A pressurized formation apparatus for solid-state batteries

Abstract

The present application relates to the field of battery production, in particular to a pressurized formation equipment for solid-state battery. The adjusting mechanism of the present application is arranged on both sides of the pressing plate mechanism; the fixing mechanism comprises a motor mounting plate, a spring upper plate, a guide shaft assembly, a cylindrical hole self-aligning ball bearing, an equal-height guide shaft, a baffle, a bottom mounting seat and an inductor mounting plate; the head and tail of the fixing mechanism are connected through the equal-height guide shafts arranged symmetrically on both sides, and there are 4 equal-height guide shafts in total, 2 on each side; the motor mounting plate is arranged on the head, and the servo motor of the driving mechanism is mounted on the motor mounting plate; the speed reducer, the shaft coupling and the bearing seat of the driving mechanism are mounted in the head frame; the ball screw of the driving mechanism is mounted on the bearing seat and the cylindrical hole self-aligning ball bearing; the cylindrical hole self-aligning ball bearing is arranged in the fixing mechanism; and the tail of the fixing mechanism comprises the bottom mounting seat. Through the multi-directional uniform pressure scheme, the present application ensures the uniform distribution of pressure in the high-pressure environment, and meets the technical requirements of special battery formation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of battery production, in particular to a pressurized formation equipment for solid-state batteries. BACKGROUND

[0002] With the rapid development of new energy technology, solid-state batteries have gradually become an important development direction of next-generation battery technology due to their high energy density, long cycle life, and high safety advantages. In the manufacturing process of solid-state batteries, pressurized formation is a key step, which aims to fully contact the materials inside the battery by applying a certain pressure to ensure the performance and consistency of the battery. However, the existing pressurized formation equipment often has problems such as pressure and pressurization cycle not meeting performance requirements, uneven pressure distribution, poor adaptability, etc. when dealing with different models of solid-state batteries, resulting in substandard battery performance, and even possible damage to the battery surface.

[0003] The existing pressurized formation equipment usually adopts a single pressure application method, which is difficult to adapt to solid-state batteries of different sizes and shapes, especially when the length of the battery cell changes. The equipment cannot flexibly adjust the distance between the conductive clamps, resulting in uneven pressure distribution and affecting the formation effect of the battery. For example, Chinese utility model patent "Battery formation press clamp" (Application No. CN202020211679.X). In addition, the pressure control precision of traditional equipment in high pressure environment (such as greater than 50MPa) is insufficient, which is difficult to meet the formation requirements of special batteries, resulting in inconsistent performance of each single battery in the battery pack, affecting the overall performance of the battery pack. SUMMARY

[0004] In view of the blank of existing formation technology for solid-state batteries, the present application provides a pressurized formation equipment for solid-state batteries. Through the cooperative work of the pressurizing mechanism and the fixing mechanism, the present application ensures the uniform distribution of pressure in high pressure environment through the multi-directional pressure equalization scheme, and meets the technical requirements of special battery formation.

[0005] The technical scheme of the present application is: a pressurized formation equipment for solid-state batteries, comprising a fixing mechanism, a driving mechanism, a pressure plate mechanism, a pressurizing mechanism and an adjusting mechanism; the driving mechanism is installed on one side of the fixing mechanism, the driving mechanism is connected with the pressurizing mechanism, the pressurizing mechanism moves forward and backward by driving of the driving mechanism, the pressure plate mechanism is arranged in the cavity between the pressurizing mechanism and the fixing mechanism, the driving mechanism comprises a servo motor, a speed reducer, a shaft coupling, a bearing seat, a bearing locking nut and a ball screw, the servo motor is connected with the shaft coupling through the speed reducer, the bearing locking nut is arranged at the front part of the bearing seat, the ball screw is arranged inside the bearing locking nut, characterized in that: the adjusting mechanism is arranged on both sides of the pressure plate mechanism; the fixing mechanism comprises a motor mounting plate, a spring upper plate, a guide shaft assembly, a cylindrical hole self-aligning ball bearing, an equal-height guide shaft, a baffle, a bottom mounting seat and an inductor mounting plate, the head and tail of the fixing mechanism are connected through the equal-height guide shafts arranged symmetrically on both sides, there are 4 equal-height guide shafts in total, 2 on each side; the motor mounting plate is arranged at the head, the servo motor of the driving mechanism is mounted on the motor mounting plate, the speed reducer, the shaft coupling and the bearing seat of the driving mechanism are mounted in the head frame, and the ball screw of the driving mechanism is mounted on the cylindrical hole self-aligning ball bearing; the cylindrical hole self-aligning ball bearing is arranged inside the fixing mechanism; the tail of the fixing mechanism comprises the bottom mounting seat, the baffle and the spring upper plate are arranged at the front part of the bottom mounting seat, the baffle is used for mounting the photoelectric sensor, the spring upper plate is used for resisting the pressure conducted by the pressurizing mechanism through the pressure plate mechanism, so that the battery cell in the pressure plate mechanism receives the extrusion force from the pressurizing mechanism and the spring upper plate respectively; the guide shaft assembly is arranged at the rear side of the spring upper plate, the guide shaft assembly plays a guiding role on the spring upper plate during the extrusion of the battery cell; the spring lower plate is arranged behind the spring upper plate, and the rectangular spring is arranged between the spring upper plate and the spring lower plate; the pressurizing mechanism comprises a first moving pressure plate, a second moving pressure plate, a first linear bearing, a second linear bearing and an equal-height connecting shaft, the first moving pressure plate and the second moving pressure plate are connected through the four equal-height connecting shafts, four first linear bearings are arranged on the first moving pressure plate, four second linear bearings are arranged on the second moving pressure plate, the first linear bearings and the second linear bearings are respectively mounted on the equal-height guide shafts, and the second moving pressure plate is connected with the ball screw.

[0006] According to the pressurized formation equipment for solid-state batteries, characterized in that: a weighing sensor is arranged behind the spring lower plate, the weighing sensor monitors the pressure borne by the battery cell in real time and feeds back to the control system.

[0007] According to the pressurized formation equipment for solid-state batteries, characterized in that: a guide shaft and a shoulder hinge pin are arranged behind the spring lower plate, the guide shaft plays a guiding role on the spring lower plate, and the shoulder hinge pin prevents the spring lower plate from accidentally overflowing during maintenance.

[0008] The application discloses a pressurization formation equipment for solid-state batteries.

[0009] The application discloses a pressurization formation equipment for solid-state batteries.

[0010] The application discloses a pressurization formation equipment for solid-state batteries.

[0011] The application discloses a pressurization formation equipment for solid-state batteries.

[0012] The application discloses a pressurization formation equipment for solid-state batteries.

[0013] The application discloses a pressurization formation equipment for solid-state batteries.

[0014] The application discloses a pressurization formation equipment for solid-state batteries.

[0015] The beneficial effects of the present application are: the distance between the two sides of the conductive clamp can be adjusted according to the length of the battery cell, so that the device of the present application can adapt to different models of solid-state batteries. It is suitable for special batteries that can withstand more than 50MPa and maintain pressure for more than 24 hours, such as special batteries that can withstand 60MPa. The pressure deviation of different parts is less than 0.2%, which meets the technical index of special battery formation. The device is miniaturized, and can complete the formation of solid-state batteries with large pressure, and can meet the formation test of various models, thereby reducing the production cost of solid-state batteries. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present application.

[0017] Figure 2 It is an exploded view of each component of the present application.

[0018] Figure 3 It is a structural schematic diagram of the fixing mechanism.

[0019] Figure 4 It is another perspective view of the structural schematic diagram of the fixing mechanism.

[0020] Figure 5 It is a structural schematic diagram of the driving mechanism.

[0021] Figure 6 It is a structural schematic diagram of the pressing plate mechanism.

[0022] Figure 7 It is a structural schematic diagram of the pressure mechanism.

[0023] Figure 8 It is a structural schematic diagram of the adjusting mechanism.

[0024] Explanation of reference signs: fixing mechanism 1, motor mounting plate 11, spring upper plate 12, rectangular spring 121, spring lower plate 122, load cell 123, guide shaft assembly 13, guide shaft 131, shoulder hinge pin 132, cylindrical hole self-aligning ball bearing 14, isometric guide shaft 15, baffle 16, bottom mounting seat 17, deep groove ball bearing 171, vertical plate 172, helical gear 173, gear shaft 174, reinforcing rib plate 175, locking block 176, hand wheel 177, inductor mounting plate 18, driving mechanism 2, servo motor 21, speed reducer 22, shaft coupling 23, bearing seat 24, bearing locking nut 25, ball screw 26, pressing plate mechanism 3, heat insulation pad 31, sliding groove 32, first bearing plate 33, bolt 34, pressing plate 35, spring 36, pressurizing mechanism 4, first moving pressing plate 41, second moving pressing plate 42, first linear bearing 43, second linear bearing 44, anti-collision rod 45, isometric connecting shaft 46, inductor mounting plate 47, profile groove 48, adjusting mechanism 5, profile plate 51, connecting plate 52, second bearing plate 53, helical gear 54, linear bearing 55, fixed connecting plate 56, trapezoidal screw 57, second deep groove ball bearing 58, locking block 59. DETAILED DESCRIPTION

[0025] The technical solutions of the present application are further described below in combination with the drawings.

[0026] As shown in Figure 1 and Figure 2 , a pressurizing formation device for solid-state batteries of the present application comprises a fixing mechanism 1, a driving mechanism 2, a pressing plate mechanism 3, a pressurizing mechanism 4 and an adjusting mechanism 5; the driving mechanism 2 is installed on one side of the fixing mechanism 1, the driving mechanism 2 is connected with the pressurizing mechanism 4, the pressurizing mechanism 4 is driven to move forward and backward by the driving mechanism 2, the pressing plate mechanism 3 is arranged in the cavity between the pressurizing mechanism 4 and the fixing mechanism 1, and the pressurizing mechanism 4 applies pressure to the pressing plate mechanism 3 when moving forward. The adjusting mechanism 5 is arranged on both sides of the pressing plate mechanism 3, when the solid-state battery is changed, the length of the battery cell of the solid-state battery will change, and the adjusting mechanism 5 can adjust the distance between the two sides of the conductive clamp according to the length of the battery cell, so that the device of the present application can adapt to different models of solid-state batteries.

[0027] As shown in Figure 3 and Figure 4As shown, the fixing mechanism 1 of the present application includes a motor mounting plate 11, a spring upper plate 12, a guide shaft assembly 13, a guide shaft 131, a shoulder hinge pin 132, a cylindrical hole self-aligning ball bearing 14, an isometric guide shaft 15, a baffle plate 16, a bottom mounting seat 17, an inductor mounting plate 18, the head and tail of the fixing mechanism 1 are connected through the isometric guide shaft 15 symmetrically arranged on both sides, and the isometric guide shaft 15 has a total of 4, 2 on each side. The motor mounting plate 11 is arranged at the head, and the servo motor 21 of the driving mechanism 2 is installed on the motor mounting plate 11. The speed reducer 22, the shaft coupling 23 and the bearing seat 24 of the driving mechanism 2 are installed in the head frame, and the ball screw 26 of the driving mechanism 2 is installed on the cylindrical hole self-aligning ball bearing 14. The cylindrical hole self-aligning ball bearing 14 is arranged inside the fixing mechanism 1. The tail of the fixing mechanism 1 of the present application includes the bottom mounting seat 17, the front of the bottom mounting seat 17 is provided with the baffle plate 16 and the spring upper plate 12, the baffle plate 16 is used for installing the photoelectric sensor, and the spring upper plate 12 is used for resisting the pressure conducted by the pressing plate mechanism 3 through the pressing mechanism 4, so that the battery core in the pressing plate mechanism 3 respectively receives the extrusion force from the pressing mechanism 4 and the spring upper plate 12. The rear side of the spring upper plate 12 is respectively provided with the guide shaft assembly 13, and the guide shaft assembly 13 plays a guiding role on the spring upper plate 12 during the extrusion process of the battery core, so as to ensure that the battery core is uniformly pressed. The rear of the spring upper plate 12 is provided with a spring lower plate 122, and the spring upper plate 12 and the spring lower plate 122 are provided with a rectangular spring 121 therebetween. The deviation correction function and the buffering function of the rectangular spring 121 can eliminate the uneven pressure caused by the cumulative thickness deviation of the battery core and avoid the damage to the surface of the battery core. The rear of the spring lower plate 122 is provided with a load cell 123, and the load cell 123 can monitor the pressure borne by the battery core in real time and feedback to the control system. The rear of the spring lower plate 122 is provided with the guide shaft 131 and the shoulder hinge pin 132, the guide shaft 131 plays a guiding role on the spring lower plate 122, and the shoulder hinge pin 132 can prevent the spring lower plate 122 from accidentally overflowing during the maintenance process. After the above mechanism is installed, the cumulative thickness error of the battery core between the pressing plate mechanism 3 and the spring upper plate 12 can be eliminated, the battery core is uniformly pressed, and the surface of the battery core is avoided to be damaged. The bottom mounting seat 17 of the present application includes a deep groove ball bearing 171, a vertical plate 172, a helical gear 173, a gear shaft 174, a reinforcing rib plate 175, a hand wheel 177 and a locking block 176; the vertical plate 172 is perpendicular to the bottom, a plurality of reinforcing rib plates 175 are arranged at the rear of the vertical plate 172, so that the rear of the device of the present application can bear more than 50MPa. The vertical plate 172 is provided with the deep groove ball bearing 171, the rear side of the deep groove ball bearing 171 is connected with the helical gear 173 and the hand wheel 177 through the gear shaft 174, the distance between the profiled plates 51 on both sides of the adjusting mechanism 5 can be changed by adjusting the hand wheel 177, so as to adapt to different models of solid-state batteries. The locking block 176 of the present application is used for guiding the pressing plate mechanism 3.

[0028] As Figure 5As shown, the driving mechanism 2 of the present application includes a servo motor 21, a speed reducer 22, a shaft coupling 23, a bearing seat 24, a bearing locking nut 25, and a ball screw 26. The servo motor 21 is connected to the shaft coupling 23 through the speed reducer 22. The bearing locking nut 25 is arranged at the front of the bearing seat 24, and the ball screw 26 is arranged inside the bearing locking nut 25. Thus, the servo motor 21 can drive the ball screw 26. The ball screw 26 is connected to the pressing mechanism 4 through flanges, keys, keyways, and other structures. The pressing mechanism 4 is driven to move linearly forward or backward.

[0029] As shown, Figure 6 The pressing plate mechanism 3 includes heat insulation pads 31, sliding grooves 32, first bearing plates 33, bolts 34, pressing plates 35, and springs 36. The heat insulation pads 31 are arranged on both sides. The first bearing plates 33 are connected to the solid-state batteries. The bolts 34 are arranged on the first bearing plates 33. Adjacent first bearing plates 33 are connected to each other through moving plates. One side of the moving plate is fixed on the first bearing plate 33, and the other side is connected to the bolts 34 of the adjacent first bearing plate 33 through a groove. The bolts 34 can be external thread type high bolts. The pressing plates 35 are arranged on the upper part of the first bearing plates 33. Thus, the first bearing plates 33 can move relative to each other under the condition of pressure change. The sliding grooves 32 are arranged on the lower part of the first bearing plates 33. The springs 36 can also be arranged between adjacent first bearing plates 33 to have a moving tension between them, so as to facilitate the installation of the solid-state batteries into the pressing plate mechanism 3 with a certain clamping force.

[0030] As shown, Figure 7As shown, the pressing mechanism 4 of the present application includes a first moving pressing plate 41, a second moving pressing plate 42, a first linear bearing 43, a second linear bearing 44, an anti-collision rod 45, an isometric connecting shaft 46, and a sensor mounting plate 47. The first moving pressing plate 41 and the second moving pressing plate 42 are connected by four isometric connecting shafts 46. Four first linear bearings 43 are arranged on the first moving pressing plate 41, and four second linear bearings 44 are arranged on the second moving pressing plate 42. The first linear bearings 43 and the second linear bearings 44 are respectively installed on the isometric guide shafts 15. The second moving pressing plate 42 is connected with the ball screw 26 through flanges, keys, key grooves and other structures, so as to push the second moving pressing plate 42 to move linearly forward or backward. The force of the second moving pressing plate 42 can be evenly transmitted to the first moving pressing plate 41 through the isometric guide shafts 15 and the isometric connecting shafts 46, so that the pressure of the first moving pressing plate 41 can be evenly conducted to the heat insulation pad 31. Thus, the device of the present application can uniformly apply pressure to each part of the solid-state battery during the pressure test, ensuring that the performance of each single battery in the battery pack is consistent, and improving the overall performance of the battery pack. The device of the present application is suitable for special batteries that can withstand more than 50 MPa, such as special batteries that can withstand 60 MPa. Because the eight-directional pressure equalization scheme is adopted, the pressure deviation of different parts measured on the side of the vertical plate 172 is less than 0.2%, which meets the technical indicators of the special battery formation. The front part of the first moving pressing plate 41 can be provided with an anti-collision rod 45 to prevent the first moving pressing plate 41 from colliding with the fixing mechanism 1. The front side of the second moving pressing plate 42 can be provided with a sensor mounting plate 47, which is used to install the required sensors, such as position detection sensors, to measure the position information of the profile plate 51 when it is working.

[0031] As Figure 8As shown, the adjusting mechanism 5 of the present application comprises a profiled plate 51, a connecting plate 52, a second bearing plate 53, a helical gear 54, a linear bearing 55, a fixed connecting plate 56, a trapezoidal screw 57, a second deep groove ball bearing 58, and a locking block 59. The profiled plate 51 can be a 2040 profiled plate. The connecting plate 52 fixes the upper and lower profiled plates 51 together. The trapezoidal screw 57 is connected to the connecting plate 52 through the linear bearing 55. One end of the trapezoidal screw 57 is connected to the fixed connecting plate 56, and the other end is connected to the second bearing plate 53. The helical gear 54 is connected to the outer side of the trapezoidal screw 57 in the middle. The fixed connecting plate 56 and the second bearing plate 53 are fixedly connected to the fixing mechanism 1. By adjusting the helical gear 54, the connecting plate 52 moves on the trapezoidal screw 57, thereby adjusting the distance between the two conductive clamps. According to different battery models, the conductive clamps can be arranged on the profiled plate 51 at the corresponding positions of the battery cell charging and discharging. The distance can also be adjusted according to the length of the battery cell, thereby adjusting the distance between the two conductive clamps. The second bearing plate 53 is provided with the second deep groove ball bearing 58, and the trapezoidal screw 57 passes through the second deep groove ball bearing 58. The locking block 59 can also be arranged on the second bearing plate 53 for position locking after adjustment. In the present application, the profiled plate 51 is connected to the front and rear sides of the fixing mechanism 1 through the profiled groove 48 of the pressing mechanism 4, and the uniform force of the front and rear movement pressing plate is also considered, thereby realizing the miniaturization of the equipment, completing the large pressing of the solid-state battery formation, meeting the formation test of various models, and reducing the production cost of the solid-state battery.

Claims

1. A pressurized formation equipment for solid-state battery, comprising a fixing mechanism, a driving mechanism, a pressure plate mechanism, a pressurizing mechanism and an adjusting mechanism; the driving mechanism is installed on one side of the fixing mechanism, the driving mechanism is connected with the pressurizing mechanism, the pressurizing mechanism moves forward and backward by the driving mechanism, the pressure plate mechanism is arranged in the cavity between the pressurizing mechanism and the fixing mechanism, the driving mechanism comprises a servo motor, a speed reducer, a shaft coupling, a bearing seat, a bearing locking nut and a ball screw, the servo motor is connected with the shaft coupling through the speed reducer, the bearing locking nut is arranged at the front part of the bearing seat, and the ball screw is arranged in the bearing locking nut, characterized in that: The adjusting mechanism is arranged on both sides of the pressing plate mechanism; the fixing mechanism comprises a motor mounting plate, a spring upper plate, a guide shaft assembly, a cylindrical hole self-aligning ball bearing, an equal-height guide shaft, a baffle, a bottom mounting seat, an inductor mounting plate, a head and a tail of the fixing mechanism are connected through the equal-height guide shafts arranged symmetrically on both sides, and the equal-height guide shafts are four in total, two on each side; the motor mounting plate is arranged on the head, and a servo motor of the driving mechanism is mounted on the motor mounting plate; a speed reducer, a shaft coupling and a bearing seat of the driving mechanism are mounted in the head frame; a ball screw of the driving mechanism is mounted on the cylindrical hole self-aligning ball bearing; the cylindrical hole self-aligning ball bearing is arranged in the fixing mechanism; the tail of the fixing mechanism comprises the bottom mounting seat, the baffle and the spring upper plate are arranged on the front part of the bottom mounting seat, the baffle is used for mounting a photoelectric sensor, the spring upper plate is used for resisting the pressure conducted by the pressing mechanism through the pressing plate mechanism, so that the battery cell in the pressing plate mechanism receives extrusion forces from the pressing mechanism and the spring upper plate respectively; the guide shaft assembly is arranged on the rear side of the spring upper plate, and the guide shaft assembly plays a guiding role on the spring upper plate during the extrusion of the battery cell; the spring lower plate is arranged behind the spring upper plate, and the rectangular spring is arranged between the spring upper plate and the spring lower plate; the pressing mechanism comprises a first moving pressing plate, a second moving pressing plate, a first linear bearing, a second linear bearing and an equal-height connecting shaft, the first moving pressing plate and the second moving pressing plate are connected through the four equal-height connecting shafts, four first linear bearings are arranged on the first moving pressing plate, four second linear bearings are arranged on the second moving pressing plate, and the first linear bearings and the second linear bearings are respectively mounted on the equal-height guide shafts; the second moving pressing plate is connected with the ball screw.

2. A pressurized formation apparatus for solid-state batteries according to claim 1, characterized in that: A load cell is arranged behind the spring lower plate, and the load cell monitors the pressure borne by the battery cell in real time and feeds back to the control system.

3. The pressurized formation apparatus for solid-state batteries of claim 1, wherein: A guide shaft and a shoulder hinge pin are arranged behind the spring lower plate, the guide shaft plays a guiding role on the spring lower plate, and the shoulder hinge pin prevents the spring lower plate from accidentally overflowing during maintenance.

4. The pressurized formation apparatus for solid-state batteries of claim 1, wherein: The bottom mounting seat comprises a deep groove ball bearing, a vertical plate, a helical gear, a gear shaft, a reinforcing rib plate and a hand wheel; the vertical plate is perpendicular to the bottom, and a plurality of reinforcing rib plates are arranged on the rear part of the vertical plate; the deep groove ball bearing is arranged on the vertical plate, and the rear side of the deep groove ball bearing is connected with the helical gear and the hand wheel through the gear shaft; the distance between the profiled plates on both sides of the adjusting mechanism is changed by adjusting the hand wheel.

5. The pressurized formation apparatus for solid-state batteries of claim 1, wherein: An anti-collision rod is arranged on the front part of the first moving pressing plate, so as to prevent the first moving pressing plate from colliding with the fixing mechanism.

6. The pressurized formation apparatus for solid-state batteries of claim 1, wherein: An inductor mounting plate is arranged on the front side of the second moving pressing plate.

7. The pressurized formation apparatus for solid-state batteries of claim 1, wherein: The pressing plate mechanism comprises heat insulation pads, sliding grooves, first bearing plates, bolts and springs; the heat insulation pads are arranged on both sides; the first bearing plates are connected with the solid-state battery; the bolts are arranged on the first bearing plates; adjacent first bearing plates are connected with each other through moving plates; one side of the moving plate is fixed on the first bearing plate, and the other side is connected with the bolts of the adjacent first bearing plates through the grooves; the sliding grooves are arranged on the lower parts of the first bearing plates; and the springs are arranged between adjacent first bearing plates.

8. The pressurized formation apparatus for solid-state batteries of claim 7, wherein: The bolts are external thread type equal-height bolts.

9. The pressurized formation apparatus for solid-state batteries of claim 1, wherein: The adjusting mechanism comprises profiled plates, a connecting plate, a second bearing plate, a helical gear, a linear bearing, a fixed connecting plate and a trapezoidal screw, the connecting plate fixes the upper and lower profiled plates together, the trapezoidal screw is connected with the connecting plate through the linear bearing, one end of the trapezoidal screw is connected with the fixed connecting plate, the other end of the trapezoidal screw is connected with the second bearing plate, the helical gear is connected with the outer side of the trapezoidal screw, and the fixed connecting plate and the second bearing plate are fixedly connected on the fixing mechanism.

10. The pressurized formation apparatus for solid-state batteries of claim 9, wherein: Locking blocks are arranged on the second bearing plate and used for locking the position after adjustment, four profiled grooves are arranged on the pressing mechanism, and the profiled plates are connected on the front and rear sides of the fixing mechanism after penetrating through the profiled grooves.

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