A molding fixture clamp for a low-loss dielectric waveguide filter and a method of use

Abstract

The present application relates to the technical fields of forming tool fixture, especially to a forming tool fixture for low-loss dielectric waveguide filter and a using method thereof, comprising a die base, a lower die cavity arranged at the middle position of the die base and a punch press connector for connecting with a punch press, the middle position of the die base is provided with the lower die cavity, a pushing plate is installed at one side of the upper end of the lower die cavity, an upper die head is arranged at the upper end of the lower die cavity, and the upper die head is fixedly connected with the punch press connector for connecting with the punch head of the punch press; the upper die head comprises a head main body, a communicating device is installed at the middle position of the head main body, and a piston assembly is installed in the communicating device. The present application constructs an active exhaust passage linked with the head descending during the punching process, so that the gas in the die cavity which is sharply compressed can be timely and orderly dissipated through the flow guide channel arranged at the core rod fixing plate, and the high-pressure gas is prevented from forming a stagnant bubble in the powder.

Description

Technical Field

[0001] This invention relates to a molding fixture and its usage method for a low-loss dielectric waveguide filter, belonging to the field of molding fixture technology. Background Technology

[0002] The existing dielectric waveguide filter blanks are mainly prepared by ceramic powder dry pressing molding process. The conventional tooling fixture consists of an upper die head, a lower die cavity and multiple forming mandrels fixed on the die head. During the stamping process, the upper die head drives the mandrels to move down quickly and extrudes the powder in the die cavity.

[0003] Because the mold cavity is closed and traditional fixtures lack any channels or follow-up venting mechanisms for venting internal gas, the air inside the cavity is rapidly compressed as the pressure head is pressed down. It can only slowly escape through the gaps between powder particles, resulting in a large amount of gas failing to escape in time before the powder densifies. Especially when multiple mandrels are simultaneously forming multiple resonant holes, multiple independent air chambers are formed in the area between the bottom of each mandrel and the bottom surface of the mold cavity. The high-pressure gas produces a significant air cushion effect, which not only hinders the powder from filling around and to the bottom of the mandrel, but also leaves high-pressure air bubbles inside the blank. After demolding, these air bubbles and stress concentration points form internal defects such as pores, microcracks, or interlayer separation. In addition, residual powder often adheres to the surface of the mandrel and the venting gaps after forming. If not cleaned in time, it will affect the dimensional accuracy and surface quality of subsequent stamping. Existing fixtures lack online dust removal and self-cleaning functions during the forming process, requiring manual cleaning during machine shutdown, which seriously affects the efficiency and consistency of continuous production. Therefore, it is urgent to improve the forming tooling fixture and usage method of a low-loss dielectric waveguide filter to solve the above-mentioned problems. Summary of the Invention

[0004] The purpose of this invention is to provide a forming fixture and method for a low-loss dielectric waveguide filter. During the entire stamping process, especially during the synchronous forming of multiple resonant holes, the gas in the mold cavity is efficiently and orderly discharged, thereby avoiding uneven density and internal microcracks in the blank caused by gas retention. At the same time, it also takes into account the online removal of residual powder on the mold surface, so as to ensure that the filter blank has high density and uniformity, thereby reducing the dielectric loss of the final product from the source and improving the yield and stability of mass production.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A forming fixture and method for a low-loss dielectric waveguide filter, comprising a mold base, a lower mold cavity located in the middle of the mold base, and a stamping machine connector for connection with a stamping machine. The lower mold cavity is located in the middle of the mold base. A pusher plate is installed on one side of the upper end of the lower mold cavity. An upper mold head is located at the upper end of the lower mold cavity. A stamping machine connector for connection with a stamping machine stamping head is fixedly connected to the upper end of the upper mold head. The upper mold head includes a head body, in which... A communicating vessel is installed between the pressure head and a piston assembly is installed inside the communicating vessel. The lower end of the pressure head body is connected to a mandrel fixing plate through a sealing shell and a guide rod. Multiple mandrels for stamping resonant holes are fixedly connected to the middle of the lower end of the pressure head body. The mandrel fixing plate includes a plate body. Multiple mandrel through holes for limiting the mandrels are opened inside the plate body. Protrusions are fixedly connected to the inner walls of the mandrel through holes. Guide holes are opened inside the protrusions. Mounting grooves for connecting with guide rods are opened at the upper ends of the four corners of the plate body.

[0007] Furthermore, an electric push rod is installed at the end of the push plate away from the lower mold cavity, and the fixed end of the electric push rod is connected to the mold base by bolts through a mounting seat.

[0008] Furthermore, the pressure head body includes a vertical plate, a hollow cavity for installing a communicating vessel is provided in the middle of the vertical plate, a non-closed limiting cavity for limiting the sealing shell and a non-closed sliding hole for limiting the guide rod are provided at the lower end of the vertical plate, and a positioning hole and an air hole for limiting the piston assembly are provided at the bottom end of the hollow cavity.

[0009] Furthermore, the upper end of the vertical plate is connected to the connecting part of the stamping machine, and the micro-holes that connect the non-closed limiting cavity and the non-closed sliding hole to the outside are both opened at the top position. There are two air holes, which are set on both sides of the positioning hole, and the opening positions of the positioning hole and the air holes are offset from the mandrel.

[0010] Furthermore, the communicating vessel includes a fixed shell, the lower end of which is open, and the upper end of which has a circular hole in the middle. A spring is installed on the upper end of the fixed shell, and the lower end of the fixed shell is fixedly connected to the inner wall of the hollow cavity.

[0011] Furthermore, the core rod includes a core rod body, which has two structural configurations: one with a circular vertical projection and the other with a cross-shaped vertical projection. The core rod body has an adapter groove on each side.

[0012] Furthermore, the piston assembly includes a cylindrical piston rod, one end of which is fixedly connected to a piston plate with a vertically rectangular projection, and the included angle between the piston rod and the piston plate is 90°.

[0013] Furthermore, the piston plate is installed inside the fixed shell via a sealing ring on its outer side, and the end of the piston plate away from the piston rod is fixedly connected to the other end of the spring. The piston rod passes through the bottom of the vertical plate, and the end of the piston rod away from the piston plate is fixedly connected to the mandrel fixing plate.

[0014] Furthermore, the mandrel is disposed inside the sealed shell, and the mandrel is connected to the plate at a 90° angle through a mandrel through-hole. The protrusion fixed inside the mandrel through-hole is adapted to the adapter groove opened on the side of the mandrel body inside the mandrel.

[0015] Furthermore, it includes the following steps:

[0016] Step 1: Place the materials required for producing ceramic dielectric waveguide filters into the mold cavity as shown below. After placement, control the stamping machine to move the stamping machine connector and the upper mold head downward to perform the stamping process.

[0017] Step 2: During the downward movement of the upper mold pressure head, the mandrel exposed on the outer side of the lower end of the mandrel fixing plate first enters the lower mold cavity for stamping the resonant hole of the ceramic dielectric waveguide filter. At the same time, the bottom end of the mandrel fixing plate contacts the material at the upper end of the lower mold cavity for forming the upper end of the ceramic dielectric waveguide filter.

[0018] Step 3: As the mandrel continues to move downward, the gap between its bottom and the bottom of the mandrel fixing plate increases continuously. During the formation of the resonant hole, the internal gas is discharged through the guide hole to reduce the amount of internal gas.

[0019] During this process, the piston rod is pushed by the core plate fixing plate to control the piston plate to move upward, and the gas inside the space formed by the upper end of the core plate fixing plate and the sealing shell is continuously discharged through the air hole, which also assists in the discharge of the gas inside the ceramic dielectric waveguide filter during the molding process.

[0020] Step 4: Continue pressing down to complete the forming of the ceramic dielectric waveguide filter. After the ceramic dielectric waveguide filter is formed, the press drives the upper mold head to move upward through the press connector and separates from the lower mold cavity. At this time, the piston plate is reset under the action of the spring and squeezes the gas through the air hole into the sealed shell for cleaning the inside of the guide hole and cleaning the outer surface of the auxiliary core rod.

[0021] Step 5: After the upper mold pressure head is fully reset, the mechanism inside the lower mold cavity pushes the extruded ceramic dielectric waveguide filter to the upper end of the mold base, and the pusher plate pushes the stamped ceramic dielectric waveguide filter away from the upper end of the lower mold cavity, completing the production.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. This invention constructs an active exhaust path that moves with the downward movement of the press head during the stamping process. This allows the rapidly compressed gas in the mold cavity to escape in a timely and orderly manner through the guide channel opened at the mandrel fixing plate. This avoids the formation of stagnant bubbles in the powder due to high pressure gas. At the same time, the independent air chambers between the bottom of multiple mandrels and the bottom surface of the mold cavity are eliminated due to the optimization of the exhaust path. This ensures that the powder is fully densified and filled around and at the bottom of the mandrel. After molding, the internal density distribution of the blank is uniform, without structural damage such as delamination or microcracks. After high-temperature sintering, it will not produce irreversible electromagnetic scattering sources, thereby effectively reducing the dielectric loss tangent of the filter and enabling it to stably meet the stringent requirements of communication systems for ultra-low loss devices.

[0024] 2. In the demolding stage after stamping, the present invention uses a spring-reset piston assembly to return to its original position, actively introducing external gas into the sealed shell and blowing it outward along the guide channel. This reverse airflow can clean the residual powder adhering to the outer surface of the mandrel and the inner wall of the guide hole online. This self-cleaning action is automatically executed after each stamping cycle, effectively avoiding the gradual accumulation of powder in the mandrel and the venting gap. There is no need to stop the machine for manual cleaning. As a result, the mold remains clean throughout the continuous production process, and the consistency and dimensional accuracy of each batch of products are reliably guaranteed, significantly improving the yield rate and equipment utilization rate of mass production.

[0025] 3. This invention, through a guiding and limiting structure consisting of a guide rod and a sealing shell between the pressure head body and the mandrel fixing plate, ensures the verticality of the upper die pressure head's movement and the repeatability of its positioning accuracy during repeated stamping processes. This avoids mandrel bending or mold cavity wear caused by uneven loading or shaking. At the same time, the integrated design of the piston assembly and the communicating vessel allows pneumatic transmission and mechanical transmission to work together, effectively buffering and uniformly transmitting the impact load during the stamping process. This reduces fatigue damage to key components. The overall structure is compact and easy to assemble and disassemble, extending the overall service life of the tooling fixture and reducing the frequency and cost of daily maintenance. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the upper mold pressure head structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the location structure of the non-enclosed limiting cavity of the present invention;

[0029] Figure 4 This is a schematic diagram of the communicating vessel structure of the present invention;

[0030] Figure 5 This is a schematic diagram of the installation position of the sealing shell of the present invention;

[0031] Figure 6 This is a schematic diagram of the mandrel mounting position structure of the present invention;

[0032] Figure 7 For the present invention Figure 6 Enlarged structural diagram at point A in the middle;

[0033] Figure 8 This is a schematic diagram of the mandrel fixing plate structure of the present invention;

[0034] Figure 9 For the present invention Figure 8 Enlarged structural diagram at point B;

[0035] Figure 10 This is a schematic diagram of the piston assembly structure of the present invention.

[0036] In the diagram, 1. Mold base; 2. Lower mold cavity; 3. Push plate; 4. Press machine connector; 5. Upper mold head; 51. Head body; 511. Vertical plate; 512. Hollow cavity; 513. Non-enclosed limiting cavity; 514. Non-enclosed sliding hole; 515. Positioning hole; 516. Air hole; 52. Communicating vessel; 521. Fixed shell; 522. Round hole; 523. Spring; 53. Mandrel fixing plate; 531. Plate body; 532. Mounting groove; 533. Mandrel through hole; 534. Protrusion; 535. Guide hole; 54. Sealing shell; 55. Guide rod; 56. Mandrel; 561. Mandrel body; 562. Adaptor groove; 57. Piston assembly; 571. Piston rod; 572. Piston plate. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] like Figures 1-10As shown, this embodiment provides a forming fixture for a low-loss dielectric waveguide filter, including a mold base 1, a lower mold cavity 2 located in the middle of the mold base 1, and a stamping machine connector 4 for connecting to a stamping machine. The lower mold cavity 2 is located in the middle of the mold base 1. A pusher plate 3 is installed on one side of the upper end of the lower mold cavity 2. An upper mold head 5 is provided at the upper end of the lower mold cavity 2. The upper end of the upper mold head 5 is fixedly connected to the stamping machine connector 4 for connecting to the stamping head of the stamping machine. The upper mold head 5 includes a head body 51. A communicating vessel 52 is installed in the middle of the head body 51. A piston assembly 57 is installed inside the communicating vessel 52. The lower end of the head body 51 is connected to a core rod fixing plate 53 through a sealing shell 54 and a guide rod 55. Multiple core rods 56 for stamping resonant holes are fixedly connected in the middle of the lower end of the head body 51. The core rod fixing plate 53 includes a plate The plate 531 has multiple mandrel through holes 533 inside for limiting the mandrel 56. A protrusion 534 is fixedly connected to the inner wall of the mandrel through hole 533. A guide hole 535 is opened inside the protrusion 534. The upper corners of the plate 531 are all provided with mounting grooves 532 for connecting with guide rods 55. Through the cooperation of the mold base 1, the lower mold cavity 2 and the upper mold pressure head 5, the integrated stamping of the filter blank is realized. At the same time, the mandrel 56 is precisely limited by the mandrel through holes 533 of the mandrel fixing plate 53, ensuring the consistency of the position of the resonant hole. The setting of the guide hole 535 effectively discharges the gas in the cavity during the stamping process and avoids porosity defects. The combination of the sealing shell 54 and the guide rod 55 ensures the guiding accuracy and stability of the upper mold pressure head 5 in its up and down movement, significantly improving the dimensional accuracy and internal quality of the formed product.

[0039] In one possible embodiment, an electric push rod is installed at the end of the push plate 3 away from the lower mold cavity 2. The fixed end of the electric push rod is connected to the mold base 1 by bolts through the mounting seat. The push plate 3 is driven by the electric push rod to realize the automatic ejection of the product after molding, reducing manual intervention. The bolt-connected mounting seat structure is easy to disassemble and maintain, improving the degree of production automation and material output efficiency.

[0040] In one possible embodiment, the pressure head body 51 includes a vertical plate 511, with a hollow cavity 512 in the middle for mounting the communicating vessel 52. The lower end of the vertical plate 511 has a non-closed limiting cavity 513 for limiting the sealing shell 54 and a non-closed sliding hole 514 for limiting the guide rod 55. The bottom end of the hollow cavity 512 has a positioning hole 515 and an air hole 516 for limiting the piston assembly 57. The vertical plate 511 provides a stable installation space for the communicating vessel 52 through the hollow cavity 512. The non-closed limiting cavity 513 and the non-closed sliding hole 514 not only ensure the guiding function of the sealing shell 54 and the guide rod 55, but also facilitate the quick disassembly and replacement of parts. The positioning hole 515 ensures the accurate movement trajectory of the piston assembly 57. The overall structure is compact and easy to maintain.

[0041] In one possible embodiment, the upper end of the vertical plate 511 is connected to the stamping machine connector 4. The micro-holes that connect the non-closed limiting cavity 513 and the non-closed sliding hole 514 to the outside are both opened at the top position. There are two air holes 516. The air holes 516 are arranged on both sides of the positioning hole 515. The positions of the positioning hole 515 and the air holes 516 are staggered from the mandrel 56, which further improves the smoothness of the device during operation.

[0042] In one possible embodiment, the communicating vessel 52 includes a fixed shell 521 with an open lower end and a circular hole 522 in the middle of the upper end. A spring 523 is installed on the upper end of the fixed shell 521. The lower end of the fixed shell 521 is fixedly connected to the inner wall of the hollow cavity 512. The opening at the lower end of the fixed shell 521 facilitates the installation and movement of the piston assembly 57. The circular hole 522 ensures the passage and guidance of the piston rod 571. The spring 523 enables the piston assembly 57 to automatically reset, allowing it to actively control the airflow to clean the mandrel 56 after molding. The fixed connection between the fixed shell 521 and the hollow cavity 512 ensures the rigidity of the overall structure.

[0043] In one possible embodiment, the mandrel 56 includes a mandrel body 561, which has two structural configurations: one with a circular vertical projection and the other with a cross-shaped vertical projection. The mandrel body 561 has an adapter groove 562 on each side. The mandrel body 561 provides two cross-sectional structures, circular and cross-shaped, which can meet the forming requirements of different resonant hole shapes. The adapter groove 562 cooperates with the protrusion 534 to achieve circumferential positioning, prevent the mandrel 56 from rotating during the stamping process, and ensure the accuracy and consistency of the resonant hole shape.

[0044] In one possible embodiment, the piston assembly 57 includes a cylindrical piston rod 571, one end of which is fixedly connected to a piston plate 572 with a vertical projection that is rectangular. The angle between the piston rod 571 and the piston plate 572 is 90°. The piston rod 571 and the piston plate 572 are vertically fixed, which can effectively convert vertical movement into sliding of the piston plate 572 within the fixed housing 521. This results in high transmission efficiency. The rectangular piston plate 572, together with the sealing ring, can form a good sealing effect, ensuring the sensitivity and reliability of the pneumatic drive.

[0045] In one possible embodiment, the piston plate 572 is installed inside the fixed shell 521 via a sealing ring. The end of the piston plate 572 away from the piston rod 571 is fixedly connected to the other end of the spring 523. The piston rod 571 passes through the bottom of the vertical plate 511, and the end of the piston rod 571 away from the piston plate 572 is fixedly connected to the mandrel fixing plate 53. The sealing ring ensures the airtightness between the piston plate 572 and the fixed shell 521, making the pneumatic transmission stable and reliable. The piston rod 571 passes through the bottom of the vertical plate 511 and is fixedly connected to the mandrel fixing plate 53, realizing the synchronous linkage between the up and down movement of the mandrel fixing plate 53 and the movement of the piston plate 572. The spring 523 ensures that the piston plate 572 can automatically return to its original position after molding, driving the airflow to clean the guide hole 535 and the mandrel 56.

[0046] In one possible embodiment, the mandrel 56 is disposed inside the sealing shell 54. The mandrel 56 is connected to the plate 531 at a 90° angle through the mandrel through hole 533. The protrusion 534 fixed inside the mandrel through hole 533 is adapted to the adapter groove 562 opened on the side of the mandrel body 561 inside the mandrel 56. The mandrel 56 is perpendicularly connected to the plate 531 at a 90° angle, ensuring that the stamping direction is consistent with the axis of the resonant hole. The adaptation structure of the protrusion 534 and the adapter groove 562 realizes the anti-rotation positioning of the mandrel 56, so that the mandrel 56 always maintains a fixed posture during multiple stamping processes, which greatly improves the repeatability accuracy of resonant hole forming and the service life of the mold.

[0047] like Figures 1-10 As shown in the figure, the principle of the method for using the forming fixture of a low-loss dielectric waveguide filter provided in this embodiment is as follows:

[0048] Includes the following steps:

[0049] Step 1: Place the materials required for producing ceramic dielectric waveguide filters into the mold cavity 2 as shown below. After placement, control the stamping machine to move the stamping machine connector 4 and the upper mold head 5 downward to perform the stamping process.

[0050] Step 2: During the downward movement of the upper mold pressure head 5, the core rod 56 exposed on the outer side of the lower end of the core rod fixing plate 53 first enters the lower mold cavity 2 for stamping and forming the resonant hole of the ceramic dielectric waveguide filter. At the same time, the bottom end of the core rod fixing plate 53 contacts the material at the upper end of the lower mold cavity 2 for forming the upper end of the ceramic dielectric waveguide filter.

[0051] Step 3: As the core rod 56 continues to move downward, the distance between its bottom and the bottom of the core rod fixing plate 53 increases continuously. During the formation of the resonant hole, the internal gas is discharged through the guide hole 535 to reduce the internal gas.

[0052] During this process, the piston rod 571, under the push of the core rod fixing plate 53, controls the piston plate 572 to move upward, and continuously discharges the gas inside the space formed by the upper end of the core plate fixing plate 53 and the sealing shell 54 through the air hole 516, while assisting in the discharge of the gas inside the ceramic dielectric waveguide filter during the molding process.

[0053] Step 4: Continue pressing down to complete the forming of the ceramic dielectric waveguide filter. After the ceramic dielectric waveguide filter is formed, the press drives the upper mold head 5 to move upward through the press connector 4 and separates from the lower mold cavity 2. At this time, the piston plate 572 is reset under the action of the spring 523 and squeezes the gas through the air hole 516 into the sealing shell 54 for cleaning the inside of the guide hole 535 and the outer surface of the auxiliary core rod 56.

[0054] Step 5: After the upper mold pressure head 5 is fully reset, the mechanism inside the lower mold cavity 2 pushes the extruded ceramic dielectric waveguide filter to the upper end of the mold base 1, and the pusher plate 3 pushes the stamped ceramic dielectric waveguide filter away from the upper end of the lower mold cavity 2 to complete the production.

[0055] Steps 1 to 5 form a complete automated stamping process. In step 2, the mandrel 56 contacts the material before the mandrel fixing plate 53, achieving priority pre-forming of the resonant hole and avoiding interference from lateral material flow. In step 3, the guide hole 535 and the piston assembly 57 work together to exhaust air, significantly reducing the porosity inside the product. In step 4, the spring 523 drives the piston plate 572 to reset and generate reverse airflow, achieving online cleaning of the guide hole 535 and the surface of the mandrel 56, preventing powder accumulation from affecting subsequent forming accuracy. In step 5, the pusher plate 3 automatically pushes the product away, requiring no manual intervention throughout the process, effectively ensuring product quality consistency and production efficiency.

[0056] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0057] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A forming fixture for a low-loss dielectric waveguide filter, comprising a mold base (1), a lower mold cavity (2) formed in the middle of the mold base (1), and a stamping machine connector (4) for connecting with a stamping machine, characterized in that: The mold base (1) has a lower mold cavity (2) in the middle. A pusher plate (3) is installed on one side of the upper end of the lower mold cavity (2). An upper mold head (5) is provided at the upper end of the lower mold cavity (2). A stamping machine connector (4) for connecting with the stamping head of the stamping machine is fixedly connected to the upper end of the upper mold head (5). The upper mold press head (5) includes a press head body (51), a communicating vessel (52) is installed in the middle of the press head body (51), a piston assembly (57) is installed inside the communicating vessel (52), a core rod fixing plate (53) is connected to the lower end of the press head body (51) through a sealing shell (54) and a guide rod (55), and multiple core rods (56) for stamping resonant holes are fixedly connected in the middle of the lower end of the press head body (51). The core rod fixing plate (53) includes a plate body (531). The plate body (531) has multiple core rod through holes (533) for limiting the core rod (56). A protrusion (534) is fixedly connected to the inner wall of the core rod through hole (533). A guide hole (535) is provided inside the protrusion (534). The upper ends of the four corners of the plate body (531) are provided with mounting grooves (532) for connecting with the guide rod (55).

2. The forming fixture for a low-loss dielectric waveguide filter according to claim 1, characterized in that: An electric push rod is installed at one end of the push plate (3) away from the lower mold cavity (2), and the fixed end of the electric push rod is connected to the mold base (1) by bolts through the mounting seat.

3. The forming fixture for a low-loss dielectric waveguide filter according to claim 1, characterized in that: The pressure head body (51) includes a vertical plate (511), a hollow cavity (512) for installing a communicating vessel (52) is provided in the middle of the vertical plate (511), a non-closed limiting cavity (513) for limiting the sealing shell (54) and a non-closed sliding hole (514) for limiting the guide rod (55) are provided at the lower end of the vertical plate (511), and a positioning hole (515) and an air hole (516) for limiting the piston assembly (57) are provided at the bottom end of the hollow cavity (512).

4. The forming fixture for a low-loss dielectric waveguide filter according to claim 3, characterized in that: The upper end of the vertical plate (511) is connected to the stamping machine connector (4). The micro-holes of the non-closed limiting cavity (513) and the non-closed sliding hole (514) that are connected to the outside are all opened at the top position. There are two air holes (516). The air holes (516) are set on both sides of the positioning hole (515), and the positions of the positioning hole (515) and the air holes (516) are offset from the mandrel (56).

5. The forming fixture for a low-loss dielectric waveguide filter according to claim 1, characterized in that: The communicating vessel (52) includes a fixed shell (521), the lower end of the fixed shell (521) is open, the upper end of the fixed shell (521) has a circular hole (522) in the middle, a spring (523) is installed on the upper end of the fixed shell (521), and the lower end of the fixed shell (521) is fixedly connected to the inner wall of the hollow cavity (512).

6. The forming fixture for a low-loss dielectric waveguide filter according to claim 1, characterized in that: The core rod (56) includes a core rod body (561), which has two structural configurations: a circle in vertical projection and a cross in vertical projection. The core rod body (561) has an adapter groove (562) on each side.

7. The forming fixture for a low-loss dielectric waveguide filter according to claim 1, characterized in that: The piston assembly (57) includes a cylindrical piston rod (571), one end of which is fixedly connected to a piston plate (572) with a vertical projection of a rectangle, and the included angle between the piston rod (571) and the piston plate (572) is 90°.

8. The forming fixture for a low-loss dielectric waveguide filter according to claim 7, characterized in that: The piston plate (572) is installed inside the fixed shell (521) through a sealing ring on the outside. The end of the piston plate (572) away from the piston rod (571) is fixedly connected to the other end of the spring (523). The piston rod (571) passes through the bottom of the vertical plate (511). The end of the piston rod (571) away from the piston plate (572) is fixedly connected to the mandrel fixing plate (53).

9. The forming fixture for a low-loss dielectric waveguide filter according to claim 1, characterized in that: The core rod (56) is disposed inside the sealing shell (54). The core rod (56) is connected to the plate (531) at a 90° angle through the core rod through hole (533). The protrusion (534) fixed inside the core rod through hole (533) is adapted to the adapter groove (562) opened on the side of the core rod body (561) disposed inside the core rod (56).

10. A molding fixture and method for using a low-loss dielectric waveguide filter, characterized in that: Includes the following steps: Step 1: Place the materials required for producing ceramic dielectric waveguide filters into the mold cavity (2) as shown below. After placement, control the stamping machine to drive the stamping machine connector (4) and the upper mold head (5) to move down and perform the stamping process. Step 2: During the downward movement of the upper mold pressure head (5), the mandrel (56) exposed on the outer side of the lower end of the mandrel fixing plate (53) first enters the lower mold cavity (2) for stamping the resonant hole of the ceramic dielectric waveguide filter. At the same time, the bottom end of the mandrel fixing plate (53) contacts the material at the upper end of the lower mold cavity (2) for forming the upper end of the ceramic dielectric waveguide filter. Step 3: As the core rod (56) continues to move downward, the distance between the bottom of the core rod and the bottom of the core rod fixing plate (53) increases continuously. During the formation of the resonant hole, the internal gas is discharged through the guide hole (535) to reduce the internal gas. During this process, the piston rod (571) is pushed by the core rod fixing plate (53) to control the piston plate (572) to move upward, and through the air hole (516) to continuously discharge the gas inside the space formed by the upper end of the core plate fixing plate (53) and the sealing shell (54), while assisting the discharge of the gas inside the ceramic dielectric waveguide filter during the molding process. Step 4: Continue pressing down to complete the forming of the ceramic dielectric waveguide filter. After the ceramic dielectric waveguide filter is formed, the press drives the upper mold head (5) to move upward through the press connector (4) and separates from the lower mold cavity (2). At this time, the piston plate (572) is reset under the action of the spring (523) and squeezes the gas through the air hole (516) into the sealed shell (54) for cleaning the inside of the guide hole (535) and the outer surface of the auxiliary core rod (56). Step 5: After the upper mold pressure head (5) is fully reset, the mechanism inside the lower mold cavity (2) pushes the extruded ceramic dielectric waveguide filter to the upper end of the mold base (1), and the pusher plate (3) pushes the stamped ceramic dielectric waveguide filter away from the upper end of the lower mold cavity (2) to complete the production.

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