CN103776989B - Device and method for detecting conical forging lubricating effect - Google Patents

Abstract

The invention discloses a device and a method for detecting a conical forging lubricating effect in the technical field of a plastic formation technology. The device comprises an upper die fixing plate connected with a material test machine, a conical upper die fixed below the upper die fixing plate, a planar lower die corresponding to the conical upper die, two positioning rings and a lubricated sample to be detected, wherein one positioning ring is in clearance fit with the upper surface of the upper die fixing plate, and the other positioning ring is in clearance fit with the upper surface of the conical upper die; a conical cavity is formed in the middle of the bottom of the conical upper die; a through hole is formed above the conical cavity; the sample is arranged below the conical cavity and above the planar lower die. The device is very simple, convenient to mount, debug and manufacture, accurate in travel control, low in cost and good in test stability. The lubricating effect is directly evaluated by measuring the height of a conical part on the deformed sample; meanwhile, a forging forming force is obtained by virtue of a force data acquisition system of the material test machine to assist in evaluation of the lubricating effect.

Description

Taper forging lubricant effect pick-up unit and method

Technical field

What the present invention relates to is a kind of device of plastic forming technology field, specifically a kind of taper forging lubricant effect pick-up unit and method.

Background technology

Good lubricating status, is the important process condition ensureing that the smooth enforcement of metal forging and forming technology and forging surface quality are good, is conducive to the serviceable life of raising forging mold simultaneously.At present, the widely used lubricant of industry member or lubricating method, do not in environment friendly, Some Enterprises is making great efforts to attempt using environment protective lubricant and lubricating method, and this just needs the suitable instrument in greasy property assessment, apparatus and method.

The friction wear testing machine of standard, as pin disc type or four-ball friction and wear test machine etc., evaluated greasy property by indexs such as the friction factor that records, but this type of friction wear testing machine cost is comparatively large, equipment is comparatively heavy.The lubricating oil combination property evaluation testing device of more existing simplification structures at present, directly observation oil temperature draws the relative differential of two oil products with polishing scratch size, and evaluation result is more directly perceived.But this type of friction-wear test of carrying out in the mode of relative sliding between friction pair or rolling, is not too applicable to the assessment of forging lubricant effect, because always there is plastic yield in forging process and form a large amount of fresh surface.

Ring compression method of testing, propose the sixties, be a kind of method measuring plastic-forming friction coefficient, can be used for evaluating the effect of Plastic Forming lubrication, but the method need to carry out a series of ring compression test and in conjunction with calibration curve to determine the friction factor under different lubricating condition.But the self-deformation degree of ring compression process is relatively little, so forging lubricant effect can not be identified under certain conditions.

Taper forging deformation process has merged recurrent plastic deformation modes in crimp and Upsetting two kinds of forging processes simultaneously, possesses typical Forging Technology feature.Through the retrieval of existing document, the people such as Isogawa are at paper " Proposal of anevaluating method on lubrication " (CIRP Annals-Manufacturing Technology, 1982, 41 (1): 263-266.) taper forging method of testing is proposed in (a kind of evaluation method of lubrication), patrix plane devises one group of concentric shallow slot for setting circle cylindricality sample, and placed two pressure transducers in a set of comparatively complicated taper forging mold, although forging and molding force data can be gathered, but make mould structure more complicated, increase manufacture difficulty and the implementation cost of a whole set of test macro.

The application of taper forging method of testing is more, but every covering device all has respective design parameter, and its die device needs to coordinate with pressing machine, and this makes the depression stroke of actual test be difficult to accurately control, especially under the condition using hydropress; But inconsistent stroke, will inevitably final appraisal results be affected, particularly for the situation that two kinds of lubricant effect difference is little.

Summary of the invention

The present invention is directed to prior art above shortcomings, a kind of taper is provided to forge lubricant effect pick-up unit and method, adopt the taper forging mold parameter comparatively responsive to lubrication, devise a set of can the easy device of direct compounding ingredient testing machine, the control system of Material Testing Machine is utilized to control taper forging mold accurately steadily descending, carry out sample by centring ring with band chamfering sample automatically to locate, make sample that extruding and jumping-up composite deformation occur, by measuring the height of the rear upper conical part of sample of distortion, directly assess lubricant effect; Meanwhile, the force data acquisition system utilizing Material Testing Machine to carry obtains forging and molding power, the evaluation of lubrication assistant effect; Whole pick-up unit is very simple, and Installation and Debugging are convenient, and Stroke Control is accurate, easily manufactured and with low cost, and test process stability is strong.

The present invention is achieved by the following technical solutions:

The present invention relates to a kind of taper and forge lubricious pick-up unit, comprise: for connecting material testing machine upper mould fixed plate, be fixed on the taper patrix below upper mould fixed plate, the plane counterdie corresponding with taper patrix and two centring rings, wherein: the upper surface clearance fit of a centring ring and upper mould fixed plate, the upper surface clearance fit of another centring ring and taper patrix, taper die cavity is provided with in the middle of the bottom of taper patrix, the top of this taper die cavity is provided with through hole, and the height h1 of this through hole and the height h2 of taper die cavity meets: $\frac{h1}{h1+h2}=40\%~50\%.$

The sample to be tested through lubrication is provided with between described taper die cavity and plane counterdie.

The diameter d of described through hole and the diameter D0 of sample meet:

The upper cone angle of described taper die cavity is 9 °, and lower cone angle beta is 15 °, and knuckle radius r and specimen finish D0 meets:

$\frac{r}{D0}=35\%~45\%.$

Surface roughness value Ra≤0.20 μm of the lower surface of described taper patrix and the inside surface of taper die cavity.

Surface roughness value Ra≤0.20 μm of described plane counterdie.

Described sample is cylindrical shape, and the ratio of its diameter and height is

The present invention relates to a kind of method based on the said equipment test lubricant effect, meet through the different diameter of lubrication strategies lubricated to be measured and the ratio of height cylindrical sample be located at above-mentioned taper and forge in lubricious pick-up unit, start taper patrix to press down, its depression stroke is to 60% ~ 75% of specimen height, then the height of the conical section that sample is formed after measuring distortion, pressure data in the height H of the conical section of the distortion sample relatively collected and test process, the height H value of conical section is larger, and the pressure peak of forging and molding is less, then lubricant effect is better.

Technique effect

Compared with prior art, pick-up unit of the present invention is very simple, and Installation and Debugging are convenient, and Stroke Control is accurate, easily manufactured and with low cost, and test process stability is strong.

Accompanying drawing explanation

Fig. 1 is the structural representation of apparatus of the present invention;

Fig. 2 is the schematic diagram of sample of the present invention;

Fig. 3 is the structural representation of taper patrix;

In figure: a is side view; B is upward view;

Fig. 4 is the structural representation of upper mould fixed plate;

In figure: a is side view; B is upward view;

Fig. 5 is the schematic diagram of sample after distortion.

Embodiment

Elaborate to embodiments of the invention below, the present embodiment is implemented under premised on technical solution of the present invention, give detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.

Embodiment 1

As shown in Figure 1, Figure 3 and Figure 4, the proving installation that the present embodiment relates to comprises: upper mould fixed plate 1, centring ring 2, taper patrix 4, with it just to the plane counterdie 6 arranged and the sample 5 that is arranged between taper patrix 4 and plane counterdie 6, wherein:

Upper mould fixed plate 1 and taper patrix 4 adopt equally distributed 4 screws 3 to be connected;

Two centring rings 2 are placed in two grooves of upper mould fixed plate 1 respectively, and two described centring rings 2 adopt clearance fit with upper mould fixed plate 1 and taper patrix 4 respectively.

By the left-hand thread (LHT) A of upper mould fixed plate 1 upper end, taper patrix 4 is installed in Material Testing Machine together.

Described taper die cavity upper end and upper surface are provided with through hole, and via height h1 and taper die cavity height h2 meets:

$\frac{h1}{h1+h2}=50\%.$

As shown in Figure 2, described taper die cavity upper end through hole, its diameter d and sample 5 diameter D0 meet:

Described taper die cavity, on it, cone angle is preferably 9 °, and its lower cone angle beta is preferably 15 °, and its knuckle radius r and sample 5 diameter D0 meets:

Taper die cavity and the lower surface of described taper patrix 4 need polishing, and its surface roughness value Ra is 0.10 μm;

Described plane counterdie 6, its surface roughness value Ra is 0.10 μm;

Embodiment 2

Based on the equipment described in embodiment 1, sample 5 to be assessed for preprepared is placed on immediately below the die cavity of taper patrix 4 by the present embodiment, and taper patrix 4 moves downward after stroke reaches workpiece height 60% ~ 75%, starts backhaul and moves upward, take out workpiece, complete a working cycle.

As shown in Figure 2, the first step, sample prepare: be ready in advance be 0.91 and x place, end is provided with the cylindrical sample of 30 ° of chamferings, as sample to be assessed through the blade diameter length ratio of different lubrication strategies lubricated.Specimen size is: φ 20.0mm*22.0mm, material and state: Al6082 annealed state aluminium alloy.Lubricated scheme: for VG32 lubricating oil, uses hairbrush evenly to apply sample; For multifunctional lubricating grease, adopt manual uniform application specimen surface; For PTFE dry type lubricating fluid, adopt spray nozzle to be sprayed on sample and mold cavity surface simultaneously.Often kind of lubricated scheme prepares 3 samples.

Second step, proving installation are installed: utilized by proving installation left-hand thread (LHT) to be installed in 250kN Instron Material Testing Machine.

3rd step, location sample: sample 5 is placed in immediately below cone-shaped lower die 4, utilize the micro-tensioning system of Material Testing Machine, taper patrix is made to press down and be increased to 0.05kN to load, under this side crops industry effect, realized the automatic location of sample by two centring rings 2, make sample be automatically positioned on the middle also close contact of conical cavity.

4th step, the test of execution lubrication: predetermined material testing machine stroke is workpiece height 70%, starting testing machine makes taper patrix 4 move downward enforcement taper forging, backhaul is started to preset strokes, take out sample as shown in Figure 5 after being out of shape, the force data acquisition system utilizing testing machine to carry in the process gathers forging and molding power.

Sample after 5th step, measurement distortion, obtains the height H of sample conical section, and shifts to an earlier date the peak value of forging and molding power, and be recorded in table 1.

6th step, repetition the 3rd step, to the 5th step, complete the test of next sample; The like, complete the assessment test of all samples.

By the height H recording sample conical section and the forging and molding power peak-data collected, as shown in table 1ly to be analyzed, can find out, lubricant effect order of quality: PTFE dry type lubricating fluid > multifunctional lubricating grease >VG32 lubricating oil.

Table 1 evaluation test data

Claims (8)

1. lubricious pick-up unit is forged in a taper, it is characterized in that, comprise: for connecting material testing machine upper mould fixed plate, be fixed on the taper patrix below upper mould fixed plate, the plane counterdie corresponding with taper patrix and two centring rings, wherein: the upper surface clearance fit of a centring ring and upper mould fixed plate, the upper surface clearance fit of another centring ring and taper patrix;

Is provided with taper die cavity in the middle of the bottom of described taper patrix, between described taper die cavity and plane counterdie, is provided with the sample to be tested through lubrication;

The top of described taper die cavity is provided with through hole; The height h1 of described through hole and the height h2 of taper die cavity meets: $50\%\≥\frac{h1}{h1+h2}\≥40\%.$

2. device according to claim 1, is characterized in that, the diameter d of described through hole and the diameter D0 of sample to be tested meet: $32\%\≥\frac{d}{D0}\×28\%.$

3. device according to claim 1, is characterized in that, the upper cone angle of described taper die cavity is 9 °, and lower cone angle beta is 15 °, and knuckle radius r and sample to be tested diameter D0 meets:

4. the device according to any one of claim 1-3, is characterized in that, surface roughness value Ra≤0.20 μm of the lower surface of described taper patrix and the inside surface of taper die cavity.

5. the device according to any one of claim 1-3, is characterized in that, surface roughness value Ra≤0.20 μm of described plane counterdie.

6. the device according to any one of claim 1-3, is characterized in that, described sample to be tested is cylindrical shape, and the ratio of its diameter and height is $1.0\≥\frac{D0}{H0}\≥0.8.$

7. a method for the device to test lubricant effect of application described in above-mentioned any one, is characterized in that, meets through the different diameter of lubrication strategies lubricated to be measured and the ratio of height cylindrical sample to be tested be located at described taper and forge in lubricious pick-up unit, start taper patrix to press down, its depression stroke is to 60% ~ 75% of sample to be tested height, then the height of the conical section that sample to be tested is formed after measuring distortion, pressure data in the height H of the conical section of the distortion sample to be tested relatively collected and test process, the height H value of conical section is larger, and the pressure peak of forging and molding is less, then lubricant effect is better.

8. method according to claim 7, is characterized in that, the end face of described sample to be tested is provided with 30 ^ochamfering.