A drill bit automatic replacement device for PCB board drilling

Abstract

The present invention relates to the field of PCB punching, and relates to an automatic drill bit replacement device for PCB board drilling, comprising: a base plate; a circulating conveying device, which is installed on the base plate; a connecting block, which is evenly installed on the conveying end of the edge of the circulating conveying device; a swing plate, which is hingedly arranged on the connecting block; a driving gear, which is coaxially installed on the hinge point of the swing plate; an intermediate gear, which is arranged in the connecting block and meshes with the driving gear; a sleeve, which is connected to the end of the swing plate; a driving gear rod, which is rotatably arranged on the edge of the base plate; and a second driving member, which is installed at the bottom of the base plate and is connected to the driving gear rod through a hole in the base plate. The present invention installs a storage unit capable of storing drill bits on the circulating conveying device. When the drill bit of a processing spindle needs to be replaced, it only needs to lift the processing spindle and drive the swing plate to flip with the drill bit through the driving gear rod, so that the drill bit flips to the bottom of the processing spindle, so that the drill bit can be directly and quickly replaced.

Description

Technical Field

[0001] The invention relates to the field of PCB punching, and in particular to an automatic drill bit replacement device for PCB drilling. Background Art

[0002] During the processing of PCB boards, it is necessary to drill holes of different sizes on the same board. The purpose of drilling holes is to allow the connection between layers, and some holes are reserved for installing the pins of electronic components. Therefore, the diameters of holes with different functions are also different, and the drill bits required for different hole diameters are also different. Therefore, the drill bits need to be replaced frequently during the drilling of boards. The common way to replace drill bits in board drilling equipment is to store the drill bits to be used at the edge of the processing platform. When the processing spindle needs to replace the drill bit, it is moved to the edge of the platform, and then the original drill bit is put back to its original position through the processing spindle, and then the drill bit is moved to the top of the drill bit to be installed and installed on the processing spindle. In this way, the drill bit replacement is completed. This replacement method is more cumbersome in terms of travel and will increase unnecessary processing time. At the same time, the drill bit is placed on the edge of the processing table, which is easy to splash the debris and impurities generated during drilling, and it is easy to get stuck on the processing spindle during the process of replacing the drill bit. Summary of the invention

[0003] The present invention aims to solve the technical problems existing in the above-mentioned prior art. To this end, the present invention provides an automatic drill bit replacement device for drilling holes in a PCB board.

[0004] To achieve the above-mentioned purpose, the present invention provides such an automatic drill bit replacement device for drilling holes in a PCB board, comprising: a base plate, on which supporting feet are symmetrically arranged; a circulating conveying device, which is installed on the base plate; a connecting block, which is evenly installed at intervals on the conveying end of the edge of the circulating conveying device; a swing plate, which is hingedly arranged on the connecting block and swings up and down around the edge of the circulating conveying device; a driving gear, which is coaxially installed on the hinge point of the swing plate; an intermediate gear, which is arranged in the connecting block and meshed with the driving gear; a sleeve, which is connected to the end of the swing plate; a driving gear rod, which is rotatably arranged on the edge of the base plate; a first notch is opened at the bottom of the connecting block, and when the connecting block moves with the circulating conveying device, the connecting block moves over the driving gear rod through the first notch, and in this process the intermediate gear is meshed with the driving gear rod; a second driving member, which is installed at the bottom of the base plate and is drivingly connected to the driving gear rod through a hole opened on the base plate; the swing plate swings with the rotation of the driving gear rod; a counting sensor, which is installed on the circulating conveying device and corresponds to the position of the driving gear rod.

[0005] As a further improvement of the solution, the tooth edges on both sides of the driving gear rod and the intermediate gear are beveled edges.

[0006] As a further improvement of the scheme, the second driving member includes: a driving motor installed at the bottom of the base plate; a universal shaft, one end of which is connected to the driving motor, and the other end passes through a hole opened in the base plate and is obliquely connected to the end of the driving gear rod.

[0007] As a further improvement of the scheme, it also includes: through openings, which are evenly opened on the side walls around the upper part of the sleeve; spring pieces, which are arranged on the side walls of the sleeve according to the number of the through openings; and friction blocks, which are installed on the spring pieces and movably penetrate through the through openings and protrude into the sleeve.

[0008] As a further improvement of the scheme, it also includes: a bevel wedge, which is symmetrically slidably arranged on the edge side wall of the bottom plate through a fixed block, and is located on both sides opposite to the counting sensor; after the swing plate moves between the two bevel wedges and rotates and swings, the swing plate can be clamped between the two bevel wedges; a spring, which is arranged between the bevel wedge and the fixed block; a connecting piece, which is connected to the bevel wedge; a sliding rod, which is fixed on the connecting piece; a positioning ring, which is arranged on the sliding rod; a pushing cylinder, which is slidably arranged on the sliding part of the sliding rod; a telescope, whose two ends are respectively connected to the pushing cylinders on both sides.

[0009] As a further improvement of the scheme, it also includes: fixed rods, which are arranged at intervals on the circulating conveying device; a limiting pressure plate, which is fixedly installed on the fixed rods and rests on the top of the swing plate at a distributed position around the swing plate; and a second notch is opened on the limiting pressure plate at a position opposite to the counting sensor to allow the swing plate to pass through.

[0010] As a further improvement of the solution, it also includes: a top cover, which is movably hinged on the fixing rod and has a size capable of covering all the sleeves; a through hole is opened at the position of the top cover facing the second notch to allow the sleeve to swing through.

[0011] As a further improvement of the solution, the circulating conveying device is a chain transmission device, and the power unit thereon is a first driving member installed on the back; the chain transmission device is fixedly installed on the base plate, and the connecting block is installed on the transmission chain at the edge of the chain transmission device.

[0012] As a further improvement of the scheme, the circulating conveying device is a disc; the disc is rotatably arranged on the base plate; an inner gear ring is fixedly provided on the disc, a full gear is rotatably arranged on the base plate and meshes with the inner gear ring, and the connecting block is installed on the edge of the disc.

[0013] As a further improvement of the scheme, it also includes: a sliding opening is opened on the edge of the disc, and the connecting block is movably installed on the disc through the sliding opening; a straightening plate is installed on the bottom plate and close to the driving gear rod, and the bottom of the connecting block slides and contacts with the straightening plate during the rotation of the disc.

[0014] The present invention brings at least the following effects:

[0015] 1. The present invention installs a storage unit capable of storing drill bits on a circulating conveying device, and then sets up the circulating conveying device on the mounting back plate of the drilling equipment. Each processing spindle can be installed with a corresponding automatic drill bit replacement device. When the drill bit of the processing spindle needs to be replaced, it is only necessary to lift the processing spindle and drive the swing plate with the drill bit to flip through the driving gear rod, so that the drill bit is flipped to the bottom of the processing spindle, so that the drill bit replacement operation can be completed directly and quickly.

[0016] 2. The tooth edges on both sides of the driving gear rod and the intermediate gear are set as bevel edges, which can prevent the driving gear rod and the intermediate gear from getting stuck or colliding when they are meshed.

[0017] 3. The friction block on the sleeve can make the drill bit stored on the sleeve more stable, preventing the drill bit from falling off when the sleeve is turned over.

[0018] 4. The beveled wedge provided in the present invention can provide stable support when the machining spindle replaces the drill bit, thereby preventing the driving gear and the intermediate gear from slipping or hitting when the machining spindle pushes the sleeve.

[0019] 5. The limiting pressure plate provided in the present invention can limit and fix the swing plate and the sleeve, thereby preventing the sleeve from swinging on its own when following the movement of the circulating conveying device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a complete schematic diagram of the present invention.

[0021] Figure 2 For the present invention Figure 1 Schematic diagram of installation on the mounting backplane.

[0022] Figure 3 It is a schematic diagram of the installation back plate, lifting device and processing spindle of the present invention.

[0023] Figure 4 This is a schematic diagram of the present invention after the top cover and the first driving member are hidden.

[0024] Figure 5 It is a schematic diagram of the connecting block, the swing plate and the sleeve of the present invention.

[0025] Figure 6It is a schematic diagram of the driving relationship among the second driving member, the driving gear and the intermediate gear of the present invention.

[0026] Figure 7 It is a schematic diagram of the driving gear and the intermediate gear of the present invention.

[0027] Figure 8 It is a schematic diagram of the through opening, spring sheet and friction block of the present invention.

[0028] Fig. 9 It is a schematic diagram of the bevel wedge, fixed block, slide rod, push cylinder and telescopic device of the present invention.

[0029] Fig.10 It is a schematic diagram of a second embodiment of the circulating conveying device of the present invention.

[0030] Fig.11 For the present invention Fig.10 A partial schematic diagram of .

[0031] The corresponding relationship between the reference numerals and the names of the components in the accompanying drawings is as follows:

[0032] 1-bottom plate, 101-supporting foot, 3-connecting block, 31-first notch, 32-driving gear, 33-intermediate gear, 4-swing plate, 5-sleeve, 6-driving gear rod, 7-second driving member, 8-counting sensor;

[0033] 61-bevel edge;

[0034] 71-driving motor, 72-universal shaft;

[0035] 51-through port, 52-spring sheet, 53-friction block;

[0036] 9-bevel wedge, 91-fixed block, 92-spring, 93-connecting piece, 94-sliding rod, 95-positioning ring, 96-pushing cylinder, 97-retractor, 98-sliding part;

[0037] 11-fixing rod, 111-limiting pressure plate, 112-second notch;

[0038] 12-top cover, 121-through opening;

[0039] 102-first driving member, 2-chain transmission device;

[0040] 13-disc, 131-inner gear ring, 132-full gear;

[0041] 133-sliding opening, 134-straightening plate;

[0042] 301-installing back plate, 302-lifting device, 303-machining spindle, 304-connecting port, 305-drill bit. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It will be appreciated that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some but not all structures related to the present application are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present application.

[0044] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0045] Embodiment 1: The present invention specifically discloses an automatic drill bit replacement device for drilling holes in a PCB board, such as Figure 1-Figure 7 As shown, it comprises: a bottom plate 1 with supporting feet 101, the supporting feet 101 are symmetrically arranged on the bottom plate 1, and when in use, the bottom plate 1 is installed on the mounting back plate 301 through the supporting feet 101, and a lifting device 302 is arranged in the middle of the mounting back plate 301, and a processing spindle 303 is installed on the lifting device 302, and the processing spindle 303 is located between the two supporting feet 101. The PCB board drilling equipment usually has multiple processing spindles 303 working together, so each processing spindle 303 can be matched with a bottom plate 1. In this embodiment, only one processing spindle 303 is used as an example; a circulating conveying device is installed on the bottom plate 1, and this embodiment In the embodiment, the circulating conveying device is a chain transmission device 2, and the power unit thereon is a first driving member 102 installed on the back. The first driving member 102 is a reduction motor, and the chain transmission device 2 is driven by the reduction motor to realize transmission. The transmission chain is at the edge of the chain transmission device 2, and the connecting blocks 3 are evenly fixedly installed on the transmission chain. In this embodiment, twenty-two connecting blocks 3 are installed. The chain transmission device 2 can arrange the transmission chain into a curved shape according to needs, so that more connecting blocks 3 can be installed; a swing plate 4 is hingedly provided on the connecting block 3. Since the swing plate 4 is at the edge of the chain transmission device 2, according to Figure 4 and Figure 5 As shown, the swinging plate 4 on the connecting block 3 has two states of swinging, one is a flat state on the chain transmission device 2, and the other is a vertical state after the swinging plate 4 swings 270 degrees at the hinge point.

[0046] according to Figure 5 As shown, a driving gear 32 is coaxially fixed on the hinge point of the swing plate 4, and the driving gear 32 rotates with the swing of the swing plate 4. An intermediate gear 33 is also rotatably provided in the connecting block 3, and the intermediate gear 33 is engaged with the driving gear 32. A sleeve 5 is fixedly installed at the end of the swing plate 4, and a drill bit 305 used for drilling holes in the PCB board can be placed in the sleeve 5. A single connecting block 3, the swing plate 4 and the sleeve 5 constitute a storage unit for the drill bit 305.

[0047] Specifically, according to Figure 3 and Figure 4 As shown, as the chain transmission device 2 drives the connecting piece 93 to move the sleeve 5 to a position corresponding to the axis of the machining spindle 303, the machining spindle 303 rises and retracts, and the swing plate 4 swings the sleeve 5 to a vertical state. At this time, the drill bit 305 in the sleeve 5 will be placed directly below the connecting port 304 of the machining spindle 303. As the machining spindle 303 moves downward and the connecting port 304 is connected to the drill bit 305, the machining spindle 303 is lifted again to take the drill bit 305 out of the sleeve 5, and then the swing plate 4 rotates and swings the sleeve 5 to a flat state, thereby completing the replacement of the drill bit 305.

[0048] Among them, according to Figure 8 As shown, a through opening 51 leading to the interior is opened on the surrounding side walls of the upper part of the sleeve 5, and a spring piece 52 with the same number as the through opening 51 is provided at a position near the through opening 51 on the sleeve 5, and a friction block 53 is fixedly installed on the spring piece 52, and the friction block 53 is movably inserted into the through opening 51 and protruded into the sleeve 5. The friction block 53 is a rubber block. After the drill bit 305 is placed in the sleeve 5, the elastic force can be applied by the spring piece 52 to make the friction block 53 tightly press against the side surface of the drill bit 305. The friction block 53 is provided with an arc-shaped recess that fits the circular surface of the drill bit 305, so that after the drill bit 305 is placed in the sleeve 5 and follows the process of the sleeve 5 turning over, the drill bit 305 can still be stably placed in the sleeve 5 to avoid falling off.

[0049] according to Figure 4 and Figure 6As shown, a driving gear rod 6 is rotatably arranged at the edge of the bottom plate 1, and the driving gear rod 6 is arranged on the bottom plate 1 at a position corresponding to the axis of the processing spindle 303. A first notch 31 is opened at the bottom of the connecting block 3. When the connecting block 3 moves following the chain transmission device 2, the connecting block 3 moves over the driving gear rod 6 through the first notch 31, and during this process, the intermediate gear 33 is meshed with the driving gear rod 6. Therefore, after the intermediate gear 33 is meshed with the driving gear rod 6, the swing plate 4 can be swung by rotating the driving gear rod 6. A second driving member 7 is fixedly installed at the bottom of the bottom plate 1. The second driving member 7 includes: a driving motor installed at the bottom of the bottom plate 1; The machine 71, the output shaft of the driving motor 71 is connected to one end of the universal shaft 72, and the other end of the universal shaft 72 passes through the hole opened on the base plate 1 and is obliquely connected to the end of the driving gear rod 6. The driving gear rod 6 is rotated by the second driving member 7, so that the swing plate 4 can rotate and swing on the connecting block 3; a counting sensor 8 is fixedly installed on the chain transmission device 2, and the installation position of the counting sensor 8 corresponds to the position of the driving gear rod 6. The function of the counting sensor 8 is to assist the drilling equipment to replace the required drill bit 305, and the position of the drill bit 305 is determined by counting, so as to complete the replacement of the drill bit 305 more quickly.

[0050] Among them, according to Figure 7 As shown, both side tooth edges of the driving gear rod 6 and the intermediate gear 33 are beveled edges 61. The beveled edges 61 can make the driving gear rod 6 and the intermediate gear 33 mesh better and avoid being stuck with each other and unable to form an effective meshing state.

[0051] The present invention installs a storage unit capable of storing the drill bit 305 on the circulating conveying device, and then sets up the circulating conveying device on the mounting back plate 301 of the drilling equipment. When the drill bit 305 needs to be replaced on the machining spindle 303, it is only necessary to lift the machining spindle 303 and drive the swing plate 4 with the drill bit 305 to flip over by driving the gear rod 6, so that the drill bit 305 is flipped to the bottom of the machining spindle 303. In this way, the operation of replacing the drill bit 305 can be completed directly and quickly, which can effectively shorten the travel of replacing the drill bit 305 of the equipment, thereby reducing the machining time. In addition, since the storage position of the drill bit 305 is above the machining spindle 303, the drill bit 305 will not be contaminated by machining impurities during the machining process.

[0052] Embodiment 2: Based on the previous embodiment, Figure 4 and Fig. 9As shown, it also includes: a beveled wedge 9 symmetrically slidably arranged on the edge side wall of the bottom plate 1 through a fixed block 91, the fixed block 91 is fixed on the side edge of the bottom plate 1, the beveled wedge 9 is slidably arranged on the fixed block 91, the end faces on both sides of the beveled wedge 9 that are close to each other are inclined end faces, and the beveled wedge 9 is located on both sides facing the counting sensor 8; after the sleeve 5 to be replaced moves to the area between the two beveled wedges 9, as the swing plate 4 rotates and swings, the swing plate 4 will be stuck between the two beveled wedges 9, and thereby restrict the swing plate 4 from moving. At this time, when the processing spindle 303 moves downward to connect or release the drill bit 305, the reverse force applied to the swing plate 4 will act on the beveled wedge 9 and be resisted by the beveled wedge 9, so that the swing plate 4 can be prevented from swinging in the opposite direction and causing the driving gear 32 to rotate, thereby avoiding the situation where the driving gear 32 and the intermediate gear 33 slip or hit the teeth.

[0053] according to Fig. 9 As shown, a spring 92 is further provided between the bevel wedge 9 and the fixed block 91, and the spring 92 is used to keep the two bevel wedges 9 in a state of being close to each other; a connecting piece 93 is fixedly installed on the bevel wedge 9, and a sliding rod 94 is fixedly provided on the connecting pieces 93 on both sides, a positioning ring 95 is fixed on the middle part of the sliding rod 94, and a pushing cylinder 96 is slidably provided on the sliding part 98 of the sliding rod 94; the pushing cylinders 96 slidably provided on both sides are connected to the same telescopic device 97, and when the bevel wedge 9 needs to be released after the drill bit 305 is removed or connected, the telescopic device 97 extends, thereby pushing the pushing cylinders 96, the sliding rod 94, the connecting piece 93 and the bevel wedge 9 on both sides away from each other. At this time, the bevel wedge 9 no longer restricts the swing plate 4 and can swing freely. After the telescopic device 97 is retracted, the bevel wedge 9 returns to its original position again.

[0054] Embodiment 3: Based on the previous embodiment, Figure 2 and Figure 4 As shown, it also includes: a fixed rod 11 arranged on the circulating conveying device at intervals, and a limiting pressure plate 111 is fixedly installed on the fixed rod 11. The limiting pressure plate 111 is against the top of the swing plate 4 at the distribution position around the swing plate 4. A second notch 112 allowing the swing plate 4 to pass through is opened at the position of the limiting pressure plate 111 facing the counting sensor 8. The swing plate 4 is limited by the set limiting pressure plate 111. When the swing plate 4 and the sleeve 5 move following the chain transmission device 2, the swing plate 4 can be effectively prevented from swinging by itself; a top cover 12 is movably hinged on the fixed rod 11, and the size of the top cover 12 can cover all the sleeves 5. Covering the sleeve 5 with the top cover 12 can effectively prevent the drill bit 305 from being contaminated and collided; a through hole 121 allowing the sleeve 5 to swing through is opened at the position of the top cover 12 facing the second notch 112, so that the sleeve 5 will not be blocked by the top cover 12 during the turning process.

[0055] Embodiment 4: Based on the previous embodiment, Fig.10 and Fig.11 As shown, this embodiment is different from Embodiment 1 in that the circulating conveying device is a disc 13, and the disc 13 is suitable for drilling equipment with a small number of drill bits 305. At the same time, the structure of the disc 13 is simpler than that of the chain transmission device 2, and is more convenient to maintain; the disc 13 is rotatably set on the base plate 1, and an inner gear ring 131 is fixed on the disc 13, and a full gear 132 is rotatably set on the base plate 1 and meshes with the inner gear ring 131. After the full gear 132 is driven to rotate by an external motor, the disc 13 can be moved with the connecting block 3 and other components installed on the connecting block 3, thereby completing the replacement operation of the drill bit 305.

[0056] Among them, according to Fig.11 As shown, in this embodiment, the connecting block 3 follows the circular motion of the disc 13, and the moving trajectory of the intermediate gear 33 is circular, so there is a possibility that it cannot mesh with the driving gear rod 6. Therefore, a sliding opening 133 is opened on the edge of the disc 13, and the connecting block 3 is movably installed on the disc 13 through the sliding opening 133. At the same time, a spring 92 is provided in the sliding opening 133. The spring 92 keeps the connecting block 3 in a fixed position in the sliding opening 133, and a straightening plate 134 is fixedly installed on the bottom plate 1. The straightening plate 134 is close to the driving gear rod 6. At this time, the bottom of the connecting block 3 will slide in contact with the straightening plate 134 during the rotation of the disc 13. Under the action of the straightening plate 134, the connecting block 3 will move in a straight trajectory in this area, and the intermediate gear 33 of the connecting block 3 can mesh with the driving gear rod 6 under the movement of the straight trajectory.

[0057] The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person skilled in the art, several modifications, improvements and substitutions can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. An automatic drill bit replacement device for drilling holes in a PCB board, comprising: A base plate (1) on which supporting feet (101) are symmetrically arranged; a circulating conveying device is installed on the base plate (1); characterized in that it also includes: connecting blocks (3) installed at uniform intervals on the conveying end of the edge of the circulating conveying device; a swing plate (4) hingedly arranged on the connecting block (3) and swinging up and down around the edge of the circulating conveying device; a driving gear (32) coaxially installed on the hinge point of the swing plate (4); an intermediate gear (33) arranged in the connecting block (3) and meshing with the driving gear (32); a sleeve (5) connected to the end of the swing plate (4); a driving gear rod (6) rotatably arranged on the base plate ( 1) edge; a first notch (31) is formed at the bottom of the connecting block (3); when the connecting block (3) moves with the circulating conveying device, the connecting block (3) passes through the first notch (31) and moves over the driving gear rod (6), and in the process the intermediate gear (33) meshes with the driving gear rod (6); a second driving member (7) is mounted at the bottom of the base plate (1) and is drivingly connected to the driving gear rod (6) via a hole formed in the base plate (1); the swing plate (4) swings with the rotation of the driving gear rod (6); a counting sensor (8) is mounted on the circulating conveying device and corresponds to the position of the driving gear rod (6); The device also includes: a bevel wedge (9) which is symmetrically slidably arranged on the edge side wall of the bottom plate (1) through a fixed block (91) and is located on both sides opposite to the counting sensor (8); after the swing plate (4) moves between the two bevel wedges (9) and rotates and swings, the swing plate (4) can be clamped between the two bevel wedges (9); a spring (92) is arranged between the bevel wedge (9) and the fixed block (91); a connecting member (93) is connected to the bevel wedge (9); a sliding rod (94) is fixedly arranged on the connecting member (93); a positioning ring (95) is arranged on the sliding rod (94); a pushing cylinder (96) is slidably arranged on the sliding part (98) of the sliding rod (94); and a telescoping device (97) whose two ends are respectively connected to the pushing cylinder (96) on both sides.

2. The automatic drill bit replacement device for PCB board drilling according to claim 1 is characterized in that: The tooth edges on both sides of the driving gear rod (6) and the intermediate gear (33) are both bevel edges (61).

3. The automatic drill bit replacement device for PCB board drilling according to claim 2 is characterized in that: The second driving member (7) comprises: a driving motor (71) mounted on the bottom of the base plate (1); a universal shaft (72), one end of which is connected to the driving motor (71) and the other end of which passes through a hole opened on the base plate (1) and is obliquely connected to the end of the driving gear rod (6).

4. The automatic drill bit replacement device for PCB board drilling according to claim 3 is characterized in that: Also includes: Through openings (51) are evenly arranged on the side walls around the upper part of the sleeve (5); spring pieces (52) are arranged on the side walls of the sleeve (5) according to the number of the through openings (51); and friction blocks (53) are installed on the spring pieces (52) and movably penetrate through the through openings (51) and protrude into the sleeve (5).

5. The automatic drill bit replacement device for PCB board drilling according to claim 4 is characterized in that: Also includes: Fixed rods (11) are arranged at intervals on the circulating conveying device; a limiting pressure plate (111) is fixedly mounted on the fixed rod (11) and is disposed around the distribution position of the swing plate (4) and abuts against the top of the swing plate (4); a second notch (112) is provided on the limiting pressure plate (111) at a position facing the counting sensor (8) to allow the swing plate (4) to pass through.

6. The automatic drill bit replacement device for drilling holes in a PCB board according to claim 5, characterized in that: It also comprises: a top cover (12) movably hinged on the fixing rod (11) and having a size capable of covering all the sleeves (5); a through hole (121) for allowing the sleeves (5) to swing through is formed at a position of the top cover (12) directly opposite to the second notch (112).

7. The automatic drill bit replacement device for PCB board drilling according to any one of claims 1 to 6, characterized in that: The circulating conveying device is a chain transmission device (2), the power unit of which is a first driving member (102) installed on the back; the chain transmission device (2) is fixedly installed on the bottom plate (1), and the connecting block (3) is installed on the transmission chain at the edge of the chain transmission device (2).

8. The automatic drill bit replacement device for PCB board drilling according to any one of claims 1 to 6, characterized in that: The circulating conveying device is a disc (13); the disc (13) is rotatably arranged on the base plate (1); an inner gear ring (131) is fixedly arranged on the disc (13); a full gear (132) is rotatably arranged on the base plate (1) and meshes with the inner gear ring (131); and the connecting block (3) is installed on the edge of the disc (13).

9. The automatic drill bit replacement device for PCB board drilling according to claim 8, characterized in that: Also includes: The disc (13) has a sliding opening (133) at its edge, and the connecting block (3) is movably mounted on the disc (13) through the sliding opening (133); a straightening plate (134) is mounted on the bottom plate (1) and is close to the driving gear rod (6), and the bottom of the connecting block (3) is in sliding contact with the straightening plate (134) during the rotation of the disc (13).

Images