Inner hole grinding clamp

Abstract

The invention discloses an inner hole grinding clamp which is used for clamping a plunger sleeve in a plunger sleeve inner hole grinding process or a bypass valve sleeve middle hole grinding process and comprises a base, a base positioning mandrel, a positioning plate, a lining, a flange plate positioning mandrel, a pressing assembly, a flange plate and a balancing weight. The lining is assembled in a center hole of the positioning plate in an interference mode, and the flange plate positioning mandrel is fixedly connected to the middle of the flange plate; the lower part of the base positioning mandrel is fixedly connected with the base; when the positioning plate is placed on the base and matched with the pressing assembly to clamp the plunger sleeve, the middle of the base positioning mandrel is in clearance fit with the lining, and the upper portion of the base positioning mandrel is in clearance fit with an inner hole of the plunger sleeve or in clearance fit with a middle hole of the bypass valve sleeve. When the positioning plate which is matched with the pressing assembly to clamp the plunger sleeve is fixedly connected to the flange plate, the upper portion of the flange plate positioning mandrel is in clearance fit with the lining. By adopting the device, the problem that the special-shaped irregular parts need to be aligned when being ground on the internal grinding machine for multiple times can be solved, and the device is quick to clamp and disassemble.

Description

Technical Field

[0001] The invention belongs to the field of grinding processing, and in particular relates to an inner hole grinding fixture. Background Art

[0002] The electronically controlled unit pump is a component of the second generation fuel injection system. Figure 1 As shown, the plunger sleeve 10 in the electric control unit pump and the bypass valve sleeve 20 which is interference-fitted in the inner hole 106 of the plunger sleeve are both key components. When assembling the bypass valve sleeve 20, it is necessary to ensure that the bypass valve sleeve middle hole 201 (i.e., the central inner hole of the bypass valve sleeve) and the side plane of the plunger sleeve 10 (i.e., the baffle mounting plane 103 and the solenoid valve mounting plane 104) have good verticality to ensure its performance. Due to the particularity of the plunger sleeve and the bypass valve sleeve, they need to be ground twice on the internal grinding machine: the first time is to grind the inner hole 106 of the plunger sleeve, and the second time is to grind the bypass valve sleeve middle hole 201 and the sealing cone surface of the bypass valve sleeve 20 which is interference-fitted in the inner hole of the plunger sleeve.

[0003] Due to the structural irregularity of the plunger sleeve 10 (with the baffle mounting plane 103, the solenoid valve mounting plane 104 and the protruding flange 102), it must be clamped and ground twice on an internal grinding machine, which not only requires high processing accuracy, but also requires high repeated positioning accuracy twice. The existing fixture design not only requires alignment and adjustment of each part, but also is very inconvenient to clamp, has low processing efficiency, and increases the economic cost of the enterprise. Summary of the invention

[0004] The purpose of the present invention is to provide an inner hole grinding fixture for clamping a plunger sleeve in the inner hole grinding process of a plunger sleeve or the middle hole grinding process of a bypass valve sleeve, so as to solve the problem of multiple grindings on an internal cylindrical grinder requiring part alignment.

[0005] The inner hole grinding fixture of the present invention is used to clamp the plunger sleeve in the inner hole grinding process of the plunger sleeve or the middle hole grinding process of the bypass valve sleeve, and includes a base, a base positioning spindle, a positioning plate, a bushing, a flange positioning spindle, a clamping assembly, a flange fixedly connected to the spindle of the internal cylindrical grinder, and a counterweight connected to the oil inlet threaded end of the plunger sleeve. The bushing is interference fitted in the center hole of the positioning plate, and the positioning plate can be fixedly connected to the flange; the flange positioning spindle is fixedly connected to the middle of the flange and can be gap-matched with the bushing; the lower part of the base positioning spindle is fixedly connected to the base, the middle part can be gap-matched with the bushing, and the upper part can be gap-matched with the inner hole of the plunger sleeve or the middle hole of the bypass valve sleeve.

[0006] When the positioning plate is placed on the base and cooperates with the clamping assembly to clamp the plunger sleeve, the middle part of the base positioning spindle extends into the sleeve and cooperates with the sleeve gap, and the upper part of the base positioning spindle extends into the inner hole of the plunger sleeve and cooperates with the inner hole of the plunger sleeve or extends into the middle hole of the bypass valve sleeve and cooperates with the middle hole of the bypass valve sleeve, thereby realizing self-positioning when clamping the plunger sleeve, so that the center line of the positioning plate coincides with the center line of the inner hole of the plunger sleeve or the center line of the middle hole of the bypass valve sleeve.

[0007] When the positioning plate that cooperates with the clamping assembly to clamp the plunger sleeve is fixedly connected to the flange (that is, the clamping assembly, the plunger sleeve, and the positioning plate are fixedly connected to the flange as a whole to be ground through the positioning plate), the upper part of the flange positioning mandrel extends into the bushing and cooperates with the bushing clearance to ensure that the plunger sleeve is accurately positioned when it is fixed on the flange through the clamping assembly and the positioning plate. Since the grinding center line coincides with the center line of the flange, the center line of the flange coincides with the center line of the positioning plate, and the center line of the positioning plate coincides with the center line of the inner hole of the plunger sleeve, the grinding center line coincides with the center line of the inner hole of the plunger sleeve, thereby achieving accurate positioning when the inner hole of the plunger sleeve is ground. Since the grinding center line coincides with the center line of the flange, the center line of the flange coincides with the center line of the positioning plate, and the center line of the positioning plate coincides with the center line of the center hole of the bypass valve sleeve, the grinding center line coincides with the center line of the center hole of the bypass valve sleeve, thereby achieving accurate positioning when the center hole of the bypass valve sleeve is ground.

[0008] Preferably, the clamping assembly includes a pressure plate and a pressure plate screw, a grinding avoidance hole is opened in the center of the pressure plate, the force plane of the pressure plate is fitted with the baffle mounting plane of the plunger sleeve, the upper end surface of the positioning plate is fitted with the solenoid valve mounting plane of the plunger sleeve, the grinding avoidance hole corresponds to the inner hole of the plunger sleeve, the pressure plate screw passes through the pressure plate and is screwed to the positioning plate, so that the plunger sleeve is clamped by the pressure plate, the positioning plate and the pressure plate screw, thereby ensuring the verticality requirement of the inner hole of the plunger sleeve and the side plane (i.e., the baffle mounting plane and the solenoid valve mounting plane).

[0009] Preferably, the positioning plate is provided with n gourd holes evenly opened along the circumference near the edge, and the flange is provided with n screw holes evenly opened along the circumference near the edge corresponding to the n gourd holes, and n locking screws are respectively passed through the n gourd holes and screwed with the corresponding n screw holes, so that the positioning plate can be fixedly connected to the flange. The locking screws are pre-installed in the screw holes, and the large hole and small hole of the gourd hole can be used to realize that the locking screws do not need to be completely screwed out of the flange during disassembly and assembly, thereby making the fixing and disassembly of the flange and the positioning plate faster.

[0010] Preferably, the positioning plate is provided with a square hole for avoiding the protruding flange of the plunger sleeve, and the upper end surface of the positioning plate is provided with a first arc groove for avoiding the multi-stage shaft of the plunger sleeve and a second arc groove for avoiding the counterweight block, thereby ensuring that the upper end surface of the positioning plate can fit the solenoid valve installation plane of the plunger sleeve.

[0011] Preferably, a countersunk platform is provided in the middle of the upper end surface of the flange, the lower part of the flange positioning shaft is interference fit with the center hole of the countersunk platform, the middle part of the flange positioning shaft is provided with a connecting step, the lower end surface of the connecting step is fitted with the upper end surface of the countersunk platform, and the first fixing screw passes through the connecting step and is threadedly connected to the countersunk platform, so that the flange positioning shaft is fixedly connected to the middle part of the flange, thereby better ensuring that the grinding center line coincides with the center line of the inner hole of the plunger sleeve or the center line of the center hole of the bypass valve sleeve.

[0012] Preferably, the lower end surface of the positioning plate is provided with an annular groove for accommodating the installation of the first fixing screw, and the annular groove is intersecting and communicating with the square hole.

[0013] Preferably, a boss is provided in the middle of the bottom surface of the flange, the boss has an external thread and a tapered hole is opened in the center for fitting and positioning with the end of the internal cylindrical grinder spindle, a pin hole is opened in the circumferential direction near the edge of the boss, the pin shaft and the pin hole are positioned in cooperation, and the flange can be threadedly connected to the internal cylindrical grinder spindle through the external thread on its boss, thereby ensuring that the flange and the internal cylindrical grinder spindle are firmly connected.

[0014] Preferably, the lower part of the base positioning spindle is interference fit with the center hole of the base, a washer is located below the base positioning spindle and fits with the middle part of the bottom surface of the base, and the second fixing screw passes through the washer and is threadedly connected to the lower part of the base positioning spindle, so that the lower part of the base positioning spindle is fixedly connected to the base, thereby ensuring that the base positioning spindle is firmly connected to the base.

[0015] Preferably, n=4, and the four calabash holes are distributed at intervals of 90° along the circumference of the positioning plate. The four screw holes provided on the flange are distributed at intervals of 90° along the circumference of the flange.

[0016] Preferably, there are two pressing plate screws, which pass through two end portions of the pressing plate and are screwed to the positioning plate respectively.

[0017] The present invention has the following effects: (1) The inner hole grinding fixture is designed in a split type. The middle part of the base positioning mandrel is matched with the clearance between the bushing and the upper part is matched with the clearance between the inner hole of the plunger sleeve, so that the self-positioning when clamping the plunger sleeve is realized. The upper part of the flange positioning mandrel is matched with the clearance between the bushing to ensure that the plunger sleeve is accurately positioned when it is fixed on the flange through the clamping assembly and the positioning plate, and to ensure that the grinding center line coincides with the center line of the inner hole of the plunger sleeve or the center line of the bypass valve sleeve, thereby achieving positioning when grinding the inner hole of the plunger sleeve or the bypass valve sleeve, thereby ensuring that multiple plunger sets of the same specification to be processed are accurately clamped and positioned, and multiple clamping does not require part alignment.

[0018] (2) When connecting with the flange, you only need to tighten the locking screw and loosen the locking screw (a total of 2 operations), without any auxiliary adjustment. It is fast to clamp and disassemble, and the operation is simple and quick.

[0019] (3) The overall structure is ingenious. By replacing the base positioning spindle and counterweight block of different specifications, it can be suitable for the plunger sleeve and bypass valve sleeve of a variety of electronically controlled single pumps. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of the plunger sleeve and the bypass valve sleeve in an embodiment of the present invention.

[0021] Figure 2 It is a structural schematic diagram of a base positioning spindle fixedly connected to a base in an embodiment of the present invention.

[0022] Figure 3 Schematic diagram of the structure in which the flange positioning spindle is fixedly connected to the flange in an embodiment of the present invention (with locking screws pre-installed).

[0023] Figure 4 This is one of the isometric views of the positioning plate in the embodiment of the present invention.

[0024] Figure 5 This is the second axonometric view of the positioning plate in the embodiment of the present invention.

[0025] Figure 6 It is a schematic diagram of positioning when clamping the plunger sleeve in the inner hole grinding process of the plunger sleeve according to an embodiment of the present invention.

[0026] Figure 7 It is an axonometric view of the bypass valve sleeve when the plunger sleeve is clamped in the hole grinding process of the bypass valve sleeve according to the embodiment of the present invention.

[0027] Figure 8 It is a schematic diagram of the positioning when clamping the plunger sleeve in the bypass valve sleeve center hole grinding process according to an embodiment of the present invention.

[0028] Fig. 9 This is an axonometric view of the entire body to be ground above the flange in the bypass valve sleeve center hole grinding process according to an embodiment of the present invention (with locking screws pre-installed).

[0029] Fig.10 This is an axonometric view of the bypass valve sleeve center hole grinding process in an embodiment of the present invention, in which the entire body to be ground is fixedly connected to the flange.

[0030] Fig.11 It is a top view of the bypass valve sleeve central hole grinding process in an embodiment of the present invention, in which the whole to be ground is fixedly connected to the flange.

[0031] Fig.12 for Fig.11 AA section view. DETAILED DESCRIPTION

[0032] In order to enable a more detailed understanding of the features and technical contents of the embodiments of the present invention, the implementation of the embodiments of the present invention is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not intended to limit the embodiments of the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0034] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0035] It should also be pointed out that the terms "first\second" involved in the embodiments of the present invention are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0036] like Figures 1 to 12 As shown, the inner hole grinding fixture in the embodiment of the present invention is used to clamp the plunger sleeve in the inner hole grinding process of the plunger sleeve or the middle hole grinding process of the bypass valve sleeve. The inner hole grinding fixture includes a base 1, a base positioning spindle 2, a positioning plate 3, a bushing 4, a flange positioning spindle 7, a clamping assembly, a flange 8 fixedly connected to the spindle of the internal cylindrical grinder, and a counterweight 9 connected to the oil inlet threaded end 101 of the plunger sleeve. The bushing 4 is interference fitted in the center hole 31 of the positioning plate 3, and the positioning plate 3 can be fixedly connected to the flange 8. The flange positioning spindle 7 is fixedly connected to the middle part of the flange 8 and can be loosely matched with the bushing 4. The lower part of the base positioning spindle 2 is fixedly connected to the base 1, the middle part of the base positioning spindle 2 can be loosely matched with the bushing 4, and the upper part of the base positioning spindle 2 can be loosely matched with the inner hole 106 of the plunger sleeve or with the middle hole 201 of the bypass valve sleeve. The clamping assembly cooperates with the positioning plate 3 to clamp the plunger sleeve 10.

[0037] In some embodiments, the lower portion of the base positioning spindle 2 is interference fit with the center hole of the base 1, a washer 13 is located below the base positioning spindle 2 and fits with the middle portion of the bottom surface of the base 1, and a second fixing screw 14 passes through the washer 13 and is threadedly connected to the lower portion of the base positioning spindle 2, so that the lower portion of the base positioning spindle 2 is fixedly connected to the base 1.

[0038] In some embodiments, a sink 81 is provided in the middle of the upper end surface of the flange 8, the lower part of the flange positioning spindle 7 is interference fit with the middle hole of the sink 81, the middle part of the flange positioning spindle 7 is provided with a connecting step 71, the lower end surface of the connecting step 71 is fitted with the upper end surface of the sink 81, and the four first fixing screws 12 pass through the connecting step 71 and are screwed to the sink 81, so that the flange positioning spindle 7 is fixedly connected to the middle part of the flange 8 (see Figure 3 , Fig.12 ).

[0039] In some embodiments, a boss 84 is provided in the middle of the bottom surface of the flange 8. The boss 84 has an external thread and a tapered hole 82 is opened in the center to fit and position with the end of the internal cylindrical grinder spindle. A pin hole 83 is opened along the circumferential direction near the edge of the boss. The pin shaft (not shown in the figure) is positioned in cooperation with the pin hole 83. The flange 8 is threadedly connected to the internal cylindrical grinder spindle through the external thread on its boss 84.

[0040] In some embodiments, a square hole 33 is provided on the positioning plate 3 for avoiding the protruding flange 102 of the plunger sleeve, and a first arc groove 34 for avoiding the multi-stage shaft 102 of the plunger sleeve and a second arc groove 35 for avoiding the counterweight block 9 are provided on the upper end surface of the positioning plate 3.

[0041] In some embodiments, the positioning plate 3 is provided with four gourd holes 32 at 90° intervals along the circumferential direction near the edge, and the flange 8 is provided with four screw holes corresponding to the four gourd holes at 90° intervals along the circumferential direction near the edge. The four locking screws 11 pass through the four gourd holes 32 and are screwed to the corresponding four screw holes, so that the positioning plate 3 can be fixedly connected to the flange 8. When in use, the four locking screws 11 are installed in the four screw holes, and there is no need to completely screw out the screw holes (see Figure 3 ).

[0042] In some embodiments, a ring groove 36 for accommodating the installation of the first fixing screw 12 is formed on the lower end surface of the positioning plate 3 , and the ring groove 36 is connected to the square hole 33 .

[0043] In some embodiments, the clamping assembly includes a clamping plate 5 and two clamping plate screws 6. A grinding avoidance hole 51 is provided at the center of the clamping plate 5.

[0044] like Figure 6As shown, in the process of grinding the inner hole of the plunger sleeve, when clamping the plunger sleeve 10 for self-positioning, the positioning plate 3 is placed on the base 1, the middle part of the base positioning spindle 2 extends into the bushing 4 and matches with the bushing 4 clearance, the plunger sleeve 10 is placed on the positioning plate 3, the upper end surface of the positioning plate 3 is in contact with the solenoid valve mounting plane 104 of the plunger sleeve 10, the upper part of the base positioning spindle 2 extends into the inner hole 106 of the plunger sleeve and matches with the inner hole of the plunger sleeve clearance, the force-applying plane of the pressure plate 5 is in contact with the baffle mounting plane 103 of the plunger sleeve 10, the grinding avoidance hole 51 corresponds to the inner hole 106 of the plunger sleeve, and the two pressure plate screws 6 pass through the two ends of the pressure plate 5 and are screwed to the positioning plate 3, so that the plunger sleeve 10 is clamped by the pressure plate 5, the positioning plate 3 and the two pressure plate screws 6.

[0045] like Figure 7 , Figure 8 As shown, in the bypass valve sleeve center hole grinding process, when the plunger sleeve 10 is clamped for self-positioning, the positioning plate 3 is placed on the base 1, and the middle part of the base positioning spindle 2 extends into the bushing 4 and matches with the bushing 4 clearance. The plunger sleeve 10 is placed on the positioning plate 3, and the upper end surface of the positioning plate 3 fits with the solenoid valve mounting plane 104 of the plunger sleeve 10, and the upper part of the base positioning spindle 2 extends into the bypass valve sleeve center hole and matches with the bypass valve sleeve center hole clearance. The force-applying plane of the pressure plate 5 fits with the baffle mounting plane 103 of the plunger sleeve 10, and the grinding avoidance hole 51 corresponds to the inner hole of the plunger sleeve. The two pressure plate screws 6 pass through the two ends of the pressure plate 5 and are screwed to the positioning plate 3, so that the plunger sleeve 10 is clamped by the pressure plate 5, the positioning plate 3, and the two pressure plate screws 6. The parts used in the bypass valve sleeve center hole grinding process are basically the same as the clamping parts used in the plunger sleeve inner hole grinding process, the only difference is that the upper outer circle size of the base positioning spindle 2 used is different.

[0046] After clamping the plunger sleeve 10, remove the clamping assembly, plunger sleeve, and positioning plate from the base 1 as a whole to be ground and place them on the flange 8. The lower end surface of the positioning plate 3 fits the flange 8, the upper part of the flange positioning spindle 7 extends into the bushing 4 and fits with the bushing 4, and the heads of the four locking screws 11 extend into the large holes of the four gourd holes 32 respectively (see Fig. 9 Then rotate the aforementioned whole to be ground counterclockwise until the rod of the locking screw 11 is located in the small hole of the gourd hole 32, and the head of the locking screw 11 extends to the upper end surface of the positioning plate 3, and then tighten the locking screw 11 (see Figures 10 to 12 ). The bypass valve sleeve center hole grinding can be carried out later.

[0047] When disassembling after grinding, it is only necessary to loosen the locking screws 11 slightly without unscrewing them all, and then rotate the ground whole (composed of the clamping assembly, the ground plunger sleeve, and the positioning plate) clockwise to the disassembly position (that is, when the heads of the four locking screws 11 enter the large hole parts of the four gourd holes 32), and the ground whole can be directly and quickly removed from the flange 8.

[0048] In some embodiments, the upper outer circle size of the base positioning spindle 2 can be adjusted (i.e., a base positioning spindle with a different upper outer circle size is selected) to adapt to the inner hole grinding of the plunger sleeve or the middle hole grinding of the bypass valve sleeve with different apertures.

[0049] In some embodiments, the size and shape of the counterweight 9 can be adjusted to be suitable for plunger sleeves of different shapes and weights.

Claims

1. An inner hole grinding fixture, used for clamping the plunger sleeve in the inner hole grinding process of the plunger sleeve or the middle hole grinding process of the bypass valve sleeve, characterized in that: The invention comprises a base (1), a base positioning spindle (2), a positioning plate (3), a bushing (4), a flange positioning spindle (7), a clamping assembly, a flange (8) fixedly connected to the spindle of an internal grinding machine, and a counterweight (9) connected to the oil inlet threaded end (101) of a plunger sleeve; the bushing (4) is interference-fitted in the center hole (31) of the positioning plate (3), and the positioning plate (3) can be fixedly connected to the flange (8); the flange positioning spindle (7) is fixedly connected to the middle part of the flange (8) and can be clearance-matched with the bushing (4); the lower part of the base positioning spindle (2) is fixedly connected to the base (1), the middle part can be clearance-matched with the bushing (4), and the upper part can be clearance-matched with the inner hole of the plunger sleeve or with the middle hole of the bypass valve sleeve; When the positioning plate (3) is placed on the base (1) and cooperates with the clamping assembly to clamp the plunger sleeve (10), the middle part of the base positioning spindle (2) extends into the bushing (4) to be clearance-matched with the bushing (4), the upper part extends into the inner hole (106) of the plunger sleeve to be clearance-matched with the inner hole of the plunger sleeve, or extends into the middle hole (201) of the bypass valve sleeve to be clearance-matched with the middle hole of the bypass valve sleeve; When the positioning plate (3) that cooperates with the clamping assembly to clamp the plunger sleeve (10) is fixedly connected to the flange (8), the upper part of the flange positioning spindle (7) extends into the bushing (4) and is clearance-matched with the bushing (4).

2. The inner hole grinding fixture according to claim 1, characterized in that: The clamping assembly comprises a pressing plate (5) and a pressing plate screw (6); a grinding avoidance hole (51) is provided at the center of the pressing plate (5); a force-applying plane of the pressing plate (5) is in contact with a baffle mounting plane (103) of the plunger sleeve (10); an upper end surface of the positioning plate (3) is in contact with a solenoid valve mounting plane (104) of the plunger sleeve (10); the grinding avoidance hole (51) corresponds to an inner hole (106) of the plunger sleeve; and the pressing plate screw (6) passes through the pressing plate (5) and is screwed to the positioning plate (3).

3. The inner hole grinding fixture according to claim 2, characterized in that: The positioning plate (3) is provided with n calabash holes (32) evenly arranged along the circumferential direction near the edge, and the flange (8) is provided with n screw holes evenly arranged along the circumferential direction near the edge corresponding to the n calabash holes. N locking screws (11) are respectively passed through the n calabash holes (32) and are screwed to the corresponding n screw holes, so that the positioning plate (3) can be fixedly connected to the flange (8).

4. The inner hole grinding fixture according to claim 2, characterized in that: The positioning plate (3) is provided with a square hole (33) for avoiding the protruding flange (102) of the plunger sleeve, and the upper end surface of the positioning plate (3) is provided with a first arc groove (34) for avoiding the multi-stage shaft (105) of the plunger sleeve and a second arc groove (35) for avoiding the counterweight block (9).

5. The inner hole grinding fixture according to claim 4, characterized in that: A sink (81) is provided in the middle of the upper end surface of the flange (8); the lower part of the flange positioning spindle (7) is interference fit with the middle hole of the sink (81); the middle part of the flange positioning spindle (7) has a connecting step (71); the lower end surface of the connecting step (71) is in contact with the upper end surface of the sink (81); a first fixing screw (12) passes through the connecting step (71) and is screwed to the sink (81), so that the flange positioning spindle (7) is fixedly connected to the middle part of the flange (8).

6. The inner hole grinding fixture according to claim 5, characterized in that: The lower end surface of the positioning plate (3) is provided with an annular groove (36) for accommodating the installation of the first fixing screw (12), and the annular groove (36) is intersectingly connected with the square hole (33).

7. The inner hole grinding fixture according to any one of claims 1 to 6, characterized in that: A boss (84) is provided in the middle of the bottom surface of the flange (8), the boss having an external thread and a tapered hole (82) in the center thereof for fitting and positioning with the end of the internal grinder spindle, and a pin hole (83) is provided in the circumferential direction near the edge, the pin shaft and the pin hole are matched for positioning, and the flange (8) is threadedly connected to the internal grinder spindle via the external thread on the boss.

8. The inner hole grinding fixture according to any one of claims 1 to 6, characterized in that: The lower part of the base positioning spindle (2) is interference-fitted with the middle hole of the base (1); a washer (13) is located below the base positioning spindle (2) and fits with the middle part of the bottom surface of the base (1); a second fixing screw (14) passes through the washer (13) and is screwed to the lower part of the base positioning spindle (2), so that the lower part of the base positioning spindle (2) is fixedly connected to the base (1).

9. The inner hole grinding fixture according to any one of claims 3 to 6, characterized in that: The n=4, the four gourd holes (32) are distributed at intervals of 90° along the circumference of the positioning plate (3); and the four screw holes provided on the flange (8) are distributed at intervals of 90° along the circumference of the flange (8).

10. The inner hole grinding fixture according to any one of claims 3 to 6, characterized in that: There are two pressing plate screws (6), which pass through two ends of the pressing plate (5) and are screwed to the positioning plate (3).

Images