Metal plate blanking device

By fixing the position of the metal plate with magnetic adsorption and pulley limiting groove, combined with precision mold design and automated push plate collection components, the problem of positional deviation during the metal plate punching process is solved, achieving high-precision and high-efficiency punching production.

CN223655834UActive Publication Date: 2025-12-12GUANGDONG DONGGUAN XIN METAL MATERIALS TECH CO LTD
View PDF 0 Cites 0 Cited by

Patent Information

Application Number
CN202520018840.4
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2025-01-03
Publication Date
2025-12-12
Estimated Expiration
2035-01-03

AI Technical Summary

Technical Problem

During the stamping process, metal sheets are prone to positional deviation due to insufficient friction, uneven surface, or precision issues with the conveying device, which affects stamping accuracy. Furthermore, speed fluctuations and external vibrations in high-speed production lines may cause the sheet material to deviate from its intended position.

Method used

Multiple evenly distributed magnets are used to attract metal plates, and the synchronous belt and limiting groove of the pulley assembly are used to fix the position of the metal plates. The push plate assembly and the collection assembly are used to realize automated production. The precision-matched mold design ensures the consistency and high quality of the punching.

Benefits of technology

It effectively prevents the metal sheet from moving during the punching process, ensures high-precision punching, reduces the defect rate, improves production efficiency, reduces the risk of manual intervention, extends the life of mechanical parts, and enables continuous production.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure CN223655834U_ABST
    Figure CN223655834U_ABST
Patent Text Reader

Abstract

The utility model relates to the technical field of metal plate blanking, in particular to a metal plate blanking device which comprises a base and a bearing column, the bearing column is installed in the middle of the rear portion of the base, a first electric push rod with a downward driving end is installed on the top of the bearing column, and a first pressing plate is arranged on the upper portion of a telescopic rod of the first electric push rod. A second pressing plate is slidably arranged at the bottom of the first pressing plate, supporting columns are arranged at all corners of the top of the base, a workbench is jointly arranged between the outer portions of all the supporting columns, and a controller is installed at the position, close to the corners, of the side portion of the workbench. According to the utility model, the metal plate is firmly fixed through the plurality of magnets which are uniformly distributed, so that movement in the blanking process is prevented, and high precision is ensured; a synchronous belt of the belt pulley assembly is embedded into a limiting groove of the lower die, power is transmitted, the position of the metal plate is further fixed, and offset errors are avoided; manual intervention is reduced through cooperation of the push plate assembly and the collecting assembly, and the risk that operators make contact with dangerous equipment is reduced.
Need to check novelty before this filing date? Find Prior Art

Description

TECHNICAL FIELD

[0001] The utility model relates to metal plate blanking technology field especially relates to a metal plate blanking device. BACKGROUND

[0002] Metal plate refers to the flat plate shaped component made of metal material, has certain thickness, width and length.

[0003] Blanking is a kind of stamping process, it utilizes die to make part material or workpiece and another part material, workpiece or waste material separate one kind of stamping process.

[0004] In prior art, metal plate blanking process, transmission link can cause plate position deviation, and then influence blanking accuracy.Specifically, metal plate on the conveyer belt can slide due to insufficient friction, uneven surface or precision problem of transmission device.In addition, speed fluctuation in high-speed production line, concentricity error of transmission roller and external vibration and air flow and other factors can make plate deviate from the predetermined position.

[0005] Therefore, it is needed to design a kind of metal plate blanking device to solve the above technical problems. INVENTION CONTENTS

[0006] In order to overcome the shortcomings of the prior art, the utility model provides a kind of metal plate blanking device.

[0007] The utility model discloses a kind of metal plate blanking devices, including base, supporting column, support column, pressing die assembly, motor and pulley assembly, supporting column is installed in the middle of the rear part of base, supporting column top is installed with the first electric push rod of driving end downward, the upper portion of the telescopic rod of first electric push rod is provided with first pressing plate, the second pressing plate is slidably arranged in the bottom of first pressing plate, the top of each corner of base is provided with support column, the workbench is commonly provided between the outside of each support column, controller is installed in the side of workbench, the first sleeve rod is arranged through the inside of first pressing plate and second pressing plate in the top of each support column, first pressing plate and second pressing plate are slidably connected with first sleeve rod, the second guide rod that a plurality of evenly distributed is slidably arranged in the middle of first pressing plate, the second guide rod bottom is connected with the top of second pressing plate, a plurality of first springs are symmetrically distributed between the lower portion of second guide rod and the top of second pressing plate, the pressing die assembly that the metal plate is blanked is commonly provided on first pressing plate, second pressing plate and workbench, motor is installed in the side of workbench, pulley assembly is installed in the middle of workbench, the output shaft of motor is connected with two pulleys of pulley assembly, the synchronous belt of pulley assembly is around the outside of workbench, and embedded in workbench, the synchronous belt of pulley assembly is in contact with the upper surface of lower pressing die, and a plurality of evenly distributed and used for adsorbing metal plate's magnet is embedded in the synchronous belt.

[0008] As a further preferred, the die assembly comprises an upper die, a first punch, a third spring, a first die, a lower die, a second die, a second punch and a fourth spring, the upper die is embedded in the middle of the first and second pressing plates, the first punch is slidingly arranged at the center of the middle of the upper die, the first punch is connected with the telescopic rod of the first electric push rod, the middle of the first punch is protruded, the protruded part is provided with the third spring between the upper die of the first pressing plate, the lower part of the first punch is sleeved with the first die, the first die is connected with the inside of the second pressing plate, the lower die is embeddedly arranged in the middle of the workbench and is in contact with the first die and the upper die, the second die is arranged in the middle of the lower die, the second punch is slidingly arranged in the second die, and the fourth spring is arranged between the bottom of the second punch and the second die.

[0009] As a further preferred, two limiting grooves are formed in the upper part of the lower die, and the synchronous belt of the pulley assembly is embedded in the limiting grooves to form limiting and contact.

[0010] As a further preferred, the first guide rod is further included, the first guide rod is symmetrically arranged on the top of the second pressing plate, and the second pressing plate is slidingly connected with the first pressing plate through the first guide rod.

[0011] As a further preferred, the second spring is further included, the first sleeve rod is slidingly connected with the support column through the second sleeve rod, and the second spring is arranged between the second sleeve rod and the support column.

[0012] As a further preferred, the push plate assembly is further included, the mounting groove is formed in the middle of the supporting column, and the push plate assembly for pushing the formed metal plate is arranged in the mounting groove, the push plate assembly comprises a second electric push rod and a pushing rod, the second electric push rod with the driving end facing forward is arranged in the mounting groove, the pushing rod is arranged on the telescopic rod of the second electric push rod, the pushing rod is located above the workbench, and the recess groove corresponding to the outer contour of the pushing rod is formed in the lower part of the second pressing plate.

[0013] As a further preferred, the side of the base is provided with a closed door, and the cavity is formed in the inside of the base.

[0014] As a further preferred, still includes a collection assembly, the workbench front and the base inside jointly provided with a collection assembly for collecting the profiled sheet, the collection assembly includes a first blocking frame, a first guide plate, a second blocking frame, a fifth spring, a guide pipe, a second guide plate and a collection frame, the first blocking frame is embedded in the front of the workbench, the first guide plate is arranged in the front of the lower die on the top front side of the workbench, the plane end of the upper part of the first guide plate is flush with the lower die, and the pushing rod is in sliding contact with the plane end of the first guide plate, the second blocking frame is slidably arranged in the upper part of the first blocking frame, a plurality of fifth springs are symmetrically arranged between the first blocking frame and the second blocking frame, the guide pipe extending downward is arranged on the lower part of the workbench corresponding to the first blocking frame, the guide pipe extends into the upper part of the cavity of the base, the second guide plate is also arranged in an inclined manner on the front side of the bottom of the guide pipe, and the collection frame is slidably arranged in the cavity of the base, and the second guide plate is arranged above the collection frame.

[0015] The beneficial effects of the utility model are: 1. the utility model discloses a plurality of evenly distributed magnets are used for fixing the metal plate, prevent moving in the punching process, ensure high precision, the synchronous belt of the belt pulley assembly is embedded in the limiting groove of the lower die, power transmission and further fixed metal plate position are avoided to offset error, the cooperation of the push plate assembly and the collection assembly reduces manual intervention, and the risk that operating personnel contacts dangerous equipment is reduced.

[0016] 2. the utility model discloses the precise cooperation of upper die, first punch column, third spring and other components, the consistency and high quality of each time punching are guaranteed, and the defective rate is reduced, the design of second punch column and fourth spring makes the die can be quickly reset after each time punching, prepares for the next time punching, shortens the production cycle, and the second spring between the supporting column and the first sleeve rod design absorbs the vibration generated in the punching process, reduces the impact on the equipment, and prolongs the service life of mechanical components.

[0017] 3. after punching is completed, the finished product is automatically pushed out by the push plate assembly, and enters the collection frame through the guide pipe and the second guide plate, realizes continuous production, and improves overall production efficiency, the cavity is arranged in the base, which facilitates regular cleaning of waste and inspection and maintenance, and ensures long-term stable operation of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a three-dimensional structure schematic view of the utility model.

[0019] Figure 2 It is a three-dimensional structure schematic view of the utility model first pressing plate, second pressing plate and workbench and other components.

[0020] Figure 3 It is a three-dimensional structure schematic view of the utility model first sleeve rod, first guide rod and second guide rod and other components.

[0021] Figure 4 This is a partial cross-sectional three-dimensional structural diagram of the components of this utility model, including the upper mold column, the first pressure knife, and the third spring.

[0022] Figure 5 This is a partial cross-sectional plan view of the first mold, lower mold column, and second mold components of this utility model.

[0023] Figure 6 This is a partial cross-sectional three-dimensional structural diagram of the motor, pulley assembly, magnet, and other components of this utility model.

[0024] Figure 7 This is a partial cross-sectional plan view of the guide post, second guide plate, and collection frame of this utility model.

[0025] The meanings of the reference numerals in the figure are as follows: 1: Base, 11: Support column, 12: First electric push rod, 13: First pressure plate, 14: Second pressure plate, 15: Support column, 16: Workbench, 17: Controller, 2: First sleeve rod, 21: First guide rod, 22: Second guide rod, 23: First spring, 24: Second sleeve rod, 25: Second spring, 3: Press mold assembly, 31: Upper mold, 32: First punch, 33: Third spring, 34: First mold, 35: Lower mold, 36: Limiting groove, 37: Second mold, 38: Second punch, 39: Fourth spring, 4: Motor, 41: Pulley assembly, 42: Magnet, 5: Second electric push rod, 51: Push rod, 52: Groove, 6: First stop frame, 61: First guide plate, 62: Second stop frame, 63: Fifth spring, 64: Guide tube, 65: Second guide plate, 66: Collection frame. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] Example: A metal sheet punching device, such as Figures 1-7As shown, the device includes a base 1, a support column 11, a support column 15, a molding assembly 3, a motor 4, and a pulley assembly 41. The base 1 serves as the basic structure of the entire device, providing mechanical support and enclosed space to accommodate the internal components. The base 1 has a closed door on its side and an internal cavity. The support column 11 is welded to the center of the rear of the base 1, providing vertical support and a mounting platform. A first electric push rod 12 with its drive end facing downward is mounted on the top of the support column 11. A first pressure plate 13 is provided on the upper part of the telescopic rod of the first electric push rod 12, and a second pressure plate 14 is slidably arranged at the bottom of the first pressure plate 13. The first electric push rod 12 controls the first pressure plate 13 and the second pressure plate. The lifting mechanism of the base 14 directly participates in the punching or forming process, applying necessary pressure to complete the processing. Support columns 15 are installed at each corner of the top of the base 1. A worktable 16 is connected to the outside of each support column 15. The worktable 16 supports the metal plate to be processed and provides a platform for other components to be installed on or near it, ensuring coordinated operation of all components. The support columns 15 support the worktable 16. A controller 17 is installed on the side corner of the worktable 16. The controller 17 centrally controls the operating sequence of each electrical component in the system, adjusts parameters, and ensures the correct execution of the automated process. A through-plate 13 is installed at the top of each support column 15. The first sleeve rod 2 is slidably connected to the first sleeve rod 2 inside the second pressure plate 14. Multiple second guide rods 22 are slidably arranged in the middle of the first pressure plate 13, evenly distributed circumferentially. The bottom of the second guide rods 22 is connected to the top of the second pressure plate 14. Multiple first springs 23 are symmetrically distributed between the lower part of the second guide rods 22 and the top of the second pressure plate 14. A die assembly 3 for punching metal sheets is jointly arranged on the first pressure plate 13, the second pressure plate 14, and the worktable 16. The first pressure plate 13 and the second pressure plate 14 act together on the die assembly 3, wherein the first pressure plate 13 is fixed, while the second pressure plate 14 can slide relative to it. Pressure is applied to the metal sheet to assist in the punching or forming operation. A motor 4 is installed on the side of the worktable 16, and a pulley assembly 41 is installed in the middle of the worktable 16. The output shaft of the motor 4 is connected to two of the pulleys of the pulley assembly 41. The synchronous belt of the pulley assembly 41 is wrapped around the outside of the worktable 16 and embedded in the worktable 16. The synchronous belt of the pulley assembly 41 is in contact with the upper surface of the lower die. Multiple evenly distributed magnets 42 for adsorbing the metal sheet are embedded in the synchronous belt. The motor 4 drives the pulley assembly 41 to make the synchronous belt rotate, thereby driving the magnets 42 to adsorb and fix the metal sheet to be processed, preventing it from moving during the processing.

[0028] like Figures 3-7As shown, the molding assembly 3 includes an upper mold 31, a first punch 32, a third spring 33, a first mold 34, a lower mold 35, a second mold 37, a second punch 38, and a fourth spring 39. The upper mold 31 is respectively built into the middle of the first pressure plate 13 and the second pressure plate 14. The first punch 32 is slidably disposed at the center of the middle of the upper mold 31. The first punch 32 is connected to the telescopic rod of the first electric push rod 12. The first punch 32 is driven by the first electric push rod 12 to perform specific stamping actions. The middle of the first punch 32 protrudes, and the third spring 33 is provided between the protruding part and the upper mold 31 of the first pressure plate 13. The third spring 33 provides a buffer for the first punch 32 to protect the equipment from impact damage. The lower part of the first punch 32 is fitted with the first mold 34, which is connected to the second pressure plate 14 and participates in the molding process. In operation, the first mold 34 is internally connected to the second pressure plate 14. A lower mold 35 is embedded in the middle of the worktable 16, which is in contact with the first mold 34 and the upper mold 31. The lower mold 35 contacts the upper mold 31 to complete the forming or cutting task. The upper mold 31 cooperates with the lower mold 35 to complete the forming or cutting of the metal plate. Two limiting grooves 36 are opened in the upper part of the lower mold 35. The synchronous belt of the pulley assembly 41 is embedded in the limiting grooves 36 to form a limiting and contact. A second mold 37 is set in the middle of the lower mold 35. The second mold 37 is used for forming specific shapes. A second punch 38 is slidably set inside the second mold 37. A fourth spring 39 is set between the bottom of the second punch 38 and the second mold 37. The second punch 38 can slide up and down in the second mold 37 and achieve rapid reset with the help of the fourth spring 39.

[0029] like Figure 3 , Figure 4 , Figure 5 and Figure 7 As shown, it also includes a first guide rod 21, and the first guide rod 21 is symmetrically arranged on the top of the second pressure plate 14. The second pressure plate 14 is slidably connected to the first pressure plate 13 via the first guide rod 21.

[0030] like Figure 3 , Figure 4 , Figure 5 and Figure 7 As shown, it also includes a second spring 25. The first sleeve rod 2 is slidably connected to the support column 15 via the second sleeve rod 24, and the second spring 25 is provided between the second sleeve rod 24 and the support column 15.

[0031] like Figures 4-7As shown, it also includes a pusher assembly. The support column 11 has a mounting groove in the middle, and the pusher assembly for pushing the formed metal plate is provided in the mounting groove. The pusher assembly includes a second electric push rod 5 and a push rod 51. The second electric push rod 5 with the drive end facing forward is installed in the mounting groove. The push rod 51 is provided on the telescopic rod of the second electric push rod 5. The push rod 51 is located above the worktable 16. The lower part of the second pressure plate 14 has a groove 52 corresponding to the outer contour of the push rod 51. After the punching is completed, the second electric push rod 5 drives the push rod 51 to move forward and push the punched metal plate out of the worktable 16 for subsequent processing or collection.

[0032] like Figure 1 , Figure 6 and Figure 7 As shown, it also includes a collection component. The front of the workbench 16 and the interior of the base 1 are jointly provided with a collection component for collecting the formed sheet metal. The collection component is responsible for receiving the formed metal sheet pushed out by the pusher assembly. The collection component includes a first baffle 6, a first guide plate 61, a second baffle 62, a fifth spring 63, a guide tube 64, a second guide plate 65, and a collection frame 66. The first baffle 6 is embedded in the front of the workbench 16. The first guide plate 61, which is inclined, is provided on the front side of the top of the workbench 16 in front of the lower die. The flat end of the upper part of the first guide plate 61 is flush with the lower die, and the pusher rod 51 slides in contact with the flat end of the first guide plate 61. The second baffle is slidably provided in the upper part of the first baffle 6. Multiple fifth springs are symmetrically arranged between the first baffle 6 and the second baffle. 63. The fifth spring 63 allows the second stop frame 62 to have a certain degree of elasticity to accommodate metal plates of different sizes. The front part of the workbench 16 is provided with a downward-extending guide tube 64 corresponding to the lower part of the first stop frame 6. The first stop frame 6 and the second stop frame 62 guide and restrict the path of the metal plate so that it falls smoothly into the guide tube 64. The guide tube 64 extends into the upper part of the cavity of the base 1. The bottom front side of the guide tube 64 is provided with a second guide plate 65 that is also inclined. The guide tube 64 and the second guide plate 65 form a conveying path from the workbench to the collection frame 66 to ensure that the finished product arrives safely in the collection area. The collection frame 66 is slidably placed in the cavity of the base 1. The second guide plate 65 is located above the collection frame 66. The collection frame 66 is used to store the processed metal plate for easy removal later.

[0033] In use, a metal plate is placed on the worktable 16. The embedded magnet 42 in the belt of the pulley assembly 41 automatically attracts the metal plate, preventing it from moving during the punching process. The output shaft of the motor 4 is connected to the two pulleys of the pulley assembly 41. The synchronous belt wraps around the outside of the worktable 16 and is embedded in the limiting groove 36, ensuring that the synchronous belt is in close contact with the upper surface of the lower die 35. When punching is required, the controller 17 activates the first electric push rod 12, causing its telescopic rod to push the first pressure plate 13 and the second pressure plate 14 downward. As the pressure plates descend, the first punch 32... The first mold 34 moves downward and eventually contacts the lower mold 35 embedded in the worktable 16 to complete the punching action. During the punching process, the second punch 38 will be reset under the action of the fourth spring 39 to ensure that the mold can quickly return to its original state after each punching and prepare for the next punching. After the punching is completed, the second electric push rod 5 is started, and the push rod 51 pushes the punched metal plate out of the worktable 16. The pushed metal plate slides down along the first guide plate 61 into the guide tube 64, and then enters the collection frame 66 through the second guide plate 65 to realize the automated collection of finished products.

[0034] Those skilled in the art should understand that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by means of equivalent substitution or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A metal sheet punching device, characterized in that, The system includes a base (1), a support column (11), a support column (15), a molding assembly (3), a motor (4), and a pulley assembly (41). The support column (11) is installed at the center of the rear of the base (1). A first electric push rod (12) with its drive end facing downward is installed on the top of the support column (11). A first pressure plate (13) is provided on the upper part of the telescopic rod of the first electric push rod (12). A second pressure plate (14) is slidably provided at the bottom of the first pressure plate (13). Support columns (15) are provided at each corner of the top of the base (1). A workbench (16) is provided between the outside of each support column (15). A controller (17) is installed on the side corner of the workbench (16). A first sleeve rod (2) is provided on the top of each support column (15) and penetrates the inside of the first pressure plate (13) and the second pressure plate (14). The first pressure plate (13) and the second pressure plate (14) are slidably connected to the first sleeve rod (2). The first pressure plate (13) is slidably connected to the first sleeve rod (2). The lower part is slidably provided with multiple second guide rods (22) evenly distributed in the circumferential direction. The bottom of the second guide rod (22) is connected to the top of the second pressure plate (14). Multiple first springs (23) are symmetrically distributed between the lower part of the second guide rod (22) and the top of the second pressure plate (14). The first pressure plate (13), the second pressure plate (14) and the worktable (16) are jointly provided with a die assembly (3) for punching metal plates. A motor (4) is installed on the side of the worktable (16). A pulley assembly (41) is installed in the middle of the worktable (16). The output shaft of the motor (4) is connected to two of the pulleys of the pulley assembly (41). The synchronous belt of the pulley assembly (41) is wrapped around the outside of the worktable (16) and embedded in the worktable (16). The synchronous belt of the pulley assembly (41) is in contact with the upper surface of the lower die. Multiple magnets (42) evenly distributed for adsorbing metal plates are embedded in the synchronous belt.

2. The metal sheet punching device according to claim 1, characterized in that, The die assembly (3) includes an upper die (31), a first punch (32), a third spring (33), a first die (34), a lower die (35), a second die (37), a second punch (38), and a fourth spring (39). The upper die (31) is respectively built into the middle of the first pressure plate (13) and the second pressure plate (14). The first punch (32) is slidably disposed at the center of the middle of the upper die (31). The first punch (32) is connected to the telescopic rod of the first electric push rod (12). The middle part of the first punch (32) protrudes, and this protruding part is connected to the first pressure plate (13). A third spring (33) is provided between the upper mold (31) and the upper mold (31). The lower part of the first punch (32) is fitted with the first mold (34). The first mold (34) is internally connected to the second pressure plate (14). The middle part of the worktable (16) is provided with a lower mold (35) that is in contact with the first mold (34) and the upper mold (31). The middle part of the lower mold (35) is provided with a second mold (37). The second punch (38) is slidably provided inside the second mold (37). A fourth spring (39) is provided between the bottom of the second punch (38) and the second mold (37).

3. The metal sheet punching device according to claim 2, characterized in that, Two limiting grooves (36) are provided in the upper part of the lower mold (35). The synchronous belt of the pulley assembly (41) is embedded in the limiting grooves (36) to form a limiting and contact.

4. A metal sheet punching device according to claim 3, characterized in that, It also includes a first guide rod (21), the first guide rod (21) is symmetrically arranged on the top of the second pressure plate (14), and the second pressure plate (14) is slidably connected to the first pressure plate (13) by the first guide rod (21).

5. A metal sheet punching device according to claim 4, characterized in that, It also includes a second spring (25), the first sleeve (2) is slidably connected to the support column (15) via the second sleeve (24), and the second spring (25) is provided between the second sleeve (24) and the support column (15).

6. A metal sheet punching device according to claim 5, characterized in that, It also includes a push plate assembly. The support column (11) has a mounting groove in the middle. The mounting groove is equipped with a push plate assembly for pushing the formed metal plate. The push plate assembly includes a second electric push rod (5) and a push rod (51). The second electric push rod (5) with the drive end facing forward is installed in the mounting groove. The push rod (51) is provided on the telescopic rod of the second electric push rod (5). The push rod (51) is located above the worktable (16). The lower part of the second pressure plate (14) has a groove (52) corresponding to the outer contour of the push rod (51).

7. A metal sheet punching device according to claim 6, characterized in that, The base (1) has a closed door on its side and a cavity inside the base (1).

8. A metal sheet punching device according to claim 7, characterized in that, It also includes a collection component. The front of the workbench (16) and the interior of the base (1) are jointly provided with a collection component for collecting the molded sheet. The collection component includes a first baffle (6), a first guide plate (61), a second baffle (62), a fifth spring (63), a guide tube (64), a second guide plate (65), and a collection frame (66). The first baffle (6) is embedded in the front of the workbench (16). The first guide plate (61) is inclined on the front side of the top of the workbench (16) in front of the lower mold. The flat end of the upper part of the first guide plate (61) is flush with the lower mold, and the push rod (51) is also provided. The first guide plate (61) slides in contact with the flat end of the first guide plate (61). The upper part of the first baffle (6) is slidably provided with a second baffle. Multiple fifth springs (63) are symmetrically arranged between the first baffle (6) and the second baffle. The front part of the worktable (16) is provided with a downwardly extending guide tube (64) corresponding to the lower part of the first baffle (6). The guide tube (64) extends into the upper part of the cavity of the base (1). The bottom front side of the guide tube (64) is provided with a second guide plate (65) that is also inclined. The collection frame (66) is slidably placed in the cavity of the base (1). The second guide plate (65) is located above the collection frame (66).