CN218450720U

CN218450720U - Golden finger inner bevel edge mechanism for circuit board

Info

Publication number: CN218450720U
Application number: CN202221501580.9U
Authority: CN
Inventors: 朱仁红
Original assignee: Huizhou Trustwin Electronic Technology Co ltd
Current assignee: Huizhou Trustwin Electronic Technology Co ltd
Priority date: 2022-06-16
Filing date: 2022-06-16
Publication date: 2023-02-03
Anticipated expiration: 2032-06-16

Abstract

The utility model discloses an hypotenuse mechanism in golden finger for circuit board relates to circuit board processing technology field, comprises a workbench, the fixed plate is installed at the top of workstation, it leads to the groove to be equipped with the bar on the fixed plate, the inside that the groove is led to the bar is equipped with the fixture that is used for fixed circuit board, fixture includes splint and two-way lead screw, two-way lead screw rotates the inside of installing in the groove is led to the bar, splint threaded connection is on two-way lead screw, the interior roof slidable mounting of fixed plate has cutting tool, the top of fixed plate is equipped with the straight-line motion mechanism who is used for controlling cutting tool horizontal migration. The utility model discloses in, the fixture of setting is convenient for carry out the centre gripping to the circuit board fixed, can avoid the too big circuit board damage that leads to of clamping-force simultaneously, and the clearance mechanism of setting can be collected the utilization to the sweeps that processing produced, has realized the purpose that the sweeps was collected.

Description

Golden finger inner bevel edge mechanism for circuit board

Technical Field

The utility model relates to a circuit board processing technology field especially relates to a hypotenuse mechanism in golden finger for circuit board.

Background

The circuit board has the name: ceramic circuit board, alumina ceramic circuit board, aluminum nitride ceramic circuit board, PCB board, aluminum substrate, high frequency board, thick copper board, impedance board, PCB, ultra-thin circuit board, printed (copper etching technology) circuit board, etc. The circuit board enables the circuit to be miniaturized and visualized, and plays an important role in batch production of fixed circuits and optimization of electrical appliance layout.

The golden fingers are arranged on two sides of the lower portion of the plug-in type circuit board, so that the positions, corresponding to the golden fingers, of the two sides of the lower portion of the circuit board need to be chamfered in order to facilitate plug-in of the circuit board, and bevel edge machining of the circuit board is called in the industry, and therefore a golden finger beveling machine suitable for the circuit board needs to be designed.

The prior patent (publication number: CN 215499779U) proposes a golden finger beveling machine for a circuit board, which comprises a workbench, a cutter arranged on the workbench and used for beveling a golden finger of the circuit board, a positioning mechanism arranged on the upper part of the cutter and used for clamping the circuit board, and a driving mechanism arranged on the workbench and used for driving the positioning mechanism to move so as to enable the circuit board on the positioning mechanism to be in contact with the cutter; the driving mechanism comprises two groups of supporting plates which are arranged on the workbench at intervals, guide rails arranged on the supporting plates, a moving plate arranged on the guide rails through the transmission of a sliding block, a lead screw arranged on the workbench and positioned between the two groups of supporting plates, a motor in transmission connection with the lead screw and a nut sleeve which is arranged on the lead screw in transmission and connected with the moving plate; the cutter is located between two sets of backup pads and is located the outside of lead screw, can be used for the hypotenuse processing of circuit board golden finger.

The golden finger beveling machine has the following disadvantages when in use: adopt pneumatic centre gripping fixed circuit board, be difficult to control the centre gripping dynamics, because circuit board own material is softer and comparatively fragile, the too big circuit board that easily leads to of centre gripping power damages, and lacks the function of collecting the waste material, is difficult to collect the piece that the cutting produced, and the piece drops and needs artifical clearance again consuming time hard on the workstation, is difficult to satisfy the factory production needs. Therefore, the golden finger inner-bevel mechanism for the circuit board is provided to solve the problems.

SUMMERY OF THE UTILITY MODEL

The utility model provides an interior hypotenuse mechanism of golden finger for circuit board has solved and has adopted pneumatic centre gripping fixed circuit board, the difficult control centre gripping dynamics, because the material of circuit board itself is softer and comparatively fragile, the too big circuit board that easily leads to of clamping-force damages, and lacks the function of collecting the waste material, is difficult to collect the piece that the cutting produced, the piece drops and needs artifical clearance again consuming time hard on the workstation, is difficult to satisfy the technical problem that the factory production needs.

For solving the technical problem, the utility model provides a pair of hypotenuse mechanism in golden finger for circuit board, comprises a workbench, the fixed plate is installed at the top of workstation, it leads to the groove to be equipped with the bar on the fixed plate, the inside that the groove is led to the bar is equipped with the fixture that is used for fixed circuit board, fixture includes splint and two-way lead screw, two-way lead screw rotates to be installed in the inside that the groove is led to the bar, splint threaded connection is on two-way lead screw, the interior roof slidable mounting of fixed plate has cutting tool, the top of fixed plate is equipped with the rectilinear movement mechanism who is used for controlling cutting tool horizontal migration, the opening has been seted up at the top of workstation, the internally mounted of opening has the mesh board, arrange the material pipe in the bottom of workstation, the top of workstation is equipped with the clearance mechanism that is used for clearing up the sweeps.

Preferably, fixture still includes first motor, pressure switch and centre gripping pad, one side at the fixed plate is installed to first motor, the drive end and two-way lead screw one end fixed connection, two of first motor pressure switch and centre gripping pad are all installed to the relative one side of splint, pressure switch and first motor electric connection are convenient for carry out the centre gripping to the circuit board and are fixed, can avoid the too big circuit board damage that leads to of clamping-force simultaneously.

Preferably, linear movement mechanism includes movable block, threaded rod and second motor, it has seted up the mounting groove to run through on the fixed plate, the movable block is installed to the internal rotation of mounting groove, threaded rod sliding connection is in the inside of mounting groove, threaded rod and movable block threaded connection, the second motor is installed on the lateral wall of fixed plate, the drive end and the threaded rod one end fixed connection of second motor can drive cutting tool horizontal slip, realize wholly carrying out the hypotenuse processing to the circuit board.

Preferably, clearance mechanism is including inhaling the bits pump, inhaling bits pipe, chip removal pipe and inhaling the bits cover, it installs in workstation top left side to inhale the bits pump, inhale the bits pipe and all be connected with inhaling the bits pump with the chip removal pipe, inhale the one end that the bits pump was kept away from to the bits pipe and install and inhale the bits cover, inhale the bits cover and install at the workstation top surface, the chip removal pipe is kept away from the one end of inhaling the bits pump and is extended to the inside of workstation, inhales the bits cover through inhaling the bits pump drive and absorbs workstation surface sweeps to through the inside of chip removal pipe transport to the workstation, collect the utilization to the sweeps that the cutting produced, realized being convenient for carrying out the purpose of collecting to the piece that the cutting produced.

Preferably, clearance mechanism still includes air-blower, connecting pipe, exhaust tube and blows the bits pipe, the air-blower is installed on workstation top right side, the connecting pipe all is connected with the air-blower with the exhaust tube, the connecting pipe is kept away from the one end of air-blower and is installed and blow the bits pipe, blow the bits pipe and install at the workstation top surface, through air-blower drive exhaust tube extraction gas, again by blowing the bits pipe and discharging, the in-process that the air current blew off blows off the sweeps, avoids the sweeps to glue at the initial point, improves the efficiency that the sweeps was collected.

Preferably, the inside of workstation is equipped with the chamber that holds of accomodating the sweeps, the guide plate is installed to the inner diapire that holds the chamber, plays the water conservancy diversion effect.

Preferably, all install the guide block on the lateral wall around the movable block, set up on the lateral wall of mounting groove and supply the gliding guide way of guide block, play the effect of direction for the movable block slides more stably.

Preferably, the centre gripping pad is the rubber material, the centre gripping pad sets up in pressure switch outside, and the rubber material has certain elastic deformation effect, utilizes the elasticity of centre gripping pad can play certain buffering effect when fixed circuit board, avoids the clamping-force too big.

Preferably, the bottom of workstation is equipped with four supporting legs, four the supporting leg sets up respectively in workstation bottom four corners department, plays the effect of support.

Preferably, arrange and seted up the breach on the material pipe, the inside grafting of breach has the shutoff board, plays the effect that the material pipe was arranged in the shutoff, prevents to leak at the in-process sweeps of collecting from arranging the material pipe, is convenient for discharge the sweeps after collecting the completion simultaneously.

Compared with the prior art, the utility model provides a pair of hypotenuse mechanism in golden finger for circuit board has following beneficial effect:

1. the utility model discloses in, rotate through the two-way lead screw of first motor drive, two-way lead screw drives two splint relative movement, splint relative movement's in-process is hugged closely with the circuit board lateral wall, realize the fixed effect to the circuit board centre gripping, prevent that offset from appearing in the in-process circuit board of processing, pressure switch detects pressure when splint and circuit board laminating, pressure when the centre gripping surpasss the scope value back pressure switch power off of settlement, control first motor and close, effectual control centre gripping dynamics, avoid the too big circuit board damage that leads to of clamping-force.

2. The utility model discloses in, the sweeps falls into inside the workstation through the mesh board, inhale bits cover absorption workstation surface sweeps through inhaling bits pump drive, and convey the inside of workstation through the chip removal pipe, collect the utilization to the sweeps that the cutting produced, the purpose of being convenient for carry out the collection to the piece that the cutting produced has been realized, extract the external gas through air-blower drive exhaust tube, blow to the workstation surface by blowing the bits pipe again, the in-process that the air current blew off will be attached to the sweeps on workstation surface and blow up, avoid the sweeps to glue at the initial point, the efficiency of sweeps collection is improved.

Drawings

FIG. 1 is a schematic diagram of a golden finger inside bevel mechanism for a circuit board;

FIG. 2 is a cross-sectional view of a golden finger inside bevel mechanism for a circuit board;

FIG. 3 is a schematic diagram of a discharging tube in a golden finger inside bevel edge mechanism for a circuit board;

fig. 4 is a schematic structural diagram of a movable block in a golden finger inner bevel edge mechanism for a circuit board.

Reference numbers in the figures: 1. a work table; 2. a fixing plate; 3. a splint; 4. a bidirectional screw rod; 5. a first motor; 6. a pressure switch; 7. a clamping pad; 8. a movable block; 9. cutting a cutter; 10. a threaded rod; 11. a second motor; 12. a guide block; 13. a mesh plate; 14. a discharge pipe; 15. a scrap suction pump; 16. a scrap suction pipe; 17. a chip removal pipe; 18. a scrap suction cover; 19. a blower; 20. a connecting pipe; 21. an air exhaust pipe; 22. a scrap blowing pipe; 23. a baffle; 24. supporting legs; 25. a plugging plate.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are used in the orientation or positional relationship indicated on the basis of the drawings, it is only for convenience of description and simplicity of description, and it is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected. Either mechanically or electrically. Either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

The first embodiment is given by figures 1-4, a golden finger inner bevel edge mechanism for a circuit board, which comprises a workbench 1, wherein a fixed plate 2 is installed at the top of the workbench 1, a strip-shaped through groove is formed in the fixed plate 2, a clamping mechanism for fixing the circuit board is arranged inside the strip-shaped through groove, the clamping mechanism comprises a clamping plate 3 and a two-way screw rod 4, the two-way screw rod 4 is rotatably installed inside the strip-shaped through groove, the clamping plate 3 is in threaded connection with the two-way screw rod 4, a cutting tool 9 is slidably installed on an inner top wall of the fixed plate 2, a linear moving mechanism for controlling the horizontal movement of the cutting tool 9 is arranged at the top of the fixed plate 2, an opening is formed in the top of the workbench 1, a mesh plate 13 is installed inside the opening, a discharge pipe 14 is installed at the bottom of the workbench 1, a cleaning mechanism for cleaning scraps is arranged at the top of the workbench 1, the fixed plate 2 is usually set to be of an L-shaped structure, the fixed plate 2 is fixed on the rear side of the top surface of the workbench 1 through welding or bolting, the two clamping plates 3 are driven to move relatively through the two-way screw rod 4, the clamping plate 3 moves relatively, the clamping plate moves relatively in the circuit board moving process and clings to the side wall of the circuit board, and the circuit board in the circuit board clamping mechanism can be prevented from shifting position in the circuit board processing process.

Second embodiment, on the basis of first embodiment, fixture still includes first motor 5, pressure switch 6 and centre gripping pad 7, first motor 5 is installed in one side of fixed plate 2, the drive end and the 4 one end fixed connection of two-way lead screw of first motor 5, pressure switch 6 and centre gripping pad 7 are all installed to one side that two splint 3 are relative, pressure switch 6 and first motor 5 electric connection, be convenient for carry out the centre gripping to the circuit board fixed, pressure switch 6 detects pressure when splint 3 and circuit board laminating, pressure switch 6 disconnection power after the pressure of centre gripping exceeds the scope value of settlement, control first motor 5 and close, effectual control centre gripping dynamics, avoid the too big circuit board damage that leads to of clamping force.

Embodiment three, on the basis of embodiment one, linear moving mechanism includes movable block 8, threaded rod 10 and second motor 11, the mounting groove has been seted up in running through on the fixed plate 2, the inside rotation of mounting groove installs movable block 8, threaded rod 10 sliding connection is in the inside of mounting groove, threaded

rod

10 and 8 threaded connection of movable block, second motor 11 is installed on the lateral wall of fixed plate 2, the drive end and the 10 one end fixed connection of threaded rod of second motor 11, can drive cutting tool 9 horizontal slip, realize wholly carrying out hypotenuse processing to the circuit board, threaded rod 10 drives 8 horizontal migration of movable block, movable block 8 drives 9 synchronous motion of cutting tool, make cutting tool 9 remove along the department of processing of treating of circuit board, after through the blade, can realize the hypotenuse processing of circuit board.

Fourth embodiment, on the basis of first embodiment, the cleaning mechanism includes chip suction pump 15, chip suction pipe 16, chip removal pipe 17 and chip suction cover 18, chip suction pump 15 is installed on the left side of the top of workbench 1, chip suction pipe 16 and chip removal pipe 17 are all connected with chip suction pump 15, chip suction cover 18 is installed at the end of chip suction pipe 16 far away from chip suction pump 15, chip suction cover 18 is installed on the top surface of workbench 1, the end of chip removal pipe 17 far away from chip suction pump 15 extends to the inside of workbench 1, chip suction cover 18 is driven by chip suction pump 15 to suck the chip on the surface of workbench 1, and the chip is conveyed to the inside of workbench 1 through chip removal pipe 17, the chip generated by cutting is collected and utilized, the purpose of conveniently collecting the chip generated by cutting is achieved, the cleaning mechanism further includes connecting pipe 19, connecting pipe 20, air suction pipe 21 and chip blowing pipe 22, air blower 19 is installed on the top surface of workbench 1, air blower 19 is installed on the right side of the top of workbench 1, connecting pipe 20 and air blower 21 is installed on the air blower, the air blower 21 is installed on the top surface, the air blower is used for avoiding the chip from being stuck in the chip removal process of collecting the chip generated by the chip, and the air flow of the air blower.

In addition, the inside of workstation 1 is equipped with the chamber that holds of accomodating the sweeps, and the guide plate 23 is installed to the inner diapire that holds the chamber, plays the water conservancy diversion effect, and for better messenger's sweeps discharge, the top surface of guide plate 23 sets up for the slope, such structure for the slope in the middle of the guide plate 23 both sides orientation can guide the sweeps flow direction to arrange material pipe 14, thereby makes the sweeps discharge from arranging material pipe 14 more effectively.

In order to enable the movable block 8 to stably slide in the mounting groove, the front and rear side walls of the movable block 8 are respectively provided with a guide block 12, and the side wall of the mounting groove is provided with a guide groove for the guide block 12 to slide, so that the guide effect is achieved, and the movable block 8 can slide more stably;

in order to improve the stability of fixing the circuit board, the clamping pad 7 is made of rubber, the clamping pad 7 is arranged outside the pressure switch 6, the rubber has a certain elastic deformation effect, a certain buffering effect can be achieved by utilizing the elasticity of the clamping pad 7 when the circuit board is fixed, and the clamping force is prevented from being too large;

in order to enable the workbench 1 to be far away from the ground, four supporting legs 24 are arranged at the bottom of the workbench 1, and the four supporting legs 24 are respectively arranged at four corners of the bottom of the workbench 1 to play a supporting role;

in order to conveniently concentrate the discharge to the sweeps, arrange and seted up the breach on the material pipe 14, the inside grafting of breach has shutoff board 25, plays the effect that the material pipe 14 was arranged in the shutoff, prevents to leak from arranging material pipe 14 at the in-process sweeps of collecting, is convenient for discharge the sweeps after the collection is accomplished simultaneously.

The blocking plate 25 is usually configured as a square plate structure adapted to the material discharging pipe 14, and a handle is fixedly disposed on one side of the blocking plate 25 extending to the outside of the material discharging pipe 14 to facilitate drawing of the blocking plate 25, so that an operator can draw the handle to take out the blocking plate 25 from the inside of the material discharging pipe 14.

The working principle is as follows: when the circuit board positioning device is used, a circuit board is vertically placed between two clamping plates 3, then a first motor 5 is started, a bidirectional screw rod 4 is driven to rotate by the first motor 5, the bidirectional screw rod 4 drives the two clamping plates 3 to move relatively, the clamping plates 3 are tightly attached to the side wall of the circuit board in the relative movement process, the effect of clamping and fixing the circuit board is realized, the circuit board is prevented from position deviation in the processing process, a pressure switch 6 detects pressure when the clamping plates 3 are attached to the circuit board, the pressure switch 6 is powered off after the clamping pressure exceeds a set range value, the first motor 5 is controlled to be turned off, the clamping force is effectively controlled, the circuit board is prevented from being damaged due to overlarge clamping force, after the circuit board is positioned, the V-shaped cutting edges of a cutting tool 9 of the circuit board to be processed are opposite, and a second motor 11 is started to drive a threaded rod 10 to rotate, threaded rod 10 drives 8 horizontal migration of movable block, movable block 8 drives cutting tool 9 synchronous motion, make cutting tool 9 remove along treating processing department of circuit board, after through the blade, can realize the hypotenuse processing of circuit board, in the course of working, the sweeps falls into workstation 1 inside through mesh board 13, inhale 1 surperficial sweeps of workstation through inhaling 15 drive sweeps of bits pump cover 18, and carry the inside of workstation 1 through chip removal pipe 17, the sweeps that the cutting produced are collected and utilized, the purpose of being convenient for collect the sweeps that the cutting produced has been realized, drive exhaust tube 21 through air-blower 19 and extract external gas, blow to workstation 1 surface by blowing bits pipe 22 again, the in-process that the air current blew off will be attached to the sweeps on workstation 1 surface and blow up, avoid the sweeps to glue at the initial point, the efficiency that the sweeps was collected is improved.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a hypotenuse mechanism in golden finger for circuit board, includes workstation (1), its characterized in that, fixed plate (2) are installed at the top of workstation (1), it leads to the groove to be equipped with the bar on fixed plate (2), the inside that the groove was led to the bar is equipped with the fixture that is used for fixed circuit board, fixture includes splint (3) and two-way lead screw (4), two-way lead screw (4) are rotated and are installed the inside that leads to the groove in the bar, splint (3) threaded connection is on two-way lead screw (4), the interior roof slidable mounting of fixed plate (2) has cutting tool (9), the top of fixed plate (2) is equipped with the rectilinear movement mechanism who is used for controlling cutting tool (9) horizontal migration, row's material pipe (14) is installed to the bottom of workstation (1), the top of workstation (1) is equipped with the clearance mechanism that is used for clearing up the sweeps.

2. The golden finger inner bevel edge mechanism for the circuit board is characterized in that the clamping mechanism further comprises a first motor (5), a pressure switch (6) and a clamping pad (7), the first motor (5) is installed on one side of the fixing plate (2), the driving end of the first motor (5) is fixedly connected with one end of the bidirectional screw rod (4), the pressure switch (6) and the clamping pad (7) are installed on the opposite sides of the two clamping plates (3), and the pressure switch (6) is electrically connected with the first motor (5).

3. The golden finger inner oblique edge mechanism for the circuit board as claimed in claim 2, wherein the linear moving mechanism comprises a movable block (8), a threaded rod (10) and a second motor (11), a mounting groove is formed in the fixing plate (2) in a penetrating mode, the movable block (8) is rotatably mounted inside the mounting groove, the threaded rod (10) is slidably connected inside the mounting groove, the threaded rod (10) is in threaded connection with the movable block (8), the second motor (11) is mounted on the side wall of the fixing plate (2), and the driving end of the second motor (11) is fixedly connected with one end of the threaded rod (10).

4. The inner golden finger bevel edge mechanism for the circuit board as claimed in claim 3, wherein the cleaning mechanism comprises a chip suction pump (15), a chip suction pipe (16), a chip discharge pipe (17) and a chip suction cover (18), the chip suction pump (15) is installed on the left side of the top of the workbench (1), the chip suction pipe (16) and the chip discharge pipe (17) are connected with the chip suction pump (15), the chip suction pipe (16) is far away from one end of the chip suction pump (15) and is installed with the chip suction cover (18), the chip suction cover (18) is installed on the top surface of the workbench (1), and one end of the chip discharge pipe (17) far away from the chip suction pump (15) extends to the inside of the workbench (1).

5. The golden finger inner bevel edge mechanism for the circuit board as claimed in claim 4, wherein the cleaning mechanism further comprises an air blower (19), a connecting pipe (20), an air exhaust pipe (21) and a scrap blowing pipe (22), the air blower (19) is installed on the right side of the top of the workbench (1), the connecting pipe (20) and the air exhaust pipe (21) are both connected with the air blower (19), the scrap blowing pipe (22) is installed at one end, away from the air blower (19), of the connecting pipe (20), and the scrap blowing pipe (22) is installed on the top surface of the workbench (1).

6. A golden finger inner bevel edge mechanism for a circuit board according to claim 1, wherein the inside of the workbench (1) is provided with a containing cavity for containing scraps, and a flow guide plate (23) is installed on the inner bottom wall of the containing cavity.

7. The inner golden finger bevel edge mechanism for the circuit board as claimed in claim 3, wherein the front and rear side walls of the movable block (8) are respectively provided with a guide block (12), and the side wall of the mounting groove is provided with a guide groove for the guide block (12) to slide.

8. A golden finger inside-bevel mechanism for a circuit board according to claim 2, wherein the clamping pad (7) is made of rubber, and the clamping pad (7) is arranged outside the pressure switch (6).

9. A golden finger inner inclined edge mechanism for a circuit board as claimed in claim 1, wherein the bottom of the workbench (1) is provided with four supporting legs (24), and the four supporting legs (24) are respectively arranged at four corners of the bottom of the workbench (1).

10. The inner golden finger bevel edge mechanism for the circuit board as claimed in claim 1, wherein a gap is formed on the discharging pipe (14), and a plugging plate (25) is inserted into the gap.