Clamping device for cobalt removal of polycrystalline diamond compact

Abstract

The utility model relates to the technical field of insertion preforms, in particular to a clamping device for cobalt removal of a polycrystalline diamond compact. A clamping device for cobalt removal of a polycrystalline diamond compact comprises a clamping sleeve arranged in a sectioning mode and a connecting structure which is used for connecting the ends of every two adjacent clamping sleeve sections so that the clamping sleeve sections can be connected into a whole in the circumferential direction, and the clamping sleeve is used for being directly or indirectly clamped on the periphery of a cobalt removal sealing piece. Circumferential adjusting gaps are formed between the clamping sleeve sections, and at least one connecting structure is an adjustable connecting structure, so that the clamping sleeve clamps the cobalt-free sealing element by controlling the size of the adjusting gaps. Adjustment can be carried out according to actual conditions in the long-term use process, the long-term good sealing effect is guaranteed, and corrosion of the hard alloy substrate is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of insert preforms, in particular to a clamping device for removing cobalt from a polycrystalline diamond composite sheet. Background Art

[0002] Polycrystalline diamond composite sheets are made of diamond powder, cemented carbide substrate and a small amount of additives through high temperature and high pressure sintering. It has the ultra-high hardness, wear resistance and thermal conductivity of diamond, as well as the strength, impact toughness and good weldability of cemented carbide. It is currently widely used in high-tech fields such as mechanical processing, fossil energy mining, geological exploration and advanced manufacturing.

[0003] The mechanism of diamond-diamond bond (DD bond) in sintered polycrystalline diamond can be summarized as follows: when the synthesis chamber is heated to a specific temperature, the metal catalyst cobalt powder will melt and penetrate the gaps between the diamond powders, graphitizing the surface of the diamond grains. When the liquid is supersaturated with carbon and the sintering environment is in the stable zone of the diamond phase, carbon atoms will precipitate to form diamond. As the liquid cobalt migrates, the carbon atoms on the surface of the diamond continue to dissolve and precipitate, forming more and more DD bonds, and the diamond grains are bonded to each other through DD bonds.

[0004] There is a huge difference in the thermal expansion coefficients of cobalt and diamond. When polycrystalline diamond is prepared under high temperature and high pressure, there is a large amount of thermal stress inside it. A large amount of thermal stress may cause the diamond skeleton to tear and the diamond grains to fall off in the application of polycrystalline diamond composite sheets. In addition, when the application temperature reaches above 700 ℃, cobalt will catalyze the conversion of diamond to graphite. The higher the cobalt content, the more obvious the catalytic effect. Based on this, it is necessary to remove the cobalt from the polycrystalline diamond composite sheet to improve its comprehensive performance. The most common method for decobalting is to use acid leaching to remove cobalt, using hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, etc. for decobalting. However, the acid leaching method is prone to cause corrosion of the cemented carbide substrate. Therefore, the decobalting seal is generally wrapped around the cemented carbide substrate of the polycrystalline diamond composite sheet through an injection molding sealing process, so that the upper polycrystalline diamond layer of the polycrystalline diamond composite sheet is exposed outside the decobalting seal. However, the sealing between the decobalting seal and the polycrystalline diamond composite sheet is poor, and the cemented carbide substrate is prone to corrosion during high-temperature decobalting. Therefore, it is also necessary to clamp the decobalting seal from the periphery to ensure good sealing between the decobalting seal and the polycrystalline diamond composite sheet.

[0005] The utility model patent with authorization announcement number CN214323969U provides a polycrystalline diamond composite sheet cobalt-free sealing clamping device, which presses the cobalt-free seal into the clamping sleeve and uses the interference fit between the clamping sleeve and the cobalt-free seal to achieve enhanced sealing. In the process of forcibly pressing the cobalt-free seal into the clamping sleeve, there is a risk of the clamping sleeve breaking. In addition, as the number of uses of the clamping sleeve increases, the inner diameter of the clamping sleeve gradually increases, and the interference fit tolerance gradually decreases, resulting in insufficient sealing tightening force and a certain corrosion risk. Utility Model Content

[0006] The utility model aims to provide a clamping device for decobalting a polycrystalline diamond composite sheet, which is used to solve the problems that the existing polycrystalline diamond composite sheet decobalting sealing clamping device uses the interference fit between the clamping sleeve and the decobalting sealing member to achieve enhanced sealing, and there are problems such as the clamping sleeve being broken and the sealing tightening force being insufficient due to long-term use.

[0007] The utility model discloses a clamping device for decobalting a polycrystalline diamond composite sheet, which adopts the following technical scheme: a clamping device for decobalting a polycrystalline diamond composite sheet, comprising a clamping sleeve arranged in petals and a connecting structure for connecting the ends of each two adjacent petals of the clamping sleeve so that the petals of the clamping sleeve are connected as a whole in the circumferential direction; the clamping sleeve is used to clamp directly or indirectly on the periphery of the decobalting seal; there is a circumferential adjustment gap between the petals of the clamping sleeve; at least one connection structure is an adjustable connection structure, so that the clamping sleeve can clamp the decobalting seal by controlling the size of the adjustment gap.

[0008] Furthermore, the clamping device further comprises an elastic sealing structure, which is used to be arranged between the clamping sleeve and the cobalt-removing seal so that the clamping sleeve is indirectly clamped on the outer periphery of the cobalt-removing seal.

[0009] Furthermore, there are more than two elastic sealing structures, which are used to be evenly arranged along the axial direction of the decobaltized sealing element.

[0010] Furthermore, the clamping sleeve is formed by two arc-shaped clamping sleeves that are buckled in two petals.

[0011] Furthermore, the adjustable connection structure is a bolt connection structure.

[0012] Furthermore, radially extending lugs are respectively provided at the buckling points of the petals of each clamping sleeve, and the lugs are connected by a bolt connection structure.

[0013] Furthermore, the elastic sealing structure is an O-ring.

[0014] Furthermore, the length of the clamping sleeve is used to meet the distance between two coaxially arranged decobaltized seals.

[0015] The clamping device for decobalting a polycrystalline diamond composite sheet of the utility model is a newly designed clamping device for decobalting a polycrystalline diamond composite sheet, and the beneficial effects of the clamping device for decobalting a polycrystalline diamond composite sheet of the utility model are: the clamping sleeves arranged in petals are connected as a whole in the circumferential direction of the decobalting seal through a connecting structure, and the decobalting seal is clamped from the periphery, so that the decobalting seal and the polycrystalline diamond composite sheet are tightly fitted, and no gap is generated between the two to affect the decobalting effect, and there is a circumferential adjustment gap between the petals of each clamping sleeve, and the gap size is adjusted by the adjustable connecting structure to ensure a better clamping effect, and it can be adjusted according to actual conditions during long-term use to ensure a good long-term sealing effect and prevent corrosion of the cemented carbide substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of an embodiment of the clamping device for decobalting a polycrystalline diamond composite sheet of the utility model when in use;

[0017] Figure 2 for Figure 1 Cross-sectional view from AA perspective.

[0018] In the figure: 1, polycrystalline diamond layer; 2, cemented carbide substrate; 3, decobaltized seal; 4, clamping sleeve; 5, groove; 6, O-ring; 7, lug; 8, connecting bolt. DETAILED DESCRIPTION

[0019] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0020] First, the technical solution of the utility model is generally described as follows:

[0021] Since the polycrystalline diamond composite sheet is generally treated with acid leaching for cobalt removal, which can easily cause corrosion of the carbide substrate of the polycrystalline diamond composite sheet, a cobalt-removing seal is generally wrapped around the carbide substrate of the polycrystalline diamond composite sheet through an injection molding sealing process, so that the upper polycrystalline diamond layer of the polycrystalline diamond composite sheet is exposed outside the cobalt-removing seal. In order to achieve a sealing effect between the cobalt-removing seal and the polycrystalline diamond composite sheet and prevent the two from loosening, a cobalt-removing sealing clamping device for a polycrystalline diamond composite sheet is designed in the prior art. The cobalt-removing seal is pressed into a clamping sleeve, and the interference fit between the clamping sleeve and the cobalt-removing seal is utilized to achieve enhanced sealing. However, in the process of forcibly pressing the cobalt-removing seal into the clamping sleeve, the clamping sleeve is at risk of breaking. In addition, as the number of uses of the clamping sleeve increases, the inner diameter of the clamping sleeve gradually increases, and the interference fit tolerance gradually decreases, resulting in insufficient sealing tightening force and a certain corrosion risk.

[0022] Therefore, based on the above-mentioned problems, the utility model designs a clamping device for cobalt removal of polycrystalline diamond composite sheets, including a clamping sleeve and a connecting structure arranged in petals, the clamping sleeve arranged in petals being connected as a whole in the circumferential direction of the cobalt removal seal through the connecting structure, the clamping sleeve is used to clamp the outer periphery of the cobalt removal seal directly or indirectly, and there is a circumferential adjustment gap between the petals of each clamping sleeve, at least one connecting structure is an adjustable connecting structure, and the size of the adjustment gap is controlled to enable the clamping sleeve to clamp the cobalt removal seal, so that the cobalt removal seal and the polycrystalline diamond composite sheet are closely fitted, and no gap is generated between the two to affect the cobalt removal effect, thereby ensuring a better clamping effect, and can be adjusted according to actual conditions during long-term use to ensure a good long-term sealing effect and prevent corrosion of the cemented carbide substrate.

[0023] Specific embodiment of the clamping device for removing cobalt from polycrystalline diamond composite sheet of the utility model:

[0024] The structural schematic diagram of the clamping device for removing cobalt from a polycrystalline diamond composite sheet of the utility model is as follows Figure 1-2 As shown, a clamping device for decobalting a polycrystalline diamond composite sheet comprises a clamping sleeve 4, in which a polycrystalline diamond composite sheet wrapping a decobalting seal 3 is placed, the clamping sleeve 4 is arranged in petals, and there is a circumferential adjustment gap between each clamping sleeve petal, the clamping sleeve 4 is used to clamp directly or indirectly on the periphery of the decobalting seal 3, so that the decobalting seal 3 and the polycrystalline diamond composite sheet fit more closely, and ensure that there is no gap between the decobalting seal 3 and the polycrystalline diamond composite sheet to cause acid to flow in and corrode the cemented carbide substrate 2, the petals of the clamping sleeve are connected by a connecting structure, the connecting structure connects the ends of each adjacent two clamping sleeve petals so that the clamping sleeve petals are connected as a whole in the circumferential direction of the periphery of the decobalting seal 3, at least one connecting structure is an adjustable connecting structure, and then the size of the adjustment gap is controlled by the adjustable connecting structure to ensure that the clamping sleeve 4 clamps the decobalting seal 3.

[0025] The clamping sleeve 4 is directly clamped on the cobalt-depleted seal 3 to achieve a good clamping effect. However, due to the stress concentration between the clamping sleeve 4 and the cobalt-depleted seal 3, in order to achieve a better clamping effect, preferably, the clamping device of the cobalt-depleted polycrystalline diamond composite sheet also includes an elastic sealing structure, which is used to be arranged between the clamping sleeve 4 and the cobalt-depleted seal 3 so that the clamping sleeve 4 is indirectly clamped on the outer periphery of the cobalt-depleted seal 3. By arranging the elastic sealing structure between the clamping sleeve 4 and the cobalt-depleted seal 3, when the adjustment gap between each clamping sleeve petal is adjusted by the adjustable connecting structure, the elastic sealing structure has toughness and elasticity, thereby providing a suitable fastening force to the cobalt-depleted seal 3, avoiding brittle fracture of the cobalt-depleted seal 3 due to excessive pressure, and ensuring a better clamping effect and anti-slip effect.

[0026] In order to ensure that the elastic sealing structure can achieve a better clamping effect during the tightening process, preferably, there are more than two elastic sealing structures, and each elastic sealing structure is evenly arranged along the axial direction of the decobalt seal 3, so that the decobalt seal 3 is evenly stressed in the axial direction, ensuring the reliability of the clamping sleeve 4 clamping the decobalt seal 3. Of course, in other embodiments, a whole piece of elastic rubber pad can also be arranged in the clamping sleeve 4 corresponding to the position of the decobalt seal 3, so that the elastic rubber pad covers the decobalt seal 3 to ensure a good clamping effect.

[0027] When considering how to set the clamping sleeve 4 to achieve better clamping effect, more convenient use, and simpler structure, preferably, the clamping sleeve 4 is formed by two arc-shaped clamping sleeves that are buckled together. Since most of the cobalt-removing seals 3 are cylindrical structures, the clamping sleeve 4 is configured to be formed by two arc-shaped structures that are buckled together, which matches the structure of the cobalt-removing seal 3, and the two halves of the structure are simple to make and convenient to assemble. Of course, in other embodiments, the clamping sleeve 4 can also be surrounded by a three-petal arc-shaped clamping sleeve, which is clamped on the periphery of the cobalt-removing seal 3 through a connecting structure and connected as a whole.

[0028] In order to achieve convenient adjustment and higher structural strength after adjustment, preferably, the adjustable connection structure is a bolt connection structure, specifically, the bolt connection structure includes a connection bolt 8 and a nut, and the adjustment gap between each clamping sleeve petal is adjusted by the connection bolt 8 and the nut. On the one hand, the operation is simple and convenient, and on the other hand, after the adjustment is completed, the structural strength of the connection bolt 8 is high, which can ensure a better connection effect between each clamping sleeve petal, so that the clamping sleeve 4 has a better clamping effect on the decobalt seal 3. Of course, in other embodiments, when the ends of one end of the two clamping sleeve petals are connected by a hinge, the ends of the other ends are connected by an adjustable connection structure. Specifically, the ends of the two clamping sleeve petals located at the adjustable connection structure are respectively provided with protrusions, and the adjustable connection structure includes a U-shaped buckle sleeved on the two protrusions, and a bolt hole is provided on the side wall of the U-shaped buckle. Bolts are inserted into the bolt holes, and the bolts are pressed against the protrusions to adjust the gap size.

[0029] Based on the bolt connection structure to adjust the adjustment gap between each clamping sleeve petal, in order to facilitate operation and better clamping force after clamping, preferably, each clamping sleeve petal buckle is respectively provided with a radially extending lug 7, and each lug 7 is connected by a bolt connection structure. The bolt connection structure is arranged on the radially extending lug 7, and the position of the bolt connection structure is in the same horizontal plane with the clamped decobalt seal 3 in the radial direction, ensuring a better clamping effect. Of course, in other embodiments, axially extending lugs 7 can also be respectively provided at the buckle of each clamping sleeve petal, and each lug 7 can be connected by a bolt connection structure.

[0030] In order to improve the elastic fastening effect of the elastic sealing structure, preferably, the elastic sealing structure is an O-ring 6 made of a fluorine-containing rubber ring. Specifically, a groove 5 is provided on the clamping sleeve 4, and the O-ring 6 is placed in the groove 5, so that the decobalt seal 3 is subjected to the same elastic clamping force in the circumferential direction, the force is balanced, and the clamping effect is better. Of course, in other embodiments, arc grooves can also be evenly provided in the circumference of the clamping sleeve 4, and arc-shaped elastic strips are provided in each arc groove.

[0031] In order to improve the production efficiency when the clamping device is used, preferably, the length of the clamping sleeve 4 satisfies the distance between two coaxially arranged decobaltized seals 3, and the polycrystalline diamond layers 1 of the polycrystalline diamond composite sheets in the two decobaltized seals 3 are arranged back to back. In this way, two polycrystalline diamond composite sheets can share one clamping device, which has high production efficiency and convenient operation. Of course, in other embodiments, the length of the clamping sleeve 4 may also satisfy the distance for clamping only one polycrystalline diamond composite sheet.

[0032] Through the above description of the specific embodiment of the clamping device for decobalting of polycrystalline diamond composite sheet of the utility model, it can be seen that the clamping device for decobalting of polycrystalline diamond composite sheet of the utility model connects the clamping sleeve with petals arranged circumferentially on the decobalting seal as a whole through the adjustable connecting structure, so that the decobalting seal and the polycrystalline diamond composite sheet are tightly fitted, and no gap will be generated between the two to affect the decobalting effect, and there is a circumferential adjustment gap between the petals of each clamping sleeve. The gap size is adjusted by the adjustable connecting structure to ensure a better clamping effect. During long-term use, it can be adjusted according to actual conditions to ensure a good long-term sealing effect and prevent corrosion of the cemented carbide substrate.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the description and drawings of the present invention shall be included in the protection scope of the present invention.

Claims

1. A clamping device for removing cobalt from a polycrystalline diamond composite sheet, characterized in that: It comprises a clamping sleeve arranged in petals and a connecting structure connecting the ends of each two adjacent clamping sleeve petals so that the clamping sleeve petals are connected as a whole in the circumferential direction. The clamping sleeve is used to directly or indirectly clamp the outer periphery of the decobaltizing seal. There is a circumferential adjustment gap between the clamping sleeve petals. At least one connecting structure is an adjustable connecting structure so that the clamping sleeve can clamp the decobaltizing seal by controlling the size of the adjustment gap.

2. The clamping device for removing cobalt from a polycrystalline diamond compact according to claim 1 is characterized in that: The clamping device also includes an elastic sealing structure, which is used to be arranged between the clamping sleeve and the cobalt-removing sealing member so that the clamping sleeve is indirectly clamped on the outer periphery of the cobalt-removing sealing member.

3. The clamping device for removing cobalt from a polycrystalline diamond compact according to claim 2, characterized in that: There are more than two elastic sealing structures, which are used to be evenly arranged along the axial direction of the decobaltized sealing element.

4. The clamping device for removing cobalt from a polycrystalline diamond compact according to any one of claims 1 to 3, characterized in that: The clamping sleeve is formed by two arc-shaped clamping sleeves which are divided into two petals and buckled together.

5. The clamping device for removing cobalt from a polycrystalline diamond compact according to any one of claims 1 to 3, characterized in that: The adjustable connection structure is a bolt connection structure.

6. The clamping device for removing cobalt from a polycrystalline diamond compact according to claim 5, characterized in that: The buckling joints of the petals of each clamping sleeve are respectively provided with radially extending lugs, and the lugs are connected by a bolt connection structure.

7. The clamping device for removing cobalt from a polycrystalline diamond compact according to claim 2, characterized in that: The elastic sealing structure is an O-ring.

8. The clamping device for removing cobalt from a polycrystalline diamond compact according to any one of claims 1 to 3, characterized in that: The length of the clamping sleeve is designed to meet the distance between two coaxially arranged decobaltized seals.

Images