Screening equipment for tomato sauce processing
The combination of the rotary screening drum and the stirring mechanism solves the problem of poor screening effect of screening equipment in the prior art, achieves efficient screening of tomatoes, and ensures the quality of tomato sauce.
Patent Information
- Application Number
- CN202510959797.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-11
- Publication Date
- 2025-09-26
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The screening equipment used for tomato paste processing in the prior art uses a single screening method through a static sieve plate, resulting in poor screening effect, which easily allows unqualified tomatoes to be mixed in, affecting the quality of the processed tomato paste.
The rotating screening drum and stirring mechanism are used to accelerate the screening speed by using centrifugal force, and the tomatoes inside the screening drum are stirred by the stirring mechanism to enhance the screening effect and reduce the probability of unqualified tomatoes being missed.
It improves the screening speed and efficiency, ensures the quality of tomato paste, reduces the risk of unqualified tomatoes being mixed in, and realizes comprehensive screening of tomatoes.
Smart Images
Figure CN120696065A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present disclosure relate to the technical field of screening equipment, and in particular, to a screening equipment for tomato sauce processing. Background Art
[0002] Ketchup is a well-known and beloved condiment that occupies an important position in food culture around the world. Whether it is a classic accompaniment to fast food such as French fries and hamburgers, or it is used to add a unique flavor to various dishes, ketchup plays an irreplaceable role. Ketchup is a concentrated tomato paste product. It is made from ripe red tomatoes, which are crushed, pulped, peeled and seeded, and then concentrated, canned and sterilized. The finished product is a bright red paste with a unique tomato flavor. Screening equipment is used to screen tomatoes during the processing and production of tomato paste. There are many types of screening equipment. The present application is based on size screening equipment. The size screening equipment is used to screen tomato raw materials of different sizes, screen out unqualified fruits, and retain qualified fruits to ensure the quality and taste of subsequent tomato sauce processing. The screening equipment used for tomato sauce processing in the prior art usually screens tomatoes through a static sieve plate. The screening method is relatively simple and it is difficult to achieve comprehensive screening of tomatoes, resulting in poor screening effect of tomatoes. It is easy for unqualified tomatoes to be mixed in, which may affect the quality of the processed tomato sauce. Summary of the Invention
[0003] In order to overcome the above-mentioned defects, the embodiments of the present disclosure provide a screening device for tomato sauce processing, which is used to solve the technical problem that the screening equipment in the prior art usually screens tomatoes through a static sieve plate, and the screening method is relatively simple, making it difficult to achieve comprehensive screening of tomatoes, resulting in poor screening effect of tomatoes, and easily causing unqualified tomatoes to mix in, which may affect the quality of the tomato sauce after processing.
[0004] According to one aspect, at least one embodiment of the present disclosure provides a screening device for tomato sauce processing, comprising a screening box, a discharge port being provided on the lower side of the screening box, a trapezoidal lower portion of the screening box, a wide upper portion and narrow lower portion of the screening box, a buffer layer being provided on the inner wall of the screening box, the buffer layer being used for buffering between the screening box and the tomatoes, the lower portion of the screening box being provided with support legs, and also comprising a mounting plate, a screening drum and a stirring mechanism, two mounting plates being plugged into the screening box, the mounting plates being able to move vertically inside the screening box, and the screening drum being rotated by a mounting column The stirring mechanism is mounted on the mounting plate on one of the two sides and moves synchronously with the mounting plate. A plurality of sieve holes are provided on the outer side of the screening cylinder. A driving member for driving the mounting column to rotate is provided on the mounting plate connected to the screening cylinder. The stirring mechanism is rotatably mounted on the mounting plate on the other side of the two sides and moves synchronously with the mounting plate. A driving member for driving the stirring mechanism to rotate is provided on the mounting plate connected to the stirring mechanism. The main body of the stirring mechanism is provided inside the screening cylinder, and the stirring mechanism is used to stir the tomatoes inside the screening cylinder.
[0005] The stirring mechanism includes a stirring shaft, a stirring rod, a mounting ring and a toggle plate. The stirring shaft is rotatably mounted on the mounting plate. A plurality of stirring rods are mounted on the outside of the stirring shaft. The stirring rods rotate synchronously with the stirring shaft. The mounting ring is mounted on the outer end of the stirring rod and rotates synchronously with the stirring rod. A plurality of toggle plates are mounted on both sides of the mounting ring. The toggle plates rotate synchronously with the mounting ring. The toggle plates are used to toggle tomatoes trapped in the sieve holes.
[0006] As a preferred embodiment of the screening equipment for tomato sauce processing according to the present invention, in order to enhance the stirring effect of the tomatoes inside the screening cylinder and thus ensure the screening effect of the tomatoes, the stirring rod is V-shaped, and a plurality of the stirring rods are arranged in a ring shape on the outside of the stirring shaft.
[0007] As a preferred solution of the screening equipment for tomato sauce processing described in the present invention, in order to block the tomatoes inside the screening box during the screening process and reduce the probability of tomatoes flying out of the screening box, a cover plate is installed on the upper side of the mounting plate, and the cover plate moves synchronously with the mounting plate.
[0008] As a preferred embodiment of the screening device for ketchup processing according to the present invention, in order to achieve the installation positioning of the mounting plate and thus ensure the installation effect of the mounting plate, square grooves are provided on both sides of the inner wall of the screening box, and square bars are installed on both sides of the mounting plate, and the width of the square bars is adapted to the width of the square grooves.
[0009] As a preferred embodiment of the screening device for tomato sauce processing according to the present invention, in order to adjust the feeding state of the screening cylinder and position the opening and closing plate, two opening and closing plates are slidably arranged on one of the two sides of the screening cylinder, and two spring positioning pins are provided on the side of the screening cylinder on which the opening and closing plates are mounted.
[0010] As a preferred embodiment of the screening equipment for tomato sauce processing described in the present invention, in order to adjust the height of the screening cylinder, an adjustment mechanism is provided on one of the two sides of the screening box, and the adjustment mechanism includes a frame, an L-shaped frame and an electric push rod. The frame is installed on the screening box through a mounting block, the L-shaped frame is inserted into the upper side of the frame and can move vertically inside the frame, the electric push rod is provided on the inner bottom wall of the frame, and the telescopic end of the electric push rod is connected to the L-shaped frame.
[0011] As a preferred solution of the screening equipment for tomato sauce processing described in the present invention, in order to adjust the inclination angle of the screening cylinder and position the screening cylinder during the screening process, the cover plate and the adjustment mechanism are connected by a connecting mechanism, and the connecting mechanism includes a connecting seat, a connecting column, a connecting ear and a positioning insertion strip. The connecting seat is installed on the L-shaped frame and moves synchronously with the L-shaped frame. The connecting columns are installed on both sides of the connecting seat, and the connecting columns move synchronously with the connecting seat. The connecting ears are rotatably installed on the outer side of the connecting columns. The lower side of the connecting ear is connected to the upper side of the cover plate. A driving member for driving the connecting ear to rotate is provided on the connecting ear on one of the two sides. Two positioning insertion strips are inserted into the connecting seat, and the positioning insertion strips can move vertically inside the connecting seat.
[0012] The beneficial effects of the embodiments of the present disclosure are: In the present disclosure, tomatoes are screened by replacing a stationary screen plate with a rotating screening drum. The centrifugal force generated when the screening drum rotates can accelerate the screening speed of the tomatoes. The stirring mechanism can achieve stirring of the tomatoes inside the screening drum during the screening process. Compared with the screening equipment in the prior art, tomatoes are usually screened by a stationary screen plate, and the screening method is relatively simple, making it difficult to achieve comprehensive screening of the tomatoes, resulting in poor screening effect of the tomatoes, and it is easy for tomatoes of unqualified quality to be mixed in, which may affect the quality of the tomato sauce after processing. The technical problem is that the screening box and the stirring mechanism that rotate in both directions can accelerate the screening speed of the tomatoes inside the screening drum and improve the work efficiency. The stirring mechanism can stir the tomatoes during the screening process, reducing the probability of tomatoes accumulating inside the screening drum, enhancing the screening effect of the tomatoes, achieving comprehensive screening of the tomatoes, and reducing the probability of unqualified tomatoes being missed, thereby ensuring the quality of the tomato sauce produced subsequently. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] To more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following briefly describes the drawings required for use in describing the embodiments of the present disclosure. Obviously, the drawings described below are merely some exemplary embodiments of the present disclosure. Those skilled in the art can, without inventive effort, derive other drawings based on the content of the exemplary embodiments of the present disclosure and these drawings.
[0014] Figure 1 It is a schematic structural diagram of the present invention as a whole; Figure 2 This is a schematic structural diagram of the present invention from another perspective; Figure 3 It is a vertical cross-sectional view of the internal structure of the screening box of the present invention; Figure 4 This is a schematic diagram of the structure of the mounting column, screening cylinder, opening and closing plate and spring positioning pin of the present invention; Figure 5 Schematic diagram of the composition of the stirring mechanism structure of the present invention; Figure 6 It is a vertical cross-sectional schematic diagram of the adjustment mechanism structure of the present invention; Figure 7 For the present invention Figure 1 A magnified schematic diagram of the local structure at point A.
[0015] In the figure: 1. Screening box; 2. Mounting plate; 3. Screening cylinder; 4. Cover plate; 5. Opening and closing plate; 6. Spring positioning pin; 7. Observation window; 101. stirring shaft; 102. stirring rod; 103. mounting ring; 104. toggle plate; 201, frame; 202, L-shaped frame; 203, electric push rod; 301. Connecting seat; 302. Connecting column; 303. Connecting ear; 304. Positioning insert. DETAILED DESCRIPTION
[0016] The present disclosure will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, rather than to limit the present disclosure.
[0017] To simplify the drawings, only the parts relevant to the disclosure are schematically shown in each figure; they do not represent the actual structure of the product. Furthermore, to simplify the drawings and facilitate understanding, in some figures, only one of the components with the same structure or function is schematically shown or labeled. In this document, "one" not only means "only one" but also "more than one," and "several" includes "two" and "more than two."
[0018] It should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on the specific circumstances.
[0019] In the present disclosure, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.
[0020] In the description of this embodiment, the terms "up", "down", "left", "right", etc., and the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present disclosure.
[0021] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.
[0022] like Figures 1 to 7 As shown, a screening device for tomato paste processing in one embodiment of the present disclosure is shown, which includes a screening box 1, a mounting plate 2, a screening drum 3 and a stirring mechanism. Compared with the screening devices in the prior art, tomatoes are usually screened by a static screen plate, and the screening method is relatively single, which makes it difficult to achieve comprehensive screening of tomatoes, resulting in poor screening effect of tomatoes and easy mixing of unqualified tomatoes, which may affect the quality of the processed tomato paste. In this embodiment, tomatoes are screened by a rotating screening drum 3 instead of a static screen plate. The centrifugal force generated when the screening drum 3 rotates can accelerate the screening speed of tomatoes, thereby improving work efficiency. The stirring mechanism is used to stir the tomatoes inside the screening drum 3 during the screening process, so that the tomatoes can keep rolling inside the screening drum 3, reducing the probability of tomatoes accumulating inside the screening drum 3, enhancing the screening effect of tomatoes, achieving comprehensive screening of tomatoes, and reducing the probability of unqualified tomatoes being missed, thereby ensuring the quality of the tomato paste produced subsequently. like Figure 1 As shown, a discharge port is provided on the lower side of the screening box 1, through which the screened tomatoes can be discharged. A buffer layer is provided on the inner wall of the screening box 1, which can buffer the space between the screening box 1 and the tomatoes, thereby reducing the impact force received by the tomatoes when they hit the inner wall of the screening box 1, thereby reducing the probability of tomato damage. An observation window 7 is provided on one of the two sides of the screening box 1, through which staff can observe the screening status of the tomatoes in the screening box 1 and the screening cylinder 3; like Figure 3 As shown, two mounting plates 2 are plugged into the screening box 1, and square grooves are provided on both sides of the inner wall of the screening box 1. Square bars are installed on both sides of the mounting plate 2, and the width of the square bars is adapted to the width of the square grooves. When the mounting plate 2 is inserted into the interior of the screening box 1, the screening box 1 can position the mounting plate 2 through the square grooves and the square bars, thereby realizing the positioning and installation of the mounting plate 2, ensuring the plugging effect of the mounting plate 2, and the screening cylinder 3 is rotatably mounted on the mounting plate 2 on one of the two sides through the mounting column, and a driving member for driving the mounting column to rotate is provided on the mounting plate 2 connected to the screening cylinder 3, and the stirring mechanism is rotatably mounted on the mounting plate 2 on the other side of the two sides. The main body of the stirring mechanism is arranged inside the screening cylinder 3, and a driving member for driving the stirring mechanism to rotate is provided on the mounting plate 2 connected to the stirring mechanism. Figure 5As shown, the stirring mechanism includes a stirring shaft 101, a stirring rod 102, a mounting ring 103 and a toggle plate 104. The stirring rod 102 is V-shaped. A plurality of stirring rods 102 are arranged in a ring shape on the outside of the stirring shaft 101. The V-shaped stirring rod 102 can better angle the tomatoes inside the screening drum 3, thereby enhancing the stirring effect of the tomatoes, thereby enhancing the screening effect of the screening drum 3 on the tomatoes. Through the bidirectional rotation of the screening drum 3 and the stirring mechanism, stirring is achieved during the screening process of the tomatoes, thereby enhancing the screening effect of the tomatoes. like Figure 3 As shown, a cover plate 4 is installed on the upper side of the mounting plate 2. The cover plate 4 can be fastened to the upper side of the screening box 1 during the screening process of the screening cylinder 3, thereby blocking unqualified tomatoes screened out by the screening cylinder 3, thereby reducing the probability of tomatoes screened out by the screening cylinder 3 flying out of the screening box 1. like Figure 4 As shown, two opening and closing plates 5 are slidably provided on one side of the two sides of the screening drum 3, and two spring positioning pins 6 are provided on the side of the screening drum 3 where the opening and closing plates 5 are installed. The staff can adjust the feeding state of the screening drum 3 by adjusting the opening and closing state of the opening and closing plates 5, thereby facilitating the staff to add materials to the inside of the screening drum 3 or take out the tomatoes that have passed the screening in the screening drum 3. The spring positioning pins 6 can insert and position the screening drum 3 and the opening and closing plates 5, thereby ensuring the stability of the opening and closing plates 5 when opening or closing. like Figure 2 As shown, an adjustment mechanism is provided on one of the two sides of the screening box 1, such as Figure 6 As shown, the adjustment mechanism includes a frame 201, an L-shaped frame 202 and an electric push rod 203. Figure 7 As shown, the cover plate 4 and the adjustment mechanism are connected by a connecting mechanism, which includes a connecting seat 301, a connecting column 302, a connecting ear 303 and a positioning insert 304. The adjustment mechanism can drive the screening drum 3 and the stirring mechanism to rise and fall through the connecting mechanism, the cover plate 4 and the mounting plate 3, thereby realizing the adjustment of the height position of the screening drum 3 and the stirring mechanism, so that the staff can adjust the height position of the screening drum 3 and the stirring mechanism according to the use requirements, which is convenient for the staff to operate the device. The adjustment mechanism can adjust the inclination angle of the screening drum 3, thereby facilitating the staff to add tomatoes to the inside of the screening drum 3 or pour out the tomatoes that have passed the screening in the screening drum 3, thereby facilitating the staff to load or discharge the screening drum 3, realizing semi-automatic discharging of the device, and reducing the labor intensity of the staff. The driving members in this embodiment are all forward and reverse motors.
[0023] Working principle: The electric push rod 203 is started, and the telescopic end of the electric push rod 203 extends to push the L-shaped frame 202 to move upward inside the frame 201. The L-shaped frame 202 drives the cover plate 4 to move upward through the connecting mechanism, and the cover plate 4 drives the mounting plate 2 to move upward, and the mounting plate 2 drives the screening drum 3 and the stirring mechanism to move upward. When the screening drum 3 and the stirring mechanism move out of the screening box 1, the staff pulls the spring positioning pin 6 to cancel the positioning between the screening drum 3 and the opening and closing plate 5 by the spring positioning pin 6, and then opens the opening and closing plate 5 to put the opening and closing plate 5 in the open state. The staff pours the tomatoes that need to be screened into the interior of the screening drum 3. After pouring, the staff closes the opening and closing plate 5 to put it in the closed state, and then positions the screening drum 3 and the opening and closing plate 5 through the spring positioning pin 6, thereby realizing the loading of the inside of the screening drum 3; Then, the electric push rod 203 is started, and the electric push rod 203 drives the L-shaped frame 202 to move upward inside the frame 201. The L-shaped frame 202 drives the cover plate 4 to move downward through the connecting mechanism. The cover plate 4 drives the screening drum 3 and the stirring mechanism to move downward through the mounting plate 2, so that the cover plate 4 is buckled on the screening box 1. At this time, the screening drum 3 and the stirring mechanism are inside the screening box 1. Then, the two forward and reverse motors located on the two mounting plates 2 are started. The forward and reverse motors connected to the mounting column keys drive the mounting columns to rotate, and the mounting columns drive the screening drum 3 to rotate. The screening drum 3 screens the tomatoes inside it. During the screening process, The forward and reverse motor connected to the shaft 101 drives the stirring shaft 101 to rotate in the opposite direction to the screening drum 3. The stirring shaft 101 drives the stirring rod 102 to rotate. The stirring rod 102 stirs the tomatoes inside the screening drum 3. The stirring rod 102 drives the mounting ring 103 to rotate. The mounting ring 103 drives the toggle plate 104 to rotate. The toggle plate 104 toggles the tomatoes at the sieve holes of the screening drum 3, thereby stirring and screening the tomatoes inside the screening drum 3. The unqualified tomatoes screened out by the screening drum 3 fall through the sieve holes into the inside of the screening box 1, and are then discharged from the discharge port on the lower side of the screening box 1 to the inside of the unqualified tomato collection box outside. After the screening is completed, the electric push rod 203 is started, and the telescopic end of the electric push rod 203 is extended to push the L-shaped frame 202 to move upward inside the frame 201. The L-shaped frame 202 drives the cover plate 4 to move upward through the connecting mechanism, and the cover plate 4 drives the mounting plate 2 to move upward, and the mounting plate 2 drives the screening drum 3 and the stirring mechanism to move upward. After moving to the corresponding position, the staff pulls the spring positioning pin 6 to cancel the positioning between the screening drum 3 and the opening and closing plate 5 by the spring positioning pin 6, and then the staff opens the opening and closing plate 5. After opening, the screening drum 3 and the opening and closing plate 5 are positioned by the spring positioning pin 6, so that the opening and closing plate 5 is in the open state. Then, the staff removes the positioning strip 304 from the The connecting seat 301 is pulled out, and the positioning between the connecting seat 301 and the cover plate 4 by the positioning strip 304 is cancelled. Then, the forward and reverse motors located inside the connecting mechanism are started. The forward and reverse motors drive the connecting ears 303 to deflect with the connecting column 302 as the center. The connecting ears 303 drive the cover plate 4 to deflect. The cover plate 4 drives the screening cylinder 3 to deflect through the mounting plate 2. During the deflection of the screening cylinder 3, the tomatoes that have passed the screening inside the screening cylinder 3 roll through the opening to the inside of the screening box 1, thereby realizing the discharge of the tomatoes that have passed the screening inside the screening cylinder 3. After rolling into the screening box 1, the tomatoes are discharged through the discharge port to the qualified tomato collection box outside, thereby realizing the use of the screening equipment.
[0024] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure and are not limiting. Although the present disclosure has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present disclosure may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present disclosure, and all of these should be included in the scope of the claims of the present disclosure.
Claims
1. A screening device for tomato paste processing, comprising a screening box (1), characterized in that: Also includes: Mounting plates (2), two of the mounting plates (2) are plugged into the screening box (1), and the mounting plates (2) are capable of vertically moving inside the screening box (1); A screening drum (3), wherein the screening drum (3) is rotatably mounted on the mounting plate (2) on one of the two sides via a mounting column and moves synchronously with the mounting plate (2); a driving member for driving the mounting column to rotate is provided on the mounting plate (2) connected to the screening drum (3); A stirring mechanism is rotatably mounted on a mounting plate (2) on the other of the two sides and moves synchronously with the mounting plate (2). A driving member for driving the stirring mechanism to rotate is provided on the mounting plate (2) connected to the stirring mechanism. The main body of the stirring mechanism is provided inside the screening cylinder (3). The stirring mechanism is used to stir the tomatoes inside the screening cylinder (3).
2. A screening device for tomato paste processing according to claim 1, characterized in that: The stirring mechanism comprises: a stirring shaft (101), the stirring shaft (101) being rotatably mounted on the mounting plate (2); Stirring rods (102), a plurality of stirring rods (102) are installed on the outside of the stirring shaft (101), and the stirring rods (102) rotate synchronously with the stirring shaft (101); A mounting ring (103), the mounting ring (103) being mounted on the outer end of the stirring rod (102) and rotating synchronously with the stirring rod (102); A plurality of toggle plates (104) are installed on both sides of the mounting ring (103), and the toggle plates (104) rotate synchronously with the mounting ring (103).
3. A screening device for ketchup processing according to claim 2, characterized in that: The stirring rod (102) is V-shaped, and a plurality of the stirring rods (102) are arranged in a ring shape on the outside of the stirring shaft (101).
4. The screening device for ketchup processing according to claim 1, characterized in that: A cover plate (4) is mounted on the upper side of the mounting plate (2), and the cover plate (4) moves synchronously with the mounting plate (2).
5. The screening device for ketchup processing according to claim 1, characterized in that: Square grooves are provided on both sides of the inner wall of the screening box (1), and square bars are installed on both sides of the mounting plate (2), with the width of the square bars matching the width of the square grooves.
6. The screening device for ketchup processing according to claim 1, characterized in that: Two opening and closing plates (5) are slidably arranged on one of the two sides of the screening drum (3), and two spring positioning pins (6) are arranged on the side of the screening drum (3) on which the opening and closing plates (5) are installed.
7. The screening device for ketchup processing according to claim 4, characterized in that: An adjustment mechanism is provided on one of the two sides of the screening box (1), and the adjustment mechanism comprises: A frame (201), the frame (201) being mounted on the screening box (1) via a mounting block; An L-shaped frame (202), the L-shaped frame (202) being plugged into the upper side of the frame (201) and capable of vertically moving inside the frame (201); An electric push rod (203) is arranged on the inner bottom wall of the frame (201), and a telescopic end of the electric push rod (203) is connected to the L-shaped frame (202).
8. The screening device for ketchup processing according to claim 7, characterized in that: The cover plate (4) and the adjustment mechanism are connected via a connecting mechanism, and the connecting mechanism comprises: A connecting seat (301), the connecting seat (301) being mounted on the L-shaped frame (202) and moving synchronously with the L-shaped frame (202); Connecting posts (302), the connecting posts (302) are installed on both sides of the connecting seat (301), and the connecting posts (302) move synchronously with the connecting seat (301); a connecting ear (303), the connecting ear (303) being rotatably mounted on the outside of the connecting column (302), the lower side of the connecting ear (303) being connected to the upper side of the cover plate (4), and a driving member for driving the connecting ear (303) to rotate being provided on the connecting ear (303) on one of the two sides; Positioning inserts (304), two positioning inserts (304) are inserted into the connecting seat (301), and the positioning inserts (304) are capable of vertically moving inside the connecting seat (301).