Grinding fixture for high-precision eccentric shaft

Abstract

The grinding clamp comprises a shaft sleeve, the shaft sleeve is provided with a positioning step face used for positioning and sleeving the high-precision eccentric shaft, the shaft sleeve is provided with a plurality of first strip-shaped holes which are located in the positioning step face and evenly distributed in the circumferential direction, and movable blocks are arranged in the first strip-shaped holes; a mandrel is in threaded connection with the interior of the shaft sleeve, an expansion part for supporting the movable block is arranged on the mandrel, and the movable block is in conical surface fit with the expansion part; the mandrel is rotated to enable the expansion part to push the movable block to be exposed out of the shaft sleeve and expand the high-precision eccentric shaft; after the high-precision eccentric shaft is sleeved and positioned through the positioning step surface, the mandrel is rotated to enable the expansion part to be matched with the conical surface of the movable block, then the movable block is pushed to be exposed out of the first strip-shaped hole so as to expand and position the inner hole of the high-precision eccentric shaft, a worn part is transferred to the movable block, and the movable block can be directly replaced when precision deviation occurs. Overall replacement is not needed, so that the cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of grinding fixtures, and in particular to a high-precision grinding fixture for an eccentric shaft. Background Technology

[0002] like Figure 1 The diagram shows the structure of a high-precision eccentric shaft. When two grinding processes are required, namely the outer circumferential surface and the outer eccentric circumferential surface, it needs to be positioned and clamped through the internal shaft hole. Conventional fixtures use a positioning shaft that matches the shaft hole for direct locking and positioning. However, the force during the machining process causes certain deformation of the mating surface, resulting in low clamping accuracy. The mating surface between the shaft hole and the positioning shaft has extremely high requirements. If the accuracy changes, the entire positioning shaft needs to be replaced, which also increases the cost. Utility Model Content

[0003] The purpose of this utility model is to provide a grinding fixture for a high-precision eccentric shaft, which solves the problem in the prior art that the positioning shaft used to match the high-precision eccentric shaft is used for internal hole positioning. When the accuracy is affected by the force, the entire fixture must be replaced, which increases the cost.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A grinding fixture for a high-precision eccentric shaft includes a bushing with a positioning step surface for positioning and fitting the high-precision eccentric shaft. The bushing has multiple first strip-shaped holes evenly distributed circumferentially on the positioning step surface, each containing a movable block. A mandrel is internally threaded onto the bushing, and the mandrel has an expansion portion supporting the movable blocks. The movable block and the expansion portion are in a tapered fit. Rotating the mandrel causes the expansion portion to push the movable block out of the bushing and tighten the high-precision eccentric shaft.

[0006] Preferably, the movable block is provided with a first conical surface and a second conical surface at intervals; the expansion part includes a first conical surface and a second conical surface, the first conical surface mates with the first conical surface, and the second conical surface mates with the second conical surface; a first step structure is provided between the first conical surface and the second conical surface, and a first limiting step is provided between the first conical surface and the second conical surface, the first limiting step being used to limit the first step structure from sliding forward.

[0007] Preferably, the bushing is provided with a positioning step, which is used to position the end face of the high-precision eccentric shaft.

[0008] Preferably, the bushing has at least two second strip-shaped holes located at the positioning step, and a positioning block is inserted into the second strip-shaped hole. The positioning block has a T-shaped structure.

[0009] Preferably, the mandrel includes a threaded head, and the bushing has a threaded hole that mates with the threaded head.

[0010] Preferably, the mandrel includes a first sliding portion located between the expansion portion and the threaded head, and the bushing has a first sliding hole that slides with the first sliding portion.

[0011] Preferably, the mandrel includes a second sliding portion located at the end of the expansion portion, and the bushing has a second sliding hole that slides with the second sliding portion.

[0012] Preferably, the bushing has positioning center holes at both ends.

[0013] Preferably, the bushing has positioning conical surfaces at both ends.

[0014] Beneficial effects:

[0015] After positioning the high-precision eccentric shaft by using the positioning step surface, the rotating spindle causes the expansion part to engage with the conical surface of the movable block, pushing the movable block out from the first strip hole to tighten and position the inner hole of the high-precision eccentric shaft. This transfers the worn parts to the movable block, so that when there is a precision deviation, the movable block can be replaced directly instead of replacing the whole shaft, thereby reducing costs.

[0016] At the same time, the use of conical surfaces to evenly push out the movable block during the expansion and tightening process can meet the circumference requirements, and after one positioning, it can achieve the machining of the outer circle and the eccentric outer circle on the high-precision eccentric shaft, ensuring that the same positioning datum will not change. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0018] Figure 2 This is a schematic diagram of the bushing structure in an embodiment of the present utility model;

[0019] Figure 3 This is a schematic diagram of the mandrel structure in an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the structure of the movable block in an embodiment of this utility model;

[0021] Figure 5 This is a schematic diagram of the positioning block in an embodiment of the present invention;

[0022] Figure 6 A schematic diagram of the matching top clamping in an embodiment of this utility model;

[0023] Figure 7A schematic diagram of the anti-center clamping assembly for an embodiment of this utility model;

[0024] exist Figures 1 to 7 In the diagram, the correspondence between component names or lines and the drawing numbers is as follows:

[0025] 1. Bushing; 2. Positioning step surface; 3. First strip hole; 4. Movable block; 5. Mandrel; 6. Expansion part; 7. First conical surface; 8. Second conical surface; 9. First conical surface; 10. Second conical surface; 11. First step structure; 12. First limiting step; 13. Positioning step; 14. Second strip hole; 15. Positioning block; 16. Threaded head; 17. Threaded hole; 18. First sliding part; 19. Second sliding part; 20. Second sliding hole; 21. Positioning center hole; 22. Positioning conical surface; 23. High-precision eccentric shaft; 100. Center; 200. Anti-center; 300. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0027] See Figures 1-7 As shown in the embodiment of this utility model, a grinding fixture for a high-precision eccentric shaft is proposed, which is adapted to be clamped onto an external cylindrical grinding machine to perform internal hole positioning and clamping of the high-precision eccentric shaft 100, thereby realizing the grinding of the outer circle and eccentric outer circle of the high-precision eccentric shaft 100. Specifically, it includes a bushing 1, which has a positioning step 13 surface 2 for positioning and fitting the high-precision eccentric shaft 100. The bushing 1 has a plurality of first strip-shaped holes 3 located on the positioning step 13 surface 2 and evenly distributed circumferentially. A movable block 4 is provided in the first strip-shaped hole 3. The movable block 4 can slide relative to the first strip-shaped hole 3 to be exposed on the positioning step 13 surface 2. The positioning step 13 surface 2 can initially position the inner hole of the high-precision eccentric shaft 100. After the movable block 4 is pushed out, it achieves expansion support and positioning of the inner hole, ensuring that the high-precision eccentric shaft 100 will not rotate relative to the hole after clamping. Thus, it can ensure the stability and reliability of the grinding process with only one clamping.

[0028] Meanwhile, a mandrel 5 is threaded into the bushing 1. The mandrel 5 is provided with an expansion part 6 that supports the movable block 4. The movable block 4 and the expansion part 6 are in conical contact. Rotating the mandrel 5 causes the expansion part 6 to push the movable block 4 out of the bushing 1 and tighten the high-precision eccentric shaft 100. By rotating the mandrel 5, the expansion part 6 and the movable block 4 are moved to push multiple circumferentially distributed movable blocks 4 to slide outward simultaneously under the action of the conical contact, so as to achieve uniform tightening of the inner hole of the high-precision eccentric shaft 100.

[0029] In this embodiment, to ensure uniform expansion as much as possible, the number of the first strip hole 3 and the movable block 4 are both 6.

[0030] Specifically, to improve the overall smoothness of the sliding of the movable block 4 and enhance the reliability of the conical surface fit, a first conical surface 7 and a second conical surface 8 are spaced apart on the movable block 4. The expansion part 6 includes a first conical surface 9 and a second conical surface 10. The first conical surface 7 fits with the first conical surface 9, and the second conical surface 8 fits with the second conical surface 10. By simultaneously achieving conical surface fit at two locations, the movable block 4 can slide smoothly when pushed out, ensuring positioning accuracy. Meanwhile, a first step structure 11 is provided between the first conical surface 7 and the second conical surface 8, and a first limiting step 12 is provided between the first conical surface 9 and the second conical surface 10. The first limiting step 12 is used to limit the forward sliding of the first step structure 11. The first limiting step 12, in conjunction with the first step structure 11, limits the movable block 4 from sliding too deeply inward and prevents it from completely sliding out of the first strip hole 3.

[0031] Specifically, a positioning step 13 is provided on the bushing 1. The positioning step 13 is used to position the end face of the high-precision eccentric shaft 100. The high-precision eccentric bushing 1 is positioned by the positioning step 13. At the same time, at least two second strip-shaped holes 14 are provided on the bushing 1 at the positioning step 13. Positioning blocks 15 are inserted into the second strip-shaped holes 14. The positioning blocks 15 have a T-shaped structure. The step on the high-precision eccentric shaft is further positioned by the positioning blocks 15 at the two positions, thereby achieving double positioning during end face positioning and ensuring that the end face positioning meets the processing size requirements.

[0032] Specifically, the mandrel 5 includes a threaded head 16, and the bushing 1 has a threaded hole 17 that mates with the threaded head 16. The mandrel 5 can be moved and adjusted within the bushing 1 by the engagement of the threaded head 16 and the threaded hole 17, and the adjusted position can be self-locked to prevent loosening during processing.

[0033] Specifically, the mandrel 5 includes a first sliding part 18 located between the expansion part 6 and the threaded head 16, and the bushing 1 has a first sliding hole 19 that slides with the first sliding part 18. The first sliding part 18 and the first sliding hole 19 cooperate to ensure the accuracy requirement of the mandrel 5 sliding in the bushing 1.

[0034] Meanwhile, the mandrel 5 includes a second sliding part 20 located at the end of the expansion part 6, and the bushing 1 has a second sliding hole 21 that slides with the second sliding part 20, which further guides and positions the sliding of the end of the expansion part 6, thereby ensuring the reliability and accuracy of the tapered surface fit when the entire mandrel 5 moves within the bushing 1.

[0035] Thus, by rotating the spindle 5 relative to the bushing 1, the expansion part 6 moves, which in turn pushes the movable block 4 outward to achieve the expansion and positioning of the inner hole of the high-precision eccentric shaft 100.

[0036] After the high-precision eccentric shaft 100 is clamped, the entire fixture is directly installed on the cylindrical grinding machine for clamping, which facilitates the machining of the outer diameter and eccentric outer diameter of the high-precision eccentric shaft 100.

[0037] Specifically, positioning center holes 22 are respectively provided at both ends of the bushing 1. When machining the outer circle, the center 200 on the outer cylindrical grinding machine is used to position the bushing at the positioning center holes 22 at both ends.

[0038] When machining the outer eccentric circle, the positioning is achieved by the anti-center 300 on the outer cylindrical grinding machine. Specifically, positioning cone surfaces 23 are provided at both ends of the bushing 1. The anti-center 300 and the positioning cone surfaces 23 cooperate to achieve clamping and positioning.

[0039] This allows for the clamping of a high-precision eccentric shaft after a single positioning and clamping process, simply by changing the center 200 and the anti-center 300 on the external cylindrical grinding machine, eliminating the need to change other fixtures and improving processing efficiency.

[0040] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0041] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A grinding jig for a high-precision eccentric shaft, characterized by: Including the shaft sleeve (1), the shaft sleeve (1) is equipped with the positioning step (13) surface (2) for positioning the sleeve high-precision eccentric shaft (100), the shaft sleeve (1) is opened in the multiple first strip holes (3) of the positioning step (13) surface (2) and is evenly distributed along the circumference, the first strip hole (3) is equipped with the movable block (4) in; The core shaft (5) is threadedly connected in the shaft sleeve (1), the core shaft (5) is equipped with the expansion part (6) of supporting the movable block (4), the movable block (4) and the expansion part (6) are taper surface cooperation; The core shaft (5) is rotated to make the expansion part (6) push the movable block (4) to expose the shaft sleeve (1) and expand the high-precision eccentric shaft (100).

2. The grinding jig for a high-precision eccentric shaft according to claim 1, characterized in that: The movable block (4) is equipped with the first taper surface (7) and the second taper surface (8) at intervals; The expansion part (6) includes the first conical surface (9) and the second conical surface (10), the first taper surface (7) is matched with the first conical surface (9), and the second taper surface (8) is matched with the second conical surface (10); The first taper surface (7) and the second taper surface (8) are provided with a first step structure (11), and the first conical surface (9) and the second conical surface (10) are provided with a first limiting step (12), and the first limiting step (12) is used to limit the first step structure (11) to slide forward.

3. The grinding jig for a high-precision eccentric shaft according to claim 2, characterized in that: The shaft sleeve (1) is provided with a positioning step (13), and the positioning step (13) is used for positioning the end face of the high-precision eccentric shaft (100).

4. The grinding jig for a high-precision eccentric shaft according to claim 3, characterized in that: The shaft sleeve (1) is provided with at least two second strip holes (14) at the positioning step (13), and the second strip hole (14) is inserted with a positioning block (15), and the positioning block (15) is a T-shaped structure.

5. The grinding jig for a high-precision eccentric shaft according to claim 4, characterized in that: The core shaft (5) includes a threaded head (16), and the shaft sleeve (1) is provided with a threaded hole (17) matched with the threaded head (16).

6. The grinding jig for a high-precision eccentric shaft according to claim 5, characterized in that: The core shaft (5) includes a first sliding part (18) between the expansion part (6) and the threaded head (16), and the shaft sleeve (1) is provided with a first sliding hole (19) in sliding cooperation with the first sliding part (18).

7. The grinding jig for a high-precision eccentric shaft according to claim 6, characterized in that: The core shaft (5) includes a second sliding part (20) at the end of the expansion part (6), and the shaft sleeve (1) is provided with a second sliding hole (21) in sliding cooperation with the second sliding part (20).

8. The grinding fixture of a high-precision eccentric shaft according to any one of claims 1-7, characterized in that: The shaft sleeve (1) is provided with a positioning center hole (22) at both ends.

9. The grinding fixture of any one of claims 1-7, wherein: The shaft sleeve (1) is provided with a positioning taper surface (23) at both ends.

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