JP2012052938A - Shaft centering device for material testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft centering device for material testing machines capable of easily adjusting the shaft center of a gripper despite a relatively small and simple configuration.SOLUTION: A shaft centering device 20 includes: a connecting rod 31 to be connected to a lower gripper 22; a spherical bush 32 fixed to the lower end of the connecting rod 31 and having a substantially spherical shape; and a bush housing 33 coming into contact with the spherical bush 32 to support the connecting rod 31 swingably about the spherical bush 32. The outer periphery of the bush housing 33 is surrounded by a casing 34 such that the bush housing 33 is movable in the horizontal direction in the casing 34. A fixed wedge 44 and a moving wedge 43 are disposed at the lower part of the bush housing 33. The spherical bush 32 and the bush housing 33 are clamped and fixed by the moving wedge 43 and the casing 34.

Description

  The present invention relates to a shaft center adjusting device for a material testing machine for adjusting the shaft center of a pair of grips that grip both ends of a test piece, and in particular, a material fatigue strength test using a resin film or a metal foil as a test target. The present invention relates to an axial center adjusting device that can be suitably applied to an electromagnetic micromaterial testing machine or the like.

  In such a material testing machine, an upper gripping tool and a lower gripping tool are mounted on a load frame composed of a table and a cross head, and both ends thereof are gripped between the upper gripping tool and the lower gripping tool. A test force is applied to the test piece, and the test force at that time is detected by a load cell.

  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 disposed (see Patent Document 1).

  The shaft center adjusting device described in Patent Document 1 is interposed between a crosshead and an upper gripping tool, a connecting shaft for connecting the crosshead and the upper gripping tool, and a center of the connecting shaft. A frame member fixed to the frame, an angle adjusting collar member disposed on the outer periphery of the connecting shaft and fixed to the crosshead inside the frame member, and an outer periphery of the connecting shaft disposed inside the frame member. And a collar member for position adjustment fixed to the upper gripping tool, and has a configuration for adjusting the connecting shaft angle and position using elastic deformation of the connecting shaft.

  In addition, in order to adjust the axial center of the upper gripper and the lower gripper using such an axial center adjustment device, both ends of the test piece to which a plurality of strain gauges are attached are connected to the upper gripper and the lower gripper. There is also a material testing machine that can correct the misalignment of the shaft center by automatically adjusting the position of the upper gripper or the lower gripper based on the detected values of a plurality of strain gauges at that time (Patent) Reference 2).

Japanese Patent No. 3849331 JP-A 64-31033

  In particular, in material testing machines such as electromagnetic micromaterial testing machines that perform material fatigue strength tests on resin films and metal foils as a test subject, the shaft center adjustment is relatively small and simple, and has good operability. A device is required. However, since the shaft center adjusting device described in Patent Document 1 is configured to adjust the connecting shaft angle and position using elastic deformation of the connecting shaft, the entire device becomes larger and complicated, The adjustment operation of the axis is also complicated.

  Moreover, when using a resin film, metal foil, etc. as a test piece, as described in Patent Document 2, it is impossible to measure the deviation of the axial center using a strain gauge.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and provides a shaft adjusting device for a material testing machine capable of easily adjusting the shaft center of a gripping tool while having a relatively small and simple configuration. The purpose is to provide.

  The invention according to claim 1 is an axis adjusting device for a material testing machine fixed to a load frame for adjusting the axis of a pair of grips holding both ends of a test piece, wherein the grip A connecting rod connected to the tool, a spherical bush fixed to the end of the connecting rod, and abutting the spherical bush, thereby supporting the connecting rod in a swingable manner around the spherical bush. And a bush housing movable in the horizontal direction, a plurality of horizontal position adjusting members for moving the bush housing in the horizontal direction, and a fixing means for fixing the connecting rod and the bush housing. It is characterized by.

  The invention according to claim 2 further includes a casing surrounding the outer periphery of the bush housing according to the invention according to claim 1, wherein the horizontal position adjusting member is screwed into the casing and the tip thereof is The screw member is in contact with the bush housing.

  According to a third aspect of the present invention, in the second aspect of the present invention, the fixing means corresponds to a fixed wedge fixed to the apparatus main body and having an inclined surface on the bush housing side, and an inclined surface of the fixed wedge. A movable wedge disposed between the fixed wedge and the bush housing, and a screw member for moving the movable wedge relative to the fixed wedge, the movable As the wedge moves, the connecting rod and the bush housing are fixed by moving the surface opposite to the inclined surface of the moving wedge to the bush housing side and pressing the spherical bush by the bush housing. To do.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the shaft centers of the pair of gripping tools are forcedly gripped by collectively holding the pair of gripping tools. The fixing means further fixes the connecting rod and the bush housing after the chuck guides forcibly match the axes of the pair of grippers.

  According to the first aspect of the present invention, it is possible to easily grasp a relatively small and simple structure by the action of the connecting rod that can be swung by the action of the spherical bush and the bush housing that can move in the horizontal direction. It becomes possible to adjust the axis of the tool.

  According to the second aspect of the invention, the horizontal position of the bush housing can be easily adjusted by the action of the screw member.

  According to the third aspect of the present invention, it is possible to easily execute fixing and releasing of the connecting rod and the bush housing by moving the moving wedge.

  According to the fourth aspect of the present invention, by using the chuck guide, the connecting rod and the bush housing can be fixed after the axes of the pair of grips are easily aligned.

It is a front view of the material testing machine to which the shaft center adjusting device according to the present invention is applied. It is a side view of a material testing machine to which the shaft center adjusting device according to the present invention is applied. It is a front view which shows the axial center adjustment apparatus 20 which concerns on this invention with the lower gripper 22 and the table 11. FIG. It is a side view which shows the axial center adjustment apparatus 20 which concerns on this invention with the lower holding tool 22 and the table 11. FIG. It is a top view of the axial center adjustment apparatus 20 which concerns on this invention. It is a schematic diagram showing a chuck guide together with an upper gripping tool 21 and a lower gripping tool 22.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a material testing machine to which an axial center adjusting device according to the present invention is applied, and FIG. 2 is a side view thereof.

  This material testing machine is an electromagnetic micromaterial testing machine that performs a material fatigue strength test using a resin film or a metal foil as a test object. The material testing machine includes a pair of support rods 12 erected on a table 11 and these support rods 12. The yoke 14 disposed on the upper end of the head and the cross head 15 are provided. The table 11, the pair of support frames 12, and the cross head 15 constitute a load frame for applying a load to the test piece.

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

  The cross head 15 is provided with an electromagnetic actuator 26. An upper grip 21 is disposed at the lower end of the actuator 26 via a screw-type attachment 23. In addition, a lower grip 22 is disposed on the upper portion of the table 11 via an axial center adjusting device 20, a load cell adapter 24, a load cell 25, and a screw-type attachment portion 26 which will be described later. The test piece is gripped at both ends by the upper gripping tool 21 and the lower gripping tool 22.

  Next, the configuration of the shaft center adjusting device according to the present invention will be described. FIG. 3 is a front view showing the shaft center adjusting device 20 according to the present invention together with the lower gripping tool 22 and the table 11, and FIG. 4 is a side view thereof. FIG. 5 is a plan view of the axis adjusting device 20 according to the present invention.

  The shaft center adjusting device 20 according to the present invention adjusts the shaft center of the upper gripper 21 and the lower gripper 22 for gripping both ends of the test piece by adjusting the position and angle of the shaft center of the lower gripper 22. The connecting rod 31 is connected to the lower gripping tool 22 through the load cell adapter 24, the load cell 25, and the mounting portion 26. A spherical bush 32 having a substantially spherical shape is fixed to the lower end portion of the connecting rod 31.

  The shaft center adjusting device 20 includes a bush housing 33 that supports the connecting rod 31 in a swingable manner about the spherical bush 32 by contacting the spherical bush 32. The bush housing 33 is surrounded by a casing 34 and is movable in the horizontal direction within the casing 34. As shown in FIG. 3, a screw member 35 that includes a screw portion 36 that is screwed into a screw hole formed in the casing 34, and whose tip abuts against the bush housing 33, is centered on the axis of the connecting rod 31. Three are arranged at equal angular positions. The bush housing 33 moves in the horizontal direction in the casing 34 by rotating these screw members 35 respectively.

  Thus, when the connecting rod 31 swings and the bush housing 33 moves horizontally, the lower grip 22 connected to the connecting rod 31 via the load cell adapter 24, the load cell 25, and the attachment portion 26. The angle of the shaft center and the position of the shaft center are changed. Thereby, it becomes possible to adjust so that the axial center of the upper gripper 21 and the lower gripper 22 may correspond.

  Below the bush housing 33, there is a fixed wedge 44 fixed to the apparatus main body and having an inclined surface on the bush housing 33 side, and an inclined surface corresponding to the inclined surface of the fixed wedge 44. The fixed wedge 44 and the bush housing 33 are provided. A moving wedge 43 disposed between and a screw portion 42 screwed into a screw hole formed in the moving wedge 43, and a screw that moves the moving wedge 43 relative to the fixed wedge 44. A fixing means including the member 41 is provided.

  When the moving wedge 43 moves due to the rotation of the screw member 41, the surface opposite to the inclined surface of the moving wedge 43 moves toward the bush housing 33 as the moving wedge 43 moves. As a result, the bush housing 33 presses the spherical bush 32 toward the casing 34. In this state, the spherical bush 32 and the bush housing 33 are sandwiched between the moving wedge 43 and the casing 34. For this reason, the swinging of the connecting rod 31 and the horizontal movement of the bush housing 33 are restricted, and the connecting rod 31 and the bush housing 33 are fixed at that position.

  As shown in FIG. 3, the lower gripping tool 22 includes a pair of gripping teeth 61 for sandwiching the end of the test piece, and a knob for moving these gripping teeth 61 toward or away from each other. 62. The upper gripping tool 21 shown in FIGS. 1 and 2 has the same configuration as the lower gripping tool 22.

  The shaft center adjusting device 20 further includes a chuck guide for fixing the connecting rod 31 and the bush housing 33 so that the shaft centers of the upper gripper 21 and the lower gripper 22 can be easily aligned. I have.

  FIG. 6 is a schematic view showing the chuck guide together with the upper gripping tool 21 and the lower gripping tool 22. 6A shows a longitudinal section of the chuck guide, FIG. 6B shows a side surface of the chuck guide, and FIG. 6C shows a plane of the chuck guide.

  The chuck guide includes a pair of gripping portions 51 and 52 that collectively grip the upper gripping tool 21 and the lower gripping tool 22 arranged at positions close to each other according to the sample length, and the pair of gripping portions 51 and 52. And a screw portion 53 for urging them in the directions close to each other. The outer shapes of the upper gripping tool 21 and the lower gripping tool 22 are formed with high accuracy. For this reason, by using this chuck guide, the upper gripper 21 and the lower gripper 22 are collectively gripped by the pair of gripping portions 51 and 52 so that the axes of the upper gripper 21 and the lower gripper 22 are aligned. It is possible to forcibly match.

  When adjusting the shaft centers of the upper gripper 21 and the lower gripper 22 in the material testing machine using the shaft center adjusting device 20 having the above-described configuration, the crosshead lifting handle 16 shown in FIGS. 1 and 2 is operated. The cross head 15 is lowered and arranged at a position where the upper gripping tool 21 and the lower gripping tool 22 are close to each other. Then, at that position, the pair of left and right crosshead clamps 17 are operated to fix the height position of the crosshead 15.

  Next, the screw member 35 shown in FIGS. 3 and 5 is loosened, and its tip is separated from the bush housing 33. Further, the screw member 41 shown in FIG. 4 is loosened, and the pressing force applied to the bush housing 33 by the moving wedge 43 is released. Thereby, the rocking of the connecting rod 31 and the horizontal movement of the bush housing 33 are possible. In this state, as shown in FIG. 6, the upper gripper 21 and the lower gripper 22 are collectively gripped by the pair of gripping portions 51 and 52 in the chuck guide, so that the upper gripper 21 and the lower gripper 22 are gripped. The axis of the tool 22 is forcibly matched.

  Thereafter, each screw member 35 is rotated and moved to a position where its tip abuts against and presses against the bush housing 33. Further, the screw member 41 shown in FIG. 4 is rotated, and the spherical bush 32 and the bush housing 33 are held between the moving wedge 43 and the casing 34. Thereby, the rocking | fluctuation of the connection rod 31 and the horizontal movement of the bush housing 33 are controlled, and the connection rod 31 and the bush housing 33 are fixed in the position. Accordingly, the lower gripping tool 22 is fixed in a state in which the axial centers of the upper gripping tool 21 and the lower gripping tool 22 are matched.

  When the axial center adjustment of the upper gripper 21 and the lower gripper 22 is completed, the chuck guide is removed and the material test is executed.

  As described above, according to the shaft center adjusting device 20 according to the present invention, the screw member 41 is operated to change and fix the angle of the shaft center and the position of the shaft center of the lower gripping tool 22. In addition, the axis centers of the upper gripping tool 21 and the lower gripping tool 22 can be easily matched by the chuck guide. Therefore, it is possible to easily adjust the axis of the upper gripping tool 21 and the lower gripping tool 22 while having a relatively small and simple configuration.

  In the above-described embodiment, the upper gripper 21 and the lower gripper 22 are collectively held using the chuck guide, and the axial centers of the upper gripper 21 and the lower gripper 22 are forcibly matched. Thus, before the connecting rod 31 and the bush housing 33 are fixed, the axial centers of the upper gripper 21 and the lower gripper 22 are forcibly matched. However, the connection rod 31 and the bush housing 33 may be fixed after finely adjusting the position of the upper grip 21 or the lower grip 22 using a micrometer or the like.

  In the embodiment described above, the shaft center adjusting device 20 according to the present invention is disposed between the lower gripping tool 22 and the table 11, but the present invention is interposed between the upper gripping tool 21 and the crosshead 15. The axis adjusting device 20 according to the above may be arranged.

DESCRIPTION OF SYMBOLS 11 Table 12 Support rod 15 Crosshead 16 Crosshead raising / lowering handle 17 Crosshead clamp 20 Axis center adjustment device 21 Upper gripper 22 Lower gripper 25 Load cell 26 Actuator 31 Connecting rod 32 Spherical bush 33 Bush housing 34 Casing 35 Screw member 41 Screw Member 43 Wedge 44 Fixed wedge 51 Gripping part 52 Gripping part 53 Screw part

Claims (4)

An axis adjustment device for a material testing machine fixed to a load frame for adjusting the axis of a pair of grips that grip both ends of a test piece,
A connecting rod connected to the grip;
A spherical bush fixed to the end of the connecting rod;
A bush housing capable of moving in the horizontal direction while supporting the connecting rod in a swingable manner around the spherical bush by contacting the spherical bush;
A plurality of horizontal position adjusting members for moving the bush housing in a horizontal direction;
Fixing means for fixing the connecting rod and the bush housing;
A shaft adjusting device for a material testing machine, comprising: The axis adjusting device of the material testing machine according to claim 1,
A casing that surrounds the outer periphery of the bush housing;
The horizontal position adjusting member is an axis adjusting device for a material testing machine, which is constituted by a screw member screwed into the casing and having a tip abutting against the bush housing. The axis adjusting device for a material testing machine according to claim 2,
The fixing means includes
A fixed wedge fixed to the apparatus body and having an inclined surface on the bush housing side;
A movable wedge having an inclined surface corresponding to the inclined surface of the fixed wedge and disposed between the fixed wedge and the bush housing;
A screw member for moving the moving wedge relative to the fixed wedge;
As the moving wedge moves, the surface opposite to the inclined surface of the moving wedge is moved to the bush housing side, and the spherical bush is pressed by the bush housing, so that the connecting rod, the bush housing, Axis adjustment device for material testing machine to fix the. In the axis adjusting device of the material testing machine according to any one of claims 1 to 3,
A chuck guide that forcibly aligns the axes of the pair of grips by gripping the pair of grips collectively;
The fixing means is an axis adjusting device for a material testing machine for fixing the connecting rod and the bush housing after the chuck guide forcibly matches the axes of the pair of grippers.

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