JP6017195B2 - Crankshaft quenching equipment - Google Patents

Description

The present invention relates to a quench apparatus of the crankshaft, an apparatus for performing hardening treatment by high-frequency induction heating, particularly for a journal portion or a pin portion of a crankshaft for an internal combustion engine.

  As a method for quenching this type of crankshaft, for example, a method described in Patent Document 1 has been proposed. In the technique described in Patent Document 1, as shown in FIG. 13, a so-called semi-open saddle-shaped heating coil 101 having a semicircular shape or an arch shape is attached to a journal portion or a pin portion on the crankshaft side that is the workpiece W. This is a method in which the workpiece W is quenched while rotating the workpiece W side, and is generally referred to as an erotherm method.

  In this method, the heating coil 101, the workpiece, and W rotate relative to each other, and the temperature on the workpiece W side gradually rises while alternately repeating heating and temperature reduction. Extra heat storage on the W side will also occur, and the time required for cooling will also increase.

  Therefore, as shown in FIG. 15, assuming a workpiece fixing method in which the workpiece W is positioned in the loop-shaped heating coil 102 and quenching is performed without rotating the workpiece W as shown in FIG. 15. The heating coil 103 has been proposed in which the heating coil 103 is substantially superposed in two stages in series.

  In the method shown in FIG. 14, the heating coil 102 is divided into two in a direction (radial direction) orthogonal to the workpiece axial direction, and the energization loop that makes one round of the workpiece W by abutting the halved heating coils 102 together. Here, this method is referred to as a half-one-turn method or a half-one-loop method.

  On the other hand, in the method shown in FIG. 15, the heating coil 103 makes two rounds of the work W around the workpiece W on the premise that the half-shaped heating coils 103 are abutted with each other as in FIG. An energization loop is formed, and this method is referred to herein as a half-two-turn method or a half-two-loop method.

  In the method called the half-split two-turn method or the half-split two-loop method, since it is necessary to form an energization loop that makes two rounds of the workpiece W on the assumption that the heating coil 103 itself has a half-split shape, After the shape heating coils 103 are abutted with each other and clamped by clamping means (not shown) at a position corresponding to the contact point Q in FIG. This ensures the continuity of.

  According to this method, an energization loop that circulates the work is formed, so that the heating efficiency is good, and the contact portion is located outside the energization loop and relatively away from the work. It is said that there is an advantage that becomes smaller.

JP 2004-107685 A

  However, in a method called a half-split one-turn method or a half-split one-loop method as shown in FIG. 14, an oil hole for metal lubrication is formed in the journal portion or pin portion of the crankshaft. In this case, the current density (or magnetic flux density) inside the journal part or the pin part changes due to the change in the surface area or cross-sectional area at the part, and the heating temperature is likely to be uneven. Therefore, there is a limit in achieving uniform quenching quality such as quenching width, quenching depth, and hardness after quenching.

  Moreover, since it is a system which surrounds the circumference | surroundings of the journal part or pin part of a crankshaft by abutting two heating coils, anyway, the current density (or magnetic flux density) in the abutting surface of heating coils tends to decrease, Unevenness in heating temperature is likely to occur. Therefore, similarly to the above, there is a limit in achieving uniform quenching quality such as quenching width, quenching depth, and hardness after quenching.

  And in the method called the half-split two-turn method or the half-split two-loop method as shown in FIG. 15, the half-split one-turn method of FIG. Since this is only different from what is called a half-split one-loop system, the half-turn two-turn system or half-split two-loop system shown in FIG. The same problem as the one remains.

  In addition, in a method called a half-split two-turn method or a half-split two-loop method as shown in FIG. 15, the contact portion Q in FIG. The bending deformation of the heating coil 103 due to the clamping force cannot be ignored, leaving room for further improvement.

  For example, when the heating coil 103 is bent and deformed by receiving a clamping force, the clearance between the heating coils 103 forming a current-carrying loop of two series loops, and the distance between the heating coils 103 (two clearances between the heating coils are separated). The effective coil width of one heating coil is changed, and there is a concern about the influence on the quenching quality such as the quenching width, the quenching depth, and the hardness after quenching. In particular, since the oil hole as described above is formed in the journal portion or the pin portion of the crankshaft, the surface area or the cross-sectional area is relatively increased unless sufficient consideration is given to the bending deformation of the heating coil 103 as described above. There is a possibility of causing overheating (administration of an excessive amount of heat) in the vicinity of the opening of a small oil hole.

The present invention has been made paying attention to such problems, and when quenching the journal portion or pin portion of the crankshaft, the presence of oil holes formed in the journal portion or pin portion is quenched. The present invention provides a quenching apparatus that is considered not to affect the quality.

The present invention relates to a pair of halved heating coils having a semicircular arch portion surrounding a journal portion or a pin portion of a crankshaft and straight portions extending radially outward from both ends of the arch portion. The journal portion or pin portion of the crankshaft to be processed is disposed so as to face each other so as to face each other, and the axial direction of the oil hole formed in the journal portion or pin portion is set in the pair of heating coils. This is an apparatus for subjecting the journal part or the pin part to quenching treatment by high-frequency induction heating by energizing the heating coil in a state where it is aligned in the longitudinal direction of the straight part .

In addition, the pair of heating coils are overlapped with each other with a clearance between the pieces, and a semicircular arch portion surrounding the journal portion or the pin portion, and radially outward from both ends of the arch portion. first, a second coil segment, between a first coil segment and a second coil segment forming the respective heating coil for chromatic extending been a straight portion, respectively A spacer that is interposed at least around the arch portion and regulates a clearance between the first coil piece and the second coil piece, and the first and second coils. Attached to the straight portion of the element piece, a contact portion for connecting the first coil element pieces and the second coil element pieces, the first coil element piece, and the second coil element piece, respectively. A contact portion for connecting, and When a pair of heating coils are arranged opposite to each other at regular positions and the contact portion is clamped in the overlapping direction of the first and second coil pieces by the clamping means, the first coil pieces and the first coil pieces The two coil pieces are connected in series with each other, and the first coil piece and the second coil piece are connected in series. A surrounding energization loop is formed.
Furthermore, a relief recess is formed in a portion facing the opening of the oil hole formed in the journal portion or the pin portion of the butt portion between the pair of heating coils,
The distance formed between the opening of the oil hole and the relief recess is set to be larger than the distance formed between the part other than the opening of the oil hole and the pair of heating coils on the outer peripheral surface of the journal part or the pin part. Is.

According to the present invention, in a state that is matched with the axial oil hole which meantime current density (or magnetic flux density) is formed in a direction and a journal portion or a pin portion of the abutting surface of the heating coils mutually easily reduced, moreover In order to carry out processing in consideration of the bending deformation of the heating coil, the outer corner formed by the arch part and straight part of the heating coil substantially faces the vicinity of the opening of the oil hole formed in the journal part or pin part. Processing will be performed in the state. As a result, the vicinity of the opening of the oil hole formed in the journal part or the pin part has a relatively small surface area or cross-sectional area compared to other parts, so that the current density (or magnetic flux density) decreases. Even if the heat dose is relatively reduced, the heating conditions are not greatly affected, and the treatment can be performed in the vicinity of the opening of the oil hole under almost the same conditions as the other parts. The quenching quality in the circumferential direction can be made uniform and improved.

Explanatory drawing which shows an example of the crankshaft used as the hardening process object by this invention. Cross-sectional explanatory drawing of the principal part of FIG. Schematic illustration of quench heads in quenching is device of the present invention. The schematic explanatory drawing only of the heating coil of FIG. The principal part expansion explanatory drawing of FIG. Exploded view of FIG. FIG. 4 is an explanatory view showing a state in which the first and second quenching units are butted together in the quenching head of FIG. 3. The schematic explanatory drawing only of the heating coil of FIG. FIGS. 4 and 8 are cross-sectional views of FIGS. 4 and 8, in which (A) is an enlarged cross-sectional explanatory view taken along line A1-A1 in FIG. 4, and (B) is an enlarged cross-sectional explanatory view taken along line B1-B1 in FIG. FIGS. 4 and 8 are cross-sectional views of FIGS. 4 and 8, in which (A) is an enlarged cross-sectional explanatory view taken along line A2-A2 in FIG. 4, and (B) is an enlarged cross-sectional explanatory view taken along line B2-B2 in FIG. The figure which shows typically the horizontal sectional view in the butt | matching state of the quenching head which consists of a 1st, 2nd quenching unit shown in FIG. FIG. 12 is an entire cross-sectional explanatory view of FIG. The schematic explanatory drawing of the heating coil called what is called an erotherm system. Schematic explanatory drawing of the heating coil called a half 1 turn system or a half 1 loop system. Schematic explanatory drawing of the heating coil called a half split 2 turn system or a half split 2 loop system.

1 to 12 are diagrams showing a more specific form for carrying out the crankshaft quenching apparatus according to the present invention. FIGS. 1 and 2 schematically show the crankshaft 1 to be processed. Shows the structure of the quenching head 10 of the quenching machine that controls the quenching process for the crankshaft 1.

  1 and 2 show an example of a four-cylinder type crankshaft 1. As is well known, this crankshaft 1 is supported by a plurality of bearings that are rotatably supported via a bearing metal with respect to a cylinder head. It comprises a journal portion 1, a plurality of pin portions 3 provided at a position offset by a predetermined amount from the axis of each journal portion 2, a plurality of counterweights 4, etc. A connecting rod (not shown) is connected through the metal.

  The crankshaft 1 is formed with oil holes 6 penetrating the journal portions 2 and the pin portions 3 in the radial direction in addition to the oblique oil holes 5 as shown in FIGS. Necessary lubricating oil is supplied to the bearing portions of the journal portions 2 and the pin portions 3 from the side. In addition to the oblique oil holes 5, the openings of some of the oil holes 6 out of the oil holes 6 penetratingly formed in the radial direction of each journal portion 2 and the pin portion 3 are subsequently closed by a plug. Sometimes.

  The respective journal portions 2 and pin portions 3 in the crankshaft 1 are subjected to a quenching process by a quenching head 10 described later.

  The quenching head 10 of FIG. 3 includes a first quenching unit 11 and a second quenching unit 12 that have heating coils 13 or 14 and have substantially the same structure, and both heating coils 13, 14. A quenching process is performed by arranging the processing object so as to be opposed to each other with a minute gap therebetween so that they are not in direct contact with each other. It is formed as a divided half structure.

  As shown in FIG. 3, in the first and second quenching units 11, 12, a long bar-shaped heating coil is subjected to insulation treatment on the long side portion side of the substantially rectangular coil support 15 or 16. 13 or 14 is supported on each. FIG. 4 shows a state in which only the heating coils 13 and 14 are extracted from FIG. 3, and each of the heating coils 13 and 14 includes an upper first coil piece 17 and a lower second coil piece. 18 are arranged so as to overlap two upper and lower stages after being subjected to insulation treatment while separating a clearance between minute pieces. Each of the first and second coil pieces 17 and 18 has a semicircular arch portion 19 and a straight portion 20 extending from both ends of the arch portion 19 to the radially outer peripheral side. 5 and 6, the first and second coils described above are provided between the first and second coil pieces 17 and 18, particularly around the arch portion 19. A spacer 21 made of an insulating material is interposed between the pieces 17 and 18 so as to ensure a minute clearance C between the pieces. That is, the distance between the first and second coil pieces 17 and 18 is regulated by the spacer 21, and the thickness of the spacer 21 is between the first and second coil pieces 17 and 18. A small clearance C between the elements corresponding to the above is ensured.

  As shown in FIG. 4, on the first quenching unit 11 side, the contact portion 22 continuous to the left end of the upper first coil piece 17 forming the heating coil 13 and the lower second coil. A contact portion 23 continuous with the element piece 18 is formed to extend, and an insulator 24 is interposed between the contact portions 22 and 23. Similarly, a contact portion 25 that is continuous with the right end of the lower second coil piece 18 forming the heating coil 13 is extended together with the insulator 26, and between the contact portions 22 and 23. An insulator 24 is interposed between the two. Further, an electrode plate 27 as a positive electrode continuous with the right end of the upper first coil piece 17 is formed to extend.

  On the other hand, on the second quenching unit 12 side, the contact portion 28 continuing to the left end of the upper first coil piece 17 forming the heating coil 14 and the lower second coil piece 18 are provided. A continuous contact portion 29 is extended. Similarly, two sets of contact portions 30 extending from the right end of the upper second coil piece 17 forming the heating coil 14 are extended. Furthermore, an electrode plate 31 as a negative electrode continuous with the right end of the lower second coil piece 18 is formed to extend. 4 are provided with respective insulators 28a, 29a, and 30a as shown in FIGS. 9 and 10, which are not shown in FIG. is there.

  7 shows a state in which the first and second quenching units 11 and 12 shown in FIG. 3 are brought into contact with each other, and FIG. 8 shows a state in which only the heating coils 13 and 14 are extracted from FIG. As is clear from FIGS. 7 and 8, when the first and second quenching units 11 and 12 are brought into contact with each other, the contact portions 28 and 29 on the second quenching unit 12 side are placed between each other. A pair of contact portions 22 and 23 on the first quenching unit 11 side enter and overlap each other. Similarly, the contact portion 25 on the first quenching unit 11 side enters between the contact portions 30 and 30 on the second quenching unit 12 side so as to overlap each other.

  Then, by clamping the contact portions 28 and 29 on the second quenching unit 12 side with a clamper described later, the other contact on the first quenching unit 11 side is placed between the contact portions 28 and 29. The parts 22 and 23 are sandwiched so that the contact parts 22 and 28 and the contact parts 23 and 29 are brought into pressure contact with each other to be conducted. That is, when the first and second quenching units 11 and 12 are brought into contact with each other, the first coil pieces 17 on the upper side of the respective heating coils 13 and 14 with conduction between the contact portions 22 and 28 are provided. Similarly, the second coil pieces 18 and 18 on the lower side of the heating coils 13 and 14 are mechanically and electrically connected to each other by connecting the contact portions 23 and 29 to each other. It will be.

  Similarly, when the first and second quenching units 11 and 12 are brought into contact with each other as described above, the first quenching is performed between the contact portions 30 and 30 on the second quenching unit 12 side. As described above, the other contact portion 25 on the unit 11 side enters and overlaps with each other. And the other contact part 25 is inserted | pinched between the contact parts 30 and 30 by clamping the contact parts 30 and 30 with the clamper mentioned later, and the contact parts 30 and 25 mutually press-contact. It is designed to conduct. That is, when the first and second quenching units 11 and 12 are brought into contact with each other, the first coil piece 17 on the upper side in the second quenching unit 12 is brought into conduction with the contact portions 30 and 25. The lower first coil element 18 in the first quenching unit 11 is mechanically and electrically connected.

  More specifically, FIG. 9A shows a cross-sectional view taken along line A1-A1 in FIG. 4, and FIG. 9B shows a cross-sectional view taken along line B1-B1 in FIG. After the first and second quenching units 11 and 12 are brought into contact with each other and clamped by the clamper 32, the state shown in FIG. 9A changes to the conductive state shown in FIG. It will be.

  Similarly, FIG. 10A is a cross-sectional view taken along line A2-A2 of FIG. 4, and FIG. 10B is a cross-sectional view taken along line B2-B2 of FIG. When the first and second quenching units 11 and 12 are brought into contact with each other and then clamped by the clamper 33, the state shown in FIG. 10A changes to the conductive state shown in FIG. become.

  Further, as is apparent from FIGS. 3 and 4, an electrode plate 27 as a positive electrode is disposed at the right end of the upper first coil piece 17 in the first quenching unit 11, and the lower in the second quenching unit 12. As described above, the electrode plate 31 serving as the negative electrode is extended at the right end of the second coil piece 18 on the side. When the first and second quenching units 11 and 12 are brought into contact with each other, the electrode plates 27 and 31 face each other. Then, as shown in FIGS. 3, 4 and 7, 8, the other side electrodes 34, 35 are sandwiched between the electrode plates 27, 31 and are not shown in the same manner as in FIG. A predetermined high frequency current is applied between the heating coils 13 and 14 in the first and second quenching units 11 and 12 by clamping the electrode plates 27 and 31 with each other. .

  Therefore, in the quenching head 10 composed of the first and second quenching units 11 and 12, which are halved, as described above with reference to FIG. 15, the first and second quenching units 11 and 12 are performed. By abutting each other, the heating coils 13 and 14 circulate the work W twice to form a series 2-loop energization loop.

  Here, as shown in FIGS. 5 and 6 in addition to FIG. 3, the spacer 21 is interposed between the arch portions 19 of the first and second coil pieces 17 and 18. As described above, a plurality of cooling liquid injection holes 36 are formed radially in the spacer 21, and cooling liquid such as oil is supplied from the cooling liquid supply pipe 37 shown in FIG. 3 to each cooling liquid injection hole 36. It is designed to be supplied and circulated. Then, as will be described later, following the heat treatment by the heating coils 13, 14, the coolant can be sprayed onto the heating part as necessary.

  FIG. 11 shows a halved first and second quenching unit 11, 12 shown in FIG. 3 to treat the journal part 2 or the pin part 3 of the crankshaft 1 shown in FIGS. The horizontal sectional view in the butt | matching state of the quenching head 10 which consists of is shown typically. Further, FIG. 12 shows a full sectional view of FIG. Here, for convenience, the journal unit 2 or the pin unit 3 to be processed is referred to as a workpiece W.

  As described above, after the halved first and second quenching units 11 and 12 are butted together so as to surround the workpiece W to be processed, the contact portions 28 and 22 in FIG. In addition to the contact portions 29, 23 and the contact portions 30, 26, 30 of FIG. 10, the pair of electrode plates 27, 31 and the counterpart electrodes 34, 35 shown in FIGS. And clamp. As a result, the heating coils 13 and 14 of the first and second quenching units 11 and 12 substantially make two turns around the work W, and the work W is placed around the work W as shown in FIG. A current-carrying loop that goes around is formed. Then, a predetermined high frequency current is applied between the electrode plates 27 and 31 shown in FIGS. 7 and 8 to perform heat treatment by high frequency induction heating.

  In this case, as shown in FIG. 15, since an energization loop is formed around the work W so as to make two turns around the work W, heat treatment can be performed efficiently. Further, since each contact portion shown in FIGS. 9 and 10 is located at a position relatively distant from the workpiece W, there is an advantage that the influence of the magnetic flux change on the workpiece W can be reduced. Further, as shown in FIG. 12 in addition to FIGS. 9 and 10, the contact portions 28 and 22 in FIG. 9, the contact portions 29 and 23, and the contact portions 30 and 26 in FIG. 10 are clamped by a clamper 32 or 33. As a result, the straight portions 20 of the first and second coil pieces 17 and 18 are bent and deformed. In particular, the contact portions 28 and 22, the contact portions 29 and 23, and the contact portions 30 and 26 of the straight portion 20. The portion closer to each other is bent and deformed so that the inter-element clearance C between the first and second coil elements 17 and 18 becomes smaller.

  If the workpiece W is heat-treated for a predetermined time, the energization to the heating coils 13 and 14 is cut off. Instead, the workpiece W is removed from the coolant injection hole 36 formed in the spacer 21 as shown in FIGS. Cooling liquid is sprayed to the heating part for a predetermined time to rapidly cool the heating part of the workpiece W. As a result, the workpiece W is subjected to a quenching process with a predetermined processing width and a predetermined depth.

  In this case, as shown in FIG. 11 in addition to FIGS. 1 and 2, the journal portion 2 and the pin portion 3 as the workpiece W are formed with the oil holes 6 penetrating them in the radial direction. It was. In the vicinity of the oil hole 6, the surface area or the cross-sectional area is relatively smaller than the other parts by the opening area of the oil hole 6, so that the journal part 2 and the pin part 3 are evenly distributed over the entire circumference. When the heat treatment is performed, a relatively excessive amount of heat is administered at a portion where the oil hole 6 is open, which may result in so-called overheating.

  Therefore, in the present embodiment, as shown in FIG. 11, the axial direction of the oil hole 6 formed in the workpiece W is the arch portion 19 in the butt surface between the first and second quenching units 11 and 12. In a state in which it is aligned so that the longitudinal direction in the removed portion is oriented, that is, the axial direction of the oil hole 6 is oriented in the longitudinal direction of the straight portion 20 in the first and second coil pieces 17, 18. Processing shall be performed.

  In this state, the direction of the butting surfaces of the straight portions 20 and 20 in the first and second coil pieces 17 and 18 and the journal portion which is the work W are said to be easily reduced in current density (or magnetic flux density). 2 or the axial direction of the oil hole 6 formed in the pin portion 3 is nothing but the state. Therefore, the outer corner portion formed by the arch portion 19 and the straight portion 20 in the first and second coil pieces 17 and 18 faces the vicinity of the opening portion of the oil hole 6 formed in the journal portion 2 or the pin portion 3. Processing will be performed in the state. As a result, the vicinity of the opening of the oil hole 6 formed in the journal portion 2 or the pin portion 3 originally has a relatively small surface area or cross-sectional area as compared with other portions, so that the current density (or magnetic flux density) Even if the heat dose is relatively decreased with the decrease, the heating condition is not greatly affected. As a result, processing can be performed in the vicinity of the opening of the oil hole 6 under substantially the same conditions as other parts, and the quenching quality in the circumferential direction of the journal part 2 or the pin part 3 is made uniform and improved. Can be planned.

  In addition, as shown in FIG. 11, the outer corner (corner portion) formed by the arch portion 19 and the straight portion 20 in the first and second coil pieces 17 and 18 forming the heating coils 13 and 14. ) In a state where the first and second quenching units 11 and 12 are abutted with each other, at a position facing the opening of the oil hole 6, A substantially triangular relief recess 38 is formed by butting the chamfered portions 38a. The chamfered portion 38a is remarkably depicted in FIGS.

  By doing so, the part where the oil hole 6 is open in the journal part 2 and the pin part 3 as the workpiece W is opposed to the relief recess 38, and as a result, the opening part of the oil hole 6 and the heating part are heated. The distance formed between the coils 13 and 14 (the first and second coil pieces 17 and 18) is relatively large compared to other parts. Therefore, the heat dose (heat input amount) around the opening of the oil hole 6 having a small surface area or cross-sectional area corresponding to the opening of the oil hole 6 is relatively small, and the opening of the oil hole 6 is relatively small. Heat treatment can be performed under the same conditions as those of other parts in the vicinity of.

  Here, as shown in FIG. 12 in addition to FIGS. 9 and 10, the contact portions 28 and 22 in FIG. 9, the contact portions 29 and 23, and the contact portions 30 and 26 in FIG. As a result, the straight portions 20 of the first and second coil pieces 17 and 18 are bent and deformed. In particular, the contact portions 28 and 22, the contact portions 29 and 23, and the contact portions 30 and 30 of the straight portion 20, As described above, the portion closer to 26 is bent and deformed so that the clearance C between the first and second coil pieces 17 and 18 becomes smaller.

  In the journal portion 2 and the pin portion 3 that are the workpiece W as described above, the portion where the oil hole 6 is open faces the escape recess 38, thereby the first and second coil pieces 17. , 18, even if the first and second coil pieces 17, 18 are bent and deformed so that the clearance C between the pieces becomes small, the influence on the quenching quality can be avoided. As described above, the heat treatment can be performed around the opening of the oil hole 6 under substantially the same conditions as other parts. Therefore, special measures against the bending deformation of the first and second coil pieces 17 and 18 are not necessary.

  In other words, the portions corresponding to the relief recesses 38 of the heating coils 13 and 14, that is, the R portion of FIGS. 11 and 12 are also affected by the bending deformation, and the first and second coil pieces 17 and 18 are connected to each other. The clearance C between the elements is slightly reduced, and the heat treatment width by the first and second coil pieces 17 and 18 is reduced by the clearance reduction. However, the reduction of the heat treatment width is also reduced. This contributes to a relatively small heat dose (heat input) around the opening of the oil hole 6.

  That is, the straight portions of the first and second coil pieces 17 and 18 are subjected to the clamping force between the contact portions 28 and 22 in FIG. 9, the contact portions 29 and 23, and the contact portions 30 and 26 in FIG. As 20 is bent and deformed, the heat treatment width (effective coil width) by the first and second coil pieces 17 and 18 with the clearance C between the pieces separated is relatively smaller than other parts. However, since the heat treatment width is applied to the portion where the width of the heat treatment is reduced with the vicinity of the opening of the oil hole 6 formed in the journal portion 2 or the pin portion 3 facing, Since the vicinity of the opening of the formed oil hole 6 originally has a relatively small surface area or cross-sectional area as compared with other parts, the reduction in the heat treatment width does not greatly affect the heating conditions, and the heating coil For flexural deformation Not only measures is not required, so that attained the quenching uniformity of quality.

  As described above, according to the present embodiment, when the quenching process is performed on the journal portion 2 or the pin portion 3 of the crankshaft 1, the portion where the oil hole 6 is opened and the portion where the oil hole 6 is not opened are processed almost evenly. Therefore, the quenching quality is improved.

  Here, some of the journal portions 2 of the crankshaft 1 are not formed with the oil holes 6 as described above. When the quenching process is performed on the journal portion 2 that does not have the oil hole 6, the journal portion 2 side is placed on the crankshaft 1 with respect to the first and second quenching units 11 and 12 that face each other. It is assumed that the processing is performed while rotating the whole. By doing so, it is possible to uniformly quench the entire circumference of the journal portion 2 that does not have the oil holes 6.

DESCRIPTION OF SYMBOLS 1 ... Crankshaft 2 ... Journal part 3 ... Pin part 6 ... Oil hole 10 ... Quenching head 11 ... 1st quenching unit 12 ... 2nd quenching unit 13 ... Heating coil 14 ... Heating coil 17 ... 1st Coil element 18 ... Second coil element 19 ... Arch part 20 ... Straight part 21 ... Spacer 22 ... Contact part 23 ... Contact part 25 ... Contact part 27 ... Electrode plate 28 ... Contact part 29 ... Contact part 30 ... Contact part 31 ... Electrode plate 32 ... Clamper 33 ... Clamper 36 ... Coolant injection hole 38 ... Relief recess C ... Clearance between pieces W ... Workpiece

Claims (2)

A pair of halved heating coils having a semicircular arch portion surrounding the journal portion or pin portion of the crankshaft and a straight portion extending radially outward from both ends of the arch portion are abutted against each other. In this manner, the journal portion or pin portion of the crankshaft to be processed is surrounded by being arranged oppositely, and the axial direction of the oil hole formed in the journal portion or pin portion is the length of the straight portion in the pair of heating coils. A device that performs quenching treatment by high frequency induction heating on the journal part or the pin part by energizing the heating coil in a state aligned in a direction ,
The pair of heating coils
Each of them has a semicircular arch part that is overlapped with each other with a clearance between the element pieces and surrounds the journal part or the pin part, and a straight part that extends from both ends of the arch part to the radially outer side. First and second coil segments to
The first coil piece and the second coil piece are interposed between the first coil piece and the second coil piece forming the respective heating coils and at least around the arch portion. A spacer that regulates the clearance between the coil pieces;
Contact points for connecting the first coil pieces and the second coil pieces respectively to the straight portions of the first and second coil pieces, and the first coil pieces, A contact portion for connecting the second coil segment;
Have
When the pair of heating coils are opposed to each other at regular positions and the contact portion is clamped in the overlapping direction of the first and second coil pieces by the clamping means, the first coil pieces and The second coil pieces are connected in series with each other, and the first coil pieces and the second coil pieces are connected in series. An energizing loop that makes two rounds is formed,
Furthermore, a relief recess is formed in a portion facing the opening of the oil hole formed in the journal portion or the pin portion of the butt portion between the pair of heating coils,
The distance formed between the opening of the oil hole and the relief recess is set to be larger than the distance formed between the part other than the opening of the oil hole and the pair of heating coils on the outer peripheral surface of the journal part or the pin part. A crankshaft quenching device characterized by that. The spacer is formed with a coolant injection hole,
2. The crankshaft hardening apparatus according to claim 1, wherein the coolant can be sprayed from the coolant spray hole to the journal portion or the pin portion .

Images