CN219352009U

CN219352009U - Positioning mechanism and PCB processing equipment

Info

Publication number: CN219352009U
Application number: CN202223324469.XU
Authority: CN
Inventors: 刘鹏; 谭艳萍; 谢强; 王星; 黎勇军; 杨朝辉
Original assignee: Shenzhen Hans CNC Technology Co Ltd
Current assignee: Shenzhen Hans CNC Technology Co Ltd
Priority date: 2022-12-12
Filing date: 2022-12-12
Publication date: 2023-07-14
Anticipated expiration: 2032-12-12

Abstract

The utility model provides a positioning mechanism which comprises a main frame assembly, a pressing assembly and a driving assembly, wherein the main frame assembly, the pressing assembly and the driving assembly are connected with a processing main shaft; the main frame assembly comprises a main frame and a bearing seat, and the bearing seat is assembled on the main frame; the driving assembly comprises a driving piece and a positioning guide shaft connected with the driving piece; the positioning guide shaft is assembled on the bearing seat, one end of the positioning guide shaft is connected with the pressing assembly, and the pressing assembly is driven to longitudinally displace relative to the main frame assembly and used for pressing and positioning the PCB; in the utility model, the bearing seat is assembled on the main frame and can be detached, the position of the bearing seat on the main frame is adjustable, meanwhile, the positioning guide shaft is assembled on the bearing seat, and the position of the positioning guide shaft on the bearing seat is also adjustable, so that the position of the compression assembly can be jointly adjusted through the bearing seat and the positioning guide shaft, thereby being convenient for adjusting the centering problem of the middle through holes of the main frame and the compression assembly.

Description

Positioning mechanism and PCB processing equipment

Technical Field

The utility model belongs to the technical field of PCB forming and processing structures, and particularly relates to a positioning mechanism and PCB processing equipment.

Background

The PCB is a key interconnection piece of electronic products, along with the development demands of high quality, high precision and high end in the PCB industry, the difficulty of precise machining of the circuit board is also increased, in order to save cost, the circuit board required by customers is often cut from a large circuit board, the traditional forming mode mainly comprises the steps of cutting and edge milling the circuit board through a numerical control gong machine, the numerical control gong machine has the unique advantages of safe operation, high forming precision, high machining efficiency and the like, the numerical control gong machine is widely applied, and the development direction of the PCB is microminiaturization and precision, so that certain difficulty and challenges are brought to the precise machining field of the circuit board.

At present, when a PCB circuit board factory is used for forming a PCB circuit board, pins are used for positioning, so that the PCB circuit board is ensured not to be loosened during processing, and further the forming and processing precision is ensured. However, with the development of the electronic industry, part of the PCB circuit boards have no positioning pin holes due to design requirements, so that the forming precision cannot be ensured by using a pin positioning mode.

In the prior art, the following two methods are mainly used for carrying out the forming processing operation on the PCB circuit board without pin hole positioning in the board: a mechanical structure forming machine designed by adopting a vacuum adsorption platform is used for pumping air of a PCB circuit board and a machine table surface, and the PCB circuit board is fixed by using the atmospheric pressure of the plate surface to carry out forming processing operation. Because the vacuum can only absorb one plate contacted with the table top, the method can only stack one plate, and the processing efficiency is low. The other is to use the mode of sticking the adhesive tape to fix the PCB circuit board to carry out the processing operation, the fixing effect is determined by the adhesive tape, the fixing effect is poor and the human factor is large, and in order to achieve the fixing effect of the adhesive tape to the PCB circuit board and ensure the processing precision, the method can only stack one board, and has low processing efficiency and unstable processing precision. When the PCB circuit board factory is used for forming and processing the PCB circuit boards, in order to greatly improve the processing efficiency, a plurality of boards are often stacked together and processed simultaneously, so that the problem of low processing efficiency of a plurality of PCB circuit boards is needed to be solved.

Disclosure of Invention

The utility model provides a positioning mechanism and PCB processing equipment, which are used for solving the problem that the existing equipment is poor in PCB processing effect.

A positioning mechanism comprises a main frame component, a pressing component and a driving component; the main frame assembly comprises a main frame and a bearing seat, wherein the main frame is used for connecting a processing main shaft, and the bearing seat is detachably assembled on the main frame; the driving assembly comprises a driving piece and a positioning guide shaft connected with the driving piece; the positioning guide shaft is assembled on the bearing seat, one end of the positioning guide shaft is connected with the pressing assembly, and the pressing assembly is driven to longitudinally displace relative to the main frame assembly and used for pressing and positioning the PCB; the positioning mechanism further comprises a limiting structure arranged on the main frame assembly, the positioning guide shaft penetrates through the limiting structure, and the limiting structure is used for limiting radial displacement of the positioning guide shaft.

Preferably, the limiting structure comprises a first limiting hole arranged on the bearing seat, a second limiting hole is arranged on the pressing component, and the first limiting hole and the second limiting hole are coaxially arranged; the positioning guide shaft penetrates through the first limiting hole and the second limiting hole.

Preferably, the main frame is also provided with a fixing hole; the bearing seat is assembled in the fixing hole, the bearing seat can be movably arranged in the fixing hole, and the positioning guide shaft is arranged in the first limiting hole of the bearing seat and the second limiting hole of the pressing assembly in a penetrating mode.

Preferably, a ball bearing is further provided on the main frame, and the ball bearing is arranged between the main frame and the pressing assembly.

Preferably, the positioning mechanism further comprises a pressure release bearing, and the pressure release bearing is sleeved outside the positioning guide shaft and at a position opposite to the limiting structure.

Preferably, the compression assembly comprises a platen; the clamp plate pass through the location guiding axle with the driving piece links to each other, the first side of clamp plate orientation the body frame, the second side of clamp plate is used for pressing the PCB circuit board.

Preferably, the hold down assembly further comprises a brush disposed on the second side of the platen.

Preferably, an inner hole for the processing spindle to pass through is formed in the pressing plate, and a broken cutter detection device is arranged on the inner hole.

Preferably, the main frame is provided with a cantilever pin, and the pressing plate is provided with a pin hole corresponding to the cantilever pin; the cantilever pin is matched with the pin hole, so that a fit clearance between the pressing plate and the main frame is always in a stable state.

The PCB circuit board processing equipment comprises a positioning mechanism and a presser foot cylinder, wherein the positioning mechanism is connected with the telescopic end of the presser foot cylinder.

The main frame component comprises a main frame and a bearing seat; the bearing frame is assembled on the body frame, can split down, and the position of bearing frame on the body frame is adjustable, and the location guiding axle is assembled on the bearing frame simultaneously, and the position of location guiding axle on the bearing frame is also adjustable, and the one end of location guiding axle links to each other with compressing tightly the subassembly, just so can adjust the position of compressing tightly the subassembly jointly through bearing frame and location guiding axle to be convenient for adjust body frame and compress tightly the middle through-hole centering problem of subassembly. The driving assembly comprises a driving piece and a positioning guide shaft connected with the driving piece; the positioning guide shaft is assembled on the bearing seat, one end of the positioning guide shaft is connected with the pressing assembly, and the pressing assembly is driven to longitudinally displace relative to the main frame assembly and used for pressing and positioning the PCB. The main frame component is connected with the processing main shaft, is arranged below the processing main shaft, and can penetrate through the main frame and the pressing component.

The driving piece drives the pressing assembly to generate longitudinal displacement relative to the main frame assembly through the positioning guide shaft and is used for pressing and positioning the PCB. In the example, the driving piece adopts the lifting air cylinder, can be quickly opened and closed, can enable the opening and the closing to be switched at one moment, does not need to add other actions in the processing process, and improves the operability and the convenience of the mechanism. The lifting air cylinder (or the telescopic air cylinder, serving as a function of the guide shaft) is used as a driving source to drive the positioning guide shaft to carry out fine positioning, so that when the PCB circuit board is integrally pressed, the accurate matching positioning of the pressing assembly and the main frame can be realized.

The positioning mechanism further comprises a limiting structure arranged on the main frame assembly and the pressing assembly, and the positioning guide shaft is arranged on the limiting structure in a penetrating mode, so that the radial displacement of the positioning guide shaft is limited by the limiting structure, and the machining effect of the PCB is improved.

Drawings

FIG. 1 is an exploded view of a positioning mechanism of the present utility model;

FIG. 2 is a cross-sectional view of the positioning mechanism of the present utility model;

fig. 3 is an overall view of the positioning mechanism of the present utility model.

1, a main frame component; 11. a main frame; 12. a bearing seat; 13. a fixing hole; 2. a compression assembly; 21. a pressing plate; 22. a brush; 23. a broken knife detection device; 24. a second limiting hole; 3. a drive assembly; 31. a driving member; 32. positioning a guide shaft; 4. a limit structure; 41. a first limiting hole; 5. a ball bearing; 6. a pressure release bearing; 7. a cantilever pin; 8. a pin hole; 9. a presser foot cylinder.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects solved by the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

In the description of the present utility model, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships that are based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present utility model and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. In the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

The embodiment of the utility model provides a positioning mechanism, referring to fig. 1-3, the positioning mechanism comprises a main frame component 1, a compacting component 2 and a driving component 3, wherein the main frame component 1 is connected with a processing main shaft; the main frame assembly 1 comprises a main frame 11 and a bearing seat 12, wherein the bearing seat 12 is assembled on the main frame 11; the driving assembly 3 comprises a driving piece 31 and a positioning guide shaft 32 connected with the driving piece 31; the positioning guide shaft 32 is assembled on the bearing seat 12, one end of the positioning guide shaft 32 is connected with the pressing assembly 2, and the pressing assembly 2 is driven to longitudinally displace relative to the main frame assembly 1 so as to press and position the PCB circuit board; the positioning mechanism further comprises a limiting structure 4 arranged on the main frame assembly 1, and the positioning guide shaft 32 is arranged on the limiting structure 4 in a penetrating mode, so that the limiting structure 4 limits radial displacement of the positioning guide shaft 32.

As an example, the main frame assembly 1 of the prior art is mostly integrated, and thus, the position of the pressing assembly 2 can be adjusted only by positioning the guide shaft 32, which is inconvenient to adjust the centering problem of the middle through hole between the pressing assembly 2 and the main frame assembly 1. In this example, the main frame assembly 1 comprises a main frame 11 and a bearing housing 12; the bearing pedestal 12 is assembled on the main frame 11 and can be detached, the position of the bearing pedestal 12 on the main frame 11 is adjustable, meanwhile, the positioning guide shaft 32 is assembled on the bearing pedestal 12, the position of the positioning guide shaft 32 on the bearing pedestal 12 is also adjustable, one end of the positioning guide shaft 32 is connected with the compression assembly 2, and thus, the position of the compression assembly 2 can be jointly adjusted through the bearing pedestal 12 and the positioning guide shaft 32, and the centering of the middle through holes of the main frame 11 and the compression assembly 2 is convenient to adjust. The driving assembly 3 comprises a driving piece 31 and a positioning guide shaft 32 connected with the driving piece 31; the positioning guide shaft 32 is assembled on the bearing seat 12, one end of the positioning guide shaft 32 is connected with the pressing assembly 2, and the pressing assembly 2 is driven to longitudinally displace relative to the main frame assembly 1 for pressing and positioning the PCB. The main frame assembly 1 is connected with a processing main shaft, is arranged below the processing main shaft, and the processing main shaft can pass through the main frame 11 and the pressing assembly 2.

The driving piece 31 drives the pressing assembly 2 to longitudinally displace relative to the main frame assembly 1 through the positioning guide shaft 32, and is used for pressing and positioning the PCB. In this example, the driving member 31 employs a lifting cylinder, which can be opened and closed quickly, and can be switched on and off at one instant without adding other actions during the machining process, improving the operability and convenience of the mechanism. The lifting cylinder (or the telescopic cylinder, which serves as a guide shaft) is used as a driving source to drive the positioning guide shaft 32 to perform fine positioning, so that when the PCB circuit board is integrally pressed, the accurate matching positioning of the pressing assembly 2 and the main frame 11 can be realized.

The positioning mechanism further comprises a limiting structure 4 arranged on the main frame assembly 1, and the positioning guide shaft 32 is arranged on the limiting structure 4 in a penetrating mode, so that the limiting structure 4 limits radial displacement of the positioning guide shaft 32, and the machining effect of the PCB is improved.

In an embodiment, referring to fig. 2, the limiting structure 4 includes a first limiting hole 41 disposed on the bearing seat 12, and the pressing component 2 is provided with a second limiting hole 24, where the first limiting hole 41 and the second limiting hole 24 are coaxially disposed; the positioning guide shaft 32 is inserted into the first limiting hole 41 and the second limiting hole 24.

As an example, a first limiting hole 41 and a second limiting hole 24 are described, the first limiting hole 41 is arranged on the bearing seat 12, the second limiting hole 24 is arranged on the compression assembly 2, and the first limiting hole 41 and the second limiting hole 24 are coaxially arranged; the positioning guide shaft 32 is arranged in the first limiting hole 41 and the second limiting hole 24 in a penetrating mode, radial displacement of the positioning guide shaft 32 is limited by the two limiting holes which are coaxially arranged, longitudinal displacement of the pressing assembly 2 relative to the main frame assembly 1 is smoother and safer, and machining efficiency is improved.

In an embodiment, referring to fig. 2, the main frame 11 is further provided with a fixing hole 13; the bearing seat 12 is assembled in the fixing hole 13, the bearing seat 12 can be movably arranged in the fixing hole 13, and the positioning guide shaft 32 is arranged in the first limiting hole 41 of the bearing seat 12 and the second limiting hole 24 of the pressing assembly 2 in a penetrating manner.

As an example, by setting the fixing hole 13, the bearing seat 12 is assembled in the fixing hole 13, the bearing seat 12 can move in the fixing hole 13, the positioning guide shaft 32 is arranged in the first limiting hole 41 in the bearing seat 12 and the second limiting hole 24 on the pressing assembly 2 in a penetrating manner, and the position of the bearing seat 12 in the fixing hole 13 is adjusted, so that the centering of the middle through holes of the main frame 11 and the pressing assembly 2 is convenient to adjust.

In an embodiment, referring to fig. 1, the main frame 11 is further provided with a ball bearing 5, and the ball bearing 5 is disposed between the main frame 11 and the pressing assembly 2.

As an example, the ball bearing 5 is disposed on the main frame 11, and the ball bearing 5 is disposed between the main frame 11 and the compressing assembly 2, so that the friction between the main frame 11 and the compressing assembly 2 can be greatly reduced, and even if the positioning mechanism is under higher pressure, the main frame 11 and the compressing assembly 2 still can be in pure rolling friction, so that the relative movement can be smoothly performed, the PCB circuit board is kept still, the service lives of the main frame 11 and the compressing assembly 2 are prolonged, and the processing precision of the PCB circuit board is improved.

In an embodiment, referring to fig. 1, the positioning mechanism further includes a pressure release bearing 6, where the pressure release bearing 6 is sleeved outside the positioning guide shaft 32 and opposite to the limiting structure 4.

By way of example, through the arrangement of the pressure release bearing 6, the pressure release bearing 6 is sleeved at the position, which is opposite to the limiting structure 4, outside the positioning guide shaft 32, and by utilizing the rigidity of the pressure release bearing 6, the direct contact collision between the positioning guide shaft 32 and the inner wall of the limiting structure 4 can be avoided, the pressure of the positioning guide shaft 32 to the inner wall of the limiting structure 4 can be reduced, the stability and reliability of the positioning mechanism can be improved, the service life of parts can be prolonged, the accurate matching positioning can be realized, and the friction force of matched parts can be reduced.

In one embodiment, referring to fig. 1 and 2, the compression assembly 2 includes a platen 21; the pressing plate 21 is connected with the positioning guide shaft 32, a first side of the pressing plate 21 faces the main frame 11, and a second side of the pressing plate 21 is used for pressing the PCB circuit board.

As an example, the pressing assembly 2 is described as including the pressing plate 21, the pressing plate 21 is connected to the driving member 31 through the positioning guide shaft 32, the first side of the pressing plate 21 faces the main frame 11, and the second side of the pressing plate 21 is used for pressing the PCB circuit board, so that the PCB circuit board to be processed is pressed stably, thereby improving the processing precision and efficiency.

In one embodiment, referring to fig. 1, the compression assembly 2 further includes a brush 22 disposed on a second side of the platen 21.

As an example, the pressing assembly 2 is described as further including a brush 22 disposed on the second side of the pressing plate 21, where the brush 22 is relatively soft, so as to avoid the pressing plate 21 from directly contacting the PCB to damage the PCB, and also to use a presser foot to improve the protection of the PCB.

In one embodiment, referring to fig. 1 and 2, the pressing plate 21 is provided with an inner hole for the processing spindle to pass through, and the inner hole is provided with a break detection device 23.

As an example, it is described that the pressing plate 21 is provided with an inner hole for the processing spindle to pass through, and the inner hole is provided with a broken cutter detecting device 23, so that the condition of the processing cutter is always detected in the process of processing the PCB circuit board, and the processing continuity is ensured.

In an embodiment, referring to fig. 1 and 2, a cantilever pin 7 is provided on a main frame 11, and a pin hole 8 corresponding to the cantilever pin 7 is provided on a pressing plate 21; the cantilever pin 7 is matched with the pin hole 8, so that the fit clearance between the pressing plate 21 and the main frame 11 is always in a stable state.

As an example, cantilever pin 7 and pin hole 8 are described, cantilever pin 7 is provided on main frame 11, and pin hole 8 corresponding to cantilever pin 7 is provided on pressing plate 21; the cantilever pin 7 is matched with the pin hole 8, so that the fit clearance between the pressing plate 21 and the main frame 11 is always in a stable state, and the accurate and rapid return between the pressing plate 21 and the main frame 11 is improved.

The embodiment of the utility model provides PCB (printed circuit board) processing equipment, which comprises a positioning mechanism and a presser foot cylinder 9, wherein the positioning mechanism is connected with the telescopic end of the presser foot cylinder 9, and referring to FIG. 3.

In this example, the presser foot cylinder 9 can provide two pressures of strong pressure and weak pressure for the positioning mechanism according to actual processing conditions, then the lifting or stretching of the driving member 31 is used to determine whether the external positioning function is effective, and when the external positioning function is not needed, the pressing assembly 2 and the main frame 11 do not have relative movement, and at this time, the positioning mechanism presses the PCB circuit board with smaller pressure and does not conflict with normal gong machining. When the external positioning function is used, the positioning mechanism presses the PCB circuit board with larger pressure, so that the friction force between the pressing component 2 and the PCB circuit board is increased. During processing, two types of pressure are used, because the brush 22 and the PCB can relatively move during ordinary gong and cutting, and the damage of the brush 22 to the PCB can be reduced by weak pressure. The brush 22 and the PCB are not moved relatively during breaking, so that the friction force between the PCB and the board can be increased by strong pressure, and the PCB is ensured not to move all the time during breaking and milling. Therefore, the pressing assembly 2 and the main frame 11 can move relatively under the condition that the PCB is not moved, and the PCB is broken in milling.

Be provided with ball bearing between compressing tightly subassembly 2 and the body frame 11, but the frictional force between greatly reduced body frame 11 and the compressing tightly subassembly 2, even positioning mechanism still can be pure rolling friction under higher pressure between body frame 11 and the compressing tightly subassembly 2, can be smooth and easy do relative motion, and the PCB circuit board keeps motionless, has improved the life of body frame 11 and compressing tightly subassembly 2, improves the machining precision of PCB circuit board simultaneously.

After the machining is finished, the driving assembly 3 and the pressing assembly 2 are matched and positioned (matched tolerance) to realize the accurate positioning (accurate centering) of the pressing assembly 2 and the main frame 11, and then the broken knife detection device 23 can be used for detecting whether the machining knife is broken or broken (light path detection, and the broken knife passes through).

When a PCB circuit board is processed, firstly, a large circuit board is partitioned into a plurality of areas containing small circuit boards, breaking positions are reserved on the routing track of each small circuit board, then the large circuit board is positioned on a platform through pins, then the positioning mechanism can drive a positioning guide shaft 32 to stretch through a telescopic cylinder or other driving parts 31, so that when the positioning guide shaft 32 is driven to be in a contracted state, the pressing component 2 presses the main frame 11 (when the positioning guide shaft 32 is driven to be in an extended state, the pressing component 2 releases the main frame 11), the PCB circuit board is pressed through the positioning mechanism, then a cutter is driven to conduct routing on the large circuit board through a driving processing main shaft according to a preset track, so that the small circuit board is needed, the reserved breaking positions are skipped in the routing process, in the process, the main frame 11 and the pressing component 2 included in the positioning mechanism move synchronously along with the processing main shaft, so that the PCB circuit board is not influenced by the routing through the main frame 11, and the PCB circuit board is processed by the processing main shaft.

A PCB circuit board processing method based on a positioning mechanism comprises the following steps:

firstly, a large circuit board is positioned on a platform by pins, then a gong-cutting track is configured, and a breaking position is additionally arranged.

And then the positioning mechanism presses the large circuit board with smaller pressure to start the routing of the large circuit board so as to obtain the required small circuit board, and the reserved breaking position is skipped in the routing process.

And finally, the positioning mechanism presses the circuit board with larger pressure to start routing and cutting the breaking position.

In order to improve the operability of the mechanism, the driving member 31 of the present utility model only performs the function of opening and closing, which ensures that the opening and closing can be switched over at a moment without adding other actions to the mechanism during the machining process, such as raising the mechanism first when the mechanism is opened. When the brush 22 may be used as the brush 22, it is a key measure to reduce the elastic deformation of the brush 22 during the processing process in order to improve the processing accuracy, because the brush 22 directly contacts the PCB, its elastic deformation directly affects the compacting effect of the mechanism. Therefore, the mechanism can cut off the PCB circuit board once in the machining process, and the PCB circuit board can be machined to a position where the function is required to be started along the deformation direction of the hairbrush 22 in one machining process, software sends instructions to the driving piece 31 to act, and other parts of the mechanism do not need to act, so that the machining precision and efficiency can be greatly improved.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims

1. The positioning mechanism is characterized by comprising a main frame assembly, a pressing assembly and a driving assembly;

the main frame assembly comprises a main frame and a bearing seat, wherein the main frame is used for connecting a processing main shaft, and the bearing seat is detachably assembled on the main frame;

the driving assembly comprises a driving piece and a positioning guide shaft connected with the driving piece; the positioning guide shaft is assembled on the bearing seat, one end of the positioning guide shaft is connected with the pressing assembly, and the pressing assembly is driven to longitudinally displace relative to the main frame assembly and used for pressing and positioning the PCB;

the positioning mechanism further comprises a limiting structure arranged on the main frame assembly, the positioning guide shaft penetrates through the limiting structure, and the limiting structure is used for limiting radial displacement of the positioning guide shaft.

2. The positioning mechanism according to claim 1, wherein the limiting structure comprises a first limiting hole arranged on the bearing seat, a second limiting hole is arranged on the pressing component, and the first limiting hole and the second limiting hole are coaxially arranged;

the positioning guide shaft penetrates through the first limiting hole and the second limiting hole.

3. The positioning mechanism according to claim 2, wherein the main frame is further provided with a fixing hole;

the bearing seat is assembled in the fixing hole, the bearing seat can be movably arranged in the fixing hole, and the positioning guide shaft is arranged in the first limiting hole of the bearing seat and the second limiting hole of the pressing assembly in a penetrating mode.

4. The positioning mechanism of claim 1, wherein a ball bearing is further provided on the main frame, the ball bearing being disposed between the main frame and the compression assembly.

5. The positioning mechanism of claim 1, further comprising a pressure relief bearing sleeved outside the positioning guide shaft in a position opposite the limit structure.

6. The positioning mechanism of claim 1, wherein the compression assembly comprises a platen; the clamp plate pass through the location guiding axle with the driving piece links to each other, the first side of clamp plate orientation the body frame, the second side of clamp plate is used for pressing the PCB circuit board.

7. The positioning mechanism of claim 6, wherein the compression assembly further comprises a brush disposed on the second side of the platen.

8. The positioning mechanism of claim 6, wherein the pressure plate is provided with an inner bore for passing through the machining spindle, and wherein the inner bore is provided with a break detector.

9. The positioning mechanism according to claim 6, wherein the main frame is provided with a cantilever pin, and the pressing plate is provided with a pin hole corresponding to the cantilever pin; the cantilever pin is matched with the pin hole, so that a fit clearance between the pressing plate and the main frame is always in a stable state.

10. A PCB circuit board processing apparatus comprising the positioning mechanism of any one of claims 1-9 and a presser foot cylinder, the positioning mechanism being connected to the telescoping end of the presser foot cylinder.