Silver graphite contact safety unit

Abstract

The application discloses a silver graphite contact safety unit, which comprises a fixed unit, a static contact assembly and a dynamic contact assembly. The static contact assembly is installed at a groove of the fixed unit, and the dynamic contact assembly is installed on the upper part of an operating mechanism and placed in a U-shaped part of the fixed unit. In a normally open state, the dynamic contact in the dynamic contact assembly and the silver graphite contact in the static contact assembly are oppositely arranged at a specified distance. The static contact assembly comprises a static contact sheet, a fixed clamp and a silver graphite contact. The silver graphite contact is in abutment with the static contact sheet and is wrapped together through the fixed clamp. The three are fixed to form the static contact assembly through tin soldering. One end of the static contact sheet is stretched out of the fixed clamp as a wiring end. The silver graphite contact with anti-fusion welding property is adopted, so that the dynamic contact and the static contact do not adhere to each other in the use process, the anti-fusion welding capacity is improved, and better safety and service life are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to a relay, in particular to a silver graphite contact safety unit. BACKGROUND

[0002] The current railway signal relay is a special electromagnetic switch device for various signal devices or systems of railway, which is composed of an electromagnetic coil, a contact assembly, a transmission part and a part for ensuring the contact closure or disconnection. In application, reliability and safety are necessary requirements for ensuring the normal work of various automatic control and remote control signal devices. Therefore, the railway puts forward strict technical indexes for the signal relay, the contact system must be consistent, reliable and accurate, has sufficient closure and disconnection functions and service life, and has high electrical insulation strength under the condition of great changes of external temperature and humidity; has stable time characteristics and electrical parameter characteristics.

[0003] The structure of the contact assembly in the existing railway signal relay adopts spot welding or riveting to fix the contact on the contact sheet, and the contact sheet and the holder are spot welded together to form the contact assembly by injection molding. The existing contact material has poor resistance to fusion welding, which affects the service life of the relay.

[0004] The existing structure drives the pull rod to act through the armature, the pull rod drives the moving contact to act, and then the moving contact and the static contact are disconnected, which belongs to a clapping structure, has large volume and occupies installation space. Meanwhile, the original static contact is a cylindrical shape placed horizontally in the axial direction, has no redundancy design, has small contact area with the moving contact, obvious contact rebound and poor stability. SUMMARY

[0005] In view of the poor resistance to fusion welding of the relay contact and the poor contact stability between the contacts in the prior art, the present application aims to provide a silver graphite contact safety unit with high reliability and long service life.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0007] The silver graphite contact safety unit comprises a fixed unit, a static contact assembly and a moving contact assembly, wherein the static contact assembly is installed at the groove of the fixed unit, the moving contact assembly is installed at the upper part of an operating mechanism and placed in the U-shaped part of the fixed unit, and the moving contact in the moving contact assembly and the silver graphite contact in the static contact assembly are oppositely arranged at a specified distance in the normally open state.

[0008] The static contact assembly comprises a static contact sheet, a fixed clamp and a silver graphite contact, wherein the silver graphite contact abuts against the static contact sheet and is wrapped together by the fixed clamp, and the three are fixed by tin soldering to form the static contact assembly, and one end of the static contact sheet extends out of the fixed clamp as a wiring end.

[0009] The silver graphite contact is trapezoidal table shape, the upper bottom surface is wide plane, and is fixed and welded with the static contact piece, the lower bottom surface is narrow plane which separates and combines with the movable contact.

[0010] The movable contact assembly comprises a movable contact piece, a movable piece insert and a movable contact, the movable contact piece is H-shaped, the middle connecting part of the H-shaped movable contact piece has a round hole, each top end of the H-shaped movable contact piece is fixedly installed with a movable contact, the movable piece insert is two pieces of upper and lower pieces which can be buckled, the middle connecting part of the movable contact piece is clamped between the upper and lower pieces, and the movable piece insert has a round hole which is concentrically sleeved on the operating mechanism with the round hole of the movable contact piece.

[0011] The operating mechanism is a top rod, a first step is arranged on the upper part of the top rod, a groove is arranged on the upper end of the top rod, and the movable contact assembly is sleeved between the step and the groove of the top rod; the upper end of the movable piece insert of the movable contact assembly abuts against the first stop bottom surface, the first stop top surface abuts against the open check ring, and the open check ring is clamped in the groove on the upper end of the top rod; and the top rod is fixedly connected with the iron core.

[0012] The second stop is further arranged, the bottom surface of the second stop abuts against the step, and the upper surface of the second stop sleeves a spring between the movable piece insert of the movable contact assembly and the top rod.

[0013] The back plate is further arranged, the fixed unit is installed on one side of the back plate, and the wiring end of the static contact piece extends through the back plate to the other side of the back plate.

[0014] The inner side of the U-shaped part of the fixed unit has an arc-shaped protrusion.

[0015] The silver graphite contact safety unit has the following beneficial effects and advantages:

[0016] 1. The silver graphite contact in the silver graphite contact safety unit is resistant to fusion welding, and the silver graphite contact is designed to be flat, so that the contact area of the movable contact and the static contact is increased, the contact resistance is stable, the movable contact and the static contact do not stick together during use, the anti-fusion welding capability is improved, and better safety and service life are ensured.

[0017] 2. The inner side of the U-shaped part of the fixed unit in the application adopts an arc-shaped protrusion, which can limit the excessive rotation of the movable contact assembly, so as to ensure that the movable contact abuts against the silver graphite contact.

[0018] 3. The movable contact in the application adopts a redundant design, which can ensure better contact reliability.

[0019] 4. The static contact piece in the application has a step design, so that the static contact assembly can be reliably installed on the fixed unit and will not fall out.

[0020] 5. The second stop is provided with the bottom surface abutting against the step and the upper surface sleeving the spring on the top rod between the moving piece insert of the moving contact assembly, the spring in the compressed state can provide enough counterforce to the moving contact assembly, and the moving and static contacts can reliably contact during the attraction process, and the contact rebound phenomenon is not easy to occur. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The figure is the structure schematic diagram of the silver graphite contact safety unit of the present application.

[0022] Figure 2 The figure is the isometric view of the present application.

[0023] Figure 3 The figure is the structure schematic diagram of the top rod of the present application.

[0024] Figure 4A The figure is the front view of the silver graphite contact of the present application.

[0025] Figure 4B The figure is the left view of the present application. Figure 4A The figure is the top view of the present application.

[0026] Figure 4C The figure is the top view of the present application. Figure 4A

[0027] The figure is the structure schematic diagram of the static contact assembly of the present application. Figure 5

[0028] The figure is the structure schematic diagram of the moving contact assembly of the present application. Figure 6

[0029] The figure is the structure schematic diagram of the fixed unit of the present application. Figure 7

[0030] The figure is the schematic diagram of the fixed unit after the static contact piece is installed. Figure 8 The figure is the schematic diagram of the fixed unit after the static contact piece is installed.

[0031] The figure is the schematic diagram of the fixed unit after the static contact piece is installed. DETAILED DESCRIPTION

[0032] The present application is further described below in combination with the drawings of the present application.

[0033] The figure is the schematic diagram of the fixed unit after the static contact piece is installed. Figure 1As shown, the present invention provides a silver graphite contact safety unit, including a fixed unit 2, a stationary contact assembly 3, and a moving contact assembly 4, wherein the stationary contact assembly 3 is installed in the groove 201 of the fixed unit 2, and the moving contact assembly 4 is installed on the upper part of an operating mechanism and placed in the U-shaped part 202 of the fixed unit 2; in the normally open state, the moving contact 403 in the moving contact assembly 4 and the silver graphite contact 303 in the stationary contact assembly 3 are arranged relative to each other at a predetermined distance.

[0034] In this invention, the stationary contact assembly 3 includes a stationary contact piece 301, a fixing clip 302, and a silver graphite contact 303. The silver graphite contact 303 abuts against the stationary contact piece 301 and is wrapped together by the fixing clip 302. The three are fixed together by soldering to form the stationary contact assembly 3. One end of the stationary contact piece 301 extends out from the fixing clip 302 as a wiring terminal.

[0035] like Figures 7-8 As shown, the fixing unit 2 includes a groove 201 and a U-shaped portion 202. The groove 201 has an opening at its upper part, and the protrusion on the stationary contact piece 301 is fixed in the opening. The U-shaped portion has round holes on both sides, and screws pass through the round holes to fix the bottom surface of the U-shaped portion of the fixing unit to the yoke of the existing safety unit. The U-shaped portion of the fixing unit 2 is installed on one side of a back plate 1, and the wiring terminal of the stationary contact piece 301 extends through the back plate 1 to the other side of the back plate 1.

[0036] like Figures 4A-4C As shown, the silver graphite contact 303 is trapezoidal, with a wide flat surface on the upper bottom extending to both sides as a base, which is fixedly welded to the stationary contact piece 301. The lower bottom surface is a narrow flat surface, which separates from the moving contact 403.

[0037] The stationary contact piece 301 is a metal strip that is recessed in the middle width direction. The fixing clip 302 is bent at the recessed position to wrap the silver graphite contact 303 and the stationary contact piece 301 around the stationary contact piece 301.

[0038] In this embodiment, the fixing clip 302 is a thin, soft, and bendable copper sheet with a large central perforation and two smaller perforations on either side. The large central perforation allows the trapezoidal platform of the silver graphite contact 303 to pass through and be blocked by the base. The smaller perforations on either side, after bending, fit precisely into the recessed portion of the stationary contact piece 301 on the side of the silver graphite contact 303, and are then bent again to tighten onto the back of the stationary contact piece 301. Finally, it is fixed by soldering, forming a shape as shown in the image. Figure 5 The static contact assembly 3 is shown.

[0039] like Figure 6As shown, the movable contact assembly 4 includes movable contact sheet 401, movable sheet insert 402 and movable contact 403, wherein the movable contact sheet 401 is H-shaped with a round hole in the middle connecting part, one movable contact 403 is fixedly installed at each of the four vertexes of the H-shaped, the movable sheet insert 402 is two pieces of upper and lower pieces which can be buckled, the middle connecting part of the movable contact sheet 401 is clamped between the upper and lower pieces, and the movable sheet insert 402 has a round hole which is concentrically sleeved on the operating mechanism with the round hole of the movable contact sheet 401.

[0040] As shown in the figure, Figures 2-3 The operating mechanism is a top rod 8, the upper part of the top rod 8 is provided with a first step 801, the upper end of the top rod 8 is provided with a groove 802, and the movable contact assembly 4 is sleeved between the step 801 and the groove 802 of the top rod 8; the upper end of the movable sheet insert 402 of the movable contact assembly 4 abuts against the bottom surface of the first stop 5, the top surface of the first stop 5 abuts against the open check ring 9, and the open check ring 9 is clamped in the groove 802 at the upper end of the top rod 8; and the bottom end of the top rod 8 is fixedly connected with the iron core of the existing safety unit.

[0041] The application also provides a second stop 6, the bottom surface of which abuts against the step 801, and the top surface of which is sleeved with a spring 7 on the top rod 8 between the movable sheet insert 402 of the movable contact assembly 4, as shown in the figure. Figure 1

[0042] The working process and principle of the application are as follows:

[0043] 1) Attraction process

[0044] The coil sleeved outside the iron core is electrified, the iron core drives the top rod 8 to move upwards under the action of electromagnetic force, further drives the movable contact assembly 4 to move upwards, and makes the movable contact 403 abut against and close together with the silver graphite contact 303 in the stationary contact assembly 3, at this time, the movable contact assembly 4 is driven to move downwards by 0.5mm under the action of the abutting force, and the first stop 5 is also driven to move downwards by 0.5mm at the same time. The spring 7 is also compressed by 0.5mm between the movable sheet assembly 4 and the second stop 6 provided at the step 801, and is in an energy storage state, so that the attraction is stable. In the embodiment, the length of the spring 7 in the breaking state is 4mm, and the length in the free state before installation is 5mm.

[0045] 2) Breaking process

[0046] The coil sleeved outside the iron core loses electricity, the iron core loses the electromagnetic attraction, and drives the top rod 8 to move downwards under the action of its own gravity and the restoring force of the large spring in the magnetic dynamic mechanism, and returns to the position in the original breaking state, the spring 7 also restores the original length, the movable contact assembly 4 drives the first stop 5 to rise again, and the first stop 5 stops at the open check ring 9.

[0047] Due to the setting of the spring 7 and the two stops, the breaking is not adhered and the attraction force is stable.​

[0048] The whole structure of the application is small in size, which can be reduced to one fourth of the original structure, saves the installation space, and the inner side of the U-shaped part of the fixing unit adopts the arc-shaped protrusions 202A (a total of four), which can limit the excessive rotation of the movable contact assembly, so as to ensure that the movable contact and the silver graphite contact abut.

[0049] In the application, the static contact in the silver graphite contact safety unit adopts the silver graphite contact with anti-fusion welding property, and the silver graphite contact is designed to be flat, the contact area of the movable contact and the static contact is increased, which is more conducive to the stable contact resistance, ensures that the movable contact and the static contact do not stick in the use process, and ensures better safety. The movable contact adopts a redundant design, that is, each side of the movable contact piece 401 has two movable contacts, a total of four, and the contact surface of each static contact 303 and the movable contact 403 can ensure better contact reliability.

Claims

1. A silver-graphite contact safety unit, characterized by: The fixed unit, the static contact point assembly and the dynamic contact point assembly, wherein the static contact point assembly is installed in the groove of the fixed unit, the dynamic contact point assembly is installed on the upper part of the operating mechanism and placed in the U-shaped part of the fixed unit; the dynamic contact point in the dynamic contact point assembly and the silver graphite contact point in the static contact point assembly are oppositely arranged at a specified distance in the normally open state; The static contact point assembly includes the static contact point sheet, the fixed clamp and the silver graphite contact point, wherein the silver graphite contact point is in contact with the static contact point sheet and wrapped together by the fixed clamp, the three are fixed by tin soldering to form the static contact point assembly, and one end of the static contact point sheet is stretched out by the fixed clamp as a wiring end; The silver graphite contact point is in the shape of a trapezoidal table, the upper bottom surface is a wide flat surface fixedly welded with the static contact point sheet, and the lower bottom surface is a narrow flat surface for separating and combining with the dynamic contact point.

2. The silver graphite contact safety unit according to claim 1, characterized in that: The dynamic contact point assembly includes the dynamic contact point sheet, the dynamic sheet insert and the dynamic contact point, wherein the dynamic contact point sheet is in the shape of H, the middle connecting part of the H-shaped dynamic contact point sheet has a round hole, each top end of the H-shaped dynamic contact point sheet is fixedly installed with a dynamic contact point, the dynamic sheet insert is a two-piece upper and lower piece that can be buckled, the middle connecting part of the dynamic contact point sheet is clamped between the upper and lower pieces, and the dynamic sheet insert has a round hole concentrically sleeved with the round hole of the dynamic contact point sheet and placed on the operating mechanism.

3. The silver graphite contact safety unit of claim 1, wherein: The operating mechanism is a top rod, the upper part of the top rod is provided with a first step, the upper end of the top rod is provided with a groove, and the dynamic contact point assembly is sleeved between the step and the groove of the top rod; the upper end of the dynamic sheet insert of the dynamic contact point assembly is in contact with the first stop bottom surface, the first stop top surface is in contact with the open blocking ring, and the open blocking ring is clamped in the groove at the upper end of the top rod; the top rod is fixedly connected with the iron core.

4. The silver graphite contact safety unit of claim 2, wherein: A second stop is further provided, the bottom surface of the second stop is in contact with a step at the upper part of the operating mechanism, and the upper surface of the second stop is sleeved with a spring on the top rod between the dynamic sheet insert of the dynamic contact point assembly.

5. The silver graphite contact safety unit of claim 1, wherein: A back plate is further provided, the fixed unit is installed on one side of the back plate, and the wiring end of the static contact point sheet extends through the back plate to the other side of the back plate.

6. The silver graphite contact safety unit of claim 1, wherein: The inner side of the U-shaped part of the fixed unit has an arc-shaped protrusion.

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