JP2006322065A - Automotive member, and heat treatment apparatus for quenching the automotive member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automotive member which is quenched by a direct energization process, and to provide a heat treatment apparatus for quenching the automotive member. <P>SOLUTION: A door beam 1 is composed of: a main body part 11 having almost fixed cross sectional area in the longitudinal direction; and a pair of fitting parts 12, 12 arranged by interposing this main body part 11 in the longitudinal direction, and the main body part is positioned and fixed by using both fitting parts 12 as the fixed member, and the main body part 11 is heated by the direct energization process in the longitudinal direction of the main body part 11 while using both fitting parts 12 as the energization portions, and the heated main body part 11 is rapidly cooled, thereby quenching the main body part 11q to obtain the door beam. Further, the heat treatment apparatus for quenching the door beam is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an automobile member quenched by direct energization and a heat treatment apparatus for quenching the automobile member.

Many automotive parts are required to have high structural strength (high bending strength, high torsional strength, high tensile strength, etc.). The above requirements can be met by selecting materials such as high-strength steel plates and ultra-high-strength steel plates (590 N / mm ² or more), increasing the thickness of automobile members, or adding reinforcing members. In addition, it is possible to produce a member for an automobile using a general steel plate / high-tensile steel plate (270 N / mm ^{2 to} 440 N / mm ² ) that is inexpensive and has good workability, and realize high structural strength.

  As described above, a door beam can be exemplified as a member for an automobile that is required to be inexpensive and easily processed with a high structural strength and to be lightweight. For example, in Patent Document 1, a door beam is configured by three members, a main body portion and a pair of attachment portions (mounting brackets). After attaching the attachment portions to both ends of the main body portion by welding, It is said that a heat treatment such as pouring and annealing is performed ([0076] and others).

  In Patent Document 2, while forming a door beam with one member by press molding, the cost is reduced due to heat treatment such as quenching and annealing, and for the purpose of preventing the occurrence of residual stress due to the heat treatment, such as quenching and annealing, etc. The use of high-strength steel that does not require heat treatment is selected ([0019] et al.). On the other hand, Patent Document 3 has a problem of an increase in sheet thickness and weight due to heat treatment such as quenching and annealing, while the door beam is composed of one member like the door beam of Patent Document 2 described above. As described above, the necessary structural strength is satisfied by subjecting a thin plate-shaped press-formed product to heat treatment such as quenching and annealing ([Claim 1] and others).

  In addition, Patent Document 4 considers a continuous production line, and induction hardening (electromagnetic induction heating) that allows heat treatment such as quenching and annealing while moving the door beam after press forming along the line. Is used. Specifically, only the main body part (intermediate part) of the door beam that is required to be improved in structural strength is induction-hardened, and there is a demand for it to be easily processed at a low cost with a high structural strength. Satisfies ([0007] others).

  If batch processing is acceptable, direct energization can also be used as a quenching means for the door beam. Patent Document 5 discloses a heat treatment method in which a pulse current is directly applied to a door-beam-like long object to be heated and instantaneously quenched and annealed. In Patent Document 5, heating by energizing a pulse current (alternating current) controls the pulse width that can realize instantaneous quenching and annealing in consideration of the “skin effect” that occurs concentrated on the surface of the object to be heated. is doing.

Japanese Patent No. 3139984 JP-A-10-166860 Japanese Patent Laid-Open No. 2003-094943 JP 09-002066 A Japanese Patent Publication No. 44-014455

  In order to partially harden a car member having a complicated structure, high-frequency quenching using an electromagnetic induction coil is often used, but a car member having a simple structure, particularly a cross-sectional area in the extending orthogonal direction is used. In the case of a substantially constant automobile member, quenching by direct energization is preferable. This is because the structure of the necessary heat treatment apparatus can be simplified, and the automobile member can be quenched in a short time by uniformly heating and rapidly cooling the automobile member.

  Here, in the case of quenching by direct energization, there is a restriction that heating is not possible except for the portion where the electrode as the energization means is in contact with the area sandwiched between the electrodes. Further, while quenching, it is necessary to fix the position of the automobile member with a chuck that is a fixing means. However, this chuck has a restriction that it must not hinder the path of the flowing current and prevent heating or cooling. Therefore, the identification of the automotive member suitable for quenching by direct energization and the configuration of a heat treatment apparatus for quenching the automotive member by direct energization were studied.

  What has been developed as a result of the study is a main body portion having a substantially constant cross-sectional area in the extending direction or the extending orthogonal direction, and a pair of mounting portions provided with the main body portion sandwiched in the extending direction or the extending orthogonal direction. The body part is fixed in position with both mounting parts as fixing parts, and the main body part is directly energized by using both mounting parts as energization parts to heat the main body part, and the heated main body part is rapidly cooled. It is the member for motor vehicles which hardened the main-body part. The current to be energized is preferably direct current or low frequency (˜300 Hz) alternating current. Here, the “substantially constant” cross-sectional area means a structure in which there is no significant change in the cross-sectional area due to a change in cross-sectional shape, and preferably the cross-sectional area changes within ± 10%.

  The present invention specifies an automobile member to be treated so that it can be quenched by direct energization for a short time, preferably by direct energization for a short time and only once. The automotive member to which the present invention is applied has a structure in which attachment portions serving as a fixing portion and a current-carrying portion are provided at both ends of the main body portion, and is fixed at an attachment portion that does not require quenching, and the main body portion is fixed via the attachment portion. By directly energizing, the main body can be quenched. Here, if the cross-sectional area in the extending direction or the extending orthogonal direction is a substantially constant body part, the resistance value of the body part in the direction in which the cross-sectional area is substantially constant becomes substantially constant. It becomes uniform and can be quenched by direct energization for a short time and once.

  In the case of a long automobile member provided with an attachment portion across the longitudinal direction of the main body portion, such as a door beam or a bumper beam, the configuration is specifically as follows. That is, it consists of a main body part having a substantially constant cross-sectional area in the longitudinal direction and a pair of attachment parts provided with the main body part sandwiched in the longitudinal direction. And it is the member for motor vehicles obtained by energizing directly the longitudinal direction of a main-body part by using both attachment parts as an electricity supply part, heating this main-body part, quenching the heated said main-body part, and quenching this main-body part. .

  Further, in the case of a long automobile member, such as a side member, a cross member, a pillar, etc., in which the attachment portion is provided across the short direction of the main body portion, the configuration is specifically as follows. In other words, it consists of a main body part with a substantially constant cross-sectional area in the short direction and a pair of attachment parts provided across the main body part in the short direction, and the main body part is fixed in position with both attachment parts as fixing parts. In addition, an automotive member obtained by directly energizing the main body portion in the short direction of the main body portion using both mounting portions as energized portions, heating the main body portion, quenching the heated main body portion and quenching the main body portion. It is.

  The heat treatment apparatus for quenching each automobile member has the following configuration. That is, an automobile member comprising a main body portion having a substantially constant cross-sectional area in the extending direction or the extending orthogonal direction, and a pair of mounting portions provided with the main body portion sandwiched in the extending direction or the extending orthogonal direction. A pair of fixing means for fixing the position of the main body portion with both mounting portions as fixing portions, and the main body portion by directly energizing the main body portion with both mounting portions as energization portions. It is the heat processing apparatus which consists of a pair of electricity supply means which heats, and a cooling means to quench the heated said main-body part.

  Examples of the fixing means include a chuck that can fix the position of the automobile member during quenching. Since the present invention uses the attachment portion for fixing the position of the main body portion, the fixing means may be any configuration that can utilize the attachment structure of the attachment portion. The energizing means is brought into contact with the automobile member within the range sandwiched between the fixing means so as not to be affected by current leakage to the fixing means, heating or cooling by the fixing means, and directing or alternating current to the automobile member. A clip electrode or the like that can be energized can be exemplified. The energizing means may be a chuck electrode that also serves as a fixing means. Examples of the cooling means include a liquid cooling means that can rapidly cool the heated automobile member.

  The automotive members such as the door beam, the bumper beam, the side member, the cross member, and the pillar are all made of a thin steel plate (plate thickness t = 1.6 mm). The main body may be locally bent, twisted or warped. Therefore, the heat treatment apparatus is provided with deformation suppressing means between the pair of energizing means. The deformation suppressing means includes a lower jig that is fixed at a position below the main body portion of the automobile member. The lower jig is provided with a suppression convex portion on a surface facing the main body portion of the automobile member, and the suppression convex portion. The part preferably has a structure in which a gap equal to or less than the allowable deformation amount of the body part of the automobile member is formed on the outer surface of the body part.

  The lower jig of the deformation suppressing means, when the main body portion of the automobile member is deformed, causes the suppression convex portion to abut on the outer surface of the deformed main body portion and suppresses deformation after the suppression convex portion abuts. . Thus, since the suppression convex part suppresses deformation of the main body part of the member for an automobile, in a part where the deformation of the main body part is likely to occur, for example, in the intermediate part of the main body part corresponding to the middle of a pair of energizing means, What is necessary is just to provide about several suppression convex parts with respect to the outer surface of the main-body part which is likely to deform | transform. Here, the suppression convex portion is not brought into contact with the outer surface of the main body portion from the beginning, in addition to preventing leakage from the main body portion, the suppression convex portion is in contact with the main body portion of the automobile member, so that the amount of heat is increased. This is to prevent leakage.

  As described above, the restraining convex portion in the lower jig of the deformation restraining means does not have a possibility of coming into contact with the outer surface of the main body unless the main body is deformed. Even if not, it is desirable to provide insulation so as to avoid problems due to electric leakage. In addition to heat resistance, the restraining convex portion desirably has heat insulation properties in order to prevent an excessive amount of heat from flowing out when it comes into contact with an automotive member deformed during cooling. In addition, the lower jig may be provided with insulating properties or heat insulating properties. In this case, the suppression convex portion having heat resistance and insulation may be provided on the surface of the lower jig having heat resistance and heat insulation. It may be provided on the surface of the lower jig having the property and the insulating property.

  Since the lower jig of the deformation suppressing means is fixed with respect to the main body portion of the automobile member, the lower jig has a surface facing the main body portion of the automobile member, and the coolant injection hole is formed on the surface. It is preferable that a large number of openings be used as the cooling means. That is, the lower jig is used as a cooling jacket, and conversely, the cooling jacket is used as a lower jig, and restraining convex portions are provided at necessary places. In this case, a sufficient gap is provided between the outer surface of the main body portion of the automobile member and the lower jig in order to allow the excess of the coolant injected from the coolant injection hole to flow down. The cooling liquid is preferably water having a large heat of vaporization and specific heat in order to obtain a quenching effect by rapid cooling.

  The deformation suppressing means is composed of an upper jig that is positioned and fixed above the main body portion of the automobile member, and the upper jig is provided with a suppressing convex portion on the inner surface facing the main body portion of the automotive member, and this suppressing convex portion. May be configured such that a gap equal to or less than the allowable deformation amount of the main body of the automobile member is formed on the outer surface of the main body. The upper jig of the deformation suppressing means can be used in combination with the lower jig of the deformation suppressing means. The point where the insulating property or the heat insulating property is required for either the upper jig or the suppression convex portion, the configuration of the combination, the function of the suppression convex portion, and the like are the same as the description of the lower jig and the suppression convex portion described above. Furthermore, the above-mentioned Shijia may also be configured such that the upper jig has an inner surface facing the main body of the automobile member, and a plurality of coolant injection holes are opened on the inner surface to serve also as a cooling means. Same as ingredients.

  If the elongation in the longitudinal direction of the automobile member during the heat treatment is excessively constrained, the automobile member may be distorted. Therefore, the pair of fixing means may be movable forward and backward in the direction in which the other fixing means connects the two fixing means with respect to one fixing means. Similarly, it is preferable that the pair of energizing means be movable forward and backward in the direction in which the other energizing means connects both energizing means with respect to one energizing means. As a result, the extension of the automobile member is allowed, and the occurrence of distortion of the automobile member can be suppressed.

  The advancing / retreating mechanism of the other fixing means or energizing means is preferably a slide mechanism that limits the extension of the automobile member in one direction. Here, the energization means may be configured to energize the clip electrode sandwiched between the automobile members with a flexible cable, but in this case, the energization means does not restrain the automobile member. Therefore, it is not necessary to make the other energizing means freely movable.

  The present invention relates to a long automobile member, such as a door beam or a bumper beam, provided with a mounting portion across the longitudinal direction of the main body, a side member, a cross member, a pillar, etc. The main body portion of the long automobile member provided with the attachment portion on the side can be quenched by direct energization only once in a short time. Thus, high structural strength required for the main body of each automobile member can be easily realized while using inexpensive steel plates for door beams, bumper beams, side members, cross members, pillars, and the like. That is, the present invention has an effect of enabling the production of an automobile member having excellent cost effectiveness.

  Further, the heat treatment apparatus of the present invention directly applies the body part of the automobile member such as the door beam, bumper beam, side member, cross member, pillar, etc., which is made of a relatively thin steel plate (thickness t = about 1.6 mm). The deformation of the main body that may occur when quenching by energization is suppressed by the deformation suppressing means, and the expansion of the deformation is prevented by the advancing and retracting fixing means or the energizing means. There is an effect that the main body can be quenched by direct energization without impairing accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an example of a door beam 1 to be quenched according to the present invention, FIG. 2 is a side view of a heat treatment apparatus 2 in which the door beam 1 is fixed, and FIG. 3 is a heat treatment in which the door beam 1 is fixed. 4 is a partial cross-sectional view taken along line AA in FIG. 2, FIG. 5 is a plan view corresponding to FIG. 3 of another heat treatment apparatus 3 in which the door beam 1 is fixed, and FIG. FIG. 7 is a side view corresponding to FIG. 2 of the heat treatment apparatus 2 using the upper jig 235 covering the door beam 1, and FIG. 8 is a heat treatment apparatus using the upper jig 235 covering the door beam 1. 3 is a plan view corresponding to FIG. 3, FIG. 9 is a partial cross-sectional view taken along the line CC in FIG. 7, and FIG.

As shown in FIG. 1, the door beam 1 of the present example includes a main body portion 11 having a substantially constant cross-sectional area in the longitudinal direction, and a pair of attachment portions 12 provided with the main body portion 11 sandwiched in the longitudinal direction. 12 is a member for automobiles. This door beam 1 is made of a general steel plate / high-tensile steel plate (270 N / mm ^{2 to} 440 N / mm ² ) that is inexpensive and has good workability by press forming, roll forming or hydraulic forming (hydroforming, etc.). The U-shaped main body 11 having ribs 111 and 111 on both side edges is formed, and the mounting portion 12 has a flange shape as it is. The main body 11 has only a change in the cross-sectional shape of the steel plate, the cross-sectional area changes within ± 10%, the cross-sectional area in the longitudinal direction becomes substantially constant, and exhibits a substantially constant resistance value in the longitudinal direction. Further, the flange-like attachment portion 12 is easily sandwiched by the chuck electrode 21 of the heat treatment apparatus 2.

  As shown in FIGS. 2 to 4, the heat treatment apparatus 2 for quenching the door beam 1 includes a chuck electrode 21 which is a fixing means and an energizing means for fixing the position of the door beam 1 and energizing the door beam 1. It comprises a lower restraining means 22 and an upper restraining means 23 which are deformation restraining means / cooling means for restraining deformation at the time of rapid cooling while jetting water into the system 1. Before the door beam 1 is carried in, the lower jig 223 of the lower restraining means 22 is lowered while the upper jig 232 of the upper restraining means 23 is retracted (see the phantom line in FIG. 4). After fixing the door beam 1 with the electrodes 21 and 21, the lower jig 223 of the lower restraining means 22 is raised and the upper jig 232 of the upper restraining means 23 is lowered. In order to take out the door beam 1 after the heat treatment, the procedure is reversed.

  The chuck electrode 21 is provided with current-carrying blocks 213 and 213 for fixing the position of the chuck electrode 21 in contact with the upper and lower surfaces of the attachment portion 12 of the door beam 1 and for supplying current to the tip of the chuck claw 212 that is attached to the chuck body 211 so as to be freely opened and closed. Installed and configured. The energization block 213 is a conductor, but the chuck claws 212 and the chuck main body 211 are insulated, and an electric wire (not shown) or the like is passed from the chuck main body 211 to the inside of the chuck claws 212 to supply current to the energization block 213. Send it in. In this example, the chuck electrode 21 located on the left side in each figure does not move with the chuck body 211 fixed, but the chuck electrode 21 located on the right side in each figure moves the chuck body 211 in the longitudinal direction of the door beam 1. The slider 214, which is a sliding advance / retract mechanism, is mounted on the slider 214, and the longitudinal extension of the door beam 1 during heat treatment is absorbed by the retraction of the chuck electrode 21.

  In the chuck electrode 21 of this example, the energization blocks 213 and 213 sandwich the mounting portion 12 of the door beam 1 to fix the position of the door beam 1 and energize the energization blocks 213 and 213. However, for example, as in another heat treatment apparatus 3 shown in FIG. 5, a fixing block 311 that holds the mounting portion 12 of the door beam 1 and an energizing block 312 that only energizes the chuck claws 313 are separately provided. The chuck electrode 31 may be configured by being attached to the tip. Even in this case, the separate fixing block 311 and energizing block 312 are both attached to the same chuck claw 313, and also serve as the slider 314 as an advance / retreat mechanism. In addition, although not shown, chuck electrodes may be configured in which separate fixing blocks and energization blocks are assigned separate advance / retreat mechanisms.

  As shown in FIG. 4, the lower restraining means 22 of this example forms a protrusion 221 that fits into the main body 11 of the door beam 1 from below, and a surface 222 that faces substantially the entire main body 11. (See FIG. 6), the lower jig 223 has a large number of cooling liquid injection holes 224 for injecting water as a cooling liquid, and corresponds to a longitudinal intermediate portion of the main body 11. A plurality of lower suppression convex portions 225 are provided. A part of the coolant injection hole 224 is opened with being shifted in the longitudinal direction of the door beam 1 with respect to the lower suppressing projection 225. That is, the lower suppressing means 22 in this example also serves as a cooling jacket. The lower restraining means 22 can be moved up and down by a hydraulic cylinder 226 (not shown) that supports the lower jig 223, and is lowered and retracted before the door beam 1 is fixed to the heat treatment apparatus 2. After the position of the door beam 1 is fixed by the electrode 21, the position is fixed in a state where the protrusion 221 of the lower jig 223 raised by the hydraulic cylinder 226 is loosely fitted to the main body 11 of the door beam 1.

  The upper restraining means 23 corresponds to the lower restraining convex portion 225, and is attached to the tip of the rotating arm 231 that is pivotally mounted on the lower jig 223 and can be moved up and down, and on the upper surface of the main body 11 of the door beam 1. An upper jig 232, which is a copied U-shaped block, is attached, and an upper restraining projection 234 is provided on the inner surface 233 of the upper jig 232. The lower jig 223 of the lower restraining means 22 of this example that also serves as a cooling jacket is a long member along the longitudinal direction of the main body 11 because the coolant injection hole 224 is provided over substantially the entire main body 11. . However, since the upper jig 232 of the upper restraining means 23 is only intended to restrain the deformation of the main body part 11, the upper jig 232 corresponds to the lower restraining convex part 225 provided on the lower jig 223. It is a short member only in the vicinity of the intermediate part.

  The lower restraining convex portion 225 and the upper restraining convex portion 234 are composed of a ceramic block having insulating properties and heat resistance, a carbon block having heat resistance, or the like, and in this example, the portion most likely to be deformed upon cooling. For example, it is arranged near the edge of the rib 111 or near the bent edge 112 of the main body 11. In this way, if the lower suppression convex portion 225 or the upper suppression convex portion 234 is disposed at a portion that is most likely to be deformed, the deformation of the main body portion 11 can be sufficiently and sufficiently suppressed. The lower restraining convex portion 225 and the upper restraining convex portion 234 are positioned so as not to contact the main body portion 11 as long as the main body portion 11 does not deform beyond the allowable deformation amount ΔS. Specifically, as shown in FIG. 6, the surface 222 of the lower jig 223 and the inner surface 233 of the upper jig 232 are separated from the outer surface 113 of the main body part 11 by a larger amount than the allowable deformation amount ΔS of the main body part 11. However, the gap t formed by the lower suppressing protrusion 225 and the upper suppressing protrusion 234 with respect to the outer surface 113 of the main body 11 is set to be equal to or less than the allowable deformation amount ΔS of the main body 11. Thereby, the deformation of the main body part 11 is limited to a range until it comes into contact with the lower suppression convex part 225 or the upper suppression convex part 234, and excessive deformation of the main body part 11 can be suppressed.

  Next, the quenching procedure of the door beam 1 by the heat treatment apparatus 2 of this example will be described. After the press molding, the door beam 1 is sandwiched between flange-shaped attachment portions 12 by chuck electrodes 21 and fixed to the heat treatment apparatus 2 in position. When this position is fixed, the upper restraining means 23 jumps up the upper jig 232 by the rotating arm 231 to open the upper part, and the lower restraining means 22 lowers the lower jig 223 so that the door beam 1 Does not interfere with position fixing work. Here, although not shown in the figure, for example, if a positioning projection is provided in each lower energizing block in both chuck electrodes, and a positioning hole corresponding to the positioning projection is opened in the door beam mounting portion, heat treatment is performed. The positional relationship of the door beam with respect to the apparatus can be uniquely determined.

  When the position of the door beam 1 is fixed, the lower jig 223 of the lower restraining means 22 is raised by the hydraulic cylinder 226, and the protrusion 221 is fitted into the main body 11 in a loosely fitted state. The moving arm 231 is lowered and the upper jig 232 is put on the intermediate portion of the main body 11. In this way, as shown in FIGS. 2 to 4, preparation for energization of the main body 11 of the door beam 1 is completed. In this energization preparation stage, as shown in FIG. 6, the lower restraining convex portion 225 and the upper restraining convex portion 234 are not in contact with the main body portion 11 with a gap t (≦ deformation allowance ΔS). . However, since the gap t is very small (0.5 mm to 1.5 mm), if the door beam 1 after molding is slightly twisted or bent, the lower restraining convex portion 225 or the upper restraining convex portion 234 becomes the main body portion. There is also a risk of touching 11. For this reason, the lower restraining convex portion 225 or the upper restraining convex portion 234 is configured by a ceramic block having insulation and heat resistance or a carbon block having heat resistance.

  The thickness of the door beam 1 is around 1.6 mm, and the length of the main body 11 is 600 mm to 1500 mm, although it varies depending on the vehicle type. From now on, when the main body 11 of the door beam 1 is quenched by direct energization, if the low frequency alternating current of about 50 Hz to 250 Hz and about 3000 A is energized for about several tens of seconds, the main body 11 is heated to 1000 ° C. to 1200 ° C. Can be heated. The heating temperature of the main body 11 can be adjusted, for example, by adjusting the current value. However, if the current value is lowered, the heating time becomes longer, which causes a problem that the production efficiency is lowered. Here, since the heating temperature is proportional to the amount of electric power, the heating temperature of the main body 11 can be adjusted by adjusting the energization time. From now on, the energizing time is set so that the heating temperature required for quenching is 850 ° C to 950 ° C or higher and the heating limit of the steel plate that is the raw material for automobile parts such as door beams is not exceeded, and thereafter energizing The heating temperature may be finely adjusted depending on the time.

  After the main body 11 of the door beam 1 reaches the heating temperature (1000 ° C. to 1200 ° C.) required for quenching for a predetermined energization time, the energization is stopped, and this time the lower restraining means 22 of the lower jig 223 Water is jetted from the coolant jet hole 224 to quench the main body 11. Since the automotive member targeted by the present invention is thin like the door beam 1 of this example, the heat capacity proportional to the volume is small, and it can be easily cooled in a short time by jetting water with high specific heat. As described above, the present invention has an advantage that the door beam 1 in which the main body 11 is quenched can be efficiently produced by finishing the heating and cooling in a short time.

  When the main body portion 11 of the door beam 1 is deformed during the rapid cooling, the lower restraining convex portion 225 of the lower jig 223 and the upper restraining convex portion 234 of the upper jig 232 abut against the deformed outer surface 113 of the main body portion 11, respectively. Excessive deformation of the part 11 is suppressed. Further, when the longitudinal extension of the door beam 1 occurs due to the deformation of the main body 11, in this example, the chuck electrode 21 located on the right side of each figure is retracted according to the slider 214 and absorbs the longitudinal extension. To do.

  Here, in order to uniformly and rapidly cool the main body portion 11 of the door beam 1, as shown in FIGS. 7 to 9, a cover-like shape covering almost the entire upper surface of the main body portion 11 of the door beam 1 is used. The upper restraining means 23 composed of the upper jig 235 may be used. The upper jig 235 approaches or separates from the main body 11 from above by various conventionally known lifting means such as an expansion cylinder (not shown) and covers the main body 11 of the door beam 1. , Fix the position. This cover-like upper jig 235 is provided with an upper restraining convex portion 237 on the inner surface 236 like the upper jig 232 described above, and has a number of coolant injection holes 238 opened as in the lower jig 223. Yes. A part of the coolant injection hole 238 is shifted from the upper restraining projection 237 in the longitudinal direction of the door beam 1 and opens.

  As shown in FIG. 10, the main body 11 of the door beam 1 has water W through the coolant injection hole 224 of the lower jig 223 from below and the coolant injection hole 238 of the upper jig 235 from above. Is cooled rapidly. Here, since the coolant injection holes 238 of the upper jig 235 are evenly arranged in the longitudinal direction of the main body 11, the main body 11 of the door beam 1 is even in the longitudinal direction despite rapid cooling. To be cooled. Further, since the upper restraining convex portion 237 is provided on the inner surface 236 of the upper jig 235, deformation of the main body portion 11 due to rapid cooling is restrained. After the cooling is finished, the upper jig 235 is retracted upward (see FIG. 9).

  The present invention is for an automobile composed of a main body portion having a substantially constant cross-sectional area in the extending direction or the extending orthogonal direction and a pair of mounting portions provided with the main body portion sandwiched in the extending direction or the extending orthogonal direction. Applicable to members. FIG. 11 is a perspective view showing a fixed position of the bumper beam 4 by the chuck electrode 5 when the present invention is applied to the bumper beam 4, and FIG. 12 is a chuck when the present invention is applied to the cross member 6. FIG. 6 is a perspective view showing a position fixing state of the cross member 6 by an electrode 7.

  For example, as the above-described door beam 1, as an automobile member comprising a main body portion having a substantially constant cross-sectional area in the longitudinal direction and a pair of mounting portions provided with the main body portion sandwiched in the longitudinal direction, 11, the present invention can be applied to the bumper beam 4. In the case of the bumper beam 4, the main body portion and the mounting portion are not clearly separated as in the above-described exemplary door beam 1 (see FIG. 1), but the bumper beam 4 to which the bumper support member is attached Both ends 41 are used as attachment parts, and both ends 41 of the bumper beam 4 are sandwiched between chuck electrodes 5 and 5 as fixing means and energization means, and the bumper main body 42 is directly energized and quenched.

  Further, as a member for an automobile composed of a main body part having a substantially constant cross-sectional area in the short direction and a pair of attachment parts provided with the main body part sandwiched in the short side direction, for example, as seen in FIG. The present invention can also be applied to the cross member 6. In the case of this cross member 6, the mounting portion is a flange 62 projecting on both sides of the member main body 61, and the flange 62 extending along the member main body 61 is sandwiched between the plurality of chuck electrodes 7, 7 Energize in the direction. Thus, by using a plurality of chuck electrodes 7, there is an advantage that the elongation in the longitudinal direction of the cross member 6 can be absorbed by the expansion of the gap between the chuck electrodes 7, 7.

It is a perspective view showing an example of a door beam to be quenched according to the present invention. It is a side view of the heat processing apparatus which fixed the position of the door beam. It is a top view of the heat processing apparatus which fixed the position of the door beam. FIG. 3 is a partial cross-sectional view taken along line AA in FIG. 2. It is a top view equivalent to FIG. 3 of the heat processing apparatus of another example which fixed the position of the door beam. FIG. 5 is an enlarged view of a portion indicated by an arrow B in FIG. 4. It is a side view equivalent to FIG. 2 of the heat processing apparatus using the upper jig | tool which covers a door beam. It is a top view equivalent to FIG. 3 of the heat processing apparatus using the upper jig | tool which covers a door beam. It is CC sectional view taken on the line in FIG. FIG. 10 is an enlarged view of a portion indicated by an arrow D in FIG. 9. It is a perspective view showing the position fixed state of the bumper beam by the chuck electrode when the present invention is applied to the bumper beam. It is a perspective view showing the position fixing state of the side member by the chuck electrode when the present invention is applied to a cross member.

Explanation of symbols

1 Door beam
11 Body
12 Mounting part 2 Heat treatment equipment
21 Chuck electrode
22 Lower suppression means
223 Lower jig
225 Lower restraining projection
23 Upper suppression means
232 Upper jig
234 Upper restraining projection
235 Upper jig
237 Upper restraining convex part 4 Bumper beam 5 Chuck electrode 6 Cross member 7 Chuck electrode W Coolant (water)

Claims (10)

It consists of a main body part with a substantially constant cross-sectional area in the extending direction or the extending orthogonal direction and a pair of attaching parts provided with the main body part sandwiched in the extending direction or the extending orthogonal direction. The body part is fixed as a part, and the body part is heated by directly energizing the body part with both mounting parts as energized parts, and the heated body part is quenched to quench the body part. Automotive parts. It consists of a main body part with a substantially constant cross-sectional area in the longitudinal direction and a pair of mounting parts provided with the main body part sandwiched in the longitudinal direction. A member for an automobile, in which the main body is heated by quenching the heated main body by heating the main body by directly energizing the main body in the longitudinal direction of the main body. A main body portion having a substantially constant cross-sectional area in the short direction and a pair of mounting portions provided sandwiching the main body portion in the short direction, and fixing the position of the main body portion with both mounting portions as fixing portions; and A member for an automobile in which both attachment portions are used as energized portions to directly energize in a short direction of the main body to heat the main body, quench the heated main body, and quench the main body. The automobile member comprising a main body portion having a substantially constant cross-sectional area in the extending direction or the extending orthogonal direction, and a pair of mounting portions provided with the main body portion sandwiched in the extending direction or the extending orthogonal direction. A heat treatment apparatus for quenching the main body part, and a pair of fixing means for fixing the position of the main body part with both mounting parts as fixing parts, and heating the main body part by directly energizing the main body part with both mounting parts as current-carrying parts. The heat processing apparatus which consists of a pair of electricity supply means to perform and the cooling means to quench the heated said main-body part. A deformation suppressing means is provided between the pair of energizing means, and the deformation suppressing means is composed of a lower jig fixed at a position below the main body portion of the automobile member, and the lower jig is a main body portion of the automotive member. 5. A heat treatment according to claim 4, wherein a restraining convex portion is provided on the surface facing the inner surface, and the restraining convex portion is formed with a gap less than a deformation allowable amount of the main body portion of the member for automobiles to the outer surface of the main body portion. apparatus. The heat treatment apparatus according to claim 5, wherein the lower jig has a surface facing the main body of the automobile member, and a plurality of coolant injection holes are opened on the surface to serve as cooling means. A deformation suppressing means is provided between the pair of energizing means, and the deformation suppressing means is composed of an upper jig that is positioned and fixed above the main body portion of the automobile member, and the upper jig is the main body portion of the automotive member. 5. A heat treatment according to claim 4, wherein a restraining convex portion is provided on the inner surface facing the inner surface, and the restraining convex portion is formed with a gap less than a deformation allowable amount of the main body portion of the automobile member on the outer surface of the main body portion. apparatus. The heat treatment apparatus according to claim 7, wherein the upper jig has a surface facing the main body portion of the member for an automobile, and a plurality of coolant injection holes are opened on the surface to serve as cooling means. The heat treatment apparatus according to any one of claims 4 to 8, wherein the pair of fixing means is movable forward and backward in an arrangement direction in which the other fixing means connects the two fixing means with respect to the one fixing means. The heat treatment apparatus according to any one of claims 4 to 9, wherein the pair of energizing means is movable forward and backward in an arrangement direction in which the other energizing means connects both energizing means with respect to one energizing means.

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