Variable diameter universal internal thread measuring tool

Abstract

This invention discloses a variable-diameter universal internal thread measuring tool, comprising a probe rod, a radially movable probe, and an axially movable probe. The probe rod is cylindrical, with a groove and a threaded hole at one end. The axis of the threaded hole is set along a radius of the probe rod, and the groove is set along the axis of the probe rod. The plane containing the generatrix of the threaded hole and the center line of the groove passes through the center line of the probe rod. The axially movable probe includes a slider and a probe, with the probe perpendicular to the slider and set on the center line of the slider. The probe includes a cylindrical section I and a conical section I connected to the slider; the slider is embedded in the groove. The radially movable probe includes a cylindrical section II and a conical section II. The cylindrical section II has an external thread that mates with the threaded hole. The invention has a simple structure and low cost. It is easy to operate and can measure internal threads of various specifications, offering good versatility. Furthermore, it eliminates the need for plug gauges for various internal thread specifications, further reducing production costs.

Description

Technical Field

[0001] This invention discloses a variable diameter universal internal thread measuring tool. Background Art

[0002] In the machining and production of mechanical parts, the inspection of internal threads is quite difficult. Currently, the only standard measuring tool for internal thread inspection in China is the thread plug gauge, namely the go gauge and no-go gauge. Since each type of thread plug gauge can only inspect internal threads of a single specification and size, and given the large number of thread specifications, using thread plug gauges for measurement is inconvenient and inefficient. Different thread specifications require different specifications of thread plug gauges, resulting in high costs for a complete set. As a production tool, improving efficiency and reducing costs is significant for enterprise development. Furthermore, it cannot measure the actual dimensions during the machining process. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a variable-diameter universal internal thread measuring tool that is simple in structure, low in cost, and capable of measuring internal threads of various specifications, thereby improving measurement efficiency.

[0004] The technical solution adopted in this invention is as follows: a variable diameter universal internal thread measuring tool, comprising a probe rod, a radially movable probe, and an axially movable probe; the probe rod is cylindrical, and one end of the probe rod is provided with a groove and a threaded hole, the axis of the threaded hole is set along a radius of the probe rod, the groove is set along the axis of the probe rod, and the plane containing the generatrix of the threaded hole and the center line of the groove passes through the center line of the probe rod; the axially movable probe includes a slider and a probe, the probe being set perpendicular to the slider on the center line of the slider, the probe including a cylindrical section I and a conical section I connected to the slider; the slider is embedded in the groove; the radially movable probe includes a cylindrical section II and a conical section II, the cylindrical section II being provided with an external thread, the external thread engaging with the threaded hole.

[0005] Furthermore, a locking nut is provided on the external thread of the radially movable probe.

[0006] Furthermore, the tips of conical segments I and II are rounded to form spheres; the cone angles of conical segments I and II are 60°.

[0007] Furthermore, the radius of the rounding is 0.1-0.3 mm.

[0008] Furthermore, the chute adopts a dovetail groove structure.

[0009] Furthermore, the other end of the probe is equipped with a handle, the side of which is knurled.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] This invention features a simple structure and low cost. When in use, the probe inspects the tooth profile and dimensions of the internal thread of a part. The radially movable probe can adjust its extension via the thread, and after adjusting the major diameter of the thread, it is locked in place by a locking nut. The axially movable probe adjusts its pitch by moving a slider in a groove on the probe rod. Operation is simple, and this invention can measure internal threads of various specifications, offering good versatility. Furthermore, it eliminates the need to prepare plug gauges for different specifications of internal threads, further reducing production costs. Attached Figure Description

[0012] Figure 1 This is a structural diagram of the present invention.

[0013] Figure 2 This is the left view of the present invention.

[0014] Figure 3 This is a perspective view of the probe rod of the present invention.

[0015] Figure 4 This is a structural diagram of the present invention in use.

[0016] Figure 5 This is a schematic diagram illustrating the principle of pitch calculation in this invention.

[0017] Figure 6 This is a schematic diagram illustrating the principle of calculating the distance between the cone tip and the rounded tip in this invention. Detailed Implementation

[0018] The present invention will now be further described with reference to the accompanying drawings.

[0019] like Figure 1-3 As shown, the present invention includes a probe rod 1, a radially movable probe 2, and an axially movable probe 3. The probe rod 1 is cylindrical, and one end of the probe rod 1 is provided with a groove 11 and a threaded hole 12. The axis of the threaded hole 12 is set along a radius of the probe rod, and the groove 11 is set along the axis of the probe rod 1. The plane containing the generatrix of the threaded hole 12 and the center line of the groove 11 passes through the center line of the probe rod 1. The groove 11 adopts a dovetail groove structure. The other end of the probe rod 1 is provided with a handle 4, and the side of the handle 4 is knurled.

[0020] The axially movable side head 3 includes a slider and a probe. The side head is positioned perpendicular to the slider on the center line of the slider. The probe includes a cylindrical section I and a conical section I connected to the slider. The cylindrical section I and the conical section I are coaxial. The slider 31 is embedded in the slide groove 11. The radially movable probe 2 includes a cylindrical section II and a conical section II, which are coaxial. The cylindrical section II is provided with an external thread 21, which mates with a threaded hole. A locking nut 22 is provided on the external thread 21 of the radially movable probe 2.

[0021] The tips of the conical segments I and II are rounded to form a spherical shape, with a rounding radius of 0.1-0.3 mm. The cone angle of the conical segments I and II is 60°.

[0022] In use, this invention employs a radially movable probe 2 and an axially movable probe 3 to inspect the thread profile and dimensions of the internal threads of a part. The radially movable probe 2 can be adjusted by extending its thread to reach the major diameter value M', and then locked in place by a locking nut 22. The axially movable probe 3 is moved by a slider within a groove 11 on the probe rod 1, adjusting the measured pitch P (P=S2-S1, where S1 and S2 are the distances from cylindrical segment II and cylindrical segment I to the end of the probe rod 1 without the handle, respectively, which can be measured using a depth vernier caliper). It is then locked in place by a set screw on the slider of the axially movable probe 3. Finally, S1 and S2 are measured using a depth vernier caliper to calculate the pitch P.

[0023] like Figure 5 , 6 As shown, the principle of this invention for measuring the pitch and major diameter of internal threads is as follows:

[0024] For inspecting the tooth profile and dimensions of the internal threads of parts, the radial movable probe 2 can be inserted and removed through the thread. After adjusting the major diameter value M' of the thread, it is then locked and fixed by the lock nut 22. The axial movable probe 3 is moved by the dovetail fixing block in the dovetail groove on the probe rod to adjust the pitch P, P=S2-S1, where S1 and S2 are the distances from the end face of the probe rod 1 to the radial movable probe 2 and the axial movable probe 3, respectively, which can be measured by a depth vernier caliper.

[0025] The cone angle of conical segment I and conical segment II is 60°. To avoid interference between the pointed end and the bottom of the tooth groove, the fillet radius R is used. Therefore, when measuring the major diameter M' of the thread, M' should be M' = measured value m + 2b, where b is the distance between the tip of conical segment I or conical segment II and the vertex of the sphere formed after filleting.

[0026]

[0027] R is the fillet radius, which is generally 0.1-0.3mm.

Claims

1. A variable diameter universal internal thread measuring tool, characterized in that: The device includes a probe rod, a radially movable probe, and an axially movable probe. The probe rod is cylindrical, with a groove and a threaded hole at one end. The axis of the threaded hole is set along a radius of the probe rod, and the groove is set along the axis of the probe rod. The plane containing the generatrix of the threaded hole and the center line of the groove passes through the center line of the probe rod. The axially movable probe includes a slider and a probe. The probe is set perpendicular to the slider and on the center line of the slider. The probe includes a cylindrical section I and a conical section I connected to the slider. The slider is embedded in the groove. The radially movable probe includes a cylindrical section II and a conical section II. The cylindrical section II is provided with an external thread that mates with the threaded hole. For inspecting the tooth profile and dimensions of the internal threads of parts, the radial movable probe can be inserted and removed through the thread. After adjusting the major diameter value M' of the thread, it can be locked and fixed by the lock nut. The axial movable probe is adjusted by moving the dovetail fixed block in the dovetail groove on the probe rod to adjust the pitch P, P=S2-S1, where S1 and S2 are the distances from the end face of the probe rod to the radial movable probe and the axial movable probe, respectively, which can be measured with a depth vernier caliper. The cone angle of conical segment I and conical segment II is 60°. To avoid interference between the pointed end and the bottom of the tooth groove, the fillet radius R is used. Therefore, when measuring the major diameter M' of the thread, M' should be M' = measured value m + 2b, where b is the distance between the tip of conical segment I or conical segment II and the vertex of the sphere formed after filleting.

2. The variable diameter universal internal thread gauge according to claim 1, characterized in that: The radial movable probe is provided with a locking nut on its external thread.

3. The variable diameter universal internal thread gauge according to claim 1, characterized in that: The radius of the rounding is 0.1-0.3 mm.

4. The variable diameter universal internal thread gauge according to claim 1, characterized in that: The chute adopts a dovetail groove structure.

5. The variable diameter universal internal thread gauge according to claim 1, characterized in that: The other end of the probe is equipped with a handle, and the side of the handle is knurled.

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