A quick-change positioning pin structure for machining fixtures

Abstract

A quick-change locating pin structure for a mechanical processing fixture belongs to the field of mechanical processing; it includes: a diamond locating pin, a diamond locating pin base, a first adjustment limit support, a second adjustment limit support, a third adjustment limit support, a circular locating pin, a circular locating pin base, a fourth adjustment limit support, and a clamp body; the diamond locating pin base and the circular locating pin base are respectively fixed on the left and right sides of the clamp body; the diamond locating pin is installed on the diamond locating pin base, and the circular locating pin is installed on the circular locating pin base and locked respectively; the first adjustment limit support and the second adjustment limit support are respectively connected to the diamond locating pin and the clamp body for positioning, and the connection relationship between the circular pin locating base and the third adjustment limit support and the fourth adjustment limit support is the same as that of the diamond locating pin. This structure is suitable for precise positioning and position accuracy adjustment of workpieces on the fixture, and meets the overload protection of the fixture when the locating pin hole is damaged due to positioning error of the workpiece, and the locating pin can be quickly removed when it is damaged.

Description

Technical Field

[0001] The utility model belongs to the field of mechanical processing, and relates to a positioning fixture, in particular to a quick-change positioning pin structure for a mechanical processing fixture. Background Art

[0002] As we all know, locating pins are widely used in mechanical processing. They play a role in limiting the freedom of the workpiece in the fixture positioning. They are used to determine the correct position of the workpiece in the fixture to ensure the correct position of the workpiece relative to the tool and machine tool during the processing. For example, the most commonly used "one side two pins" fixture positioning method uses a short cylindrical pin and a short chamfered pin to limit the two degrees of freedom of movement and one degree of freedom of rotation of the workpiece being processed.

[0003] Generally, locating pins are arranged in groups at positions relatively far from the workpiece positioning base surface. The installation and connection method of the locating pins and the fixture is related to both the positioning accuracy and the installation and removal of the locating pins. Since the locating pins are vulnerable parts and are affected by the clamping and unclamping of the workpiece, the deviation of the center distance of the grouped locating pins will cause the locating pins to wear faster, break and be damaged, and the locating pins need to be disassembled and replaced. The deviation of the center distance of the grouped locating pins will cause many adverse effects in mechanical processing, such as: when the strength of the locating pin is low, the locating pin will shear and break, and the half-section locating pin in the clamp body is difficult to remove quickly; when the structural strength of the locating pin is high, it will cause problems such as inadequate positioning, load impact deformation of the locating pin clamp body installation hole, and loss of displacement accuracy of the clamp body.

[0004] After searching, the utility model patent with announcement number: CN220128243U and application number: 2023209651820 discloses a locating pin structure for mechanical processing; the utility model patent with announcement number: CN214722272U and application number: 2021204695147 discloses a special fixture positioning device for a combined machine tool. The locating pin structure involved only considers the replacement of the locating pin when the locating pin is worn, and does not consider the problem of removing the locating pin due to shear fracture, nor does it consider the impact caused by the deviation of the center distance of the grouped locating pins.

[0005] Based on the above reasons, it is absolutely necessary to provide a quick-change safety locating pin structure which is compact, easy to use and highly functional. Utility Model Content

[0006] The purpose of the utility model is to provide a quick-change safety positioning pin structure with compact structure, easy use and strong functionality, so as to solve the positioning requirements of equipment fixtures and solve the technical problems occurring in the processing of workpieces.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a quick-change locating pin structure for a mechanical processing fixture, comprising: a diamond locating pin, a diamond locating pin base, a diamond locating pin locking top screw, a first adjustment limit support, a first adjustment gasket, a second adjustment limit support, a cylindrical pin, a circular locating pin, a third adjustment limit support, a third adjustment gasket, a circular locating pin base, a circular locating pin locking top screw, a fourth adjustment gasket, a fourth adjustment limit support, a second adjustment gasket, and a clamp body; the diamond locating pin base and the circular locating pin base are respectively fixed to the left and right sides of the clamp body by four bolts; the diamond locating pin is installed on the diamond locating pin base, and the circular locating pin is installed on the circular locating pin base, and is respectively fixed by the diamond locating pin locking top screw and the circular locating pin locking top screw Lock; the first adjustment limit support and the second adjustment limit support are respectively connected by bolts, positioning pins and clamping bodies, and the side of the first adjustment limit support and the second adjustment limit support adjacent to the diamond positioning pin base is used as a limiting surface; the first adjustment gasket and the second adjustment gasket are respectively installed between the two side surfaces adjacent to the first adjustment limit support and the second adjustment limit support and the diamond positioning pin base, and the first adjustment gasket and the diamond positioning pin base are positioned on the limiting surface of the first adjustment limit support by bolts, and the second adjustment gasket and the diamond positioning pin base are positioned on the limiting surface of the second adjustment limit support by bolts, and the connection relationship between the circular pin positioning base and the third adjustment gasket, the third adjustment limit support, the fourth adjustment gasket and the fourth adjustment limit support is the same as that of the diamond positioning pin base.

[0008] The diamond locating pin includes: a conical guide section, a conical positioning section, and a conical mounting section; a first threaded hole is arranged at the center of the conical mounting section at the lower part of the diamond locating pin, and a first safety groove, a first chamfer, and a first wedge-shaped positioning surface are arranged on the outside of the conical mounting section; the taper of the conical guide section at the upper part of the diamond locating pin is not greater than 60 degrees, and the top is spherical; the conical positioning section at the lower part of the conical guide section is a chamfered diamond with a diameter not greater than 15 mm.

[0009] The circular locating pin comprises: a circular guide section, a circular positioning section, and a circular mounting section; a second threaded hole is arranged at the center of the circular mounting section at the lower part of the circular locating pin, and a second safety groove, a second chamfer, and a second wedge-shaped positioning surface are arranged on the outside of the circular mounting section; the taper of the circular guide section at the upper part of the circular locating pin is not greater than 60 degrees, and the top is spherical; the circular positioning section at the lower part of the circular guide section is cylindrical with a length of less than 15 mm.

[0010] The diamond-shaped positioning pin base and the circular positioning pin base are provided with positioning pin installation holes, and the two adjacent side positioning surfaces are respectively provided with adjustment bolt threaded holes and positioning pin locking top screw installation holes.

[0011] The first adjustment limit support is provided with two bolt mounting holes, two cylindrical pin holes and one adjustment positioning bolt connection hole.

[0012] The structures of the second adjustment limit support, the third adjustment limit support and the fourth adjustment limit support are the same as those of the first adjustment limit support; the first adjustment limit support and the second adjustment limit support are respectively positioned and fastened to the clamp body by two cylindrical pins and two bolts, and are respectively located on both sides of the diamond positioning pin base.

[0013] The third adjustment limit support and the fourth adjustment limit support are respectively positioned and fastened to the clamp body through two cylindrical pins and two bolts, and are respectively located on both sides of the circular positioning pin base.

[0014] The first adjusting gasket has the same structure as the second adjusting gasket, the third adjusting gasket and the fourth adjusting gasket, but has different thicknesses, and all are provided with a U-shaped groove through which the adjusting screw passes.

[0015] The beneficial effects achieved by the utility model after adopting the above technical solution are: the utility model has a compact structure, reasonable design, strong functionality and is easy to use. It is suitable for precise positioning and position accuracy adjustment of workpieces on the fixture during mechanical processing, and the spacing error of the positioning pin holes can meet the requirements of low precision of automatic clamping and loading. It is particularly suitable for the two-pin structure design of the one-sided two-pin positioning fixture, which can meet the overload protection of the fixture when the positioning pin holes are damaged due to positioning errors and pin hole center distance errors of the workpiece, and can quickly remove the positioning pins when they are worn and broken. The positioning pin structure is easy and quick to adjust, the positioning is stable and reliable, and the compatibility is strong, which effectively meets the precision requirements of processing different batches and different types of parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of a quick-change positioning pin structure for a machining fixture of the utility model;

[0017] Figure 2 This is a structural schematic diagram of a diamond-shaped positioning pin of a quick-change positioning pin structure for a machining fixture of the utility model;

[0018] Figure 3 This is an installation cross-sectional view of a diamond locating pin and a diamond locating pin base of a quick-change locating pin structure for a machining fixture of the utility model;

[0019] Figure 4 It is a structural schematic diagram of a first adjustment limit support of a quick-change positioning pin structure for a machining fixture of the utility model;

[0020] Figure 5 This is a schematic diagram of a circular positioning pin structure of a quick-change positioning pin structure for a machining fixture of the utility model;

[0021] Figure 6The utility model is a structural schematic diagram of a first adjusting gasket of a quick-change safety locating pin structure for a machining fixture.

[0022] In the figure: 1. Diamond locating pin, 2. Diamond locating pin base, 3. Diamond locating pin locking screw, 4. First adjustment limit support, 5. First adjustment gasket, 6. Second adjustment limit support, 7. Cylindrical pin, 8. Round locating pin, 9. Third adjustment limit support, 10. Third adjustment gasket, 11. Round locating pin base, 12. Round locating pin locking screw, 13. Fourth adjustment gasket, 14. Fourth adjustment limit support, 15. Second adjustment gasket, 16. Clamp body; 1.1. Conical guide section, 1.2. Conical locating section, 1.3. First safety groove, 1.4. Conical installation section, 1.5. First chamfer, 1.6. First wedge-shaped positioning surface; 1.7. First threaded hole; 2.1. Adjustment bolt threaded hole, 2.2. Positioning pin locking screw mounting hole, 2.3. Positioning pin mounting hole; 4.1. Bolt mounting hole, 4.2. Cylindrical pin hole, 4.3. Adjustment positioning bolt connection hole; 5.1. U-shaped groove; 8.1. Circular guide section, 8.2. Circular positioning section, 8.3. Second safety groove, 8.4. Circular mounting section, 8.5. Second chamfer, 8.6. Second wedge-shaped positioning surface, 8.7. Second threaded hole. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that the protection scope of the present invention is not limited by the specific implementation methods.

[0024] like Figure 1-6 As shown: a quick-change locating pin structure for a mechanical processing fixture, including: a diamond locating pin 1, a diamond locating pin base 2, a diamond locating pin locking top screw 3, a first adjustment limit support 4, a first adjustment gasket 5, a second adjustment limit support 6, a cylindrical pin 7, a circular locating pin 8, a third adjustment limit support 9, a third adjustment gasket 10, a circular locating pin base 11, a circular locating pin locking top screw 12, a fourth adjustment gasket 13, a fourth adjustment limit support 14, a second adjustment gasket 15, and a clamp body 16.

[0025] In this embodiment, the diamond locating pin base 2 and the circular locating pin base 11 are fixed to the left and right sides of the clamp body 16 by four bolts respectively; the diamond locating pin 1 is installed on the diamond locating pin base 2, and the circular locating pin 8 is installed on the circular locating pin base 11. And they are locked by the diamond locating pin locking top screw 3 and the circular locating pin locking top screw 12 respectively; the first adjustment limit support 4 and the second adjustment limit support 6 are respectively positioned and connected by bolts and locating pins and the clamp body 16, and the first adjustment limit support 4 and the second adjustment limit support 6 are adjacent to the diamond locating pin base 2. The side is used as the limiting surface; the first adjustment gasket 5 and the second adjustment gasket 15 are respectively installed between the first adjustment limit support 4 and the second adjustment limit support 6 and the two adjacent side surfaces of the diamond locating pin base 2, and the first adjustment gasket 5 and the diamond locating base 2 are fixed by bolts. The pin base 2 is positioned on the limiting surface of the first adjustment limit support 4, and the bolts are connected from the adjustment positioning bolt connecting hole 4.3 of the first adjustment limit support 4 and the U-shaped groove 5.1 of the first adjustment gasket 5 to the adjustment bolt threaded hole 2.1 of the diamond positioning pin base 2, and the second adjustment gasket 15 and the diamond positioning pin base 2 are positioned on the limiting surface of the second adjustment limit support 6 by bolts; the connection relationship between the circular pin positioning base 11 and the third adjustment gasket 10, the third adjustment limit support 9, the fourth adjustment gasket 13, and the fourth adjustment limit support 14 is the same as that of the diamond positioning pin 2.

[0026] The matching installation form of the diamond locating pin 1 and the diamond locating pin base 2 is the same as the matching connection form of the circular locating pin 8 and the circular locating pin base 11, and only the matching installation form of the diamond locating pin 1 and the diamond locating pin base 2 is described.

[0027] The conical mounting section 1.4 of the diamond locating pin 1 and the locating pin mounting hole 2.3 of the diamond pin locating base 2 are matched and connected, and the diamond locating pin locking top screw 3 is used to act on the first wedge-shaped locating surface 1.6 through the locating pin locking top screw mounting hole 2.2, thereby forming a rotation limit and axial locking for the diamond locating pin 1; the first adjustment gasket 5 and the second adjustment gasket 15 are respectively located on the two adjacent sides of the first adjustment limit support 4, the second adjustment limit support 6 and the diamond locating pin base 2, and the three are positioned together by using an adjusting bolt, and the position of the diamond locating pin 1 in two directions can be accurately adjusted by changing the thickness of the first adjustment gasket 5 and the second adjustment gasket 15.

[0028] The tapered guide section 1.1 of the diamond locating pin 1 has a taper of no more than 60 degrees and a spherical top. This shape is conducive to the smooth positioning of the workpiece and improves the error adaptability of the automatic clamping of the workpiece loading; the tapered positioning section 1.2 is a chamfered diamond with a length of no more than 15 mm, which acts as a short pin to limit the freedom of movement of the workpiece; the tapered mounting section 1.4 can improve the positioning accuracy level of the locating pin by adopting different combinations with the locating pin mounting hole 2.3, and the first chamfer 1.5 on the tapered mounting section 1.4 is conducive to the installation of the locating pin. The first safety groove 1.3 on the tapered mounting section 1.4 can play an overload protection role. When the positioning deviation of the part is too large, the center distance deviation is too large, causing a large shear force on the locating pin, or when the part is mispositioned and accidentally hits the locating pin, the locating pin can be broken in time from the first safety groove 1.3 to avoid the diamond locating pin 1 causing displacement changes of the diamond locating pin base 2, the first adjustment limit support 4, and the second limit adjustment limit support 6, thereby causing deviations in positioning accuracy.

[0029] The first threaded hole 1.7 is arranged inside the diamond locating pin 1. When the diamond locating pin 1 is sheared and broken, the diamond locating pin locking top screw 3 can be loosened, and the first mounting section 1.4 can be smoothly pulled out from the locating pin mounting hole 2.3 by a pin puller through the threaded hole at the first safety groove 1.3. The conical locating section 1.2 inserted into the workpiece can also be smoothly and quickly pulled out by the pin puller, which can avoid the positioning accuracy error caused by secondary installation after being knocked out from the tail of the locating pin mounting hole 2.3 when disassembling the diamond locating pin base 2, the first adjustment gasket 5, and the second adjustment gasket 15. This locating pin structure is more suitable for situations where the locating pin mounting hole is a blind hole and is difficult to disassemble.

[0030] The first adjustment limit support 4, the second adjustment limit support 6, the third adjustment limit support 9, and the fourth adjustment limit support 14 have the same structure, and are positioned by two cylindrical pins 7 through two cylindrical pin holes 4.2 and corresponding pin holes on the clamp body 16, and are fastened by two bolts through the bolt mounting holes 4.1 and the clamp body 16 to independently limit one direction of the diamond locating pin base 2 and the circular locating pin base 11.

[0031] The matching and installation form of the circular positioning pin 8 and the circular positioning pin base 11 is handled in the same manner as the matching and installation form of the diamond-shaped positioning pin 1 and the diamond-shaped positioning pin base 2 mentioned above.

[0032] The circular positioning pin 8 comprises: a circular guide section 8.1, a circular positioning section 8.2, and a circular mounting section 8.4; a second threaded hole 8.7 is arranged at the center of the circular mounting section 8.4 at the lower part of the circular positioning pin 8, and a second safety groove 8.3, a second chamfer 8.5, and a second wedge-shaped positioning surface 8.6 are arranged on the outside of the circular mounting section 8.4; the taper of the circular guide section 8.1 at the upper part of the circular positioning pin 8 is not greater than 60 degrees, and the top is spherical; the circular positioning section 8.2 at the lower part of the circular guide section 8.1 is cylindrical with a length of less than 15 mm.

[0033] The utility model is particularly suitable for the two-pin structure design of the positioning fixture with two pins on one side. It can meet the overload protection of the fixture when the positioning pin hole is damaged or broken due to positioning error and pin hole center distance error of the workpiece, and can quickly remove the positioning pin when it is worn and broken; the positioning pin structure is easy and quick to adjust, the positioning is stable and reliable, and the compatibility is strong, which can effectively meet the precision requirements of processing different batches and different types of parts.

[0034] The practical application is not limited to the situation described in this embodiment, and all technical solutions and improvements that do not deviate from the essential content of the utility model should fall within the scope of the claims of the utility model.

Claims

1. A quick-change positioning pin structure for a machining fixture, comprising: A diamond locating pin (1), a diamond locating pin base (2), a diamond locating pin locking top screw (3), a first adjustment limit support (4), a first adjustment gasket (5), a second adjustment limit support (6), a cylindrical pin (7), a circular locating pin (8), a third adjustment limit support (9), a third adjustment gasket (10), a circular locating pin base (11), a circular locating pin locking top screw (12), a fourth adjustment gasket (13), a fourth adjustment limit support (14), a second adjustment gasket (15), and a clamp body (16); characterized in that: the diamond locating pin base (2) and the circular locating pin base (11) are respectively fixed to the left and right sides of the clamp body (16) by four bolts; the diamond locating pin (1) is mounted on the diamond locating pin base (2), and the circular locating pin (8) is mounted on the circular locating pin base (11), and is locked by the diamond locating pin locking top screw (3) and the circular locating pin locking top screw (12) respectively; the first adjustment limit support (4), the second adjustment limit support (6) are respectively positioned and connected by bolts, positioning pins and clamp bodies (16), and the side of the first adjustment limit support (4), the second adjustment limit support (6) adjacent to the diamond positioning pin base (2) is used as a limiting surface; the first adjustment gasket (5) and the second adjustment gasket (15) are respectively installed between the two side surfaces adjacent to the first adjustment limit support (4), the second adjustment limit support (6) and the diamond positioning pin base (2), and the first adjustment gasket (5) and the diamond positioning pin base (2) are positioned on the limiting surface of the first adjustment limit support (4) by bolts, and the second adjustment gasket (15) and the diamond positioning pin base (2) are positioned on the limiting surface of the second adjustment limit support (6) by bolts. The connection relationship between the circular positioning pin base (11) and the third adjustment gasket (10), the third adjustment limit support (9), the fourth adjustment gasket (13), and the fourth adjustment limit support (14) is the same as that of the diamond positioning pin base (2).

2. The quick-change positioning pin structure for a machining fixture according to claim 1, characterized in that: The diamond shaped positioning pin (1) comprises: a tapered guide section (1.1), a tapered positioning section (1.2), and a tapered mounting section (1.4); a first threaded hole (1.7) is arranged at the center of the tapered mounting section (1.4) at the bottom of the diamond shaped positioning pin (1), and a first safety groove (1.3), a first chamfer (1.5), and a first wedge-shaped positioning surface (1.6) are arranged outside the tapered mounting section (1.4); the taper of the tapered guide section (1.1) at the top of the diamond shaped positioning pin (1) is not greater than 60 degrees, and the top is spherical; the tapered positioning section (1.2) at the bottom of the tapered guide section (1.1) is a chamfered diamond with a diameter not greater than 15 mm.

3. The quick-change positioning pin structure for a machining fixture according to claim 1, characterized in that: The diamond-shaped positioning pin base (2) and the circular positioning pin base (11) are provided with positioning pin mounting holes (2.3), and two adjacent side positioning surfaces are respectively provided with adjustment bolt threaded holes (2.1) and positioning pin locking top screw mounting holes (2.2).

4. The quick-change positioning pin structure for a machining fixture according to claim 1, characterized in that: The first adjustment limit support (4) is provided with two bolt mounting holes (4.1), two cylindrical pin holes (4.2), and an adjustment positioning bolt connection hole (4.3).

5. The quick-change positioning pin structure for a machining fixture according to claim 1, characterized in that: The first adjusting gasket (5), the second adjusting gasket (15), the third adjusting gasket (10), and the fourth adjusting gasket (13) are all provided with a U-shaped groove (5.1) through which the adjusting screw passes.

6. The quick-change positioning pin structure for a machining fixture according to claim 1, characterized in that: The second adjustment limit support (6), the third adjustment limit support (9), and the fourth adjustment limit support (14) have the same structure as the first adjustment limit support (4); the first adjustment limit support (4) and the second adjustment limit support (6) are respectively positioned and fastened to the clamp body (16) by means of two cylindrical pins (7) and two bolts, and are respectively located on both sides of the diamond-shaped positioning pin base (2).

7. The quick-change positioning pin structure for a machining fixture according to claim 1, characterized in that: The circular positioning pin (8) comprises: a circular guide section (8.1), a circular positioning section (8.2), and a circular mounting section (8.4); a second threaded hole (8.7) is arranged at the center of the circular mounting section (8.4) at the bottom of the circular positioning pin (8); a second safety groove (8.3), a second chamfer (8.5), and a second wedge-shaped positioning surface (8.6) are arranged outside the circular mounting section (8.4); the taper of the circular guide section (8.1) at the top of the circular positioning pin (8) is not greater than 60 degrees, and the top is spherical; the circular positioning section (8.2) at the bottom of the circular guide section (8.1) is cylindrical and less than 15 mm long.

8. The quick-change positioning pin structure for a machining fixture according to claim 1, characterized in that: The third adjustment limit support (9) and the fourth adjustment limit support (14) are respectively positioned and fastened to the clamp body (16) via two cylindrical pins (7) and two bolts, and are respectively located on both sides of the circular positioning pin base (11).

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