Hardness testing machine

Abstract

To provide a hardness tester that can set a wide range of loads to be applied to an indenter.SOLUTION: A hardness tester 10 includes: a base member 120 supported so that it can be raised and lowered; a motor 110 being a driving device that drives the vertical movement of the base member 120; and a load cell switching device 130 having a first load cell 141 having a first indenter connecting member 141a and a second load cell 142 having a second indenter connection member 142a, and provided on the base member 120 to be switchable between the first load cell 141 and the second load cell 142.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to a hardness tester.

Background Art

[0002] Conventionally, a hardness tester equipped with a load cell (load sensor) has been disclosed. For example, in Patent Document 1, in order to measure the height of a soft specimen such as a gel-like organic material or a biological substance with high accuracy, a hardness tester is disclosed that includes an indenter, a load sensor that detects a predetermined load applied to the indenter, and a position sensor that can measure the position of a stage on which the specimen is placed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In hardness testers, dedicated machines specialized for specific measurement objects are also provided. On the other hand, there is also a demand to perform hardness tests on measurement objects of various materials, that is, measurement objects from low-hardness materials to high-hardness materials, using a single hardness tester. In this case, if the material is relatively soft, a low load is applied to the indenter to form an indentation, and if the material is hard, a high load is applied to the indenter to form an indentation. Also, these loads may be loads defined by standards in some cases, or arbitrary loads may be applied to the indenter in other cases.

[0005] An object of the present invention is to provide a hardness tester capable of widely setting the load range applied to the indenter. <000)0029>

Means for Solving the Problems

[0006] The hardness testing machine according to the present invention is characterized by comprising a base member that is supported to be able to move up and down, a drive device that drives the up and down movement of the base member, a first load cell having a first indenter connecting member, and a second load cell having a second indenter connecting member, and a load cell switching device provided on the base member that can switch between the first load cell and the second load cell. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a hardness testing machine that can set a wide range of loads applied to the indenter. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing a hardness testing machine according to the first embodiment of the present invention. [Figure 2] This is a perspective view from the front and above showing the load-loading unit of a hardness testing machine according to the first embodiment of the present invention. [Figure 3] This is a rear-upper perspective view showing the load-applying unit of a hardness testing machine according to the first embodiment of the present invention. [Figure 4] This is a rear-left perspective view showing the load application unit of a hardness testing machine according to the first embodiment of the present invention. [Figure 5] This is a VV cross-sectional view of Figure 2, showing the load loading unit of a hardness testing machine according to the first embodiment of the present invention, with the fixing plate, motor as a drive device, etc., omitted. [Figure 6] This is a bottom view of the slider of the load-loading unit of a hardness testing machine according to the first embodiment of the present invention. [Figure 7] This is a front-upper perspective view showing the load-loading unit of a hardness testing machine according to a second embodiment of the present invention. [Figure 8] This is a perspective view from the front left, showing the load application unit of a hardness testing machine according to a second embodiment of the present invention. [Figure 9]This is a plan view of the area around the slider of the load-applying unit of a hardness testing machine according to a second embodiment of the present invention, as seen from the lower surface of the base member, with the fixing plate and the like omitted. [Modes for carrying out the invention]

[0009] (First Embodiment) A first embodiment of the present invention will be described with reference to the drawings. The hardness tester 10 is formed in a roughly C-shape in side view and comprises a base portion 11 with legs 12 for installation, a column portion 13, and a head portion 14. A sample stage device 20 is provided on the base portion 11. The sample stage device 20 is provided with a table (not shown) for placing a sample, and the table can be raised and lowered by manually rotating a handle (not shown). In addition, an operation panel 15 is provided on the front of the base portion 11 for performing various operations and settings.

[0010] In the following explanation, the upper side of the hardness tester 10 will be referred to as "up," the lower side as "down," the side on which the control panel 15 is located as the front, the opposite side as the back, and the left side as viewed from the front of the hardness tester 10 as "left" and the right side as "right."

[0011] A turret device 30 is provided on the head section 14 facing the sample stage device 20. The turret device 30 is equipped with an indenter unit 320 having an indenter 32 and an objective lens 33 on a circular turret plate 31, which are selected as appropriate according to the operation. Although not shown, multiple indenters 32 and objective lenses 33 are provided on the turret plate 31. The turret plate 31 is rotatable around a tilting axis 31a, but when the indenters 32 and objective lenses 33 are positioned at selected positions on the axis 20a of the sample stage device 20, the axes of the indenters 32 and objective lenses 33 coincide with the axis 20a of the sample stage device 20.

[0012] A load-bearing unit 100 is provided inside the head section 14. The load-bearing unit 100 will be described in detail below with reference to Figures 2 to 6. As shown in the perspective views of the load-bearing unit 100 in Figures 2 to 4, the load-bearing unit 100 has a fixing plate 101 that is positioned below with its planar side parallel to the horizontal direction. The fixing plate 101 is fixed to the internal structure of the head section 14 of the hardness tester 10. The fixing plate 101 is equipped with a motor 110, which serves as a drive device for driving the lifting and lowering movement of the base member 120, which will be described later.

[0013] The motor 110 is positioned with its output shaft facing upward in the vertical direction. The output shaft of the motor 110 is connected to a gear inside the gearbox 111 (not shown). The output shaft from the gearbox 111 is also positioned facing upward in the vertical direction. The output shaft from the gearbox 111 is connected to a coupling 112 provided on the fixing plate 101. The coupling 112 is connected to the ball screw shaft 113a of the ball screw mechanism 113. The ball screw shaft 113a is screwed into the nut 113b of the ball screw mechanism 113. The nut 113b is fixed to the base member 120.

[0014] The base member 120 is formed in a substantially plate shape, positioned substantially parallel to the fixing plate 101, and supported so as to be able to move up and down relative to the fixing plate 101. Specifically, the base member 120 is provided with sliding members for guide posts 121 fixed to the left and right rear sides of the fixing plate 101, and movable members for slide guides 122 fixed to the left and right front sides of the fixing plate 101. The nut 113b of the ball screw mechanism 113 is provided between the guide posts 121 on the rear side of the base member 120.

[0015] At the rear end of the fixed plate 101, a sensor base 102 having a substantially L-shaped side view is provided. On the upper surface of the sensor base 102, three optical sensors 103 are provided. In each optical sensor 103, a set of light transmitting and receiving elements is provided. On the other hand, on the right side of the rear end of the base member 120, a plate-shaped detection member 123 that can be inserted between the light transmitting and receiving elements of the optical sensor 103 is provided. The detection members 123 are formed with different lengths. The upper and lower limits of the rise of the base member 120 are detected by the three optical sensors 103. By providing the optical sensors 103 behind the load-bearing unit 100, maintenance of the optical sensors 103 can be easily performed by removing the rear cover of the column portion 13 of the hardness tester 10.

[0016] On the front side of the base member 120, a load cell switching device 130 is provided. The load cell switching device 130 is provided with a guide portion 131 having a substantially rectangular hole shape that is slightly longer in the left-right direction in front of the base member 120. In the guide portion 131, a guide receiving portion 131a extending in the left-right direction is formed. As shown in FIG. 5, the guide receiving portion 131a has a flat continuous surface with the base member 120 on the lower surface, is formed in a plate shape protruding from the inner wall surfaces of the front and rear sides of the hole-shaped guide portion 131, and a flat guide surface is formed on the upper surface. A guide rod 132 extends in the left-right direction between the front and rear guide receiving portions 131a.

[0017] A slider 133 is provided in the guide portion 131 of the load cell switching device 130. The slider 133 is formed in a substantially T shape in a cross-sectional view in the front-rear direction (the cross-sectional view of FIG. 5). A bush 133a is provided at the central portion of the slider 133 in the front-rear direction, and the guide rod 132 is inserted therethrough. Further, slide members 133b are provided on the lower surfaces of the portions of the slider 133 that project in the front-rear direction (portions corresponding to the horizontal bars of the T shape).

[0018] As shown in FIG. 6, the slide member 133b has a plurality of roller bearings 133b2 arranged such that their axes are orthogonal to the moving direction of the slider 133 (the direction in which the guide rod 132 extends), and the roller bearings 133b2 are rotatably held around the axis by a holder 133b1. The holder 133b1 is fixed to the T-shaped main body portion of the slider 133. The plurality of roller bearings 133b2 of each slide member 133b of the slider 133 are placed on the front and rear guide receiving portions 131a of the guide portion 131. Therefore, the slider 133 is provided so as to be movable in the left-right direction along the guide portion 131.

[0019] As shown in FIGS. 2 to 4, a motor 134 is provided on the front base member 120 of the slider 133. The motor 134 is arranged with its output shaft directed in the front-rear direction. A pinion gear 134a is provided on the output shaft of the motor 134. The pinion gear 134a meshes with a rack gear 133d provided on the upper surface of the slider 133. An encoder 134b is provided on the motor 134. The slider 133 is driven in the left-right direction by the motor 134.

[0020] As shown in FIGS. 2 and 3, a positioning member 133c is provided on the upper surface on the rear side of the slider 133. On the other hand, at the edge of the hole of the guide portion 131 in the base member 120, at a position corresponding to the positioning member 133c, as two limit switches, a first LS 135a is provided on the left side and a second LS 135b is provided on the right side. A V-shaped groove portion extends in the vertical direction on the surface of the positioning member 133c facing the first LS 135a and the second LS 135b.

[0021] When the slider 133 is in the right position, the V-shaped groove of the positioning member 133c engages with the detection part of the second LS135b (a pin protruding from the second LS135b), turning the second LS135b ON and detecting that the slider 133 is in the right position (position shown in Figures 2 and 3). Similarly, when the slider 133 is in the left position, the first LS135a detects that the slider 133 is in the left position. Optical sensors 135, each with an integrated light-emitting and receiving section, are positioned on the front sides of the left and right ends of the guide section 131 (on the left and right sides of the motor 134). Detection plates 133d1, which are mounted to protrude from the left and right ends of the rack gear 133d, are inserted through the optical sensors 135 to detect the lateral overrun of the slider 133.

[0022] The slider 133 is provided with a first load cell 141 and a second load cell 142 connected to it. Specifically, the first load cell 141, located on the right side of the load cell switching device 130, is connected to the slider 133 via a first connection block 143 located on the underside of the slider 133. Similarly, the second load cell 142, located on the left side of the load cell switching device 130, is connected to the slider 133 via a second connection block 144 located on the underside of the slider 133. Figure 5 shows the state in which the second load cell 142 is connected to the slider 133 via the second connection block 144.

[0023] A rod-shaped first indenter connecting member 141a extending downward is provided at the front end of the first load cell 141. Similarly, a rod-shaped second indenter connecting member 142a extending downward is provided at the front end of the second load cell 142.

[0024] Here, the first load cell 141 is a cantilever-type load cell that corresponds to a large test load (e.g., tens of gf to hundreds of gf). The second load cell 142 is a cantilever-type load cell that corresponds to a small test load (e.g., a few gf).

[0025] The first indenter connecting member 141a and the second indenter connecting member 142a are formed to be connectable to the indenter 32 when the indenter 32 of the turret device 30 in Figure 1 is positioned at the axis 20a of the sample stage device 20. More specifically, when the indenter 32 is selected in the turret device 30, and the slider 133 is positioned to the left and the axis of the first indenter connecting member 141a aligns with the axis 20a, the first indenter connecting member 141a can contact and connect to the movable axis (not shown, a member that connects to the indenter 32) of the indenter unit 320 (see Figure 1) which includes the indenter 32, while the second indenter connecting member 142a is not connected to the indenter 32. Similarly, when the slider 133 is positioned to the right (as shown in Figures 2-4) and the axis of the second indenter connecting member 142a aligns with the axis 20a, the second indenter connecting member 142a can contact and connect to the movable axis of the indenter unit 320 equipped with the indenter 32, while the first indenter connecting member 141a is not connected to the indenter 32.

[0026] By providing the slider 133 with a first load cell 141 having a first indenter connecting member 141a and a second load cell 142 having a second indenter connecting member 142a, the load cell switching device 130 is made compact.

[0027] The hardness tester 10, formed in this manner, performs hardness measurement as follows. First, the sample is placed on a table (not shown) provided on the sample stage device 20, and the sample stage device 20 is manually raised using a handle (not shown) to within the vertical stroke range of the indenter 32 (i.e., the stroke range of the base member 120). Then, the objective lens 33 is focused by aligning it with the axis 20a.

[0028] Next, the desired indenter 32 is set on the axis 20a. Then, the load cell switching device 130 of the load loading unit 100 sets the indenter connecting member (first indenter connecting member 141a or second indenter connecting member 142a) of the load cell (first load cell 141 or second load cell 142) that matches the set test load on the axis 20a, and the indenter 32 and the indenter connecting member are connected (the movable shaft to which the indenter is connected and the indenter connecting member are in contact).

[0029] After the hardness test preparations are complete, the motor 110 is started and the base member 120 descends. At this time, the descent speed is increased until just before the tip of the indenter 32 contacts the sample, and when the tip of the indenter 32 is in contact with the sample and a load is applied (the hardness test is being performed), the motor 110 is controlled by a control device (not shown) so that the indenter 32 descends at a specified speed and holding time in accordance with the predetermined hardness test method. The action of making an indentation in the sample with the indenter 32 (i.e., the action of driving the motor 110 to descend the base member 120 and stopping the base member 120 for a predetermined holding time) is controlled by a detected value that is detected as the load applied to the indenter 32 by a load cell (first load cell 141 or second load cell 142) corresponding to the indenter connecting member set on the axis 20a.

[0030] After the hardness test is completed, the motor 110 raises the base member 120, separating the sample from the indenter 32.

[0031] In the hardness tester 10, depending on the load in the selected or set hardness test, for example, by selecting the first load cell 141 in the high load range and the second load cell 142 in the low load range, a single hardness tester 10 can perform hardness tests that correspond to a wide range of set loads.

[0032] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to Figures 7 to 9. In this embodiment, the load-bearing unit 100A replaces the left and right slide guides 122 in the load-bearing unit 100 of the first embodiment with guide posts 125. Furthermore, in this embodiment, the load-bearing unit 100A has a structure in which the slide member 133b, which is equipped with a holder 133b1 and a roller bearing 133b2 that are the guide mechanism of the slider 133 in the load-bearing unit 100 of the first embodiment, uses a cross roller guide 138. In the following description, the same or equivalent components as in the load-bearing unit 100 of the first embodiment will be denoted by the same reference numerals, and their descriptions will be simplified or omitted.

[0033] Guide posts 125 are fixedly installed on the left and right sides of the front of the fixing plate 101. The base member 120 is supported by the two front guide posts 125 and the two rear guide posts 121 so as to be able to move up and down relative to the fixing plate 101.

[0034] A plate-shaped connecting plate 145 is provided on the lower surface of the slider 133. The connecting plate 145 is provided so that its front end protrudes from the front end of the base member 120. A first connecting block 143 and a second connecting block 144 are fixed to the lower surface of the connecting plate 145. A first load cell 141 is fixed to the first connecting block 143. A second load cell 142 is fixed to the second connecting block 144.

[0035] Furthermore, as shown in Figure 8, a linear guide 150 is provided between the lower surface of the base member 120 and the upper surface of the connecting plate 145 to guide the slider 133 in the left-right direction. The two movable members 151 of the linear guide 150 are fixed to the upper surface of the connecting plate 145. The rail 152 that engages with the movable members 151 in the linear guide 150 is provided on the lower surface of the base member 120.

[0036] Furthermore, as shown in Figure 9, the guide section 131 is provided with cross roller guides 155 on the front and rear sides of the slider 133. The cross roller guide 155 includes a roller cage 155a that holds cylindrical rollers 155b alternately with their axial orientations changed. The roller cage 155a is sandwiched between a movable member 156 and a fixed member 157. In this way, the movable member 156 and the fixed member 157 of the cross roller guide 155 are able to move relatively linearly.

[0037] The movable members 156 of the cross roller guide 155 are fixed to the front and rear sides of the slider 133. Fixing members 157 are provided on the concave stepped surface 131b located above the lower surface of the base member 120, on the front and rear sides of the guide portion 131 of the base member 120. Thus, the slider 133 is held so as to be movable in the left-right direction by the cross roller guide 155. The cross roller guide 155 can operate the movable member 156 while receiving a predetermined load. Thus, the load cell switching device 130 of the load loading unit 100A eliminates the guide rod 132 of the load loading unit 100 in the first embodiment, while guiding the slider 133 in the left-right direction with ease of assembly and high precision.

[0038] Although embodiments of the present invention have been described above, the present invention is not limited to these embodiments and can be implemented with various modifications. For example, the load cells connected to the indenter are not limited to two types (first load cell 141, second load cell 142), but two or more types can be provided. Also, although the base member 120 is provided to be vertically movable relative to the fixing plate 101, it is sufficient if it is vertically movable relative to the frame of the hardness tester 10. For the configuration that guides the base member 120 to move vertically, slide guides or guide posts can be appropriately selected, and other methods can also be adopted. Also, for the configuration that guides the slider 133 in the left-right direction, in addition to the type using roller bearings or the type using cross roller guides, other types can also be appropriately selected. Also, although the load cell is a cantilever type, other types of load cells can also be used. Also, the drive device is not limited to the motor 110, and other drive devices can be used. [Explanation of Symbols]

[0039] 10 Test machine 11 Base part 12 Leg section 13 Column section 14 Head unit 15 Control panel 20 Sample stage apparatus 20a Axis 30 Turret device 31 Turret panel 31a Tilt axis 32 Indenter 33 Objective lens 100 Load load unit 101 Fixing plate 102 Sensor base 103 Light sensor 110 Motor 111 Gearbox 112 Coupling 113 Ball screw mechanism 113a Ball screw shaft 113b Nut 120 Base component 121 Guidepost 122 Slide guide 123 Detection member 125 Guide post 130 Load cell switching device 131 Guide section 131a Guide receiving section 132 Guide Rod 133 Slider 133a Bushing 133b Sliding member 133b1 Retainer 133b2 Roller bearing 133c Positioning member 133d Rack gear 133d1 Detection plate 134 Motor 134a Pinion gear 134b Encoder 135 Optical sensor 141 First load cell 141a First indenter connecting member 142 Second load cell 142a Second indenter connecting member 143 First connecting block 144 Second connection block 145 Connection plate 150 Linear guide 151 Movable member 152 Rail 155 Cross Roller Guide 155a Roller cage 155b Roller 156 Movable member 157 Fixed member 320 Indenter Unit

Claims

1. A base member that is supported so as to be able to move up and down, A first load cell and a second load cell with different test load ranges, An indenter that contacts the object to be measured via the first load cell or the second load cell, A slider having the first load cell and the second load cell arranged side by side, It has, The slider is movable in a left-right direction perpendicular to the axis of the indenter along a guide portion formed on the base member. By moving the slider, only one of the first load cell or the second load cell is connected to the indenter. Hardness testing machine.

2. A plurality of optical sensors for detecting the upper limit and lower limit of the base member, Multiple optical sensors for detecting the left-right movement limits of the slider, Having, The hardness tester according to claim 1.

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