A tap for tapping curved surface workpiece and its use method

Abstract

The present invention discloses a tap for tapping a curved surface workpiece, comprising a sleeve and a nut screwed to the lower side of the sleeve through a thread, the upper end of the sleeve is fixed to the lower end of a vertically coaxial tap body, the upper end surface of the nut is symmetrically provided with two spacer rods, the sleeve has a through hole, the tap body is formed by connecting a cylindrical thread blade and a conical thread blade, and a chip outlet groove penetrating the cylindrical and conical parts and communicating with the through hole is provided on the outer cylindrical surface of the main body; a method for tapping the inner and outer surfaces of a circular cylindrical workpiece is also disclosed. When the tap of the present invention is used for tapping a curved surface workpiece, it can ensure that the tap body is always perpendicular to the workpiece processing surface, and the quality of the processed screw holes is stable and reliable.

Description

Technical Field

[0001] The invention belongs to the field of mechanical processing, and particularly relates to a tap for tapping a curved surface workpiece, and a method of using the tap. Background Art

[0002] Currently in the field of mechanical processing, when manually tapping curved workpieces, the tap cannot be completely perpendicular to the workpiece processing surface, which easily causes the processed screw holes to be skewed. As a result, the processing quality is very unstable and the workpiece is easily scrapped. Summary of the Invention

[0003] In view of the above problems, one of the objectives of the present invention is to provide a tap for tapping a workpiece with a curved surface.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a tap for tapping curved surface workpieces, including a sleeve and a nut screwed to the lower side of the sleeve through a thread, the upper end of the sleeve is fixed to the lower end of the vertically coaxial tap body, the upper end surface of the nut is symmetrically provided with two spacer rods, the outer wall of the sleeve has a full-length external thread, the external thread is consistent with the internal thread of the nut, the lower ends of the left and right spacer rods are symmetrically fixed to the upper parts of the left and right sides of the nut, the sleeve has a through hole, the main body of the tap body is connected by a cylindrical thread blade and a conical thread blade, and a chip outlet groove is provided on the outer cylindrical surface of the main body, which passes through the cylindrical and conical parts and is connected to the through hole.

[0005] The tap for tapping a curved surface workpiece has a support rod with a cross section that is circular, elliptical, triangular or L-shaped.

[0006] A second object of the present invention is to provide a method for tapping the inner and outer surfaces of a circular cylindrical workpiece using the above-mentioned tap, the steps of which are as follows:

[0007] Step 1: Open a hole on the workpiece to allow the sleeve to pass through;

[0008] Step 2: Pass the sleeve through the hole of the workpiece from the concave / convex side of the workpiece, with the spacer rod facing the convex / concave side of the workpiece, and screw the nut onto the sleeve from bottom to top until the left and right spacers tightly press against the curved surface of the convex / concave side of the workpiece under the blocking action of the thread blade. The left and right spacers are parallel to the axis of the cylindrical workpiece, and the spacers form line contact with the curved surface.

[0009] Step 3. Press the nut with your hand to keep it stationary relative to the workpiece, rotate the tap to ensure that the sleeve and the tap are always coaxial with the hole, the thread blade cuts the inner wall of the hole and moves downward, the iron chips fall from the iron chip chute through the through hole to the ground, the sleeve rotates and moves downward with the tap, at this time the two pads are always against the curved surface of the workpiece, after tapping is completed, unscrew the nut.

[0010] Furthermore, when tapping the inner and outer surfaces of a conical cylinder workpiece with upper and lower openings, the method is exactly the same as the above method, except that the left and right pads are inclined with the slope of the conical cylinder wall, and the sleeve and tap are also ensured to be coaxial with the hole.

[0011] Compared with the prior art, the beneficial effects of the present invention include: when the tap of the present invention is used for tapping a curved surface workpiece, it can ensure that the tap body is always perpendicular to the workpiece processing surface, and the quality of the processed screw holes is stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic cross-sectional view of the overall structure of the present invention.

[0013] Figure 2 It is an exploded cross-sectional schematic diagram of the present invention;

[0014] Figure 3 This is a schematic diagram of tapping a reverse arc surface workpiece;

[0015] Figure 4 It is a top view of the nut and its spacer rod of the present invention;

[0016] Figure 5 to Figure 7 It is a schematic diagram of the cross-section of several pad rods.

[0017] The reference numerals are: 1—sleeve, 2—nut, 3—chip groove, 4—workpiece, 5—thread blade, 6—external thread, 8—through hole, 9—hole, 10—spacer rod, 11—tap. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] Reference Figures 1 to 4 As shown, the present invention discloses a tap for tapping a curved surface workpiece, comprising a sleeve 1 and a nut 2 screwed to the lower side of the sleeve 1 through a thread, the upper end of the sleeve 1 is fixed to the lower end of a vertically coaxial tap body 11, the upper end surface of the nut 2 is symmetrically and horizontally provided with two spacer rods 10, the outer wall of the sleeve 1 has a full-length external thread 6, the external thread 6 is consistent with the internal thread 7 of the nut 2, the lower ends of the left and right spacer rods 10 are symmetrically fixed to the upper parts of the left and right sides of the nut 2, the sleeve 1 has a through hole 8, the main body of the tap body 11 is formed by connecting a cylindrical thread blade 5 and a conical thread blade 5, and a chip outlet groove 3 is provided on the outer cylindrical surface of the main body, which passes through the cylindrical and conical parts and is connected to the through hole 8.

[0020] Reference Figures 5 to 7 As shown, the cross section of the pad rod 10 is circular, elliptical, triangular or L-shaped.

[0021] The method of tapping the inner and outer surfaces of a circular cylindrical workpiece by this patented tap is:

[0022] Step 1: Open a hole 9 on the workpiece 4 to allow the sleeve 1 to pass through.

[0023] Step 2, pass the sleeve 1 through the hole 9 of the workpiece 4 from the concave side (or convex side) of the workpiece 4, make the pad rod 10 face the convex side (or concave side) of the workpiece 4, and screw the nut 2 onto the sleeve 1 from bottom to top until the left and right pad rods 10 are tightly pressed against the arc surface of the convex side (or concave side) of the workpiece 4 under the blocking action of the threaded blade 5, and the left and right pad rods 10 are parallel to the axis of the cylindrical workpiece 4, and the pad rods 10 form linear contact with the arc surface.

[0024] Step 3. Press the nut 2 with your hand to keep it stationary relative to the workpiece 4, rotate the tap 11, ensure that the sleeve 1 and the tap 11 are always coaxial with the hole 9, and the thread blade 5 cuts the inner wall of the hole 9 of the workpiece 4 and moves downward. Iron chips fall to the ground from the iron chip groove 3 of the tap 11 through the through hole 8 of the sleeve 1. The sleeve 1 rotates and moves downward with the tap 11. At this time, the two pads 10 always press against the curved surface of the workpiece 4. After tapping is completed, unscrew the nut 2.

[0025] The present invention is exactly the same as the above-mentioned method for tapping the inner and outer surfaces of a conical cylindrical workpiece with upper and lower openings, except that the left and right spacer rods 10 are inclined with the slope of the conical cylinder wall, which also ensures that the vertical axis of the sleeve 1 and the tap 11 is always parallel to the inner surface of the hole 9 of the workpiece 4; the tapping of a workpiece with flat inner and outer surfaces is also exactly the same as the above-mentioned method.

[0026] The present invention solves the problem that the tap cannot be completely perpendicular to the workpiece processing surface when manually tapping a curved surface workpiece, and can ensure that the tap body 11 is always perpendicular to the processing surface of the curved surface workpiece, and the quality of the processed screw holes is stable and reliable.

[0027] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A method for using a tap, characterized in that: The tap comprises a sleeve (1) and a nut (2) screwed onto the lower side of the sleeve (1) through a thread, the upper end of the sleeve (1) is fixed to the lower end of the tap body (11), two spacer rods (10) are symmetrically arranged on the upper end surface of the nut (2), and the cross section of the spacer rods (10) is circular, elliptical, triangular or L-shaped. The sleeve (1) has a through hole (8), and the tap body (11) is formed by connecting a cylindrical thread blade (5) and a conical thread blade (5), and an iron chip outlet groove (3) connected to the through hole (8) is provided on the outer cylindrical surface of the tap body; the steps for tapping the inner and outer surfaces of the circular cylindrical workpiece (4) are as follows: Step 1, a hole (9) is opened on the workpiece (4) to accommodate the sleeve (1) passing through; Step 2: Pass the sleeve (1) through the hole (9) of the workpiece (4) from the inner concave side or the outer convex side of the workpiece (4), so that the spacer rod (10) faces the other side of the workpiece (4), and screw the nut (2) onto the sleeve (1) from bottom to top until the left and right spacer rods (10) support the arc surface on the other side of the workpiece (4); Step 3: Press the nut (2) by hand to keep the nut (2) stationary relative to the workpiece (4), rotate the tap (11), ensure that the sleeve (1) and the tap (11) are always coaxial with the hole (9), and the sleeve (1) rotates and moves downward with the tap (11). After the tapping is completed, unscrew the nut (2); When tapping the inner and outer surfaces of a truncated cone workpiece (4) with upper and lower openings, the pad rod (10) is inclined along the slope of the truncated cone wall to ensure that the sleeve (1) and the tap (11) are coaxial with the hole (9).

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