Grinding tool and elastic sleeve for grinding tool

Abstract

The utility model discloses grinding frock and grinding frock is used elastic cover, including body, the body is equipped with the through hole for the workpiece through in axial penetration, at least one part of the outer peripheral wall of body is constituted for the tapered surface of cooperation with external conical cavity, one end of body is the clamping end of being equipped with a plurality of interstices, each interstice is along the clamping end evenly spaced distribution in the circumference, and interstice is linked together with the through hole. The tapered surface is cooperated with external conical cavity, so that the body can produce even radial contraction when being pressed in the axial direction. The interstice of clamping end setting provides the necessary elastic deformation space for the radial contraction of this end, so that it can firmly hold the workpiece. Avoid the bruise and scratch of traditional rigid clamping to the workpiece surface, be applicable to the precision workpiece of clamping surface finish requirement high.

Description

Technical Field

[0001] This utility model relates to the field of automotive steering gear parts processing technology, specifically to grinding fixtures and elastic sleeves for grinding fixtures. Background Technology

[0002] In the field of precision machining, especially in the manufacturing of key components such as valve cores for automotive steering systems, the clamping method of the workpiece directly determines the machining quality of the final product. The rotary valve of an automotive steering system consists of a valve core and a screw integrally formed with it. During production, the screw is mostly formed through processes such as investment casting. After casting, the end of the screw inevitably has residual gating gates, flash, or dimensional allowances, requiring precision grinding to ensure the flatness of the end face. Currently, for grinding such workpieces, traditional cylindrical grinders or surface grinders are often used with a three-jaw chuck to clamp the valve core. However, this method has significant drawbacks. Because the surface finish of the rotary valve core requires extremely high smoothness, directly clamping the outer diameter of the valve core with a three-jaw chuck easily causes surface scratches and damage, leading to defective products. Utility Model Content

[0003] To address the aforementioned technical problems, this utility model proposes a grinding fixture and an elastic sleeve for the grinding fixture. The gap at the clamping end provides the necessary elastic deformation space for radial contraction at that end, thereby enabling it to firmly grip the screw of the workpiece steering valve. This avoids the pressure marks and scratches on the valve core surface caused by traditional rigid clamping.

[0004] The technical solution adopted by this utility model is as follows: an elastic sleeve for grinding tooling includes a body, the body having an axially penetrating through hole for workpieces to pass through, at least a portion of the outer peripheral wall of the body being constructed as a conical surface for cooperating with an external conical cavity, one end of the body being a clamping end having multiple gaps, each gap being evenly spaced along the circumference of the clamping end, and the gaps being connected to the through hole.

[0005] Optionally, the body includes a first sleeve, a second sleeve, and a third sleeve connected in sequence. The outer peripheral walls of the first sleeve and the third sleeve are respectively the conical surfaces. The diameter of the second sleeve is smaller than the diameter of the third sleeve and the diameter of the first sleeve, and the diameter of the third sleeve is smaller than the diameter of the first sleeve. The gap is provided in the third sleeve and extends to the second sleeve.

[0006] Optionally, the second sleeve is provided with a plurality of pressure relief holes, and the pressure relief holes are connected to the gaps one by one.

[0007] Optionally, the through hole includes a first section for placing the valve core, a second section for placing the screw, and a third section for the screw to pass through, which are connected in sequence. The third section is a tapered hole, and the diameter of the tapered hole gradually decreases along the screw insertion direction.

[0008] Optionally, a limiting part is provided at the end of the first sleeve that is away from the second sleeve, and the diameter of the limiting part is larger than the diameter of the first sleeve.

[0009] Optionally, the outer peripheral wall of the first sleeve is provided with a locking protrusion for axial sliding engagement with the locking groove on the outer conical cavity.

[0010] This utility model also discloses a grinding fixture, including an outer fixed sleeve, an inner fixed sleeve and the elastic sleeve mentioned above. The inner fixed sleeve is rotatably nested inside the outer fixed sleeve, and one end of the inner fixed sleeve protrudes from the outer fixed sleeve. The inner fixed sleeve is provided with a conical cavity that is press-fitted to the body.

[0011] The inner wall of the conical cavity is provided with a groove that slides axially with the protrusion on the outer wall of the main body, and the length of the groove is greater than that of the protrusion.

[0012] The beneficial effects of this invention are as follows: the conical surface and the external conical cavity cooperate to allow the body to generate uniform radial contraction when subjected to axial pressure. The gap at the clamping end provides the necessary elastic deformation space for radial contraction, thus enabling it to firmly grip the screw of the workpiece steering valve. This avoids the pressure marks and scratches on the valve core surface caused by traditional rigid clamping (such as a three-jaw chuck), and is particularly suitable for clamping precision workpieces with high surface finish requirements. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the elastic sleeve for grinding tooling proposed in an embodiment of this utility model;

[0014] Figure 2 This is a schematic diagram of the through hole of the elastic sleeve for grinding tooling proposed in an embodiment of this utility model;

[0015] Figure 3 An exploded view of the fit between the elastic sleeve and the conical cavity in the grinding fixture proposed in this embodiment of the present invention;

[0016] Figure 4 This is a schematic diagram of the grinding fixture proposed in an embodiment of the present invention.

[0017] The labels in the attached figures are as follows: 100, body; 101, first sleeve; 102, second sleeve; 103, third sleeve; 104, through hole; 104a, first hole segment; 104b, second hole segment; 104c, third hole segment; 105, limiting part; 106, locking protrusion; 107, gap; 108, pressure relief hole; 1, frame; 2, transmission assembly; 21, first rotary motor; 22, driving wheel; 23, synchronous belt; 24, driven wheel; 3, first clamping assembly; 33, first connecting plate; 4, second clamping assembly; 52, outer fixing sleeve; 53, inner fixing sleeve; 531, conical cavity; 532, slot; 6, clamping assembly; 7, grinding assembly; 71, second rotary motor; 72, grinding disc; 75, slide rail; 8, spray head; 9, workpiece. Detailed Implementation

[0018] The present application will now be described in further detail with reference to the accompanying drawings and embodiments.

[0019] like Figures 1 to 4 As shown, this embodiment discloses a tooling for grinding a steering valve workpiece 9, including an outer fixed sleeve 52, an inner fixed sleeve 53, and an elastic sleeve 100. The elastic sleeve 100 is made of spring steel through quenching and tempering, exhibiting good elasticity and wear resistance. The elastic sleeve 100 is a single integral piece, its body comprising a first sleeve portion 101, a second sleeve portion 102, and a third sleeve portion 103 connected coaxially in sequence. The elastic sleeve 100 has an axially penetrating through hole 104 at its center for the steering valve screw to pass through. The through hole 104 specifically includes three sections: a first hole section 104a located in the first sleeve 101, which has a larger diameter and is used to accommodate and limit the valve core of the directional valve; a second hole section 104b located in the second sleeve 102, whose diameter is adapted to the diameter of the workpiece screw; and a third hole section 104c located in the third sleeve 103, which is a tapered hole whose diameter gradually narrows along the workpiece insertion direction (from left to right in the figure), serving to guide the screw to be inserted smoothly.

[0020] The outer peripheral walls of the first sleeve portion 101 and the third sleeve portion 103 are respectively constructed as tapered surfaces, and both have the same taper. The diameter (radial dimension) of the second sleeve portion 102 is smaller than the diameters of the first sleeve portion 101 and the third sleeve portion 103, thereby forming a flexible neck with a smaller radial dimension in the middle of the entire sleeve body. At the end of the first sleeve portion 101 away from the second sleeve portion 102, a radially outwardly extending limiting portion 105 is provided, the diameter of which is larger than the diameter of the first sleeve portion 101, forming an annular shoulder. An axially extending locking protrusion 106 is provided on the outer peripheral wall of the first sleeve portion 101. At the end of the third sleeve portion 103 away from the second sleeve portion 102, four through slits 107 are milled circumferentially at uniform intervals. These slits 107 communicate with through holes 104 and divide the end of the third sleeve portion 103 into multiple independently elastically deformable petal-shaped structures. Each of the aforementioned slits 107 extends axially into the interior of the second sleeve 102 by a certain length. On the second sleeve 102 (flexible neck), a pressure relief hole 108 is provided corresponding to the position of each slit 107. These pressure relief holes 108 are round holes or oblong holes, corresponding one-to-one with the slits 107 and communicating with them.

[0021] The grinding fixture in this embodiment also includes a frame 1, a fixed plate, a transmission assembly 2, a first clamping assembly 3, a second clamping assembly 4, a clamping assembly 6, and a grinding assembly 7. The fixed plate is vertically fixed to the frame 1 by bolts. The outer fixing sleeve 52 is press-fitted or fixed to the central through hole of the fixed plate by a flange. The inner fixing sleeve 53 is rotatably nested in the outer fixing sleeve 52 by a pair of high-precision angular contact bearings 55, with one end protruding from the outer fixing sleeve 52. The inner hole of the inner fixing sleeve 53 is a tapered cavity 531, the diameter of which gradually decreases along the workpiece insertion direction, and its taper matches the tapered surfaces of the first sleeve portion 101 and the third sleeve portion 103 of the elastic sleeve 100. An axially extending groove 532 is machined on the inner wall of the tapered cavity 531. The axial length of the groove 532 is greater than the axial length of the retaining protrusion 106 on the elastic sleeve 100. The elastic sleeve 100 is press-fitted into the tapered cavity 531 of the inner fixed sleeve 53 with its tapered surface. During assembly, the retaining protrusion 106 on the elastic sleeve 100 slides along the retaining groove 532 of the inner fixed sleeve 53, forming a sliding fit. The transmission assembly 2 is used to drive the inner fixed sleeve 53 to rotate, and includes a first rotary motor 21, a drive wheel 22, a timing belt 23, and a driven wheel 24. The driven wheel 24 is fixedly installed on the right end of the protruding inner fixed sleeve 53 and receives power from the motor through the timing belt 23. The first clamping assembly 3 and the second clamping assembly 4 are respectively arranged on the left and right sides of the fixed plate to clamp the workpiece from both ends and provide axial positioning. The grinding assembly 7 includes a second rotary motor 71 and a grinding disc 72, which can be moved by the slide rail 75 for feeding grinding. At the same time, the spray head 8 is aimed at the grinding area to cool, remove dust, and rinse.

[0022] During clamping, the operator inserts the screw of the steering valve workpiece 9 into the through hole 104 of the elastic sleeve 100. The tapered inlet and petal-like structure of the third hole section 104c provide guidance and allow the screw to be smoothly inserted after expanding the slot 107 until the valve core portion abuts against the step formed by the first hole section 104a. The clamping assembly 6 clamps the limiting portion 105 of the elastic sleeve 100 and pushes it to the left, pressing it deeper into the tapered cavity 531 of the inner fixing sleeve 53. As the insertion depth increases, the inner wall of the tapered cavity 531 continuously compresses the tapered surfaces of the first sleeve portion 101 and the third sleeve portion 103 of the elastic sleeve 100 under a huge, uniform radial pressure. This process causes the third hole section 104c to further contract, generating an extremely strong and uniform radial clamping force on the workpiece screw inside, achieving high-precision centering clamping without damage. The slot 107 provides the elastic deformation space required for the radial contraction of the petal-like structure. The design of the second sleeve 102 alleviates stress at this point, and the pressure relief hole 108 connects with the gap 107, further releasing internal stress and effectively preventing fatigue fracture of the elastic sleeve 100 at the second sleeve 102 during repeated use, greatly improving service life and reliability. The cooperation between the locking protrusion 106 and the locking groove 532 ensures that the torque during grinding can be effectively transmitted from the inner fixed sleeve 53 to the elastic sleeve 100 and the workpiece 9, preventing slippage. Then, the clamping components 3 and 4 are activated to clamp both ends of the workpiece. The first rotary motor 21 is started to drive the workpiece to rotate; the grinding component 7 is started to grind the end of the rotating workpiece. After grinding, the drive mechanism pushes the elastic sleeve 100 back to the right, causing it to exit the compression area of ​​the conical cavity 531. The third sleeve 103 resets under its own elasticity, and the aperture becomes larger, allowing the workpiece to be easily removed.

[0023] It is understood that the specific embodiments described above are merely for explaining the relevant utility model and not for limiting the utility model. It should also be noted that, for ease of description, only the parts related to the utility model are shown in the accompanying drawings. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not contradict or conflict with each other. All equivalent structural transformations made based on the content of this utility model specification and drawings, directly or indirectly applied to other related technical fields, are similarly included within the protection scope of this utility model.

Claims

1. An elastic sleeve for grinding fixtures, characterized in that, The device includes a body having an axially penetrating through hole for a workpiece to pass through, at least a portion of the outer peripheral wall of the body being configured as a tapered surface for engaging with an external tapered cavity, and one end of the body being a clamping end having multiple slits, each slit being evenly spaced along the circumference of the clamping end, and the slits being connected to the through hole.

2. The elastic sleeve for grinding tool according to claim 1, wherein The main body includes a first sleeve, a second sleeve, and a third sleeve connected in sequence. The outer peripheral walls of the first sleeve and the third sleeve are respectively the conical surfaces. The diameter of the second sleeve is smaller than the diameter of the third sleeve and the diameter of the first sleeve, and the diameter of the third sleeve is smaller than the diameter of the first sleeve. The gap is provided in the third sleeve and extends to the second sleeve.

3. The elastic sleeve for grinding fixtures according to claim 2, characterized in that, The second sleeve is provided with multiple pressure relief holes, and each pressure relief hole is connected to the gap in a corresponding manner.

4. The elastic sleeve for grinding tool according to claim 1, wherein The through hole includes a first section for placing the valve core, a second section for placing the screw, and a third section for the screw to pass through, which are connected in sequence. The third section is a tapered hole, and the diameter of the tapered hole gradually decreases along the screw insertion direction.

5. The elastic sleeve for grinding tool according to claim 2, wherein A limiting part is provided at the end of the first sleeve that is away from the second sleeve, and the diameter of the limiting part is larger than the diameter of the first sleeve.

6. The elastic sleeve for grinding fixtures according to claim 2, characterized in that, The outer peripheral wall of the first sleeve is provided with a locking protrusion for axial sliding engagement with the locking groove on the external conical cavity.

7. A grinding tool characterized by, It includes an outer fixing sleeve, an inner fixing sleeve, and an elastic sleeve as described in any one of claims 1 to 6, wherein the inner fixing sleeve is rotatably nested within the outer fixing sleeve, and one end of the inner fixing sleeve protrudes from the outer fixing sleeve, and the inner fixing sleeve is provided with a conical cavity that is press-fitted to the body.

8. The grinding fixture according to claim 7, characterized in that, The inner wall of the conical cavity is provided with a groove that slides axially with the protrusion on the outer wall of the main body, and the length of the groove is greater than that of the protrusion.

Images