Automatic flaw detection machine for outer ring of transmission shaft

Abstract

A transmission shaft outer ring automatic flaw detection machine belongs to detection equipment, and adopts the technical scheme that the transmission shaft outer ring automatic flaw detection machine comprises a magnetizing mechanism, a feeding and discharging transfer mechanism, a feeding slide way, a discharging slide way, a material receiving disc and a magnetic suspension box which are arranged on a rack, the magnetizing mechanism comprises an electrode mechanism A and an electrode mechanism B, and the feeding slide way and the discharging slide way are respectively arranged on two sides of the electrode mechanism B; the electrode mechanism A comprises an electrode tip A and a driving mechanism for driving the electrode tip A to move up and down, the electrode mechanism B comprises a frame body, an electrode tip B, a floating positioning disc, a spring, a correlation sensor A, a correlation sensor B and a spraying head, and the correlation sensor A and the correlation sensor B are arranged on the two sides of the electrode tip B respectively and fixedly connected with the floating positioning disc. The spraying heads are fixedly installed on the floating positioning disc respectively, the transferring mechanism automatically feeds and discharges the outer ring, magnetizes the outer ring and then conveys the outer ring to the receiving disc, and the technology can rapidly detect whether the outer ring has cracks or not, reduce the labor intensity of operators and improve the detection efficiency.

Description

Technical Field

[0001] The present invention relates to an automatic detection device, specifically an automatic flaw detector for the outer ring of a drive shaft. Background Art

[0002] The constant velocity universal joint drive shaft of a car consists of a fixed end joint, an intermediate shaft, and a mobile end joint. Among them, the fixed end joint is directly connected to the hub of the car wheel, and the mobile end joint is directly connected to the differential of the engine. The power of the engine is transmitted to the wheel through the differential, the mobile end joint, the intermediate shaft, the fixed end joint, and the hub, thereby driving the wheel to rotate. The fixed end joint mainly consists of an outer ring, a cage, steel balls, and an inner ring; the mobile end joint mainly consists of an outer sleeve, a cage, steel balls, and an inner sleeve. The magnetic particle flaw detection process of the outer ring of the fixed end joint is extremely important. If there are cracks in the outer ring, especially cracks in the handle part and the table end of the outer ring, it will cause the outer ring to break, resulting in the drive shaft losing its function, endangering the safety of people and vehicles, and causing claims from customers. In the past, the flaw detection of the outer ring was manually operated one by one on a flaw detector with thick flannel covering the light. The operator needed to manually load the material, magnetize, detect cracks, and unload the material manually. This not only has a high labor intensity, a poor working environment, but also low efficiency, affecting delivery. Therefore, there is an urgent need for a magnetic particle flaw detector in the production site that can automatically load and unload the outer ring of the drive shaft and magnetize it. Summary of the Invention

[0003] The purpose of the present invention is to provide a machine that can automatically load and unload the outer ring of the drive shaft and automatically magnetize it. Using this technology, the outer ring of the drive shaft can be quickly subjected to magnetic particle flaw detection, which not only reduces the labor intensity of the operator, but also greatly improves the efficiency.

[0004] The technical solution of the present invention is: an automatic flaw detector for the outer ring of a transmission shaft, comprising a frame, characterized in that: an automatic magnetization mechanism, a loading and unloading transfer mechanism, a feeding chute, a discharging chute, a receiving tray, and a magnetic suspension liquid tank are installed on the frame. The magnetic suspension liquid tank is located at the bottom of the frame, and a pump is fixedly installed on the magnetic suspension liquid tank. The receiving tray is located below the discharging chute, and an opposed sensor C and an opposed sensor D are fixedly installed on the receiving tray. The automatic magnetization mechanism comprises an electrode mechanism A and an electrode mechanism B. The feeding chute and the discharging chute are respectively arranged on both sides of the electrode mechanism B. The electrode mechanism A comprises an electrode head A and a driving mechanism for driving the electrode head A to move up and down. The housing of the electrode mechanism A is fixedly connected to the frame. The electrode mechanism B comprises a frame body, an electrode head B, a floating positioning disk, a spring, an opposed sensor A, an opposed sensor B, and a spray head. The upper part of the electrode head B is opposite to the electrode head A, and the lower end is fixedly connected to the frame body. The bottom surface of the floating positioning disk is pressed against one end of the spring, and the other end of the spring is supported and connected by the frame body. The floating positioning disk is provided with a central hole, and a cylindrical positioning socket is arranged outside the circular hole. The electrode head B is located in the central hole of the floating positioning disk, and there is a gap between the electrode head B and the inner wall of the central hole. The opposed sensor A and the opposed sensor B are respectively installed on both sides of the electrode head B and are fixedly connected to the floating positioning disk. The spray heads are multiple, and each spray head is fixedly installed on the floating positioning disk, and each spray head is connected to the magnetic suspension liquid tank through a pipeline. The transfer mechanism comprises an electric cylinder A, a double guide rail A, a stopper A, and a stopper B fixedly connected to the frame. A slide plate A is slidably connected to the double guide rail A. The telescopic end of the electric cylinder A is fixedly connected to the slide plate A through a coupling. A vertical plate is fixedly installed on the slide plate A, and an electric cylinder B, a double guide rail B, and a stopper C are fixedly installed on the vertical plate. A slide plate B is slidably connected to the double guide rail B. The telescopic end of the electric cylinder B is fixedly connected to the slide plate B through a coupling. A horizontally placed connecting plate is fixedly installed on the slide plate B, and a cylinder A, two support brackets A, and two support brackets B are fixedly installed on the connecting plate. A guide post A is fixedly installed between the two support brackets A, and a guide post B is fixedly installed between the two support brackets B. A slide plate C is sleeved on the guide post A and the guide post B and is slidably connected to the guide post A and the guide post B. The telescopic end of the cylinder A is fixedly connected to the slide plate C. The fixed ends of the clamping cylinders B and C are fixedly connected to the slide plate C, and the telescopic ends of the clamping cylinders B and C are respectively fixedly connected to a clamping jaw A and a clamping jaw B. The clamping jaw A is provided with a cylindrical concave arc surface A, and the clamping jaw B is provided with a cylindrical concave arc surface B.

[0005] A frame is installed on the frame, and an audible and visual alarm, a safety light curtain A, and a safety light curtain B are fixedly installed on the frame. An electric control cabinet is installed on the side of the frame, and a touch display screen is fixedly installed on the electric control cabinet. A start button and an emergency stop switch are provided on the touch display screen.

[0006] A fluorescent lamp is provided above the receiving tray.

[0007] The principle of the present invention is as follows: The outer ring is automatically loaded and unloaded by a transfer mechanism, the equipment automatically magnetizes, and the magnetized outer ring is sent to the receiving tray by the transfer mechanism. When a certain number is reached, the operator quickly checks whether the outer ring has cracks, and then transfers the outer ring to the next cleaning process.

[0008] The advantages of the present invention are as follows: Through the transfer mechanism, the present invention can automatically load and unload the outer ring of the transmission shaft, and through automatic magnetization, the operator can quickly and centrally detect whether the outer ring has cracks, which not only reduces the labor intensity of the operator, but also greatly improves the efficiency, ensures timely delivery, increases customer satisfaction, and enhances the core competitiveness of the enterprise. Brief Description of the Drawings

[0009] Figure 1 It is a schematic structural diagram of the automatic flaw detector for the outer ring of the transmission shaft of the present invention.

[0010] Figure 2 is Figure 1 The top view of the middle connecting plate and its attachments.

[0011] Figure 3 It is the top view of the electrode B mechanism.

[0012] Figure 4 is Figure 3 The partial sectional view in the A-A direction of

[0013] Figure 5 It is an enlarged schematic structural diagram of the outer ring.

[0014] Figure 6 is Figure 1 The enlarged view of part Ⅰ in

[0015] In the figure: 1 magnetic suspension liquid tank, 2 pump, 3 double guide rail A, 4 slide plate A, 5 stopper A, 6 electric cylinder A, 7 safety grating A, 8 electric cylinder B, 9 vertical plate, 10 double guide rail B, 11 stopper C, 12 slide plate B, 13 feeding chute, 14 frame, 15 slide plate C, 16 clamping cylinder B, 17 guide post A, 18 bracket A, 19 opposed sensor A, 20 spray head, 21 electrode head B, 22 electrode head A, 23 cylinder A, 24 bracket B, 25 guide post B, 26 opposed sensor B, 27 floating positioning disk, 28 clamping cylinder C, 29 connecting plate, 30 sound and light alarm, 31 frame, 32 fluorescent lamp, 33 discharging chute, 34 electric control cabinet, 35 touch control display screen, 36 start button, 37 emergency stop switch, 38 receiving tray, 39 opposed sensor C, 40 opposed sensor D, 41 safety grating B, 42 stopper B, 43 jaw A, 44 cylindrical concave arc surface A, 45 jaw B, 46 cylindrical positioning socket, 47 gap, 48 cylindrical surface, 49 handle part, 50 table end, 51 bottom, 52 cylindrical concave arc surface B. Detailed Embodiment

[0016] The present invention is a device for automatically detecting flaws in the outer ring components of a constant velocity universal joint drive shaft for a car. Referring to the attached Figures 1 to 6 as shown, specific embodiments are described. The automatic flaw detector for the outer ring of the drive shaft, the technical solution includes a frame 14, on which an automatic magnetizing mechanism, a loading and unloading transfer mechanism, a feeding chute 13, an unloading chute 33, a receiving tray 38, and a magnetic suspension liquid tank 1 are installed. The magnetic suspension liquid tank 1 is located at the bottom of the frame 14, and a pump 2 is fixedly installed on the magnetic suspension liquid tank 1. The receiving tray 38 is located below the unloading chute 33, and an opposed sensor C39 and an opposed sensor D40 are fixedly installed on the receiving tray 38. The automatic magnetizing mechanism includes an electrode mechanism A and an electrode mechanism B. The feeding chute 13 and the unloading chute 33 are respectively arranged on both sides of the electrode mechanism B. The electrode mechanism A includes an electrode head A22 and a driving mechanism for driving the electrode head A to move up and down. The housing of the electrode mechanism A is fixedly connected to the frame 14. The electrode mechanism B includes a frame body, an electrode head B21, a floating positioning plate 27, a spring, an opposed sensor A19, an opposed sensor B26, and a spray head 20. The upper part of the electrode head B21 is opposite to the electrode head A22, and the lower end is fixedly connected to the frame body. The bottom surface of the floating positioning plate 27 is pressed against one end of the spring, and the other end of the spring is supported by the frame body. The floating positioning plate 27 is provided with a central hole, and a cylindrical positioning socket 46 is provided outside the circular hole. The electrode head B21 is located in the central hole of the floating positioning plate 27, and a gap 47 is provided between the electrode head B21 and the inner wall of the central hole. The opposed sensor A19 and the opposed sensor B26 are respectively installed on both sides of the electrode head B21 and are fixedly connected to the floating positioning plate 27. The spray heads 20 are multiple, and each spray head is fixedly installed on the floating positioning plate 27, and each spray head is respectively connected to the magnetic suspension liquid tank 1 through a pipeline. The transfer mechanism includes an electric cylinder A6, a double guide rail A3, a stopper A5, and a stopper B42 fixedly connected to the frame. A slide plate A4 is slidably connected to the double guide rail A3. The telescopic end of the electric cylinder A6 is fixedly connected to the slide plate A4 through a coupling. A vertical plate 9 is fixedly installed on the slide plate A4. An electric cylinder B8, a double guide rail B10, and a stopper C11 are fixedly installed on the vertical plate 9. A slide plate B12 is slidably connected to the double guide rail B10. The telescopic end of the electric cylinder B8 is fixedly connected to the slide plate B12 through a coupling. A horizontally placed connecting plate 29 is fixedly connected to the slide plate B12. A cylinder A23, two support brackets A18, and two support brackets B24 are fixedly connected to the connecting plate 29. A guide post A17 is fixedly installed between the two support brackets A18, and a guide post B25 is fixedly installed between the two support brackets B24. A slide plate C15 is sleeved on the guide post A17 and the guide post B25 and is slidably connected to the guide post A17 and the guide post B25. The telescopic end of the cylinder A23 is fixedly connected to the slide plate C15. The fixed ends of the clamping cylinder B16 and the clamping cylinder C28 are fixedly connected to the slide plate C15. The telescopic ends of the clamping cylinder B16 and the clamping cylinder C28 are respectively fixedly connected with a jaw A43 and a jaw B46. The jaw A43 is provided with a cylindrical concave arc surface A44, and the jaw B45 is provided with a cylindrical concave arc surface B52.

[0017] A frame 31 is also installed on the described frame 14. An audible and visual alarm 30, a safety light curtain A7, and a safety light curtain B41 are fixedly installed on the frame 31. An electric control cabinet 34 is provided on the side of the frame 14. A touch display screen 35 is fixedly installed on the electric control cabinet. A start button 36 and an emergency stop switch 37 are provided on the touch display screen 35.

[0018] Above the receiving tray 38 of the present invention, there is a high-intensity fluorescent lamp 32. The main function of the fluorescent lamp in the magnetic particle flaw detector is to enhance the visibility of defects. During the magnetic particle flaw detection process, the fluorescent lamp irradiates with ultraviolet light, causing the magnetic powder coated with fluorescent substances to emit yellow-green fluorescence, thereby more clearly showing the defects on the surface of the workpiece. This fluorescence effect enables the defects to be clearly observed even in a relatively dark environment, improving the accuracy and reliability of the detection.

[0019] The outer ring automatic flaw detector of this transmission shaft is controlled by an automatic control system. The components of the automatic control system include a controller and an electric cylinder, an opposed sensor, a cylinder, a clamping cylinder, a pump, a limiter, an audible and visual alarm, a safety light curtain, and a touch display screen that are electrically connected to the controller through signal lines. Each electric cylinder, opposed sensor, cylinder, clamping cylinder, pump, limiter, audible and visual alarm, and safety light curtain component is installed in its corresponding unit, and the controller is installed in the electric control cabinet.

[0020] The outer ring described in the present invention is a main accessory of the fixed end joint in the constant velocity universal joint drive shaft of a car.

[0021] The basic principle of the described magnetic particle flaw detection is that after ferromagnetic materials are magnetized, leakage magnetic fields will be formed at the defects on their surfaces and near surfaces. These leakage magnetic fields are caused by magnetic field distortions due to discontinuities or defects inside the material. When magnetic powder is scattered on the surface of the material to be tested, the magnetic powder will be adsorbed by the leakage magnetic field and accumulate at the defects, forming visible magnetic powder accumulations, thereby indicating information such as the position, shape, and size of the defects. The two electrode heads of the magnetic particle flaw detector are basic configurations, used to clamp and hold the part to be tested tightly from both ends, and apply a magnetic field by charging the part to be tested through the two electrode heads. The magnetic particle flaw detection technology has the advantages of high sensitivity, simple operation, and low cost, so it has been widely used in industrial production.

[0022] The cylinder described in this article is a mechanical product of the prior art. Generally, the cylinder has a cylinder body as the fixed end, which is fixedly installed on its corresponding component. The cylinder also has a telescopic end as the moving end, which is also called the telescopic rod. The telescopic end reciprocates along its axial direction within the designed stroke. Telescopic cylinders are mainly divided into pneumatic telescopic cylinders, electric telescopic cylinders, electromagnetic telescopic cylinders, and hydraulic telescopic cylinders, etc. In this application, pneumatic telescopic cylinders (cylinders) and electric telescopic cylinders are preferably selected; among them, the pneumatic telescopic cylinder is a prior art product that converts pressurized gas into mechanical motion.

[0023] The electric cylinder described is a product of the prior art. The electric cylinder is a modular product with an integrated design of a servo motor and a lead screw, which converts the rotational motion of the servo motor into linear motion.

[0024] For the described safety grating, when a human hand or other object intrudes into the plane range between the two gratings, the machine tool stops moving.

[0025] The described frame is used to support the components in each of the devices at a specified position above the ground. In this application, a frame enclosure is installed on the frame. The frame, electric cylinder, through-beam sensor, air cylinder, clamping air cylinder, pump, and stopper are located in the frame enclosure for protecting each component; the frame enclosure is formed by enclosing with translucent or opaque plates between the frames 31.

[0026] To make the drawings clear, all pipelines, wires, and standard parts in the drawings are omitted.

[0027] The human-machine interface of the controller is preferably a touch display screen 35. The touch display screen 35 is provided on the surface of the electrical cabinet or installed on the frame 31, which is convenient for on-site staff to operate. The staff can control the operation of the whole machine on this touch display screen 35. An audible and visual alarm 30 is installed on the frame 31 or the electrical cabinet, which is used to emit specific sounds and lights to indicate the working status of the automatic flaw detector for the outer ring of the transmission shaft, or to adjust various parameters, or to give an audible and visual alarm for the occurring faults.

[0028] Working process of the present invention: Press the start button 36, the electric cylinder A6 in the transfer mechanism drives the slide plate A4 to move left to the set position and contact the stopper A5, and the electric cylinder A6 stops moving. At this time, the clamping cylinder B16 opens the jaw A43, and the clamping cylinder C28 opens the jaw B45. The clamping cylinder B16 faces the staying direction of the washed outer ring on the feeding chute 13, and the clamping cylinder C28 faces the direction of the electrode head B21. The cylinder A23 drives the slide plate C15 and the clamping cylinder B16 and the clamping cylinder C28 thereon to move forward to the extreme position. At this time, the cylindrical surface 48 part of the outer ring (workpiece) is located in the cylindrical concave arc surface A44 of the opened jaw A43, and another outer ring is on the electrode head B21, and its cylindrical surface 48 part is located in the cylindrical concave arc surface B52 of the opened jaw B45. The clamping cylinder B16 and the clamping cylinder C28 drive the jaw A43 and the jaw B45 to retract and clamp the workpiece respectively. The electric cylinder B8 drives the connecting plate 29 to rise to the set position. At this time, the lower plane of the outer ring on the jaw A43 and the jaw B45 is higher than the spray head 20, the opposed sensor A19 and the opposed sensor B26. The electric cylinder A6 drives the slide plate A4 to move right to the set position and contact the stopper B42, and the electric cylinder A6 stops moving. At this time, the jaw A43 clamping the outer ring is directly above the electrode head B21, and the clamped jaw B45 is directly above the discharge chute 33. The electric cylinder B8 drives the connecting plate 29 to descend to the set position (contact with the stopper C11). At this time, the outer ring in the jaw A43 contacts the cylindrical positioning socket 46 of the floating positioning disk 27, and the bottom 51 of the outer ring contacts the electrode head B21. The clamping cylinder B16 and the clamping cylinder C28 drive the jaw A43 and the jaw B45 to open respectively. The purpose of opening the jaw A43 is to place the outer ring on the floating positioning disk 27, and the purpose of opening the jaw B45 is to place the outer ring thereon on the discharge chute 33. The electric cylinder B8 drives the slide plate B12 to rise to the set position. The cylinder A23 drives the slide plate C15 and the clamping cylinder B16 and the clamping cylinder C28 thereon to retract to the extreme position. Synchronously, when the opposed sensor A19 and the opposed sensor B26 sense the outer ring, the driving mechanism in the electrode mechanism A drives the electrode head A22 to move downward, contact the outer ring handle 49 and continue to move downward. At this time, the outer ring in the floating positioning disk 27 will have a certain downward displacement (the function of the floating positioning disk 27 is: when the electrode head A22 presses the outer ring downward, the outer ring can move downward on the floating positioning disk 27, so that the electrode head B21 can reliably contact the bottom 51 of the outer ring, avoiding poor contact and burning the outer ring when energized due to poor contact.), until the bottom 51 of the outer ring contacts the electrode head B21. At this time, the electrode head A22 stops moving. The electrode head A22 and the electrode head B21 are in reliable contact with the outer ring. The device starts to energize the outer ring. At the same time, the pump 2 starts to spray the magnetic suspension liquid in the magnetic suspension liquid tank 1 through the spray head 20 onto the handle 49 and the table end 50 of the outer ring. After reaching the set time, the spraying stops and the power supply stops. The drive mechanism in the electrode mechanism A drives the electrode head A22 to retract upward to the original position. Synchronously, the electric cylinder A6 drives the slide plate A4 to move left to the set position and contact the stopper A5. The electric cylinder A6 stops moving. The electric cylinder B8 drives the connecting plate 29 to descend to the set position (contact with the stopper C). The cylinder A23 drives the slide plate C15 and the clamping cylinders B16 and C28 thereon to advance to the extreme position, entering the next cycle...

[0029] The outer rings on the discharge chute 33 slide under the action of gravity and enter the receiving tray 38. When the number of outer rings in the receiving tray 38 is large enough and accumulates to the point where the opposed sensors C39 and D40 sense the outer rings, the audible and visual alarm 30 prompts the operator to inspect the outer rings. The operator can quickly check whether the outer rings have cracks. After inspection, the outer rings are conveyed to the next cleaning process.

Claims

1. A transmission shaft outer ring automatic flaw detector, comprising a frame (14), characterized in that: The frame (14) is equipped with an automatic magnetizing mechanism, a loading and unloading transfer mechanism, a feed chute (13), a discharge chute (33), a receiving tray (38), and a magnetic suspension tank (1). The magnetic suspension tank (1) is located at the bottom of the frame (14). A pump (2) is fixedly installed on the magnetic suspension tank (1). The receiving tray (38) is located below the discharge chute (33). A counter-beam sensor C (39) and a counter-beam sensor D (40) are fixedly installed on the receiving tray (38). The automatic magnetizing mechanism includes an electrode mechanism A and an electrode mechanism B. The feed chute (13) and the discharge chute (33) are respectively arranged on both sides of the electrode mechanism B. The electrode mechanism A includes an electrode head A (22) and a driving mechanism for driving the electrode head A (22) to move up and down. The housing of the electrode mechanism A is fixedly connected to the frame (14); the electrode mechanism B comprises a frame, an electrode head B (21), a floating positioning plate (27), a spring, a beam sensor A (19), a beam sensor B (26), and a shower head (20); the electrode head B (21) is opposite to the electrode head A (22) at the top, and is fixedly connected to the frame at the bottom; the bottom surface of the floating positioning plate (27) is crimped to one end of the spring, and the other end of the spring is supported and connected by the frame; the floating positioning plate (27) is provided with a center hole, and a cylindrical positioning recess (46) is provided on the periphery of the circular hole; the electrode head B (21) is located in the center hole of the floating positioning plate (27); a gap (47) is provided between the electrode head B (21) and the inner wall of the center hole; the beam sensor A (19) and the beam sensor B (26) are provided. The device B (26) is installed on both sides of the electrode head B (21) and is respectively fixedly connected to the floating positioning plate (27). The spray head (20) is multiple, each of which is fixedly installed on the floating positioning plate (27). Each of the spray heads is respectively connected to the pipeline of the magnetic suspension tank (1). The transfer mechanism includes an electric cylinder A (6) fixedly connected to the frame, a double guide rail A (3), a stopper A (5), and a stopper B (42). The double guide rail A (3) is provided with a slide plate A (4) slidably connected. The telescopic end of the electric cylinder A (6) is fixedly connected to the slide plate A (4) through a coupling. The slide plate A (4) is fixedly connected to a vertical plate (9). The vertical plate (9) is fixedly connected to an electric cylinder B (8), a double guide rail B (10), and a stopper C (11). The double guide rail B (10) is provided with a slideway. The slide plate B (12) is connected, the telescopic end of the electric cylinder B (8) is fixedly connected to the slide plate B (12) through a coupling, the slide plate B (12) is fixedly connected to a horizontally placed connecting plate (29), the connecting plate (29) is fixedly connected to a cylinder A (23), two brackets A (18), and two brackets B (24), a guide column A (17) is fixedly installed between the two brackets A (18), and a guide column B (25) is fixedly installed between the two brackets B (24), the slide plate C (15) is sleeved on the guide column A (17) and the guide column B (25), and is slidably connected to the guide column A (17) and the guide column B (25), the telescopic end of the cylinder A (23) is fixedly connected to the slide plate C (15), and the fixed ends of the clamping cylinders B (16) and C (28) are fixedly connected to the slide plate C (15),The telescopic ends of the clamping cylinder B (16) and the clamping cylinder C (28) are respectively fixedly connected with a clamping jaw A (43) and a clamping jaw B (45), wherein the clamping jaw A (43) is provided with a cylindrical concave arc surface A (44), and the clamping jaw B (45) is provided with a cylindrical concave arc surface B (52).

2. The automatic flaw detector for the outer ring of the transmission shaft according to claim 1 is characterized in that: The frame (14) is provided with a frame (31), on which an audible and visual alarm (30), a safety light A (7), and a safety light B (41) are fixedly mounted. An electric control cabinet (34) is provided on the side of the frame (14), on which a touch screen (35) is fixedly mounted. The touch screen (35) is provided with a start button (36) and an emergency stop switch (37).

3. The automatic flaw detector for the transmission shaft outer ring according to claim 1 is characterized in that: A fluorescent lamp (32) is provided above the receiving tray (38).

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