JP2013224873A - Material testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material testing machine capable of reducing a load applied to a bearing of an actuator with a rectilinear shaft by releasing component force in a direction different from a loading direction.SOLUTION: An actuator 31 is disposed with a fixing jig 40 for fixing a specimen 1, and a crosshead 15 is disposed with compression load jig 50 via a load cell 25. The compression load jig 50 has a connecting member 51 fixed to a screw type fixing part 26 provided on the load cell 25, via a joint 27, and a movable member 55 coming into contact with the specimen 1. The movable member 55 is connected to the connecting member 51 by a screw 54 as an elastic member. A ball 59 as a sliding member is interposed between the connecting member 51 and the movable member 55.

Description

  The present invention relates to a material testing machine that performs a fatigue / durability test for evaluating durability by repeatedly applying a load to a specimen fixed to a fixing jig.

  A material testing machine attaches a jig to a load frame composed of a base, a crosshead, etc., applies various loads to the specimen supported by these jigs, and applies the load at that time to a load cell, etc. It has the structure which detects with a load detector. The jig mounted on the load frame in such a material testing machine can be replaced according to the purpose of the test and the type of specimen (see Patent Document 1).

  FIG. 6 is an explanatory view showing the fixing jig 40 and the compression load jig 150 of the specimen 1 in a conventional material testing machine. The specimen 1 is an artificial tooth root made of a metal material used for dental implant treatment, and the fixing jig 40 and the compression load jig 150 are jigs for fatigue / durability testing of an artificial tooth root.

  The fixing jig 40 is fixed on the pedestal 41 connected to the screw-type mounting portion 33 formed at the tip of the shaft 32 of the actuator 31 by the nut 43, and the specimen 1 is attached to the load direction. And a fixed base 42 for supporting in a tilted state. On the other hand, the compression load jig 150 includes a joint 152 connected via a joint 27 to a screw-type mounting portion 26 provided in a load cell 25 disposed on a crosshead (not shown), and a platen 151. The joint 152 includes a ball portion 155 provided with a mounting bolt for coupling to the joint 27, and a holder portion 156 that connects the platen 151.

  When performing the fatigue / endurance test, the crosshead is moved to a position where the platen 151 contacts the upper end of the specimen 1. Thereafter, the specimen 31 is repeatedly pressed against the platen 151 by driving the actuator 31 to move the shaft 32 up and down. Thereby, a compression load is repeatedly given to the specimen 1.

  The specimen 1 is fixed to the fixed base 42 at an angle of about 30 degrees with respect to the load direction which is the vertical direction of the paper surface in FIG. The specimen 1 bends when a compression load is applied. Thus, when bending deformation occurs in the specimen 1, a component force is generated in the horizontal direction. Since the joint 152 is fixed to the load cell 25 and the shaft 32 to which the pedestal 41 is connected is moved, the horizontal component force is received by the linear motion bearing 34 that supports the shaft 32.

  As shown in FIG. 6, the conventional compression load jig 150 employs a joint 152 having a spherical sliding surface on the inner surface. And the holder part 156 freely rotates with respect to the ball part 155 of the joint 152 fixed to the crosshead side so as to release the horizontal component force.

JP 2008-196880 A

  However, the joint 152 in the conventional compression load jig 150 is insufficient to release the component force in the direction other than the load direction. That is, when the holder portion 156 of the joint 152 is rotated along with the bending deformation of the specimen 1, the contact surface of the platen 151 connected to the holder portion 156 with the specimen 1 is also inclined. For this reason, the component force in the horizontal direction cannot be released, and the component force in a direction different from the load direction in which the component force cannot be released is a load on the linear motion bearing 34. Such a load has also been a cause of shortening the life of the linear motion bearing 34.

  The present invention has been made to solve the above-described problem, and is a material test capable of releasing a component force in a direction different from the load direction and reducing a load applied to a bearing of an actuator having a linearly moving shaft. The purpose is to provide a machine.

  According to the first aspect of the present invention, an actuator having a bearing and a linearly moving shaft provided in the bearing is disposed on one of the load members facing each other, and between the actuator and the other load member. In the material testing machine in which a specimen is placed on the specimen, and a load is repeatedly applied to the specimen by driving the actuator, and the load load at that time is detected by a load detector, the specimen is connected to the shaft, and the specimen is loaded in the load direction. A fixing jig for inclining and fixing with respect to the fixing jig, a connecting member fixed to a load member facing the fixing jig, a movable member connected to the connecting member by an elastic member, the connecting member, and the And a compression load jig provided between the movable member and a sliding member that moves the movable member in a direction perpendicular to the load direction.

  According to a second aspect of the present invention, in the first aspect of the present invention, the sliding member is a ball.

  According to a third aspect of the present invention, in the first aspect of the present invention, the elastic member is a spring.

  According to the invention described in claim 1 to claim 3, the compression load jig includes a connection member fixed to the load member facing the fixing jig, a movable member connected to the connection member by an elastic member, Since the sliding member is disposed between the connecting member and the movable member, the movable member is moved in a direction perpendicular to the load direction according to the bending deformation of the specimen, and the load direction The component force generated in the direction that intersects perpendicularly can be released. As a result, the load on the bearing of the actuator can be reduced.

  According to the second aspect of the present invention, since the sliding member is a ball, the movable member can be moved regardless of the direction in which the specimen is inclined.

  According to the third aspect of the present invention, since the elastic member is a spring, when a load is applied to the specimen, the load is applied to the specimen by extending with the movement of the movable member with respect to the horizontal component force. When is unloaded, the movable member can be returned to the original position by the restoring force. The restoring force of the spring is small enough that the influence on the bearing can be ignored.

It is a front view of the material testing machine which concerns on this invention. It is a side view of the material testing machine which concerns on this invention. It is a top view of the material testing machine which concerns on this invention. It is explanatory drawing which shows the arrangement | positioning state of a jig | tool. It is explanatory drawing of the compression load jig | tool 50. FIG. It is explanatory drawing which shows the arrangement | positioning state of the jig | tool in the conventional material testing machine.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a front view of a material testing machine according to the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a plan view thereof. In FIG. 1, illustration of a jig and the like described later is omitted, and in FIG. 2, illustration of the actuator 31 is omitted.

  This material testing machine includes a pair of support columns 12 erected on a base 11, a yoke 14 disposed at the upper ends of these support columns 12, and a crosshead 15 movably installed on these support columns 12. With. The base 11, the pair of support columns 12, and the crosshead 15 constitute a load frame for applying a load to the specimen, and the base 11 and the crosshead 15 correspond to a load member in the present invention.

  A rack 13 is attached to the rear surface of the support column 12, and a pinion (not shown) that meshes with the rack 13 and is connected to the lifting handle 16 is disposed on the cross head 15. For this reason, the crosshead 15 moves up and down along the pair of columns 12 by rotating the lifting handle 16. The height position of the cross head 15 is fixed by operating the pair of left and right clamp handles 17.

  An electromagnetic actuator 31 is disposed on the base 11. The actuator 31 includes a shaft 32 that linearly moves (moves up and down) in the vertical direction, and a jig corresponding to the purpose of the test is disposed at the upper end of the shaft 32. In addition, a jig corresponding to the purpose of the test is disposed under the crosshead 15 via a load cell adapter 24, a load cell 25, and a screw-type attachment portion 26. In this material testing machine, the actuator 31 is disposed on the base 11 and the load cell 25 is disposed on the crosshead 15. However, the arrangement of the actuator 31 and the load cell 25 may be reversed.

  Next, the jig of this material testing machine will be described. FIG. 4 is an explanatory view showing the arrangement state of the jig. FIG. 4 shows a state in which a jig for performing a fatigue / durability test of an artificial dental root made of a metal material used for dental implant treatment as the specimen 1 is arranged. 5 is an explanatory diagram of the compression load jig 50, FIG. 5 (a) is a bottom view of the connection member 51, and FIG. 5 (b) is a plan view of the movable member 55.

  The actuator 31 is provided with a fixing jig 40 for fixing the specimen 1. The fixing jig 40 includes a pedestal 41 and a fixing base 42 for fixing the specimen 1 at an angle with respect to the load direction. The fixing jig 40 is coupled to the shaft 32 by connecting a pedestal 41 to a screw-type mounting portion 33 provided at the tip of the shaft 32 of the actuator 31 and fastening a nut 43 from the outside. A fixed base 42 is fixed to the base 41. The fixed base 42 supports the specimen 1 in a state where it is inclined about 30 degrees with respect to the load direction which is the vertical direction of the paper surface of FIG.

  The cross head 15 is provided with a compression load jig 50 via a load cell 25. The compression load jig 50 includes a connection member 51 that is fixed to a screw-type attachment portion 26 provided in the load cell 25 via a joint 27, and a movable member 55 that contacts the specimen 1. The movable member 55 is connected to the connection member 51 by a spring 54 that is an elastic member. A ball 59 that is a sliding member is inserted between the connecting member 51 and the movable member 55.

  Four support rods 52 are arranged at equal intervals on the side surface of the connection member 51, and a convex portion 53 is formed on the lower side of the connection member 51, that is, on the side to which the movable member 55 is connected. Yes.

  On the side surface of the movable member 55, four support rods 56 are arranged at equal intervals similarly to the connection member 51, and a concave portion 57 is formed on the upper side of the movable member 55, that is, on the side connected to the connection member 51. Is formed. A circular guide portion 58 having a slightly larger inner diameter than the diameter of the ball 59 is provided in the concave portion 57, and the ball 59 is disposed in the guide portion 58. The balls 59 are arranged on the guide portion 58 so that the distance between them is kept constant without moving in the recess 57. Note that the number of guide portions 58 formed in the recess 57 is appropriately changed according to the size and number of the balls 59. In addition, a cylindrical roller can be used in place of the ball 59, but when using a cylindrical roller, it is fixed so that the tilt direction of the specimen 1 and the rotation direction of the cylindrical roller are in phase. It should be noted that the jig 40 and the compression load jig 50 must be attached.

  The concave portion 57 of the movable member 55 has an inner diameter larger than the outer diameter of the convex portion 53 of the connecting member 51. For this reason, when the concave portion 57 and the convex portion 53 are combined with the ball 59 disposed on the guide portion 58, a gap is formed between the concave portion 57 and the convex portion 53. The spring 54 is bridged between a support bar 52 protruding from the connection member 51 and a support bar 56 protruding from the movable member 55. Therefore, the movable member 55 can move by rotating the ball 59 in the horizontal direction, which is a direction perpendicular to the load direction, within a range in which the spring 54 extends.

  In the material testing machine having such a configuration, when performing the durability / vibration test, the operator attaches the specimen 1 to the fixed base 42. The specimen 1 is fixed to the fixing base 42 with screws not shown. Next, the operator operates the lifting handle 16 to lower the cross head 15 to a position where the lower surface of the movable member 55 of the compression load jig 50 comes into contact with the specimen 1 and then operates the clamp handle 17. The height position of the crosshead 15 is fixed. Thus, the center of the tip of the specimen 1 is arranged on the same vertical line (load axis) connecting the axis of the screw-type mounting portion 26 on the crosshead 15 side and the axis of the shaft 32 of the actuator 31. become.

  When the specimen 1 and the compression load jig 50 are arranged at a position where the test is performed, the test is started and the actuator 31 is driven. Then, the shaft 32 of the actuator 31 moves up and down with a constant stroke. Accordingly, the pedestal 41 connected to the shaft 32 and the fixed base 42 fixed to the pedestal 41 also move up and down, and the tip of the specimen 1 supported by the fixed base 42 becomes the movable member 55 of the compression load jig 50. Pressed repeatedly. In this way, a vertical compression load is repeatedly applied to the specimen 1.

  When the shaft 32 of the actuator 31 moves upward and the tip of the specimen 1 is pressed against the movable member 55 of the compression load jig 50, a vertical compressive load is applied to the specimen 1. Then, it bends like a bow with the part fixed to the fixed base 42 as a fulcrum. When bending deformation occurs in the specimen 1 in this way, a component force is generated in the horizontal direction perpendicular to the load direction along the load axis. At this time, in the compression load jig 50, the movable member 55 moves in the horizontal direction with respect to the horizontal component force, and the horizontal component force is released.

  As described above, the compression load jig 50 includes the connection member 51 and the movable member 55, and both of them are in close contact with the spring 59 with the ball 59 interposed therebetween. For this reason, the movable member 55 is freely movable in the horizontal direction with respect to the connection member 51 in a state where the movable member 55 is pulled toward the connection member 51 by the spring 54. When a load is applied to the specimen 1, the movable member 55 moves in the horizontal direction according to the bending deformation of the specimen 1 as the ball 59 rotates. The movable member 55 moves horizontally flexibly with respect to the direction of the component force generated when the specimen 1 is bent and deformed. At this time, the contact surface of the movable member 55 with the specimen 1 is horizontal with respect to the load direction. Therefore, the specimen 1 is not pressed in a tilted state like the conventional platen 151. Thus, even if the specimen 1 is deformed, the compression load jig 50 can move away from the movable member 55 only in the horizontal direction without inclining the contact surface with the specimen 1. The vertical compressive load can be continuously applied to the specimen 1 while releasing the component force.

  When the shaft 32 of the actuator 31 moves downward and the load applied to the specimen 1 is unloaded, the bending deformation is reduced by the deformation of the elastic region of the specimen 1 being restored, and the movable member 55 Is returned to its original position by the restoring force of the spring 54 using the rotational force of the ball 59.

  As described above, in this material testing machine, when a load is repeatedly applied to the specimen 1, the movable member 55 of the compression load jig 50 moves in accordance with the bending deformation of the specimen 1. The force can be released and the load on the linear motion bearing 34 of the actuator 31 can be reduced.

DESCRIPTION OF SYMBOLS 1 Specimen 11 Base 12 Column 13 Rack 14 Yoke 15 Crosshead 16 Lifting handle 17 Clamp handle 24 Load cell adapter 25 Load cell 26 Mounting part 31 Actuator 32 Shaft 33 Mounting part 34 Linear motion bearing 40 Fixing jig 41 Base 42 Fixing base 43 Nut 50 Compression load jig 51 Connection member 52 Support rod 53 Convex portion 54 Spring 55 Movable member 56 Support rod 57 Recess 58 Guide portion 59 Ball 150 Compression load jig 151 Platen 152 Joint 153 Nut 155 Ball portion 156 Holder portion

Claims (3)

An actuator including a bearing and a linearly moving shaft provided in the bearing is disposed on one of the load members facing each other, and a specimen is disposed between the actuator and the other load member, In a material testing machine that repeatedly applies a load to a specimen by driving an actuator and detects the load load at that time by a load detector,
A fixing jig connected to the shaft and for tilting and fixing the specimen to a load direction;
A connecting member fixed to the load member facing the fixing jig; a movable member connected to the connecting member by an elastic member; and the movable member disposed between the connecting member and the movable member. A compression load jig having a sliding member that moves in a direction perpendicular to the load direction;
A material testing machine characterized by comprising: The material testing machine according to claim 1,
The material testing machine, wherein the sliding member is a ball. The material testing machine according to claim 1,
The material testing machine, wherein the elastic member is a spring.

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