Method of dry pressing ceramic parts

Abstract

The present application relates to a ceramic piece forming dry pressing method, comprising the following steps: step one, filling, adding part of the powder for making ceramic body to the lower die assembly in the dry pressing equipment, through auxiliary knocking, driving the limit pressing block to shrink through the cylinder, driving the hammering block to continuously stretch and shrink to knock the lower die assembly, the present application relates to the ceramic piece forming technical field. The ceramic piece forming dry pressing method can realize multiple knocking for powder homogenization through a single structure, and can also realize positioning locking and demolding effect, which can improve the processing efficiency while improving the product quality, and when knocking, the lower die assembly is not in a fixed state, can move slightly left and right, the acting force on the internal powder is larger, and the forming effect is better.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic part forming, in particular to a dry pressing method for ceramic part forming. BACKGROUND

[0002] Dry pressing or die pressing is a forming method of metal powder and ceramic powder, which fills dry powder blank into a metal mold cavity and applies pressure to make it into a dense blank. During the dry pressing process, the upper and lower molds are usually pressed together. During the dry pressing process, the internal gas is not easy to discharge, and air pits are easily left on the surface of the blank, resulting in scrap of the blank. When adding powder, the direct feeding has a large gap between the particles of the powder, and after extrusion, the compactness is poor, resulting in unqualified products. When the dry pressing is demolded, the dry pressing blank is easily separated and broken during demolding.

[0003] According to the dry pressing method and device for ceramic part forming of patent No. CN111941597A, during the filling process, the material powder for making ceramic blank is added to the lower mold. During the filling process, the swing motor works to drive the swing rod to rotate, which can push the fixed rod. After the swing rod and one end of the fixed rod are separated, the vibration rod is stretched under the stretching action of the return spring, and the knocking rod and the lower mold are knocked and touched, which realizes the vibration and flattening of the powder in the lower mold, improves the compactness of the powder, ensures the uniform distribution of the powder, and can be extruded more smoothly. However, during the knocking, the lower mold is in a fixed state, the internal powder is under small stress and cannot be effectively homogenized, and demolding is difficult. The structure is too complex. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a dry pressing method for ceramic part forming, which solves the above problems.

[0005] To achieve the above purpose, the present application realizes the following technical scheme: a dry pressing method for ceramic part forming, comprising the following steps:

[0006] Step one, filling, adding part of the material powder for making ceramic blank into the lower mold assembly of the dry pressing equipment, assisting in knocking, driving the cylinder to drive the limit pressing block to shrink, driving the hammering block to continuously stretch and contract to knock the lower mold assembly, and realizing the vibration and flattening of the powder in the lower mold;

[0007] Step 2, pre-compression: At this time, the lower mold assembly is limited by the auxiliary components. The drive cylinder drives the limiting pressure block to extend and abut against the side of the lower mold assembly. At this time, the hammer block is squeezed and compressed, and the reset spring retracts into the through groove. The hammer block retracts into the inner groove. One side of the limiting pressure block forms an arc concave surface that matches the surface of the lower mold assembly. The limiting pressure blocks on both sides extend at the same time to hold the lower mold assembly in place. The upper mold operation pushes the lower mold assembly down, increasing the powder density at the bottom of the lower mold assembly.

[0008] Step 3: Secondary filling. Add the remaining powder from making the ceramic body into the lower mold assembly, and then tap it again to homogenize.

[0009] Step 4: Apply pressure again, and the lower mold assembly comes to a standstill, thus repressurizing the powder.

[0010] Step 5: Protect the demolding process. After pressing, lift the upper mold, and drive the cylinder to retract the limit block slightly, so that it loses contact with the lower mold assembly. Then, the lifting block drives the cylinder to rise, which in turn lifts the limit block, causing the slot to contact the side baffle. Then, through the simultaneous upward pulling action of the limit blocks on both sides, the mold ring is lifted to demold the workpiece.

[0011] As a further aspect of the present invention: the striking in steps one and three specifically involves driving the cylinder to drive the limiting pressure block to contract, thereby causing the hammer block to continuously extend and retract to strike the lower mold assembly, thus achieving vibration and spreading of the powder material inside the lower mold.

[0012] As a further aspect of the present invention: when limiting the lower mold assembly in step two, the driving cylinder drives the limiting pressure block to extend and abut against the side of the lower mold assembly. At this time, the hammer block is squeezed and compressed, and the reset spring retracts into the through groove. At this time, the hammer block retracts into the inner groove. One side of the limiting pressure block forms an arc concave surface that matches the surface of the lower mold assembly. The limiting pressure blocks on both sides extend simultaneously to hold the lower mold assembly in place for limiting.

[0013] As a further aspect of the present invention: during demolding in step five, the upper mold is lifted, the driving cylinder drives the limiting block to retract slightly, losing contact with the lower mold assembly, and then the lifting block drives the driving cylinder to rise, driving the limiting block to rise, driving the slot to contact the side baffle, and then the mold ring is lifted to demold the workpiece by the simultaneous upward pulling action of the limiting blocks on both sides.

[0014] As a further aspect of the present invention: the lower mold assembly includes a fixed base and a mold ring, the top of the fixed base is fixedly connected with a protruding ring that engages with the inner cavity of the mold ring, and the top of the fixed base and the inner cavity of the mold ring form a molding groove.

[0015] The dry pressing equipment comprises an extrusion table and a support frame fixed above the extrusion table, a top of the extrusion table is provided with a lower die assembly and an auxiliary mechanism for knocking, limiting and demolding the lower die assembly, the lower die assembly comprises a fixed seat and a die ring, a top of the fixed seat is fixedly connected with a convex ring matched with an inner cavity of the die ring, the top of the fixed seat and the inner cavity of the die ring form a forming groove, the lower die assembly is formed by matching the die ring in the convex ring on the top of the fixed seat, when the upper die is extruded, the workpiece is formed, and then the die ring is lifted to demold the workpiece at variable speed, only the up-and-down movement of the die ring is driven to demold and close the die, a side of the die ring is fixedly connected with a side baffle, the auxiliary mechanism comprises a fixed frame fixed on a surface of the extrusion table, an inner cavity of the fixed frame is slidably connected with a lifting block driven by a motor, one side of the lifting block is fixedly connected with a driving cylinder, one end of a piston rod of the driving cylinder is fixedly connected with a limiting pressing block, one side of the limiting pressing block is fixedly connected with a supporting block, the limiting pressing block is internally provided with a return spring through a penetrating groove, one end of the return spring is fixedly connected with one side of the supporting block, the other end of the return spring is fixedly connected with a hammering block, the inner cavity of the limiting pressing block is provided with an inner recess groove for accommodating the hammering block, and the inner cavity of the limiting pressing block is provided with a clamping groove matched with a surface of the side baffle, in use, when powder is input into the lower die assembly, the limiting pressing block is driven to shrink by the driving cylinder, the hammering block is continuously stretched and contracted to knock the lower die assembly, the powder in the lower die is vibrated and leveled, after the knocking and vibration, the limiting pressing block is extended to abut against a side of the lower die assembly, the hammering block is compressed to be retracted into the penetrating groove, the hammering block is retracted into the inner recess groove, one side of the limiting pressing block forms an arc concave surface matched with a surface of the lower die assembly, the two limiting pressing blocks are extended to limit the lower die assembly, the upper die is pressed to form, after the forming, the limiting pressing block is retracted a little by the driving cylinder, the driving cylinder is lifted by the lifting block, the limiting pressing block is lifted, the clamping groove is contacted with the side baffle, and then the die ring is lifted to demold the workpiece by the upward pulling action of the two limiting pressing blocks, the powder is homogenized by multiple knocking, the workpiece is positioned and locked and demolded, the product quality is improved, the processing efficiency is improved, the lower die assembly can be slightly moved leftward and rightward during the knocking, the force acting on the internal powder is larger, and the forming effect is better.

[0016] Compared with the prior art, the present application has the following advantages:

[0017] 1. The present application can realize the homogenization of powder material by multiple knocking, positioning locking and demolding at the same time through a single structure, which can improve the processing efficiency while improving the quality of finished products, and when knocking, the lower die assembly is not in a fixed state and can move slightly left and right, which can generate a greater force on the internal powder material and achieve better molding effect.

[0018] 2. When the powder material is input into the lower die assembly, the driving cylinder drives the limiting pressing block to retract, drives the hammering block to continuously extend and retract to knock the lower die assembly, realizes the vibration and flattening of the powder material in the lower die, after the knocking and vibration are completed, the driving cylinder drives the limiting pressing block to extend and abut against the side surface of the lower die assembly, at this time, the hammering block is retracted into the recessed groove in the side surface of the limiting pressing block, and the limiting pressing block is retracted into the recessed groove in the side surface of the limiting pressing block. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structure diagram of the dry pressing equipment of the present application.

[0020] Figure 2 It is a structure diagram of the lower die assembly of the present application.

[0021] Figure 3 It is a structure top view of the limiting pressing block of the present application.

[0022] Figure 4 It is a structure side view of the limiting pressing block of the present application.

[0023] In the figure: 1, extrusion table; 2, support frame; 3, fixed frame; 4, lifting block; 5, driving cylinder; 6, limiting pressing block; 7, upper pressing die; 8, fixed seat; 9, die ring; 10, protruding ring; 11, side baffle; 12, supporting block; 13, through groove; 14, return spring; 15, inner recess; 16, clamping groove; 17, hammering block. DETAILED DESCRIPTION

[0024] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the specific embodiments, structures, features and effects according to the present application are described in detail as follows in combination with the drawings and preferred embodiments.

[0025] Please refer to Figures 1-4 The present application provides a technical solution: a ceramic part forming dry pressing method, comprising the following steps:

[0026] Step one, fill the lower mold assembly in the dry pressing equipment with part of the powder for making ceramic body, knock by auxiliary, drive cylinder 5 to drive the limiting block 6 to retract, drive the hammering block 17 to retract and extend continuously to knock the lower mold assembly, realize the vibration and flat laying of the powder in the lower mold.

[0027] Step two, pre-press, limit the lower mold assembly by auxiliary assembly, drive cylinder 5 to drive the limiting block 6 to extend and abut against the side of the lower mold assembly, at this time the hammering block 17 is retracted into the through slot 13 under the compression of the reset spring 14, at this time the hammering block 17 is retracted into the inner recess 15, one side of the limiting block 6 forms a circular arc concave surface matched with the surface of the lower mold assembly, the two limiting blocks 6 extend at the same time to limit the lower mold assembly, the upper pressing die 7 pushes down the lower mold assembly to increase the density of the powder at the lower part of the lower mold assembly.

[0028] Step three, secondary filling, add the remaining powder for making ceramic body to the lower mold assembly, and knock again to homogenize.

[0029] Step four, re-pressing, the lower mold assembly is stationary to realize re-pressing of the powder.

[0030] Step five, protection demolding, after pressing, lift the upper pressing die 7, drive cylinder 5 drives the limiting block 6 to retract a little, lose contact with the lower mold assembly, then drive cylinder 5 is lifted by lifting block 4, drive the limiting block 6 to rise, drive the clamping slot 16 to contact with the side baffle 11, then the mold ring 9 is lifted by the upward pulling action of the two limiting blocks 6 to demold the workpiece.

[0031] The knocking in step one and step three is that the drive cylinder 5 drives the limiting block 6 to retract, drives the hammering block 17 to retract and extend continuously to knock the lower mold assembly, realizes the vibration and flat laying of the powder in the lower mold.

[0032] In step two, when limiting the lower mold assembly, the drive cylinder 5 drives the limiting block 6 to extend and abut against the side of the lower mold assembly, at this time the hammering block 17 is retracted into the through slot 13 under the compression of the reset spring 14, at this time the hammering block 17 is retracted into the inner recess 15, one side of the limiting block 6 forms a circular arc concave surface matched with the surface of the lower mold assembly, the two limiting blocks 6 extend at the same time to limit the lower mold assembly.

[0033] In step five, when demolding, the upper pressing die 7 is lifted, the drive cylinder 5 drives the limiting block 6 to retract a little, loses contact with the lower mold assembly, then the drive cylinder 5 is lifted by the lifting block 4, drives the limiting block 6 to rise, drives the clamping slot 16 to contact with the side baffle 11, then the mold ring 9 is lifted by the upward pulling action of the two limiting blocks 6 to demold the workpiece.

[0034] The lower mold assembly comprises a fixed seat 8 and a mold ring 9, the top of the fixed seat 8 is fixedly connected with a convex ring 10 which is clamped with the inner cavity of the mold ring 9, and the top of the fixed seat 8 and the inner cavity of the mold ring 9 form a forming groove.

[0035] The dry pressing equipment comprises an extrusion table 1 and a support frame 2 fixed above the extrusion table 1, the lower portion of the support frame 2 is provided with an upper pressing die 7 driven by a hydraulic mechanism, the top portion of the extrusion table 1 is respectively provided with a lower die assembly and an auxiliary mechanism for knocking, limiting and demolding the lower die assembly, the lower die assembly comprises a fixed seat 8 and a die ring 9, the top portion of the fixed seat 8 is fixedly connected with a protruding ring 10 clamped with the inner cavity of the die ring 9, the top portion of the fixed seat 8 and the inner cavity of the die ring 9 form a forming groove, the lower die assembly is formed by clamping the die ring 9 in the protruding ring 10 on the top portion of the fixed seat 8, at this time, the upper pressing die 7 is extruded, after the workpiece is formed, the workpiece can be demolded at variable speed by lifting the die ring 9, only the up-down movement of the die ring 9 is driven, and the die ring 9 can be demolded and closed, the side edge of the die ring 9 is fixedly connected with a side baffle 11, the auxiliary mechanism comprises a fixed frame 3 fixed on the surface of the extrusion table 1, the inner cavity of the fixed frame 3 is slidably connected with a lifting block 4 driven by a motor, one side of the lifting block 4 is fixedly connected with a driving cylinder 5, one end of the piston rod of the driving cylinder 5 is fixedly connected with a limiting pressing block 6, one side of the limiting pressing block 6 is fixedly connected with a supporting block 12, the inner cavity of the limiting pressing block 6 is built-in a reset spring 14 through a through groove 13, one end of the reset spring 14 is fixedly connected with one side of the supporting block 12, the other end of the reset spring 14 is fixedly connected with a hammering block 17, the inner cavity of the limiting pressing block 6 is provided with an inner recess 15 for accommodating the hammering block 17, the inner cavity of the limiting pressing block 6 is provided with a clamping groove 16 matched with the surface of the side baffle 11, in use, when the powder is input into the lower die assembly, the limiting pressing block 6 is driven to shrink by the driving cylinder 5, the hammering block 17 is constantly stretched and contracted to knock the lower die assembly, the powder in the lower die is vibrated and leveled, after the knocking and vibration are completed, the limiting pressing block 6 is extended to abut against the side surface of the lower die assembly by the driving cylinder 5, at this time, the hammering block 17 is extruded and compressed to retreat into the through groove 13, at this time, the hammering block 17 retreats into the inner recess 15, one side of the limiting pressing block 6 forms a circular arc concave surface matched with the surface of the lower die assembly, the two limiting pressing blocks 6 are simultaneously extended to abut against the lower die assembly to limit, at this time, the upper pressing die 7 is pressed downward to form, after the forming is completed, the limiting pressing block 6 is retracted a little by the driving cylinder 5 to lose the contact with the lower die assembly, then the driving cylinder 5 is lifted by the lifting block 4 to lift the limiting pressing block 6, the clamping groove 16 is contacted with the side baffle 11, then the die ring 9 is lifted to demold the workpiece by the upward lifting action of the two limiting pressing blocks 6, the powder is homogenized by multiple knocking, the die ring 9 is demolded and closed, the positioning and locking are realized, the demolding is realized, the product quality is improved, the processing efficiency is effectively improved, when the knocking is performed, the lower die assembly is not in a fixed state and can be slightly moved leftward and rightward, the force acting on the internal powder is larger, and the forming effect is better.

[0036] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, as long as the changes or modifications do not deviate from the technical solution of the present application. Any modification, change, equivalent change and modification of the above embodiments made according to the technical essence of the present application still belong to the scope of the technical solution of the present application.

Claims

1. A dry pressing method for forming ceramic parts, characterized in that: Includes the following steps: Step 1: Filling. Add some of the ceramic blank material powder into the lower mold assembly inside the dry pressing equipment, and then tap it with the auxiliary components. Step 2, pre-compression: At this time, the lower mold assembly is limited by the auxiliary components, and the upper mold (7) pushes the lower mold assembly down to increase the powder density at the bottom of the lower mold assembly; Step 3: Secondary filling. Add the remaining powder from making the ceramic body into the lower mold assembly, and then tap it again to homogenize. Step 4: Apply pressure again, and the lower mold assembly comes to a standstill, thus repressurizing the powder. Step 5: Protect the demolded parts; The specific striking action in steps one and three is that the driving cylinder (5) drives the limiting pressure block (6) to retract, which in turn causes the hammer block (17) to continuously extend and retract to strike the lower mold assembly, thereby achieving vibration and spreading of the powder in the lower mold. In step two, when the lower mold assembly is limited, the driving cylinder (5) drives the limiting block (6) to extend and abut against the side of the lower mold assembly. At this time, the hammer block (17) is squeezed and compressed, and the reset spring (14) retracts into the through groove (13). At this time, the hammer block (17) retracts into the inner groove (15). One side of the limiting block (6) forms an arc concave surface that matches the surface of the lower mold assembly. The limiting blocks (6) on both sides extend at the same time to hold the lower mold assembly in place and limit its position. In step five, when demolding, the upper mold (7) is lifted, the driving cylinder (5) drives the limiting block (6) to retract slightly, losing contact with the lower mold assembly. Then, the lifting block (4) drives the driving cylinder (5) to rise, which in turn drives the limiting block (6) to rise, causing the slot (16) to contact the side baffle (11). Then, through the simultaneous upward pulling action of the limiting blocks (6) on both sides, the mold ring (9) is lifted to demold the workpiece. The lower mold assembly includes a fixed base (8) and a mold ring (9). The top of the fixed base (8) is fixedly connected to a protruding ring (10) that engages with the inner cavity of the mold ring (9). The top of the fixed base (8) and the inner cavity of the mold ring (9) form a molding groove.

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