An internal mixer ram drive mechanism and control method

Abstract

The present application relates to rubber mixing technology field, provide a kind of mixing machine upper ram drive mechanism, it includes the electric upper ram structure installed in the upper of mixing main machine, the electric upper ram structure includes electric cylinder, and the output shaft of connecting in electric cylinder is pressed lump;Pressure sensor is installed in the upper of pressed lump;Mixing main machine is provided with mixing chamber, and pressed lump is installed in the feeding port of mixing chamber, and pressed lump is driven by electric cylinder and moves along vertical direction, adjusts the mixing volume of mixing chamber.The electric upper ram structure is designed in the present application, uses electric cylinder to replace original hydraulic or pneumatic upper ram, simplifies the complexity of mixing machine, improves the reliability of system.The three operating modes of electric upper ram are designed in the present application, respectively applicable to different scenarios, can effectively avoid the damage of mixing machine due to excessive pressure, avoid excessive power peak, save mixing energy consumption, increase the pressure in mixing chamber to some extent, improve mixing effect.

Description

Technical Field

[0001] This invention relates to the field of rubber mixing technology, specifically to a top bolt drive mechanism and control method for an internal mixer, and an internal mixer and control method. Background Technology

[0002] With the continuous development of the rubber industry, there are increasingly higher requirements for the accuracy and response speed of parameters such as mixing time, mixing process, and temperature of internal mixers.

[0003] The top bolt, a core component of the internal mixer, primarily provides stable pressure to the rubber compound within the mixing chamber via a pressure block mounted on it. Early internal mixers used mechanically locked top bolts, requiring manual operation for each run and maintenance, resulting in high workload and slow pressing speed. Later, hydraulic or pneumatic top bolts were mostly adopted.

[0004] Hydraulic top plugs are expensive to operate, require a hydraulic power unit, are prone to leakage causing rubber contamination, and generally have a response time of over 500ms, making them unsuitable for real-time, precise adjustment. Furthermore, the incompressible hydraulic cylinder means that excessive pressure within the mixing chamber cannot be released promptly. While pneumatic top and bottom plugs are contamination-free, they offer less force and are typically used in smaller equipment. They also suffer from the same problem of difficulty in timely pressure release and replenishment.

[0005] Therefore, designing a transmission method that is simple in structure, low in cost, fast in response, powerful, and does not cause pollution to optimize the top bolt of the internal mixer and simplify the complexity of the internal mixer control system is a problem that needs to be solved. Summary of the Invention

[0006] To address the problems existing in the background art, the present invention provides a top bolt drive mechanism for an internal mixer, comprising:

[0007] An electric top bolt structure installed above the mixing machine, the electric top bolt structure including an electric cylinder and a pressure block connected to the output shaft of the electric cylinder;

[0008] A pressure sensor installed above the slab;

[0009] The internal mixer is equipped with a mixing chamber. The pressing block is installed at the feeding port of the mixing chamber and is driven by an electric cylinder to move vertically to adjust the mixing volume of the mixing chamber.

[0010] In a preferred embodiment, the bottom of the compact has a double-arc surface structure.

[0011] An internal mixer includes a motor, a gearbox, drive shafts, a main mixer, a heating mechanism, and a control cabinet. Two drive shafts are provided, with the motor power output to both shafts via the gearbox. These drive shafts rotate the rotor within the mixing chamber of the main mixer. The control cabinet houses a control system connected to an electric top-loading mechanism, the heating mechanism, and the motor, used to control the operation of the electric top-loading mechanism and the main mixer. The main mixer includes a mixing chamber with a feeding port. The pressure of the electric top-loading mechanism can seal and open the feeding port. A lower top-loading mechanism, a motor-driven tilting bucket, is located at the bottom of the mixing chamber. At least one temperature sensor connected to the control system is installed within the mixing chamber for detecting the temperature of the rubber compound.

[0012] In the preferred embodiment, a first proximity switch and a second proximity switch are installed in the feeding port of the mixing chamber. The positions of the first proximity switch and the second proximity switch are the extreme positions of the pressing block when it moves upward and downward, respectively.

[0013] The internal mixer control method includes the following steps:

[0014] S1. Close the lower top bolt of the mixing chamber, raise the output shaft of the electric upper top bolt structure, open the feeding port, and fully feed the material into the mixing chamber;

[0015] S2. The motor starts, driving the rotor in the mixing chamber to rotate through the gearbox and drive shaft. The heating mechanism is activated, and the mixing process begins.

[0016] S3, Set the maximum pressure threshold P of the mixing chamber. max Working pressure threshold P work Minimum pressure threshold P min Maximum temperature threshold T max ;

[0017] S4. Set the operating modes of the electric top bolt, including Mode A, Mode B, Mode C, and a safety mode. Modes A, B, and C can be operated individually or alternately. Modes B and C can operate simultaneously.

[0018] Safe Mode: Regardless of the running mode, when P>P max This triggers the pressure overload protection, causing the pressure block to lift; when T>T max This triggers the overheat protection, causing the pressure block to lift up;

[0019] Mode A: Fixed-position locking mode. In this mode, the output shaft of the electric cylinder reciprocates between two fixed points, causing the pressure block to lift or lock; the pressure sensor monitors the pressure P in the mixing chamber in real time. When P ≤ P max When P > P, the block is locked; max This triggers overload protection, causing the compressed mass to lift up.

[0020] Mode B: Pressure and temperature following mode. In this mode, the pressure sensor collects the pressure value of the mixing chamber in real time within a time period t and sends it to the control system to obtain the average pressure P within the time period t. 均 The temperature sensor collects the temperature value of the mixing chamber in real time within a time period t and sends it to the control system to obtain the average temperature T within the time period t. 均 ;

[0021] When P 均 >P work Or when T 均 >T max When the electric cylinder is in a non-moving state, the control system sends a signal, and the electric cylinder moves the pressure block position upward by 2mm to prevent the temperature of the mixed material from rising too quickly; when P 均 <P min At this time, the electric cylinder moves the pressure block position down by 1mm, increasing the pressure in the mixing chamber and improving the mixing efficiency;

[0022] During operation in Mode B, when the pressure bar moves upward to the first proximity switch, a signal is sent to the control system to stop its upward movement; when the pressure bar moves downward to the second proximity switch, a signal is sent to the control system to stop its downward movement.

[0023] Mode C: During the pressing stage after feeding, when the power curve change rate is detected to be greater than 3.7, the downward pressing speed of the electric cylinder is reduced, controlling the power curve change rate to be close to 1. During the mixing stage, when the power curve change rate is detected to be greater than 1.7, the control system sends a signal, and the electric cylinder moves the pressing block position upward by 1mm, controlling the power curve change rate to be close to 1. During the mixing stage, when the power curve change rate is detected to be less than -1.7, the control system sends a signal, and the electric cylinder moves the pressing block position downward by 1mm, increasing the pressure inside the cylinder, thereby improving the power curve and increasing the mixing efficiency.

[0024] S5. After the mixing process is completed, rotate the bottom bolt to open it, and the mixing process is finished.

[0025] The beneficial effects achieved by this invention are as follows:

[0026] First, this invention designs an electric top bolt structure, using an electric cylinder to replace the original hydraulic or pneumatic top bolt, simplifying the complexity of the internal mixer and improving system reliability. Compared to traditional hydraulic cylinders and pneumatic cylinders, electric cylinders do not require hydraulic oil or air as a medium, their performance is less affected by the external environment, and they do not require complex pumps, valves, etc. like hydraulic systems. They have advantages such as simple structure, high precision, fast response, and high stability, with a response speed of less than 10ms.

[0027] Secondly, this invention designs three operating modes of electric top bolt, which are suitable for different scenarios. They can effectively avoid damage to the internal mixer due to excessive pressure, avoid excessive power peak, save mixing energy consumption, and at the same time increase the pressure in the mixing chamber to a certain extent, thereby improving the mixing effect. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the internal mixer structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the electric top bolt structure;

[0030] Figure 3 This is a schematic diagram of the cross-sectional structure of the mixing chamber;

[0031] Figure 4 This is the control flowchart for the internal mixer;

[0032] Figure 5 This is a schematic diagram of the parameters of an internal mixer, where T1, T2, and T3 are the temperatures of the mixing chamber, TM is the material temperature, Tq is the power curve before power adjustment, Tq2 is the power curve after power adjustment, and SP is the rotational speed.

[0033] Numbering on the map:

[0034] 1. Motor; 2. Gearbox; 3. Drive shaft; 4. Internal mixer; 41. Internal mixer chamber; 42. First proximity switch; 43. Second proximity switch; 44. Temperature sensor; 5. Electric top bolt structure; 51. Pressure sensor; 52. Pressing block; 53. Electric cylinder. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Reference Figures 1-5 A top-mounted bolt drive mechanism for an internal mixer includes an electrically operated top-mounted bolt structure 5 mounted above the internal mixer 4. The electrically operated top-mounted bolt structure 5 includes an electric cylinder 53 and a pressure block 52 connected to the output shaft of the electric cylinder 53; a pressure sensor 51 is mounted above the pressure block 52; the internal mixer 4 is provided with a mixing chamber 41, and the pressure block 52 is installed at the feeding port of the mixing chamber 41. The electric cylinder 53 drives the pressure block 52 to move vertically, adjusting the mixing volume of the mixing chamber 41. The bottom of the pressure block 52 is preferably a double-arc surface structure.

[0037] The pressure sensor 51 is preferably a spoke-type pressure sensor 51. The spoke-type pressure sensor 51 is installed between the electric cylinder 53 and the pressure block 52 and is used to measure the pressure in the mixing chamber 41 of the internal mixing plant. The electric cylinder 53 used in this invention has a thrust design value of more than 10 tons, a response speed of less than 10ms, and a maximum movement speed of 1m / s.

[0038] This invention also provides an internal mixer, comprising a motor 1, a gearbox 2, a drive shaft 3, an internal mixer 4, a heating mechanism, and a control cabinet 6. It also includes an electric top-mounted bolt structure 5, with two drive shafts 3. Power from the motor 1 is output to the two drive shafts 3 via the gearbox 2, driving the rotor in the mixing chamber 41 of the internal mixer to rotate. The control cabinet 6 houses a control system connected to the electric top-mounted bolt structure 5, the heating mechanism, and the motor 1, used to control the operation of the electric top-mounted bolt structure 5 and the internal mixer 4. The internal mixer 4 includes a mixing chamber 41 with a feeding port. The pressure block 55 of the electric top-mounted bolt structure 5 can seal and open the feeding port. A bottom-mounted bolt, which is a tilting bucket driven by the motor 1, is located at the bottom of the mixing chamber 41. At least one temperature sensor 44, connected to the control system, is installed inside the mixing chamber 41 for detecting the temperature of the rubber compound. Preferably, the control cabinet 6 also includes a cooling device for cooling the control system.

[0039] The feeding port of the mixing chamber 41 is equipped with a first proximity switch 42 and a second proximity switch 43. The positions of the first proximity switch 42 and the second proximity switch 43 are the extreme positions of the pressing block 55 when it moves upward and downward, respectively.

[0040] Example 1:

[0041] In this embodiment, the internal mixer operates according to the following steps:

[0042] S1. Close the lower top bolt of the mixing chamber 41, raise the output shaft of the electric upper top bolt structure 5, open the feeding port, and feed the material into the mixing chamber 41 completely.

[0043] S2, Motor 1 starts, and drives the rotor in the mixing chamber 41 to rotate through gearbox 2 and transmission shaft 3. The heating mechanism is started, and the mixing process begins.

[0044] S3, Set the maximum pressure threshold P of the mixing chamber 41 max Working pressure threshold P work Minimum pressure threshold P min Maximum temperature threshold T max ;

[0045] S4. Set the operating mode of the electric top bolt, such as... Figure 4As shown, the operating modes include Mode A, Mode B, Mode C, and a security mode. Modes A, B, and C can be run individually or alternately. Modes B and C can run simultaneously.

[0046] Safe Mode: Regardless of the running mode, when P>P max This triggers the pressure overload protection, causing the pressure block 52 to lift; when T>T max This triggers the overheat protection, causing the pressure block to lift at 52°C.

[0047] Mode A: Fixed-position locking mode. In this mode, the output shaft of the electric cylinder 53 reciprocates between two fixed points, causing the pressure block 52 to lift or lock; the pressure sensor 51 detects the pressure P in the mixing chamber 41 in real time. When P ≤ P max When P > P, the block is locked at 52; max This triggers overload protection, causing the pressure plate 52 to lift.

[0048] Mode B: Pressure and temperature following mode. In this mode, pressure sensor 51 collects the pressure value of mixing chamber 41 in real time within time period t and sends it to the control system to obtain the average pressure P within time period t. 均 Temperature sensor 44 collects the temperature value of mixing chamber 41 in real time within time period t and sends it to the control system to obtain the average temperature T within time period t. 均 ;

[0049] When P 均 >P work Or when T 均 >T max When the electric cylinder is in a non-moving state, the control system sends a signal, and the electric cylinder 53 moves the pressure block 52 upward by 2mm to prevent the temperature of the mixed material from rising too quickly; when P 均 <P min At the same time, the electric cylinder 53 drives the pressure block 52 to move down by 1mm, increasing the pressure in the mixing chamber 41 and improving the mixing efficiency;

[0050] During operation in mode B, when the pressure bar 52 moves upward to the first proximity switch 42, a signal is sent to the control system to stop its upward movement; when the pressure bar 52 moves downward to the second proximity switch 43, a signal is sent to the control system to stop its downward movement.

[0051] Mode C: During the pressing stage after feeding, when the power curve change rate is detected to be greater than 3.7, the downward pressing speed of electric cylinder 53 is reduced, controlling the power curve change rate to be close to 1; during the mixing stage, when the power curve change rate is detected to be greater than 1.7, the control system sends a signal, and electric cylinder 53 moves the pressing block 52 upward by 1mm; the power curve change rate is controlled to be close to 1; during the mixing stage, when the power curve change rate is detected to be less than -1.7, the control system sends a signal, and electric cylinder 53 moves the pressing block 52 downward by 1mm; the pressure inside the cylinder is increased, thereby improving the power curve and increasing the mixing efficiency;

[0052] S5. After the mixing process is completed, rotate the bottom bolt to open it, and the mixing process is finished.

[0053] Example 2:

[0054] In this embodiment, unlike in embodiment 1, the operating mode set in step S4 is not used.

[0055] The operating parameters for Examples 1 and 2 are as follows: Figure 5 As shown in the figure, under the precise control of the pressure sensor and electric cylinder, compared with the original curve, the power curve tg2 shows a slower increase in the first half, indicating a longer mixing time and a reduced temperature rise. The power curve decreases more slowly in the second half, increasing mixing efficiency. The use of the new top plug reduces peak power and improves the work done in other stages, resulting in a lower overall process temperature rise, lower energy consumption, and a clearer process flow.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling an internal mixer, characterized in that, The internal mixer used in the control method includes a motor (1), a gearbox (2), a transmission shaft (3), a mixing main unit (4), a heating mechanism, and a control cabinet (6), and also includes an electric top bolt drive mechanism for the internal mixer, which includes: An electric top bolt structure (5) is installed above the mixing host (4). The electric top bolt structure (5) includes an electric cylinder (53) and a pressure block (52) connected to the output shaft of the electric cylinder (53). Pressure sensor (51) installed above the pressure block (52); The mixing host (4) is equipped with a mixing chamber (41), and the pressing block (52) is installed at the feeding port of the mixing chamber (41). The pressing block (52) is driven by an electric cylinder (53) to move in the vertical direction to adjust the mixing volume of the mixing chamber (41). The control method includes the following steps: S1. Close the lower top bolt of the mixing chamber (41), raise the output shaft of the electric upper top bolt structure (5), open the feeding port, and feed the material into the mixing chamber (41) completely; S2. The motor (1) starts and drives the rotor in the mixing chamber (41) to rotate through the gearbox (2) and transmission shaft (3). The heating mechanism starts and the mixing process begins. S3. Set the maximum pressure threshold P of the mixing chamber (41). max Working pressure threshold P work Minimum pressure threshold P min Maximum temperature threshold T max ; S4. Set the operating modes of the electric top bolt, including Mode A, Mode B, Mode C, and a safety mode. Modes A, B, and C can be operated individually or alternately. Modes B and C can operate simultaneously. Safe Mode: Regardless of the running mode, when P>P max This triggers the pressure overload protection, causing the pressure block (52) to lift; when T>T max This triggers the overheat protection, causing the pressure block (52) to lift up; Mode A: Fixed-position locking mode. In this mode, the output shaft of the electric cylinder (56) moves back and forth between two fixed points, causing the pressure block (52) to lift or lock; the pressure sensor (51) detects the pressure P in the mixing chamber (41) in real time. When P≤P max When, the block (52) is locked; when P>P max This triggers overload protection, causing the pressure block (52) to lift. Mode B: Pressure and temperature following mode. In this mode, the pressure sensor (51) collects the pressure value of the mixing chamber (41) in real time within the time period t and sends it to the control system to obtain the average pressure P within the time period t. 均 The temperature sensor (44) collects the temperature value of the mixing chamber (41) in real time within the time period t and sends it to the control system to obtain the average temperature T within the time period t. 均 ; When P 均 >P work Or when T 均 >T max When the electric cylinder is in a non-moving state, the control system sends a signal, and the electric cylinder (56) moves the pressure block (52) up by 2mm to prevent the temperature of the mixed material from rising too quickly; when P 均 <P min At that time, the electric cylinder (56) drives the pressure block (52) to move down by 1mm, increasing the pressure in the mixing chamber (41) and improving the mixing efficiency; During the operation of mode B, when the pressure ball (52) moves upward to the first proximity switch (42), a trigger signal is sent to the control system to stop the upward movement; when the pressure ball (52) moves downward to the second proximity switch (43), a trigger signal is sent to the control system to stop the downward movement. Mode C: During the pressing stage after feeding, when the power curve change rate is detected to be greater than 3.7, the pressing speed of the electric cylinder (56) is reduced, and the power curve change rate is controlled to be close to 1. During the mixing stage, when the power curve change rate is detected to be greater than 1.7, the control system sends a signal, and the electric cylinder (56) drives the pressing block (52) to move up 1mm; the power curve change rate is controlled to be close to 1 (45°); during the mixing stage, when the power curve change rate is detected to be less than -1.7, the control system sends a signal, and the electric cylinder (56) drives the pressing block (52) to move down 1mm; the pressure inside the cylinder is increased, thereby increasing the power curve and improving the mixing efficiency. S5. After the mixing process is completed, rotate the bottom bolt to open it, and the mixing process is finished.

2. The method according to claim 1, characterized in that: The bottom of the compact (52) has a double arc surface structure.

3. The method according to claim 2, characterized in that: The mixing chamber (41) is equipped with a first proximity switch (42) and a second proximity switch (43). The positions of the first proximity switch (42) and the second proximity switch (43) are the extreme positions of the pressing block (52) going up and down, respectively.

4. The method according to claim 3, characterized in that: There are two drive shafts (3). The power of the motor (1) is output to the two drive shafts (3) through the gearbox (2). The two drive shafts (3) drive the rotor in the mixing chamber (41) of the mixing machine to rotate. The control cabinet (6) is equipped with a control system connected to the electric top bolt structure (5), the heating mechanism and the motor (1) to control the operation of the electric top bolt structure (5) and the mixing machine (4). The mixing machine (4) includes a mixing chamber (41). The mixing chamber (41) is equipped with a feeding port. The pressing block (52) of the electric top bolt structure (5) can seal and open the feeding port. The bottom of the mixing chamber (41) is equipped with a bottom bolt, which is a tilting bucket driven by the motor (1). The mixing chamber (41) is equipped with at least one temperature sensor (44) connected to the control system for detecting the temperature of the rubber compound.

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