Compliance unit

Abstract

A compliance unit (10) comprises: a base member (12); a table unit (14) that is arranged so as to be movable with respect to the base member along an XY plane in which the Y-direction is the vertical direction and the X-direction is a direction orthogonal to the Y direction; a compliance mechanism (16) that is interposed between the base member and the table unit so as to be movable in the X-direction and the Y-direction with respect to the base member and the table unit; and a pressing part (156) that is provided to the base member and presses the table unit upward.

Description

Compliance Unit

[0001] The present disclosure relates to a compliance unit.

[0002] For example, Japanese Patent Application Laid-Open No. 2002-172582 discloses a compliance unit including a base member, a table unit, and a compliance mechanism. The table unit is disposed so as to be movable along the XY plane relative to the base member. The compliance mechanism is interposed between the base member and the table unit so as to be movable in the X and Y directions relative to the base member and the table unit. The compliance unit can lock the table unit in a state where it has been returned to its original position relative to the base member.

[0003] It would be desirable to provide a better compliant unit.

[0004] The present invention aims to solve the above-mentioned problems.

[0005] An aspect of the present disclosure is a compliance unit comprising: a base member; a table unit arranged to be movable relative to the base member along an XY plane, with the Y direction being the up-down direction and the X direction being the direction perpendicular to the Y direction; a compliance mechanism interposed between the base member and the table unit so as to be movable in the X direction and the Y direction relative to the base member and the table unit; and a pressing portion provided on the base member that presses the table unit upward.

[0006] According to the present invention, a better compliance unit can be provided.

[0007] The above objects, features and advantages will be easily understood from the following description of the embodiments, which will be described with reference to the accompanying drawings.

[0008] FIG. 1 is a perspective view of a compliance unit according to the first embodiment. FIG. 2 is an exploded perspective view of the compliance unit according to the first embodiment. FIG. 3 is an exploded perspective view of the compliance unit according to the first embodiment. FIG. 4 is a longitudinal cross-sectional view of the compliance unit according to the first embodiment. FIG. 5 is a partially omitted cross-sectional view taken along line V-V in FIG. 4. FIG. 6 is a longitudinal cross-sectional view taken along line VI-VI in FIG. 4. FIG. 7 is a partially omitted cross-sectional view taken along line VII-VII in FIG. 6. FIG. 8 is an explanatory diagram of the operation of the compliance unit according to the first embodiment. FIG. 9 is an explanatory diagram of the operation of the compliance unit. FIG. 10 is an explanatory cross-sectional view of a compliance unit according to the second embodiment. FIG. 11 is an explanatory cross-sectional view of a compliance unit according to the third embodiment. FIG. 12 is an explanatory cross-sectional view of the compliance unit according to the third embodiment, with partial omission. FIG. 13 is an explanatory cross-sectional view of the compliance unit according to the third embodiment, with partial omission. FIG. 14 is an explanatory cross-sectional view of the compliance unit according to the third embodiment, with partial omission. FIG. 15 is an explanatory cross-sectional view of a compliance unit according to the fourth embodiment.

[0009] Incidentally, the above-described conventional compliance unit may be arranged so that the Y direction corresponds to the up-down direction. In this case, when the table unit is not locked to the base member (when the table unit is unlocked), the table unit may move downward (in the direction of gravity) relative to the base member due to its own weight. As a result, when no external force is acting on the table unit, the table unit may shift downward from its origin position relative to the base member due to its own weight. An object of the present disclosure is to suppress movement of the table unit relative to the base member due to gravity.

[0010] First Embodiment A compliance unit 10 according to a first embodiment of the present invention will be described with reference to the drawings. The compliance unit 10 is a device for correcting misalignment (misalignment) during the assembly of a workpiece, for example. Specifically, as shown in FIG. 1 , in the compliance unit 10, for example, a robot hand (not shown) is connected to a base member 12, and a chuck member (not shown) for gripping the workpiece is attached to a table unit 14.

[0011] In this embodiment, an example will be described in which the compliance unit 10 is disposed so that the Y1 direction is downward (the direction of gravity). The X direction is a direction perpendicular to the Y direction. The Z direction is a direction perpendicular to the X and Y directions.

[0012] When the table unit 14 is in an unlocked state, the table unit 14 is movable along the XY plane relative to the base member 12. Furthermore, when the table main body 50 of the table unit 14 is not locked to the table support portion 48 (when the table main body 50 is in an unlocked state), it is tiltable about a first axis Ax1 along the X direction (horizontal direction) relative to the table support portion 48. Furthermore, when the table main body 50 is in an unlocked state, the table main body 50 is tiltable about a second axis Ax2 along the Y direction (up and down direction) relative to the table support portion 48.

[0013] With this type of compliance unit 10, even if misalignment occurs during workpiece assembly, for example, by inserting the workpiece into a specified hole, the table unit 14 is movable in the X and Y directions and the table main body 50 is tiltable relative to the table support portion 48, making it possible to easily correct the misalignment. Note that the use of the compliance unit 10 is not limited to inserting a workpiece into a hole. The compliance unit 10 can also be used in a state where it is positioned so that the Z direction is the direction of gravity. The configuration of the compliance unit 10 will be described in detail below.

[0014] As shown in Figures 1 to 4, the compliance unit 10 includes a base member 12, a table unit 14, a pair of compliance mechanisms 16, a first origin return mechanism 18, a second origin return mechanism 20, a pressing mechanism 22, and a tilt suppression unit 24.

[0015] As shown in FIGS. 2 to 4 , the base member 12 has a first base portion 26 and a second base portion 28. The first base portion 26 is a plate-like member extending in the X and Y directions. When viewed from the Z direction, the first base portion 26 is formed in a quadrangular shape with chamfered corners. At each corner of the first base portion 26, an attachment hole 30 is formed for attaching the first base portion 26 to a robot hand (not shown). A first through-hole 32 is formed in the center of the first base portion 26 (see FIGS. 3 and 4 ). The shape, size, etc. of the first base portion 26 can be set as appropriate.

[0016] 2 and 4 , the second base portion 28 is attached to a surface of the first base portion 26 facing the Z1 direction. A second through-hole 34 is formed in the center of the second base portion 28. That is, the second base portion 28 is formed in an annular (e.g., circular) shape. The second through-hole 34 communicates with the first through-hole 32.

[0017] As shown in FIG. 4 , the second base portion 28 includes a first base plate 36, an intermediate member 38, a second base plate 40, and a presser member 42. The first base plate 36, the intermediate member 38, the second base plate 40, and the presser member 42 are stacked in this order in the Z1 direction and fixed to the first base portion 26 by a plurality of fastening members 44 (see FIG. 2 ). The fastening members 44 are, for example, screw members. Each of the first base plate 36, the intermediate member 38, the second base plate 40, and the presser member 42 is formed in an annular shape.

[0018] As shown in FIG. 4 , the first base plate 36 is disposed on the surface of the first base portion 26 facing the Z1 direction. The intermediate member 38 is disposed on the surface of the first base plate 36 facing the Z1 direction. The thickness dimension of the intermediate member 38 in the Z direction is larger than the thickness dimension of the first base plate 36 in the Z direction. The inner diameter of the intermediate member 38 is larger than the inner diameter of the first base plate 36. The second base plate 40 is disposed on the surface of the intermediate member 38 facing the Z1 direction. The inner diameter of the second base plate 40 is the same as the inner diameter of the first base plate 36. In other words, a space 46 is formed between the first base plate 36 and the second base plate 40.

[0019] 2 and 4, a surface of the second base plate 40 facing the Z1 direction is provided with a plurality of receiving members 126 that constitute the first origin return mechanism 18. The configuration of the receiving members 126 will be described later. The pressing member 42 fixes the plurality of receiving members 126 to the second base plate 40.

[0020] 1 to 4, the table unit 14 is disposed so as to be movable along the XY plane relative to the base member 12. The table unit 14 has a table support portion 48 and a table main body 50.

[0021] 2 to 4, the table support portion 48 has a first support member 52, a support plate 54, and a second support member 56. The first support member 52 is formed in a block shape. The first support member 52 includes a first support body 58, a first shaft portion 60, and a pair of connecting protrusions 62.

[0022] The first support body 58 is attached with the first origin return mechanism 18, the second origin return mechanism 20, and the tilt suppression unit 24. As shown in FIGS. 3 and 4 , the first shaft 60 protrudes from the first support body 58 toward the first base 26 (Z2 direction). The first shaft 60 is inserted into the second through-hole 34 of the second base 28. The first shaft 60 is located at the center of the first support body 58 in the X direction (see FIG. 3 ). A central protrusion 64 protruding in the Z2 direction is provided at the center of the end face of the first shaft 60 in the protruding direction (Z2 direction).

[0023] 2 and 4 , the pair of connecting protrusions 62 protrude in the Z1 direction from the outer periphery of the surface of the first support body 58 facing the Z1 direction. The pair of connecting protrusions 62 are arranged side by side with a gap in the X direction. The pair of connecting protrusions 62 support the table body 50.

[0024] 4, the support plate 54 is formed in an annular shape. The support plate 54 is disposed in the second through-hole 34 of the second base portion 28. In other words, the support plate 54 is disposed in the space 46 between the first base plate 36 and the second base plate 40. The central protrusion 64 is inserted into a hole 66 on the inner side of the support plate 54.

[0025] The second support member 56 has a second support body 68, a second shaft portion 70, and a bearing 72. The second support body 68 covers the inner peripheral end of the support plate 54 from the Z2 direction. The second support body 68 and the support plate 54 are fixed to the first shaft portion 60 by a plurality of fastening members 74. The fastening members 74 are, for example, screw members. The support plate 54 is sandwiched between the first shaft portion 60 and the second support body 68.

[0026] The second shaft portion 70 protrudes in the Z2 direction from the second support body 68. The second shaft portion 70 is inserted into the first through-hole 32 of the first base portion 26. The second shaft portion 70 is located in the center of the second support body 68.

[0027] The bearing 72 is, for example, a rolling bearing. The bearing 72 may be a plain bearing. The bearing 72 has an inner ring 76, a plurality of rolling elements 78, and an outer ring 80. The inner ring 76 is fixed to the outer peripheral surface of the second shaft portion 70. The plurality of rolling elements 78 are located between the inner ring 76 and the outer ring 80 and are arranged in the circumferential direction of the second shaft portion 70. The outer ring 80 is a hollow roller portion 82 in which the second shaft portion 70 is disposed. The roller portion 82 is rotatable relative to the second shaft portion 70.

[0028] The table support portion 48 has a shaft portion 84 formed by a first shaft portion 60 and a second support member 56. The shaft portion 84 is located in the center of the table unit 14 in the X direction. The shaft portion 84 is inserted into a through hole 86 in the base member 12. The through hole 86 is formed by the first through hole 32 and the second through hole 34. An appropriate gap is formed between the outer peripheral surface of the shaft portion 84 and the inner peripheral surface of the base member 12 so that the table unit 14 can move in the X direction and the Y direction relative to the base member 12.

[0029] A pair of compliance mechanisms 16 are provided on the support plate 54 of the table support portion 48. In other words, the pair of compliance mechanisms 16 are interposed between the table unit 14 and the base member 12 so as to be movable in the X and Y directions relative to the base member 12 and the table unit 14. One compliance mechanism 16 is interposed between the first base plate 36 and the support plate 54. The other compliance mechanism 16 is interposed between the second base plate 40 and the support plate 54. Hereinafter, one compliance mechanism 16 may be referred to as the "first compliance mechanism 16a," and the other compliance mechanism 16 may be referred to as the "second compliance mechanism 16b."

[0030] The first compliance mechanism 16a has a plurality of balls 88 and a plate-shaped retainer 90. The balls 88 are, for example, steel balls. The balls 88 come into contact with a flat surface of the first base plate 36 facing in the Z1 direction and a flat surface of the support plate 54 facing in the Z2 direction.

[0031] The retainer 90 supports the plurality of balls 88 in a rollable manner. The retainer 90 is formed in an annular shape. The outer diameter of the retainer 90 is smaller than the inner diameter of the intermediate member 38. The inner diameter of the retainer 90 is larger than the inner diameter of the first base plate 36.

[0032] Movement of the first compliance mechanism 16a along the XY plane is limited by a first stopper 92. The first stopper 92 is attached to a plane of the support plate 54 facing the Z2 direction by a fastening member (not shown). The first stopper 92 is formed in an annular shape. The first stopper 92 is located inside the retainer 90 of the first compliance mechanism 16a. The outer diameter of the first stopper 92 is smaller than the inner diameter of the retainer 90 of the first compliance mechanism 16a.

[0033] The second compliance mechanism 16b has the same configuration as the first compliance mechanism 16a. Therefore, a detailed description of the configuration of the second compliance mechanism 16b will be omitted. Note that the multiple balls 88 of the second compliance mechanism 16b come into contact with a flat surface of the second base plate 40 facing in the Z2 direction and a flat surface of the support plate 54 facing in the Z1 direction.

[0034] Movement of the second compliance mechanism 16b along the XY plane is limited by a second stopper 94. The second stopper 94 is attached to a plane of the support plate 54 facing the Z1 direction by a fastening member (not shown). The second stopper 94 is formed in an annular shape. The second stopper 94 is located inside the retainer 90 of the second compliance mechanism 16b. The outer diameter of the second stopper 94 is smaller than the inner diameter of the retainer 90 of the second compliance mechanism 16b.

[0035] The shafts 84 of the table unit 14 extend toward the base member 12 through the holes 17 of the pair of compliance mechanisms 16 .

[0036] As shown in Figures 2 to 4, the table body 50 has a first table body portion 96 and a second table body portion 98. The first table body portion 96 is formed in an annular shape. The first table body portion 96 extends in the Y direction. As shown in Figures 1 and 5, the first table body portion 96 is disposed between a pair of connecting protrusions 62 of the table support portion 48. In other words, the pair of connecting protrusions 62 are located on both sides of the first table body portion 96 in the X direction.

[0037] 2, 3, and 5, the first table main body 96 is supported by a pair of first pins 100 so as to be tiltable relative to the pair of connecting protrusions 62. The first pins 100 are inserted so as to straddle a first connecting hole 102 of the connecting protrusions 62 and a first insertion hole 104 of the first table main body 96.

[0038] The first connection hole 102 penetrates the connection protrusion 62 in the X direction. The first insertion hole 104 is formed in a portion of the first table main body 96 adjacent to the first connection hole 102. The first pin 100 is fixed to the connection protrusion 62 by a first fixing member 106 (see FIG. 5 ). The first pin 100 is not fixed to the first table main body 96. The first table main body 96 tilts about a first axis Ax1 of the first pin 100. The first axis Ax1 extends along the X direction.

[0039] As shown in Figures 2 to 4, the second table main body 98 includes a connecting portion 108 and a table plate 110. The connecting portion 108 is inserted into the inside of the first table main body 96 (see Figures 1, 4, and 5). The connecting portion 108 is supported by a pair of second pins 112 so as to be tiltable relative to the first table main body 96. The second pins 112 are inserted so as to straddle a second insertion hole 114 of the first table main body 96 and a second connection hole 116 of the connecting portion 108.

[0040] The pair of second insertion holes 114 are provided in portions of the first table main body 96 that face each other in the Y direction. That is, the second insertion holes 114 penetrate the first table main body 96 in the Y direction. The second connection hole 116 is formed in a portion of the connecting portion 108 adjacent to the second insertion hole 114. The second pin 112 is fixed to the connecting portion 108 by a second fixing member 117 (see FIG. 4 ). The second pin 112 is not fixed to the first table main body 96. The second table main body 98 tilts about a second axis Ax2 of the second pin 112. The second axis Ax2 extends along the Y direction. The second axis Ax2 extends in a direction perpendicular to the first axis Ax1.

[0041] The table plate 110 is provided at the end of the connecting portion 108 in the Z1 direction. The table plate 110 protrudes outward beyond the connecting portion 108. The table plate 110 is formed with a plurality of mounting holes 118 for mounting chuck members (not shown).

[0042] The first origin return mechanism 18 can lock the table unit 14 to the base member 12 in a state where the table unit 14 has been returned to the origin position. The first origin return mechanism 18 has a plurality of origin return units 120. In this embodiment, the first origin return mechanism 18 has three origin return units 120. The three origin return units 120 are arranged at equal intervals (e.g., 120° intervals) around the circumferential direction of the shaft portion 84 of the table support portion 48.

[0043] The origin return unit 120 includes a first cylinder unit 122, a first holding unit 124, and a receiving member 126. As shown in FIG. 4 , the first cylinder unit 122 is, for example, a fluid pressure cylinder that operates using fluid pressure. Specifically, the first cylinder unit 122 is a pneumatic cylinder that operates using air pressure. The configuration of the first cylinder unit 122 can be set as appropriate. The same applies to the second cylinder unit 136, the third cylinder unit 152, and the fourth cylinder unit 178, which will be described later.

[0044] The first cylinder portion 122 has a first cylinder bore 128, a first piston portion 130, a first cover member 132, and a first biasing member 134. The first cylinder bore 128 is formed in the outer periphery of the first support body 58 so as to extend in the Z direction. The first cylinder bore 128 opens on a surface of the first support body 58 facing the Z2 direction.

[0045] The first piston portion 130 slides in the Z direction on the inner surface of the first cylinder bore 128. The first cover member 132 is attached to the first support body 58 so as to close the opening of the first cylinder bore 128 in the Z2 direction. The first biasing member 134 is interposed between the first piston portion 130 and the first cover member 132. The first biasing member 134 biases the first piston portion 130 in the Z1 direction. The first biasing member 134 is, for example, a compression coil spring. The first biasing member 134 may also be a rubber member or the like.

[0046] The first holding portion 124 protrudes in the Z2 direction from the first piston portion 130. The first holding portion 124 penetrates the first cover member 132. A first holding surface 124a is provided at the end of the first holding portion 124 in the protruding direction (Z2 direction). The first holding surface 124a is a conical convex surface.

[0047] The receiving member 126 is attached to the second base portion 28 so as to face the first holding portion 124. The receiving member 126 has a first receiving surface 126a that is concave and can come into contact with the end portion in the Z2 direction of the first holding portion 124. The first receiving surface 126a is a conical concave surface.

[0048] In this first origin return mechanism 18, when the table unit 14 is to be unlocked, the first holding portion 124 is positioned at the unlocked position (the position of the first holding portion 124 shown in FIG. 4 ). In this state, the first holding surface 124 a is not pressed toward the first receiving surface 126 a by the first piston portion 130, and therefore the table unit 14 becomes movable relative to the base member 12 along the XY plane.

[0049] When the table unit 14 is locked by the first origin return mechanism 18, the first piston portion 130 is moved in the Z2 direction by supplying air to the first cylinder portion 122. This causes the first holding surface 124a to press the first receiving surface 126a, so that the table unit 14 is returned to the origin position relative to the base member 12 and locked. In other words, when the table unit 14 is locked, it cannot move along the XY plane relative to the base member 12.

[0050] In this embodiment, the first piston portion 130 is biased in the direction opposite to the first receiving surface 126a by the first biasing member 134. This makes it possible to prevent an excessive pressing force (origin return force) from being applied to the receiving member 126 from the first holding portion 124 when a pressure equal to or greater than the minimum operating pressure of a pressure reducing valve (not shown) is applied to the first cylinder portion 122.

[0051] 2 and 4, the second origin return mechanism 20 can lock the table unit 14 to the table support portion 48 while the table unit 14 is returned to the origin position. As shown in FIG. 4, the second origin return mechanism 20 includes a second cylinder portion 136 and a second holding portion 138. The second cylinder portion 136 has a second cylinder hole 140, a second piston portion 142, a second cover member 144, and a second biasing member 146. The second cylinder hole 140 is formed in the center of the first support body 58 so as to extend in the Z direction. The second cylinder hole 140 opens on a surface of the first support body 58 facing the Z1 direction.

[0052] The second piston portion 142 slides in the Z direction on the inner surface of the second cylinder bore 140. The second cover member 144 is attached to the first support body 58 so as to close the opening of the second cylinder bore 140 in the Z1 direction. The second biasing member 146 is interposed between the second piston portion 142 and the second cover member 144. The second biasing member 146 biases the second piston portion 142 in the Z2 direction. The second biasing member 146 is, for example, a compression coil spring. The second biasing member 146 may also be a rubber member or the like.

[0053] The second holding portion 138 includes a rod portion 148 and a holding body 150. The rod portion 148 protrudes in the Z1 direction from the second piston portion 142. The rod portion 148 passes through the second cover member 144. The holding body 150 is attached to the protruding end of the rod portion 148. The holding body 150 is formed in a flat plate shape. The holding body 150 has a flat second holding surface 150a facing in the Z1 direction. The second holding surface 150a can press the second receiving surface 110a of the table plate 110 facing in the Z2 direction in the Z1 direction.

[0054] In this second origin return mechanism 20, when the table body 50 is to be put into an unlocked state, the second holding portion 138 is positioned at the unlocked position (the position of the second holding portion 138 shown in FIG. 4 ). In this state, the second holding surface 150a is not pressed toward the second receiving surface 110a by the second piston portion 142, and therefore the table body 50 can tilt about the first axis Ax1 and can also tilt about the second axis Ax2.

[0055] When the table body 50 is locked by the second origin return mechanism 20, air is supplied to the second cylinder 136 to move the second piston 142 in the Z1 direction. This causes the second holding surface 150a to press the second receiving surface 110a, so that the table body 50 is returned to the origin position relative to the table support 48 and locked. In other words, when the table body 50 is locked, it cannot tilt about the first axis Ax1 or the second axis Ax2 relative to the table support 48.

[0056] In this embodiment, the second piston portion 142 is biased in the direction opposite to the second receiving surface 110a by the second biasing member 146. This makes it possible to prevent an excessive pressing force (origin return force) from being applied to the table body 50 from the second holding portion 138 when a pressure equal to or greater than the minimum operating pressure of a pressure reducing valve (not shown) is applied to the second cylinder portion 136.

[0057] As shown in Figure 6, the pressing mechanism 22 is provided on the base member 12 and presses the table unit 14 in the Y2 direction (upward). The pressing mechanism 22 has a pair of third cylinder portions 152, a connecting member 154, and a pressing portion 156. The pair of third cylinder portions 152 is provided on the first base portion 26. The pair of third cylinder portions 152 are aligned in the X direction. The third cylinder portions 152 have a third cylinder hole 158, a third piston portion 160, a third cover member 162, a third biasing member 166, and a rod portion 164.

[0058] The third cylinder bore 158 is formed in the first base portion 26 so as to extend in the Y direction. The third cylinder bore 158 opens to the side surface of the first base portion 26 facing the Y1 direction. The third piston portion 160 slides in the Y direction on the inner surface of the third cylinder bore 158. The third cover member 162 is attached to the first base portion 26 so as to close the Y1 end of the third cylinder bore 158. The third biasing member 166 is provided in the third cylinder bore 158 so as to bias the third piston portion 160 in the Y1 direction. The third biasing member 166 is, for example, a compression coil spring. The third biasing member 166 may also be a rubber member or the like. The rod portion 164 protrudes in the Y1 direction from the third piston portion 160. The rod portion 164 penetrates the third cover member 162.

[0059] The connecting member 154 connects the Y1-direction ends of the pair of rod portions 164. The pressing portion 156 extends in the Y direction. The Y1-direction ends of the pressing portion 156 are fastened to the connecting member 154 by a plurality of fastening members 167. The fastening members 167 are, for example, screw members.

[0060] As shown in FIG. 7 , the pressing portion 156 is inserted into a guide groove 172 formed in the first base portion 26. The guide groove 172 communicates with the first through-hole 32 (see FIG. 6 ). The guide groove 172 includes a first groove portion 174 and a second groove portion 176. The second groove portion 176 communicates with the first groove portion 174 and opens to the Z2-direction surface of the first base portion 26. The dimension of the first groove portion 174 in the X direction is greater than the dimension of the second groove portion 176 in the X direction.

[0061] The pressing portion 156 includes a first portion 168 disposed in the first groove portion 174 and a second portion 170 disposed in the second groove portion 176. The dimension of the first portion 168 in the X direction is greater than the dimension of the second groove portion 176 in the X direction. This prevents the pressing portion 156 from slipping out of the guide groove 172 in the Z2 direction. As shown in FIG. 6 , a flat pressing surface 156a is provided on the end face of the pressing portion 156 in the Y2 direction. The pressing surface 156a contacts the outer peripheral surface 82a of the roller portion 82.

[0062] 4, the tilt suppression portion 24 suppresses tilting of the table main body 50 relative to the table unit 14 due to gravity. The tilt suppression portion 24 has a fourth cylinder portion (tilt suppression cylinder portion) 178 and a contact portion 180. The fourth cylinder portion 178 includes a fourth cylinder hole 182, a fourth piston portion 184, a fourth cover member 186, and a fourth biasing member (tilt suppression biasing member) 188.

[0063] The fourth cylinder hole 182 is formed at the Y1-direction end of the first support body 58 so as to extend in the Z direction. The fourth cylinder hole 182 opens to a surface of the first support body 58 facing the Z1 direction.

[0064] The fourth piston portion 184 slides in the Z direction on the inner surface of the fourth cylinder bore 182. The fourth cover member 186 is attached to the first support main body 58 so as to close the opening of the fourth cylinder bore 182 in the Z1 direction. The fourth biasing member 188 is interposed between the fourth piston portion 184 and the fourth cover member 186. The fourth biasing member 188 biases the fourth piston portion 184 in the Z2 direction. In other words, the fourth biasing member 188 biases the contact portion 180 in a direction away from the table main body 50. The fourth biasing member 188 is, for example, a compression coil spring. The fourth biasing member 188 may be a rubber member or the like.

[0065] The contact portion 180 protrudes in the Z1 direction from the fourth piston portion 184. The contact portion 180 penetrates the fourth cover member 186. A contact surface 180a is provided at the end of the contact portion 180 in the protruding direction. The contact surface 180a is a curved surface that protrudes in an arc shape in the Z1 direction. The contact surface 180a faces the end of the first table main body 96 in the Y1 direction.

[0066] Incidentally, when the compliance unit 10 is arranged so that the Y1 direction is the direction of gravity and the table unit 14 is in an unlocked state, the table unit 14 attempts to move downward relative to the base member 12 due to its own weight. In this embodiment, the pressing portion 156 presses the roller portion 82 of the table unit 14 in the Y2 direction (upward), so that the table unit 14 can be prevented from shifting downward from the origin position relative to the base member 12.

[0067] Specifically, in this embodiment, the pair of third piston portions 160 are pressed upward by supplying air to each of the pair of third piston portions 160. As a result, the pressing portion 156 is pushed upward by the third piston portions 160, and therefore presses the roller portion 82 of the table unit 14 upward.

[0068] When the third piston portion 160 moves upward in the third cylinder bore 158, the third biasing member 166 is compressed, and a resilient force from the third biasing member 166 acts on the third piston portion 160. This resilient force increases as the amount of upward movement of the third piston portion 160 increases. This makes it possible to position the third piston portion 160 at the intermediate position of the stroke when the table unit 14 is positioned at the origin (a state in which the weight of the table unit 14 and the pressing force of the pressing portion 156 are balanced).

[0069] Furthermore, when the compliance unit 10 is positioned so that the Y1 direction is the direction of gravity and the table body 50 is unlocked, as shown in Figure 8, the table unit 14 becomes more likely to tilt relative to the table support part 48 due to its own weight so that the upper end of the table body 50 protrudes in the Z1 direction more than the lower end.

[0070] 9 , air is supplied to the fourth piston portion 184 of the tilt suppression portion 24 to move the fourth piston portion 184 in the Z1 direction. This causes the contact surface 180a to press the lower end portion of the table main body 50 in the Z1 direction, thereby suppressing tilting of the table main body 50 due to its own weight relative to the table support portion 48. In other words, even if the compliance unit 10 is disposed so that the Y1 direction is the direction of gravity, it is possible to suppress deviation (tilting) of the table main body 50 from the original posture relative to the table support portion 48 due to its own weight.

[0071] When the fourth piston portion 184 moves in the Z1 direction, the fourth biasing member 188 is compressed, and a resilient force from the fourth biasing member 188 acts on the fourth piston portion 184. This resilient force increases as the amount of movement of the fourth piston portion 184 in the Z1 direction increases. This makes it possible to position the fourth piston portion 184 at an intermediate position of the stroke when the table main body 50 is positioned in the origin posture (a state in which the weight of the table main body 50 and the pressing force of the contact portion 180 are balanced).

[0072] Note that the contact portion 180 and the fourth piston portion 184 are movable in the Z2 direction when the table body 50 is supported by the contact portion 180. Therefore, for example, when an external force acts on the table body 50 when the table body 50 is supported by the table support portion 48, the table body 50 can tilt about the first axis Ax1 so that the upper end of the table body 50 protrudes in the Z1 direction beyond the lower end.

[0073] According to this embodiment, the compliance unit 10 includes the pressing portion 156 that is provided on the base member 12 and presses the table unit 14 upward, so that the table unit 14 can be prevented from moving downward relative to the base member 12 due to its own weight. Therefore, a better compliance unit 10 can be provided.

[0074] Second Embodiment Next, a compliance unit 10A according to a second embodiment will be described. In the compliance unit 10A according to this embodiment, the same components as those in the compliance unit 10 of the first embodiment described above are given the same reference numerals, and detailed description thereof will be omitted. In the compliance unit 10A, the same configuration as that of the compliance unit 10 provides the same effects.

[0075] Fig. 10 is an explanatory cross-sectional view of a compliance unit 10A according to the second embodiment. As shown in Fig. 10, the compliance unit 10A includes a control device 200 that controls the operation of the third cylinder portion 152. In the compliance unit 10A, each third cylinder portion 152 is provided with an exhaust port 201 that connects a portion 203 of the third cylinder bore 158 that is further in the Y2 direction than the third piston portion 160 with the outside. The exhaust port 201 can exhaust air from the portion 203 of the third cylinder bore 158 to the outside. The control device 200 includes a valve 202, a control unit (controller) 204, a position sensor 206, and a pressure sensor 208.

[0076] The valves 202 are provided in supply / discharge flow paths 212 that communicate with the pressurizing chambers 210 of the respective third piston portions 160. The pressurizing chambers 210 are provided between the third piston portions 160 and the third cover members 162. In other words, the pressurizing chambers 210 are located below the third piston portions 160. The valves 202 can continuously control the pressure of the fluid in the pressurizing chambers 210. Note that, for example, air is used as the fluid, but oil may also be used.

[0077] The valve 202 is, for example, a servo valve. The valve 202 can control the flow rate of fluid supplied to the pressurizing chamber 210. The valve 202 includes an output port 214, a supply port 216, and an exhaust port 218. The output port 214 is connected to the supply / exhaust flow path 212. The supply port 216 is supplied with fluid (compressed fluid) from a supply source (not shown). The exhaust port 218 is connected to the outside air. The valve 202 can supply fluid to the pressurizing chamber 210 by connecting the supply port 216 with the output port 214. The valve 202 can discharge the fluid from the pressurizing chamber 210 to the outside by connecting the output port 214 with the exhaust port 218. The valve 202 is not limited to a servo valve and may be an electro-pneumatic regulator.

[0078] The position sensor 206 detects the position of the pressing portion 156. The position sensor 206 is provided on the first base portion 26. A detection signal from the position sensor 206 is output to the control portion 204. The pressure sensor 208 detects the pressure in the pressurizing chamber 210. The pressure sensor 208 is provided in, for example, the supply / discharge flow path 212. A detection signal from the pressure sensor 208 is output to the control portion 204.

[0079] The control unit 204 includes a calculation unit 220 and a storage unit 222. The calculation unit 220 is configured by a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). In other words, the calculation unit 220 is configured by processing circuitry.

[0080] The calculation unit 220 includes a position acquisition unit 224, a pressure acquisition unit 226, and a valve control unit 228. The position acquisition unit 224, the pressure acquisition unit 226, and the valve control unit 228 can be realized by the calculation unit 220 executing a program stored in the storage unit 222. Note that at least a portion of the position acquisition unit 224, the pressure acquisition unit 226, and the valve control unit 228 may be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). Furthermore, at least a portion of the position acquisition unit 224, the pressure acquisition unit 226, and the valve control unit 228 may be configured by an electronic circuit including discrete devices.

[0081] The storage unit 222 is composed of a volatile memory (not shown) and a non-volatile memory (not shown). Examples of the volatile memory include RAM (Random Access Memory). The volatile memory is used as a working memory for the processor and temporarily stores data necessary for processing or calculations. Examples of the non-volatile memory include ROM (Read Only Memory) and flash memory. The non-volatile memory is used as a storage memory and stores programs, tables, maps, etc. At least a portion of the storage unit 222 may be provided in the processor, integrated circuit, etc. described above.

[0082] The position acquisition unit 224 acquires the position of the table unit 14 based on the signal detected by the position sensor 206. The pressure acquisition unit 226 acquires the pressure in the pressurizing chamber 210 based on the signal detected by the pressure sensor 208.

[0083] The valve control unit 228 controls the operation of the valve 202. The valve control unit 228 feedback-controls the operation of the valve 202 so that the table unit 14 is located at a predetermined origin position. The valve control unit 228 feedback-controls the operation of the valve 202 based on the position acquired by the position acquisition unit 224. The valve control unit 228 feedback-controls the operation of the valve 202 based on the pressure acquired by the pressure acquisition unit 226.

[0084] Specifically, the valve control unit 228 includes a position control unit 230 and a pressure control unit 232. The position control unit 230 calculates the amount of deviation of the table unit 14 from the origin position based on a predetermined origin position signal and a position signal corresponding to the position of the table unit 14 acquired by the position acquisition unit 224. The origin position signal is stored in the storage unit 222. The position control unit 230 calculates the pressure (set pressure) of the pressurizing chamber 210 required for positioning the table unit 14 at the origin position based on the amount of deviation. The position control unit 230 outputs a set pressure signal corresponding to the set pressure.

[0085] The pressure control unit 232 calculates and outputs a control signal for the valve 202 based on the set pressure signal and a pressure signal corresponding to the pressure in the pressurized chamber 210 acquired by the pressure acquisition unit 226. The control signal output from the pressure control unit 232 is supplied to the valve 202 via a power amplifier (not shown). The valve 202 changes its opening based on the control signal supplied from the power amplifier.

[0086] When the table unit 14 is positioned below the origin position, the valve control unit 228 controls the operation of the valve 202 so that the opening of the valve 202 increases. This increases the pressure in the pressurizing chamber 210, causing the third piston portion 160 to move upward relative to the base member 12. As a result, the table unit 14 moves upward relative to the base member 12, and the position of the table unit 14 approaches the origin position.

[0087] On the other hand, when the table unit 14 is positioned above the origin position, the valve control unit 228 controls the operation of the valve 202 so that the opening of the valve 202 becomes smaller. This reduces the pressure in the pressurizing chamber 210, causing the third piston portion 160 to move downward relative to the base member 12. As a result, the table unit 14 moves downward relative to the base member 12, and the position of the table unit 14 approaches the origin position.

[0088] In this embodiment, the valve control unit 228 feedback-controls the operation of the valve 202 so that the table unit 14 is located at the origin position. As a result, even if the position of the table unit 14 deviates from the origin position when no external force is acting on the table unit 14, the position of the table unit 14 can be returned to the origin position by the valve control unit 228.

[0089] Third Embodiment Next, a compliance unit 10B according to a third embodiment will be described. In the compliance unit 10B according to this embodiment, the same components as those in the compliance unit 10 according to the first embodiment described above are given the same reference numerals, and detailed description thereof will be omitted. In the compliance unit 10B, the same configuration as the compliance unit 10 provides the same effects.

[0090] 11 is a cross-sectional explanatory view of a compliance unit 10B according to the third embodiment. As shown in FIG. 11, the compliance unit 10B includes a pressing mechanism 22a instead of the pressing mechanism 22 described above.

[0091] The pressing mechanism 22a has a pair of spool valves 252a, 252b, a connecting flow path 254, an on-off valve 256, a connecting member 154, and a pressing portion 156. The pair of spool valves 252a, 252b are aligned in the X direction.

[0092] The spool valve 252a includes a valve hole 258, a sleeve 260, a head cover 262, a retaining ring 264, a valve element 266, a rod portion 268, an inlet port 270, an outlet port 272, an air port 274, and a communication passage 276. The valve hole 258 extends along the Y direction. The valve hole 258 opens to a side surface of the base member 12 facing the Y1 direction (a downward-facing side surface). The sleeve 260 is formed in a cylindrical shape. The sleeve 260 is made of, for example, but not limited to, metal. The sleeve 260 is disposed in the valve hole 258.

[0093] The head cover 262 is provided at the Y1-direction end of the valve hole 258. The head cover 262 prevents the sleeve 260 from slipping out in the Y1 direction. An insertion hole 278, through which the rod portion 268 passes, is formed in the head cover 262. A guide portion 280 is provided on the inner circumferential surface of the insertion hole 278. The guide portion 280 guides the rod portion 268 so that it moves smoothly in the Y direction relative to the head cover 262. The retaining ring 264 prevents the head cover 262 from coming off the valve hole 258. A valve chamber 282 is formed inside the sleeve 260.

[0094] The valve element 266 is disposed in the valve chamber 282. The valve element 266 slides in the Y direction on the inner circumferential surface of the sleeve 260. The valve element 266 is made of, for example, but not limited to, metal. The valve element 266 divides the valve chamber 282 into a first chamber 284 and a second chamber 286. The first chamber 284 is located below the valve element 266 (in the Y1 direction). In other words, the first chamber 284 is formed between the valve element 266 and the head cover 262. A biasing member 288 is disposed in the first chamber 284, biasing the valve element 266 upward (in the Y2 direction). The second chamber 286 is located above the valve element 266 (in the Y2 direction). A biasing member 290 is disposed in the second chamber 286, biasing the valve element 266 downward (in the Y1 direction). Each of the biasing members 288, 290 is, for example, a compression coil spring. An annular groove 292 is formed in the middle of the valve body 266 in the Y direction.

[0095] The rod portion 268 extends downward (in the Y1 direction) from the valve element 266. The rod portion 268 is inserted through an insertion hole 278 in the head cover 262. The extending end of the rod portion 268 is provided with a male thread portion 296 that screws into a female thread portion 294 formed in the connecting member 154. A position adjustment nut 298 and a fixing nut 300 are screwed onto the male thread portion 296. The position adjustment nut 298 can adjust the position of the valve element 266 within the valve chamber 282 so that the valve element 266 is positioned at a predetermined reference position with the table unit 14 positioned at the origin position. The fixing nut 300 prevents the position adjustment nut 298 from loosening.

[0096] The inlet port 270, the exhaust port 272, the air port 274, and the communication passage 276 are each formed by communication between a hole formed in the first base portion 26 and a hole formed in the sleeve 260. The inlet port 270 introduces fluid into the valve chamber 282. The exhaust port 272 can communicate with the annular groove 292. The air port 274 communicates with the second chamber 286. The inlet port 270, the exhaust port 272, and the air port 274 are aligned in this order in the Y2 direction.

[0097] The communication passage 276 communicates between the first chamber 284 and the annular groove 292. The communication passage 276 is provided with a variable throttle portion 301. The variable throttle portion 301 can change the flow path cross-sectional area of ​​the communication passage 276.

[0098] The spool valve 252b is basically configured similarly to the spool valve 252a. The spool valve 252b does not have the inlet port 270, the outlet port 272, the communication passage 276, or the variable throttle portion 301 that the spool valve 252a has. The pair of spool valves 252a, 252b are connected to each other via a connecting passage 254. The connecting passage 254 connects the communication passage 276 of one spool valve 252a to the first chamber 284 of the other spool valve 252b. The rod portion 268 of the spool valve 252b is not provided with a position adjustment nut 298. Furthermore, the valve body 266 of the spool valve 252b is not provided with an annular groove 292.

[0099] The on-off valve 256 opens and closes a supply / discharge flow path 302 that communicates with the inlet port 270. The on-off valve 256 has an output port 304 and a supply port 306. The output port 304 communicates with the supply / discharge flow path 302. A fluid (compressed fluid) is supplied to the supply port 306 from a supply source (not shown). When the on-off valve 256 is open, the fluid from the supply source is guided to the inlet port 270 via the supply / discharge flow path 302. When the on-off valve 256 is closed, the supply of fluid from the supply source to the supply / discharge flow path 302 is stopped.

[0100] The on-off valve 256 is turned on when the compliance unit 10B is in use and turned off when the compliance unit 10B is not in use. The on-off valve 256 is maintained in a closed state in the off state. This makes it possible to reduce the energy consumption of the compliance unit 10B. In particular, if the sleeve 260 is made of metal, turning off the on-off valve 256 when the compliance unit 10B is not in use can minimize fluid leakage (air leakage).

[0101] The compliance unit 10B includes a control unit 308 that controls the operation of the on-off valve 256. The control unit 308 includes a calculation unit (not shown) and a storage unit (not shown). The calculation unit is configured by a processor such as a CPU or GPU. In other words, the calculation unit is configured by a processing circuit. In the compliance unit 10B, the on-off valve 256 may be configured to be manually switchable between an open state and a closed state.

[0102] Next, the operation of the compliance unit 10B will be described. Figures 12 to 14 are explanatory views of the operation of the compliance unit 10B according to the third embodiment, with some parts omitted. When the table unit 14 is positioned above the original position, as shown in Figures 11 and 12, the inlet port 270 of the spool valve 252a is closed by the valve element 266. Furthermore, in each spool valve 252a, the outlet port 272 communicates with the annular groove 292. The air port 274 communicates with the second chamber 286.

[0103] As a result, the fluid in the first chamber 284 of the spool valve 252a is discharged to the outside via the communicating passage 276, the annular groove 292, and the discharge port 272. Also, the fluid in the first chamber 284 of the spool valve 252b is discharged to the outside via the connecting flow path 254, the communicating passage 276, the annular groove 292, and the discharge port 272. Therefore, the valve element 266 moves downward relative to the base member 12 due to the biasing force of the biasing member 290. As a result, the table unit 14 moves downward relative to the base member 12, allowing the table unit 14 to approach the original position.

[0104] When the table unit 14 is positioned below the home position, as shown in FIG. 13 , in the spool valve 252 a, the inlet port 270 communicates with the annular groove 292, and the outlet port 272 is closed by the valve body 266. The air port 274 communicates with the second chamber 286. This causes fluid supplied to the inlet port 270 from a supply source (not shown) to be guided to the first chamber 284 via the annular groove 292 and the communication passage 276. Furthermore, fluid introduced from the inlet port 270 of the spool valve 252 a into the annular groove 292 and the communication passage 276 of the spool valve 252 a is guided to the first chamber 284 of the spool valve 252 b via the connecting passage 254 (see FIG. 11 ).

[0105] As a result, the pressure between the annular groove 292 and the first chamber 284 in the spool valve 252a increases, and the pressure in the first chamber 284 in the spool valve 252b increases, causing the valve body 266 to move upward relative to the base member 12. As a result, the table unit 14 moves upward relative to the base member 12, allowing the table unit 14 to approach the origin position.

[0106] In this embodiment, the position adjustment nut 298 adjusts the valve element 266 to the position shown in FIG. 14 when the table unit 14 is in the home position. In this case, the valve element 266 of the spool valve 252a closes the inlet port 270 and the outlet port 272 when in the home position. In other words, the annular groove 292 of the spool valve 252a does not communicate with both the inlet port 270 and the outlet port 272. This seals the first chamber 284 of each spool valve 252a, 252b.

[0107] In this state, the weight of the table unit 14 and the like is balanced with the force of the fluid (compressed air) sealed in the first chambers 284 of the pair of spool valves 252a, 252b, and the table unit 14 stops at the origin position. Here, the weight of the table unit 14 and the like includes the weight of the table unit 14 and the weight of the chuck member (hand) attached to the table unit 14.

[0108] In this compliance unit 10B, the fluid flows through the variable throttle portion 301 when it flows through the communication passage 276, and therefore it is possible to suppress vibration of the base member 12 when the fluid is supplied to or discharged from the first chamber (pressurizing chamber) 284. The flow path cross-sectional area (throttling amount) of the variable throttle portion 301 can be adjusted according to the weight of the table unit 14.

[0109] When the compliance unit 10B is not used, the control unit 308 turns off the on-off valve 256 to close the supply / discharge flow path 302.

[0110] In this embodiment, the valve body 266 of the spool valve 252a and the pressing portion 156 are connected by the connecting member 154. As a result, even if the position of the table unit 14 deviates from the original position when no external force is acting on the table unit 14, the position of the table unit 14 can be returned to the original position by the spool valve 252a.

[0111] (Fourth Embodiment) Next, a compliance unit 10C according to a fourth embodiment will be described. In the compliance unit 10C according to this embodiment, the same components as those of the compliance units 10, 10A, and 10B according to the first to third embodiments described above are given the same reference numerals, and detailed description thereof will be omitted. In the compliance unit 10C, the same configuration as that of the compliance units 10, 10A, and 10B provides the same effects.

[0112] 15 is a cross-sectional explanatory view of a compliance unit 10C according to the fourth embodiment. As shown in FIG. 15, the compliance unit 10C includes a pressing mechanism 22b instead of the pressing mechanism 22 described above.

[0113] The pressing mechanism 22b has a pair of third cylinder portions 152, a spool valve 400, an on-off valve 256, a connecting member 154, and a pressing portion 156. Each third cylinder portion 152 is provided with the above-mentioned exhaust port 201. The spool valve 400 is located on the X-direction side of the third cylinder portions 152.

[0114] The spool valve 400 includes a valve hole 258, a sleeve 260, a head cover 262, a retaining ring 264, a valve element 266, a rod portion 268, an inlet port 270, a discharge port 272, an air port 274, an exhaust port 275, and a communicating passage 276. An externally threaded portion 296 of the rod portion 268 is threadedly engaged with an internally threaded portion 294 formed in the connecting member 154. A position adjustment nut 298 and a fixing nut 300 are threadedly engaged with the externally threaded portion 296. A variable throttle portion 301 is provided in the communicating passage 276. The communicating passage 276 is connected to a supply / discharge flow path 212. The supply / discharge flow path 212 is in communication with the pressurizing chamber 210 of each third cylinder portion 152.

[0115] The on-off valve 256 opens and closes the supply / discharge flow path 302 that communicates with the introduction port 270. The compliance unit 10C includes a control unit 308 that controls the operation of the on-off valve 256.

[0116] In this compliance unit 10C, when the table unit 14 is positioned above the original position, the introduction port 270 is closed by the valve body 266. This causes the fluid in the pressurizing chamber 210 of each third cylinder portion 152 to be discharged to the outside via the supply / discharge flow path 212, the communication passage 276, the annular groove 292, and the discharge port 272.

[0117] As a result, the pressure in the pressurizing chamber 210 in each third cylinder portion 152 decreases, causing the third piston portion 160 to move downward relative to the base member 12. This causes the table unit 14 to move downward relative to the base member 12, and the position of the table unit 14 approaches the origin position.

[0118] On the other hand, when the table unit 14 is positioned below the home position, in the spool valve 400, the inlet port 270 communicates with the annular groove 292, and the outlet port 272 is closed by the valve element 266. This causes fluid supplied to the inlet port 270 from a supply source (not shown) to be guided to the pressurizing chamber 210 of each third cylinder portion 152 via the annular groove 292, the communicating passage 276, and the supply / discharge flow path 212. As a result, the pressure in the pressurizing chamber 210 in each third cylinder portion 152 increases, causing the third piston portion 160 to move upward relative to the base member 12. This causes the table unit 14 to move upward relative to the base member 12, bringing the position of the table unit 14 closer to the home position.

[0119] In this embodiment, the valve element 266 of the spool valve 400 closes the inlet port 270 and the outlet port 272 when the table unit 14 is in the home position. In other words, the annular groove 292 of the spool valve 400 does not communicate with both the inlet port 270 and the outlet port 272. This seals the pressurizing chamber 210 of each third cylinder portion 152.

[0120] In this state, the weight of the table unit 14 and the like and the force of the fluid (compressed air) sealed in the pressure chambers 210 of the pair of third cylinder portions 152 are balanced, and the table unit 14 stops at the origin position.

[0121] Such a configuration provides the same effects as the compliance units 10, 10A, and 10B described above.

[0122] The following additional notes are further disclosed regarding the above embodiment.

[0123] (Supplementary Note 1) The compliance unit (10, 10A, 10B, 10C) of the present disclosure comprises a base member (12), a table unit (14) arranged movably relative to the base member along an XY plane in which the up-down direction is the Y direction and the direction perpendicular to the Y direction is the X direction, a compliance mechanism (16) interposed between the base member and the table unit so as to be movable in the X direction and the Y direction relative to the base member and the table unit, and a pressing portion (156) provided on the base member that presses the table unit upward.

[0124] According to this configuration, the compliance unit is provided with a pressing portion that is attached to the base member and presses the table unit upward, so that the table unit can be prevented from moving downward relative to the base member due to its own weight, thereby providing a better compliance unit.

[0125] (Appendix 2) In the compliance unit described in Appendix 1, the table unit has an axis portion (84) located in the center of the table unit in the X direction, the axis portion extends toward the base member through a hole portion (17) of the compliance mechanism, and the pressing portion may press the axis portion upward.

[0126] With this configuration, it is possible to prevent the table unit pressed by the pressing portion from tilting in the circumferential direction of the shaft portion due to its own weight.

[0127] (Appendix 3) In the compliance unit described in Appendix 2, the table unit may have a hollow roller portion (82) in which the shaft portion is arranged and which is rotatable relative to the shaft portion, and the pressing portion may press the roller portion upward while in contact with an outer peripheral surface (82a) of the roller portion.

[0128] With this configuration, the pressing portion contacts the outer peripheral surface of the roller portion, which makes it possible to relatively reduce the frictional resistance between the pressing portion and the table unit, thereby allowing the table unit to move smoothly in the Y direction relative to the base member, for example.

[0129] (Supplementary Note 4) The compliance unit according to Supplementary Note 3 may further include a cylinder portion (152) for pressing the pressing portion upward.

[0130] According to this configuration, the cylinder portion presses the pressing portion upward, thereby making it possible to press the table unit upward.

[0131] (Supplementary Note 5) The compliance unit according to Supplementary Note 4 may further include a biasing member (166) for biasing the pressing portion downward.

[0132] With this configuration, the piston of the cylinder portion can be positioned at the intermediate position of the stroke in a state where the weight of the table unit and the pressing force of the pressing portion are balanced.

[0133] (Appendix 6) In the compliance unit described in any one of Appendices 1 to 5, the table unit may be provided with a table support portion (48), a table body (50) provided on the table support portion so as to be tiltable around an axis along the X direction, and a tilt suppression portion (24) provided on the table support portion to suppress tilting of the table body relative to the table unit due to gravity.

[0134] With this configuration, when the compliance unit is arranged so that the Y direction is the up-down direction, it is possible to prevent the table body from tilting due to its own weight relative to the table unit.

[0135] (Supplementary Note 7) In the compliance unit according to Supplementary Note 6, the tilt suppression portion may press the lower end of the table body in a direction opposite to the direction in which the table support portion presses.

[0136] With this configuration, tilting of the table body due to its own weight can be easily suppressed.

[0137] (Supplementary Note 8) The compliance unit described in Supplementary Note 7 may include a contact portion (180) that contacts the table body, and a tilt suppression cylinder portion (178) that presses the contact portion toward the table body.

[0138] According to this configuration, the tilt suppression cylinder portion presses the contact portion, thereby making it possible to press the lower end portion of the table body in the direction opposite to the table support portion.

[0139] (Supplementary Note 9) The compliance unit according to Supplementary Note 8 may further include a tilt suppression biasing member (188) that biases the contact portion in a direction away from the table body.

[0140] With this configuration, the piston of the tilt suppression cylinder portion can be positioned at the intermediate position of the stroke when the weight of the table body and the pressing force of the contact portion are balanced.

[0141] (Appendix 10) A compliance unit according to any one of Appendices 1 to 9, comprising: a cylinder section for moving the pressing section in the Y direction relative to the base member; a valve (202) for controlling the flow rate of fluid supplied to or discharged from a pressure chamber (210) of the cylinder section; and a valve control section (228) for controlling the operation of the valve, wherein the valve control section may feedback-control the operation of the valve so that the table unit is positioned at an origin position when no external force is acting on the table unit.

[0142] With this configuration, even if the position of the table unit deviates from the origin position when no external force is acting on the table unit, the position of the table unit can be returned to the origin position by the valve control unit.

[0143] (Appendix 11) The compliance unit described in Appendix 10 may include a position acquisition unit (224) that acquires the position of the table unit relative to the base member in the vertical direction based on a signal detected by a position sensor (206), and the valve control unit may feedback-control the operation of the valve based on the position acquired by the position acquisition unit.

[0144] With this configuration, the position of the table unit can be returned to the origin position with even greater accuracy.

[0145] (Supplementary Note 12) The compliance unit according to Supplementary Note 10 may include a pressure acquisition unit (226) that acquires the pressure of the pressurized chamber based on a signal detected by a pressure sensor (208), and the valve control unit may feedback-control the operation of the valve based on the pressure acquired by the pressure acquisition unit.

[0146] With this configuration, the position of the table unit can be returned to the origin position with even greater accuracy.

[0147] (Appendix 13) The compliance unit according to any one of Appendices 1 to 9 may include a valve chamber (282) provided in the base member, spool valves (252a, 252b) having a valve body (266) that moves in the Y direction within the valve chamber, and a connecting member (154) that connects the valve body and the pressing portion.

[0148] According to this configuration, the valve body of the spool valve and the pressing portion are connected by a connecting member, so that even if the position of the table unit deviates from the original position when no external force is acting on the table unit, the position of the valve body of the spool valve can be adjusted to return the table unit to the original position.

[0149] (Appendix 14) In the compliance unit described in Appendix 13, the valve chamber includes a first chamber (284) located below the valve body and a second chamber (286) located above the valve body, and a biasing member (290) that biases the valve body downward is disposed in the second chamber, and when the table unit is positioned above the origin position with no external force acting on the table unit, fluid in the first chamber is discharged to the outside of the first chamber, causing the valve body to move downward relative to the base member due to the biasing force of the biasing member, and when the table unit is positioned below the origin position with no external force acting on the table unit, fluid is supplied into the first chamber, causing the valve body to move upward relative to the base member while pressing the biasing member.

[0150] According to this configuration, the table unit can be returned to the origin position with a simple structure.

[0151] (Supplementary Note 15) In the compliance unit described in Supplementary Note 14, an annular groove (292) is formed in the valve body, and the spool valve has an inlet port (270) for introducing fluid into the valve chamber, a discharge port (272) that can communicate with the annular groove, and a communication passage (276) that communicates the first chamber with the annular groove, and when the table unit is positioned above the original position with no external force acting on the table unit, the inlet port is closed by the valve body and the fluid in the first chamber is discharged from the discharge port via the communication passage and the annular groove, causing the valve body to move downward relative to the base member due to the biasing force of the biasing member, and when the table unit is positioned below the original position with no external force acting on the table unit, the discharge port is closed by the valve body and fluid is introduced from the inlet port into the first chamber via the annular groove and the communication passage, causing the valve body to move upward relative to the base member while pressing the biasing member.

[0152] According to this configuration, the table unit can be returned to the origin position with a simple structure.

[0153] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

Claims

1. A compliance unit (10, 10A, 10B, 10C) comprising: a base member (12); a table unit (14) arranged so as to be movable relative to the base member along an XY plane, with the vertical direction being the Y direction and the direction perpendicular to the Y direction being the X direction; a compliance mechanism (16) interposed between the base member and the table unit so as to be movable in the X direction and the Y direction relative to the base member and the table unit; and a pressing portion (156) provided on the base member for pressing the table unit upward.

2. A compliance unit as described in claim 1, wherein the table unit has an axis portion (84) located in the center of the table unit in the X-direction, the axis portion extends toward the base member through a hole portion (17) of the compliance mechanism, and the pressing portion presses the axis portion upward.

3. A compliance unit as described in claim 2, wherein the table unit has a hollow roller portion (82) in which the shaft portion is disposed and which is rotatable relative to the shaft portion, and the pressing portion presses the roller portion upward while in contact with the outer peripheral surface (82a) of the roller portion.

4. A compliance unit according to claim 3, comprising a cylinder portion (152) for pushing the pressing portion upward.

5. A compliance unit according to claim 4, comprising a biasing member (166) for biasing the pressing portion downward.

6. A compliance unit as described in any one of claims 1 to 5, wherein the table unit comprises: a table support portion (48); a table body (50) provided on the table support portion so as to be tiltable around an axis along the X-direction; and a tilt suppression portion (24) provided on the table support portion for suppressing tilting of the table body relative to the table unit due to gravity.

7. A compliance unit as set forth in claim 6, wherein the tilt suppressing portion presses the lower end of the table body in the opposite direction to the table support portion.

8. A compliance unit according to claim 7, comprising: a contact portion (180) that contacts the table body; and a tilt suppression cylinder portion (178) for pressing the contact portion toward the table body.

9. A compliance unit according to claim 8, comprising a tilt suppression biasing member (188) that biases the contact portion in a direction away from the table body.

10. A compliance unit as described in claim 1, comprising: a cylinder section for moving the pressing section in the Y direction relative to the base member; a valve (202) for controlling the flow rate of fluid supplied to and discharged from the pressure chamber (210) of the cylinder section; and a valve control section (228) for controlling the operation of the valve, wherein the valve control section feedback controls the operation of the valve so that the table unit is positioned at the origin position when no external force is acting on the table unit.

11. A compliance unit as described in claim 10, comprising a position acquisition section (224) that acquires the position of the table unit relative to the base member in the vertical direction based on a signal detected by a position sensor (206), and the valve control section feedback controls the operation of the valve based on the position acquired by the position acquisition section.

12. A compliance unit as described in claim 10, comprising a pressure acquisition section (226) that acquires the pressure of the pressurized chamber based on a signal detected by a pressure sensor (208), and the valve control section feedback-controls the operation of the valve based on the pressure acquired by the pressure acquisition section.

13. A compliance unit as described in claim 1, comprising: a spool valve (252a, 252b) having a valve chamber (282) provided in the base member and a valve body (266) that moves in the Y direction within the valve chamber; and a connecting member (154) that connects the valve body and the pressing portion.

14. A compliance unit as described in claim 13, wherein the valve chamber includes a first chamber (284) located below the valve body, and a second chamber (286) located above the valve body, and a biasing member (290) for biasing the valve body downward is disposed in the second chamber, and when the table unit is positioned above the original position with no external force acting on the table unit, fluid within the first chamber is discharged to the outside of the first chamber, causing the valve body to move downward relative to the base member due to the biasing force of the biasing member, and when the table unit is positioned below the original position with no external force acting on the table unit, fluid is supplied into the first chamber, causing the valve body to move upward relative to the base member while pressing the biasing member.

15. A compliance unit as described in claim 14, wherein the valve body has an annular groove (292), and the spool valve has an inlet port (270) for introducing fluid into the valve chamber, an outlet port (272) that can communicate with the annular groove, and a communication passage (276) that communicates the first chamber and the annular groove, and when the table unit is positioned above the original position with no external force acting on the table unit, the inlet port is blocked by the valve body and the fluid in the first chamber is discharged from the outlet port via the communication passage and the annular groove, causing the valve body to move downward relative to the base member due to the biasing force of the biasing member, and when the table unit is positioned below the original position with no external force acting on the table unit, the outlet port is blocked by the valve body and fluid is introduced from the inlet port into the first chamber via the annular groove and the communication passage, causing the valve body to move upward relative to the base member while pressing the biasing member.

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