Limiting device
By designing the base and moving parts of the limiting device, the problem of low adhesive limiting efficiency in the processing of large parts is solved, achieving efficient and convenient part fixing and cost reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SICHUAN ZHONGJING AEROSPACE TECH CO LTD
- Filing Date
- 2025-04-23
- Publication Date
- 2026-05-01
AI Technical Summary
Existing technologies using adhesives for limiting the size of large parts suffer from problems such as low efficiency, inconvenient cleaning, easy delamination, and high cost.
A limiting device, including a base and a moving part, is used to achieve detachable limiting of the parts through an acute-angled inclined surface and a through-hole structure, avoiding the use of adhesives.
It achieves efficient and convenient part positioning, avoids delamination problems, reduces costs, and improves processing efficiency.
Smart Images
Figure CN224182585U_ABST
Abstract
Description
A limiting device Technical Field
[0001] This utility model relates to the field of machining, and specifically to a limiting device. Background Technology
[0002] When machining large parts, it is difficult to clamp them using the corresponding tools when the parts are large in size. For example, when the size to be clamped is greater than 350 mm*350 mm, its size will be greater than the maximum clamping size of the jaws of the vise model. For this situation where the clamping size is exceeded, the existing technology usually uses adhesives to bond and fix the parts to the machining area of the machine tool in order to limit the position of the parts.
[0003] However, this method has several drawbacks: First, the time required for application and curing of adhesives is long, reducing processing efficiency and making cleaning inconvenient. Second, the bonding strength is affected by the type and properties of the adhesive, and parts are prone to delamination and movement during processing due to external forces such as cutting forces, increasing the scrap rate. Third, the utilization efficiency of the adhesive is low, and the cost is relatively high. Summary of the Invention
[0004] In view of this, the present invention provides a limiting device to solve the problems of low working efficiency, inconsistent adhesive cleaning, easy delamination, low utilization efficiency and high cost that easily occur when bonding and limiting parts with large dimensions in the prior art.
[0005] This utility model provides a limiting device, comprising: a base, including a top surface, a first bottom surface, and a first inclined surface, wherein the angle between the first inclined surface and the first bottom surface is a first included angle, the first included angle being acute; the first bottom surface being adapted to be fixedly connected to a support surface of the processing area where the part to be limited is located; and a first through hole extending toward the first bottom surface provided on the first inclined surface; and a movable member, including a second inclined surface, the second inclined surface having an adjustment state that abuts against the first inclined surface and slides along the first inclined surface under external force to move the movable member away from or toward the part to be limited; and a first through hole extending toward the first bottom surface provided on the second inclined surface. A second through hole is provided in the same direction as the first through hole. In the horizontal direction parallel to the support surface, the horizontal extension direction of the second through hole is in the same direction as the horizontal movement direction of the moving member relative to the base under the action of external force. A limiting fitting part is provided on the first through hole and the second through hole. A first limiting part is provided in the first through hole and the second through hole and is detachably connected to the limiting fitting part for limiting connection of the base and the moving member. An abutment part is provided on the moving member along the side of the moving member opposite to the second inclined surface and is suitable for abutting and limiting the member to be limited.
[0006] Beneficial effects:
[0007] The base is fixed to the support surface of the processing area where the component to be limited is located via the first bottom surface. The second inclined surface on the moving component is set to the adjustment state. Under external force, the second inclined surface is driven to move along the first inclined surface. The setting of the acute angle between the first inclined surface and the first bottom surface can convert the relative movement between the two inclined surfaces into the relative movement between the moving component and the base in the horizontal direction of the support surface.
[0008] Since the base is fixed to the support surface, the distance between the base and the component to be limited is fixed, and the abutment portion on the side of the moving member facing away from the second inclined surface can abut against the component to be limited, the moving member is positioned between the base and the component to be limited. Therefore, the movement of the moving member relative to the base can be correspondingly set to adjust the distance between the moving member and the component to be limited on the support surface. Furthermore, a first through hole and a second through hole are respectively provided on the first and second inclined surfaces. When the moving member is adjusted to a preset position abutting against the component to be limited, the first limiting portion passes through the two types of through holes, locking the movement of the moving member relative to the base and the component to be limited, thus effectively limiting the movement of the moving member relative to the component to be limited by the limiting device.
[0009] When multiple limiting devices are set in each direction around the part to be limited as needed, the part to be limited can be effectively limited. This setting can meet the effective limiting of parts of different sizes, and there is no need to use adhesive, apply or clean the structure, avoiding the problem of delamination. It is also easy to disassemble and adjust, with high work efficiency. At the same time, the device can be reused and the cost is low.
[0010] In one optional embodiment, the limiting fitting part includes: a first fitting part disposed on the inner wall of the first through hole, which is detachably fitted with the first limiting part for limiting; and a second fitting part disposed on the top side of the second through hole away from the support surface, which is adapted to accommodate the end of the first limiting part for limiting.
[0011] In one optional embodiment, the first limiting part is configured as a first screw; the first mating part is configured as an internal thread; the second through hole is configured as a countersunk hole; and the second mating part is configured as a countersunk head.
[0012] In one alternative implementation, the first included angle is set between 30 and 60 degrees.
[0013] In one alternative implementation, the second inclined surface is arranged parallel to the first inclined surface.
[0014] In one alternative implementation, the first included angle is 45 degrees.
[0015] In one optional embodiment, the base further includes: a connecting through hole extending from the top surface through the first bottom surface, with a third mating portion provided on its inner wall; and a second limiting portion extending into the connecting through hole and being limitedly connected to the third mating portion and the supporting surface.
[0016] In one alternative embodiment, the second limiting part is configured as a second screw; the connecting through hole is configured as a countersunk hole, and its top side away from the support surface is adapted to accommodate the end of the limiting part that limits the second limiting part.
[0017] In an optional embodiment, the limiting device further includes: at least one first guide structure disposed on the first inclined surface and extending in a direction away from the member to be limited; and at least one second guide structure disposed on the second inclined surface, corresponding to and cooperating with the first guide structure and movably limiting it, adapted to move along the first guide structure under the action of external force so as to align the first through hole and the second through hole.
[0018] In one alternative implementation, the first guide structure is provided as a guide groove and / or a guide rail.
[0019] In one alternative embodiment, the abutting portion is detachably limited to the movable member, and / or, the abutting portion is provided with an anti-slip portion on the side facing the member to be limited.
[0020] In one alternative embodiment, the anti-slip portion includes a plurality of anti-slip grooves.
[0021] In one optional embodiment, the base further includes a recessed portion disposed on the first bottom surface and along the periphery of the first through hole. Attached Figure Description
[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0023] Figure 1 is a three-dimensional structural schematic diagram of a limiting device according to an embodiment of the present utility model;
[0024] Figure 2 is an exploded view of the limiting device shown in Figure 1;
[0025] Figure 3 is a cross-sectional schematic diagram of the limiting device in Figure 1;
[0026] Figure 4 is a top view of the limiting device in Figure 1;
[0027] Figure 5 is a front view of the base of the limiting device in Figure 1;
[0028] Figure 6 is a top view of the base of the limiting device in Figure 5;
[0029] Figure 7 is a front view of the moving part of the limiting device in Figure 1;
[0030] Figure 8 is a schematic diagram of the abutment part of the limiting device in Figure 1;
[0031] Figure 9 is a cross-sectional schematic diagram of the abutment part of the limiting device in Figure 8;
[0032] Figure 10 is a structural schematic diagram of multiple limiting devices in Figure 1 limiting the component to be limited;
[0033] Figure 11 is a top view of the component to be limited by multiple limiting devices in Figure 10.
[0034] Figure 12 is a schematic diagram of the structure of the existing vise clamping the part to be limited;
[0035] Explanation of reference numerals in the attached figures:
[0036] 1. Base; 11. Top surface; 12. First bottom surface; 13. First inclined surface; 14. First through hole; 15. Connecting through hole; 16. Third mating part; 17. Second limiting part; 18. First guide structure; 19. Recessed part; 2. Moving part; 21. Second inclined surface; 22. Second through hole; 23. Second guide structure; 3. Limiting mating part; 31. First mating part; 32. Second mating part; 4. First limiting part; 5. Abutting part; 51. Anti-slip part; 6. Part to be limited. Detailed Implementation
[0037] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0038] Figure 12 shows a perspective view of using a vise of the prior art to clamp a component 6 to be limited. As shown in Figure 12, the component 6 to be limited is clamped and fixed between the two parallel jaws C1 and C2 of the vise for machining. The distance between the two parallel jaws of the vise can be adjusted to accommodate components 6 of different dimensions. The maximum distance between the two parallel jaws of the vise can be called the maximum clamping size. If the dimensions of the component 6 to be limited are larger than the maximum clamping size of the vise jaws, it is impossible to clamp the component 6 using the vise. The maximum distance between the two parallel jaws of a commonly used vise is 350 mm. Therefore, if the dimensions of the component 6 to be limited are larger than 350 mm * 350 mm, it is impossible to clamp the component 6 using a commonly used vise.
[0039] The embodiments of this utility model are described below with reference to Figures 1 to 11.
[0040] As shown in Figures 1-9, this utility model provides a limiting device, including: a base 1, a movable part 2, a first limiting part 4, and an abutting part 5.
[0041] The base 1 is block-shaped and includes a top surface 11, a first bottom surface 12, and a first inclined surface 13. The first inclined surface 13 is correspondingly disposed on the side of the base 1. The top surface 11 is opposite to the first bottom surface 12. Specifically, the first bottom surface 12 is adapted to be fixedly connected to the support surface of the processing area where the limiting member 6 is located. The fixing method is preferably a detachable connection, such as a screw connection, but it can also be a fixed connection, such as welding. The included angle between the first inclined surface 13 and the first bottom surface 12 is a first included angle, which is an acute angle. The first inclined surface 13 is provided with a first through hole 14 extending toward the first bottom surface 12. Preferably, the first through hole 14 is disposed along the vertical support surface, but it can also be offset from the support surface at a preset angle.
[0042] The movable component 2 is also block-shaped, including a second inclined surface 21. The second inclined surface 21 abuts against the first inclined surface 13 and slides along the first inclined surface 13 under external force, allowing the movable component 2 to move away from or towards the component to be limited 6 in an adjustable state. The second inclined surface 21 is provided with a second through hole 22 arranged in the same direction as the first through hole 14. In the horizontal direction parallel to the support surface, the horizontal extension direction of the second through hole 22 is in the same direction as the horizontal movement direction of the movable component 2 relative to the base 1 under external force. In this embodiment, the horizontal direction of the support surface refers to the plane direction of the support surface. In this embodiment, the second through hole 22 is preferably an elongated hole, with its two ends pointing towards the base 1 and the component to be limited 6, respectively.
[0043] The limiting fitting part 3 is provided on the first through hole 14 and the second through hole 22. The first limiting part 4 passes through the first through hole 14 and the second through hole 22 and is detachably limited and connected to the limiting fitting part 3, which is suitable for limiting the connection base 1 and the moving part 2.
[0044] The abutting part 5 is provided on the movable part 2, along the side of the movable part 2 facing away from the second inclined surface 21, and is suitable for abutting against the limiting part 6.
[0045] The base 1 is fixed to the support surface of the processing area where the limiting member 6 is located via the first bottom surface 12. The second inclined surface 21 on the moving member 2 is set to the adjustment state. Under external force, the second inclined surface 21 is driven to move along the first inclined surface 13. The angle between the first inclined surface 13 and the first bottom surface 12 is set to an acute angle, which can convert the relative movement between the two inclined surfaces into the relative movement between the moving member 2 and the base 1 in the horizontal direction of the support surface.
[0046] Since the base 1 is fixed on the support surface, the distance between the base 1 and the member to be limited 6 is fixed, and the abutment part 5 provided on the side of the moving member 2 facing away from the second inclined surface 21 can abut against the member to be limited 6, the moving member 2 is positioned between the base 1 and the member to be limited 6. Therefore, the movement of the moving member 2 relative to the base 1 can be correspondingly set to adjust the distance between the moving member 2 and the member to be limited 6 on the support surface. In addition, a first through hole 14 and a second through hole 22 are respectively provided on the first inclined surface 13 and the second inclined surface 21. When the moving member 2 is adjusted to the preset position abutting against the member to be limited 6, the first limiting part 4 passes through the two types of through holes to lock the movement of the moving member 2 relative to the base 1 and the member to be limited 6, thus completing the effective limiting of the limiting device on the side of the member to be limited 6.
[0047] When multiple limiting devices are set in each direction around the circumference of the part to be limited 6 as needed, the part to be limited 6 can be effectively limited. This setting can meet the effective limiting of parts to be limited 6 of different sizes, and there is no need to set adhesive, no need to apply or clean the structure, avoiding the problem of delamination. It is also convenient to disassemble and adjust, with high work efficiency. At the same time, the device can be reused and the cost is low.
[0048] As shown in Figures 10 and 11, during clamping, multiple limiting devices are respectively positioned on the four sides of the part 6 to be limited, and abut against and press against the four sides of the part 6 to be limited, thereby clamping the part 6 to be limited in the machining area of the machine tool. Two limiting devices are provided on each of the four sides of the part 6 to be limited. As an alternative implementation, other numbers of limiting devices can be provided on each of the four sides of the part 6 to be limited. For example, one, three, or more limiting devices can be provided on each of the four sides of the part 6 to be limited. As an alternative implementation, the number of limiting devices on the four sides of the part 6 to be limited can be different. As an alternative implementation, the number of limiting devices on one side of the four sides of the part 6 to be limited can be different from the number of limiting devices on another side. For example, one limiting device can be provided on one side of the four sides of the part 6 to be limited, and two limiting devices can be provided on another side.
[0049] In this embodiment, the limiting fitting part 3 includes: a first fitting part 31 and a second fitting part 32, wherein the first fitting part 31 is disposed on the inner wall of the first through hole 14 and is detachably fitted with the first limiting part 4 for limiting; the second fitting part 32 is disposed on the top side of the second through hole 22 away from the support surface and is suitable for accommodating the end of the first limiting part 4 for limiting.
[0050] Specifically, the first limiting part 4 is configured as a first screw; the first mating part 31 is configured as an internal thread; the second through hole 22 is configured as a countersunk hole; and the second mating part 32 is configured as a countersunk head. As an alternative implementation, the first mating part 31 and the second mating part 32 can be slots, and the first limiting part 4 can be a locking block, a barb, a pin, etc.
[0051] Preferably, the first included angle is set between 30 degrees and 60 degrees. Furthermore, the included angle between the second inclined surface 21 of the movable member 2 and the supporting surface is the second included angle, preferably between 30 degrees and 60 degrees.
[0052] In this embodiment, preferably, the second inclined surface 21 is arranged parallel to the first inclined surface 13. This arrangement increases the contact area between the first inclined surface 13 and the second inclined surface 21, avoids stress concentration, and improves structural stability. Experimental verification shows that when the first included angle is 45 degrees, and the second included angle is also 45 degrees, the stability of the limiting device is relatively high.
[0053] In addition, the base 1 also includes a connecting through hole 15 and a second limiting part 17. The connecting through hole 15 passes through the first bottom surface 12 from the top surface 11, and a third mating part 16 is provided on its inner wall; the second limiting part 17 passes through the connecting through hole 15 and is limitedly connected with the third mating part 16 and the support surface. Preferably, the connecting through hole 15 is provided along the vertical support surface, but it can also be offset from the support surface at a preset angle.
[0054] Preferably, a threaded hole is provided on the support surface, which is threadedly engaged with the second limiting part 17. Understandably, the support surface can also be connected to the second limiting part 17 by means of snap-fit or other methods.
[0055] As an alternative implementation, the connecting through hole 15 and the second limiting part 17 may be omitted, and the first limiting part 4 may pass through the first through hole 14 and the second through hole 22 and then be limited and connected to the support surface. In addition, the slope portion where the first inclined surface 13 is located may be separately or integrally provided with the main body portion of the base 1 provided with the connecting through hole 15 and the second limiting part 17.
[0056] Specifically, in this embodiment, the second limiting part 17 is configured as a second screw, and the connecting through hole 15 is countersunk, with its top side away from the support surface suitable for accommodating the end of the second limiting part 17. As an alternative implementation, the second limiting part 17 and the connecting through hole 15 can also be limiting structures such as a locking block and a locking groove.
[0057] As a variable implementation, the second limiting part 17 and the first limiting part 4, or one of them, can be provided in two or more, and can be matched with a corresponding number of through holes.
[0058] The limiting device further includes at least one first guide structure 18 and at least one second guide structure 23.
[0059] The first guide structure 18 is disposed on the first inclined surface 13 and extends in a direction away from the member to be limited 6; the second guide structure 23 is disposed on the second inclined surface 21, and corresponds to and is movable to limit the first guide structure 18, and is suitable for moving along the first guide structure 18 under the action of external force so as to align the first through hole 14 and the second through hole 22.
[0060] Preferably, the first guide structure 18 may be a guide groove, a guide rail, or both a guide groove and a guide rail. The first guide structure 18 is provided with a corresponding guide rail, guide groove, or both a guide rail and a guide groove.
[0061] As an alternative implementation, the first guide structure 18 and the second guide structure 23 may be omitted.
[0062] In one optional embodiment, the abutment portion 5 and the movable member 2 are detachably connected and restrained, which can be by snap-fit, adhesive, or integrally formed. Preferably, the movable member 2 has a screw hole on the side facing the member to be restrained 6 and on the abutment portion 5. The abutment portion 5 also has a countersunk groove, through which a screw is inserted to detachably restrain the abutment portion 5 and the movable member 2. The countersunk groove accommodates the end of the screw. Preferably, the side of the movable member 2 facing the member to be restrained 6 is perpendicular to the support surface.
[0063] Furthermore, an anti-slip portion 51 is provided on the side of the contact portion 5 facing the side of the member to be limited 6, to increase the friction between the contact portion 5 and the side of the member to be limited 6. Specifically, the anti-slip portion 51 includes a plurality of anti-slip grooves. The anti-slip grooves are preferably arranged in parallel. As an alternative embodiment, the anti-slip portion 51 may also include a plurality of anti-slip protrusions.
[0064] As an alternative implementation, the anti-slip part 51 and the abutting part 5 are detachably limited to the moving part 2, and only one of them may be provided.
[0065] The base 1 also includes a recess 19, which is disposed on the first bottom surface 12 and along the periphery of the first through hole 14. Preferably, the recess 19 may extend to the periphery of the connecting through hole 15.
[0066] Work process:
[0067] In operation, when it is necessary to clamp the part to be limited 6 (e.g., a large flat part), the part to be limited 6 can be placed on the support surface in the machining area of the machine tool. Then, a plurality of limiting devices according to the present disclosure are respectively provided on the four sides of the part to be limited 6. The limiting devices are provided on the support surface in the machining area of the machine tool such that the first bottom surface 12 of the base 1 of each limiting device rests on the support surface in the machining area of the machine tool, and the anti-slip part 51 of the abutment part 5 of each limiting device is close to the corresponding side of the part to be limited 6. Then, the second limiting part 17 can be screwed to fix the base 1 of each limiting device to the support surface in the machining area of the machine tool. Then, the first limiting part 4 can be screwed, and the screw head of the first limiting part 4 applies downward pressure on the moving part 2 of each limiting device, so that the moving part 2 of each limiting device and the abutment part 5 connected thereto move obliquely downward or obliquely upward relative to the base 1 along the interface between the second inclined surface 21 and the first inclined surface 13. The movement of the moving part 2 and the abutment part 5 connected thereto in each limiting device can be decomposed into movement toward or away from the support surface in the machining area of the machine tool, and movement toward or away from the corresponding side of the member to be limited 6. The movement toward the corresponding side of the member to be limited 6 causes the anti-slip part 51 of the abutment part 5 to abut against and press against the corresponding side of the member to be limited 6, thereby clamping the member to be limited 6 onto the support surface in the machining area of the machine tool.
[0068] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A limiting device, characterized in that, include: The base (1) includes a top surface (11), a first bottom surface (12), and a first inclined surface (13). The angle between the first inclined surface (13) and the first bottom surface (12) is a first included angle, which is an acute angle. The first bottom surface (12) is adapted to be fixedly connected to the support surface of the processing area where the limiting member (6) is located. The first inclined surface (13) is provided with a first through hole (14) extending toward the first bottom surface (12). The moving member (2) includes a second inclined surface (21). The second inclined surface (21) has an adjustment state that abuts against the first inclined surface (13) and slides along the first inclined surface (13) under external force, so that the moving member (2) moves away from or closer to the limiting member (6). The second inclined surface (21) is provided with a support surface that abuts against the first inclined surface (13) and slides along the first inclined surface (13) under external force, so that the moving member (2) moves away from or closer to the limiting member (6). The second inclined surface (21) is provided with a support surface that abuts against the first inclined surface (13) and slides along the first inclined surface (13) to make the moving member (2) move away from or closer to the limiting member (6). The second through hole (22) is arranged in the same direction as the through hole (14). In the horizontal direction parallel to the support surface, the horizontal extension direction of the second through hole (22) is arranged in the same direction as the horizontal movement direction of the moving member (2) relative to the base (1) under the action of external force. The limiting fitting part (3) is arranged on the first through hole (14) and the second through hole (22). The first limiting part (4) is inserted into the first through hole (14) and the second through hole (22) and is detachably limited and connected to the limiting fitting part (3), which is suitable for limiting and connecting the base (1) and the moving member (2). The abutting part (5) is arranged on the moving member (2) along the side of the moving member (2) away from the second inclined surface (21), which is suitable for abutting and limiting the member to be limited (6).
2. The limiting device according to claim 1, characterized in that, The limiting fitting part (3) includes: a first fitting part (31) disposed on the inner wall of the first through hole (14) and detachably fitting with the first limiting part (4) for limiting; and a second fitting part (32) disposed on the top side of the second through hole (22) away from the support surface, suitable for accommodating the end of the first limiting part (4) for limiting.
3. The limiting device according to claim 2, characterized in that, The first limiting part (4) is configured as a first screw; the first mating part (31) is configured as an internal thread; the second through hole (22) is configured as a countersunk hole; and the second mating part (32) is configured as a countersunk head.
4. The limiting device according to claim 1, characterized in that, The first included angle is set between 30 degrees and 60 degrees.
5. The limiting device according to claim 4, characterized in that, The second inclined surface (21) is arranged parallel to the first inclined surface (13).
6. The limiting device according to claim 5, characterized in that, The first included angle is 45 degrees.
7. The limiting device according to any one of claims 1-6, characterized in that, The base (1) further includes: a connecting through hole (15) that passes through the first bottom surface (12) from the top surface (11), and a third mating part (16) is provided on its inner wall; and a second limiting part (17) that passes through the connecting through hole (15) and is limitedly connected to the third mating part (16) and the supporting surface.
8. The limiting device according to claim 7, characterized in that, The second limiting part (17) is configured as a second screw; the connecting through hole (15) is countersunk, and its top side away from the support surface is adapted to accommodate the end of the limiting part (17).
9. The limiting device according to any one of claims 1-6 and 8, characterized in that, Also includes: At least one first guide structure (18) is disposed on the first inclined surface (13) and extends in a direction away from the limiting member (6); at least one second guide structure (23) is disposed on the second inclined surface (21) and corresponds to and is movable to limit the first guide structure (18), and is adapted to move along the first guide structure (18) under the action of external force so that the first through hole (14) and the second through hole (22) are aligned.
10. The limiting device according to claim 9, characterized in that, The first guide structure (18) is provided with a guide groove and / or a guide rail.
11. The limiting device according to any one of claims 1-6, 8, and 10, characterized in that, The abutting part (5) is detachably limited to the moving part (2), and / or, the abutting part (5) is provided with an anti-slip part (51) on the side facing the part to be limited (6).
12. The limiting device according to claim 11, characterized in that, The anti-slip part (51) includes a plurality of parallel anti-slip grooves.
13. The limiting device according to any one of claims 1-6, 8, 10, and 12, characterized in that, The base (1) further includes a recess (19) disposed on the first bottom surface (12) and disposed around the first through hole (14).