Circuit board pin clamping equipment of PCB drilling machine
By designing a combined structure of the air clamp front base plate and the air clamp front support plate, precise positioning of circuit board pins is achieved, solving the problem of insufficient positioning accuracy in existing PCB drilling machines and improving processing precision and stability.
Patent Information
- Application Number
- CN202423044212.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-12-05
- Estimated Expiration
- 2034-12-10
AI Technical Summary
Existing PCB drilling machines have insufficient positioning accuracy for circuit boards, which affects processing precision.
A circuit board pin clamping device for a PCB drilling machine was designed. Through the combination structure of the air clamp front base plate, air clamp front support plate, air clamp front clamping block and cylinder, the pins of the circuit board are accurately positioned. The cylinder drives the movement of the guide rail and clamping block connector to clamp or release the pins, thereby improving the positioning accuracy and stability.
It improves the positioning accuracy and stability of circuit board pins, avoids movement caused by vibration during processing, and enhances processing precision.
Smart Images
Figure CN223630474U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to PCB drilling machine technical field, especially relate to a line road board pin clamping equipment of PCB drilling machine. BACKGROUND
[0002] PCB board Chinese name is printed circuit board, also called printed wiring board, is important electronic component, is the support of electronic components, is the carrier of electronic components electrical interconnection, the main advantage of adopting circuit board is to greatly reduce wiring and assembly error, improve automation level and production labor rate.
[0003] In the production process of printed circuit board, in order to facilitate the connection between line layer and the installation of electronic components in later period, drilling machine is needed to drill on processing board, the processing board positioning mode of the existing PCB drilling machine is bakelite pin positioning, positioning hole is drilled on bakelite, then pin is pressed into the positioning hole, corresponding via is also punched on processing board, pinhole cooperation is used to fix processing board on bakelite, multiple hole positioning is used for bakelite fixing, positioning precision is high, but different types of plate need to be re-punched and positioned, it is time-consuming and laborious, and the efficiency is low, and when the drilling on the surface of bakelite is too much, it cannot be used continuously, needs to be replaced, and the maintenance cost is high.The processing board positioning mode of the existing another kind of PCB drilling machine is air clamp pin positioning, that is, two-point positioning is used to fix processing board through pneumatic clamping principle, when using, processing board fixed with pin is put into air clamp with pin aligning V-shaped positioning groove, then air cylinder pushes and presses pin, but positioning precision is low, and the size change of pin outer diameter will affect the positioning precision of air clamp. SUMMARY
[0004] The utility model wants to solve technical problem is to the existing PCB drilling machine for the line road board and carry out the defect of the work of punching, because the existing PCB board positioning mode is not accurate enough, thereby affecting the processing precision, provide a kind of line road board pin clamping equipment of PCB drilling machine.
[0005] The technical scheme adopted by the utility model to solve the above technical problems is as follows:
[0006] The application provides a PCB drill machine's circuit board pin clamping device, which comprises a gas clamp front bottom plate, one side edge of the top of the gas clamp front bottom plate is provided with a containing groove along the length direction, the containing groove is provided with a U-shaped gas clamp front supporting plate, a through hole which is matched with the gas clamp front supporting plate and penetrates through the gas clamp front bottom plate is formed in the containing groove, the gas clamp front supporting plate comprises two spaced side blocks and a bottom block arranged between the two side blocks, the top of each side block extends out of the top of the bottom block, a first gas clamp front clamping block fixed on the bottom block and a second gas clamp front clamping block located at the through hole are sequentially arranged in the gas clamp front supporting plate, one side of the first gas clamp front clamping block opposite to the second gas clamp front clamping block is provided with a mounting position for placing a circuit board pin, the bottom of the second gas clamp front clamping block is provided with a clamping block connecting piece located in the through hole, the bottom of the gas clamp front bottom plate is provided with a guide rail located at the bottom of the clamping block connecting piece and close to the through hole, the guide rail is provided with two first inserting rods which respectively penetrate through the clamping block connecting piece and are inserted into the second gas clamp front clamping block, the bottom of the gas clamp front bottom plate is provided with a gas cylinder, one side of the gas cylinder close to the guide rail is provided with a gas cylinder connecting piece located below the guide rail, the gas cylinder connecting piece is provided with two second inserting rods which are respectively inserted into the guide rail, when the gas cylinder moves forward and backward, the guide rail is driven to move by the gas cylinder connecting piece, the guide rail drives the clamping block connecting piece and the second gas clamp front clamping block to move, so that the second gas clamp front clamping block moves to the first gas clamp front clamping block, thereby the circuit board pin can be clamped or released.
[0007] Further, the first gas clamp front clamping block is provided with a first notch flush with the side block along the two side edges of the width of the gas clamp front bottom plate, and the second gas clamp front clamping block is provided with a second notch flush with the side block and corresponding to the first notch along the two side edges of the width of the gas clamp front bottom plate.
[0008] Further, the two side blocks are respectively provided with a gas clamp front pressing strip, and the gas clamp front pressing strips are respectively pressed on the first notch and the second notch.
[0009] Further, the two side blocks are respectively provided with a plurality of first fixing holes penetrating through the upper and lower surfaces thereof, the two side edges of the containing groove along the width direction of the gas clamp front bottom plate are respectively provided with a plurality of second fixing holes corresponding to the first fixing holes, and the gas clamp front pressing strips are respectively provided with a plurality of third fixing holes penetrating through the upper and lower surfaces thereof and corresponding to the first fixing holes, and the gas clamp front pressing strips and the gas clamp front supporting plate are fixed in the containing groove through the cooperation of the bolts, the first fixing holes, the second fixing holes and the third fixing holes.
[0010] Further, the first air clamp front clamping block is provided with a plurality of fourth fixing holes penetrating through the upper and lower surfaces thereof, the bottom block is provided with a plurality of fifth fixing holes corresponding to the fourth fixing holes, the accommodating groove is provided with a plurality of sixth fixing holes corresponding to the fifth fixing holes, and the first air clamp front clamping block is fixed in the first air clamp front clamping block through cooperation of bolts, the fourth fixing holes, the fifth fixing holes and the sixth fixing holes.
[0011] Further, the air cylinder is detachably fixed to the bottom of the air clamp front bottom plate through an air cylinder fixing frame.
[0012] Further, the guide rail is detachably fixed to the bottom of the air clamp front bottom plate through a guide rail fixing frame, and the guide rail is slidably arranged relative to the guide rail fixing frame.
[0013] Further, the guide rail fixing frame is provided with a plurality of seventh fixing holes, the bottom of the air clamp front bottom plate is provided with a plurality of eighth fixing holes corresponding to the seventh fixing holes, and the guide rail is fixed to the bottom of the air clamp front bottom plate through cooperation of bolts, the seventh fixing holes and the eighth fixing holes.
[0014] Further, the clamping block connecting piece is provided with two first insertion holes respectively adapted to the first insertion rods and penetrating through the upper and lower surfaces of the clamping block connecting piece, the bottom of the second air clamp front clamping block is provided with two second insertion holes respectively corresponding to the first insertion holes, and the guide rail, the clamping block connecting piece and the second air clamp front clamping block are connected together through cooperation of the first insertion rods, the first insertion holes and the second insertion holes.
[0015] Further, the bottom of the guide rail is provided with two third insertion holes respectively adapted to the second insertion rods, and the guide rail and the air cylinder connecting piece are connected together through cooperation of the second insertion rods and the third insertion holes.
[0016] The line board pin clamping equipment of the PCB drilling machine provided in the above embodiment of the utility model has a containing groove arranged on one side edge of the top of the front bottom plate along the length direction of the containing groove, a gas clamping front supporting plate is arranged in the containing groove, a through hole that is adapted to the gas clamping front supporting plate and penetrates through the gas clamping front bottom plate is arranged in the containing groove, a first gas clamping front clamping block fixed on the bottom block and a second gas clamping front clamping block located at the through hole are sequentially arranged in the gas clamping front supporting plate, the bottom of the second gas clamping front clamping block is provided with a clamping block connecting piece located in the through hole, the position of the bottom of the gas clamping front bottom plate close to the through hole is provided with a guide rail located at the bottom of the clamping block connecting piece, the guide rail is provided with two first inserting rods that respectively penetrate through the clamping block connecting piece and are inserted in the second gas clamping front clamping block, the bottom of the gas clamping front bottom plate is provided with a gas cylinder, one side of the gas cylinder close to the guide rail is provided with a gas cylinder connecting piece located below the guide rail, the gas cylinder connecting piece is provided with two second inserting rods that are respectively inserted in the guide rail, in this way, when the gas cylinder acts forward and backward, the guide rail is driven to move through the gas cylinder connecting piece, the guide rail drives the clamping block connecting piece and the second gas clamping front clamping block to move, so that the second gas clamping front clamping block reciprocally displaces relative to the first gas clamping front clamping block, thereby the pin can be clamped or released, the clamping block clamps the line board pin, and the positioning precision and stability of the line board pin can be improved, the line board pin is prevented from moving up and down due to vibration in the machining process, and the defect that the positioning is not accurate enough due to the existing line board positioning mode when the existing PCB drilling machine performs the punching work on the line board is effectively solved. BRIEF DESCRIPTION OF DRAWINGS
[0017] In order to more clearly illustrate the technical scheme of the utility model, the following will briefly introduce the drawings needed to be used in the embodiment, obviously, the drawings in the following description are only some embodiments of the utility model, and for the ordinary skilled in the art, other drawings can also be obtained according to these drawings without creating labor.
[0018] Figure 1 It is the overall schematic view of the line board pin clamping equipment of the PCB drilling machine provided in an embodiment of the utility model.
[0019] Figure 2 It is Figure 1 The enlarged schematic view of A in the figure.
[0020] Figure 3 It is another overall schematic view of the line board pin clamping equipment of the PCB drilling machine provided in an embodiment of the utility model.
[0021] Figure 4 It is Figure 3 The enlarged schematic view of B in the figure.
[0022] Figure 5 It is still another overall schematic view of the line board pin clamping equipment of the PCB drilling machine provided in an embodiment of the utility model.
[0023] Figure 6 is an explosion schematic view of the circuit board pin clamping equipment of the PCB drilling machine provided by an embodiment of the utility model.
[0024] Figure 7 is another explosion schematic view of the circuit board pin clamping equipment of the PCB drilling machine provided by an embodiment of the utility model.
[0025] Figure 8 is still another explosion schematic view of the circuit board pin clamping equipment of the PCB drilling machine provided by an embodiment of the utility model.
[0026] Figure 9 is a structural schematic view of the air clamp front supporting plate of the circuit board pin clamping equipment of the PCB drilling machine provided by an embodiment of the utility model.
[0027] Figure 10 is a structural schematic view of the first air clamp front clamping block and the second air clamp front clamping block of the circuit board pin clamping equipment of the PCB drilling machine provided by an embodiment of the utility model.
[0028] Figure 11 is still another structural schematic view of the first air clamp front clamping block and the second air clamp front clamping block of the circuit board pin clamping equipment of the PCB drilling machine provided by an embodiment of the utility model. DETAILED DESCRIPTION
[0029] In order to make the technical problems, technical schemes and beneficial effects solved by the utility model more clearly understood, the utility model is further described in detail below by combining with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model.
[0030] Please refer to Figures 1 to 11The utility model provides a kind of line board pin clamping equipment for PCB drilling machine, including a gas clamp front bottom plate 100, the gas clamp front bottom plate 100 top side edge is equipped with a containing groove 101 along its length direction, the containing groove 101 is equipped with a U-shaped gas clamp front backing plate 200, the containing groove 201 is equipped with a through hole 102 being adapted with the gas clamp front backing plate 200 and penetrating the gas clamp front bottom plate 100, the gas clamp front backing plate 200 includes two interval arrangement side blocks 201 and bottom block 202 being arranged between two side blocks 201, two side blocks 201 top respectively extend the top of bottom block 202, the first gas clamp front clamping block 300 being fixed on the bottom block 202 and the second gas clamp front clamping block 400 being located at the through hole 102 are sequentially equipped in the gas clamp front backing plate 200, so, accommodating recess is formed between two side blocks 201 and bottom block 202, the first gas clamp front clamping block 300 is fixedly arranged in the accommodating recess, the first gas clamp front clamping block 300 is equipped with a mounting position 301 for placing line board pin on the side opposite to the second gas clamp front clamping block 400, the second gas clamp front clamping block 400 bottom is equipped with a clamping block connecting piece 500 being located in the through hole 102, the position of guide rail 600 being located at the bottom of clamping block connecting piece 500 is equipped in the through hole 102 of gas clamp front bottom plate 100 bottom, the first plug rod 601 being respectively penetrated clamping block connecting piece 500 and inserted in the second gas clamp front clamping block 400 is equipped on the guide rail 600, the gas cylinder 700 bottom is equipped with a gas cylinder 700, the side of gas cylinder 700 close to guide rail 600 is equipped with a gas cylinder connecting piece 800 being located below guide rail, the second plug rod 801 being respectively inserted in guide rail 600 is equipped on the gas cylinder connecting piece 800, so, when the gas cylinder 700 acts forward and backward, the guide rail 600 is moved by the gas cylinder connecting piece 800, the clamping block connecting piece 500 and the second gas clamp front clamping block 400 are moved by the guide rail 600, so that the second gas clamp front clamping block 400 is displaced back and forth relative to the first gas clamp front clamping block 300, so that line board pin can be clamped or released, the clamping of line board pin is completed, so that the positioning accuracy and stability of line board pin can be improved, the line board pin is avoided to move up and down due to vibration in processing process, effectively solve the defect that the positioning of existing line board is not accurate enough when existing PCB drilling machine is punched, so as to affect processing precision.
[0031] In the embodiment, the first air clamp front clamping block 300 is provided with a first notch 302 flush with the side block 201 along the two side edges of the air clamp front bottom plate 100, and the second air clamp front clamping block 400 is provided with a second notch 401 flush with the side block 201 and corresponding to the first notch 302 along the two side edges of the air clamp front bottom plate 100.
[0032] In the embodiment, the air clamp front pressing strip 900 is further arranged on the two side blocks 201, and the air clamp front pressing strip 900 is respectively pressed on the first notch 302 and the second notch 302, so that the air clamp front pressing strip 900 plays a role of fixing the first air clamp front clamping block 300 and the second air clamp front clamping block 400.
[0033] In the embodiment, the two side blocks 201 are respectively provided with a plurality of first fixing holes 2011 penetrating the upper and lower surfaces thereof, the receiving groove 101 is respectively provided with a plurality of second fixing holes 1011 corresponding to the first fixing holes 2011 along the two side edges of the air clamp front bottom plate 100 in the width direction, and the air clamp front pressing strip 900 is respectively provided with a plurality of third fixing holes 901 penetrating the upper and lower surfaces thereof and corresponding to the first fixing holes 2011, so that the air clamp front pressing strip 900 and the air clamp front supporting plate 200 are fixed in the receiving groove 101 through cooperation of the bolts, the first fixing holes 2011, the second fixing holes 1011 and the third fixing holes 901, thereby playing a fixing role.
[0034] In the embodiment, the first air clamp front clamping block 300 is provided with a plurality of fourth fixing holes 303 penetrating the upper and lower surfaces thereof, the bottom block 202 is provided with a plurality of fifth fixing holes 2021 corresponding to the fourth fixing holes 303, and the receiving groove 101 is provided with a plurality of sixth fixing holes 1012 corresponding to the fifth fixing holes 2021, so that the first air clamp front clamping block 300 is fixed in the first air clamp front clamping block 200 through cooperation of the bolts, the fourth fixing holes 303, the fifth fixing holes 2021 and the sixth fixing holes 1012, thereby playing a role.
[0035] In the embodiment, the air cylinder 700 is detachably fixed to the bottom of the air clamp front bottom plate 100 through an air cylinder fixing frame 701.
[0036] In the embodiment, the guide rail 600 is detachably fixed to the bottom of the air clamp front bottom plate 100 through a guide rail fixing frame 602, and the guide rail 600 is slidably arranged relative to the guide rail fixing frame 602.
[0037] In the embodiment, as shown in Figure 6As shown, the top of the guide rail fixing frame 602 is provided with a plurality of seventh fixing holes 6021, the bottom of the front air clamp bottom plate 100 is provided with a plurality of eighth fixing holes 104 corresponding to the seventh fixing holes 6021, and the guide rail 600 is fixed at the bottom of the front air clamp bottom plate 100 through the cooperation of bolts, the seventh fixing holes 6021 and the eighth fixing holes 104.
[0038] In this embodiment, as shown in Figure 6 and Figure 8 As shown, the clamp block link 500 is provided with two first insertion holes 501 penetrating the upper and lower surfaces of the clamp block link 500 and adapted to the first insertion rod 601, and the bottom of the second front air clamp block 400 is provided with two second insertion holes 402 corresponding to the first insertion holes 501, and the guide rail 600, the clamp block link 500 and the second front air clamp block 400 are connected together through the cooperation of the first insertion rod 601, the first insertion holes 501 and the second insertion holes 402, so that when the air cylinder 700 moves forward and backward, the guide rail 600 is driven to move by the air cylinder connecting piece 800, the guide rail 600 drives the clamp block link 500 and the second front air clamp block 400 to move, so that the second front air clamp block 400 moves back and forth relative to the first front air clamp block 300, so as to clamp or release the circuit board pins.
[0039] In this embodiment, as shown in Figure 8 As shown, the bottom of the guide rail 600 is provided with two third insertion holes 603 adapted to the second insertion rod 801, and the guide rail 600 and the air cylinder connecting piece 800 are connected together through the cooperation of the second insertion rod 801 and the third insertion holes 603, so that when the air cylinder 700 moves forward and backward, the guide rail 600 is driven to move by the air cylinder connecting piece 800, the guide rail 600 drives the clamp block link 500 and the second front air clamp block 400 to move, so that the second front air clamp block 400 moves back and forth relative to the first front air clamp block 300, so as to clamp or release the circuit board pins.
[0040] The line board pin clamping equipment of the PCB drilling machine provided by the above-mentioned embodiments of the utility model, one accommodating groove is arranged on one side edge of the top of the front bottom plate along the length direction of the front bottom plate, one air clamp front supporting plate is arranged in the accommodating groove, one through hole which is adapted to the air clamp front supporting plate and penetrates the air clamp front bottom plate is arranged in the accommodating groove, a first air clamp front clamping block which is fixed on the bottom block and a second air clamp front clamping block which is located at the through hole are sequentially arranged in the air clamp front supporting plate, a clamping block connecting piece which is located in the through hole is arranged on the bottom of the second air clamp front clamping block, a guide rail which is located at the bottom of the clamping block connecting piece is arranged on the position of the air clamp front bottom plate which is close to the through hole, two first inserting rods which penetrate the clamping block connecting piece and are inserted in the second air clamp front clamping block are arranged on the guide rail, a cylinder is arranged on the bottom of the air clamp front bottom plate, a cylinder connecting piece which is located below the guide rail is arranged on the side of the cylinder which is close to the guide rail, two second inserting rods which are inserted in the guide rail are arranged on the cylinder connecting piece, when the cylinder acts forward and backward, the guide rail is driven to move by the cylinder connecting piece, the guide rail drives the clamping block connecting piece and the second air clamp front clamping block to move, so that the second air clamp front clamping block reciprocally displaces relative to the first air clamp front clamping block, thereby the pin can be clamped or released, the clamping block clamps the line board pin, thereby the positioning precision and stability of the line board pin can be improved, the line board pin is prevented from moving up and down due to vibration in the processing process, and the defect that the existing PCB drilling machine affects the processing precision when the line board is punched because the existing line board positioning mode is not accurate enough is effectively solved.
[0041] The above only describes preferred embodiments of the utility model and is not used to limit the utility model, any modification, equivalent replacement and improvement within the spirit and principle of the utility model should be included in the protection scope of the utility model.
Claims
1. A board pin chucking apparatus of a PCB drill, characterized by, The utility model provides a front air clamp bottom plate, and one side edge of the top of the front air clamp bottom plate is provided with a containing groove along the length direction, and the containing groove is provided with a U-shaped front air clamp support plate, and the containing groove is provided with a through hole which is matched with the front air clamp support plate and penetrates the front air clamp bottom plate, and the front air clamp support plate comprises two spaced side blocks and a bottom block arranged between the two side blocks, and the top of the two side blocks respectively extends out of the top of the bottom block, and the front air clamp support plate is sequentially provided with a first front air clamp block fixed on the bottom block and a second front air clamp block located at the through hole, and one side of the first front air clamp block opposite to the second front air clamp block is provided with a mounting position for placing a circuit board pin, and the bottom of the second front air clamp block is provided with a clamp link located in the through hole, and the bottom of the front air clamp bottom plate is provided with a guide rail located at the bottom of the clamp link near the through hole, and the guide rail is provided with two first insertion rods respectively penetrating the clamp link and inserted in the second front air clamp block, and the bottom of the front air clamp bottom plate is provided with a pneumatic cylinder, and one side of the pneumatic cylinder near the guide rail is provided with a pneumatic cylinder connecting piece located below the guide rail, and the pneumatic cylinder connecting piece is provided with two second insertion rods respectively inserted in the guide rail, and when the pneumatic cylinder acts forward and backward, the guide rail is driven to move through the pneumatic cylinder connecting piece, the guide rail drives the clamp link and the second front air clamp block to move, so that the second front air clamp block is displaced to the first front air clamp block, so that the circuit board pin can be clamped or released.
2. The circuit board pin chuck apparatus of claim 1, wherein The first front air clamp block is provided with a first notch flush with the side block along the two side edges of the width of the front air clamp bottom plate, and the second front air clamp block is provided with a second notch flush with the side block and corresponding to the first notch along the two side edges of the width of the front air clamp bottom plate.
3. The circuit board pin chucking apparatus of claim 2 wherein, The two side blocks are respectively provided with a front air clamp pressing strip, and the front air clamp pressing strips are respectively pressed on the first notch and the second notch.
4. The circuit board pin chuck apparatus of claim 3 wherein, The two side blocks are respectively provided with a plurality of first fixing holes penetrating the upper and lower surfaces thereof, the two side edges of the containing groove along the width direction of the front air clamp bottom plate are respectively provided with a plurality of second fixing holes corresponding to the first fixing holes, the front air clamp pressing strips are respectively provided with a plurality of third fixing holes penetrating the upper and lower surfaces thereof and corresponding to the first fixing holes, and the front air clamp pressing strips and the front air clamp support plate are fixed in the containing groove through the cooperation of bolts, the first fixing holes, the second fixing holes and the third fixing holes.
5. The circuit board pin chucking apparatus of claim 1, wherein The first front air clamp block is provided with a plurality of fourth fixing holes penetrating the upper and lower surfaces thereof, the bottom block is provided with a plurality of fifth fixing holes corresponding to the fourth fixing holes, and the containing groove is provided with a plurality of sixth fixing holes corresponding to the fifth fixing holes, and the first front air clamp block is fixed in the first front air clamp block through the cooperation of bolts, the fourth fixing holes, the fifth fixing holes and the sixth fixing holes.
6. The circuit board pin chuck apparatus of claim 1, wherein The pneumatic cylinder is detachably fixed on the bottom of the front air clamp bottom plate through a pneumatic cylinder fixing frame.
7. The circuit board pin chucking apparatus of claim 1 wherein, The guide rail is detachably fixed on the bottom of the front bottom plate of the air clamp through a guide rail fixing frame, and the guide rail is slidably arranged relative to the guide rail fixing frame.
8. The circuit board pin chuck apparatus of claim 7 wherein, The top of the guide rail fixing frame is provided with a plurality of seventh fixing holes, and the bottom of the front bottom plate of the air clamp is provided with a plurality of eighth fixing holes corresponding to the seventh fixing holes, and the guide rail is fixed on the bottom of the front bottom plate of the air clamp through the cooperation of bolts, the seventh fixing holes and the eighth fixing holes.
9. The circuit board pin chucking apparatus of claim 1, wherein The clamp block connecting piece is provided with two first insertion holes penetrating the upper and lower surfaces of the clamp block connecting piece and respectively matched with the first insertion rods, the bottom of the second front clamp block of the air clamp is provided with two second insertion holes respectively matched with the first insertion holes, and the guide rail, the clamp block connecting piece and the second front clamp block of the air clamp are connected together through the cooperation of the first insertion rods, the first insertion holes and the second insertion holes.
10. The circuit board pin chucking apparatus of claim 1, wherein The bottom of the guide rail is provided with two third insertion holes respectively matched with the second insertion rods, and the guide rail and the air cylinder connecting piece are connected together through the cooperation of the second insertion rods and the third insertion holes.