WO2022218055A1

WO2022218055A1 - Upper cover of washing machine and washing machine

Info

Publication number: WO2022218055A1
Application number: PCT/CN2022/079216
Authority: WO
Inventors: 李文明; 韩珊珊; 刘让雷; 赵成龙
Original assignee: 重庆海尔洗衣机有限公司; 海尔智家股份有限公司
Priority date: 2021-04-14
Filing date: 2022-03-04
Publication date: 2022-10-20
Also published as: CN113279221A; JP2024517392A

Abstract

Provided is an upper cover of a washing machine. A hinged base (2) protruding outwards is arranged at a rear end of the upper cover, and is provided with a plurality of vertically penetrating water diversion openings (3); and the periphery of each water diversion opening is provided with a retaining rib (4) higher than the water diversion opening. The retaining ribs are arranged at the water diversion openings of the upper cover of the washing machine, such that a water flow flowing onto the hinged base is collected at the water diversion openings, and is prevented from splashing into the washing machine and damaging an internal element of the washing machine. In addition, further provided is a washing machine equipped with the upper cover of a washing machine.

Description

A washing machine cover and washing machine

technical field

The invention belongs to the field of household appliances, and in particular relates to a washing machine upper cover and a washing machine.

Background technique

The purpose of the micro switch on the washing machine is to ensure that during the washing process of the washing machine, especially during the dehydration process, when the user suddenly opens the washing machine cover or the tub is running eccentrically, the detection signal is quickly transmitted to the washing machine controller and controls the washing machine. Stop the rotation, so as to avoid the injury of the high-speed rotating tub to the user or the impact on the washing machine box when the eccentricity is large.

At present, in order to save costs, the existing washing machines generally use the opening and closing of the micro switch to identify the opening and closing of the upper cover. However, the use of the micro switch has a significant disadvantage: because the cooperation between the upper cover and the tray is movable Therefore, there will be a large gap between the two, and the micro switch is directly in contact with the upper cover, and the metal sheet of the micro switch is directly exposed, so when water is poured between the upper cover and the disc seat When opening and closing the upper cover, water may touch the metal sheet of the micro switch, posing a safety hazard.

In view of this, the present invention is proposed.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art, and to provide a washing machine upper cover and a washing machine, which can prevent the water between the gap between the upper cover and the tray base from contacting the metal sheet of the micro switch, and realize the protection of the micro switch. The overflow protection function improves the product service life of the micro switch, and also ensures the product quality of the washing machine.

In order to solve the above-mentioned technical problems, the basic conception of the technical scheme adopted in the present invention is:

An upper cover of a washing machine, the rear end of the upper cover is provided with a hinge seat protruding outwards, the hinge seat is provided with a plurality of water diversion openings that pass through up and down, and the outer circumference of the water diversion opening is provided with a retaining rib higher than the water diversion opening .

Further, the retaining rib protrudes upward and encloses a water diversion chamber with an upward opening.

Further, one side of the water diversion chamber is provided with a vertical rib extending up and down, the lower end of the vertical rib is provided with a horizontally bent hem, and the highest part of the vertical rib is higher than the retaining rib;

Preferably, the vertical rib and the retaining rib are arranged in close contact with each other;

Further preferably, the vertical rib and the retaining rib are integrally formed.

Further, the upper plane of the folded edge is provided with a plurality of grooves through which the water flows.

Further, a plurality of downwardly extending water guiding grooves are arranged along the inner wall of the water guiding port, and the water guiding grooves extend along the vertical rib to the folded end.

Further, the water diversion grooves on the lower plane of the folded edge and the grooves on the upper plane of the folded edge are arranged staggered.

Further, the hinge base includes an arc-shaped hinge head, and the hinge head is provided with a mounting hole.

The present invention also introduces a washing machine, the upper end of the washing machine is provided with a tray seat, the washing machine is equipped with the above-mentioned washing machine upper cover, the upper cover is installed in the tray seat of the washing machine through the hinge seat, and the tray seat is provided with There is a micro switch, one end of the micro switch is fixed on the hinge seat, and the other end is fixed in the disk seat.

Further, the hinge seat is provided with a mounting hole, and the disk seat is provided with a protruding shaft, and the protruding shaft is inserted into the mounting hole, so that the upper cover can be turned over and opened in the disk seat.

Further, the washing machine is provided with a mounting plate, the mounting plate is provided with a through hole, and one end of the upper cover is correspondingly provided with a plurality of plug-in parts;

Preferably, the maximum width of the cross section of the plug-in portion is larger than the diameter of the through hole, so as to fit in the through hole by interference.

After adopting the above-mentioned technical scheme, the present invention has the following beneficial effects compared with the prior art:

1. By setting the retaining rib on the water inlet of the upper cover of the washing machine, the water flowing into the hinge seat can be collected to the water inlet, and at the same time, it can be prevented from splashing into the washing machine and damaging the internal components of the washing machine.

2. By setting the structure of retaining ribs and vertical ribs on the hinge seat, the micro switch is prevented from rusting in contact with water vapor, which makes the micro switch poor contact, thereby ensuring the product quality of the washing machine.

3. The present invention is provided with vertical ribs on the hinge seat, which can form a drainage of water, so that it flows down vertically, and further ensures that the water will not flow into the micro switch.

4. The present invention adds grooves on the folded edges of the vertical ribs and the contact surface of the micro switch, and the depth of the groove will be increased as much as possible under the premise of ensuring the strength. If the user makes water flow into the upper cover and the micro switch through abnormal operations The contact surface of the switch, at this time, the water will flow directly to the inner tub of the washing machine along the groove without touching the micro switch.

At the same time, the invention has simple structure and remarkable effect, and is suitable for popularization and use.

The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

Description of drawings

The accompanying drawings, as a part of the present invention, are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the drawings in the following description are only some embodiments, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort. In the attached image:

1 is a schematic diagram of an explosion structure between an upper cover and a disk seat in an embodiment of the present invention;

Fig. 2 is the partial enlarged schematic diagram of Fig. 1 in the embodiment of the present invention;

3 is a schematic diagram of an explosion structure between the upper cover and the disc base at different angles in the embodiment of the present invention;

Fig. 4 is the partial enlarged schematic diagram of Fig. 2 in the embodiment of the present invention;

5 is a schematic diagram of an explosion structure of an upper cover in an embodiment of the present invention;

FIG. 6 is an enlarged schematic diagram of a part of FIG. 4 in an embodiment of the present invention.

Description of main components: 100, upper cover; 200, disc seat; 1, micro switch; 2, hinged seat; 3, water inlet; 4, retaining rib; 5, vertical rib; 6, folded edge; 7, groove; 8. Water outlet; 9. Water diversion groove; 10. Hinged joint; 11. Mounting hole; 12. Protruding shaft; 13. Mounting plate; 14. Insertion part; 15. Water diversion chamber.

It should be noted that these drawings and written descriptions are not intended to limit the scope of the present invention in any way, but to illustrate the concept of the present invention to those skilled in the art by referring to specific implementations.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and the following embodiments are used to illustrate the present invention , but are not intended to limit the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; it can be mechanical connection or electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Example 1

As shown in FIG. 1 to FIG. 6 , in the embodiment of the present invention, an upper cover of a washing machine is introduced. The hinge end is also installed with a hinge seat 2 for overflow protection of the micro switch 1 , and the hinge seat 2 is installed above the micro switch 1 . Since the micro switch 1 is exposed when exposed to water, it is easy to rust when exposed to water. By arranging a hinge seat 2 at the hinge end of the upper cover 100 and the disc base 200 that can protect the micro switch 1 from overflowing, the washing machine can be improved. product life.

In the embodiment of the present invention, the rear end of the upper cover 100 is provided with a hinged seat 2 protruding outward. Preferably, the hinged seat 2 and the upper cover 100 are integrally formed. The hinge seat 2 is provided with a plurality of water diversion openings 3 that penetrate through the upper and lower sides, and the surrounding of the water diversion opening 3 is provided with retaining ribs 4 higher than the water diversion opening 3 .

As shown in FIG. 4 , by providing the water guide port 3 in the hinge base 2 , when water enters the gap between the upper cover 100 and the disc base 200 , the water will flow directly to the inner tub of the washing machine along the water guide port 3 In the middle, without contacting the metal sheet of the micro switch 1, at the same time, a retaining rib 4 higher than the water diversion port 3 is arranged around the water inlet 3. Preferably, the retaining rib 4 and the hinge seat 2 are integrally injection molded. The protruding extends upward, and encloses a water diversion chamber 15 with an upward opening, which can collect the water flow to the water diversion port 3, and at the same time can prevent the water flow from splashing around. In addition, in the embodiment of the present invention, one side of the water diversion chamber 15 There is no side wall, and it is set for a gap. Preferably, the gap is opened on the left side. The purpose of this setting is to prevent excessive water flow and untimely drainage of the water inlet, which can flow into the inner barrel through the end without the side wall.

As shown in FIGS. 2 to 6 , in the embodiment of the present invention, one side of the water diversion chamber 15 is provided with a vertical rib 5 extending up and down. At the position of the retaining rib 4, the lower end of the vertical rib 5 has a folded edge 6 that is horizontally bent in the direction away from the retaining rib 4. By setting the vertical rib 5 extending up and down, the water can flow to the lower end along the direction of the vertical rib 5 and follow the fold. Edge 6 flows into the inner tub of the washing machine. The highest end of the vertical rib 5 is set higher than the retaining rib 4 , which can effectively block the water flow ready to flow into the contact surface between the micro switch 1 and the retaining rib 4 . Preferably, the vertical rib 5 and the blocking rib 4 are arranged in close contact; further preferably, the vertical rib 5 and the blocking rib 4 are integrally formed. The retaining ribs 4 and the vertical ribs 5 are integrally formed, which facilitates the mold opening of the upper cover 100, can be mass-produced, and reduces the cost. At the same time, the hinge seat 2 can be applied to more upper covers 100 of the washing machine.

In the embodiment of the present invention, the upper plane of the folding edge 6 is provided with a plurality of grooves 7 through which the water flows. By arranging the grooves 7 on the folding edge 6, when the user operates abnormally, water flows into the folding edge 6. When on, the water flow can flow into the inner tub along the groove.

In the embodiment of the present invention, a plurality of downwardly extending water diversion grooves 9 are provided along the inner wall of the water diversion opening 3, the lower end of the water diversion opening 3 is the water outlet 8, and the water diversion grooves 9 extend along the vertical rib 5 to the folded edge 6 end department. By arranging a plurality of water guide grooves 9 at the water outlet 8, the water from the water guide port 3 can flow through the water outlet 8 and flow into the inner tub of the washing machine along the water guide groove 9. At the same time, the water guide groove 9 extends all the way to the end of the folded edge 6 When the upper cover 100 is opened, the water diversion groove 9 on the folded edge 6 is in a vertical state, so that the water remaining on the hinge seat 2 can flow down vertically along the water diversion groove 9 of the folded edge 6 .

As shown in FIG. 6, in the embodiment of the present invention, the water diversion groove 9 extends from the water outlet 8 to the end of the folded edge 6, and the side wall of the water diversion groove 9 located at the water outlet 8 gradually narrows, similar to In the triangle, when the water flows in from the water inlet 3 at the upper end, and when the water flows out from the water outlet 8, the water pressure is relatively large, and the water flow will splash. Due to the function of diversion, the water flows to the inner tub of the washing machine along the water diversion groove 9 in the peripheral wall.

In the embodiment of the present invention, the hinge base 2 is further provided with a hinge head 10 . The hinge head 10 is partially arc-shaped and is integrally formed with the hinge base 2 . The hinge head 10 is provided with a mounting hole 11 , and the disk base 200 has a protruding shaft 12 , and the protruding shaft 12 is inserted into the mounting hole 11 , so that the upper cover 100 can be flipped open in the disk base 200 . .

By opening the mounting hole 11 on the hinge head 10, the assembly between the upper cover 100 and the disc base 200 is facilitated, and the disassembly and maintenance in the later stage are facilitated.

Embodiment 2

This embodiment introduces a washing machine. The washing machine is installed with a washing machine upper cover 100 described in the above embodiments. The washing machine includes a tray base 200, and the upper cover 100 is rotatably connected to the tray base 200 through hinges.

The hinged manner is specifically set as the disk base 200 is provided with a damper, the damper has a protruding protruding shaft 12, the upper cover 100 has an integrally formed hinge base, and the hinge base has a horizontal mounting hole 11, The protruding shaft 12 is put into the mounting hole 11 to form a rotatable hinge structure.

Due to the aesthetic requirements of the upper cover 100, each exposed connection structure is decorated with a cover body or a foot pad. A buffering and shockproof structure is formed between the upper cover 100 and the disk base 200 , which can also play a waterproof role for the screws and has an aesthetic effect.

A micro switch 1 is fixedly installed in the disc base 200. The micro switch 1 is installed at the lower end of the hinge base 2, and one end is in contact with the hinge base 2, so as to avoid contact with water vapor and rust, so as to avoid poor contact of the micro switch 1 and ensure The quality of the washing machine; the pressure rod in the micro switch 1 is connected to the upper cover 100 outside the micro switch 1 by snapping into the groove, and it can move with the groove as a fulcrum. The connection method is simple, and the pressure rod is inserted into different grooves. Inside, the stroke of the micro switch 1 can be changed correspondingly, that is, the rotation angle of the pressure rod with the connected groove as the fulcrum will change accordingly, so that the stroke of the micro switch 1 can be adjusted.

The micro switch 1 can be arranged in the control panel seat 200 of the washing machine, and is matched with the hinge end of the upper cover 100, and the force end of the pressing rod is overlapped on the hinge seat 2, so that when the upper cover 100 is switched on and off, the upper cover 100 is released. Or press the lever to make the moving contact and the stationary contact contact or disengage.

In the embodiment of the present invention, one end of the micro switch 1 is fixed on the folded edge 6, and the other end is fixed in the disc base 200. The contact surface of the micro switch 1 and the folded edge 6 is provided with a groove 7 through which the water flows. , the peripheral wall of the groove 7 is set as high as possible. By setting the groove 7, the water flow can flow down along the vertical rib 5 and flow to the designated inner tub of the washing machine along the groove 7, which can effectively avoid the water flow and the micro switch. 1 contact. In addition, a certain gap is provided between the micro switch 1 and the vertical rib 5 , so that the water can flow along the vertical rib 5 to the folded edge 6 .

When there is water flow in the gap between the upper cover 100 and the disc base 200, it first flows into the inner tub of the washing machine through the water inlet 3 along the vertical ribs 5 to avoid the contact between the water flow and the micro switch 1. Make the water flow into the contact surface of the hinge seat 2 and the micro switch 1, at this time, the water will flow directly into the inner tub of the washing machine along the groove 7 between the micro switch 1 and the hinge seat 2 without touching the micro switch 1.

In the embodiment of the present invention, by setting the water diversion port on the hinge seat, the water can be led into the inner barrel to prevent the water flow from contacting the micro switch. The retaining ribs are also arranged on the outer periphery of the water diversion port to prevent the water flow from contacting the micro switch. , the above settings can play the role of overflow protection for the micro switch.

In the embodiment of the present invention, the washing machine includes a box body, and the box body includes a mounting plate 13 installed at the clothes drop opening. The surface of the mounting plate 13 defines a number of through holes, and each plug portion 14 at one end of the upper cover 100 is respectively Inserted into the through hole, the rear end of the upper cover 100 is connected to the disc base 200 through the hinge base 2 .

In the above solution, each plug portion 14 at the front end of the upper cover 100 is inserted into the through hole of the mounting plate 13 , the rear end of the upper cover 100 is inserted into the disc base 200 , the upper cover 100 is rotated, and finally the disc base 200 is assembled as a whole on the box. When the user needs to open the upper cover 100, the mounting plate can be turned upward around the plug-in portion, and the upper cover is in a half-open state.

In the embodiment of the present invention, the disk base 200 has an accommodating slot, and the accommodating slot is used to place the display module and/or the control module. After the display module is placed in the accommodating slot, the display panel of the display module is combined with the cover plate. , a display area is formed at the corresponding position of the cover plate; similarly for the control module, after the control module is placed in the accommodating slot, the control panel of the display module is combined with the upper cover 100 to form a control area with the corresponding position of the upper cover 100 .

During the assembly process, after the display control module is placed into the accommodating groove, in order to prevent the display control module from falling off or shifting, the display control module needs to be fixed in the accommodating groove to facilitate the subsequent assembly process.

The disk base 200 has an accommodating slot for placing and fixing the display control module, and a wire outlet is provided on one side of the accommodating slot to facilitate the electrical connection between the display control module and the computer board and other structures. A wire card is provided outside the wire outlet for fixing the wires and other structures, so as to prevent the wires from moving inside the upper cover 100 and causing circuit failure due to wear and tear of the wires.

Since the upper cover 100 needs to be connected with the disc base 200, the disc base 200 is further provided with a connecting part for avoiding parts. The disc base 200 has a damper mounting part and a hinge base escape part. The damper can be fixed on the On the disc base 200, since the damper needs to be rotatably connected with the hinge base installed on the upper cover 100, the disc base 200 is provided with a hinge base avoidance part for avoiding the hinge base so that the hinge structure can rotate normally.

In the embodiment of the present invention, the display control module is an electrified component, the washing machine has washing water inside, and the upper cover 100 is located in the upper part of the inner tub, so there is a risk of water ingress, so the corresponding position of the upper cover 100 should be provided with a waterproof structure to ensure the display control module normal function is not impaired.

A sealing ring is arranged between the upper cover 100 and the disc base 200 and is arranged at the frame of the observation window. The sealing structure uses a waterproof material to block the washing water that may enter from the accommodating tank to prevent it from entering the display control module. After the upper cover 100 and the disk base 200 are assembled, the sealing ring stops against the upper cover 100 and the disk base 200 respectively, so that the accommodating groove forms a waterproof space. The sealing ring may be a rubber sealing ring.

A first sealing ring groove is arranged around the accommodating groove. After the first sealing ring groove is placed in the first sealing ring, after the upper cover 100 is assembled and fixed with the disc base 200 , the sealing ring is connected to the upper cover 200 by the disc base 200 . The cover 100 is squeezed to form a sealing structure, which isolates the washing water outside the accommodating tank and prevents it from entering the power consumption module.

In the embodiment of the present invention, the connection structure between the upper cover 100 and the disk base 200 is a plug-in structure, the upper cover 100 has a mounting hole 11, the disk base 200 has a protruding shaft 12, and the protruding shaft 12 is integrally provided with the disc base 200 ; or the upper cover 100 has an integrally provided protruding shaft 12 , and the disc base 200 has a mounting hole 11 .

Since the protruding shaft 12 and the disc base 200 are integrally disposed, the disc base 200 itself can form a connecting structure without additional connecting parts, which not only reduces the assembly steps, but also reduces the overall cost.

The protruding shaft 12 is provided with a protrusion in the circumferential direction of the top, and the edge of the protrusion also has a limit for the inclined surface to slide into the installation hole 11. Correspondingly, the front end of the installation hole 11 also has a slope to facilitate the insertion of the protrusion into the limit. inside the mounting hole 11.

In addition to the integrated display and control functions, the upper cover 100 may also have an observation function. Generally, the upper cover 100 of the washing machine is made of transparent material, and the user can observe the washing machine through the upper cover 100 .

As shown in FIG. 5 , in the embodiment of the present invention, the front side of the upper cover 100 is provided with a mounting plate 13 , the mounting plate 13 is provided with a through hole, and one end of the upper cover 100 is correspondingly protruded with a plurality of plug connectors The maximum width of the cross-section of the plug-in portion 14 is larger than the diameter of the through hole, so as to fit in the through hole by interference.

In the above solution, the plug-in portion 14 is a horizontally protruding columnar structure, and the plug-in portion 14 is inserted into the through hole on the mounting plate 13 by interference, then when the upper cover 100 is installed, each plug at one end of the upper cover 100 The connecting portions 14 are respectively inserted into the through holes, then the mounting plate 13 and the upper cover 100 are installed in the disk base 200 to seal the opening of the disk base 200 . The through-hole cuts the insertion portion 14 to form a slot, thereby more effectively limiting the position of the upper cover 100, preventing the upper cover 100 from shifting during transportation or dropping, and the connection between the upper cover 100 and the mounting plate 13 is prevented. The increase in the assembly gap leads to poor product refinement and affects the user experience.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Without departing from the scope of the technical solutions of the present invention, when the technical content indicated above can be used to make some changes or modifications to equivalent examples of equivalent changes, the implementations in the above-mentioned examples can be further combined or replaced, but any Departing from the content of the technical solution of the present invention, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the solution of the present invention.

Claims

An upper cover of a washing machine, the rear end of the upper cover is provided with a hinge seat (2) protruding outward, characterized in that the hinge seat (2) is provided with a plurality of water diversion openings (3) that penetrate up and down, The outer periphery of the water diversion port (3) is provided with a retaining rib (4) higher than the water diversion port (3).
The upper cover of a washing machine according to claim 1, wherein the retaining rib (4) protrudes and extends upward to enclose a water diversion chamber (15) with an upward opening.
The upper cover of a washing machine according to claim 2, characterized in that a vertical rib (5) extending up and down is provided on one side of the water diversion chamber (15), and a lower end of the vertical rib (5) is provided with a vertical rib (5). For the folded edge (6) bent horizontally, the highest point of the vertical rib (5) is higher than the retaining rib (4);

Preferably, the vertical ribs (5) are arranged in close contact with the retaining ribs (4);

Further preferably, the vertical rib (5) and the retaining rib (4) are integrally formed.
The upper cover of a washing machine according to claim 3, wherein the upper plane of the folded edge (6) is provided with a plurality of grooves (7) through which the water flows.
The upper cover of a washing machine according to any one of claims 1 to 4, wherein a plurality of downwardly extending water guiding grooves (9) are provided along the inner wall of the water guiding port (3), and the water guiding grooves (9) ) extends along the vertical rib (5) to the end of the folded edge (6).
The upper cover of a washing machine according to claim 5, characterized in that the water diversion grooves (9) on the lower plane of the folded edge (6) and the grooves (7) on the upper plane of the folded edge (6) are staggered.
The upper cover of a washing machine according to any one of claims 1 to 4, wherein the hinge seat (2) comprises an arc-shaped hinge head (10), and the hinge head (10) is provided with an installation hole.
A washing machine, the upper end of the washing machine is provided with a tray seat, characterized in that, an upper cover of the washing machine according to any one of the above claims 1-7 is installed, and the upper cover is installed in the tray seat of the washing machine through a hinge seat, A micro switch (1) is arranged in the disc base (200), one end of the micro switch (1) is fixed on the hinge base, and the other end is fixed in the disc base (200).
A washing machine according to claim 8, characterized in that the hinge seat (2) is provided with a mounting hole (11), the disk seat (200) is provided with a protruding shaft (12), The output shaft (12) is inserted into the installation hole (11), so that the upper cover (100) can be turned over and opened in the disk seat (200).
The washing machine according to claim 8, characterized in that the washing machine is provided with a mounting plate (13), a through hole is formed on the mounting plate (13), and one end of the upper cover (100) corresponds to a convex The outlet is provided with a plurality of plug-in parts (14);

Preferably, the maximum width of the cross-section of the plug-in portion (14) is larger than the diameter of the through hole, so as to fit in the through hole by interference.