CN217193700U - Device for assisting in mounting camshaft bush - Google Patents

Abstract

The application discloses a device for assisting installation camshaft bush belongs to the appurtenance field. The sum of the lengths of the second column section and the third column section of the device along the axial direction is less than the width of the camshaft bush, and the camshaft bush can be sleeved outside the camshaft bush; the outer diameters of the first column section and the fourth column section are consistent with the outer diameter of the camshaft lining; the axis position of the guide post is provided with a threaded hole, the axis position of the positioning post is provided with a through hole, and the bolt is used for penetrating through the through hole and then being screwed into the threaded hole to fix the guide post and the positioning post; a through hole penetrating through the third column section in the radial direction is formed in the third column section, and when the camshaft bush is installed on the device, the through hole is aligned with the oil hole of the camshaft bush; the outer side wall of the guide post is provided with at least one group of guide structures along the axial direction, and the extending direction of the guide structures is parallel to the axis of the guide post. The device of this application can guarantee that the oilhole on the camshaft bush and the mistake oilhole on the crankcase body are adjusted well, adjusts process labour saving and time saving just to adjusting well effectually.

Description

Device for assisting in mounting camshaft bush

Technical Field

The application relates to the technical field of auxiliary tools, in particular to a device for assisting in installing a camshaft bushing.

Background

The camshaft is one of air-cooled diesel engine's key spare part, but air-cooled diesel engine is at the working process, and the camshaft wearing and tearing easily, in the reality, designed the camshaft bush and reduced the wearing and tearing of camshaft, because the camshaft bush cover becomes to hold the piece of grinding in the friction pair, change when camshaft bush wearing and tearing to a certain extent, compare in changing camshaft cost-effective more.

At present, the assembler directly installs the camshaft bush through experience, guides by the camshaft bush itself, can lead to the oilhole on the camshaft bush and the oilhole of crossing on the crankcase body of air-cooled diesel engine to adjust well, adjusts the process well and wastes time and energy, adjusts well the effect still not good.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a device for assisting installation camshaft bush, can solve current camshaft bush's mounting means and lead to oilhole on the camshaft bush and the oilhole of crossing on the crankcase body to adjust well, adjust the process well and waste time and energy and adjust the problem that the effect is not good well.

The embodiment of the utility model provides a device for assisting installation camshaft bush, including guide post, reference column and bolt; the guide column comprises a first column section and a second column section, and the positioning column comprises a third column section and a fourth column section; the sum of the lengths of the second column section and the third column section along the axial direction is smaller than the width of the camshaft lining, and the camshaft lining can be sleeved outside the second column section and the third column section; the outer diameters of the first column section and the fourth column section are consistent with the outer diameter of the camshaft lining; a threaded hole is formed in the axis position of the guide post, a through hole is formed in the axis position of the positioning post, and the bolt is used for penetrating through the through hole and then being screwed into the threaded hole to fix the guide post and the positioning post; the third column section is provided with a through hole which radially penetrates through the third column section, and when the camshaft lining is installed on the device, the through hole is aligned with the oil hole of the camshaft lining; the outer side wall of the guide post is provided with at least one group of guide structures along the axial direction, and the extending direction of the guide structures is parallel to the axis of the guide post.

In one possible implementation, the guide structure includes a guide groove, and the guide groove is colored.

In one possible implementation manner, a first width of the guide groove in the circumferential direction of the guide column coincides with a second width of the through hole in the circumferential direction of the positioning column.

In one possible implementation, the guide post is recessed inwardly from an end face of the second post section to form a cavity.

In one possible implementation, the end face of the first column section of the guide column is annularly arrayed around its center with at least two lightening holes.

In one possible implementation, the positioning post is recessed inwardly from an end face of the third post segment to form a cavity.

In a possible implementation manner, the through hole is recessed inwards from the end face of the third column section along the axial direction of the guide column, and the contour of the through hole on the side wall of the third column section comprises two straight lines and a semicircular arc; the two sections of straight lines are arranged in parallel, one end of each straight line extends to the end face of the third column section, and the other end of each straight line is connected with the two ends of the semicircular arc.

In a possible implementation manner, one end of the first column section, which is away from the second column section, is a first end, and the other end of the first column section is a second end; the lateral wall of first end is preset the angle with the lateral wall of second end.

In one possible implementation, an end of the third column section near the fourth column section is recessed inward from an outer side wall of the third column section to form a ring groove.

The embodiment of the utility model provides an in one or more technical scheme, following technological effect or advantage have at least:

an embodiment of the utility model provides a device for assisting installation camshaft bush, the device includes guide post, reference column and bolt. The guide post comprises a first post section and a second post section, and the positioning post comprises a third post section and a fourth post section. The sum of the lengths of the second column section and the third column section along the axial direction is smaller than the width of the camshaft lining, and the camshaft lining can be sleeved outside the second column section and the third column section. The outer diameters of the first column section and the fourth column section are consistent with the outer diameter of the camshaft lining. The axis position department of guide post is provided with the screw hole, and the axis position department of reference column is provided with the via hole, and the bolt is used for passing the via hole back and twists the screw hole in order to fix guide post and reference column. And a through hole radially penetrating through the third column section is formed in the third column section, and when the camshaft bush is installed on the device, the through hole is aligned with the oil hole of the camshaft bush. The outer side wall of the guide post is provided with at least one group of guide structures along the axial direction, and the extending direction of the guide structures is parallel to the axis of the guide post.

The embodiment of the utility model provides a device for assisting installation camshaft bush, when in-service use, locate the third post section of reference column with camshaft bush cover earlier, later install the guide post, block the second post section of guide post on camshaft bush's hole, keep guide structure along the center of the axial central line of guide post and the through-hole in the third post section on a straight line, and keep the center of through-hole and the center of the oilhole of camshaft bush to align, screw in the screw hole on the guide post after the bolt passes the via hole on the reference column and just can fix guide post and reference column. Because the length sum of the second column section and the third column section along the axial direction is less than the width of the camshaft bush, and the camshaft bush is sleeved on the second column section and the third column section, the camshaft bush can be fixed on the device when the guide column and the positioning column are fixed. And then the device for fixing the camshaft bush is integrally inserted into a camshaft bush mounting hole of the crankcase body, the projection of the oil passing hole in the crankcase body on the guide post is kept to be positioned on the axial center line of the guide structure along the guide post, the end face of the fourth post section of the positioning post is knocked by using weights such as copper bars until the center of the oil passing hole is coincided and aligned with the center of the oil hole of the camshaft bush, at the moment, a light beam can be driven into the oil passing hole above the crankcase body and can penetrate out of the oil passing hole below, and the center of the oil passing hole can be coincided and aligned with the center of the oil hole of the camshaft bush. Adopt the embodiment of the utility model provides a device installation camshaft bush for assisting installation camshaft bush can guarantee that the oilhole on the camshaft bush and the oilhole of crossing on the crankcase body are adjusted well, adjusts process labour saving and time saving and adjusts well effectually.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an apparatus for assisting in installing a camshaft liner according to an embodiment of the present disclosure;

FIG. 2 is a schematic view of the guide post in the direction A-A of FIG. 1;

FIG. 3 is a left side view of a guide post provided in embodiments of the present application;

fig. 4 is a schematic structural diagram of a positioning pillar according to an embodiment of the present disclosure;

FIG. 5 is a first schematic diagram illustrating a first usage process of the device for assisting in mounting a camshaft liner according to the embodiment of the present application;

FIG. 6 is a schematic diagram of a second process of using the apparatus for assisting in mounting a camshaft liner according to the embodiment of the present application.

Icon: 1-a guide post; 11-a first column section; 111-a threaded hole; 112-lightening holes; 12-a second column section; 13-a guide structure; 131-a guide groove; 1311-midline; 2-a positioning column; 21-a third column section; 211-through holes; 2111-straight line; 2112-half circular arc; 212-ring groove; 22-a fourth column section; 221-a via hole; 3-a bolt; 4-camshaft liner; 41-oil hole; 5-crankcase body; 51-oil passing holes; a-a first width; b-a second width; alpha-a preset angle.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the embodiments of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience of description of the embodiments of the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. The terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Furthermore, the terms "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the embodiments of the present invention can be understood by those skilled in the art according to specific situations.

Referring to fig. 1, an embodiment of the present invention provides a device for assisting installation of a camshaft liner, including a guide post 1, a positioning post 2 and a bolt 3. The guide post 1 comprises a first post section 11 and a second post section 12, and the positioning post 2 comprises a third post section 21 and a fourth post section 22. Wherein, the first column section 11 and the second column section 12 are integrally formed, and the third column section 21 and the fourth column section 22 are integrally formed. The sum of the lengths of the second column section 12 and the third column section 21 in the axial direction is smaller than the width of the camshaft bush 4, and the camshaft bush 4 can be sleeved outside the second column section 12 and the third column section 21, in practice, the camshaft bush 4 has two sizes, and the sum of the lengths of the second column section 12 and the third column section 21 in the axial direction is smaller than the width of the camshaft bush 4 with the smallest width, because the guide column 1 and the positioning column 2 are separately arranged, when the guide column 1 and the positioning column 2 are fixed, and the camshaft bush 4 is sleeved outside the second column section 12 and the third column section 21, the sum of the lengths of the second column section 12 and the third column section 21 in the axial direction is smaller than the width of the camshaft bush 4 with the smallest width, so that the camshaft bush 4 with all sizes can be clamped, and only the opposite end faces of the second column section 12 and the third column section 21 have a certain distance after the camshaft bush 4 is clamped. The outer diameters of the second column section 12 and the third column section 21 are generally consistent with the inner diameter of the inner hole of the camshaft bush 4, so that the camshaft bush 4 cannot shake or rotate after being sleeved on the second column section 12 and the third column section 21. The outer diameters of the first column section 11 and the fourth column section 22 are the same as the outer diameter of the camshaft liner 4, so that the outer side walls of the first column section 11, the fourth column section 22 and the camshaft liner 4 are on the same cylindrical surface after the camshaft liner 4 is installed and fixed on the device.

The axis position department of guide post 1 is provided with screw hole 111, and the axis position department of reference column 2 is provided with via hole 221, and bolt 3 is used for passing behind via hole 221 and screws into screw hole 111 in order to fix guide post 1 and reference column 2. The third cylindrical section 21 is provided with a through hole 211 radially penetrating therethrough, and when the camshaft bush 4 is mounted on the apparatus, the through hole 211 is aligned with the oil hole 41 of the camshaft bush 4. At least one group of guide structures 13 along the axial direction is arranged on the outer side wall of the guide column 1, the extending direction of the guide structures 13 is parallel to the axis of the guide column 1, and fig. 1 shows a structural schematic diagram that the group of guide structures 13 along the axial direction is arranged on the outer side wall of the guide column 1.

The embodiment of the utility model provides a device for assisting installation camshaft bush, when in actual use, locate camshaft bush 4 on the third post section 21 of reference column 2 with the cover earlier, later install guide post 1, block the second post section 12 of guide post 1 on camshaft bush 4's hole, keep guide structure 13 along the center of guide post 1 axial central line 1311 and the through-hole 211 on the third post section 21 on a straight line, and keep the center of through-hole 211 and the center of the oilhole 41 of camshaft bush 4 to align, later bolt 3 twists screw hole 111 on the guide post 1 after passing through hole 221 on reference column 2 and just can be fixed with guide post 1 and reference column 2. Because the sum of the lengths of the second column section 12 and the third column section 21 in the axial direction is smaller than the width of the camshaft bush 4, and the camshaft bush 4 is sleeved on the second column section 12 and the third column section 21, the camshaft bush 4 can be fixed on the device while the guide column 1 and the positioning column 2 are fixed. Then, the device for fixing the camshaft bush 4 is integrally inserted into the camshaft bush mounting hole of the crankcase 5, the projection of the oil passing hole 514 on the crankcase 5 on the guide post 1 is kept on the center line 1311 of the guide structure 13 along the axial direction of the guide post 1, the end face of the fourth post section 22 of the positioning post 2 is knocked by using a heavy object such as a copper bar until the center of the oil passing hole 51 is coincided and aligned with the center of the oil hole 41 of the camshaft bush 4, at the moment, a light beam can be driven into the oil passing hole 51 above the crankcase 5 and can penetrate out from the oil passing hole 51 below, and therefore the coincidence and alignment of the center of the oil passing hole 51 and the center of the oil hole 41 of the camshaft bush 4 can be guaranteed. Adopt the embodiment of the utility model provides a device installation camshaft bush 4 for assisting installation camshaft bush can guarantee that oilhole 41 on camshaft bush 4 and the oilhole 51 of crossing on the crankcase body 5 are adjusted well, adjusts process labour saving and time saving and adjusts well effectually.

As can be seen from the above working process, when the camshaft liner 4 is installed by using the device, the center line 1311 of the guide structure 13 along the axial direction of the guide post 1 is aligned with the center of the through hole 211 on the third post segment 21, and the center of the through hole 211 is aligned with the center of the oil hole 41 of the camshaft liner 4, so that the projection of the center of the oil hole 41 on the positioning post 2 is located on the center line 1311 of the guide structure 13 along the axial direction of the guide post 1, and the projection of the oil passing hole 51 of the crankcase body 5 on the positioning post 2 is located on the center line 1311 of the guide structure 13 along the axial direction of the guide post 1, thereby finally ensuring the centers of the through hole 211 of the positioning post 2, the oil hole 41 of the camshaft liner 4 and the oil passing hole 51 of the crankcase body 5 to be aligned. The length of the guide post 1 is generally set to be greater than the width of the crankcase body 5 so that, after the device is inserted into the camshaft bush mounting hole of the crankcase body 5, as shown in fig. 5, when the device has not been knocked to move, it is possible to ensure that the projection of the center of the oil passing hole 51 in the crankcase body 5 on the guide post 1 and the projection of the center of the oil hole 41 in the camshaft bush 4 on the positioning post 2 are both located on the center line 1311 of the guide structure 13 in the axial direction of the guide post 1 by observing the guide structure 13 on the side of the second segment 12. As shown in fig. 6, when the tapping device is moved, it is ensured that the projections of the centers of the oil hole 51 in the crankcase 5 and the oil hole 41 in the camshaft bush 4 on the positioning post 2 are both located on the center line 1311 of the guiding structure 13 along the axial direction of the guiding post 1 by observing the guiding structure 13 on the side of the first column section 11.

As shown in fig. 1, the guide structure 13 includes the guide groove 131, and the guide groove 131 is painted with color, so that it can be ensured that the guide groove 131 and the color painted thereon will not be worn after the device for assisting in mounting a camshaft bush provided in the embodiment of the present application is used for a plurality of times, the guidance of the guide structure 13 will not be affected, the service life of the device is prolonged, and the guide shaft is painted with color to facilitate observation by an assembler. Of course, the guiding structure 13 may be a color strip, but the color strip will be worn and fall off continuously during the continuous use of the device, and the service life of the device will be shortened.

As shown in fig. 1, the first width a of the guide groove 131 in the circumferential direction of the guide post 1 is equal to the second width b of the through hole 211 in the circumferential direction of the positioning post 2, so that the installation deviation of the oil hole 41 in the camshaft bush 4 and the oil passing hole 51 in the crankcase 5 after the installation is completed can be reduced. Specifically, the alignment of the oil hole 41 of the camshaft liner 4 and the oil passing hole 51 of the crankcase 5 is ensured by the projection of the positioning post 2 on the center line 1311 of the guide groove 131 in the axial direction, and the first width a of the guide groove 131 along the circumferential direction of the guide post 1 is consistent with the second width b of the through hole 211 along the circumferential direction of the positioning post 2, so that the center of the through hole 211 of the positioning post 2 and the center line 1311 of the guide groove 131 along the axial direction can be better ensured to be on the same straight line, and the oil hole 41 of the camshaft bush 4 and the oil passing hole 51 of the crankcase body 5 are aligned with the center of the through hole 211, so that it can be ensured that the projection of the oil hole 41 of the camshaft liner 4 and the oil passing hole 51 of the crankcase 5 on the guide post 1 is more accurately positioned on the center line 1311 of the guide groove 131 in the axial direction, thus, the installation deviation of the oil hole 41 on the camshaft bush 4 and the oil passing hole 51 on the crankcase body 5 after the installation is completed can be reduced.

As shown in fig. 2, the guide post 1 is recessed inward from the end surface of the second column section 12 to form a cavity, so that the quality of the guide post 1 can be reduced and the use of the device can be facilitated.

As shown in fig. 2 and 3, the end face of the first column section 11 of the guide column 1 is annularly arrayed around the center thereof with at least two lightening holes 112, as shown in fig. 3, a structural schematic view of five lightening holes 112 is shown, and the five lightening holes 112 are arranged at equal intervals, so that the mass of the guide column 1 can be further reduced. And the arrangement of the lightening hole 112 can enable light to shine into the inner cavity of the guide post 1, thereby being convenient for an assembler to observe during assembly.

As shown in fig. 4, the positioning column 2 is recessed from the end face of the third column section 21 to form a cavity, so that the quality of the positioning column 2 can be reduced, and the use of the device is facilitated. The through holes 211 on the positioning post 2 are two holes disposed at opposite positions on the sidewall of the positioning post 2.

Referring to fig. 1 and 4, in the axial direction of the guide post 1, the through hole 211 is recessed inward from the end surface of the third post section 21, and the contour of the through hole 211 on the side wall of the third post section 21 includes two straight lines 2111 and a semicircular arc 2112. The two straight lines 2111 are arranged in parallel, one end of each straight line extends to the end face of the third column section 21, and the other end of each straight line is connected with the two ends of the semicircular arc 2112, namely the through hole 211 is in a U shape on the side wall of the third column section 21. In practice, the size of the oilhole 41 of camshaft bush 4 has different specifications, and the embodiment of the utility model provides an in the design of the profile of third column section 21, in the use, its center can align the oilhole 41 of different specifications size to can improve the application scope of device, its processing is also more convenient moreover. Of course, the through hole 211 may be provided as a circular hole.

As shown in fig. 1, one end of the first column section 11 facing away from the second column section 12 is a first end, and the other end is a second end. The outer side wall of the first end and the outer side wall of the second end form a preset angle alpha. The size of the preset angle alpha is set by the skilled person according to the actual situation, and can be set to 5 degrees. In practice, in the process of inserting the device into the camshaft bush mounting hole of the crankcase 5 and striking the device to move the device, the central axis of the device cannot be completely kept on the same straight line with the central axis of the crankcase 5, and a certain inclination exists, the outer side wall of the first end of the first column section 11 and the outer side wall of the second end form a preset angle alpha, so that the front end of the first column section 11 close to the first end is in a circular truncated cone shape, and the guide post 1 with the circular truncated cone shape at the front end has the function of automatic alignment when the central axis of the guide post and the central axis of the crankcase 5 are not on the same straight line, so that in the process of inserting the device into the camshaft bush mounting hole of the crankcase 5 and striking the device to move the device, the central axis of the device and the central axis of the crankcase 5 can be kept on the same straight line, and the position deviation of the device in the moving process is reduced.

As shown in fig. 1 and 4, an end of the third column section 21 near the fourth column section 22 is recessed inwardly from an outer side wall of the third column section 21 to form an annular groove 212. In practice, the accuracy of camshaft sleeve 4 is high, and the provision of annular groove 212 prevents deformation of the end face of camshaft sleeve 4 during the stroke advance.

The utility model provides a pair of working process of embodiment does: the assembly personnel check the cleanliness of the camshaft bush mounting hole of the device for assisting in mounting the camshaft bush and the crankcase body 5, and ensure that the surface is free of burrs and foreign matters. Firstly, the camshaft bush 4 is sleeved on the third column section 21 of the positioning column 2, then the guiding column 1 is installed, the second column section 12 of the guiding column 1 is clamped on the inner hole of the camshaft bush 4, namely, the camshaft bush 4 is installed between the second column section 12 and the third column section 21, and the projection of the oil hole 41 of the camshaft bush 4 and the center of the through hole 211 of the positioning column 2 is located on the axial center line 1311 of the guiding structure 13 of the positioning column 2. Bolt 3 passes through hole 221 on reference column 2 and then screws into threaded hole 111 on guide column 1 to fix guide column 1 and reference column 2.

Coating a circle of engine oil on a camshaft bush mounting hole of a crankcase body 5 and the outer side wall of the device (ensuring that all the engine oil is coated on a first column section 11 of a guide column 1, a camshaft bush 4 and a fourth column section 22 of a positioning column 2 of the device), enabling the projection of an oil passing hole 51 of the crankcase body 5 on the guide column 1 to be positioned on a central line 1311 of a guide structure 13 along the axial direction of the guide column 1, then integrally inserting the device provided with the camshaft bush 4 into the camshaft bush mounting hole of the crankcase body 5, using a copper bar knocking device until the center of the oil passing hole 51 on the crankcase body 5 is basically coincided with the center of an oil hole 41 on the camshaft bush 4, at the moment, dismantling a bolt 3 of the device, and taking down the guide column 1 and the positioning column 2.

The above process is repeated until all the camshaft bushes 6 are completely installed.

The embodiments in the present specification are described in a progressive manner, and the same or similar parts among the embodiments may be referred to each other, and each embodiment is described with emphasis on the difference from the other embodiments.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications or substitutions do not depart from the spirit and scope of the present disclosure.

Claims (9)

1. A device for assisting in mounting a camshaft bushing is characterized by comprising a guide post, a positioning post and a bolt;

the guide column comprises a first column section and a second column section, and the positioning column comprises a third column section and a fourth column section;

the sum of the lengths of the second column section and the third column section along the axial direction is smaller than the width of the camshaft lining, and the camshaft lining can be sleeved outside the second column section and the third column section; the outer diameters of the first column section and the fourth column section are consistent with the outer diameter of the camshaft lining;

a threaded hole is formed in the axis position of the guide post, a through hole is formed in the axis position of the positioning post, and the bolt is used for penetrating through the through hole and then being screwed into the threaded hole to fix the guide post and the positioning post;

a through hole which radially penetrates through the third column section is formed in the third column section, and when the camshaft bush is installed on the device, the through hole is aligned with the oil hole of the camshaft bush;

the outer side wall of the guide post is provided with at least one group of guide structures along the axial direction, and the extending direction of the guide structures is parallel to the axis of the guide post.

2. The apparatus of claim 1, wherein the guide structure includes a guide groove, and the guide groove is colored.

3. The apparatus for assisting in installing a camshaft bushing according to claim 2, wherein a first width of the guide groove in a circumferential direction of the guide post coincides with a second width of the through hole in the circumferential direction of the positioning post.

4. The apparatus for assisting in the installation of a camshaft liner of claim 1,

the guide post is recessed inwardly from the end face of the second post section to form a cavity.

5. The apparatus for assisting in the installation of a camshaft liner as claimed in claim 4, wherein the end face of the first column section of the guide column is annularly arrayed around its center with at least two lightening holes.

6. The apparatus of claim 1, wherein the locating posts are recessed inwardly from an end surface of the third post segment to form a cavity.

7. The apparatus for assisting in mounting a camshaft liner according to claim 1 or 6, wherein the through hole is recessed inward from an end surface of the third column section in an axial direction of the guide column, and a contour of the through hole on a side wall of the third column section includes two straight lines and one semicircular arc;

the two sections of straight lines are arranged in parallel, one end of each straight line extends to the end face of the third column section, and the other end of each straight line is connected with the two ends of the semicircular arc.

8. The apparatus of claim 1, wherein the end of the first column section facing away from the second column section is a first end and the other end is a second end;

the lateral wall of first end is preset the angle with the lateral wall of second end.

9. The apparatus of claim 1, wherein an end of the third column section adjacent to the fourth column section is recessed inwardly from an outer sidewall of the third column section to form a ring groove.

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