Grinding tool for inner ball cavity

Abstract

The utility model relates to an inner ball cavity grinding tool, the inner surface of the inner ball cavity is provided with a radius-passing spherical surface to be processed, the side wall of the inner ball cavity is provided with a window, the grinding tool comprises a fixed seat, the fixed seat is provided with a central through hole, the fixed seat comprises a plurality of mounting parts, and the plurality of mounting parts are distributed along the circumferential direction by taking the central through hole as the center; the plurality of grinding heads are in one-to-one correspondence with the plurality of mounting parts, the grinding heads are detachably mounted on the mounting parts, each grinding head is provided with a grinding cambered surface, and the plurality of grinding cambered surfaces form a grinding spherical surface matched with the radius-passing spherical surface to be processed; the expansion shaft is connected with the central through hole and is used for keeping and changing the relative positions of the plurality of mounting parts; wherein the grinding head and the fixing base are assembled into a whole after being placed into the inner spherical cavity through the window, the relative positions of the multiple installation parts are changed, the grinding spherical surface is attached to the radius-passing spherical surface to be machined, and therefore high-precision integrated forming of the inner spherical surface is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to precision machining technical field, especially a kind of inner spherical cavity grinding tool. BACKGROUND

[0002] The precision of the inner spherical surface machining is low at present, especially for the over-radius spherical surface (referring to the spherical surface across the two mutually perpendicular central sections of the sphere), the machining tool needs to be inserted into the inner cavity of the sphere, and then a complete spherical surface is formed after gradually machining multiple local spherical surfaces on the inner wall surface of the cavity. For example, the gooseneck knife is inserted into the cavity in an arc shape by artificial, and then the entire spherical surface is machined by adjusting the relative position of the tool and the workpiece.

[0003] For parts with inner spherical cavity structure, the spherical surface precision requirements of the inner spherical cavity are different according to the types and uses of the parts. For parts with high-precision inner spherical surface machining requirements, such as standard samples for measuring equipment of the inner spherical cavity of automobile differential housing, the above machining method cannot meet the requirements because of the long tool and the easy tool vibration. SUMMARY

[0004] In view of the above-mentioned shortcomings in the prior production technology, the present application provides an inner spherical cavity grinding tool, so as to realize high-precision integrated molding of the inner spherical surface.

[0005] The technical scheme adopted by the utility model is as follows:

[0006] An inner spherical cavity grinding tool, the inner surface of the inner spherical cavity is provided with an over-radius spherical surface to be machined, a window is arranged on the side wall of the inner spherical cavity, and the grinding tool comprises:

[0007] A fixing seat is provided with a central through hole, and the fixing seat comprises a plurality of mounting portions which are distributed in the circumferential direction with the central through hole as the center;

[0008] A plurality of grinding heads are one-to-one corresponding to the plurality of mounting portions, the grinding head is detachably mounted on the mounting portion, a grinding arc surface is arranged on each grinding head, and the plurality of grinding arc surfaces form a grinding spherical surface matched with the over-radius spherical surface to be machined;

[0009] An expansion shaft is connected with the central through hole and used for maintaining and changing the relative positions between the plurality of mounting portions;

[0010] The grinding head and the fixing seat are assembled into one after being put into the inner spherical cavity through the window, the relative positions between the plurality of mounting portions are changed, and the grinding spherical surface is attached to the over-radius spherical surface to be machined.

[0011] As a further improvement of the above technical scheme:

[0012] The pair of adjacent mounting portions of the plurality of mounting portions of the fixing base are separated by an open gap, and the remaining adjacent mounting portions are elastically connected by elastic arms and provided with deformation gaps penetrating both ends of the fixing base, and the plurality of mounting portions and the elastic arms enclose the center through hole;

[0013] An external force is applied to the fixing base by the expansion shaft, the elastic arms are elastically deformed, the open gap is increased, and the deformation gap is reduced, so that the grinding spherical surface is attached to the spherical surface to be machined.

[0014] The center through hole is a tapered circular hole, the expansion shaft is provided with a tapered shaft surface matched with the center through hole, one end of the expansion shaft is provided with a limiting component, the limiting component applies a pulling force to the expansion shaft and a pressure to the end surface of the fixing base, and the pulling force and the pressure are opposite, so that the elastic arms are elastically deformed.

[0015] The limiting component comprises a bolt and a gasket, the end of the expansion shaft on the small end side of the tapered shaft surface is provided with a threaded hole, the bolt is threadedly connected with the threaded hole, the gasket is in contact with the end surface of the fixing base, the pressure of the head of the bolt on the gasket is changed by changing the installation depth of the bolt in the threaded hole, and then the elastic arms are elastically deformed.

[0016] The taper of the tapered shaft surface is 1:20-1:30.

[0017] A weakening hole is arranged between the elastic arm and the deformation gap, the weakening hole is consistent in length and direction with the center through hole, and the weakening hole is in communication with the deformation gap.

[0018] A first positioning groove is arranged on the grinding head, a second positioning groove is arranged on the mounting portion, and a positioning pin is further arranged, the first positioning groove and the second positioning groove are located on both sides of the positioning pin, and after the first positioning groove and the second positioning groove are in contact with the positioning pin, the relative position of the grinding head and the mounting portion in the direction perpendicular to the axis of the center through hole is limited.

[0019] One end of the mounting portion is provided with a boss, one end of the grinding head is provided with a groove, and after the boss and the groove are matched, the relative position of the mounting portion and the grinding head in the center through hole axis direction is limited.

[0020] A through hole is arranged on the grinding head, and a fastener for detachably connecting the grinding head and the mounting portion is arranged in the through hole.

[0021] The window comprises an axial port for passing through the fixing base, and a side port for mounting a fastener.

[0022] The beneficial effects of the utility model are as follows:

[0023] The utility model discloses compact, reasonable, convenient operation, the grinding head of split design enters the inner ball cavity through the window on the inner ball cavity lateral wall, and the grinding head forms the grinding spherical surface after assembling with the fixed base in the inner ball cavity, adjusts the grinding spherical surface and carries out the grinding after making it with the to-be-processed radius spherical surface adhere, realizes the high-precision integrated molding of inner spherical surface.

[0024] Meanwhile, the utility model still has following advantages:

[0025] (1) through setting up the fixed base of elastic deformation, through the taper shaft hole structure, the center through -hole of fixed base is expanded, and the relative position of the grinding head installed on the fixed base mounting portion is changed by increasing the diameter of center through -hole, and then the grinding spherical surface is increased.

[0026] (2) the structure that the positioning pin is positioned with two positioning slots, and the cooperation structure of boss and recess realizes the transverse positioning and longitudinal positioning of grinding head and mounting portion, and the positioning structure is convenient for assisting the positioning assembly operation of grinding head and fixed base in the inner ball cavity. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is the structure schematic diagram of the inner ball cavity grinding tool of the utility model.

[0028] Figure 2 It is the top view of the inner ball cavity grinding tool of the utility model.

[0029] Figure 3 It is the front view of the inner ball cavity grinding tool of the utility model.

[0030] Figure 4 It is the explosion view of the inner ball cavity grinding tool of the utility model.

[0031] Figure 5 It is the structure schematic diagram of the grinding head of the utility model.

[0032] Figure 6 It is the structure schematic diagram of the fixed base of the utility model.

[0033] Figure 7 It is the assembly schematic diagram of the workpiece body and the inner ball cavity grinding tool of one embodiment of the utility model.

[0034] Figure 8 It is the structure schematic diagram of the workpiece body of another embodiment of the utility model.

[0035] Figure 9 It is the assembly schematic diagram of the inner ball cavity grinding tool of the utility model.

[0036] Among them:

[0037] 1, grinding head;10, grinding arc surface;11, perforation;12, first positioning slot;13, recess;

[0038] 2, fixed seat;

[0039] 21, mounting portion; 211, second positioning groove; 212, positioning pin;

[0040] 22, elastic arm; 221, deformation gap; 222, weakening hole;

[0041] 23, center through hole; 24, opening gap; 25, boss;

[0042] 3, limiting assembly; 31, bolt; 32, gasket;

[0043] 4, expansion shaft; 41, conical shaft surface;

[0044] 5, workpiece body; 50, discontinuous spherical surface;

[0045] 6, window; 61, side opening; 62, axial opening. DETAILED DESCRIPTION

[0046] The specific implementation of the present application will be described below in conjunction with the accompanying drawings.

[0047] As Figures 1-9 shown, the inner spherical cavity grinding tool provided by the embodiment of the present application is provided with a to-be-processed over-radius spherical surface on the inner surface of the inner spherical cavity, a window 6 is arranged on the side wall of the inner spherical cavity, and the grinding tool comprises a fixed seat 2, a plurality of grinding heads 1 and an expansion shaft 4.

[0048] The fixed seat 2 is provided with a center through hole 23, and the fixed seat 2 comprises a plurality of mounting portions 21 which are distributed in the circumferential direction with the center through hole 23 as the center;

[0049] The plurality of grinding heads 1 correspond to the plurality of mounting portions 21 one by one, the grinding head 1 is detachably mounted on the mounting portion 21, each grinding head 1 is provided with a grinding arc surface 10, and the plurality of grinding arc surfaces 10 form a grinding spherical surface matched with the to-be-processed over-radius spherical surface;

[0050] The expansion shaft 4 is connected with the center through hole 23 and is used for keeping and changing the relative positions between the plurality of mounting portions 21, and specifically, one end of the expansion shaft 4 is located outside the inner spherical cavity;

[0051] Among them, the grinding head 1 and the fixed seat 2 are assembled into one after being put into the inner spherical cavity through the window 6, the relative positions between the plurality of mounting portions 21 are changed, and the grinding spherical surface is attached to the to-be-processed over-radius spherical surface.

[0052] The inner spherical cavity is located on the workpiece body 5, and the over-radius spherical surface is a spherical surface spanning two mutually perpendicular central sections of a spherical body. The to-be-processed over-radius spherical surface in the embodiment can be a relatively continuous spherical surface, such as Figure 7As shown; also can be multiple discontinuous spherical surfaces 50, all discontinuous spherical surfaces 50 are located on a sphere, as shown. Figure 8 As shown.

[0053] The initial state of the to-be-processed radius spherical surface is processed by turning, and a polishing allowance of 0.02mm-0.05mm is reserved relative to the target spherical surface size, for example, when the target spherical surface diameter is 178mm, it is first processed to 177.97mm by turning, which can be obtained by the goose neck knife in the prior art. The inner spherical cavity polishing tool needs to be assembled in the inner spherical cavity before polishing the to-be-processed radius spherical surface.

[0054] After the inner spherical cavity polishing tool is assembled, the relative positions between the mounting parts 21 are adjusted to increase the polishing spherical surface and make it fit the to-be-processed radius spherical surface, which can ensure that the grinding head 1 can rotate and swing relative to the inner spherical cavity. The to-be-processed radius spherical surface and the polishing arc surface 10 have a polishing medium, such as polishing sand.

[0055] After the inner spherical cavity polishing tool is assembled, the polishing spherical surface and the to-be-processed radius spherical surface have an assembly gap, which is 0.01mm or even microns. Because the polishing allowance and the assembly gap are very small, the size change of the polishing spherical surface is very small.

[0056] During polishing, the first polishing can be performed by manually rotating and swinging the expansion shaft 4. After the first polishing is completed, the size of the current spherical surface is confirmed. When polishing is needed again, the relative positions between the mounting parts 21 are adjusted to make the polishing spherical surface fit the current to-be-processed radius spherical surface, and then the polishing is performed again until the target spherical surface is obtained.

[0057] The polishing spherical surface fits the to-be-processed radius spherical surface, which increases the acting force between the polishing spherical surface and the to-be-processed radius spherical surface and makes the polishing spherical surface and the to-be-processed radius spherical surface uniformly contact. During the polishing process, the to-be-processed radius spherical surface is taken as the reference and guide, the expansion shaft 4 is rotated and swung, and the grinding head 1 moves along the guide of the inner spherical cavity. The rotation and swing of the expansion shaft 4 can be realized by manual method or assisted swing machine.

[0058] The target spherical surface with smoother surface and more accurate size is obtained by further precisely polishing the to-be-processed radius spherical surface by the grinding head 1, and the size of the target spherical surface is accurate to 0.001-0.002 microns.

[0059] The split design grinding head 1 enters the inner spherical cavity through the window 6 on the inner spherical cavity side wall. After the grinding head 1 is assembled with the fixed seat 2 in the inner spherical cavity, the polishing spherical surface is formed. After the polishing spherical surface is adjusted to fit the to-be-processed radius spherical surface, the polishing is performed, and the high-precision integral molding of the inner spherical surface is realized.

[0060] In one exemplary embodiment, as shown in Figure 2 、 Figure 6 , a pair of adjacent mounting portions 21 among the plurality of mounting portions 21 of the fixed seat 2 are separated by an open gap 24, the remaining adjacent mounting portions 21 are elastically connected by the elastic arm 22 and provided with a deformation gap 221 passing through both ends of the fixed seat 2, and the plurality of mounting portions 21 and the elastic arm 22 enclose the central through hole 23.

[0061] By applying an external force to the fixed seat 2 by the expansion shaft 4, the elastic arm 22 is elastically deformed, the open gap 24 is increased, and the deformation gap 221 is reduced, and the grinding spherical surface is attached to the spherical surface to be machined.

[0062] The deformation gap 221 is located on the circumferential outer side of the fixed seat 2, and provides a deformation space for the relative position change of the mounting portion 21. Since the grinding allowance is small, the deformation amount of the elastic arm 22 is also small.

[0063] In this embodiment, the number of mounting portions 21 is four. The more the number of mounting portions 21, the more the number of grinding heads 1, and the higher the grinding accuracy.

[0064] Further, as shown in Figure 3 、 Figure 4 , the central through hole 23 is a tapered circular hole, the expansion shaft 4 is provided with a tapered shaft surface 41 matched with the central through hole 23, one end of the expansion shaft 4 is provided with a limiting component 3, the limiting component 3 applies a pulling force to the expansion shaft 4 and a pressure to the end face of the fixed seat 2, the directions of the pulling force and the pressure are opposite, and the elastic arm 22 is elastically deformed.

[0065] Exemplarily, as shown in Figure 4 , the limiting component 3 includes a bolt 31 and a gasket 32, the end of the expansion shaft 4 on the small end side of the tapered shaft surface 41 is provided with a threaded hole, the bolt 31 is threadedly connected with the threaded hole, the gasket 32 is in contact with the end face of the fixed seat 2, the pressure of the head of the bolt 31 on the gasket 32 is changed by changing the installation depth of the bolt 31 in the threaded hole, and then the elastic arm 22 is elastically deformed.

[0066] The grinding head 1, the fixed seat 2 and the expansion shaft 4 are relatively fixed in the cross-sectional direction, which ensures that the grinding head 1, the fixed seat 2 and the expansion shaft 4 as a whole rotate relative to the workpiece body 5. Specifically, in this embodiment, the tapered shaft surface 41 expands the tapered circular hole structure of the central through hole 23, and the elastic arm 22 is elastically deformed.

[0067] Exemplarily, the taper of the tapered shaft surface 41 is 1:20-1:30.

[0068] Specifically, when the taper of the conical shaft surface 41 is 1:25, the installation depth of the bolt 31 in the threaded hole is increased by 0.5 mm, and the diameter of the grinding spherical surface is increased by 0.01 mm. By rotating the bolt 31 to adjust the installation depth of the bolt 31 in the threaded hole, the adjustment of the micro installation depth is realized. The change of the center through hole 23 caused by rotating the bolt 31 is micro, and the size adjustment of the grinding spherical surface can be realized.

[0069] Further, the elastic arm 22 and the deformation gap 221 are provided with a weakening hole 222, the weakening hole 222 is consistent with the length and direction of the center through hole 23, and the weakening hole 222 is communicated with the deformation gap 221.

[0070] The fixed seat 2 is integrally machined from a steel piece, and the weakening hole 222 is arranged at the end of the deformation gap 221, and the elastic arm 22 is formed between the weakening hole 222 and the center through hole 23.

[0071] Preferably, the cross section of the weakening hole 222 is circular, so that the elastic deformation effect is better.

[0072] By setting the elastically deformable fixed seat 2, the center through hole 23 of the fixed seat 2 is expanded by the conical shaft hole structure, the relative position of the grinding head 1 mounted on the mounting portion 21 of the fixed seat 2 is changed by increasing the diameter of the center through hole 23, and the grinding spherical surface is further increased.

[0073] In another exemplary embodiment, as shown in Figure 4 , the grinding head 1 is provided with a first positioning groove 12, the mounting portion 21 is provided with a second positioning groove 211, and a positioning pin 212 is further included, the first positioning groove 12 and the second positioning groove 211 are located on both sides of the positioning pin 212, and after contacting with the positioning pin 212, the relative position of the grinding head 1 and the mounting portion 21 in the direction perpendicular to the axis of the center through hole 23 is limited.

[0074] Specifically, the positioning pin 212 is a circular rod, and the axis after installation is consistent with the axis direction of the expansion shaft 4, and two second positioning grooves 211 parallel to each other are arranged on each mounting portion 21.

[0075] As shown in Figure 5 , Figure 6 , one end of the mounting portion 21 is provided with a boss 25, and one end of the grinding head 1 is provided with a recess 13, and after the boss 25 cooperates with the recess 13, the relative position of the mounting portion 21 and the grinding head 1 in the center through hole 23 axis direction is limited.

[0076] As shown in Figure 4 , Figure 9 , the grinding head 1 is provided with a through hole 11, and a fastener for detachably connecting the grinding head 1 and the mounting portion 21 is installed in the through hole 11.

[0077] The window 6 comprises an axial port 62 for passing through the fixed seat 2, and a side port 61 for installing fasteners.

[0078] The positioning pin 212 cooperates with the two positioning grooves, and the boss 25 cooperates with the groove 13 to achieve the transverse positioning and longitudinal positioning of the grinding head 1 and the mounting portion 21. After the grinding head 1 and the fixed seat 2 are put into the inner spherical cavity through the window 6, the above positioning structure facilitates the positioning and assembly operation of the grinding head 1 and the fixed seat 2 inside the inner spherical cavity.

[0079] The assembly process of the inner spherical cavity grinding tool of the embodiment is as follows:

[0080] The plurality of grinding heads 1 are sequentially put into the inner spherical cavity, and can be put into through the axial port 62 or the side port 61 according to the size, and after the plurality of grinding heads 1 are distributed in the circumferential direction, the grinding head 1 is preliminarily attached to the spherical surface to be machined with a radius.

[0081] The fixed seat 2 is inserted between the plurality of grinding heads 1 from the axial port 62, and the transverse positioning is performed through the cooperation of the positioning pin 212 and the first positioning groove 12 and the second positioning groove 211, and the longitudinal positioning is completed after the boss 25 cooperates with the groove 13.

[0082] The bolt 31 and the gasket 32 are installed through the axial port 62 to connect the expansion shaft 4 with the fixed seat, and the fasteners are installed through the side port 61 to detachably connect the grinding head 1 with the mounting portion 21 on the fixed seat 2.

[0083] The use process of the inner spherical cavity grinding tool of the embodiment is as follows:

[0084] The inner spherical cavity grinding tool is assembled in the inner spherical cavity of the workpiece body 5.

[0085] The installation depth of the bolt 31 in the threaded hole is adjusted to change the relative positions between the plurality of mounting portions 21, so that the grinding spherical surface is increased and attached to the spherical surface to be machined with a radius.

[0086] The grinding head 1 is made to act on the spherical surface to be machined with a radius by regularly rotating and swinging the expansion shaft 4 with the spherical surface to be machined with a radius as a reference and guide.

[0087] It is confirmed whether the current spherical surface is the target spherical surface, and if not, the installation depth of the bolt 31 in the threaded hole is adjusted and the grinding is performed again until the target spherical surface is reached.

[0088] Before confirming the size of the current spherical surface, the fixed seat 2 and the grinding head 1 can be disconnected and taken out of the inner spherical cavity, and then the size of the current spherical surface is measured.

[0089] The above description is an explanation of the present application, not a limitation of the present application, and the scope of the present application is defined in the claims. Any modification can be made within the scope of the present application.

Claims

1. An internal spherical cavity abrasive tool characterized by: The inner surface of the inner spherical cavity is provided with a to-be-processed radius spherical surface, a window (6) is arranged on the side wall of the inner spherical cavity, and the grinding tool comprises: A fixed seat (2) is provided with a center through hole (23), the fixed seat (2) comprises a plurality of mounting parts (21), and the plurality of mounting parts (21) are distributed in the circumferential direction with the center through hole (23) as the center; A plurality of grinding heads (1) correspond to the plurality of mounting parts (21) one by one, the grinding head (1) is detachably mounted on the mounting part (21), a grinding arc surface (10) is arranged on each grinding head (1), and the plurality of grinding arc surfaces (10) form a grinding spherical surface matched with the to-be-processed radius spherical surface; An expansion shaft (4) is connected with the center through hole (23) and used for maintaining and changing the relative positions between the plurality of mounting parts (21); Wherein, the grinding head (1) and the fixed seat (2) are assembled into an integrated whole after being put into the inner spherical cavity through the window (6), the relative positions between the plurality of mounting parts (21) are changed, and the grinding spherical surface is attached to the to-be-processed radius spherical surface.

2. The inner ball cavity lapping tool of claim 1, wherein: The opening gap (24) is arranged between a pair of adjacent mounting parts (21) in the plurality of mounting parts (21) of the fixed seat (2), the remaining adjacent mounting parts (21) are elastically connected through the elastic arm (22) and are provided with a deformation gap (221) penetrating through both ends of the fixed seat (2), and the plurality of mounting parts (21) and the elastic arm (22) surround to form the center through hole (23); By applying external force to the fixed seat (2) through the expansion shaft (4), the elastic arm (22) is elastically deformed, the opening gap (24) is increased, the deformation gap (221) is reduced, and the grinding spherical surface is attached to the to-be-processed radius spherical surface.

3. The inner ball cavity lapping tool of claim 2, wherein: The center through hole (23) is a tapered circular hole, the expansion shaft (4) is provided with a tapered shaft surface (41) matched with the center through hole (23), one end of the expansion shaft (4) is provided with a limiting component (3), the limiting component (3) applies tension to the expansion shaft (4) and applies pressure to the end surface of the fixed seat (2), the directions of the tension and the pressure are opposite, and the elastic arm (22) is elastically deformed.

4. The inner ball cavity lapping tool of claim 3, wherein: The limiting component (3) comprises a bolt (31) and a gasket (32), the end of the expansion shaft (4) on one side of the small end of the tapered shaft surface (41) is provided with a threaded hole, the bolt (31) is threadedly connected with the threaded hole, the gasket (32) is in contact with the end surface of the fixed seat (2), the pressure of the head of the bolt (31) on the gasket (32) is changed by changing the mounting depth of the bolt (31) in the threaded hole, and then the elastic arm (22) is elastically deformed.

5. The inner ball cavity lapping tool of claim 3, wherein: The taper of the tapered shaft surface (41) is 1:20-1:

30.

6. The inner ball cavity lapping tool of claim 3, wherein: The elastic arm (22) and the deformation gap (221) are provided with a weakening hole (222), the weakening hole (222) is consistent with the length and direction of the center through hole (23), and the weakening hole (222) is in communication with the deformation gap (221).

7. The inner ball cavity lapping tool of claim 1, wherein: The grinding head (1) is provided with a first positioning groove (12), the mounting part (21) is provided with a second positioning groove (211), and a positioning pin (212) is further arranged, the first positioning groove (12) and the second positioning groove (211) are located on both sides of the positioning pin (212), and after the first positioning groove (12) and the second positioning groove (211) contact the positioning pin (212), the relative position of the grinding head (1) and the mounting part (21) in the direction perpendicular to the axis of the central through hole (23) is limited.

8. The inner ball cavity lapping tool of claim 1, wherein: One end of the mounting part (21) is provided with a boss (25), one end of the grinding head (1) is provided with a groove (13), and after the boss (25) and the groove (13) are matched, the relative position of the mounting part (21) and the grinding head (1) in the central through hole (23) axis direction is limited.

9. The inner ball cavity lapping tool of claim 1, wherein: The grinding head (1) is provided with a through hole (11), and a fastener for detachably connecting the grinding head (1) and the mounting part (21) is arranged in the through hole (11).

10. The inner ball cavity lapping tool of claim 9, wherein: The window (6) comprises an axial port (62) for passing through the fixed seat (2), and a side port (61) for mounting a fastener.

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