CN111975591B

CN111975591B - Workpiece inner hole polishing device

Info

Publication number: CN111975591B
Application number: CN202010703274.2A
Authority: CN
Inventors: 吴建杰; 杜金釜; 李滨阳
Original assignee: Dongfang Electric Machinery Co Ltd DEC
Current assignee: Dongfang Electric Machinery Co Ltd DEC
Priority date: 2020-07-21
Filing date: 2020-07-21
Publication date: 2022-04-12
Anticipated expiration: 2040-07-21
Also published as: CN111975591A

Abstract

The invention discloses a workpiece inner hole polishing device which comprises at least two pairs of guide devices, a grinding device arranged between the guide devices, and a connecting rod used for connecting the guide devices and the grinding device; the guide device comprises a guide frame which is sleeved on the connecting rod and can rotate around the axial direction of the connecting rod, and a plurality of support legs arranged on the guide frame; the grinding device comprises a core plate sleeved and fixed on the connecting rod and a plurality of grinding machines arranged on the core plate. The polishing tool has the advantages of good adjustability and wide application range, is convenient to install and use, and can be used for polishing workpieces (such as a main shaft of a water turbine) without being adjusted to be leveled in operation.

Description

Workpiece inner hole polishing device

Technical Field

The invention relates to the technical field of water turbine manufacturing, in particular to a workpiece inner hole polishing device.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

The water turbine is a machine which converts water energy from water flow into mechanical energy of a rotating wheel, enables the rotating wheel and a main shaft to overcome various resistances and continuously run, and then converts the mechanical energy into electric energy through a generator rotor. The main shaft of the large-scale water turbine is usually of a hollow structure, the main shafts of the through-flow type water turbine and the pumped storage type water turbine are provided with central holes, and the aperture is usually within the range of 300-500 mm.

At present, social labor is divided into more and more fine labor, a main shaft of the water turbine is usually purchased from an outsourcing place, and a central hole is usually machined in place before purchasing and returning to a factory. The central hole surface is often rusted during the process of main shaft placement and order conversion. Because the central hole has small aperture, long length and difficult surface protection, the conventional polishing mode can not be adopted for rust removal treatment.

In this regard, the inventor is aware of a way to perform surface honing rust removal using a dedicated large honing apparatus. However, the inventors have also recognized that this way of honing rust removal has the following drawbacks:

1. a special honing head is required to be prepared according to the size of a central hole of a main shaft of the water turbine;

2. the main shaft of the water turbine needs to be adjusted to be level;

3. the honing equipment occupies a large space and is inconvenient to install;

4. the treatment efficiency is low, the preparation and treatment period is long, and even about one week is needed;

5. the processing cost is high, and the honing and derusting cost of the main shaft of a single water turbine is high, even reaching 7-10 ten thousand yuan.

Disclosure of Invention

Aiming at the existing problems, the invention provides a workpiece inner hole polishing device which has the advantages of strong practicability, simple and convenient operation, high efficiency, low cost and the like.

The invention discloses a workpiece inner hole polishing device, which is characterized in that:

the grinding device comprises at least two pairs of guide devices, a grinding device arranged between the guide devices and a connecting rod used for connecting the guide devices and the grinding device;

the guide device comprises a guide frame which is sleeved on the connecting rod and can rotate around the axial direction of the connecting rod, and a plurality of support legs arranged on the guide frame;

the grinding device comprises a core plate sleeved and fixed on the connecting rod and a plurality of grinding machines arranged on the core plate.

The invention discloses an optimal polishing tool, which is characterized in that: the supporting legs are detachably connected with the guide frame, and the length of the outward extending supporting legs is adjustable.

Further, a bearing is arranged between the guide frame and the connecting rod.

Furthermore, the support legs are provided with elastic pads.

The invention discloses another preferable grinding tool, which is characterized in that: the grinding machine is connected with the core plate through a grinding seat, the grinding seat is inserted on the core plate, and the length of the outward extending part of the grinding seat is adjustable.

Furthermore, the grinding seat is provided with an insertion handle, and the core plate is provided with an insertion groove matched with the insertion handle.

Furthermore, the insertion handle comprises a handle body and a handle bottom plate, wherein a spring is clamped in the middle of the handle body.

The invention discloses another preferable grinding tool, which is characterized in that: the connecting rod is sectional, is a solid rod piece and/or a hollow pipe piece and is provided with a lengthening section with a handle.

Further, the grinding machine is a pneumatic grinder which is connected with an external compressed air source through a hollow connecting rod.

Furthermore, the guide frame and the core plate are both similar to a triangle, three corners of the guide frame are respectively provided with one support leg, and three corners of the core plate are respectively provided with one grinding machine.

By comprehensively adopting the technical scheme, the invention can obtain the following beneficial effects:

1. the device has adjustability and wide application range;

2. the main shaft does not need to be adjusted to be level, and the equipment is convenient to mount and use.

Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic perspective view of a workpiece bore grinding apparatus according to some embodiments;

FIG. 1a is a schematic plan view of a hole grinding device for a workpiece according to some embodiments;

FIG. 2 is a schematic illustration of the construction of the guide frame in some embodiments;

FIG. 2a is a schematic view of the mounting structure of the first guiding frame in some embodiments;

FIG. 2b is a schematic view of the mounting structure of the second guiding frame in some embodiments;

FIG. 3 is a schematic diagram of the grinding apparatus in some embodiments, showing only one of the grinders;

FIG. 3a is a drawing of the assembled relationship of guide pins and guide holes in some embodiments;

FIG. 4 is a schematic structural view of a handle in some embodiments;

FIG. 5 is a schematic view of the elongated tube in some embodiments;

FIG. 6 is a schematic diagram of the construction of the connection shaft in some embodiments;

FIG. 7 is a schematic diagram of the structure of a first connecting tube in some embodiments;

FIG. 8 is a schematic view of the screw configuration of some embodiments;

FIG. 8a is a cross-sectional view taken at A-A of FIG. 8;

FIG. 8b is a view showing the assembly relationship of the screw rod with the core plate and the first connecting pipe in some embodiments;

FIG. 9 is a schematic diagram of a second connector tube in some embodiments;

FIG. 9a is a drawing showing the second connecting tube in assembled relation to the second guide frame and the core plate in some embodiments;

figure 10 is a schematic illustration of a method of using the workpiece bore grinding apparatus in some embodiments.

Description of reference numerals:

1-guide device, 11-first guide device, 111-guide frame, 112-support leg, 113-elastic pad, 114-bearing, 12-second guide device, 2-grinding device, 21-lug, 211-plug-in handle, 212-spring, 213-groove side plate, 214-adjusting bolt, 215-guide pin, 216-guide hole, 22-grinding wheel machine, 23-air pipe, 24-core plate, 3-connecting rod, 31-first connecting pipe, 311-air hole, 32-second connecting pipe, 33-screw rod, 34-connecting shaft, 35-connecting pipe, 36-handle and 4-water turbine main shaft.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.

In the description of the present invention, it is to be understood that the terms indicating an orientation or positional relationship are based on the orientation or positional relationship shown in the drawings 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 operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the drawings of the present invention, it should be understood that different technical features which are not mutually substituted are shown in the same drawing only for the convenience of simplifying the drawing description and reducing the number of drawings, and the embodiment described with reference to the drawings does not indicate or imply that all the technical features in the drawings are included, and thus the present invention is not to be construed as being limited thereto.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The invention relates to a grinding device for an inner hole of a workpiece, which comprises at least two pairs of guide devices 1, a grinding device 2 arranged between the guide devices 1 and a connecting rod 3 used for connecting the guide devices 1 and the grinding device 2, and is shown in figures 1 and 1 a. During operation, the guide device 1 and the grinding device 2 are both positioned in an inner hole of a workpiece, the guide device 1 is arranged on two sides of the grinding device 2, the middle grinding device 2 is erected, the grinding device 2 can be rightly positioned in the hole, namely, the grinding device is positioned in a proper position in the hole, deviation does not occur, and grinding precision is guaranteed.

As shown in fig. 2, 2a and 2b, the guiding device 1 includes a guiding frame 111 sleeved on the connecting rod 3, and a plurality of legs 112 disposed on the guiding frame 111. In some embodiments, the guiding frame 111 is triangular-like, and three corners of the guiding frame 111 are respectively provided with a leg 112, and the legs 112 are supported on the hole wall of the inner hole of the workpiece. The guide frame 111 is designed to be triangular, so that the characteristic that the triangle has strong stability can be effectively utilized, and more stable guiding and supporting effects can be realized.

In some embodiments, the legs 112 are detachably connected to the guide frame 111, and the outward extension length of the legs 112 is adjustable to improve the adaptability of the guide device 1. When the inner hole of the workpiece to be processed is larger, the leg 112 protrudes outward with respect to the center of the guide frame 111, and the leg 112 can also be supported on the hole wall of the larger inner hole. In one embodiment, one of the support leg 112 and the guide frame 111 is provided with a long bolt hole, and the other is provided with a row of bolts; in this embodiment, the bolt is continuously movable within the elongated bolt hole, thereby allowing for stepless adjustment of the legs 112, and the diameter of the workpiece inner hole may be a range of diameters. The support legs 112 are provided with elastic pads 113, such as nylon blocks, which can reduce friction and avoid scratching inner holes of workpieces. In another embodiment, one of the support leg 112 and the guide frame 111 is provided with a bolt, and the other is provided with a row of bolt holes; in this embodiment, the bolt holes are arranged in rows with a certain spacing between the bolt holes, so that stepless adjustment of the legs is difficult to achieve, and the diameter of the inner hole of the workpiece can only be a few diameter points, but when the elastic pad 113 is arranged on the leg 112, such as a nylon block, the elastic pad 113 can expand the diameter points to a range of diameters, so that stepless adjustment can also be achieved.

In some embodiments, the guide frame 111 is fitted over the connecting rod 3 and is rotatable about the axial direction of the connecting rod 3. In at least one embodiment, a bearing 114 is provided between the guide frame 111 and the connecting rod 3. The guide frame 111 can remain relatively stationary with respect to the bore while the grinding device 2 rotates about the central axis of the bore.

As shown in fig. 3 and 3a, the grinding device 2 includes a core plate 24 sleeved and fixed on the connecting rod 3, and a plurality of grinders provided on the core plate 24. In some embodiments, the core 24 is also triangular-like, with a grinder located at each of the three corners of the core 24. The three legs of the guide frame 111 are supported on the wall of the inner hole and are kept relatively stationary with the inner hole, but the guide frame 111 can rotate around the connecting rod 3, so that the core plate 24 can be driven to rotate by rotating the connecting rod 3, and three grinding machines can grind the whole circumferential surface of the inner hole.

In some embodiments, the grinding machine is coupled to the core plate 24 by a grinding block, the clamping portion of which may be designed according to the shape and size of the grinding machine, so that grinding devices 2 may be used with different specifications or types of grinding machines, and installation of the grinding machine is facilitated. In some embodiments, the grinding seat is inserted into the core plate 24, and the outward extension length of the grinding seat is adjustable, so that the grinding device 2 is suitable for grinding inner holes with different diameters. In at least one embodiment, the grinding seat has an insertion handle 211, an insertion groove matched with the insertion handle 211 is formed in the core plate 24, an elongated circular hole is formed in the side wall of the insertion groove, a first lug plate is arranged near one end, close to the notch, of the elongated circular hole, a second lug plate capable of penetrating through the elongated circular hole is arranged on the insertion handle 211, the two lug plates are connected through a bolt and a nut matched with the bolt, the distance between the two lug plates can be adjusted through screwing in or screwing out of the nut, and therefore the extending length of the grinding seat can be adjusted. In one embodiment, the plug-in handle 211 includes a handle body and a handle base plate, a spring 212 is sandwiched between the handle body and the handle base plate, and the second ear plate is disposed on the handle base plate. Through setting up spring 212, not only can ensure that the hole wall of grinder and hole is elastic contact, avoid the scotch that hard contact leads to, still can realize automatic compensation after the grinding head wearing and tearing of grinder moreover, need not to adjust the extension length of grinding seat immediately.

In the above embodiments, the insertion groove may be a single-sided opening, or may be a double-sided opening. When the insertion slot is a double-sided opening, the side of the insertion handle 211 is provided with a slot side plate 213, and the connection between the slot side plate 213 and the core plate 24 is realized through a bolt or a screw.

In some embodiments, the plug handle 211 is further provided with a guide pin 215, the core plate 24 is provided with a guide hole 216 matching with the guide pin 215, and the plug handle 211 can be extended or retracted along the guide hole 216 through the cooperation of the guide pin 215 and the guide hole 216, and the plug handle 211 can be prevented from being removed from the plug slot. The guide pin 215 is provided on the other side of the insertion handle 211 opposite to the second lug plate, and the guide hole 216 is provided on the other side of the core plate 24 opposite to the slot side plate 213.

As shown in fig. 1, 1a, in some embodiments, the connecting rod 3 is a solid rod or a hollow tube, which is segmented. In at least one embodiment, the connecting rod 3 has an elongated section with a handle 36, and manual rotation of the handle 36 causes the grinder to rotate within the bore. When the grinder is a pneumatic grinder 22, the connecting rod 3 and its extension can be arranged in a hollow structure, serving as a delivery duct for compressed air for the grinder 22.

At least one exemplary embodiment is now provided in connection with the drawings, a detailed description of which is provided in the drawings not intended to limit the scope of the claimed invention, but is merely representative of exemplary embodiments provided in the invention.

Exemplary embodiment 1

As shown in fig. 1 and 1a, the present exemplary embodiment relates to a grinding tool for grinding a center hole of a main shaft 4 of a water turbine, which comprises a first guide device 11, a second guide device 12, a grinding device 2 arranged between two pairs of guide devices 1, and a connecting rod 3 connecting the guide devices 1 and the grinding device 2 in series.

As shown in fig. 2, 2a and 2b, the guiding device 1 includes a triangular-like guiding frame 111, the guiding frame 111 is sleeved on the connecting rod 3 through a deep groove ball bearing, three corners of the guiding frame 111 are respectively provided with a supporting leg 112, and the extending length of the supporting leg 112 is adjustable through the cooperation of a long screw hole and a bolt. Taking one of the support legs 112 as an example, the support leg 112 is provided with a long screw hole, the guide frame 111 is provided with two bolts penetrating through the long screw hole, and when the nuts on the bolts are not screwed, the support leg 112 can move along the long direction of the long screw hole. When two bolts are distributed along the radial direction of the guide frame 111, the protruding length of the supporting leg 112 can be adjusted in the radial direction.

Setting parameters: the maximum adjustment of the protruding length of the legs 112 is 20mm, which is suitable for use in a vehicle

A central bore within a diameter range. The deep groove ball bearing conforms to the standard GB/T276.60000.2LS.61908.2LS.

As shown in fig. 3 and 3a, the grinding device 2 includes a triangular-like core plate 24, a grinding machine 22 is provided at each of three corners of the core plate 24, and the grinding machine 22 is mounted on the core plate 24 via a (grinding seat) lug 21. Taking one of the ear handles 21 as an example, the ear handle 21 comprises a barrel body and an insertion handle 211 on the outer wall of the barrel body, an insertion groove matched with the insertion handle 211 is arranged on the core plate 24, two sides of the insertion groove are opened, and after the insertion handle 211 is installed in place in the insertion groove, the groove side plate 213 is covered and fixed by bolts. The insertion handle 211 includes a handle body and a handle base plate, and a spring 212 is interposed between the handle body and the handle base plate. The slot side plate 213 is provided with a long circular hole, a first lug plate is arranged near one end of the long circular hole close to the notch, a second lug plate is arranged on the handle bottom plate and penetrates through the long circular hole, the two pairs of lug plates are connected through an adjusting bolt 214, and the distance between the two lug plates can be adjusted by screwing in or screwing out an adjusting nut on the adjusting bolt 214, namely the extension length of the insertion handle 211 is adjusted. In addition, the insertion handle 211 is further provided with a guide pin 215, the core plate 24 is provided with a guide hole 216 matched with the guide pin 215, and the insertion handle 211 can extend or retract along the guide hole 216 through the matching of the guide pin 215 and the guide hole 216, and the insertion handle 211 can be prevented from being separated from the insertion groove. The guide pin 215 is provided on the other side of the insertion handle 211 opposite to the second lug plate, and the guide hole 216 is provided on the other side of the core plate 24 opposite to the slot side plate 213.

Setting parameters: the maximum adjustment of the protruding length of the ear handle 21 is 30 mm.

The connecting rod 3 is of a sectional type and is a solid rod piece and/or a hollow pipe fitting. As shown in fig. 1 and 1a, the connecting rod 3 is connected to the second connecting pipe 32, the screw 33, the first connecting pipe 31 and the connecting shaft 34 in sequence. The core plate 24 is fitted over the screw 33, and the guide frame 111 of the first guide 11 is fitted over the connecting shaft 34. The second connecting pipe 32 has both ends connected to the guide frame 111 and the core plate 24 of the second guide 12, and the first connecting pipe 31 has both ends connected to the screw 33 and the connecting shaft 34. The other end of the connecting shaft 34 is also connected with a long pipe 35 with a handle 36. The first connecting pipe 31, the connecting shaft 34 and the long connecting pipe 35 are communicated hollow structures, one end of the long connecting pipe 35, which is connected with the handle 36, is connected with an external compressed air source, and the first connecting pipe 31 is provided with an air pipe 23 for supplying compressed air to the grinder 22. The segments of the connecting rod 3 are often connected by joints, and the specifications of the joints may be selected according to actual needs.

As shown in fig. 4, the handle 36 includes two pieces of phi 16 round steel with equal length and a hollow joint, and the round steel and the joint are welded together. The adapter is connected with the long pipe 35 through screw thread. The tail part of the connector is connected with a compressed air source and is also connected through threads. During operation, the handle 36 is rotated back and forth (the rotation angle exceeds 120 degrees) and pushed, so that different parts of the hole wall can be polished.

As shown in FIG. 5, the material of the main body of the extension pipe 35 is a phi 48X4.5 seamless steel pipe 20 (L). The specification is selected according to the requirement that the inner diameter of the grinding wheel can meet the requirement of the air flow of the 3 DT-SX3Z-2 type pneumatic grinders working simultaneously. The long pipe 35 has a total length of 1611mm, and is provided with connectors (one end is an internal thread and the other end is an external thread) at the left and right sides thereof so as to be connected with adjacent components. The extension pipe 35 is provided with two pieces which have the same size and structure and can be lengthened or shortened according to the actual depth of the central hole of the main shaft 1 of the water turbine.

As shown in fig. 6, the connecting shaft 34 is made of round steel with a diameter of 56 mm, and has a hollow structure, and both ends of the connecting shaft are respectively provided with an internal thread and an external thread for respectively connecting the first connecting pipe 31 and the long pipe 35.

As shown in fig. 7, the main body of the first connecting pipe 31 is a phi 48X4.5 seamless steel pipe 20(L), both ends are provided with joints, one end of the joint is a blind hole, and the other end of the joint is a through hole. Three air holes 311 are uniformly distributed on the steel pipe along the circumference, and air pipe joint seats are welded on the steel pipe to respectively supply air for the three grinding machines 22. The air duct 23 is made of a rubber hose, and connectors are disposed at two ends of the air duct and respectively connected to the first connecting pipe 21 and the sand turbine 22. The length of the air pipe 23 is ensured to meet the radial adjustment requirement of the grinder 22.

As shown in fig. 8, 8a and 8b, both ends of the screw 33 are connected to the first connecting pipe 31 and the core plate 24, respectively, and are tightened with nuts. A three-side boss is processed on the section of the screw 33 and matched with a three-side groove arranged at the center of the core plate 24 so as to be relatively fixed.

As shown in fig. 9 and 9a, the second connecting pipe 32 is a sleeve flange structure, one end of which is matched with the core plate 24 through a spigot and is fastened by three socket head cap screws; the other end is connected with the guide frame 111 of the second guide device 12 through a deep groove ball bearing.

Referring to fig. 10, the use method of the grinding tool is as follows:

the main shaft 4 of the water turbine to be derusted is horizontally placed on the operation platform, and the main shaft 4 of the water turbine does not need to be leveled;

the grinding wheel 22 used for the grinding tool selects a phi 80 polishing fiber wheel;

the connection part of each pipeline joint through which compressed air passes is wound and sealed by using a raw adhesive tape;

each joint part of the polishing tool is pre-tightened, spot welding can be carried out if necessary, and the fact that threads are not loosened when the device rotates is guaranteed;

after the polishing tool is assembled, opening an air pipe switch, checking the idle running condition of three grinding machines, and closing the air pipe switch after ensuring no abnormity;

adjusting the guide device 1 and the grinding device 2 to the size matched with the central hole of the main shaft 4 of the water turbine, and ensuring that the polishing fiber wheel has a certain compression amount;

the grinding tool is arranged in a central hole of the main shaft 4 of the water turbine, and support legs 112 of the two auxiliary guide frames 111 are supported on the hole wall;

the handle 36 is operated to rotate left and right and pull the polishing tool back and forth, so that flexible movement is ensured;

turning on an air pipe switch, rotating the polishing tool left and right, observing and ensuring that the three grinding machines can be started normally;

rotating the polishing fiber wheel left and right for 2-3 times at the same axial position, wherein the rotation angle is not less than 120 degrees and not more than 180 degrees every time, then pushing the handle 36 to move along the axial direction of the central hole by a distance not exceeding the thickness of the polishing fiber wheel, and pulling back the handle 36 appropriately according to the field conditions;

the steps of rotating and pushing and pulling the handle 36 are repeated;

when the length of the long extension pipe 35 is insufficient, connecting another long extension pipe 35, and continuing the operation;

after the center hole with half length is polished, the polishing tool can be pulled out, and the center hole is replaced with the other end of the center hole for derusting operation;

replacing the polishing fiber wheel after the single-side abrasion loss of the polishing fiber wheel exceeds 10 mm;

and after rust removal is finished, taking out the polishing tool, blowing out dust in the central hole by using the air pipe 23, and timely coating rust preventive oil on the inner surface of the central hole.

Above-mentioned frock of polishing is used for the centre bore rust cleaning of hydraulic turbine main shaft, for the honing equipment among the prior art, has following technical advantage:

the polishing tool has adjustability and wide application range;

the main shaft does not need to be adjusted to be level, and the equipment is convenient to mount and use;

the working efficiency is high, and the derusting treatment period is obviously shortened;

the treatment cost is greatly reduced, and the single treatment cost can be as low as about 5 percent of the honing scheme.

The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.

Claims

1. The utility model provides a work piece hole grinding device which characterized in that:

the grinding device comprises a core plate sleeved and fixed on the connecting rod and a plurality of grinding machines arranged on the core plate;

the support legs are detachably connected with the guide frame, and the length of the outward extending support legs is adjustable; the support legs are provided with elastic pads;

one of the support leg and the guide frame is provided with a long bolt hole, and the other support leg and the guide frame are provided with a row of bolts; the bolts continuously move in the long bolt holes and the support legs are provided with elastic pads, so that stepless adjustment of the support legs is realized;

a bearing is arranged between the guide frame and the connecting rod; when the guide frame rotates around the central axis of the inner hole in the grinding device, the guide frame and the inner hole can keep relatively static;

the grinding machine is connected with the core plate through a grinding seat, the grinding seat is inserted on the core plate, and the length of the outward extending part of the grinding seat is adjustable;

the grinding seat is provided with an insertion handle, and the core plate is provided with an insertion groove matched with the insertion handle; the side wall of the insertion groove is provided with a long circular hole, a first lug plate is arranged near one end of the long circular hole close to the notch, a second lug plate capable of penetrating through the long circular hole is arranged on the insertion handle, the first lug plate and the second lug plate are connected through a bolt and a nut matched with the bolt, the distance between the first lug plate and the second lug plate can be adjusted through screwing in or screwing out of the nut, and the extending length of the grinding seat can be adjusted;

the inserting handle comprises a handle body and a handle bottom plate, wherein a spring is clamped in the middle of the handle body; the spring is used for automatic compensation after the grinding head is worn;

the plug handle is also provided with a guide pin, the core plate is provided with a guide hole matched with the guide pin, and the plug handle can extend out or retract along the guide hole through the matching of the guide pin and the guide hole and can be prevented from falling out of the plug groove.

2. The workpiece bore grinding device of claim 1, wherein: the connecting rod is sectional, is a solid rod piece and/or a hollow pipe piece and is provided with a lengthening section with a handle.

3. The workpiece bore grinding device of claim 1, wherein: the grinding machine is a pneumatic grinder and is connected with an external compressed air source through a hollow connecting rod.

4. The workpiece bore grinding device of claim 1, wherein: the guide frame and the core plate are both triangular, the supporting legs are arranged at three corners of the guide frame respectively, and the grinding machine is arranged at each of the three corners of the core plate.