Carboxyl butyronitrile latex reaction kettle with stirring function
By adopting the integrated design of mechanical detection and stirring in the carboxyl nitrile latex reactor, the shortcomings of traditional reactors in detection, cleaning and maintenance are solved, and higher detection accuracy and maintenance convenience are achieved.
Patent Information
- Application Number
- CN202411894988.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-21
- Publication Date
- 2025-01-21
AI Technical Summary
The existing carboxyl nitrile latex reactors have shortcomings in detecting reaction completion and cleaning and maintenance. Electronic sensors are susceptible to environmental impact and cause failure and are difficult to clean.
Design a carboxyl nitrile latex reactor with stirring function. It adopts mechanical detection method to judge the completion of stirring through the asynchronous rotation of the stirring outer rod and the stirring inner rod, and uses the surface tension of the emulsion to drive the display unit. , visually display the mixing completion status.
It improves the accuracy and reliability of detection, simplifies the equipment structure, reduces maintenance costs, and makes cleaning and maintenance more convenient.
Smart Images
Figure CN119327402A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of reactors, in particular to a carboxyl nitrile latex reactor with a stirring function. Background Art
[0002] In the chemical industry, the production process of carboxy nitrile latex is of vital importance. The performance of the reactor, as the core equipment, directly affects the quality and production efficiency of the product. The traditional carboxy nitrile latex reactor has a certain technical accumulation in stirring and cleaning, but the detection of the completion status of the reaction still mainly relies on electronic detection methods such as electronic sensors.
[0003] However, these electronic detection equipment have exposed many shortcomings in practical applications. On the one hand, due to the complex working environment, electronic detection equipment is easily affected by harsh conditions such as emulsions, high temperature, and high pressure during long-term use, which may lead to equipment failure and affect the accuracy and reliability of detection. On the other hand, electronic detection equipment also has great difficulties in cleaning and maintenance. Since there are often sticky substances such as latex remaining inside the reactor, these substances are easy to adhere to the surface and inside of the electronic detection equipment, resulting in equipment performance degradation or even damage. Cleaning these electronic detection equipment often takes a lot of time and effort, and the cleaning process may also cause secondary damage to the equipment. For this reason, we propose a carboxy nitrile latex reactor with a stirring function. Summary of the invention
[0004] A technical problem to be solved by the present application is: how to design a carboxyl nitrile latex reactor with stirring function which can accurately judge the completion of the reaction and is easy to clean and maintain.
[0005] In order to solve the above technical problems, the embodiment of the present application provides a carboxyl nitrile latex reactor with a stirring function, comprising a body and a plurality of cleaning rods movably arranged in the body, and also comprising: A stirring outer rod, the stirring outer rod is rotatably arranged in the middle of the body, a plurality of cleaning rods are evenly arranged around the stirring outer rod, and the middle of the stirring outer rod is a hollow structure; An inner stirring rod, the inner stirring rod being rotatably arranged in the middle of the outer stirring rod through a sealed bearing; A switching assembly, which is arranged on the body and connected to the stirring outer rod and the stirring inner rod, and is used to control the rotation state of the stirring outer rod and the stirring inner rod; The detection unit is arranged on the main body and connected with the switching component. When the switching component is working, the surface tension of the emulsion on the stirring inner rod is used to make the stirring outer rod and the stirring inner rod rotate asynchronously, thereby showing the staff the completion of the stirring of the solution.
[0006] In some embodiments, the switching assembly includes a driving motor arranged on the main body, a driving shaft is arranged on the main body, the driving shaft is connected to the output end of the driving motor, an output gear is arranged at one end of the stirring outer rod located on the outside of the main body, an input gear meshing with the output gear is arranged on the driving shaft, and a locking piece is arranged at one end of the stirring outer rod located on the outside of the main body, which is used to cancel the fixation of the stirring outer rod and the stirring inner rod after the solution is stirred for a period of time.
[0007] In some embodiments, the locking member includes an electromagnet arranged at one end of the stirring outer rod located outside the main body, a top block is arranged at the end of the electromagnet, a slot matching the top block is opened on the stirring inner rod, and a battery electrically connected to the electromagnet is arranged on the stirring outer rod.
[0008] In some embodiments, the detection unit includes a mounting bracket arranged on the main body, and a display is arranged on the mounting bracket for displaying the stirring completion status of the solution to the staff. An elastic connecting piece is arranged between the stirring outer rod and the stirring inner rod for ensuring that the stirring outer rod and the stirring inner rod rotate asynchronously after the top block and the slot are disengaged. A contact detection component cooperating with the display is arranged on the main body, and the display is driven to work by utilizing the surface tension of the emulsion on the stirring inner rod.
[0009] In some embodiments, the display component includes a fixed cavity arranged on the mounting bracket, a piston plate is slidably arranged in the fixed cavity, a telescopic rod is arranged in the fixed cavity, the end of the telescopic rod is connected to the piston plate, a return spring is sleeved on the outer side of the telescopic rod, a display cavity is arranged on the mounting bracket, an observation plate is slidably arranged in the display cavity, and the fixed cavity and the display cavity are connected by a hose.
[0010] In some embodiments, the elastic connecting member includes a plurality of fixing seats respectively arranged on adjacent sides of the stirring inner rod and the stirring outer rod. The fixing seats located on the stirring inner rod and the adjacent fixing seats located on the stirring outer rod are grouped together, and a connecting spring is arranged between each group of fixing seats.
[0011] In some embodiments, the contact detection assembly includes a fixed rod arranged on the inner stirring rod, and the outer stirring rod is provided with an ejector used in conjunction with the fixed rod, which is used to drive the ejector to lift the piston plate when the fixed rod is working.
[0012] In some embodiments, the ejector includes a fixed spring arranged on the inner wall of one end of the stirring outer rod located on the outside of the main body, a shift rod movably penetrates the stirring outer rod, the fixed spring is sleeved on the outside of the shift rod, and the fixed spring is fixedly connected to the shift rod, a bull's eye axis is arranged at one end of the shift rod close to the piston plate, and the end of the shift rod away from the bull's eye axis is an inclined structure.
[0013] In some embodiments, two ejection members are provided, and the inclined surfaces of the two shift rods are both provided on a side close to the fixed rod.
[0014] In some embodiments, a stop block is provided on the outer stirring rod, and a cushion block matching with the stop block is provided on the inner stirring rod. When the connecting spring drives the inner stirring rod to reset, the cushion block will hit the stop block.
[0015] The present invention has at least the following beneficial effects: 1. Innovative integrated design of stirring and detection: By cleverly combining the outer stirring rod and the inner stirring rod and setting a switching component and a detection unit between the two, the integration of stirring and detection is achieved, which not only simplifies the equipment structure but also improves production efficiency; 2. Mechanical detection improves reliability: Abandoning traditional electronic sensors, mechanical detection is adopted, using the change in the surface tension of the emulsion on the stirring rod to judge the completion of stirring, effectively avoiding the problem of electronic sensors failing due to harsh environments, and improving the accuracy and reliability of detection; 3. Easy to clean and maintain: Since key components such as the detection unit and stirring rod are mechanically constructed, they are not easily affected by viscous substances such as emulsions, so cleaning and maintenance are more convenient, reducing the maintenance cost of the equipment; 4. Intuitive display method: The display unit in the detection unit can intuitively display the stirring completion status of the solution through the cooperation of the piston plate and the observation plate, which is convenient for the staff to understand and grasp the production progress in time. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 For the present invention Figure 1 Another structural diagram; Figure 3 For the present invention Figure 1 Schematic diagram of the local cross-section structure; Figure 4 This is a schematic diagram of the structure of the switching component and the detection unit of the present invention; Figure 5 It is a schematic diagram of the partial cross-sectional structure of the fixed cavity and the display cavity of the present invention; Figure 6 For the present invention Figure 5 Schematic diagram of the enlarged structure of the middle A area; Figure 7 It is a schematic diagram of the cross-sectional structure of the display element of the present invention; Figure 8 This is a schematic diagram of the structure of the stirring outer rod of the present invention; Fig. 9 It is a schematic diagram of the structure of the electromagnet and the top block after being separated from the slot of the present invention; Fig.10 For the present invention Figure 8 Schematic diagram of the local cross-section structure; Fig.11 For the present invention Fig.10 Schematic diagram of the enlarged structure of the middle B area; Fig.12 For the present invention Fig.10 Schematic diagram of the local cross-section structure; Fig.13 This is a schematic diagram of the structure of the abutment block and the cushion block in Example 2 of the present invention; Fig.14 For the present invention Fig.13 Schematic diagram of the enlarged structure of area C in the middle.
[0017] In the figure: 1. body; 2. cleaning rod; 3. switching assembly; 31. driving motor; 32. driving shaft; 33. output gear; 34. input gear; 4. locking member; 41. electromagnet; 42. ejector block; 43. slot; 44. battery; 5. detection unit; 51. mounting bracket; 6. display member; 61. fixed cavity; 62. piston plate; 63. telescopic rod; 64. reset spring; 65. display cavity; 66. observation plate; 7. elastic connector; 71. fixing seat; 72. connecting spring; 8. contact detection assembly; 81. fixed rod; 9. ejector; 91. fixed spring; 92. shift rod; 93. bull's eye shaft; 10. stop block; 11. cushion block; 12. stirring outer rod; 13. stirring inner rod. DETAILED DESCRIPTION
[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example
[0019] See also Figure 1-Figure 12 , the present invention provides a technical solution: A carboxyl nitrile latex reactor with stirring function includes a body 1 and a plurality of cleaning rods 2 movably arranged in the body 1. The body 1 and the cleaning rods 2 are common existing structures. An emulsifier and other structures can be added to the body 1 according to needs. No further details are given here. The following are also included: A stirring outer rod 12, which is rotatably arranged in the middle of the body 1, and a plurality of cleaning rods 2 are evenly arranged around the stirring outer rod 12, and the middle of the stirring outer rod 12 is a hollow structure; The inner stirring rod 13 is rotatably arranged in the middle of the outer stirring rod 12 through a sealed bearing. The inner stirring rod 13 and the outer stirring rod 12 are rotatably connected through a sealed bearing to ensure the vacuum effect inside the reactor; A switching assembly 3, which is disposed on the body 1 and connected to the stirring outer rod 12 and the stirring inner rod 13, and is used to control the rotation state of the stirring outer rod 12 and the stirring inner rod 13; The detection unit 5 is arranged on the body 1 and connected with the switching component 3. When the switching component 3 is working, the surface tension of the emulsion on the stirring inner rod 13 is used to make the stirring outer rod 12 and the stirring inner rod 13 rotate asynchronously, thereby showing the staff the completion of the stirring of the solution. Because the emulsion after stirring has a certain viscosity, it can adhere to the stirring rod at the bottom of the stirring inner rod 13. In this way, when the stirring inner rod 13 rotates, there will be a certain resistance, making the stirring inner rod 13 and the stirring outer rod 12 asynchronous. Of course, this detection requires setting an appropriate rotation speed and being able to know the surface tension of the produced emulsion in advance. The surface tension can be determined according to the arrow corresponding to the mixed emulsion. The final judgment standard is: observe whether the arrow on the observation plate 66 in the display part 6 is stable on a certain scale, and whether the scale is consistent with the surface tension known in advance. If the arrow is not stable or the scale corresponding to the arrow is inconsistent with the surface tension known in advance, the mixing is not yet completed; if the arrow is stable and consistent with the surface tension known in advance, the mixing is completed; The switching assembly 3 includes a driving motor 31 disposed on the body 1, a driving shaft 32 is disposed on the body 1, and the driving shaft 32 is connected to the output end of the driving motor 31, an output gear 33 is disposed at one end of the stirring outer rod 12 located outside the body 1, an input gear 34 meshing with the output gear 33 is disposed on the driving shaft 32, and a locking member 4 is disposed at one end of the stirring outer rod 12 located outside the body 1, which is used to cancel the fixing of the stirring outer rod 12 and the stirring inner rod 13 after the solution is stirred for a period of time; The locking member 4 includes an electromagnet 41 arranged at one end of the stirring outer rod 12 located outside the body 1, a top block 42 is arranged at the end of the electromagnet 41, a slot 43 matching the top block 42 is provided on the stirring inner rod 13, and a battery 44 electrically connected to the electromagnet 41 is arranged on the stirring outer rod 12. The battery 44 provides energy to the electromagnet 41 to ensure the normal operation of the electromagnet 41. The power consumption is small, so the battery 44 is sufficient to meet the power demand, and the energy supply of the drive motor 31 can be directly connected to an external power supply; The detection unit 5 includes a mounting bracket 51 arranged on the body 1, and a display element 6 is arranged on the mounting bracket 51 for displaying the stirring completion status of the solution to the staff. An elastic connecting member 7 is arranged between the stirring outer rod 12 and the stirring inner rod 13 for ensuring that the stirring outer rod 12 and the stirring inner rod 13 rotate asynchronously after the top block 42 and the slot 43 are separated. A contact detection component 8 cooperating with the display element 6 is arranged on the body 1, and the surface tension of the emulsion on the stirring inner rod 13 is used to drive the display element 6 to work; The display member 6 comprises a fixed cavity 61 arranged on the mounting bracket 51, a piston plate 62 is slidably arranged in the fixed cavity 61, a telescopic rod 63 is arranged in the fixed cavity 61, the end of the telescopic rod 63 is connected to the piston plate 62, a return spring 64 is sleeved on the outer side of the telescopic rod 63, a display cavity 65 is arranged on the mounting bracket 51, an observation plate 66 is slidably arranged in the display cavity 65, the fixed cavity 61 and the display cavity 65 are connected by a hose, a bright color layer is arranged on the surface of the observation plate 66 for the convenience of observation by the staff, and a ring groove is arranged below the piston plate 62 for providing guidance for the bull's eye shaft 93; The elastic connecting member 7 includes a plurality of fixing seats 71 respectively arranged on the adjacent sides of the stirring inner rod 13 and the stirring outer rod 12. The fixing seats 71 located on the stirring inner rod 13 and the adjacent fixing seats 71 located on the stirring outer rod 12 form a group with each other, and a connecting spring 72 is arranged between each group of fixing seats 71. The contact detection assembly 8 includes a fixed rod 81 disposed on the stirring inner rod 13, and an ejector 9 used in conjunction with the fixed rod 81 is disposed on the stirring outer rod 12, and is used to drive the ejector 9 to lift the piston plate 62 when the fixed rod 81 is working; The ejector 9 includes a fixed spring 91 arranged on the inner wall of the end of the stirring outer rod 12 located on the outer side of the body 1, and a shift rod 92 is movably penetrated on the stirring outer rod 12. The fixed spring 91 is sleeved on the outer side of the shift rod 92, and the fixed spring 91 is fixedly connected to the shift rod 92. A bull's eye shaft 93 is arranged at one end of the shift rod 92 close to the piston plate 62, and the end of the shift rod 92 away from the bull's eye shaft 93 is an inclined structure; There are two ejector members 9, and the inclined surfaces of the two shift rods 92 are both arranged on the side close to the fixed rod 81, so that the detection work can be performed in both forward and reverse rotations of the driving motor 31, thereby improving the detection range and further ensuring the accuracy of the detection of the completion of emulsion mixing.
[0020] When in use, in the initial state, the stirring outer rod 12 and the stirring inner rod 13 are connected to the body 1 through the switching assembly 3 (including the driving motor 31, the driving shaft 32, the input gear 34, and the output gear 33), and the stirring inner rod 13 is fixedly connected to the stirring outer rod 12 through the locking member 4 (including the electromagnet 41, the top block 42, and the battery 44). At this time, the stirring outer rod 12 and the stirring inner rod 13 rotate synchronously; When the driving motor 31 is started, the stirring outer rod 12 starts to rotate. Due to the action of the locking member 4, the stirring inner rod 13 rotates synchronously with the stirring outer rod 12 to stir the emulsion in the reactor. At the same time, the cleaning rod 2 cleans the inner wall of the reactor driven by the stirring outer rod 12. After stirring for a period of time, the electromagnet 41 is powered off by controlling the top block 42 in the locking member 4 to disengage from the slot 43 on the stirring inner rod 13, and the fixed connection between the stirring inner rod 13 and the stirring outer rod 12 is cancelled. At this time, due to the surface tension of the emulsion on the stirring inner rod 13, the stirring inner rod 13 will encounter a certain resistance when rotating, resulting in the stirring inner rod 13 and the stirring outer rod 12 rotating asynchronously. When the stirring inner rod 13 and the stirring outer rod 12 rotate asynchronously, the fixed rod 81 on the stirring inner rod 13 will periodically contact the ejector 9 (including the fixed spring 91, the shift rod 92, and the bull's eye shaft 93) on the stirring outer rod 12. Each time the contact occurs, the shift rod 92 in the ejector 9 is displaced under the action of the fixed rod 81, and the force is transmitted to the piston plate 62 through the bull's eye shaft 93, so that the piston plate 62 slides in the fixed cavity 61. The movement of the piston plate 62 is transmitted to the observation plate 66 in the display cavity 65 through the hose, and the observation plate 66 moves accordingly, and the arrow on it points to different scales; The judgment can be made by observing whether the arrow on the observation plate 66 in the display unit 6 is stable on a certain scale and whether the scale is consistent with the scale corresponding to the surface tension of the emulsion known in advance: If the arrow is stable and consistent with the previously known surface tension, the emulsion has been mixed; If the arrow is not stable or the scale is inconsistent, continue stirring; After the reaction is completed, the driving motor 31 is turned off and the stirring is stopped. Since the main components of the equipment are mechanical structures, it is only necessary to directly rinse the stirring rod, the stirring outer rod 12, the stirring inner rod 13 and other components during cleaning. Example
[0021] See also Figure 13-Figure 14 , the present invention provides a technical solution: Different from Example 1, a stop block 10 is provided on the stirring outer rod 12, and a pad block 11 matching with the stop block 10 is provided on the stirring inner rod 13. When the connecting spring 72 drives the stirring inner rod 13 to reset, the pad block 11 will hit the stop block 10. When the emulsion is stirred and mixed, the stirring inner rod 13 is manually rotated. At this time, the stirring outer rod 12 is in a fixed state and does not rotate. Then the stirring inner rod 13 is released. In this way, under the elastic force of the connecting spring 72, the stirring inner rod 13 can be driven to reset, and the pad block 11 will also hit the stop block 10, so that the emulsion on the stirring rod at the bottom of the stirring inner rod 13 will be vibrated and brought down, so as to avoid residual emulsion on the stirring rod at the bottom of the stirring inner rod 13.
[0022] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.
[0023] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the invention.
Claims
1. A carboxylated nitrile latex reactor with a stirring function, comprising a body (1) and a plurality of cleaning rods (2) movably arranged in the body (1), characterized in that: Also included are: An outer stirring rod (12), the outer stirring rod (12) being rotatably arranged in the middle of the body (1), a plurality of cleaning rods (2) being evenly arranged around the outer stirring rod (12), and the middle of the outer stirring rod (12) being a hollow structure; An inner stirring rod (13), the inner stirring rod (13) being rotatably arranged in the middle of the outer stirring rod (12) via a sealed bearing; A switching assembly (3), the switching assembly (3) being arranged on the main body (1) and connected to the stirring outer rod (12) and the stirring inner rod (13), and being used to control the rotation state of the stirring outer rod (12) and the stirring inner rod (13); A detection unit (5) is arranged on the body (1) and connected to the switching assembly (3). When the switching assembly (3) is in operation, the surface tension of the emulsion on the stirring inner rod (13) is used to cause the stirring outer rod (12) and the stirring inner rod (13) to rotate asynchronously, thereby showing the staff the completion of the stirring of the solution.
2. The carboxyl nitrile latex reactor with stirring function according to claim 1, characterized in that: The switching assembly (3) comprises a driving motor (31) arranged on a body (1); a driving shaft (32) is arranged on the body (1); the driving shaft (32) is connected to the output end of the driving motor (31); an output gear (33) is arranged at one end of the stirring outer rod (12) located outside the body (1); an input gear (34) meshing with the output gear (33) is arranged on the driving shaft (32); and a locking member (4) is arranged at one end of the stirring outer rod (12) located outside the body (1) for canceling the fixing of the stirring outer rod (12) and the stirring inner rod (13) after the solution is stirred for a period of time.
3. The carboxyl nitrile latex reactor with stirring function according to claim 2, characterized in that: The locking member (4) comprises an electromagnet (41) arranged at one end of the stirring outer rod (12) located outside the body (1), a top block (42) is arranged at the end of the electromagnet (41), a slot (43) matching with the top block (42) is provided on the stirring inner rod (13), and a storage battery (44) electrically connected to the electromagnet (41) is arranged on the stirring outer rod (12).
4. The carboxylated nitrile latex reactor with stirring function according to claim 3, characterized in that: The detection unit (5) comprises a mounting bracket (51) arranged on the body (1); a display element (6) is arranged on the mounting bracket (51) for displaying the stirring completion status of the solution to the staff; an elastic connecting element (7) is arranged between the stirring outer rod (12) and the stirring inner rod (13) for ensuring that the stirring outer rod (12) and the stirring inner rod (13) rotate asynchronously after the top block (42) and the slot (43) are separated; and a contact detection component (8) matched with the display element (6) is arranged on the body (1) for driving the display element (6) to work by utilizing the surface tension of the emulsion on the stirring inner rod (13).
5. The carboxylated nitrile latex reactor with stirring function according to claim 4, characterized in that: The display member (6) comprises a fixed cavity (61) arranged on the mounting bracket (51), a piston plate (62) being slidably arranged in the fixed cavity (61), a telescopic rod (63) being arranged in the fixed cavity (61), an end of the telescopic rod (63) being connected to the piston plate (62), a return spring (64) being sleeved on the outer side of the telescopic rod (63), a display cavity (65) being arranged on the mounting bracket (51), an observation plate (66) being slidably arranged in the display cavity (65), and the fixed cavity (61) and the display cavity (65) being connected via a hose.
6. The carboxylated nitrile latex reactor with stirring function according to claim 5, characterized in that: The elastic connecting member (7) comprises a plurality of fixing seats (71) respectively arranged on adjacent sides of the stirring inner rod (13) and the stirring outer rod (12); the fixing seats (71) located on the stirring inner rod (13) and the adjacent fixing seats (71) located on the stirring outer rod (12) form a group with each other, and connecting springs (72) are arranged between each group of fixing seats (71).
7. The carboxylated nitrile latex reactor with stirring function according to claim 6, characterized in that: The contact detection assembly (8) comprises a fixed rod (81) arranged on the stirring inner rod (13), and the stirring outer rod (12) is provided with an ejector (9) used in conjunction with the fixed rod (81) for driving the ejector (9) to lift the piston plate (62) when the fixed rod (81) is in operation.
8. The carboxylated nitrile latex reactor with stirring function according to claim 7, characterized in that: The ejector (9) comprises a fixing spring (91) arranged on the inner wall of one end of the stirring outer rod (12) located on the outer side of the body (1); a shift rod (92) movably penetrates the stirring outer rod (12); the fixing spring (91) is sleeved on the outer side of the shift rod (92), and the fixing spring (91) is fixedly connected to the shift rod (92); a bull's eye shaft (93) is arranged at one end of the shift rod (92) close to the piston plate (62); and an end of the shift rod (92) away from the bull's eye shaft (93) is an inclined structure.
9. The carboxylated nitrile latex reactor with stirring function according to claim 8, characterized in that: Two ejection members (9) are provided, and the inclined surfaces of the two shift rods (92) are both provided on a side close to the fixed rod (81).
10. The carboxylated nitrile latex reactor with stirring function according to claim 6, characterized in that: The outer stirring rod (12) is provided with a stopper (10), and the inner stirring rod (13) is provided with a cushion block (11) that matches the stopper (10). When the connecting spring (72) drives the inner stirring rod (13) to return to its original position, the cushion block (11) will collide with the stopper (10).