JP5291318B2 - Induction heating billet heater - Google Patents

Description

  The present invention relates to an induction heating billet heater.

  Conventionally, metal parts of automobiles and the like are often manufactured by forging, and the metal material immediately before forging is a metal billet (metal rod-like body, hereinafter referred to as “a metal rod-like body” in an induction heating type billet heater. For example, around 1250 ° C., and is heated to a high temperature necessary for forging.

  This heating is generally introduced sequentially into a dielectric heating billet heater in a state where each billet of a fixed length (predetermined length) according to a desired forged product is aligned in series. Done. The length of the billet heater is configured to be long enough for the billet to have a processing length (processing time) sufficient to perform the heat treatment until the surface temperature and the center temperature of the billet are substantially the same. (See Patent Documents 1-4).

  The size of each billet is not particularly limited and may vary depending on the shape of the desired forged product. In general, the short billet is about 50 mm long, and the long billet is not long. Some have a length of about 200 mm, and in some cases, a length of about 500 mm, and more than that.

  These billets are usually placed and conveyed on a conveyor until just before introduction into the billet heater, and pass through a pair of driven pinch roller mechanisms in the vicinity of the outlet of the conveyor to enter the billet heater. In the billet heater, by being sequentially pushed by the billet that is sent out later, it is guided by a guide rail that extends and is installed in the induction heating coil. Heated.

  As described above, generally, in the billet heater, the heating billet is not positively conveyed, but is pushed by the heating billet sequentially sent by the pinch roller mechanism and proceeds.

  Therefore, depending on the heating conditions, the front and rear heated billets may come out of the heater outlet in a welded state.

  In addition, when the heating billet is placed on the pair of guide rails and passes through the induction heating coil, the heating billet is a portion where the heating billet and the guide rail come into contact with each other. Heat transfer cooling occurred, and as a result, the billet could not be heated uniformly, and a temperature difference sometimes occurred between the billet upper part and the billet lower part.

  These two problems seen when passing the heated billet through the induction heating billet heater may occur both at the same time or only one of them depending on the heating conditions. In some cases, there was a direct impact on the quality of the forging process in the subsequent process.

  Therefore, in order to eliminate the temperature difference in the cross-sectional direction of the billet, a proposal has been made to rotate the heating billet during conveyance and in the atmosphere (see Patent Document 1).

  However, in the proposal of Patent Document 1, the billet transport roller is large, and no specific method for rotating the billet on the transport rail has been proposed.

  In addition, a technique for preventing the front and rear billets from being welded has been proposed (see Patent Documents 2-4). For example, a pair of lift and horizontal carry type walking beams for transferring the billet are arranged in the billet heater. Has been proposed (see Patent Document 2).

  However, the one proposed in Patent Document 2 has a drawback that the walking beam is in direct contact with the billet, and further, the induction heating coil has an oval shape, and the structure of the walking beam portion becomes large.

  Also, a thermocouple is provided on the liner or skid rail in the billet heater, and the temperature is constantly measured at the center of the billet heater, particularly the rear end of the carry-out billet, and becomes a predetermined temperature below the melting point of the billet. Has been proposed to prevent billet welding by controlling the energization of the induction heating coil (see Patent Document 3). A mechanism for performing the above is required, which is not preferable.

In addition, a proposal has been made that a skid rail is provided in the billet heater, and a vibrator is provided to vibrate the skid rail, thereby vibrating the billet and preventing welding of the billet (Patent Document). 4), in this proposal, no specific proposal was made regarding the installation of a specific vibrator or the like.
JP 2001-129610 A JP-B-2-31470 JP-A-9-139281 Japanese Utility Model Publication No. 52-46883

  In view of the above-described points, the first object of the present invention is to exit the heater outlet with the front and rear heating billets welded as seen when the billet is passed through the induction heating billet heater. It is an object of the present invention to provide an induction heating billet heater that can prevent the billet from coming to the next process in a state where each billet is reliably separated.

  The second object of the present invention is that the heating billet and the billet guide rail are in contact with each other, and the billet cannot be heated uniformly due to heat transfer cooling to the guide rail. It is an object of the present invention to provide an induction heating billet heater that can prevent a temperature difference from occurring and can be heated with a uniform heating temperature distribution over the entire cross section of the billet.

  A third object of the present invention is to provide an induction heating billet heater that realizes both the first and second objects of the present invention described above.

The induction heating billet heater of the present invention that achieves the first to third objects described above has the following configuration (1).
(1) Two parallel guide rails are arranged in the induction heating coil arranged in the lateral direction, and a vibration motor is connected to the guide rail located on the outlet side of the induction heating coil to connect the guide rail. In the apparatus configured to vibrate, supplying billets one after another from the inlet side of the induction heating coil, and carrying out the heating billet from the outlet side,
The billet travel direction is not parallel to the direction of vibration given to the guide rail by the vibration motor, and the heated billet is given induction vibration while moving on the guide rail while being given an angle. moves with a rotation by the vibration imparted to the guide rail, it is characterized by being configured to be carried out from the outlet side of the induction heating coil.

In addition, the induction heating billet heater of the present invention has the following configurations (2) and (3) as a more specific and preferable aspect.
(2) The angle between the billet traveling direction and the center axis direction of the vibration motor is 45 ° to 90 °, and moves with rotation by vibration applied to the guide rail, and exits the induction heating coil It is configured to be carried out from the side.
(3) The guide rail is made of a pipe-shaped material, and cooling water is circulated inside the pipe-shaped material to cool the guide rail.

According to the induction heating billet heater of the present invention according to claim 1, when the billet is seen to pass through the induction heating billet heater, the heating billet before and after the outlet is welded out from the heater outlet. In this state, each billet can be sent to the next process in a state where each billet is reliably separated, that is, not welded.
According to the induction heating billet heater of the present invention according to claim 1 , the temperature difference between the upper part and the lower part of the billet due to the heat transfer cooling to the guide rail at the part where the heating billet and the guide rail come into contact. Therefore, it is possible to provide an induction heating billet heater that can be heated with a uniform heating temperature distribution over the entire cross section of the billet.
Furthermore, according to the induction heating billet heater of the present invention has well-balanced two effects described above, the production efficiency is good, it is possible to provide an induction heating billet heater can produce high quality forgings.

  According to the induction heating billet heater of the present invention according to claim 2, the effect of the induction heating billet heater of the present invention according to claim 1 can be further enhanced.

According to the induction heating billet heater of the present invention according to claim 3 , in particular, the guide rail in the induction heating billet heater can be prevented from becoming high temperature, and a device having excellent durability can be obtained. It is possible to provide an induction heating billet heater capable of satisfactorily preventing unevenness in the distribution state of the heating temperature on the cross section and realizing a uniform heating state.

  Hereinafter, the induction heating billet heater of the present invention will be described in more detail with reference to the drawings.

  In the induction heating billet heater of the present invention, a vibration motor is directly connected to a pair of guide rails that extend by forming a passage path by placing a heating billet in an induction heating coil, and the heating billet is placed and passed therethrough. The present invention is characterized in that a vibration motion is applied to the guide rail to be operated.

  FIG. 1 is a schematic front view illustrating the induction heating billet heater of the present invention as a model, and FIG. 2 is a schematic plan view illustrating the induction heating billet heater of the present invention as a model.

In FIG. 1, a rail 3 for guiding a billet 2 introduced from a billet introduction direction A extends to a billet outlet direction B in an induction heating coil box 1 having an induction heating coil (not shown) inside. In the vicinity of the end of the guide rail 3 on the outlet side, the vibration motor 4 is not parallel to the longitudinal direction of the guide rail 3 and vibrates in the lateral direction corresponding to the angle formed by the central axis of the vibration motor 4. Are connected to each other.

  As the vibration motor 4, it is preferable to use a frequency-variable inverter-equipped vibration motor whose frequency can be arbitrarily set. However, normally, the vibration motor 4 can give a vibration with a vibration frequency of around 50 Hz and an amplitude of about 0.5 mm. I just need it.

  By conveying the billet 2 while applying vibration to the guide rail 3 in this way, the front and rear billets are not in contact with each other for a long time during the conveyance of the heated billet. As a result, both billets are welded together. It is possible to prevent sticking. Further, by conveying the billet 2 while applying vibration to the guide rail 3, generally, since the cross-sectional shape of the billet is a circle, the billet being heated and conveyed is subjected to the vibration on the guide rail 3. It can be conveyed while being rotated little by little, and therefore, a specific part of the billet is not always in contact with the guide rail 3, and a more uniform heating state on the billet cross section Is preferable.

  When the vibration motor 4 is attached, it is preferable that the billet traveling direction and the center axis direction of the vibration motor are not parallel but configured with an angle. 3 can be given a more effective vibration action.

  According to the knowledge of the present inventors, the angle θ formed by the billet traveling direction and the center axis direction of the vibration motor is preferably 45 ° to 90 °.

  As the vibration motor 4, it is preferable to use a frequency-variable inverter-equipped vibration motor whose frequency can be arbitrarily set. However, normally, the vibration motor 4 can give a vibration with a vibration frequency of around 50 Hz and an amplitude of about 0.5 mm. I just need it.

  As described above, the vibration motor 4 is preferably attached to the attachment surface (attachment plate 8) at an angle of θ = 45 ° to 90 ° to impart vibration. .

  As for the position where the guide rail 3 and the vibration motor 4 are connected, it is preferable to connect the guide rail 3 and the vibration motor 4 on the position side where the guide rail 3 comes out of the induction heating coil. The billet 2 that is transported while being heated is given a vibrating motion near the highest temperature, that is, near the exit of the heating coil, and the billet is rotated by receiving such a vibrating motion. Because is important. In order to rotate, as described above, the frequency of the vibration motor may be changed, the frequency and amplitude may be changed as appropriate, and the installation position and orientation of the vibration motor may be adjusted as appropriate. it can. In addition, the rotational motion generated in the billet does not need to be a strict and steady rotational motion such as rotating at a constant rotational speed and rotational speed, and continues a fine motion that rotates slowly and moderately. If it happens, it is enough.

  FIG. 3 is a schematic right side view for explaining the induction heating billet heater of the present invention as a model.

  When the vibration motor 4 and the guide rail 3 are connected, the attachment plate 8 and the guide rail 3 are connected. The mounting plate 8 is preferably provided with a rubber damper 5 so that the vibration of the vibration motor 4 is not transmitted directly other than being transmitted to the guide rail 3.

  FIG. 4 is a schematic model perspective view for explaining a vibration motor portion in the induction heating billet heater of the present invention, wherein 10 is an inductor coil, and 11 is a coil lining. The vibration motor 4 is directly connected to the guide rail 3 and moves on the guide rail 3 in a state where the billet 2 is free. By receiving slight vibration, the billet end surfaces are less likely to be welded to each other, and the billet Even if 2 is viewed as a single unit, it will gradually move while rotating finely and the like, and it can be prevented that the billet cross section has temperature unevenness and temperature distribution.

  The structure of the guide rail 3 is not particularly limited, but is also called a skid rail (sliding rail). Even if the guide rail 3 does not have an active conveying action, the guide rail (skid) It is preferable that the rail is configured to have a low frictional resistance with the billet so that the billet can be guided in the traveling direction by the rail 3. The rail preferably has a pipe-like structure so as not to reach a high temperature as much as possible in the induction coil, and the cooling water is circulated inside the pipe-like structure. It is preferable that This is because the cooling effect / action can be sufficiently exerted by adopting this configuration, and according to the induction heating billet heater of the present invention, the guide rail 3 having such a higher cooling effect is used. Even when heat transfer cooling is strongly generated at the contact point with the guide rail 3, the billet itself proceeds while gradually rotating and moving finely, so that the heating temperature in the billet section is increased. It can exhibit a synergistic effect that unevenness and heating temperature distribution hardly occur.

  Therefore, according to the present invention, it is possible to prolong the life of the apparatus and the like, and to manufacture a high-quality and highly homogeneous forged product with high accuracy.

  1-3, 6 and 7 have shown the hose connection port for the circulation of a cooling water. The guide rail is preferably composed of two parallel straight rods (cylindrical tubes). In order to maintain the parallelism and strength between the two guide rails 3, a rail bridge plate 9 is provided between the two guide rails 3. Is preferably passed at appropriate intervals.

  The diameter (outer diameter) of the guide rail 3 is preferably about 10 mm to 15 mm in diameter, but is not particularly limited. In short, it is preferable that the material, size, and structure have moderate rigidity and flexibility so that vibration can be propagated well. For example, the cross-sectional shape of the guide rail 3 may not be a perfect circle, but may be an elliptical shape, a polygonal shape with an uneven cross section, or a star shape. In particular, in order to make it easy for the traveling billet to spontaneously generate minute rotational movement, the surface of the guide rail (skid rail) is obliquely cut or provided with a plurality of continuous protrusions. Such a configuration is also effective.

FIG. 1 is a schematic front view illustrating the induction heating billet heater of the present invention in a model manner. FIG. 2 is a schematic plan view for schematically explaining the induction heating billet heater of the present invention. FIG. 3 is a schematic plan view illustrating the induction heating billet heater of the present invention in a model manner. FIG. 4 is a schematic model perspective view for explaining a vibration motor portion in the induction heating billet heater of the present invention.

Explanation of symbols

1: induction heating coil box 2: billet 3: guide rail 4: vibration motor 5: rubber damper 6: hose connection port for circulating cooling water 7: hose connection port for circulating cooling water 8: mounting plate for vibration motor 9: rail crossing plate 10 : Inductor coil 11: Coil lining A: Billet introduction direction B: Billet exit direction θ: Angle formed by billet travel direction and central axis direction of vibration motor

Claims (3)

Two parallel guide rails are arranged in the induction heating coil arranged in the lateral direction, and a vibration motor is connected to the guide rail located on the outlet side of the induction heating coil so as to vibrate the guide rail. In the apparatus configured to supply billets one after another from the inlet side of the induction heating coil and to carry out the heating billets from the outlet side,
The billet traveling direction is not parallel to the direction of vibration applied to the guide rail by the vibration motor, and vibration is applied from an angled direction, and the induction rail is heated while moving on the guide rail. The induction heating billet heater is configured such that the billet is moved with rotation by vibration applied to the guide rail and is carried out from an outlet side of the induction heating coil. The angle between the traveling direction of the billet and the central axis direction of the vibration motor is 45 ° to 90 °, and the billet moves with rotation by vibration applied to the guide rail, and the induction heating coil The induction heating billet heater according to claim 1, wherein the induction heating billet heater is configured to be carried out from an outlet side. 3. The induction heating billet heater according to claim 1, wherein the guide rail is constituted by a pipe-like material, and cooling water is circulated inside the pipe-like material for cooling.