JP4765787B2 - Material testing machine - Google Patents

Description

  The present invention relates to a material testing machine having a cross head that can be raised and lowered.

  2. Description of the Related Art Conventionally, there has been known a material testing machine that raises and lowers a cross head along a support column, grips a specimen with a pair of grips between a base and the cross head, and performs a tensile test or the like. As a load actuator for applying a test force to a specimen, there are one using a hydraulic cylinder (for example, see Patent Document 1) and one using a pneumatic cylinder (for example, see Patent Document 2).

JP-A-8-304249 JP 2005-195414 A

  In this type of material testing machine, when the cross head is moved up and down by manual operation (for example, handle operation), an operation force corresponding to the weight of the cross head is required, which imposes a heavy burden on the user.

According to a first aspect of the present invention, there is provided a material testing machine comprising a pair of uprights vertically arranged on a base, a crosshead that can be moved up and down along the support, a lifting mechanism that lifts and lowers the crosshead, and a lifting mechanism a load actuator to load a specimen while fixing the post in the lifting and crosshead predetermined fixed position, is juxtaposed a pair of posts, and a pair of gas springs for supporting the cross-head, gas spring, the upper The cylinder tube is arranged on the bottom, the piston rod is arranged on the lower side, and a position adjustment mechanism for adjusting the support position of the crosshead at a plurality of positions in the vertical direction is provided on the circumferential surface of the cylinder tube of the gas spring. when not fixed to the strut, the gas springs via the position adjustment mechanism is characterized by supporting the own weight of the crosshead
According to a second aspect of the present invention, in the material testing machine according to the first aspect, the position adjusting mechanism is engaged with one of the slits provided at a plurality of positions in the vertical direction on the peripheral surface of the cylinder tube and the plurality of slits. It has a support plate to be fixed, and the lower surface of the cross head and the upper surface of the support plate engaged and fixed to any of the plurality of slits are in contact with each other.
According to a third aspect of the present invention, in the material testing machine according to the second aspect, the support plate is a U-shaped elastic member that can expand and contract in the radial direction of the cylinder tube, and is engaged from the side of the cylinder tube. It is characterized by.
According to a fourth aspect of the present invention, in the material testing machine according to any one of the first to third aspects, the elevating mechanism is formed by a single or a plurality of spur gears rotated by manual operation and a support, and the spur gear And a rack to which rotation of the motor is transmitted .

  According to the present invention, since the cross head is supported by the gas spring, the weight of the cross head is canceled by the gas spring, and the cross head can be easily raised and lowered.

Hereinafter, an embodiment of a material testing machine according to the present invention will be described with reference to FIGS.
1A is a front view of a material testing machine according to an embodiment of the present invention, FIG. 1B is a side view, and FIG. 2 is a plan view. In the following, the configuration of each part will be described with the front-rear and left-right directions defined as shown.

  The material testing machine includes a pair of left and right columns 2 erected on the base 1, a cross head 4 that moves up and down along the column 2, and a pair of left and right gas springs 3 that supports the cross head 4 to be movable up and down, Elevating mechanism 5 for raising and lowering crosshead 4, upper gripping tool 6 and lower gripping tool 7 for gripping specimen TP between base 1 and crosshead 4, load actuator 8 for loading specimen TP, load And a load cell 9 for detecting a load applied to the actuator 8. Each gas spring 3 is erected on the diagonally rear side of each column 2 so as to be substantially parallel to the column 2.

  The load actuator 8 is a pneumatic cylinder that is driven by compressed air supplied from an air source. The piston rod of the pneumatic cylinder passes through the cross head 4 and is connected to the upper gripping tool 6, and the pneumatic gripping cylinder 6 drives the upper gripping tool 6 to apply a load to the specimen TP. As a result, it is not necessary to use a hydraulic device such as a hydraulic cylinder as a load actuator, so that the test can be performed in a clean environment. In the present embodiment, the load actuator 8 is attached to the upper surface of the cross head 4, but it can also be attached to the lower surface of the cross head 4. The load actuator 8 may be supported on the upper surface of the base 1 and the lower gripping tool 7 may be driven by the load actuator 8 to apply a load to the specimen TP.

  The configuration of the lifting mechanism 5 will be described. 3 is a cross-sectional view taken along line III-III in FIG. 1A, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. As shown in FIGS. 3 and 4, racks 11 are formed on the rear surface of each column 2 in the vertical direction. Each rack 11 is engaged with a pinion 12, and a right side pinion 12 is engaged with a gear 13. The pinion 12 and the gear 13 are spur gears.

  As shown in FIG. 3, a rotation shaft 14 extends in the left-right direction at the rear portion of the cross head 4, and the rotation shaft 14 is rotatably supported by a bearing portion 4 a provided in the cross head 4. Pinions 12 are supported at both ends of the rotating shaft 14 so as to be rotatable integrally with the rotating shaft 14.

  A rotating shaft 15 extends in the left-right direction behind the right gas spring 3, and the rotating shaft 15 is rotatably supported by a bearing portion 4 b provided in the cross head 4. A gear 13 is supported at one end of the rotating shaft 15 so as to be rotatable integrally with the rotating shaft 15, and a handle 16 is supported at the other end of the rotating shaft 15 so as to be rotatable integrally with the rotating shaft 15. .

  When the handle 16 is rotated, the gear 13 is rotated via the rotation shaft 15. The rotation of the gear 13 is transmitted to the pinion 12, and the left and right pinions 12 rotate simultaneously via the rotation shaft 14. As a result, the pinion 12 moves along the rack 11 and the crosshead 4 moves up and down. When the cross head 4 is moved up and down to a predetermined position, the clamp 10 (FIG. 1) is operated to fix the cross head 4 to the column 2.

  By the way, if the user wants to raise the crosshead 4 only by operating the handle, the user must rotate the handle 11 against the weight of the crosshead 4, load actuator 8, load cell 9, and the like. Therefore, a large operating force is required, and the burden on the user is large. In the present embodiment, by using the gas spring 3, the burden on the user is reduced as follows.

  FIG. 5A is a front view of the gas spring 3, FIG. 5B is a cross-sectional view, and FIG. As shown in FIG. 6, a gas chamber 101 filled with nitrogen gas is formed in the gas spring. The oil chambers 102 and 103 are pressurized from the gas chamber 101 via the slidable free piston 104, and a repulsive force in the extending direction always acts on the piston rod 105. When the piston rod 105 moves, the oil moves through the oil holes 102 and 103 through the orifice hole 106. At this time, the volume of the oil chambers 102 and 103 changes by the volume change of the rod 105, and the internal pressure of the gas chamber 101 changes. The magnitude and extension speed of the repulsive force acting on the piston rod 105 can be adjusted by adjusting the volume and internal pressure of the gas chamber 101.

  As shown in FIG. 5 (a), slits 31 are provided at three locations in the height direction on the peripheral surface of the cylinder tube of the gas spring 3. As shown in FIG. 5B, a substantially U-shaped support plate 35 can be engaged with each slit 31 from the side. The support plate 35 is an elastic member that can expand and contract in the radial direction of the cylinder tube with a notch 35 a provided at the center as a fulcrum, and an inner surface 35 b thereof is formed in an R shape corresponding to the shape of the slit 31. ing. Thereby, the support plate 35 can be engaged and fixed to the slit 31.

  On the upper surface of the support plate 35 engaged with the slit 31, the cross head 4 is placed. Since the repulsive force in the extending direction is always applied to the gas spring 3, the weight of the cross head 4 is supported by the gas spring 3, and the cross head 4 is supported from the gas spring 3 via the support plate 35. As a result, the user can raise and lower the crosshead 4 with a light handle operation.

The repulsive force of the gas spring 3 changes according to the amount of expansion / contraction of the piston rod 32. In the present embodiment, regardless of the size of the specimen TP, that is, the length of the specimen TP between the grips 6, 7, the crosshead 4 has a substantially constant repulsive force acting on the crosshead 4. Adjust the support position. For example, when the specimen TP is a standard size, the cross head 4 is supported by engaging the support plate 35 with the central slit 31 as shown in FIG. When the specimen TP is smaller than the standard size, the crosshead 4 is supported by engaging the support plate 35 with the lowermost slit 31 as shown in FIG. When the specimen TP is larger than the standard size, the cross head 4 is supported by engaging the support plate 35 with the uppermost slit 31 as shown in FIG. As a result, regardless of the size of the specimen TP, the amount of expansion and contraction of the gas spring 3 becomes substantially constant, and a substantially constant repulsive force can be applied.

  A test procedure by the material testing machine according to the present embodiment will be described. First, in accordance with the size of the specimen TP, the support plate 35 is engaged with either the upper or lower slit 31 on the circumferential surface of the gas spring to support the cross head 4. Next, the crosshead 4 is moved up and down by a handle operation, and the specimen TP is gripped by the upper gripping tool 6 and the lower gripping tool 7. In this case, since the weight of the crosshead 4 is canceled by the gas spring 3, a large operating force is not required when operating the handle, and the burden on the user can be reduced.

  Next, the clamp 10 is operated to fix the crosshead 4 to the column 2 and the load actuator 8 is driven to load the specimen TP. In this case, if forgetting the clamp 10 and loading the specimen TP, the load acts on the gas spring 3 via the crosshead 4 and the gas spring 3 is degenerated. As a result, the load of the load actuator 8 is absorbed by the gas spring 3, and it is possible to prevent an overload from being applied to the gear and the like of the elevating mechanism 5.

According to the present embodiment, the following operational effects can be achieved.
(1) Since the gas spring 3 is erected substantially parallel to the support 2 and the cross head 4 is supported from the gas spring 3 so as to be movable up and down, the weight of the cross head 4 is canceled by the gas spring 3. The raising / lowering operation of the crosshead 4 can be performed easily.
(2) Since the crosshead 4 is elastically supported by the gas spring 3, it is possible to prevent the gears of the lifting mechanism 5 from being damaged when the test is performed without forgetting to clamp the crosshead 4.
(3) In this case, since the pinion 12 and the gear 13 of the elevating mechanism 5 are configured as spur gears, the rotation resistance of the gear is smaller than that of the worm gear, and the gear rotates smoothly when the gas spring 3 expands and contracts. Can do.
(4) Since it is not necessary to raise and lower the crosshead 4 by a hydraulic cylinder or the like, when a pneumatic cylinder is used as the load actuator 8, a testing machine can be configured without using hydraulic equipment, and a clean environment Can be tested at
(5) Since the support plate 35 is provided so as to be engageable with the peripheral surface of the gas spring 3 and the support plate 35 can be adjusted in the vertical direction, the crosshead 4 is substantially constant regardless of the size of the specimen TP. The repulsive force can be imparted.

  In the above embodiment, a pneumatic cylinder is used as the load actuator 8, but a hydraulic cylinder may be used. In this case, the cross head 4 may be moved up and down by hydraulic pressure. Even when the cross head 4 is lifted or lowered by hydraulic pressure, the cross head 4 is supported by the gas spring 3 so that the weight of the cross head 4 is canceled. Therefore, the cross head 4 can be lifted and lowered easily with a small hydraulic pressure.

  If the gas spring 3 that supports the cross head 4 so as to be movable up and down is provided, the type of the material testing machine is not limited to that described above. For example, a cross yoke is horizontally mounted on the upper end portion of the support column 2, the cross head 4 is provided so as to be movable up and down along the support column 2 between the table and the cross yoke, and a load actuator 8 is disposed below the table, so that the specimen TP May be supported by the crosshead 4 and the lower end of the specimen TP may be loaded by a load actuator 8 penetrating the table. In this case as well, the gas spring 3 may be erected to support the cross head 4.

  Although the rotation of the handle 16 is transmitted to the rack 11 via the gear 13 and the pinion 12, the configuration of the lifting mechanism is not limited to this. For example, the rotation of the handle 16 may be transmitted to the rack 11 via more spur gears or via a single spur gear. The spur gear may be rotated by a manual operation other than the handle operation.

  Although the free piston type gas spring 3 is used, other types of gas springs may be used. Although the support plate 35 is engaged with the slit 31 on the circumferential surface of the gas spring to adjust the support position of the cross head 4, the position adjustment mechanism is not limited to this. That is, as long as the features and functions of the present invention can be realized, the present invention is not limited to the material testing machine of the embodiment.

(A) is a front view of the material testing machine which concerns on embodiment of this invention, (b) is a side view. The top view of the material testing machine which concerns on embodiment of this invention. III-III sectional view taken on the line of Fig.1 (a). IV-IV sectional view taken on the line of Fig.1 (a). (A) is a front view of the gas spring of FIG. 1, (b) is sectional drawing. The figure explaining the principle of operation of a gas spring. The figure which shows an example of operation | movement of the material testing machine which concerns on embodiment of this invention.

Explanation of symbols

2 Strut 3 Gas Spring 4 Crosshead 5 Elevating Mechanism 8 Load Actuator 11 Rack 12 Pinion 13 Gear 31 Slit 35 Support Plate

Claims (4)

A pair of pillars erected vertically on the base;
A crosshead that can be moved up and down along the column;
An elevating mechanism for elevating the crosshead;
A load actuator that loads the specimen in a state where the crosshead raised and lowered by the elevating mechanism is fixed to the column at a predetermined fixing position ;
A pair of gas springs juxtaposed with the pair of struts and supporting the crosshead ;
The gas spring has a cylinder tube disposed above and a piston rod disposed below.
On the peripheral surface of the cylinder tube of the gas spring, a position adjustment mechanism for adjusting the support position of the crosshead at a plurality of positions in the vertical direction is provided,
The material testing machine, wherein the gas spring supports the weight of the crosshead through the position adjusting mechanism when the crosshead is not fixed to the column . The material testing machine according to claim 1,
The position adjusting mechanism has slits provided at a plurality of locations in the vertical direction on the circumferential surface of the cylinder tube, and a support plate engaged and fixed to any of the plurality of slits.
A material testing machine , wherein a lower surface of the crosshead and an upper surface of the support plate engaged and fixed to any of the plurality of slits are in contact with each other . The material testing machine according to claim 2 ,
The material testing machine , wherein the support plate is a U-shaped elastic member that can expand and contract in a radial direction of the cylinder tube, and is engaged from a side of the cylinder tube . In the material testing machine according to any one of claims 1 to 3,
The lifting mechanism is
Single or multiple spur gears that rotate manually,
A material testing machine comprising: a rack formed on the support column and to which rotation of the spur gear is transmitted.

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