A container tray positioning, clamping and flipping unloading device

Abstract

The present invention discloses a container plate positioning, clamping and flipping feeding device, comprising a flip bracket, a clamping mechanism, a flipping mechanism, and a positioning mechanism. The flip bracket has a flipping axis, and a placement position for placing a container plate of an external device is arranged on the flip bracket; the clamping mechanism is installed on the flip bracket; the flipping mechanism is used to drive the flip bracket to flip around the flipping axis; the positioning mechanism has a trigger end for sequentially triggering the clamping mechanism to clamp the container plate of the external device and the flipping mechanism to drive the flip bracket to flip. After the container plate is positioned by the trigger end of the positioning mechanism, the clamping mechanism is triggered to clamp the container plate to the placement position, and then the flipping mechanism drives the flip bracket to flip its own flipping axis. The device can realize the three functions of automatic positioning, clamping and flipping feeding of the container plate, thereby improving the efficiency and accuracy of feeding.

Description

Technical Field

[0001] The invention relates to the fields of smart home appliances, smart kitchens and cooking technology, and in particular to a container plate positioning, clamping and flipping feeding device. Background Art

[0002] Traditional material delivery is generally done manually, which increases the labor intensity of workers and causes inaccurate delivery. Some automated feeding equipment has appeared on the market to reduce the burden on workers, but for some liquid materials or some special items, container plates are required. In the field of smart kitchens, when using container plates, it is necessary to realize the functions of rapid positioning, clamping, and flipping of the container plates for feeding (feeding). However, traditional feeding equipment has a single function and cannot realize the above functions in one mechanism. It usually requires manual intervention to operate the container plate for positioning, clamping, flipping and feeding, which is not good for the user's operating experience. In addition, the traditional feeding equipment also has the problems of large equipment size and inability to guarantee positioning accuracy. Summary of the invention

[0003] The object of the present invention is to provide a container tray positioning, clamping and flipping unloading device to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or create conditions.

[0004] The technical solutions adopted to solve the above technical problems are:

[0005] A container tray positioning, clamping and flipping feeding device comprises: a flip bracket, a clamping mechanism, a flipping mechanism, and a positioning mechanism. The flip bracket has a flip axis, and a placement position for placing an external container tray is arranged on the flip bracket; the clamping mechanism is installed on the flip bracket, and the clamping mechanism is used to clamp the external container tray at the placement position; the flipping mechanism is used to drive the flip bracket to flip around the flip axis; the positioning mechanism has a trigger end for sensing that the external container tray reaches the placement position and sequentially triggering the clamping mechanism to clamp the external container tray and the flipping mechanism to drive the flip bracket to flip.

[0006] The beneficial effect of the present invention is that when in use, the container plate containing materials is placed on the placement position, and at the same time, after the trigger end of the positioning mechanism senses that the container plate is in place (that is, after the container plate is positioned), the trigger end of the positioning mechanism triggers the clamping mechanism to clamp the container plate and fix it on the placement position, that is, the container plate is clamped, and then the flipping mechanism drives the flipping bracket to flip its own flipping axis, that is, the container plate is flipped and fed. The device can realize the three functions of automatic positioning, clamping and flipping of the container plate for feeding (feeding), thereby improving the efficiency and accuracy of feeding.

[0007] As a further improvement of the above technical solution, the positioning mechanism includes a position switch arranged at the placement position, the position switch has the trigger end, and the trigger end is configured to sense the container disk of the external device reaching the placement position by interfering with the container disk of the external device, thereby triggering the clamping mechanism to clamp the container disk of the external device and the flipping mechanism to drive the flipping bracket to flip.

[0008] When in use, the position switch is connected to the electric control system of the peripheral device, and the electric control system of the peripheral device can control the actions of the clamping mechanism and the flipping mechanism. When the container tray is placed in the placement position, the container tray will conflict with the position switch, triggering the position switch, and then the position switch controls the clamping mechanism to clamp the container tray of the peripheral device and the flipping mechanism to drive the flip bracket to flip through the electric control system of the peripheral device.

[0009] The position switch can be set at different positions according to actual conditions. The position switch in this solution is set on the edge of the placement position and is pressed down by the weight of the container tray to ensure that the container tray is placed in place. The position switch can output the correct switch signal to ensure that the whole machine runs stably, safely and reliably.

[0010] As a further improvement of the above technical solution, a plurality of the position switches are evenly distributed on the edge of the placement position.

[0011] The container plate is sensed by a plurality of position switches to improve the accuracy of positioning. When the container plate contacts the plurality of position switches, the actions of the clamping mechanism and the turning mechanism are triggered.

[0012] As a further improvement of the above technical solution, the clamping mechanism includes clamping fingers, a clamping drive assembly, and a clamping transmission assembly. The number of the clamping fingers is multiple, and the multiple clamping fingers are evenly distributed on the edge of the placement position. The clamping drive assembly is connected to the multiple clamping fingers through the clamping transmission assembly.

[0013] When the container tray needs to be clamped, the clamping drive assembly drives multiple clamping fingers to move synchronously through the clamping transmission assembly to clamp the container tray at the placement position. The container tray can be clamped at different positions by changing the installation position of the clamping fingers and according to the structure of the container tray. The outer side surface and the outer bottom surface of the container tray can be clamped. This solution clamps the upper edge of the container tray, and the clamping fingers clamp the upper edge of the container tray at the edge of the placement position.

[0014] As a further improvement of the above technical solution, the multiple clamping fingers are divided into two rows of clamping fingers, and the two rows of clamping fingers are symmetrically arranged on the two side edges of the symmetrical placement position; the clamping transmission assembly includes a clamping driven shaft, and the number of the clamping driven shafts is two, and the clamping fingers on the same row are rotatably mounted on the flip bracket through the clamping driven shaft; the clamping drive assembly is transmission-connected to the two clamping driven shafts.

[0015] The clamping drive assembly drives two clamping driven shafts to drive two rows of clamping fingers on the placement position to move synchronously, which reduces the volume of the transmission structure and makes the device more compact.

[0016] As a further improvement of the above technical solution, the clamping transmission assembly also includes a clamping driving shaft rotatably mounted on the flip bracket, a clamping driving wheel and a clamping driving pulley fixedly mounted on the clamping driving shaft, a clamping driven wheel fixedly mounted on one of the clamping driven shafts, a clamping driven pulley fixedly mounted on the other clamping driven shaft, and a clamping synchronous belt connected between the clamping driving pulley and the clamping driven pulley, the clamping driving wheel is transmission-connected to the clamping driven wheel, and the clamping drive assembly includes a clamping drive unit transmission-connected to the clamping driving shaft.

[0017] When the clamping driving unit drives the clamping active shaft to rotate, the clamping active shaft drives one of the clamping driven shafts to rotate through the transmission of the clamping active wheel and the clamping driven wheel. At the same time, the clamping active shaft drives the other clamping driven shaft to rotate through the transmission of the clamping active pulley, the clamping driven pulley and the clamping synchronous belt. Therefore, under the drive of one clamping driving unit, two rows of clamping fingers can be driven to move synchronously, making the transmission structure simpler, reducing the number of clamping driving units and reducing the manufacturing cost.

[0018] As a further improvement of the above technical solution, the present invention further comprises a base, the flip bracket is mounted on the base, and the flip bracket can rotate around the flip axis relative to the base;

[0019] The flip mechanism includes: a flip transmission assembly and a flip drive assembly, the flip transmission assembly includes a flip driven pulley, a flip driving pulley, and a flip synchronous belt connected between the flip driven pulley and the flip driving pulley, the flip driven pulley is relatively fixedly connected to the flip bracket, and the flip driven pulley is coaxially arranged with the flip axis; the flip drive assembly is installed on the base, and the flip drive assembly is used to drive the flip driving pulley to rotate.

[0020] When the flip bracket is flipped, the flip driving assembly drives the flip driving pulley to rotate, and the flip driving pulley drives the flip driven pulley to rotate through the flip synchronous belt, and then the flip driven pulley can drive the flip bracket to rotate around the flip axis.

[0021] As a further improvement of the above technical solution, two flip transmission assemblies are provided, and the two flip transmission assemblies are arranged at intervals along the flip axis. A flip transmission shaft is connected between the two flip transmission assemblies, and the flip transmission shaft is coaxially fixedly connected to two flip driving pulleys at the same time. The flip drive assembly is connected to the flip transmission shaft in transmission.

[0022] The flipping drive assembly can drive the two flipping active pulleys to rotate synchronously through the flipping transmission shaft, and then drive the two flipping driven pulleys to rotate synchronously. On the one hand, the flipping stability of the flipping bracket can be improved. On the other hand, one flipping drive assembly can drive the two driven pulleys to rotate synchronously, making the transmission structure simpler and more compact, reducing the number of flipping drive assemblies, and further reducing manufacturing costs.

[0023] As a further improvement of the above technical solution, the flip bracket is a rectangular frame structure, the inner frame of the rectangular frame structure is the placement position, and an inner retaining wall arranged in an inclined manner is arranged on the inner periphery of the placement position.

[0024] The inner retaining wall arranged in an inclined manner on all sides plays a guiding role for the container tray, making it convenient to take and put the container tray. The inner frame of the rectangular frame structure is determined according to the size of the container tray.

[0025] As a further improvement of the above technical solution, an annular positioning platform is protruding upward from the edges around the placement position, an inner retaining wall is arranged at an angle on the inner periphery of the positioning platform, the inner retaining wall extends to the inner periphery of the placement position, and an outer retaining wall is arranged on the outer periphery of the positioning platform.

[0026] When placing the container tray, the positioning platform plays a certain positioning role on the container tray, and the inner retaining wall contacts the container tray, and the outer retaining wall also contacts the outer edge of the container tray, so that the container tray can be firmly positioned at the placement position. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments;

[0028] Figure 1 This is a schematic structural diagram of a container tray positioning, clamping and flipping feeding device provided by the present invention before flipping of one embodiment;

[0029] Figure 2 This is a schematic structural diagram of a container tray positioning, clamping and flipping feeding device provided by the present invention after flipping one embodiment;

[0030] Figure 3 It is a structural schematic diagram of an embodiment of the flip bracket, the clamping mechanism and the flip mechanism provided by the present invention;

[0031] Figure 4 It is a structural schematic diagram of an embodiment of the flip bracket and the clamping mechanism provided by the present invention;

[0032] Figure 5 The cross section of one embodiment of the flip bracket provided by the present invention when it has a positioning platform Figure 1 ;

[0033] Figure 6 It is a cross-sectional view of an embodiment of the flip bracket provided by the present invention when it does not have a positioning platform;

[0034] Figure 7 The cross section of one embodiment of the flip bracket provided by the present invention when it has a positioning platform Figure 2 . DETAILED DESCRIPTION

[0035] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0036] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, 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, and therefore should not be understood as a limitation on the present invention.

[0037] In the description of the present invention, if there are words such as "several", it means one or more, "more" means more than two, greater than, less than, exceed, etc. are understood as not including the number, and above, below, within, etc. are understood as including the number.

[0038] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0039] Reference Figures 1 to 4 The container tray positioning, clamping and flipping feeding device of the present invention is implemented as follows:

[0040] The container tray positioning, clamping and flipping unloading device of this embodiment includes: a flip bracket 100, a base 500, a clamping mechanism, a flipping mechanism, and a positioning mechanism.

[0041] like Figure 1 and Figure 2As shown, the flip bracket 100 is mounted on the base 500, and the flip bracket 100 can rotate around the flip axis relative to the base 500. A placement position 110 for placing a container plate of an external device is provided on the flip bracket 100, and the flip bracket 100 is a rectangular frame structure, and the inner frame of the rectangular frame structure is the placement position 110, wherein the inner frame of the rectangular frame structure is determined according to the size of the container plate. The shape and size of the placement position 110 can also be determined according to the container plate, not just the rectangular inner frame structure in this embodiment.

[0042] like Figure 3 and Figure 4 As shown, the clamping mechanism of this embodiment is installed on the flip bracket 100, and the clamping mechanism is used to clamp the external container tray on the placement position 110. Specifically, the clamping mechanism includes a plurality of clamping fingers 300, a clamping drive assembly, and a clamping transmission assembly. The plurality of clamping fingers 300 are divided into two rows of clamping fingers 300, and the two rows of clamping fingers 300 are symmetrically arranged on the symmetrical side edges of the placement position 110. The clamping transmission assembly includes two clamping driven shafts 310, a clamping active shaft 320 rotatably installed on the flip bracket 100, and a fixed A clamping driving wheel 321 and a clamping driving pulley 322 fixedly sleeved on the clamping driving shaft 320, a clamping driven wheel 311 fixedly sleeved on one of the clamping driven shafts 310, a clamping driven pulley 312 fixedly sleeved on the other clamping driven shaft 310, and a clamping synchronous belt 330 connected between the clamping driving pulley 322 and the clamping driven pulley 312, wherein the clamping driving wheel 321 is transmission-connected with the clamping driven wheel 311, and the clamping drive assembly includes a clamping drive unit 400 transmission-connected with the clamping driving shaft 320. The clamping drive unit 400 in this embodiment is a clamping servo motor, and in some other embodiments, it can be a rotating drive element such as a drive motor. Under the drive of a clamping drive unit 400, two rows of clamping fingers 300 can be driven to move synchronously, so that the transmission structure is simpler, the number of clamping drive units 400 is reduced, and the manufacturing cost is reduced.

[0043] like Figure 1 and Figure 3As shown, the flip mechanism of this embodiment includes: a flip transmission assembly 600 and a flip driving assembly, wherein the flip transmission assembly 600 includes a flip driven pulley 610, a flip driving pulley 620, and a flip synchronous belt 630 connected between the flip driven pulley 610 and the flip driving pulley 620, wherein the flip driven pulley 610 is coaxially arranged with the flip axis; and the flip driving assembly is mounted on the base 500, and the flip driving assembly is used to drive the flip driving pulley 620 to rotate. The flip driving assembly drives the flip driving pulley 620 to rotate, and the flip driving pulley 620 drives the flip driven pulley 610 to rotate through the flip synchronous belt 630, and then the flip driven pulley 610 can drive the flip bracket 100 to rotate around the flip axis.

[0044] Furthermore, two flip transmission assemblies 600 are provided, and the two flip transmission assemblies 600 are arranged at intervals along the flip axis. A flip transmission shaft 700 is connected between the two flip transmission assemblies 600, and the flip transmission shaft 700 is coaxially fixedly connected with two flip driving pulleys 620 at the same time. The flip drive assembly is connected to the flip transmission shaft 700 in a transmission manner. The flip drive assembly of this embodiment is a flip servo motor, and in some other embodiments, it can be a rotating drive element such as a drive motor. The two flip transmission assemblies 600 can improve the flip stability of the flip bracket 100, and secondly, one flip drive assembly can drive the two driven pulleys 610 to rotate synchronously, making the transmission structure simpler and more compact, reducing the number of flip drive assemblies, and further reducing the manufacturing cost.

[0045] The positioning mechanism in this embodiment includes a position switch 200 arranged on the placement position 110, and a plurality of position switches 200 are arranged, and the plurality of position switches 200 are evenly distributed on the edge of the placement position 110, wherein each position switch 200 has a trigger end, and the trigger end is configured to sense that the container disk of the external device reaches the placement position 110 by interfering with the container disk of the external device. When in use, the position switch 200 is connected to the electrical control system of the external device, and the electrical control system of the external device can control the actions of the clamping mechanism and the flipping mechanism.

[0046] The position switch 200 can be set at different positions according to actual conditions. In this solution, the position switch 200 is set at the edge of the placement position 110, and is pressed down by the weight of the container tray to ensure that the container tray is placed in place. The position switch 200 can output a correct switch signal to ensure that the whole machine runs stably, safely and reliably. The position switch 200 can be mechanical, photoelectric, or proximity sensor switch.

[0047] When the container tray is placed in place on the placement position 110, the container tray will conflict with the multiple position switches 200 and trigger the multiple position switches 200, and then the multiple position switches 200 control the clamping mechanism to clamp the container tray of the external device and the flip mechanism to flip the flip bracket 100 in sequence through the external electric control system. Specifically, when the clamping drive unit 400 drives the clamping active shaft 320 to rotate, the clamping active shaft 320 drives one of the clamping driven shafts 310 to rotate through the transmission of the clamping active wheel 321 and the clamping driven wheel 311, and at the same time, the clamping active shaft 320 drives the other clamping driven shaft 310 to rotate through the transmission of the clamping active pulley 322, the clamping driven pulley 312 and the clamping synchronous belt 330, so that under the drive of one clamping drive unit 400, two rows of clamping fingers 300 can be driven to clamp the container tray synchronously, making the transmission structure simpler, reducing the number of clamping drive units 400, and reducing the manufacturing cost. In some other implementations, the outer side surface, outer bottom surface, etc. of the container disk can be clamped by changing the installation position of the clamping finger 300 and clamping different positions of the container disk according to the structure of the container disk. The present solution clamps the upper edge of the container disk, and the clamping finger 300 clamps the upper edge of the container disk on the edge of the placement position 110; the clamping finger 300 can rotate within a range of 90 degrees in the horizontal direction, and the angle value can be any angle, and any angle can be allowed when the structure allows rotation without interference. When the flip bracket 100 is flipped, the flip drive assembly drives the two flip driving pulleys 620 to rotate synchronously through the flip transmission shaft 700, and drives the two flip driven pulleys 610 to rotate synchronously, and then the flip driven pulley 610 can drive the flip bracket 100 to rotate around the flip axis to realize flipping and unloading of the container disk. The present device can realize the three functions of automatic positioning, clamping and flip unloading (feeding) of the container disk, thereby improving the efficiency and accuracy of unloading.

[0048] The flip bracket 100 can rotate within a range of 180 degrees in the horizontal direction, and the flip angle value of the flip bracket 100 can be any angle, and any angle can be any angle when the structure allows rotation without interference. The flip drive component can realize a back and forth shaking action to ensure that the objects and liquids in the container tray are not left on the container wall.

[0049] For the placed container tray, it can realize automatic positioning, clamping, and flipping of materials. When used with the whole machine, it can ensure positioning accuracy and provide a good user experience. And through the mechanical clamping finger 300, compared with the electromagnetic suction device, it will not generate strong magnetism and will not affect the surrounding components. The sucked container tray can be firmly grasped due to the different distances of manual placement, and has precise positioning and clamping functions.

[0050] In some embodiments, a flip shell is provided at the bottom of the flip bracket 100, which can effectively protect the container plate and the transmission structure on the flip bracket 100, and can avoid being contaminated by oil smoke and debris. It is suitable for use in products in the fields of smart home appliances, smart kitchens, and cooking technology.

[0051] like Figure 5 As shown, an annular positioning platform 120 is protruded upwards from the edge around the placement position 110, an inner retaining wall 111 is arranged at an angle on the inner periphery of the positioning platform 120, and the inner retaining wall 111 extends to the inner periphery of the placement position 110, and an outer retaining wall 121 is arranged on the outer periphery of the positioning platform 120. When placing the container tray, the positioning platform 120 plays a certain positioning role on the container tray, and the inner retaining wall 111 contacts the container tray, which is convenient for taking and placing the container tray, and the outer retaining wall 121 also contacts the outer edge of the container tray, so that the container tray can be firmly positioned on the placement position 110, ensuring the stability and safety of the container tray placed on the flip bracket 100.

[0052] In other embodiments, Figure 7 As shown, the outer retaining wall 121 around the outer side of the edge of the flip bracket 100 can also be made into a groove structure.

[0053] In some other implementations, such as Figure 6 As shown, only the inner periphery of the placement position 110 is provided with an inner retaining wall 111 which is arranged in an inclined manner.

[0054] The preferred embodiments of the present invention are specifically described above, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A container tray positioning, clamping and flipping device, characterized in that: include: A turning bracket (100) having a turning axis, wherein a placement position (110) for placing a container tray of an external device is arranged on the turning bracket (100); A clamping mechanism, mounted on the flip bracket (100), the clamping mechanism being used to clamp a container tray of an external device on the placement position (110); A turning mechanism, used for driving the turning bracket (100) to turn around the turning axis; A positioning mechanism having a trigger end for sensing that the container plate of the peripheral device has reached the placement position (110) and then sequentially triggering the clamping mechanism to clamp the container plate of the peripheral device and the flipping mechanism to drive the flip bracket (100) to flip; The positioning mechanism comprises a position switch (200) arranged on the placement position (110), the position switch (200) having the trigger end, the trigger end being configured to sense the container tray of the external device reaching the placement position (110) by coming into contact with the container tray of the external device, thereby sequentially triggering the clamping mechanism to clamp the container tray of the external device and the flipping mechanism to drive the flip bracket (100) to flip; A plurality of position switches (200) are evenly distributed on the edge of the placement position (110); when the container tray is placed in place on the placement position (110), the container tray will collide with the plurality of position switches 200) and trigger the plurality of position switches (200); then, the plurality of position switches (200) sequentially control the clamping mechanism to clamp the container tray of the peripheral device and the flipping mechanism to drive the flip bracket (100) to flip through the electrical control system of the peripheral device; The clamping mechanism comprises a clamping finger (300), a clamping drive assembly, and a clamping transmission assembly. The number of the clamping fingers (300) is multiple, and the multiple clamping fingers (300) are evenly distributed on the edge of the placement position (110). The clamping drive assembly is transmission-connected to the multiple clamping fingers (300) via the clamping transmission assembly. The plurality of clamping fingers (300) are divided into two rows of clamping fingers (300), and the two rows of clamping fingers (300) are symmetrically arranged on two symmetrical side edges of the placement position (110); The clamping transmission assembly comprises a clamping driven shaft (310), the number of the clamping driven shafts (310) is two, and the clamping fingers (300) on the same row are rotatably mounted on the flip bracket (100) via the clamping driven shafts (310); The clamping drive assembly is in driving connection with two clamping driven shafts (310); The clamping transmission assembly further comprises a clamping driving shaft (320) rotatably mounted on the flip bracket (100), a clamping driving wheel (321) and a clamping driving pulley (322) fixedly sleeved on the clamping driving shaft (320), a clamping driven wheel (311) fixedly sleeved on one of the clamping driven shafts (310), a clamping driven pulley (312) fixedly sleeved on the other clamping driven shaft (310), and a clamping synchronous belt (330) connected between the clamping driving pulley (322) and the clamping driven pulley (312); the clamping driving wheel (321) is transmission-connected to the clamping driven wheel (311); The clamping drive assembly comprises a clamping drive unit (400) drivingly connected to the clamping drive shaft (320); It also comprises a base (500), the flip bracket (100) being mounted on the base (500), and the flip bracket (100) being rotatable relative to the base (500) around the flip axis; The flipping mechanism comprises: A flip transmission assembly (600), the flip transmission assembly (600) comprising a flip driven pulley (610), a flip driving pulley (620), and a flip synchronous belt (630) connected between the flip driven pulley (610) and the flip driving pulley (620), the flip driven pulley (610) being relatively fixedly connected to a flip bracket (100), and the flip driven pulley (610) being coaxially arranged with the flip axis; A flip driving assembly, mounted on the base (500), the flip driving assembly being used to drive the flip driving pulley (620) to rotate; Two flip transmission assemblies (600) are provided, and the two flip transmission assemblies (600) are arranged at intervals along the flip axis. A flip transmission shaft (700) is connected between the two flip transmission assemblies (600), and the flip transmission shaft (700) is coaxially fixedly connected to two flip driving pulleys (620). The flip drive assembly is in transmission connection with the flip transmission shaft (700); The flip bracket (100) is a rectangular frame structure, and the inner frame of the rectangular frame structure is the placement position (110); An annular positioning platform (120) is protruding upwards from the edges around the placement position (110), an inner retaining wall (111) is arranged at an angle on the inner periphery of the positioning platform (120), the inner retaining wall (111) extends to the inner periphery of the placement position (110), and an outer retaining wall (121) is arranged on the outer periphery of the positioning platform (120).

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