Metal lining pair

Abstract

The utility model belongs to the technical field of metal materials, and particularly relates to a metal lining pair which comprises a first metal lining and a second metal lining which are oppositely arranged. One end of the first metal lining is provided with a first boss, and one end of the second metal lining is provided with a second boss; the first boss and the second boss are oppositely arranged, a metal sheet is arranged between the first boss and the second boss, the metal sheet is provided with a first surface adjacent to the first boss, and the metal sheet is provided with a second surface adjacent to the second boss; a rubber cylinder is arranged in the metal lining pair, and the metal lining pair is fixedly arranged on the rubber cylinder in a sleeved mode. The utility model provides a simple and rapid stack plating protection metal lining pair, which has a good protection effect and does not cause the phenomenon of'cadmium leakage '. The electroplating efficiency can be improved by more than one time; clamp marks cannot be generated in the electroplating process, and the protection performance of the plating layer can be better improved; the device can be repeatedly used, so that the production cost is saved to a great extent; and the universality is high.

Description

Technical Field

[0001] The utility model belongs to the technical field of metal materials, in particular to a metal bushing pair. Background Art

[0002] The metal bushing is a part in the grader that produces relative sliding and friction with the end of the oil cylinder. The structure of the metal bushing with a boss is as described in the prior art CN201149038Y, including a hollow cylindrical alloy substrate with a boss. In various existing models of graders and other mechanical equipment, most of the bushings used are made of integral copper alloy. When designing the material, in order to ensure the normal use of the oil cylinder and its accessories that produce relative sliding without being worn, the bushing is made of copper alloy, and is generally an integral copper alloy part. Due to the poor wear resistance of copper alloy, it is easy to wear during use. After the bushing is worn, the oil cylinder shake increases and the stability is reduced. It must be replaced frequently and in a timely manner, resulting in a great waste of copper alloy.

[0003] The copper alloy bushing needs to be protected, and cadmium plating is generally used as surface protection. The inner hole and end face of the bushing do not need cadmium plating. During the electroplating process, insulating tape is generally used to protect the surface that does not need to be electroplated. However, the insulating protective tape sometimes falls off during the electroplating process, resulting in "cadmium leakage", and the electroplating time of a single bushing is long, and the electroplating efficiency is low. Utility Model Content

[0004] The utility model aims to provide a metal bushing pair which is convenient for electroplating.

[0005] In order to achieve the above purpose, the technical solution of the utility model is as follows:

[0006] A pair of metal bushings comprises a first metal bushing and a second metal bushing arranged opposite to each other; one end of the first metal bushing has a first boss, and one end of the second metal bushing has a second boss; the first boss and the second boss are arranged opposite to each other, a metal sheet is arranged between the first boss and the second boss, the metal sheet has a first surface adjacent to the first boss, and the metal sheet has a second surface adjacent to the second boss; a rubber tube is arranged inside the metal bushing pair, and the metal bushing pair is sleeved and fixed on the rubber tube.

[0007] In one preferred embodiment, the two ports of the rubber tube are flush with the two ports of the metal bushing pair, or are embedded by 1-2 mm. The embedded means that one or both ports of the rubber tube are 1-2 mm lower than the ports of the metal bushing pair.

[0008] In one preferred embodiment, the rubber tube is made of fluororubber.

[0009] Fluororubber has good elasticity and can fix the metal bushing well. At the same time, the acid and alkali resistance, non-conductivity and other properties of fluororubber can also be used to protect the two superimposed metal bushings with bosses from the inner wall.

[0010] In one preferred embodiment, the rubber tube is formed by a rectangular rubber sheet.

[0011] In one preferred embodiment, the thickness of the rubber tube is 1.5 mm to 2.5 mm.

[0012] If the thickness of the rubber layer is too small, the strength of the rubber layer around the bushing is too weak, which may cause the two bushings to fall off. If the thickness is too large, the rubber is not easy to bend into a round lining in the bushing.

[0013] In one preferred embodiment, the length of the rubber sheet is 1-2 mm smaller than the sum of the lengths of the two metal bushings, and the width is 0.1-0.5 mm larger than the circumference of the inner diameter of the metal bushings.

[0014] The length and width of the rubber sheet have an important impact on the protection of the bushing. If the length is too long, the two ends will be rubber pads, and the bushing base parts cannot contact the hook for conductivity. If the length is too short, it will not protect the two ends of the bushing inner hole. If the width is too small, the fluororubber liner in the bushing inner hole cannot form a complete circle and fit on the inner wall of the bushing to play a protective role. If the width is too large, the fit is not good and there is no protection.

[0015] In one preferred embodiment, the first boss of the first metal bushing and the second boss of the second metal bushing are connected by a plurality of metal sheets.

[0016] In one preferred embodiment, the number of metal sheets is 1-10.

[0017] Adding multiple metal sheets to the overlapping portion of the end faces of the two bushing bosses can better ensure the conductivity of the two bushings.

[0018] Before the two bushing bosses are superimposed and protected, no sandblasting or other deoxidation operations are performed. The metal itself will oxidize under natural conditions and form an oxide film, which will affect the conductive effect. After adding the metal sheet, bushing 1, the metal sheet and bushing 2 form a series relationship in sequence, which ensures a better conductive effect, resulting in the two bushings being better in appearance, thickness and coating uniformity after electroplating than without adding.

[0019] In one preferred embodiment, the electrical conductivity of the metal sheet is greater than 50*10 6 Siemens / m.

[0020] In one preferred embodiment, the metal sheet is copper foil.

[0021] On the one hand, copper has good ductility and can be very thin. It can be sandwiched between the bushing bosses without affecting the fit of the two bosses. More importantly, copper has good electrical conductivity, with a conductivity of up to 59.6*10 6 Siemens / meter is conducive to the improvement of the spraying speed. In addition, the metal bushing is generally a copper alloy bushing, and the use of copper foil between the copper alloy bushings will not generate an electric potential between the metals, thereby avoiding the generation of galvanic corrosion.

[0022] In one preferred embodiment, the thickness of the copper foil is 0.1 mm to 0.2 mm.

[0023] If the thickness of the copper foil is too large, the copper foil will separate the bushings where the two bosses are bonded, resulting in poor adhesion, which will affect the conductive performance and will also cause the two bushings to tilt at a certain angle. Therefore, while ensuring continuity, the thickness of the copper foil should be reduced as much as possible.

[0024] In one preferred embodiment, the copper foil is rectangular, and its length and width cannot exceed the boss of the bushing.

[0025] This arrangement will compact the copper foil in the middle of the two bushing bosses and will not contact other metal parts to cause "electric shock" and other problems.

[0026] In one of the preferred embodiments, the inner walls of the first metal bushing and the second metal bushing are provided with oil grooves in the length direction; the oil grooves of the first metal bushing and the second metal bushing are connected; the wall of the oil groove and the outer wall of the rubber tube form a channel with openings at both ends, and the channel is sealed away from the opening of the boss.

[0027] The horizontal axis of the coordinate is the length direction.

[0028] In one of the preferred embodiments, a sealing material is used to seal the opening of the channel structure away from the boss.

[0029] In one preferred embodiment, the sealing material is silica gel mud.

[0030] The sealing material can also be other filling materials as long as it can achieve sealing. However, silica gel is preferred because this material is acid and alkali resistant, will not affect the tank liquid, and has good plasticity, and can be molded into any required shape according to the part that needs to be sealed.

[0031] The utility model uses silica gel mud to fill the gap of the oil groove in the inner hole of the bushing, which can prevent the electroplating solution from entering the inner hole of the bushing and prevent "cadmium leakage". In addition, the silica gel mud will not adhere to the parts or the surface of fluororubber and is easy to remove.

[0032] In one preferred embodiment, the pair of protective metal bushings are suspended on hooks during the electroplating process.

[0033] In one preferred embodiment, the hook is in the shape of a "branch" or a "fishbone".

[0034] The "branch" or "fishbone" shaped hooks can be used to hang multiple protected bushing pairs at one time. During electroplating, the bushing end surface substrate and the hanger are used for electrical conduction. The bushing can be rotated during the electroplating process to avoid fixture marks.

[0035] The method for preparing the protective metal bushing pair comprises:

[0036] S1. Overlap the bosses of two metal bushings with bosses, and embed a metal sheet between the overlapping bosses;

[0037] S2, attaching the rubber sheet to the inner walls of the two bushings to fix the two bushings;

[0038] S3, filling the sealing material into the gap between the oil groove of the bushing and the rubber sheet to obtain a bushing pair;

[0039] S4. Hang the bushing pair on the hook and perform spin spraying.

[0040] The working principle of the utility model is as follows:

[0041] 1. When the metal sheet is embedded in the middle of the two bushing bosses, the two bushings need to be fixed to clamp them so that the copper foil will not fall off. The two bushings are fixed and clamped mainly by the fluororubber sheet. A complete fluororubber sheet is inserted into the middle of the two overlapping bushings in the shape of a rectangle. The rubber sheet is squeezed into a cylinder in the inner holes of the two bushings, tightly attached to the inner wall of the overlapping bushings, and plays a good fixing role.

[0042] 2. When the fluororubber sheet is fixed on the inner wall of the overlapping bushing in a cylindrical shape, the oil groove on the inner hole surface of the copper alloy bushing is blocked under the rubber sheet. After the fluororubber gasket is used to protect the inner hole, the oil groove is between the gasket and the bushing matrix. At this time, the oil groove seen at the openings at both ends of the bushing becomes a small hole, which is located as the oil groove hole. With the support of the fluororubber sheet in the middle of the bushing, the silicone mud is plugged into the oil groove hole to protect the oil groove and prevent the electroplating solution from penetrating from the oil groove hole.

[0043] 3. Both ends of the bushing have chamfers of about 1mm. Therefore, when selecting the length of the fluororubber sheet in the length direction of the bushing, both ends should be 1-2mm smaller than the end face of the bushing. This ensures that when the overlapping bushing is hung on the "fishbone-shaped" hook, the bushing edges that are not blocked by the fluororubber sheet and the "fishbone-shaped" copper hook are in contact and conductive.

[0044] The utility model invents a simple and quick stacked-plated protective metal bushing pair through the exploration and research of the copper alloy cadmium plating process, which has good protection effect and will not cause "cadmium leakage" phenomenon; the protective material used in the utility model is green and environmentally friendly, and will not cause harm to the bath solution, the environment and the human body; the electroplating efficiency can be increased by more than double; no fixture marks will be generated during the electroplating process, which can better improve the protective performance of the coating; the stacked-plated protective metal bushing pair can be used repeatedly, which greatly saves production costs; it has strong versatility and can be used in electroplating processes such as cadmium plating and chromium plating of copper alloys and other metal materials.

[0045] The advantages of the utility model are as follows:

[0046] 1. It is easy to operate and can quickly protect parts with good protection effect without "cadmium leakage".

[0047] 2. The protective device is made of fluororubber and silicone mud, which is low-cost, green and environmentally friendly, will not harm the environment and human body, and will not pollute the electroplating tank liquid.

[0048] 3. The clamping method of the utility model can ensure good conductivity and coating quality, and more than double the electroplating efficiency.

[0049] 4. This method will not produce fixture marks on the surface of parts, and can better improve the protective performance of the coating.

[0050] 5. The utility model has strong versatility and can be used for electroplating processes such as cadmium plating and chromium plating of copper alloys and other metal materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the structure of a metal bushing and a rubber cylinder;

[0052] Figure 2 It is a schematic diagram of the structure of a metal bushing and copper foil;

[0053] Figure 3 It is a schematic diagram of the structure of the metal bushing to the inner wall oil groove and the silica gel mud;

[0054] Figure 4 The overall installation diagram for electroplating of metal bushings;

[0055] Figure 5 Local installation diagram for electroplating of metal bushings;

[0056] Figure 6 This is the electroplating process flow chart of copper alloy bushing;

[0057] In the figure, 1-rubber tube, 2-first metal bushing, 3-second metal bushing, 4-first boss, 5-second boss, 6-metal sheet, 7-oil tank, 8-silica gel, 9-"fishbone" shaped copper hook. DETAILED DESCRIPTION

[0058] Example 1

[0059] 1) If Figure 1 As shown, item 1# is a rubber tube, item 2# is the first metal bushing, item 3# is the second metal bushing, item 4# is the first boss, and item 5# is the second boss. Before protection, the rubber tube is a rectangular rubber sheet. The rubber sheet is gently folded in half and embedded in the inner hole of the bushing where the two bosses overlap. At this time, the rubber sheet forms a rubber tube in the hole of the bushing pair. Adjust the rubber tube to ensure that it is level and pressed in the hole of the bushing pair and the two end faces. The outer diameter of the rubber tube is slightly larger than the inner diameter of the bushing pair, so that it undergoes elastic deformation to fix and support the bushing. The two ends of the rubber tube are flush with the two ends of the bushing pair or slightly embedded by 1-2mm.

[0060] 2) If Figure 2 As shown, the 6# piece is a metal sheet. Before the two bushings are not equipped with rubber rings, the metal sheet 6 is embedded into the overlapping surface of the two bushing bosses to ensure good electrical conductivity.

[0061] 3) If Figure 3 As shown, part 7# is the oil tank and part 8# is the silicone mud. After the fluororubber ring is installed, use pointed tweezers to embed the granular silicone mud into the opening of the channel with both ends opened by the oil tank and the rubber tube, which is far away from the boss, to ensure that the tank liquid will not penetrate during electroplating and cause "cadmium leakage".

[0062] 4) If Figure 4 and 5 As shown, the 9# piece is a "fishbone" shaped copper hook. Install the protected copper alloy bushing assembly on the copper hook. According to the specifications of the electroplating tank, multiple bushings can be installed at one time. During electroplating, the copper alloy bushing and the main rod of the fishbone hook form contact and conduction. During the electroplating process, the current can be interrupted and the copper alloy bushing assembly can be rotated in a certain direction, so that the fixture mark on the contact point will also be plated.

[0063] according to Figure 1-Figure 5As shown, the metal bushing pair comprises a first metal bushing 2 and a second metal bushing 3 arranged opposite to each other; the first metal bushing 2 is provided with a first boss 4, and the second metal bushing 3 is provided with a second boss 5; the first boss and the second boss are connected to each other, and a metal sheet 6 is sandwiched between the first boss and the second boss; a rubber tube 1 is provided on the inner wall of the metal bushing pair. An oil groove 7 in the length direction is provided on the inner wall of the first metal bushing 2 and the second metal bushing 3; the oil groove of the first metal bushing is connected to the oil groove of the second metal bushing; the wall of the oil groove 7 and the outer wall of the rubber tube 1 form a channel with openings at both ends, and the opening of the channel away from the boss is sealed with silicone mud 8.

[0064] The horizontal axis of the coordinate is the length direction.

[0065] Optionally, the first boss of the first metal bushing and the second boss of the second metal bushing are connected by two metal sheets. Adding multiple metal sheets at the overlapped end surfaces of the two bushing bosses can better ensure the conductivity of the two bushings, and the metal sheet is a copper foil with a thickness of 0.15 mm. The copper foil is rectangular, and the length and width do not exceed the boss of the bushing.

[0066] The metal bushing pair is suspended on a hook during the electroplating process, and the hook is a copper alloy hook in a "fishbone" shape.

[0067] The stacking plating protection method of the metal bushing comprises the following steps:

[0068] S1. Overlap the bosses of two metal bushings with bosses, and embed a piece of copper foil between the overlapping bosses;

[0069] S2, attaching the rubber sheet to the inner walls of the two bushings to fix the two bushings;

[0070] S3, filling the gap between the oil groove of the bushing and the rubber sheet with silica gel mud to obtain a bushing pair;

[0071] S4. Hang the bushing pair on the hook and perform spin spraying.

[0072] The thickness of the copper foil is 0.12mm. The copper foil is rectangular, and the length and width do not exceed the boss of the bushing. The rubber sheet is a fluororubber sheet, and the thickness of the rubber sheet is 2.0mm. The rubber sheet is rectangular, the length is 1-2mm less than the sum of the heights of the two metal bushings, and the width is equal to the circumference of the inner diameter of the metal bushing. The hook is in the shape of a "fishbone".

[0073] The "fishbone" shaped copper hook can be used to hang multiple protected bushing pairs at one time. During electroplating, the bushing end surface substrate and the hanger are used for electrical conduction. The bushing can be rotated during the electroplating process to avoid fixture marks.

[0074] 5) If Figure 6As shown, electroplating is carried out according to the process flow and related process parameters of copper alloy bushing electroplating. This process is also applicable to the electroplating of other copper alloy parts. The process includes 16 steps: acceptance before plating 1, organic solvent degreasing 2, shielding and protection 3, electrochemical degreasing 4, deionized cold water washing 5, acid activation 6, deionized cold water washing 7, 30-second water film continuity check 8, electroplating 9, deionized cold water washing 10, light 11, deionized cold water washing 12, passivation 13, deionized cold water washing 14, drying 15, coating inspection 16.

[0075] Process Description:

[0076] 1) Organic solvent cleaning (step 2): Use acetone for manual cleaning until the oil stains are completely removed.

[0077] 2) Shielding and protection (process step 3): shielding and protection tools and materials used in the utility model.

[0078] 3) Electrochemical degreasing (process step 4): Sodium hydroxide: 50g / L±5g / L, sodium carbonate: 70g / L±10g / L; temperature: room temperature; current density: 10A / dm2~15A / dm2; the cathode and anode are replaced every 20 seconds, and the anode is used for the last time.

[0079] 4) Deionized cold water washing (step 5): temperature: room temperature; time: 1 min to 2 min.

[0080] 5) Acidic activation (step 6): sulfuric acid (d = 1.83) 3% to 5%; temperature: room temperature; time: ≤ 10s.

[0081] 6) Deionized cold water washing (step 7): temperature: room temperature; time: 1 min to 2 min.

[0082] 7) 30s water film continuity check (step 8): Perform a 30s water film continuity check on the cleaned parts. The parts are qualified if the water film does not break within 30s.

[0083] 8) Cadmium electroplating (step 9): Cadmium: 23g / L~27g / L, sodium cyanide: 110g / L±20g / L, sodium carbonate: <100g / L, sodium hydroxide: <20g / L; temperature: 18℃~30℃; current density: 1.5A / dm2~2.5A / dm2.

[0084] 9) Deionized cold water washing (step 10): temperature: room temperature; time: 1 min to 2 min.

[0085] 10) Light emission (step 11): nitric acid (d=1.83): 1 ml / L~2 ml / L; temperature: room temperature; time: 5 s~10 s.

[0086] 11) Deionized cold water washing (step 12): temperature: room temperature; time: 1 min to 2 min.

[0087] 12) Passivation (process step 13): sodium dichromate: 180g / L~205g / L, sulfuric acid (1.83): 10ml / L-12ml / L; temperature: room temperature; time: 5s~15s.

[0088] 13) Deionized cold water washing (step 14): temperature: room temperature; time: 1 min to 2 min.

[0089] 14) Drying (step 15): Dry the surface of the parts with clean compressed air at a temperature not exceeding 50°C.

[0090] 15) Coating inspection (step 16): Visually inspect the appearance of the coating; use a micrometer to measure the thickness of the coating (it is necessary to measure the dimensions before and after plating); use the bending method to measure the bonding strength of the coating; use a neutral salt spray test to measure the corrosion resistance of the coating.

Claims

1. A metal bushing pair, characterized in that: It includes a first metal bushing and a second metal bushing which are arranged opposite to each other; one end of the first metal bushing has a first boss, and one end of the second metal bushing has a second boss; the first boss and the second boss are arranged opposite to each other, and a metal sheet is arranged between the first boss and the second boss, and the metal sheet has a first surface adjacent to the first boss, and the metal sheet has a second surface adjacent to the second boss; a rubber tube is arranged inside the metal bushing pair, and the metal bushing pair is fixed on the rubber tube.

2. The metal bushing pair according to claim 1, characterized in that: The two ports of the rubber tube are flush with the two ports of the metal bushing pair, or are 1-2 mm lower than the ports of the metal bushing pair.

3. The metal bushing pair according to claim 1, characterized in that: The rubber tube is made of fluororubber.

4. The metal bushing pair according to claim 1, characterized in that: The thickness of the rubber tube is 1.5 mm to 2.5 mm.

5. The metal bushing pair according to claim 4, characterized in that: The circumference of the rubber tube is equal to the inner diameter circumference of the metal bushing.

6. The metal bushing pair according to claim 1, characterized in that: The number of the metal sheets is 1-10.

7. The metal bushing pair according to claim 1, characterized in that: The conductivity of the metal sheet is greater than 50*10 6 Siemens / m.

8. The metal bushing pair according to claim 7, characterized in that: The thickness of the metal sheet is 0.1 mm to 0.2 mm.

9. The metal bushing pair according to claim 7, characterized in that: The metal sheet is rectangular, and its length and width do not exceed the boss of the bushing.

10. The metal bushing pair according to any one of claims 1 to 9, characterized in that: The inner walls of the first metal bushing and the second metal bushing are provided with oil grooves in the length direction; the oil grooves of the first metal bushing and the second metal bushing are connected; the wall of the oil groove and the outer wall of the rubber tube form a channel with openings at both ends, and the channel is sealed away from the opening of the boss.

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