Linear displacement mechanism

Abstract

The present application belongs to the technical field of precision instruments, and particularly relates to a linear displacement mechanism, which comprises a base, a fixed guide rail arranged on the base, a moving guide rail arranged beside the fixed guide rail, and a limit block detachably connected to the fixed guide rail and / or the base. The limit block comprises a limiting part extending to the displacement path of the retainer. The moving guide rail moves under the drive of a driving mechanism and drives the retainer to displace. When the retainer is displaced to abut against the limiting part, the limiting part prevents the retainer from moving in the original direction. In the present application, the limit block has a small volume and is convenient to install. Under the premise of realizing miniaturization of the linear displacement mechanism, the limit block does not participate in the precision positioning of the fixed guide rail, the moving guide rail and the retainer, so as to effectively ensure the positioning accuracy of the displacement mechanism.

Description

Technical Field

[0001] This invention belongs to the field of precision instrument technology, and specifically relates to a linear displacement mechanism. Background Technology

[0002] In optical instruments, high-precision displacement mechanisms are commonly used to adjust the displacement of optical components such as lenses. To meet the displacement adjustment requirements, the maximum stroke of the displacement mechanism is usually greater than the allowable displacement stroke of the component mounted on it. If the displacement exceeds the limit, adjacent components may collide and be damaged. However, the stroke range of the displacement mechanism is usually fixed. Therefore, to prevent the component from exceeding the displacement range, a limiting mechanism is usually required on the component mounting base. This results in more instrument parts, increasing costs and making it difficult to achieve instrument miniaturization.

[0003] Existing technologies, such as Chinese patent CN205184284U, disclose a simple machine tool stroke adjustment structure, including a slide saddle, a linear guide rail, a front slider, a rear slider, and a slide plate. The front and rear sliders are respectively mounted on the linear guide rail, and the slide plate is connected to the front and rear sliders respectively by fixing bolts. The linear guide rail is connected to the slide saddle by fixing bolts. A limit block is also provided at the end of the slide saddle, located inside the linear guide rail. In this design, the slide plate transitions with the linear guide rail through the front and rear sliders, respectively. This means that the machining accuracy of the front and rear sliders, as well as the assembly accuracy of the front and rear sliders with the linear guide rail and slide plate, will directly affect the positioning accuracy of the slide plate. When applied to precision instruments, this will greatly increase the production and adjustment costs of the displacement mechanism. Summary of the Invention

[0004] The purpose of this invention is to provide a linear displacement mechanism that has a compact structure and can reliably adjust the stroke range of the displacement mechanism.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a linear displacement mechanism, including a base, a fixed guide rail on the base, a movable guide rail on the side of the fixed guide rail, a retainer between the fixed guide rail and the movable guide rail, and rolling elements on the retainer forming a rolling engagement with the fixed guide rail and the movable guide rail respectively; a limiting block is detachably connected to the fixed guide rail and / or the base, the limiting block including a limiting part extending to the displacement path of the retainer, and a fixing part attached to the fixed guide rail and / or the base; the movable guide rail moves under the drive of the driving mechanism and drives the retainer to move, when the retainer moves to the position abutting against the limiting part, the limiting part prevents the retainer from moving in the original direction.

[0006] Compared with existing technologies, the present invention has the following technical advantages: The stroke range of the linear displacement mechanism can be adjusted simply by adding a limiting block without altering the existing linear displacement mechanism. The limiting block is small in size and easy to install. While ensuring the miniaturization of the linear displacement mechanism, the limiting block does not participate in the precise positioning of the fixed guide rail, moving guide rail, or cage, thus effectively guaranteeing the positioning accuracy of the linear displacement mechanism.

[0007] In use, by replacing the limit block, the stroke range can be adjusted at low cost while ensuring the displacement accuracy of the linear displacement mechanism. This makes the linear displacement mechanism suitable for different stroke requirements, expands its applicability, and reduces production costs.

[0008] When operating at non-full stroke, selecting appropriate limit blocks or adjusting the installation position of the limit blocks can reduce the stroke of the moving guide rail, thereby shortening the zeroing stroke and improving the working efficiency of the instrument.

[0009] During transportation, limit blocks are installed to constrain the displacement of the moving guide rail, minimizing its travel range, in order to avoid damage to components that may be caused by the displacement of the moving guide rail due to transportation vibration. Attached Figure Description

[0010] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings within them:

[0011] Figure 1 This is a three-dimensional schematic diagram of Embodiment 1;

[0012] Figure 2 This is a three-dimensional schematic diagram of the movable guide rail and a limiting block in the separated state in Embodiment 1;

[0013] Figure 3 This is a three-dimensional schematic diagram of Embodiment 2;

[0014] Figure 4 This is a three-dimensional schematic diagram of the movable guide rail and a limiting block in the separated state in Embodiment 2;

[0015] Figure 5 This is a three-dimensional schematic diagram of Example 3;

[0016] Figure 6 This is a three-dimensional schematic diagram of the movable guide rail and a limiting block in the separated state in Embodiment 3;

[0017] Figure 7 This is a three-dimensional schematic diagram of the cage;

[0018] Figure 8 This is a side view of the state of the limit block and a retainer after removing the limit block in Embodiment 3. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and through the description of the examples.

[0020] Example 1

[0021] A linear displacement mechanism includes a base 10, on which a fixed guide rail 21 is mounted. A movable guide rail 22 is located beside the fixed guide rail 21. A retainer 23 is provided between the fixed guide rail 21 and the movable guide rail 22. Rolling elements mounted on the retainer 23 form a rolling engagement with both the fixed guide rail 21 and the movable guide rail 22. In this embodiment, the fixed guide rail 21, the movable guide rail 22, and the retainer 23 form a crossed roller guide pair. See attached figure for details. Figure 1 , 2 As shown, the fixed guide rail 21 and the movable guide rail 22 are generally in the shape of strips, as shown in the attached figure. Figure 7 , 8 As shown, the cage 23 is a vertically arranged plate-like structure. Rollers are located in the middle of the cage 23, with adjacent roller cores perpendicular to each other, and the outlines of the two sets of rollers coincide in the side view of the linear displacement mechanism. (See attached image) Figure 8 As shown, the fixed guide rail 21 and the movable guide rail 22 are respectively provided with guide grooves on the surfaces near the cage 23. Each guide groove has two guide surfaces with mutually perpendicular walls. Rollers mounted on the cage 23, sandwiched between the fixed guide rail 21 and the movable guide rail 22, form a rolling fit with the guide surfaces of the guide grooves. In the assembled state, half of the rollers bear the vertical force, and the other half bears the horizontal force. The roller array allows the guide rail pair to simultaneously withstand torque loads in the up-down and left-right directions, ensuring high rigidity in all directions. In other embodiments, the cage 23 can also be provided with balls or other common rolling elements to achieve a rolling fit with the guide grooves. In this embodiment, to ensure smooth and reliable displacement of the movable guide rail 22, two fixed guide rails 21 are provided parallel to each other on the base 10, and the movable guide rail 22 is located between the two fixed guide rails 21. Specifically, in this embodiment, the movable guide rail 22 has a relatively large volume to facilitate the installation of components. Only one movable guide rail 22 is provided between the two fixed guide rails 21. That is, both sides of the movable guide rail 22 are connected to the adjacent fixed guide rail 21 via retainers 23 to form a linear displacement engagement. This reduces the volume of the displacement mechanism while ensuring the linearity and stability of the movable guide rail 22's displacement. In other embodiments, two movable guide rails 22 can be provided, with one movable guide rail 22 engaging with one fixed guide rail 21 to form a linear displacement engagement. The movable guide rail 22 can be located between or outside the two fixed guide rails 21; alternatively, one fixed guide rail 21 can be used to engage with one movable guide rail 22 for displacement, aiming to achieve the linear displacement of the movable guide rail 22.

[0022] To adjust the displacement stroke of the moving guide rail 22 and to prevent the moving guide rail 22 and the cage 23 from exceeding their displacement limits and detaching from the base 10, this embodiment provides a limiting block 30 on the fixed guide rail 21. The limiting block 30 includes a limiting part 31 extending into the displacement path of the cage 23 and a fixing part 32 attached to the fixed guide rail 21.

[0023] As attached Figure 2 As shown, in this embodiment, limiting portions 31 are provided at both ends of the displacement path of the cage 23, that is, limiting blocks 30 are used to limit the displacement path of the cage 23 at both ends. In other embodiments, if the end of the moving guide rail 22 has other limiting structures, limiting blocks 30 can also be provided only at the other end of the cage 23 as needed.

[0024] In this embodiment, the driving mechanism is located at the bottom of the moving guide rail 22 and includes a piezoelectric actuation unit 41 and a mover 42. The piezoelectric actuation unit 41 is located below the mover 42, and the mover 42 is located below the moving guide rail 22 and is in contact with the bottom surface of the moving guide rail 22. The mover 42 and the moving guide rail 22 are synchronously displaced. The piezoelectric actuation unit 41 drives the mover 42 to move, thereby realizing the displacement of the moving guide rail 22.

[0025] In practice, the movable guide rail 22 moves under the drive mechanism, causing the cage 23 to shift. The cage 23 maintains the posture and mounting position of the roller and does not bear the main driving force itself. Therefore, the cage 23 will shift at the same speed and direction as the roller's shaft. Ideally, the roller performs pure rolling motion between the fixed guide rail 21 and the movable guide rail 22, and the translational speed of the roller's shaft is half the displacement speed of the movable guide rail 22. When the cage 23 shifts to the position where it abuts against the limiting part 31, the limiting part 31 prevents the cage 23 from moving in the original direction. The shaft of the roller on the cage 23 can no longer continue to translate in the original direction. If the movable guide rail 22 attempts to continue moving, the rolling engagement between the movable guide rail 22 and the roller will change to a sliding engagement. The movable guide rail 22 needs to overcome a large amount of sliding friction to shift. However, the drive mechanism cannot provide sufficient driving force, so the displacement of the movable guide rail 22 is also limited. The two sides of the cage 23 are precisely positioned with the fixed guide rail 21 and the moving guide rail 22 respectively to ensure the positioning accuracy of linear displacement. In this embodiment, the limiting part 31 only forms a stop and limit fit with the end face of the cage 23, and will not cause additional positioning errors due to the manufacturing tolerance or installation deviation of the limiting block 30, thereby ensuring the displacement positioning accuracy of the displacement mechanism. In use, by adjusting the position of the limiting part 31 on the displacement path of the cage 23, that is, adjusting the connection position between the fixed part 32 and the fixed guide rail 21, or adjusting the length of the limiting part 31, that is, replacing the limiting block 30 with a length that meets the requirements, the total displacement stroke of the cage 23 can be adjusted, thereby realizing the adjustment of the stroke range of the moving guide rail 22. Therefore, in order to meet the stroke adjustment requirements of the moving guide rail 22, the limiting block 30 is detachably connected to the fixed guide rail 21 in this embodiment.

[0026] In this embodiment, the limiting part 31 of the limiting block 30 is suspended between the fixed guide rail 21 and the moving guide rail 22, and abuts against the end of the retainer 23 to achieve limiting. It does not cooperate with the positioning surfaces such as the guide groove of the displacement mechanism. The installation of the limiting block 30 also avoids the positioning surfaces such as the guide groove of the fixed guide rail 21 and the moving guide rail 22, thus realizing the adjustment of the stroke range at low cost without affecting the displacement accuracy of the displacement mechanism.

[0027] Details are as attached Figure 2As shown, in this embodiment, the limiting block 30 is generally L-shaped, and the limiting part 31 and the fixing part 32 are generally plate-shaped. The fixing part 32 is connected to the end face of the fixed guide rail 21. The plate edge of the fixing part 32 near the retainer 23 extends into the gap between the moving guide rail 22 and the fixed guide rail 21 to form the limiting part 31. The fixing part 32 and the limiting part 31 are generally square. The fixing part 32 has a hole, and the screw passes through the hole and is fixedly connected to the end face of the fixed guide rail 21. The overhanging edge of the limiting part 31 matches the adjacent edge of the retainer 23 to ensure the reliability of the limiting.

[0028] In this embodiment, the cross-section of the fixed guide rail 21 is generally square. If the space at the end face of the fixed guide rail 21 is limited and cannot accommodate the fixing part 32, the fixing part 32 can be connected to the circumferential sidewall of the fixed guide rail 21. (See attached...) Figure 2 As shown, the fixed guide rail 21 includes a bottom wall fixedly connected to the base 10 surface, and a top wall opposite to the bottom wall. The side wall of the fixed guide rail 21 that connects to the bottom wall mates with the retainer 23. When the installation space is limited and the limiting block 30 cannot be installed at the end face of the fixed guide rail 21, the fixing part 32 can be connected to the other side wall, meaning the limiting block 30 is arranged in a U-shaped folded plate around the outer periphery of the fixed guide rail 21. Specifically, the upper edge of the limiting part 31 first extends laterally outward along a direction parallel to the top wall of the fixed guide rail 21, and then extends downward along a direction parallel to the limiting part 31 to form the fixing part 32. The fixing part 32 is fixedly connected to the outer side wall of the fixed guide rail 21 away from the retainer 23, meaning the limiting block 30 is a downward-opening groove. Alternatively, the edge of the limiting part 31 near the end face of the fixed guide rail 21 can first extend vertically outward in a direction parallel to the end face of the fixed guide rail 21, and then extend towards the other end face of the fixed guide rail 21 in a direction parallel to the limiting part 31 to form the fixing part 32. The fixing part 32 is still fixedly connected to the outer wall of the fixed guide rail 21 away from the retainer 23, and the limiting block 30 is a groove with an opening pointing towards the other end face of the fixed guide rail 21. Alternatively, the fixing part 32 can be connected to the top wall of the fixed guide rail 21, that is, the upper edge of the limiting part 31 extends in a direction parallel to the top wall of the fixed guide rail 21 to form the fixing part 32, and the limiting block 30 is an L-shaped folded plate covering the top wall of the fixed guide rail 21 and the surface where the guide groove is located.

[0029] The fixed guide rail 21 in the linear displacement mechanism is fixedly connected to the base 10 and serves as a fastener. To achieve the fixed installation of the limit block 30, the installation position of the limit block 30 and the fixed guide rail 21, base 10, and other fasteners can be adjusted according to requirements, and the shape and structure of the limit block 30 can also be adjusted accordingly.

[0030] Example 2

[0031] The difference between this embodiment and embodiment one is that the fixing part 32 is attached to the base 10, that is, the fixing part 32 is connected to the base 10 to realize the installation and positioning of the limiting block 30.

[0032] Specifically, this implementation example is attached. Figure 3 , 4 As shown, the base 10 includes a base plate 11, which is flat. A vertical plate 12 is provided on the edge of the base plate 11. A fixed guide rail 21 is arranged adjacent to the vertical plate 12, and the length direction of the fixed guide rail 21 is parallel to the surface of the vertical plate 12. The limiting block 30 is L-shaped and folded. The upper edge of the vertically arranged limiting part 31 located between the fixed guide rail 21 and the moving guide rail 22 extends in a direction parallel to the base plate 11 to form a fixing part 32. The fixing part 32 spans the fixed guide rail 21 and is connected to the top surface of the vertical plate 12.

[0033] In other embodiments, to avoid adjacent components, the fixing part 32 may also be folded or have other shapes, as long as it can be reliably connected to the base 10. For example, when other components need to be avoided above the upright plate 12, the fixing part 32 can be fixedly connected to the end face of the upright plate 12 or the base plate 11, and the limiting block 30 can be L-shaped folded plate. Alternatively, the fixing part 32 can span the top surface of the fixing guide rail 21 and the upright plate 12 and be connected to the outer side surface of the upright plate 12. The limiting block 30 can be a groove with an opening pointing towards the base plate 11. Alternatively, the fixing part 32 can be fixedly connected to the bottom surface of the base plate 11. That is, the edge of the limiting part 31 near the end of the fixing guide rail 21 first folds and extends towards the end face of the fixing guide rail 21 / upright plate 12, and then extends towards the bottom of the base plate 11 and connects with it, so as to achieve a reliable connection between the limiting block 30 and the base 10 while meeting the installation requirements.

[0034] This implementation example is attached. Figure 4 As shown, the fixing part 32 has an oblong hole, the length of which is parallel to the linear displacement direction of the moving guide rail 22. A screw passes through this oblong hole and connects to the top surface of the upright plate 12. In specific implementation, when the bolt is not fully tightened, the oblong hole provides continuous linear movement space for the installation of the limiting block 30, allowing the limiting block 30 to be infinitely adjustable during installation. Further, as shown in the attached... Figure 4 As shown, the upright plate 12 has two mounting holes spaced apart along the linear displacement direction of the moving guide rail 22 for engagement with bolts. This widens the limiting range of the limiting block 30, fully meeting the user's stroke range adjustment needs. Specifically, the number of mounting holes on the upright plate 12 can be increased or decreased as needed, and the arrangement of the mounting holes can also be adjusted as required. In other embodiments, when the fixing part 32 is connected to the fixed guide rail 21, the fixed guide rail 21 is provided with the aforementioned mounting holes, and the number of mounting holes can be adjusted according to the stroke range adjustment needs.

[0035] Example 3

[0036] The difference between this embodiment and embodiment two is that the fixing part 32 is in the shape of a strip plate, and the end plate edge of the fixing part 32 is connected to the limiting part 31 to form an L-shaped or U-shaped folded plate.

[0037] As attached Figure 5 , 6 In the illustrated embodiment, the fixing part 32 is connected to the seat surface of the base 10, and the end plate edge of the fixing part 32 extends upward to form a limiting part 31, so that a limiting block 30 can simultaneously limit the two retainers 23. In this embodiment, in order to achieve miniaturization of the linear displacement mechanism, the fixing part 32 is located below the moving guide rail 22. The moving guide rail 22 needs to be moved to the position where the fixing part 32 is exposed before the fixing part 32 and the base 10 can be installed or disassembled. In another embodiment, if the installation space meets the requirements, the end of the base 10 can be allowed to extend outward, and the fixing part 32 is fixedly connected to the seat surface of the base 10 exposed outside the end of the moving guide rail 22. The plate edge of the fixing part 32 is folded upward and then extends into the gap between the fixing guide rail 21 and the moving guide rail 22 to form a limiting part 31.

[0038] In another embodiment, the fixing part 32 can be connected to the wall at the end of the base 10, that is, the fixing part 32 is connected to the end face of the base 10 to realize the installation of the limiting block 30. The fixing part 32 is U-shaped and covers the end face of the base 10 and the fixed guide rail 21. The edge of the end plate of the fixing part 32 extends parallel to the length direction of the fixed guide rail 21 to the side where the fixed guide rail 21 is located to form the limiting part 31.

[0039] This implementation example is attached. Figure 6 As shown, the base 10 has two mounting holes on its seat surface. The two mounting holes are arranged at intervals along the length of the fixed guide rail 21, and the length of the fixed guide rail 21 is parallel to the linear displacement direction of the moving guide rail 22.

Claims

1. A linear displacement mechanism, characterized in that: Includes a base (10), a fixed guide rail (21) is provided on the base (10), a movable guide rail (22) is provided on the side of the fixed guide rail (21), a retainer (23) is provided between the fixed guide rail (21) and the movable guide rail (22), and a rolling element provided on the retainer (23) forms a rolling fit with the fixed guide rail (21) and the movable guide rail (22) respectively; A limiting block (30) is detachably connected to the fixed guide rail (21) and / or base (10). The limiting block (30) includes a limiting part (31) extending into the displacement path of the cage (23) and a fixing part (32) attached to the fixed guide rail (21) and / or base (10). The moving guide rail (22) moves under the drive of the drive mechanism and causes the cage (23) to be displaced. When the cage (23) moves to the position where it abuts against the limiting part (31), the limiting part (31) prevents the cage (23) from moving in the original direction.

2. The linear displacement mechanism according to claim 1, characterized in that: Limiting parts (31) are provided at both ends of the displacement path of the cage (23).

3. The linear displacement mechanism according to claim 1, characterized in that: The limiting block (30) is in the shape of an L-shaped folded plate. The fixing part (32) is connected to the end face of the fixed guide rail (21). The plate edge of the fixing part (32) near the side where the retainer (23) is located extends into the gap between the moving guide rail (22) and the fixed guide rail (21) to form the limiting part (31).

4. The linear displacement mechanism according to claim 1, characterized in that: The cross-section of the fixed guide rail (21) is generally square, and the fixing part (32) is connected to the circumferential side wall of the fixed guide rail (21); The fixed guide rail (21) includes a bottom wall that is fixedly connected to the seat surface of the base (10). The side wall of the fixed guide rail (21) that is connected to the bottom wall is engaged with the retainer (23). The fixing part (32) is connected to the other side wall. The limiting block (30) is U-shaped and surrounded on the outer periphery of the fixed guide rail (21); or the fixing part (32) is connected to the top wall of the fixed guide rail (21). The limiting block (30) is L-shaped.

5. The linear displacement mechanism according to claim 1, characterized in that: The base (10) includes a base plate (11), and a vertical plate (12) is provided on the edge of the base plate (11). A fixed guide rail (21) is arranged near the vertical plate (12) and the length direction of the fixed guide rail (21) is parallel to the surface of the vertical plate (12). The limiting block (30) is in the shape of an L-shaped folded plate. The upper edge of the limiting part (31) located between the fixed guide rail (21) and the moving guide rail (22) spans the fixed guide rail (21) and is connected to the top surface of the vertical plate (12) to form a fixing part (32).

6. The linear displacement mechanism according to claim 1, characterized in that: The fixing part (32) is connected to the base (10). The fixing part (32) is in the shape of a strip plate. The end plate edge of the fixing part (32) is connected to the limiting part (31) to form an L-shaped or U-shaped folded plate.

7. The linear displacement mechanism according to any one of claims 4-6, characterized in that: The fixing part (32) is connected to the fixing guide rail (21) or the base (10) by screws. The fixing part (32) has a waist-shaped hole, the length direction of which is parallel to the linear displacement direction of the moving guide rail (22). The fixing guide rail (21) or the base (10) has two or more mounting holes, which are arranged at intervals in the linear displacement direction of the moving guide rail (22) to cooperate with the screws.

8. The linear displacement mechanism according to claim 6, characterized in that: The fixing part (32) is connected to the seat surface of the base (10), and the end plate edge of the fixing part (32) extends upward to form a limiting part (31). Alternatively, the fixing part (32) is connected to the wall at the end of the base (10) and the edge of the end plate of the fixing part (32) extends parallel to the length direction of the fixing guide rail (21) to the side where the fixing guide rail (21) is located to form a limiting part (31).

9. The linear displacement mechanism according to claim 1, characterized in that: Two fixed guide rails (21) are provided parallel to each other on the base (10), and a movable guide rail (22) is provided between the two fixed guide rails (21).

10. The linear displacement mechanism according to claim 1, characterized in that: The drive mechanism is located at the bottom of the moving guide rail (22) and includes a piezoelectric actuation unit (41) and a mover (42). The mover (42) and the moving guide rail (22) are synchronously displaced.

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