Welding carrier for automobile lamp circuit board shielding frame

Abstract

The invention discloses a welding carrier for a car lamp circuit board shielding frame, and belongs to the field of shielding frame welding, the welding carrier comprises a carrier base and an upper cover, a car lamp circuit board is placed on the carrier base, a placing groove for placing the shielding frame is formed in the side wall of the upper cover, and a fixing piece for fixing the shielding frame is arranged in the placing groove. A guide piece is arranged between the upper cover and the carrier base, and the upper cover and the carrier base are matched to be used for pressing a shielding frame on a vehicle lamp circuit board. The method has the effect of improving the positioning precision and the fitting degree between the shielding frame and the PCB in the welding process.

Description

Technical Field

[0001] This application relates to the technical field of shielded frame welding, and in particular to a welding carrier for a shielded frame of a vehicle lamp circuit board. Background Art

[0002] With the rapid development of automotive electronic technology, in-vehicle LED lighting systems have gradually become an important part of modern vehicles. As one of the key components, the performance of the PCB board directly affects the stability and reliability of the entire lighting system. To meet the electromagnetic compatibility requirements in high-frequency signal environments, shielded frames are widely used in the design of PCB boards to suppress electromagnetic interference and ensure the normal operation of the circuit. The global market scale of in-vehicle LED lighting is constantly expanding, driving the rapid development of related supporting equipment and technologies. Especially in the field of welding processes, the demand for high precision and high efficiency is increasing day by day.

[0003] Currently, the industry generally uses laser welding or reflow soldering processes to achieve the permanent connection between the shielded frame and the circuit board. During the high-precision welding process, the welding carrier is prone to problems such as thermal deformation and positioning drift, resulting in unstable welding quality. Especially on PCB boards with multiple shielded frames, the phenomenon of false soldering is relatively common. These problems not only affect the electrical performance of the product but also increase the defect rate during the production process, thus restricting the further improvement of production efficiency. Therefore, how to improve the positioning accuracy and stability between the shielded frame and the PCB board during the welding process has become a technical problem to be solved urgently. Summary of the Invention

[0004] In order to improve the positioning accuracy and fitting degree between the shielded frame and the PCB board during the welding process, this application provides a welding carrier for a shielded frame of a vehicle lamp circuit board.

[0005] The welding carrier for a shielded frame of a vehicle lamp circuit board provided by this application adopts the following technical solutions: A welding carrier for a shielded frame of a vehicle lamp circuit board includes a carrier base and an upper cover. The vehicle lamp circuit board is placed on the carrier base. A shielded frame placement groove is provided on the side wall of the upper cover. A fixing member for fixing the shielded frame is arranged in the placement groove. A guiding member is arranged between the upper cover and the carrier base. The upper cover and the carrier base cooperate to press the shielded frame on the vehicle lamp circuit board.

[0006] By adopting the above technical solution, before welding, the staff first place the headlight circuit board on the carrier base, and then place the shielding frame in the placement groove on the upper cover. The shielding frame is fixed in position under the action of the fixing member, which is convenient for the staff to install the shielding frame on the headlight circuit board. Then, the staff flip the upper cover, align the shielding frame in the upper cover with the headlight circuit board on the carrier base through the guiding member, and after tightening the upper cover on the carrier base, place it in the welding pool to weld between the shielding frame and the headlight circuit board, thereby reducing the occurrence of problems such as poor soldering and offset, and further improving the welding quality.

[0007] Preferably, a limiting groove for placing the headlight circuit board is provided on the carrier base.

[0008] By adopting the above technical solution, the staff place the headlight circuit board in the limiting groove, and the limiting groove can limit the movement of the headlight circuit board, which is beneficial to align the shielding frame with the headlight circuit board, thereby reducing the deviation of welding and improving the welding quality.

[0009] Preferably, the fixing member is a magnet, the magnet is fixed on the inner wall of the placement groove, the number and distribution of the magnets are set according to the size and shape of the shielding frame, and the magnet attracts the shielding frame.

[0010] By adopting the above technical solution, the magnet can fix the shielding frame in the placement groove, so that when it is flipped and abuts against the carrier base, the shielding frame does not fall off. At the same time, it can avoid problems such as position offset during welding, reduce the occurrence of poor soldering and welding deviation, and improve the welding quality.

[0011] Preferably, the guiding member is four guide posts, the four guide posts are respectively fixedly connected to the four corners of the upper cover, and guide holes for inserting the guide posts are correspondingly provided at the four corners of the carrier base.

[0012] By adopting the above technical solution, the guide posts and guide holes are provided for positioning the upper cover and the carrier base to ensure that the relative positions of the upper cover and the carrier base are the same every time welding is performed.

[0013] Preferably, a buffer plate is arranged in the carrier base, the buffer plate slides in the limiting groove, and a plurality of buffer springs are arranged between the buffer plate and the limiting groove, and the headlight circuit board abuts against the buffer plate.

[0014] By adopting the above technical solution, the buffer plate and the buffer springs can effectively avoid the situation that the headlight circuit board is squeezed when the upper cover and the carrier base are connected. At the same time, the buffer springs and the buffer plate can push the headlight circuit board and the shielding frame to fit tightly, improving the welding quality.

[0015] Preferably, a layer of flexible material is provided on the upper surface of the buffer plate.

[0016] By adopting the above technical solution, the flexible material can avoid rigid contact between the buffer plate and the headlight circuit board, and avoid causing friction or damage to the headlight circuit board.

[0017] Preferably, a first magnetic strip is fixedly connected to the upper cover, a groove is formed in the carrier base, a second magnetic strip is arranged in the groove, and the first magnetic strip and the second magnetic strip are magnetically different and attract each other.

[0018] By adopting the above technical solution, when the upper cover and the carrier base are connected through guide posts and guide holes, the first magnet is inserted into the groove and attracts the second magnet, so that the upper cover and the carrier base can be closely attached, thereby improving the fitting degree between the shielding frame and the headlight circuit board.

[0019] Preferably, connecting blocks and connecting grooves are respectively arranged on the opposite side walls of the carrier base. The two carrier bases can be placed adjacent to each other. The connecting block is inserted into the adjacent connecting groove, and a fixing component fixed to the inner wall of the connecting groove is arranged on the connecting block.

[0020] By adopting the above technical solution, the connecting block on one side of the carrier base is inserted into the connecting groove of another carrier base, and under the action of the fixing component, the two carrier bases are fixedly connected, so that multiple shielding frames can be welded at one time according to the size of the welding pool, thereby improving the welding efficiency.

[0021] Preferably, the fixing component includes a fixing block and a fixing spring. A placement groove is formed in the side wall of the connecting block. The fixing spring is arranged in the placement groove. The fixing block is slidably connected in the placement groove, and one end of the fixing spring is fixedly connected to the side wall of the fixing block. A first inclined surface is arranged on the fixing block, and the first inclined surface abuts against the side wall of the carrier base. A fixing groove for inserting the fixing block is arranged in the connecting groove, and a releasing component for releasing the fixing effect of the fixing block is arranged on the side wall of the carrier base.

[0022] By adopting the above technical solution, when the staff inserts the connecting block on the carrier base into the connecting groove on another carrier base, the first inclined surface on the fixing block abuts against the inner wall of the connecting groove and pushes the fixing block to compress the fixing spring and move into the placement groove. When the fixing block is completely in the placement groove, the connecting block is inserted into the connecting groove. At this time, the fixing block is aligned with the fixing groove, and the fixing block is inserted into the fixing groove under the thrust of the fixing spring, thereby reducing the possibility of the connecting block disengaging from the connecting groove, and further connecting the adjacent carrier bases.

[0023] Preferably, the unlocking component includes a built-in block, a push rod and a limiting spring. The built-in block is slidably connected to the inner wall of the fixed groove. A limiting block is fixedly connected to the side wall of the built-in block, and a limiting groove for the limiting block to slide is formed in the inner wall of the fixed groove. A second inclined surface is provided on the built-in block. The push rod penetrates and slides in the fixed groove. The limiting spring is sleeved on the push rod. A pulling block is fixedly connected to the end of the push rod. Two ends of the limiting spring are respectively fixedly connected to the pulling block and the side wall of the carrier base. An abutting block slides in the inner wall of the connecting groove. A reset spring is arranged between the abutting block and the inner wall of the connecting groove. The connecting block abuts against the abutting block.

[0024] By adopting the above technical solution, when the connecting block is inserted into the connecting groove, the connecting block will abut against and push the abutting block to compress the reset spring. When the staff needs to disassemble multiple connected carrier bases, the staff pushes the push rod to move towards the carrier base to compress the limiting spring. The movement of the push rod pushes the built-in block to move downward through the second inclined surface. The downward movement of the built-in block pushes the fixing block to move downward to compress the fixing spring. When the fixing block is pushed into the placement groove, at this time, the abutting block pushes the connecting block out of the connecting groove under the action of the reset spring, so that the fixing block moves away from the fixed groove and abuts against the inner wall of the connecting groove, thereby facilitating the staff to separate two adjacent carrier bases.

[0025] In summary, the present application includes at least one of the following beneficial technical effects: 1. Before welding, the staff first places the headlight circuit board on the carrier base, and then places the shielding frame in the placement groove on the upper cover. The shielding frame is fixed in position under the action of the fixing member, which is convenient for the staff to install the shielding frame on the headlight circuit board. Then, the staff flips the upper cover, aligns the shielding frame in the upper cover with the headlight circuit board on the carrier base through the guiding member, and after tightening the upper cover on the carrier base, puts it into the welding pool to weld between the shielding frame and the headlight circuit board, thereby reducing the occurrence of problems such as poor soldering and offset, and further improving the welding quality; 2. The magnet can fix the shielding frame in the placement groove, so that when it is flipped and abuts against the carrier base, the shielding frame does not fall off. At the same time, during welding, problems such as position offset can be avoided, and situations such as poor soldering and welding deviation can be reduced, improving the welding quality; 3. The arrangement of the guide posts and guide holes is used to position the upper cover and the carrier base to ensure that the relative positions of the upper cover and the carrier base are consistent during each welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is an exploded view of the structure in Embodiment 1 of the present application.

[0027] Figure 2 is a schematic diagram of the structure of the placement groove on the upper cover highlighted in Embodiment 1 of the present application.

[0028] Figure 3 It is a cross-sectional view of the overall structure of the second embodiment of the present application.

[0029] Figure 4 It is a schematic structural diagram of the protruding fixing component in the third embodiment of the present application.

[0030] Explanation of the reference numerals in the drawings: 1. Vehicle base; 2. Upper cover; 3. Placing groove; 4. Restricting groove; 5. Guide post; 6. Guide hole; 7. Buffer plate; 8. Buffer spring; 9. First magnetic strip; 10. Groove; 11. Second magnetic strip; 12. Connecting block; 13. Connecting groove; 14. Fixing component; 15. Fixing block; 16. Fixing spring; 17. Placing groove; 18. First inclined surface; 19. Fixing groove; 20. Release component; 21. Built-in block; 22. Push rod; 23. Restricting spring; 24. Limiting block; 25. Limiting groove; 26. Second inclined surface; 27. Pulling block; 28. Abutting block; 29. Reset spring; 30. Magnet; 31. Shielding frame; 32. Circuit board. Detailed implementation manners

[0031] The following further elaborates on the present application in conjunction with the attached Figures 1-4 drawings.

[0032] Embodiment 1 Embodiment 1 of the present application discloses a welding carrier for a shielding frame 31 of a vehicle lamp circuit board 32. As Figure 1 and Figure 2 shown, it includes a vehicle base 1 and an upper cover 2. The circuit board 32 is placed on the vehicle base 1, and a restricting groove 4 for placing the circuit board 32 is formed on the vehicle base 1. Four vehicle lamp circuit boards 32 are arranged on a square circuit board 32, and a cross groove is formed among the four vehicle lamp circuit boards 32. The placing groove 3 in the restricting groove 4 of the vehicle base 1 is evenly divided into four parts by a cross shape. When the circuit board 32 is placed in the restricting groove 4, each part corresponds to a vehicle lamp circuit board 32; the restricting groove 4 clamps the circuit board 32 therein, reducing the possibility of the circuit board 32 moving and shifting when connecting with the shielding frame 31.

[0033] As Figure 2As shown in the figure, placing grooves 3 for placing shielding frames 31 are formed on the side walls of the upper cover 2. The number of placing grooves 3 is the same as that of the vehicle lamp circuit boards 32. Four shielding frames 31 can be placed on one upper cover 2. Fixing members for fixing the shielding frames 31 are arranged in the placing grooves 3. The fixing members are magnets 30. The number and distribution of the magnets 30 are set according to the size and shape of the shielding frames 31. The magnets 30 can cooperate with the shielding frames 31. Guide members are arranged between the upper cover 2 and the vehicle base 1. The guide members are four guide posts 5. The guide posts 5 are cylindrical and are vertically arranged on the surface of the upper cover 2. The four guide posts 5 are respectively fixedly welded at the four corners of the upper cover 2. Corresponding guide holes 6 for inserting the guide posts 5 are formed at the four corners of the vehicle base 1. The guide posts 5 are inserted into the guide holes 6.

[0034] The principle of the first implementation of the embodiment of the present application is as follows: Before welding, the staff first place the circuit board 32 in the limiting groove 4 on the vehicle base 1, and then place the shielding frame 31 in the placing groove 3 on the upper cover 2. The shielding frame 31 maintains a stable position under the action of the magnet 30. When it is turned over and abuts against the vehicle base 1, the shielding frame 31 does not fall off. Subsequently, the staff turn over the upper cover 2, face one side of the shielding frame 31 towards the circuit board 32, and insert it into the corresponding guide hole 6 on the vehicle base 1 through the guidance of the guide posts 5, so that the vehicle base 1 and the upper cover 2 are aligned. The upper cover 2 is tightly covered on the vehicle base 1 so that the shielding frame 31 is closely attached to the vehicle lamp circuit board 32, and then it is placed in a welding pool to weld between the shielding frame 31 and the vehicle lamp circuit board 32, thereby reducing the occurrence of problems such as false soldering and offset, and further improving the welding quality.

[0035] Embodiment 2 As Figure 3 shown, a buffer plate 7 slides in the limiting groove 4 inside the vehicle base 1. A layer of flexible material is arranged on the upper surface of the buffer plate 7. The flexible material can be ceramic fiber, flexible graphite, superalloy fiber material, silicon carbide fiber material, etc. These materials are not only high-temperature resistant, but also have stable properties and certain soft properties. A buffer spring 8 is fixedly welded to the bottom inner wall of the limiting groove 4. The other end of the buffer spring 8 is fixedly connected to the lower end surface of the buffer plate 7. The circuit board 32 abuts against the flexible material on the buffer plate 7. The flexible material can prevent the buffer plate 7 from rigidly contacting the vehicle lamp circuit board 32 and avoid causing friction or damage to the vehicle lamp circuit board 32. A first magnetic strip 9 is fixedly arranged on the surface of the upper cover 2, that is, on the same side wall as the shielding frame 31. A groove 10 corresponding to the first magnetic strip 9 is formed on the same side wall of the vehicle base 1 and the circuit board 32. A second magnetic strip 11 is fixedly arranged on the bottom inner wall of the groove 10. The first magnetic strip 9 and the second magnetic strip 11 have different magnetic polarities and attract each other.

[0036] The implementation principle of the second embodiment of this application is as follows: when the staff covers the upper cover 2 on the carrier base 1, the first magnetic strip 9 is inserted into the groove 10, and the first magnetic strip 9 and the second magnetic strip 11 attract and fit with each other. At the same time, the upper cover 2 and the carrier base 1 are tightly fitted, so that the shielding frame 31 is tightly fitted to the circuit board 32. At the same time, under the action of the buffer spring 8, the buffer plate 7 can not only prevent the shielding frame 31 from exerting too much pressure on the circuit board 32 and causing extrusion, but also push the circuit board 32 to fit against the buffer plate of the shielding frame 31, thereby improving the fitting degree between the shielding frame 31 and the circuit board 32, and further improving the welding quality.

[0037] Embodiment Three As Figure 4 shown, two sets of connection blocks 12 and connection grooves 13 are respectively arranged on the side wall of the carrier base 1. When two carrier bases 1 are placed horizontally adjacent to each other, the connection block 12 on one carrier base 1 can be inserted into the connection groove on the adjacent carrier base 1 to connect the two carrier bases 1. Thus, the number of connected carrier bases 1 can be adjusted according to the size of the welding pool, and then multiple carrier bases 1 can be placed in one welding pool to weld multiple circuit boards 32 at the same time, improving the welding efficiency. A fixing component 14 fixed to the inner wall of the connection groove 13 is arranged on the connection block 12. The fixing component 14 includes a fixing block 15 and a fixing spring 16. A placement groove 17 is formed on the side wall of the connection block 12. The fixing block 15 is slidably connected to the placement groove 17 in the vertical direction. The fixing spring 16 is arranged in the placement groove 17 in the vertical direction, and its two ends are respectively fixedly welded to the bottom end of the fixing block 15 and the inner wall of the bottom of the placement groove 17. The top end of the fixing block 15 is provided with a first inclined surface 18, and the first inclined surface 18 abuts against the inner wall of the connection groove 13. A fixing groove 19 for inserting the fixing block 15 is arranged on the inner wall of the connection groove 13 in the vertical direction. A contact block 28 is slidably arranged in the connection groove 13, a return spring 29 is arranged in the connection groove 13 in the horizontal direction, and the connection block 12 abuts against the contact block 28.

[0038] As Figure 4 shown, a release component 20 for releasing the fixing effect of the fixing block 15 is arranged on the side wall of the carrier base 1. The release component 20 includes an inner block 21, a push rod 22 and a limiting spring 23. The inner block 21 is slidably connected to the inner wall of the fixing groove 19 in the vertical direction. A limiting block 24 is fixedly welded to the side wall of the inner block 21. A limiting groove 25 for the limiting block 24 to slide is formed in the fixing groove 19 in the vertical direction. A second inclined surface 26 is arranged at the top of the inner block 21. The push rod 22 penetrates and slides in the fixing groove 19 in the horizontal direction. A pull block 27 is fixedly welded to the end of the push rod 22 away from the inner block 21. The limiting spring 23 is arranged horizontally and sleeved on the push rod 22. The two ends of the limiting spring 23 are respectively fixedly welded to the pull block 27 and the side wall of the carrier base 1 with a contact block 28.

[0039] The implementation principle of the third embodiment of this application is as follows: When the staff needs to splice the vehicle base 1, the staff inserts the connecting block 12 on the vehicle base 1 into the connecting groove 13 on another vehicle base 1. The first inclined surface 18 on the fixing block 15 abuts against the inner wall of the connecting groove 13 and pushes the fixing block 15 to compress the fixing spring 16 and move into the placement groove 17. After the connecting block 12 is inserted into the connecting groove 13, it will abut against the abutting block 28 and push the abutting block 28 to compress the return spring 29 and move until the fixing block 15 is aligned with the fixing groove 19. At this time, the fixing block 15 is inserted into the fixing groove 19 under the thrust of the fixing spring 16 and pushes the built-in block 21 to move upward. At this time, the connecting block 12 is fixed in the connecting groove 13, and two adjacent vehicle bases 1 are fixedly connected to each other. When the staff needs to disassemble multiple connected vehicle bases 1, the staff pushes the push rod 22 along the horizontal direction through the pulling block 27 to compress the limiting spring 23 and move toward the vehicle base 1. The movement of the push rod 22 pushes the built-in block 21 to move downward through the second inclined surface 26. The downward movement of the built-in block 21 pushes the fixing block 15 to compress the fixing spring 16 and move. When the fixing block 15 is pushed into the placement groove 17, at this time, the abutting block 28 pushes the connecting block 12 out of the connecting groove 13 under the action of the return spring 29, so that the fixing block 15 moves away from the fixing groove 19 and abuts against the inner wall of the connecting groove 13, facilitating the staff to separate two adjacent vehicle bases 1.

[0040] In this application, only the shielding frame 31 and the circuit board 32 in the solder pool undergo a welding reaction, and the rest of the structures are made of inert materials and will not react or be welded in the solder pool.

[0041] The above are all the preferred embodiments of this application. The protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A welding carrier for a shielding frame (31) of a vehicle lamp circuit board (32), characterized in that: It includes a vehicle base (1) and an upper cover (2). The vehicle lamp circuit board (32) is placed on the vehicle base (1). A placement groove (3) for placing a shielding frame (31) is formed on the side wall of the upper cover (2). A fixing member for fixing the shielding frame (31) is arranged in the placement groove (3). A guiding member is arranged between the upper cover (2) and the vehicle base (1). The upper cover (2) and the vehicle base (1) cooperate to press the shielding frame (31) on the vehicle lamp circuit board (32).

2. The welding carrier for the shielding frame (31) of the vehicle lamp circuit board (32) according to claim 1, characterized in that: A limiting groove (4) for placing the vehicle lamp circuit board (32) is formed on the vehicle base (1).

3. A welding carrier for a shielding frame (31) of a vehicle lamp circuit board (32) according to claim 1, characterized in that: The fixing member is a magnet (30). The magnet (30) is fixed on the inner wall of the placement groove (3). The quantity and distribution of the magnets (30) are set according to the size and shape of the shielding frame (31). The magnet (30) and the shielding frame (31) attract each other.

4. A soldering carrier for a shielding frame (31) of a vehicle lamp circuit board (32) according to claim 1, characterized in that: The guiding member is four guide posts (5). The four guide posts (5) are respectively fixedly connected to four corners of the upper cover (2). Guide holes (6) for inserting the guide posts (5) are correspondingly formed at four corners of the vehicle base (1).

5. A welding carrier for a shielding frame (31) of a vehicle lamp circuit board (32) according to claim 2, characterized in that: A buffer plate (7) is arranged in the vehicle base (1). The buffer plate (7) slides in the limiting groove (4). A plurality of buffer springs (8) are arranged between the buffer plate (7) and the limiting groove (4). The vehicle lamp circuit board (32) abuts against the buffer plate (7).

6. A welding carrier for a shielding frame (31) of a vehicle lamp circuit board (32) according to claim 5, characterized in that: A layer of flexible material is arranged on the upper surface of the buffer plate (7).

7. A welding carrier for a shielding frame (31) of a vehicle lamp circuit board (32) according to claim 1, characterized in that: A first magnetic strip (9) is fixedly connected to the upper cover (2). A groove (10) is formed on the vehicle base (1). A second magnetic strip (11) is arranged in the groove (10). The first magnetic strip (9) and the second magnetic strip (11) have different magnetic polarities and attract each other.

8. A welding carrier for a shielding frame (31) of a vehicle lamp circuit board (32) according to claim 1, characterized in that: Connecting blocks (12) and connecting grooves (13) are respectively arranged on opposite side walls of the vehicle base (1). Two vehicle bases (1) can be placed adjacent to each other. The connecting block (12) is inserted into the adjacent connecting groove (13). A fixing assembly (14) fixed to the inner wall of the connecting groove (13) is arranged on the connecting block (12).

9. A soldering carrier for a shielding frame (31) of a vehicle lamp circuit board (32) according to claim 8, characterized in that: The fixing assembly (14) includes a fixing block (15) and a fixing spring (16). A placement groove (17) is formed on the side wall of the connecting block (12). The fixing spring (16) is arranged in the placement groove (17). The fixing block (15) is slidably connected in the placement groove (17) and one end of the fixing spring (16) is fixedly connected to the side wall of the fixing block (15). A first inclined surface (18) is arranged on the fixing block (15). The first inclined surface (18) abuts against the side wall of the vehicle base (1). A fixing groove (19) for inserting the fixing block (15) is arranged in the connecting groove (13). A releasing assembly (20) for releasing the fixing effect of the fixing block (15) is arranged on the side wall of the vehicle base (1).

10. A welding carrier for a shielding frame (31) of a vehicle lamp circuit board (32) according to claim 9, characterized in that: The release component (20) includes a built-in block (21), a push rod (22), and a limiting spring (23). The built-in block (21) is slidably connected to the inner wall of the fixed groove (19). A limiting block (24) is fixedly connected to the side wall of the built-in block (21). A limiting groove (25) for the limiting block (24) to slide is formed in the inner wall of the fixed groove (19). A second inclined surface (26) is provided on the built-in block (21). The push rod (22) passes through and slides in the fixed groove (19). The limiting spring (23) is sleeved on the push rod (22). A pulling block (27) is fixedly connected to the end of the push rod (22). The two ends of the limiting spring (23) are respectively fixedly connected to the pulling block (27) and the side wall of the vehicle base (1). An abutting block (28) slides on the inner wall of the connecting groove (13). A reset spring (29) is arranged between the abutting block (28) and the inner wall of the connecting groove (13). The connecting block (12) abuts against the abutting block (28).

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