JP3019652B2 - Heating device and heating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating apparatus and a heating method for heating a field of, for example, an electromagnetic clutch for an automobile and thermally curing a resin material filled in a coil housing space of the field.

[0002]

2. Description of the Related Art Conventionally, as electromagnetic clutches for automobiles,
In some cases, the field is formed in a substantially cylindrical shape. This type of field has a structure in which a coil is inserted into a coil housing space inside a peripheral wall, and the coil is fixed by filling and curing the resin in the coil housing space. As the resin, an epoxy resin which is a thermosetting resin has been used.

That is, the field is heated to a resin curing temperature to cure the epoxy resin filled in the coil accommodating space. This heating was performed by fitting a substantially cylindrical heater block into the hollow portion of the field. Hereinafter, this conventional heating device will be described with reference to FIGS.

FIG. 6 is a plan view showing a state where a field is heated by a conventional heating device, and FIG.
FIG. 8 is a perspective view of a field for an electromagnetic clutch as a cylindrical member to be heated, which is partially cut away in FIG. FIG. 9 is a connection diagram of a heater of a conventional heating device.

In these figures, reference numeral 1 denotes a field of an electromagnetic clutch for a vehicle, and reference numeral 2 denotes a heating block for heating this field. The field 1 is formed by fixing a cylindrical flange 4 to the outer peripheral portion of a ring 3 by shrink fitting, and is formed substantially in a substantially cylindrical shape. The ring 3 has a concave groove 5 having a substantially V-shaped cross section formed in the outer peripheral portion along the entire circumference along the circumferential direction.
A letter-shaped insulating spacer 6 is fitted. The coil 7 is wound inside the insulating spacer 6. The insulating spacer 6 is a coil 7 for the ring 3 and the flange 4.
It is installed to insulate.

The coil 7 has a diameter of 1 covered with an insulating material.
Insulation spacer 6 mm copper wire (magnet wire) multiple times
The copper wire is formed at both ends by electrode terminals 8.
Is electrically connected to This electrode terminal 8 is a ring 3
And is connected to an excitation power supply (not shown).

That is, the flange 4 is fitted to the ring 2 in a state where the insulating spacer 6 and the coil 7 are mounted in the concave groove 5, so that the insulating spacer 6 and the coil 7 Is housed in the coil housing space inside.

Reference numeral 10 denotes an epoxy resin for preventing the coil 7 from vibrating in the coil accommodating space to cut the magnet wire or peel off the insulating coating, thereby preventing a rare short between the magnet wires. The epoxy resin 10 is injected into the coil housing space from the resin injection port 3a of the ring 3 with the coil 7 mounted in the coil housing space as described above, and the heating block 2 heats the field main body 9 to a predetermined temperature. As a result, the coil 7 is hardened in the coil housing space and the coil 7 is fixed to the field main body 9. When the resin is injected, the internal air is exhausted from an exhaust port 3b formed in the ring 3. A vacuum device (not shown) is connected to the exhaust port 3b for evacuating the coil housing space to a vacuum.

In order to cure the epoxy resin 10,
As described above, the heating is performed by heating the field main body 9 to the resin curing temperature. In order to quickly cure the epoxy resin 10 which is a thermosetting resin, the field main body 9 is heated to about 180 ° C. This heating is performed by fitting the heating block 2 into the inner peripheral portion of the field main body 9.

The heating block 2 comprises a cylindrical portion 11 fitted into the inner peripheral portion of the field main body 9 and a flange portion 12 provided integrally with one end of the cylindrical portion 11 and in contact with the axial end surface of the field main body 9. Is formed. Column 11
A contact portion between the outer peripheral surface of the field main body 9 and the inner peripheral surface of the field main body 9 is denoted by reference numeral 13, and a contact portion between the flange portion 12 and the axial end surface of the field main body 9 is denoted by reference numeral 14.

A heater 15 is built in the column portion 11 and the flange portion 12. This heater 15
Is formed by filling a metal outer cylinder with an inorganic insulator and inserting a nichrome wire that generates heat when energized, and is arranged at intervals in the circumferential direction of the heating block 2.

The heaters 15 are all connected in parallel as shown in FIG. A relay 17 is interposed between the parallel circuit and the power supply 16, and the relay 1
7, the switching of the current to all the heaters 15 is switched.

Next, the operation of the conventional heating device thus configured will be described. First, the heater 15 is energized to heat the heating block 2 to 300 ° C. Then, the field main body 9 in which the coil 7 has been assembled is attached to the heating block 2. At this time, the column part 11 is fitted into the inner peripheral part of the field main body 9, and the field main body 9 is supported by the flange part 12.

When the field main body 9 is mounted on the heating block 2 as described above, the heat of the heating block 2 is transferred to the contact portion 1.
The electric power is transmitted to the field main body 9 through the third and the fourth transmissions 14. Due to this heat conduction, the temperature of the field main body 9 which is the same as the room temperature is raised to about 180 ° C. After the temperature rise, the air in the coil accommodating space is exhausted from the exhaust port 3b to make the coil accommodating space substantially in a vacuum state. In this state, the epoxy resin 10 melted from the resin inlet 3b is injected into the field main body 9.

The epoxy resin 10 filled in the coil accommodating space is cured by the heat of the field main body 9 heated to about 180.degree. In the conventional heating device, the field main body 9 is heated in this way, and the epoxy resin 10 is cured.

[0016]

However, in the heating device configured as described above, it takes a long time to cure the epoxy resin 10, and there is a problem that productivity is low. This is because, when the heating is performed by fitting the heating block 2 to the field main body 9, the inner diameter gradually increases as the temperature of the field main body 9 increases, and as a result, the ring-shaped gap at the contact portion 13 expands. Because it would

That is, as the temperature of the field main body 9 increases, the amount of heat conducted through the contact portion 13 (the amount of heat conduction) gradually decreases. In addition, heating block 2
Since the contact portion 14 in which the flange portion 12 and the field main body 9 contact each other extends in the radial direction, even if the field main body 9 thermally expands, the amount of heat conduction is relatively hard to change. FIG. 10 shows a change in the gap of the contact portion 13.

FIG. 10 is a graph showing the relationship between the temperature of the field main body and the gap of the fitting portion when heating is performed by a conventional heating device. In the case where the ring-shaped gap at the contact portion 13 when attached to the heating block 2 at 0.1 ° C. is 0.1 mm, the change in the ring-shaped gap until the temperature of the field main body 9 rises to 180 ° C. is shown. As can be seen from the figure, the inner diameter of the field main body 9 expands according to the linear expansion coefficient of the ring 3 of 12 × 10 ^-6 1 / ° C.
At about ° C, a gap of about 0.25 mm is generated, and the amount of heat conduction from the heating block 2 decreases.

Therefore, it took a long time of about 5 minutes to raise the temperature of the field main body 9 to 180 ° C. FIG. 11 shows the temperature change of the field main body 9 after the start of heating.
Shown in FIG. 11 is a graph showing the relationship between the elapsed time when heating is performed by a conventional heating device and the temperature of the ring of the field main body. As can be seen from the figure, the ring temperature sharply rises early after the start of heating, but the rate of rise of the ring temperature decreases with time (as the temperature of the field body 9 increases).

Further, in the conventional heating device, there is a problem that the amount of current of a circuit for supplying electricity to the heater 15 easily exceeds an allowable value of an earth leakage breaker (not shown), and the power supply is frequently shut off. This is because heating was performed by energizing all the heaters 15 at the same time. That is, each heater 1
5, there is a slight leakage current, but the leakage current value of each heater 15 becomes particularly large on a humid day or when the one that has not been used for a long time is used, and this is added by the number of heaters. As a result, the amount of current in the heater energizing circuit becomes a large value exceeding the allowable value.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a heating device capable of rapidly raising the temperature of a field main body 9 to a resin curing temperature, and to provide a heating device capable of causing a short circuit due to electric leakage of a heater. To obtain a heating method in which the power supply is not interrupted.

[0022]

A heating apparatus according to the present invention is constituted by dividing a heating block into a plurality of sections in a circumferential direction as an aggregate of divided heating blocks, and each divided heating block has a built-in heater. An outer diameter variable mechanism for moving each divided heating block in the radial direction is connected.

In the heating method according to the present invention, when heating the divided heating blocks of the heating device, the heaters are simultaneously energized by the number of heaters whose sum of the leakage currents of the individual heaters does not exceed an allowable value. By sequentially changing the heaters to be turned on, all the heaters are energized.

[0024]

In the heating apparatus according to the present invention, by moving the divided heating blocks radially outward, each divided heating block is kept in close contact with the heated member even if the inner diameter of the heated member is increased. .

In the heating method according to the present invention, current is supplied to each heater whose sum of leakage currents does not exceed the allowable value, and all heaters are not supplied simultaneously. Is always less than the amount of current at which the earth leakage breaker operates.

[0026]

【Example】

Embodiment 1 FIG. Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 is a perspective view showing a heating block of the heating device according to the present invention, FIG. 2 is a plan view of the same heating block, FIG. 3 is a sectional view taken along line III-III in FIG.
Is a connection diagram of a heater of the heating device according to the present invention, and FIG. 5 is a graph showing a relationship between an elapsed time and a temperature of a member to be heated when heating is performed by the heating device according to the present invention. In these drawings, the same or equivalent members as those described in FIGS. 6 to 9 are denoted by the same reference numerals, and detailed description is omitted.

In these figures, reference numeral 21 denotes a heating block of the heating device according to the present invention.
Has a structure to be fitted into a hollow portion of the field main body 9 as a member to be heated, similarly to the conventional heating block. This heating block 21 divides a cylindrical metal body on which a cylindrical portion 21 a and a flange portion 21 are formed into a plurality of pieces (eight pieces in this embodiment) in the circumferential direction.
Are configured as an aggregate.

The cylindrical metal body forming the heating block 21 is made of a metal material having a linear expansion coefficient of 12 × 10 ^-6 1 / ° C., and has an outer diameter of the cylindrical portion 21 a when heated to 300 ° C. It is formed to be 160.31 mm. That is, a curved surface corresponding to the cylindrical portion 21a of the divided heating block 22 formed by dividing the cylindrical metal body (this curved surface is hereinafter referred to as a cylindrical surface and denoted by reference numeral 22a) is
The curvature becomes equal to a circle having an outer diameter of 160.31 mm. The outer diameter of the cylindrical portion 21a in a state where the divided heating blocks 22 are assembled as shown in FIG. 1 to form the heating block 21 is such that the cylindrical portion 21a is fitted into the field main body 9 as shown in FIG. It is set to dimensions that can be used. The inner diameter of the field body 9 is 16 in this embodiment.
It was 0.00 mm. For this reason, since the radius of curvature of the cylindrical surface 22a of the divided heating block 22 is larger than the radius of curvature of the inner peripheral surface of the field main body 9, when the cylindrical portion 21a is fitted to the field main body 9, FIG. Middle code G
The arc-shaped gap shown by is formed.

Each divided heating block 22 has a cylindrical portion 21a.
The heater 15 is mounted on each of the inside portion and the inside portion of the flange portion 21b.
And is configured to be able to advance and retreat in the radial direction of the heating block 21. Further, a heat insulating plate 24 for preventing the heat of the divided heating blocks 22 from radiating to the outside is fixed to the fan-shaped bottom surface of each divided heating block 22.

As shown in FIG. 4, each of the heaters 15 incorporated in each of the divided heating blocks 22 has a relay 17 respectively.
Are connected in series. In this embodiment, since two heaters 15 are provided for each of the eight divided heating blocks 22, a total of 16 relays 17 are also used. That is, the heaters 15 are configured so as to be able to perform the on / off operation individually. In the present embodiment, all the heaters 15 are energized by sequentially turning on and off the sixteen relays 17 and sequentially changing the heaters 15 to be energized. Therefore, during heating,
The heater 15 will not be energized at the same time.

The variable outer diameter mechanism 23 includes a tension coil spring 25 that urges each of the divided heating blocks 22 toward the axis and connects all the divided heating blocks 22 integrally.
And a diameter expanding device 26 for urging each divided heating block 22 radially outward. The tension coil spring 25 is formed in an annular shape, and a concave groove 24 a is formed on the outside of the heat insulating plate 24 so as to extend over the entire heat insulating plate 24.
It has been loaded inside. That is, each divided heating block 2
2 is urged toward the axial center by the tension coil spring 25 together with the heat insulating plate 24.

The diameter expanding device 26 has a structure in which each divided heating block 22 is urged radially outward by an air cylinder 27, and a piston 27a of the air cylinder 27 is provided.
The piston rod 27b connected to the heating block 21
And a spring washer 28 is attached to the tip of the piston rod 27b. The air cylinder 27 supplies pressurized air to a rising air supply pipe 29 so that the piston 27a and the piston rod 27b
The piston 27a and the piston rod 27 are moved upward at a time to supply compressed air to the descending air supply pipe 30.
It has a conventionally well-known structure in which b moves downward.

The spring washer 28 attached to the tip of the piston rod 27b is a leaf spring formed by cutting a conical metal body into a petal shape as shown in FIG. Eight pressing pieces 32 respectively attached to the surface 31 are integrally provided. The upper inclined surface 31 is formed so that the inner diameter of the hollow portion of the heating block 21 gradually decreases from the upper portion of the heating block 21 to the lower portion.

The material of the spring washer 28 is 300
For example, Inconel, which does not lose its elasticity even when heated to ° C., is used. The spring washer 28 is fixed to the piston rod 27b by screwing a nut 33 to the tip of the piston rod 27b.
The pressing position of the spring washer 28 on the divided heating block 22 can be changed by changing the screwing position of the nut 33.

That is, by driving the air cylinder 27 to move the spring washer 28 downward together with the piston rod 27b, the pressing piece 32 of the spring washer 28 slides on the inclined surface 31 to move the divided heating block 22 radially outward. To press. When the divided heating block 22 is biased in this way, when the biasing force becomes larger than the elastic force of the tension coil spring 25, the divided heating block 22 moves radially outward from the initial position shown in the drawing. . In other words, the outer diameter of the cylindrical portion 21a of the heating block 21 increases. When the spring washer 28 is raised together with the piston rod 27b in the state where the diameter is expanded as described above, the force of the pressing piece 32 pressing the inclined surface 31 is lost, and the divided heating block 22 applies the spring force of the tension coil spring 25. To the initial position.

Next, the operation of the heating apparatus according to the present invention having the above-described structure will be described. First, pressurized air is supplied to the ascending air supply pipe 29 of the air cylinder 27 to position each of the divided heating blocks 22 at the initial position.
Heat to ° C. At this time, the outer diameter of the cylindrical portion 21a is slightly smaller than the inner diameter of the hollow portion of the field main body 9. For heating, the relay 17 is turned on and off for each heater 15.
In this way, the heaters 15 are sequentially turned on and off one by one, and the two heaters 15 are not turned on at the same time.

After the heating block 21 is heated, the field main body 9 is fitted to the cylindrical portion 21a. At this time, the temperature of the field main body 9 is equal to room temperature, and
60.00. Then, pressurized air is supplied to the descending air supply pipe 30 of the air cylinder 27, and the divided heating blocks 22 are urged radially outward by the spring washers 28 so as to be pressed against the inner peripheral surface of the field main body 9. The pressurized air is continuously supplied until the temperature of the field main body 9 is raised.

At this time, the field main body 9 has an inner diameter of 160.00 mm, and the curvature of the cylindrical surface 22a of the divided heating block 22 is equivalent to a circle of 160.31 mm.
The divided heating block 22 has both ends in the circumferential direction abutting on the field main body 9, and an arc-shaped gap indicated by a symbol G in FIG. Therefore, in the initial stage of heating, heat is conducted from the contact portion and the contact portion 14 between the flange portion 21b and the field main body 9, and the temperature of the field main body 9 is increased.

The inner diameter of the ring 3 of the field main body 9 increases in proportion to the linear expansion coefficient of 12 × 10 ^-6 1 / ° C. as the temperature increases. However, the air cylinder 27
Continuously urges the spring washer 28 downward, and a pressing force is applied to each divided heating block 22 in a radially outward direction, so that each divided heating block 22 abuts on the inner peripheral surface of the field main body 9. The state is maintained. Therefore, the heat conductivity does not decrease due to an increase in the ring-shaped gap as in the related art, and the heat of the heating block 21 is efficiently conducted to the field main body 9.

When the inner diameter of the field main body 9 expands due to thermal expansion, the cylindrical surface 22a of the divided heating block 22 is opened.
The arc-shaped gap G between the gap and the field main body 9 gradually narrows. This is because the inner diameter of the field main body 9 approaches a diameter 160.31 mm of a circle having the same curvature as the cylindrical surface 22a of the divided heating block 22. For this reason, as the temperature of the field main body 9 increases, the arc-shaped gap G narrows and the area of the contact portion between the field main body 9 and the divided heating block 22 increases, so that the heat transfer coefficient to the field main body 9 is reduced. 9 increases as the temperature increases. In general, the heat transfer rate increases as the temperature difference between two objects in contact increases, and decreases as the temperature decreases.
However, according to the heating device of the present embodiment, the smaller the temperature difference between the two objects, the larger the contact area between the two objects, so that the heat transfer speed does not decrease. For this reason, FIG.
As shown in the figure, the temperature of the field body 9 of about 7 kg could be raised to 180 ° C. in a short time of only 90 seconds.

Regarding the heat transfer efficiency, when the split heating block 22 is urged by using the spring washer 28 as shown in the present embodiment, the following advantages are obtained. A method of bringing the heating block 21 into contact with the inner peripheral surface of the cylindrical member to be heated (the field main body 9) to raise the temperature is as follows.
If the roundness of a and the roundness of the inner peripheral portion of the field main body 9 are each highly accurate and the centers of the two do not coincide with each other, the eight divided heating blocks 22 The heat transfer efficiency is reduced without uniformly contacting the inner peripheral surface of the main body 9. In the present embodiment, this problem has been solved by employing a spring washer 28 having a spring function.

That is, eight pressing pieces 32 of the spring washer 28 are provided in the same number as the number of the divided heating blocks 22, each of which is in contact with the divided heating block 22. And
When the spring washer 28 is lowered in a state where each pressing piece 32 is in contact with the divided heating block 22, each pressing piece 32 presses the eight divided heating blocks 22 against the inner peripheral surface of the field main body 9, respectively. . At this time, if the roundness of the inner peripheral surface of the divided heating block 22 or the field main body 9 is incorrect, or if the center of each circle is shifted, 8
Some of the divided heating blocks 22 come into contact with the field main body 9 and others do not, so that the heat transfer efficiency is reduced. Since the load applied from the air cylinder 27 is larger than the spring force of the spring washer 28, the pressing piece 32 pressing the divided heating block 22 in contact with the field main body 9 is pressed by all other divided heating blocks 22 (field main body 22). 9 that are not in contact with the field main body 9 are elastically deformed.

For this reason, by using the spring washer 28, the eight divided heating blocks 22 can be connected to the field main body 9 without depending on the roundness of the fitting portion of the field main body 9 and the heating block 21 and the positional accuracy of both. 9 can be evenly brought into contact with the inner peripheral surface, and the heat transfer coefficient can be improved.

As described above, the field body 9 is
After the temperature is raised to ° C., pressurized air is supplied to the rising air supply pipe 29 of the air cylinder 27 to raise the spring washer 28. In this manner, each divided heating block 22 returns to the initial position by the spring force of the tension coil spring 25. Thereafter, the field main body 9 is taken out from the heating block 21 and the internal air is removed from the exhaust port 3b, and the epoxy resin 10 is injected from the resin injection port 3a. By doing so, the epoxy resin 1 hardens in the coil housing space in the field main body 9 in about one minute. Thus, a commercialized field can be obtained.

Therefore, according to the heating device configured as described above, by moving the divided heating blocks 22 radially outward, even if the inner diameter of the field main body 9 is increased, each divided heating block 22 can be expanded. 9 can be kept in close contact, so that the heat transfer efficiency does not decrease. Further, since the heaters 15 are energized one by one and all the heaters 15 are not energized at the same time, the amount of current of the circuit for energizing the heater 15 is always smaller than the amount of current for operating the earth leakage breaker.

Embodiment 2 FIG. In this embodiment, an example is shown in which the heating block 21 is divided into eight divided heating blocks 22, but the number of divided heating blocks is not limited to this. That is, the heat transfer efficiency can be further improved by increasing the number of divisions. When energizing the heater 15 of each divided heating block 22,
It is not necessary to perform the processing one by one as shown in this embodiment. That is, if the sum of the currents leaking from the individual heaters 15 does not exceed the allowable value, it is also possible to energize two heaters or three heaters. Further, the order of energization of the heaters 15 is such that the heaters 1 positioned substantially diagonally on the
5 can be alternately energized, or energized sequentially in the circumferential direction.

[0047]

As described above, the heating apparatus according to the present invention is configured such that the heating block is divided into a plurality of pieces in the circumferential direction to form an aggregate of divided heating blocks.
In addition to the built-in heaters, and connected to the variable outer diameter mechanism to advance and retreat each divided heating block in the radial direction,
By moving the divided heating blocks radially outward, each divided heating block is kept in close contact with the heated member even if the inner diameter of the heated member is increased.

Therefore, the heat transfer efficiency can be improved, and the temperature of the member to be heated can be raised quickly, so that the productivity can be improved.

In the heating method according to the present invention, when heating each of the divided heating blocks of the heating device, the number of heaters whose total sum of the leakage currents of the individual heaters does not exceed an allowable value is simultaneously applied, and Since all the heaters are energized by sequentially changing the heaters to be turned on, all the heaters are not energized at the same time. Therefore, the amount of current in the circuit that energizes the heaters is always smaller than the amount of current that the earth leakage breaker operates.

Therefore, even if the heater is leaked, heating can be performed without interruption of power supply, so that efficiency does not decrease.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a heating block of a heating device according to the present invention.

FIG. 2 is a plan view of a heating block of the heating device according to the present invention.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a connection diagram of a heater of the heating device according to the present invention.

FIG. 5 is a graph showing a relationship between an elapsed time and a temperature of a member to be heated when heating is performed by the heating device according to the present invention.

FIG. 6 is a plan view showing a state where a field is heated by a conventional heating device.

FIG. 7 is a sectional view taken along line VII-VII in FIG. 6;

FIG. 8 is a perspective view of a field for an electromagnetic clutch as a cylindrical member to be heated, which is partially cut away in FIG.

FIG. 9 is a connection diagram of a heater of a conventional heating device.

FIG. 10 is a graph showing a relationship between a temperature of a field main body and a clearance of a fitting portion when heated by a conventional heating device.

FIG. 11 is a graph showing a relationship between an elapsed time when heating is performed by a conventional heating device and a temperature of a ring of a field main body.

[Explanation of symbols]

 9 Field main body 15 Heater 17 Relay 21 Heating block 22 Split heating block 23 Variable outer diameter mechanism 25 Tension coil spring 27 Air cylinder 28 Spring washer 31 Inclined surface 32 Pressing piece

Continued on the front page (72) Inventor Toshiki Okamoto 148, Hikami-cho, Hikami-gun, Hyogo Pref. Meisho Kiko Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) H01F 7/06

Claims (2)

(57) [Claims] 1. A heating device for heating a member to be heated by inserting a cylindrical heating block having a built-in heater that generates heat when energized by being inserted into an inner peripheral portion of a cylindrical member to be heated. A plurality of divided heating blocks in the circumferential direction to form a set of divided heating blocks, and each divided heating block has a built-in heater and a variable outer diameter mechanism that advances and retreats each divided heating block in the radial direction. A heating device, comprising: 2. When heating the divided heating blocks of the heating device according to claim 1, the heaters are simultaneously energized by the number of heaters whose sum of currents leaking from the individual heaters does not exceed an allowable value.
A heating method characterized in that all heaters are energized by sequentially changing the energized heaters.