 contains copper at a rate of 99% or more. Therefore, even when the contact member 9 is made of a copper alloy, the "relative density" of the contact member 9 made of low-density copper is determined as the ratio of the density of the contact member 9 to the theoretical value of the density of C1020 (oxygen-free copper) (8.94 g / cm 3 Alternatively, the density may be calculated as the ratio of the density of the contact member 9 to the density of the contact member 9.

[0016] The contact member 9 of this embodiment is particularly made of low-density copper having a relative density of 80% or more and 95% or less.

[0017] (1.2) Details of contact components Hereinafter, the contact member 9 of this embodiment will be described in detail with reference to actual samples 1 to 5 of low-density copper made of copper.

[0018] Table 1 shows the densities and relative densities of Samples 1 to 5.

[0019] [Table 1]

[0020] The "density" in Table 1 is the measured density of each sample. The "relative density" in Table 1 is the density of C1020 (oxygen-free copper) (8.94 g / cm 3 ) is the ratio of the measured density of each sample to the actual density of the sample, expressed as a percentage.

[0021] 1 to 5 show cross-sectional images Im1 to Im5 of the cross sections of Samples 1 to 5 photographed using an optical microscope. A scale bar representing 50 μm is also shown in each of the cross-sectional images Im1 to Im5 in FIGS.

[0022] In a contact member 9 made of low-density copper, the portions other than copper or copper alloy are voids. For example, in a contact member 9 with a relative density of 80%, voids occupy 20% (=100%-80%) of the total volume of the contact member 9. In Figures 1 to 5, the voids are shown as relatively dark areas.

[0023] In this way, the contact member 9 made of low-density copper has pores therein in an amount that corresponds to the relative density.

[0024] (1.2.1) Conductivity The contact member 9 preferably has high conductivity in order to be used as the first contact 110 or the second contact 120 of the contact device 1. Table 2 shows the measured values ​​of the conductivity of Samples 1 to 5.

[0025] [Table 2]

[0026] As shown in Table 2, the conductivity of the contact member 9 decreases as the relative density decreases. This is presumably because the proportion of pores that do not contribute to current flow increases as the relative density decreases.

[0027] From the viewpoint of ensuring the electrical conductivity of an electrical path including the contact member 9, the electrical conductivity is preferably 75% IACS or more. Therefore, the relative density of the contact member 9 is preferably 80% or more. Furthermore, from the viewpoint of ensuring the electrical conductivity of 85% IACS or more, the relative density of the contact member 9 may be 85% or more.

[0028] Furthermore, from the viewpoint of the electrical conductivity of the electrical circuit including the contact member 9, it is preferable that the conductor resistance of the contact member 9 is equal to or less than the contact resistance between the fixed contact (first contact 110) and the movable contact (second contact 120) in the temperature range in which the contact member 9 is used.

[0029] (1.2.2) Hole Variation If there is a large variation in the pores in the contact member 9, the contact member 9 may become brittle and the strength of the contact member 9 may decrease. Therefore, it is preferable that the pores are uniformly (randomly) dispersed in the contact member 9. In other words, it is preferable that the variation in the pores in the contact member 9 is small.

[0030] One index for determining porosity variation is the ratio of area non-porosity to volume non-porosity.

[0031] In the present disclosure, the term "volume non-porosity" refers to the proportion of the volume of the portion other than pores (copper or copper alloy) to the entire volume of the contact member 9. The volume non-porosity coincides with the relative density.

[0032] In the present disclosure, the term "area non-porosity" refers to the proportion of areas other than pores in a cross-sectional image of a cross section of the contact member 9. In the present disclosure, the size of the contact member 9 used to determine the areal non-porosity (the size of the contact member 9 shown in the cross-sectional image) is not particularly limited, but is, for example, about 200 μm × 200 μm. The cross-sectional image may be an optical microscope image or a scanning electron microscope (SEM) image.

[0033] It can be said that the closer the areal non-porosity determined in any cross section is to the volume non-porosity (relative density), the more uniform (random) the distribution of pores is within the contact member 9. From the viewpoint of reducing pore variation, the areal non-porosity may be 80% or more and 120% or less, or 85% or more and 115% or less, of the volume non-porosity (relative density).

[0034] Table 3 shows the relative densities of Samples 1 to 5 and the areal non-porosities calculated using cross-sectional images Im1 to Im5. In Table 3, the areal non-porosity value for each sample is calculated by dividing the cross-sectional image into 4 × 4 sections, calculating the areal non-porosity for each of the 16 divided cross-sectional images, and averaging the calculated values.

[0035] [Table 3]

[0036] Another index for determining porosity variation is the standard deviation of areal porosity.

[0037] In the present disclosure, the term "area porosity" refers to the proportion of pores in a cross-sectional image of the contact member 9 taken.

[0038] It can be said that the smaller the standard deviation of the areal porosity, the smaller the variation in the areal porosity, and the closer to a uniform (random) distribution of pores in the contact member 9. From the viewpoint of reducing the variation in pores, the standard deviation of the areal porosity may be 10 or less, or may be 8 or less.

[0039] Table 4 shows the relative densities of Samples 1 to 5 and the standard deviations of the areal porosities calculated using cross-sectional images Im1 to Im5. In Table 4, the standard deviation value for each sample is calculated by dividing the cross-sectional image into 4x4 sections, calculating the areal porosity for each of the 16 divided cross-sectional images, and then showing the value obtained as the standard deviation of the calculated areal porosity.

[0040] [Table 4]

[0041] In the contact member 9 of the embodiment (samples 1 to 4), the ratio of the area non-porosity to the relative density is 85% or more and 115% or less, and the standard deviation is 8 or less. Therefore, it can be said that copper or copper alloy is uniformly (randomly) dispersed in the contact member 9, and that the contact member 9 has high strength.

[0042] (1.2.3) Suppression of contact welding The contact member 9 made of low-density copper of this embodiment can suppress contact welding. In this disclosure, "contact welding" refers to a phenomenon in which, after the first contact 110 and the second contact 120 of the contact device 1 come into contact with each other, the surfaces of the contacts melt due to heat or the like, joining the first contact 110 and the second contact 120 together and making it impossible to separate them.

[0043] Although not all the reasons why contact welding can be suppressed by contact members 9 made of low-density copper have been clarified, one reason is that the contact members 9 contain a certain amount of pores. In other words, in contact members 9 containing pores, even if the contact surface of the contact member 9 melts and the contact member 9 joins with another contact member, the contact member 9 can be peeled off from the other contact member by separating at an interface other than the contact surface. This is thought to make contact welding less likely to occur.

[0044] (1.2.4) Peel test The peel test conducted to verify the peelability of the contact member 9 of this embodiment and the test results will be described below. The peel test was conducted on each of Samples 1 to 5 and the contact member made of C1020 (Sample 0).

[0045] The test method for the peel test will be described with reference to FIGS.

[0046] First, a pair of fixed terminals 11 and a movable contactor 12 was prepared for each sample. The movable contactor 12 had a pair of second contacts 120 (movable contacts) each having a contact member 9 (low-density copper) corresponding to the sample under test. On the other hand, the first contact 110 (fixed contact) of the fixed contact 11 was made of a dense copper alloy (relative density 100%).

[0047] Next, the movable contact 12 and the pair of fixed terminals 11 were placed in a furnace 80 with the first contact 110 of the fixed terminal 11 and the second contact 120 of the movable contact 12 in contact with each other, and a weight 81 was placed on the movable contact 12 with a heat insulating material interposed therebetween (see FIG. 6). Then, the furnace 80 was heated according to a predetermined temperature profile while adjusting the atmosphere inside the furnace 80. Samples 0 to 4 were heated according to a temperature profile P1 (see FIG. 7) with a maximum temperature of 650°C, and Sample 5 was heated according to a temperature profile P2 (see FIG. 7) with a maximum temperature of 550°C. The atmosphere inside the furnace 80 was an N2 atmosphere during a preheating period T1 (set temperature 100°C), an H2 atmosphere of 3% and N2 atmosphere during a main heating period T2 from the end of preheating to the end of heating, and an N2 atmosphere during a cooling period T3 (set temperature 20°C) after the end of heating. As a result of heating, it was confirmed that in all of Samples 0 to 5, the first contact 110 and the second contact 120 were joined together.

[0048] After the heating was completed, the bonded assembly of a pair of fixed terminals 11 and movable contactor 12 was removed from the furnace 80, and a force in the direction of moving the second contact 120 (movable contactor) away from the first contactor 110 (fixed contactor) (a downward force in Figure 8) was applied to the center of the movable contactor 12 using a peel test jig 85 shown in Figure 8, and it was confirmed whether the second contactor 120 could be peeled away from the first contactor 110.

[0049] Table 5 shows the results of the peel test.

[0050] [Table 5]

[0051] In Table 5, the "standard," "2x," and "3x" in the test results column indicate the magnitude of the force applied by the peel test jig 85, where "standard" is 40N, "2x" is 80N, and "3x" is 120N.

[0052] In Table 5, "x" indicates that peeling was not possible. "△" indicates that one second contact 120 was peeled off first, and then the other second contact 120 was peeled off. Note that even if there is a "△", in an actual contact device 1, the current is interrupted when one of the second contacts 120 (movable contact) separates from the first contact 110 (fixed contact), so it can be determined that there is no problem with peeling. "◯" indicates that both second contacts 120 were peeled off almost simultaneously (ideal peeling state).

[0053] As shown in Table 5, contact member 9 (samples 1 to 5) made of low-density copper can be peeled off with less force than contact member (sample 0) made of C1020, and it can be seen that contact welding can be suppressed.

[0054] From the viewpoint of improving peelability, the relative density of the contact member 9 is preferably 95% or less, and may be 90% or less.

[0055] (1.2.5) Advantages of Contact Materials As described above, the contact member 9 of this embodiment is made of copper or a copper alloy containing copper as its main component, and is made of low-density copper with a relative density of 80% to 95%. This makes it possible to suppress contact welding while ensuring the conductivity of the contact member 9. Furthermore, contact welding can be suppressed without complicating the structure of the contact device 1 in which the contact member 9 is used.

[0056] Furthermore, in the contact member 9 of this embodiment, the non-porous area ratio is 80% or more and 120% or less of the relative density, which makes it possible to improve the strength of the contact member 9.

[0057] (1.2.6) Manufacturing method In one example, the contact member 9 made of low-density copper in this embodiment is formed by sintering. More specifically, the contact member 9 made of low-density copper is formed by pressure sintering. That is, the contact member 9 is formed by heating a raw material powder or compact of copper or copper alloy at a temperature below its melting point while applying pressure. The amount of voids and the relative density can be adjusted by adjusting the pressure applied during pressure sintering. Note that the contact member 9 does not have to be formed directly by sintering. For example, the contact member 9 may be formed by subjecting a low-density copper member formed by sintering to an appropriate process such as cutting, which does not substantially change the relative density.

[0058] (1.2.7) Contact device 9 and 10 show an example of a contact device 1 including a contact member 9 of this embodiment. The contact device 1 of this embodiment, together with an electromagnet device 2, constitutes a plunger-type electromagnetic relay 3.

[0059] For convenience, the following description will be given by defining three axes (X-axis, Y-axis, and Z-axis) of a right-handed three-dimensional Cartesian coordinate system for the electromagnetic relay 3 as follows. That is, the direction in which the shaft 23 of the electromagnetic relay 3 extends is defined as the Z-axis direction. The direction in which the movable contactor 12 extends, which is perpendicular to the Z-axis direction, is defined as the X-axis direction. The direction perpendicular to both the X-axis direction and the Z-axis direction is defined as the Y-axis direction. For convenience of description, the Z-axis direction is defined as the up-down direction, the X-axis direction is defined as the left-right direction, and the Y-axis direction is defined as the front-rear direction. However, the definitions of axes and directions in this disclosure merely indicate the relative positional relationships between the components of the electromagnetic relay 3 and do not limit the orientation of the electromagnetic relay 3 during use, etc.

[0060] As shown in FIG. 9, the contact device 1 includes a pair of fixed terminals 11, a movable contact 12, and a case 13.

[0061] The case 13 is formed in a box shape having an internal space 130. The material of the case 13 is not particularly limited, and may be, for example, a ceramic material, a resin material, or a metal material.

[0062] The fixed terminal 11 is formed of a conductive material such as copper. The fixed terminal 11 has a cylindrical shape that is long in the vertical direction. A pair of fixed terminals 11 are arranged side by side in the horizontal direction. The fixed terminal 11 has a first contact 110 (fixed contact) at its lower end. The first contact 110 is formed by a contact member 9 made of low-density copper. The first contact 110 may be formed integrally with the fixed terminal 11 from the same material as the fixed terminal 11, or may be formed from a separate member from the fixed terminal 11 and fixed to the fixed terminal 11. When the first contact 110 is formed integrally with the fixed terminal 11, the fixed terminal 11 may also be made of low-density copper. The fixed terminal 11 is held in the case 13 so that the first contact 110 is located in the internal space 130 of the case 13.

[0063] The movable contactor 12 is made of a conductive material such as copper. The movable contactor 12 is a flat plate that is long in the left-right direction. The movable contactor 12 has a pair of second contacts 120 (movable contacts) on both left and right ends of its upper surface. The pair of second contacts 120 face the first contacts 110 of the pair of fixed terminals 11 in the up-down direction. The second contacts 120 are formed by a contact member 9 made of low-density copper. The second contacts 120 may be formed integrally with the movable contactor 12 from the same material as the movable contactor 12, or may be formed from a separate member from the movable contactor 12 and fixed to the movable contactor 12. When the second contacts 120 are formed integrally with the movable contactor 12, the movable contactor 12 may also be made of low-density copper. The movable contactor 12 is disposed in an internal space 130 of the case 13.

[0064] The movable contactor 12 is driven in the vertical direction by the electromagnet device 2. As a result, a pair of second contacts 120 (movable contacts) of the movable contactor 12 move between a closed position (first position; see FIG. 10) in which they are in contact with the first contacts 110, and an open position (second position; see FIG. 9) in which they are not in contact with the first contacts 110. When the pair of second contacts 120 are in the closed position, the pair of fixed terminals 11 are electrically connected via the movable contactor 12. On the other hand, when the pair of second contacts 120 are in the open position, the pair of fixed terminals 11 are electrically disconnected.

[0065] The electromagnet device 2 includes a fixed iron core 20, a movable iron core 21, an exciting coil 22, a shaft 23, a holder 24, a contact pressure spring 25, and a return spring 26. The electromagnet device 2 may also include a coil bobbin (not shown) around which the exciting coil 22 is wound.

[0066] The fixed core 20 is formed in a cylindrical shape. The upper end of the fixed core 20 is fixed to the lower wall of the case 13.

[0067] The movable core 21 is formed in a cylindrical shape and is disposed below the fixed core 20 so as to be movable in the up and down direction.

[0068] The excitation coil 22 is disposed so as to surround the fixed iron core 20 and the movable iron core 21. In the electromagnet device 2, when current is applied to the excitation coil 22, the magnetic flux generated by the excitation coil 22 attracts and moves the movable iron core 21 upward (see FIG. 10). In addition, in the electromagnet device 2, when current is stopped from being applied to the excitation coil 22, the spring force of the return spring 26 moves the movable iron core 21 downward (see FIG. 9).

[0069] The shaft 23 is made of a non-magnetic material. The shaft 23 is a round bar that is long in the vertical direction. The lower end of the shaft 23 is fixed to the movable iron core 21. The upper end of the shaft 23 passes through a through-hole 131 formed in the center of the lower wall of the case 13 and is located within the internal space 130 of the case 13.

[0070] The holder 24 is disposed within the internal space of the case 13. The holder 24 is a rectangular frame having a through-hole penetrating in the left-right direction. The upper end of the shaft 23 is fixed to the lower plate of the holder 24. The movable contact 12 is passed through the through-hole of the holder 24.

[0071] The contact pressure spring 25 is a coil spring and is disposed between the lower plate of the holder 24 and the movable contact 12, and biases the movable contact 12 upward.

[0072] The return spring 26 is a coil spring and is disposed between the bottom wall of the case 13 and the movable iron core 21, and biases the movable iron core 21 downward.

[0073] The electromagnet device 2 may also include a yoke that surrounds the exciting coil 22. The yoke, together with the fixed core 20 and the movable core 21, forms a magnetic circuit through which passes magnetic flux generated when current is applied to the exciting coil 22. The electromagnet device 2 may also include a housing case that houses the fixed core 20, the movable core 21, the exciting coil 22, and the yoke.

[0074] The operation of the electromagnetic relay 3 will now be briefly described.

[0075] When the exciting coil 22 is not energized (see FIG. 9), no magnetic attraction force is generated between the fixed core 20 and the movable core 21. Therefore, the elastic force of the return spring 26 causes the movable core 21 to be spaced apart from the fixed core 20. Therefore, the holder 24 connected to the movable core 21 via the shaft 23 is also positioned relatively lower, and the movable contactor 12 passed through the through hole of the holder 24 is also positioned relatively lower. As a result, the pair of second contacts 120 (movable contacts) are spaced apart from the pair of first contacts 110 (fixed contacts), and the pair of fixed terminals 11 are electrically isolated from each other.

[0076] When the exciting coil 22 is energized, the movable core 21 is attracted to the fixed core 20 and moves upward. This causes the holder 24 to move upward, and the movable contactor 12 is pushed by the pressure spring 25 and moves upward, so that the pair of second contacts 120 (movable contacts) come into contact with the pair of first contacts 110 (fixed contacts), respectively. As a result, the pair of fixed terminals 11 are electrically connected via the movable contactor 12.

[0077] Even after the pair of second contacts 120 come into contact with the pair of first contacts 110, the movable core 21 continues to move upward until it comes into contact with, for example, the fixed core 20, and the holder 24 also moves upward. This causes the contact pressure spring 25 located between the lower plate of the holder 24 and the movable contactor 12 to be compressed. Then, the compressed contact pressure spring 25 presses the movable contactor 12 upward, thereby increasing the contact pressure between the second contacts 120 and the first contacts 110.

[0078] As described above, in the electromagnetic relay 3 of this embodiment, the first contact 110 (fixed contact) and the second contact 120 (movable contact) are each formed from the contact member 9 made of low-density copper. This improves the ease with which the second contact 120 (movable contact) can be peeled off from the first contact 110 (fixed contact), making it possible to prevent contact welding. Furthermore, contact welding can be prevented without complicating the structure of the contact device 1.

[0079] In particular, since both the first contact 110 and the second contact 120 are formed from a contact member 9 made of low-density copper and the density of the first contact 110 is the same as the density of the second contact 120, the ease of peeling the second contact 120 (movable contact) from the first contact 110 (fixed contact) is further improved.

[0080] (2) Variations The above embodiment is merely one of various embodiments of the present disclosure. The above embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the embodiment are listed below. The above embodiment and the modifications described below can be applied in appropriate combination.

[0081] In one modified example, the contact device 1 does not need to have both the first contact 110 (fixed contact) and the second contact 120 (movable contact) formed from the contact member 9 made of low-density copper. For example, only the first contact 110 (fixed contact) may be formed from the contact member 9 made of low-density copper. Alternatively, only the second contact 120 (movable contact) may be formed from the contact member 9 made of low-density copper. Even in these cases, the second contact 120 (movable contact) can be easily peeled from the first contact 110 (fixed contact), making it possible to suppress contact welding. Furthermore, by forming one of the movable contact and the fixed contact from dense copper or a copper alloy, the current-carrying performance of the contact device 1 is improved.

[0082] In one modified example, both the first contact 110 (fixed contact) and the second contact 120 (movable contact) may be formed of contact members 9 made of low-density copper, and the densities of the first contact 110 and the second contact 120 may be different from each other. Even in this case, the second contact 120 (movable contact) can be easily peeled from the first contact 110 (fixed contact), and contact welding can be suppressed.

[0083] In one modified example, the contact member 9 is not limited to being used as a contact of the plunger-type electromagnetic relay 3, but may also be used as a contact of a hinge-type electromagnetic relay, for example.

[0084] (3) Mode As can be seen from the above embodiments and modifications, the present specification discloses the following aspects.

[0085] The contact device (1) of the first aspect includes a first contact (110) and a second contact (120). The second contact (120) moves between a first position where it is in contact with the first contact (110) and a second position where it is not in contact with the first contact (110). The first contact (110) is made of copper or a copper alloy containing copper as its main component, low-density copper, with a relative density of 80% or more and 95% or less.

[0086] According to this aspect, it is possible to prevent the structure of the contact device (1) from becoming complicated and to prevent the welding of the contacts.

[0087] In the contact device (1) of the second embodiment, the density of the first contacts (110) is lower than the density of the second contacts (120) in the first embodiment.

[0088] According to this embodiment, the density of the second contacts (120) is increased, thereby improving the current-carrying performance of the contact device (1).

[0089] In the contact device (1) of the third embodiment, the density of the first contacts (110) is the same as the density of the second contacts (120) in the second embodiment.

[0090] According to this embodiment, by forming both the first contact (110) and the second contact (120) from a contact member (9) made of low-density copper, the ease of peeling the second contact (120) from the first contact (110) is further improved, making it possible to further suppress contact welding.

[0091] In the contact device (1) of the fourth aspect, in any one of the first to third aspects, the standard deviation of the pore area ratio, which is calculated as the proportion of pores in a cross-sectional image of the cross section of the first contact (110), for multiple cross-sectional images is 10 or less.

[0092] According to this embodiment, the variation in the holes in the contact member (9) is reduced, and the strength of the contact member (9) is improved.

[0093] In the contact device (1) of the fifth aspect, in any one of the first to fourth aspects, the relative density is determined as the ratio of the density of the first contact (110) to the density of C1020.

[0094] According to this aspect, it is possible to prevent the structure of the contact device (1) from becoming complicated and to prevent the welding of the contacts.

[0095] In the contact device (1) of the sixth aspect, in the fifth aspect, the non-void area ratio, which is calculated as the proportion of areas other than voids in a cross-sectional image of a cross section of the first contact (110), is 80% or more and 120% or less of the relative density.

[0096] According to this embodiment, the variation in the holes in the contact member (9) is reduced, and the strength of the contact member (9) is improved.

[0097] The contact device (1) of the seventh aspect includes a first contact (110) and a second contact (120). The second contact (120) moves between a first position where it is in contact with the first contact (110) and a second position where it is not in contact with the first contact (110). The second contact (120) is made of copper or a copper alloy containing copper as its main component, low-density copper having a relative density of 80% or more and 95% or less.

[0098] According to this aspect, it is possible to prevent the structure of the contact device (1) from becoming complicated and to prevent the welding of the contacts.

[0099] The contact device (1) of the eighth aspect is the same as that of the seventh aspect, and further includes a movable contactor (12) having a second contact (120) and moving together with the second contact (120). The second contact (120) is formed integrally with the movable contactor (12) from the same material.

[0100] According to this aspect, it is possible to prevent the structure of the contact device (1) from becoming complicated and to prevent the welding of the contacts.

[0101] In the contact device (1) of the ninth aspect, in the seventh or eighth aspect, the relative density is determined as the ratio of the density of the second contact (120) to the density of C1020.

[0102] According to this aspect, it is possible to prevent the structure of the contact device (1) from becoming complicated and to prevent the welding of the contacts.

[0103] A contact member (9) of a tenth aspect is used as the first contact (110) or the second contact (120) in a contact device (1) including a first contact (110) and a second contact (120). The second contact (120) moves between a first position in contact with the first contact (110) and a second position in not contacting the first contact (110). The contact member (9) is made of copper or a copper alloy containing copper as its main component, low-density copper with a relative density of 80% or more and 95% or less.

[0104] According to this aspect, it is possible to prevent the structure of the contact device (1) from becoming complicated and to prevent the welding of the contacts.

[0105] In the contact member (9) of the eleventh embodiment, in the tenth embodiment, the relative density is determined as the ratio of the density of the contact member (9) to the density of C1020.

[0106] According to this aspect, it is possible to prevent the structure of the contact device (1) from becoming complicated and to prevent the welding of the contacts. [Explanation of symbols]

[0107] 1 Contact device 110 First Contact 12 Movable contact 120 Second Contact 9 Contact parts

Claims

1. A first contact point; a second contact that moves between a first position in contact with the first contact and a second position out of contact with the first contact; The first contact is made of copper or a copper alloy containing copper as a main component, and has a low density of 80% or more and 95% or less in relative density. Contact device.

2. the density of the first contacts is less than the density of the second contacts; The contact device according to claim 1 .

3. The density of the first contacts is the same as the density of the second contacts. The contact device according to claim 1 .

4. a standard deviation of a void area ratio, which is calculated as a ratio of voids in a cross-sectional image of a cross section of the first contact, for a plurality of the cross-sectional images is 10 or less; The contact device according to any one of claims 1 to 3.

5. the relative density being determined as a ratio of the density of the first contact to the density of C1020; The contact device according to any one of claims 1 to 4.

6. a non-void area ratio, which is calculated as the ratio of areas other than voids in a cross-sectional image of a cross section of the first contact, is 80% or more and 120% or less of the relative density; The contact device according to claim 5 .

7. A first contact point; a second contact that moves between a first position in contact with the first contact and a second position out of contact with the first contact; The second contact is made of copper or a copper alloy containing copper as a main component, and has a low density of 80% or more and 95% or less in relative density. Contact device.

8. a movable contactor having the second contact and moving together with the second contact; The second contact is integrally formed from the same material as the movable contactor. The contact device according to claim 7.

9. the relative density being determined as a ratio of the density of the second contact to the density of C1020; The contact device according to claim 7 or 8.

10. A contact member used as the first contact or the second contact in a contact device including a first contact and a second contact that moves between a first position in contact with the first contact and a second position in not in contact with the first contact, The contact member is made of copper or a copper alloy containing copper as a main component, and is made of low-density copper having a relative density of 80% or more and 95% or less. Contact material.

11. The relative density is determined as a ratio of the density of the contact member to the density of C1020. The contact member according to claim 10.

Images