JP2016169943A - Shaft center adjusting device and material test machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save a space and decrease weight of a shaft center adjusting device of a material test machine.SOLUTION: A first base portion 30 and a second base portion 50 are coupled with each other by four fixing bolts 61 and four supporting bolts 71, while sandwiching a center adjusting mechanism 40. In an abutting portion between a head portion of the fixing bolt 61 and a base flange 51 of the second base portion 50, and an abutting portion between a nut 65 side of the fixing bolt 61 and the first base portion 30, spherical washers 63 and 64 in which convex portions and concave portions having spherical surfaces corresponding to each other make pairs, are inserted. Between an abutting portion between a head portion of the supporting bolt 71 and a base flange 51 of the second base portion 50, and an abutting portion between a double nut 75 of the supporting bolt 71 and the first base portion 30, spherical washers 73 and 74 are inserted as same as the case of the fixing bolt 61.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shaft center adjusting device for adjusting a shaft center of a test jig arranged in a load frame of a material testing machine, and a material testing machine including the same.

  A test jig corresponding to the purpose of a test such as a tensile test or a fatigue test is attached to the material testing machine. Such a material testing machine, for example, detects a load cell and displacement while applying a test load to a test piece held in a load frame of the material testing machine via a pair of grips as a test jig. The test force and displacement at that time are measured by the instrument. In the material test, an accurate test cannot be performed unless the axis of the test jig is aligned with the load axis. For this reason, such a material testing machine is provided with an axis adjustment device for adjusting the axis of the test jig. An example of the shaft center adjusting device is described in Patent Document 1.

  FIG. 4 is a schematic diagram of a conventional shaft center adjusting device 120. 5 is a cross-sectional view taken along the line AA in FIG. In addition, illustration of the connection part 159 is abbreviate | omitted in FIG.

  The shaft center adjusting device 120 includes a first base portion 130 connected to a crosshead and a base constituting a load frame of the material testing machine, a first connection portion 170 contacting the first base portion 130, a gripping tool, and the like. The second base portion 150 connected to the test jig via the connecting portion 159, the second connection portion 180 contacting the second base portion 150, the first base portion 130, and the second base portion 150, respectively. And an alignment mechanism 140 that adjusts the shaft centers to coincide with each other. The aligning mechanism 140 includes a support portion 141 having a spherical convex portion, an angle adjusting collar member 142 that comes into spherical contact with the spherical convex portion of the support portion 141, and a flat surface opposite to the spherical convex portion of the support portion 141. A position adjusting collar member 143 in contact with the surface; an inclination adjusting screw 144 in contact with the angle adjusting collar member 142; and a horizontal position adjusting screw 145 in contact with the position adjusting collar member 143. In the example of this figure, the second base unit 150 is a load cell and functions also as a sensor for measuring the test force.

  The aligning mechanism 140 includes the first base by a connecting shaft 190 that passes through the angle adjusting collar member 142, the support portion 141, and the position adjusting collar member 143 and connects the first base portion 130 and the second base portion 150. It is disposed at a position between the part 130 and the second base part 150. Then, the angle adjusting collar member 142 and the position adjusting collar member 143 are moved by operating the inclination adjusting screw 144 and the horizontal position adjusting screw 145 to adjust the angle of the axis of the connecting shaft 190 and the position of the axis. Thus, the axis of the test jig is adjusted.

  In the conventional shaft center adjusting device 120, the connecting shaft 190 is screwed to the first base portion 130 and the second base portion 150, and the backlash nut 160 is connected to the alignment mechanism 140 and the second connection portion 180. It is arranged in between. Further, spherical nuts 172 and 182 that are in contact with the ball seat surfaces 171 and 181 are provided on the first connection portion 170 and the second connection portion 180 so as to correspond to the inclination of the connecting shaft 190.

JP 2000-171366 A

  In the conventional shaft center adjusting device 120, since the shaft center is adjusted by moving the connecting shaft 190, it is not easy to shorten the length of the connecting shaft 190 from the viewpoint of securing the adjustment width. Further, in order to prevent rattling from occurring in the aligning mechanism 140 due to the force corresponding to the bending that acts on the connecting shaft 190 during the adjustment of the shaft center, the same shape 2 is applied to the connecting shaft 190 from the lower side of the aligning mechanism 140. The nuts 161 and 162 are fastened together as a set, and a backlash removing nut 160 is provided to move the nuts 161 and 162 apart from each other to remove backlash. At both ends of the connecting shaft 190, a ball seat surface 171 and a spherical nut are provided. The ball seat portion 173 by 172 and the ball seat portion 183 by the ball seat surface 181 and the spherical nut 182 are provided to absorb the force generated when the connecting shaft 190 is tilted. For this reason, conventionally, the dimension of the longitudinal direction of the shaft center adjusting device 120 becomes long. If it does so, the test space in the load frame in a material testing machine will become narrow, and the problem that the test range of a load axis direction (longitudinal direction) will be restricted will arise.

  Moreover, since the load shaft 190 plays a role of supporting each member constituting the shaft center adjusting device 120 at the center, the load shaft 190 itself is a heavy member. Furthermore, since the adjustment of the shaft center depends on the movement of the connecting shaft 190, ball seats 173 and 183 for receiving the force generated when the connecting shaft 190 is tilted, and the backlash nut 160 are provided. There is a need. For this reason, the weight of the shaft center adjustment device 120 is heavy. Therefore, the shaft center adjusting device 120 is attached to a movable part (for example, a cylinder rod of a fluid cylinder) of an actuator of a material testing machine that drives a test such as a fatigue test and repeatedly applies a test force to a test piece. It was difficult.

  The present invention has been made to solve the above-described problems, and has an object to provide a shaft center adjusting device that is space-saving and lighter than the conventional one and a material testing machine including the same. To do.

  The invention according to claim 1 is an axis adjusting device for adjusting an axis of a test jig arranged in a load frame of a material testing machine, and is fixed to the load frame or the load frame. A first base connected to the load means; a second base connected to the test jig; and a shaft of the test jig disposed between the first base and the second base. A centering mechanism that adjusts the angle of the center and the position of the shaft center, a contact portion with the first base portion that is disposed on the outer periphery of the centering mechanism and that acts on the tightening force, and the second base portion; A spherical washer is inserted into the contact portion of the first base portion, and an elastic member is inserted into the contact portion side with the first base portion or the contact portion side with the second base portion. And a plurality of supporting bolts connecting the second base portion.

  According to a second aspect of the present invention, there is provided the shaft center adjusting device according to the first aspect, wherein the shaft center adjusting device is disposed on an outer periphery of the aligning mechanism and is in contact with the first base portion on which a tightening force is applied. And a plurality of fixing bolts for connecting the first base portion and the second base portion with a spherical washer interposed between the two base portions.

  According to a third aspect of the present invention, in the shaft center adjusting device according to the first aspect, the second base portion includes a contact member that contacts the alignment mechanism, and a base that is spherically engaged with the contact member. And a flange.

  According to a fourth aspect of the present invention, in the shaft center adjusting device according to the first aspect, the elastic member is a disc spring.

  According to a fifth aspect of the present invention, a gripping tool for gripping a test piece is provided as a test jig in the load frame, and the gripping tool is moved to the load frame to apply a load to the test piece. A material testing machine provided with a fluid cylinder for disposing the shaft center adjusting device according to any one of claims 1 to 4 between the fluid cylinder and the gripping tool. It is characterized by that.

  According to the first to fourth aspects of the present invention, the contact portion with the first base portion and the contact portion with the second base portion, which are arranged on the outer periphery of the alignment mechanism and to which the tightening force acts, are provided. A spherical washer is inserted, and an elastic member is inserted between the first base part and the second base part, or the first base part and the second base part are connected. By providing a plurality of supporting bolts, the space can be saved and the weight can be reduced as compared with the conventional shaft center adjusting device.

  According to the second aspect of the present invention, since the fixing bolt is provided in addition to the supporting bolt, it is possible to flexibly cope with the replacement of the test jig and the accompanying shaft center adjustment work.

  According to the third aspect of the present invention, the second base portion includes the abutting member that abuts the aligning mechanism and the base flange that is spherically engaged with the abutting member. It is possible to absorb more force generated by the inclination of the.

  According to the fourth aspect of the present invention, a constant tension force is applied to the supporting bolt by the disc spring so that the shaft center of the test jig after the shaft center adjustment does not change while having a simpler configuration. In addition, the tightening force on the entire shaft adjusting device can be made appropriate. The alignment mechanism can be held in a state where alignment is possible on the support bolt.

  According to the fifth aspect of the present invention, it is possible to connect to a movable member such as a cylinder rod of a fluid cylinder of a material testing machine by reducing the weight of the conventional shaft center adjusting device. In addition, by reducing the overall height of the shaft center adjustment device, the test space within the load frame of the material testing machine is widened, and material testing with a wider test range in the load axis direction (longitudinal direction) than before is performed. Is also possible.

1 is a schematic diagram of a material testing machine to which an axial center adjusting device 20 according to the present invention is applied. 1 is a longitudinal sectional view of an axis adjusting device 20 according to the present invention. It is an AA cross-sectional arrow view in the axial center adjustment apparatus 20 of FIG. It is a schematic diagram of the conventional axial center adjustment apparatus 120. It is an AA cross-sectional arrow view in the conventional axial center adjustment apparatus 20 of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a material testing machine to which an axial center adjusting device 20 according to the present invention is applied.

  The material testing machine includes a base 16 and a cross head 15 supported by a pair of support columns 14 provided upright on the base 16. The base 16, the column 14, and the crosshead 15 constitute a load frame for applying a test force to the test piece 10.

  The cross head 15 is fixed to an arbitrary height position of the support column 14 by a clamp 17 using hydraulic pressure or pneumatic pressure. An upper grip 11 is attached to the cross head 15 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.

  In the material testing machine shown in FIG. 1, an example in which the upper gripping tool 11 and the lower gripping tool 12 are arranged in the load frame as test jigs is shown. However, tests such as a tensile test and a fatigue test are shown. Depending on the purpose, a test jig (for example, a platen) other than the upper gripper 11 and the lower gripper 12 is disposed in the load frame.

  Further, the crosshead 15 is provided with a fluid cylinder 18 such as a hydraulic cylinder or an air cylinder. The cylinder rod 19 in the fluid cylinder 18 protrudes downward from the cross head 15. By moving the cylinder rod 19 of the fluid cylinder 18, a test force is applied to the test piece 10. The magnitude of the test force at this time is measured by the load cell 13.

  FIG. 2 is a longitudinal sectional view of the axis adjusting device 20 of the material testing machine according to the present invention. Moreover, FIG. 3 is an AA cross-sectional arrow view in FIG.

  The axial center adjusting device 20 is for adjusting the axial center of the upper gripping tool 11 and the lower gripping tool 12 by adjusting the position and angle of the axial center of the upper gripping tool 11. In the shaft center adjusting device 20, the upper gripper 11 is connected to the first base portion 30 that is connected to the cylinder rod 19 that passes through the crosshead 15 that constitutes the load frame and protrudes into the load frame, and the load cell 13. And a centering mechanism 40 that adjusts the axial centers of the first base portion 30 and the second base portion 50 to coincide with each other. The aligning mechanism 40 aligns the upper gripper 11 connected to the second base unit 50 by aligning the second base unit 50.

  The alignment mechanism 40 is disposed between the first base portion 30 and the second base portion 50. The alignment mechanism 40 includes a support portion 41 having a spherical convex portion, an angle adjusting collar member 42 that spherically contacts the support portion 41 by a spherical concave portion corresponding to the spherical convex portion of the support portion 41, and the support portion 41. On the side surface of the position adjusting collar member 43 that contacts the side surface of the angle adjusting collar member 42 and the position adjusting collar member 43 that contacts the flat surface on the opposite side of the spherical convex portion. It has four horizontal position adjusting screws 45 that come into contact. In addition, a concave portion that fits a contact convex portion of a contact member 52 of the second base portion 50 described later is formed on the surface opposite to the contact surface of the position adjusting collar member 43 with the support portion 41. Has been.

  The second base portion 50 includes a contact member 52 that contacts the alignment mechanism 40 and a base flange 51. The contact member 52 is disposed in a recess formed in the base flange 51. The contact member 52 has a spherical contact surface having a shape corresponding to the contact surface with the recess of the base flange 51 on one surface, and the alignment mechanism 40 on the other surface. The position adjusting collar member 43 has an abutting convex portion that fits into the concave portion. Further, the contact member 52 is provided with a connecting portion 58 that protrudes from the base flange 51. The load cell 13 is connected to the connection unit 58.

  Since the concave portion of the position adjusting collar member 43 of the alignment mechanism 40 and the contact convex portion of the contact member 52 are fitted together, the movement of the position adjusting collar member 43 causes the load cell 13 to connect the upper gripper 11. It is reflected in the position. In this embodiment, the load cell 13 is connected to the connection portion 58, but the upper grip 11 and other test jigs may be directly connected to the connection portion 58.

  The first base portion 30 and the second base portion 50 are connected to each other with four alignment bolts 61 and four support bolts 71 sandwiching the alignment mechanism 40. The four fixing bolts 61 and the four supporting bolts 71 are arranged on the outer periphery of the aligning mechanism 40 so that the intervals between the fixing bolts 61 are equal and the intervals between the supporting bolts 71 are the same. It arrange | positions at equal intervals on the same periphery so that it may become equal intervals.

  The fixing bolt 61 penetrating the first base portion 30 and the second base portion 50 has a contact portion with the first base portion 30 on which the tightening force acts and a contact portion with the second base portion 50, Spherical washers 63 and 64 are inserted. As shown in FIG. 2, a contact portion between the head of the fixing bolt 61 and the base flange 51 of the second base portion 50, in which a tightening force is applied by fastening a nut 65 to the fixing bolt 61, and The fixing portion 61 is fixed in a state in which spherical washers 63 and 64 in which convex portions and concave portions each having a corresponding spherical surface are paired are inserted into a contact portion between the nut 65 side of the fixing bolt 61 and the first base portion 30. A bolt 61 is disposed.

  In addition, the supporting bolt 71 penetrating the first base part 30 and the second base part 50 has a contact part with the first base part 30 to which the tightening force is applied and a contact part with the second base part 50. Spherical washers 73 and 74 are inserted, and a disc spring 76 as an elastic member is inserted in a contact portion with the first base portion 30 or a contact portion with the second base portion 50. As shown in FIG. 2, a contact portion between the head of the support bolt 71 and the base flange 51 of the second base portion 50, in which a tightening force is applied by fastening a double nut 75 to the support bolt 71, In addition, spherical washers 73 and 74 are inserted into the contact portion between the double nut 75 side of the support bolt 71 and the first base portion 30 in the same manner as in the case of the fixing bolt 61, and the double nut of the support bolt 71 is inserted. A support bolt 71 is disposed at a contact portion between the 75 side and the first base portion 30 with a disc spring 76 as an elastic member interposed therebetween.

  When assembling the shaft center adjusting device 20 of the material testing machine having the above-described configuration, the alignment mechanism 40 is sandwiched between the first base portion 30 and the second base portion 50, and the first base portion 30 and the first base portion 30 are 2 A support bolt 71 is inserted into a hole passing through the base flange 51 of the base portion 50, and a double nut 75 is fastened to a screw portion of the support bolt 71. Thereby, the 1st base part 30 and the 2nd base part 50 are connected. Next, the fixing bolt 61 is inserted into a hole passing through the first base portion 30 and the base flange 51 of the second base portion 50, and the nut 65 is loosely screwed into the screw portion of the fixing bolt 61. .

  When the assembled shaft adjusting device 20 is arranged in the material testing machine shown in FIG. 1, the first base portion 30 is connected to the cylinder rod 19 of the fluid cylinder 18 via a connecting member.

  In this state, when the shaft center adjustment is performed using the shaft center adjustment device 20, the upper gripping tool 11 is attached to the connection portion 58 via the load cell 13. The lower grip 12 is attached to the base 16. In order to align the axial centers of the upper gripping tool 11 and the lower gripping tool 12, for example, as described in Japanese Patent Application Laid-Open No. 64-31033, both end portions of the test piece 10 to which a plurality of strain gauges are attached are The operation of adjusting the axial center position and angle of the upper gripping tool 11 while being gripped by the gripping tool 11 and the lower gripping tool 12, and confirming the consistency of the shaft center based on the detected value of the strain gauge at that time. Is executed.

  At the time of this adjustment, the angle adjusting collar member 42 is moved along the spherical convex portion of the support portion 41 by rotating the four tilt adjusting screws 44 and moving them in a predetermined direction, and four horizontal adjustment screws 44. By rotating the position adjusting screw 45 and moving it in a predetermined direction, the position adjusting collar member 43 is moved along the flat surface of the support portion 41. That is, the first base portion 30 and the aligning mechanism 40 move relatively, and the angle of the axis of the upper gripper 11 is changed. Further, by moving the four horizontal position adjusting screws 45 in a predetermined direction, the second base portion 50 and the alignment mechanism 40 move relatively, and the horizontal direction of the axis of the upper gripper 11 is determined. The position of is changed.

  When adjusting the shaft center, the nut 65 of the fixing bolt 61 is in a loosened state. Therefore, the aligning mechanism 40 is connected to the first base portion 30 and the first base member 30 by the fastening force of the support bolt 71 and the double nut 75. 2 in a state of being held between the two base portions 50. Since the disc spring 76 is inserted in the support bolt 71, the pressing force from the first base portion 30 and the second base portion 50 is applied to the aligning mechanism 40 while the support portion 41 is in contact. On the other hand, the angle adjusting collar member 42 and the position adjusting collar member 43 are movable.

  By operating the tilt adjusting screw 44 and the horizontal position adjusting screw 45 in such a state, the position adjusting collar member 43 and the angle adjusting collar member 42 are moved, and the axis of the upper gripper 11 is adjusted. . It should be noted that a constant tensile force is applied to the support bolt 71 by the disc spring 76, so that the axial force of the upper gripper 11 after the axial center adjustment does not change so that the clamping force applied to the entire shaft center adjusting device 20 is increased. Is appropriate.

  If the angle and position of the shaft center of the upper gripper 11 can be adjusted, the nut 65 is fastened to the threaded portion of the fixing bolt 61. The force corresponding to the bending when the fixing bolt 61 and the supporting bolt 71 are tilted by moving the position adjusting collar member 43 and the angle adjusting collar member 42 is the spherical washer 63, 64, 73. , 74. Further, since the abutting member 52 of the second base portion 50 and the base flange 51 are spherically engaged, the fixing bolt 61 is obtained by moving the position adjusting collar member 43 and the angle adjusting collar member 42. The force generated by the inclination of the support bolt 71 can be absorbed. In addition, it is not an essential structure for this invention that the 2nd base part 50 consists of two members, the contact member 52 and the base flange 51, and they are carrying out spherical connection. When the second base portion 50 is integrally formed as one member, the force generated by the inclination of the fixing bolt 61 and the supporting bolt 71 is absorbed by the spherical washers 63, 64, 73, 74. Can do. The spherical coupling between the abutting member 52 and the base flange 51 makes it more reliable.

  After the axial center adjustment operation is finished, the nut 65 is fastened to the fixing bolt 61 so that the relative positional relationship after the movement of the angle adjusting collar member 42 and the position adjusting collar member 43 is fixed by the fixing bolt 61. The axial center is not changed even when a test force is applied to the upper gripping tool 11. When the test jig is replaced, the nut 65 of the fixing bolt 61 is loosened, and the above-described series of shaft center adjustment operations are executed.

  In the embodiment described above, the fixing bolt 61 is provided separately from the supporting bolt 71. However, if the fixing bolt 61 is not provided, the disc spring 76 does not function as the supporting bolt 71. It may be completely tightened until the shaft is adjusted. In the case where the shaft center adjusting device of the present invention is arranged in a material testing machine that has very few opportunities to adjust the shaft center by changing the test jig because only the same test is repeatedly performed, the fixing bolt 61 is thus attached. It may be omitted.

  As described above, the connecting shaft 190 (see FIGS. 4 and 5) penetrating the first base portion 130, the shaft center adjusting mechanism 140, and the second base portion 150 of the conventional shaft center adjusting device 120 becomes unnecessary. Thus, the overall height of the shaft center adjusting device 20 can be reduced. Therefore, the test space in the load frame in the material testing machine is widened, and a material test with a wider test range in the load axis direction (longitudinal direction) than before can be performed.

  Further, the conventional shaft center adjusting device 120 is heavier due to the connecting shaft 190, the ball seats 173 and 183, the backlash nut 160, and the like. Since the shaft 190, the ball seats 173 and 183, and the rattling nut 160 are not required, it is possible to reduce the weight of the device (for example, about 30% less than the conventional weight). Therefore, as in the material testing machine shown in FIG. 1, it is possible to connect the shaft center adjusting device 20 to the cylinder rod 19 of the fluid cylinder 18 that reciprocates and perform a fatigue test.

  In the above-described embodiment, the fluid cylinder 18 disposed in the cross head 15 is employed as the load means for the test piece 10. However, the load cylinder is installed on the screw rod as the load means for the test piece 10. In a material testing machine that employs a crosshead lifting mechanism or the like, the shaft center adjusting device 20 of the present invention can be disposed directly on the crosshead. Even when the axis adjusting device 20 is arranged in such a material testing machine, the test space in the load frame in the material testing machine is widened, and the material having a wider test range in the load axis direction (longitudinal direction) than in the past. A test can be performed.

DESCRIPTION OF SYMBOLS 10 Test piece 11 Upper gripping tool 12 Lower gripping tool 13 Load cell 14 Strut 15 Crosshead 16 Base 17 Clamp 18 Fluid cylinder 19 Cylinder rod 20 Axis center adjustment device 30 First base part 40 Alignment mechanism 41 Support part 42 For angle adjustment Collar member 43 Position adjustment collar member 44 Inclination adjustment screw 45 Horizontal position adjustment screw 50 Second base portion 51 Base flange 52 Contact member 58 Connection portion 61 Fixing bolt 63 Spherical washer 64 Spherical washer 65 Nut 71 Support bolt 73 Spherical surface Washer 74 Spherical washer 75 Double nut 76 Belleville spring 120 Center of axis adjustment device 130 First base part 140 Alignment mechanism 141 Support part 142 Angle adjustment collar member 143 Position adjustment collar member 150 Second base part 159 Connecting part 160 Backlash removal 190 nuts Axis

Claims (5)

An axis adjustment device for adjusting the axis of a test jig arranged in a load frame of a material testing machine,
A first base portion coupled to the load frame or a load means fixed to the load frame;
A second base portion to which the test jig is coupled;
An alignment mechanism that is disposed between the first base portion and the second base portion and adjusts the angle of the axis of the test jig and the position of the axis;
A spherical washer is inserted into the contact portion with the first base portion and the contact portion with the second base portion, which is arranged on the outer periphery of the alignment mechanism and acts with a tightening force, and the first base A plurality of supporting bolts that connect the first base part and the second base part by inserting an elastic member on the contact part side with the part or the contact part side with the second base part;
An axial center adjusting device comprising: The shaft center adjusting device according to claim 1,
A spherical washer is inserted into the contact portion with the first base portion and the contact portion with the second base portion, which are arranged on the outer periphery of the aligning mechanism, and a tightening force acts on the first base portion. The shaft center adjustment device further comprising a plurality of fixing bolts connecting the second base portion. The shaft center adjusting device according to claim 1,
The second base portion includes an abutting member that abuts on the alignment mechanism and a base flange that is spherically engaged with the abutting member. The shaft center adjusting device according to claim 1,
The shaft center adjustment device, wherein the elastic member is a disc spring. A gripping tool for gripping the test piece as a test jig is provided in the load frame, and a fluid cylinder for moving the gripping tool is provided in the load frame to apply a load to the test piece. A material testing machine,
A material testing machine, wherein the shaft center adjusting device according to any one of claims 1 to 4 is disposed between the fluid cylinder and the gripping tool.

Images