A dry granulator roller gap adjustment mechanism and roller gap control method thereof

Abstract

The present invention discloses a roller gap adjustment mechanism for a dry granulator, comprising a machine body, a fixed roller shaft, a floating roller shaft and a control system, wherein the shaft ends of the fixed roller shaft and the floating roller shaft are fixedly provided with a fixed roller and a floating roller, respectively, the machine body is fixedly connected to a support plate, the fixed roller shaft passes through the support plate and is rotatably connected to the support plate through a first bearing, the fixed roller is located on the outside of the support plate, and the machine body is fixedly connected to a first hinge seat. The present invention adopts an inclined layout of the floating roller and the fixed roller, eliminates the guide column, and connects the floating roller shaft, the floating roller and the swing arm into a whole by providing a first hinge seat and a swing arm, and hinges the whole with the first hinge seat. By providing a floating roller driving mechanism, the whole is driven to rotate around the hinge point of the first hinge seat, thereby solving the problems of the prior art in which the roller gap changes and the guide column gets stuck during powder loading, thereby affecting the powder compaction effect and loading accuracy control.

Description

Technical Field

[0001] The invention relates to the technical field of dry granulators, in particular to a roller gap adjustment mechanism for a dry granulator and a roller gap control method thereof. Background Art

[0002] Dry granulators are primarily used for rolling powders into flakes and are widely used in material processing applications in the pharmaceutical, food, and chemical industries. Existing dry granulators typically have rollers arranged vertically or horizontally. In dry granulators with rollers arranged vertically, the upper and lower rollers are pivotally connected to the upper and lower housings, respectively, via roller shafts. These rollers extend outward from the housings, forming a cantilevered configuration. Guide posts are positioned between the upper and lower housings, creating a gap between the guide posts and the housings to facilitate the upward and downward movement of the upper housing along the guide posts. This allows for the adjustment of the gap between the upper and lower rollers to accommodate varying powder compaction requirements. In practice, as powder flows between the upper and lower rollers, it squeezes them. Due to the cantilevered nature of the rollers, this often causes the upper roller to lift. This not only changes the gap between the rollers, resulting in suboptimal powder compaction, but also causes the upper housing to tilt slightly, leading to stagnation on the guide posts and significantly impacting loading accuracy. Therefore, how to improve the structure in which the pressure roller slides up and down through the guide pillar to overcome the above problems, and how to adjust and control the pressure roller gap after the improvement, have become technical problems that technical personnel in this field urgently need to solve. Summary of the Invention

[0003] The present invention aims to provide a roller gap adjustment mechanism for a dry granulator and a roller gap control method thereof, thereby optimizing the structure of an existing dry granulator and realizing roller gap detection and control functions, so as to solve the problems mentioned in the background art, such as the roller gap changing and the guide pin getting stuck during powder loading, which affect the powder compaction effect and loading accuracy control.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] The cam is connected to the support plate and the floating roller is connected to the support plate by a first bearing. The cam is located at the outer side of the support plate. The cam is connected to the support plate by a first bearing. The cam is connected to the support plate by a first bearing. The floating roller is connected to the support plate by a second bearing. The floating roller is flush with the end face of the fixed roller and is inclined in the vertical direction. A floating roller driving mechanism is connected between the support plate and the swing arm, for driving the floating roller to rotate around the hinge point of the first hinge seat. The floating roller is provided with a displacement sensor for detecting the horizontal displacement of the floating roller, and the displacement sensor is electrically connected to the control system.

[0006] Furthermore, the floating roller drive mechanism includes a sliding rod, a slider and an oil cylinder, one end of the sliding rod is fixedly connected to a second articulated seat, the second articulated seat is hinged to the top of the left end of the support plate, the other end of the sliding rod floats, the slider is sleeved on the sliding rod and is slidably connected to the sliding rod, the lower part of the slider is fixedly connected to a third articulated seat, the third articulated seat is hinged to the upper part of the swing arm, the piston rod end of the cylinder is fixedly connected to the outward end of the slider, the bottom end of the cylinder is hinged to the machine body, and the cylinder is electrically connected to the control system.

[0007] Furthermore, the inclination angle θ of the floating pressure roller relative to the fixed pressure roller ranges from 25° to 35°.

[0008] Furthermore, the displacement sensor is an elastic contact displacement sensor.

[0009] Furthermore, the displacement sensor is fixedly arranged on the machine body, and the height position of the axis of the displacement sensor remains unchanged in the initial state of the granulator and in the working state of the granulator.

[0010] Furthermore, in the initial state, the floating pressure roller is tangent to the fixed pressure roller, the displacement sensor is in contact with the floating pressure roller, and is in a critical working state, and the axis of the displacement sensor passes through the center of the floating pressure roller.

[0011] A method for controlling the gap between rollers of a dry granulator comprises the following steps:

[0012] S1, the control system presets the gap setting value E0 between the fixed pressure roller and the floating pressure roller, and calculates the β0 value in the initial state, according to the triangle O1O2O3 side length formula (2R) 2 =P 2 +Q 2 -2PQcosβ0, we get , where O1 is the center point of the fixed pressure roller, which is fixed and does not move; O2 is the center point of the floating pressure roller; O3 is the center point of the first hinged seat, which is fixed and does not move; R is the radius of the fixed pressure roller, and the radius of the floating pressure roller is the same as that of the fixed pressure roller; P is the distance between O1O2, which is a constant; Q is the distance between O2O3, which is a constant; and β0 is the angle between the line segment O1O3 and the line segment O2O3;

[0013] S2. The control system calculates the Z0 value in the initial state: Z0=R-X0=R-Qcos(α+β0), where Z0 is the distance between the perpendicular bisectors of J1 and O3, J1 is the tangent point between the displacement sensor and the floating roller, and α is the horizontal angle between the line segment O1O3, which is a constant.

[0014] When the floating roller S3 is working, the oil cylinder drives the slider to move along the slide bar under the action of the control system, and then pushes the swing arm and the floating roller to rotate around O3 away from the fixed roller and press the displacement sensor. The displacement sensor obtains the horizontal relative displacement △Z of the floating roller and transmits the △Z value to the control system;

[0015] S4, the control system calculates the Z1 value in the working state, Z1 = Z0 + △Z, Z1 is the distance between J2 and the perpendicular midline of O3, and J2 is the contact point between the displacement sensor (14) and the floating pressure roller (4);

[0016] S5. The control system calculates the β1 value in the working state, and substitutes the formula Y=Qsin(α+β1)-H and X1=Qcos(α+β1) into the side length formula R of the triangle 02J2J3. 2 =Y 2 +(X1+Z1) 2 , and substitute the specific values ​​of R, Q, Z1, H, and α to obtain the β1 value, where H is the vertical distance between O3 and the axis of the displacement sensor, and X1 is the horizontal distance between the perpendicular bisectors of O2 and O3;

[0017] S6, the control system calculates the E1 value in the working state, according to the triangle O1O2O3 side length formula (2R+ E1) 2 =P 2 +Q 2 -2PQcosβ1 formula, we get , where E1 is the gap between the fixed pressure roller and the floating pressure roller;

[0018] S7, the control system compares the E1 value with the E0 value. When E1 is less than E0, the control cylinder continues to push the floating pressure roller outward to increase the E1 value. When E1 is greater than E0, the control cylinder moves in the opposite direction to move the floating pressure roller closer to the fixed pressure roller to reduce the E1 value. When E1 is equal to E0, the cylinder stops moving to make E1 always equal to E0.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention adopts an inclined layout of floating pressure rollers and fixed pressure rollers, eliminates the guide column, and connects the floating pressure roller shaft, floating pressure roller and swing arm into a whole by arranging a first hinge seat and a swing arm, and hinges the whole with the first hinge seat. By arranging a floating roller driving mechanism, the whole is driven to rotate around the hinge point of the first hinge seat, thereby solving the problems of the prior art in that the pressure roller gap changes and the guide column gets stuck during the powder loading process, thereby affecting the powder compaction effect and loading accuracy control, and realizing the pressure roller gap adjustment function. By arranging a displacement sensor, the displacement sensor measures the horizontal movement distance of the floating pressure roller in real time and transmits the data to the control system. The control system realizes the monitoring and control function of the pressure roller gap through a preset program and a preset pressure roller gap value, thereby achieving the effect of stable powder tableting. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a three-dimensional schematic diagram of the structure of the present invention (front view);

[0022] Figure 2 This is a three-dimensional schematic diagram of the structure of the present invention (back view);

[0023] Figure 3 This is a schematic diagram of the main structure of the present invention (initial state);

[0024] Figure 4 This is a schematic diagram of the main structure of the present invention (working state);

[0025] Figure 5 It is a schematic diagram of an existing dry granulator with vertically distributed pressing rollers;

[0026] In the picture:

[0027] 1-fixed pressure roller shaft, 2-floating pressure roller shaft, 3-fixed pressure roller, 4-floating pressure roller, 5-support plate, 6-first bearing, 7-first articulated seat, 8-swing arm, 9-second bearing, 10-slide rod, 11-slider, 12-second articulated seat, 13-third articulated seat, 14-displacement sensor, 15-lower box, 16-upper box, 17-guide column, 18-powder. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] See also Figures 1-4 , an embodiment provided by the present invention:

[0030] A dry granulator roller gap adjustment mechanism includes a machine body, a fixed roller shaft 1, a floating roller shaft 2 and a control system. The fixed roller shaft 1 and the floating roller shaft 2 are respectively fixedly provided with a fixed roller 3 and a floating roller 4 at their shaft ends. The machine body is fixedly connected to a support plate 5. The fixed roller shaft 1 passes through the support plate 5 and is rotatably connected to the support plate 5 through a first bearing 6. The fixed roller 3 is located outside the support plate 5. The machine body is fixedly connected to a first hinge seat 7. The first hinge seat 7 is hinged with a swing arm 8. The floating roller shaft 2 passes through the swing arm 8 and is rotatably connected to the swing arm 8 through a second bearing 9. The end faces of the floating roller 4 and the fixed roller 3 are flush and inclined in the vertical direction. The oblique distribution, on the one hand, is a structural adjustment for the dry granulator with vertically distributed pressure rollers, which facilitates the position setting of the floating roller drive mechanism and the first articulated seat 7; on the other hand, compared with the dry granulator with parallel pressure rollers, it can reduce the accumulation weight of the powder 18 on the floating pressure roller 4, which is convenient for feeding. A floating roller drive mechanism is connected between the support plate 5 and the swing arm 8, which is used to drive the floating pressure roller 4 to rotate around the hinge point of the first articulated seat 7, so that the floating pressure roller 4 leaves the fixed pressure roller 3 to form a feeding space for the powder 18. The floating pressure roller 4 is provided with a displacement sensor 14 for detecting the horizontal displacement of the floating pressure roller 4, and the displacement sensor 14 is electrically connected to the control system.

[0031] Among them, the floating roller drive mechanism includes a slide rod 10, a slider 11 and a cylinder (not shown in the figure). One end of the slide rod 10 is fixedly connected to a second articulated seat 12, and the second articulated seat 12 is hinged to the top of the left end of the support plate 5. The other end of the slide rod 10 floats, and the slider 11 is sleeved on the slide rod 10 and slidably connected to the slide rod 10. The lower part of the slider 11 is fixedly connected to a third articulated seat 13, and the third articulated seat 13 is hinged to the upper part of the swing arm 8. The piston rod end of the cylinder is fixedly connected to the outward end of the slider 11, and the bottom end of the cylinder is hinged to the machine body. The cylinder is electrically connected to the control system. Under the action of the control system, the cylinder drives the slider 11 to move and then drives the swing arm 8, the floating pressure roller shaft 2 and the floating pressure roller 4 to rotate around the hinge point of the first articulated seat 7.

[0032] The inclination angle θ of the floating pressure roller 4 relative to the fixed pressure roller 3 is in the range of 25°-35°, and in this embodiment, θ=30°.

[0033] The displacement sensor 14 is an elastic contact displacement sensor, which is fixed on the machine body, and the height position of the axis of the displacement sensor 14 remains unchanged in the initial state of the pelletizer and in the working state of the pelletizer.

[0034] In the initial state, the floating pressure roller 4 is tangent to the fixed pressure roller 3, that is, the floating pressure roller 4 is in contact with the fixed pressure roller 3, and there is no gap between the floating pressure roller 4 and the fixed pressure roller 3. The displacement sensor 14 is in contact with the floating pressure roller 4 and is in a critical working state. The axis of the displacement sensor 14 passes through the center of the floating pressure roller 4, which is used as a reference to facilitate the calculation of the vertical displacement distance of the floating pressure roller 4 in the working state.

[0035] A method for controlling the gap between rollers of a dry granulator comprises the following steps:

[0036] S1. First, program the control system and input the R, P, Q, α, and H values. The control system presets the gap setting value E0 between the fixed pressure roller 3 and the floating pressure roller 4, E0=2.0mm, and calculates the β0 value in the initial state. According to the triangle O1O2O3 side length formula (2R) 2 =P 2 +Q 2 -2PQcosβ0, we get =51.6°, where O1 is the center point of the fixed pressure roller 3, which is stationary; O2 is the center point of the floating pressure roller 4; O3 is the center point of the first hinged seat 7, which is stationary; R is the radius of the fixed pressure roller 3, which is 49 mm; the floating pressure roller 4 and the fixed pressure roller 3 have the same radius; P is the distance between O1 and O2, which is 125 mm; Q is the distance between O2 and O3, which is 75 mm; and β0 is the angle between the line segment O1 and O3 and the line segment O2 and O3.

[0037] S2. The control system calculates the Z0 value in the initial state: Z0 = R-X0 = R-Qcos(α+β0) = 9.9 mm, where Z0 is the distance between the perpendicular midlines of J1 and O3, J1 is the tangent point between the displacement sensor 14 and the floating roller 4, and α is the horizontal angle between the line segments O1 and O3, α = 7°.

[0038] When S3 and the floating roller 4 are working, the fixed roller 3 and the floating roller 4 rotate while the oil cylinder drives the slider 11 to move along the slide bar 10 under the action of the control system, thereby pushing the swing arm 8 and the floating roller 4 to rotate around O3 away from the fixed roller 3 and press the displacement sensor 14. The displacement sensor 14 obtains the horizontal relative displacement △Z of the floating roller 4 and transmits the △Z value to the control system;

[0039] S4, the control system calculates the Z1 value in the working state, Z1 = Z0 + △Z, Z1 is the distance between the perpendicular line of J2 and O3, J2 is the contact point between the displacement sensor (14) and the floating pressure roller (4), and the change of the Z1 value indirectly reflects the change of the gap between the fixed pressure roller 3 and the floating pressure roller 4;

[0040] S5. The control system calculates the β1 value in the working state, and substitutes the formula Y=Qsin(α+β1)-H and X1=Qcos(α+β1) into the side length formula R of the triangle 02J2J3. 2 =Y 2 +(X1+Z1) 2, and substitute the specific values ​​of R, Q, Z1, H, and α to obtain the β1 value, where H is the vertical distance between O3 and the axis of the displacement sensor 14, H=64mm, and X1 is the horizontal distance between the perpendicular lines of O2 and O3;

[0041] S6, the control system calculates the E1 value in the working state, according to the triangle O1O2O3 side length formula (2R+ E1) 2 =P 2 +Q 2 -2PQcosβ1 formula, we get , where E1 is the gap between the fixed pressure roller 3 and the floating pressure roller 4;

[0042] S7. The control system compares the E1 value with the E0 value. When E1 is less than E0, the control cylinder continues to push the floating pressure roller 4 outward to increase the E1 value. When E1 is greater than E0, the control cylinder moves in the opposite direction to move the floating pressure roller 4 closer to the fixed pressure roller 3 to reduce the E1 value. When E1 is equal to E0, the cylinder stops moving to make E1 always equal to E0, thereby realizing the gap detection function and gap control function between the fixed pressure roller 3 and the floating pressure roller 4, and achieving the effect of stable tableting of the powder 18.

[0043] Comparative Example:

[0044] like Figure 5 As shown, in the existing dry granulator with vertically distributed pressure rollers, the floating pressure roller 4 and the fixed pressure roller 3 are rotatably connected to the upper box body 16 and the lower box body 15 respectively through the pressure roller shaft and extend out of the box body in a cantilever state. A guide post 17 is passed between the upper box body 16 and the lower box body 15. A certain gap is left at the joint between the guide post 17 and the upper box body 16 and the lower box body 15 to facilitate the upper box body 16 to slide up and down along the guide post 17, thereby achieving the purpose of adjusting the gap between the floating pressure roller 4 and the fixed pressure roller 3 to meet different powder compaction requirements. In actual operation, when the powder flows between the floating pressure roller 4 and the fixed pressure roller 3, the powder exerts a squeezing effect on the floating pressure roller 4 and the fixed pressure roller 3. Due to the cantilever characteristics of the pressure rollers, the floating pressure roller 4 is often lifted up, which not only changes the gap between the floating pressure roller 4 and the fixed pressure roller 3, so that the powder compaction effect does not meet the predetermined requirements, but also causes the upper box body 16 to tilt slightly, resulting in jamming on the guide post 17, which has a great impact on the control of loading accuracy.

[0045] The present invention adopts an inclined layout of a floating pressure roller 4 and a fixed pressure roller 3, eliminates the guide column 17, and connects the floating pressure roller shaft 2, the floating pressure roller 4 and the swing arm 8 into a whole by setting a first hinged seat 7 and a swing arm 8, and hinges the whole with the first hinged seat 7. By setting a floating roller driving mechanism, the whole is driven to rotate around the hinge point of the first hinged seat 7, solving the problems of the prior art in that the pressure roller gap changes and the guide column 17 gets stuck during powder loading, affecting the powder compaction effect and loading accuracy control, and realizing the pressure roller gap adjustment function. By setting a displacement sensor 14, the displacement sensor 14 measures the horizontal movement distance of the floating pressure roller 4 in real time and transmits the data to the control system. The control system realizes the monitoring and control function of the pressure roller gap through a preset program and a preset pressure roller gap value, thereby achieving the effect of stable tableting of the powder 18.

[0046] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A roller gap adjustment mechanism for a dry granulator, comprising a machine body, a fixed roller shaft (1), a floating roller shaft (2) and a control system, wherein the fixed roller shaft (1) and the floating roller shaft (2) are respectively fixedly provided with a fixed roller (3) and a floating roller (4) at their shaft ends, and characterized in that: The machine body is fixedly connected to a support plate (5), the fixed pressure roller shaft (1) passes through the support plate (5) and is rotatably connected to the support plate (5) through a first bearing (6), the fixed pressure roller (3) is located outside the support plate (5), the machine body is fixedly connected to a first hinge seat (7), the first hinge seat (7) is hinged to a swing arm (8), the floating pressure roller shaft (2) passes through the swing arm (8) and is rotatably connected to the swing arm (8) through a second bearing (9), the floating pressure roller (4) and the fixed pressure roller (3) have end faces flush and are inclined in the vertical direction, a floating roller driving mechanism is connected between the support plate (5) and the swing arm (8), and is used to drive the floating pressure roller (4) to rotate around the hinge point of the first hinge seat (7), the floating pressure roller (4) is provided with a displacement sensor (14) for detecting the horizontal displacement of the floating pressure roller (4), and the displacement sensor (14) is electrically connected to the control system; The floating roller driving mechanism includes a slide bar (10), a slider (11) and an oil cylinder. One end of the slide bar (10) is fixedly connected to a second articulated seat (12), and the second articulated seat (12) is hinged to the top of the left end of the support plate (5). The other end of the slide bar (10) floats. The slider (11) is sleeved on the slide bar (10) and is slidably connected to the slide bar (10). The lower part of the slider (11) is fixedly connected to a third articulated seat (13), and the third articulated seat (13) is hinged to the upper part of the swing arm (8). The piston rod end of the oil cylinder is fixedly connected to the outward end of the slider (11). The bottom end of the oil cylinder is hinged to the machine body. The oil cylinder is electrically connected to the control system.

2. The roller gap adjustment mechanism of a dry granulator according to claim 1, characterized in that: The inclination angle θ of the floating pressure roller (4) relative to the fixed pressure roller (3) ranges from 25° to 35°.

3. The roller gap adjustment mechanism of a dry granulator according to claim 1, characterized in that: The displacement sensor (14) is an elastic contact type displacement sensor.

4. The roller gap adjustment mechanism of a dry granulator according to claim 3, characterized in that: The displacement sensor (14) is fixedly arranged on the machine body, and the height position of the axis of the displacement sensor (14) remains unchanged in the initial state of the pelletizer and in the working state of the pelletizer.

5. The roller gap adjustment mechanism of a dry granulator according to claim 1, characterized in that: In the initial state of the granulator, the floating pressure roller (4) is tangent to the fixed pressure roller (3), the displacement sensor (14) is in contact with the floating pressure roller (4), and is in a critical working state, with the axis of the displacement sensor (14) passing through the center of the floating pressure roller (4).

6. A method for controlling the gap between rollers of a dry granulator, used in the roller gap adjustment mechanism of a dry granulator according to claim 5, characterized in that: The steps include: S1, the control system presets the gap setting value E0 between the fixed pressure roller (3) and the floating pressure roller (4), and calculates the β0 value in the initial state, according to the triangle O1O2O3 side length formula (2R) 2 =P 2 +Q 2 -2PQcosβ0, we get , where O1 is the center point of the fixed pressure roller (3) and is fixed, O2 is the center point of the floating pressure roller (4), O3 is the center point of the first hinge seat (7) and is fixed, R is the radius of the fixed pressure roller (3), the floating pressure roller (4) and the fixed pressure roller (3) have the same radius, P is the distance between O1O2 and is a constant, Q is the distance between O2O3 and is a constant, and β0 is the angle between the line segment O1O3 and the line segment O2O3; S2. The control system calculates the Z0 value in the initial state, Z0=R-X0=R-Qcos(α+β0), where Z0 is the distance between the perpendicular lines of J1 and O3, J1 is the tangent point between the displacement sensor (14) and the floating pressure roller (4), and α is the horizontal angle between the line segment O1O3, which is a constant; When S3 and the floating pressure roller (4) are working, the oil cylinder drives the slider (11) to move along the slide bar (10) under the action of the control system, thereby pushing the swing arm (8) and the floating pressure roller (4) to rotate around O3 and leave the fixed pressure roller (3) and press the displacement sensor (14). The displacement sensor (14) obtains the horizontal relative displacement △Z of the floating pressure roller (4) and transmits the △Z value to the control system; S4, the control system calculates the Z1 value in the working state, Z1 = Z0 + △Z, Z1 is the distance between J2 and the perpendicular midline of O3, and J2 is the contact point between the displacement sensor (14) and the floating pressure roller (4); S5. The control system calculates the β1 value in the working state, and substitutes the formula Y=Qsin(α+β1)-H and X1=Qcos(α+β1) into the side length formula R of the triangle 02J2J3. 2 =Y 2 +(X1+Z1) 2 , and substitute the specific values ​​of R, Q, Z1, H, and α into the equation to obtain the value of β1, where H is the vertical distance between O3 and the axis of the displacement sensor (14), and X1 is the horizontal distance between the perpendicular lines of O2 and O3; S6, the control system calculates the E1 value in the working state, according to the triangle O1O2O3 side length formula (2R+ E1) 2 =P 2 +Q 2 -2PQcosβ1 formula, we get , wherein E1 is the gap between the fixed pressure roller (3) and the floating pressure roller (4); S7, the control system compares the E1 value with the E0 value. When E1 is less than E0, the control cylinder continues to push the floating pressure roller (4) outward to increase the E1 value. When E1 is greater than E0, the control cylinder moves in the opposite direction to make the floating pressure roller (4) close to the fixed pressure roller (3) to reduce the E1 value. When E1 is equal to E0, the cylinder stops moving to make E1 always equal to E0.

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