Linear guide rail machining process method

Abstract

The invention provides a linear guide rail machining process method, and belongs to the technical field of linear guide rails. A first datum plane, a second datum plane, a third datum plane and a fourth datum plane are machined on the blank, four sets of clamping holes are machined in the first datum plane, and the two sets of clamping holes are located in the two ends of the blank respectively and located in the middle of the blank; the four sets of clamping holes are all located in the machining allowance of the blank. The blank is fixedly installed on a clamp with the first datum plane as the bottom face, and two sets of threaded holes are machined in the fourth datum plane; mounting on a clamp by taking the fourth reference surface as a bottom surface, and cutting the blank into two linear guide rails; heat treatment; and finish machining. According to the linear guide rail machining process method, the clamp can clamp and position the blank more conveniently and accurately, it is guaranteed that the blank machining and positioning difficulty is small, when the machining allowance and the clamping hole are cut off from the blank, the blank is divided into the two linear guide rails, and the production efficiency is also improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of linear guide rails, and more specifically, relates to a linear guide rail processing method. Background Art

[0002] Linear guides are used in high-precision or high-speed linear reciprocating motion situations, and can bear a certain torque, and can achieve high-precision linear motion under high load. When processing linear guides, forged long strips of material are often used as blanks. The blanks have a similar outline to the linear guides, and the blanks have sufficient processing allowances, and then the blanks are processed to produce linear guides. At present, when processing linear guides, the processing positioning accuracy of linear guides is poor, and the positioning difficulty is relatively large, which affects the production efficiency of linear guides. Summary of the invention

[0003] The purpose of the present invention is to provide a linear guide rail processing method to solve the technical problems in the prior art that the linear guide rail processing positioning accuracy is poor and the positioning difficulty is relatively large.

[0004] To achieve the above object, the technical solution adopted by the present invention is: to provide a linear guide rail processing method, comprising:

[0005] S1: Select a blank, the length of which is greater than the length of the two linear guide rails and retains a machining allowance; perform preliminary straightening along the length direction of the blank;

[0006] S2: machining a first reference surface on the upper end surface of the blank, machining four groups of symmetrically arranged clamping holes on the first reference surface, wherein two groups of clamping holes are respectively located at the two ends of the blank, and the other two groups of the clamping holes are located in the middle of the blank; and the four groups of the clamping holes are all located on the machining allowance of the blank; machining two symmetrically arranged second reference surfaces on the side surface of the blank; machining third reference surfaces on both end surfaces of the blank;

[0007] S3: connecting the first reference surface as a bottom surface to the fixture, and using bolts to connect to the clamping hole to fix the blank on the fixture;

[0008] S4: performing rough machining on the surface of the blank and the matching grooves on both sides;

[0009] S5: machining a fourth reference surface on the upper end surface of the blank, taking the second reference surface and one of the third reference surfaces as machining references, and machining a group of threaded holes on the fourth reference surface; taking the second reference surface and another of the third reference surfaces as machining references, and machining another group of threaded holes on the fourth reference surface;

[0010] S6: The fourth reference plane is used as the bottom surface to be installed on the fixture, and the blank is fixed on the fixture by connecting to the threaded hole with bolts;

[0011] S7: Cutting the blank into two equal linear guide rails based on the threaded hole, and cutting off the clamping holes at both ends of the linear guide rails;

[0012] S8: heat treatment;

[0013] S9: Finishing.

[0014] In a possible implementation, the machining allowance of the blank is greater than the sum of the dimensions of the four groups of clamping holes in the length direction of the blank, and a cutting spacing is provided between two groups of clamping holes located in the middle of the blank.

[0015] In a possible implementation, the number of the two groups of clamping holes located in the middle of the blank is two, and the clamping holes in the two groups of clamping holes located in the middle of the blank correspond to each other one by one and are staggered.

[0016] In a possible implementation, when the two groups of threaded holes are processed using the second reference plane and the third reference plane in S5, the multiple threaded holes in the same group are evenly arranged between the two groups of clamping holes; the axes of the multiple threaded holes are located on the same plane, and the threaded holes are equidistant from both sides of the blank; and the two groups of threaded holes are symmetrically arranged on the blank.

[0017] In a possible implementation, the clamp includes a bearing plate, and a lower end of the bearing plate is provided with mounting holes corresponding to the clamping holes and the threaded holes respectively.

[0018] In a possible implementation, the supporting plate is further provided with a plurality of elongated holes, the length direction of the elongated holes is consistent with the width direction of the blank; the length of the elongated holes is greater than the width of the blank; the plurality of elongated holes are respectively opened at the end and the middle position of the supporting plate, and the plurality of elongated holes respectively correspond to a plurality of cutting positions of the blank; the cutting position of the cutting knife is located directly above the corresponding elongated hole.

[0019] In a possible implementation, the number of the elongated holes is five, two of which are respectively opened at the two ends of the supporting plate, and three of which are located in the middle of the supporting plate; the two ends of the blank are cut twice, and the middle of the blank is cut three times.

[0020] In a possible implementation, the linear guide rail machining process method further includes:

[0021] S10: Perform rust-proof treatment on the surface of the linear guide.

[0022] In a possible implementation, the straightness of the linear guide is tested after the linear guide is processed; the linear guide is placed on one side of a plurality of rollers arranged in parallel and spaced apart, and the central axes of the plurality of rollers are located on the same plane; different side surfaces of the linear guide are controlled to abut against the plurality of rollers in turn, and the bending position of the linear guide is determined according to the change in the distance between the side surfaces of the linear guide and the rollers, and a hammer press is used to act on the bending position of the linear guide to squeeze the linear guide straight.

[0023] In one possible implementation, the roller includes a central axis and a rotating sleeve rotatably connected to the central axis, a pressure sensor is provided between the central axis and the rotating sleeve, and an indicator light is provided on each central axis; a hollow cavity and a control unit installed in the hollow cavity are provided in the central axis; the pressure sensor and the indicator light are electrically connected to the control unit.

[0024] The linear guide processing method provided by the present invention has the beneficial effect that: compared with the prior art, the linear guide processing method of the present invention, when producing and processing the linear guide, first selects a suitable blank, and the length of the blank is greater than the length of the two linear guides, so that the blank has sufficient machining allowance and can be processed into two linear guides; then the first reference plane, the second reference plane and the third reference plane are processed on the blank, and four groups of clamping holes are processed on the first reference plane, and the blank is mounted on the fixture through inversion, and the bolts on the fixture are used to penetrate the clamping holes to fix the blank on the fixture, and the side surface of the blank and the matching groove on the side surface are rough-machined with the first reference plane, etc.; and the fourth reference plane is processed on the upper end surface of the blank, and the fourth reference plane is used as the bottom surface to be reversely mounted on the fixture, and the blank is fixedly connected to the fixture by passing the bolts through the threaded holes again; at this time, the clamping holes located on the machining allowance are no longer fixedly connected to the fixture, and most of the machining allowance and the clamping holes are cut off, and two linear guides are formed by machining at the same time, and finally the two linear guides are heat treated and fine-machined. In this way, the length of the blank is selected to be greater than the length of the two linear guides, and the clamping hole is opened on the machining allowance for the first positioning and installation. It is more convenient and accurate to use a fixture to clamp and position the blank. The second positioning uses the end face of the linear guide and finally cuts off the machining allowance and the clamping hole together to ensure that the blank processing and positioning is less difficult. When the machining allowance and the clamping hole are cut off from the blank, the blank is divided into two linear guides, which also improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 Schematic diagram of a linear guide rail machining process provided by an embodiment of the present invention Figure 1 ;

[0027] Figure 2 Schematic diagram of a linear guide rail machining process provided by an embodiment of the present invention Figure 2 ;

[0028] Figure 3 Schematic diagram of a linear guide rail machining process provided by an embodiment of the present invention Figure 3 ;

[0029] Figure 4 Schematic diagram of a linear guide rail machining process provided by an embodiment of the present invention Figure 4 ;

[0030] Figure 5 A schematic structural diagram of a roller provided in an embodiment of the present invention.

[0031] Among them, the reference numerals in the figure are:

[0032] 10. Blank; 11. First reference plane; 12. Clamping hole; 13. Fourth reference plane; 14. Threaded hole; 15. Cutting spacing; 16. Carrying plate; 17. Long hole; 18. Roller; 19. Center axis; 20. Rotating sleeve; 21. Indicator light; 22. Pressure sensor. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0035] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] See also Figures 1 to 4 Now, the linear guide rail processing method provided by the present invention is described. A linear guide rail processing method comprises:

[0038] S1: Select a blank 10, the length of which is greater than the length of the two linear guide rails and retains a machining allowance; perform preliminary straightening along the length direction of the blank 10;

[0039] S2: Processing a first reference surface 11 on the upper end surface of the blank 10, and processing four groups of symmetrically arranged clamping holes 12 on the first reference surface 11, wherein two groups of clamping holes 12 are respectively located at the two ends of the blank 10, and the other two groups of clamping holes 12 are located in the middle of the blank 10; and the four groups of clamping holes 12 are all located on the machining allowance of the blank 10; processing two symmetrically arranged second reference surfaces on the side surface of the blank 10; processing third reference surfaces on both end surfaces of the blank 10;

[0040] S3: Connect the first reference surface 11 as the bottom surface to the fixture, and use bolts to connect to the clamping hole 12 to fix the blank 10 on the fixture;

[0041] S4: Rough machining the surface of the blank 10 and the matching grooves on both sides;

[0042] S5: machining a fourth reference surface 13 on the upper end surface of the blank 10, taking the second reference surface and one third reference surface as machining references, and machining a group of threaded holes 14 on the fourth reference surface 13; taking the second reference surface and another third reference surface as machining references, machining another group of threaded holes 14 on the fourth reference surface 13;

[0043] S6: The fourth reference surface 13 is installed on the fixture as the bottom surface, and the blank 10 is fixedly installed on the fixture by connecting to the threaded hole 14 with a bolt;

[0044] S7: Cut the blank 10 into two equal linear guides based on the threaded hole 14, and cut off the clamping holes 12 at both ends of the linear guides;

[0045] S8: heat treatment;

[0046] S9: Finishing.

[0047] Compared with the prior art, the linear guide processing method provided by the present invention is as follows: when producing and processing the linear guide, firstly, a suitable blank 10 is selected, and the length of the blank 10 is greater than the length of the two linear guides, so that the blank 10 has sufficient processing allowance and can be processed into two linear guides; then, a first reference surface 11, a second reference surface and a third reference surface are processed on the blank 10, and four groups of clamping holes 12 are processed on the first reference surface 11, and the blank 10 is mounted on the fixture by inverting, and the bolts on the fixture are penetrated through the clamping holes 12 to fix the blank 10. The blank 10 is fixed on the fixture, and the side surface and the matching groove on the side surface are rough-machined with the first reference surface 11; and the fourth reference surface 13 is machined on the upper end surface of the blank 10, and the blank 10 is reversely installed on the fixture with the fourth reference surface 13 as the bottom surface, and the bolts are used again to pass through the threaded holes 14 to fix the blank 10 on the fixture; at this time, the clamping hole 12 located on the machining allowance is no longer fixedly connected to the fixture, and then most of the machining allowance and the clamping hole 12 are cut off, and two linear guides are formed at the same time, and finally the two linear guides are heat treated and fine-machined. In this way, the length of the blank 10 is selected to be greater than the length of the two linear guide rails, and the clamping hole 12 is opened on the machining allowance in the first positioning and installation. It is more convenient and accurate to use a clamp to clamp and position the blank 10. The second positioning uses the end face of the linear guide and finally cuts off the machining allowance and the clamping hole 12 together to ensure that the machining and positioning of the blank 10 is less difficult. When the machining allowance and the clamping hole 12 are cut off from the blank 10, the blank 10 is divided into two linear guide rails, which also improves production efficiency.

[0048] The clamping hole 12 will not affect the linear guide rail itself, nor will it cause quality problems for the linear guide rail. When the machining allowance is cut off, the linear guide rail has a finishing allowance.

[0049] See also Figure 1As a specific implementation of the linear guide processing method provided by the present invention, the machining allowance of the blank 10 is greater than the sum of the dimensions of the four groups of clamping holes 12 in the length direction of the blank 10, and a cutting spacing 15 is provided between the two groups of clamping holes 12 located in the middle position of the blank 10; therefore, after accurately machining the four groups of clamping holes 12 on the blank 10, there is still enough advance to machine the blank 10, and when the blank 10 is cut into multiple parts, it will not affect the size of the linear guide. The cutting spacing 15 is set between the two groups of clamping holes 12 in the middle position, so that when the blank 10 is cut to form two linear guides, the cutting process is more stable, and the two linear guides are first completely separated by means of the cutting spacing 15, and then the clamping holes 12 on the machining allowance on both sides of the linear guides are cut off respectively, so that the machining of the two linear guides is not affected by each other.

[0050] See also Figure 1 As a specific implementation of the linear guide machining process provided by the present invention, the number of the two groups of clamping holes 12 located in the middle of the blank 10 is two, and the clamping holes 12 in the two groups of clamping holes 12 located in the middle of the blank 10 correspond to each other and are arranged in a staggered manner; that is, each group of clamping holes 12 has two clamping holes 12, so that the blank 10 is fixed more firmly, and there will be no uneven fixing force and inaccurate machining. And the four clamping holes 12 in the two groups of clamping holes 12 located in the middle are staggered along the width direction of the blank 10, and the four staggered clamping holes 12 make the blank 10 evenly stressed in the width direction, and the force distribution range is denser.

[0051] See also Figures 1 to 4 As a specific implementation of the linear guide rail processing method provided by the present invention, when two groups of threaded holes 14 are processed by the second reference plane and the third reference plane in S5, multiple threaded holes 14 of the same group are evenly arranged between the two groups of clamping holes 12; the axes of the multiple threaded holes 14 are located on the same plane, and the threaded holes 14 are equidistant from both sides of the blank 10; the two groups of threaded holes 14 are symmetrically arranged on the blank 10; in order to ensure the accuracy of the processing of the threaded holes 14, the two groups of threaded holes 14 are processed on the blank 10 with the help of the second reference plane and the third reference plane, and the number of threaded holes 14 in each group of threaded holes 14 is multiple, and the two groups of threaded holes 14 are evenly arranged between the two groups of clamping holes 12 on a linear guide, and the central axis 19 of the threaded hole 14 is located in the middle of both sides of the blank 10, so that after the threaded hole 14 is processed, the processing allowance on the blank 10 is evenly arranged on the outer side of the blank 10, which is convenient for subsequent processing and ensures processing accuracy.

[0052] See also Figure 1 and Figure 2As a specific implementation of the linear guide rail processing method provided by the present invention, the fixture includes a supporting plate 16, and the lower end of the supporting plate 16 is provided with mounting holes corresponding to the clamping holes 12 and the threaded holes 14 respectively; the lower end of the supporting plate 16 is provided with a plurality of support blocks, and the mounting holes penetrate the supporting plate 16. Therefore, with the help of a plurality of support blocks, the blank 10 is installed on the supporting plate 16, and bolts are used to pass through the mounting holes from bottom to top and connected with the clamping holes 12 or the threaded holes 14, thereby achieving the purpose of fixing the supporting plate 16 to the blank 10.

[0053] See also Figure 2 As a specific embodiment of the linear guide machining process provided by the present invention, a plurality of elongated holes 17 are also provided on the carrier plate 16, and the length direction of the elongated holes 17 is consistent with the width direction of the blank 10; the length of the elongated holes 17 is greater than the width of the blank 10; the plurality of elongated holes 17 are respectively opened at the end and the middle position of the carrier plate 16, and the plurality of elongated holes 17 respectively correspond to the plurality of cutting positions of the blank 10; the cutting position of the cutting knife is located directly above the corresponding elongated holes 17; the elongated holes 17 are mainly used for the blank 10 to cut, and the elongated holes 17 play the role of the carrier plate 16 avoiding the cutting tool. When the cutting tool cuts the blank 10, the existence of the elongated holes 17 enables the cutting tool to cut the blank 10 thoroughly and quickly.

[0054] See also Figure 2 As a specific embodiment of the linear guide rail processing method provided by the present invention, the number of the long strip holes 17 is five, two of which correspond to the cutting positions at the two ends of the blank 10, and three of which correspond to the middle position of the blank 10. The three long strip holes 17 correspond to the three cutting positions in the middle position of the blank 10. When the cutting tool cuts the blank 10, the cutting tool can smoothly complete the cutting work of the blank 10 under the avoidance effect of the long strip holes 17. The two ends of the blank 10 are cut twice, and the middle position of the blank 10 is cut three times.

[0055] As a specific implementation of the linear guide rail processing method provided by the present invention, the linear guide rail processing method also includes S10: performing rust-proof treatment on the surface of the linear guide rail; by performing rust-proof treatment on the surface of the linear guide rail, it is ensured that the linear guide rail is used more accurately and smoothly and has a longer service life.

[0056] See also Figure 5, as a specific implementation of the linear guide processing technology method provided by the present invention, after the linear guide is processed, the straightness of the linear guide is detected; the linear guide is placed on one side of a plurality of rollers 18 arranged in parallel at intervals, and the central axes 19 of the plurality of rollers 18 are located on the same plane; the different sides of the linear guide are controlled to abut against the plurality of rollers 18 in sequence, and the bending position of the linear guide is judged according to the change in the distance between the side surface of the linear guide and the rollers 18, and a hammer press is used to act on the bending position of the linear guide to squeeze the linear guide straight; during detection, the linear guide is placed on one side of the plurality of rollers 18, and the side surface of the linear guide is in contact with the plurality of rollers 18. The staff judges the bending position of the linear guide according to the distance between the linear guide and the side surface of the rollers 18, and then the staff places the bending position under the hammer press, and then the hammer press presses on the bending position of the linear guide, making the straightness of the linear guide higher. A rolling plane is arranged on one side of the rollers 18, and a plurality of rolling shafts are arranged on the rolling plane. The linear guide is placed on the plurality of rolling shafts, making the movement of the linear guide smoother and faster.

[0057] Please refer to Figure 5 , as a specific implementation of the linear guide processing technology method provided by the present invention, the roller 18 includes a central shaft 19 and a rotating sleeve 20 rotatably connected to the central shaft 19. A pressure sensor 22 is arranged between the central shaft 19 and the rotating sleeve 20, and an indicator light 21 is arranged on each central shaft 19; a hollow cavity is arranged in the central shaft 19 and a control unit installed in the hollow cavity; the pressure sensor 22 and the indicator light 21 are both electrically connected to the control unit; specifically in use, the staff controls the linear guide to abut against the rotating sleeve 20 outside the plurality of rollers 18, and since the linear guide contacts the rotating sleeve 20 and generates a force, the rotating sleeve 20 presses on the pressure sensor 22, and the indicator light 21 is turned on and emits light by means of the controller, while the bending position cannot act on the rotating sleeve 20 of the corresponding roller 18, and the indicator light 21 at this position is in the off state. Therefore, the staff can quickly and accurately find the bending position of the linear guide.

[0058] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A linear guide rail processing method, characterized in that: include: S1: Select a blank, the length of which is greater than the length of the two linear guide rails and retains a machining allowance; perform preliminary straightening along the length direction of the blank; S2: machining a first reference surface on the upper end surface of the blank, machining four groups of symmetrically arranged clamping holes on the first reference surface, wherein two groups of clamping holes are respectively located at the two ends of the blank, and the other two groups of the clamping holes are located in the middle of the blank; and the four groups of the clamping holes are all located on the machining allowance of the blank; machining two symmetrically arranged second reference surfaces on the side surface of the blank; machining third reference surfaces on both end surfaces of the blank; S3: connecting the first reference surface as a bottom surface to the fixture, and using bolts to connect to the clamping hole to fix the blank on the fixture; S4: performing rough machining on the surface of the blank and the matching grooves on both sides; S5: machining a fourth reference surface on the upper end surface of the blank, taking the second reference surface and one of the third reference surfaces as machining references, and machining a group of threaded holes on the fourth reference surface; taking the second reference surface and another of the third reference surfaces as machining references, and machining another group of threaded holes on the fourth reference surface; S6: The fourth reference plane is used as the bottom surface to be installed on the fixture, and the blank is fixed on the fixture by connecting to the threaded hole with bolts; S7: Cutting the blank into two equal linear guide rails based on the threaded hole, and cutting off the clamping holes at both ends of the linear guide rails; S8: heat treatment; S9: Finishing.

2. The linear guide rail processing method according to claim 1, characterized in that: The machining allowance of the blank is greater than the sum of the dimensions of the four groups of clamping holes in the length direction of the blank, and a cutting spacing is provided between the two groups of clamping holes located in the middle of the blank.

3. The linear guide rail processing method according to claim 2, characterized in that: The number of the two groups of clamping holes located in the middle of the blank is two each, and the clamping holes in the two groups of clamping holes located in the middle of the blank correspond to each other one by one and are arranged alternately.

4. The linear guide rail processing method according to claim 1, characterized in that: When the two groups of threaded holes are processed by the second reference plane and the third reference plane in S5, the multiple threaded holes in the same group are evenly arranged between the two groups of clamping holes; the axes of the multiple threaded holes are located on the same plane, and the threaded holes are equidistant from both sides of the blank; the two groups of threaded holes are symmetrically arranged on the blank.

5. The linear guide rail processing method according to claim 1, characterized in that: The clamp comprises a bearing plate, and the lower end of the bearing plate is provided with mounting holes corresponding to the clamping holes and the threaded holes respectively.

6. The linear guide rail machining method according to claim 5, characterized in that: The carrier plate is also provided with a plurality of elongated holes, the length direction of the elongated holes is consistent with the width direction of the blank; the length of the elongated holes is greater than the width of the blank; the plurality of elongated holes are respectively opened at the end and the middle position of the carrier plate, and the plurality of elongated holes respectively correspond to the plurality of cutting positions of the blank; the cutting position of the cutting knife is located directly above the corresponding elongated hole.

7. The linear guide rail machining method according to claim 6, characterized in that: The number of the long strip holes is five, two of which are respectively opened at the two ends of the bearing plate, and three of which are located in the middle of the bearing plate; two cuts are made at the two ends of the blank, and three cuts are made in the middle of the blank.

8. The linear guide rail machining method according to claim 1, characterized in that: The linear guide rail processing method also includes: S10: Perform rust-proof treatment on the surface of the linear guide.

9. The linear guide rail machining method according to claim 1, characterized in that: After the linear guide is processed, the straightness of the linear guide is tested; the linear guide is placed on one side of a plurality of rollers arranged in parallel and spaced apart, and the central axes of the plurality of rollers are located on the same plane; different side surfaces of the linear guide are controlled to abut against the plurality of rollers in turn, and the bending position of the linear guide is determined according to the change in the distance between the side surface of the linear guide and the rollers, and a hammer press is used to act on the bending position of the linear guide to squeeze the linear guide straight.

10. The linear guide rail machining method according to claim 9, characterized in that: The roller includes a central axis and a rotating sleeve rotatably connected to the central axis, a pressure sensor is provided between the central axis and the rotating sleeve, and an indicator light is provided on each central axis; a hollow cavity and a control unit installed in the hollow cavity are provided in the central axis; the pressure sensor and the indicator light are electrically connected to the control unit.

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