CN111181342A

CN111181342A - Z-axis zooming assembly of VCM motor

Info

Publication number: CN111181342A
Application number: CN202010049680.1A
Authority: CN
Inventors: 卢煌杰; 白华
Original assignee: Chengdu Yixun Photoelectric Technology Co Ltd
Current assignee: Chengdu Yixun Photoelectric Technology Co Ltd
Priority date: 2020-01-16
Filing date: 2020-01-16
Publication date: 2020-05-19

Abstract

The invention discloses a Z-axis zooming component of a VCM motor, which is arranged outside a lens module and enables the lens module to move directionally to change focal length by electromagnetic control, and comprises a bracket, an upper spring piece and a lower spring piece, wherein the upper spring piece and the lower spring piece are arranged on two sides of the bracket; the support is internally provided with a carrier which can linearly move in the support, and the carrier is connected with the upper spring piece and the lower spring piece and provides restoring force through the upper spring piece and the lower spring piece; the carrier is sleeved with a coil, the bracket is provided with a magnet for forming a magnetic field, the upper spring piece is controlled by electrifying the coil to move in the bracket and comprises two identical groups of elastic components arranged on the same plane, and each elastic component comprises an outer elastic piece fixed on the bracket and an inner elastic piece arranged on the carrier; the outer spring plate and the inner spring plate are connected by at least two string wires and provide elastic restoring force. The invention has better stability, small volume and more compact internal structure by optimizing the internal structure design.

Description

Z-axis zooming assembly of VCM motor

Technical Field

The invention belongs to the technical field of electric control equipment, and particularly relates to a Z-axis zooming component of a VCM motor.

Background

The voice coil motor is the zoom mechanism that uses commonly in present small-size or miniature camera module, and along with the development of science and technology, the continuous renewal of mobile internet technique, the miniaturization precision that many electronic equipment is also continuous, because mobile terminal equipment integrated level is higher and higher, then need keep original function with large-scale spare part and reduce, just can integrate multiple functions on terminal equipment. For example, a camera, originally a digital camera, needs to perform two basic functions of photographing and shooting, and at least needs to be able to exchange light entering the device into a sensor for processing and transmitting digital signals, and also needs to be able to accurately enter a lens module, and at the same time needs to be able to move the lens module to perform an automatic focusing assembly. In order to adapt to the technical trend of miniaturization, and meanwhile, to be capable of focusing accurately and have higher focusing efficiency, many original mechanical motors cannot adapt to the existing mobile terminal equipment.

Because the voice coil motor is a non-commutation type power device, the positioning accuracy is completely dependent on the feedback and control system, and is independent of the voice coil motor. The positioning accuracy can easily reach 10nm by adopting a proper positioning feedback and induction device. The basic principle is the same whether the device is linear or swinging. When passing through a magnetic field, the energized conductor generates a force perpendicular to the magnetic field lines, the magnitude of which depends on the length of the conductor passing through the field, the strength of the magnetic field and the current. The magnitude of the thrust generated by the voice coil motor depends on the design structure and the current intensity, and the relationship between the current and the generated force is represented by force sensitivity in the linear type voice coil motor and torque sensitivity in the rotary type voice coil motor. The voice coil motor is a simple device, converts current into mechanical force, so the positioning and force control are achieved through a position feedback device and a controller, the precision of the position feedback device and the controller is determined by the controller, and the accuracy of the position feedback device and the controller is irrelevant to the voice coil motor.

The existing voice coil motor sequentially comprises a shell, a front gasket, an upper elastic sheet, a support, a carrier, a coil, a lower elastic sheet, a rear gasket and a base from top to bottom, wherein the coil is arranged on the carrier, and a permanent magnet for generating a fixed magnetic field is arranged on the support or the base. Because the upper spring piece and the lower spring piece are used for limiting the carrier to move in the bracket in a zooming mode, the existing upper spring piece, the carrier and the bracket structure are often too large and frequent in movement range, and if the elastic bending part of the upper spring piece is easy to fatigue fracture.

Disclosure of Invention

In order to solve the problems of the prior art, the present invention provides a Z-axis zoom assembly of a VCM motor.

The technical scheme adopted by the invention is as follows:

a Z-axis zooming component of a VCM motor is arranged outside a lens module and enables the lens module to move directionally to change focal length through electromagnetic control, and comprises a bracket, an upper spring piece and a lower spring piece, wherein the upper spring piece and the lower spring piece are arranged on two sides of the bracket;

the support is internally provided with a carrier which can linearly move in the support, and the carrier is connected with the upper spring piece and the lower spring piece and provides restoring force through the upper spring piece and the lower spring piece;

the carrier is sleeved with a coil, a magnet forming a magnetic field is arranged on the bracket, and the carrier is controlled to move in the Z-axis direction in the bracket by electrifying the coil;

the upper spring piece comprises two identical groups of elastic components arranged on the same plane, and each elastic component comprises an outer elastic piece fixed on the support and an inner elastic piece arranged on the carrier;

the outer spring plate and the inner spring plate are connected by a plurality of string wires and provide elastic restoring force.

The voice coil motor structure is applied to the camera to provide an automatic focusing effect, so that the electromagnetic control precision is high, and the focusing efficiency is high due to the small volume size. In order to realize the basic functions, the camera of the existing mobile terminal device comprises a sensor, a lens module and a voice coil motor, wherein the lens module is arranged in the voice coil motor, a hall magnet is fixed on the voice coil motor to sense the moving position, and an action mechanism of the voice coil motor drives the surface of the sensor to generate directional displacement compared with the fixed sensor, so that the effect of adjusting the focal length is achieved.

The invention is applied to controlling the lens module to move axially in the voice coil motor, because the lens module belongs to a moving part relative to the sensor, the lens module is connected through two structures capable of moving relatively, namely a bracket and a carrier. The carrier is used for bearing the lens module, the support is fixedly connected with the sensor, the carrier can do linear reciprocating motion in the support, and the position of the carrier is limited through the inner wall plane of the top surface of the shell and the four blades of the carrier.

That is to say, through the upper spring leaf and the lower spring leaf that are equipped with be connected with the carrier simultaneously, under the condition that does not receive external force, the whole carrier receives gravity and the pulling force of two spring leaves and forms static equilibrium, then the carrier is the suspended state for the support this moment. In order to accurately move the carrier, a magnet is arranged on the bracket to form a magnetic field, and a coil fixedly connected with the carrier is arranged on the carrier to form electromagnetic induction force, so that the movement of the carrier is controlled by controlling the current magnitude and direction of an input coil.

Because the movement of the carrier realizes accurate positioning through the combined action of the two spring pieces and the coil, in the voice coil motor with the OIS anti-shake function, the lower spring piece needs to provide restoring force on an X/Y plane, and the upper spring piece needs to have a good rebound effect and good stability and structural strength. In order to prolong the service life and reduce the processing and manufacturing difficulty, the upper spring piece is divided into two identical parts. The carrier and the bracket are both annular mechanisms, and the upper spring leaf is divided into two identical structural rings which are symmetrical by a point of the central point of the bracket when being installed. In order to provide better resilience performance, an inner layer connecting structure and an outer layer connecting structure are arranged, and a plurality of string wires are connected.

Furthermore, a control wire and a power supply wire are arranged in the bracket, a contact A connected with the control wire and a contact B connected with the power supply wire are arranged on the surface of one side provided with the upper spring piece, and the contact A and the contact B are arranged at the gap between the two elastic components;

the outer elastic sheet of the elastic assembly is in contact with the contact A and the contact B, and the inner elastic sheet of the elastic assembly is connected with the contact C which is arranged on the carrier and used for connecting the coil.

Furthermore, the carrier is provided with a positioning permanent magnet convenient to position, and the support is provided with a Hall sensor which performs information feedback corresponding to the positioning permanent magnet.

Furthermore, the support is provided with a groove which is convenient for the string wire to swing up and down.

Furthermore, a positioning column for fixing the upper spring piece is arranged on the support.

Furthermore, the inner side of the carrier is provided with a hole or a non-threaded hole for fixing the lens module with threads.

Furthermore, guide vanes are arranged on the outer side of the carrier, and a plurality of limiting grooves which are matched with the guide vanes to realize linear motion are arranged on the inner side of the support.

Furthermore, the control wiring and the power supply wiring in the bracket are both formed by injection molding the conductive material with a conductive function or a metal stamping part together with the bracket base material through circuit design.

Furthermore, the side surface of the support provided with the lower spring piece is provided with at least four mounting grooves, and the magnet is nested in the mounting grooves.

Furthermore, a plurality of strip-shaped bulges of a glue storage groove for providing the magnet with the stored glue are arranged on the inner surface of the mounting groove.

The invention has the beneficial effects that:

(1) the upper spring piece is arranged into two parts, each elastic component is designed into an inner part and an outer part, and the inner part and the outer part are connected through the plurality of string wires, so that the stability of the whole limiting elastic mechanism is improved, and meanwhile, the length of the string wires is increased, so that the fatigue fracture of the material due to the large bending amplitude of the spring component caused by the over-short moment arm is avoided;

(2) the invention forms an integrated circuit structure by injecting a conductive material circuit into the frame body or integrally injecting and molding the conductive material circuit by adopting a stamping circuit mode, thereby avoiding external wiring or adopting a PCB soft board for conducting control, utilizing the inner wall plane of the top surface of the shell and the four blades of the carrier for limiting, and simultaneously conducting electricity for the coil by using the metal material thereof, thereby reducing assembly stations and assembly personnel, and avoiding the situation of stability reduction caused by more wiring or parts.

Drawings

FIG. 1 is a schematic view of the assembly of the entire voice coil motor of the present invention;

FIG. 2 is a schematic view of the entire zoom assembly of the present invention in a disassembled configuration;

FIG. 3 is an enlarged schematic view of the present invention of FIG. 2;

FIG. 4 is an assembled view of the entire zoom assembly of the present invention;

FIG. 5 is a schematic illustration of a disassembled structure of the bracket and the circuit embedded in the bracket of the invention;

FIG. 6 is a schematic bottom view of the zoom assembly of the present invention showing the position of the magnets;

fig. 7 is a structural schematic view of the entire stent of the present invention.

In the figure: 1-bracket, 2-upper spring leaf, 2.1-outer spring leaf, 2.2-inner spring leaf, 2.3-string wire, 3-lower spring leaf, 4-carrier, 5-coil, 6-guide blade, 7-magnet and 8-Hall magnet.

Detailed Description

The invention is further explained below with reference to the drawings and the specific embodiments.

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present application, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are used for indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship which is usually placed when the product of the application is used, the description is only for convenience and simplicity, and the indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation and be operated, and thus, should not be construed as limiting the present application. Furthermore, the appearances of the terms "first," "second," and the like in the description herein are only used for distinguishing between similar elements and are not intended to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical" and the like when used in the description of the present application do not require that the components be absolutely horizontal or overhanging, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present application, it should also be noted that, unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" should be interpreted broadly, e.g., as being fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

Example 1:

first, the present embodiment is applied to control the axial movement of the lens module in the voice coil motor, because the lens module belongs to the moving part relative to the sensor, and is connected by two structures capable of performing relative movement, namely the bracket 1 and the carrier 4.

The carrier 4 is used for bearing a lens module, the support 1 is fixedly connected with a sensor, a Hall magnet 8 used for sensing the position is fixed on the carrier 4, the coil 5 is electrified and generates magnetic field sensing with a plurality of magnets 7 in the support 1, linear reciprocating motion can be carried out in the support 1, and the position is limited by the magnets 7 arranged at four corners of the support 1, the inner wall plane of the top surface of the whole voice coil motor shell and four guide blades 6 of the carrier 4.

The embodiment discloses a Z-axis zooming component of a VCM motor, which comprises a bracket 1, an upper spring piece 2 and a lower spring piece 3, wherein the upper spring piece 2 and the lower spring piece 3 are arranged on two sides of the bracket 1; the support 1 is internally provided with a carrier 4 which can linearly move in the support 1, and the carrier 4 is connected with the upper spring piece 2 and the lower spring piece 3 and provides restoring force through the upper spring piece 2 and the lower spring piece 3. Under the condition that the driving force generated when the coil is electrified is not received, the gravity borne by the whole carrier 4 and the tensile force of the two spring pieces form static equilibrium, and then the carrier 4 is in a suspension state relative to the bracket 1. In order to accurately move the carrier 4, a magnet 7 is arranged on the bracket 1 to form a magnetic field, and a coil 5 fixedly connected with the carrier 4 is arranged on the carrier 4 to form electromagnetic induction force, so that the movement of the carrier 4 is controlled by controlling the current magnitude and direction of the input coil 5, and the position of Z-axis movement is controlled by a Hall magnet 8 fixed on the carrier 4.

A coil 5 is sleeved on the carrier 4, a magnet 7 for forming a magnetic field is arranged on the bracket 1, and the movement of the carrier 4 in the bracket 1 is controlled by electrifying the coil 5; the upper spring piece 2 comprises two identical groups of elastic components arranged on the same plane, and each elastic component comprises an outer elastic piece 2.1 fixed on the support 1 and an inner elastic piece 2.2 arranged on the carrier 4; the outer elastic sheet 2.1 and the inner elastic sheet 2.2 are connected by 4 string wires 2.3 and provide elastic restoring force.

Because the movement of the carrier 4 is realized by the combined action of the two spring pieces and the coil 5, the accurate positioning of the accurate displacement is realized by the hall magnet 8 fixed on the carrier 4 and the sensor on the bracket 1, and in the voice coil motor with the OIS anti-shake function, the lower spring piece 3 needs to provide restoring force on an X/Y plane, and then the upper spring piece 2 needs to have a better rebound effect and has better stability and structural strength. In order to prolong the service life and reduce the processing and manufacturing difficulty, the upper spring piece 2 is divided into two same parts. The carrier 4 and the bracket 1 are both annular mechanisms, and the upper spring leaf 2 is divided into two identical structural rings and is point-symmetrical about the center point of the bracket 1 when being installed. In order to provide better resilience performance, an inner layer and an outer layer of fixed connection structures are formed on the support 1 through the fixed elastic sheet 2.1 and the fixed elastic sheet 2.3 on the carrier 4, and the fixed connection structures are connected by adopting 4 string wires 2.3.

As shown in fig. 1, because the carrier 4 and the bracket 1 are both in an annular structure, and the central hole is used for mounting the lens module, the gap between the carrier 4 and the bracket 1 is smaller, but according to the elastic characteristics and rules of the material, increasing the length of the moment arm can increase the yield strength on the premise of adopting the same material, that is, the locally larger deformation caused in the state of short moment arm is uniformly distributed in each section of the material after the length of the material is increased.

The spring plate can only be prevented from breaking due to fatigue when the carrier 4 moves by increasing the length of the string 2.3. In fig. 2, it can be seen that the string 2.3 extends from the outer shell 2.1 circumferentially along the central axis of the carrier 4 as 4 identical strings

Example 2:

the embodiment specifically discloses a Z-axis zoom assembly of a VCM motor, as shown in fig. 1-7, as seen in the overall view, mainly comprises a bracket 1, an upper spring plate 2 and a lower spring plate 3 disposed at both sides of the bracket 1, and a carrier 4 structure disposed in the bracket 1.

The frame 1 and the carrier 4 can be seen as a set of nested ring assemblies because the frame 1 is provided with the carrier 4 capable of moving on the frame 1 in the Z-axis direction, and the carrier 4 is connected with the upper spring plate 2 and the lower spring plate 3 and provides restoring force through the upper spring plate 2 and the lower spring plate 3. Under the condition that the coil is not electrified and the magnet generates magnetic force, the gravity borne by the whole carrier 4 and the tensile force of the two spring pieces form static equilibrium, and then the carrier 4 is in a suspension state relative to the bracket 1.

An annular groove is arranged at the lower part of the carrier 4, and a coil 5 is sleeved on the groove. The coil 5 can be fixed on the carrier 4 by direct winding or assembly of dispensing, baking and curing, and the carrier 4 is pushed to move by electrifying the coil 5 and forming a magnetic field with the magnet 7 of the bracket 1.

In order to form a fixed magnetic field, the magnet 7 for forming the magnetic field is arranged on the bracket 1, and the movement of the carrier 4 in the Z-axis direction of the bracket 1 is controlled by electrifying the coil 5; the upper spring piece 2 comprises two identical groups of elastic components arranged on the same plane, and each elastic component comprises an outer elastic piece 2.1 fixed on the support 1 and an inner elastic piece 2.2 arranged on the carrier 4; the outer elastic sheet 2.1 and the inner elastic sheet 2.2 are connected by 4 string wires 2.3 and provide elastic restoring force.

A control wire and a power supply wire are arranged in the bracket 1, a contact A connected with the control wire and a contact B connected with the power supply wire are arranged on the surface of one side provided with the upper spring piece 2, and the contact A and the contact B are arranged at the gap between the two elastic components; the outer elastic sheet 2.1 of the elastic component is contacted with the contact A and the contact B, and the inner elastic sheet 2.2 of the elastic component is connected with the contact C which is arranged on the carrier 4 and is used for connecting the coil 5.

As shown in fig. 5, the material as the circuit is moved outward as a whole to form a schematic diagram, and the circuit is formed by injection molding of a conductive material or a metal stamping. Because support 1 is the structure that is used for restricting carrier 4 to carry out the axis direction motion in the voice coil motor, is equipped with coil 5 on carrier 4, thereby coil 5 need be through electrically conductive formation circular telegram wire of being connected with last shell fragment electricity, and goes up the shell fragment and divide into interior outer lane structure, and inner circle structure and 4 contacts of carrier use the tin cream welding, and outer lane structure and the use of support body upper portion electrically conductive silver thick liquid or tin soldering or then modes such as laser welding weld electrically conductive. In this embodiment, the integrated molding manner is to modify the PCB or flexible flat cable manner into a structure in which the conductive material is directly injection molded to form the circuit or the metal stamping circuit is integrally injection molded. General voice coil motor all adopts split type circuit design, and soft board or PCB board need artifical equipment and point to glue fixedly, sets up a plurality of independent coupling assembling alone, not only reduces assembly efficiency, also can influence the yield simultaneously. In the embodiment, the conductive material is directly cast or the metal stamping circuit is integrally injection molded, so that a regular solid circuit strip is formed in the shell of the bracket 1, and then the conductive silver paste or tin soldering or laser welding is used for realizing conduction connection after the components are fixed during installation, so that the convenience and the rapidness are realized.

In order to form closed-loop control, a Hall magnet 8 convenient for sensing with a sensor is fixedly arranged on the inner side of the carrier 4, and a Hall sensor for feeding back information corresponding to the positioning permanent magnet is arranged on the support 1. When the carrier 4 moves, the positioning permanent magnet moves relative to the Hall sensor, so that the magnet is positioned through the Hall sensor and data is sent to the control IC, and the feedback adjustment effect is achieved.

The support 1 is provided with a groove convenient for the string wires 2.3 to swing up and down, and the support 1 is provided with a positioning column used for fixing the upper spring piece 2. Fig. 7 is a structural display diagram of the upper end surface of a single support 1, in which it can be seen that the outer ring of the upper end surface of the support 1 is provided with an outer spring piece 2.1 positioning column and a bearing surface for fixing the upper spring piece 2, and the inner side is provided with a limit groove and a sinking platform structure. The outer elastic sheet 2.1 is fixed on the outer edge surface of the support 1 and is fixed through a plurality of positioning columns, and the joint of the string 2.3 and the outer elastic sheet 2.1 is widened, so that the structural strength of the joint part is improved.

The inner side of the carrier 4 is provided with a hole for fixing the lens module, the outer side of the carrier 4 is provided with 4 guide blades 6, and the inner side of the bracket 1 is provided with 4 limit grooves which are matched with the guide blades 6 to realize linear motion.

The control wiring and the power supply wiring in the bracket 1 are both formed by injection molding the base material with the conductive function and the base material of the bracket 1 together through circuit design. The side of the support 1 provided with the lower spring piece 3 is provided with at least four mounting grooves, and the magnet 7 is embedded in the mounting grooves in a dispensing fixing mode and is arranged in the mounting grooves.

Claims

1. A Z-axis zooming component of a VCM motor is arranged outside a lens module and enables the lens module to move directionally through electromagnetic control to carry out focal length conversion, and is characterized in that: comprises a bracket (1), an upper spring leaf (2) and a lower spring leaf (3) which are arranged on two sides of the bracket (1);

a carrier (4) capable of moving linearly in the support (1) is arranged in the support (1), and the carrier (4) is connected with the upper spring piece (2) and the lower spring piece (3) and provides restoring force through the upper spring piece (2) and the lower spring piece (3);

the carrier (4) is sleeved with a coil (5), a magnet (7) forming a magnetic field is arranged on the support (1), and the carrier (4) is controlled to move in the support (1) by electrifying the coil (5);

the upper spring piece (2) comprises two identical groups of elastic components arranged on the same plane, and each elastic component comprises an outer elastic piece (2.1) fixed on the support (1) and an inner elastic piece (2.2) arranged on the carrier (4);

the outer elastic sheet (2.1) and the inner elastic sheet (2.2) are connected by a plurality of string wires (2.3) and provide elastic restoring force.

2. A Z-axis zoom assembly of a VCM motor according to claim 1, wherein: a control wire and a power supply wire are arranged in the support (1), a contact A connected with the control wire and a contact B connected with the power supply wire are arranged on the surface of one side provided with the upper spring piece (2), and the contact A and the contact B are arranged at the gap between the two elastic components;

the outer elastic sheet (2.1) of the elastic component is in contact with the contact A and the contact B, and the inner elastic sheet (2.2) of the elastic component is connected with the contact C which is arranged on the carrier (1) and is used for being connected with the coil (5).

3. A Z-axis zoom assembly of a VCM motor according to claim 1 or 2, wherein: the Hall magnet 8 convenient for induction positioning is arranged on the carrier (4), and a Hall sensor for performing information feedback on the corresponding positioning permanent magnet is arranged on the support (1).

4. A Z-axis zoom assembly of a VCM motor according to claim 1 or 2, wherein: the support (1) is provided with a groove convenient for the string wire to swing up and down.

5. A Z-axis zoom assembly of a VCM motor according to claim 1 or 2, wherein: and the support (1) is provided with a positioning column for fixing the upper spring piece (2).

6. A Z-axis zoom assembly of a VCM motor according to claim 1 or 2, wherein: the inner side of the carrier (1) is provided with a through hole for fixing the lens module.

7. A Z-axis zoom assembly of a VCM motor according to claim 1 or 2, wherein: the carrier (1) outside is equipped with guide vane (6) to be equipped with a plurality of spacing grooves that realize spacing linear motion with guide vane (6) cooperation in support (1) inboard.

8. A Z-axis zoom assembly of a VCM motor according to claim 2 or 3, wherein: the control wiring and the power supply wiring in the support (1) are formed by injection molding together with a support base material through circuit design of a conductive material or a metal stamping part with a conductive function.

9. A Z-axis zoom assembly of a VCM motor according to claim 1 or 2, wherein: the side surface of the support (1) provided with the lower spring piece (3) is provided with at least four mounting grooves, and the magnet (7) is nested in the mounting grooves.

10. A Z-axis zoom assembly of a VCM motor according to claim 9, wherein: the inner surface of the mounting groove is provided with a plurality of strip-shaped protruding glue storage grooves for providing glue storage for the magnets.