ES2704873T3 - Spigot adapter with corrosion protection - Google Patents

Abstract

A neck adapter (2) for a rock drilling machine, which neck adapter (2) comprises an elongated body (4), which elongated body (4) has an outer surface, an end surface (18) and an inner surface forming a through hole (12) extending through said elongated body between a first external surface shower part (17) and said end surface (18), wherein said first part (17) of said external surface is constituted by a cylindrical surface (17), whose first part (17) of the external surface is adapted to constitute a contact surface for a stationary arranged seal of the rock drilling machine, and in which at least a part of said surface internal (12) is provided with a protective coating against corrosion, characterized in that said first part (17) of said external surface is provided with a first protective coating against corrosion and a second part of said external surface and / or at least a part of said internal surface (12) is provided with a second protective coating against corrosion, wherein said first protective coating against corrosion is constituted by a layer of chromium and said second coating Corrosion protector is constituted by a conversion layer, in which said conversion layer comprises any or more of zinc phosphate, zinc manganese phosphate or manganese phosphate and in which said conversion layer is oiled or waxed.

Description

DESCRIPTION

Spigot adapter with corrosion protection

Technical field

The present invention relates to a neck adapter according to the preamble of claim 1. The invention relates, furthermore, to a rock trephine comprising a neck adapter and a method for protecting an adapter from corrosion. neck.

Background

When rock is being drilled, rock drilling machines from which rotational power, power and impact energy are transferred to a drilling tool, usually under intermediate coupling of splicing bars. Through a longitudinal hole in the splice rods, a sweeping means, for example water, is supplied to the area of the piercing tool. The sweeping medium has the task of partially cooling the tool and partially removing the drilling detritus from the drilling hole. To transfer the rotational power, power and impact energy from the rock drilling machine to the splicing bars and the drilling tool, a so-called neck adapter is used. This neck adapter is mounted on the perforated machine and has a protruding part. The protruding part constitutes a connection end arranged to be connected with junction rods or the piercing tool. A through hole is present in the neck adapter for transferring the sweeping medium from the rock drilling machine to the splicing bars and the drilling tool.

The neck adapter is exposed to corrosive attacks, partially from the water used as a sweeping medium, partly from the corrosive environments in which a rock drilling machine is placed during its use and transport. The water that is available and used as a sweeping medium, for example when the drilling machine is used for mining, is often very corrosive. Corrosive attacks shorten the life of a neck adapter. To protect the neck adapters against corrosion, tests have been carried out with, for example, chrome-plated and varnished neck adapters.

Coating the neck adapter with a chrome layer is partially costly but is also adversely affected by drawbacks since the neck adapter is exposed to blows on a specific striking surface. Chromium scale is released from this striking surface. These scale can cause problems in the rock drilling machine. The same problem can occur with varnished neck adapters.

International patent document WO 2003/078788 A1 describes a method for protection against corrosion of a neck adapter. According to the method described, the parts exposed to corrosion are coated with zinc phosphate, manganese phosphate and zinc or manganese phosphate with subsequent greasing or waxing. The phosphating of the neck adapter is made internally in the through hole and on a cylindrical outer surface.

The cylindrical outer surface of the neck adapter constitutes a surface against which a seal of the rock drilling machine rests. It turned out that this seal is exposed to wear as a result of the conversion layer that forms during phosphating and that has an abrasive impact on the seal when the neck adapter rotates in the rock drilling machine. Especially, the conversion layer will have an abrasive impact when corrosion begins to occur on the cylindrical surface. The conversion layer will then have a relatively rough surface.

U.S. Pat. US 6,109,620 discloses a tang adapter formed by two blocks made of different materials having specific properties adapted for the use of each of the adapter parts.

Summary of the invention

An object of the present invention is to provide a neck adapter protected against corrosion which at least partially prevents the aforementioned drawbacks.

This object is obtained, according to one aspect of the invention, with a neck adapter for a rock drilling machine whose adapter comprises an elongated body. The elongated body has an external surface and an internal surface. The elongate body further has an end surface and a through hole extending through the elongated body between the first part of the outer surface and the end surface. The first part of the external surface is constituted by a cylindrical surface and the internal surface comprises a limiting surface formed by the elongate body in the through hole. At least a part of the external surface and a part of the internal surface are provided with a protective coating against corrosion. The first part of the external surface is provided with a first protective coating against corrosion and a second part of the external surface and / or at least part of the internal surface is provided. of a second protective coating against corrosion. The first corrosion protection coating is constituted by a chromium layer and the second corrosion protection coating is constituted by a conversion layer.

Since the first and second corrosion protective coatings are made of different material used on different parts of the neck adapter, corrosion protective coatings with properties that are suitable for the respective parts of the neck adapter can be used. For example, the first corrosion protective coating may have a smoother surface than the second corrosion protective coating. The second protective coating against corrosion can be chosen according to other criteria than the surface roughness, for example, the cost of the coating. Thus, a neck adapter is provided which, on an external sealing surface, is provided with a chrome surface but which is protected against corrosion on other surfaces with a conversion layer which is relatively simple and inexpensive to manufacture. Consequently, the object mentioned above is achieved.

Neck adapters are used in a rock drilling machine to transfer rotational power, power and impact energy to splicing bars and drilling tools. The inner surface of the neck adapter can form a through hole for the passage therethrough of a sweeping means. The neck adapter is made, suitably, of steel material, for example, hardened steel. Corrosion protection coatings should extend the life of the neck adapter when it is exposed to corrosive attacks during operation, interruption of operation and transport. "Coated" means a coating on at least a portion of the surface of the neck adapters that has been applied to the surface in at least one step of the manufacturing process of the neck adapter. For example, lubricants applied for the operation or assembly should not be viewed as a coating in accordance with the present invention. The through hole can be used for the flow through it of a sweeping means, for example water, from the rock drilling machine to a drilling tool.

According to embodiments, the first corrosion protective coating can have a smoother surface than the second corrosion protective coating. In this way, the first corrosion protective coating can be chosen with a surface roughness to enable a seal to rest against the first part of the outer surface without exposure to the same amount of wear as if it were resting against a surface coated with the second. protective coating against corrosion. The second protective coating against corrosion can be chosen by other criteria than surface roughness, for example, the cost of the coating.

According to embodiments, the conversion layer, for example, can be constituted by a phosphate layer. According to embodiments, the conversion layer can be oiled or waxed. A conversion layer such as a phosphate layer is porous and its corrosion protection properties can be improved with greasing or waxing.

According to embodiments, the first coating can have a surface roughness Ra 1.0 pm maximum. The first part of the outer surface thus constitutes a suitable surface for contacting a seal of the rock drilling machine.

According to embodiments, the conversion layer may comprise one or more of zinc phosphate, manganese phosphate and zinc or manganese phosphate.

According to embodiments, the first corrosion protective coating can have a thickness between 20 150 pm. In this way, good protection against corrosion of the first part of the external surface can be obtained. In the event that the first corrosion protective coating is constituted by a chromium layer, the first corrosion protective coating may have a weight per unit area within 140-2100 g / m2.

According to embodiments, the second corrosion protective coating can have a thickness between 10-50 μm, preferably around 30 μm. In this way, good corrosion protection of the second part of the external surface and / or the inner surface can be obtained. In case the second corrosion protective coating is constituted by a conversion layer comprising zinc phosphate, manganese phosphate and zinc or manganese phosphate, the second corrosion protective coating may have a weight per unit area inside. from 15-85 g / m2, preferably, around 50 g / m2.

A thickness of a surface coating means the height of the coating on the neck adapter, ie on the material from which the neck adapter is made, for example, cemented steel. The height of the coating is measured, for example, under a microscope on a cross-section through a neck adapter in the area of the relevant surface. The cross section runs perpendicular to the relevant surface. If the cross section through the neck adapter is made in parts having, for example, a cylindrical shape, the cross-sectional plane is at right angles to the central axis passing through the elongate body of the neck adapter.

According to embodiments, only the first part of the outer surface can be provided with the first corrosion protective coating and the other surfaces of the neck adapter can be provided with the second corrosion protective coating. In this way, the first corrosion protective coating on the neck adapter can first be applied in a first process. After this, in a second process, the remaining surfaces of the neck adapter can simply be provided with the second corrosion protective coating. Since in the second process it is not necessary to take into account all surfaces that are not going to be treated superficially, the second process is especially simple to perform.

According to one aspect, the present invention also relates to a rock drilling machine comprising a neck adapter according to any of the aspects mentioned above and / or the embodiments mentioned above.

According to embodiments, the neck adapter is arranged so that it can rotate in the rock drilling machine. The first part of the external surface may constitute a bearing surface for a seal stationary in the rock drilling machine.

According to embodiments, the rock drilling machine can be arranged to pump a liquid via a limited space by, inter alia, the seal and the first part of the outer surface, to the through hole of the neck adapter.

According to one aspect, the present invention also relates to a method for protecting against corrosion a neck adapter according to any of the above-mentioned aspects and / or the embodiments mentioned above. According to the method, the neck adapter is first subjected to an electrolytic process to provide the first corrosion protective coating to the first part of the external surface. After that, the neck adapter is subjected to a second process to provide the second corrosion protective coating to the second part of the external surface and / or said part of the inner surface. The first process may comprise immersing the neck adapter in a solution comprising chromium ions to coat the first part of the outer surface with a chromium layer.

According to embodiments, the second process may include the application of a solution comprising phosphoric acid and zinc ions or zinc and manganese ions or manganese ions especially the neck adapter. In this way, the first protective coating against corrosion can be applied to the neck adapter in the first process. When the first corrosion protective coating is constituted, for example, by a chromium layer, in the second process the second corrosion protective coating can simply be provided to the remaining surfaces of the neck adapter as the solution applied in the second process it does not affect the chromium layer.

Other features and advantages of the present invention appear from the appended claims and the detailed description that follows. The expert within the area realizes that different features of the invention can be combined to create second embodiments different from those described below. This can be done without deviating from the scope of protection of the present invention defined by the appended claims.

Brief description of the figures

Different approaches of the invention, including specific features and advantages, are shown from the detailed description that follows and the accompanying figures, in which Figures 1 and 2 show different views of a neck adapter according to embodiments ,

Figure 3 schematically shows a rock drilling machine with a neck adapter according to embodiments, and

Figure 4 shows a method for surface treatment of a neck adapter according to embodiments.

Detailed description

The present invention will now be described in more detail with reference to the appended figures, in which examples of embodiments are shown. The invention should not be construed as being limited to the examples of embodiments described. Equal reference numbers in the figures refer to the same elements. For simplicity, well-known functions and constructions will not necessarily be described in detail.

Figures 1 and 2 show different views of a neck adapter 2 according to embodiments. The neck adapter 2 is designed to be arranged in a rock drilling machine to transfer rotational power, feed and impact energy from the rock drilling machine to a drilling tool via splicing bars. The neck adapter 2 comprises an elongated body 4. The elongate body 4 is substantially cylindrical and is made of, for example, hardened steel. A central axis X extends through the longitudinal direction of the elongate body 4. At one end, the neck adapter 2 is provided with a drive part. The drive part comprises outside grooves 6 to enable the neck adapter 2 is rotated in the rock drilling machine. In addition, the drive part comprises a striking surface 8 for receiving and transferring moment from the drilling machine to the drilling tool. At the second end, the neck adapter 2 is provided with a clamping device 10 arranged to hold a piercing tool or a splice rod. The clamping device 10 is exemplified in the form of a filleting. A through hole 12 extends through the neck adapter 2. The through hole 12 has an inlet opening 14 disposed in a portion of an outer cylindrical surface 17 of the neck adapter 2. At least a portion of the cylindrical surface 17 constitutes a first part of an external surface of the elongate body 4 and thus of the neck adapter 2. The through hole 12 has an outlet opening 16 in an end surface 18 of the neck adapter 2. The through hole 12 is arranged for conducting a sweeping medium, for example water, from the drilling machine to the splicing bars and the drilling tool. The through hole 12 is formed, in this embodiment, in two parts with a radial hole 13, also called a sweep hole, and an axial hole 15.

In figure 2 there is shown, in addition to the neck adapter 2, also a chamber 20 enclosing a part of the neck adapter 2. The chamber 20 is disposed around the neck adapter 2 in the area of the cylindrical surface 17. The camera 20 is provided with an inlet pipe 22. Thus, a sweeping means can be conducted via the inlet pipe 22 to the chamber 20 and from there through the neck adapter 2 via the inlet opening 14, the through hole 12 and the outlet opening 16. The chamber 20 is included in a rock drilling machine not shown further and constitutes a space limited by, among others, two seals 24, 24 'and the cylindrical surface 17 of the adapter neck 2. The two seals 24, 24 'rest against the neck adapter 2 and seal against the cylindrical surface 17.

Figure 3 shows schematically a rock drilling machine 30 with a neck adapter 2 according to embodiments. The rock drilling machine 30 comprises a drilling machine 32 from which the neck adapter 2 protrudes a little. Several connecting rods 34 and a drilling tool 36 are connected to the neck adapter 2 and are rotated by the drilling machine 32. To transport drilling debris from a drilling hole 38 being drilled, a flushing means, for example water, is added to the drilling tool 36 via the neck adapter 2 and the splicing bars 34. The drilling machine 32 comprises a sweep head 40 to which a feed conduit 42 for the sweeping means is connected.

When comparing Figures 2 and 3, it is clear that the scanning head 40 comprises the chamber 20 and that the supply conduit 42 is connected to the inlet pipe 22. The rock drilling machine 30 comprises a pump 44 shown schematically connected to the feed conduit 42. During operation, the neck adapter 2 is rotated in the punching machine 32 while the seals 24, 24 'seal against the cylindrical surface 17 of the neck adapter 2 so that the sweeping means can be pumped by through the chamber 20 and the through hole 12 of the neck adapter 2 to the piercing tool 36.

The neck adapter 2 is exposed to corrosive environment among others during the operation, in the interruption of the operation and in the transports. Especially exposed areas of the neck adapter 2 are areas in contact with the scanning medium, for example on the cylindrical surface 17 in the chamber 20 and in the through hole 12. To protect the cylindrical surface 17 against corrosion, the neck adapter 2, at least in the area of chamber 20 and seals 24, 24 ', is provided with a first corrosion protective coating in the form of a chrome layer with a thickness of about 40 μm. The chromium layer can also have a different thickness, for example, within 20-150 pm. To ensure that the seals 24, 24 'have a sufficient seal function also after a long operating time, the chrome layer has a fine surface roughness. In addition to the good corrosion protection of the chrome layer, the roughness of the surface has the advantage that the intervals between changes of the seals 24, 24 'can be kept relatively long. For example, the chromium layer can have a surface roughness Ra 1.0 pm maximum. In the through hole 12 and on the end surface 18, the neck adapter 2 is provided with a second corrosion protective coating in the form of a conversion layer. The conversion layers comprise, for example, one or more of zinc phosphate, zinc and manganese phosphate or manganese phosphate. Such a conversion layer is porous and suitably oiled or waxed to obtain the best possible corrosion protection properties. The conversion layer has a thickness between 10-50 μm, preferably around 30 μm. These thicknesses of a porous conversion layer comprising zinc phosphate, zinc phosphate and manganese or manganese phosphate correspond to a weight per unit area, before greasing or waxing, within 15-85 g / m2, preferably around 50 g / m2.

Alternatively, the through hole 12 may be partially provided with the first corrosion protective coating in the form of a chromium layer. For example, the neck adapter 2 as a whole or in parts of the radial hole 13 can be provided with a chrome layer and the remaining parts of the neck adapter 2 in the through hole 12, ie in the axial hole 15 and any remaining parts of the radial hole 13, be provided with a conversion layer.

According to an embodiment of the neck adapter 2, the cylindrical surface 17 is provided with a first protective coating against corrosion and the remaining surfaces of the neck adapter 2 are provided with a second corrosion protective coating comprising zinc phosphate, zinc and manganese phosphate and / or manganese phosphate. The remaining surfaces comprise, among other external surfaces such as the striking surface 8, the surface in the clamping device 10, the surface in the grooves 6, the end surface 18 and an internal surface of the elongate body 4 in the through hole 2. The second corrosion protective coating can thus easily be obtained by immersing the neck adapter 2 in a solution comprising phosphoric acid and zinc ions or zinc and manganese ions or manganese ions.

Figure 4 shows a method for surface treatment of a neck adapter 2 according to embodiments. The reference numerals used refer partially to details in the previous figures, especially FIGS. 1 and 2. Between some of the steps of the method below, other steps may be performed such as, for example, cleaning of process liquids. one step from the previous method.

In step 50, which is optional and depends on the surface roughness of the neck adapter after previous manufacturing steps, the cylindrical surface 17 is frosted to a surface roughness of about 1 μm.

In step 52, surfaces of the neck adapter 2 are masked except for the cylindrical surface 17.

- In step 54, a first process is made in the form of an electrolytic coating of the cylindrical surface 17 with a first corrosion protective coating, for example, a chromium layer through electrolysis in a liquid comprising ions of chrome.

In step 56, the remaining surfaces of the neck adapter 2 are coated with a second corrosion protective coating in the form of a conversion layer in a second process comprising immersing the neck adapter 2 in a solution comprising phosphoric acid and zinc ions or zinc and manganese ions or manganese ions.

In step 58, the conversion layer is oiled or waxed.

In step 60 it can optionally be performed and comprises polishing the cylindrical surface with the first corrosion protective coating.

Step 60 may, optionally, be optionally carried out after step 54. In case the first corrosion protective coating is a chromium layer, before step 56 this chromium layer does not need to be masked.

The expert in the field realizes that the embodiments described above can be combined. Also, different modifications are evident to the expert. For example, the surface of the elongate body can be coated with the first corrosion protective coating on other parts other than the first part, for example a second part of the outer surface can be coated with the first corrosion protective coating. The second part of the outer surface, then, for example, can constitute a bearing surface for another seal or a bearing seat.

In addition, several parts of the inner surface can be coated with the second protective coating against corrosion. When it comes to the cylindrical surface 17, in some cases other surface roughness may be sufficient before and / or after coating with the first protective coating against corrosion, for example, a surface roughness Ra 2.0 pm maximum or Ra 3 , 0 p.m. maximum. In addition, the sweep head 40 can be more integrated in the punching machine 32 than according to the embodiments shown in Figure 3. The sweep head 40 can incorporate bearing members and drive force by transferring parts of the punching machine 32. In addition, the pump 44, shown in Figure 3, as an alternative, can be arranged separately and thus need not be part of the rock drilling machine 30. In addition, the solution comprising phosphoric acid and zinc ions or ions of Zinc and manganese or manganese ions, for example, can be applied to the neck adapter by spraying instead of immersing in the solution. In addition, the masking mentioned in step 52 of the method shown in Figure 4 can be obtained in several different ways. For example, two tubes can be threaded onto the neck adapter so that the parts that are not to be coated with the first corrosion protective coating are covered by these tubes.

Thus, the invention is not limited to the described embodiments. The invention is limited only by the scope of protection defined in the claims.

Claims (11)

A neck adapter (2) for a rock drilling machine, the neck adapter (2) of which comprises an elongate body (4), the elongated body (4) of which has an external surface, an end surface (18) and an inner surface forming a through hole (12) extending through said elongate body between a first external surface shower portion (17) and said end surface (18), wherein said first part (17) of said surface external is constituted by a cylindrical surface (17), whose first part (17) of the external surface is adapted to constitute a contact surface for a stationary stationary seal of the rock drilling machine, and in which at least a part of said internal surface (12) is provided with a protective coating against corrosion, characterized in that said first part (17) of said external surface is provided with a first protective coating against corrosion and a second part of said external surface and / or at least a part of said inner surface (12) is provided with a second corrosion protective coating, wherein said first corrosion protective coating is constituted by a layer of chromium and said second corrosion protective coating is constituted by a conversion layer, wherein said conversion layer comprises any one or more of zinc phosphate, zinc and manganese phosphate or manganese phosphate and wherein said conversion layer is oiled or waxed The neck adapter (2) according to claim 1, wherein said first corrosion protective coating has a smoother surface than said second corrosion protective coating. The neck adapter (2) according to any one of the preceding claims, wherein said first corrosion protective coating has a surface roughness R a maximum of 1.0 μm. The neck adapter (2) according to any of the preceding claims, wherein said first corrosion protective coating has a thickness between 20-150 μm. The neck adapter (2) according to any of the preceding claims, wherein said second corrosion protective coating has a thickness between 10-50 μm, preferably around 30 μm. The neck adapter (2) according to any of the preceding claims, wherein only said first part of said outer surface is provided with said first protective coating against corrosion and other surfaces of said neck adapter (2) they are provided with said second protective coating against corrosion. 7. A rock drilling machine (30) comprising a neck adapter (2) according to any of claims 1-6. The rock drilling machine (30) according to claim 7, wherein said neck adapter (2) is rotatably arranged in said rock drill (30) and said first part (17) of said external surface constitutes a contact surface for a seal (24, 24 ') stationary in the rock drilling machine (30). The rock drilling machine (30) according to claim 8, wherein the rock drilling machine (30) is arranged to pump a liquid, via a space delimited by said seal (24, 24 'among others). ) and said first part (17) of said external surface up to said through hole (12) of said neck adapter (2). A method for protection against corrosion of a neck adapter according to any of claims 1-6, wherein said first neck adapter is subjected to an electrolytic process to provide said first part of said external surface of said first protective coating against corrosion and, thereafter, is subjected to a second process for providing said second part of said external surface and / or said part of said internal surface of said second protective coating against corrosion. The method according to claim 10, wherein said second process includes the application of a solution comprising phosphoric acid and zinc ions or zinc and manganese ions or manganese ions, especially the neck adapter.