JP2012166235A - Press molding method and press molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press molding method which can improve the quality of a molded product by reducing, to the minimum, a size of a gap ([draft clearance]) which is formed between the external peripheral face of a protrusion and the internal face of a recess when performing press molding, and to provide a press molding device.SOLUTION: The press molding method employs the press molding device 1 in which there are arranged a punch 2 and the die 3 which is arranged so as to oppose the punch 2, the protrusion 2a is formed by the punch 2 at a side opposite to the die 3, the recess 3a is formed by the die 3 at a side opposite to the punch 2, at least one of them is movably arranged so that the punch 2 and the die 3 relatively approach and separate from each other along the opposing direction, and the protrusion 2a is made to have the draft clearance at the recess 3a by the approach of the punch 2 and the die 3. The draft clearance between the protrusion 2a and the recess 3a is adjusted by: changing temperatures of the punch 2 and/or the die 3; and adjusting a temperature difference between the punch 2 and the die 3.

Description

  The present invention relates to a technology of a press molding method and a press molding apparatus in which a softened material is sandwiched and pressed by a convex portion formed on a punch and a concave portion formed on a die, and the material is press-molded. .

Conventionally, a component having a laminated structure such as a motor core (more specifically, a stator or the like; hereinafter the same) is often formed by press molding.
More specifically, the motor core is formed by forming a plurality of laminated electromagnetic steel plates by caulking, then heating and softening the entire plate, and then forming convex portions and punches formed on the punch. By being pressed (press-molded) while being sandwiched between the formed recesses, it is punched into a predetermined shape and molded.

By the way, improving the quality of a press-molded product (motor core) is an effective means for improving the efficiency of a motor provided with the motor core.
In the press molding of the motor core, various countermeasures have been conventionally taken to improve the quality. As an example, press working is performed while maintaining the punch and die temperatures at the same and constant temperature. A technique is known (see, for example, “Patent Document 1”).
More specifically, for example, in a press molding apparatus, an oil circulation function is provided for each of a punch holder and a die holder for fixing and holding the punch and the die, and a predetermined temperature is set via the oil circulation function. The technology is known in which the temperature of the punch and the die holder is adjusted to the same temperature by circulating the temperature-controlled circulating oil to keep the temperature of the punch and the die constant and constant. It has been.
Further, for example, a technique is known in which the entire press molding apparatus is placed in a temperature-controlled room kept at a constant temperature, so that the temperature of the punch and the die is kept the same and constant and press working is performed.

JP 2003-260535 A

By using such a technique for pressing while maintaining the punch and die temperatures at the same and constant temperature, the adverse effect caused by the temperature difference between the punch and the die is eliminated, and the motor core that is a molded product is removed. Quality can be improved.
That is, when a gap formed by the outer peripheral surface of the convex portion of the punch and the inner peripheral surface of the concave portion of the die during press molding increases (hereinafter referred to as “punch clearance”), the convex portion and the concave portion As a result, the shear stress applied to the material (in this example, laminated magnetic steel sheets) is reduced, and a “working distortion” occurs in the press-formed product (in this example, the motor core). If the technology is used, it is possible to improve the quality of the motor core, which is a molded product, without causing a difference in thermal expansion due to the temperature difference between the punch and the die and increasing the “punch clearance”. .
However, even if the punch and die “punch clearance” was initially adjusted to an appropriate value, as the press molding continued, the wear of the punch convex portion and the die concave portion progressed, and the “punch clearance” Will gradually increase. As a result, since “processing distortion” occurs in the molded motor core, it has been difficult to reliably maintain the improved quality of the motor core over a long period of time.
Moreover, as a practical problem, when considering variations due to manufacturing errors of these punches and dies, assembling errors when assembling to the press machine, etc., the “clearance” can sufficiently absorb the variations. In order to improve the quality of the motor core, which is a molded product, it is necessary to set the size in advance, and there has been a limit to reducing the size of the “pull-out clearance” as much as possible.

  The present invention has been made in view of the above-described current problems, and presses while holding a softened material between a convex portion formed on a punch and a concave portion formed on a die, A press molding method and a press molding apparatus for performing press molding on the material, and a gap formed between the outer peripheral surface of the convex portion and the inner peripheral surface of the concave portion ("punch clearance") during press molding It is an object of the present invention to provide a press molding method and a press molding apparatus that improve the quality of a molded product by minimizing the size of).

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, according to the first aspect of the present invention, a punch and a die disposed opposite to the punch are provided, and a convex portion is formed on the side facing the die in the punch, and the punch includes A recess is formed on the opposite side of the punch, and at least one of the punch and the die is movably provided so that the punch and the die are relatively close to each other along the facing direction. Is a press molding method using a press molding apparatus in which the convex portion is fitted with a gap in the concave portion, the temperature of the punch and / or the die is changed, and the punch The gap between the convex part and the concave part is adjusted by adjusting the temperature difference between the convex part and the die.

  The press molding method according to claim 1, wherein the temperature difference between the punch and the die is adjusted by heating the punch and / or the die and heating the punch and / or the die. Alternatively, it is performed by maintaining the temperature of the die at a predetermined temperature.

  The press molding method according to claim 1, wherein the temperature difference between the punch and the die is adjusted by cooling the punch and / or the die, and the cooled punch and / or Alternatively, it is performed by maintaining the temperature of the die at a predetermined temperature.

  According to a fourth aspect of the present invention, the punch includes a punch and a die disposed so as to face the punch, and a convex portion is formed on the side facing the die in the punch, and the die faces the punch. A recess is formed on the side, and at least one of the punch and the die is movably provided so that the punch and the die are relatively close to each other along the facing direction, and the punch and the die are close to each other. By doing so, the convex part is a press molding apparatus fitted with a gap in the concave part, the punch and / or the die is provided with a temperature adjustment function, respectively, by the temperature adjustment function, The gap between the convex portion and the concave portion is adjusted by changing the temperature of the punch and / or the die and adjusting the temperature difference between the punch and the die. It is intended to.

  5. The press molding apparatus according to claim 4, wherein the temperature adjusting function detects a heating means for heating the punch and / or the die, and a temperature of the punch and / or the die. Temperature detecting means.

  6. The press molding apparatus according to claim 4, wherein the temperature adjusting function detects a cooling means for cooling the punch and / or the die, and a temperature of the punch and / or the die. Temperature detecting means.

  As effects of the present invention, the following effects can be obtained.

  That is, according to the press molding method and the press molding apparatus of the present invention, the softened material is pressed and sandwiched between the convex portion formed on the punch and the concave portion formed on the die, and the material is press molded. , The size of the gap formed between the outer peripheral surface of the convex portion and the inner peripheral surface of the concave portion (“extraction clearance”) can be reduced as much as possible to improve the quality of the molded product. Can be planned.

The partial cross section front view which showed the whole structure of the press molding apparatus which concerns on 1st Example of this invention. The partial cross section front view which showed the whole structure of the press molding apparatus which concerns on the 2nd Example of this invention.

  Next, embodiments of the invention will be described.

[Overall configuration of press forming apparatus 1 (first embodiment)]
First, the overall configuration of a press forming apparatus 1 in the first embodiment embodying the present invention will be described with reference to FIG.
In addition, regarding the following description, for convenience, the vertical direction in FIG. 1 is described as the vertical direction of the press forming apparatus 1.

The press molding apparatus 1 according to the present embodiment presses the softened material 100 while pressing the softened material 100 between the convex portion 2a formed on the punch 2 and the concave portion 3a formed on the die 3, and press-molds the material 100. It is a device that applies.
More specifically, the press molding apparatus 1 in the present embodiment heats the punch 2 and the die 3 individually, or heats one of the punch 2 and the die 3, and the temperature difference between the two is increased. By adjusting (temperature control) so as to be a predetermined value, the difference in expansion coefficient between the punch 2 and the die 3 after thermal expansion is adjusted, and the outer peripheral surface of the convex portion 2a and the inner peripheral surface of the concave portion 3a This is an apparatus that makes it possible to make the gap formed (hereinafter referred to as “pullout clearance”) as small as possible.

  In the present embodiment, a case will be described in which a laminated body composed of a plurality of electromagnetic steel sheets is used as the material 100, and a motor core (more specifically, a stator or the like; hereinafter the same) is press-formed as a molded product. The material and the molded product to be processed by the press molding apparatus according to the present invention are not limited to the material 100 and the motor core, and the molded product generally molded by press molding, Includes all of the underlying materials.

  The press molding apparatus 1 includes a pair of punches 2 and a die 3, a pair of punch holders 21 and a die holder 31, a control device 4 that controls the operation of the entire press molding apparatus 1, and the like.

The punch 2 and the die 3 are portions that are in direct contact with the material 100 when press forming the material 100.
The punch 2 and the die 3 are arranged to face each other and, as will be described later, through the punch holder 21 and the die holder 31 along the facing direction (in this embodiment, the vertical direction; the same applies hereinafter). At least one of the punch 2 and the die 3 is movably provided so as to be relatively close to each other.

In the punch 2, a convex portion 2 a that protrudes downward is formed on the side surface (the lower surface in the present embodiment) opposite to the die 3.
On the other hand, in the die 3, a concave portion 3a corresponding to the shape of the convex portion 2a is formed on the side surface (upper surface in the present embodiment) opposite to the punch 2.
In addition, these convex part 2a and the recessed part 3a are comprised so that a mutual fitting is possible.

Then, when the punch 2 and the die 3 are moved in a relatively close direction and are brought into contact with each other (hereinafter referred to as “mold closed state”), the convex portion 2a is formed on the concave portion 3a. It is fitted to the inner peripheral part (a space surrounded by the inner peripheral surface; the same applies hereinafter).
In the “mold closed state”, a “pull-out clearance” having a dimension value d is formed between the outer peripheral surface of the convex portion 2 a and the inner peripheral surface of the concave portion 3 a.

The punch holder 21 and the die holder 31 are parts that relatively move the punch 2 and the die 3 along the facing direction while fixing and holding them.
The punch holder 21 and the die holder 31 are arranged in the vertical direction (opposing direction with respect to the punch 2 and the die 3). The punch 2 is detachably fixed and held on the lower surface of the punch holder 21 with the convex portion 2a facing downward. On the upper surface of the die holder 31, the die 3 faces the concave portion 3a upward. It is fixed and held detachably in the opened posture.
That is, in the press molding apparatus 1, the punch holder 21, the punch 2, the die 3, and the die holder 31 are sequentially arranged from the top to the bottom, and the convex portion 2 a of the punch 2 and the concave portion 3 a of the die 3. Is located on the same axis.

The die holder 31 is provided with a lifting mechanism (not shown) such as a hydraulic cylinder, and the die holder 31 is lifted by the lifting mechanism so that the punch 2 and the die 3 are relatively close to each other. Moved.
Due to the rise of the die 3, the convex portion 2 a of the punch 2 is fitted into the inner peripheral portion of the concave portion 3 a of the die 3, and the punch 2 and the die 3 are in a “die closed state”.

  The object provided with the lifting mechanism is not particularly limited to the die holder 31, and at least one of the punch 2 and the die 3 moves so that the punch 2 and the die 3 are relatively close to each other. Any configuration is possible as long as it is possible. For example, the punch holder 21 may be provided with the lifting mechanism, or both the punch holder 21 and the die holder 31 may be provided with the lifting mechanism.

Here, the punch holder 21 and the die holder 31 are respectively provided with a first temperature adjustment function 25 and a second temperature adjustment function 35.
The first temperature adjusting function 25 and the second temperature adjusting function 35 directly heat the punch holder 21 and the die holder 31, and individually control the temperatures of the punch 2 and the die 3 through the punch holder 21 and the die holder 31, respectively. It is a function to adjust to.

The first temperature adjustment function 25 includes a first heating unit 22, a first temperature detection unit 23, and the like. The second temperature adjustment function 35 includes a second heating unit 32, a second temperature detection unit 33, and the like.
Since the first temperature adjustment function 25 and the second temperature adjustment function 35 have the same configuration, only the first temperature adjustment function 25 will be described below, and the second temperature adjustment function 35 will be described. The description about is omitted.

The first heating means 22 is a means for heating the punch 2 to a predetermined temperature and adjusting (temperature adjustment) via the punch holder 21.
The 1st heating means 22 is comprised by the known strip | belt-shaped electric heater etc., for example, and is affixed on the outer peripheral surface of the punch holder 21. FIG. Moreover, the 1st heating means 22 is electrically connected with the control apparatus 4 via an electrical cord etc.

The first heating means 22 is activated by an output signal from the control device 4 to heat the punch holder 21.
Then, the heat of the punch holder 21 is transmitted to the punch 2 and the punch 2 is heated.
That is, the first heating means 22 heats the punch 2 via the punch holder 21.

  The first heating means 22 is not limited to a belt-shaped electric heater as shown in this embodiment. For example, a separate burner (combustion device) may be provided for the press molding device 1. In addition, a piping path may be formed inside the punch holder 21 and the die holder 31, and an electromagnetic valve may be provided in the middle of the piping path to cause the temperature-controlled liquid to flow through the piping path.

The first temperature detection means 23 is a means for measuring the temperature of the heated punch 2 through the punch holder 21.
The first temperature detection means 23 is constituted by, for example, a known contact temperature sensor, and is disposed so as to always touch the outer peripheral surface of the punch holder 21. The first temperature detection means 23 is electrically connected to the control device 4 through an electric cord or the like.

Then, heating of the punch 2 (more specifically, the punch holder 21; the same applies hereinafter) by the first heating means 22 is started. The temperature of the punch 2 to be heated, that is, the temperature of the punch holder 21 that is equivalent to the punch 2 due to the effect of heat conduction, is detected one by one by a first temperature detection means 23 at a certain period, and the detected value is When the predetermined temperature is reached, the first heating means 22 is controlled by the control device 4 so that the temperature of the punch 2 (more specifically, the punch holder 21; the same applies hereinafter) is maintained at the predetermined temperature. The
As described above, the first temperature detecting means 23 detects the temperature of the punch 2 through the punch holder 21.

  The configuration of the first temperature detecting means 23 is not particularly limited to the contact type temperature sensor as shown in the present embodiment, and may be a non-contact type temperature sensor using infrared rays, for example. .

  Thus, in the press molding apparatus 1 in the present embodiment, the first temperature adjustment function 25 and the second temperature adjustment function 35 are provided for both the punch holder 21 and the die holder 31, respectively. The press molding apparatus according to the present invention is not limited to this.

  That is, the press molding apparatus 1 embodying the present invention is characterized by changing the temperature difference between the punch 2 and the die 3 and adjusting the difference in thermal expansion amount between the punch 2 and the die 3. Only one of the die holders 31 may be provided with the first temperature adjustment function 25 or the second temperature adjustment function 35.

The control device 4 includes a storage unit and a calculation unit, and the storage unit includes a program related to the operation of the first temperature adjustment function 25 and the second temperature adjustment function 35, as well as a lifting mechanism provided in the die holder 31. Programs relating to driving are stored in advance. Further, the control device 4 is provided with input means such as a touch panel and output means such as a monitor.
And the control apparatus 4 is comprised so that the operation | movement of the press molding apparatus 1 whole may be controlled.

[Molding method of press molding apparatus 1 (first embodiment)]
Next, a forming method of the press forming apparatus 1 in the first embodiment will be described with reference to FIG.

First, the die holder 31 is stopped at a predetermined lowermost predetermined position (hereinafter referred to as “lower limit position”), and the die 3 is most separated from the punch 2 (hereinafter referred to as “die”). In the press molding apparatus 1 in the “open state”), an electrical signal related to the start of operation of the press molding apparatus 1 (hereinafter referred to as “operation start command”) is input to the control device 4 via the input means. Is done.
Then, the control device 4 starts heating control for the punch holder 21 and the die holder 31 based on the “operation start command”.

  That is, the control device 4 starts the operation of the first heating unit 22 and the second heating unit 32 based on the “operation start command”, and the first heating unit 22 and the second heating unit 32 that have started the operation are Heating of the punch holder 21 and the die holder 31 is started.

  On the other hand, when the “operation start command” is input, the control device 4 thereafter performs the first temperature detection unit 23 and the controller at every predetermined time (hereinafter referred to as “measurement time”). The detected values of the temperature of the punch 2 and the die 3 by the second temperature detecting means 33 are inputted.

That is, during the operation of the press molding apparatus 1, the temperature of the punch holder 21 detected by the first temperature detection means 23 is input to the control device 4 one by one as the “current temperature (t1)” of the punch 2. Further, the temperature of the die holder 31 detected by the second temperature detecting means 33 is inputted to the control device 4 one by one as the “current temperature (t2)” of the die 3.
The “current temperature (t1)” and “current temperature (t2)” input to the control device 4 are temporarily stored in the storage unit of the control device 4.

Here, the “set temperature (T1)” and “set temperature (T2)” of the punch 2 and the die 3 are stored in advance in the storage unit of the control device 4.
The “set temperature (T1)” and “set temperature (T2)” are determined based on the temperature difference between the punch 2 and the die 3 at which the “extraction clearance” has a predetermined size. Is a preset temperature.

  In the control device 4, “current temperature (t 1)” and “current temperature (t 2)” temporarily stored in the storage unit, and “set temperature (T 1)” and “set temperature” that are also stored in the storage unit. (T2) "is compared with each other.

  As a result, for example, in the punch 2, when the “current temperature (t1)” has not yet reached the “set temperature (T1)” (t1 <T1), the first heating means 22 heats the punch holder 21. Will continue. On the other hand, when the “current temperature (t1)” reaches the “set temperature (T1)”, the control device 4 controls the first heating means 22 so as to hold the punch 2 at the “set temperature (T1)”. To do. When the “current temperature (t1)” exceeds the “set temperature (T1)”, the heating of the punch 2 by the first heating means 22 is temporarily stopped, and the temperature of the punch 2 is set to the “set temperature (T1)”. The first heating means 22 is controlled so that the temperature of the punch 2 is maintained at the “set temperature (T1)”.

  In the die 3, when the “current temperature (t2)” has not yet reached the “set temperature (T2)” (t2 <T2), the heating of the die holder 31 by the second heating means 32 is continued. The On the other hand, when the “current temperature (t2)” reaches the “set temperature (T2)”, the control device 4 controls the second heating means 32 so as to hold the die 3 at the “set temperature (T2)”. To do. When the “current temperature (t2)” exceeds the “set temperature (T2)”, the heating of the die 3 by the second heating means 32 is temporarily stopped, and the temperature of the die 3 is set to the “set temperature (T2)”. After the temperature decreases to “”, the second heating means 32 is controlled so that the temperature of the die 3 is maintained at “set temperature (T2)”.

Then, in both the punch 2 and the die 3, when the “current temperature (t1) (t2)” reaches the “set temperature (T1) (T2)”, press molding by the press molding apparatus 1 is started.
That is, the punch 100 and the die 3 are both heated to the “set temperature (T1) (T2)” and the material 100 made of a sheet-like laminate is placed on the press molding apparatus 1 in the “die open state”. Is put in a softened state in advance.

The input material 100 is disposed between the punch 2 and the die 3 so that the stacking direction is the same as the opposing direction of the punch 2 and the die 3.
Thereafter, the raising / lowering mechanism of the die holder 31 is controlled to be raised by the control device 4, and the die holder 31 is raised.

  The die holder 31 that has started to rise eventually reaches a predetermined uppermost predetermined position (hereinafter referred to as “upper limit position”). Then, the lifting mechanism is stopped by the control device 4, the die holder 31 is stopped at the "upper limit position", and the punch 2 and the die 3 are in the "die closed state".

Thus, when the state of the punch 2 and the die 3 changes to the “die closed state”, the material 100 is pressed while being sandwiched between the convex portion 2 a of the punch 2 and the concave portion 3 a of the die 3.
When the punch 2 and the die 3 are in the “mold closed state”, the material 100 is completely punched into a shape along the inner peripheral surface of the recess 3a, and the press molding is completed.

After the die holder 31 stops at the “upper limit position” and the press molding of the material 100 is completed, the lifting mechanism is controlled to be lowered by the control device 4, and the die holder 31 starts to descend.
The die holder 31 that has started descending eventually reaches the “lower limit position”. Then, the lowering control of the raising / lowering mechanism by the control device 4 is stopped, the die holder 31 is stopped at the “lower limit position”, the punch 2 and the die 3 are in the “die open state”, and the press-molded molded product (motor core) Is taken out from the recess 3 a of the die 3.

When the molded product (motor core) is taken out from the recess 3 a of the die 3, the material 100 is again fed into the press molding apparatus 1.
After that, as described above, the die holder 31 is raised and the punch 2 and the die 3 are in the “mold closed state”, so that the material 100 is press-molded, the die holder 31 is lowered, and the punch 2 and the die are moved. After 3 is in the “mold open state”, the press-molded product (motor core) is taken out from the recess 3 a of the die 3.
In this way, when the press molding of the material 100 is continuously repeated and a predetermined number of molded products (motor cores) are molded, the operation of the press molding apparatus 1 is completed.

  In the molding method in the press molding apparatus 1 of the present embodiment, the “current temperature (t1) (t2)” of the punch 2 and the die 3 is set by the control device 4 even after the press molding of the material 100 is started. , Each of them is monitored whether it is held at “set temperature (T1) (T2)”, and the punch 2 and the die 3 are always held at “set temperature (T1) (T2)” while the press molding apparatus 1 is in operation. As described above, temperature adjustment (temperature adjustment) is performed.

  Thus, in the press molding method and the press molding apparatus 1 in the present embodiment (first embodiment), the first temperature adjusting function 25 and the second temperature adjusting function 35 are provided for the punch holder 21 and the die holder 31. The temperature of the punch 2 and the die 3 is individually adjusted by individually heating the punch holder 21 and the die holder 31 using the first temperature adjusting function 25 and the second temperature adjusting function 35. It has a configuration.

  Thus, by adjusting the temperatures of the punch 2 and the die 3 individually, the temperature difference between the punch 2 and the die 3 can be freely changed, and based on this, the punch 2 and the die after heating are changed. 3 can be adjusted, and the size of the “pull-out clearance” (dimension value d in FIG. 1; the same applies hereinafter) can be freely changed.

Therefore, in the conventional press molding apparatus, the “clearance clearance” is set to a large value in advance so that variations due to these errors can be sufficiently absorbed in consideration of punch and die manufacturing errors and assembly errors. However, according to the press molding apparatus 1 in the present embodiment, the actual shape of the punch 2 and the die 3 (more specifically, the convex portion 2a and the concave portion 3a) are required. In addition, it is possible to freely adjust the size of the “pull-out clearance” while considering the assembly position and set the value as small as possible (approximately several μm).
Further, in the conventional press molding apparatus, the gap tends to gradually increase due to wear generated in the convex portions and the concave portions, but according to the press molding apparatus 1 in the present embodiment, these convex portions 2a and Since the temperature difference between the punch 2 and the die 3 can be changed according to the amount of wear generated in the recess 3a and the difference in thermal expansion between the punch 2 and the die 3 can be adjusted, It is possible to keep the thickness constant.

  From these facts, according to the press molding method and press molding apparatus 1 in the present embodiment (first embodiment), the size of the “punch clearance” is as much as possible as compared with the conventional press molding method and press molding apparatus. It becomes small and can always be kept constant, the occurrence of “working distortion” during press molding is reduced, and the quality of the motor core, which is a molded product, can be improved.

Moreover, in the press molding method and press molding apparatus 1 in the present embodiment (first embodiment), the first temperature adjusting function 25 and the second temperature are used as means for changing the temperature difference between the punch 2 and the die 3. The adjusting function 35 is used to individually “heat” the punch 2 and the die 3.
Therefore, for example, the first temperature adjustment function 25 and the second temperature adjustment function 35 can each be realized by a device having a relatively easy configuration such as a strip-shaped electric heater as shown in the present embodiment. In addition, there is no need to separately provide other devices having a complicated configuration, and the equipment cost does not increase.

According to the verification test conducted by the present inventor, when press molding is performed by the press molding apparatus 1 based on the molding method in the first embodiment, the size of the “punch clearance” is 20-30 [ It has been confirmed that it can be reduced to about 5 [μm] with respect to [μm].
And it has been found that the efficiency of a motor provided with a motor core (molded product) formed by such press molding is improved by about 3% compared to a conventional motor. On the basis of the above, it has been confirmed that when press molding is performed by the press molding apparatus 1, it is possible to reliably improve the quality of the molded product.

[Overall configuration of press forming apparatus 201 (second embodiment)]
Next, the overall configuration of the press forming apparatus 201 in the second embodiment that embodies the present invention will be described with reference to FIG.
In addition, regarding the following description, for convenience, the vertical direction in FIG. 2 will be defined as the vertical direction of the press molding apparatus 201.

The press molding apparatus 201 in the present embodiment (second embodiment) has the same main configuration as the press molding apparatus 1 in the first embodiment described above, while the first temperature adjustment function 25 of the press molding apparatus 1. And it replaces with the 2nd temperature control function 35, and is different from the press molding apparatus 1 by the point provided with the 1st temperature control function 225 and the 2nd temperature control function 235.
In addition, below, description about the structure similar to the press molding apparatus 1 in a 1st Example is abbreviate | omitted, and mainly the structure of the 1st temperature adjustment function 225 and the 2nd temperature adjustment function 235 is demonstrated.

The first temperature adjustment function 225 includes a first cooling unit 222, a first temperature detection unit 223, and the like. The second temperature adjusting function 235 includes a second cooling unit 232, a second temperature detecting unit 233, and the like.
Since the first temperature adjustment function 225 and the second temperature adjustment function 235 have the same configuration, only the first temperature adjustment function 225 will be described below, and the second temperature adjustment function 235 will be described. Description is omitted.

The first cooling means 222 is a means for cooling the punch 202 to a predetermined temperature and adjusting (temperature adjustment) via the punch holder 221.
The 1st cooling means 222 is comprised by the cooling unit which consists of the main-body part 222a, the cooling plate 222b, etc., for example.

  The main body 222a includes a tank for storing cooling water, a piping path for guiding the cooling water to the outside of the main body 222a, a discharge pump provided in the middle of the piping path, and the like. In addition, the cooling plate 222b is configured to have a sheet-like member having high thermal conductivity, a flow path arranged while meandering on the sheet-like member, and the like.

  The piping path of the main body part 222a and the circulation path of the cooling plate 222b are in communication with each other, and the cooling water discharged from the main body part 222a is guided again into the main body part 222a through the cooling plate 222b. . The main body 222 a is electrically connected to the control device 204 via an electric cord or the like, and the cooling plate 222 b is disposed along the outer peripheral surface of the punch holder 221.

In the first cooling means 222 having such a configuration, the main body portion 222a is operated by the control of the control device 204, and the cooling water discharged from the main body portion 222a is guided into the cooling plate 222b. As a result, the punch holder 221 is cooled by the first cooling means 222, and the punch 202 is cooled by heat conduction between the punch holder 221 and the punch 202. That is, the first cooling means 222 cools the punch 202 via the punch holder 221.
In addition, about the structure of the 1st cooling means 222, it is not limited to a cooling unit as shown in a present Example, For example, an air-cooled cooler etc. may be sufficient.

The first temperature detection means 223 is a means for measuring the temperature of the punch 202 after cooling via the punch holder 221.
The first temperature detection means 223 is constituted by, for example, a known contact temperature sensor, and is disposed so as to always come into contact with the outer peripheral surface of the punch holder 221. The first temperature detection means 223 is electrically connected to the control device 204 via an electric cord or the like.

After the cooling of the punch 202 (more specifically, the punch holder 221; the same applies hereinafter) is started by the first cooling means 222, the temperature of the punch 202, that is, the effect of heat conduction, is equivalent to the punch 202. The temperature of the punch holder 221 is detected by the first temperature detection means 223 one by one at regular intervals, and when the detected value reaches a predetermined temperature, the first cooling means 222 is The temperature of the punch 202 (more specifically, the punch holder 221; the same applies hereinafter) is controlled to be maintained at a predetermined temperature.
As described above, the first temperature detecting means 223 detects the temperature of the punch 202 via the punch holder 221.

  The configuration of the first temperature detecting means 223 is not particularly limited to the contact temperature sensor as shown in the present embodiment, and may be, for example, a non-contact temperature sensor using infrared rays. .

  Thus, in the press molding apparatus 201 in the present embodiment (second embodiment), the first temperature adjustment function 225 and the second temperature adjustment function 235 are provided for both the punch holder 221 and the die holder 231, respectively. However, the press molding apparatus according to the present invention is not limited to this.

  That is, the press forming apparatus 201 embodying the present invention is characterized by changing the temperature difference between the punch 202 and the die 203 and adjusting the difference in thermal expansion between the punch 202 and the die 203. Only one of the die holders 231 may be provided with the first temperature adjustment function 225 or the second temperature adjustment function 235.

[Molding method of press molding apparatus 201 (second embodiment)]
Next, a forming method of the press forming apparatus 201 in the second embodiment will be described with reference to FIG.

The molding method in the second embodiment has the same main procedure as the molding method in the first embodiment described above. On the other hand, as a procedure for changing the temperature difference between the punch 202 and the die 203, these punch 202 are used. And the point which is done by cooling the dice 203 individually is different.
In the following description, the description of the part having the same procedure as the molding method in the first embodiment is omitted, and the punch 202 and the die 203 mainly by the first temperature adjustment function 225 and the second temperature adjustment function 235 are omitted. The cooling procedure will be described.

First, in the press molding apparatus 201 in which the punch 202 and the die 203 are in the “die open state”, an “operation start command” is input to the control device 204 via the input means.
Then, the control device 4 starts cooling control for the punch holder 221 and the die holder 231 based on the “operation start command”.

  That is, the control device 204 starts the operation of the main body portion 222a of the first cooling means 222 and the main body portion 232a of the second cooling means 232 based on the “operation start command”, and the main body portions 222a. 232a causes cooling water to flow into the cooling plates 222b and 232b, and starts cooling the punch holder 221 and the die holder 231.

  On the other hand, when the “operation start command” is inputted, the control device 204 thereafter performs the temperature of the punch 2 and the die 3 by the first temperature detection means 223 and the second temperature detection means 233 for each “measurement time”. The detected value is input.

That is, during the operation of the press molding apparatus 1, the temperature of the punch holder 221 detected by the first temperature detection means 223 is input to the control device 204 one by one as the “current temperature (t21)” of the punch 202. Further, the temperature of the die holder 231 detected by the second temperature detecting means 233 is input to the control device 204 one by one as “current temperature (t22)” of the die 203.
The “current temperature (t21)” and “current temperature (t22)” input to the control device 204 are temporarily stored in the storage unit of the control device 4.

Here, the “set temperature (T21)” and “set temperature (T22)” of the punch 202 and the die 203 are stored in the storage unit of the control device 204 in advance.
The “set temperature (T21)” and “set temperature (T22)” are based on the temperature difference between the punch 202 and the die 203 at which the “extraction clearance” has a predetermined size. Is a preset temperature.

  In the control device 4, “current temperature (t 21)” and “current temperature (t 22)” temporarily stored in the storage unit, and “set temperature (T 21)” and “set temperature” that are also stored in the storage unit. (T22) "is compared with each other.

  As a result, for example, in the punch 202, when the “current temperature (t21)” is still higher than the “set temperature (T1)” (t1> T1), the punch holder 221 is cooled by the first cooling means 222. Will continue. On the other hand, when the “current temperature (t21)” decreases to the “set temperature (T21)”, the control device 4 keeps the punch 202 at the “set temperature (T21)”. To control. When the “current temperature (t21)” is lower than the “set temperature (T21)”, the cooling of the punch 2 by the first cooling means 222 is temporarily stopped, and the temperature of the punch 2 is set to the “set temperature ( After the temperature decreases to “T21)”, the first cooling means 222 is controlled so that the temperature of the punch 2 is maintained at the “set temperature (T21)”.

  When the “current temperature (t22)” is still higher than the “set temperature (T22)” in the die 203 (t2> T2), the cooling of the die holder 231 by the second cooling means 232 is continued. On the other hand, when the “current temperature (t22)” reaches the “set temperature (T22)”, the control device 4 controls the second cooling means 232 so as to hold the die 3 at the “set temperature (T22)”. To do. When the “current temperature (t2)” is lower than the “set temperature (T2)”, the cooling of the die 3 by the second cooling means 232 is temporarily stopped, and the temperature of the die 3 is set to the “set temperature ( After the temperature has decreased to “T2)”, the second cooling means 232 is controlled so that the temperature of the die 3 is maintained at the “set temperature (T2)”.

  Then, when “current temperature (t21) (t22)” reaches “set temperature (T21) (T22)” in both the punch 202 and the die 203, press molding by the press molding apparatus 201 is started.

That is, similar to the molding method in the first embodiment described above, the material 100 made of a sheet-like laminate is put into the press molding apparatus 201 in a softened state in advance.
The input material 100 is disposed between the punch 202 and the die 203 so that the stacking direction thereof is the same as the opposing direction of the punch 202 and the die 203.

  Then, the die holder 231 is raised, and the punch 202 and the die 203 are in the “mold closed state”, whereby the material 100 is press-molded. After the material 100 is press-molded, the die holder 231 is lowered and the punch 202 and the die 203 are in the “open mold state”, and then the press-molded product (motor core) is taken out from the recess 203 a of the die 203. .

  Thereafter, the raw material 100 is again input to the press molding apparatus 201, and the press molding is continuously repeated. When a predetermined number of molded products (motor cores) are molded, the operation of the press molding apparatus 201 is performed. Ends.

  Similar to the molding method in the first embodiment described above, in the molding method in the press molding apparatus 201 of this embodiment, the punch 202 and the die are controlled by the controller 204 even after the press molding of the material 100 is started. It is monitored whether the “current temperature (t21) (t22)” of 203 is maintained at “set temperature (T21) (T22)”, and the punch 202 and the die 203 are always in operation during the operation of the press molding apparatus 201. Is maintained at the “set temperature (T21) (T22)”.

  Thus, in the press molding method and press molding apparatus 201 in the present embodiment (second embodiment), the first temperature adjustment function 225 and the second temperature adjustment function 235 are provided for the punch holder 221 and the die holder 231. The temperature of the punch 202 and the die 203 is individually adjusted by individually cooling the punch holder 221 and the die holder 231 using the first temperature adjusting function 225 and the second temperature adjusting function 235. It has a configuration.

  As a result, like the press forming method and press forming apparatus 201 in the first embodiment described above, the size of the “punch clearance” is as small as possible and always constant as compared with the conventional press forming method and press forming apparatus. Therefore, the occurrence of “working distortion” during press molding is reduced, and the quality of the motor core that is a molded product can be improved.

Further, in the press molding method and press molding apparatus 201 in the present embodiment (second embodiment), the first temperature adjustment function 225 and the second temperature are used as means for changing the temperature difference between the punch 202 and the die 203. The adjustment function 235 is used to individually “cool” the punch 202 and the die 203.
Therefore, compared with the press molding method and press molding apparatus 1 in the first embodiment described above, the punch 202 and the die 203 are not in a high temperature state, and even a material made of a member having a relatively low melting temperature, It is possible to improve the quality of a molded product by reducing the occurrence of “working distortion” during press molding.

  As described above, as shown in the first embodiment and the second embodiment described above, the press molding method embodying the present invention is provided with the punch 2 (202) and facing the punch 2 (202). A convex portion 2a (202a) is formed on a side of the punch 2 (202) facing the die 3 (203), and the punch 2 is formed on the die 3 (203). A recess 3a (203a) is formed on the side facing the (202), and the punch 2 (202) and the die 3 (203) are relatively close to each other along the facing direction. 202) and at least one of the dice 3 (203) is movably provided, and the convex 2a (202a) is formed into the concave by bringing the punch 2 (202) and the dice 3 (203) close to each other. a (203a) is a press forming method using a press forming apparatus 1 (201) which is fitted with a “punching clearance” (gap; dimension value d in FIG. 1), the punch 2 (202 ) And / or the temperature of the die 3 (203) is changed, and the temperature difference between the punch 2 (202) and the die 3 (203) is adjusted, whereby the convex portion 2a (202a) and the concave portion 3a are adjusted. The “extraction clearance” (gap) between (203a) is adjusted.

  Further, as shown in the first and second embodiments described above, the press molding apparatus embodying the present invention is provided with a punch 2 (202) and facing the punch 2 (202). A convex portion 2a (202a) is formed on a side of the punch 2 (202) facing the die 3 (203), and the punch 2 is formed on the die 3 (203). A recess 3a (203a) is formed on the side facing the (202), and the punch 2 (202) and the die 3 (203) are relatively close to each other along the facing direction. 202) and at least one of the dice 3 (203) is movably provided, and the convex 2a (202a) is formed into the concave by bringing the punch 2 (202) and the dice 3 (203) close to each other. a press forming apparatus 1 (201) fitted to a (203a) with a “pull-out clearance” (gap; dimension value d in FIG. 1), the punch 2 (202) and / or the die 3 (203) includes a first temperature adjustment function 25 (225) and / or a second temperature adjustment function 35 (235), respectively, and these first temperature adjustment function 25 (225) and / or second temperature adjustment function. By changing the temperature of the punch 2 (202) and / or the die 3 (203) by 35 (235) and adjusting the temperature difference between the punch 2 (202) and the die 3 (203), The “extraction clearance” (gap) between the convex portion 2a and the concave portion 3a (203a) is adjusted.

  By having such a configuration, according to the press molding method and press molding apparatus 1 (201) in the present embodiment (first embodiment and second embodiment), the convex portion formed on the punch 2 (202). 2a (202a) and the concave portion 3a (203a) formed in the die 3 (203), the softened material 100 is pressed while being sandwiched, and the convex portion 2a ( 202a) and the inner peripheral surface of the concave portion 3a (203a) can be reduced as much as possible, and the quality of the molded product can be improved. be able to.

That is, according to the press molding method and press molding apparatus 1 (201) in the present embodiment (first embodiment and second embodiment), the actual punch 2 (202) and die 3 (203) (more specifically, In consideration of the shape and assembly position of the convex part 2a (202a) and concave part 3a (203a), the size of the “pull-out clearance” is freely adjusted so as to be as small as possible (approximately several μm). It becomes possible to set.
Further, the temperature difference between the punch 2 (202) and the die 3 (203) is changed based on the amount of wear generated in the convex portion 2a (202a) and the concave portion 3a (203a), and the difference in thermal expansion amount is adjusted. Therefore, it is possible to always keep the size of the “extraction clearance” constant.
Therefore, it is possible to keep the size of the “punch clearance” as small as possible and always constant, reduce the occurrence of “working distortion” during press molding over a long period of time, and improve the quality of the molded product. It can be maintained.

  Further, as shown in the first embodiment, in the press molding method embodying the present invention, the temperature difference between the punch 2 and the die 3 is adjusted by adjusting the punch 2 and / or the die 3. The temperature of the heated punch 2 and / or the die 3 (“current temperature (t1)” and / or “current temperature (t2)”) is changed to a predetermined temperature (“set temperature (T1)” and / Or “set temperature (T2)”).

  Further, as shown in the first embodiment described above, in the press molding apparatus 1 embodying the present invention, the first temperature adjustment function 25 and / or the second temperature adjustment function 35 are the punch 2 and / or the A first heating means 22 and / or a second heating means 32 for heating the die 3, and a first temperature detecting means 23 and / or a second temperature detecting means 33 for detecting the temperature of the punch 2 and / or the die 3. , And is configured to have.

  By having such a configuration, according to the press molding method and the press molding apparatus 1 in the present embodiment (first embodiment), for example, by a device having a relatively easy configuration, such as a strip-shaped electric heater. In addition, the first temperature adjustment function 25 and the second temperature adjustment function 35 can be realized, respectively, and it is not necessary to separately provide devices having a complicated configuration, and the equipment cost does not increase.

  Further, as shown in the second embodiment, in the press molding method embodying the present invention, the temperature difference between the punch 202 and the die 203 is adjusted by cooling the punch 202 and / or the die 203. Then, the temperature of the cooled punch 202 and / or the die 203 (“current temperature (t21)” and / or “current temperature (t22)”) is set to a predetermined temperature (“set temperature (T21)” and / or Or “set temperature (T22)”).

  In addition, as shown in the second embodiment described above, in the press forming apparatus 201 embodying the present invention, the first temperature adjusting function 225 and / or the second temperature adjusting function 235 is the punch 202 and / or the A first cooling means 222 and / or a second cooling means 232 for cooling the die 203; a first temperature detecting means 223 and / or a second temperature detecting means 233 for detecting the temperature of the punch 202 and / or the die 203; , And is configured to have.

  By having such a configuration, according to the press molding method and press molding apparatus 201 in the present embodiment (second embodiment), compared with the press molding method and press molding apparatus 1 in the first embodiment described above, Even if the punch 202 and the die 203 are not in a high temperature state, even if the material is made of a material having a relatively low melting temperature, the occurrence of “working distortion” at the time of press molding can be reduced to improve the quality of the molded product. It can be planned.

DESCRIPTION OF SYMBOLS 1 Press molding apparatus 2 Punch 2a Convex part 3 Dies 3a Concave 22 First heating means 23 First temperature detection means 25 First temperature adjustment function 32 Second heating means 33 Second temperature detection means 35 Second temperature adjustment function 201 Press molding Device 202 Punch 202a Convex part 203 Die 203a Concave part 222 First cooling means 223 First temperature detection means 225 First temperature adjustment function 232 Second cooling means 233 Second temperature detection means 235 Second temperature adjustment function

Claims (6)

A punch and a die disposed opposite to the punch, wherein the punch has a convex portion formed on the side facing the die, and the die has a concave portion formed on the side facing the punch. And at least one of the punch and the die is movably provided so that the punch and the die are relatively close to and separated from each other in the opposing direction. A press molding method using a press molding apparatus in which a portion is fitted with a gap in the concave portion,
By changing the temperature of the punch and / or the die and adjusting the temperature difference between the punch and the die, the gap between the convex portion and the concave portion is adjusted,
The press molding method characterized by the above-mentioned. Adjustment of the temperature difference between the punch and the die is
The punch and / or the die is heated, and the temperature of the heated punch and / or the die is maintained at a predetermined temperature.
The press molding method according to claim 1, wherein: Adjustment of the temperature difference between the punch and the die is
The punch and / or the die is cooled, and the temperature of the cooled punch and / or the die is maintained at a predetermined temperature.
The press molding method according to claim 1, wherein: A punch and a die disposed opposite to the punch, wherein the punch has a convex portion formed on the side facing the die, and the die has a concave portion formed on the side facing the punch. And at least one of the punch and the die is movably provided so that the punch and the die are relatively close to and separated from each other in the opposing direction. A press molding apparatus in which a portion is fitted with a gap in the recess,
The punch and / or the die are each provided with a temperature control function,
By changing the temperature of the punch and / or the die by the temperature adjustment function, and adjusting the temperature difference between the punch and the die, the gap between the convex portion and the concave portion is adjusted.
A press molding apparatus characterized by that. The temperature control function is
Heating means for heating the punch and / or the die;
Temperature detecting means for detecting the temperature of the punch and / or the die;
Configured with
The press molding apparatus according to claim 4, wherein The temperature control function is
Cooling means for cooling the punch and / or the die;
Temperature detecting means for detecting the temperature of the punch and / or the die;
Configured with
The press molding apparatus according to claim 4, wherein

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