JPS6134481B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hardening device for locally hardening a predetermined portion of the inner wall of a cylinder whose one end surface is closed using induction heating means.

In general, in induction heating quenching, the material to be treated and the heating coil are moved relative to each other, and the heated surface of the material to be treated is sequentially heated as the heating coil moves relative to the heating coil. The moving hardening method, in which the material is rapidly cooled with a cooling fluid injected from a jacket, is said to produce less distortion than the one-shot hardening method, in which the entire surface of the material to be processed is heated by a heating coil and rapidly cooled at the same time.

By the way, when the inner wall of a cylinder whose one end face is closed is to be treated, a heating coil is inserted from the open end side of the cylinder, and the heating coil is moved toward the bottom face. In moving hardening, the inner wall is heated sequentially from the open end direction, and the surface to be heated is rapidly cooled with cooling fluid from a cooling jacket that follows the heating coil. The heated inner wall portion h cannot receive the jet of cooling fluid from the cooling jacket J, and therefore the quenching of the inner wall of the cylinder is limited to the portion indicated by Q'.

Therefore, one-shot hardening is performed in which the surface to be treated is the entire depth of the inner wall of a cylinder whose one end surface is closed.

Conventionally, a plurality of grooves T along the axial direction are formed on the inner wall of a cylinder W whose one end surface is a closed surface as shown in FIGS. 2a and b, and a Q is formed on the side wall of each groove T. When performing the quenching shown in the figure, one-shot quenching was performed using a quenching device equipped with a specially shaped heating coil for the above-mentioned reasons. This is shown in FIG. In Fig. 3, C″ is a heating coil connected to a high-frequency power source E, and the conductor of the heating coil C″ has a shape in which a plurality of gate-shaped heating conductor portions Ch are erected on a loop. The heating conductor part Ch is located in the groove part T of the cylindrical body W.
The parallel extending portion C1 of each heating conductor portion Ch is set to a height commensurate with the width and length of the groove that can be inserted into
C1 is configured to face both side walls of the groove T with a predetermined gap therebetween. The plurality of heating conductor parts
In the space surrounded by Ch, a cooling jacket indicated by J'' can be inserted as shown by arrow a, or is fixedly arranged in the space.In addition, a magnetic material is placed at a predetermined position in each of the above-mentioned extending portions C1. is fitted,
The magnetic flux is effectively guided toward the side wall.
In the hardening, for example, the hardening device is fixed, each heating conductor part Ch of the hardening device is housed in the cylinder W, and the cylinder W is opened from the direction of the open end so that each extending part C1 faces the side wall. Move the coil according to the arrow b to cover it, turn on the power E, and heat the heating coil for a predetermined period of time.
C'' is energized, and cooling fluid is injected from the cooling jacket J'' to the entire inner wall of the cylinder, including the side walls of the groove T, which has been heated to a predetermined quenching temperature due to the energization, to rapidly cool it down. ing.

Although the conventional hardening equipment described above is capable of hardening each side wall of the groove to its full depth, it is not possible to harden the inner wall of the cylindrical body, which has extremely variable wall thickness, in one shot, heating and rapidly cooling the inner wall in stripes at once. Therefore, there is a risk of distortion occurring, and in such a case, it would be necessary to undergo a straightening process after hardening.

The present invention has been made in order to solve the above-mentioned problems existing in the conventional hardening equipment.The present invention generates extremely little distortion, eliminates the need for post-process correction at all, and allows a predetermined surface to be treated to be heated over the entire length. To provide a hardening device that can reliably harden all parts.

The present invention will be explained according to the embodiment shown in FIG. 4a.

In FIG. 4a, the heating coil of the hardening apparatus of the present invention is an L-shaped conductor, as shown by C, which has one side extending horizontally and connecting to the lead R, and the other side standing upright over a predetermined length. 1, and a heating conductor portion 20 provided at the tip of the upright side of the conductor 1. The heating conductor portion 20 is connected to one pole of the lead R at the tip of the upright side of the conductor 1.
The conductor 1a on the Ra side is bent at a right angle and separated in the circumferential direction, and then the heating loop 2 of a predetermined shape is formed while approaching the tip of the original conductor 1a. Other pole Rb
It consists of a conductor connected to the tip of the side conductor 1b. In this embodiment, since the cylindrical body has three grooves, the separation and proximity of the conductor is repeated three times, and the three heating loops created by this repetition are heating loops 21 and 22, respectively. and 2
form 3. The heating loops 21, 22 and 23 have the same shape, and when inserted into the cylinder from the open end surface of the cylinder with the heating conductor section 20 facing forward, the heating loops 21, 22 and 23
Each of them must be set in a size and shape that can be accommodated in the groove of the cylindrical body, and can face the side wall of the groove with a predetermined gap. An insulating material 8 is interposed between adjacent portions of conductors that repeatedly move apart and close to each other to ensure electrical insulation of the conductor that goes around the circumferential direction. A U-shaped core made of a ferromagnetic material is fitted into the heating loop 22 as shown in the attached state.

The quenching apparatus of the present invention is provided with a number of cooling jackets corresponding to the number of heating loops 2. Therefore, three cooling jackets 4, designated 41, 42 and 43, are used in this embodiment. The end faces of each of the cooling jackets 41, 42, and 43 are formed to a size that can be accommodated in the groove, and a plurality of cooling fluid injection holes 5 are bored in the side surface facing the side wall of the groove. A double-walled pipe is connected to the lower end surface of each of the cooling jackets 41, 42, 43.
The outer tube 6 of the double structure tube opens into the cavity of the cooling jacket 4, and the inner tube 7 passing through the outer tube 6 reaches the cooling jacket 4 and then extends further to pass through the cavity of the cooling jacket 4. An opening 8 is formed through the end wall at approximately the center of the upper end face.

The other ends of the outer tube 6, one end of which opens into the cavities of each of the cooling jackets 41, 42 and 43, are joined together and connected to a cooling fluid supply source P via a control valve _B1 to form a first cooling fluid supply pipe. The other ends of the inner pipes, one end of which is open at the upper end wall surface of each of the cooling jackets 41, 42 and 43, are joined together and connected to a cooling fluid supply source P via a control valve _B2 ;
A second cooling fluid supply pipe is formed. Therefore control valve
By individually manipulating B ₁ and B ₂ , the first
The supply of cooling fluid to the cooling fluid supply pipe and the cooling fluid in the second cooling fluid supply pipe can be freely controlled. The cooling jackets 41, 42 and 43 to which the double-walled pipes as described above are connected are located on the lower surface of each of the heating loops 21, 22 and 23, for example, in close proximity to the heating loop 22 as shown in the arrangement. The heating coil C and the heating coil C constitute a hardening device. The hardening device may be configured to be movable in the vertical direction by a drive source (not shown), or may be arranged in a fixed manner.

Next, using the hardening apparatus of the present invention having the above configuration,
The case of hardening the groove side wall of the cylinder will be explained according to the embodiment shown in FIGS. 4b and 4c.

FIGS. 4 and b each show one of the plurality of combinations of heating loops 2 and cooling jackets 2 in the hardening apparatus shown in FIG. For example, the groove T of the cylindrical body W having a groove T is shown as a cross section taken along the line AA in FIG. 2b. Although it is necessary for the cylindrical body W and the quenching device to move relative to each other during the quenching process, in this embodiment, the cylindrical body W is stationary and the quenching device is movable up and down.

When the cylindrical body W is fixed at the hardening position with the open end surface facing downward, the quenching device with the heating conductor portion 20 facing upward starts to rise by a drive source (not shown), and the heating conductor portion 20 moves toward the cylindrical body W. When it reaches the open end surface of
A high frequency power source (not shown) is turned on to start energizing the heating coil C, and after a predetermined time, the control valve _B1 for supplying cooling fluid to the first cooling fluid supply pipe 6 is opened. Since the stationary state of the cylindrical body W is set in a predetermined manner, each heating loop 2 in the heating conductor portion 20 that is energized continues to rise within each groove T of the cylindrical body W at a predetermined speed. As the heating loop 2 rises, the side wall of each groove T is such that the core 3 fitted in the side wall facing portion of the conductor forming the heating loop 2 converges the magnetic flux generated from the heating loop 2, and Since it is guided toward the side wall, it is heated sequentially from the open end surface direction to a predetermined quenching temperature. The side wall heated to the above prescribed quenching temperature is
As the heating loop 2 rises, it comes face to face with the cooling jacket 4, which is disposed close to and immediately below the heating loop 2 and which follows and rises. As described above, the supply of cooling fluid to the first cooling fluid supply pipe 6 has already been started, and the cooling fluid injection hole 5 of the cooling jacket 4 to which the first cooling fluid supply pipe 6 is open has already started.
Since the cooling fluid is flowing out from the groove T and the jet is directed toward the side wall of the groove T, the side wall portion heated to the above-mentioned quenching temperature is rapidly cooled by the cooling fluid. In this manner, as the hardening device ascends, the side wall of the groove T is heated by the magnet of the preceding heating loop 2, and the side wall of the groove T is heated from the direction of the open end surface by the cooling fluid injected from the side surface of the following cooling jacket 4. Hardening indicated by Q ₂ is applied sequentially toward the bottom surface. When the heating loop 2 is raised to a position close to the bottom surface,
Turn off the drive source and stop the quenching device from rising. After a predetermined time has elapsed since the quenching device has stopped, the high frequency power source is turned off and the energization to the heating coil C is stopped, and at the same time,
Open control valve _B2 . The cooling fluid is supplied to the second cooling fluid supply pipe 7, is jetted out from the upper end face opening 8 of the cooling jacket 4 at a predetermined injection pressure, passes through the loop of the heating loop 2 according to the arrow, and enters the groove T.
The liquid collides with the bottom surface of the wall, flows along the bottom surface toward the peripheral wall, reaches the peripheral wall, and flows down. Due to the cooling fluid flowing down the peripheral wall, the side wall, which has been heated to the above-mentioned hardening temperature but cannot be impacted by the cooling fluid injected from the side surface of the cooling jacket 4, is rapidly cooled and hardened as shown by _Q2. Ru. When sufficient cooling is achieved, control valves B ₁ and B ₂ are closed in sequence, and the drive source is turned on to lower the quenching device to escape from the inside of the cylindrical body W, and the cylindrical body W is placed in the fixed position for quenching. The quenching process is then completed.

According to the quenching apparatus of the present invention, even if the wall thickness of the cylinder body is extremely variable, the side wall of the groove along the axial direction provided on the inner wall of the cylinder body can be heated locally. Since the heated part is immediately rapidly cooled by moving hardening, it is possible to harden the part with almost no quenching distortion, and the inner wall of the object has a closed end surface, which was previously considered impossible with moving hardening. This makes it possible to harden up to the surface near the bottom of the steel. The present invention has the effect of simplifying the process by omitting the straightening process from the conventional manufacturing process, and improving the quality of the item by guaranteeing hardening of the groove sidewall over the entire depth. It is prized for its great practical value.

[Brief explanation of the drawing]

Fig. 1 is a front cross-sectional view for explaining the drawbacks when hardening the inner wall of an object having a closed end surface using a conventional mobile hardening device, and Fig. 2 a and b are front cross-sectional views of the object to be hardened, respectively. A bottom view, FIG. 3 is an exploded perspective view showing a conventional one-shot hardening device, FIG. 4 a is a perspective view showing the hardening device of the present invention, and FIGS. FIG. 3 is a partial front sectional view illustrating a case where 11a, 11b...Conductor, 2, 21, 22, 2
3... Heating loop, 20... Heating conductor section, 3...
Ferromagnetic core, 4, 41, 42, 43... Cooling jacket, 6... First cooling fluid supply pipe which is an outer pipe, 7... Second cooling fluid supply pipe which is an inner pipe, 8...
...Opening, C... Heating coil, R, Ra, Rb...
Lead part.

Claims (1)

[Claims] 1. In a cylinder whose inner wall has a plurality of grooves extending in the axial direction and whose one end is closed, the side wall of the groove is hardened, and the conductor connected to the lead on the power supply side is bent in the right angle direction. The conductor is repeatedly separated and approached in the same number of grooves in the circumferential direction of the conductor to form a plurality of heating loops, and each of the heating loops faces the grooves with a predetermined gap between them and heats the conductor. It consists of a movable induction heating coil forming a conductor part, and a cooling jacket fixedly arranged behind each heating loop in the direction of movement of the induction heating coil, and at a predetermined position of each heating loop. A ferromagnetic core is fitted without closing the center of the loop, a double structure tube is connected to each of the cooling jackets, and the outer tube of the double structure tube opens into the cavity of the cooling jacket, Inner tubes extend through the cavity of the cooling jacket and open into the centrally facing end wall of the heating loop to form first and second cooling fluid supply tubes, respectively, and A quenching apparatus characterized in that the supply of cooling fluid to each tube can be individually controlled in a predetermined manner.