JPH0439564Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a material testing machine that can conduct tests by switching load cells with different measurement ranges or sensitivities depending on the magnitude of the force applied to one load axis.

Prior Art When measuring the physical strength of a material, it is generally not possible to arbitrarily select the load to be applied to a test piece. In order to improve measurement accuracy, it has been common practice to select a testing machine that can apply an appropriate load depending on the strength of the material. Since it is uneconomical to prepare testing machines with different capacities for different strengths of materials, for example,
As shown in the figure, a load cell c provided between a frame a and a load axis b was made removable, and a load cell having a measurement range corresponding to the load on the test piece was selected and attached.

However, it generally takes time to attach and detach the load cell installed between the load shaft and the testing machine frame, and it also requires time for adjustment, so testing efficiency will be significantly reduced if you try to change the measurement range. There was a problem.

Therefore, a combination type load cell consisting of load cells with different measurement ranges connected in parallel or in series is installed between the load axis and the testing machine frame, and one of the load cells and the load axis can be selectively switched and connected. There is a proposal to do so.
However, in this switching method, the load cells are assembled in a complex structure, so the combination of load cells is fixed, and changing the measurement range is more difficult than conventional single load cells that are attached and removed. The disadvantage is that it is also much more difficult.

Problems to be Solved: Therefore, the present invention allows for easy and quick switching between load cells with different measurement ranges, eliminates the need to worry about storing load cells, and is capable of dealing with changes in measurement ranges and malfunctions. The purpose of the present invention is to provide a load measurement range switching mechanism that makes it extremely easy to replace the load cell.

Means for Solving Problems The object of the present invention is to provide a load cell switching mechanism of a material testing machine with a load shaft in which a first locking protrusion and a second locking protrusion are spaced apart in the axial direction. , a double lock nut type locking member movably screwed onto a male thread formed between the first locking protrusion and the second locking protrusion of the load shaft; A first shearing type load cell is provided so that the load axis passes through the locking member, and a shearing type first load cell is provided so that the load axis passes through the second locking protrusion and the locking member. 2 load cells, and when the sensing part of one of the load cells is clamped between the locking protrusion of either one and the locking member, the sensing part of the other load cell is clamped between the locking protrusion of the other one and the locking member. This is achieved by configuring it so that it is released from the locking clamp between the locking protrusion and the locking member.

Examples of the present invention will be further described below.

Embodiment In FIG. 1, 1 is a frame of a testing machine, 2 is a load axis thereof, 3 and 4 are load cells whose detection ranges of measured loads are different from each other, and 5 and 6 are nuts.

A first locking protrusion 2a and a second locking protrusion 2b are protruded from the load shaft 2, and the intermediate portion thereof is slightly tapered and has a thread 2c cut around it, into which nuts 5 and 6 are inserted. They are screwed together. Nuts 5 and 6 form a double lock nut which can move on screw 2c and can be fixed at any position by tightening them together.

The load cell 3 is fixed to the frame 1 so as to be located between the first locking protrusion 2a and the nut 5, and when the nut 5 is rotated to approach the first locking protrusion 2a, the load shaft 2 is moved to the second locking protrusion 2a. The sensing part 3a of the load cell 3 moves in the direction of the stop protrusion 2b (downward in the figure).
is clamped and locked between the first locking protrusion 2a and the nut 5. Furthermore, the nut 6 is tightened to the nut 5 to fix the nut 5 so that it does not move. At this time, the sensing part 4a of the load cell 4 did not come into contact with either the second locking protrusion 2b or the nut 6, and was hung on a test piece (not shown) attached to the end of the load shaft 2. The load is directly transmitted to the load shaft 2, and only the load cell 3 detects the load.

Also, contrary to the above, when the nut 6 is rotated and brought closer to the second locking protrusion 2b, the load shaft 2 moves in the direction of the first locking protrusion 2a (upward in the figure),
The sensing portion 4a of the load cell 4 is clamped and locked between the second locking protrusion 2b and the nut 6. Further, tighten the nut 5 toward the nut 6 to fix the nut 6 so that it does not move. In this way, the load cell 3 is opened, and the switching from the load cell 3 to the load cell 4 is completed.

Effects of the invention The load cell switching mechanism of the invention allows two load cells with different load measurement ranges to be switched from one to the other by simply moving and fixing the locking member while keeping the two load cells attached to the frame. Since it can be easily switched, the measurement range can be changed reliably and in a short period of time, which not only significantly improves the efficiency of material testing, but also makes it possible to easily install and use a general-purpose shear type load cell as a load cell. Another advantage is that changing the measurement range and maintaining the device are extremely easy.

[Brief explanation of the drawing]

FIG. 1a is a cross-sectional view showing the structure of an embodiment of the load cell switching mechanism according to the present invention, FIG. 1b is a cross-sectional view showing one of the load cells connected to the load shaft, and FIG. , is a front view of an example of a conventionally known material testing machine.

Claims (1)

[Scope of utility model registration request] A load shaft having a first locking protrusion and a second locking protrusion spaced apart in the axial direction, and a load shaft formed between the first locking protrusion and the second locking protrusion of the load shaft. A double lock nut type locking member movably screwed onto the male thread;
a first shearing type load cell provided so that a load axis passes through the first locking protrusion and the locking member;
A second shearing type load cell is provided so that the load axis passes through between the locking protrusion and the locking member, and the sensing part of one of the load cells is connected to either of the locking protrusions. A material testing machine configured such that when the other load cell is clamped between the locking member and the other load cell, the sensing part of the other load cell is released from the locking clamp between the other locking protrusion and the locking member. load cell switching mechanism.