JPS59221638A - Sample fixing type hardness tester - Google Patents

Abstract

PURPOSE:To press a sample and to impose simply both preliminary and testing loads only by up-and down operations of a beam, by providing two plate springs to the ascending and descending beam and pressing a load shaft by the plate springs. CONSTITUTION:A base 2 for receiving sample is provided on a bed 1, and the sample 13 is laid thereon. Screw shafts 4 are provided to a supporting frame 3, and a beam 5 is provided to the shaft 4. The beam 5 ascends and descends by a revolution of the shaft 4. Plate springs 11a, 11b are provided by interposing them among shafts 6a, 6b, 6c in the beam 5. When a pressing plate 12 is pressed by a spring 8 through levers 7 to lower the beam 5, the sample 13 is pressed down by an energized force of the spring 8. If the beam 5 is furthermore lowered, the preliminary load is applied by the spring 11a. Next, if the beam 5 is furthermore lowered, an energized force of the spring 11b is added to apply the testing load.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hardness tester that measures hardness based on the depth of penetration of an indenter at the lower end of a load axis into a sample, and in particular, the present invention relates to a hardness tester that measures hardness based on the depth of penetration of an indenter at the lower end of a load axis into a sample. This invention relates to a sample-fixed hardness meter that can measure the hardness of a sample after fixing it.

Conventionally, in order to avoid errors in measuring the amount of penetration of the indenter into the sample, the sample is held down on the sample holder; after the sample is fixed, a preliminary load and a main load are sequentially applied to the sample. A sample-fixed hardness tester has been proposed.

However, with this type of conventional sample-fixed hardness tester,
This method requires multiple sets of load-applying mechanisms, and as a result, the operations from pressing the sample through preliminary loading to applying a test load are complicated due to the relationship between the load-applying mechanisms and the timing of their loads.

There is also the problem that the displacement detection mechanism and load detection device (armor) are complicated, leading to high costs.

The present invention aims to solve these problems.
By simply lowering and raising the beam that is driven vertically along the hardness tester body, a series of operations from pushing the sample to applying preload and test load, and vice versa, can be performed. 2.
An object of the present invention is to provide a sample-fixed hardness tester that can accurately apply a preload and a test load by using two leaf springs.

For this reason, the sample-fixed hardness tester of the present invention has a beam that is driven downward along the hardness tester body in the 11z direction of the sample holder, and a beam that is supported from above by the support section of the beam. A cylindrical sample holding member is provided to be movable up and down relative to the beam, and the sample holding member is supported by the member and coaxially therewith, and this sample holding member is independent from the member. The load shaft and the sample holder are provided with a displacement detector fτj that is integrally attached to one of the members along the central axis of the load shaft and the sample holder. , a contact member that is integrally attached to the external force and contacts the displacement detector 1, and in order to apply a preload and a test load through the load axis, the The holder is provided with a pair of plates that are arranged and can press the two ends of the load shaft.

Hereinafter, a sample-fixed hardness tester as an embodiment of the present invention will be explained with reference to the drawings.
The figure is an enlarged partial view of part i in figure 1, and figure 3 is a partial view showing part i in figure 1.
Fig. 4 is a partial perspective view for explaining the mechanism that guides the beam, Fig. 5 is an enlarged view of the vicinity of the indenter, and Fig. 6 is an enlarged cross-sectional view of Fig. The operation timing diagram, FIG. 7, is a block diagram showing the measurement system.

As shown in FIG. 1, a gate-shaped support frame 3 is rigidly erected on the bend 1, and the bed 1 and the support frame 3 constitute a hardness tester main body H.

In addition, a sample holder 2 is provided on the bed 1.
A sample 13 is placed on this sample holder 2''.

Further, screw shafts 4 extending vertically are provided on both inner sides of the support frame 3. They are synchronously rotated in the same direction by a motor 102 (see FIG. 7).

As shown in FIG. 4, these screw shafts 4 are provided with
A nut 29 outside the guide piece 30 is screwed together, each guide piece 30 is fitted into a guide groove 3a of the support frame 3, and a support plate 5 as a beam is inserted between these guide pieces 30. A pair of them are installed.

As a result, these support plates 5 are driven as one in the vertical direction along the hardness meter main body H above the sample holder 2.

By the way, as shown in FIG. 3, there is a space between the support plates 5, 5.
A guide portion 28 is provided, and a cylindrical sample holding member 27 is provided on the guide portion passing through the guide member 28 above and below.
is fitted so as to be movable in the vertical direction.

The sample presser is attached to the connecting plate 2 at the upper end of the member 27.
6 are fixed with bolts or the like, and the lower surface of the connecting plate 26 is supported by the second end support portion 28g of the guide member 28. As a result, the sample presser member 27 is supported from above via the connecting plate 26 by the guide member 28 located on the support plate 541.

A cylindrical sample holding part 15 having a predetermined length is fixed to the lower part of the sample holding part J27 with a bolt or the like.

A load shaft 19 is fitted coaxially into the sample holding part 1H27, and a conical enlarged receiving part 19a is formed in the shape of I& in the middle part of this load shaft 19. The 7-lunge-shaped spring receiving surface on the lower side of the receiving part 19a and the sample holding part are in part 1.
A spring 18 that urges the load shaft 19 upward is interposed between the spring receiving surface 5 and the spring receiving surface 5 .

Then, by this spring 18, the receiving portion 19a of the load shaft 19
The sample holder is brought into contact with the stopper portion 27g of the member 27 from below, so that the sample holder is supported by the member 27 while the load shaft 19 is restricted from moving upward. Therefore, the load axis 1 resists the spring 18.
By pushing down the load shaft 19, the sample can be held down.
It can be lowered independently from the retaining member 27. Note that when the push-down force is relaxed, the load shaft 19 rises due to the bias of the spring 18.

Further, as shown in FIGS. 3 and 5, an indenter 14 is attached to the lower end of the load shaft 19 so as to be inserted into the sample holding part 15.

A displacement meter support 24 is attached to the connecting plate 26 with the sample holding member 27 via four connecting rods 25, and a displacement meter (displacement detection 9 is attached. The displacement meter 9 is arranged along the central axis of the sample holding member 2'i.

Further, a connecting plate 20 is attached to the upper end of the load shaft 19, and a connecting plate 22 having the same shape as the connecting plate 20 is attached to the connecting plate 20 via four connecting rods 25. The connecting plate 22 is provided with a contact piece (contact member) 23 that contacts the displacement meter 9 from below.

A first leaf spring 1 is disposed between the support plates 5 and 5 along the longitudinal direction thereof.
3. a and the second leaf spring 11-b are disposed over two levels below ``1''. and these leaf springs], 1a, 11b
has three shafts 6a at both ends as shown in Figure 11.4,
6b.

It is supported by the support plate 5 in such a way as to be sandwiched by the support plate 6c.

Moreover, as shown in FIGS. 1 to 4, between the support plates 5 and 5,
The upper leaf spring (second
A support rod 31 is interposed to support the intermediate portion (center portion) of the leaf spring 11b from below, and the support rod 31 is arranged so as to be guided along an elongated hole 5a formed in the support plate 5. has been done.

Further, the support rod 31 is supported by a pillow member 32 fitted into the elongated hole 5a so that the support rod 31 can support the second leaf spring 11b with the center portion of the second leaf spring 11b slightly lifted. There is. This gives preliminary deformation to the second leaf spring 11b.

Note that the first leaf spring lla is used for preload loading,
The test load is applied by the first leaf spring Ila and the second leaf spring Ilb.

Therefore, the spring constant of the first leaf spring lla is set smaller than that of the second leaf spring 11b.

By the way, a load cell (load detector) 10 is attached to the lower side of the longitudinal center portion of the first leaf spring lla so as to face the upper end of the load shaft 19 and to extend along the central axis of the load shaft 19. As a result, the load cell 10 is elastically supported by the support plate 5 via the first leaf spring lla, and as the support plate 5 descends, the load cell 10
When the load cell 10 comes into contact with the load shaft 19 and a load is transmitted, the load cell 10 can detect the applied load from the preload state to the test load state.

At the bottom of the member 27 for holding the sample, there is a conical enlarged receiving part 27.
1) is formed, and on this receiving portion 27b is a plate 1 with a presser (the intermediate member with the presser) also having a conical receiving surface.
2 is provided.

Further, a pair of left and right levers 7 facing each other are pivotally attached to the outer surfaces of both support plates 5, and left and right levers 7 are mounted on the left and right levers 7.
A contraction spring 8 is interposed between the long arms. (
(See Figure 1) Furthermore, a shaft 17 with a roller 16 is mounted between the short arms of the left and right levers 7 that face each other with the support plate 5 in between (1). 16#f presser foot is in contact with the plate 12.

As a result, the force of I/n (=j) can be magnified by the lever 7 and transmitted to the presser foot plate 12.

Note that a lever 7 is attached to the support plate 5 due to contraction by a spring 8.
In order to prevent the spring 8 from rotating further in the contraction direction of the spring 8 than the predetermined position, a stopper bin 33 is provided protrudingly.
Thereby, the biasing force of the spring 8 transmitted to the plate 12 via the lever 7 can be maintained at a predetermined value or more.

By the way, as shown in FIG. 7, the detection signals from the displacement meter 9 and the load cell 10 are sent to the drive motor 102 of the screw shaft 4, the control unit 101 for the clutch, and the Brinell hardness of the sample via the interface 100. Calculation/display/recording unit 103 that calculates, displays, and records tlB
It is now sent to.

Then, the motor control unit 101 receives each displacement and load detection signal and controls the motor 10 according to the measured displacement and load.
By controlling 2 and a clutch (not shown), vJ6
The load F, displacement x, and pressing as shown in the figure realize the characteristics A, B, and C of force f.

Further, the calculation/display/recording unit 103 receives the detection signal corresponding to the displacement X, calculates the Brinell hardness HB of the sample by calculating the following equation based on the detection signal, and further displays and records the result.

HB=(A/Δx)×B Here, ΔX(- is the difference in the displacement X of the indenter 14 when preload is applied two times before and after sliding by a series of operations of this hardness tester.

In addition, A and B are constants obtained through experiments, for example, if the pre-III load is 3 (1) OkgF + test load is 30
If the diameter of the 00kgL indenter 14 is lf)mu+, then A
The constant is ≠47 tB'=66.

In order to measure the Brinell hardness HB of a sample using the double configuration, a desired sample 13 is first placed on the sample holder 2-.

Thereafter, the motor 102 is driven while controlling its rotational state (including the engaged state of the clutch) according to the timing chart shown in FIG. First, from time t0,
During this time, turn the motor] and 02 quickly to remove the support plate 5.
descending at high speed. When n1lt+ is reached at the time of return, that is, when the lower end of the specimen holder 15 comes close to the surface of the specimen 13, the speed of the motor 102 is reduced. As a result, the support plate 5 is lowered at a low speed.

Then, at time t9, the lower end of the sample holding section 15 comes into contact with the surface of the sample 13. As a result, the connecting plate 26 with the sample holding member 27 separates from the guide member 28, so that the old force by the spring 8 is expanded by the lever 7, and the sample holding force is applied to the sample surface via the plate 12 and the sample holding member 15. At time t3, a fully expanded spring biasing force is applied to the sample 13. As a result, the unevenness on the back surface of the sample 13 is crushed and the sample 13 is fixed.

Note that at time t2, the sudden rise of the push force f is caused by the stopper pin 33 and the spring 8 (=1
This is because the structure is such that the force does not become smaller than a predetermined value, so that the desired pressing force (1700 kgf in this embodiment) can be applied in a short time.

As the support plate 5 further lowers, the load cell 10 comes into contact with the load shaft 19 at time t4, and gradually
is going down. At this time, the attitude of the load shaft 19 is maintained by the load cell 10. Then, the indenter 14 presses the sample surface, and a preload is applied at time t5.

In addition, if you temporarily stop the motor 102 and zero-set the displacement meter 9 while maintaining the preload state.

In this state, the biasing force by the second slope spring 11b is not acting, and the biasing force by the first leaf spring l1g and the load axis J9 are not acting.
The weight of the sample is applied to the sample surface via the load shaft 19 and the indenter 14.

After the above-mentioned zero setting is completed (at the time point), the motor 102 is driven at low speed again to lower the support plate 5. As a result, as the load increases on the sample 13, the output of the displacement meter 9 also changes. Then, after a period of time L7, a test load is applied.

In this state, in addition to the tJ force and the weight of the load shaft 19, the force of the second leaf spring 11b also acts.

In addition, the sudden rise of the load F at time , is due to
This is because the second leaf spring llb is pre-deformed by 411 by the support rod 31, so that a desired test load can be applied in a short time.

In this state, the total force for pressing the sample is set to be as large as possible so that the change in posture between the preliminary load and the test load is tolerable for hardness measurement.

At this time, the motor is temporarily stopped again to maintain the test load state, and then the motor 102 is driven in the opposite direction at low speed to raise the support plate 5.
Time opening tt Itl. After that, a preload is applied again at time opening tl+.

At this time, the motor 102 is temporarily stopped and the displacement X is detected by the displacement meter 9 while maintaining the preload state.

In this state, as mentioned above, the (fJ force) exerted by the second leaf spring llb is not acting, but due to the plastic deformation of the sample 13, there is a difference in the displacement of the indenter 14 during the two preloads before and after preloading. Then, based on this displacement difference ΔX (actually, the displacement meter 9 is zero-set in the first preload state, the displacement of the second surface during preload corresponds to this displacement difference). The formula HB=(A/ΔX)×B is calculated, and based on the result of this calculation, the Brinell hardness HB is displayed and recorded.

Note that at a desired time L12 after the completion of the calculation, the motor 10
2 is rotated at a higher speed.

As a result, first, the load cell 10 separates, and the displacement meter 9 separates from the contact piece 23 (at time 115), and finally, at time L14, the lower end of the sample holder 15 begins to separate from the sample 13, and at time At the 11th point, at time 5, the sample holding part 15 is completely separated from the sample 13.

Then, at time tlf+, the hardness measurement operation is completed by stopping the motor 102, but all of the above operations are performed automatically.

Alternatively, the displacement meter 9 may be integrally attached to the load shaft 19 side, and the contact piece 23 may be integrally attached to the sample holder (=I-holder member 27111).

As described in detail above, the fixed sample hardness tester of the present invention provides the following effects and advantages.

(1) The operations of holding down the sample, applying a preliminary load, and applying a test load can be accomplished simply by lowering the beam, simplifying the operations and facilitating automation.

(2) A pair of leaf springs are arranged in two stages, upper and lower, along the beam, so first apply a preload to the lower leaf spring, then apply a test load to the upper leaf spring. This allows both the preload and the test load to be applied accurately.

(3) After the test load is applied from the preload state, the hardness is measured again based on the relative displacement of the preload state quantities before and after the preload state. The error caused by the amount of distortion compared to the test load is canceled out, improving measurement accuracy.

(4) The displacement detector is built into the hardness tester so that it is placed along the central axis of the sample holding member and the load shaft, so it has a simple configuration and can measure relative displacement with high accuracy. It can be detected by −>f.

(5) It can be easily applied to large samples and also to the measurement of Brinell hardness.

[Brief explanation of the drawing]

The figures show a sample-fixed hardness tester as an embodiment of the present invention. Fig. 1 is a front view thereof, Fig. 2 is an enlarged partial view of the section ■ in Fig. 1, and Fig. 153 is a 11 Figure m4 is a partial perspective view for explaining the indenter structure that guides the beam, Figure 5 is an enlarged view of the vicinity of the indenter, and Figure 6 is its operation. Timing diagram! ll'S
FIG. 7 is a block diagram showing the measurement system. 1. Bed, 2. Sample holder, 3. Support frame, 3a.
・Guide groove, 4. Screw shaft, 5. Support plate as beam, 5a. Long hole, 6a, 61), 6c. Shaft, 7. Lever, 8. Spring, 9. Displacement detection. Displacement meter as a device,
10... Load cell as a load detector, 11. a,
11b...plate spring, 12...presser foot (=I'-1 plate as intermediate member, 13...sample, 14...indenter,
15. Sample holding part, 16. Roller, 17.
・Shaft, 18... Spring, 19... Load shaft, 19a... Receiving part, 20... Connecting plate, 21... Connecting rod, 22... Connecting plate,
23... Contact piece as a contact member, 24... Displacement meter support material, 25... Connecting rod, 26... Connecting plate, 27... Sample holding member, 27a, 27b... Receiving part, 28... - Guide member, 28a... Support part, 29... Nut, 3o... Guide piece, 31... Support rod, 32... Pillow member, 33... Stopper pin, 100... Interface, 1oi - Split hook part. , 1.02...Motor, 103...Calculation/Display/
Recording section, I... Hardness tester body. Agent Patent Attorney Yoshihiko Iinuma Figure 1 Figure 1 ■ Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 BfFl'JI - Figure 7

Claims (1)

[Claims] () On one side of the sample holder, a beam driven vertically along the hardness tester body and a beam supported from above by the support section of the beam are positioned relative to each other. A cylindrical sample holder is provided so as to be movable up and down, and the sample holder is supported by the member and coaxially therewith, and the sample holder is provided so as to be movable up and down independently of the member. The load shaft and the sample holder are equipped with a
A displacement detector which is integrally attached to one of the two members along the central axis of the two members, and a contact member which is integrally attached to one of the members and comes into contact with the displacement detector. A pair of leaf springs are provided along the beam in two stages, upper and lower, and capable of pressing the upper end of the load shaft. (2) The sample holding device has a conical receiving part formed at the lower part of the member, and an intermediate member is provided in the holding part from above. and an L-shaped lever pivotally connected to the beam, and a spring for biasing the lever, and the biasing force of the spring is amplified by the lever and the pressing force is transmitted to the intermediate member. The sample-fixed hardness tester according to claim 1, which is configured to The sample-fixed hardness tester according to claim 2, further comprising a stopper bin for restricting the rotation of the lever so that the lever is held at The load shaft and the sample holder are interposed between the parts, and the sample holder contacts the stopper part of part 2 from below in the middle of the load axis, and the load shaft is moved upwardly. The sample-fixed hardness tester according to claim 1, in which a conical receiving portion is formed to restrict movement. (5) Preliminary deformation is applied to the upper leaf spring of the pair of leaf springs ( =] In order to give a slight force to the upper leaf spring, a support rod supporting the upper leaf spring from below in a manner like a two-legged arm is installed on the force ejection beam, and the support rod is attached to the upper leaf spring.・In order to accommodate the movement of ＼ by 8″,
Sample fixing method (6) according to claim 1: Based on the six sections of displacement difference obtained by the displacement detector (g) before and after two preload loadings, the sample is determined by the following formula. A sample-fixed hardness tester according to claim 1, which is provided with a calculator for calculating the Brinell hardness HB of HI3=(A/Δx)+13, where ArB is a constant obtained by experiment.