Double-layer ceramic supporting plate for metal powder injection molding of rod-shaped parts

Abstract

The application discloses a double-layer ceramic supporting plate for metal powder injection molding of a rod-shaped part, which comprises a first supporting plate, a second supporting plate and a supporting column, a plurality of first through holes and a plurality of first positioning holes are arranged on the first supporting plate, a plurality of second through holes and a plurality of second positioning holes are arranged on the second supporting plate, the first supporting plate and the second supporting plate are of the same size, the first through holes and the second through holes are one-to-one corresponding in position, the first positioning holes and the second positioning holes are one-to-one corresponding in position, and the supporting column is installed between the first positioning holes and the second positioning holes. The application considers the shape of a circular product, selects a vertical placement mode, and reduces deformation caused by gravity collapse when placed horizontally as much as possible, fully considers the difficulty of processing, and reasonably designs the interval between each hole to ensure maximum production capacity.

Description

Technical Field

[0001] This invention relates to the field of metal powder injection molding technology, and more particularly to a double-layer ceramic support plate for metal powder injection molding of rod-shaped parts. Background Technology

[0002] Cylindrical actuators are a very common type of basic mechanical component. Their core functions are to transmit linear motion, withstand axial forces, or provide precise positioning. They are widely used in applications requiring high motion accuracy, reliability, and spatial arrangement. These applications place extremely high demands on the miniaturization, weight reduction, and consistency of the components. In these applications, if traditional machining methods (such as turning and milling) are used to manufacture these actuators, especially those with complex structures, irregular shapes, or large production runs, problems such as significant material waste, high costs, difficulty in miniaturization and complication, and low production efficiency will arise.

[0003] These very limitations provide a vast stage for the application of MIM technology. MIM is a near-net-shape forming technology that combines the efficient complex shape forming capabilities of plastic injection molding with the near-net-shape forming capabilities of powder metallurgy sintering, making it ideal for manufacturing "small and delicate" parts such as cylindrical push rods.

[0004] However, since the rod-shaped structure of the pusher mechanism has a certain length, the traditional flat-laying method of sintering occupies a large volume of space and has low sintering efficiency. During the sintering process, the green body will shrink, and the flat-laying method results in a large contact area between the rod-shaped structure and the firing plate, which is prone to deformation. If the placement is not reasonable, the suspended part of the green body will collapse due to gravity. Summary of the Invention

[0005] To address the problems of existing technologies, embodiments of the present invention provide a double-layer ceramic support plate for metal powder injection molding of rod-shaped parts. The technical solution is as follows: In one aspect, a double-layer ceramic sintering plate for metal powder injection molding of rod-shaped parts is provided, comprising: a first sintering plate, a second sintering plate, and a support column; The first bearing plate is provided with a plurality of first through holes and a plurality of first positioning holes; The second firing plate is provided with multiple second through holes and multiple second positioning holes; The first firing plate and the second firing plate are the same size, the first through hole and the second through hole are in one-to-one correspondence, and the first positioning hole and the second positioning hole are in one-to-one correspondence; The support column is installed between the first positioning hole and the second positioning hole.

[0006] Furthermore, the second through hole is a stepped hole, consisting of a first hole segment and a second hole segment of different diameters.

[0007] Furthermore, the first positioning hole and the second positioning hole have the same diameter.

[0008] Furthermore, the diameters of the two ends of the support column are smaller than the diameters of the first positioning hole and the second positioning hole, and the lengths of the two ends are smaller than the depths of the first positioning hole and the second positioning hole.

[0009] Furthermore, the support column is 32.8 mm long and has a diameter of 2.8 mm at both the top and bottom ends.

[0010] Furthermore, the first hole has a diameter of 8.8 mm and a depth of 1.2 mm; the second hole has a diameter of 7.76 mm and a depth of 1.8 mm.

[0011] Furthermore, the first through hole has a diameter of 7.2 mm and a depth of 3.0 mm.

[0012] Furthermore, four first positioning holes are provided, each located at one of the four corners of the first firing plate; four second positioning holes are provided, each located at one of the four corners of the second firing plate.

[0013] Secondly, a sintering method for the double-layer ceramic support plate described in the first aspect is provided, wherein the method employs a first support plate, a second support plate, and four support columns, and the specific steps include: The first firing plate is placed below, the second firing plate is placed above, and the support column is installed between the first positioning hole and the second positioning hole, connecting and spacing the first firing plate and the second firing plate. The green rod-shaped part to be sintered is placed with the large-diameter end facing upward in the first through hole of the first sintering plate and the second through hole of the second sintering plate, and then placed in the sintering furnace for sintering.

[0014] Secondly, a sintering method for the double-layer ceramic support plate described in the first aspect is provided, the method employing two second support plates and four support columns, the specific steps of which include: One second firing plate is placed below, and another second firing plate is placed above. The support column is installed between the second positioning holes of the two second firing plates, connecting and spacing the two second firing plates. The green rod-shaped part to be sintered is placed with the smaller diameter end facing down in the second through hole of the lower second sintering plate and the second through hole of the upper second sintering plate, and then placed in the sintering furnace for sintering.

[0015] The beneficial effects of the technical solution provided by the embodiments of the present invention are as follows: The double-layer ceramic support plate for metal powder injection molding of rod-shaped parts of this application includes: a first support plate, a second support plate, and a support column; the first support plate is provided with a plurality of first through holes and a plurality of first positioning holes; the second support plate is provided with a plurality of second through holes and a plurality of second positioning holes; the first support plate and the second support plate are the same size, the positions of the first through holes and the second through holes correspond one-to-one, and the positions of the first positioning holes and the second positioning holes correspond one-to-one; the support column is installed between the first positioning holes and the second positioning holes. Considering the shape of the circular product, the double-layer ceramic support plate for metal powder injection molding of rod-shaped parts of this application is placed vertically to minimize deformation caused by gravity collapse when placed horizontally; and the spacing between each hole is reasonably designed to maximize production capacity, taking into full account the ease of processing. The ceramic support column is round to ensure accurate positioning, and an appropriate margin is reserved in the design to ensure convenient assembly of the support column and the support plate in actual production. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the first firing plate in the double-layer ceramic firing plate for metal powder injection molding of rod-shaped parts provided in the embodiments of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of the second ceramic support plate in the double-layer ceramic support plate for metal powder injection molding of rod-shaped parts provided in the embodiments of the present invention.

[0019] Figure 3 This is a cross-sectional view of the second ceramic support plate in the double-layer ceramic support plate for metal powder injection molding of rod-shaped parts provided in the embodiments of the present invention.

[0020] Figure 4 This is a schematic diagram of the support column in the double-layer ceramic sintering plate for metal powder injection molding of rod-shaped parts provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Terms indicating relative spatial positions, such as “above,” “over,” “below,” “under,” “first end,” “second end,” “one end,” and “other end,” as used in this application, are for ease of explanation to describe the relationship of one unit or feature relative to another unit or feature as shown in the accompanying drawings. The terms indicating relative spatial positions may be intended to include different orientations of the device in use or operation other than those shown in the figures. For example, if the device in the figures is flipped, a unit described as being “below” or “under” other units or features would be located “above” other units or features. Therefore, the exemplary term “below” can encompass both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or other orientations), and the spatially related descriptive terms used herein will be interpreted accordingly.

[0022] Furthermore, the terms "installation," "setup," "equipped with," "connection," "sliding connection," "fixed," and "sleeve connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] like Figure 1-4 As shown, an embodiment of the present invention provides a double-layer ceramic sintering plate for metal powder injection molding of rod-shaped parts, comprising: a first sintering plate 1, a second sintering plate 2, and a support column 3.

[0024] The first firing plate 1 and the second firing plate 1 have the same dimensions, both being 120*100*3mm.

[0025] The first firing plate 1 has 68 first through holes 11 and 4 first positioning holes 12. The diameter of the first through holes 11 is 7.2 mm, the diameter of the first positioning holes 12 is 3 mm, and the four first positioning holes 12 are respectively located at the four corners of the first firing plate 1.

[0026] The second firing plate 2 is also provided with 68 second through holes 21 and 4 second positioning holes 22. The second through holes 21 are stepped holes, consisting of first hole sections 211 and second hole sections 212 of different diameters. The first hole section 211 has a diameter of 8.8 mm and a depth of 1.2 mm; the second hole section 212 has a diameter of 7.76 mm and a depth of 1.8 mm. The second positioning holes 22 have a diameter of 3 mm, and the four second positioning holes 22 are respectively located at the four corners of the second firing plate 2.

[0027] The positions of the first through hole 11 and the second through hole 21 are one-to-one, and their centers are in the same position. The positions of the first positioning hole 12 and the second positioning hole 22 are one-to-one.

[0028] The support column 3 is cylindrical, 32.8 mm long, and consists of three sections: the column body 31 is 27.2 mm long and 5.6 mm in diameter, and the upper and lower end pieces 32 are 2.8 mm long and 2.8 mm in diameter. The diameters of the upper and lower end pieces 32 are slightly smaller than the diameters of the first positioning hole 12 and the second positioning hole 22 for easy assembly; the lengths of the upper and lower end pieces 32 are also slightly smaller than the depths of the first positioning hole 12 and the second positioning hole 22 to prevent the support column 3 from tilting.

[0029] The support column 3 is installed between the first positioning hole 12 and the second positioning hole 22. The support column 3 mainly serves to support and limit movement, so it can also be rectangular, triangular, or other shapes; the height of the support column 3 can also be adjusted according to the actual height of the product.

[0030] The double-layer ceramic support plate for metal powder injection molding of rod-shaped parts in this application can be used in two ways: Method 1: Use a first firing plate 1, a second firing plate 2, and four support columns 3.

[0031] The first firing plate 1 is placed below, and the second firing plate 2 is placed above, with the second section 212 of the second through hole 21 facing upwards (the smaller diameter side of the second through hole 21 facing upwards). Four support columns 3 are respectively installed between the four first positioning holes 12 of the first firing plate 1 and the four second positioning holes 22 of the second firing plate 2. The support columns 3 connect and separate the first firing plate 1 and the second firing plate 2.

[0032] The green rod-shaped part to be sintered is placed with the large diameter end facing upward in the first through hole 11 of the first sintering plate 1 and the second through hole 21 of the second sintering plate 2, and then placed in the sintering furnace for sintering.

[0033] The diameter of the first through hole 11 and the second through hole 21 can be about 0.2 mm larger than the diameter of the rod-shaped part blank. This allows for a certain margin when placing the rod-shaped part blank, preventing it from getting stuck on the firing plate. After sintering, the rod-shaped part blank will shrink along the center.

[0034] Method 2: Use two second bearing plates 2 and four support columns 3 as described above.

[0035] A second firing plate 2 is placed below, with the second section 212 of the second through hole 21 facing downwards (the smaller diameter side of the second through hole 21 faces downwards); another second firing plate 2 is placed above, with the second section 212 of the second through hole 21 facing upwards (the smaller diameter side of the second through hole 21 faces upwards). Four support columns are respectively installed between the eight second positioning holes 22 of the two second firing plates 2. The support columns 3 connect and separate the two second firing plates 2.

[0036] The green rod-shaped part to be sintered is placed with the smaller diameter end facing down in the second through hole 21 of the lower second sintering plate 2 and the second through hole 21 of the upper second sintering plate 2, and then placed in the sintering furnace for sintering.

[0037] The second through hole 21 is a stepped hole, having a first hole section 211 and a second hole section 212. Each of the two hole sections has a diameter allowance of 0.2 mm, and each of the two hole sections also has a depth allowance of 0.2 mm.

[0038] To prevent the product from directly contacting the graphite or molybdenum plates of the sintering furnace during sintering, a flat ceramic plate of the same size as the sintering plate can be pre-placed under the lower sintering plate.

[0039] The double-layer ceramic sintering plate for metal powder injection molding of rod-shaped parts in this application adopts a double-layer porous sintering plate, which makes full use of vertical space, increases the number of products placed in a unit space, and the design of the support column ensures that there is enough gap between the upper and lower ceramic plates, which facilitates the degreasing of products and the flow of air during sintering.

[0040] The number of through holes on the firing plate can be determined by the actual working conditions. If the spacing between each through hole on the firing plate is too large, it will reduce the number of products that can be placed, affecting production capacity; if the spacing is too small, the firing plate will be more difficult to process and its overall strength will be reduced, and the firing plate may break after multiple sinterings.

[0041] The diameter of the through holes in the two firing plates is determined by the diameter of the product. In order to allow for the placement of the product, the diameter of the through holes is 0.2mm larger than the diameter of the green blank, which facilitates the placement and removal of the product.

[0042] The double-layer ceramic support plate for metal powder injection molding of rod-shaped parts in this application is designed with the following considerations: considering the shape of the circular product, a vertical placement method is chosen to minimize deformation caused by gravity collapse when placed horizontally; and the spacing between each hole is rationally designed to maximize production capacity, taking into full account the ease of processing. The ceramic support columns are circular to ensure precise positioning, and appropriate allowances are reserved in the design to ensure convenient assembly of the support columns and the support plate in actual production.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A double-layer ceramic bearing plate for metal powder injection molding of rod-shaped parts, characterized in that, include: First firing plate, second firing plate, and support column; The first bearing plate is provided with a plurality of first through holes and a plurality of first positioning holes; The second firing plate is provided with multiple second through holes and multiple second positioning holes; The first firing plate and the second firing plate are the same size, the first through hole and the second through hole are in one-to-one correspondence, and the first positioning hole and the second positioning hole are in one-to-one correspondence; The support column is installed between the first positioning hole and the second positioning hole.

2. The double-layer ceramic firing plate according to claim 1, characterized in that, The second through hole is a stepped hole, consisting of a first hole segment and a second hole segment of different diameters.

3. The double-layer ceramic firing plate according to claim 1, characterized in that, The first positioning hole and the second positioning hole have the same diameter.

4. The double-layer ceramic firing plate according to claim 3, characterized in that, The diameters of the two ends of the support column are smaller than the diameters of the first positioning hole and the second positioning hole, and the lengths of the two ends are smaller than the depths of the first positioning hole and the second positioning hole.

5. The double-layer ceramic firing plate according to claim 4, characterized in that, The support column is 32.8mm long and has a diameter of 2.8mm at both the top and bottom ends.

6. The double-layer ceramic firing plate according to claim 2, characterized in that, The first hole has a diameter of 8.8 mm and a depth of 1.2 mm; the second hole has a diameter of 7.76 mm and a depth of 1.8 mm.

7. The double-layer ceramic firing plate according to claim 1, characterized in that, The first through hole has a diameter of 7.2 mm and a depth of 3.0 mm.

8. The double-layer ceramic firing plate according to claim 1, characterized in that, The first positioning hole has four holes, which are respectively located at the four corners of the first firing plate; the second positioning hole has four holes, which are respectively located at the four corners of the second firing plate.

9. A sintering method for a double-layer ceramic support plate as described in claim 1, characterized in that, The method employs a first firing plate, a second firing plate, and four support columns. Specific steps include: The first firing plate is placed below, the second firing plate is placed above, and the support column is installed between the first positioning hole and the second positioning hole, connecting and spacing the first firing plate and the second firing plate. The green rod-shaped part to be sintered is placed with the large-diameter end facing upward in the first through hole of the first sintering plate and the second through hole of the second sintering plate, and then placed in the sintering furnace for sintering.

10. A sintering method for a double-layer ceramic support plate as described in claim 1, characterized in that, The method employs two second firing plates and four support columns, and the specific steps include: One second firing plate is placed below, and another second firing plate is placed above. The support column is installed between the second positioning holes of the two second firing plates, connecting and spacing the two second firing plates. The green rod-shaped part to be sintered is placed with the smaller diameter end facing down in the second through hole of the lower second sintering plate and the second through hole of the upper second sintering plate, and then placed in the sintering furnace for sintering.

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