Hot press forming die for ceramic bond diamond thinning grinding wheel agglomerated green body

Abstract

The utility model discloses a ceramic bond diamond thinning grinding wheel agglomerated green body hot press forming die which comprises a clamp, an assembling die and a clamping piece. The assembling mold is positioned in the clamp; the clamping piece is positioned in the clamp and outside the assembling mold; the inner length of the clamp is larger than the outer length of the assembling die. The inner width of the clamp is larger than the outer width of the assembling die. The assembling die is provided with a plurality of die cavities, an upper pressing head and a lower pressing head are arranged in each die cavity, and the lower pressing heads in different die cavities are mutually independent; and a bolt is arranged on the side edge of the clamp. The hot press forming die is simple in structure and high in practicability, can press a plurality of thinned grinding wheel agglomerated green bodies at a time, solves the problem that only one thinned grinding wheel agglomerated green body can be pressed at a time in existing production, effectively improves production efficiency, the lower pressing heads in the die cavities are mutually independent and do not interfere with each other, a clamp does not need to be taken out when the die is unloaded, and production efficiency is improved. And the situation that the caked blank of the thinning grinding wheel is possibly damaged is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of grinding wheel forming dies, in particular to a hot pressing forming die for a ceramic bonded diamond thinning grinding wheel agglomerate. Background Art

[0002] With the rapid development of microelectronics and optoelectronics technologies, single crystal silicon, sapphire, diamond and other substrates are widely used as high-performance substrates in aerospace, optoelectronics, integrated circuits and other fields. To meet the high-precision requirements, the substrate processing tools must have extremely high surface integrity and geometric accuracy during the processing process.

[0003] As a type of abrasive tool, thinning grinding wheels have the advantages of strong stability, superior grinding ability, and high processing precision during the processing process. They have been used for grinding and thinning substrates. Thinning grinding wheels are mostly agglomerated structures, made up of multiple agglomerates bonded together. During the hot pressing process, the temperature is 150-200°C and the pressing time is 10-15 minutes. Due to the short pressing time, the mold must have good heat transfer efficiency to ensure the uniformity of the agglomerated green body structure. Currently, the existing production process can only press one agglomerate at a time, which has low production efficiency and is difficult to meet the needs of modern mass production. Therefore, in response to the above problems and technical requirements, it is necessary to improve the existing hot pressing mold for thinning grinding wheels. Summary of the Invention

[0004] The purpose of the utility model is to provide a hot pressing molding die for a ceramic bond diamond thinning grinding wheel agglomerate blank, which has a simple structure and strong practicality. It can press multiple thinning grinding wheel agglomerate blanks at a time, effectively improving production efficiency. The lower pressure heads in each mold cavity are independent of each other and do not interfere with each other. There is no need to remove the clamp when unloading the mold, avoiding the possibility of damaging the thinning grinding wheel agglomerate blank.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A hot pressing forming die for a ceramic bond diamond thinning grinding wheel agglomerate, comprising a fixture, an assembly die and a clip; the assembly die is located in the fixture; the clip is located in the fixture and outside the assembly die; the inner length of the fixture is greater than the outer length of the assembly die; the inner width of the fixture is greater than the outer width of the assembly die; the assembly die is provided with a plurality of die cavities, each die cavity is provided with an upper pressure head and a lower pressure head, and the lower pressure heads in different die cavities are independent of each other; bolts are provided on the side of the fixture.

[0007] In the present invention, the clip is used to fix the assembly mold to prevent the assembly mold from shifting during the hot pressing process, which would affect the quality of the pressed thinning wheel agglomerate blank. The inner length of the fixture is greater than the outer length of the assembly mold, and the inner width of the fixture is greater than the outer width of the assembly mold, leaving a certain amount of space to facilitate mold removal. In actual application, the clip is pressed against the assembly mold and locked with bolts, and then hot pressed. After the hot pressing is completed, the mold can be removed by simply removing the clip in the fixture and moving the assembly mold. There is no need to remove the clip or the fixture, which saves time and effort. The lower pressure heads in each mold cavity are independent of each other, which means that the use of each lower pressure head does not interfere with each other and can be used at will.

[0008] As common sense, the size of the upper and lower rams matches the mold cavity, and together they form a feeding cavity.

[0009] Preferably, the assembly mold includes two outer molds and one or more inner molds; the two outer molds are symmetrically positioned on either side of the inner mold; grooves are provided on the inner sides of the outer molds and on both sides of the inner mold; the grooves of the outer molds and the grooves of the inner molds together form a mold cavity. The mold cavity is used for feeding materials and pressing the thinned grinding wheel agglomerate blank. The number of inner molds can be selected as needed in actual application.

[0010] Preferably, a group of adjacent edges of the clamp are provided with positioning holes and fixing holes; the inner wall of the positioning hole is a smooth structure; a vertically connected connecting rod is provided on the clip; the connecting rod is located in the positioning hole; the inner wall of the fixing hole is a threaded structure; the bolt passes through the fixing hole and abuts the clip.

[0011] In the present invention, the connecting rod can slide in the positioning hole. During pressing, the clip is pressed against the assembly mold. The bolt passes through the fixing hole and abuts the clip, locking the clip and the assembly mold. After pressing is completed, the bolt is removed, and the clip can be moved to fit the inner wall of the contact fixture. The outer mold and the inner mold are then moved in sequence to complete the demolding. Since the forming mold is mostly made of steel, which is heavy and inconvenient to handle, the mold of the present invention does not require the fixture to be removed when the mold is unloaded. This effectively avoids the situation where the friction between the fixture and the assembly mold when removing the fixture may cause the assembly mold to touch the thinning grinding wheel agglomerate blank and damage the thinning grinding wheel agglomerate blank.

[0012] Preferably, there are two clips, one located in the length direction and the other in the width direction of the assembly mold. Further preferably, the length of the clip located in the length direction of the assembly mold is consistent with the outer length of the assembly mold. The clip is movable within the fixture. In the pressing state, the clip is tightly attached to the assembly mold and locked with bolts to secure the assembly mold.

[0013] Preferably, the inner length of the assembly mold is 65% to 75% of the inner length of the fixture; the inner width of the assembly clamp mold is 80% to 90% of the inner width of the fixture. Further preferably, the inner length of the assembly mold is 65% to 70% of the inner length of the fixture; the inner width of the assembly clamp mold is 80% to 85% of the inner width of the fixture. A certain amount of space is left inside the fixture to allow the clip to move within the fixture and also to store the upper and lower pressure heads when not in use.

[0014] Preferably, the four corners of the inner wall of the fixture are arc-shaped through holes. After the material is added, the powder floating on the mold surface needs to be cleaned. Compared with the right-angle structure, this can prevent some hard powders, such as diamond, from falling into the right-angle gap and rubbing against the mold, generating dirt that is difficult to clean, thereby affecting the fit between the various components and further affecting the quality of the pressed thinning grinding wheel agglomerate.

[0015] Due to the application of the above technical solutions, the hot pressing forming mold for ceramic bond diamond thinning grinding wheel agglomerate of the utility model has the following advantages: First, compared with the prior art, the utility model can press multiple thinning grinding wheel agglomerates at a time, thereby improving production efficiency, solving the problem that the prior art can only press one at a time, and reducing the labor intensity and production cost of workers; second, the assembly mold is a split structure, the inner length of the clamp is greater than the outer length of the assembly mold, the inner width of the clamp is greater than the outer width of the assembly mold, and there is a certain amount of remaining space, the clip can move in the clamp, and the flexibility is high, especially convenient for demolding. After the pressing is completed, the demolding can be completed by simply removing the clip in the clamp and moving the assembly mold, avoiding the need to remove the clamp during demolding, which rubs against the assembly mold and causes the assembly mold to hit The thinning grinding wheel agglomerate blank may be damaged; thirdly, the upper pressure head and the lower pressure head in each mold cavity of the utility model are independent of each other and do not interfere with each other. Compared with the integrated pressure head, it is simpler to prepare and convenient to replace when damaged, and has good heat transfer efficiency, which is conducive to the pressing of the thinning grinding wheel agglomerate blank; fourthly, the clamp of the utility model is provided with a vertically connected connecting rod, and the connecting rod is located in the positioning hole. When assembling the mold, the connecting rod can be held to make the clamp close to the assembled mold to avoid scratches on the clamp and the pressing table due to long-term use; fifthly, the four corners of the inner wall of the clamp are arc-shaped through holes, which are not easy to hide dirt and grime compared to the right-angle structure, and are easy to clean, so that the mold maintains a good fit during normal use and prepares precise thinning grinding wheel agglomerate blanks. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural schematic diagram of the hot pressing molding die for the ceramic bonded diamond thinning grinding wheel agglomerate in Example 1 when in use.

[0017] Figure 2 Schematic diagram of the structure of the clamp of Example 1.

[0018] Figure 3 It is a structural diagram of the assembly mold of Example 1.

[0019] Figure 4 It is a structural schematic diagram of the mold cavity of Example 1.

[0020] Figure 5 This is a schematic diagram of the size structure of the hot pressing mold for the ceramic bonded diamond thinning grinding wheel agglomerate green body of Example 1.

[0021] Figure 6 This is a structural diagram of Comparative Example 1.

[0022] Figure 7 This is a structural diagram of comparative example 2.

[0023] Figure 8 This is a side view of the assembly mold and the lower pressure head of Example 3.

[0024] Figure 9 Schematic diagram of the lower pressure head structure of comparative example three.

[0025] Among them: fixture 1, assembly mold 2, upper pressure head 3, lower pressure head 4, clip 5, positioning hole 6, fixing hole 7, bolt 8, arc-shaped through hole 9, feeding cavity 10, bottom plate 11, outer mold 201, inner mold 202, mold cavity 203, connecting rod 501. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and preferred embodiments. The specific components involved are prior art, and the connection and use methods between the specific components are conventional technologies.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this invention pertains; the terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this invention; for example, the directions or positions indicated by terms such as "length", "width", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", and "outside" are based on the directions or positions shown in the accompanying drawings and are for ease of description only and should not be construed as limiting this technical solution.

[0028] The raw materials for preparing the thinning grinding wheel agglomerate blank are existing products that meet the conventional requirements for grinding wheels. The creativity of the utility model lies in the new forming mold, which can prepare multiple thinning grinding wheel agglomerate blanks at a time, improving production efficiency. When removing the mold, it is only necessary to move the clamp and move the assembly mold, without removing the clamp. This avoids the need to remove the clamp during mold removal, which would cause friction with the assembly mold, causing the assembly mold to touch the thinning grinding wheel agglomerate blank, thereby potentially damaging the thinning grinding wheel agglomerate blank. Example 1

[0029] like Figures 1 to 5 As shown:

[0030] A hot pressing forming die for a ceramic bond diamond thinning grinding wheel agglomerate blank comprises a fixture 1, an assembly die 2, an upper pressing head 3, a lower pressing head 4, and a clamping piece 5. Bolts 8 are provided on the side of the fixture.

[0031] The assembly mold includes two outer molds 201 and four inner molds 202; the two outer molds are symmetrically arranged on both sides of the inner mold; grooves are provided on the inner side of the outer mold and on both sides of the inner mold; the grooves of the outer mold and the grooves of the inner mold are combined to form 25 mold cavities 203, and the mold cavities are each provided with an upper pressure head and a lower pressure head. The lower pressure heads in different mold cavities are independent of each other, and the size of the upper pressure head and the lower pressure head matches the mold cavity, and together they form a feeding cavity 10.

[0032] A positioning hole 6 and a fixing hole 7 are provided on a set of adjacent sides of the clamp; the inner wall of the positioning hole is a smooth structure; a vertically connected connecting rod 501 is provided on the clip, and the connecting rod is located in the positioning hole; the inner wall of the fixing hole is a threaded structure; the bolt passes through the fixing hole and abuts the clip.

[0033] In this embodiment, there are two clips, which are located in the length direction and width direction of the assembly mold respectively. The length of the clip located in the length direction of the assembly mold is consistent with the inner length of the clamp, and the length of the clip located in the width direction of the assembly mold is consistent with the outer width of the assembly mold.

[0034] In this embodiment, the assembly mold is located inside the fixture; the clip is located inside the fixture and outside the assembly mold. The inner length of the fixture is 330mm and the inner width is 170mm. The outer length of the assembly mold is 120mm and the outer width is 280mm. Figure 5 .

[0035] The four corners of the inner wall of the fixture are arc-shaped through holes 9.

[0036] The method for using the hot pressing mold for the ceramic bonded diamond thinning grinding wheel agglomerate body of this embodiment is as follows:

[0037] (1) Press Figure 1 Assemble the mold as shown, leaving only the upper pressure head unassembled, then weigh the theoretical feed amount and feed it into the mold cavity;

[0038] (2) Clean the powder floating on the surface of the mold and place the upper pressure head into the mold cavity;

[0039] (3) Hot pressing (existing process) is performed to obtain a thinned grinding wheel agglomerate body. Example 2

[0040] Based on Example 1, the difference of this embodiment is that the length of the clip located in the length direction of the assembly mold is adjusted to be consistent with the outer length of the assembly mold, and the length of the clip located in the width direction of the assembly mold is adjusted to be consistent with the inner width of the fixture, and the rest is the same. Comparative Example 1

[0041] Based on the first embodiment, the difference of this embodiment is that the arc-shaped through hole is omitted, that is, the four corners of the inner wall of the clamp are right-angled structures, see Figure 6 In actual application, it is found that hard powder falling into the right-angle gap will rub the mold and produce dirt, which is difficult to clean. After long-term use, it will affect the coordination between the various components and cause the quality of the pressed thinning grinding wheel to agglomerate and deteriorate. Comparative Example 2

[0042] Based on the first embodiment, the difference of this embodiment is that the positioning hole, the fixing hole, the connecting rod and the clip are omitted, and the inner length of the clamp is adjusted to be consistent with the outer length of the assembly mold. The clip is located in the length direction of the assembly mold. In order to facilitate the removal of the clip, the length of the clip is adjusted to be slightly shorter than the outer length of the assembly mold. The side wall of the clamp is provided with a threaded hole, and the bolt is inserted into the threaded hole and abuts against the clip. Figure 7 Since the molds used to prepare the thinning grinding wheel agglomerate are mostly made of steel, which is heavy and inconvenient to handle, and the hardness of the thinning grinding wheel agglomerate after hot pressing is relatively low, actual application has found that when removing the bolts, clips, and fixtures, the molds will rub against each other during the demolding process. Long-term use will wear the molds, affect the fitting accuracy, and even damage the thinning grinding wheel agglomerate. Comparative Example 3

[0043] Based on the first embodiment, the difference of this embodiment is that the five lower pressure heads are designed as an integrated structure, connected by a bottom plate 11 to form an integrated structure. Due to the difficulty of mold opening and high precision requirements, in order to reduce the difficulty of processing and the matching error caused by uncontrollable deformation, the overall upper surface area of ​​the bottom plate of the integrated structure is smaller than the upper surface area of ​​the assembled mold. Figure 8 、 Figure 9 , the rest is the same.

[0044] Application Experiment

[0045] The conventional method is used to prepare the powder of the ceramic bond diamond thinning grinding wheel agglomerate body, and the steps are as follows:

[0046] (1) Silicon dioxide, aluminum oxide, boric acid, potassium carbonate, calcium carbonate, and titanium dioxide are mixed uniformly in a mass ratio of 43:27:17:9:4, and then smelted in a frit furnace at 1550°C. The molten material falls into water and is rapidly cooled, and then wet-milled in a ball mill. The powder is dried at 180°C and sieved. The powder that can pass through a 600-mesh standard sieve but cannot pass through an 800-mesh standard sieve is taken to obtain a ceramic binder;

[0047] (2) Ceramic bond, diamond abrasive, white corundum, pore former and phenolic resin powder were put into a three-dimensional mixer in a mass ratio of 50:20:5:15:10. The mixing time was 60 min to obtain ceramic bond diamond thinning grinding wheel agglomerate powder.

[0048] Referring to the method of using the above mold, the molds of Example 1 and Comparative Example 3 were used to prepare thinned grinding wheel agglomerates, respectively. The hot pressing temperature was 150°C and the time was 15 minutes. After hot pressing, the thinned grinding wheel agglomerates were taken out and placed in an electric furnace. The sintering curve was as follows: room temperature was heated to 300°C over 2 hours, kept warm for 2 hours, then heated to 500°C over 2 hours, kept warm for 3 hours, then heated to 700°C over 2 hours, kept warm for 3 hours, and then cooled with the furnace to obtain a vitrified bond diamond grinding wheel abrasive layer.

[0049] The vitrified bond diamond grinding wheel abrasive layers prepared by the molds of Example 1 and Comparative Example 3 were measured using a Rockwell hardness tester. The hardness of the 25 vitrified bond diamond grinding wheel abrasive layers prepared by the mold of Example 1 was 48~52HRH, and the hardness of the mold prepared by Comparative Example 3 was 46~52HRH.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the principles of the present invention, and these should also be considered to fall within the scope of protection of the present invention.

Claims

1. A hot pressing mold for a ceramic bonded diamond thinning grinding wheel agglomerate, characterized by: It includes a fixture, an assembly mold and a clip; the assembly mold is located in the fixture; the clip is located in the fixture and outside the assembly mold; the inner length of the fixture is greater than the outer length of the assembly mold; the inner width of the fixture is greater than the outer width of the assembly mold; the assembly mold is provided with a plurality of mold cavities, each mold cavity is provided with an upper pressure head and a lower pressure head, and the lower pressure heads in different mold cavities are independent of each other; the side of the fixture is provided with bolts.

2. The hot pressing mold for forming a ceramic bonded diamond thinning grinding wheel agglomerate according to claim 1, characterized in that: The assembly mold includes two outer molds and one or more inner molds; the two outer molds are symmetrically arranged on both sides of the inner mold; grooves are provided on the inner side of the outer mold and on both sides of the inner mold; the grooves of the outer mold and the grooves of the inner mold are combined to form a mold cavity.

3. The hot pressing mold for forming a ceramic bonded diamond thinning grinding wheel agglomerate according to claim 1, characterized in that: A group of adjacent sides of the clamp are provided with positioning holes and fixing holes.

4. The hot pressing mold for forming a ceramic bonded diamond thinning grinding wheel agglomerate according to claim 3, characterized in that: The inner wall of the positioning hole is a smooth structure.

5. The hot pressing mold for forming a ceramic bonded diamond thinning grinding wheel agglomerate according to claim 4, characterized in that: A vertically connected connecting rod is provided on the clip; the connecting rod is located in the positioning hole.

6. The hot pressing mold for forming a ceramic bonded diamond thinning grinding wheel agglomerate according to claim 3, characterized in that: The inner wall of the fixing hole is a threaded structure.

7. The hot pressing mold for forming a ceramic bonded diamond thinning grinding wheel agglomerate according to claim 6, characterized in that: The bolt passes through the fixing hole and abuts against the clip.

8. The hot pressing mold for forming a ceramic bonded diamond thinning grinding wheel agglomerate according to claim 1, characterized in that: There are two clips, which are respectively located in the length direction and the width direction of the assembly mold; the length of the clip located in the length direction of the assembly mold is consistent with the outer length of the assembly mold.

9. The hot pressing mold for forming a ceramic bonded diamond thinning grinding wheel agglomerate according to claim 1, characterized in that: The inner length of the assembly mold is 65% to 75% of the inner length of the fixture; the inner width of the assembly mold is 80% to 90% of the inner width of the fixture.

10. The hot pressing mold for forming a ceramic bonded diamond thinning grinding wheel agglomerate according to claim 1, characterized in that: The four corners of the inner wall of the clamp are arc-shaped through holes.

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