Resiliometer with perpendicularity assisting function
By designing the verticality auxiliary function in the rebound meter, using technical means such as the main mounting ring, accommodating sleeve and induction components, the problem of difficult to ensure the perpendicularity of the rebound meter and the concrete surface is solved, and the detection accuracy is significantly improved.
Patent Information
- Application Number
- CN202421862884.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-02
- Publication Date
- 2025-06-06
- Estimated Expiration
- 2034-08-02
AI Technical Summary
When the existing rebound instrument detects the compressive strength of concrete, it is difficult to ensure the perpendicularity with the concrete surface to be measured, which affects the measurement accuracy.
A rebound meter with verticality assist function is designed. By setting the main mounting ring and the receiving sleeve in the vertical direction on the outside of the rebound meter main body, and installing an annular partition plate, guide column, adjustment legs and elastic parts in the receiving sleeve. The induction component and display unit are used to remind the user when ensuring that the adjustment legs are perpendicular to the concrete surface.
It effectively improves the perpendicularity between the rebound meter and the concrete surface, ensures detection accuracy, and reduces errors caused by hand shaking of the measuring personnel.
Smart Images
Figure CN222952145U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of concrete strength testing equipment, and in particular to a rebound hammer with a verticality auxiliary function. Background Art
[0002] The rebound tester is a non-destructive testing instrument used to test the compressive strength of hardened concrete in building structures. Its basic principle is to use a spring to drive a heavy hammer, so that the heavy hammer hits the impact rod in vertical contact with the concrete surface with constant kinetic energy, thereby causing local concrete deformation and absorbing part of the energy, and the other part of the energy is converted into the rebound kinetic energy of the heavy hammer. When the rebound kinetic energy is fully converted into potential energy, the heavy hammer rebounds to the maximum distance, and the instrument displays the maximum rebound distance of the heavy hammer in the name of the rebound value.
[0003] Common types of rebound testers include: ordinary rebound testers, high-strength rebound testers and digital rebound testers. When in use, the surveyor places the rebound tester contact vertically on the surface of the test component, and after hearing a "click" sound, record the reading of the position of the cursor on the rebound tester. The verticality of the existing rebound tester on the wall is mainly maintained by the surveyor's bare hands. The general method is that the surveyor keeps the rebound tester perpendicular to the concrete surface to be tested with one hand during the test, and controls the rebound tester with the other hand. In this way, it is difficult to ensure the verticality of the rebound tester and the concrete surface to be tested during the test. If the surveyor's hand shakes slightly, the rebound tester will tilt on the concrete surface to be tested, affecting the final measurement accuracy. Utility Model Content
[0004] The present application provides a rebound hammer with a verticality auxiliary function, which can ensure the verticality between the rebound hammer and the concrete surface to be tested when the measurement personnel test the compressive strength of concrete.
[0005] The above-mentioned purpose of the present application is achieved through the following technical solutions:
[0006] A rebound hammer with a verticality auxiliary function comprises a rebound hammer body; a main mounting ring and a receiving sleeve are coaxially sleeved on the outer side of the rebound hammer body in sequence from top to bottom along the vertical direction, and the interiors of the main mounting ring and the receiving sleeve are both hollow structures.
[0007] An annular partition plate is fixedly installed in the middle position of the accommodating sleeve, and a plurality of guide pillars are evenly inserted on the annular partition plate along its circumference, and the guide pillars are slidably connected to the annular partition plate;
[0008] The upper end of the guide column is connected to the display unit arranged on the main mounting ring through the induction component, the lower end of the guide column is fixedly connected to the upper end of the adjustment leg, the lower end of the adjustment leg penetrates the lower end plate of the accommodating sleeve and the two are slidably connected; the adjustment leg is connected to the annular partition plate through an elastic member;
[0009] The display unit can prompt the user when the plurality of adjustment legs are in a vertical state with the concrete surface to be measured.
[0010] Furthermore, the elastic member is a spring, the upper end of the spring is fixedly connected to the lower side of the annular partition plate, the lower end of the spring is fixedly connected to the upper end of the adjustment leg, and the spring is sleeved on the area of the guide column below the annular partition plate.
[0011] Furthermore, the display unit includes a display light and an energy storage battery installed on the upper side of the main mounting ring, the energy storage battery is installed in the main mounting ring, and the display light is connected to the energy storage battery through an induction component.
[0012] Furthermore, the sensing component includes a first wire and a second wire, and the display light is connected to the positive and negative electrodes of the energy storage battery through the first wire and the second wire respectively; a plurality of contact switches are provided on the second wire, and the number of the plurality of contact switches is the same as the plurality of guide columns, and their positions correspond one to one; the guide column can control the on and off of the second wire through the corresponding contact switch.
[0013] Furthermore, the contact switch includes two metal contacts and a conductive gasket parallel to each other. The middle positions of the two metal contacts are fixedly installed in the accommodating sleeve by clips. The upper ends of the two metal contacts are connected to the second electric wire. The two ends of the conductive gasket are respectively located below the lower ends of the two metal contacts. The lower side of the middle position of the conductive gasket is fixedly connected to the upper end of the guide column at the corresponding position.
[0014] Furthermore, avoidance notches are provided at positions on the main mounting ring and the accommodating sleeve corresponding to the indication observation area on the rebound tester body.
[0015] Furthermore, a guide protrusion is provided on the outer side of the rebound tester body, and a guide groove matching the guide protrusion is provided on the inner sides of the main mounting ring and the accommodating sleeve.
[0016] In summary, the present application includes at least one of the following beneficial technical effects:
[0017] When the tester needs to test the compressive strength of concrete, he can first place the lower ends of the multiple adjustment legs in the accommodating sleeve against the concrete surface to be tested, and then adjust the angles of the multiple adjustment legs while observing the status of the display unit on the guide column. When the display unit displays information that the multiple adjustment legs are perpendicular to the concrete surface to be tested, the tester will pass the rebound tester body through the center of the main mounting ring and the accommodating sleeve. When the end contact of the rebound tester is used to test the concrete surface, it can always be in a perpendicular state to the concrete surface under the guidance of the main mounting ring and the accommodating sleeve. Compared with the existing technology, it can effectively improve the test accuracy of the compressive strength of concrete. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0019] Figure 1 It is a schematic diagram of the overall structure of this application;
[0020] Figure 2 It is a schematic diagram of the structure after the main mounting ring and the accommodating sleeve of the present application are cut apart;
[0021] Figure 3 It is a schematic diagram of the overall structure of the main mounting ring and the receiving sleeve of the present application;
[0022] Figure 4 It is a schematic diagram of the structure of the rebound tester body, the main mounting ring and the accommodating sleeve after being disassembled.
[0023] Figure numerals: 1. Rebound tester body; 2. Main mounting ring; 3. Accommodating sleeve; 4. Annular partition plate; 5. Guide column; 6. Sensing component; 61. First wire; 62. Second wire; 63. Contact switch; 631. Metal contact; 632. Conductive gasket; 633. Clip; 7. Display unit; 71. Display light; 72. Energy storage battery; 8. Adjustment leg; 9. Elastic member; 10. Avoidance gap; 11. Guide protrusion; 12. Guide groove. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application is clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work also fall within the scope of protection of the present application.
[0025] like Figure 1-Figure 3 As shown, a rebound tester with a verticality auxiliary function disclosed in the present application comprises a rebound tester body 1; a main mounting ring 2 and a receiving sleeve 3 are coaxially sleeved on the outer side of the rebound tester body 1 in sequence from top to bottom in the vertical direction, the interiors of the main mounting ring 2 and the receiving sleeve 3 are both hollow structures, an annular partition plate 4 is fixedly installed at the middle position in the receiving sleeve 3, a plurality of guide columns 5 are evenly inserted on the annular partition plate 4 along its circumference, and the guide columns 5 are slidably connected to the annular partition plate 4; the upper end of the guide column 5 is connected to a display unit 7 arranged on the main mounting ring 2 through a sensing component 6, the lower end of the guide column 5 is fixedly connected to the upper end of an adjusting leg 8, the lower end of the adjusting leg 8 passes through the lower end plate of the receiving sleeve 3 and the two are slidably connected; the adjusting leg 8 and the annular partition plate 4 are connected by an elastic member 9; the display unit 7 can prompt the user when a plurality of adjusting legs 8 are in a vertical state with the concrete surface to be measured.
[0026] In the above embodiments, the outer diameter of the rebound test body 1 of the present application is equal to the inner diameter of the main mounting ring 2 and the inner diameter of the accommodating sleeve 3, so that when the rebound test body 1 moves along the axial direction of the main mounting ring 2 and the accommodating sleeve 3, the inner walls of the main mounting ring 2 and the accommodating sleeve 3 can play a limiting and guiding effect for the rebound test body 1, preventing the rebound test body 1 from tilting during the movement in the main mounting ring 2 and the accommodating sleeve 3. The interiors of the main mounting ring 2 and the accommodating sleeve 3 are both hollow structures, so that there is a certain amount of space inside them for installing related components.
[0027] The lower end of the guide column 5 of the present application is connected to the upper end of the adjustment leg 8, and the adjustment leg 8 is slidably connected to the lower end plate of the accommodating sleeve 3, and the guide column 5 is slidably connected to the annular partition plate 4 in the accommodating sleeve 3, so that when the guide column 5 and the adjustment leg 8 move along the axial direction of the accommodating sleeve 3, the lower end plate of the accommodating sleeve 3 and the annular partition plate 4 can provide them with a limiting guide function at the same time, so that the moving direction of the guide column 5 and the adjustment leg 8 is always consistent with the axial direction of the accommodating sleeve 3. The number of the guide column 5 and the adjustment leg 8 is not less than three, so that it can be ensured that after all the adjustment legs 8 are perpendicular to the concrete surface to be measured, the main mounting ring 2 and the accommodating sleeve 3 will not tilt easily.
[0028] The display unit 7 provided on the main mounting ring 2 is connected to the multiple guide posts 5 through the sensing component 6, and the upper end of the adjustment leg 8 and the lower side of the annular partition plate 4 are connected through the elastic member 9. The elastic member 9 can play a certain limiting effect on the adjustment leg 8 when it is in the ready-to-use state, preventing the adjustment leg 8 from shaking in the accommodating sleeve 3. In addition, when the elastic member 9 is squeezed, the length of the elastic member 9 will be deformed, so that the distance between the adjustment leg 8 and the guide post 5 and the sensing component 6 will change, and the sensing component 6 can display this information through the display unit 7, so that the tester can judge the state of the multiple adjustment legs 8 through the information on the display unit 7, so that the tester can quickly judge the state of the multiple adjustment legs 8 supporting the main mounting ring 2 and the accommodating sleeve 3.
[0029] Normally, when testing the compressive strength of the concrete surface, it is necessary to ensure that the surface of the concrete to be tested is flat and clean. This is because the state of the concrete surface directly affects the test results of the rebound tester. If there are impurities, dirt or unevenness on the concrete surface, the rebound tester may not fit the concrete surface well, thus affecting the accuracy of the test. Therefore, in actual testing, the biggest influence on the verticality of the rebound tester and the concrete surface to be tested is the stability of the tester's hand holding the rebound tester. Since the surface of the concrete to be tested is generally a flat and dirt-free area, the tester will simultaneously face the multiple adjustment legs 8 in the accommodating sleeve 3 to the area to be tested, and adjust the multiple adjustment legs 8 to be perpendicular to the concrete surface. In this process, the elastic member 9 is squeezed synchronously, and the sensing component 6 will display this information to the tester, so that the tester can intuitively judge the verticality between the axis of the main mounting ring 2 and the accommodating sleeve 3 and the concrete surface. After the axes of the main mounting ring 2 and the receiving sleeve 3 are perpendicular to the surface of the concrete to be tested, the main body 1 of the rebound tester is inserted into the main mounting ring 2 and the receiving sleeve 3, and then the detection work can be started according to the normal process. Since the main body 1 of the rebound tester is guided by the adjusted main mounting ring 2 and the receiving sleeve 3 during the detection process, the rebound tester will continue to maintain the verticality with the concrete surface during the detection. Compared with the prior art, this application can effectively improve the detection accuracy of the main body 1 of the rebound tester during the detection.
[0030] Furthermore, if Figure 2 and Figure 3 As shown, the elastic member 9 is a spring, the upper end of the spring is fixedly connected to the lower side of the annular partition plate 4, the lower end of the spring is fixedly connected to the upper end of the adjustment leg 8, and the spring is sleeved on the area of the guide column 5 below the annular partition plate 4.
[0031] In the above embodiment, the spring used as the elastic member 9 in the present application is arranged in the above manner, which can not only provide support force for the adjustment leg 8 through the annular partition plate 4 when in use to prevent it from shaking in the accommodating sleeve 3, but also can change the distance between the adjustment leg 8 and the annular partition plate 4 by deformation as needed when in use. In addition, the spring is sleeved on the guide column 5, so that during the deformation process of the spring, the guide column 5 can guide the spring to make the spring deform evenly.
[0032] Furthermore, if Figure 2 and Figure 3 As shown, the display unit 7 includes a display light 71 and an energy storage battery 72 installed on the upper side of the main mounting ring 2. The energy storage battery 72 is installed in the main mounting ring 2, and the display light 71 is connected to the energy storage battery 72 through the induction component 6.
[0033] In the above embodiments, the display light 71 of the present application is connected to the energy storage battery 72 in the main mounting ring 2 through the sensing component 6, and the sensing component 6 is connected to the multiple guide columns 5. When the ends of the multiple guide columns 5 connected to the sensing component 6 are flush, the sensing component 6 can connect the display light 71 and the energy storage battery 72, so that the display light 71 is lit. In this way, the display light 71 facing the tester can prompt the tester that the guide legs connected to the multiple guide columns 5 are all in a vertical state with the concrete surface to be tested, thereby facilitating the tester to quickly judge this information.
[0034] Furthermore, if Figure 2 and Figure 3 As shown, the sensing component 6 includes a first wire 61 and a second wire 62, and the display light 71 is connected to the positive and negative electrodes of the energy storage battery 72 through the first wire 61 and the second wire 62 respectively; a plurality of contact switches 63 are provided on the second wire 62, and the number of the plurality of contact switches 63 is the same as the plurality of guide columns 5, and their positions correspond one to one; the guide column 5 can control the on and off of the second wire 62 through the contact switch 63 corresponding thereto.
[0035] In the above embodiment, one end of the display light 71 of the present application is connected to the positive electrode of the energy storage battery 72 through the first wire 61, and the other end is connected to the negative electrode of the energy storage battery 72 through the second wire 62, and a plurality of contact switches 63 are sequentially connected in series on the second wire 62, and the plurality of contact switches 63 correspond to the plurality of guide posts 5 one by one. The plurality of guide posts 5 can control the on and off of the plurality of contact switches 63 by changing their positions. When the ends of the adjustment legs 8 connected to the plurality of guide posts 5 that contact the surface of the concrete to be tested are coplanar and displaced in the direction of the contact switches 63 due to extrusion, the plurality of guide posts 5 can turn on the plurality of contact switches 63, thereby forming a closed loop between the energy storage battery 72 and the display light 71, so that the tester can clearly know through the display light 71 whether the axes of the main mounting ring 2 and the accommodating sleeve 3 are perpendicular to the surface of the concrete to be tested at this time.
[0036] Furthermore, if Figure 2 and Figure 3 As shown, the contact switch 63 includes two metal contacts 631 parallel to each other and a conductive gasket 632. The middle positions of the two metal contacts 631 are fixedly installed in the accommodating sleeve 3 by means of a clip 633. The upper ends of the two metal contacts 631 are connected to the second wire 62, and there is a gap between the connection points of the second wire 62 and the two metal contacts 631. The two ends of the conductive gasket 632 are respectively located below the lower ends of the two metal contacts 631, and the lower side of the middle position of the conductive gasket 632 is fixedly connected to the upper end of the guide column 5 at the corresponding position.
[0037] In the above embodiment, the second electric wire 62 is in a disconnected state at the connection point with the two metal contacts 631. Only when the guide column 5 carries the conductive gasket 632 and makes the two ends of the conductive gasket 632 contact with the lower ends of the two metal contacts 631 at the same time, the two metal contacts 631 will be conductive. Since the lower ends of the metal contacts 631 provided in the accommodating sleeve 3 are all located in the same plane and they are fixed in the accommodating sleeve 3 by means of the clips 633, and the lengths of all the adjusting legs 8 and the guide posts 5 are the same, when all the guide posts 5 carry the corresponding conducting gaskets 632 to make the metal contacts 631 in all the contact switches 63 conductive, the second electric wire 62 can be completely in a conductive state, so that the display light 71 can be illuminated. Correspondingly, when the display light 71 is illuminated, the contact ends of all the adjusting legs 8 and the surface of the concrete to be tested are in a coplanar state. Since the surface of the area used for testing the concrete to be tested is flat, the axis of the adjusting legs 8 is also perpendicular to the surface of the concrete to be tested, and the axis of the main mounting ring 2 and the accommodating sleeve 3 supported by the multiple adjusting legs 8 are also perpendicular to the surface of the concrete to be tested. If one of the adjustment legs 8 is not perpendicular to the surface of the concrete to be tested, the second wire 62 will not supply power to the display light 71 because the corresponding contact switch 63 is turned on. Therefore, the tester can judge whether the multiple adjustment legs 8 are perpendicular to the concrete surface to be tested by the state of the display light 71 when using it.
[0038] Furthermore, if Figure 1 As shown, avoidance notches 10 are provided at positions on the main mounting ring 2 and the accommodating sleeve 3 corresponding to the indication observation area on the rebound hammer body 1 .
[0039] In the above embodiments, the avoidance notch 10 on the main mounting ring 2 and the accommodating sleeve 3 can facilitate the tester to quickly read the reading of the display observation area on the rebound hammer body 1 during the use of the rebound hammer.
[0040] Furthermore, if Figure 4As shown, a guide protrusion 11 is provided on the outer side of the rebound hammer body 1 , and a guide groove 12 matching the guide protrusion 11 is provided on the inner sides of the main mounting ring 2 and the accommodating sleeve 3 .
[0041] In the above embodiments, when the tester inserts the rebound tester body 1 into the main mounting ring 2 and the accommodating sleeve 3, the guide grooves 12 on the inner sides of the main mounting ring 2 and the accommodating sleeve 3 can cooperate with the guide protrusions 11 on the outer sides of the rebound tester body 1 to achieve the positioning and guiding effect of the rebound tester body 1, thereby preventing the indication observation area of the rebound tester body 1 from not being aligned with the avoidance notch 10 in the main mounting ring 2 and the accommodating sleeve 3, which is not conducive to the tester to read the data quickly.
[0042] The implementation principle of this embodiment is as follows: when in use, the tester first takes out the main body 1 of the rebound tester, the main mounting ring 2, and the accommodating sleeve 3 from the packaging box, then picks up the main mounting ring 2 and the accommodating sleeve 3, and makes the multiple adjustment legs 8 in the accommodating sleeve 3 face the pre-processed concrete surface. Then continue to move the main mounting ring 2 toward the concrete surface, and after the multiple adjustment legs 8 are evenly in contact with the concrete surface, continue to squeeze the multiple adjustment legs 8 until the multiple adjustment legs 8 are connected to the corresponding contact switch 63 with the corresponding conduction gasket 632 through the guide column 5 connected to each other. At this time, the tester can clearly see from the main mounting ring 2 that the display light 71 on the main mounting ring 2 is on, which also indicates that the mutually distant ends of the multiple guide columns 5 and the multiple adjustment legs 8 are all in the same plane, and the axis of the adjustment legs 8 and the guide column 5 is in a vertical state with the surface of the concrete to be tested, and the corresponding axis of the main mounting ring 2 and the accommodating sleeve 3 is also in a vertical state with the surface of the concrete to be tested. Finally, the tester only needs to insert the rebound test hammer body 1 into the main mounting ring 2 and the containing sleeve 3 along the center of the main mounting ring 2, and move along the inner walls of the main mounting ring 2 and the containing sleeve 3 to make the axis of the rebound test hammer body 1 always be perpendicular to the concrete surface to be tested. Due to the guidance of the main mounting ring 2 and the containing sleeve 3, the rebound test hammer body 1 will not be easily skewed during the test process, thereby effectively improving the detection accuracy of the rebound test hammer body 1.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A rebound hammer with verticality auxiliary function, characterized in that: The invention comprises a rebound tester body (1); a main mounting ring (2) and a receiving sleeve (3) are coaxially sleeved on the outer side of the rebound tester body (1) in sequence from top to bottom in the vertical direction; the interiors of the main mounting ring (2) and the receiving sleeve (3) are both hollow structures. An annular partition plate (4) is fixedly installed in the middle position of the accommodating sleeve (3), and a plurality of guide pillars (5) are evenly inserted on the annular partition plate (4) along its circumference, and the guide pillars (5) are slidably connected to the annular partition plate (4); The upper end of the guide column (5) is connected to a display unit (7) arranged on the main mounting ring (2) through a sensing component (6); the lower end of the guide column (5) is fixedly connected to the upper end of an adjustment leg (8); the lower end of the adjustment leg (8) penetrates the lower end plate of the accommodating sleeve (3) and the two are slidably connected; the adjustment leg (8) and the annular partition plate (4) are both connected through an elastic member (9); The display unit (7) can prompt the user when the plurality of adjustment legs (8) are in a vertical state with the concrete surface to be measured.
2. The rebound hammer with verticality auxiliary function according to claim 1, characterized in that: The elastic member (9) is a spring, the upper end of which is fixedly connected to the lower side of the annular partition plate (4), the lower end of which is fixedly connected to the upper end of the adjustment leg (8), and the spring is sleeved on the area of the guide column (5) below the annular partition plate (4).
3. The rebound hammer with verticality auxiliary function according to claim 2, characterized in that: The display unit (7) comprises a display light (71) mounted on the upper side of the main mounting ring (2) and an energy storage battery (72); the energy storage battery (72) is mounted inside the main mounting ring (2); and the display light (71) is connected to the energy storage battery (72) via an induction component (6).
4. The rebound hammer with verticality auxiliary function according to claim 3, characterized in that: The induction component (6) comprises a first wire (61) and a second wire (62); the display light (71) is connected to the positive and negative electrodes of the energy storage battery (72) through the first wire (61) and the second wire (62), respectively; a plurality of contact switches (63) are provided on the second wire (62); the number of the plurality of contact switches (63) is the same as the number of the plurality of guide posts (5), and their positions correspond one to one; the guide post (5) can control the on and off of the second wire (62) through the contact switch (63) corresponding thereto.
5. The rebound hammer with verticality auxiliary function according to claim 4, characterized in that: The contact switch (63) comprises two mutually parallel metal contacts (631) and a conductive gasket (632); the middle positions of the two metal contacts (631) are fixedly installed in the accommodating sleeve (3) through a clip (633); the upper ends of the two metal contacts (631) are connected to the second electric wire (62), and there is a gap between the connection points of the second electric wire (62) and the two metal contacts (631); the two ends of the conductive gasket (632) are respectively located below the lower ends of the two metal contacts (631); and the lower side of the middle position of the conductive gasket (632) is fixedly connected to the upper end of the guide column (5) at the corresponding position.
6. The rebound hammer with verticality auxiliary function according to any one of claims 1 to 5, characterized in that: The main mounting ring (2) and the accommodating sleeve (3) are both provided with avoidance notches (10) at positions corresponding to the indication observation area on the rebound hammer body (1).
7. The rebound hammer with verticality auxiliary function according to claim 6, characterized in that: A guide protrusion (11) is provided on the outer side of the rebound tester body (1), and a guide groove (12) matching the guide protrusion (11) is provided on the inner sides of the main mounting ring (2) and the accommodating sleeve (3).