CN217101241U

CN217101241U - Structure for detecting SMT tray feeding and discharging rack by using photoelectric sensor

Info

Publication number: CN217101241U
Application number: CN202220260570.4U
Authority: CN
Inventors: 黄正文
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-02-09
Filing date: 2022-02-09
Publication date: 2022-08-02
Anticipated expiration: 2032-02-09

Abstract

The utility model belongs to the technical field of electron material storage device, concretely relates to use photoelectric sensor to detect structure that SMT charging tray advances discharge frame, include: the photoelectric sensor comprises a supporting piece, a circuit board, n rotating pieces, n photoelectric sensors and a shielding part, wherein the n rotating pieces are arranged on the supporting piece and can rotate relative to the supporting piece; the shielding parts correspond to the photoelectric sensors respectively and are used for shielding the photoelectric sensors at corresponding positions; the photoelectric sensor is positioned at the outer side of the movement path of the shielding part corresponding to the photoelectric sensor; n is an integer and n is not less than 2. In the prior art, a material tray is matched with a photoelectric sensor, and the material trays are not manufactured by adopting the same standard, so that the current intelligent material rack is difficult to accurately judge the material tray taking and placing conditions of a certain material tray clamping position; the utility model discloses compare with prior art's like product, have the charging tray that the intelligence work or material rest of being convenient for accurately judges a certain charging tray screens and get the condition of putting, avoid the effect of the loss because of the erroneous judgement of intelligence work or material rest leads to.

Description

Structure for detecting SMT tray feeding and discharging rack by using photoelectric sensor

Technical Field

The utility model relates to an electron material storage device technical field specifically indicates an adopt photoelectric sensor to detect the structure of the charging tray business turn over discharge frame of depositing the SMT material.

Background

An SMT electronic factory produces a circuit board, and thousands of parts are mounted and assembled together. Because the part kind is many, and material access management consumes the manpower very much, consequently deposits the intelligent work or material rest of SMT electronic material and popularizes gradually. In the early stage, a bar code is pasted on each storage position, when a user puts materials in storage, the bar code on the material plate is firstly brushed, and then the bar code on the storage position is brushed, so that a computer for managing the material frame remembers the storage position of the material plate, and when the materials are taken, the computer can control a lamp on the material taking storage position to guide the user to take the materials. However, in this way, besides the user must swipe the barcode twice, the misplaced storage space cannot be warned, and the user still lacks the barcode. Therefore, it is important to automatically detect which storage location is put into after the user swipes the barcode on the tray.

The general sensing mode is mostly finished by using a photoelectric sensor, the state of putting in or taking out the charging tray is detected by judging whether the charging tray is put in or taken out by judging whether the charging tray is received or not because the light is not completely intercepted when the charging tray is made of transparent or semitransparent materials, the received luminous flux must be measured, and the charging tray is not or is a transparent charging tray is judged by counting or even an AI algorithm, although the mode can solve part of problems, the power of a transmitter and the sensitivity of a receiver which form the photoelectric sensor can change along with the change of environment and service time, and environmental light can interfere the photoelectric sensor, so that the detection judgment is not accurate; particularly, for SMT material suppliers, the problem of a photoelectric sensor does not need to be considered, so that the color and the material of the material tray are not standardized by the industry; and most of the SMT material suppliers use semi-transparent sheet plastics to manufacture material trays based on cost consideration. As for the practical use condition of the SMT electronic factory, the electronic element error can cause the whole batch of circuit boards to be scrapped, the storage record is inaccurate, and the intelligent material rack can lose the practical value, so that the misjudgment of the intelligent material rack can cause serious consequences and bring great economic loss.

SUMMERY OF THE UTILITY MODEL

In order to overcome prior art's weak point, the utility model aims to provide an use photoelectric sensor to detect SMT charging tray advance and discharge the structure of work or material rest, it aims at solving current intelligent work or material rest and is difficult to the accurate problem of judging the charging tray and getting the put the condition.

In order to achieve the above object, the utility model adopts the following technical scheme: the utility model provides an use photoelectric sensor to detect structure that SMT charging and discharging frame of charging and discharging dish, includes: the photoelectric sensor comprises a supporting piece, a circuit board, n rotating pieces, n photoelectric sensors and a shielding part, wherein the n rotating pieces are arranged on the supporting piece and can rotate relative to the supporting piece; the n shielding parts correspond to the n photoelectric sensors respectively and are used for shielding the photoelectric sensors at corresponding positions; the photoelectric sensor is positioned at the outer side of the movement path of the shielding part corresponding to the photoelectric sensor; n is an integer and n is not less than 2.

Preferably, the support member is connected with a circuit board; the photoelectric sensor is arranged on one surface of the circuit board.

Preferably, the photoelectric sensor comprises a receiver and a transmitter, and n through holes for accommodating the n shielding parts respectively are arranged in the circuit board; the receiver and the transmitter of each photoelectric sensor are respectively positioned on two sides of one of the through holes.

Preferably, the rotating member comprises a receiving bar, a transfer plate with one end fixedly connected with one end of the receiving bar, and a rotating shaft with two ends respectively movably connected with the top of the supporting member; one end of the shielding part is connected with the other end of the adapter plate.

Preferably, the other end of the bearing strip is provided with a transverse strip perpendicular to the bearing strip; a first corner is formed at the connecting position of the bearing strip and the adapter plate, and a second corner is formed at the connecting position of the adapter plate and the shielding part; the rotating shaft is arranged on the outer side of the first corner and is perpendicular to the bearing strip and the adapter plate.

Preferably, the vehicle-mounted solar module further comprises a balancing weight which is arranged on the outer side of the second corner and is perpendicular to the shielding part and the adapter plate.

Preferably, the transverse bar, the receiving bar, the adapter plate and the shielding part are integrally formed; the shielding part is in a flat plate shape, and deep color coatings are arranged on two surfaces of the shielding part; the rotating piece and the shielding part are both made of shading materials.

Preferably, the supporting member comprises a supporting base, n rotating brackets arranged on the supporting base, and a transverse connecting strip connected with the tops of the n rotating brackets; each rotating support comprises two supporting vertical plates which are parallel to each other, and the top of each supporting vertical plate is provided with a notch; the n rotating supports are respectively connected with the n rotating pieces, and two ends of each rotating shaft are respectively placed in two notches of one rotating support.

Preferably, the supporting base, the rotating bracket and the transverse connecting strip are integrally formed; the supporting piece is made of shading materials.

Preferably, the side surface of the top of each supporting vertical plate is provided with a hook integrally formed with the supporting vertical plate, the top of the circuit board is provided with 2n hanging notches, and the hook passes through the hanging notch at the corresponding position to be hung at the top of the circuit board; the hook is positioned on the front side of the notch.

The beneficial technical effects are as follows: by adopting the structure of the feeding and discharging rack for detecting the SMT tray, the blocking part is arranged on the rotating part and is used for exciting the photoelectric sensor; the material rack comprises a plurality of material tray clamping positions, and each material tray clamping position corresponds to one rotating part; when a material tray is placed in a certain material tray clamping position, the material tray is contacted with the rotating piece, the rotating piece rotates relative to the supporting piece under the action of gravity of the material tray, and when the material tray is taken out, the rotating piece reversely rotates; when the material disc is placed in the material disc clamping position, the side wall of the material disc is in contact with the rotating part, the rotating part rotates relative to the supporting part, the shielding part on the rotating part rotates along with the rotating part and is separated from the photoelectric sensor, the photoelectric sensor is in light connection, namely the photoelectric sensor is excited, and outputs a signal to the circuit board, so that the situation that the material disc is placed in the material disc clamping position is indicated, and the signal is recorded by the computer; after the material tray is taken away, the shielding part returns to the initial position, the light of the photoelectric sensor is shielded, a signal is sent to the circuit board, and the computer records the information that the material tray clamped by the material tray is taken away; by adopting the structure of the feeding and discharging rack for detecting the SMT tray, the shielding part made of opaque materials is used for matching with the photoelectric sensor, so that the accuracy is ensured; in the prior art, due to the matching of the material trays and the photoelectric sensors, the material trays used by different suppliers for providing materials are not manufactured by the same standard, so that some material trays are opaque, and some material trays are semi-transparent or completely transparent, so that the current intelligent material rack is difficult to accurately judge the material tray taking and placing conditions of a certain material tray clamping position; therefore, the utility model discloses compare with prior art's like product, have the charging tray of the accurate judgement a certain charging tray screens of intelligence work or material rest of being convenient for and get the condition of putting, avoid the effect of the loss because of the erroneous judgement of intelligence work or material rest leads to.

Drawings

Fig. 1 is a perspective view of an embodiment of the present invention;

fig. 2 is another perspective view of the embodiment of the present invention;

fig. 3 is an exploded view of an embodiment of the present invention;

FIG. 4 is a perspective view of a support member according to an embodiment of the present invention;

fig. 5 is a perspective view of a rotating member according to an embodiment of the present invention;

FIG. 6 is a schematic view of the structure of the embodiment of the present invention when the tray is placed in the structure;

FIG. 7 is a schematic view of the structure of the embodiment of the present invention when the tray is taken out;

fig. 8 is a schematic view of a structural application scenario according to an embodiment of the present invention;

FIG. 9 is a left side view of the tray with the structure of the embodiment of the present invention;

fig. 10 is a left side view of the structure of the embodiment of the present invention when the tray is taken out.

Detailed Description

In order to make the technical field of the present invention better understand, the present invention is further described in detail with reference to the accompanying drawings and embodiments.

As shown in fig. 1-3, the embodiment of the utility model provides an use photoelectric sensor to detect structure of SMT charging tray business turn over discharge frame, include: the device comprises a supporting piece 1, a circuit board 2, n rotating pieces 3 which are arranged on the supporting piece 1 and can rotate relative to the supporting piece, n photoelectric sensors 4 connected with the circuit board 2, and a shielding part 5 arranged on each rotating piece. The supporting member 1 can be made of plastic, and therefore can be processed by an injection molding process, and therefore, in consideration of the maximum part size which can be processed by injection molding equipment, the rigidity and the strength of the supporting member, and other factors, the supporting member 1 of the embodiment can be composed of a plurality of supporting units which are connected together to form the complete supporting member 1; in fact, during assembly, the supporting member 1 is connected with the circuit board 2, so that connecting each supporting unit with the circuit board 2 forms the complete supporting member 1 without a connecting structure between two adjacent supporting units; therefore, although the supporting member 1 needs to be manufactured in segments due to the process and the like, it is assembled as a whole, and thus it will be described as a whole.

The n shielding parts 5 correspond to the n photoelectric sensors 4 respectively, and the shielding parts 5 are used for shielding the photoelectric sensors 4 at corresponding positions, that is, each photoelectric sensor 4 corresponds to one shielding part 5, and the shielding parts are used for shielding the corresponding photoelectric sensor, so that the shielding parts 5 need to be made of a light shielding material for preventing light from passing through; the photoelectric sensor 4 is positioned outside the moving path of the shielding part 5 corresponding to the photoelectric sensor; n is an integer and n is not less than 2. Obviously, since the shielding portion 5 is disposed on the rotating member 3, when the rotating member 3 rotates on the supporting member 1, the shielding portion 5 necessarily rotates along with the rotating member, and the shielding portion 5 has a movement path (track), and the photoelectric sensor 4 needs to correspond to the shielding portion 5, that is, the shielding portion 5 is disposed to shield the light of the photoelectric sensor 4, so that the photoelectric sensor 4 cannot be located exactly on the movement path of the shielding portion 5, but only on the side of the movement path, that is, the photoelectric sensor 4 can be shielded without interfering with the movement of the shielding portion 5. The term "shield portion is used to shield the corresponding photosensor" as used herein means that the photosensors 4 and the shield portions 5 of the present embodiment correspond to each other one by one, and for example, as shown in fig. 3, the photosensor 4 positioned on the leftmost side and the shield portion 5 positioned on the leftmost side are a pair of members corresponding to each other.

It is obvious that although the number of the rotating member 3, the photoelectric sensor 4 and the shielding portion 5 is defined as n, the number of the rotating member, the photoelectric sensor 4 and the shielding portion 5 is the same, n is an integer and n is greater than or equal to 2; actually, because the number of the trays 6 required to be stored on the intelligent rack is large, and one tray 6 needs one tray position lock 7, the number of the rotating member 3, the photoelectric sensor 4 and the shielding portion 5 is often much larger than two, and in practical application, the number of the three is not particularly limited, and the three is generally customized according to the requirement of a manufacturer using the intelligent rack, as shown in fig. 6.

The photoelectric sensor 4 used in the present embodiment is a commercially available standard component, and includes a receiver 401 and a transmitter 402.

As shown in fig. 8, the utility model discloses on the structure is applied to intelligent work or material rest, intelligent work or material rest is including two carriage bodies 8 that are parallel to each other, and the utility model discloses an in one of them carriage body 8 was located to the structure, on two carriage bodies 8 were located to a plurality of charging tray screens 7, a charging tray 6 can be placed to every charging tray screens 7, and charging tray 6 contacts and pushes down and rotate piece 3 with rotating piece 3, makes it rotate certain angle, breaks away from until occlusion part 5 and photoelectric sensor 4.

In accordance with the characteristics of the shielding portion 5 and the photoelectric sensor 4, in the present embodiment, the photoelectric sensor 4 is disposed on one surface of the circuit board 2; n through holes 201 for accommodating the n shielding portions 5 are formed in the circuit board 2; the receiver 401 and the transmitter 402 of each photosensor 4 are located on either side of one of the perforations 201. With this structure, the shielding portion 5 passes through the through hole 201 during the rotation process, and the shielding portion 5 is located in the through hole 201 as an initial state in this embodiment, so that each through hole 201 is not only the accommodating space of the shielding portion 5 corresponding to the through hole 201, but also a part of the movement path thereof, and the receiver 401 and the transmitter 402 are located at two sides of the through hole 201, that is, the photoelectric sensor 4 is located at the outer side of the movement path of the shielding portion 5; it is obvious that in the initial state of the present embodiment, the shielding portion 5 shields the light of the photoelectric sensor 4, and when the rotating member 3 rotates with the shielding portion 5, the shielding portion 5 is separated from the through hole 201, and the light of the photoelectric sensor 4 is not shielded.

Although the present embodiment directly mounts the n photosensors 4 on the circuit board 2, this is obviously not the only connection method, and as an alternative structure, a thin plate may be provided for mounting the n photosensors 4, and the photosensors 4 may be connected to the circuit board 2 by wires, which, although achieving similar effects, will inevitably increase the cost and make the structure more complicated.

As shown in fig. 3 and 5, specifically, the rotating member 3 includes a receiving bar 301, an adapter plate 302 having one end fixedly connected to one end of the receiving bar, and a rotating shaft 303 having two ends movably connected to the top of the supporting member 1; one end of the shielding part 5 is connected with the other end of the adapter plate 302.

The other end of the bearing strip 301 is provided with a transverse strip 304 perpendicular to the bearing strip; a first corner is formed at the connecting position of the adapting strip 301 and the adapter plate 302, and a second corner is formed at the connecting position of the adapter plate 302 and the shielding part 5; the rotating shaft 303 is disposed outside the first corner, and the rotating shaft 303 is perpendicular to the receiving strip 301 and the adapter plate 302. When the tray 6 is put in, the outer side wall of the tray is firstly contacted with the receiving strip 301, and the thickness of the tray 6 and the receiving strip 301 is smaller, so that the tray 6 needs to be aligned with the receiving strip 301 and then can be put in, and the transverse strip 304 is arranged, namely the receiving strip 301 extends towards two sides, at the moment, a user does not need to align the receiving strip 301, the put-in tray can be contacted with the transverse strip 304 necessarily, so that the pressure from the tray is transmitted to the rotating piece 3, and the rotating piece is enabled to rotate relative to the supporting piece 1.

After the tray 6 is taken away, in order to make the rotating member 3 return to the initial position, a weight block 305 is further included, which is disposed outside the second corner and perpendicular to the blocking portion 5 and the adapter plate 302.

Specifically, the rotating member 3 and the shielding portion 5 of the present embodiment can be made of plastic, and the transverse bar 304, the receiving bar 301, the adapter plate 302 and the shielding portion 5 are integrally formed by an injection molding process; that is, the shielding part 5 is actually a part of the rotation member 3, and is listed separately for easy understanding; and the adoption of the integrated design is favorable for simplifying the design of the rotating part 3, is convenient for one-time processing, can also reduce the production cost and is convenient for assembly. In particular, the rotor 3, like the shield 5, is likewise made of a light-shielding material, which means a light-impermeable material, such as a conventional light-impermeable plastic.

The shielding part 5 and the adapter plate 302 are flat, so that the weight of the rotating part 3 is reduced, and materials are saved; dark color coatings (not shown) are provided on both surfaces of the shielding portion 5 in order to reduce the influence of ambient light.

The rotating shaft 303 is cylindrical and is formed by integrally forming a large diameter section 303a and two small diameter sections 303b respectively arranged at two ends of the large diameter section 303a, and the joint of the large diameter section and the small diameter sections has a transitional arc-shaped surface.

For the foregoing reasons, the support 1 is not of an integral structure, but is constituted by several identical support units, for example, as shown in fig. 1-2, where the support 1 comprises three support units, but in practice there is no limit to the number of support units constituting the support 1.

As shown in fig. 3 to 4, here, fig. 4 shows a perspective view of one of the support units, and in general, the support member 1 includes a support base 101, n number of rotation brackets 102 provided on the support base, and a transverse connecting bar 103 connected to the tops of the n number of rotation brackets 102; each rotating bracket 102 comprises two supporting vertical plates 102a which are parallel to each other, and the top of each supporting vertical plate 102a is provided with a notch 102 b; the n rotating supports 102 are respectively connected with the n rotating members 3, and two ends of each rotating shaft 303 are respectively placed in the two notches 102b of one rotating support 102. Here, the notch 102b is obliquely disposed, the oblique disposition means that an included angle a is formed between a longitudinal center line (plane) of the notch 102b and the upper surface of the supporting

base

101, and 0 ° < a <90 °, when assembling, the two small-diameter sections 303b on the rotating shaft 303 are respectively embedded in the two notches 102b of a certain rotating bracket 102, and by using the obliquely disposed notch 102b, when the rotating member 3 rotates, two ends of the rotating shaft 303 which synchronously rotates move relative to the rotating bracket 102 and even are separated from the rotating bracket 102, thereby causing inconvenience in use. As shown in fig. 9-10, especially when the supporting member 1 is assembled with the circuit board 2, the circuit board 2 is located at the front side of the notch 102b, so as to prevent the two ends of the rotating shaft 303 from being pulled out from the notch 102 b.

The number of the rotation brackets 102 is the same as that of the rotation members 3, and they are also in a one-to-one correspondence relationship.

The supporting member 1 of the present embodiment is composed of a plurality of supporting units, but is assembled to form a whole.

The support member 1 of the present embodiment is made of a light shielding material.

In order to realize the quick assembly and disassembly of the support member 1 and the circuit board 2, the side surface of the top of each supporting vertical plate 102a is provided with a hook 102c which is integrally formed with the supporting vertical plate, the top of the circuit board 2 is provided with 2n hanging notches 202, and the hook 102c passes through the hanging notch 202 at the corresponding position to be hung on the top of the circuit board 2; the hook is located on the front side of the notch 102b as shown in fig. 3.

To sum up, in this embodiment, the initial state is the state of the rotating member 3 when the tray 6 is not placed in the tray clamp 7, in this state, the blocking portion 5 is located in the through hole 201 and located between the receiver 401 and the transmitter 402, and the photoelectric sensor 4 is blocked, when the tray 6 is placed in the tray clamp 7, the side wall of the tray 6 contacts with the receiving bar 301 and the transverse bar 304 of the rotating member 3, the rotating member 3 rotates relative to the supporting member 1 after being stressed, the blocking portion 5 on the rotating member 3 rotates and rotates out of the through hole 201, and separates from the photoelectric sensor 4, and the photoelectric sensor 4 is optically connected, i.e. the photoelectric sensor is excited, and outputs a signal to the circuit board 2, which indicates that the tray 6 is placed in the tray clamp 7 and is recorded by the computer, as shown in fig. 6 and fig. 9; after the tray 6 is taken away, the rotating member 3 rotates reversely under the action of the counterweight block 305, the shielding portion 5 returns to the initial position, the light of the photoelectric sensor 4 is blocked, the signal is also sent to the circuit board 2, and the computer records the information that the tray 6 of the tray block 7 has been taken away, as shown in fig. 7 and 10; by adopting the structure of the feeding and discharging rack for detecting the SMT tray, the shielding part 5 made of opaque materials is used for matching with the photoelectric sensor 4, so that the accuracy is ensured; in the prior art, the material discs 6 are matched with the photoelectric sensor 4, and the material discs used by different suppliers for providing materials are not manufactured by the same standard, so that some material discs are inevitably opaque, and some material discs are semi-transparent or completely transparent, so that the current intelligent material frame is difficult to accurately judge the material disc taking and placing conditions of a certain material disc clamping position; therefore, the utility model discloses compare with prior art's like product, have the accurate charging tray 6 of judging a certain charging tray screens 7 of intelligence work or material rest of being convenient for and get the condition of putting, avoid the effect of the loss because of the erroneous judgement of intelligence work or material rest leads to.

In the above description, it should be noted that the terms "mounted," "connected," and the like are used broadly and can be, for example, fixedly connected, detachably connected, or integrally connected; the connection can be direct connection or indirect connection through an intermediate medium, and the connection between the two components can be internal; the term "mounted" is to be understood as "mounted on" and "disposed on" and includes fixed mounting, movable mounting and the like.

It is to be understood that the above-described embodiments are merely exemplary of the invention, and are not intended to limit the scope of the invention. The present invention may be embodied in many different forms and, on the contrary, these embodiments are provided so that this disclosure will be thorough and complete. All utilize the equivalent structure that the content of the utility model discloses a specification and attached drawing was done, direct or indirect application is in other relevant technical field, all is in the same way the utility model discloses within the patent protection scope.

Claims

1. The utility model provides an use photoelectric sensor to detect structure that SMT charging and discharging frame of charging and discharging tray, its characterized in that includes: the photoelectric sensor comprises a supporting piece, a circuit board, n rotating pieces, n photoelectric sensors and a shielding part, wherein the n rotating pieces are arranged on the supporting piece and can rotate relative to the supporting piece; the n shielding parts correspond to the n photoelectric sensors respectively and are used for shielding the photoelectric sensors at corresponding positions; the photoelectric sensor is positioned at the outer side of the movement path of the shielding part corresponding to the photoelectric sensor; n is an integer and n is not less than 2.

2. The structure for detecting the feeding and discharging rack of the SMT tray by using the photoelectric sensor as set forth in claim 1, wherein the supporting member is connected with the circuit board; the photoelectric sensor is arranged on one surface of the circuit board.

3. The structure for detecting the feeding and discharging rack of the SMT tray according to claim 2, wherein the photoelectric sensor comprises a receiver and a transmitter, and n through holes for respectively accommodating the n shielding portions are formed in the circuit board; the receiver and the transmitter of each photoelectric sensor are respectively positioned on two sides of one of the through holes.

4. The structure for detecting the feeding and discharging frame of the SMT tray using the photoelectric sensor as claimed in claim 2, wherein the rotation member comprises a receiving bar, an adapter plate having one end fixedly connected to one end of the receiving bar, and a rotation shaft having two ends movably connected to the top of the support member, respectively; one end of the shielding part is connected with the other end of the adapter plate.

5. The structure for detecting the feeding and discharging racks of the SMT tray by using the photoelectric sensor as set forth in claim 4, wherein a transverse strip perpendicular to the receiving strip is arranged at the other end of the receiving strip; a first corner is formed at the connecting position of the bearing strip and the adapter plate, and a second corner is formed at the connecting position of the adapter plate and the shielding part; the rotating shaft is arranged on the outer side of the first corner and is perpendicular to the bearing strip and the adapter plate.

6. The structure for detecting the feeding and discharging rack of the SMT tray using the photoelectric sensor as claimed in claim 5, further comprising a weight block disposed outside the second corner and perpendicular to the shielding portion and the adapter plate.

7. The structure for detecting the feeding and discharging rack of the SMT tray by using the photoelectric sensor as claimed in claim 5, wherein the transverse bar, the receiving bar, the adapter plate and the shielding portion are integrally formed; the shielding part is in a flat plate shape, and deep color coatings are arranged on two surfaces of the shielding part; the rotating piece and the shielding part are both made of shading materials.

8. The structure for detecting the feeding and discharging rack of the SMT tray by using the photoelectric sensor as claimed in claim 4, wherein the supporting member comprises a supporting base, n rotating brackets arranged on the supporting base, and a transverse connecting strip connected with the tops of the n rotating brackets; each rotating support comprises two supporting vertical plates which are parallel to each other, and the top of each supporting vertical plate is provided with a notch; the n rotating supports are respectively connected with the n rotating pieces, and two ends of each rotating shaft are respectively placed in the two notches of one rotating support.

9. The structure for detecting the feeding and discharging racks of the SMT tray according to claim 8, wherein the supporting base, the rotating bracket and the transverse connecting strips are integrally formed; the supporting piece is made of shading materials.

10. The structure for detecting the feeding and discharging rack of the SMT tray by using the photoelectric sensor as claimed in claim 4, wherein a hook is integrally formed on a side surface of the top of each supporting vertical plate, 2n hooking notches are formed in the top of the circuit board, and the hook is hooked on the top of the circuit board through the corresponding hooking notch; the hook is positioned on the front side of the notch.