JP2012047622A - Shaft center adjusting device for material testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft center adjusting device for a material testing machine that can be attached without forming through holes on a load frame and allows a user to adjust tensile force after the attachment.SOLUTION: A shaft center adjusting device for a material testing machine includes: a fixed-side base portion 30 connected with a cross head 23; a movable-side base portion 50 connected with an upper gripper through a load cell 13; a connecting shaft 90 for connecting the fixed-side base portion 30 and the movable-side base portion 50; a center adjusting mechanism 40 for adjusting an angle and a position of a shaft center of the connecting shaft 90; and a wedge member 80 for generating tensile force to the connecting shaft 90.

Description

  The present invention relates to an axis adjusting device for a material testing machine fixed to a load frame for adjusting the axis of a gripping tool for holding a test piece.

  A material testing machine to which such an axis adjusting device is applied is designed to apply a load to a test piece gripped at both ends by an upper gripping tool and a lower gripping tool, while using a load cell and a displacement detector. And the displacement are measured to obtain the test force-displacement characteristic of the test piece and the SN diagram. In such a material testing machine, an accurate material test cannot be performed unless the axes of the upper gripper and the lower gripper are aligned. For this reason, in such a material testing machine, a shaft center adjusting device for adjusting the shaft centers of the upper gripping tool and the lower gripping tool is provided.

  FIG. 8 is a schematic diagram of such a conventional shaft center adjusting device 113.

  The shaft center adjusting device 113 is interposed between the cross head 23 and the upper gripper 111, a connection shaft 131 that connects the crosshead 23 and the upper gripper 111, and a center of the connection shaft 131. A frame member 139 fixed to the section, an angle adjusting collar member 134 disposed on the outer periphery of the connecting shaft 131 inside the frame member 139 and fixed to the crosshead 23, and a connecting shaft inside the frame member 139. A position adjusting collar member 135 disposed on the outer periphery of 131 and fixed to the upper gripper 111.

  The connecting shaft 131 passes through the angle adjusting collar member 134, the frame member 139, and the position adjusting collar member 135, and the upper end portion of the connecting shaft 131 is screwed with the mounting plate 132. Is screwed with the upper gripper 111. The mounting plate 132 is connected to the cross head 23 via a pair of jack bolts 133. For this reason, the upper gripper 111 can be fastened to the crosshead 23 with a predetermined force by moving the mounting plate 132 upward with respect to the crosshead 23 using a pair of jack bolts 133.

  The frame member 139 includes a support portion 137 that is screwed and fixed to the connecting shaft 131, and a rectangular frame portion 136 that surrounds the connecting shaft 131. A hemispherical convex portion 138 is formed on the upper surface of the support portion 137, and a hemispherical concave portion having a shape corresponding to the convex portion 138 is formed on the lower surface of the angle adjusting collar member 134. Further, the lower surface of the support portion 137 has a planar shape, and is in contact with the upper surface of the planar position adjusting collar member 135.

  FIG. 9 is a schematic plan view of the vicinity of the angle adjusting collar member 134 in the conventional shaft center adjusting device 113.

  The angle adjusting collar member 134 has a rectangular shape or a circular shape in plan view, and its outer peripheral surface has four screws 141, 142, 143, which are screwed with the frame portion 136 of the frame member 139. 144 is in contact with the tip of 144. For this reason, by adjusting the four screws 141, 142, 143, and 144, the frame member 139 can be inclined together with the connecting shaft 131 to adjust the angle of the upper gripper 111. That is, of the four screws 141, 142, 143, 144, one of the two screws facing each other is loosened and the other is tightened, and the hemispherical convex portion 138 of the frame member 139 is moved to the angle adjusting collar member. The frame member 139 can be tilted together with the connecting shaft 131 by being moved along the hemispherical concave portion 134. As the connecting shaft 131 is inclined, the upper gripper 111 is inclined.

  FIG. 10 is a schematic plan view of the vicinity of the position adjusting collar member 135 in the conventional shaft center adjusting device 113.

  The position adjusting collar member 135 has a rectangular shape or a circular shape in plan view, and its outer peripheral surface has four screws 151, 152, 153, which are screwed with the frame portion 136 of the frame member 139. 154 is in contact with the tip of 154. For this reason, by adjusting the four screws 151, 152, 153, and 154, the position of the upper gripper 111 can be adjusted by moving the frame member 139 together with the connecting shaft 131. That is, of the four screws 151, 152, 153, 154, the frame member 139 is moved along the upper surface of the position adjusting collar member 135 in a state where one of the two screws facing each other is loosened and the other screw is tightened. By doing so, the frame member 139 can be moved relative to the position adjusting collar member 135 together with the connecting shaft 131. The upper gripper 111 moves with the relative movement of the connecting shaft 131.

  In this conventional shaft center adjusting device 113, the hemispherical convex portion 138 is formed on the upper surface of the support portion 137 of the frame member 139 and the lower surface of the support portion 137 is planar, but the hemispherical convex portion 138 is formed. In consideration of the high manufacturing cost, a pair of collars in which concave portions made of cylindrical curved surfaces are formed on both upper and lower surfaces of the frame member 139 and convex portions made of cylindrical curved surfaces are formed on the upper and lower sides thereof. An axis adjusting device provided with a member has also been proposed (see Patent Document 1). Also in the shaft center adjusting device described in Patent Document 1, by adjusting the screws corresponding to the four screws 141, 142, 143, 144 and the four screws 151, 152, 153, 154 described above, The position and angle of the upper grip connected to the connecting shaft can be adjusted.

Japanese Patent No. 3849331

  In the conventional shaft center adjusting device, the mounting plate 132 is attached to the crosshead 23 using a pair of jack bolts 133 so that the shaft center of the upper gripper 111 does not change even when a test force is applied to the test piece. On the other hand, it is necessary to apply a large tensile force to the connecting shaft 131 by moving it upward, and to fasten the upper gripper 111 to the cross head 23 with a predetermined force. That is, since the conventional shaft center adjusting device uses the connecting shaft 131 that penetrates the cross head 23, it is difficult to add the shaft center adjusting device to an existing material testing machine.

  Since the conventional shaft center adjusting device is configured to apply a tensile force to the connecting shaft 131 using a pair of jack bolts 133, the shaft center adjusting device is disposed on the main body table on the lower gripper side. In some cases, it is difficult to apply a tensile force. Further, even when a shaft center adjustment device that does not have a connecting shaft that passes through the cross head as in the prior art is adopted, the shaft center adjustment device is attached to the cross head, or a load cell or the like is attached to the shaft center adjustment device. After the is attached, there is a problem that the tensile force cannot be adjusted.

  The present invention has been made to solve the above problems, and can be mounted without forming a through-hole or the like in the load frame, and the shaft of the material testing machine capable of adjusting the tensile force even after mounting. An object is to provide a center adjustment device.

  The invention according to claim 1 is an axis adjusting device for a material testing machine fixed to a load frame for adjusting an axis of a gripping tool for gripping a test piece, and is connected to the load frame. A fixed-side base portion, a moving-side base portion connected to the gripper, a connecting shaft for fastening the fixed-side base portion and the moving-side base portion, and the fixed side in the outer peripheral portion of the connecting shaft A centering mechanism that is disposed at a position between the base portion and the moving-side base portion and adjusts the angle of the shaft center of the connecting shaft and the position of the shaft center, and generates a tensile force on the connecting shaft. And a wedge mechanism.

  The invention according to claim 2 is the invention according to claim 1, wherein the wedge mechanism is connected to the connecting shaft, and an inclined surface inclined with respect to a plane perpendicular to the axis of the connecting shaft is the connecting shaft. A taper member formed on the outer periphery of the shaft and an inclined surface corresponding to the inclined surface formed on the taper member, and is movable between a position close to the connecting shaft and a position separated from the connecting shaft. A plurality of wedge members, and by moving the plurality of wedge members, a tensile force is generated on the connecting shaft.

  According to a third aspect of the present invention, in the second aspect of the present invention, the taper member is attached to a nut member disposed at one end of the connecting shaft.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the wedge mechanism has a cylindrical shape surrounding an outer peripheral portion of the connection shaft, and one end edge of the wedge mechanism is an axis of the connection shaft. A pair of annular wedges having a spiral shape that is parallel to a plane perpendicular to the center and whose other edge is inclined with respect to a plane perpendicular to the axis of the connecting shaft; Are arranged opposite to each other in a state of abutting each other, and the pair of annular wedges are rotated relative to the connection shaft at the outer peripheral portion of the connection shaft relative to the connection shaft. To generate a tensile force.

  According to a fifth aspect of the present invention, in the invention according to any one of the second to fourth aspects, the centering mechanism has a center on one side of the fixed side base portion or the movable side base portion. An alignment member having a spherical contact surface facing the gripper and having a flat contact surface formed on the other side of the fixed base portion or the movable base portion, and the connecting shaft A plurality of adjusting screws arranged with the axis oriented in the direction toward the axis of the connecting shaft, and the position of the axis of the connecting shaft. And a plurality of adjusting screws arranged with the axis oriented in the direction toward the axis of the connecting shaft.

  According to the first aspect of the present invention, since it is configured to apply a tensile force to the connecting shaft using the wedge mechanism, the shaft center adjusting device can be used as a load frame without forming a through hole or the like. It is possible to adjust the tensile force after mounting to the load frame or after mounting the load cell or the like.

  According to the second and third aspects of the invention, the tensile force can be easily adjusted by moving the wedge member so as to be close to or away from the connecting shaft, and the tensile force can be adjusted. Since it can carry out from the side of a connecting shaft, it becomes possible to comprise the whole axial center adjustment apparatus compactly.

  According to the invention described in claim 4, the tensile force can be easily adjusted by relatively rotating the pair of annular wedges, and the tensile force can be adjusted from the side of the connecting shaft. Therefore, the entire shaft center adjusting device can be configured compactly.

  According to the fifth aspect of the present invention, a plurality of adjustment screws are used by the action of the spherical and flat contact surfaces formed on the fixed side base portion, the movable side base portion and the alignment member. It becomes possible to easily adjust the angle of the axis of the connecting shaft and the position of the axis.

It is a schematic diagram of the material testing machine to which this invention is applied. It is a longitudinal cross-sectional view of the axial center adjustment apparatus 20 of the material testing machine which concerns on 1st Embodiment of this invention. 3 is a perspective view of a wedge member 80. FIG. It is the perspective view which looked at the spherical liner 32 from the back surface side. FIG. 6 is a perspective view of the alignment member 41. It is a longitudinal cross-sectional view of the axial center adjustment apparatus 20 of the material testing machine which concerns on 2nd Embodiment of this invention. 7 is a perspective view of an annular wedge 81. FIG. It is a schematic diagram of the conventional axial center adjustment apparatus 113. FIG. 10 is a schematic plan view of the vicinity of an angle adjusting collar member in a conventional shaft center adjusting device. FIG. 10 is a schematic plan view of the vicinity of a position adjusting collar member 135 in a conventional shaft center adjusting device 113.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a material testing machine to which the present invention is applied.

  The material testing machine includes a base 16, a pair of left and right screw rods 17 erected on the base 16, and a nut portion screwed with the pair of left and right screw rods 17. And a cross head 23 that moves up and down. The base 16, the pair of screw rods 17 and the cross head 23 constitute a load frame for applying a load to the test piece 10. The upper grip 11 is attached to the cross head 23 via the shaft center adjusting device 20 and the load cell 13 according to the present invention. A lower grip 12 is attached to the base 16. The both ends of the test piece 10 are gripped by the upper grip 11 and the lower grip 12.

  Synchronous pulleys 21 that engage with the synchronous belt 22 are disposed at the lower ends of the pair of screw rods 17, respectively. The synchronous belt 22 is also engaged with a synchronous pulley 19 that is rotated by driving of the motor 18. For this reason, the pair of screw rods 17 rotate in synchronization with the drive of the motor 18. Then, as the pair of screw rods 17 rotate in synchronization, the cross head 23 moves up and down in the axial direction of the pair of screw rods 17.

  The test force applied to the test piece 10 is detected by the load cell 13. Further, the displacement amount between the upper and lower gauge points of the test piece 10 is detected by the displacement meter 14. Signals from the load cell 13 and the displacement meter 14 are input to a control circuit (not shown). The control circuit creates a drive control signal for the motor 18 based on signals from the load cell 15 and the displacement meter 14. Thereby, the rotation of the motor 18 is controlled, and various material tests such as tension and compression are performed.

  FIG. 2 is a longitudinal sectional view of the axis adjusting device 20 of the material testing machine according to the first embodiment of the present invention.

  The shaft center adjusting device 20 is for adjusting the position and angle of the shaft center of the lower gripper 11 so as to align the shaft centers of the upper gripper 11 and the lower gripper 12, and a load frame. The fixed base portion 30 fixed to the cross head 23 constituting the above, the nut member 70 contacting the fixed side base portion 30 via the taper member 71 and the wedge member 80, and the upper grip 11 via the load cell 13. The movable side base portion 50, the nut member 70 and the movable side base portion 50 are coupled to each other, and the fixed side base portion 30 and the movable side base portion 50 at the outer peripheral portion of the coupling shaft 90 are connected to each other. And a centering mechanism 40 that adjusts the angle of the connecting shaft 90 and the position of the shaft center.

  The nut member 70 is screwed with a male screw portion formed at the upper end of the connecting shaft 90 and is fixed to the connecting shaft 90. A taper member 71 is attached to the nut member 70, and the taper member 71 is connected to the connecting shaft 90 via the nut member 70. The tapered member 71 has a configuration in which an inclined surface that is inclined with respect to a plane perpendicular to the axis of the connecting shaft 90 is formed on the outer peripheral portion of the connecting shaft 90.

  FIG. 3 is a perspective view of the wedge member 80.

  As shown in FIG. 2, the wedge member 80 has a radial shape around the connecting shaft 90 between a taper member 71 attached to the nut member 70 and a fixed base flange 31 constituting the fixed base portion 30. 4 are arranged in each. That is, each wedge member 80 has an inclined surface 89 corresponding to the inclined surface formed on the taper member 71, and the inclined surface 89 is arranged in a state of contacting the inclined surface of the taper member 71. In addition, the bottom surface of each wedge member 80 is disposed in contact with the planar bottom surface of a recess formed in the fixed base flange 31 described later.

  Each of the four wedge members 80 is connected to a position adjusting screw 84 disposed on the fixed-side base flange 31. By rotating the position adjusting screw 84, each wedge member 80 can be moved between a position close to the connecting shaft 90 and a position separated from the connecting shaft 90. The movement of the wedge member 80 causes the distance between the nut member 70 fixed to the upper end of the connecting shaft 90 and the fixed base flange 31, in other words, the nut member 70 fixed to the upper end of the connecting shaft 90 and the connecting shaft. The distance from a later-described moving base flange 51 fixed to the lower end of 90 changes, and the tensile force applied to the connecting shaft 90 changes accordingly.

  Referring to FIG. 2 again, the fixed side base portion 30 includes a fixed side base flange 31 and a spherical liner 32. The spherical liner 32 is disposed in a recess formed in the fixed base flange 31. The fixed-side base flange 31 is attached to the cross head 23 by a plurality of fixing screws 36.

  FIG. 4 is a perspective view of the spherical liner 32 as viewed from the back side.

  The spherical liner 32 has a spherical contact surface 38 having a shape corresponding to a spherical contact surface 45 formed on the aligning member 41 described later on one surface thereof. The spherical liner 32 is made of a material having an appropriate strength. A through hole 39 through which the connecting shaft 90 passes is formed in the center of the spherical liner 32.

  Referring to FIG. 2 again, the moving side base portion 50 includes a moving side base flange 51 and a flat liner 52. The planar liner 52 is disposed in a recess formed in the moving side base flange 51. The moving-side base flange 51 is screwed with a male screw portion formed at the lower end of the connecting shaft 90 and is fixed to the connecting shaft 90. A load cell 13 indicated by an imaginary line in FIG. 2 is fixed to the moving side base flange 51 by a plurality of fixing screws 49. As shown in FIG. 1, the upper gripping tool 11 is fixed to the load cell 13.

  The planar liner 52 has a planar abutting surface having a shape corresponding to a planar abutting surface formed on the alignment member 41 described later on one surface thereof. The flat liner 52 is made of a material having an appropriate strength. A through hole through which the connecting shaft 90 passes is formed in the center of the planar liner 52.

  The alignment member 41, the four inclination adjusting screws 42, and the four horizontal position adjusting screws are located at a position between the fixed base portion 30 and the moving base portion 50 in the outer peripheral portion of the connecting shaft 90 described above. 43 and a centering mechanism 40 that adjusts the angle of the shaft center of the connecting shaft 90 and the position of the shaft center is disposed.

  FIG. 5 is a perspective view of the alignment member 41.

  A spherical contact surface 45 whose center faces the upper gripper 11 side is formed on the fixed base portion 30 side of the aligning member 41. The contact surface 45 has a shape corresponding to the spherical contact surface 38 of the spherical liner 32 described above. Further, a planar contact surface is formed on the side of the moving base portion 50 of the aligning member 41. The alignment member 41 is made of a material having an appropriate strength. A through hole 44 through which the connecting shaft 90 passes is formed in the center of the alignment member 41.

  A counterbore 46 is formed at a position of the side surface of the aligning member 41 that contacts the tip of the inclination adjustment screw 42, and a counterbore 47 is formed at a position of contact with the tip of the horizontal position adjustment screw 43. Is formed. The inclination adjusting screw 42 is oriented in a direction in which its axis is directed toward the axis of the connecting shaft 90, and its tip is in contact with a counterbore 46 formed on the outer peripheral surface of the aligning member 41. 30 is disposed on the fixed-side base flange 31. On the other hand, the horizontal position adjusting screw 43 is moved in a state where its axis is directed in the direction toward the axis of the connecting shaft 90 and its tip is in contact with the spot facing portion 47 formed on the outer peripheral surface of the aligning member 41. The movable base flange 51 is disposed in the side base portion 50. Four of these inclination adjustment screws 42 and horizontal position adjustment screws 43 are arranged for each 90 ° angular position in plan view.

  When assembling the shaft center adjusting device 20 of the material testing machine having the above-described configuration, first, the moving-side base flange 51 is screwed into the lower end portion of the connecting shaft 90. Then, the planar liner 52, the alignment member 41, the spherical liner 32, the fixed-side base flange 31, and the wedge member 80 are sequentially stacked on the outer peripheral portion of the connecting shaft 90, and a taper member 71 is formed on the upper end portion of the connecting shaft 90. By screwing the attached nut member 70, these members are integrated. Further, the position adjusting screw 84, the inclination adjusting screw 42 and the horizontal position adjusting screw 43 are installed at necessary positions.

  Then, the upper gripping tool 11 is attached to the moving-side base flange 51 via the load cell 13. Further, the fixed side base flange 31 is attached to the cross head 23 by a plurality of fixing screws 36. A lower grip 12 is attached to the base 16.

  In this state, the axial center between the upper gripper 11 and the lower gripper 12 is adjusted by adjusting the position and angle of the axial center of the lower gripper 12 using the axial center adjustment device 20 according to the present invention. Align. In this case, for example, as described in Japanese Patent Application Laid-Open No. 64-31033, the both ends of the test piece to which a plurality of strain gauges are attached are held by the upper gripping tool 11 and the lower gripping tool 12. An operation for adjusting the position and angle of the axis of the gripping tool 12 and confirming the consistency of the axis based on the detected value of the strain gauge at that time is executed.

  At the time of this adjustment, the angle of the axis of the connecting shaft 90 is adjusted by rotating the tilt adjusting screw 42, and the position of the axis of the connecting shaft 90 is adjusted by rotating the horizontal position adjusting screw 43. To do. That is, by rotating the four inclination adjusting screws 42 in a predetermined direction, a force in a fixed direction is generated between the fixed base flange 31 and the alignment member 41. Thus, the fixed base portion 30 and the aligning member 41 are in contact with the spherical contact surface of the spherical liner 32 in the fixed base portion 30 and the spherical contact surface 45 of the aligning member 41. Are relatively moved, and the angle of the axis of the connecting shaft 90 is changed. Further, by rotating the four horizontal position adjusting screws 43 in a predetermined direction, a force in a certain direction is generated between the moving base flange 51 and the alignment member 41. As a result, in a state where the planar contact surface of the planar liner 52 in the moving side base portion 50 and the planar contact surface in the aligning member 41 are in contact, the moving base portion 50 and the aligning member 41 Will move relatively, and the horizontal position of the axial center of the connecting shaft 90 is changed.

  If the angle and the position of the shaft center of the connecting shaft 90 (that is, the upper gripper 11) can be adjusted, the tensile force preliminarily applied to the connecting shaft 90 is adjusted as necessary to tighten the shaft adjusting device 20 as a whole. Make power appropriate. In this case, the four wedge members 80 are moved in the axial direction of the connecting shaft 90 by rotating the position adjusting screw 84. Accordingly, the distance between the nut member 70 fixed to the upper end of the connecting shaft 90 and the fixed-side base flange 31, in other words, the nut member 70 fixed to the upper end of the connecting shaft 90 and the lower end portion of the connecting shaft 90 is fixed. In addition, the distance from a later-described moving base flange 51 increases, and accordingly, a necessary tensile force is applied to the connecting shaft 90.

  In the shaft center adjusting device 20, the necessary tensile force can be applied to the connecting shaft 90 by adjusting the position of the wedge member 80. At this time, since the adjustment operation of the tensile force can be executed from the lateral position of the shaft center adjusting device 20, not only the shaft center adjusting device 20 can be made compact, but also the shaft Even after the center adjusting device 20 is connected to the load frame such as the crosshead 23 or the load cell 13, the tensile force can be adjusted. For this reason, it becomes a suitable thing when adding this axial center adjustment apparatus 20 to the existing material testing machine.

  In the above-described embodiment, the fixed-side base portion 30 includes the spherical liner 32 formed with the spherical contact surface 38 and the fixed-side base flange 31, and the moving-side base portion 50 has a planar contact. A contact member 53 having a surface and a moving base flange 51 are provided. As a result, the spherical liner 32 and the flat liner 52 can be made of a strong material, and the fixed base flange 31 and the moving base flange 51 can be made of a material with good workability. However, by directly processing the fixed base flange 31 and the movable base flange 51, a spherical contact surface is formed on the fixed base flange 31 itself, and a flat surface is formed on the movable base flange 51 itself. A contact surface may be formed.

  Next, another embodiment of the present invention will be described. FIG. 6 is a longitudinal sectional view of the shaft center adjusting device 20 of the material testing machine according to the second embodiment of the present invention.

  The shaft center adjusting device 20 includes a fixed base flange 37 fixed to the crosshead 23 constituting the load frame, a nut member 72 that abuts on the fixed base flange 37, and the upper grip 11 via the load cell 13. The connecting side base flange 53, the pair of annular wedges 81, the contact member 35, the connecting shaft 90 that connects the nut member 72 and the moving side base flange 53, and the outer periphery of the connecting shaft 90 An alignment mechanism 60 is provided which is disposed at a position between the contact member 35 and the moving-side base flange 53 and adjusts the angle of the connecting shaft 90 and the position of the axis.

  The nut member 72 is screwed with a male screw portion formed at the upper end of the connecting shaft 90 and is fixed to the connecting shaft 90. The fixed side base flange 37 is attached to the cross head 23 by a plurality of fixing screws 36. A load cell 13 indicated by a virtual line in FIG. 6 is fixed to the moving side base flange 53 by a plurality of fixing screws 49. As in the case of the first embodiment, the upper gripping tool 11 is fixed to the load cell 13 as shown in FIG.

  FIG. 7 is a perspective view of the annular wedge 81.

  This annular wedge 81 has a cylindrical shape in which a through hole 83 of the connecting shaft 90 is formed at the center thereof and can surround the outer peripheral portion of the connecting shaft 90. The lower surface of the annular wedge 81 is a parallel plane that is a plane perpendicular to the axis of the connecting shaft 90 when the annular wedge 81 is mounted on the outer periphery of the connecting shaft 90. On the other hand, the upper surface of the annular wedge 81 is an inclined surface having a spiral shape that is inclined with respect to a plane perpendicular to the axis of the coupling shaft 90 when the annular wedge 81 is mounted on the outer peripheral portion of the coupling shaft 90. 85. A rotating hole 82 for rotating the annular wedge 81 on the outer peripheral portion of the connecting shaft 90 is formed on the outer peripheral portion of the annular wedge 81.

  As shown in FIG. 6, a pair of annular wedges 81 are arranged opposite to each other with the spiral inclined surfaces 85 in contact with each other on the outer peripheral portion of the connecting shaft 90, and the pair of annular wedges 81 are connected to the connecting shaft 90. 6, the height occupied by the pair of annular wedges 81 is changed by the action of the inclined surface 85 having a spiral shape, and the lower surface of the fixed-side base flange 31 shown in FIG. And the upper surface of the contact member 35 are changed. As a result, a tensile force is generated on the connecting shaft 90.

  The abutting member 35 disposed at a position where it abuts with the pair of annular wedges 81 has the same shape as the spherical liner 32 shown in FIG. That is, the contact member 35 has a spherical contact surface on one surface thereof. The contact member 35 is made of a material having an appropriate strength. Further, a through hole through which the connecting shaft 90 passes is formed in the center of the contact member 35.

  A centering member 61, four inclination adjusting screws 62, and four horizontal position adjusting screws 63 are positioned between the contact member 32 and the moving base flange 51 on the outer peripheral portion of the connecting shaft 90. An alignment mechanism 60 configured to adjust the angle of the shaft center of the connecting shaft 90 and the position of the shaft center is provided.

  A spherical contact surface whose center faces the upper gripper 11 side is formed on the contact member 35 side of the aligning member 61. The contact surface has a shape corresponding to the spherical contact surface of the contact member 35 described above. In addition, a planar contact surface is formed on the side of the alignment member 61 on the moving side base flange 53 side. The alignment member 61 is made of a material having an appropriate strength. A through hole through which the connecting shaft 90 passes is formed in the center of the aligning member 61.

  The aligning member 61 includes a flange-like protrusion, and four inclination adjustment screws 62 and horizontal position adjustment screws 63 are disposed at each angle position of 90 degrees in plan view. Yes. The inclination adjusting screw 62 is disposed on the aligning member 61 such that its axis is directed in the direction toward the axis of the connecting shaft 90 and its tip is in contact with the outer peripheral surface of the contact member 35. On the other hand, the horizontal position adjusting screw 63 is disposed on the aligning member 61 with its axis oriented in the direction toward the axis of the connecting shaft 90 and its tip abutting the outer peripheral surface of the moving base flange 53. ing.

  In addition, the contact surface of the spherical liner 32, the contact surface of the planar liner 52, the spherical contact surface 45 and the planar contact surface of the aligning member 41, and the spherical contact surface of the contact member 35 described above. DLC (Diamond-Like Carbon) coating is applied to necessary portions of the surface, the spherical contact surface of the aligning member 61 and the flat contact surface in order to improve wear resistance and reduce friction. Has been made.

  When assembling the shaft center adjusting device 20 of the material testing machine having the above-described configuration, first, the moving-side base flange 53 is screwed into the lower end portion of the connecting shaft 90. Then, the alignment member 61, the contact member 35, the pair of annular wedges 81, and the fixed-side base flange 37 are sequentially stacked on the outer peripheral portion of the connecting shaft 90, and the nut member 72 is attached to the upper end portion of the connecting shaft 90. These members are integrated by screwing. Further, the inclination adjusting screw 62 and the horizontal position adjusting screw 63 are installed at necessary positions.

  Then, the upper gripping tool 11 is attached to the moving-side base flange 53 via the load cell 13. Further, the fixed side base flange 37 is attached to the cross head 23 by a plurality of fixing screws 36. A lower grip 12 is attached to the base 16.

  In this state, the axial center between the upper gripper 11 and the lower gripper 12 is adjusted by adjusting the position and angle of the axial center of the lower gripper 12 using the axial center adjustment device 20 according to the present invention. Align. Also in this case, the position and angle of the axis of the lower grip 12 are adjusted in a state where both ends of the test piece to which a plurality of strain gauges are attached are gripped by the upper grip 11 and the lower grip 12. An operation for confirming the alignment of the shaft center is performed based on the detected value of the strain gauge.

  At the time of this adjustment, the angle of the connecting shaft 90 is adjusted by rotating the tilt adjusting screw 62, and the position of the connecting shaft 90 is adjusted by rotating the horizontal position adjusting screw 63. To do. That is, by rotating the four inclination adjusting screws 62 in a predetermined direction, a force in a certain direction is generated between the contact member 35 and the alignment member 61. As a result, the contact member 35 and the aligning member 61 relatively move in a state where the spherical contact surface of the contact member 35 and the spherical contact surface of the aligning member 61 contact each other. Accordingly, the fixed-side base flange 37 and the alignment member 61 move relatively, and the angle of the axis of the connecting shaft 90 is changed. Further, by rotating the four horizontal position adjusting screws 63 in a predetermined direction, a force in a certain direction is generated between the moving base flange 53 and the aligning member 61. As a result, the moving-side base flange 53 and the aligning member 61 are relatively brought into contact with each other while the planar contact surface of the moving-side base flange 53 and the planar contact surface of the aligning member 61 are in contact with each other. The position of the connecting shaft 90 in the horizontal direction is changed.

  If the angle and position of the shaft center of the connecting shaft 90 (that is, the upper gripper 11) can be adjusted, the tensile force applied to the connecting shaft 90 is adjusted as necessary to tighten the shaft center adjusting device 20 as a whole. Make power appropriate. In this case, the pair of annular wedges 81 are rotated relatively around the axis of the connecting shaft 90 at the outer peripheral portion of the connecting shaft 90 using the rotation holes 82. Thereby, the distance between the lower surface of the fixed-side base flange 31 and the upper surface of the contact member 35 is changed, and a necessary tensile force is applied to the connecting shaft 90.

  Here, when it is difficult to relatively rotate the pair of annular wedges 81 due to the frictional force, the upper gripping tool 11 and the lower gripping tool 12 hold both ends of the dummy test piece in this state. A maximum test force (for example, a larger tensile force than that during material testing) is applied to the dummy test piece, and the pair of annular wedges 81 are relatively rotated in this state. As a result, it is possible to cause the connecting shaft 90 to have a sufficient tensile force to execute the material test.

  Also in the shaft center adjusting device 20 according to the second embodiment, a necessary tensile force can be applied to the connecting shaft 90 by adjusting the rotation angle position of the pair of annular wedges 81. Accordingly, as with the shaft center adjustment device 20 according to the first embodiment, the tension force adjustment operation can be executed from the lateral position of the shaft center adjustment device 20, so that the shaft center adjustment device 20 is compact. Not only can this be achieved, but also after the shaft center adjusting device 20 is connected to a load frame such as the crosshead 23 or the load cell 13, the tensile force can be adjusted. For this reason, it becomes a suitable thing when adding this axial center adjustment apparatus 20 to the existing material testing machine.

  In the embodiment described above, the shaft center adjusting device according to the present invention is applied to a material testing machine that applies a test force to the test piece 10 by the action of the cross head 23 that moves up and down by the rotation of the pair of screw rods 17. Although the case has been described, the present invention may be applied to a hydraulic servo type, electromagnetic type or pneumatic type fatigue and durability tester.

DESCRIPTION OF SYMBOLS 10 Test piece 11 Upper gripping tool 12 Lower gripping tool 13 Load cell 14 Displacement meter 17 Screw rod 18 Motor 20 Axis center adjusting device 23 Crosshead 30 Fixed side base part 31 Fixed side base flange 32 Spherical liner 35 Contact member 37 Fixed side base Flange 40 Alignment mechanism 41 Alignment member 42 Inclination adjustment screw 43 Horizontal position adjustment screw 44 Abutment surface 50 Moving side base 51 Moving side base flange 52 Planar liner 53 Abutting member 54 Moving side base flange 60 Alignment mechanism 61 Alignment Core member 62 Inclination adjusting screw 63 Horizontal position adjusting screw 70 Nut member 71 Taper member 72 Nut member 80 Wedge member 81 Annular wedge 84 Position adjusting screw 90 Connecting shaft

Claims (5)

An axis adjustment device for a material testing machine fixed to a load frame for adjusting the axis of a gripping tool for gripping a test piece,
A fixed base portion connected to the load frame;
A moving base connected to the gripping tool;
A connecting shaft for fastening the fixed side base portion and the moving side base portion;
A centering mechanism that is disposed at a position between the fixed base portion and the movable base portion on the outer peripheral portion of the connecting shaft, and adjusts the angle of the shaft center and the position of the shaft center of the connecting shaft;
A wedge mechanism for generating a tensile force on the connecting shaft;
An apparatus for adjusting an axis of a material testing machine, comprising: The axis adjusting device of the material testing machine according to claim 1,
The wedge mechanism is
A taper member connected to the connecting shaft and having an inclined surface formed on an outer peripheral portion of the connecting shaft that is inclined with respect to a plane perpendicular to the axis of the connecting shaft;
A plurality of wedge members having an inclined surface corresponding to the inclined surface formed on the taper member, and movable between a position close to the connecting shaft and a position separated from the connecting shaft;
An axis adjusting device for a material testing machine that generates a tensile force with respect to the connecting shaft by moving the plurality of wedge members. The axis adjusting device for a material testing machine according to claim 2,
The taper member is an axis adjusting device for a material testing machine attached to a nut member disposed at one end of the connecting shaft. The axis adjusting device of the material testing machine according to claim 1,
The wedge mechanism is
The connecting shaft has a cylindrical shape surrounding an outer peripheral portion, and one end edge of the connecting shaft is parallel to a plane perpendicular to the axis of the connecting shaft, and the other end is the axis of the connecting shaft. A pair of annular wedges having a spiral shape that is inclined with respect to a plane perpendicular to each other, with the spiral edges facing each other,
A shaft center adjustment device for a material testing machine that generates a tensile force with respect to the connection shaft by rotating the pair of annular wedges relative to the connection shaft at the outer periphery of the connection shaft. . The shaft center adjusting device for a material testing machine according to any one of claims 2 to 4,
The alignment mechanism is
A spherical contact surface whose center faces the gripper side is formed on one side of the fixed side base portion or the movable side base portion, and on the other side of the fixed side base portion or the movable side base portion. An alignment member formed with a planar contact surface;
A plurality of adjustment screws arranged for adjusting the angle of the axis of the connecting shaft toward the direction of the axis of the connecting shaft;
A plurality of adjusting screws arranged for adjusting the position of the axis of the connecting shaft toward the direction of the axis of the connecting shaft;
An axis adjusting device for a material testing machine comprising

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