Clamping device for precise thread detection

Abstract

The invention provides a clamping device for precise thread detection. The clamping device comprises a first clamping block, a second clamping block, a cushion block, a guide rail and a base. The center is arranged in the middle of the base to position the bottom of a part; the guide rail is installed on the base and supports the first clamping block, the second clamping block and the cushion block to move in the horizontal direction, and the moving direction is parallel to a main shaft of the thread detection device. The lower end of the first clamping block keeps away from the bottom of the part; the second clamping block is fixed above the cushion block, the cushion block is assembled on the guide rail, and the cushion block lifts the second clamping block and keeps away from the bottom of the part; the V-shaped structures at the front ends of the first clamping block and the second clamping block are opposite, and the part is clamped at the middle position of the part, so that the part is perpendicular to the main shaft of the thread detection device in the vertical direction. The problem that the concentricity of the bottom of the part and the measured part is not high or the precise thread of the part of which the bottom cannot be clamped is difficult to measure is solved, and high-precision positioning of the measured part of the unconventional part is realized.

Description

Technical Field

[0001] This invention belongs to the field of thread inspection technology, and relates to a clamping device for precision thread inspection, particularly a clamping device for vertical precision thread inspection, which is suitable for the inspection of precision mechanical parts such as planetary roller screws and studs. Background Technology

[0002] Currently, vertical thread measuring devices primarily use clamping mechanisms of either upper and lower centers or V-shaped clamping plates. Upper and lower center clamps have a larger volume and are suitable for large parts, requiring the measured part to be concentric with the upper and lower centers. V-shaped clamping plates are positioned at the bottom of the part and are suitable for parts where the bottom is the measured element, such as general-purpose thread plug gauges. V-shaped clamping plates have a limitation: they require a completely symmetrical bottom structure and a high degree of concentricity between the bottom and the measured element. They are not suitable for parts where the bottom and the measured element are not highly concentric, or where the bottom is incomplete and cannot be clamped and aligned.

[0003] Currently, the demand for precision thread inspection, represented by planetary roller screw studs, is surging, and the requirements for inspection accuracy are also getting higher and higher. Existing clamping devices are unable to achieve accurate inspection. Summary of the Invention

[0004] The technical problem solved by this invention is: for the problem of difficulty in measuring the precision threads of parts with poor concentricity between the bottom and the measured part, or parts whose bottom cannot be clamped, a clamping device for vertical precision thread detection is provided, which can achieve high-precision positioning of the measured part of unconventional parts, and the positioning accuracy between the measured part and the vertical precision thread detection device reaches within 5μm.

[0005] The technical solution provided by this invention is as follows:

[0006] A clamping device for precision thread inspection includes a first clamping block, a second clamping block, a pad, a guide rail, and a base;

[0007] The base is fixed on the thread testing device. A tip is installed in the middle of the base and protrudes from the base to position the bottom of the threaded part being tested.

[0008] The guide rail is mounted on the base, supporting the horizontal movement of the first clamping block, the second clamping block, and the pad block. The direction of movement is parallel to the main shaft of the thread detection device.

[0009] The first clamping block is mounted on the guide rail, with its lower end avoiding the bottom of the threaded part being measured.

[0010] The second clamping block is fixed above the pad block, which is mounted on the guide rail. The pad block raises the second clamping block and avoids the bottom of the threaded part being measured.

[0011] The contact area between the front ends of the first clamping block and the second clamping block and the threaded part being tested is a V-shaped structure. The threaded part being tested is clamped at the middle position, so that the threaded part being tested is perpendicular to the main shaft of the thread testing device in the vertical direction. The threaded part being tested is released or clamped by sliding or fixing the first clamping block and the second clamping block on the guide rail.

[0012] The clamping device for precision thread inspection provided by the present invention has the following advantages:

[0013] (1) The present invention provides a clamping device for precision thread inspection, which directly clamps and positions the part to be measured at the middle of the part, and can achieve a perpendicularity of the measured element to the instrument spindle within 5μm. Compared with the traditional clamping method, it can effectively avoid the positioning error caused by the misalignment between the bottom of the part and the part to be measured, and can also solve the problem that some parts cannot be clamped at the bottom, resulting in the inability to detect precision threads.

[0014] (2) The clamping device for precision thread inspection provided by the present invention uses a bottom-point positioning and a middle double V-shaped positioning method to clamp the part. Compared with the traditional clamping method, the perpendicularity of the part to the vertical precision thread inspection device is easier to ensure, especially for parts with a high length-to-diameter ratio, which are less likely to tilt during the measurement process.

[0015] (3) The present invention provides a clamping device for precision thread inspection, which uses spring tension as clamping force. Compared with the threaded connection clamping method, it realizes rapid replacement of parts and improves the efficiency of repeated clamping of parts in batch measurement.

[0016] (4) The clamping device for precision thread inspection provided by the present invention adopts a separate design of pad and clamping block, which realizes the replaceability of clamping block. For situations where the clamping block is prone to wear due to frequent clamping, the clamping block can be replaced at low cost.

[0017] (5) The present invention provides a clamping device for precision thread inspection. The clamping and positioning method can realize the vertical clamping of small parts with a diameter of less than 5mm and a length of less than 30mm. The operation is simple and easy to implement. Attached Figure Description

[0018] Figure 1 This is a perspective view of a clamping device for precision thread inspection according to the present invention;

[0019] Figure 2 This is a cross-sectional view of a clamping device for precision thread inspection according to the present invention;

[0020] Figure 3 This is the front view of the base;

[0021] Figure 4 This is a side view of the base;

[0022] Figure 5 This is a schematic diagram of the clamping block. Detailed Implementation

[0023] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0024] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0025] See Figure 1 and Figure 2 The present invention provides a clamping device for precision thread inspection, comprising a first clamping block 2, a second clamping block 4, a pad 5, a guide rail 6 and a base 8.

[0026] See Figures 2-4 The bottom of the base 8 is fixed to the vertical precision thread testing device through a positioning structure. A tip is installed in the middle of the base 8 and the tip protrudes from the base for positioning the bottom of the threaded part being tested.

[0027] See Figure 1 and Figure 2 The guide rail 6 is mounted on the base 8 with threaded fasteners, supporting the horizontal movement of the first clamping block 2, the second clamping block 4 and the pad 5, ensuring that the movement direction is parallel to the main shaft of the vertical precision thread detection device.

[0028] See Figure 1 and Figure 2 The pad 5 is fixed to the guide rail 6 via a dovetail groove, and the second clamping block 4 is fixed above the pad 5 via a threaded connector. The pad 5 elevates the second clamping block 4 and avoids the bottom of the threaded part being measured. Since the bottom of the threaded part being measured is not the measured part and has various shapes, it is often impossible to clamp it correctly. Therefore, moving the clamping point from the bottom to the middle can solve this problem. At the same time, positioning directly based on the measured part of the threaded part avoids positioning errors caused by the misalignment of the bottom of the threaded part and the measured part, achieving higher clamping accuracy. In addition, the separate design of the pad 5 and the second clamping block 4 enables the replaceability of the second clamping block 4. Clamping blocks that are prone to wear due to long-term frequent clamping can be quickly replaced at a low replacement cost.

[0029] The first clamping block 2 engages with the guide rail 6 via a dovetail groove, enabling relative movement with the guide rail 6, and its lower end avoids the bottom of the threaded part being tested. The center, pad 5, and two clamping blocks (2, 4) form the clamping assembly. The center determines the specific installation position of the threaded part being tested in the horizontal plane; the contact area between the front ends of the two clamping blocks (2, 4) and the threaded part being tested is a V-shaped structure, clamping the threaded part at its center to ensure that it is perpendicular to the main shaft of the vertical precision thread testing device. Therefore, dual positioning is achieved through the bottom center and the double V-shaped structure in the middle, solving the problem of the perpendicularity of the threaded part being tested relative to the vertical precision thread testing device.

[0030] As an alternative implementation, the structure of the first clamping block 2 is the same as that of the second clamping block 4. Another pad 5 is provided below the structure of the first clamping block 2. The pad 5 is fixed in the guide rail 6 by a dovetail groove. The first clamping block 2 is fixed above the pad 5 by a threaded connector.

[0031] As an alternative implementation, the second clamping block 4 has the same structure as the first clamping block 2. The second clamping block 4 does not have an independent pad 5 below it (it is integrally formed as a structural part of the second clamping block 4). It cooperates with the guide rail 6 through the dovetail groove to achieve relative movement with the guide rail 6, and its lower end avoids the bottom of the threaded part being measured.

[0032] See Figure 5 The V-shaped structure of the first clamping block 2 and the second clamping block 4 has a circular cavity at the rear end. During the measurement process, the probe of the vertical precision thread testing device moves up and down along the threaded part being tested in the circular cavity, and the inspector can clearly observe the measurement situation at any time through the circular cavity.

[0033] The first clamping block 2 and the second clamping block 4 slide or are fixed on the guide rail 6, which can easily realize the loosening or clamping of the threaded part being tested, ensuring the alignment of the two clamping blocks (2, 4) relative to the vertical precision thread testing device, and ultimately ensuring the alignment of the threaded part being tested relative to the vertical precision thread testing device.

[0034] In order to enable the first clamping block 2 and the second clamping block 4 to slide and be fixed on the guide rail 6, a threaded fastener connection method can be adopted. By installing and removing the threaded fastener, the threaded part being tested can be loosened / clamped or replaced.

[0035] See Figure 1In order to further improve the alignment of the two clamping blocks (2, 4) relative to the vertical precision thread testing device, the second clamping block 4 is determined to be a fixed clamping block and is fixed to the guide rail 6 by means of threaded fastener connection, so that its position does not change with the adjustment of the threaded part being tested; the first clamping block 2 is a movable clamping block, which moves under the guidance of the guide component when the threaded part being tested is adjusted, and is fixed to the guide rail 6 by means of threaded fastener connection when locking the threaded part being tested.

[0036] Preferably, the guide assembly includes at least two parallel push rods 3 and a baffle 7. The baffle 7 is fixed to the end of the guide rail 6 on the side of the first clamping block 2, and multiple through holes are formed on the baffle 7. One end of each of the at least two parallel push rods 3 is mounted on the first clamping block 2, and the other end passes through the through holes on the baffle 7 and is limited by a nut on the outside of the baffle 7. The clamping block 2 achieves connection and relative movement with the baffle 7 through the parallel push rods 3.

[0037] See Figure 1 To enable rapid loosening / clamping or replacement of the threaded part being tested, this invention also includes an elastic adjustment component. This component comprises two springs 1, one end of which is symmetrically fixed to the end of the guide rail 6 on the side of the second clamping block 4, and the other end is connected to small posts symmetrically arranged on the first clamping block 2. The spring tension serves as the clamping force, thereby clamping the threaded part being tested. In a static state, the springs are in a stretched state, and the threaded part being tested is clamped by the spring tension. When the threaded part being tested needs to be replaced, the first clamping block 2 is manually pulled backward. After the first clamping block 2 moves backward, the threaded part being tested is released. After a new threaded part being tested is installed, the threaded part being tested is automatically clamped again by the spring tension, thus enabling rapid replacement of the threaded part being tested. The parallel push rod 3 passes through the limiting nut fixed on one end of the baffle 7, which serves to limit the movement of the movable clamping block 2. Especially when the elastic adjustment component is installed, it can prevent the two clamping blocks (2, 4) from being squeezed together without a threaded part being tested.

[0038] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0039] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A clamping device for precision thread inspection, characterized in that, It includes a first clamping block (2), a second clamping block (4), a pad (5), a guide rail (6), and a base (8); The base (8) is fixed on the thread detection device. A tip is installed in the middle of the base (8) and the tip protrudes from the base for positioning the bottom of the threaded part being tested. The guide rail (6) is mounted on the base (8) to support the horizontal movement of the first clamping block (2), the second clamping block (4) and the pad (5), with the movement direction parallel to the main shaft of the thread detection device; The first clamping block (2) is mounted on the guide rail (6), with its lower end avoiding the bottom of the threaded part being measured; The second clamping block (4) is fixed above the pad (5). The pad (5) is mounted on the guide rail (6). The pad (5) raises the second clamping block (4) and avoids the bottom of the threaded part being tested. The V-shaped structures at the front ends of the first clamping block (2) and the second clamping block (4) are opposite each other, clamping the threaded part to be tested at the middle position, so that the threaded part to be tested is perpendicular to the main shaft of the thread detection device in the vertical direction; by sliding or fixing the first clamping block (2) and the second clamping block (4) on the guide rail (6), the loosening or clamping of the threaded part to be tested is completed.

2. The clamping device for precision thread inspection according to claim 1, characterized in that, Another structure of the first clamping block (2) is as follows: the structure of the first clamping block (2) is the same as that of the second clamping block (4). Another pad is provided below the structure of the first clamping block (2). The pad is mounted on the guide rail (6) and can move along the guide rail (6). The first clamping block (2) is fixed above the pad by a threaded connector.

3. The clamping device for precision thread inspection according to claim 1, characterized in that, Another structure of the second clamping block (4) is as follows: the second clamping block (4) has the same structure as the first clamping block (2). There is no independent pad (5) below the second clamping block (4). The second clamping block (4) cooperates with the guide rail (6) and can move along the guide rail (6), and its lower end avoids the bottom of the threaded part being tested.

4. The clamping device for precision thread inspection according to claim 1, characterized in that, The V-shaped structure of the first clamping block (2) and the second clamping block (4) has a cavity at the rear end. During the measurement process, the probe of the thread detection device moves up and down along the threaded part being measured in the cavity and serves as an observation window to observe the measurement.

5. The clamping device for precision thread inspection according to claim 1, characterized in that, The first clamping block (2) and the second clamping block (4) are fixed on the guide rail (6) by threaded fasteners. The threaded parts under test are adjusted or replaced by installing and removing the threaded fasteners.

6. The clamping device for precision thread inspection according to claim 1, characterized in that, The first clamping block (2) and the second clamping block (4) are fixed on the guide rail (6) with threaded fasteners. The second clamping block (4) is a fixed clamping block and its position does not change with the adjustment of the threaded part being tested. The first clamping block (2) is a movable clamping block. When the threaded part being tested is adjusted, it moves under the guidance of the guide assembly. When the threaded part being tested is locked, the threaded fastener is locked on the guide rail (6).

7. The clamping device for precision thread inspection according to claim 6, characterized in that, The guide assembly includes at least two parallel push rods (3) and a baffle (7). The baffle (7) is fixed to the end of the guide rail (6) on the side of the first clamping block (2). Multiple through holes are opened on the baffle (7). One end of the at least two parallel push rods (3) is installed on the first clamping block (2), and the other end passes through the through hole on the baffle (7) and is limited by the nut on the outside of the baffle (7).

8. The clamping device for precision thread inspection according to claim 1, characterized in that, The clamping device also includes an elastic adjustment component, which includes two springs (1). One end of each spring (1) is symmetrically fixed to the end of the guide rail (6) on the side of the second clamping block (4), and the other end is connected to the small post symmetrically arranged on the first clamping block (2). The spring tension serves as the clamping force to clamp the threaded part being tested.

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