JPS6149397B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an electroforming device.

Electroforming is widely used to manufacture parts and molds with shapes that are difficult to machine.

Generally, the shape of the electrode mold on which the electroformed shell is electrodeposited is complex, and the electrodeposition surface is rich in undulations and irregularities of varying degrees of slope and depth.

Therefore, in electroforming, the most important thing is generally the transfer accuracy of the electroform, and the thickness of the electroformed shell is not required to have very high precision except for special machine parts.

However, it goes without saying that it is desirable for the electroformed shell to have a uniform thickness or a desired thickness distribution.

That is, if the electroformed shell has a portion that is too thin, its strength and service life will be reduced, and if the electroformed shell has a portion that is too thick, materials, power, working time, etc. will be wasted. Moreover, these problems become even more serious when the electroformed shell is further machined to be finished into a mechanical part or the like.

Conventionally, in order to give each part of an electroformed shell a desired thickness, a large number of electrodes are used and are appropriately distributed on the electrodeposited surface, so that each electrode has a substantially specific local voltage. A method is adopted in which casting is carried out and a desired overall thickness distribution is obtained.

However, with this method, it is difficult for even a highly skilled person to achieve the desired accuracy without making corrections based on several test machinings, and therefore it is difficult to achieve the desired accuracy by repeatedly making many parts of the same shape. Although it is good for electroforming, it is extremely inconvenient when manufacturing molds for various purposes in small quantities.

In addition, when using electroformed shells as molds or electrodes for electrical machining, it is generally desirable to deposit thinly on the convex parts of the mold and thickly on the concave parts; This requirement goes against the natural tendency of electrodeposition, and it has been difficult to control the amount of electrodeposition.

The present invention has been made based on the above-mentioned viewpoints, and its purpose is to easily and reliably achieve the desired results without requiring special skill or experience, and without using test processing or the like. An object of the present invention is to provide an electroforming device that can obtain an electroformed shell having a thickness distribution.

Therefore, the gist of the present invention is to provide a large number of ultrasonic thickness gauges in the electroforming mold close to the surface of the electroformed shell to be electrodeposited, and to detect the growth rate of the electroformed shell using these. The object is to increase or decrease the amount of current applied to the electrode near the part in accordance with the slowing speed, thereby obtaining an electroformed shell having a desired thickness distribution.

Hereinafter, details of the present invention will be explained with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of the electroforming apparatus according to the present invention, FIG.
4 is a partial circuit diagram showing a variation of the embodiment shown in FIG. 1, and FIG. FIG. 3 is a distribution explanatory diagram of ultrasonic oscillation elements.

In FIGS. 1 and 2, 1 is an electroforming tank, 2 is a plastic mold whose predetermined electrodeposition surface 2a has been subjected to conductive treatment, 3, 4 and 5 are ultrasonic oscillation elements, 6, 7 and 8 are electrodes made of electroformed material;
9 is an electroforming shell, 10 is an electroforming bath, 11 is a DC power source for electroforming, 12 is a contact of a main power relay (not shown), 13, 14 and 15 are electrodes 6,
7 and 8 are switching elements for energizing and electroforming; 16, 17 and 18 are semi-fixed resistors; 19, 20 and 21 are pulse oscillators for operating the ultrasonic oscillation elements 3, 4 and 5, respectively; 22 , 23 and 24 are resistors, 25 is a constant voltage power supply circuit, 26, 27 and 28 are resonance detection circuits, 29 is a timer for setting standard working time Ts, 30
is a pulse counter, 31 is an input/output conversion circuit, 32
is a starting push button switch, 33 to 41 are
RS bistable element, 42 to 51
is an AND circuit, 52 to 55 are OR circuits, 56
58 is an inhibit circuit, 59, 60 and 61 are timers for setting the energization time, 62 to 67 are monostable elements, 68 is a ring counter, 69, 70 and 71 are preset counters, and 72 is a work end command pulse signal. It is an output terminal.

The ultrasonic oscillation elements 3, 4, and 5 are all provided inside the electromold 2 in close proximity to the electrodeposition surface 2a of the electromold 2, as shown in FIG. In Figure 2,
2a is a plated surface to enable electrodeposition, 2b is a chamber for accommodating an ultrasonic oscillation element, 2c is a plastic member constituting a lid, and 2d is a lead wire 3a, 4.
This is a plastic member that seals around a or 5a.

The thickness d of the plastic member 2c is sufficiently shorter than the half wavelength of the ultrasonic wave passing through the plastic member 2c,
Further, it is provided in close contact with the ultrasonic oscillation element so as not to create a gap, and its outer end surface is plated together with the surface portion constituting the electrodeposition surface of the electrode mold.

Further, in this embodiment, the ultrasonic oscillation frequency is selected such that one wavelength of the ultrasonic wave passing through the electroformed shell is equal to the desired finished thickness D of the electroformed shell.

Furthermore, in this example, the ultrasonic oscillation elements 3, 4, and 5 correspond to the electrodes 6, 7, and 8, respectively, and are provided in the center of the electroforming area of each electrode. , this configuration is made to simplify the drawing and explanation; in reality, more electrodes and ultrasonic oscillation elements are provided, and the two form a higher-order organic bond. be.

The electromold provided with the ultrasonic oscillation elements 3, 4, and 5 is set in the electroforming bath 1, and electrodes supported by a support device (not shown) are disposed and wired as shown.

Standard working time required to perform desired electroforming
Ts is calculated and set in the timer 29. The timer 29 oscillates short pulses at times T ₁ and T ₂ corresponding to Ts/2±ΔT after starting, respectively, to increment the counter 30.

When starting electroforming, the push button switch 32 is pressed. In such a case, although not shown, the power of the entire control circuit is turned on, the RS bistable elements 36 to 38 are set, and the counter 30 and ring counter 6 are turned on.
8, preset counters 69 to 71, and
RS bistable elements 33 to 35,
39 to 41 are reset, timer 29 is started, and at the same time relay contact 12 is closed.

Also, at this time, the timer 6
0 starts. This timer 60 is a timer that sets a standard energization time τ ₀ for each electrode once, and is configured so that its output remains in state 1 until time τ ₀ has elapsed after starting. Also timer 59
and 61 are set to a time τ ₋ shorter than this time τ ₀ and a time τ ₊ longer than this time τ 0 , respectively.

On the other hand, the inhibit circuits 56, 57 and 58 control the first bit 68-1 of the ring counter, respectively.
This is an OR circuit that uses the outputs of the second bit 68-2 and the third bit 68-3 as inhibition negation inputs, and the inputs other than the inhibition negation inputs are timers 59, 60 and 6.
This is the output of 1.

Therefore, in the illustrated state, the first bit 68-1 of the ring counter 68 is in state 1;
Since the output of the timer 60 is also in state 1, the output of the inhibit circuit 56 is in state 1, the switching element 13 becomes conductive, and the electrode 6 performs electroforming.

Then, the predetermined time τ ₀ has elapsed, and the timer 60
When the output of is in state 0, the inhibit circuit 56
The output also becomes state 0, and the switching element 13 is cut off. At this time, however, the monostable element 62 oscillates an output pulse and advances the ring counter 68, so that the 1st display position becomes the 2nd bit. 68-2, the monostable element 66 is triggered, and its output pulse passes through the AND circuit 46 and the OR circuit 53 to restart the timer 60.

Therefore, this time, the output pulse of timer 60 is
It passes through the inhibit circuit 57, turns on the switching element 14, and causes the electrode 7 to perform electroforming.

Then, when the time τ ₀ has elapsed again, the conduction of the switching element 14 is cut off by the same process as described above, and the conduction of the switching element 15 becomes conductive, so that electroforming is performed by the electrode 8, and the same cycle is repeated thereafter. Electroforming progresses repeatedly. Such energization control for various electrodes may be performed by dividing n electrodes into a plurality of groups of m electrodes each, or by using other energization control means, and it is not necessarily necessary to conduct energization in rotation.

Then, when the electroformed shell 9 grows on the electrodeposited surface 2a and its thickness matches the half wavelength of the ultrasonic wave passing through the electroformed shell, a resonance phenomenon occurs, and the electroformed shell 9 remains stationary within the electroformed shell. A wave appears. In such a case, the ultrasonic oscillation element also resonates and its oscillating voltage changes rapidly, so this resonance is immediately detected by the resonance detection circuit.

Now, it is assumed that the thickness D of the electroformed shell to be manufactured is equal to the wavelength of the ultrasonic wave propagating within the electroformed shell, and the thickness of the electroformed shell is changed at a time T ₂ after a time T ₁ has elapsed from the start of electroforming. It is assumed that D should be reached before .

However, here, T ₁ =Ts/2-ΔT T ₂ =Ts/2+ΔT.

In other words, when electroforming is performed at such a speed, by continuing electroforming under the same conditions, it is possible to achieve good electroforming within the desired thickness tolerance range after the standard working time Ts has elapsed. This is what gives you the shell.

However, for some reason, for example, due to inappropriate electrode arrangement or current distribution ratio, an error has occurred in the growth rate of the electroformed shell, and the ultrasonic oscillation elements 3,
It is assumed that the electroformed shell growth in the vicinity of 4 and 5 becomes as shown in the lines and in FIG. 3.

In such a case, resonance occurs at a time t ₁ earlier than the allowable time T ₁ in the portion of the electroformed shell 9 where the ultrasonic oscillation element 3 faces, and the resonance detection circuit 26 oscillates an output pulse.

On the other hand, the displayed value of the counter 30 is 000 before time T ₁ has elapsed after the start of electroforming, 00 after T ₁ has elapsed and before T ₂ has elapsed, and
The input/output conversion circuit 31 is configured so that the value becomes 010 after T ₂ elapses, and when the resonance detection circuits 26, 27 and 28 respectively oscillate an output pulse, the input from the counter 30 is 000. oscillates an output pulse from its output terminals a, b, and c, respectively, and when it is 010, it oscillates an output pulse from its output terminals d, e, and f, respectively, but the input from the counter 30
When the value is 001, the configuration is such that no output pulse is oscillated.

Therefore, in the above case, while the input from the counter 30 is 000, the resonance detection circuit 26 operates and oscillates an output pulse, so the input/output conversion circuit 31 outputs an output pulse from its output terminal a. oscillates, and for this reason, the RS bistable element 3
3 is inverted to the set state, and 36 is inverted to the reset state.

In this case, the first bit 68-1 of the ring counter 68 becomes state 1, and when the electrode 6 is energized to perform electroforming, the output pulse of the monostable element 65 cannot pass through the AND circuit 45. Instead, the signal passes through 42 and starts the timer 59 via the OR circuit 52.

Therefore, the setting time τ _- of the current 59 is shorter than the setting time τ ₀ of the current 60, and therefore, the electroforming time through the electrode 6 is shortened, so that the time t ₁ is shorter as shown in FIG. Thereafter, the growth rate of the electroformed shell in the vicinity of the ultrasonic oscillation element 3 is slowed down, and the growth rate of other parts of the electroformed shell is relatively sped up.

As electroforming progresses in this state, resonance in the opposing electroformed shells of the ultrasonic oscillator 3 will eventually end,
Next, at time _t2 shown in FIG. 3, resonance occurs in the opposing portions of the ultrasonic oscillation element 4.

However, at this time, the displayed value of the counter 30 is 001.
Therefore, the input/output conversion circuit 31 does not generate any output, and the energization time for electroforming does not change.

As the electroforming progresses further, resonance occurs on the opposing surface of the ultrasonic oscillation element 5, and the resonance detection circuit 28
oscillates an output pulse.

If the oscillation time t ₃ of this output pulse is earlier than T ₂ , the energization time to each electrode is not changed and electroforming is allowed to proceed as it is, but as shown in Figure 3. , if resonance occurs after T ₂ , then the display on the counter 30 will be 010.
Since the input/output conversion circuit 31 oscillates an output pulse from its output terminal f, the RS
The bistable element 38 is reversed to the reset state, and the bistable element 41 is reversed to the set state,
The energization time for the electrode 8 is changed to τ+ set in the timer 61. This τ+ is longer than _τ0 , so that the rate of electrodeposition in the vicinity of the ultrasonic oscillation element 5 is increased, and the rate of electrodeposition in other parts is relatively reduced.

Thereafter, electroforming is continued until the initially set time Ts elapses. By that time, the thickness of the electroformed shell 9 becomes equal to one wavelength λ of the ultrasonic wave, resonance occurs within the electroformed shell again, and each resonance detection circuit 2
6, 27 and 28 oscillate output pulses again. These pulses are counted by preset counters 69, 70 and 71, respectively, which in this embodiment have a preset value of 2, so that each of these preset counters has a corresponding resonance. The output of counting this second input pulse from the sensing circuit will be state 1. When the outputs of all the preset counters become state 1, the output of the AND circuit 51 becomes state 1, and the end of the work is commanded.

In the above explanation, it is assumed that the electroformed shell growth rate is too high near the ultrasonic oscillation element 3 and too small near the ultrasonic oscillation element 5 in the first half of electroforming.
However, whatever the slow speed in these parts, when the electroforming operation is approximately half completed,
It will be clear that locally appropriate electroforming rate modifications may be made.

As mentioned above, when using the apparatus of the present invention, the electrodeposition speed of each part is checked during electroforming, and the electrodeposition speed is corrected based on the results. An electroformed shell having a thickness distribution can be obtained.

It should be noted that a wide variety of variations are possible for the embodiments described above.

First, in addition to the timers whose set times are τ ₋ , τ ₀ and τ ₊ , there are also timers that set the set times τ ₋ and τ ₊₊ , which have a larger amount of correction. Time Ts/2-3ΔT, Ts/2-ΔT, Ts/2+ΔT, and T
The output pulse is oscillated at s/2+3 ΔT, and the energization time for each electrode is controlled in five stages.Then, the frequency of the ultrasonic wave used is increased so that its half wavelength is equal to the desired electroformed shell thickness D. It is conceivable to set the electrodeposition rate to 1/3 or an integer fraction of 4 or more, and to adjust the electrodeposition rate every time the thickness of the electroformed shell reaches an integral multiple of a half wavelength.

In addition, from the viewpoint of control reliability and power efficiency, it is recommended that the amount of current applied to each electrode be controlled mainly by the amount of current applied, but this control is also possible by controlling the amount of current applied. Even if it is
Moreover, it can also be achieved by controlling only the amount of current to be applied instead of controlling the current application time.

For example, in the embodiment shown in FIG. 1, if circuits 16', 17' and 18' in FIG. 4 are used instead of semi-fixed resistors 16, 17 and 18, each It is possible to change the energizing current as well as the energizing time of the electrode.

Therefore, in Figure 4, 16-1 to 3, 17-
1 to 3 and 18-1 to 3 are adjustment resistors, 16-4 to 6, 17-4 to 6 and 18-4 to 6 are switching elements, and 33' to 41' are respectively shown in FIG. R.S.
Terminals 56' to 58' are connected to the set output terminals of bistable elements 33 to 41, and are connected to output terminals of OR circuits 56 to 58, respectively.

Therefore, the adjustment resistors 16-1, 17-1 and 1
The resistance values of 8-1 are all the same R ₁ and the same 16
-2, 17-2 and 18-2 have the same resistance value R ₂ , 16-3, 17-3 and 1
The resistance values of 8-3 are all equal R ₃ ,
And R ₁ > R ₂ > R ₃ .

For this reason, for example, when energizing from the electrode 6, the RS bistable element 36 is in the set state, the timer 60 is activated, and the energization is performed for a time _τ0 per time, the switching element 16-5 is turned on and energization is carried out with the standard current, but for example, if the RS bistable element 33 or 39 is in the set state and the timer 59 or 61 respectively sets _{the time τ - or} the extended time When energizing τ ⁺ , each switching element 1
Instead of 6-5, 16-4 or 16-6 is turned on, and the current applied decreases or increases with the energization time.

Further, for example, the configuration of the electroforming tank 1, the arrangement of the electroforming mold 2 and the electrodes 6 to 8, etc. in the above-mentioned embodiments do not limit the electroforming tank in the scope of the claims.

That is, even in the illustrated embodiment, the electroforming bath 10
Not only can the new electroforming bath 10 be supplied by flowing in, radiating, or spouting from outside the tips 6 to 8 with continuous or intermittent overflow,
The electroforming bath 10 in the tank 1 can be stirred or the like by appropriate means, and the electroforming bath within the scope of the claims may also include, for example, an electroforming bath receiving tank provided with an upwardly open receiving tank. A crosspiece made of a suitable material is provided over the opening of the electrode 6, and the electroforming mold 2 is placed on the crosspiece by attaching it to an auxiliary electroforming frame tank as described in Japanese Utility Model Publication No. 52-21711. 8 is attached to this auxiliary frame bath in the same way, and therefore electroforming mold 2 is attached to electroforming bath 1.
Electroforming is performed by pumping up the electroforming bath from the lower receiving tank and radiating it from diagonally above, that is, by circulating it, and the upper part of the crosspiece is not immersed in the bath. Various modifications are possible, such as making the electroforming tank covered with an exhaust means.

In addition, the number and arrangement method of electrodes and ultrasonic oscillation elements are selected appropriately depending on the purpose of electroforming, required thickness accuracy, dimensions and shape of the electroform, and the number of both is not necessarily determined. They are not considered to be the same number.

FIG. 5 shows an example of a desirable planar arrangement of electrodes and ultrasonic oscillation elements. In the figure, 80,
The 〓 mark indicated by 80 is an ultrasonic oscillation element provided in the electric mold, and the ● marks indicated by 90 and 90 are electrodes provided at positions facing the ultrasonic oscillation elements 80 and 80, respectively. The Γ marks 91 and 91 are electrodes arranged in a mesh pattern at intermediate positions.

Thus, the amount of current supplied to one electrode 90 is controlled only by a control circuit including one ultrasonic oscillation element 80 facing it, but the electrode 91 located at an intermediate position has an electric current flowing within its electroforming area. It has three ultrasonic oscillation elements, and the amount of current supplied thereto is organically controlled by a control circuit that includes them.

Furthermore, the configuration of the circuit shown in FIG.
The design of the ultrasonic thickness gauge can be changed freely within the scope of the purpose of the present invention.For example, the ultrasonic thickness gauge may not be of the resonant type as mentioned above, but may be of the echo type or other type, and other circuit elements may also be different. Of course, known ones may be substituted, and the present invention encompasses all of these.

Since the present invention is constructed as described above, it is possible to easily and reliably produce a good electroformed shell having a desired thickness distribution, no waste material, and no too thin parts. Moreover, it can be manufactured in a minimum amount of working time.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the electroforming device according to the present invention, Fig. 2 is a partially enlarged sectional view showing details of the ultrasonic oscillation element provided in the electroforming mold, and Fig. 3
The figure is a time chart to explain its operation and effect, Figure 4 is a partial circuit diagram showing a variation of the embodiment shown in Figure 1, and Figure 5 is an electrode and ultrasonic oscillation diagram showing still another embodiment. FIG. 3 is an explanatory diagram of the distribution of elements. 1: electroforming tank, 2: electromold, 3, 4, 5, 80: ultrasonic oscillation element, 6, 7, 8, 90, 91: electrode,
9: Electroformed shell, 10: Electroformed bath, 19, 20, 21:
Pulse oscillator, 25: Constant voltage power supply circuit, 26, 2
7, 28: Resonance detection circuit, 29, 59, 60, 6
1: Timer, 30: Counter, 31: Input/output conversion circuit, 68: Ring counter, 69, 70, 7
1: Preset counter.

Claims (1)

[Scope of Claims] 1. An electroforming device comprising the components described in the following items a to e. a Electroformed mold with multiple ultrasonic oscillation elements arranged directly below the electroplated surface of the electroformed shell. b. An electroforming tank in which the electroforming mold is housed or installed, a desired electroforming bath is injected or radiated onto the electroforming mold, and the electroforming bath is arranged with respect to a plurality of electrodes and the electroforming mold to perform electroforming. c. A power supply circuit that can form an electroformed shell by applying current between the electromold and each of the plurality of electrodes. d Electrodeposition speed consisting of an oscillation circuit provided for each ultrasonic oscillation element installed in the electromold and a detection circuit that uses each oscillation wave to detect the electrodeposition speed of the electroformed shell in the vicinity of the ultrasonic oscillation element. Detector. e. An energization control circuit that controls the amount of current applied to the electrodes that perform electrodeposition on the portion in accordance with the slowness of the electrodeposition speed detected by the electrodeposition speed detector. 2. The electroforming apparatus according to claim 1, wherein the energization control circuit is a circuit that controls the duty factor or energization time of the energization pulse to each electrode. 3. The electroforming apparatus according to claim 1, wherein the energization control circuit is a circuit that controls the energization current to each electrode. 4. The electroforming apparatus according to claim 1, wherein the energization control circuit is a circuit that controls the duty factor or energization time of the energization pulse to each electrode, and the energization current.