JPS598457B2 - Laminated core manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for manufacturing a laminated iron core for electrical equipment, and more particularly to an improvement in an apparatus for manufacturing a laminated iron core using an in-mold caulking method known in Japanese Patent Publication No. 52-156305 and the like.

FIG. 1 is a schematic diagram showing a longitudinal section of a conventional laminated core manufacturing apparatus, and FIG. 2 is a plan view showing a state in which a core plate is formed.

A core plate 1, which is a material for the product laminated core, is guided into an upper mold 3 and a lower mold 4 via guide rollers 2. When the upper mold 3 descends, the iron core plate 1 is drilled at the first and second stations as shown in FIG. Outline cutting and culling are performed. Upper mold 3-1
Each time the core plate 1 is raised and lowered, a predetermined pitch of the iron core plate 1 is sent by the guide roller 2, and when this operation is sequentially repeated, the iron core plates are stacked in the station ① of the lower mold 4.
On the other hand, a micro switch 6 that detects the vertical movement of the upper mold 3
The thickness of the core plate 1 is measured by the plate thickness sensor T before it enters the mold at the timing obtained from The data is sequentially shifted and stored until the completed part is reached. Then, the control device 8 sequentially adds and totals the plate thicknesses of the mold at the first station. Now, the position of the punch 10 at the first station can be varied by a solenoid 9 as shown in FIGS. 3 and 4.
The control device 8 controls the solenoid 9 to form caulking protrusions 11 on the core plate 1 as shown in FIG. 3 when the total plate thickness addition value is less than a preset target value for the stratified core. When the added value reaches the target value, the punch 10 is projected to form a through hole as shown in FIG. 4, and at the same time, the added total value is set to zero. Then, the laminated iron core plates 5 in the mold of the first station are formed into an unbonded state for each set target thickness, and become a product laminated iron core of a predetermined thickness. By the way, a normal product laminated core is formed by stacking 40 to 100 core components, and the stacking thickness setting value is, for example, a plate thickness of 0.
For a 5 mm iron core plate, the length is 20 to 501 m. The dimensional accuracy of the product varies depending on the stacking thickness, but for example, if the specified stacking thickness is 5.
For the one with zero pass, it is about 50mm±0.511, and if the current standard value of the plate thickness is 0.51mI, 100 sheets will be laminated. In this case, the control device 8 controls the solenoid 9.
(referred to as a through-hole solenoid) is controlled to form a through-hole when the sum total value is equal to or greater than a target value T, and T is determined by the following equation. Lamination thickness setting value 501tQ1
Substituting the plate thickness of 0.511, T=49.7501! Therefore, the value of the added total laminate thickness H of the product laminated core obtained at this time is 49.7511≦H and 50.25 m1L.

On the other hand, the allowable stacking thickness of the product core is 50 m as mentioned above.
1±0.511, the allowable measurement error for the stacking thickness is ±0.2511. Therefore, the thickness measurement error for one iron core plate is ±0.0025 by dividing this value by 100 pieces.
It becomes 11. In other words, the plate thickness is 0.51! The iron core plate of soil 2
．． A plate thickness sensor 7 that can measure with an absolute accuracy of 5 μm is required. Furthermore, this plate thickness sensor must have a fast response speed capable of measuring while the core plate 1 is sequentially and intermittently fed at high speed. However, among commercially available sensors, there is currently no sensor that satisfies the above-mentioned accuracy other than a contact-type plate thickness sensor that measures the thickness by directly contacting the iron core plate. When a contact-type plate thickness sensor is used, since the sensor and the core plate are in contact with each other, the sensor gradually wears out when used for a long time, and accuracy is no longer guaranteed.
Therefore, it is necessary to perform regular maintenance over a short period of time. Furthermore, there are many cases where the specifications cannot be satisfied in terms of the response speed. Therefore, according to the conventional method, it is not possible to control the stacking thickness with high precision due to insufficient sensor accuracy.

The present invention provides a method that uses a general low-precision non-contact sensor to perform high-precision stack thickness control that could not be achieved with conventional methods, and is different from conventional methods in principle. .

The present invention will be explained based on FIGS. 5 and 6 of one embodiment.

In the figure, the parts numbered 1 to 6 and 9 to 11 are the same as those described in FIG. 1 of the conventional example. Reference numeral 13 denotes a mark hole punch, which is connected to a mark solenoid 12, and when the solenoid is operated, a mark hole 14 as shown in FIG. 6 can be formed in the iron core plate at that time.

Reference numeral 15 denotes a known mark hole proximity sensor (details will be described later) that can obtain an output signal proportional to the distance to the mark hole 14, and is installed inside the station of the lower mold 4, and is attached to the core with the mark hole 14 of the product laminated iron core. The position of the plate 16 is detected.

The analog output of sensor 15 is converted into a digital signal by AD converter 18 and input to control device 17 .
The control device 17 incorporates a microcomputer and is capable of performing addition, subtraction, multiplication, and division calculations and control of the solenoids 9 and 12. Reference numeral 19 indicates a core plate in which a through hole is formed so that the upper and lower core plates are not caulked, and the product laminated core is separated along this portion.

The portion below the core plate 19 is a finished laminated core, and the portion above is a semi-finished product. Mark hole proximity sensor 15
The relationship between the distance t between the core plate 16 with the mark hole 14 and the center line and the sensor output E8 is given by assuming that the nominal thickness of the core plate is 0.5.
11, it becomes as shown in Fig. 7, and as the iron core plate 16 approaches, the output Es of the sensor gradually increases, and when the center line of the proximity sensor and the iron core plate 16 coincide, the maximum EWI is reached.
It becomes L and becomes smaller again as you move away from it. In the mold, as the iron core plate 16 with the mark hole approaches the proximity sensor 15 in the moving direction shown in FIG. 8, and the value of the output Es falls between A and B in FIG. Between the output Es and the proximity distance t (negative value), t=C, ES+C2(C,
Since an approximate relational expression (C2 is a constant) holds true, this expression is registered in the control device 17 in advance. Then, the control device 17 can calculate the value of the proximity distance t from the sensor output Es. Now, the iron core plate 1 with the mark hole 14
Assuming that 6 is in the mold, a method for determining the accurate stacking thickness of the product core from the proximity distance t of the core plate 16 determined from the output Es of the sensor will be described.

FIG. 9 is an extracted part of FIG. 5 related to the principle of the present invention, in which the core plate is pushed downward by the iron core plate formed one after another each time the mold moves up and down, and the mark hole is detected by the proximity sensor 15. It shows the point in time when a certain iron core plate 16 was detected.
In the figure, the length from the entrance of the laminated iron core plate of the lower mold of the second station to the center line of the proximity sensor 15 is L (Mm).
, the distance between the center lines of the proximity sensor 15 and the core plate 16 is t (77! m) (negative value), and the number of laminated core plates B stacked above the core plate 16 is Including N pieces. Now, considering the average plate thickness Ta of these N iron core plates, since the center line of the iron core plate 16 has been detected, it can be calculated as 0.5, so Ta can be determined by the following equation. By the way, the JIS standard for electromagnetic rigid plates used in iron cores for electrical equipment allows a tolerance of ±10%.

Therefore, the average thickness of the iron core plate is, for example, if the standard thickness is 0.
5m7! If it is L, 0.45mm-0.55m1
Varies within the range of L. However, when considering the core plate as a raw material divided into certain lengths, comparing the average thickness of one part of the core plate to the next part shows that the situation in the manufacturing process of the core plate used does not change suddenly. Therefore, the average thickness of each plate is almost the same. That is, the average plate thicknesses of the core plate group B above the core plate 16 with the mark hole in FIG. 5 and the core plate group A below it can be considered to be approximately equal, and this can be confirmed by actual measurement. Further, the average plate thickness of a certain number of iron core plates to be formed and sequentially stacked on the iron core plate group B is approximately equal to the average plate thickness of the iron core plate group B. Therefore,
Now, if the core plate 19 in core group B is a core plate with a through hole, the n core plates above the iron gap plate are semi-finished products in the mold, and their stacking thickness is: It may be considered that it is equal to the result of multiplying the average plate thickness Ta calculated previously by the number of plates n, that is, Taxn.

Each time the upper mold 3 rises and falls once, adding the average plate thickness to this multiplication result will result in the stacking of the semi-finished products at that point in time, so this value becomes the target value. At this time, if the through hole solenoid 9 is controlled to form through holes in the iron core plate, a product with accurate lamination thickness can be obtained. Now, if the average plate Ta of the iron core plates in the mold can be calculated accurately in this way, highly accurate stacking thickness control can be performed.

In order to do this, L, t of equation (2) in the prone state shown in FIG.
, N needs to be known by the control device 17. The value of L is a constant that is stored in advance in the control device 17 by actually measuring the distance from the upper end surface of the lower mold to the center of the proximity sensor 15.

Also, as mentioned above, from the relationship shown in Figure 7, the sensor output E8
The value of t can be determined by inputting the value of t to the pedestal device 17 via the A-D converter 18. On the other hand, since the value of N is the number of core plates stacked after the mark hole solenoid 12 is operated, it becomes a known value in the control device 17 by counting the signals from the micro switch 6.
Therefore, by applying these values to equation (2), the average plate thickness can be calculated. If the Fbl unit 17 is configured to have a built-in microcomputer, processing such as data storage and calculation can be performed with a simple configuration. On the other hand, since the average plate thickness needs to be newly calculated one after another, the solenoid 12 that forms the iron core plate with the marked hole for calculating the average plate thickness is activated when the proximity sensor 15 detects the marked hole 14. , that is, the operation is started when the state becomes as shown in FIG. Then, core plates with marked holes are fed into the mold every N sheets, and the average plate thickness can be calculated. Furthermore, even if the solenoid 12 is operated unconditionally every time a certain number of sheets are used, the calculation of the average sheet thickness can be updated in the same way. By the way, at the beginning of operating the manufacturing equipment, the aforementioned timing for operating the mark hole solenoid 12 cannot be obtained, so the mark hole solenoid 12 is operated unconditionally to produce a core plate with mark holes. A control circuit is built into the control device 17. Now, in the conventional equipment, the product thickness is 501m±0.51m.
In order to obtain a value of 1, the measurement error of the plate thickness must be ±0.002511 according to the calculation described above.

In this example, since the average plate thickness is determined by calculation, the measurement error x of L+t in equation (2) only needs to be within a predetermined range, which is equivalent to the conventional measurement error of 0.0025 m11t per sheet. In order to do this, x=0.0025n×(
The number of iron core plates from the upper end surface of the mold to the sensor may be L+TN).

From equation (2), since Ta is N21+0.5, for example, L+t+40m1, . If ta+0.5mm, then N+
80, so x=0.2m! becomes.

Therefore, it is necessary to use a mark hole proximity sensor 15 with a measurement error of 0.2U1 or less, but if this level of accuracy is required, the mold 4 with the structure shown in Fig. 10 and the air Back pressure sensor 20 [for example, A made by Tokyo Seimitsu Co., Ltd.
-E converter (model E-DT-AG) and a dedicated amplifier], the mark hole proximity sensor 15 can be configured. FIG. 10 is a cross-sectional view of the lower mold 4 near the sensor,
Air with a pressure of several Kf/(1771) passes through the back pressure sensor 20, passes through the jet nozzle 21, the mark hole 14, and exits from the exhaust port 22.The jet nozzle 21 is a square hole with a height of 0.5 mI. When there is a mark hole 14, air flows and the air back pressure decreases as shown in Fig. 10, but if there is no mark hole, the air does not flow and the air back pressure increases. The back pressure changes approximately in proportion to the cross-sectional area where the mark hole 14 and the jet nozzle 21 overlap.As a result, the output characteristics are as shown in Fig. 7.As mentioned above, the output Es of the mark hole proximity sensor 15 and the proximity distance The approximate relationship between t and t has an error of 0.2
m! Since the following is permissible, even if the linearity is poor in the portions A and B in FIG. 7, there is no particular problem. So far, we have explained the mark hole proximity sensor using compressed air, but the proximity distance of the mark hole on the iron core plate is 0.5 m from the tip.
7! It is also possible to detect by embedding in the mold 4 an eddy current type proximity sensor having a sharp directivity and having a size of approximately L. In the present invention, the mark hole 14 is formed and detected by the proximity sensor 15, but for example, paint is sprayed on the iron core plate as a mark on the part of the iron core plate that does not come in direct contact with the mold, and this paint is used as a mark. A similar principle can be used for a method of detecting marks using a sensor. However, the distance L from the upper end surface of the lower mold to the center of the proximity sensor must also be measured with an error of 0.211 or less, but it is easy to measure with this accuracy using calipers, micrometers, etc. .

In the explanation so far, the mark hole solenoid 12 and the through hole solenoid 9 have been considered to be controlled separately, but as shown in FIG. Mark holes 14 may also be formed. At this time, it becomes N2n in FIG. So far, we have only described the case where there is one semi-finished product between the upper end of the lower mold and the center of the proximity sensor 15, but if there is one product and one semi-finished product as shown in Fig. If the number of plates is Nl,n, then the average plate thickness Ta can be obtained as follows.

On the other hand, when the mark hole solenoid 9 is controlled separately, the average plate thickness Ta is calculated using equation (3) using the stacked number Nl,n of the iron core plate with the mark hole. As described above, according to the present invention, the sensor accuracy is about 0.2 m1, and the thickness of the laminated iron core plate can be calculated with high accuracy.

Therefore, compared to the conventional method, maintenance of the sensor section to maintain the precision of the manufacturing device is much easier. Moreover, the cost of the sensor becomes cheaper.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a vertical cross section of a conventional laminated core manufacturing device, and FIG. 2 is a plan view showing the lying state in which the core plate is formed.
FIG. 3 is a diagram of the formation of caulking protrusions of the core plate, FIG. 4 is a diagram of the formation of through holes, FIG. 5 is a schematic longitudinal cross-sectional view of a laminated core manufacturing apparatus according to an embodiment of the present invention, and FIG. 6 7 is a characteristic diagram of the proximity sensor, FIG. 8 is a diagram showing the positional relationship between the proximity sensor and the core plate with mark holes in the mold, and FIG. FIG. 9 is a detailed diagram showing the principle of an embodiment, FIG. 10 is a schematic diagram of a pneumatic sensor as one embodiment, and FIG. 11 is a detailed diagram showing the principle of another embodiment. 6...Micro switch for counting the number of laminated sheets, 9.
...Through hole solenoid, 12, 21...
・Solenoid for mark hole, 14... Mark hole on iron core plate, 15... Proximity sensor, 17...
・Control device, 18...A-D converter, 20...
...Air back pressure type proximity sensor.

Claims (1)

[Claims] 1 A lamination method in which caulking protrusions are provided on a part of the core plate, and the thickness of the product laminated core is determined by intermittent punching control of the protrusions, which is laminated using the mutual fitting and caulking action of the protrusions. In core manufacturing equipment, a marking mechanism that selectively marks the side surface of the punched portion of the core plate and a proximity sensor that outputs a signal corresponding to the proximity distance of the marked core plate during manufacture are installed in the mold. a means for measuring a laminated thickness dimension fixedly provided to the core; a means for generating a timing signal each time the manufacturing apparatus laminates one sheet; a means for presetting a target value for the laminated thickness dimension of the product core; An intermittent punching mechanism that can electrically control the operation of whether or not to form a child part and the mark mechanism are operated at any time, and the value obtained by counting the timing signals thereafter is defined as the number of laminated sheets, and the mark is The laminated thickness dimension calculated from the measurement value obtained when a proximity sensor detects a certain iron core plate is divided by the number of laminated sheets to calculate the average plate thickness value of one iron core plate, and A laminated iron core manufacturing apparatus characterized by comprising: a control device that adds and totals the average plate thickness for each of the timing signals, and controls the operation of the punching mechanism when the cumulative value exceeds the target value.