A prawn clamping part, clamping unit and segmented clamping mechanism

Abstract

The present invention discloses a shrimp clamping part, a clamping unit and a segmented clamping mechanism, wherein the shrimp clamping part includes a clamping surface of the clamping part having, from top to bottom, a support surface for supporting the side of the shrimp body, an upper clamping surface for clamping the shrimp body, a transition surface and a lower clamping surface for clamping the ventral foot and tail of the shrimp; the lower clamping surface is a plane, and the remaining surfaces are curves. The present invention designs a multi-point force-applying clamping surface to achieve adaptive clamping of the shrimp. The segmented shrimp holding mechanism includes a turntable and a number of shrimp clamping units evenly distributed around the turntable. The shrimp clamping units move under the driving force of the turntable and automatically pick up a corresponding number of shrimp clamping units according to the length of the shrimp to segmentally clamp the corresponding positions of the shrimp body; wherein the shrimp clamping unit includes the shrimp clamping part. The present invention achieves adaptive segmented and stable clamping of the shrimp, providing a guarantee for the subsequent processes of opening the back, removing the intestines, and removing the kernel.

Description

Technical Field

[0001] The present invention relates to the technical field of aquatic product processing machinery, and in particular to a prawn clamping part, a clamping unit and a segmented clamping mechanism. Background Art

[0002] Whiteleg shrimp (Penaeus vannamei) are a major commercial shrimp species worldwide. China, India, Vietnam, Ecuador, Indonesia, and Thailand are the world's leading shrimp producers. Their rapid growth, wide temperature and salinity tolerance, strong disease resistance, and low nutritional requirements make them the most widely farmed shrimp in the world. Shrimp, the primary product of primary shrimp processing, is delicious, nutritious, high in protein, low in fat, and rich in various minerals. It is a high-quality ingredient for cooking and preparing a variety of flavorful foods, and is highly sought after by consumers worldwide. With the development of the shrimp processing industry and rising labor costs, traditional manual shelling methods are no longer sufficient for large-scale shrimp production. Mechanized, directional shelling is the primary method for producing high-quality shrimp.

[0003] The directional shelling process primarily involves five steps: sorting and orienting, clamping, back opening, deveining, and kernel removal. This shelling process utilizes a piece-by-piece process, ensuring both deveining and shell removal. Clamping is crucial for directional shelling of shrimp. Its primary purpose is to stabilize the shrimp's position, facilitating back opening, deveining, and kernel removal. Clamping requires individual shrimp to be clamped, with the back exposed. Currently, two main shrimp clamping methods are stationary and belt-type. The turntable shrimp peeling machine developed by Jonsson in the United States utilizes a stationary clamping mechanism that secures the shrimp's tail and provides stable support on both sides. This clamping mechanism ensures stable clamping, which is one of the reasons it can produce a variety of shrimp styles. The belt-type clamping mechanism consists of two conveyor belts arranged side by side to form a V-shaped angle. The shrimp are placed within the V-shaped groove. The two belts apply pressure to the shrimp's sides, securing the shrimp. The synchronous movement of the belts ensures the shrimp's transport. The belt clamping method is inferior to the station-type clamping method in terms of clamping stability and adaptability. Since the station-type clamping has high requirements for the position and distance of the shrimp conveying, the shrimp need to be placed at a fixed spacing and posture during the shrimp feeding process, otherwise the clamping mechanism will not be able to stably clamp the shrimp. The clamping requirements for shrimp orientation and positioning lead to great difficulties in the automated feeding of shrimp. Currently, there is still a lack of effective solutions in industrial applications, and the loading process of the shrimp peeling machine still relies on manual labor. Therefore, the clamping mechanism is a key factor that restricts the full mechanization of the shrimp directional shelling process. Getting rid of the clamping mechanism's requirements for the shrimp's posture and position and realizing adaptive clamping of shrimp is an effective way to reduce the difficulty of shrimp sorting and orientation and realize automatic feeding. Therefore, it is of great significance to provide an adaptive clamping mechanism for shrimp.

[0004] The clamping surface is the part where the clamping claws and the shrimp are in direct contact during the clamping process. Its shape and size have a great influence on the clamping effect. Figure 1 The linear clamping surface and the shrimp each have a single-point contact, generating clamping forces F5 and F6, where 1 is the axial cross-sectional profile of the shrimp, 2 is the clamping surface profile, F5 is the support force exerted by the left clamping surface on the shrimp, N; F6 is the support force exerted by the right clamping surface on the shrimp, N; and α3 is the inclination angle of the clamping surface, (°). As the inclination angle α3 of the clamping surface decreases, the force point gradually shifts from the shrimp body to the abdomen. During this process, the clamping force continuously exerts pressure on the shrimp body, hindering the shell removal process. Simultaneously, the downward shift of the force point weakens the support on both sides of the shrimp, resulting in a decrease in the horizontal clamping stability of the shrimp. This may cause the shrimp to wobble from side to side during shelling, compromising the peeling effect. Therefore, a simple linear structure cannot meet the clamping requirements of the shrimp shelling process. The shape of the clamping surface should be designed based on the shrimp's external characteristics. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a shrimp clamping part, which is designed with a multi-point force-applying clamping surface to achieve adaptive clamping of the shrimp according to the radial cross-sectional profile of the shrimp body.

[0006] On the one hand, the present invention provides a shrimp clamping part, including a clamping surface of the clamping part having, from top to bottom, a support surface for supporting the side of the shrimp body, an upper clamping surface for clamping the shrimp body, a transition surface and a lower clamping surface for clamping the ventral foot and tail of the shrimp; the lower clamping surface is a plane, and the remaining surfaces are curved.

[0007] On the other hand, the present invention provides a prawn clamping unit, which includes a pair of clamping members, which rotate around a rotating shaft to open and close relative to each other. The clamping members have a clamping portion on one side of the rotating shaft, which is the prawn clamping portion, and a connecting portion on the other side of the rotating shaft. The angle between the clamping portion and the connecting portion is obtuse; the obtuse angles of the two clamping members are arranged opposite to each other; a support rod provided with a rotating shaft is sleeved with a sliding block, and the sliding block is connected to the connecting portion by a connecting rod. The sliding block moves up and down along the support rod, and the sliding block pulls the connecting rod to open or close the two clamping portions.

[0008] In another aspect, the present invention provides a segmented shrimp holding mechanism comprising a turntable and a plurality of shrimp clamping units evenly distributed around the turntable. The shrimp clamping units move under the driving force of the turntable, automatically picking up a corresponding number of shrimp clamping units based on the shrimp's length and clamping the shrimp in sections at corresponding locations on the shrimp's body; wherein the shrimp clamping units include the aforementioned shrimp clamping portion. To address the aforementioned problems, the present invention provides a segmented, adaptive shrimp clamping mechanism that achieves adaptive, segmented, and stable shrimp clamping, ensuring the subsequent back-opening, deveining, and kernel extraction processes.

[0009] Beneficial effects

[0010] (1) The clamping surface based on the cross-sectional profile characteristics of the shrimp can adapt to the clamping needs of different positions of the shrimp and solve the problem of difficult stable clamping of the shrimp.

[0011] (2) The clamping units are evenly distributed around the turntable in a dense and uniform manner, ensuring that there are clamping units in an open state at the clamping station at any time. Multiple continuous clamping units can be freely formed into a clamp according to the length and position of the shrimp. Multiple clamping units clamp the shrimp in segments, and adaptive clamping is achieved through segmented clamping and multi-point force application.

[0012] (3) The segmented adaptive shrimp clamping mechanism has the characteristics of non-positioning clamping, which can adapt to the working conditions where the position of shrimp is uncertain after orientation, reduce the difficulty of shrimp sorting and orientation, and help to get rid of the dependence on manual placement and loading, and realize the full mechanization of shrimp directional shelling. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the structure of the prior art in which the straight clamping surface and the prawn are in single-point contact;

[0014] FIG2( a ) is a schematic structural diagram of a prawn clamping portion provided in Example 1 of the present invention;

[0015] FIG2( b ) is a schematic diagram of the structure of the clamping surface of a prawn clamping portion provided in Example 1 of the present invention;

[0016] Figure 3 shows three schematic diagrams of the radial cross-sectional profiles of the shrimp body.

[0017] Figure 4 This is a coordinate diagram of a comprehensive clamping curve of a clamping surface of a prawn clamping portion provided in Example 1 of the present invention;

[0018] Figure 5 Schematic diagram of force analysis of a shrimp shell during the clamping process of a shrimp clamping portion provided by Example 1 of the present invention;

[0019] FIG6( a ) is a schematic structural diagram of the prawn clamping unit in an open state provided by Example 2 of the present invention;

[0020] FIG6( b ) is a schematic structural diagram of the closed state of the prawn clamping unit provided in Example 2 of the present invention;

[0021] Figure 7 This is one of the structural schematic diagrams of a segmented shrimp clamping mechanism provided in Example 2 of the present invention;

[0022] Figure 8 This is the second structural diagram of a segmented shrimp clamping mechanism provided by Example 2 of the present invention;

[0023] Figure 9 This is a schematic diagram of force analysis of a prawn clamping unit of a segmented prawn clamping mechanism provided by Example 2 of the present invention;

[0024] FIG10( a ) is a schematic diagram of the arc track structure of a segmented shrimp clamping mechanism provided in Example 2 of the present invention;

[0025] FIG10( b ) is a coordinate diagram of the track curved surface profile of a segmented prawn clamping mechanism provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0027] Example 1

[0028] Referring to Figure 2, a shrimp clamping device comprises, from top to bottom, a support surface 1, an upper clamping surface 2, a transition surface 3, and a lower clamping surface 4. The lower clamping surface is flat, while the remaining surfaces are arcuate, with the arcs centered on the same side of the clamping surface. The upper clamping surface is used to clamp the shrimp body, while the lower clamping surface is used to hold the shrimp's ventral feet and tail. The transition surface ensures a smooth transition between the upper and lower clamping surfaces and provides support for the shrimp. The support surface provides a certain degree of support for the shrimp's sides, preventing the shrimp from swaying and improving clamping stability.

[0029] The clamping surface of the clamping part of the shrimp clamping unit is formed by stretching the clamping curve, so the design of the clamping curve is key. By opening and closing the two clamping parts to different degrees, the clamping curve 100 adaptively matches the radial cross-sectional profile 200 of the shrimp. The radial profile of the shrimp is mainly divided into wedge-shaped profile, diamond-shaped profile and linear profile. Referring to Figure 3(a), for the wedge-shaped profile, the focus should be on clamping the ventral foot while providing support on both sides. Therefore, the clamping line mainly consists of two sections, a straight line and a curve. The straight line provides a greater clamping force for the ventral foot, and the curve fits the side of the shrimp body and provides support. Referring to Figure 3(b), for the diamond-shaped profile, the two lower side surfaces should be clamped, and the clamping line is also straight. Since the bottom of the diamond profile has a certain width, the two clamping lines form an isosceles trapezoidal structure. See Figure 3(c). For the linear profile, since the thickness of the shrimp tail is generally around 1 mm, the clamping line of the linear profile adopts a V-shaped structure. The minimum V-shaped angle can be 0°, and the two clamping lines coincide, so tight clamping can be achieved.

[0030] The prawn clamping unit can clamp any position of the prawn, so the clamping surface should adapt to the three contours of the prawn cross section. According to this requirement, the clamping curve is designed by fusing the three clamping surface contour lines to obtain a comprehensive clamping curve. The A0B0 segment is the clamping surface contour for clamping the ventral foot and tail of the prawn, B0C0 is the transition line, C0D0 is the clamping surface contour for clamping the shrimp body, and D0E0 is the shrimp body support curve. The plane rectangular coordinate system in the coordinate diagram of the comprehensive clamping curve is established with the rotation axis O of the clamping part as the origin, and the clamping curve in the coordinate system is the clamping surface contour when the two clamping parts are at the maximum angular position. According to the external shape parameters of the prawn, see Figure 4 , the parameter design of the comprehensive clamping curve must satisfy the following formula:

[0031]

[0032] Where a is the grippable length of the ventral foot, mm;

[0033] b——the length of the bottom side of the rhombus outline of the shrimp, mm;

[0034] c – lateral height of the rhombus outline of the shrimp, mm;

[0035] d – maximum thickness of the rhombus outline of the shrimp, mm;

[0036] e——maximum thickness of shrimp, mm;

[0037] - length of the lower clamping surface;

[0038] ——The distance from the top of the lower clamping surface to the y-axis;

[0039] ——The height between the top of the upper clamping surface and the top of the lower clamping surface;

[0040] ——The distance from the bottom of the upper clamping surface to the y-axis;

[0041] ——The distance from the top of the support surface to the y-axis;

[0042] The comprehensive clamping curve equation when the clamping surface is at the maximum opening angle is obtained from formula (1):

[0043]

[0044] Taking point B of the comprehensive clamping curve as the starting point and the arc contour of the abdomen of the shrimp in its natural state as the path, the comprehensive clamping line is stretched to a certain arc length to obtain the clamping surface.

[0045] See also Figure 5The clamping force applied by the clamping unit to the shrimp is an important mechanical parameter. Since removing the kernel is the link in the peeling process where the shrimp is subjected to the greatest force, in order to determine the range of the clamping force, a mechanical analysis of the shrimp clamping is performed with kernel removal as the working condition. The number of clamping units acting on the shrimp is selected as the minimum value, and the three clamping units clamp the wedge-shaped contour area, the diamond-shaped contour area, and the tail respectively. Taking the shrimp shell as the force-bearing body, during the process of removing the kernel, the shrimp shell is subjected to the adhesion force and friction force from the shrimp kernel, as well as the pressure from the clamping surface. In order to ensure the stable clamping of the shrimp shell during the process of removing the kernel, the following formula must be satisfied:

[0046]

[0047] In the formula ——the combined force of the shrimp on the shell, N;

[0048] ——Friction force on the ventral foot, N;

[0049] ——Friction force on the shrimp body, N;

[0050] ——Friction force on the tail, N;

[0051] μ5——static friction coefficient between shrimp shell and clamping surface;

[0052] μ6——static friction coefficient between shrimp and shell;

[0053] F1'——pressure on the shrimp body by the left clamping surface, N;

[0054] F j ——pressure of the left clamping surface on the ventral foot, N;

[0055] F2'——pressure of the shrimp body on the middle clamping surface, N;

[0056] F3'——pressure of the shrimp tail on the right side of the clamp, N;

[0057] F g ——The adhesion force between the shrimp shell and the shrimp meat, N;

[0058] Arranging formula (3) yields:

[0059] 2(μ5-μ6)(F1'+F2')+2μ5(F j +F3')>F g (4)

[0060] According to the force analysis, formula (4) can be split into:

[0061] 2(μ5-μ6)(F1'+F2')>0 (5)

[0062] 2μ5(F j +F3')>F g (6)

[0063] Equation (5) indicates that relative sliding cannot occur between the clamping surface and the shrimp body, resulting in μ5>μ6. Therefore, to improve the clamping effect, the roughness of the upper clamping surface can be increased to increase the friction coefficient between the shrimp body and the clamping surface. The roughness is increased by laying conical protrusions on the upper clamping surface. Considering the dimensions of the upper clamping surface, the height of the conical protrusions is determined to be 1 mm, and the protrusions are evenly arranged in two rows.

[0064] Formula (6) indicates that the sum of the sliding friction of the shrimp's ventral foot and tail must be greater than the shell-meat adhesion force. From the previous analysis, we know that F3'>F1, so we can get the formula:

[0065] 4μ5F3'>F g (7)

[0066] Combined with the compressive rupture limit of the shrimp, the clamping force F' of the clamping plate on the shrimp must meet 2.5N <F'<19.8N。

[0067] This embodiment adapts to the radial profile of each part of the shrimp body through the multi-segment design of the clamping curve of the clamping part and the opening and closing angles of the two clamping parts. When the clamping part clamps the shrimp, the clamping part adaptively determines the opening angle according to the radial profile of the shrimp's body part, thereby overcoming the defect of the station-type clamping that has strict requirements on the position and distance of the clamped shrimp; at the same time, the multi-segment design of the clamping curve of the clamping part realizes multi-point force application of the clamping part, overcoming the single-point force application and unstable clamping defects of the belt-type clamping surface.

[0068] Example 2

[0069] See also Figure 7 The segmented shrimp clamping mechanism includes a plurality of shrimp clamping units 10, a turntable 20 and a transmission mechanism 30. The shrimp clamping units are evenly arranged around the turntable, and the transmission mechanism drives the turntable to rotate and drive the shrimp clamping units to rotate.

[0070] Referring to Figure 6 , the prawn clamping unit 10 includes a pair of clamping members 11 that rotate about a rotation axis O to open and close relative to each other. A sliding block 14 is mounted on a support rod 16 provided with the rotation axis O. On one side of the rotation axis O, the clamping member comprises the clamping portion of Example 1 for clamping the prawns. On the other side of the rotation axis O, a connecting portion is provided for connecting the sliding block via a connecting rod. The angle between the clamping and connecting portions is obtuse. The two clamping members are arranged as mirror images of the rotation axis O, extending in opposite directions away from the rotation axis O. The two connecting members are arranged as mirror images of the rotation axis O, extending in opposite directions away from the rotation axis O. When the sliding block moves downward along the support rod, it pulls the connecting rod, causing the two clamping members to move away from each other, resulting in an open state. When the sliding block moves upward along the support rod, it pushes the connecting rod, causing the two clamping members to move closer to each other, resulting in a closed clamping state.

[0071] Referring to Figures 6-8, the support rods 16 of each prawn clamping unit are located at the other end relative to the rotating shaft O and are evenly distributed circumferentially on the turntable 20. In the opening and closing direction of the clamping part of the prawn clamping unit, bearing rollers 13 are set on both sides of the sliding block, and a spring 15 is sleeved on the support rod and is located between the sliding block and the turntable. Arc tracks 40 are set on both sides of the turntable, and the arc surface of the arc track faces the rotation center of the turntable. The two rollers on both sides of the sliding block slide in cooperation with the corresponding two arc tracks. In the non-track section, there is no pressure on the rollers, and the elastic force generated by the spring forces the sliding block to slide along the support rod away from the rotation center of the turntable. The sliding block pushes the connecting rod, so that the two clamping parts are close to each other and are in a closed clamping state; in the track section, the rollers are subjected to pressure from the arc track toward the rotation center of the turntable. The elastic force generated by the deformation of the spring forces the sliding block to slide along the support rod toward the rotation center of the turntable. The sliding block pulls the connecting rod, so that the two clamping parts are away from each other and are in an open state.

[0072] See also Figure 9 The clamping unit establishes a plane rectangular coordinate system with point O as the origin. The connection point between the connecting rod and the connecting part is point G, the clamping (end) point of the upper clamping surface is A, the clamping member AOG rotates around point O, and the slider HI slides along the x-axis. According to the motion relationship, it can be considered that point H rotates around point G, so with point G as the center and l as the center, the GH The circle with radius y=l and the straight line HI The intersection of the two points is the coordinate of point H. Let the coordinate of point H be (x H ,y H ), we can get the following formula;

[0073]

[0074] The horizontal coordinate formula of point H can be obtained from formula (8):

[0075]

[0076] The calculated horizontal coordinate of point H satisfies: 25≤xH ≤29.3. Since the horizontal coordinate range of point H is the spring compression stroke, the spring compression stroke during the entire movement of the clamping unit is 4.3mm. Based on the overall dimensional design of the clamping mechanism, the spring length when the spring compression reaches its maximum value is determined to be 16mm.

[0077] The clamping unit is subjected to spring pressure F I and the support force F of the shrimp A , the force relationship of the clamping unit satisfies the following formula:

[0078]

[0079] Where α4 is the angle between the clamping claw rotating rod OG and the x-axis, (°); β4 is the angle between the connecting rod GH and the horizontal line, (°). OA The length between the rotation axis O and the end point A of the upper clamping surface, mm;

[0080] l OG is the length from the axis O to the connection point G, mm;

[0081] l GH is the length of the connecting rod GH, mm.

[0082] The spring force satisfies F I >6.2N. Therefore, the spring is always in a compressed state in the clamping unit. Since the spring force is the smallest when the spring is at the minimum compression amount, the relationship between the spring length and the spring force satisfies the following formula:

[0083] (s3-4.3-16)k3>F I (11)

[0084] Where s3 is the total length of the spring, mm

[0085] k3——spring coefficient, N / mm

[0086] From formula (11), we can get:

[0087]

[0088] From Equation (12), we can see that the spring coefficient is inversely proportional to the total length of the spring. Considering the limitation of spring compression and the prawn rupture limit, the spring coefficient and total length should not be too large. Therefore, after comprehensive consideration, the spring length is determined to be 35 mm and the spring elastic coefficient is 0.49 N / mm.

[0089] Referring to Figure 10 , the contour of the track surface 41 of the curved track 40 is curve A2B2C2D2. This contour curve is divided into three segments, all of which are circular arcs. Segment A2B2 is the open transition zone, B2C2 is the open zone, and C2D2 is the closed transition zone. Analysis of the idling process without shrimp clamping reveals that as the clamping unit moves from point A2 to point B2, the clamping plates gradually transition from a fully closed state to a fully open state. As the clamping unit moves from point B2 to point C2, the clamping plates remain open. As the clamping unit moves from point C2 to point D2, the clamping plates gradually close. In all other positions, the clamping plates remain closed. When shrimp are present, segment A2B2 primarily involves the shedding of shrimp shells. The opening of the clamping plates eliminates the clamping force, allowing the shells to fall under gravity. Segment B2C2 is where the shrimp enter the clamping mechanism; the opening of the clamping plates facilitates the entry of the shrimp into the clamping station. The clamping plates in the C2D2 section gradually exert pressure on the shrimp to achieve stable clamping.

[0090] O2 is the arc center of the opening area and B2C2 is the arc surface of the arc track. The track surface includes the track arc B2C2 where the clamping part is fully opened, the track arc C2D2 where the clamping part is gradually closed, and the track arc A2B2 where the clamping part is fully opened.

[0091] Based on the overall dimensions of the turntable and the spring's compression stroke, O2B2 = O2C2 = 76.5 mm, and O2A2 = O2D2 = 80.8 mm. Considering the potential for shrimp to slip before being stably clamped as the clamping plate rotates downward, the clamping unit must be fully closed before the shrimp reaches the slipping position to prevent this. Based on the friction angle measurement results of the shrimp's ventral foot, an inclination angle of greater than 30° is sufficient. Therefore, the inclination angles of O2D2 and O2C2 are designed to be 36° and 45°, respectively. Considering that the clamping area is the working area for back opening, deveining, and shell removal, increasing the clamping area as much as possible will provide more space for the layout of subsequent processes. Therefore, point B2 should be positioned as high as possible. When B2 moves above the horizontal axis, the clamping unit gradually applies a supporting force to the shrimp shell, which gradually offsets gravity and hinders the shell's automatic shedding. Therefore, a position of point B2 on the horizontal axis is more reasonable.

[0092] According to the analysis, the contour model of the designed track surface is as follows:

[0093]

[0094] During operation, the shrimp clamping units perform circular motion in the axial direction of the turntable, driven by the rotational force of the turntable. In the radial direction of the turntable, the shrimp clamping units perform regular opening and closing motions, driven by the support force of the track. By superimposing these two motions, the shrimp clamping mechanism achieves directional gripping, conveying, and discharge of shrimp. After orientation, the shrimp drop from the top into the gripping position, where the gripping units are open. Depending on the length of the shrimp, two to four shrimp gripping units are used to grip the shrimp, corresponding to the diamond, wedge, and linear contours of the entire shrimp body, achieving segmented gripping of the shrimp. The prawns begin to rotate, supported by multiple gripping units. Driven by the curved track's curvature, the gripping units gradually close. Each gripping unit automatically determines the gripping plate angle based on the thickness of the prawn, achieving segmented, adaptive gripping. The subsequent rotational conveying process then proceeds with the back-opening, deveining, and shell removal. After the shell and shell are separated, the shell remains gripped. When the gripping units contact the curved track again, pressure forces the gripping plates to open, releasing the shell. The gripping units then remain open, entering the next gripping cycle.

[0095] The curved track utilizes a dual-track structure, with an identical track located on each side of the turntable. Small bearings roll on the track surface, continuously applying force to the clamping mechanism. The movement is divided into two phases: a closing phase and an opening phase. Since the clamping unit in the closing phase doesn't require track pressure, no track is required for the closing phase.

[0096] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A prawn clamping part, characterized in that: include: The clamping surface of the clamping part has, from top to bottom, a support surface for supporting the side of the shrimp body, an upper clamping surface for clamping the shrimp body, a transition surface, and a lower clamping surface for clamping the ventral foot and tail of the shrimp; The radial profiles of the prawns are wedge-shaped, pentagonal, and linear. A comprehensive clamping curve is formed by merging the three radial profiles of the prawns. The parameter design of the comprehensive clamping curve must satisfy the following formula: （ ） Where a is the grippable length of the ventral foot, mm; b——the length of the bottom side of the rhombus outline of the shrimp, mm; c – lateral height of the rhombus outline of the shrimp, mm; d – maximum thickness of the rhombus outline of the shrimp, mm; e——maximum thickness of shrimp, mm; ——The length of the lower clamping surface, where A0 is the bottom endpoint of the lower clamping surface and B0 is the top endpoint of the lower clamping surface; —The distance from the top of the lower clamping surface to the y-axis, where B0 is the top endpoint of the lower clamping surface and B1 is the foot of the vertical perpendicular to the top endpoint B0 of the lower clamping surface on the y-axis; —The height between the top of the upper clamping surface and the top of the lower clamping surface, where D1 is the foot of the perpendicular to the top endpoint D0 of the upper clamping surface on the y-axis, and B1 is the foot of the perpendicular to the top endpoint B0 of the lower clamping surface on the y-axis; ——The distance from the top of the upper clamping surface to the y-axis, where D0 is the top endpoint of the upper clamping surface and D1 is the foot of the perpendicular to the top endpoint D0 on the y-axis; ——The distance from the top of the support surface to the y-axis, where E0 is the top endpoint of the support surface and E1 is the foot of the perpendicular to the top endpoint E0 on the y-axis; The comprehensive clamping curve equation when the clamping surface is at the maximum opening angle is obtained from formula (1): (2)。 2. The prawn clamping portion according to claim 1, characterized in that: The force of the clamping part on the shrimp when taking out the kernel must satisfy the following formula: （ ） In the formula ——the combined force of the shrimp on the shell, N; ——Friction force on the ventral foot, N; ——Friction force on the shrimp body, N; ——Friction force on the tail, N; ——The static friction coefficient between the shrimp shell and the clamping surface; ——The static friction coefficient between shrimp and shrimp shell; ——Pressure of the shrimp body on the left side of the clamp, N; ——pressure of the left clamping surface on the ventral foot, N; ——The pressure of the shrimp body on the middle clamp, N; ——Pressure of the shrimp tail on the right clamping surface, N; ——The adhesion force between the shrimp shell and the shrimp meat, N; Arranging formula (3) yields: （ ） According to the force analysis, Equation (4) can be split into: （ ） （ ） Formula (5) indicates that there can be no relative sliding between the clamping surface and the shrimp body, and we can get ; Formula (6) indicates that the sum of the sliding friction of the shrimp's ventral foot and tail must be greater than the shell-meat adhesion force; From the previous analysis, we know that , we can get the formula: （ ） Combined with the compressive rupture limit of the shrimp, determine the clamping force of the clamping surface on the shrimp The scope to be met.

3. The prawn clamping portion according to claim 1 or 2, characterized in that: Conical protrusions are arranged on the upper clamping surface.

4. The prawn clamping unit is characterized by: The invention comprises a pair of clamping members, which rotate around a rotating shaft to open and close relative to each other. The clamping members have a clamping portion on one side of the rotating shaft, which is the prawn clamping portion described in any one of claims 1 to 3, and a connecting portion on the other side of the rotating shaft. The angle between the clamping portion and the connecting portion is obtuse. The obtuse angles of the two clamping members are arranged opposite to each other. A sliding block is sleeved on a support rod provided with a rotating shaft. The sliding block is connected to the connecting portion through a connecting rod. The sliding block moves up and down along the support rod. The sliding block pulls the connecting rod to open or close the two clamping parts.

5. The segmented shrimp clamping mechanism is characterized by: The system includes a turntable and a plurality of shrimp clamping units evenly distributed around the turntable. The shrimp clamping units move under the driving force of the turntable and automatically pick up a corresponding number of shrimp clamping units according to the length of the shrimp and clamp the corresponding positions of the shrimp body in sections. Wherein, the prawn clamping unit comprises the prawn clamping part according to any one of claims 1 to 3.

6. The segmented shrimp clamping mechanism according to claim 5, characterized in that: The prawn clamping unit includes a pair of clamping members, which rotate around a rotating shaft to open and close relative to each other. The clamping member has a clamping portion on one side of the rotating shaft and a connecting portion on the other side of the rotating shaft, and the angle between the clamping portion and the connecting portion is obtuse. The obtuse angles of the two clamping members are arranged opposite to each other. A supporting rod provided with a rotating shaft is sleeved with a sliding block, and the sliding block is connected to the connecting portion through a connecting rod. The sliding block moves up and down along the support rod, and the sliding block pulls the connecting rod to open or close the two clamping parts.

7. The segmented prawn clamping mechanism according to claim 6, characterized in that: The support rod is located at the other end of the support rod with the rotating shaft and is evenly arranged on the turntable. In the opening and closing direction of the clamping part of the prawn clamping unit, a roller is provided on the sliding block. A spring is sleeved on the support rod and is located between the sliding block and the turntable. The deformation of the spring causes the slider to move up and down. At least one arc track is provided in the axial direction of the turntable, the arc surface of the arc track faces the rotation center of the turntable, and the roller of the sliding block slides in cooperation with the corresponding arc track.

8. The segmented prawn clamping mechanism according to claim 7, characterized in that: A plane rectangular coordinate system is established with the rotation axis O as the origin; the connection point between the connecting rod and the connecting part is point G, the clamping point of the upper clamping surface is A, the clamping part AOG rotates around point O, and the sliding block HI slides along the x-axis; according to the motion relationship, it can be considered that point H rotates around point G, with point G as the center and l as the center. GH The circle with radius y=l and the straight line HI The intersection point is the coordinate of point H. Let the coordinate of point H be ( , ), we can get the following formula: （ ） is the angle between the connecting part OG and the x-axis, (°); From formula (8), the horizontal coordinate formula of point H can be obtained: （ ） The calculated horizontal coordinate range of point H is the compression stroke of the spring. According to the overall size design of the clamping mechanism, the spring length when the spring compression reaches the maximum value is determined; The force relationship of the shrimp clamping unit satisfies the following formula: （ ） In the formula, the shrimp clamping unit is subjected to the spring pressure F I , N; clamping force F on the shrimp A , N; is the angle between the gripping claw rotation rod OG and the x-axis, (°); is the angle between the connecting rod GH and the horizontal line, (°); The length between the rotation axis O and the end point A of the upper clamping surface, mm; is the length from the axis O to the connection point G, mm; is the length of the connecting rod GH, mm; Get spring force satisfied > , spring force F I Need to be greater than In order to ensure that the clamping unit has sufficient clamping force to achieve stable clamping of the shrimp; therefore, the spring in the clamping unit is always in a compressed state. Since the spring force is the smallest when the spring is at the minimum compression amount, the relationship between the spring length and the spring force satisfies the following formula: （ ） In the formula ——is the compression stroke of the spring during the entire movement of the clamping unit, mm; ——The length of the spring when the spring compression reaches the maximum value, mm; ——Total length of spring, mm ——Spring constant, N / mm From formula (11), we can get: （ ） It can be seen from formula (12) that the spring coefficient is inversely proportional to the total length of the spring; considering the limitation of the spring compression amount and the prawn rupture limit, the spring length and spring elastic coefficient are determined.

9. The segmented prawn clamping mechanism according to claim 7 or 8, characterized in that: The track surface of the arc track includes a track arc B2C2 with the clamping portion fully opened, a track arc C2D2 with the clamping portion gradually closed, and a track arc A2B2 with the clamping portion fully opened. The contour model of the track surface of the arc track is as follows: A2B2 curve: (329.9° 360° B2C2 curve: (45° 180°) ( ) C2D2 curve: (225° 255.1°).

Images