JP3690782B2 - Mold with heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a mold with a heating device that heats an inner surface of a cylindrical mold and maintains the temperature at a predetermined temperature by heat transfer from a heating medium with a built-in heater attached along a side surface of an object to be heated. It is about.
[0002]
[Prior art]
For example, in hot forging, the press mold is set to 150 ° C. or 300 ° C. for the purpose of preventing the work material from cooling and maintaining its fluidity or evenly applying a lubricant. Raise the temperature. At this time, a method of heating by inserting a heater in a hole directly drilled in an object to be heated, such as a press die, is shown in FIG. 6 in a vertical section, and FIG. 7 shows a section AA in FIG. In a mold with a heating device, a cylinder having an inner surface having a shape corresponding to the shape of the outer surface along the outer surface of two upper and lower cylindrical objects 1 and 1 and having a built-in heater 3 The metal heating mediums 2 and 2 are respectively attached to the heating objects 2 and 2 while controlling the energization to the heater 3 while measuring the temperature with the thermocouples 5 and 5 inserted into the objects 1 and 1. There is a method in which the objects 1 and 1 are heated and maintained at a predetermined temperature by heat transfer from and the workpiece 4 is kept warm.
[0003]
[Problems to be solved by the invention]
However, although the above-described method of directly heating the object 1 to be heated is excellent in terms of heating efficiency, when the object 1 is a mold, the strength of the mold is reduced due to the formation of the heater hole. The mold needs to be large and strong. In addition, the method using the cylindrical metal heating medium 2 shown in FIG. 7 does not require drilling the object 1 to be heated, and can be shared by the object 1 having the same dimensions. Although there is an advantage such as easy mounting to the warm object 1, when the object 1 is formed of tool steel and the heating medium 2 is formed of brass material, due to the difference in thermal expansion coefficient between them, As shown in FIGS. 8A and 8B, a non-uniform gap 6 occurs between the object 1 and the heating medium 2 to reduce the heating efficiency, and the temperature of the object 1 varies depending on the location. .
[0004]
In order to prevent the gap 6 from being formed, as shown in FIG. 10, the heating medium 2 is provided with a separation groove 7 that vertically cuts the heating medium 2, and the object 1 to be heated is hung on both sides of the separation groove 7 at room temperature. A method of heating the object 1 by energizing the heater 3 in a state where the passed bolt 8 was tightened to reduce the groove width and the heating medium 2 was in close contact with the outer surface of the object 1 was also tried. In this method, the gap 6 caused by the temperature rise of the heating medium is eliminated by tightening the bolt 8, but the bolt 8 must be constantly adjusted depending on the temperature of the heating medium and the object. Further, when the temperature is raised and the bolt 8 is tightened and the temperature returns to room temperature, the thread is damaged.
[0005]
An object of the present invention is to solve the above-described problems, and to provide a die with a heating device that constantly maintains close contact between an object to be heated and a heating medium to improve heating efficiency.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has a shape corresponding to the inner side surface shape of the object to be heated, equipped with a heating medium with a built-in heater, the heat transfer from the heating medium, the subject In a die with a heating device for heating an object , an upper diameter is increased in which a separation groove for longitudinally cutting the heating medium is provided at one place or a plurality of places of the heating medium and the width of the separation groove is reduced or enlarged. A member 32 and a lower diameter-expanding member 33 are provided, and an urging body that tightens the member 32 is provided, and the heating medium is always brought into close contact with the object.
[0007]
In the above-mentioned mold with a heating device, a separation groove for longitudinally cutting the heating medium is provided at one place or a plurality of places of the heating medium.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a first embodiment of a heating medium applied to a mold with a heating device of the present invention, and is shown by a cross-sectional view taken along line AA of the mold with a heating device in FIG.
[0009]
In this example, since the mold that is the object 1 to be heated is cylindrical, the heating medium 10 has a cylindrical shape corresponding to the shape of the object 1, and the diameter of the inner surface thereof is easily attached to the object 1. As much as possible, it is slightly larger than the diameter of the outer surface of the object 1. The heater 3 is fixed inside the heater hole 12 whose both ends are open on the outer surface of the heating medium 10.
[0010]
Further, the heating medium 10 is provided with a separation groove 11 that cuts the heating medium 10 vertically, that is, extends in the axial direction of the cylinder. The female screw 13 engraved on one side of the separation groove 11, the through hole 14 opened on the outer surface of the heating medium 10 drilled on the other side, and one end loosely passing through the through hole 14 are formed on the female screw 13. The bolt 15 is screwed, the nut 16 is screwed to the other end of the bolt 15, and the compression coil spring 17 is inserted around the bolt 15 between the nut 16 and the opening of the through hole 14. A force 18 is formed. Therefore, the urging force of the urging body 18 can be adjusted by the position of the nut 16.
[0011]
Prior to heating the heating medium 10, the nut 16 of the biasing body 18 is turned to narrow the width of the separation groove 11, and the heating medium 10 is brought into close contact with the object 1 to be heated. In this example, since the object 1 is made of tool steel and the heating medium is made of brass, the heating medium 10 expands greatly due to the difference between the temperature and the thermal expansion coefficient during heating, and the width of the separation groove 11 is increased. The expansion force acts in the direction of expanding the distance, but the close contact between the two is maintained by the biasing force of the biasing body 18.
[0012]
FIG. 2 shows the surface temperature of the heating medium 10 when the temperature of the object 1 is raised to the set temperature 200 ° C. by the heating medium 10 of this embodiment, and the temperature by the thermocouple 5 inserted in the object 1. The set temperature was reached in about 40 minutes, and the maximum temperature of the heating medium 10 during that time was about 270 ° C.
The heating medium 2 has the same structure as the heating medium 10.
[0013]
9 (a) and 9 (b) are the conventional examples shown in FIGS. 8 (a) and 8 (b), respectively, in the case where a gap is generated between the object 1 and the heating medium 2. It is a figure which shows progress of temperature of this, and it measured on the same conditions as the above-mentioned 1st Example except the separation groove 11 added to the heating medium 2, and the biasing body 18. FIG.
FIG. 8A shows a case where the heating medium 2 and the object 1 are in contact with each other near the thermosensitive portion of the thermocouple 5 and the gap 6 is maximized on the opposite side when the temperature rises. ), The temperature reached a predetermined temperature after 80 minutes, and the maximum temperature of the heating medium 2 during this period was 360 ° C.
FIG. 8B shows a case where the gap between the heating medium 2 and the object 1 is maximized near the thermosensitive part of the thermocouple 5, and it takes 120 minutes to reach the predetermined temperature. The temperature was 420 ° C.
Therefore, the mold with the heating device of the first embodiment is improved in heating efficiency as compared with the conventional example, shortens the time to reach a predetermined temperature, and the maximum temperature of the heating medium is lowered to reduce the heating medium and There is an effect of suppressing the deterioration of the heater.
[0014]
FIG. 3 is a cross-sectional view showing the heating medium 20 of the second embodiment. The heating medium 10 of the first embodiment described above is provided with a notch 21 for longitudinally cutting the heating medium 20, making the heating medium 20 easy to bend and lowering the urging force of the urging body 18 for closely contacting the object 1. . The cuts 21 may be provided at a plurality of locations on the heating medium 20.
[0015]
FIG. 4 is a cross-sectional view showing the heating medium 25 of the third embodiment. This example is a rectangular cylindrical heating medium 25 applied when the object 26 to be heated has a prismatic shape, and is divided into two because the separation grooves 11 are provided at two locations. Two urging bodies 18, 18 are bridged on both sides of the separation grooves 11, 11.
[0016]
FIG. 5A is a vertical sectional view showing the heating medium 30 of the fourth embodiment, and FIG. 5B is a sectional view taken along line BB in FIG. In this example, the heating medium 30 is applied when the object 31 to be heated is cylindrical and heated from its inner surface. The shape of the outer surface of the heating medium 30 is a cylindrical shape corresponding to the shape of the inner surface of the object 31, the heater 3 is inserted in the axial direction, the separation groove 11 that cuts the heating medium 30 is provided, and the upper and lower surfaces And the edge of the inner surface is chamfered to form a conical surface.
[0017]
A frustoconical upper-diameter member 32 and a lower-diameter member 33 respectively installed on the upper and lower surfaces of the heating medium 30; a through-hole 34 with a stepped portion 38 formed in the center of the upper-diameter member 32; One end is embedded in the female screw 36 at the center of the lower diameter expanding member 33, a bolt 35 loosely passing through the through hole 34, a nut 37 screwed into the other end of the bolt 35, a step 37 of the nut 37 and the through hole 34, An urging body 40 is constituted by a compression coil spring 39 inserted around a bolt 35 between the two.
[0018]
Prior to raising the temperature of the object 31, the nut 37 of the biasing body 40 is tightened, and the upper diameter-expanding member 32 and the lower diameter-expanding member 33 are brought close to each other by the biasing force, thereby widening the width of the separation groove 11 of the heating medium 30. Then, the outer surface of the heating medium 30 is brought into close contact with the inner surface of the object 31 and heated in that state.
[0019]
In each of the above-described embodiments, the heating medium 10, 20, 25, 30 is mounted on either the outer surface or the inner surface of the object 1, 26, 31 to be heated, but both the outer surface and the inner surface are mounted. You may install in.
Further, in each of the above-described embodiments, the separation groove 11 is provided in the radial direction from the center of the objects 1, 26, 31 to be heated, but may be an oblique bias groove.
Further, in each of the above-described embodiments, the compression coil spring is used as the elastic body for applying the urging force to the urging body 11, but heat-resistant rubber, gas spring, or the like can be applied.
[0020]
【The invention's effect】
As is clear from the above description, according to the present invention, since the heating medium is always in close contact with the object to be heated, the heat conduction is good, the heating efficiency is improved, and the temperature of the object becomes uniform. The time required for temperature increase is shortened, and the heating medium is not heated more than necessary, so that deterioration of the heating medium and the heater can be suppressed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a heating medium in a first embodiment of the present invention. FIG. 2 is a view showing the temperature of a heating medium and an object during temperature increase in the first embodiment. FIG. 4 is a sectional view showing a heating medium in a third embodiment of the present invention. FIG. 5 is a vertical sectional view showing a heating medium in a fourth embodiment of the present invention and a horizontal view. FIG. 6 is a sectional view showing a mold with a heating device. FIG. 7 is a sectional view showing a conventional heating medium. FIG. 8 is a sectional view showing a conventional heating medium. FIG. 10 is a cross-sectional view showing a heating medium of a conventional example [Explanation of symbols]
1 is an object, 2 is a heating medium, 3 is a heater, 4 is a workpiece, 5 is a thermocouple, 6 is a gap, 7 is a separation groove, 8 is a bolt, 9 is a female screw, 10 is a heating medium, and 11 is a separation. Groove, 12 is a heater hole, 13 is a female screw, 14 is a through hole, 15 is a bolt, 16 is a nut, 17 is a compression coil spring, 18 is a biasing body, 20 is a heating medium, 21 is a notch, 25 is a heating medium, 26 is an object, 30 is a heating medium, 31 is an object, 32 is an upper-diameter member, 33 is a lower-diameter member, 34 is a through hole, 35 is a bolt, 36 is a female screw, 37 is a nut, and 38 is a stepped portion. , 39 is a compression coil spring, and 40 is an urging member.

Claims (1)

Oite the heating equipment for heating a cylindrical inner surface of the mold to raise the temperature, the apparatus comprising removable heating medium of the tubular corresponding to the shape of the inner surface (30), the heating medium (30) A heater (3) and a separation groove (11) for longitudinally cutting the heating medium at one or a plurality of locations of the heating medium ( 30 ), and a truncated cone on the top of the cylindrical heating medium ( 30 ) Provided with an upper-diameter member ( 32 ) and a lower-diameter member ( 33 ) at the bottom, and an urging body ( 40 ) for fastening between the upper-diameter member ( 32 ) and the lower-diameter member ( 33 ) A mold with a heating device.

Images