A single-degree-of-freedom positioning platform with a large stroke

Abstract

The present application discloses a single-degree-of-freedom positioning platform with a large stroke, which includes a flexible hinge, a displacement output platform, a driving device and a feedback device; the flexible hinge includes at least four outer frames and at least eight flexible plates; the displacement output platform is arranged within the outer frame, and at least four connection stations that are circumferentially distributed around its own central axis are provided on its outer peripheral wall; each connection station is connected to the outer frame through at least two of the flexible plates; the output end of the driving device is connected to the displacement output platform; the fixed end of the driving device is connected to the outer frame; the feedback device is installed on the displacement output platform and is used to feedback the stroke distance of the displacement output platform. The present application can effectively improve the natural frequency and stiffness of the positioning platform in the non-moving direction while ensuring that the positioning platform has a large working stroke.

Description

Technical Field

[0001] This application relates to the field of ultra-precision machining positioning platforms, and particularly to a single-degree-of-freedom positioning platform with a large stroke. Background Art

[0002] With the continuous development of science and technology, ultra-precision machining and measurement have received increasing attention. At the same time, in many fields of ultra-precision machining, there are requirements for high precision and high repeatability in positioning; flexible mechanisms are widely used in the positioning of various ultra-precision machining and measurement due to their outstanding advantages in this regard.

[0003] Currently, there are many driving types for high-precision positioning platforms, such as voice coil motor type, piezoelectric type, and electromagnetic type, etc., and there are also various structures, such as parallelogram type, multi-stage amplification type, etc. However, these positioning platforms are either complex in structure or it is difficult to achieve high stiffness and high natural frequency in the non-moving direction while also having a large movement range. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a single-degree-of-freedom positioning platform with a large stroke, which can not only achieve a large working stroke, but also has a high natural frequency and stiffness in the non-moving direction.

[0005] To achieve the above technical purpose, this application provides a single-degree-of-freedom positioning platform with a large stroke, including a flexible hinge, a displacement output platform, a driving device, and a feedback device;

[0006] The flexible hinge includes at least four outer frames and at least eight flexible plates;

[0007] The displacement output platform is arranged inside the outer frame, and at least four connection stations distributed circumferentially around its own central axis are provided on its outer peripheral wall;

[0008] Each connection station is respectively connected to the outer frame through at least two of the flexible plates;

[0009] The output end of the driving device is connected to the displacement output platform;

[0010] The fixed end of the driving device is connected to the outer frame;

[0011] The feedback device is installed on the displacement output platform for feedbacking the stroke distance of the displacement output platform.

[0012] Preferably, the feedback device includes a first backing plate, a second backing plate, a grating scale reading head, and a grating scale body;

[0013] The grating scale body is installed on the displacement output platform;

[0014] The grating scale reading head is installed on the second backing plate within the reading range of the grating scale body;

[0015] The second backing plate is fixedly connected to one of the outer frames through the first backing plate.

[0016] Preferably, the displacement output platform is specifically provided with four connection stations.

[0017] Preferably, the four connection stations are evenly distributed in a cross-shaped circle around the displacement output platform.

[0018] Preferably, the flexible hinge specifically includes four outer frames and eight flexible plates;

[0019] Each outer frame is connected to the displacement output platform through two flexible plates arranged at intervals.

[0020] Preferably, the two flexible plates connected to each outer frame are respectively arranged at both end positions of the displacement output platform.

[0021] Preferably, the driving device includes a motor and a coil fixing plate;

[0022] The motor is connected to the displacement output platform through the coil fixing plate.

[0023] Preferably, the motor is specifically a voice coil motor.

[0024] Preferably, a tool holder is further included;

[0025] The tool holder is installed on the displacement output platform.

[0026] Preferably, the tool holder and the output end of the driving device are respectively connected to symmetric ends of the displacement output platform.

[0027] It can be seen from the above technical solutions that in this application, by setting at least four outer frames and at least eight flexible plates, and setting at least four connection stations evenly distributed in a circle around its own central axis on the displacement output platform; the outer frames are connected to the displacement output platform through flexible plates, and at the same time, the ends of the outer frames are fixedly connected to the non-output end of the driving device, which can ensure that the positioning platform has a large working stroke while effectively increasing the natural frequency and stiffness of the positioning platform in the non-moving direction, and effectively reducing the harm of resonance during the high-frequency reciprocating movement of the positioning platform; a feedback device is also provided on the positioning platform, which can timely feedback the stroke distance of the displacement output platform to the control system, facilitating the timely adjustment of the output position data of the displacement output platform. Description of the Drawings

[0028] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0029] Figure 1 Schematic diagram of the overall structure of a large-stroke single-degree-of-freedom positioning platform provided in the embodiment of the present application;

[0030] Figure 2 Schematic diagram of the flexible hinge structure in a large-stroke single-degree-of-freedom positioning platform provided in the embodiment of the present application;

[0031] In the figure: 1. Flexible hinge; 2. Motor fixing plate; 3. Motor; 4. First cushion plate; 5. Second cushion plate; 6. Grating scale reading head; 7. Grating scale body; 8. Tool holder; 9. Flexible plate; 10. Displacement output platform; 11. Outer frame. Detailed implementation manners

[0032] The following will clearly and completely describe the technical solutions of the embodiments of the present application in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of them. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection required by the present application.

[0033] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present application. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0034] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a replaceable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0035] The embodiment of the present application discloses a single-degree-of-freedom positioning platform with a large stroke.

[0036] Please refer to Figures 1 to 2 , a single-degree-of-freedom positioning platform with a large stroke provided in the embodiment of the present application, includes a flexible hinge 1, a displacement output platform 10, a driving device and a feedback device; the flexible hinge 1 includes at least four outer frames 11 and at least eight flexible plates 9; the displacement output platform 10 is arranged inside the outer frame 11, and at least four connection stations are arranged on its outer peripheral wall and are evenly distributed circumferentially around its central axis; each connection station is connected to the outer frame 11 through at least two flexible plates 9; the output end of the driving device is connected to the displacement output platform 10; the fixed end of the driving device is connected to the outer frame 11; the feedback device is installed on the displacement output platform 10 and is used to feedback the stroke distance of the displacement output platform 10.

[0037] Specifically, the displacement output platform 10 is installed on the output end of the driving device, and at the same time, the outer frame 11 is fixedly connected to the non-output end of the driving device, that is, the fixed end. For example, in this embodiment, a plurality of outer frames 11 are connected to the same fixed plate, and the fixed plate is then connected to the motor housing of the driving device, so that when the driving device transmits the driving force to the output platform, the flexible hinge 1 composed of the outer frame 11 and the flexible plate 9 can improve the natural frequency and stiffness in the non-moving direction of the positioning platform; and the circumferential distribution of multiple pairs of outer frames 11 and flexible hinges around the displacement output platform 10 further improves the stiffness and natural frequency in the non-moving direction of the platform.

[0038] Among them, the driving device can be a linear motor, a voice coil motor, etc.; the feedback device can be a position sensor such as a capacitive sensor, a laser interferometer, etc., and is not specifically limited.

[0039] The above is Embodiment 1 provided by the embodiment of the present application. The following is Embodiment 2 provided by the present application. Please specifically refer to Figures 1 to 2 .

[0040] A single-degree-of-freedom positioning platform with a large stroke, includes: a flexible hinge 1, a displacement output platform 10, a driving device and a feedback device; the flexible hinge 1 includes at least four outer frames 11 and at least eight flexible plates 9; the displacement output platform 10 is arranged inside the outer frame 11, and at least four connection stations are arranged on its outer peripheral wall and are evenly distributed circumferentially around its central axis; each connection station is connected to the outer frame 11 through at least two flexible plates 9; the output end of the driving device is connected to the displacement output platform 10; the fixed end of the driving device is connected to the outer frame 11; the feedback device is installed on the displacement output platform 10 and is used to feedback the stroke distance of the displacement output platform 10.

[0041] Further, in this embodiment, the feedback device is a grating scale, which specifically includes a first backing plate 4, a second backing plate 5, a grating scale reading head 6 and a grating scale body 7; the grating scale body 7 is installed on the displacement output platform 10; the grating scale reading head 6 is installed on the second backing plate 5 within the reading range of the grating scale body 7; the second backing plate 5 is fixedly connected to an outer frame 11 through the first backing plate 4.

[0042] Specifically, the positioning platform includes at least four outer frames, and a feedback device for connecting the displacement output platform 10 or the tool rest 8 can be provided on each outer frame 11. In this embodiment, there is one feedback device. The first backing plate 4 and the second backing plate 5 are provided to facilitate the fixed connection between the grating scale reading head 6 and the outer frame 11. In actual operation, only one backing plate can also be used, as long as the grating scale reading head 6 can be fixedly installed on the outer frame 11; the grating scale body 7 transmits the stroke distance of the tool rest 8 to the controller in real time through a data cable.

[0043] Further, in this embodiment, the displacement output platform 10 is specifically provided with four connection stations. The four connection stations are evenly distributed in a cross-shaped circle around the displacement output platform. Each outer frame 11 is connected to the displacement output platform 10 through two flexural plates 9 arranged at intervals. The two flexural plates 9 connected to each outer frame 11 are respectively arranged at both ends of the displacement output platform 10.

[0044] Specifically, please refer to Table 1 below for the comparison of the simulation data of the frequency conditions in each direction when only two connection stations are set and distributed in a straight line around the displacement output platform 10 and the frequency conditions in each direction when four connection stations are set and distributed symmetrically in a circular cross shape around the displacement output platform 10 in this embodiment:

[0045]

[0046] Table 1

[0047] Please refer to Figure 2 , Figure 2 The direction indicated by the arrow in is the horizontal movement direction of the displacement output platform 10; it can be seen from the simulation comparison data in Table 1 that the natural frequency in the vertical movement direction of the cross-shaped flexure hinge with four connection stations distributed symmetrically in a circular cross shape around the displacement output platform 10 in this embodiment, that is, the natural frequency in the non-movement direction, is significantly improved compared with the case of only two connection stations arranged in a straight line.

[0048] Specifically, in this embodiment, there are a total of four outer frames 11 and eight flexural plates 9. Each outer frame 11 is connected to two flexural plates 9 arranged near both ends of the displacement output platform 10; in actual application, the system stiffness and natural frequency can be further increased by increasing the number of flexural plates.

[0049] Furthermore, the driving device includes a motor 3 and a coil fixing plate 2; the motor 3 is connected to the displacement output platform 10 through the coil fixing plate 2.

[0050] Furthermore, in this embodiment, the motor 3 is specifically a voice coil motor.

[0051] Furthermore, the tool rest 8 and the output end of the driving device are respectively and correspondingly connected to two symmetric ends of the displacement output platform 10.

[0052] It should be noted that the above is only the preferred embodiment of the present application and is not used to limit the present invention. Although the present application has been described in detail with reference to the examples, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing examples, or perform equivalent replacements on some of the technical features. However, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A single-degree-of-freedom positioning platform with a large stroke, characterized in that, It includes a flexible hinge, a displacement output platform, a driving device and a feedback device; The flexible hinge includes at least four outer frames and at least eight flexible plates; The displacement output platform is arranged inside the outer frame, and at least four connection stations are arranged on its outer peripheral wall and are circumferentially distributed around its central axis; Each connection station is respectively connected to the outer frame through at least two of the flexible plates; The output end of the driving device is connected to the displacement output platform; The fixed end of the driving device is connected to the outer frame; The feedback device is installed on the displacement output platform and is used to feedback the stroke distance of the displacement output platform; The feedback device includes a first backing plate, a second backing plate, a grating scale reading head and a grating scale body; The grating scale body is installed on the displacement output platform; The grating scale reading head is installed on the second backing plate at a position within the reading range of the grating scale body; The second backing plate is fixedly connected to one of the outer frames through the first backing plate; The driving device includes a motor and a coil fixing plate; The motor is connected to the displacement output platform through the coil fixing plate.

2. The single-degree-of-freedom positioning platform with a large stroke according to claim 1, characterized in that, The displacement output platform is specifically provided with four connection stations; The flexible hinge specifically includes four outer frames and eight flexible plates; The four connection stations are circumferentially evenly distributed in a cross shape around the displacement output platform.

3. The single-degree-of-freedom positioning platform with a large stroke according to claim 2, characterized in that The two flexible plates connected to each outer frame are respectively arranged at both ends of the displacement output platform.

4. The single-degree-of-freedom positioning platform with a large stroke according to claim 1, characterized in that, The motor is specifically a voice coil motor or a linear motor.

5. The single-degree-of-freedom positioning platform with a large stroke according to claim 1, characterized in that, It further includes a tool holder; The tool holder is installed on the displacement output platform.

6. The single-degree-of-freedom positioning platform with a large stroke according to claim 5, characterized in that The tool holder and the output end of the driving device are respectively connected to two symmetrical ends of the displacement output platform.

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