A new type of oil cylinder for a mixing fork of a mixer, a sealing device and a sealing ring wear monitoring method

Abstract

This invention discloses a novel shift fork cylinder for an internal mixer, a sealing device, and a method for monitoring the wear of the sealing ring. The novel shift fork cylinder includes a cylinder barrel and a piston rod. The piston rod has an axially extending receiving space, with one end open and the other closed. The open end of the receiving space is located at the end of the piston part away from the rod part, and a magnetic ring is installed at the open end of the receiving space. A displacement sensor is installed at the tail of the cylinder barrel, and its detection rod passes through the magnetic ring and inserts into the receiving space. This invention incorporates a displacement sensor, and the wear of the sealing ring alloy layer can be fed back in real time through the measurement results of the displacement sensor. Equipment managers can monitor the usage status of the internal mixer's sealing ring at any time and formulate reasonable downtime plans based on the production workload, making maintenance time easier to control and preventing unexpected downtime and material leakage caused by untimely replacement of the internal mixer's sealing ring.

Description

Technical Field

[0001] This invention relates to the field of sealing technology for internal mixers, specifically to a novel hydraulic cylinder fork for internal mixers, a sealing device, and a method for monitoring the wear of sealing rings. Background Technology

[0002] Internal mixers are highly efficient equipment for rubber compounding. Through shearing and extrusion in a relatively enclosed environment, they thoroughly mix raw rubber with various additives, carbon black, or fillers, rapidly increasing the temperature of the rubber compound and promoting the uniform dispersion of compounding agents. This significantly improves production efficiency and product quality, making internal mixers indispensable in rubber product manufacturing. Rotor end-face sealing devices are installed on the rotor journal and the side wall of the mixing chamber to prevent material leakage from the side wall during operation, especially preventing the loss of compounding additives and ensuring the quality of the compounded rubber.

[0003] Hydraulic fork-type sealing devices, as a common external pressure end-face contact sealing structure, not only offer excellent sealing performance and overcome rotor axial movement problems, but also allow for adjustment of the sealing surface specific pressure by changing the oil pressure to achieve the optimal sealing state with the lowest oil pressure and no material leakage at the sealing surface. The end-face sealing ring typically consists of a moving ring and a fixed ring, both with hard alloy overlays on their contact surfaces. However, the surface alloy hardness of the fixed ring is lower than that of the moving ring. This is to make the moving ring, which is less convenient to replace, more wear-resistant and have a longer service life. The moving and fixed rings are consumable spare parts, especially the fixed ring with its slightly lower surface alloy hardness, and require periodic downtime for replacement.

[0004] Factors affecting the service life of sealing rings are complex, such as whether the oil injection line leading to the contact surface of the alloy layer is unobstructed, the amount of lubricating oil on the contact surface, and whether impurities have entered the contact surface. All of these factors will affect the wear rate of the alloy layer of the sealing ring. Traditional hydraulic fork-type sealing devices lack detection methods and cannot predict the wear condition of the alloy on the contact surface of the sealing ring. Consequently, they cannot formulate a reasonable shutdown plan to replace the sealing ring based on the production situation. Especially when production orders are busy, once the rotor end face seal fails, temporary shutdown to replace the sealing ring will cause significant economic losses to the company. If production continues without stopping, material leakage will not only affect the quality of the final compound due to the influence of the proportion of each component, but will also pollute the production environment of the workshop. Summary of the Invention

[0005] The purpose of this invention is to provide a novel hydraulic fork cylinder, sealing device, and method for monitoring the wear of sealing rings in an internal mixer, aiming to improve the problem that existing hydraulic fork sealing devices cannot monitor the wear status of sealing rings in real time, which can easily lead to unexpected shutdowns or material leaks.

[0006] This invention is implemented as follows: According to a first aspect of the present invention, the present invention provides a novel hydraulic cylinder for a mixing mill, comprising a cylinder barrel and a piston rod, the piston rod comprising a piston portion and a rod portion, the piston rod having an axially extending receiving space, the receiving space being open at one end and closed at the other end, the open end of the receiving space being located at the end of the piston portion away from the rod portion, and a magnetic ring being provided at the open end of the receiving space; a displacement sensor is installed at the tail of the cylinder barrel, and the detection rod of the displacement sensor passes through the magnetic ring and is inserted into the receiving space.

[0007] Furthermore, the open end of the accommodating space is provided with a countersunk hole for installing a magnetic ring, and the magnetic ring is fixedly installed in the countersunk hole.

[0008] Furthermore, a rear end cap is threadedly installed at the tail end of the cylinder barrel, and a threaded hole is provided in the middle of the rear end cap, into which the displacement sensor is threadedly installed.

[0009] Furthermore, an end cap sealing ring is provided at the joint between the rear end cover of the hydraulic cylinder and the cylinder barrel, and a sensor sealing ring is provided between the displacement sensor and the rear end cover of the hydraulic cylinder.

[0010] Furthermore, the front end of the cylinder barrel is provided with an adapter through hole for the piston rod of the cylinder to pass through. The diameter of the adapter through hole is adapted to the outer diameter of the piston rod of the cylinder. The wall of the adapter through hole is provided with at least two annular sealing grooves, which are respectively installed with dustproof rings and piston rod sealing rings to achieve sealing protection. The outer circumferential surface of the piston part of the cylinder piston rod is also provided with an annular sealing groove, and a piston sealing ring is provided in the annular sealing groove.

[0011] Furthermore, the cylinder wall of the hydraulic cylinder is provided with two exhaust ports that communicate with the rod chamber and the rodless chamber, respectively, and each exhaust port is screwed with a plug; the cylinder wall of the hydraulic cylinder is also provided with a hydraulic oil port that communicates with the rodless chamber.

[0012] According to a second aspect of the present invention, the present invention provides a novel sealing device for a rotary mixer's shift fork cylinder, comprising the aforementioned novel rotary mixer shift fork cylinder, and further comprising a shift fork, an end support, a spring, a spring top pin, a shift fork top pin, a fixed ring fixing sleeve, a fixed ring, and a moving ring; the fixed ring is mounted on the fixed ring fixing sleeve, and the moving ring is mounted on the rotor; the shift fork is hinged to the end support, and the hinge point forms a swing fulcrum; the novel rotary mixer shift fork cylinder is mounted at the tail end of the shift fork, and its cylinder piston rod pushes the spring top pin, the spring top pin pressing against the spring disposed in the end support; the shift fork top pin is mounted at the front end of the shift fork, and under the preload of the spring and the thrust of the cylinder, it presses against the fixed ring fixing sleeve, thereby driving the alloy layer of the fixed ring to fit tightly with the alloy layer of the moving ring, forming an end face sealing fit.

[0013] Furthermore, two shift fork pins are symmetrically installed at the front end of the shift fork, and the two shift fork pins are evenly distributed along the circumference of the fixed ring sleeve so that the fixed ring is subjected to balanced force.

[0014] According to a third aspect of the present invention, the present invention provides a method for monitoring the wear of a sealing ring in an internal mixer, using the above-mentioned novel sealing device for the hydraulic cylinder of a shift fork in an internal mixer, comprising the following steps: The displacement of the cylinder piston rod detected by the displacement sensor is acquired in real time. Based on the protrusion displacement and the lever arm ratio from the front and rear ends of the shift fork to the swing fulcrum, the wear amount of the sealing ring alloy layer is calculated. When the extension displacement reaches a threshold preset based on the lever arm ratio and the maximum allowable wear of the sealing ring alloy layer, it is determined that the sealing ring has reached its service life, and a shutdown and replacement prompt signal is issued.

[0015] Furthermore, before acquiring the extension displacement of the hydraulic cylinder piston rod in real time, an initialization step is also included: It was confirmed that all components of the sealing device of the new type of shift fork cylinder of the internal mixer were assembled in place and that the alloy layers of the fixed ring and the moving ring were tightly bonded. The displacement sensor was calibrated and zeroed. The preset threshold setting has reserved the normal wear margin of the moving ring. The judgment is only made on the effective wear state of the fixed ring.

[0016] Compared with existing technologies, the advantages of this invention are: This invention incorporates a displacement sensor, allowing real-time feedback of the wear amount of the stationary ring alloy layer through the sensor's measurement results. Equipment managers can monitor the usage status of the internal mixer's sealing rings at any time and formulate reasonable downtime plans based on production workload. This makes maintenance time easier to control, preventing unexpected downtime and material leakage caused by untimely replacement of the internal mixer's sealing rings. This effectively ensures the continuous and normal operation of the internal mixer, guaranteeing both the accuracy of the compound formulation and product quality, while maintaining a clean production environment. It significantly reduces equipment maintenance costs and production losses, helping enterprises improve economic efficiency and production management efficiency. Attached Figure Description

[0017] Figure 1 A schematic diagram of the structure of the novel shift fork cylinder for a mixer provided by the present invention; Figure 2 This is a front view of the novel oil cylinder sealing device for the internal mixer provided by the present invention; Figure 3 This is a cross-sectional view of the novel oil cylinder sealing device for the internal mixer provided by the present invention; Figure 4 for Figure 3 A partial enlarged view of the contact surface of the sealing ring in the structure shown, and Figure 3Enlarged view of region I in the middle; Figure 5 This invention provides a simplified model of the lever principle for the sealing device of the novel shift fork cylinder of an internal mixer.

[0018] The components include: 1. Cylinder barrel; 2. Cylinder piston rod; 3. Magnetic ring; 4. Cylinder rear end cover; 5. Displacement sensor; 6. Dustproof ring; 7. Piston rod sealing ring; 8. Piston sealing ring; 9. Screw; 10. Plug; 11. Rear end cover sealing ring; 12. Sensor sealing ring; 13. New type of shift fork cylinder for internal mixer; 14. Shift fork; 15. Shift fork bolt; 16. Rotor; 17. Shift fork top pin; 18. Fixed ring fixing sleeve; 19. Moving ring; 20. Fixed ring; 21. End bracket; 22. Spring; 23. Spring top pin. Detailed Implementation

[0019] Example 1 like Figure 1 As shown, this embodiment provides a novel hydraulic cylinder for a mixing mill, including a cylinder barrel 1, a piston rod 2, a magnetic ring 3, a rear end cover 4, and a displacement sensor. The piston rod 2 includes a piston section and a rod section. An axially oriented receiving space is provided on the piston rod 2. This receiving space is elongated and narrow, open at one end and closed at the other. The open end is located at the end of the piston section away from the rod section, and a countersunk hole is machined at the open end. The magnetic ring 3 is fixedly installed in this countersunk hole by screws 9, ensuring that the magnetic ring 3 moves synchronously with the piston rod 2. The magnetic ring 3 acts as a displacement sensing trigger, working in conjunction with the displacement sensor 5 to accurately acquire displacement signals. When the piston rod 2 drives the magnetic ring 3 to extend or retract axially, the displacement sensor 5 senses the position change of the magnetic ring 3 and converts the mechanical displacement into an electrical signal output, providing basic data for subsequent monitoring of the wear of the mixing mill's sealing rings.

[0020] The cylinder barrel 1 is fitted with a cylinder rear end cover 4 via a threaded structure. A fine-pitch mounting thread hole is provided through the middle of the cylinder rear end cover 4. The displacement sensor 5 is threaded into the mounting thread hole. Its detection rod passes through the magnetic ring 3 and is inserted into the receiving space of the cylinder piston rod 2, so as to realize the accurate detection of the extension and retraction displacement of the cylinder piston rod 2.

[0021] To ensure sealing performance, an annular sealing groove is provided at the joint between the rear end cover 4 of the hydraulic cylinder and the cylinder barrel 1. An end cover sealing ring 11 is installed in the annular sealing groove to prevent hydraulic oil from leaking out of the rodless chamber. A sensor sealing ring 12 is provided between the displacement sensor 5 and the root of the mounting thread hole of the rear end cover 4 of the hydraulic cylinder to further enhance the sealing effect and prevent hydraulic oil leakage from affecting normal operation.

[0022] The front end of the cylinder barrel 1 has a fitting through hole for the piston rod 2 to pass through. The diameter of the through hole precisely matches the outer diameter of the rod. Two annular sealing grooves are machined on the wall of the through hole, where a dustproof ring 6 and a piston rod sealing ring 7 are respectively installed. The dustproof ring 6 prevents external dust and impurities from entering the cylinder barrel 1, while the piston rod sealing ring 7 prevents hydraulic oil leakage from the gap between the rod and the through hole. An annular sealing groove is also provided on the outer circumferential surface of the piston part of the piston rod 2, and a piston sealing ring 8 is installed in this groove to achieve a seal between the piston part and the inner wall of the cylinder barrel 1, preventing hydraulic oil from flowing between the rodless chamber and the rod chamber.

[0023] The cylinder barrel 1 has two vent ports on its wall, one communicating with the rod chamber and the other with the rodless chamber. These are used to purge air from the two chambers during equipment debugging. In operation, the vent ports are sealed with screw plugs 10. The cylinder barrel 1 also has a hydraulic oil port communicating with the rodless chamber. Hydraulic oil only needs to be connected to the rodless chamber to drive the cylinder piston rod 2, simplifying the hydraulic system connection.

[0024] Example 2 like Figure 2-4 As shown, this embodiment provides a novel sealing device for a hydraulic fork cylinder of an internal mixer, including the novel hydraulic fork cylinder 13 of the internal mixer provided in Embodiment 1, and also including a fork 14, an end bracket 21, a spring 22, a spring top pin 23, a fork top pin 17, a fixed ring fixing sleeve 18, a fixed ring 20, and a moving ring 19. The assembly relationship of each component is as follows: The fixed ring 20 is fixedly installed on the fixed ring fixing sleeve 18. The fixed ring fixing sleeve 18 can rely on the main body of the internal mixer or the end bracket 21 to form axial limiting and sliding guidance, ensuring that the fixed ring 20 can only move smoothly in the direction of contacting the moving ring 19, avoiding radial offset from affecting the sealing surface contact accuracy. The moving ring 19 is installed on the internal mixer rotor 16. The contact surfaces of the fixed ring 20 and the moving ring 19 are both overlaid with hard alloy. Since the moving ring 19 is inconvenient to replace, the hardness of the alloy layer of the moving ring 19 is higher than that of the alloy layer of the fixed ring 20, so as to extend the service life of the moving ring 19.

[0025] The end support 21 is connected to the main body of the internal mixer. The shift fork 14 is hinged to the end support 21 by the shift fork bolt 15, and the hinge point forms a stable swing fulcrum. The new type of shift fork cylinder 13 of the internal mixer is installed at the tail end of the shift fork 14. The end of its cylinder piston rod 2 pushes the spring pin 23. The spring pin 23 extends into the preset hole of the end support 21 and presses the spring 22 installed in the preset hole. The spring 22 provides the initial preload force to ensure that the alloy surfaces of the fixed ring 20 and the moving ring 19 can still fit tightly when the hydraulic system is not started.

[0026] Two shift fork pins 17 are symmetrically installed on the front end of the shift fork 14, and the two shift fork pins 17 are evenly distributed along the circumference of the fixed ring sleeve 18. Under the combined action of the preload of the spring 22 and the thrust of the new shift fork cylinder 13, the shift fork pins 17 press against the fixed ring sleeve 18, thereby driving the alloy layer of the fixed ring 20 to fit tightly with the alloy layer of the moving ring 19, forming a reliable end face sealing fit, effectively preventing material leakage from the mixing chamber.

[0027] Example 3 This embodiment provides a method for monitoring the wear of sealing rings in an internal mixer. Using the novel hydraulic cylinder sealing device for the internal mixer provided in Embodiment 2, real-time monitoring of the wear of the alloy layer of the fixed ring 20 is achieved based on the lever principle. The specific steps are as follows: Confirm that all components of the new type of hydraulic cylinder sealing device for the internal mixer are properly assembled, and that the alloy layers of the fixed ring 20 and the moving ring 19 are tightly bonded. Calibrate and zero the displacement sensor 5 to eliminate detection deviations caused by installation errors. Based on the maximum allowable wear of the alloy layer of the fixed ring 20, the normal wear allowance of the moving ring 19, and the lever arm ratio of the shift fork 14, a preset trigger threshold is established. This threshold is only used to determine the effective wear state of the fixed ring 20 to avoid false alarms.

[0028] Based on the lever principle, such as Figure 2 , Figure 4 and Figure 5 As shown, the position of the shift fork bolt 15 is simplified to the swing fulcrum D, the two shift fork top pins 17 at the front end of the shift fork 14 are simplified to lever point C, and the position of the new type of shift fork cylinder 13 at the tail end of the shift fork 14 is simplified to lever point E. During the operation of the internal mixer, the moving ring 19 rotates synchronously with the rotor 16, and the alloy layer gradually wears down. The hardness of the alloy layer of the moving ring 19 is higher than that of the alloy layer of the fixed ring 20. According to the lever principle, the alloy layer of the fixed ring 20 at lever C gradually wears down, generating a displacement S1 along the direction P. The piston rod 2 of the cylinder at lever E will then extend accordingly. The displacement sensor 5 collects and feeds back this extension displacement S2 in real time.

[0029] Based on the relationship between the lever arms L2 and L1 at the distances from lever C and lever E to the lever swing fulcrum D, once the displacement sensor 5 detects that the extension displacement S2 of the cylinder piston rod 2 has reached the preset trigger threshold, it indicates that the alloy layer of the retaining ring 20 has been severely worn and the retaining ring 20 has reached its predetermined service life. A shutdown plan can be formulated according to the production schedule to replace the retaining ring 20.

[0030] In summary, this invention incorporates a displacement sensor 5, allowing real-time monitoring of the extension displacement of the hydraulic cylinder piston rod 2. Combined with the lever transmission principle of the shift fork 14, wear on the alloy layer of the fixed ring 20 will cause the hydraulic cylinder piston rod 2 to extend accordingly via the lever arm of the shift fork 14. The wear amount and the extension displacement have a fixed linear relationship, thus enabling real-time feedback of the wear amount of the alloy layer of the fixed ring 20 through the measurement results of the displacement sensor 5. Equipment managers can monitor the usage status of the internal mixer's sealing rings at any time and formulate reasonable downtime plans based on the production workload. This makes maintenance time easier to control, preventing unexpected downtime and material leakage caused by untimely replacement of the internal mixer's sealing rings. This effectively ensures the continuous and normal operation of the internal mixer, guaranteeing the accuracy of the compound ratio and product quality, maintaining a clean production environment, significantly reducing equipment maintenance costs and production losses, and helping enterprises improve economic efficiency and production management efficiency.

[0031] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A novel hydraulic cylinder for a mixing mill, comprising a cylinder barrel (1) and a piston rod (2), wherein the piston rod (2) comprises a piston portion and a rod portion, characterized in that, The piston rod (2) of the hydraulic cylinder is provided with an axially extending receiving space. One end of the receiving space is open and the other end is closed. The open end of the receiving space is located at the end of the piston part away from the rod part. A magnetic ring (3) is provided at the open end of the receiving space. A displacement sensor (5) is installed at the tail of the cylinder barrel (1). The detection rod of the displacement sensor (5) passes through the magnetic ring (3) and is inserted into the receiving space.

2. The novel shift fork hydraulic cylinder for a mixer according to claim 1, characterized in that, The opening end of the accommodating space is provided with a countersunk hole for installing a magnetic ring (3), and the magnetic ring (3) is fixedly installed in the countersunk hole.

3. The novel shift fork cylinder for a mixer according to claim 1, characterized in that, The cylinder barrel (1) is threaded with a cylinder rear end cover (4), and the cylinder rear end cover (4) is provided with a mounting threaded hole in the middle, and the displacement sensor (5) is threadedly installed in the mounting threaded hole.

4. The novel shift fork cylinder for a mixer according to claim 3, characterized in that, An end cap sealing ring (11) is provided at the joint between the rear end cover (4) of the oil cylinder and the cylinder barrel (1), and a sensor sealing ring (12) is provided between the displacement sensor (5) and the rear end cover (4) of the oil cylinder.

5. The novel shift fork cylinder for a mixer according to claim 1, characterized in that, The cylinder barrel (1) is provided with an adapter through hole at the front end for the rod of the cylinder piston rod (2) to pass through. The diameter of the adapter through hole is adapted to the outer diameter of the rod of the cylinder piston rod (2). At least two annular sealing grooves are provided on the wall of the adapter through hole, and dustproof rings (6) and piston rod sealing rings (7) are installed respectively to achieve sealing protection. An annular sealing groove is also provided on the outer circumferential surface of the piston part of the cylinder piston rod (2), and a piston sealing ring (8) is provided in the annular sealing groove.

6. The novel shift fork cylinder for a mixer according to claim 1, characterized in that, The cylinder wall of the cylinder (1) is provided with two exhaust ports that communicate with the rod chamber and the rodless chamber respectively, and each exhaust port is screwed with a plug (10); the cylinder wall of the cylinder (1) is also provided with a hydraulic oil port that communicates with the rodless chamber.

7. A novel sealing device for a shift fork cylinder of an internal mixer, comprising the novel shift fork cylinder of an internal mixer as described in any one of claims 1-6, characterized in that, It also includes a shift fork (14), an end bracket (21), a spring (22), a spring top pin (23), a shift fork top pin (17), a fixed ring fixing sleeve (18), a fixed ring (20), and a moving ring (19); the fixed ring (20) is mounted on the fixed ring fixing sleeve (18), and the moving ring (19) is mounted on the rotor (16); the shift fork (14) is hinged to the end bracket (21), and the hinge point forms a swing fulcrum; the new type of shift fork hydraulic cylinder of the internal mixer is installed on the shift fork. At the tail end of (14), the piston rod (2) of the oil cylinder pushes the spring pin (23), and the spring pin (23) presses against the spring (22) set in the end bracket (21); the shift fork pin (17) is installed at the front end of the shift fork (14), and presses against the fixed ring fixing sleeve (18) under the preload of the spring (22) and the thrust of the oil cylinder, thereby driving the alloy layer of the fixed ring (20) to fit tightly with the alloy layer of the moving ring (19) to form an end face sealing fit.

8. The novel sealing device for the hydraulic cylinder of the internal mixer according to claim 7, characterized in that, Two fork pins (17) are symmetrically installed at the front end of the fork (14). The two fork pins (17) are evenly distributed along the circumference of the fixed ring sleeve (18) so that the fixed ring (20) is balanced by force.

9. A method for monitoring the wear of a sealing ring in an internal mixer, using the novel hydraulic cylinder sealing device for a shift fork in an internal mixer as described in claim 7 or 8, characterized in that... Includes the following steps: The displacement of the cylinder piston rod (2) detected by the displacement sensor (5) is acquired in real time. Based on the protrusion displacement and the lever arm ratio from the front and rear ends of the shift fork (14) to the swing fulcrum, the wear amount of the sealing ring alloy layer is calculated. When the extension displacement reaches a threshold preset based on the lever arm ratio and the maximum allowable wear of the sealing ring alloy layer, it is determined that the fixing ring (20) has reached its service life and a shutdown and replacement prompt signal is issued.

10. The method for monitoring the wear of the internal mixer seal ring according to claim 9, characterized in that, Before acquiring the extension displacement of the cylinder piston rod (2) in real time, an initialization step is also included: Confirm that all components of the new type of internal mixer fork cylinder sealing device are assembled in place and that the alloy layers of the fixed ring (20) and the moving ring (19) are tightly bonded. The displacement sensor (5) is calibrated and zeroed. The preset threshold setting has reserved the normal wear margin of the moving ring (19). Only the effective wear state of the fixed ring (20) is judged.

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