A variable pitch spiral blade pressing mold and adjustment method thereof

Abstract

The present invention discloses a variable pitch spiral blade pressing and forming die and an adjustment method thereof, comprising an upper die and a lower die, wherein the upper die and the lower die are respectively provided with a plurality of discretely distributed clamping parts on opposite sides, and the height of the clamping parts on the corresponding die is adjustable; the contact pressure end points of the plurality of clamping parts on the same die form a spatial point array, and the spatial point array corresponds to the spiral surface of the fitting spiral blade; a plurality of upper pressing parts and a plurality of lower pressing parts are vertically opposed to each other. The lower pressing part is replaceably arranged on the lower die; a vertical cavity is provided in the upper die, and the upper pressing part is movably arranged in the vertical cavity, and the lower end of the upper pressing part extends out of the vertical cavity; a movable limiting mechanism is also provided in the vertical cavity, and the movable limiting mechanism can limit the vertical displacement of the upper pressing part in the vertical cavity. The present invention can realize that a plurality of spiral blades with different pitches are processed by the same die, greatly improving the flexibility of spiral blade processing.

Description

Technical Field

[0001] The invention relates to the technical field of stamping dies, and in particular to a variable pitch spiral blade pressing die and an adjustment method thereof. Background Art

[0002] Screw conveyors are widely used in industries such as chemical, grain, and feed transportation, and spiral blades are essential components for conveying materials. Currently, the GX and LS series screw conveyors feature spiral blades of uniform diameter and pitch welded to the spiral shaft. These blades utilize a standard structure and can be formed through cold or hot pressing using existing mold pressing techniques. Because they are mass-produced by specialized manufacturers, their manufacturing costs are low and they can be purchased directly from the market. However, in special circumstances, such as agricultural bioengineering equipment, variable-pitch spiral structures are used for conveying materials. Research has shown that spiral blades on the same shaft with varying pitches offer advantages such as uniform material flow, the absence of static layers, and the prevention of material overhead.

[0003] The existing spiral blade mold consists of an upper die and a lower die. The upper die is connected to the movable crossbar of the hydraulic press, and the lower die is connected to the workbench base. The spiral blade blank is placed on the lower die, and the hydraulic press drives the upper die downward to press the spiral blade blank into shape. Different molds are required for spiral blades of different diameters and pitches.

[0004] Variable-pitch spiral blades are categorized into constant-diameter variable-pitch and variable-diameter variable-pitch. These specialized structures are often in low demand, but each change in design parameter requires a dedicated mold, significantly increasing production costs. Using existing technology to produce variable-pitch spiral blades requires a new die for each pitch, and demand for some sizes may be low, leading to significant mold waste. Summary of the Invention

[0005] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a variable pitch spiral blade pressing and forming die and an adjustment method thereof, which can realize the processing of multiple spiral blades with different pitches by the same die, greatly improving the flexibility of spiral blade processing, reducing manufacturing costs, and having a simple structure, easy to use, and suitable for large-scale promotion.

[0006] Technical solution: To achieve the above-mentioned purpose, the present invention provides a variable-pitch spiral blade pressing and forming mold and an adjustment method thereof, comprising an upper mold and a lower mold that can relatively clamp the spiral blade, and a plurality of discretely distributed clamping parts are respectively provided on the opposite sides of the upper mold and the lower mold, and the height of the clamping parts on the corresponding mold is adjustable; the contact and pressure end points of the plurality of clamping parts on the same mold form a spatial point array, and the spatial point array corresponds to the spiral surface of the fitting spiral blade.

[0007] Furthermore, the clamping and pressing piece corresponding to the upper mold is an upper pressing piece, and the clamping and pressing piece corresponding to the lower mold is a lower pressing piece; a plurality of upper pressing pieces and a plurality of lower pressing pieces are vertically opposed to each other.

[0008] Furthermore, the lower pressure piece is replaceably arranged on the lower mold; a vertical cavity is provided in the upper mold, and the upper pressure piece is movably arranged in the vertical cavity, and the lower end of the upper pressure piece extends out of the vertical cavity; a movable limiting mechanism is also provided in the vertical cavity, and the movable limiting mechanism can limit the vertical displacement of the upper pressure piece in the vertical cavity.

[0009] Furthermore, the activity limiting mechanism includes a limiter, which cooperates with the top limit of the upper pressure piece; there is a filler between the limiter and the top of the upper pressure piece, and by changing the filling degree of the filler, the upward movement limit of the top of the upper pressure piece can be adjusted accordingly.

[0010] Furthermore, the upper mold includes an upper mold body, a mounting seat is connected above the upper mold body, and the limiting member is a rotating disk arranged between the upper mold body and the mounting seat; the vertical cavity is arranged in the upper mold body; a plurality of accommodating cavities are provided in the rotating disk, and the accommodating cavities correspond to the fillers; the plurality of accommodating cavities correspond one-to-one to the plurality of vertical cavities, and the rotating disk can be rotated relative to the upper mold body until the accommodating cavities are vertically connected with the corresponding vertical cavities, so that the filler is filled between the limiting member and the upper pressure member under the action of gravity.

[0011] Furthermore, the filler is a plurality of stacked filling sheets, and the shape of the filling sheets is consistent with the cross-sectional shape of the vertical cavity and the cross-sectional shape of the accommodating cavity; the rotating disk fits tightly with the upper mold body to prevent the filling sheets from being stuffed between the rotating disk and the upper mold body.

[0012] Furthermore, a limiting structure is provided in the vertical cavity to prevent the upper pressing piece from detaching.

[0013] Furthermore, a socket is provided at the upper end of the lower mold, and the lower pressing piece is movably inserted into the socket; a gasket is also provided between the lower pressing piece and the socket, and the height of the lower pressing piece can be fine-tuned by changing the thickness of the gasket.

[0014] Furthermore, a method for adjusting a variable-pitch spiral blade pressing mold includes the following steps: S1: replacing the lower pressing piece on the lower mold so that the spatial point array composed of the upper ends of several lower pressing pieces corresponds to the spiral surface of the spiral blade; S2: rotating the rotating disk so that the accommodating cavity is vertically opposite to the vertical cavity, and the filler can move between the accommodating cavity and the vertical cavity; S3: the upper mold moves toward the lower mold until the lower pressing piece abuts against the corresponding upper pressing piece, thereby adjusting the position of the upper pressing piece in the vertical cavity, so that the spatial point array composed of the lower ends of several upper pressing pieces also corresponds to the spiral surface of the spiral blade; S4: rotating the rotating disk again so that the accommodating cavity and the vertical cavity are staggered; a part of the filler is left between the top of the upper pressing piece and the rotating disk, and the rotating disk and the filler can limit the upward movement limit of the upper pressing piece.

[0015] Beneficial effects: The variable pitch spiral blade pressing mold and the adjustment method thereof of the present invention have the following beneficial effects:

[0016] 1) The mold is discretely distributed with multiple clamping parts. The point array formed by the contact pressure end points of the clamping parts simulates the spiral surface of the threaded blade after molding to press the spiral blade. The height of each clamping part can also be changed to accommodate spiral blades with different pitches, thereby reducing the mold manufacturing cost.

[0017] 2) When adjusting the mold to adapt to thread blades with different pitches, the lower pressing piece on the lower mold is replaced by plugging and unplugging, which is convenient to use; and the upper pressing piece can be moved up and down in the upper mold. When the upper mold moves down until the upper pressing piece presses on the lower pressing piece, the upper pressing piece can automatically form a shape that matches the lower pressing piece, thereby quickly adjusting the upper pressing piece and being easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Attachment Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Attachment Figure 2 Schematic diagram of the internal structure of the upper mold;

[0020] Attachment Figure 3 is a side view of the lower mold;

[0021] Attachment Figure 4 is a top view of the upper mold;

[0022] Attachment Figure 5 This is the structural diagram of the spiral blade blank.

[0023] Attachment Figure 6 The present invention is a flow chart of an adjustment method for a variable pitch spiral blade pressing and forming die. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] As attached Figures 1 to 6 The variable pitch spiral blade pressing and forming mold and its adjustment method include an upper mold 1 and a lower mold 2 that can relatively clamp and press the spiral blade. The upper mold 1 is connected to the movable crossbeam of the hydraulic press, and the lower mold 2 is connected to the base of the workbench. The upper mold 1 and the lower mold 2 are vertically opposite to each other. Driven by the hydraulic press, the upper mold 1 can press the lower mold 2 to punch the spiral blade blank 16 on the lower mold 2.

[0026] The spiral blade stamping die in the existing technology is divided into two parts: the upper die and the lower die. Both the upper die and the lower die are made into spiral surfaces that adapt to the spiral blade. As long as the diameter or pitch of the spiral blade changes, its spiral surface will be different, and a corresponding die must be made.

[0027] In the present invention, the upper mold 1 and the lower mold 2 are provided with a plurality of discretely distributed clamping parts on the opposite sides. The height of the clamping parts on the corresponding mold is adjustable. The height of the clamping parts can be adjusted by replacing the clamping parts, or a corresponding height adjustment mechanism can be provided in the corresponding mold to drive the clamping parts to move up and down within the mold through the height adjustment mechanism, thereby changing the height of the clamping parts. The end of the clamping part used to clamp the spiral blade is the contact pressure end. The contact pressure end points of the plurality of clamping parts on the same mold form a spatial point array, which corresponds to the spiral surface of the finished spiral blade part 21.

[0028] The spiral blade is composed of a spiral surface, and a surface can be regarded as composed of infinite points, so it can be assumed that a surface is approximately formed by a finite number of points. According to the above-mentioned spiral surface forming principle, the spiral surface is spatially divided into a finite number of points, and the finite number of points are approximately combined to form a surface. The more clamping parts there are, the more accurate the spiral surface formed, but the cost is also higher and the rigidity is also worse, so in practical applications, it is necessary to reasonably optimize the design of the number of clamping parts. When facing spiral blades with different pitches, the height of each clamping part can be adjusted accordingly to change the shape of the spatial point array composed of the contact pressure end points of several clamping parts.

[0029] Based on the corresponding relationship between the clamping parts and the mold, the clamping part corresponding to the upper mold 1 is called the upper clamping part 3, and the clamping part corresponding to the lower mold 2 is called the lower clamping part 4. Several upper clamping parts 3 and several lower clamping parts 4 are vertically opposed to each other. When the upper clamping parts 3 press the spiral blade, the lower clamping parts 4 directly below the upper clamping parts 3 provide support, which improves the molding effect of the spiral blade.

[0030] The lower pressing member 4 is replaceably mounted on the lower mold 2, and can be replaced to accommodate spiral blades of different pitches. A vertical cavity 5 is provided within the upper mold 1, and the upper pressing member 3 is movably mounted within the vertical cavity 5. The vertical cavity 5 has a lower cavity opening, and the lower end of the upper pressing member 3 extends out of the vertical cavity 5. A movement limiting mechanism is also provided within the vertical cavity 5 to limit the vertical displacement of the upper pressing member 3 within the vertical cavity 5, thereby adjusting the length of the lower end of the upper pressing member 3 extending out of the vertical cavity 5 to accommodate spiral blades of different pitches.

[0031] In one embodiment, the activity limiting mechanism is a clamping mechanism, which is clamped and cooperated with the upper pressure piece 3. By clamping the upper pressure piece 3 that is movable and displaced in the vertical cavity 5, the length of the lower end of the upper pressure piece 3 extending out of the vertical cavity 5 can be fixed, and the length of the lower end of the upper pressure piece 3 extending out of the vertical cavity 5 can be adjusted.

[0032] In one embodiment, the movement limiting mechanism includes a limiter that cooperates with the top of the upper pressing member 3; a filler is provided between the limiter and the top of the upper pressing member 3, and by changing the filling level of the filler, the upward movement limit of the top of the upper pressing member 3 can be adjusted accordingly. When the upper mold 1 moves downward, the upper pressing member 3 presses down the spiral blades in response, and the upper pressing member 3, which is subjected to the reverse action, moves upward within the vertical cavity 5. Since the upward movement limit of the upper pressing member 3 is limited by the filler and the limiter, the minimum length of the lower end of the upper pressing member 3 extending out of the vertical cavity 5 is also limited, thereby accommodating spiral blades of different pitches.

[0033] As attached Figure 2 As shown in , the upper mold 1 includes an upper mold body 6, and a mounting seat 7 is fixedly connected to the upper part of the upper mold body 6. The upper mold body 6 is connected to the movable crossbeam of the hydraulic press through the mounting seat 7. The limiting member is a rotating disk 8 arranged between the upper mold body 6 and the mounting seat 7. There is a rotating shaft 13 between the upper mold body 6 and the mounting seat 7. The rotating disk 8 rotates with the rotating shaft 13 so that the rotating disk 8 can rotate horizontally relative to the upper mold body 6. The vertical cavity 5 is arranged in the upper mold body 6, and the vertical cavity 5 vertically penetrates the upper mold body 6. A plurality of accommodating cavities 9 are provided in the rotating disk 8. The accommodating cavities 9 are vertically arranged, and the accommodating cavities 9 correspond to accommodating the filler. A plurality of accommodating cavities 9 correspond one to one with a plurality of vertical cavities 5. The rotating disk 8 can be rotated relative to the upper mold body 6 until the accommodating cavities 9 are vertically connected to the corresponding vertical cavities 5, so that the filler is filled between the limiter and the upper pressure piece 3 under the action of gravity, thereby changing the filling degree of the filler. When the rotating disk 8 can be rotated relative to the upper mold body 6 until the accommodating cavities 9 are staggered with the corresponding vertical cavities 5, the filling degree of the filler is retained, thereby limiting the upward movement limit of the upper pressure piece 3.

[0034] As attached Figure 1As shown in the figure, there is a horizontal positioning bolt 14 between the rotating disk 8 and the mounting seat 7, and the relative position between the rotating disk 8 and the mounting seat 7 can be fixed by the positioning bolt 14. Since the mounting seat 7 and the upper mold body 6 are fixedly connected, the relative position of the rotating disk 8 and the upper mold body 6 can also be fixed by the positioning bolt 14 to adjust the state of the accommodating cavity 9 and the vertical cavity 5 to correspond to each other or be staggered with each other.

[0035] In one embodiment, the filler is a plurality of stacked filling sheets 10, and the shape of the filling sheet 10 is consistent with the cross-sectional shape of the vertical cavity 5 and the cross-sectional shape of the accommodating cavity 9, so that the filling sheet 10 can be vertically displaced in the vertical cavity 5 and the accommodating cavity 9. The rotating disk 8 fits tightly with the upper mold body 6 to prevent the filling sheet 10 from being stuffed between the rotating disk 8 and the upper mold body 6. In another embodiment, the filler is filling particles, and accordingly, the rotating disk 8 fits tightly with the upper mold body 6 to prevent the filling particles from being stuffed between the rotating disk 8 and the upper mold body 6. The thickness of the filling sheet 10 or the particle size of the filling particles are adapted to the adjustment accuracy of the clamping part. For example, if the adjustment accuracy of the lower pressing part 4 is 1 mm, the thickness of the filling sheet 10 is also 1 mm.

[0036] The vertical cavity 5 is provided with a limiting structure to prevent the upper pressing member 3 from being separated. Figure 2 As shown, a limiting ring 15 is provided at the lower cavity opening of the vertical cavity 5, the upper pressure piece 3 is a columnar body with a stepped surface, and the lower end of the upper pressure piece 3 is semi-spherical. The limiting ring 15 cooperates with the stepped surface of the upper pressure piece 3 to prevent the upper pressure piece 3 from sliding out of the vertical cavity 5 under the action of gravity.

[0037] The upper end of the lower mold 2 is provided with a socket, and the push-down member 4 is movably inserted into the socket. The push-down member 4 is also a columnar body with a stepped surface, and the upper end of the push-down member 4 is semi-spherical. A gasket 11 is also provided between the push-down member 4 and the socket, and the gasket 11 is located between the stepped surface and the socket opening. The height of the push-down member 4 can be fine-tuned by changing the thickness of the gasket 11. Since the size of each push-down member 4 located at different positions is different, each time a spiral blade is replaced, a push-down member 4 of different sizes must be processed, which will result in waste. According to the principle of universality, several push-down members 4 are produced at intervals of 10 mm, and the missing sizes are compensated by gaskets 11 of different thicknesses. The thicknesses of the gaskets 11 are 1 mm, 2 mm, and 5 mm, respectively, so that the required size of the push-down member 4 can be combined in the most economical way.

[0038] A method for adjusting a variable pitch spiral blade pressing mold comprises the following steps:

[0039] S1: Replace the lower pressing piece 4 on the lower mold 2. Pull out the old lower pressing piece 4 by plugging and unplugging, then replace it with a new one, and add the corresponding gasket 11 according to the required size; make the spatial point array formed by the upper end vertices of the plurality of lower pressing pieces 4 correspond to the spiral surface of the spiral blade finished product 21;

[0040] S2: Unscrew the positioning bolts 14 to allow the rotating disk 8 to rotate; then rotate the rotating disk 8 so that the accommodating channel 9 and the vertical channel 5 are vertically opposite each other, and then tighten the positioning bolts 14 to maintain the accommodating channel 9 and the vertical channel 5 in a state of relative alignment; at this time, the filler can move between the accommodating channel 9 and the vertical channel 5;

[0041] S3: The hydraulic press is started, which drives the upper mold 1 toward the lower mold 2 until the lower pressing pieces 4 abut against the corresponding upper pressing pieces 3, thereby adjusting the positions of the upper pressing pieces 3 within the vertical cavity 5. Since the upper pressing pieces 3 and the lower pressing pieces 4 are now opposite each other, the spatial point array formed by the lower end vertices of the upper pressing pieces 3 also corresponds to the spiral surface of the spiral blade finished product 21.

[0042] S4: Unscrew the positioning bolts 14 and rotate the rotating disk 8 again to stagger the accommodating cavity 9 and the vertical cavity 5. A portion of the filler moves with the rotation of the rotating disk 8, and the other portion of the filler is left between the top of the upper pressure piece 3 and the rotating disk 8. The rotating disk 8 and the filler can limit the upward movement limit of the upper pressure piece 3. At this time, screw on the positioning bolts 14 again to maintain the staggered state between the accommodating cavity 9 and the vertical cavity 5. At this time, the upper pressure piece 3 has also completed the adjustment to adapt to the spiral surface of the spiral blade.

[0043] The traditional mold adjustment method requires the staff to adjust the clamping parts on the upper mold 1 and the lower mold 2 respectively. However, with the mold adjustment method of the present invention, after adjusting the lower mold 4, the upper mold 3 is made to collide and match with the upper mold 3 to complete the adjustment of the upper mold 3. There is no need for the staff to repeat the adjustment twice, which can improve the adjustment work efficiency and will not cause the upper mold 1 and the lower mold 2 to be mismatched.

[0044] The shape of the spiral blade blank 16 is as shown in the attached Figure 5 As shown, the spiral blade blank 16 has an inner hole 17 in the middle, and a positioning hole 18 is also provided on the spiral blade blank 16. The center of the upper end of the lower mold 2 is provided with an upwardly extending guide post 19, which cooperates with the inner hole 17 and has a shape that matches that of the inner hole 17. The center of the bottom end of the upper mold 1 is provided with a downwardly extending sleeve 20, which is plugged into the guide post 19 for positioning.

[0045] The working process of the mold of the present invention is as follows: First, a spiral blade blank 16 is cut out on the steel plate as shown in the attached figure. Figure 5 As shown, its outer diameter, inner hole 17 and cutting angle are all determined according to the spiral blade expansion size formula. On the largest concentric circle of the installation lower pressing piece 4, the lower pressing piece 4 with the maximum height dimension is determined. The lower pressing piece 4 serves as the reference pressing column. The point corresponding to the contact between the upper end vertex of the lower pressing piece 4 and the spiral blade blank 16 is calculated, and a positioning hole 18 is drilled. The inner hole 17 of the spiral blade blank 16 is then inserted into the guide column 19 to play the role of center positioning. At the same time, the positioning hole 18 on the spiral blade blank 16 is aligned with the top of the lower pressing piece 4 with the maximum height dimension to play the role of circumferential positioning. Then the hydraulic press is started, the upper mold 1 moves downward, the upper pressing piece 3 contacts and presses down on the spiral blade blank 16, and the spiral blade blank 16 squeezed between the upper pressing piece 3 and the lower pressing piece 4 undergoes plastic deformation and finally becomes a spiral blade finished product 21.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A variable pitch spiral blade pressing mold, characterized by: The invention comprises an upper mold (1) and a lower mold (2) capable of relatively clamping and pressing a spiral blade, wherein a plurality of discretely distributed clamping parts are respectively provided on opposite sides of the upper mold (1) and the lower mold (2), and the height of the clamping parts on the corresponding mold is adjustable; the contact pressure end points of the plurality of clamping parts on the same mold form a spatial point array, and the spatial point array corresponds to the spiral surface of the fitting spiral blade; The clamping and pressing piece corresponding to the upper mold (1) is an upper pressing piece (3), and the clamping and pressing piece corresponding to the lower mold (2) is a lower pressing piece (4); a plurality of upper pressing pieces (3) and a plurality of lower pressing pieces (4) are vertically opposed to each other; The lower pressing piece (4) is replaceably arranged on the lower mold (2); a vertical cavity (5) is provided in the upper mold (1); the upper pressing piece (3) is movably arranged in the vertical cavity (5), and the lower end of the upper pressing piece (3) extends out of the vertical cavity (5); a movement limiting mechanism is also provided in the vertical cavity (5), and the movement limiting mechanism can limit the vertical displacement of the upper pressing piece (3) in the vertical cavity (5); The activity limiting mechanism includes a limiting member, which is in limited cooperation with the top end of the upper pressing member (3); a filler is provided between the limiting member and the top end of the upper pressing member (3); and by changing the filling degree of the filler, the upward movement limit of the top end of the upper pressing member (3) can be correspondingly adjusted; The upper mold (1) includes an upper mold body (6), a mounting seat (7) is connected above the upper mold body (6), and the limiting member is a rotating disk (8) arranged between the upper mold body (6) and the mounting seat (7); the vertical cavity (5) is arranged in the upper mold body (6); a plurality of accommodating cavities (9) are provided in the rotating disk (8), and the accommodating cavities (9) correspond to the fillers; the plurality of accommodating cavities (9) correspond to the plurality of vertical cavities (5) one by one, and the rotating disk (8) can be rotated relative to the upper mold body (6) until the accommodating cavities (9) are vertically connected to the corresponding vertical cavities (5), so that the fillers are filled between the limiting member and the upper pressing member (3) under the action of gravity.

2. The variable pitch spiral blade pressing mold according to claim 1, characterized in that: The filler is a plurality of stacked filling sheets (10), and the shape of the filling sheet (10), the cross-sectional shape of the vertical cavity (5), and the cross-sectional shape of the accommodating cavity (9) are consistent; the rotating disk (8) fits tightly with the upper mold body (6) to prevent the filling sheet (10) from being inserted between the rotating disk (8) and the upper mold body (6).

3. The variable pitch spiral blade pressing mold according to claim 2, characterized in that: A limiting structure for preventing the upper pressing member (3) from being separated is provided in the vertical cavity (5).

4. The variable pitch helical blade pressing mold according to claim 1, characterized in that: The upper end of the lower mold (2) is provided with an insertion hole, and the lower pressing piece (4) is movably inserted into the insertion hole; a gasket (11) is also provided between the lower pressing piece (4) and the insertion hole, and the height of the lower pressing piece (4) can be fine-tuned by changing the thickness of the gasket (11).

5. The method for adjusting a variable pitch helical blade pressing mold according to claim 1, characterized in that: The following steps are involved: S1: replacing the lower pressing piece (4) on the lower mold (2) so that the spatial point array formed by the upper ends of the plurality of lower pressing pieces (4) corresponds to the spiral surface of the spiral blade; S2: rotating the rotating disk (8) so that the accommodating cavity (9) and the vertical cavity (5) are vertically opposed to each other, and the filler can move between the accommodating cavity (9) and the vertical cavity (5); S3: The upper mold (1) moves toward the lower mold (2) until the lower pressing pieces (4) abut against the corresponding upper pressing pieces (3), thereby adjusting the positions of the upper pressing pieces (3) in the vertical cavity (5), so that the spatial point array formed by the lower ends of the plurality of upper pressing pieces (3) also corresponds to the spiral surface of the spiral blade; S4: The rotating disk (8) is rotated again to stagger the accommodating cavity (9) and the vertical cavity (5); a portion of the filler is left between the top of the upper pressing member (3) and the rotating disk (8), and the rotating disk (8) and the filler can limit the upward movement limit of the upper pressing member (3).

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