JPS6327940Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used when performing wire cut electrical discharge machining.

[Conventional technology]

One of the metal processing techniques is wire cut electrical discharge machining.

As shown in Figure 8, wire cut electric discharge machining involves applying an impulse voltage of about 60 to 300 V between the workpiece 1 and the tool wire 2 (usually a brass wire). However, intermittent spark discharge is performed, and the workpiece 1 is machined by utilizing the wear phenomenon that occurs at that time.

Since machining will not proceed if the part 4 is exposed to the atmosphere during machining, the insulating liquid 3 (machining liquid) is continuously supplied to the portion 4 to be machined. Note that, hereinafter, the shape of the entire part to be machined will also be given the same reference numeral 4, and will be referred to as a "machining line" or a "machining planned line."

Wire cut electrical discharge machining has the following two features.

・Extremely high processing accuracy.

- Process the workpiece 1 using the wire 2 in a jig saw style. Therefore, it is suitable for hollowing. Even in Figure 8, part 1a is the intended item, 1
Part b is the part to be cut off. In this specification as well, we will proceed with the case where part 1a is the target item.

Wire cut electric discharge machining is usually used to make outer molds for powder molding by taking advantage of the above two characteristics.

Since wire cut electric discharge machining itself is well known, only the names of the parts in the wire cut electric discharge machine 10 shown in FIG. 8 will be described below, and their explanations will be omitted.

11... NC device 12... Control circuit 13... Servo circuit 14... X-axis motor 15... Y-axis motor 16... Table 17... Supply reel 18... Take-up reel 19... Guide 20... Guide 21... Brake 22... Take-up roller 23... Pump 24... Insulating liquid tank 25... Processing power source Here, it should be made clear that FIG. 8 is extracted from the following literature.

Name: Wire-cut electric discharge machining technology Supervisor: Nagao Saito Author: Kazuhiko Kobayashi, Eiji Senbokuya Publisher: Nikkan Kogyo Shimbun Publication date: May 31, 1988 There are two types of wire-cut electric discharge machine 10. One is for rough machining the workpiece 1. Others process the workpiece 1 with high precision. Hereinafter, the former will be referred to as a general-purpose wire-cut electric discharge machine, and the latter will be referred to as a high-precision wire-cut electric discharge machine.

Each part of a high-precision wire-cut electrical discharge machine is made with much more precision than a general-purpose wire-cut electrical discharge machine. Therefore, highly accurate machining can be achieved. Naturally, a high-precision wire-cut electric discharge machine is more expensive than a general-purpose wire-cut electric discharge machine.

By the way, in order to obtain a high-precision article (product) 1a by wire-cut electrical discharge machining, the workpiece (material) 1 is processed at least twice by the wire-cut electrical discharge machine 10, and in the final machining process, the workpiece (material) 1 is processed by the wire-cut electrical discharge machine 10 at least twice. It is necessary to process using an electrical discharge machine.

This is due to the following reason.

That is, the workpiece 1 (material) generally contains residual stress (this is caused by hardening or the like) inside it. For this reason, once the workpiece 1 is processed, residual stress is released after processing, and the finished product 1a is distorted, albeit very slightly. This is because it is necessary to carry out processing again.

Note that processing for the second and subsequent times is usually performed not only once but twice or thrice.

Wire cut electric discharge machining, which consists of a plurality of machining steps, has conventionally been carried out by one of the following two methods. In order to simplify the explanation, this specification will proceed with an example in which the final product 1a is completed with only two processes. The first rough machining will be referred to as the "first machining", and the second finishing machining (high precision machining) will be referred to as the "second machining".

Both the first machining and the second machining are performed using the same wire cut electric discharge machine. In this method, the workpiece 1 may remain fixed to the table 16 of the wire-cut electrical discharge machine from beginning to end. However, as a wire cut electric discharge machine, it is naturally necessary to use a high precision wire cut electric discharge machine.

The first machining is performed with a general-purpose wire-cut electric discharge machine, and the second machining is performed with a high-precision wire-cut electric discharge machine. In this method, after the first machining is completed, the table 1 of the general-purpose wire cut electric discharge machine
It is necessary to remove the workpiece 1 from the machine 6 and attach it to the table 16 of a high-precision wire-cut electrical discharge machine.

[Problem that the invention attempts to solve]

The above method had the following problems.

As mentioned above, a high-precision wire-cut electric discharge machine can perform extremely high-precision machining, but even with such an excellent machine, the first machining is still only a rough machining process. In other words, it is simply a matter of applying The reason for this is that the workpiece 1 itself contains residual stress, as described above. That is, no matter how highly accurate the machining (first machining) is with a high-precision wire-cut electrical discharge machine, the item 1a will be distorted due to residual stress after machining. Therefore, in this method, it is wasteful to use an expensive high-precision wire-cut electric discharge machine for the first machining.

The above method does not have the above problems. However, instead, the following problems arose.

That is, regardless of the first machining and the second machining, when wire cut electric discharge machining is performed, centering work must be performed on the workpiece 1 (or item 1a). In this case, one has to work through a centering hole provided in part 1a of the article. Therefore, centering work is very time consuming. This is the problem with the method described above.

Let me explain this in a little more detail. To that end, first, we will explain what "centering" is.

The centering operation is not an operation of finding the center of the workpiece 1, but an operation of specifying the position of the workpiece 1 (or item 1a) with respect to the wire 2.
The reason why it is necessary to determine the position of the workpiece 1 (or item 1a) in relation to the wire 2 is as follows.

- The workpiece 1 (or item 1a) is placed on the table 16 and moves together with the table 16,
However, - The movement of the table 16 with respect to the wire 2, that is, the position of the processing line 4 with respect to the wire 2, is predetermined by the NC device 11 (FIG. 8).

Specifically, the centering operation involves determining the position of the workpiece 1 with respect to the table 16, and adjusting the position of the wire 2.
This is the task of identifying the reference position of the

To position the workpiece 1 relative to the table 16, as shown in FIG.
A reference surface 28 is provided. Further, in order to specify the reference position of the wire 2, a centering hole 29 is provided in the workpiece 1. For centering, a reference surface 28 and a centering hole 29 are required. All of these must be processed with extremely high precision.

Here, the reference plane 28 and the centering hole 29 must be provided in the part of the article 1a, not in the cut-off part 1b. This point is important. The reason for this will be explained.

That is, in the above method, after the first processing is completed,
Workpiece 1 (at this time, item 1a) is removed from table 16 of a general-purpose wire-cut electrical discharge machine. Then, for the second machining, table 1 of the high precision wire cut electric discharge machine
6, such item 1a is attached. Even at this time, centering work must be performed using the reference plane 28 and centering hole 29. When performing this centering work, the inner portion 1b of the processed line 4 has already been cut off and is no longer present. Therefore, a reference surface 28 for centering is provided in this portion 1b, and
Centering holes 29 cannot be provided. This is,
The reference plane 28 and the centering hole 29 are connected to the part 1 of the product.
This is the reason why it must be provided in a.

In the above method, centering is performed based on the reference plane 28 and centering hole 29 provided in the part of the article 1a in both the first processing and the second processing.

In this case, as can be seen from FIG. 9, since the processing line 4 is located at the center of the workpiece 1, the centering operation was performed using the reference plane 28 and centering hole 29 located at the part of the workpiece 1a. After that, in order to start wire cut electrical discharge machining, the following three steps must be performed.

・ First, Figure 10 (Figure 10 is the X-
The wire 2 is cut at the X cross-sectional view.

- Next, insert the head 27 of the wire into the start hole 46.
move it to the specified position.

- Next, connect the wires 2. Thus, in the above method, there was a problem that the centering work was very time-consuming due to the above three steps.

It should be noted that, even more troublesome, in the above method, after the first machining is completed, the item 1a is removed from the table 16 of the general-purpose wire-cut electric discharge machine;
Again, it is necessary to attach it to the table 16 of the high-precision wire-cut electrical discharge machine. Therefore, the above-mentioned centering operation is required twice. The above method also requires a lot of effort in this respect.

Even with the above method, a similar problem occurs as long as the reference plane 28 and centering hole 29 are provided in the article 1a. However, in the above case, since it is not necessary to remove the workpiece 1 from the table 16, the centering hole 29 can be provided in the cut-off portion 1b. For example, the start hole 46 and the centering hole 29 may also be used. Therefore, in the above-mentioned method, the problem that "centering takes a lot of effort" does not occur.

Note that depending on the type of product, it may be impossible to provide the reference surface 28 and centering hole 29 for centering on the product 1a (for example, if such a product exists) ). In such a case, the above method cannot of course be used, and the wire cut electric discharge machining must be performed using the above method.
Therefore, we have no choice but to accept the "waste" mentioned earlier.

The present invention has been made in order to solve the problems of such conventional techniques.

Here, the technical problems of the present invention will be stated again as follows. In other words, the technical problem of the present invention is:
The aim is to solve the following two problems (a) and (b).

(a) Uneconomical nature of using the above method (b) The above method is inefficient due to the time-consuming centering work [Means for solving the problem] Achieving this technical problem In order to (namely, solve the problems of the above-mentioned conventional technology), in the present invention, it is proposed to use the following jig.

Here, the wire-cut electric discharge machining jig according to the present invention is a jig that is attached to a workpiece for centering work in wire-cut electric discharge machining, and has an outer plate made of a flat plate. , and an inner plate which is also made of a flat plate, and the outer plate has an opening in the center and can be fixed to the workpiece. A reference surface is provided on the outer periphery for determining the position of the workpiece with respect to the table of the wire cut electric discharge machine, and the inner plate is fitted tightly and removably into the opening of the outer plate. The inner plate has a centering hole bored in its center for determining the reference position of the wire, and the centering hole is connected to the outer periphery of the inner plate by a slit. It is characterized by

[Effect]

When performing centering work using the wire cut electric discharge machining jig according to the present invention, the centering hole is located not in the part of the workpiece but in the part to be cut off (inside the machining line).

Therefore, after performing the centering work, wire cut electric discharge machining can be started directly. In other words, there is no need to cut the wire, move the wire head, and reconnect the wire.

In this way, the centering work does not take much time and inefficiency due to the centering work does not occur.

Therefore, it is extremely easy to perform the first machining with a general-purpose wire-cut electric discharge machine and the second machining with a high-precision wire-cut electric discharge machine.

Furthermore, since there is no need to provide a centering hole in the workpiece, even for items where it is impossible to provide a centering hole in the workpiece, the first machining is performed using a general-purpose wire-cut electrical discharge machine, and the second This machining can be performed using a high-precision wire-cut electrical discharge machine.

The structure (means and effect) of the present invention will become clearer from the following examples, so the examples will be described next.

〔Example〕

1A and 1B are front views of a wire cut electric discharge machining jig according to a first embodiment of the present invention.

Wire cut electrical discharge machining jig 3 according to this embodiment
3 is composed of the following two parts.

- Outer plate 31 (see a in FIG. 1) - Inner plate 32 (see b in FIG. 1) The outer plate 31 is composed of a circular flat plate in which a circular opening 34 is provided. Inner plate 3
2 is composed of a circular flat plate. The inner plate 32 can be snugly fitted into the opening 34 of the outer plate 31.

Both the outer plate 31 and the inner plate 32 have a thickness of about 3 mm. Outer plate 31
and the outer diameter of the inner plate 32 are shown in FIG. 2 (FIG. 2 is a top view of the wire cut electric discharge machining jig 33 of this embodiment attached to the workpiece 1). It is determined according to the size of the workpiece 1 and the size of the machining line (planned machining line) 4. That is, the outer plate 31 is smaller than the workpiece 1, and the inner plate 32 is larger than the processing line 4.

Returning to FIG. 1, a reference surface 28 is provided on the outer periphery 35 of the outer plate 31. As shown in FIG. Inner plate 3
2 is provided with a centering hole 29. The centering hole 29 is connected to the outer periphery 41 of the inner plate 32 by a slit 38. The width of the slit 38 is set to be large enough to allow the wire 2 (see FIG. 3, FIG. 3 is a sectional view taken along the line "--" in FIG. 2) to pass through.

In FIG. 1a, 42 is the outer plate 31
This is a bolt hole through which a bolt is passed for fixing the workpiece 1 to the workpiece 1. As can be seen from Figure 2, workpiece 1
A start hole 46 is bored approximately at the center of the hole. The diameter of the centering hole 29 of the inner plate 32 is made smaller than the diameter of the start hole 46.

Wire cut electrical discharge machining jig 3 according to this embodiment
The usage of 3 is as follows (a), (b), (c), (d), (e), (f)
Explain in this order.

In this embodiment, wire cut electrical discharge machining is performed by the method described above.

(a) In Figs. 2 and 3, 16 represents the table of a general-purpose wire-cut electric discharge machine.
When carrying out the first processing, first, as shown in FIG. 2, the outer plate 31 is fixed to the bolt 4.
5 and fixed to the surface 44 of the workpiece 1.
Then, the inner plate 32 is fitted into the opening 34 of the outer plate 31. At this time, as shown in FIG. 2, the centering hole 29 is positioned approximately in the center of the start hole 46.
The diameter of the inner plate 32 is preset so that the outer periphery 41 of the inner plate 32 is located outside the processing line 4 .

(b) Next, based on the reference plane 28, the position of the workpiece 1 with respect to the table 16 of the general-purpose wire-cut electric discharge machine is determined. This is done manually by the operator using a dial indicator (not shown).

(c) Once the position of the workpiece 1 with respect to the table 16 has been determined, as shown in FIG. Determine the position.

This work will be explained with reference to FIGS. 4 and 5. In addition, FIG. 4 and FIG. 5 are for explanation,
It should be noted that the drawing is somewhat different in dimension from FIGS. 2 and 3.

FIG. 4 shows the direction of movement of the table 16. As can be seen from a in FIG. 4 (a in FIG. 4 is a top view of b in FIG. 4), the moving directions of the table 16 are Y(+), Y(-), and X(+). ,
It is X (-).

First, as shown in a, b, and c of FIG. 5, the table 16 (FIG. 4) is moved in the Y (-) direction and the Y (+) direction to determine the center position in the Y direction. This position is the one shown in c. Next, as shown at d, e, and f in FIG. 5, the table 16 (the fourth
) in the X (-) direction and the X (+) direction to determine the center position in the X direction. This position is f
is shown. This position is also the center position in the Y direction. Therefore, the position indicated by f becomes the reference position of the wire 2 after all.

In addition, in order to determine the reference position of the wire 2,
When placing the inner plate 32 on the surface 44 of the workpiece 1 in (A) above, the direction of the slit 38 is
Needless to say, care must be taken not to coincide with the direction and the Y direction.

(d) Next, in FIG. 2, by lifting the inner plate 32 upward and pulling it out in the direction of arrow P,
Remove inner plate 32 from outer plate 31. Needless to say, the direction of the arrow P is on the extension line of the slit 38.

(E) In FIG. 2, after the inner plate 32 is pulled out in the direction of arrow P, the first processing is performed.

(f) When the first machining is completed, remove the workpiece 1 from the general-purpose wire cut electric discharge machine. At this time, the workpiece 1 is a product 1a (but has been roughly processed). The article 1a removed from the general-purpose wire-cut electric discharge machine is again attached to the table of the high-precision wire-cut electric discharge machine. Then, centering is performed. This is exactly the same as described for the general-purpose wire-cut electric discharge machine ((a) to (d) above), so the explanation thereof will be omitted.

In this embodiment, as described above, the wire cut electrical discharge machining jig 33 is used to perform the centering work, and as can be seen from FIG. It is located not in the part 1b but in the part 1b to be cut off.

Therefore, after performing the centering work, wire cut electric discharge machining can be started directly. In other words, it is no longer necessary to cut the wire 2, move the head 27 of the wire 2, and connect the wire 2 again.

In this way, the centering operation does not take much time and there is no room for inefficiency due to the centering operation.

Therefore, it is extremely easy to perform the first machining with a general-purpose wire-cut electric discharge machine and the second machining with a high-precision wire-cut electric discharge machine.

Furthermore, since it is not necessary to provide the centering hole 29 in the workpiece 1, the first machining can be performed using a general-purpose wire cut electrical discharge machine even if it is impossible to provide the centering hole 29 in the workpiece 1. It becomes possible to perform the second machining using a high-precision wire-cut electric discharge machine.

6A and 6B are front views of a wire cut electric discharge machining jig 33 according to a second embodiment of the present invention. In this embodiment, the opening 34 of the outer plate 31 is circular, while the outer shape of the inner plate 32 is triangular. The reason for this is as follows.

That is, in the first embodiment, both the opening 34 of the outer plate 31 and the outer diameter of the inner plate 32 are circular. Therefore, the inner plate 32 fits tightly into the outer plate 31. Therefore, when removing the inner plate 32 from the outer plate 31,
It may be difficult to remove. In order to eliminate this inconvenience, the inner plate 32 is triangular in this embodiment. If the inner plate 32 is triangular, when removing the inner plate 32, the inner plate 3
You can pick up 2 with your fingertips. Therefore, the inner plate 32 can be easily removed from the outer plate 31. This is the aim of this embodiment.

It goes without saying that even in the case of this embodiment, the position of the centering hole 29 with respect to the outer plate 31 does not change.

Other aspects of this embodiment are exactly the same as those of the first embodiment, so the explanation thereof will be omitted and will only be indicated by reference numerals in the drawings.

7a and 7b are front views of a wire cut electric discharge machining jig according to a third embodiment of the present invention.
In this embodiment, the opening 34 of the outer plate 31 is octagonal, and the inner plate 32 is cross-shaped. The reason for this is to make it easier to remove the inner plate 32 from the outer plate 31, as in the second embodiment.

Other aspects of this embodiment are completely the same as those of the first embodiment, so the explanation thereof will be omitted, with only reference numerals attached to the drawings.

[Effect of idea]

As can be seen from the description of the above embodiments, the present invention has the effect of being able to solve the following two problems (a) and (b).

(a) Inefficiency due to the use of a high-precision wire-cut electric discharge machine for both the first and second machining processes. (b) Inefficiency due to the time-consuming centering work required to perform the first machining process with a general-purpose wire-cut electric discharge machine and the second machining process with a high-precision wire-cut electric discharge machine.

[Brief explanation of drawings]

FIG. 1 is a front view of a wire cut electric discharge machining jig according to a first embodiment of the present invention, and FIG. 2 is a front view of a wire cut electric discharge machining jig according to a first embodiment of the present invention attached to a workpiece. 3 is a cross-sectional view of FIG. 2, and FIG. 4 is a top view of the jig for wire cut electrical discharge machining according to the first embodiment of the present invention. Similarly, FIG. 5 is an explanatory diagram illustrating the work of determining the reference position of the wire in the wire cut electric discharge machining jig according to the first embodiment of the present invention, and FIG. FIG. 7 is a front view of a wire cut electric discharge machining jig according to a second embodiment of the present invention.
A front view of a wire cut electric discharge machining jig according to a third embodiment of the present invention, FIG. 8 is an overall configuration diagram of a wire cut electric discharge machine, and FIG. 9 is an explanatory diagram illustrating a conventional centering operation. Figure 10 shows the X-
It is an X sectional view. 1... Workpiece, 10... Wire cut electric discharge machine, 16... Table, 28... Reference surface, 29
... Centering hole, 31 ... Outer plate, 32 ... Inner plate, 33 ... Wire cut electric discharge machining jig, 34 ... Opening, 35 ... Outer circumference, 38 ... Slit, 41 ... Outer circumference.

Claims (1)

[Scope of utility model registration request] It is a jig attached to a workpiece for centering work in wire cut electric discharge machining, and is composed of an outer plate made of a flat plate and an inner plate also made of a flat plate. The outer plate has an opening in the center and can be fixed to the workpiece, and the outer plate has an opening on the outer periphery that allows the workpiece to be fixed to the table of the wire-cut electrical discharge machine. A reference surface is provided for determining the position of the inner plate, and the inner plate can be closely and removably fitted into the opening of the outer plate, and the inner plate has a wire in the center thereof. 1. A jig for wire cut electric discharge machining, characterized in that a centering hole is bored for determining a reference position, and the centering hole is connected to the outer periphery of the inner plate by a slit.