JPH07113734A - Microhardness tester - Google Patents

Abstract

PURPOSE: To calibrate weight during load rod processing without influencing a load supplied to a load rod by a spring load tolerance. CONSTITUTION: Optical lens elements installed on a turret to an indenter 3 of a load rod assembly 1 formed so as to collide with a sample to test microhardness, are properly arranged. The load rod assembly 1 is freed in a test mode, and a spring 4 is used to hold a load rod 2 in a home position separate from a test sample. Load weight 94 imparted to the load rod is not influenced by a spring load tolerance, and the weight is calibrated during weight manufacturing processing. The load rod assembly 1 is removed from a tester without requring to remove an internal part. A screw-cut nonrotating collar 7 easily adjusts a gap between the load rod assembly 1 and the test sample.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load rod assembly type micro hardness tester.

[0002]

BACKGROUND OF THE INVENTION Conventional load rod assemblies include an indenter for abutting a sample to be tested for microhardness.
nter) is attached to the load rod. These load rod assemblies have springs attached to the load rods to return the load rods to their home position away from the test sample.

[0003]

The disadvantage of such an arrangement is that the weight applied to the load rod for moving the load rod and consequently the indenter on the test sample must be calibrated to compensate for the spring load. That is not the case.

Another drawback of conventional load assemblies is also the need to realign the optical lens elements when the indenter is changed to fit a new test scale, and a single focusing control is used. When used, it takes a considerable amount of time to achieve the fine focus required for the test sample. In addition, there are standard test specifications that prevent operators from rushing certain tests.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a micro with load rod assembly in which the load supplied to the load rod is unaffected by spring load tolerances and weight calibration is performed during the load rod manufacturing process. To provide a hardness tester. Another object of the present invention is to provide a microhardness tester which eliminates the need to rearrange the optical lenses when changing the test scale.
Another object of the present invention is to provide a micro hardness for rapid focusing of the test sample so that the test sample can be moved quickly by a certain distance and fatigue of the operator when performing the focusing operation can be reduced. It is to provide a testing machine.

Yet another object of the present invention is to provide a micro hardness tester which allows the load rod assembly to be removed from the tester in a simple manner without any internal removal work. Another object of the present invention is to provide a micro hardness tester capable of easily adjusting the gap between the indenter and the test sample. It is another object of the present invention to provide a micro tester that can provide a standard dwell time test that cannot be modified by the operator.

The above objects of the present invention are accomplished by the load rod assembly of the present invention in which the load actuator moves the sleeve down and depresses the retaining spring that holds the load rod in the home position. As the sleeve moves down, the restraint on the load rod cap is removed, freeing the load rod to move down and provide load to the sample. Additional weight can be provided to the load rod cap that impacts the load rod, and thus, when the load rod moves downward and the indenter impacts the test sample,
This weight is added to the test sample. for reference,
The actual travel distance is extremely small, and the total travel distance of the indenter is generally limited to 0.50 × 2.54 cm or less.

Another feature of the present invention is that the gap between the indenter and the test sample can be easily adjusted by rotating the load rod into a threaded non-rotating collar. This rotation of the load rod will allow the indenter to be raised and lowered to the desired position. Yet another important feature of the present invention is that the load rod assembly can be easily removed from the tester by removing the retaining screw and retaining ring and pulling the load rod assembly downward to remove it from the turret of the tester. Thus, the need for internal removal to remove the load rod assembly from the tester is eliminated.

Another important feature of the present invention is that it has both a rapid focusing control and a fine focusing control so that the focusing time can be reduced. In either case, the worm gear rotates the lifting screw,
Raise or lower the desired lift shaft. However, the quick focus control has a larger sprocket ratio than the fine focus control, and the quick focus control driver sprocket is rotated several times to rotate the worm gear. As mentioned above, this feature allows the test sample to be focused in the desired time in a short time and reduces operator fatigue in attempting to achieve the desired fine focus.

In an embodiment of the invention, multiple load rod assemblies are mounted on a turret. With such a configuration, once the optical lens element is aligned with the indenter of the first load rod assembly, instead of realigning the optical lens when using a subsequent second load rod indenter, The use of the second load rod assembly is facilitated because the indenter of the second load rod assembly need only be aligned with the already aligned optical lens elements. If multiple indenters are used for one turret, Knoop and Vickers indenters can be installed in one turret. Yet another aspect of the invention is that it can provide a means of preventing non-standardized tests from being performed, and can also provide an improved means of measuring indenter displacement.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, a load rod assembly 1 comprises a load rod 2 which strikes an indenter 3.
The load rod and indenter assembly is held in a home position away from the sample by a combination of an annular retaining spring, sleeve 5, and load rod cap 6. One end of the sleeve 5 is supported by one end of the spring 4, and the other end of the spring 4 is supported by the housing or body 102 of the load rod assembly. A seating surface on which the load rod cap 6 is seated is provided at the upper end of the sleeve 5. When the sleeve 5 moves upward,
Along with this operation, the load rod cap 6 and the load rod 2 also move upward. When the sleeve 5 moves downward, the load rod 2 moves downward due to gravity.

The tester also has a load actuator. The actuator has an arm 83, one end 84 of which rests on the upper edge 85 of the sleeve 5 and the other end 86 is controlled by a cam 87 which moves a cam follower 88 under the control of a motor 89. The arm 83 rotates about a fulcrum 90, and one end 84 of the arm is provided with a finger 91 that applies pressure to the upper edge 85 of the sleeve 5 described above. When the motor 89 is actuated, the other end 86 of the arm 83 is moved upwards, which causes the fingers 91 to descend, pushing the sleeve 5 downwards, freeing the load rod 2 to move downwards.

The variable load weight assembly 92 is arranged to act on the load rod cap 6. The stepped weight lift cone 93 is complementary in shape to the variable load weight assembly 92, with each step of the cone having various controls to control the amount of load weight that the pressure rod 95 presses against the load rod cap 6. Are formed to receive the weights 94a to 94g.
These variable weights are manually adjusted to place the additional weights in the corresponding depressions in the weight lift cone 93.

An upper weight rod 96 is placed on top of the variable weight assembly 92 and is a linear voltage differential transformer (LVD).
T) 97 is arranged to operate. After the weight assembly 92 is adjusted to the desired load and pressurized on the load rod cap 6, the motor 89 is activated, the finger 91 is moved, and the load rod 2 is free to move downward under the influence of gravity. By doing so, the measurement process is started. Indenter is generally 0.50x2.5
Since it does not move by 4 cm or more, the desired movement of the sleeve 5 can be easily obtained.

With the above-described configuration, the load is free from the influence of the spring load tolerance of the holding spring 4, and the weight calibration of the variable weight assembly 92 and the weights 94a to 94g can be completely performed during the weight manufacturing process. it can. In contrast, in conventional load rod assemblies, the spring is attached directly to the load rod and returns the load rod to its home position after testing. As a result, if adjustable weights are used, the weights must be calibrated to compensate for spring loading. When the test is carried out with the device according to the invention, the sleeve 5 bears against the load rod cap 6 and thereby lifts the load rod cap 6 into the initial position, so that the spring 4 returns the load rod 2 to the home position.

The gap between the indenter 3 and the sample to be tested for hardness is adjusted by rotating the load rod 2 in a threaded non-rotating collar 7. Therefore, the gap between the indenter and the test sample is easily adjusted to the focal point of the lens. This adjustment is
This is accomplished by adjusting the position of the indenter by rotating the threaded collar 7 and fixing the collar 7 to the housing 102 with the pin 13. The set screw 42 provided on the opposite side of the pin 13 pressurizes the load rod 2 and is set so as to prevent the load rod 2 from rotating with respect to the collar 7. This prevents the indenter from rotating during the test. Removal of the load rod assembly 1 from the tester is a necessary element for the removal operation.
It is simplified because it is only the retaining screw 8 which retains the retaining ring 9 against the housing 81 of the load rod.
When these screws 8 are removed from the housing 81, the load rod assembly 1 is removed from the housing 81.

The load rod 2 is made movable in the sleeve 10, and a sleeve bearing made of a low friction material is arranged between them. The sleeve 10 comprises a frustoconical body protection element 1 arranged at the lower end of the sleeve 10.
Carried in 1 and this body protection element 11 is connected to the housing 102 by means of screws 12. The screw 42 also holds the non-rotating collar 7 with respect to the load rod 2.

LVDT (linear variable differential)
transformer 97 is an indent depth (indent dept
It is used to measure h). The LVDT 97 displays the moving amount of the indenter in response to the moving amount of the magnetic element 98 moved by the upper weight rod 96 in the coil 99.

FIG. 2 illustrates another embodiment of the present invention in which a number 20 of load rod assemblies, which may be of the type shown in FIG. 1, are incorporated in a single turret. In this embodiment, optical lenses 24, 25, 26 mounted on turret 21 are aligned with the indenter of each load rod assembly for which it is desired to use. For example, these lenses are at 10x, 20x, 50x magnification. If another load rod is used, the turret 21 is rotated into its operating position under a load actuator not shown. The load is provided as described in connection with FIG. The advantage of this embodiment is that the measuring scale (indenter) can be replaced without affecting the load and without having to realign the optical lens at each replacement.

The lift unit of FIG. 3 moves the sample for microhardness testing to a proper focus using a lens alignment element attached to a turret with a load rod assembly. The lift rod 30 has a main body 31, through which the lift shaft 32 moves to change the position of a test sample (not shown). The lift shaft 32 is
This worm gear 33 is connected to the worm gear 33.
Is coupled to a lifting screw (not shown) in a conventional manner, thereby raising and lowering the lift shaft 32 by a desired distance. Manually driven quick focusing sprocket driver 34
And the non-driving quick focusing sprocket driver 35 is combined with the fine focusing sprocket driver 37 and the non-driving fine focusing sprocket 36.
Due to having a larger sprocket ratio, the quick focus feature can be achieved. As a result, the quick focus driver sprocket may be rotated a few times to rotate the worm gear. As mentioned previously, the rapid focusing feature allows the test sample to be moved faster and longer distances, reducing operator fatigue to obtain the required fine focusing.

FIG. 4 is a block diagram showing another feature of the present invention. The ASTM specification requires some set dwell time for the test to be successful. The device has a standard test button accessible to the operator, which when activated is associated with a timing circuit with a timing element set at the factory. In particular, the motor 89 is connected to the timing relay 71 and controlled by the timing relay 71. The input terminal to the relay 71 has two dwell time control circuits 72 and 7 among parameters (not shown).
Have three. These circuits are connected in parallel with each other, only one of which is a ganged switch.
Relay 71 at a certain time based on the operation of 74a, 74b
Connected to. The control circuit 72 is activated when the standard dwell time should be used. Capacitor 75
Is connected to the fixed resistor 76, and the variable resistor 77 is set at the time of factory shipment. When the standard dwell time is used, the operator actuates a switch as described above on the front panel to lock the motor dwell time. During normal operation, switch 74b is closed and switch 74a is open, thereby connecting variable dwell time circuit 73 to control timing relay 71. The variable dwell time circuit 73 has a capacitor 78 and a variable resistor 79 controlled by an operator. The timing relay shuts down the motor during the dwell period and releases it after the dwell period to raise the indenter 3 from the sample. This preset dwell time feature can prevent the operator from hasting the testing process.

Although the preferred embodiment of the present invention has been described, the present invention is not limited to the above-described embodiment, and various modifications and applications can of course be considered.

[Brief description of drawings]

FIG. 1 shows a longitudinal cross section of a load rod assembly of the present invention.

FIG. 2 illustrates a preferred embodiment of the present invention in which multiple load rod assemblies are used in a single turret.

FIG. 3 shows a side view of a lifting unit with rapid focusing means for moving a test sample to the correct focus position using an optical alignment element mounted on a turret having a load rod assembly.

FIG. 4 is a block diagram showing a standard test dwell time circuit.

[Explanation of symbols]

 1 Load Rod Assembly 2 Load Rod 3 Indenter 4 Spring 5 Sleeve 6 Load Rod Cap 8 Retaining Screw 9 Retaining Ring 13 Pin 21 Turret 24 Optical Lens 25 Optical Lens 26 Optical Lens 30 Lift Rod 31 Main Body 32 Lift Axis 33 Worm Gear 34 Rapid Focusing Sprocket driver 35 Non-driving quick focusing sprocket 36 Non-driving fine focusing sprocket driver 42 Set screw 71 Timing relay 72 Dwell time control circuit 73 Dwell time control circuit 74a Interlock switch 74b Interlock switch 75 Capacitor 76 Resistor 77 Variable resistor 78 Capacitor 79 Resistor 81 housing 83 arm 84 one end 85 upper edge 86 other end 87 cam 88 cam follower 90 fulcrum 91 finger 92 yes Weight assembly 93 stepped weights lift cone 94 load weight assembly 94a-94 g weight 95 pressure rod 96 upper weight rod 97 differential transformer 98 magnetic element 99 the coil 102 body 105 load rod assembly

Continuation of the front page (72) Thomas P. Inventor. Farrell, S. Aal. United States, 13760 New York, Enduel, Foxboro Lane 1218 (72) Inventor Geassin Barono United States, 13760 New York, Endicott, Road 3 Boxes 197 A

Claims (8)

[Claims] 1. A plurality of different indenters are used, each indenter comprising:
The microhardness of the microhardness test is carried by a load rod assembly located separately on a rotatable turret, enabling each said indenter, thereby performing different microhardness tests on one test sample. In the tester, the micro hardness tester comprises a rotatable turret fitted with at least two spaced load rod assemblies directed from the turret toward the test sample, each load rod assembly comprising: , Moving each indenter to perform a micro hardness test on the test sample,
Attached to the rotatable turret is at least one optical lens element directed from the turret toward the test sample for observing a micro hardness test to be performed. Are aligned to observe a test performed by each indenter moved by each load rod assembly attached to the turret, the turret being rotatable and actuating each indenter to activate the test sample. A micro hardness tester for observing the test without moving the test sample by actuating an optical lens element. 2. Further comprising at least two optical lens elements, each of these optical lens elements having a different magnification for observing a microhardness test,
The microhardness tester of claim 1, wherein the at least two optical lens elements are mounted on the turret for observing a microhardness test performed by the different indenters. 3. At least one of the plurality of load rod assemblies comprises a load rod and a first end of the load rod, the indenter having a function of contacting the sample during a micro hardness test. An annular spring holding the load rod at a home position away from the test sample, a sleeve having one end supported by the spring and the other end supporting the load rod cap, and moving the sleeve downward. An actuator that initiates a test by releasing the load rod, moving the load rod downwardly from the home position, and contacting the indenter with a test sample placed under the indenter. The cap provides a support surface on which the supplied weight is loaded, and the spring holds the load rod after the test is complete. The micro hardness tester according to claim 1, wherein the micro hardness tester is returned to the home position. 4. A housing, a shaft that can be moved through the housing to move the sample to a desired focus position, a worm gear that raises and lowers the shaft, and a rapid focusing device coupled to the worm gear. The micro hardness tester of claim 1, further comprising a fine focusing device coupled to a worm gear to selectively move the shaft. 5. The micro hardness tester of claim 1, further comprising an adjustable load weight device for adjusting the load applied to one of the load rod assemblies for testing. 6. A load rod, an indenter connected to a first end of the load rod and having a function of contacting the sample during a micro hardness test, and arranged around the load rod penetrating an axis. An annular spring that holds the load rod in a home position away from the test sample; a sleeve that is concentric with the spring and has one end supported by the spring; and a load that supports the sleeve from the home position. Means for releasing the rod and contacting the indenter with a test sample placed in the opposite direction during the micro hardness test, and means for applying a variable load acting on the load rod to control the hardness test A load rod assembly for a micro hardness tester, which is characterized in that 7. The load rod cap is further positioned on and in communication with the load rod, the sleeve having a seating surface at an upper end thereof, the load rod cap having a seating surface on the seating surface. The load rod assembly for a micro hardness tester according to claim 6, wherein the load rod assembly is seated. 8. A weight lifting cone of conical shape further comprising means for applying a variable load to exert a force on said load rod cap, said means for applying a variable load being cooperatively connected to a plurality of variable weights. The load rod assembly of claim 7, further comprising: