Summary of the invention
For overcome exist in the prior art be difficult to eliminate effectively end-face friction, can not truly reflect the deficiency of the mechanical property of plate when unidirectional compression, the present invention proposes a kind of determinator of true stress-strain curve.
The present invention includes upper bolster, die shoe, on insert, insert down, upper punch, low punch, guide pillar, guide pin bushing, locating piece, measurement bay and extensometer; At the two ends of upper bolster lower surface a guide pin bushing is arranged respectively, a guide pillar is respectively arranged at the two ends of die shoe upper surface, and described guide pillar be slidingly connected after described guide pin bushing is mutually nested; The upper punch base is positioned at the center of the lower surface of upper bolster; The upper surface of upper punch base and the lower surface of upper bolster are fitted, and the drift of this upper punch embeds in the bar shaped bore of the punch at the center of inserting; On insert and be fixed on the lower surface of upper bolster, upper punch and upper bolster are connected; The base of low punch is positioned at the upper surface center of die shoe; The lower surface of low punch base and the upper surface of die shoe are fitted, and the drift of this low punch embeds in the bar shaped bore of the punch of inserting down; Inserting down is fixed on the upper surface of die shoe, and low punch and die shoe are connected; Said position of inserting down with said on the position of inserting corresponding each other; Locating piece has 2, lay respectively at down the side of inserting two ends and with under insert fixing; The upper rack posts of measurement bay is fixed on the end face of upper bolster, and the lower fulcrum bar of measurement bay is fixed on the end face of die shoe, and upper rack posts and lower fulcrum bar are positioned at the same end of test unit; The sounding rod lower end of measurement bay is fixedly connected with lower fulcrum bar, and the sounding rod upper end of measurement bay is sleeved in the endoporus of upper rack posts termination, and is slidingly matched between described sounding rod and the upper rack posts endoporus; The lower end of extensometer is fixed on through the straight pin that is positioned at the upper rack posts termination on the endoporus of upper rack posts termination, and the extensometer upper end is fixed on the sounding rod that passes the upper rack posts endoporus;
The mounting hole that a guide pin bushing is respectively arranged at upper bolster length direction two ends; The mounting hole of on the surface distributed of upper bolster has, inserting; The mounting hole that a guide pillar is respectively arranged at die shoe length direction two ends; Surface distributed at die shoe has the mounting hole of inserting down;
The contour dimension of said upper punch and low punch upper punch respectively with on the interior exterior feature of through hole on inserting and descending to insert measure-alike;
One side surface of said locating piece has bar hole, the position of this bar hole be positioned at the side of inserting down on the position of mounting hole of locating piece corresponding;
The present invention is a kind of test unit based on true stress-strain curve under the unidirectional compressive state of rolling test determination plate.Through the present invention the plate test specimen is the level of state, can produce the unstability bending during pressurized, can carry out the compression deformation of big degree, to obtain the plate true stress-strain curve under the large deformation; Since adopt long and narrow drift, little with the test specimen contact area, add good lubricating, reduce the friction between plate test specimen and the drift to greatest extent, the true stress-strain curve in the time of can comparatively accurately trying to achieve the plate compression; Again because drift and test specimen contact area are little, and lubricated good, the problem of sliding, tilting may appear when receiving pressure greatly, and locating piece has then solved this type of problem well.The measurement bay of design, can change compression deformation is stretcher strain, is equipped with extensometer, can measure test specimen compressive deformation degree accurately and easily.
Embodiment
This instance comprise upper bolster 2, die shoe 10, on insert 6, insert 9 down, upper punch 7, low punch 8, guide pillar 4, guide pin bushing 3, locating piece 5, measurement bay 1 and extensometer 18.
Adopt symmetrical pillar die set, and A type guide pillar guide pin bushing, shown in Figure 1 like Figure of description.
At the two ends of upper bolster 2 lower surfaces a guide pin bushing 3 is arranged respectively; At the two ends of die shoe 10 upper surfaces a guide pillar 4 is arranged respectively; And be slidingly connected after described guide pillar 4 and described guide pin bushing 3 are mutually nested, make between the upper surface of lower surface and die shoe 10 of upper bolster 2 and form the space.Upper punch 7 bases are positioned at the center of the lower surface of upper bolster 2; The upper surface of upper punch 7 bases and the lower surface of upper bolster 2 are fitted, and the drift of this upper punch 7 embeds in the bar shaped bore of the punch at 6 centers of inserting.On insert 6 through screw retention at the lower surface of upper bolster 2, thereby upper punch 7 and upper bolster 2 are connected.The base of low punch 8 is positioned at the upper surface center of die shoe 10; The lower surface of low punch 8 bases and the upper surface of die shoe 10 are fitted, and the drift of this low punch 8 embeds in 9 the bar shaped bore of the punch inserted down; Insert 9 down through the upper surface of screw retention, thereby low punch 8 and die shoe 10 are connected at die shoe 10.Said insert down 9 position with said on insert 6 position corresponding each other.Locating piece 5 has 2, lay respectively at down 9 one sides of inserting two ends and with under insert 9 fixing.The upper rack posts 14 of measurement bay 1 is fixed on the end face of upper bolster 2, and the lower fulcrum bar 16 of measurement bay 1 is fixed on the end face of die shoe 10, and upper rack posts 14 and lower fulcrum bar 16 are positioned at the same end of test unit.Sounding rod 15 lower ends of measurement bay 1 are fixedly connected with lower fulcrum bar 16, and sounding rod 15 upper ends of measurement bay 1 are sleeved in the endoporus of upper rack posts 14 terminations, and are slidingly matched between described sounding rod 15 and upper rack posts 14 endoporus.The lower end of extensometer 18 is bundled on the endoporus of upper rack posts 14 terminations through the straight pin 17 that is positioned at upper rack posts 14 terminations with bungee, and extensometer 18 upper ends are bundled on the sounding rod 15 that passes upper rack posts 14 endoporus with bungee.
Described upper bolster 2 is the bar shaped bulk with die shoe 10.The mounting hole that a guide pin bushing 3 is respectively arranged at upper bolster 2 length direction two ends, and this guide pin bushing mounting hole connects the upper surface and the lower surface of upper bolster 2.The aperture of said guide pin bushing mounting hole is identical with the external diameter of guide pin bushing 3 links, makes guide pin bushing 3 links and said guide pin bushing mounting hole interference fit between the two.6 the mounting hole of on the surface distributed of upper bolster 2 has, inserting.
The mounting hole that a guide pillar 4 is respectively arranged at die shoe 10 length direction two ends, and this guide pillar mounting hole connects the upper surface and the lower surface of die shoe 10.The aperture of said guide pillar mounting hole is identical with the external diameter of guide pillar 4, makes guide pillar 4 and said guide pillar mounting hole interference fit between the two.Surface distributed at die shoe 10 has 9 the mounting hole of inserting down.
Insert on described 6 with under insert and 9 be rectangular panel blocks.6 the through hole of strip is arranged last inserting with 9 the center of inserting down, insert on the center line of this through hole length direction and the place 6 with the central lines of time inserting 9 length directions.Last insert 6 with 9 four angles of inserting down on be distributed with screw hole.Be distributed with the mounting hole of locating piece 5 at the two ends of 9 the side inserted down.
Described upper punch 7 is a bar blocks with low punch 8, and its profile is " T " shape, has formed base and drift.The contour dimension of the drift on said upper punch 7 and the low punch 8 respectively with on insert 6 measure-alike with the interior exterior feature of the through hole on 9 of inserting down.
Described locating piece 5 has two, and shape sees from the side, and " L " of a similar handstand stretches along thickness direction and form, and the height of locating piece 5 should guarantee when last low punch contacts, and locating piece does not touch 6 the bottom surface of inserting.One side surface of said locating piece 5 has bar hole, the position of this bar hole be positioned at 9 sides of inserting down on the position of mounting hole of locating piece 5 corresponding.
Described standard extensometer 18 models are YSJ-50/25-ZC, and gauge length is 50mm, and the maximum elongation amount is 25mm.
During assembling:
1) assembling low punch 8.Low punch 8 is passed down 9 the through hole of inserting, be stuck in down in 9 the groove inserted with convex shoulder, adjustment low punch 8 makes planar horizontal on the low punch 8.Guarantee simultaneously low punch 8 convex shoulder height greater than with under 9 depths of groove of inserting, assembling is accomplished after, low punch 8 with under insert that nothing relatively moves between 9.
2) assembling counterdie.Following the inserting that assembles 9 is placed on the die shoe 10,, clamps, on die shoe 10, get out two awl nests through two screw holes inserting down on 9 with parallel carrier by inserting 9 position under the center line centering.Take away down and insert 9, by awl socket drill thread Pilot hole and tapping, will insert down 9 places on the die shoe 10 again, fastening with trip bolt 13 behind the centering position on die shoe 10.On another diagonal line, bore at last, cut with scissors pilot hole, squeeze into register pin 12.
3) the fit on drift 7.According to 1) with quadrat method fit on drift 7.
4) assembling patrix.According to 2) same method installation patrix.
5) assembling mould bases.Guide pin bushing 3, guide pillar 4 are respectively charged into upper and lower die holder, and make the tolerance clearance of guide pillar 4 and guide pin bushing 3 even after noting installing, assurance is lubricated good, acomia puckery and stuck phenomenon when upper and lower die holder is slided relatively.
6) check and adjust upper and lower drift position.The upper die guide sleeve that installs 3 is sleeved on the counterdie guide pillar 4, closed upper and lower mould, whether low punch aligns in the inspection, whether the joint place evenly (can adopt light transmission method, the inspection of pressure testing method) everywhere.If any problem, can adopt the pad method to adjust.
7) the assembling and positioning piece 5.9 fit with inserting down locating piece 5 is inboard, pass the bar hole of locating piece 5, locating piece 5 is fixed on down inserts on 9 with bolt 11, guarantee after fixing locating piece 5 and under the relative slip of nothing between 9 of inserting.By another locating piece being installed with quadrat method.
8) the alignment measurement frame 1.The thread end of upper rack posts 14 is screwed in the screw hole of upper bolster 2 sides and tightens, and guarantee upper rack posts 14 other end endoporus horizontal positioned.By with quadrat method lower fulcrum bar 16 being fixed on the die shoe 10, the sounding rod 15 that will link to each other with lower fulcrum bar 16 passes the endoporus of upper rack posts 14.With the pilot hole on the straight pin 17 insertion upper rack posts 14.
During use, plate test specimen upper and lower surfaces, each surface of drift that contacts with test specimen and locating piece 5 inside surfaces that contact with test specimen are cleared up and sufficient lubrication, the test specimen level is placed between the upper and lower drift, make the plate axis direction vertical with the punch axis direction.Adjustment locating piece 5 positions make locating piece 5 be close to the test specimen dual-side, tighten on each locating piece bolt 11 with stationary positioned piece 5.At last a whole set of test unit is placed on unilateral stretching/compression test; Standard extensometer 18 lower ends are bundled on the endoporus of upper rack posts 14 terminations through the straight pin 17 that is positioned at upper rack posts 14 terminations with bungee; Extensometer 18 upper ends are bundled on the sounding rod 15 that passes upper rack posts 14 endoporus with bungee, and removing can start shooting behind the register pin on the standard extensometer carries out compression experiment.
During dismounting, according to the above-mentioned steps backout.