Horizontal arm support structure of coordinate measuring machine

Abstract

The present invention discloses a horizontal arm support structure of a three-dimensional coordinate measuring machine, which belongs to an internal support device of a telescopic arm, comprising a support unit and a gap adjustment device, wherein the support unit comprises an expansion sleeve body and a support seat, wherein the expansion sleeve body has an internal thread, and the axial direction of the edge of the expansion sleeve body has a plurality of circumferentially arranged support plates, and the gap adjustment device comprises a support seat, wherein the support seat is used to be installed on the three-dimensional coordinate measuring machine, and a clamping wheel assembly is movably installed on the lower part of the support seat; the gap between the rear end of the horizontal arm and the support bearing caused by the weight of the front end of the horizontal arm is compensated by the pressure of the clamping wheel assembly, and the pressure of the clamping wheel assembly on the horizontal arm can also be dynamically adjusted according to the current size of the gap, thereby reducing the deflection of the horizontal arm, avoiding fluctuations in the deflection, and improving the measurement accuracy of the three-dimensional coordinate measuring machine, and at the same time, the clamping wheel will not affect the forward and backward movement of the horizontal arm.

Description

Technical Field

[0001] The present invention relates to an inner supporting device of a telescopic arm, and more specifically, mainly to a horizontal arm supporting structure of a three-coordinate measuring machine. Background Art

[0002] During the extension and retraction process of the horizontal arm of the three-dimensional coordinate measuring machine, the deflection of the horizontal arm is easily changed due to the influence of its own gravity, thereby affecting the measurement accuracy of the three-dimensional coordinate measuring machine. Specifically, due to the excessive weight of the front end of the horizontal arm, it is easy to cause the gap between the rear end of the horizontal arm and the support bearing to change, thereby causing the deflection of the front end of the horizontal arm to change during the extension and retraction process, and as the horizontal arm is extended and retracted, the change of the above-mentioned disturbance will fluctuate linearly. In the prior art, the deflection of the above-mentioned horizontal arm extension and retraction is generally reduced by adding a core rod auxiliary support in the middle of the hollow horizontal arm, or by using a four-corner steel wire lifting method to prevent the deflection of the horizontal arm from changing during the extension and retraction process. Among them, the method of using a core rod inside the horizontal arm does not have a vibration reduction effect, and the overall rigid support cannot improve the dynamic change of the deflection of the horizontal arm. The steel wire lifting method is not only complex in structure, but also cannot achieve the purpose of lifting when facing a horizontal arm with a thicker wall. It still cannot improve the problem of the change of the deflection of the horizontal arm during the extension and retraction process, and it cannot improve the vibration problem during the extension and retraction operation of the horizontal arm. Therefore, it is necessary to study and improve the support structure of the horizontal arm of the three-dimensional coordinate measuring machine. Summary of the invention

[0003] One of the purposes of the present invention is to solve the above-mentioned shortcomings and provide a horizontal arm support structure of a three-coordinate measuring machine, in the hope of solving the technical problems in the prior art that the deflection of the three-coordinate horizontal arm is easily changed during the extension and retraction process, affecting the measurement accuracy of the three-coordinate measuring machine.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The present invention provides a horizontal arm support structure of a three-dimensional coordinate measuring machine, comprising a support unit and a gap adjustment device, wherein the support unit comprises an expansion sleeve body and a support seat, wherein the expansion sleeve body has an internal thread, and the axial direction of the edge of the expansion sleeve body has a plurality of circumferentially arranged support plates; the support seat has an external thread matching the internal thread, and the support seat is also provided with an annular inclined surface inclined radially outward; the annular inclined surface is used to gradually push the support plate to expand radially outward along the expansion sleeve body during the axial relative movement of the expansion sleeve body and the support seat, so as to form an annular support for the inner wall of the horizontal arm of the three-dimensional coordinate measuring machine; the gap adjustment device comprises a support, which is used to be installed on the three-dimensional coordinate measuring machine, and a clamping wheel assembly is movably installed at the lower part of the support, and the clamping wheel assembly is used to contact with the horizontal arm, and a spring body is provided in the inner cavity of the support, one end of the spring body contacts with a pressure-applying portion, and the other end contacts with the clamping wheel assembly; the pressure-applying portion is dynamically connected to the threaded rod, and the threaded rod is also dynamically connected to the power device.

[0006] Preferably, a further technical solution is: a connecting seat is provided on the upper part of the support, and the threaded rod is key-connected to the output shaft of the power device in the inner cavity of the connecting seat.

[0007] A further technical solution is: the power device is a hand wheel or a stepping motor.

[0008] A further technical solution is that the cross section of the inner cavity of the support is square, the pressure-applying portion is also placed in the inner cavity of the support, and the pressure-applying portion is a square nut that matches the inner cavity of the support.

[0009] A further technical solution is: the clamping wheel assembly includes a wheel seat, a wheel axle is installed horizontally below the wheel seat, a wheel body is installed on the wheel axle, the upper part of the wheel seat is in conflict with the spring body, and the wheel body is used to conflict with the horizontal arm.

[0010] A further technical solution is that the longitudinal section of the support seat is annular T-shaped, and the support seat and the expansion sleeve body both have threading channels inside.

[0011] A further technical solution is that the cross-sections of the expansion sleeve and the support seat at any position are circular.

[0012] A further technical solution is that the support plates are all rectangular in shape, and the lengths and widths of the multiple support plates are equal.

[0013] A further technical solution is that a plurality of support units are arranged in the inner cavity of the horizontal arm of the three-dimensional coordinate measuring machine at preset intervals, which are similar to the structure of bamboo joints, so as to support the horizontal arm of the three-dimensional coordinate measuring machine and prevent it from bending during the extension and retraction process, that is, reduce the deflection.

[0014] A further technical solution is that the horizontal arm of the three-dimensional coordinate measuring machine is a telescopic arm with a hollow inner cavity.

[0015] Compared with the prior art, the beneficial effects of the present invention are at least one of the following.

[0016] The gap between the rear end of the horizontal arm and the support bearing caused by the weight of the front end of the horizontal arm is compensated by the pressure of the clamping wheel assembly. The pressure of the clamping wheel assembly on the horizontal arm can also be dynamically adjusted according to the size of the current gap, thereby reducing the deflection of the horizontal arm, avoiding fluctuations in the deflection, and improving the measurement accuracy of the three-dimensional coordinate measuring machine. At the same time, the resistance of the clamping wheel will not cause excessive friction to the forward and backward movement of the horizontal arm.

[0017] Through the thrust force of the relative movement of the expansion sleeve and the support seat, the multiple support plates arranged in the circumferential direction expand outward, thereby forming annular support for the inner cavity of the horizontal arm. After arranging multiple support units according to the length of the horizontal arm and other conditions, the deflection of the horizontal arm can be reduced, and the toughness of the support plate itself has a certain vibration reduction effect after supporting the inner cavity of the horizontal arm. At the same time, the horizontal arm support structure of a three-coordinate measuring machine provided by the present invention is simple in structure, suitable for playing an internal support role in various types of horizontal arms, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the support unit structure for illustrating an embodiment of the present invention.

[0019] Figure 2 for Figure 1 Schematic diagram of the longitudinal section.

[0020] Figure 3 It is a schematic diagram of the installation state of the support unit for describing an embodiment of the present invention.

[0021] Figure 4 for Figure 3 Schematic diagram of the longitudinal section.

[0022] Figure 5 It is a schematic diagram of the support unit structure for illustrating an embodiment of the present invention.

[0023] Figure 6 for Figure 5 Schematic diagram of the longitudinal section.

[0024] In the figure, 1 is a support unit, 11 is an expansion sleeve, 12 is a support seat, 13 is a support plate, 14 is an annular inclined surface, 21 is a support, 22 is a clamping wheel assembly, 23 is a spring body, 24 is a pressure-applying part, 25 is a threaded rod, 26 is a stepping motor, 27 is a wheel seat, 28 is a wheel body, 29 is a connecting seat, and 2 is a horizontal arm of a three-dimensional coordinate measuring machine. DETAILED DESCRIPTION

[0025] The inventors found that the deflection of the horizontal arm of the three-dimensional coordinate measuring machine is prone to change during the extension and retraction process due to the influence of gravity, and the change in deflection will fluctuate with the extension and retraction state of the horizontal arm, so it is difficult to correct it through the later computer program. The aforementioned horizontal arm refers to a telescopic arm that performs telescopic movement on a given plane; the deflection is the linear displacement of the axis of the rod in a direction perpendicular to the axis when subjected to force or non-uniform temperature changes. The most effective way to reduce the aforementioned deflection is still to provide internal support for the horizontal arm so that it does not displace as much as possible during the extension and retraction process.

[0026] The present invention will be further described below in conjunction with the accompanying drawings.

[0027] refer to Figure 1 and Figure 2 As shown, one embodiment of the present invention is a horizontal arm support structure of a three-dimensional coordinate measuring machine, which includes two functional modules: a support unit 1 and a gap adjustment device. The three-dimensional coordinate measuring machine horizontal arm 2 referred to in this embodiment is a telescopic arm with a hollow inner cavity, wherein there are multiple support units 1. The aforementioned support unit 1 is a combined structure, which includes an expansion sleeve 11 and a support seat 12 that cooperate with each other through threads, wherein the expansion sleeve 11 has an internal thread, and the axial direction of the edge of the expansion sleeve 11 involves multiple circumferentially arranged support plates 13, and the orientation of these circumferentially arranged support plates 13 under normal conditions is basically consistent with the axial direction of the expansion sleeve 11. On the other hand, the aforementioned support seat 12 has an external thread that matches the internal thread of the expansion sleeve body 11, and correspondingly, the end or bottom of the support seat 12 is also designed with an annular inclined surface 14 that is inclined radially outward; the annular inclined surface 14 is used to gradually push the support plate 13 during the process of the expansion sleeve body 11 and the support seat 12 being connected by threaded cooperation and the relative movement of the two in the axial direction, so that it expands outward along the radial direction of the expansion sleeve body 11. Since the multiple support plates 13 are arranged in an annular manner, they can expand outward in different directions after being pushed by the annular inclined surface 14, and the expanded support plates 13 can form support for the inner wall of the horizontal arm 2 of the three-dimensional coordinate measuring machine in their respective orientations. When the multiple support plates 13 all form support for the inner wall of the horizontal arm 2 of the three-dimensional coordinate measuring machine, the aforementioned annular support is formed.

[0028] refer to Figure 5 and Figure 6As shown, the structure of the gap adjustment device includes a support 21, which is used to be installed at a position corresponding to the horizontal arm of the three-dimensional coordinate measuring machine, generally placed above the horizontal arm, and a clamping wheel assembly 22 is movably installed at the lower part of the support 21. The clamping wheel assembly 22 conflicts with the upper side of the horizontal arm when in use, and pressure is applied to the clamping wheel assembly 22. In addition, a spring body 23 is also required to be designed inside the support 21. In order to cooperate with the spring body, an inner cavity that cooperates with the spring body 23 can be pre-set inside the aforementioned support 21, and the spring body 23 can select a spring assembly with precise rebound force, and one end of the spring body 23 conflicts with the pressure-applying portion 24, and the other end is in contact with the clamping wheel assembly 22. The threaded rod 25 is connected with the pressure-applying part 24 by a thread (the two are movably connected in the direction of rotation), and the threaded rod 25 is also connected with the power of the power device on its upper part; the threaded rod 25 is then driven to rotate by the power device, thereby driving the pressure-applying part 24 to move up and down in the inner cavity. When the pressure-applying part 24 moves downward, pressure is applied to the spring body 23. After the spring body 23 is compressed, a rebound force is generated at both ends. The rebound force directly acts on the clamping wheel assembly 22, thereby applying corresponding pressure to the upper side of the horizontal arm; by applying pressure through the threaded rod 25 and the spring body 23, the pressure can be controlled more accurately, thereby facilitating the precise adjustment of the gap between the rear end of the horizontal arm and the support bearing.

[0029] In this embodiment, the expansion sleeve 11 and the support seat 12 are mutually squeezed to make the multiple support plates 13 arranged in the annular direction expand outward, thereby forming annular support for the inner cavity of the horizontal arm 2 of the three-dimensional coordinate measuring machine. After arranging multiple support units 1 according to the length of the horizontal arm 2 of the three-dimensional coordinate measuring machine, the deflection of the horizontal arm of the three-dimensional coordinate measuring machine can be reduced. And through the toughness of the support plate 13 itself, it has a certain vibration reduction effect after supporting the inner cavity of the horizontal arm 2 of the three-dimensional coordinate measuring machine. At the same time, the pressure of the clamping wheel assembly 22 compensates the gap between the rear end of the horizontal arm of the three-dimensional coordinate measuring machine and the support bearing caused by the weight of the front end of the horizontal arm of the three-dimensional coordinate measuring machine, and the pressure of the clamping wheel assembly 22 on the horizontal arm of the three-dimensional coordinate measuring machine can also be dynamically adjusted according to the size of the current gap, thereby reducing the deflection of the horizontal arm of the three-dimensional coordinate measuring machine, avoiding fluctuations in the deflection, and improving the measurement accuracy of the three-dimensional coordinate measuring machine. At the same time, the clamping wheel method will not bring too much friction to the forward and backward movement of the horizontal arm of the three-dimensional coordinate measuring machine.

[0030] According to another embodiment of the present invention, in order to facilitate processing and design, the longitudinal section of the support seat 12 can be designed to be annular T-shaped, that is, Figure 2 As shown, the support seat 12 and the expansion sleeve 11 have threading channels inside. Considering that the inner cavity of the horizontal arm of the three-dimensional coordinate measuring machine is circular, the support unit 1 is also designed with a circular ring design, that is, the outer contour of the cross section of the expansion sleeve 11 and the support seat 12 at any position is circular.

[0031] Furthermore, the above-mentioned support plates 13 can be designed as strip-shaped rectangles, and the lengths and widths of the multiple support plates 13 are equal. At the same time, in the circumferential arrangement, the central axis of the expansion sleeve 11 can be taken as the center, so that the angles between each two adjacent support plates 13 in the radial direction of the expansion sleeve 11 are equal, thereby forming multi-angle support for the horizontal arm 2 of the three-dimensional coordinate measuring machine. Moreover, since each support plate 13 is independently fixed on the expansion sleeve 11, the angle between the expansion of each support plate 13 and the central axis of the expansion sleeve 11 is also different, so its support adaptability is strong, and it can adapt to the irregular structure of the inner cavity of the horizontal arm 2 of the three-dimensional coordinate measuring machine, and also realize circumferential support for it, avoiding the irregular structure of the inner cavity of the horizontal arm 2 of the three-dimensional coordinate measuring machine affecting the effect of the circumferential support.

[0032] refer to Figure 3 and Figure 4 As shown, according to another embodiment of the present invention, the support unit 1 in the above embodiment can be directly Figure 3 The end of the horizontal arm 2 of the coordinate measuring machine shown is placed in its inner cavity, and then the expansion sleeve 11 and the support seat 12 cooperate with each other to make the support plate 13 expand in the inner cavity of the horizontal arm 2 of the coordinate measuring machine, thereby forming an annular support.

[0033] In the above embodiment, in order to facilitate the adjustment of the pressure of the gap adjustment device, an automatic or manual method can be used as the above power device, for example Figure 5 The stepper motor is used as the power device; or a hand wheel is used manually. In order to improve the stability of the pressure applying part 24 moving up and down, a connecting seat 29 can be designed on the upper part of the support 21, and then the threaded rod 25 is keyed to the output shaft of the hand wheel or the stepper motor in the inner cavity of the connecting seat 29.

[0034] Furthermore, in order to facilitate the pressure-applying portion 24 to press the spring body 23 downward, the cross-section of the inner cavity of the support 21 can be designed to be square, the pressure-applying portion 24 is also placed in the inner cavity of the support 21, and a square nut that matches the inner cavity of the support 21 is used as the pressure-applying portion 24.

[0035] At the same time, in this embodiment, the above-mentioned clamping wheel assembly 22 also adopts a composite structure, specifically, a wheel seat 27 can be set, and then a wheel axle is horizontally installed below the wheel seat 27, and then a wheel body 28 is installed on the wheel axle, so that the upper part of the wheel seat 27 is in conflict with the spring body 23, and the wheel body 28 is in conflict with the horizontal arm when in use.

[0036] As mentioned above, a stepper motor is used as a power device. In a preferred embodiment of the present invention, a control box matching the stepper motor can be added. After the stepper motor is connected to the control box, the real-time deflection of the horizontal arm can be sampled under the action of the sampling module in the control box, thereby obtaining the real-time deflection curve of the horizontal arm. Then, calculation is performed based on the deflection curve to obtain the gap size required for deflection compensation, thereby controlling the rotational torque of the stepper motor, and then achieving the control of the pressure of the clamping wheel to calibrate the deflection.

[0037] refer to Figures 1 to 6 As shown, in actual use, the preferred embodiment of the present invention is to calculate the number of internal supports required according to the total length and telescopic length of the horizontal arm of the three-dimensional measuring machine, and then move the support unit 1 to the position from the end of the horizontal arm 2 of the three-dimensional measuring machine in sequence, and then use the tool to make the expansion sleeve 11 and the support seat 12 of the support unit 1 rotate relative to each other from the end, and make the two gradually move relative to each other in the bearing upward through the mutually matched threads, and the overlap surface of the two in the axial direction gradually increases, and the annular support plate 13 is gradually expanded outward through the annular inclined surface 14 at the end of the support seat 12, so as to form annular support for the horizontal arm at the current position, thereby reducing the excessive deflection generated during its telescopic process. At the same time, in order to fix the support seat in the inner cavity of the horizontal arm to prevent it from rotating, the horizontal arm and the support seat can be matched in size to form a clamping between the inner cavity of the horizontal arm and the support seat. After the annularly arranged support plates 13 complete the support, the metal toughness of the support plates 13 themselves can be used to buffer the vibration generated by the telescopic movement of the horizontal arm, and thus to a certain extent, it can also play a vibration reduction role. As the telescopic arm is extended or retracted to different lengths, the pressure applied by the pressure-applying portion 24 to the spring body 23 is dynamically adjusted, thereby adjusting the pressure applied by the clamping wheel assembly 22 to the horizontal arm, thereby compensating for the gap between the rear end of the horizontal arm and the support bearing caused by the weight of the front end of the horizontal arm. The dynamic pressure change is adapted to the change in size of the aforementioned gap, thereby further reducing the deflection of the telescopic arm during the extension and retraction operation and improving the measurement accuracy of the three-dimensional coordinate measuring machine.

[0038] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present invention.

[0039] Although the present invention is described herein with reference to a number of illustrative embodiments of the present invention, it will be appreciated that those skilled in the art may devise many other modifications and implementations that fall within the scope and spirit of the principles disclosed herein. More specifically, within the scope of the present disclosure, drawings, and claims, a variety of variations and improvements may be made to the components and / or layout of the subject combination layout. In addition to variations and improvements made to the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. A horizontal arm support structure of a three-dimensional coordinate measuring machine, comprising a support unit (1) and a gap adjustment device, characterized in that: The support unit (1) comprises an expansion sleeve body (11) and a support seat (12); the expansion sleeve body (11) has an internal thread, and the edge of the expansion sleeve body (11) has a plurality of support plates (13) arranged in an annular direction in the axial direction; the support seat (12) has an external thread matching the internal thread, and the support seat (12) is also provided with an annular inclined surface (14) inclined radially outward; the annular inclined surface (14) is used to gradually push the support plate (13) to expand radially outward along the expansion sleeve body (11) during the axial relative movement between the expansion sleeve body (11) and the support seat (12), so as to form an annular support for the inner wall of the horizontal arm (2) of the three-dimensional coordinate measuring machine; The gap adjustment device comprises a support (21), the support (21) is used to be installed on a three-dimensional coordinate measuring machine, a pressure wheel assembly (22) is movably installed at the lower part of the support (21), the pressure wheel assembly (22) is used to contact with the horizontal arm, a spring body (23) is provided in the inner cavity of the support (21), one end of the spring body (23) contacts with a pressure portion (24), and the other end contacts with the pressure wheel assembly (22); the pressure portion (24) is threadedly connected to a threaded rod (25), and the threaded rod (25) is also dynamically connected to a power device.

2. The horizontal arm support structure of a three-dimensional coordinate measuring machine according to claim 1, characterized in that: A connecting seat (29) is provided on the upper portion of the support (21), and the threaded rod (25) is key-connected to the output shaft of the power device in the inner cavity of the connecting seat (29).

3. The horizontal arm support structure of a three-dimensional coordinate measuring machine according to claim 1 or 2, characterized in that: The power device is a hand wheel or a stepping motor (26).

4. The horizontal arm support structure of a three-dimensional coordinate measuring machine according to claim 1 or 2, characterized in that: The cross-section of the inner cavity of the support (21) is square, the pressure-applying portion (24) is also disposed in the inner cavity of the support (21), and the pressure-applying portion (24) is a square nut that matches the inner cavity of the support (21).

5. The horizontal arm support structure of a coordinate measuring machine according to claim 1, characterized in that: The pressure wheel assembly (22) comprises a wheel seat (27), a wheel axle is transversely mounted below the wheel seat (27), a wheel body (28) is mounted on the wheel axle, the upper part of the wheel seat (27) is in contact with the spring body (23), and the wheel body (28) is used to contact with the horizontal arm.

6. The horizontal arm support structure of a coordinate measuring machine according to claim 1, characterized in that: The longitudinal section of the support seat (12) is in a circular T-shape, and both the support seat (12) and the expansion sleeve body (11) have threading channels inside.

7. The horizontal arm support structure of a three-dimensional coordinate measuring machine according to claim 1 or 2, characterized in that: The cross-sections of the expansion sleeve body (11) and the support seat (12) at any position are circular.

8. The horizontal arm support structure of a three-dimensional coordinate measuring machine according to claim 1 or 2, characterized in that: The support plates (13) are all rectangular in shape, and the lengths and widths of the plurality of support plates (13) are equal.

9. The horizontal arm support structure of a coordinate measuring machine according to claim 1, characterized in that: A plurality of support units (1) are arranged in an inner cavity of the horizontal arm (2) of the three-dimensional coordinate measuring machine at preset intervals.

10. The horizontal arm support structure of a three-dimensional coordinate measuring machine according to claim 1, characterized in that: The horizontal arm (2) of the three-dimensional coordinate measuring machine is a telescopic arm with a hollow inner cavity.

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