JP3115233B2 - Induction quenching method and apparatus and quenched product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to partial quenching for hardening a predetermined area of a work in a desired pattern by high frequency induction heating.

[0002]

2. Description of the Related Art For example, the inner surface of a combustion chamber formed by a cylinder block of an automobile, that is, the inner surface of a cylinder bore, requires a high degree of wear resistance because the piston slides at high speed. At the same time, good lubrication for smooth sliding of the piston is also required. Conventionally, in order to satisfy this requirement, it is common practice to dispose a cylinder liner made of a material having a higher hardness than the material of the cylinder block on the inner surface of the bore of the cylinder block.
However, the structure in which such a cylinder liner is provided has a problem in that the number of parts increases and the number of steps increases, so that the manufacturing cost increases accordingly. In view of such circumstances, it has been proposed to improve the wear resistance by quenching the inner surface of a cylinder bore without using a cylinder liner. In this case, if the entire inner surface of the cylinder bore is hardened uniformly, the wear resistance can be improved over the entire sliding surface of the bore with the piston, but the lubricating oil is hardly retained in the hardened portion. Therefore, there arises a problem that the lubrication of the inner surface of the cylinder bore is reduced and the sliding resistance of the piston is increased. Therefore, in order to secure desired performance with respect to both abrasion resistance and lubricity, the inner surface of the cylinder bore is partially quenched, and in particular, quenching is performed such that a plurality of quenched portions exist in the bore inner surface in an independent and dispersed state. It has been proposed to do so.

[0003] As a method of forming such a plurality of independent distributed quenching portions on the inner surface of a cylinder bore, Japanese Patent Laid-Open Publication No.
No. 16 or JP-A-4-362117.

[0004]

In this disclosure, a laser beam is used to partially quench the inner surface of the cylinder bore. However, in the method using a laser beam, it is difficult to ensure a uniform quenching effect, and in order to achieve this, precise control is required.
There is a problem that the stability of product quality is deteriorated, and in order to solve this problem, there is a problem that equipment becomes expensive. Japanese Patent Publication No. 60-39127 discloses quenching by high-frequency induction heating in liquid. However, the disclosed induction hardening controls the supply of the coolant in order to obtain a uniform hardening depth over the entire hardened surface regardless of the uneven thickness pressure of the work, and the hardening pattern is changed. It cannot be applied to the formed partial quench. German Patent No. 39,26,571 discloses a method of hardening the inner surface of a cylinder bore in a desired pattern by high-frequency induction heating using an induction heating coil. However, in this method, although the desired characteristics of abrasion resistance can be achieved because the formed quenched portions are continuous, the retention of the lubricating oil on the inner surface of the cylinder bore becomes poor, and the desired characteristics are obtained. There is a problem that lubricity cannot be ensured. In addition, the area of the boundary between the quenched portion and the non-quenched portion is widened, and the quenched region cannot be generated in a desired pattern. Therefore, desirable characteristics for both wear resistance and lubricity are obtained. There is a problem that a quenched product cannot be stably manufactured.

[0005]

SUMMARY OF THE INVENTION The present invention has been made under such a background, and is capable of producing a quenched product which satisfies both lubricity and abrasion resistance. Is to provide a way. Still another object of the present invention is to provide an apparatus for producing a quenched product having both of the above excellent characteristics. Another object of the present invention is to provide a quenched product having a quenched part having excellent characteristics in both lubricity and wear resistance. The present invention is configured as follows to achieve the above object. That is, according to one feature of the present invention, there is provided an induction quenching method for performing partial quenching of a workpiece by performing high frequency induction heating in a liquid. A work having a quenching surface to be placed in the liquid, a quenching head for performing high frequency induction heating is placed in the liquid, and the work is induction-heated by facing the quenching head to the quenching surface of the work. Quenching a predetermined region of the quenched surface of the work, thereby partially quenching the work so as to form a quenched pattern having a plurality of substantially independent quenched portions on the quenched surface of the work. It is characterized by.

Preferably, a predetermined power is supplied to the hardening head for a predetermined time to perform a hardening step of forming a hardened portion in a partial area of a hardened surface of the work. In the quenching process, independent quenched portions are formed on the quenched surface of the work in a line in one direction.
By executing the quenching step a plurality of times while changing the relative position between the quenching head and the quenching surface, a plurality of rows of the quenching portions are formed on the quenching surface. Further, in this case, preferably, the quenching head is annular, and the work has an annular quenching surface corresponding to the quenching head. Quenching portions arranged in a line in the circumferential direction are formed, and the quenching step is repeatedly performed while moving the quenching head relative to the quenching surface of the workpiece. On the quenching surface of the workpiece, a quenching portion is formed that separates the quenching portion in the circumferential direction and in the axial direction of the quenching surface, whereby a substantially independent quenching portion is formed on the quenching surface. A plurality of the quenching patterns are formed.

According to another feature of the present invention, there is provided an induction hardening apparatus for partially hardening a workpiece by performing high frequency induction heating in a liquid. The induction hardening apparatus includes a liquid tank for storing the liquid, a quenching head for partially quenching a predetermined region on the quenching surface of the workpiece by high-frequency induction heating, and a quenching surface for the workpiece. Position detecting means for detecting the positional relationship with the immersion head, and the quenching head confronts the quenching surface of the workpiece in the liquid in the liquid tank based on the positional relation detected by the position detecting means. In such a state that the hardening surface of the work and the hardening head are positioned in a predetermined relationship, power is supplied to the hardening head under a predetermined condition so that the hardening surface of the work is subjected to high frequency. And a power supply means for performing quenching by induction heating. In a preferred embodiment, the quenching head is annular, and the work has an annular quenching surface corresponding to the quenching head. The quenching portions are formed so as to be arranged in a line in a row, and the quenching head has induction coils spaced in a circumferential direction. Further, the induction hardening device further includes a circumferential direction control means for controlling a circumferential relative position between the hardening head and the hardened surface of the work, and a relative position of the hardened surface of the work and the center axis direction of the hardened head. And an axial control means for controlling the position.

In this case, in one preferred embodiment, the circumferential direction control means controls the rotational position of the hardening head with respect to the hardened surface of the work, and the axial direction control means includes a hardening head. And lifting means for controlling the vertical position of the camera. According to another feature of the present invention, a plurality of substantially independent quenching depths having substantially the same shape and area are formed on the inner surface of the cylinder bore by high-frequency induction heating in liquid. A cylinder block provided with a quenching pattern having an insertion portion is provided.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the basic features of the present invention are that a work having a quenching surface to be quenched and a quenching head having an induction coil for quenching are both immersed in the liquid. In order to form a quenching pattern in an independent dispersed state on the quenched surface of the work by arranging and quenching the quenched surface of the work by high frequency induction heating in the liquid, the quenched part can be distinguished from the non-quenched part with a clear boundary is there. INDUSTRIAL APPLICABILITY The present invention can be suitably applied to a case where a desired quenching pattern is formed on the inner surface of a cylinder bore of a cylinder block. The quenching head used in the embodiment of the present invention is provided with an induction heating coil, and is supplied with power at a predetermined frequency, voltage and current to heat the quenched surface of the work to a quenching temperature or higher by induction heating. . In the present invention, for example, a ring-shaped one-turn coil as disclosed in JP-A-7-272845 can be suitably used as the induction heating coil. The magnetic field generated by the one-turn coil is not uniform in the circumferential direction, and a strong magnetic field is generated regularly at predetermined angular intervals. For this reason, the quenching surface of the work is heated to the quenching temperature or higher at predetermined intervals in the circumferential direction. That is, a quenched portion that is independently separated in the circumferential direction is generated.

The quenched portion formed in one quenching step of the annular quenching head according to the present invention is a quenching pattern in which quenching portions independent in the circumferential direction are arranged in a line on the quenching surface over the entire circumference. It is formed. In this case, the width of the annular quenching head in the central axis direction is generally smaller than the length of the quenching surface of the work in the same direction, and thus a quenched portion is formed over the entire work quenching surface. For this purpose, it is necessary to move the quenching head in the direction of the central axis and perform a plurality of quenching operations. When moving the quench head in the axial direction, if the quench head is rotated by an angle which is half the interval between the quench portions spaced apart in the circumferential direction, the position of the quench portion becomes hardened on both sides in the axial direction. An annular quenching pattern is formed so as to be at an intermediate angular position between the insertion portions.
As a result, the quenching pattern formed as the entire quenched surface is
A pattern in which hardened portions independent in the circumferential direction and in the axial direction are dispersedly formed. In the present invention, the quenching step is performed with both the quenching head and the work submerged in the liquid. By performing the high-frequency induction heating in the liquid in this manner, the region to be quenched can be reliably heated to the quenching temperature or higher, and the other regions are in contact with the liquid, so that the heat of the quenched part Can effectively prevent thermal influence on the area around the quenched surface. That is, since the boundary region between the quenched portion and the non-quenched portion can be reduced and the two can be clearly distinguished, a desired quenched pattern can be formed in terms of area, shape, layout, and the like. As a result, both the wear resistance and the lubricity of the entire surface having the quenching pattern can be effectively improved. Furthermore, since the thermal influence on the region other than the quenched portion can be minimized as described above, the quenching depth of the quenched portion can be reduced by performing the submerged partial quenching of the present invention.
There is an advantage that it can be formed uniformly and relatively thin throughout. Further, the presence of the liquid has the effect of preventing the quenching head from being damaged by heating due to the execution of the quenching step.

[0011] As the liquid in which the quenching step is performed, typically, water adjusted to a temperature close to the outside air temperature can be used, but it is desirable to appropriately adjust the properties of the water. For example, additives for preventing deposits on the quenching head, such as a surfactant and a pH adjuster, can be added. In performing the quenching in the liquid according to the present invention, a liquid tank for storing the liquid is prepared. This liquid tank has a size to accommodate the work and the quenching head, and is preferably
A movement control mechanism is provided so that the movement can be controlled on a plane so that the position can be adjusted with respect to the quenching head, and the quenching head is NC-controlled. When the workpiece is NC-controlled with respect to the quenching head within a predetermined error range, the quenching head moves in the axial direction with respect to the quenching surface of the workpiece, and the quenching head and the workpiece are moved together. Are precisely adjusted so that the quenching heads are in a positional relationship facing each other, and power is supplied to the quenching head to perform induction heating. One quenching operation by quenching is about several seconds, and a single quenching process forms a line of quenched portion patterns arranged in a ring at predetermined intervals. After this one quenching step is completed, the power supply is temporarily stopped, and the quenching head is moved in the axial direction so as to quench different axial (usually vertical) regions. At this position, power is supplied again to perform the quenching process.

In this case, the actuator usually moves to an adjacent position in the axial direction, but may be set to an axial position farther than the adjacent position by a predetermined distance in consideration of the influence of heat. . It is desirable to provide a liquid jetting means for jetting a liquid between the quenching surface and the quenching head during the quenching step, and to always expose the liquid to the liquid flow during the quenching step. And the thermal influence of the quenching head and the quenched surface of the work other than the quenched portion can be more effectively suppressed. The position control between the quenching head and the workpiece does not necessarily have to be moved with respect to the quenching head, and the quenching head may be NC-controlled to control the position with respect to the workpiece. . When adjusting the position with respect to the quenching head while the work is accommodated in the water tank, first, mastering provided on the support member of the liquid tank is detected, and based on the mastering, the positional relationship between the quench head and the work is determined. Is preferably adjusted. In this case, the mastering provided on the support member of the water tank is detected by a sensor having a known predetermined positional relationship with the quenching head, so that the positional relationship between the mastering and the quenching head is uniquely determined.

Next, by detecting the position of the quenching surface of the work by a sensor, the positional relationship between the quenching surface and the quenching head can be obtained. The position of the quenching surface of the work thus obtained is input to the position control mechanism of the liquid tank, and the position of the predetermined quenching surface with respect to the quenching head is determined. When the quenching head is positioned with respect to the workpiece, a similar position control mechanism may be provided for the quenching head. The work is located below the liquid surface in the quenching process, but is kept exposed above the liquid surface so that the quenched surface can be accurately detected by the sensor during the above position detection. After the position is detected, the liquid is introduced to such an extent that the hardened surface of the work is immersed. In addition, when the entire quenching process is completed, the liquid in the liquid tank is quickly drained, and the liquid tank is moved together with the work from a position coaxial with the quenching head to a predetermined spaced position. Moved, tempered in that position,
Returned to the transport line.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawings show an induction quenching method and an apparatus for quenching the inner surface of a bore of a cylinder block in an induction liquid. First, the configuration of the induction quenching apparatus will be described. In FIG. 1, FIG. 2 and FIG. The column 2 is erected in one example (the right side of FIGS. 1 and 2), and a gate-shaped frame 3 is erected and fixed at an intermediate portion of the bed 1. On the upper surface of the bed 1 described above, two horizontal and parallel Y
Axle rails 4 and 4 are attached, and a lower table 5 that can move in the front-rear direction (Y-axis direction) along the Y-axis rails 4 and 4 is provided. That is, a plurality of sliders 6 provided on the lower surface of the lower table 5 are slidably mounted on the Y-axis rail 4 described above, and a ball screw is connected to a Y-axis motor M1 mounted on one end of the bed 1. Then, by connecting a ball guide nut disposed on the ball screw via a ball to the lower table 5, the lower table 5 is moved in the front-rear direction by forward and reverse rotation of the Y-axis motor M <b> 1 (FIGS. 1 and 2). (Left-right direction of the camera).

Two horizontal and parallel X-axis rails 7, 7 are mounted on the upper surface of the above-mentioned lower table 5, and the upper movable along the X-axis rails 7, in the left-right direction (X-axis direction). A table 8 is provided. That is, while the plurality of sliders 9 provided on the lower surface of the upper table 8 are slidably mounted on the X-axis rail 7, the ball screw 10 is connected to the X-axis motor M 2 mounted on the lower table 5. By connecting a ball guide nut disposed on the ball screw 10 via a ball to the upper table 8,
The upper table 8 is configured to move in the left-right direction by the forward / reverse rotation of the X-axis motor M2. Thus, a work table 11 (a so-called XY table or cross table) is constituted by both the lower table 5 and the upper table 8, and the upper part of the work table 11 is open at the top. A box-shaped underwater quenching water tank (hereinafter simply referred to as a tank) 12 is attached. The tank 12 stores and discharges cooling water W as a cooling liquid therein. A cylinder block 14 (so-called work) as a member to be hardened is attached to and detached from the tank 12 via a support member 13. It is positioned and fixed as possible.

The above-described cylinder block 14 is made of a metal material such as cast iron that can be induction hardened, and has a number of cylinder bores 14a corresponding to the number of cylinders (an in-line four-cylinder is illustrated in the drawings). On the other hand, two parallel Z-axis rails 15, 15 extending in the vertical direction are mounted on the upright surface of the column 2 described above, and the Z-axis rails 15, 15 extend in the vertical direction (Z-axis direction).
Is provided with a movable lifting unit 16. That is, a plurality of sliders 18 are attached to a flat plate member 17 provided on the back surface (the right side surface in FIGS. 1 and 2) of the elevating unit 16, and the sliders 18 are slidably mounted on the Z-axis rail 15 described above. On the other hand, a ball screw 19 is connected to the Z-axis motor M3 mounted on the upper part of the column 2, and a ball guide nut 20 provided via a ball to the ball screw 19 is connected to the flat plate member 17 described above. The lifting unit 16 is configured to move up and down by forward and reverse rotation of the Z-axis motor M3. Here, the above-mentioned elevating unit 16 includes a flat plate member 17 and the elevating table 1 integrally attached to the front surface of the flat plate member 17. The elevating table 21 has a transformer 22 for high-frequency induction heating mounted thereon. A quenching head 23 electrically connected to the secondary side of the transformer 22 is vertically provided on the lower surface of the elevating table 21. That is, the hardening head 23 is configured to move up and down by the Z-axis motor M3.

A disk 25 is mounted on the upper surface of the elevating table 21 via a disk receiving member 24. As shown in FIG. 2, a gear 26 is partially formed integrally with a part of the disk 25. , The rotating shaft 27 of the hardening position changing motor M4
, A pinion 28 is attached, and the pinion 28 is meshed with the gear 26 described above. Thus, the aforementioned motor M4
28, the gear 26 and the disk 2
5, the transformer 22 and the quenching head 23 are integrally twisted in a virtual horizontal plane at a predetermined angle around the center (centering point) of the quenching head 23. Further, the above-described lifting unit 1
A balance air cylinder 29 is erected and fixed on both left and right sides of the bed 1 so as to face the lower surface of the bed 6, and the attachment 3 is attached to the piston rod 30 of the air cylinder 29.
1 to reduce the transfer load of the Z-axis motor M3 by applying a pressure opposing the weight of the lifting unit including the lifting unit 16 and the transformer 22 to the bracket 32 of the lifting unit 16 via doing. The piston rod 30 of the balance air cylinder 29 described above is used.
It goes without saying that the projection and depression control is performed in accordance with the elevation of the elevation unit 16.

The frame 3 is provided with a bore position measuring element 33 for measuring the position of the bore 14a of the cylinder block 14 as the work cylinder position. As the bore position measuring element 33, a differential transformer type inner diameter measuring element so-called Marpos gauge (trade name) used for measuring the inner diameter of the work is used. The position is determined. The work table 11, more specifically, the upper table 8, has an electric resistance type touch signal probe (hereinafter simply referred to as a touch probe) 34 as a measuring means for measuring the mounting position of the quenching head 23 and a table reference member. A master ring 35 having a cylindrical portion that is concavely recessed at the upper portion thereof is erected and fixed apart from each other. The above-mentioned bore position measuring element 33 is configured to be able to move in the vertical direction (Z-axis direction). That is, as shown in FIG. 4, the above-described bore position measuring element 33 is attached to the measuring element elevating table 36, while the fixing member 37 on the frame 3 side extends vertically.
A rail 38 (only one is shown in FIG. 4) is mounted, and a plurality of sliders 39 mounted on the back surface of the tracing stylus elevating table 36 are mounted on the rail 38, and a bore is formed by forward / reverse rotation of the elevating motor M5. The position tracing element 33 is configured to move in the vertical direction.

Here, a ball screw 41 is connected to the elevating motor M5 via a coupling 40, and a ball guide nut 42 provided on the ball screw 41 via a ball is connected to the above-mentioned stylus elevating / lowering element. It is connected to the platform 36.
On the other hand, the above-described hardening head 23 is configured as shown in FIGS. That is, the quenching head 23
Is a connection flange 4 connected to the secondary side of the transformer 22
3, a Cu induction heating coil 44 for quenching the bore 14a of the cylinder block 14, and a Cu lead 45 connecting the two 43, 44,
Necessary places are ethylene tetrafluoride resin or mica (mica)
Insulated by an insulating plate 46 made of aluminum. Further, in this embodiment, the above-described induction heating coil 44 is used for the purpose of simultaneously quenching the bore 14a of the cylinder block 14 in 11 equal parts on the circumference.
Are formed with eleven convex portions 47 (see FIG. 7) and eleven concave portions 48 (see FIG. 7). Each of these convex portions 47 is provided with a magnetic core 49 for the purpose of concentrating and improving magnetic flux density. It is arranged. Further, a measuring part 50 for measuring a head centering made of a synthetic resin, for example, NC nylon, is assembled below the induction heating coil 44 in a state where the head is centered with respect to the quenching head 23 in advance.

In addition, in order to detect interference with the inner surface of the cylinder bore 14a, a non-magnetic current-carrying member formed by cross-linking a stainless steel bar at the lowermost end as the insertion end of the quenching head 23 into the cylinder bore 14a. 5
1 is attached. This non-magnetic conducting member 51 is shown in FIG.
The length of the elastic member is set so as to protrude radially outward by a small amount L with respect to the outer diameter of the induction heating coil 44 as shown in FIG. An interference detection circuit using the non-magnetic conductive member 51 is configured as shown in FIG. That is,
An interference detection power supply 54 and an interference detection relay 55 are interposed in a line 53 connecting the ground 52 and the connection flange 43 of the quenching head 23, while the induction heating coil 44 and the non-magnetic conductive member 51 are SUS Made of lead wire 56
And a voltage of, for example, more than 10 volts is applied to the non-magnetic conductive member 51 by the above-described interference detection power supply 54, and the non-magnetic conductive member 51 is inserted into the bore 14a of the cylinder block 14, and the non-magnetic conductive member 51 is inserted. When the interference with the bore 14a occurs, an energizing circuit is formed and the interference detection relay 55
N. Here, the non-magnetic conducting member 51 and the lead wire 56 described in detail are made of stainless steel which satisfies all of the non-magnetic condition, the conducting condition, and the condition that is hard to be heated.

The cooling water system for supplying, discharging, and circulating the cooling water W to and from the tank 12 is constructed as shown in FIG. That is, a cooling water return passage 60 having a bottom slide structure formed at the bottom of the bed 1 (see FIG. 1) of the induction hardening device, and a cooling water drain tank 61 formed to communicate with the inclined lower end of the cooling water return passage 60. And a cooling water supply tank 62 formed at a distance from the upper end of the cooling water return passage 60. The cooling water is supplied to a strainer 63 disposed in the cooling water supply tank 62 via a suction line 64. A first pump 65 for liquid is connected, and a discharge line 66 of the first pump 65 is connected.
Is provided with a flow control valve 67. Further, the tip of the discharge line 66 is branched into three branch lines 68, 69, 70, a first valve 71 is provided in the first branch line 68, and the tip of the first branch line 68 is connected to the tank 1
2 are continuously connected to inlet ports 72 formed on both left and right sides (only one side is shown in the drawing). Similarly, a second valve 73 is interposed in the above-described second branch line 69, and the tip of the second branch line 69 is connected to the tank 12.
Are continuously connected to inlet ports 74 formed at a plurality of locations on the bottom. Here, each of the lines 66, 68, 6
Since the tanks 9 and 70 move following the work table 11, the necessary parts are of course made flexible.

A third valve 75 is interposed in the third branch line 70, and a distal end of the third branch line 70 is connected to a communication pipe 7 provided in the inner bottom of the tank 12 described above.
6 is connected to the communication pipe 76, and a cooling water injection nozzle 77 as a coolant supply means located below each of the bores 14 a corresponding to the number of cylinders of the cylinder block 14 is connected to the communication pipe 76.
Is connected. Here, the above-described first, second, and third
Each of the valves 71, 73, 75 and a fourth valve 85 described later are constituted by an electromagnetic on / off valve alone or a combination of an electromagnetic on / off valve and a flow control valve. The cooling water W in the tank 12 is discharged to the cooling water return passage 60 at a time when the pinch valve 78 attached to the bottom of the tank 12 is opened, while the cooling water W overflowing from the tank 12 is also discharged. The cooling water returns to the above-mentioned cooling water return passage 60. Further, a second pump 81 for cooling water recirculation is connected to a strainer 79 provided in the cooling water drain tank 61 via a suction line 80, and a tip of a discharge line 82 of the second pump 81 is connected to a cooling water supply tank 62. The discharge line 82 is provided with a filter 83, a cooler 84 for lowering and cooling the cooling water to a predetermined temperature, and a fourth valve 85.

A predetermined amount of a rust preventive is added to the cooling water W in advance, and the cooling water is supplied from the cooling water supply tank 62 to the tank 12 as a water tank by the configuration of the cooling water passage shown in FIG. The cooling water W used for cooling the work is supplied to the cooling water drain tank 6 through the cooling water return passage 60.
After being stored in the storage tank 1, the second pump 81 drives the cooling water supply tank 62 again through the discharge line 82 to be circulated and used. The cooling water injection nozzle 77 as the above-described cooling liquid supply means is formed in a cylindrical shape having an annular inclined surface 77a on the outer peripheral portion of the top surface as shown in FIGS.
A large number of cooling water jets 77b are formed on the annular inclined surface 77a, and the cooling water jetted from each of the cooling water jets 77b is made to flow along the inner wall surface of the cylinder bore 14a,
It is configured to form a large number of jets A. In this embodiment, the hardening head 23 is moved from the upper part (top deck side) to the lower part (oil pan side) of the cylinder bore 14a by a Z-axis motor M3 as head moving means. That is, since the quenching order direction is set in the direction of arrow B in FIG. 10, the above-described cooling water injection nozzle 77 injects and supplies the cooling water W from below the cylinder bore 14a to above.

FIG. 12 is a block diagram showing a control circuit of the induction hardening apparatus. The CPU 90 stores the signals in the ROM 86 based on various necessary signal inputs from the bore position measuring element 33, the touch probe 34, and the interference detection relay 55. According to the program, Y-axis motor M1, X-axis motor M2, Z-axis motor M3, hardening position changing motor M4, bore position measuring element elevating motor M5, balance air cylinder 29 and oscillator 87, pinch valve 78, each pump 65 , 81,
Each valve 71, 73, 75, 85 and the flow regulating valve 67
And the RAM 88 stores measurement position data of the cylinder bore 14a measured by the bore position measurement element 33, measurement position data of the mastering 35 measured by the bore position measurement element 33, and the hardening head 23 measured by the touch probe 34. Required data such as the mounting position data of the hardening head 23 measured by the touch probe 34, the position data of the bore position measuring element 33 measured by the touch probe 34, and maps. The measurement of the mounting position of the quenching head 23 by the touch probe 34 described above is performed by using a measuring unit 50 for head centering measurement made of NC nylon which is pre-centered and fixed to the quenching head 23. That is, in FIG. 7, the spherical portion of the tip of the touch probe 34 is brought into contact with the outer periphery of the measuring unit 50 at 45 degrees apart from the position where the non-magnetic conducting member 51 is disposed, and the centering position of the quenching head 23 is changed from a total of four positions. Find out. The oscillator 87 is connected to a high-frequency induction heating power supply (not shown).

Prior to the description of the induction hardening method of the present invention, coil position determination processing, coordinate zeroing processing, and bore position correction processing will be briefly described with reference to flowcharts shown in FIGS. First, the process of determining the position of the induction heating coil 44 (the position of the quenching head 23) will be described with reference to the flowchart of FIG. 13. In a first step S1, the quenching head 23 is attached by work on the secondary side of the transformer 22. , In the next second step S2, the CP
U90 measures the coil mounting error. That is, the work table 11 is connected via the Y-axis motor M1 and the X-axis motor M2.
Is moved, and the bore position measuring element 33 is
Then, the work table 11 is similarly moved, and the position of the hardening head 23 is measured by the touch probe 34. At this time, the spherical portion at the tip of the touch probe 34 is brought into contact with the measuring section 50 made of NC nylon to determine the centering position. Next, in the third step S3, the CP
U90 determines whether or not the position of the induction heating coil 44 is within the allowable range. For example, if the position is 0.1 mm or less, it is OK, and if it is more than 0.1 mm, it is NG.

Next, in a fourth step S4, the CPU 90 determines the hardening head 2 from the measured position data of the bore position measuring element 33.
The position of 3 is determined and determined. The mounting position data of the hardening head 23 determined in this way is stored in a predetermined area of the RAM 88. A series of processing shown in FIG. 13 is executed at the time of starting (at the time of starting operation) and at predetermined time intervals. Next, the coordinate zeroing process will be described with reference to the flowchart of FIG.
The PU 90 executes the position confirmation of the mastering 35. That is, the mastering 35 is moved directly below the bore position measuring element 33 via the work table 11, and then the bore position measuring element 33 is lowered via the bore position measuring element elevating motor M5. Is inserted into the mastering 35 to confirm the position of the mastering 35. Next, in a second step S12, the CPU 90 determines whether or not the coordinate error is within an allowable range. For example, if the coordinates are out of order,
If it is 0 μm or less, it is OK, and if it is more than 0 μm, it is NG. When it is determined to be OK, the process proceeds to the third step S13, and when it is determined to be NG, another fourth step S13 is performed.
Go to 14.

In the above-mentioned third step S13, the CPU 90
Performs zeroing of coordinates, while the fourth step S1
In step 4, the CPU 90 executes a machine stop. The above-described coordinate zeroing data is stored in a predetermined area of the RAM 88. A series of processing shown in FIG. 14 is executed at the time of starting (at the time of starting operation) and at predetermined time intervals. Next, the bore position correction process will be described with reference to the flowchart of FIG. 15. In a first step S21, the CPU 90 executes a process of confirming the bore position of the cylinder block 14 as a work. That is, the cylinder 14 is moved via the work table 11 so that the bore 14 a of the cylinder block 14 is located immediately below the bore position measuring element 33. Next, the bore position measuring element 33 is lowered via the bore position measuring element elevating motor M5, and the bore position measuring element 33 is inserted into the bore 14a, thereby confirming the bore position. Next, the second step S2
In 2, the CPU 90 determines whether or not the bore position is within the allowable range. For example, if the maximum correction amount for the above-mentioned coordinate zeroing value is 0.2 mm or less, it is OK.
And Then, when it is determined to be OK, the process proceeds to the next third step S23, and when it is determined to be NG, the process proceeds to another fifth step S25 to exclude the defective work.

On the other hand, in the above-mentioned third step S23, the CP
U90 determines the correction amount of the bore position by comparing the confirmation data of the bore position with the coordinate zeroing value, and executes the correction of the bore position via the work table 11 at the time of hardening corresponding to the correction amount. Note that such processing is executed for all cylinders. Next, the fourth step S2
In 4, the CPU 90 executes quenching start. It should be noted that C is required before the start of quenching in the above-described fourth step S24.
The PU 90 drives the first pump 65 and the like to store the cooling water W in advance in a position up to about half of the tank 12 indicated by the imaginary line α in FIG. Prior to the above-described quenching, the tank 12 and the cylinder block 14 are moved from the position shown in FIG. 1 to the right in FIG. 1 by the work table 11 so that the cylinder bore 14 a is positioned immediately below the quenching head 23. Non-magnetic conducting member 51 inserted into bore 14a
Is interfered with the inner surface of the bore 14a, the interference detection relay 55 is turned ON.
Although the shaft motor M3 is stopped, high-frequency quenching in liquid is performed when there is no interference in normal operation. Further, at the start of the quenching, the CPU 90 drives the first pump 65 and the like to store the cooling water W from the plurality of inlet ports 72 and 74 to a predetermined position of the tank 12 (see the solid line position in FIG. 9) in a short time.

In this embodiment, the quenching head 23 is moved at predetermined intervals from the upper part to the lower part of the cylinder bore 14a by driving the Z-axis motor M3, and quenching spots a, b, c, d, and e, f, g, h, i, j are subjected to induction hardening in a quenching order in which one row is formed in this order. One quenching step is completed in about 0.5 seconds, and the quenching head moves to the next position in about 0.5 seconds. In the case of forming five annular quenched portions, it takes about 5 seconds to quench the inner surface of one cylinder bore. At this time, the cooling water W for cooling the heated portion of the cylinder bore 14a from a direction opposite to the above-described quenching order direction (the direction of arrow B in FIG. 10).
To send. In other words, the jet flow A from the cooling water injection port 77b of the cooling water injection nozzle 77 below the cylinder bore 14a, which is pre-positioned and fixed at a fixed position, is the cylinder bore 1
The cooling water is constantly jetted so as to be formed from below to above along the inner wall surface of 4a. FIG. 16 is an explanatory view in which the bores 14a of the cylinder block 14 are unfolded and the portions where quenching spots are formed are hatched for convenience of illustration and correspond to the stroke direction of the piston in FIG. Thus, the induction heating coil 4 in the quenching head 23
The quenching sequence shown in FIG.
It is set to be formed in the order of c, d, e, f, g, h, i, j.

At this time, after the quenching spots a to e, the quenching spots f
In this case, the CPU 90 drives the quenching position changing motor M4 to rotate the quenching head 23 through the pinion 28, the gear 26 and the disk 25. The angle of the quenching head 23 is changed together with the transformer 22 by a predetermined amount. When the quenching sequence is set as described above, the portions not affected by the previous quenching heat can be sequentially quenched in the high-frequency liquid, so that the heat effect can be eliminated while saving the cooling time by the cooling water W. As a result, staggered or checkered quenching spots a to j as shown in FIG. 16 can be formed. In addition, since there is a predetermined interval between the quenching spots, quenched portions, that is, quenching spots a to j are formed in this interval portion (portion where no quenching spots are formed) while securing oil necessary for the cylinder of the engine. It is possible to improve the wear resistance by improving the surface hardness of the set portion. In short, according to the induction hardening method of the present invention, the hardening head 2
Work (see cylinder block 14) from the opposite direction to the direction of quenching sequence (see arrow B direction in FIG. 10).
This is a method of feeding the cooling water W for cooling the heating part of the work, so that the heat in the work and the cooling water can be released in the direction opposite to the quenching sequence direction along the cooling liquid supply direction. The heat generated at the quenching location is less likely to be transmitted to the next quenching location, which makes it possible to achieve uniform quenching patterns for each quench, stabilize the quenching quality, and improve the uniform quenching pattern. The formation has an effect of preventing uneven wear of the work and the like.

The present invention is not limited only to the configuration of the above embodiment. For example, quenching oil may be used instead of the cooling water W as the above-mentioned cooling liquid, or a cooling water passage for self-cooling may be formed inside the above-mentioned quenching head 23. Further, the number of quenching spots formed by quenching is not limited to that of the embodiment, and the order of formation of the quenching spots is shown in the embodiment, and the order of a, b, c, d, e, f, g is shown. , H, i, j, the order may be set to a, f, b, g, c, h, d, i, e, j. The quenching apparatus includes the column 2 provided on the bed 1 and the frame 3 provided at an intermediate portion of the bed 1 as described above. A worktable 11 movable in the Y-axis direction and the X-axis direction is arranged above the bed 1, and a tank 12 on which the work is arranged is provided on the worktable 11. Behind the frame 3, a disk 25 and a quenching head 23 arranged at the center thereof are located. As shown in FIG. 2, in the present embodiment, a tempering device is arranged adjacent to the quenching device. The tempering device includes rails 100, 100 extending in the Y-axis direction, similarly to the above-described quenching device.

On the rail 100, a table 101 on which a cylinder block 14 for tempering is mounted is movably mounted on the rail. A tempering head 102 for tempering the cylinder block 14 is provided at one end of the rail 100. In this example, since the work is a four-cylinder cylinder block having four cylinder bores, four high-frequency induction heating coils 10 on the cylinder are used to perform high-frequency induction heating of the inner surface of each cylinder bore at one time.
3, 103, 103 and 103 are provided. The high-frequency induction heating coil hangs from the tempering head 102 and is positioned with respect to the inner surface of the cylinder bore of the work in the same manner as the annular high-frequency induction heating coil 44 of the quenching head 23 of the quenching device. I have. An elevating device 104 is attached to the high-frequency induction heating coil 103 for setting and retracting the high-frequency induction heating coil 103 in the same manner as the quenching device. When the table 101 on which the work is placed is located at the first position separated from the tempering head, a box-shaped cooling water tank 105 storing cooling water for cooling the tempered and heated cylinder block with water is provided on the side. Are located. After the quenching process is performed, the work is returned from the second position, where the quenching head of the quenching device is located, to the first position while being placed in the tank 12 on the rail 4. At this first position, the work is lifted from the tank 12 by a loader (not shown), moved in the X direction along the line X1 in FIG. 2, and is carried into the tempering device.

In this case, the cylinder block 14 is disposed on the table 101 at the first position as described above. Next, the table 101 on which the work 14 is placed is moved in the Y-axis direction and positioned immediately below the tempering head 102. In this state, the elevating device 104 is driven to lower the tempering head, and each of the high-frequency induction heating coils 103 is inserted into the cylinder bore inner surface 14a of the cylinder block and arranged in a predetermined facing relationship. Then, electric power is supplied to the tempering head 102 under predetermined conditions, and the cylinder block 14 is moved from normal temperature for about one minute to about 300 minutes.
The high-frequency induction heating is performed at a temperature of from 350C to 350C. After the cylinder block 14 is held at this temperature for a predetermined time, the table 101 is driven and the tempering head 10 is moved from the second position.
2 is moved to a first position separated from the second position. In this state, the loader is driven again to grip the work on the table 101 and immerse it in the cooling bath 105. Since the cooling water tank is maintained at substantially the outside air temperature, the cylinder block 14 is cooled to the outside air temperature level in about 2 to 3 minutes. After cooling, the work is cooled by a loader into a cooling tank 105.
And is further moved in the X-axis direction, and is made to stand by on the table 106 at a position further away from the cooling bath 105 by a predetermined distance in the X-axis direction. Then, it is transferred to the belt conveyor 107 which moves in the Y-axis direction at a predetermined timing, is further loaded from the conveyor 107 onto the AGV 108 arranged at one end thereof, and thereafter returned to the normal production line.

[Brief description of the drawings]

FIG. 1 is a side view of an induction hardening apparatus used in the induction hardening method of the present invention.

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a left side view of FIG. 1;

FIG. 4 is an explanatory view showing an elevating structure of a bore position measuring element.

FIG. 5 is a front view showing a configuration of a quenching head.

FIG. 6 is a right side view of FIG.

FIG. 7 is a bottom view of FIG. 5;

FIG. 8 is an explanatory diagram showing a circuit for detecting interference.

FIG. 9 is a system diagram showing a cooling water passage.

FIG. 10 is an explanatory view showing the induction hardening method of the present invention.

FIG. 11 is a perspective view of a cooling water injection nozzle.

FIG. 12 is a control circuit block diagram.

FIG. 13 is a flowchart showing a coil position determination process.

FIG. 14 is a flowchart illustrating a coordinate zeroing process.

FIG. 15 is a flowchart showing a bore position correction process.

FIG. 16 is an explanatory view showing an example of quenching spots formed by the induction hardening method of the present invention.

[Explanation of symbols]

 14 Cylinder block (work) 14a Bore 23 Hardening head 77 Cooling water injection nozzle 77a Annular inclined surface 77b Cooling water injection port M3 Z-axis motor (head moving means).

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshihiko Kawajiri 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Yukio Hamamoto 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Inside (72) Inventor Yoshihiko Kojima 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Corporation (56) References JP-A-60-260769 (JP, A) JP-A-7-161461 (JP) JP-A-5-202418 (JP, A) JP-A-8-225846 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C21D 1/10 C21D 1/42 C21D 9/00

Claims (9)

(57) [Claims] An induction quenching method for partially quenching a workpiece by performing high frequency induction heating in a liquid, wherein a workpiece having a quenching surface to be quenched is disposed in the liquid. A quenching head for heating is arranged in the liquid, the quenching head is relatively moved from the upper part to the lower part of the work, and the quenching head is opposed to a quenching surface of the work to induction-heat the work, In the circumferential direction and axial direction of the hardened surface of the workpiece
Quenching an independent predetermined region, and supplying cooling water from a direction opposite to a moving direction of the quenching head, thereby having a plurality of substantially independent quenching portions on the quenching surface of the work. An induction hardening method characterized by partially hardening a work so as to form a quenching pattern. 2. A quenching step for forming a quenched portion in a part of a quenched surface of a workpiece according to claim 1, wherein a single quenching step is performed on the quenched surface of the workpiece. Are formed so that independent hardened portions are formed in a line in one direction. Then, the supply of power is temporarily stopped, and the workpiece is moved in the axial direction and the circumferential direction. A further quenching step is carried out by supplying quenching. 3. A quenching step according to claim 1 or 2 , wherein a predetermined power is supplied to the quench head for a predetermined time to form a quenched portion in a partial region of a quenched surface of the work. A single hardening step forms independent hardened portions in a line in one direction on the hardened surface of the work, and the relative position between the hardened head and the hardened surface. And a plurality of rows of the quenched portions are formed on the quenched surface by performing the quenching step a plurality of times while changing the quenching step. 4. The quenching head according to claim 3 , wherein the quenching head is annular, and the work has an annular quenching surface corresponding to the quenching head. The surface is formed with quenched portions spaced in a line in the circumferential direction, and the quenching step is repeated while moving the quenching head relative to the quenched surface of the workpiece. By performing, on the quenching surface of the work, a quenching portion is formed that separates the quenching portion in the circumferential direction and in the axial direction of the quenching surface, and thereby is substantially independent on the quenching surface. An induction quenching method, wherein the quenching pattern in which a plurality of quenched portions are formed is formed. 5. An induction hardening device for partially quenching a workpiece by performing high-frequency induction heating in a liquid, comprising: a liquid tank for charging the liquid; and a predetermined area on a quenched surface of the workpiece. A quenching head for partially quenching by high-frequency induction heating, position detecting means for detecting a positional relationship between a quenching surface of the work and the quenching head, and Positioning means for relatively moving the quenching head from the upper part to the lower part of the work, and positioning the quenching head so as to face the quenching surface of the work in the liquid in the liquid tank; Power supply for supplying power to the quenching head under predetermined conditions in a state where the quenching surface and the quenching head are positioned in a predetermined relationship, and induction hardening the quenching surface of the workpiece by high-frequency power to perform quenching. Means and the quenching head And a cooling means for supplying cooling water from a direction opposite to a moving direction of the metal. 6. The method of claim 5, the hardened formed on quenching the surface of the workpiece is induction hardening instrumentation, characterized in that it is formed independently in the circumferential direction and the axial direction of the baked Irimen work
Place . 7. A quenching step of forming a quenched portion in a part of a quenched surface of a workpiece according to claim 6, wherein the quenching step is performed on the quenched surface of the workpiece by one quenching step. Are formed so that independent hardened portions are formed in a line in one direction. Then, the supply of power is temporarily stopped, and the workpiece is moved in the axial direction and the circumferential direction. An induction quenching apparatus characterized in that a further quenching step is performed by supplying quenching. 8. The quenching head according to claim 6 , wherein the quenching head is annular, and the work has an annular quenching surface corresponding to the quenching head. The quenching surface is formed with spaced-apart quenched portions arranged in a line in the circumferential direction. The quenching head has induction coils spaced in the circumferential direction, and Circumferential control means for controlling the relative position of the quenching head and the quenching surface of the workpiece in the circumferential direction; and axial control means for controlling the relative position of the quenching surface of the workpiece and the quenching head in the central axis direction. An induction hardening device further provided. 9. The quenching head according to claim 8 , wherein the circumferential direction control means controls the rotational position of the quenching head with respect to the quenching surface of the workpiece, and the axial direction control means moves the quenching head up and down. An induction quenching device, which is an elevating means for controlling a direction position.