Angle Adjustment Table

Abstract

This invention provides an angle adjustment worktable that can suppress ineffective movement and position an object with high precision. The present invention includes a positioning mechanism (15) for rotating a rotary worktable (13) rotatably supported on a base (11) by means of a cross roller bearing (17) and positioning it toward a target position. The positioning mechanism (15) includes: a bracket (31) supported by the base (11) and capable of linear movement in the tangential direction of the rotary worktable (13); a ball screw device (33) for causing the bracket (31) to move linearly; a connecting part (35) supported relative to the bracket (31) and capable of linear movement in a direction orthogonal to the linear movement direction of the bracket (31), and an arm (23) connecting the bracket (31) and the rotary worktable (13) to convert the linear movement of the bracket (31) into the rotational movement of the rotary worktable (13); and a leaf spring (91) for pushing the bracket (31) and the rotary worktable (13) in opposite directions in a direction intersecting the axis of the rotary worktable (13).

Description

Technical Field

[0001] This invention relates to an angle-adjustable worktable. Prior Technology

[0002] An angle-adjusting worktable that rotates an object to a target position, and a positioning mechanism that positions the worktable after rotation.

[0003] Patent documents 1-3 disclose a positioning mechanism comprising: a bracket that moves linearly in the tangential direction of a rotary table via a linear guide; and a connecting part disposed between the arm of the rotary table and the bracket, which transmits the linear motion of the bracket to the arm of the rotary table and converts it into the rotational motion of the rotary table. Furthermore, patent document 3 discloses a structure for the connecting part: a cam follower disposed on the arm of the rotary table clamps and supports a "protrusion of a nut erected on a ball screw assembly" by a compression spring. [Previous Technical Documents] [Patent Literature]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2005-221044 [Patent Document 2] Japanese Patent Application Publication No. 2002-341076 [Patent Document 3] Japanese Patent Application Publication No. 2000-238232 Summary of the Invention

[0005] [The problem the invention aims to solve]

[0006] However, in the angle adjustment table that rotates the rotary table as described in Patent Documents 1-3 above, a large amount of starting torque is required to make the rotary table rotate. Therefore, if the rigidity of the connecting part constituting the positioning mechanism is insufficient, when the rotation direction of the rotary table is reversed, there will be lost motion between the arm of the rotary table and the bracket, which may lead to a decrease in positioning accuracy.

[0007] In view of this, the purpose of the present invention is to provide an angle adjustment worktable that can suppress invalid movement and position objects with high precision. [Solutions]

[0008] The present invention is formed by the following structure. An angle-adjustable worktable, comprising: a base; The rotary worktable, relative to the aforementioned base, is rotatable and supported by bearings. The positioning mechanism, relative to the aforementioned base, causes the aforementioned rotary table to rotate and position itself toward the target location. The aforementioned positioning mechanism has: The bracket, supported by the aforementioned base, can move linearly in the tangential direction of the aforementioned rotary worktable; The drive unit causes the aforementioned bracket to move linearly; The connecting part, relative to the aforementioned bracket, is supported so that it can move linearly in a direction orthogonal to the linear movement direction of the aforementioned bracket, connecting the aforementioned bracket and the aforementioned rotary table, and converting the linear movement of the aforementioned bracket into the rotational movement of the aforementioned rotary table; The spring-pushing component springs the aforementioned bracket and the aforementioned rotary worktable in opposite directions in a direction that intersects the axis of the aforementioned rotary worktable. [The effects of the invention]

[0009] The angle-adjusting worktable according to the present invention can suppress invalid movements and position objects with high precision. Simple Explanation of the Diagram

[0010] [Figure 1] is a top view of the angle adjustment workbench of this embodiment. [Figure 2] is the angle adjustment workbench of this embodiment as shown by arrow A in Figure 1. [Figure 3] is a partial cut-off view of the angle adjustment workbench of this embodiment, which is the view of arrow B in Figure 1. [Figure 4] is a front view of the connecting part that constitutes the positioning mechanism. [Figure 5] is a side view showing a portion of the connecting part that constitutes the positioning mechanism. Implementation

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 is a top view of the angle adjustment worktable 100 of this embodiment. Figure 2 is a view of the angle adjustment worktable 100 of this embodiment as indicated by arrow A in Figure 1. Figure 3 is a partial cut-off view of the angle adjustment worktable 100 of this embodiment, as indicated by arrow B in Figure 1.

[0012] As shown in Figures 1 to 3, the angle adjustment worktable 100 of this embodiment includes a base 11, a rotary worktable 13, and a positioning mechanism 15. The rotary worktable 13 is rotatably supported on the base 11, and the positioning mechanism 15 positions the rotary worktable 13 after it rotates on the base 11.

[0013] An angle-adjustable stage 100 is located above the rotary stage 13, on which an object, such as a semiconductor wafer, is placed. In this state, the rotary stage 13 is rotated by the positioning mechanism 15, thereby positioning the object placed on the rotary stage 13 in an inspection position or a processing position.

[0014] A cross roller bearing (bearing) 17 is provided between the base 11 and the rotary table 13. The rotary table 13 is supported on the base 11 by the cross roller bearing 17 so that it can rotate.

[0015] The base 11 has a protrusion 11a on one side that protrudes laterally, and a positioning mechanism 15 is provided on the protrusion 11a of the base 11. The rotary table 13 has an arm 23 that extends from the outer periphery toward the positioning mechanism 15.

[0016] The positioning mechanism 15 includes a bracket 31, a ball screw device (drive unit) 33, and a connecting part 35.

[0017] The bracket 31 is supported on the protrusion 11a of the base 11 by a linear guide 41. The linear guide 41 has: a guide rail 43, fixed to the protrusion 11a of the base 11 along a tangential direction orthogonal to the radial direction of the rotary table 13; and a slider 45, fixed to the bracket 31 and movable relative to the guide rail 43. The slider 45, with a plurality of rolling elements (not shown), is rotatably held in the portion opposite to the guide rail 43, and can move linearly relative to the guide rail 43 with low friction by the rolling of the rolling elements. The bracket 31 is then supported by the linear guide 41 and can move linearly in the tangential direction of the rotary table 13.

[0018] The ball screw assembly 33 consists of: a motor 51 supported on a protrusion 11a of a base 11; a screw 53 that rotates by the motor 51; and a nut 55 that is fixed to a bracket 31 and can be locked onto the screw 53.

[0019] In the ball screw assembly 33, the balls (not shown) are arranged to roll freely in a spiral ball groove formed on the outer circumferential surface of the screw 53; a spiral rolling space (not shown) is formed by the spiral ball groove formed on the inner circumferential surface of the nut 55. Then, in the ball screw assembly 33, once the screw 53 is rotated by the motor 51, the rotational motion of the screw 53 is transmitted to the plurality of balls, which, through the circulation of these balls along the spiral rolling space, cause the nut 55 to reciprocate along the screw 53. In this way, the bracket 31, supported by the linear guide 41 on the protrusion 11a of the base 11, moves linearly in the tangential direction toward the rotary table 13.

[0020] Figure 4 is a front view of the connecting portion 35 constituting the positioning mechanism 15. Figure 5 is a side view showing a portion of the connecting portion 35 constituting the positioning mechanism 15 cut off.

[0021] As shown in Figures 4 and 5, the connecting part 35 is provided between the bracket 31 and the arm 23 of the rotary table 13, and connects the bracket 31 and the arm 23. The connecting part 35 includes: a linear guide 71, a plate member 73, a rotating shaft 75, an annular housing 77, and a rolling bearing 79.

[0022] The plate member 73 is supported by the bracket 31 via the linear guide 71. The linear guide 71 includes: a guide rail 81, fixed to the bracket 31 in a direction orthogonal to the direction of movement of the bracket 31; and a slider 83, fixed to the plate member 73 and configured to move relative to the guide rail 81. The slider 83, with a plurality of rolling elements (not shown), is rotatably held in a portion opposite to the guide rail 81, and by the rolling of the rolling elements, can move linearly relative to the guide rail 81 with low friction. The plate member 73 is then supported such that it can move linearly relative to the bracket 31 in a direction orthogonal to the direction of movement of the bracket 31.

[0023] A rotating shaft 75 is erected on the plate member 73 and passes through the annular housing 77. The annular housing 77 is fixed to the arm 23 of the rotary table 13. A rolling bearing 79 is disposed between the rotating shaft 75 and the annular housing 77, allowing the rotating shaft 75 to rotate relative to the annular housing 77. Thus, the rotating shaft 75 is configured to rotate relative to the arm 23 of the rotary table 13.

[0024] The connecting part 35 has a leaf spring (spring-loaded member) 91. Since the leaf spring 91 is formed of a metal material such as carbon steel, stainless steel, nickel alloy or titanium alloy, it is plate-shaped. The lower end of the leaf spring 91 is connected to the end face 31a of the bracket 31, and the upper end is connected to the end face 23a of the arm 23. The middle part of the leaf spring 91 is narrower than the two ends.

[0025] In the angle adjustment table 100 constructed as described above, once the motor 51 of the ball screw device 33 drives the screw 53 to rotate, the nut 55, fixed to the bracket 31, reciprocates along the screw 53. This causes the bracket 31, supported by the linear guide 41 on the protrusion 11a of the base 11, to move linearly along the tangential direction of the rotary table 13. Once this is achieved, the linear movement of the bracket 31 is transmitted via the rotation shaft 75 of the connecting part 35 as a "rotational motion that causes the arm 23 of the rotary table 13 to rock." In this way, the rotary table 13, which carries the object, rotates, and the angle of the object on the rotary table 13 is adjusted and positioned at the target location.

[0026] Furthermore, when the arm 23 is rocked, the rotating shaft 75 moves along the direction of movement of the bracket 31 and slightly displaces in a direction orthogonal to the direction of movement of the bracket 31. This displacement is absorbed by the following action: the plate member 73 moves linearly in a direction orthogonal to the direction of movement of the bracket 31 via the linear guide 71. In this way, the angle adjustment worktable 100 can rotate the rotary worktable 13 without applying excessive force to the bracket 31, the rotating shaft 75, the arm 23, etc.

[0027] In a top-down view, with the end face 23a of the arm 23 of the rotary table 13 parallel to the end face 31a of the bracket 31, the rotary table 13 forms an origin position O (see Figure 1). Then, driven by the ball screw device 33, the rotary table 13 at the origin position O rotates clockwise (in the direction of arrow α in Figure 1) or counterclockwise (in the direction of arrow β in Figure 1) in a top-down view.

[0028] However, since the rotary table 13 carries large and heavy objects, a crossed roller bearing 17 is used as the bearing supporting the rotary table 13 relative to the base 11. Because this crossed roller bearing 17 has high sliding resistance, a large starting torque is required when the rotary table 13 is rotated. Therefore, if the rigidity of the connecting part 35 is low, there is a concern that a slight tilt may occur in the rotating shaft 75 of the connecting part 35, which will change when the rotation direction of the rotary table 13 is reversed.

[0029] In the angle-adjustable worktable 100 of this embodiment, a leaf spring 91 is provided, which is connected to the end face 31a of the bracket 31 that moves linearly by means of the ball screw device 33 and the end face 23a of the arm 23 of the rotating worktable 13. When the rotating worktable 13 rotates from its origin position O in a clockwise direction (α direction) or a counterclockwise direction (β direction), the leaf spring 91 elastically deforms with a slight twisting motion along with the rotation of the rotating worktable 13. Once this occurs, the elastic thrust generated by the reaction force of the elastic deformation of the leaf spring 91 acts on the arm 23 of the rotating worktable 13 and the bracket 31.

[0030] The spring force from the leaf spring 91 acts on the bracket 31 and the arm 23 of the rotary table 13, pushing them in opposite directions in the direction intersecting the axis of the rotary table 13. Furthermore, from a top-down view, the spring force from the leaf spring 91 acts in one direction throughout the rotation of the rotary table 13 from its origin position O towards the target position in a clockwise direction (α direction) and from the target position towards the origin position O in a counterclockwise direction (β direction). Conversely, from a top-down view, the spring force from the leaf spring 91 acts in the other direction throughout the rotation of the rotary table 13 from its origin position O towards the target position in a counterclockwise direction (β direction) and from the target position towards the origin position O in a clockwise direction (α direction). In other words, the spring force from the leaf spring 91 reverses its direction of action with the origin position O of the rotary table 13 as the dividing point.

[0031] Therefore, at positions other than the origin O, when the rotation direction of the rotary table 13 has reversed from clockwise (α direction) to counterclockwise (β direction), or when the rotation direction of the rotary table 13 has reversed from counterclockwise (β direction) to clockwise (α direction), although the sliding resistance of the crossed roller bearing 17 is reversed, the direction of the spring force exerted by the leaf spring 91 does not change. In other words, regardless of how the direction of the sliding resistance of the crossed roller bearing 17 is reversed, the spring force of the leaf spring 91 acts in the same direction. Therefore, with the reversal of the direction of the sliding resistance, the ineffective movement caused by the tilting change of the rotating shaft 75 of the connecting part 35 is suppressed by the spring force from the leaf spring 91.

[0032] As explained above, according to the angle adjustment table 100 of this embodiment, once the rotary table 13 rotates, the leaf spring 91 between the "linear motion bracket 31" and the "rotational motion arm 23 of the rotary table 13" is torsionally deformed. Thereby, the spring-like thrust generated by the reaction force of the elastically deformed leaf spring 91 acts as a preload between the bracket 31 and the rotary table 13. Therefore, the ineffective movement of the "connection part 35 connecting the bracket 31 and the rotary table 13" can be reduced, and the positioning accuracy of the rotary table 13 can be improved.

[0033] Furthermore, due to the simple structure of using the leaf spring 91 connected to the arm 23 and the bracket 31 as a spring-pushing component, the positioning accuracy of the rotary table 13 can be improved by reducing ineffective motion at a low cost.

[0034] In the above embodiment, although a spring-push member formed by leaf spring 91 is provided, the spring-push member that applies spring-push force to arm 23 and bracket 31 is not limited to leaf spring 91.

[0035] Furthermore, in the above embodiment, although the bracket 31 is moved by the ball screw device 33, the drive unit that moves the bracket 31 is not limited to the ball screw device 33. For example, it can also be a linear actuator or the like.

[0036] Therefore, the present invention is not limited to the above-described embodiments. Modifications and applications made by those skilled in the art based on "the combination of the various structures of the embodiments, or the description in the specification and the prior art" are also within the scope of the present invention and are included in the scope of protection of the present invention.

[0037] As explained above, the following matters are disclosed in the specification of this case. (1) An angle-adjustable worktable, comprising: Base; The rotary worktable, relative to the aforementioned base, is rotatable and supported by bearings. The positioning mechanism rotates the aforementioned rotary table relative to the base and positions it toward the target location. The aforementioned positioning mechanism has: The bracket, supported by the aforementioned base, can move linearly in the tangential direction of the aforementioned rotary worktable; The drive unit causes the aforementioned bracket to move linearly; The connecting part, relative to the aforementioned bracket, is supported so that it can move linearly in a direction orthogonal to the linear movement direction of the aforementioned bracket, connecting the aforementioned bracket and the aforementioned rotary table, and converting the linear movement of the aforementioned bracket into the rotational movement of the aforementioned rotary table; The spring-pushing component springs the aforementioned bracket and the aforementioned rotary worktable in opposite directions in a direction that intersects the axis of the aforementioned rotary worktable. The worktable is adjusted according to the angle of this structure, and has a spring-pushing member that pushes the bracket and the rotary worktable in opposite directions in a direction intersecting the axis of the rotary worktable. In this way, since the spring-pushing force of the spring-pushing member acts as a preload between the bracket and the rotary worktable, the ineffective movement of the "connection part connecting the bracket and the rotary worktable" can be reduced, and the positioning accuracy of the rotary worktable can be improved.

[0038] (2) The angle adjustment table as described in (1), wherein the aforementioned spring-pushing component is formed by a leaf spring. The aforementioned leaf spring has one end connected to an arm extending from the outer periphery of the aforementioned rotary worktable, and the other end connected to the aforementioned bracket. The worktable is adjusted according to the angle of this structure. Once the rotary worktable rotates, the leaf spring between the "linear motion bracket" and the "rotational motion arm of the rotary worktable" is torn and elastically deformed. The spring-like thrust generated by the reaction force of the elastically deformed leaf spring acts as a preload between the bracket and the rotary worktable. Therefore, the ineffective movement of the "connection between the bracket and the rotary worktable" can be reduced, improving the positioning accuracy of the rotary worktable. Furthermore, due to its simple structure that uses a leaf spring connecting the arm and the bracket as a spring-pushing component, it is possible to reduce ineffective motion and improve the positioning accuracy of the rotary table at a low cost.

[0039] 11: Base 13: Rotary worktable 15: Positioning mechanism 17: Crossed roller bearing (bearing) 23: Arms 31: Bracket 33: Ball screw assembly (drive unit) 35: Connecting parts 91: Leaf spring (spring-loaded component) 100: Angle Adjustment Table

Claims

1. An angle-adjustable worktable, comprising: a base; a rotary worktable, rotatable relative to the base by bearings; and a positioning mechanism that rotates the rotary worktable relative to the base and positions it toward a target position, wherein the positioning mechanism comprises: a bracket supported by the base and linearly movable in the tangential direction of the rotary worktable; a drive unit that causes the bracket to move linearly; a connecting unit that is supported relative to the bracket and linearly movable in a direction orthogonal to the linear movement direction of the bracket, connecting the bracket and the rotary worktable, and converting the linear movement of the bracket into the rotational movement of the rotary worktable; and a spring-pushing member that springs the bracket and the rotary worktable in opposite directions in a direction intersecting the axis of the rotary worktable.

2. The angle-adjusting worktable as described in claim 1, wherein the aforementioned spring-pushing member is formed by a leaf spring, one end of which is connected to an arm extending from the outer periphery of the aforementioned rotary worktable, and the other end is connected to the aforementioned bracket.

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