CN1042945A - The improvement of scanning induction quenching technology - Google Patents
The improvement of scanning induction quenching technology Download PDFInfo
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- CN1042945A CN1042945A CN88108182A CN88108182A CN1042945A CN 1042945 A CN1042945 A CN 1042945A CN 88108182 A CN88108182 A CN 88108182A CN 88108182 A CN88108182 A CN 88108182A CN 1042945 A CN1042945 A CN 1042945A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
A kind of scanning induction quenching technology, adopt an induction coil that is connected with alternating-current mobile gradually along the length of steel part, immediately the method for the heating position quenching of workpiece is made the steel piece surface sclerosis then, it is characterized in that, be that aligning crooked in the hard-faced workpiece is being carried out in such control in the high-frequency quenching process: promptly by the planeness of monitoring workpiece and heating and the quench cooled of utilizing resulting information Control workpiece, make workpiece form thicker hardened layer, so that produce a kind of straightening torque effect that can eliminate bending at any crooked depression.
Description
The present invention relates to adopt induction coil along the method heating steel surface that the length of workpiece moves gradually, and induction coil and put and a hardening liquid jet apparatus is housed to steel piece surface jet quenching liquid and then, thereby make steel piece surface hardened technology.Be heated to the workpiece surface about 1000 ℃, just change martensitic phase into once quenching.This martensitic stucture makes the surface of workpiece obtain high hardness and has improved the fatigue resistance of workpiece.In the technology of another kind of form, sometimes workpiece is immersed in the quenching liquid pool fully.The heat that induction coil produces makes the hardening liquid vaporization in the regional area that is heated, thereby does not quench before induction coil shifts out this zone.After induction coil left, hardening liquid quenched with the contact of workpiece heating zone.
This technology is commonly referred to " scanning induction quenching ".Induction coil generally is a kind of heavy in section individual pen ring-type around workpiece (or less than a ring-type of enclosing) copper conductor, and this ring-type copper conductor hollow forms water-cooling channel, and described induction coil is powered by a kind of high-frequency low-voltage AC power.In quenching process, it is motionless that induction coil keeps usually, and workpiece moves.But, allow induction coil move and workpiece to keep motionless also be practicable.Used in this manual term " moves " and both can refer to moving of induction coil, also can refer to workpiece movement.
When the cross section of workpiece is circle, allow it usually two top rotations, so that circumferential surface is evenly hardened.On the contrary, if owing to the structure problem of induction coil or quench rings is irregular a little when making heating slightly asymmetric, then might make the sclerosis of workpiece circumferential surface inhomogeneous.United States Patent (USP) 3,525,842 disclosed this structure, but its induction coil does not surround workpiece.
According to the present invention proposes a kind of method of in this quenching process, aligning workpiece,, the bending of workpiece aligns no matter being the present method of all can using that originally just has or hardening step causes.
To bend usually be because at the initial stage of making workpiece to workpiece in high-frequency quenching, in addition the meridional stress that is caused when when making original bar, workpiece being aligned be released so.What high-frequency induction heating discharged only is the stress of outer or " shell ", so the remaining meridional stress in the heart portion has just caused the bending of workpiece.
The various methods that address this problem had been proposed.For example, United States Patent (USP) 3,988,179 have proposed in a kind of rotating disc type device axle to be quenched.In this device, the extexine of workpiece by the heating of monopulse induction coil, moves on to second position then on a position, be pressed onto on the workpiece of red heat by one or more drifts at this place, makes it to align before quenching.The advantage of this method is to correct any bending that workpiece caused owing to surface stress release in the heating phase, but important disadvantages is also arranged, and promptly can not further prevent the bending that takes place when workpiece quenches.The present invention has overcome the shortcoming that prior art exists, and has avoided therefore, having eliminated basically as bringing out the danger of the stress crack of workpiece bending in the current methods owing to adopt the straightening force of carrying out physics generation when contact between straightening device and workpiece.
When quenching, about 2% or 3% volume change can take place in the material of the martensitic phase that forms in the shell, so the outer pressurized of workpiece and heart portion material tension.If because certain cause makes the degree of depth (diameter is that the axle of 25～30mm is generally 1.5mm) of hardened layer darker than the other side on one side, the tensile stress of then outer field stress and heart portion will be uneven, just therefore bend.This bending always makes on the workpiece the thickest one side of martensite shell outwards protrude.
In fact, the degree of eccentricity of the shell degree of depth that is to say owing to the short range heating effect causes, minimum place, the gap between workpiece and induction coil, and workpiece is heated bigger, but the variation of this influence is not linear.This degree of eccentricity may be since the original curved of workpiece, center depart from or workpiece when quenching, bend cause, therefore, in the scanning high-frequency quenching of this routine, the original curved of workpiece will be tending towards increasing.
According to the present invention, this phenomenon of bending that causes when quenching owing to the difference of the Malpighian layer degree of depth is used to overcome the distortion that takes place in the quenching process and revises primary bending in the workpiece, therefore, the workpiece that has an original curved is straight basically in the hardening step process.
The present invention is a kind of scanning induction quenching technology, the induction coil that one of this process using is connected with alternating-current moves gradually along the length of workpiece, immediately the hot spots quench cooled of workpiece is made the steel piece surface sclerosis then, it is characterized in that, it in the high-frequency quenching process, is control like this: i.e. planeness by the monitoring workpiece to carrying out in the hard-faced workpiece crooked aligning, and utilize the heating of resulting information Control workpiece or quenching or not only controlled the heating of workpiece but also controlled the quenching of workpiece, make workpiece form thicker hardened layer, so that produce a kind of straightening torque that can eliminate bending at any crooked depression.
This method can be used for position that workpiece will harden not to be cylindrical thereby to adopt the situation of non-circular induction coil.Like this, just impossible rotational workpieces when quenching, therefore, the distortion that is taken place when moving through induction coil (generally being mobile vertically downward), necessity skew that in the process that workpiece moves, produces a direction or other direction induction coil and/or quench rings according to workpiece.According to the present invention, for this situation, adopt two just in time the probe above induction coil contact with workpiece.They are positioned at the plane that is mutually the right angle, can detect the distortion of any direction.The bending of any point must be noted before the beginning of quenching in the workpiece, and this record can be the data at independent check position, or workpiece is from the amount of movement of loading position two probes when the extreme higher position that begins to quench moves through probe.Required side-play amount can be calculated out, and require to adjust continuously according to the required compensation of the distortion that takes place in the quenching process at any time according to the workpiece original-shape of record.
At workpiece is under the situation of circle, preferably makes Workpiece Rotating so that obtain hardened layer uniformly.Therefore, in order to align simultaneously when quenching, induction coil and/or quench rings should be made circumferential motion with respect to workpiece, so that synchronously keep the desirable off-set value between induction coil and axis of workpiece when Workpiece Rotating.Contact the information that just is enough to provide relevant any bending with a probe and workpiece this moment, also can provide the relevant required information in distortion orientation of determining with the angular transducer that swivel arrangement matches.When workpiece was not circle, the side-play amount of induction coil and/or quench rings equaled to correct the required off-set value sum of distortion that the required off-set value of original curved and correcting quenching cause.
In general, the tolerance broad that depth of hardening allows, for example, when the hardened layer of regulation was 1.5mm, the change in depth scope that allows hardened layer usually was 1～2mm.If the method that adopts the present invention to propose, the difference of this degree of depth generally are to be enough to align the axle of slight bending or be enough to overcome moderate unrelieved stress.
The difference of heat penetration is normally produced by the distance that changes between induction coil and the workpiece, and its method is along on the concave side of Workpiece length direction, and induction coil is nearest from workpiece, convex side then from recently.But this species diversity of the concavo-convex both sides of the workpiece martensite degree of depth also can be obtained by other method, for example, by the skew quench rings or by the local distribution situation that changes the quenchant that surrounds quench rings, make a side of workpiece prolong the preceding time of quenching, allow heat further radially permeate inward, thereby obtain darker Malpighian layer.
In order to understand the present invention better and to try out, below in conjunction with description of drawings most preferred embodiment of the present invention:
Fig. 1 is the vertical cross section of the pole that quenching with technology of the present invention.
Fig. 2 is the sectional view along A-A line among Fig. 1.
Fig. 3 is the side-view of the quenching press of realization technology of the present invention.
Fig. 4 is the sectional view along B-B line among Fig. 5.
Fig. 5 is the sectional view along C-C line among Fig. 3.
Fig. 6 is an example with workpiece of exemplary bent shape.
Fig. 7 is for giving the corrective action of induction coil in the specified moment relevant with the bending of workpiece shown in Figure 6.
Fig. 8 is the induction coil of another kind of form.
Fig. 1 and Fig. 2 show the representative section that adopts the circular shaft that technology of the present invention hardens.The axle of all supposing to harden in these two figure all has wishes that corrigent, radius is the original curved of R.According to the present invention, quenching technology is so that the degree of depth of the hardened layer of a side (being Malpighian layer) realizes greater than the mode of the hardening depth of opposite side.Therefore, its centroid from this journal offset a small distance " a ", in like manner, the centroid of unhardened heart portion then is offset a segment distance " b " round about by this axis.So the line of action of the clean pulling force P that causes thus in the line of action of net pressure P and the heart portion in the shell has moved distance " Z " (Z=a+b), this has just produced a kind of bending moment M=PZ that acts on the axle.
The outer crooked radius of curvature R in fact radius-of-curvature with heart portion bending is identical, and the distribution of moment M between shell and heart portion should be:
Ma=(EIa)/(R) and Mb=(EIb)/(R)
In the formula: Ma is the moment that acts on the shell
Mb is the moment that acts in the heart portion
Ma+Mb=M=PZ
Ia is the second moment of the centroid of shell area
Ib is the second moment of the centroid of heart portion area
E is the modulus of elasticity of material
R is the radius-of-curvature of workpiece.
Obviously, the value of Ia and Ib is relevant with the mean depth of hardened layer, and is therefore also relevant with the size of shift value " a " and radius R.
For original curved to radius-of-curvature is the axle of R, and above-mentioned moment M will increase this axle of degree assistance aligning of radius R with minimally.In like manner, if axle is that the release owing to stress bends to radius R in the process of hardening, then the skew of hardened layer will be to this crooked generation retroaction.
Fig. 3 is the side-view of a kind of quenching press constructed in accordance.
As can be seen from the figure, this machine comprises the base 1, the vertical supporting guide rod 3 that connect together with column 2, and this guide rod 3 is as the guide rail of sliding support 4, and the upper end of sliding support 4 has tailstock 6, and the lower end has headstock 7.
Can be clear that more that from Fig. 4 workpiece is surrounded by an induction coil 14, described induction coil 14 is copper conductors of an individual pen, is formed with the cooling channel 15 that links to each other with flexible pipe 16 in the conductor.Induction coil 14 is installed on the omnibus bar 17 that attracts from transformer box 18.
Adjacent a quench rings 19 is housed below induction coil 14, wherein is formed with circular channel 20, and extend one group of radially inwards hole 21 thus, so that will be to workpiece from the hardening liquid injection of flexible pipe 21a.In operation, when a round piece was quenched, workpiece was by motor 11 driven rotary, handled by electric motor 9 and screw mandrel 10 simultaneously, it moved vertically downward and by induction coil and quench rings.When workpiece was not circle, motor 11 was not worked.
Transformer 18 1 energisings just can make induction coil 14 heated parts partly, and the heat affected zone of workpiece is shown among Fig. 4 22.Then from hole 21, spray hardening liquid at once and quenched in the heat affected zone of workpiece, make its sclerosis.Making quenches like this proceeds to the whole length of workpiece or arbitrary hardened part that requires of part is quenched after heating.
Look at Fig. 5 below.As can be seen from the figure, the transformer box 18 by omnibus bar 17 supporting induction coils 14 is installed on the guide rail 50 and 53 that is mutually the right angle, and they are respectively by screw mandrel 51 and 52, servomotor 23 and 24 transmissions.Just can on a horizontal plane, do the motion of any direction by a suitable controller 25 control induction coils 14 by this mechanism, sort controller be since own coding device 12,30 and 31 signal as input signal output signal is delivered on motor 23 and 24.
For the information of relevant workpiece 5 with respect to the right alignment of top 6a and 7a is provided, two probes 26 and 27 are pressed onto on the workpiece with spring.These two probes are respectively fixed on the output shaft 28 and 29 of rotary encoder 30 and 31, and encoder then is installed on the carriage 32 that is fixed on the base 1.At workpiece is under the situation of circle and motor 11 power supplies, only provide information with a probe, but when work was not circular and does not rotate, then two probes all is used to provide information.
The suitable side-play amount of the crooked required induction coil that forms in the correcting quenching process depends on many factors, for example required average penetration of hardness, and the one-tenth of steel grades.But situation is always such, thus i.e. skew will traveling induction coil 14 and/or quench rings 19 make vertical concave side of workpiece produce darker hardened layer.In practice, suitable side-play amount depends on test and the error relevant with above-mentioned physical computing.
When workpiece originally was exactly crooked (as shown in Figure 6), then must adopt more complicated method.
For example, if the Lower Half of workpiece 5, it is straight promptly putting below 37, and its first half to be to put 35 be center, radius when being 36 case of bending, when rotating, the medullary ray 34 of this workpiece 5 will be around line 33 rotations of top 6a and 7a.
When the expression workpiece was descended with the 7a clamping is vertical by top 6a among the figure, induction coil 14 had just begun workpiece 5 is carried out hardening step, and probe 27 is being surveyed medullary ray 34 and 33 side-play amounts that increase gradually.But because workpiece was straight before the point of arrival 37, so induction coil 14 must be accurately around medullary ray 34 rotations, in case workpiece produces undesirable bending.
In equipment of the present invention, workpiece 5 is used for monitoring by the probe 26 and 27 any bendings that detect by the motion that makes progress at first of induction coil 14, and relevant therewith information is transferred in the controller 25, so that be used for controlling workpiece 5 moving down and quench subsequently.
Before beginning to quench, accurate off-set value on any point that will design in advance is recorded on the controller 25 earlier, if discharge stress when quenching with record value when inequality by probe 27 off-set values that record, rotatablely moving of induction coil 14 will make corresponding changes, so that correct this bending, so just to keep before reaching a little 37 be straight to medullary ray 34 always.More than 37, rotation radius 38 will increase to 39, thereby make vertical concave side (as shown in Figure 7) of induction coil 14 more close workpiece 5 at point, reach the degree that the medullary ray more than 37 34 is a little aligned gradually.
Then, along with induction coil 14 moves closer to top 6a, radius-of-curvature is that 36 length shortens gradually, so the value of rotation radius 39 diminishes continuously.Controller 25 is used for calculating the value of new rotation radius 39, and by the probe 27 calculated value and actual values to them compare, if difference, for example, when causing a deviation because of the release of stress in the workpiece or little miscalculation, then the rotation radius of induction coil 14 will be done suitable variation from original calculated value.
In fact, the bending that there is different curvature radius 36 at several places may appear in workpiece, and its center of circle 35 is along the Workpiece length direction, and is positioned at the some spots on the not coplanar of threaded shaft 33 at each interval.If radius-of-curvature 36 is considered the restriction of the hardened layer maximum deviation that is allowed in the workpiece technological standard than can corrigent radius little, must carry out early stage straightening operation.
Certainly, needn't represent the original curved of workpiece with a kind of radius, because the bending curvature of workpiece is a continually varying as a rule.Yet, because to minimum radius restricted (as above chatting), so require to calculate continuously instantaneous radius.
As a rule, the workpiece of having processed can allow partial bending, and therefore, it is just enough to characterize the shape of workpiece with this bending comprised greater than in esse radius.
Top explanation is example with the round piece.But, for non-circular workpiece,,, two probes will be set in quenching process if will adopt similar technology because they do not rotate, by controller 25 provide required, relevant in original curved and the quenching process the information of two aspects of generation bending.
In addition, because the workpiece of most high-frequency quenchings will discharge stress subsequently, therefore the overcorrection that any primary and other bending are carried out to a certain degree may need.Because this stress relief generally just reaches this degree, enables to bring out the rimose peak stress and discharges, therefore, this overcorrection is normally minimum.
Fig. 8 shows another kind of form of the present invention, it adopts one group of induction coil fan-shaped section 54 to surround part or all of workpiece, each fan-shaped section all links to each other with an independent controllable electric power 55, and the power density between fan-shaped section can change, so that make the concave side of workpiece produce darker Malpighian layer.
Another kind of form of the present invention is that workpiece is done the motion of various necessity and induction coil keeps motionless.
Claims (7)
1, a kind of scanning induction quenching technology, this technology system adopts an induction coil that is connected with alternating-current to move and the heated parts surface gradually along the length of steel workpiece, immediately the method for the heating position quench cooled of workpiece is made the steel piece surface sclerosis then, it is characterized in that, be that aligning crooked in the hard-faced workpiece is being carried out in such control in the high-frequency quenching process: promptly by the planeness of monitoring workpiece and heating or the quenching that utilizes resulting information Control workpiece, perhaps not only control the workpiece heating but also control workpiece and quench, make workpiece form thicker hardened layer, so that produce a kind of straightening torque effect that can eliminate bending at any crooked depression.
According to a kind of scanning quenching technology of claim 1, it is characterized in that 2, quenching is directly to be realized to the device of workpiece jet quenching liquid by a kind of.
3, according to a kind of scanning quenching technology of claim 2, it is characterized in that, utilize gained information to control relative position between induction coil and workpiece.
4, according to a kind of scanning quenching technology of claim 2, it is characterized in that, utilize the information of gained to control the hardening liquid jet apparatus, perhaps control from the jet of this device ejection with respect to workpiece movement.
5, according to a kind of scanning quenching technology of claim 1, it is characterized in that, induction coil is made up of one group of part or all fan-shaped section of surrounding workpiece, each fan-shaped section all links to each other with an independent controllable electric power, power density between fan-shaped section can change, so that make the recessed side of workpiece produce darker Malpighian layer.
6, according to a kind of scanning quenching technology of claim 1, this technology can be used for the round bar shape workpiece is carried out hardening treatment, it is characterized in that, workpiece is placed around its longitudinal axis self in quenching process, employing is pressed in the probe of workpiece surface and monitors the planeness of pole and handle encoder, and the output signal of encoder then is used for controlling quenching process.
7, according to a kind of scanning quenching technology of claim 1, it is characterized in that, before quenching process begins, the original curved situation of scrutiny workpiece, gained information also is used for controlling quenching process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN88108182A CN1020754C (en) | 1988-11-26 | 1988-11-26 | Flattening method for bending workpiece in scanning induction hardening |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN88108182A CN1020754C (en) | 1988-11-26 | 1988-11-26 | Flattening method for bending workpiece in scanning induction hardening |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1042945A true CN1042945A (en) | 1990-06-13 |
| CN1020754C CN1020754C (en) | 1993-05-19 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN88108182A Expired - Fee Related CN1020754C (en) | 1988-11-26 | 1988-11-26 | Flattening method for bending workpiece in scanning induction hardening |
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| CN (1) | CN1020754C (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102641959A (en) * | 2012-05-08 | 2012-08-22 | 哈尔滨工业大学 | Rapid uniform heating method for metal tube |
| CN103060534A (en) * | 2012-12-30 | 2013-04-24 | 上海嘉仕久企业发展有限公司 | Medium-frequency hardening inductor for steering knuckle |
| CN104513883A (en) * | 2013-10-07 | 2015-04-15 | 本田技研工业株式会社 | Thermal treatment device for external connector part and manufacture method for external connector part |
| CN108012547A (en) * | 2015-03-30 | 2018-05-08 | 伊顿伦纳德集团 | The thermal quenching processing equipment of tubulose or bar-shaped hardware with curved section |
| CN113118299A (en) * | 2020-04-27 | 2021-07-16 | 航宇智造（北京）工程技术有限公司 | Forming and quenching device and process for high-strength-toughness thin-wall component with special-shaped section and bent axis |
| CN115505704A (en) * | 2022-09-14 | 2022-12-23 | 武汉船用机械有限责任公司 | Balance block and quenching method thereof |
-
1988
- 1988-11-26 CN CN88108182A patent/CN1020754C/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102641959A (en) * | 2012-05-08 | 2012-08-22 | 哈尔滨工业大学 | Rapid uniform heating method for metal tube |
| CN103060534A (en) * | 2012-12-30 | 2013-04-24 | 上海嘉仕久企业发展有限公司 | Medium-frequency hardening inductor for steering knuckle |
| CN104513883A (en) * | 2013-10-07 | 2015-04-15 | 本田技研工业株式会社 | Thermal treatment device for external connector part and manufacture method for external connector part |
| CN108012547A (en) * | 2015-03-30 | 2018-05-08 | 伊顿伦纳德集团 | The thermal quenching processing equipment of tubulose or bar-shaped hardware with curved section |
| CN113118299A (en) * | 2020-04-27 | 2021-07-16 | 航宇智造（北京）工程技术有限公司 | Forming and quenching device and process for high-strength-toughness thin-wall component with special-shaped section and bent axis |
| CN113118299B (en) * | 2020-04-27 | 2023-11-10 | 航宇智造（北京）工程技术有限公司 | Forming and quenching device and process for high-strength and high-toughness thin-wall component with special-shaped bending axis |
| CN115505704A (en) * | 2022-09-14 | 2022-12-23 | 武汉船用机械有限责任公司 | Balance block and quenching method thereof |
| CN115505704B (en) * | 2022-09-14 | 2024-01-23 | 武汉船用机械有限责任公司 | Balance weight and quenching method thereof |
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| CN1020754C (en) | 1993-05-19 |
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