CN112371536A

CN112371536A - Thickness detection mechanism and detection picking equipment comprising same

Info

Publication number: CN112371536A
Application number: CN202011184091.0A
Authority: CN
Inventors: 瞿锦程
Original assignee: Ningbo Beckwell Intelligent Technology Co ltd
Current assignee: Ningbo Beckwell Intelligent Technology Co ltd
Priority date: 2020-10-21
Filing date: 2020-10-21
Publication date: 2021-02-19

Abstract

A thickness detection mechanism includes a base, a control center, a positioning table, and a height detection module. The positioning table is installed on the base, and a positioning hole for the installation of shaft and column parts is arranged in the positioning table. The detection module includes a first mounting plate, a first lateral slide rail, two height detection devices, a second thrust cylinder and a second slide rail, and an infrared sensor located above the positioning hole is arranged in the middle of the first lateral slide rail. The contact sensor is installed on the L-shaped slide plate, and the contact sensor corresponds to the upper end of the shaft column type part and is used to detect the height of the shaft column type part. The control center is connected to the infrared sensor, the contact sensor and the second thrust cylinder , the second thrust cylinder is connected to a first mounting plate, and the first mounting plate and the second slide rail form a guide rail to cooperate.

Description

Thickness detection mechanism and detection picking equipment comprising same

Technical Field

The invention relates to the field of mechanical part detection, in particular to a thickness detection mechanism and detection and picking equipment comprising the same.

Background

The common equipment usually comprises a large number of shaft column parts, so that the shaft column parts become one of the most common machining workpieces in the machining field, and therefore, the improvement of the detection process of the shaft column parts plays a critical role in improving the machining efficiency of the related equipment, reducing the machining cost and the like. In order to quickly detect the shaft column parts of different types and improve the processing efficiency of the shaft column parts, shaft zero detection and sorting are indispensable important links, so that the improvement of the detection equipment of the shaft column parts is particularly necessary.

Disclosure of Invention

In order to solve the above problems, the present invention provides a thickness detection mechanism:

a thickness detection mechanism comprises a base, a control center, a positioning table and a height detection module, wherein the positioning table is installed on the base, a positioning hole for installing shaft column parts is formed in the positioning table, the height detection module comprises a first installation plate, a first transverse slide rail arranged on the first installation plate, two height detection devices which form guide rail matching with the first transverse slide rail, a second thrust cylinder and a second slide rail which are both installed on a frame, an infrared sensor positioned above the positioning hole is arranged in the middle of the first transverse slide rail, the two height detection devices can move in opposite directions or back directions along the first transverse slide rail, the height detection device comprises a first thrust cylinder, an L-shaped sliding plate and a contact type sensor, the first thrust cylinder is connected with the L-shaped sliding plate and is used for driving the transverse displacement of the L-shaped sliding plate, the contact type sensor is installed on the L-shaped sliding plate and corresponds to the upper end of the shaft column part, the contact type sensor is used for detecting the height of the shaft column part, the control center is connected with the infrared sensor, the contact type sensor and the second thrust cylinder, the second thrust cylinder is connected with the first installation plate, and the first installation plate and the second sliding rail form guide rail matching.

Preferably, the lower end of the positioning hole is provided with an ejecting rod which forms an ejecting fit with the shaft column part, the lower end of the ejecting rod is provided with an upward pushing cylinder connected with the control center, and after the shaft column part is detected, the upward pushing cylinder controls the ejecting rod to move upwards to eject the shaft column part out of the positioning hole, so that the shaft column part can be conveniently grabbed.

Preferably, the side of locating platform is equipped with connection control center's correction module, correction module includes the arm lock of support and two symmetries, the support upper end is equipped with the horizontal slide rail of second, the arm lock constitutes the cooperation of sliding with the horizontal slide rail of second, the arm lock includes driving motor and arm body, driving motor linking arm body, driving motor is used for controlling two arm bodies and removes on the horizontal slide rail of second in opposite directions or back to each other, two the corresponding face of arm body is equipped with V type breach, works as two when the arm body presss from both sides each other, and two V type breachs constitute the nip mouth that the nip corrected shaft post class part, the nip mouth is located directly over the locating hole. At the in-process that column of axles class part moved to the locating hole from the top down, when infrared sensor detected column of axles class part, column of axles class part was located the locating hole top this moment, and two arm bodies of correction module are the axial direction of the correction column of axles class part of cramping each other this moment to make and detect column of axles class part just to the locating hole position, and then prevent that column of axles class part from taking place the dislocation with the locating hole at the in-process of placing.

Preferably, the positioning table is provided with a rotating device, the rotating device comprises a driving motor and a rotating installation frame connected with the driving motor in a transmission mode, the positioning hole is located in the rotating installation frame, and the rotating installation frame is used for controlling rotation of the shaft column type part. Through the rotation of rotary device control rotation mounting bracket, the control is at the circumferential direction of shaft column class part on the locating hole to make each item of shaft column class part detect more comprehensively rather than fixing in a certain region, show and improve the detection precision.

Preferably, still include the angle detection module, the angle detection module includes first detection device and second detection device, first detection device includes first laser sensor and support frame, second detection device includes second laser sensor and support frame, the laser detection direction correspondence of first laser sensor and second laser sensor treats the locating hole and forms and sets for the contained angle. Can detect the axle column class part that contains radial hole through angle detection module, control the circumference position of axle column class part through rotary device to can realize the location detection to certain fixed region of axle column class part.

Preferably, the support frame includes fixing base, vertical slide-bar, sliding block set spare, fixing base fixed mounting is on the base, vertical slide-bar fixed mounting is on the fixing base, sliding block set spare includes second mounting panel and U type clamp splice, fixed mounting has first laser sensor or second laser sensor on the second mounting panel, U type clamp splice side fixed mounting is on the second mounting panel, be equipped with the double-layered hole that presss from both sides vertical slide-bar in the middle of the U type clamp splice, install fixing bolt on the U type clamp splice, fixing bolt is used for making U type clamp splice fixed clamping vertical slide-bar.

Preferably, still include airtight detection module, airtight detection module includes the revolving stage, installs in the revolving stage upper end the revolving stage the revolving rack, install third thrust cylinder on the revolving rack, connect the mount of third thrust cylinder, install the gas tightness detector on the mount, the gas tightness detector is including aerifing the head, aerify the through-hole that the head corresponds axle column class part and is equipped with for whether the through-hole in the detection axle column class part communicates.

A detecting and picking device comprises a rack, a feeding mechanism, a detecting mechanism, a discharging mechanism and mechanical arms, wherein the feeding mechanism, the detecting mechanism and the discharging mechanism are sequentially arranged on the rack, the feeding mechanism, the detecting mechanism and the discharging mechanism are all connected with a control center, the discharging mechanism comprises a plurality of parallel discharging transmission belt devices, the mechanical arms and the upper end of the rack are provided with transverse guide rails to form guide rail matching, each mechanical arm comprises a transverse driving frame and mechanical arms arranged on two sides of the transverse driving frame, a driving motor is arranged in the transverse driving frame and used for controlling the transverse driving frame to move relative to the transverse guide rails, the transverse distance between the two mechanical arms is the same as the distance between the feeding mechanism and a positioning hole, each mechanical arm comprises a fourth thrust cylinder and a clamping jaw connected with the fourth thrust cylinder, and the fourth thrust cylinder is used for controlling the upper and lower displacement of the clamping jaw, the jack catch is used for snatching and placing shaft column class part. The feeding mechanism and the discharging mechanism are located on two sides of the detection mechanism, the mechanical arm of the equipment is provided with two mechanical arms, when the first mechanical arm grabs the shaft column parts from the feeding mechanism, the second mechanical arm directly takes out the shaft column parts from the positioning holes, the mechanical arm is moved, after the first mechanical arm places the shaft column parts into the positioning holes, the mechanical arm is moved, and the second mechanical arm places the shaft column parts into corresponding different discharging conveying belt devices according to different precision sizes.

Preferably, the feeding mechanism comprises a driving motor and two chain transmission devices connected with the driving motor, each of the two chain transmission devices comprises a gear set and a chain meshed with the gear set, a plurality of clamping blocks fixedly mounted along the chains are arranged on opposite surfaces of the two chain transmission devices, a V-shaped clamping opening is formed in the outer end surface of each clamping block, and the V-shaped clamping openings of the two clamping blocks of the two chain transmission devices are correspondingly matched to form a fixing structure for clamping shaft column parts.

Preferably, ejection of compact transmission band device includes driving motor, connects driving motor's conveyer belt, is located the limiting plate of conveyer belt both sides. The shaft column parts are placed on the conveying belt, the shaft column parts are conveyed to a set position through the conveying belt, and the limiting plate is used for placing the shaft column parts to be separated from the conveying belt.

Has the advantages that: when the shaft column part is placed on the jacking hole, the shaft column part transmits signals to the control center through the infrared sensor above the positioning hole, the control center controls the second thrust cylinder to drive the first mounting plate to move to the position near the positioning hole along the second sliding rail, the contact sensor is located above the shaft column part at the moment, the contact sensor descends to detect the height of the shaft column part, and the automatic positioning device is convenient, fast and highly automatic.

Drawings

Fig. 1 is a schematic structural view 1 of a detection mechanism.

Fig. 2 is an enlarged schematic view of a portion a of fig. 1.

Fig. 3 is a schematic structural view of the detection mechanism 2.

Fig. 4 is a schematic structural view 3 of the detection mechanism.

Fig. 5 is a schematic structural diagram of the second detecting device.

Fig. 6 is a schematic diagram of the structure of the detecting and picking device.

Fig. 7 is an enlarged schematic view of fig. 6 at B.

1. A base; 2. a positioning table; 3. a first mounting plate; 4. a first transverse slide rail; 5. a height detection device; 51. a first thrust cylinder; 52. an L-shaped slide plate; 53. a touch sensor; 6. a second thrust cylinder; 7. a second slide rail; 8. an infrared sensor; 9. a jacking rod; 10. pushing up the cylinder; 11. a support; 12. clamping arms; 13. a second transverse slide rail; 14. a V-shaped notch; 15. rotating the mounting rack; 16. a second laser sensor; 17. a fixed seat; 18. a second mounting plate; 19. a vertical slide shaft; 20. a U-shaped clamping block; 21. a rotating table; 22. a rotating frame; 23. a third thrust cylinder; 24. an inflation head; 25. a transverse guide rail; 26. a transverse driving frame; 27. a manipulator; 28. a chain transmission; 29. a clamping block; 30. a conveyor belt; 31. a limiting plate; 32. axle column class part.

Detailed Description

The invention is further illustrated in the following by reference to FIGS. 1 to 7 and example 1.

Example (b): a detecting and picking device comprises a rack, a feeding mechanism, a detecting mechanism, a discharging mechanism and a mechanical arm.

The feeding mechanism, the detection mechanism and the discharging mechanism are sequentially arranged on the frame, the feeding mechanism, the detection mechanism and the discharging mechanism are all connected with a control center, the discharging mechanism comprises a plurality of parallel discharging transmission belt devices, the mechanical arm and the upper end of the frame are provided with transverse guide rails 25 to form guide rail matching, the robot arm includes a transverse driving frame 26 and robot arms 27 mounted on both sides of the transverse driving frame 26, a driving motor is arranged in the transverse driving frame 26 and used for controlling the transverse driving frame 26 to move relative to the transverse guide rail 25, the transverse distance between the two mechanical hands 27 is the same as the distance between the feeding mechanism and the positioning hole, the manipulator 27 comprises a fourth thrust cylinder and a clamping jaw connected with the fourth thrust cylinder, the fourth thrust cylinder is used for controlling the vertical displacement of the clamping jaw, and the clamping jaw is used for grabbing and placing the shaft column part 32. The feeding mechanism and the discharging mechanism are located on two sides of the detecting mechanism, the mechanical arm of the equipment is provided with two mechanical arms 27, when the first mechanical arm 27 grabs the shaft column part 32 from the feeding mechanism, the second mechanical arm 27 directly takes the shaft column part 32 out of the positioning hole, the mechanical arm is moved, after the first mechanical arm 27 places the shaft column part 32 into the positioning hole, the mechanical arm is moved, and the second mechanical arm 27 places the shaft column part 32 into corresponding different discharging conveying belt devices according to different precision sizes.

The feeding mechanism comprises a driving motor and two chain transmission devices 28 connected with the driving motor, wherein each of the two chain transmission devices 28 comprises a gear set and a chain meshed with the gear set, a plurality of clamping blocks 29 fixedly installed along the chains are arranged on opposite surfaces of the two chain transmission devices 28, a V-shaped clamping opening is formed in the outer end surface of each clamping block 29, and the V-shaped clamping openings of the clamping blocks 29 of the two chain transmission devices 28 are correspondingly matched to form a fixing structure for clamping the shaft column type parts 32.

The discharging and conveying belt device comprises a driving motor, a conveying belt 30 connected with the driving motor and limiting plates 31 positioned on two sides of the conveying belt 30. The shaft column parts 32 are placed on the conveyor belt 30, the shaft column parts 32 are conveyed to the set position through the conveyor belt 30, and the limiting plate 31 is used for placing the shaft column parts 32 to be separated from the conveyor belt 30.

The detection mechanism comprises a base 1, a control center, a positioning table 2, a height detection module, an air tightness detection module and an angle detection module.

The positioning table 2 is installed on the base 1, and a positioning hole for installing the shaft column part 32 is formed in the positioning table 2. The lower end of the positioning hole is provided with an ejecting rod 9 which forms abutting fit with the shaft column part 32, the lower end of the ejecting rod 9 is provided with an upward pushing cylinder 10 connected with a control center, and after the shaft column part 32 is detected, the upward pushing cylinder 10 controls the ejecting rod 9 to move upwards to eject the shaft column part 32 out of the positioning hole, so that the shaft column part 32 can be conveniently grabbed. The height detection module comprises a first mounting plate 3, a first transverse slide rail 4 arranged on the first mounting plate 3, two height detection devices 5 which form a guide rail fit with the first transverse slide rail 4, and a second thrust cylinder 6 and a second slide rail 7 which are both mounted on the rack, wherein an infrared sensor 8 positioned above a positioning hole is arranged in the middle of the first transverse slide rail 4, the two height detection devices 5 can move towards or away from each other along the first transverse slide rail 4, each height detection device 5 comprises a first thrust cylinder 51, an L-shaped slide plate 52 and a contact sensor 53, the first thrust cylinder 51 is connected with the L-shaped slide plate 52 and used for driving the L-shaped slide plate 52 to move transversely, the contact sensor 53 is mounted on the L-shaped slide plate 52, the contact sensor 53 corresponds to the upper end of the column part 32 and is used for detecting the height of the column part 32, control center connects infrared sensor 8, contact sensor 53 and second thrust cylinder 6, first mounting panel 3 is connected to second thrust cylinder 6, first mounting panel 3 constitutes the guide rail cooperation with second slide rail 7. The touch sensor 53 adopted in the embodiment is a high-precision touch sensor 53 of keyence, the minimum precision value of the touch sensor is 0.5um, and the detection accuracy and the detection efficiency are greatly improved.

The side of location platform 2 is equipped with connection control center's correction module, the correction module includes the arm lock 12 of support 11 and two symmetries, support 11 upper end is equipped with second transverse slide rail 13, arm lock 12 constitutes the cooperation of sliding with second transverse slide rail 13, arm lock 12 includes driving motor and arm body, driving motor linking arm body, driving motor is used for controlling two arm bodies and removes in opposite directions or back to back on second transverse slide rail 13, two the corresponding face of arm body is equipped with V type breach 14, and when two when the arm body was mutually pressed from both sides, two V type breachs 14 constitute the nip mouth that presss from both sides and close correction shaft column class part 32, the nip mouth is located directly over the locating hole. In the process that the axle column part 32 moves to the positioning hole from top to bottom, when the infrared sensor 8 detects the axle column part 32, the axle column part 32 is located above the positioning hole, and the two arm bodies of the correction module mutually clamp and correct the axial direction of the axle column part 32, so that the detection of the axle column part is right aligned with the positioning hole, and the dislocation of the axle column part 32 with the positioning hole in the placing process is prevented. The positioning table 2 is provided with a rotating device, the rotating device comprises a driving motor and a rotating installation frame 15 connected with the driving motor in a transmission mode, the positioning holes are located on the rotating installation frame 15, and the rotating installation frame 15 is used for controlling rotation of the shaft column part 32. The rotation of the rotary mounting frame 15 is controlled through the rotating device, and the circumferential rotation of the shaft column part 32 on the positioning hole is controlled, so that all detection of the shaft column part 32 is more comprehensive rather than being fixed in a certain area, and the detection precision is obviously improved.

The angle detection module comprises a first detection device and a second detection device, the first detection device comprises a first laser sensor and a support frame, the second detection device comprises a second laser sensor 16 and a support frame, and the laser detection directions of the first laser sensor and the second laser sensor 16 correspond to the positioning holes to be treated and form a set included angle. The shaft column part 32 with the radial hole can be detected through the angle detection module, and the circumferential position of the shaft column part 32 is controlled through the rotating device, so that the positioning detection of a certain fixed area of the shaft column part 32 can be realized. The support frame includes fixing base 17, vertical slide-shaft 19, sliding block set spare, fixing base 17 fixed mounting is on

base

1, 19 fixed mounting of vertical slide-shaft is on fixing base 17, sliding block set spare includes second mounting panel 18 and U type clamp splice 20, fixed mounting has first laser sensor or second laser sensor 16 on the second mounting

panel

18, 20 side fixed mounting of U type clamp splice is on second mounting panel 18, be equipped with the double-layered hole that presss from both sides vertical slide-shaft 19 in the middle of U type clamp splice 20, install fixing bolt on the U type clamp splice 20, fixing bolt is used for making the fixed vertical slide-shaft 19 that presss from both sides of U type clamp splice 20.

Airtight detection module includes revolving stage 21, installs in revolving stage 21 upper end swivel mount 22, install third thrust cylinder 23 on swivel mount 22, connect third thrust cylinder 23 the mount, install the gas tightness detector on the mount, gas tightness detector is including aerifing head 24, aerify the through-hole that head 24 corresponds axle column class part 32 and is equipped with for detect whether the through-hole in the axle column class part 32 communicates.

It should be understood that the above-described embodiments of the present invention are merely examples for illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. There is no need or no way to give poor examples of all embodiments. And such obvious changes and modifications which are within the spirit of the invention are deemed to be covered by the present invention.

Claims

1. A thickness detection mechanism, characterized in that: comprising a base (1), a control center, a positioning stage (2), a height detection module, the positioning stage (2) is mounted on the base (1), and the The positioning table (2) is provided with positioning holes for the installation of the shaft and column parts (32), and the height detection module includes a first mounting plate (3) and a first lateral sliding plate arranged on the first mounting plate (3). a rail (4), two height detection devices (5) that cooperate with the first lateral slide rail (4) to form a guide rail, a second thrust cylinder (6) and a second slide rail (7) both mounted on the frame, An infrared sensor (8) located above the positioning hole is arranged in the middle of the first lateral slide rail (4), and the two height detection devices (5) can move toward each other or back along the first lateral slide rail (4), so The height detection device (5) includes a first thrust cylinder (51), an L-shaped slide plate (52), and a contact sensor (53), the first thrust cylinder (51) is connected to the L-shaped slide plate (52), and the first thrust cylinder (51) A thrust cylinder (51) is used to drive the lateral displacement of the L-shaped sliding plate (52), the contact sensor (53) is mounted on the L-shaped sliding plate (52), and the contact sensor (53) corresponds to the shaft column type The upper end of the part (32), the contact sensor (53) is used to detect the height of the shaft column type part (32), and the control center is connected with the infrared sensor (8), the contact sensor (53) and the second thrust cylinder (6), the second thrust cylinder (6) is connected to the first mounting plate (3), and the first mounting plate (3) and the second slide rail (7) form a guide rail fit.

2. A thickness detection mechanism according to claim 1, characterized in that: the lower end of the positioning hole is provided with a top rod (9) that is abutted against and matched with the shaft column parts (32), and the top position The lower end of the rod (9) is provided with a push-up cylinder (10) connected to the control center.

3. A thickness detection mechanism according to claim 1, characterized in that: the side of the positioning table (2) is provided with a correction module connected to the control center, and the correction module comprises a bracket (11) and two A symmetrical clamping arm (12), the upper end of the bracket (11) is provided with a second transverse slide rail (13), the clamping arm (12) and the second transverse slide rail (13) form a sliding fit, and the clamp The arm (12) includes a drive motor and an arm body, the drive motor is connected to the arm body, and the drive motor is used to control the two arm bodies to move toward or away from each other on the second transverse slide rail (13), and the two The corresponding surface of the arm body is provided with a V-shaped notch (14). When the two arm bodies are clamped with each other, the two V-shaped notches (14) constitute a clamping opening for clamping and correcting the shaft column parts (32). The clamping opening is located just above the positioning hole.

4. A thickness detection mechanism according to claim 1, characterized in that: the positioning table (2) is provided with a rotating device, and the rotating device comprises a drive motor and a rotating mounting frame (15) that is connected to the drive motor by transmission , the positioning hole is located on the rotating mounting frame (15), and the rotating mounting frame (15) is used to control the rotation of the shaft column type parts (32).

5 . The thickness detection mechanism according to claim 4 , further comprising an angle detection module, wherein the angle detection module includes a first detection device and a second detection device, and the first detection device includes a first detection device. 6 . A laser sensor and a support frame, the second detection device includes a second laser sensor (16) and a support frame, and the laser detection directions of the first laser sensor and the second laser sensor (16) correspond to the holes to be positioned and are set angle.

6. A thickness detection mechanism according to claim 5, characterized in that: the support frame comprises a fixing seat (17), a vertical sliding shaft (19), and a slider assembly, and the fixing seat (17) is fixed is mounted on the base (1), the vertical sliding shaft (19) is fixedly mounted on the fixing seat (17), and the sliding block assembly includes a second mounting plate (18) and a U-shaped clamp block (20), A first laser sensor or a second laser sensor (16) is fixedly mounted on the second mounting plate (18), and the side of the U-shaped clamping block (20) is fixedly mounted on the second mounting plate (18), so A clamping hole for clamping the vertical sliding shaft (19) is arranged in the middle of the U-shaped clamping block (20), and fixing bolts are installed on the U-shaped clamping block (20), and the fixing bolts are used to make the U-shaped clamping block (20) The vertical sliding shaft (19) is fixedly clamped.

7 . The thickness detection mechanism according to claim 1 , further comprising an airtight detection module, the airtight detection module comprising a rotary table (21) and a rotary frame mounted on the upper end of the rotary table (21). 8 . (22), a third thrust cylinder (23) installed on the rotating frame (22), a fixed frame connected to the third thrust cylinder (23), and a gas tightness detector mounted on the fixed frame, the gas tightness The detector includes an inflatable head (24), and the inflatable head (24) corresponds to a through hole provided in the shaft column type part (32), and is used for detecting whether the through hole in the shaft column type part (32) is connected.

8. A detection and picking device, characterized in that it comprises a rack, a feeding mechanism, the detection mechanism according to any one of claims 1 to 7, a discharging mechanism, and a mechanical arm, the feeding mechanism, the detection mechanism, The discharging mechanism is installed on the rack in sequence. The feeding mechanism, the detecting mechanism and the discharging mechanism are all connected to the control center. The discharging mechanism includes a plurality of parallel discharging conveyor belt devices. The mechanical arm is connected to the rack. The upper end is provided with a lateral guide rail (25) to form a guide rail fit, the mechanical arm includes a lateral drive frame (26) and a manipulator (27) installed on both sides of the lateral drive frame (26), and the lateral drive frame (26) is internally provided with There is a drive motor, the drive motor is used to control the movement of the lateral drive frame (26) relative to the lateral guide rail (25), the lateral distance between the two manipulators (27) is the same as the distance from the feeding mechanism to the positioning hole, the manipulator ( 27) Including a fourth thrust cylinder and a gripper connected to the fourth thrust cylinder, the fourth thrust cylinder is used to control the up and down displacement of the gripper, and the gripper is used to grab and place the shaft column type parts (32).

9. A detection and picking device according to claim 8, characterized in that: the feeding mechanism comprises a drive motor and two chain drives (28) connected to the drive motors, and the two chain drives (28) ) each includes a gear set and a chain meshed with the gear set, the opposite surfaces of the two chain transmission devices (28) are provided with a plurality of clamping blocks (29) fixedly installed along the chain, the clamping blocks (29) The outer end face is provided with a V-shaped clamping opening, and the V-shaped clamping openings of the clamping blocks (29) of the two chain transmission devices (28) are correspondingly matched to form a fixing structure for clamping the shaft column parts (32).

10 . The detection and picking device according to claim 9 , wherein the discharge conveyor belt device comprises a drive motor, a conveyor belt ( 30 ) connected to the drive motor, and limit plates located on both sides of the conveyor belt ( 30 ). 11 . (31).