JPH0512145B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a belt made of thermosetting polyurethane.

(Prior Art) Conventionally, thermoplastic polyurethane is widely used as the polyurethane constituting the belt, and is manufactured by injection molding, extrusion molding, or the like.

By the way, for example, for applications such as orthodontic treatment or timing belts, there are cases where it is desirable to form belts from thermosetting polyurethane due to physical properties such as tensile strength and characteristics of the resin material. .

In response to such a demand, unlike thermoplastic polyurethane, thermosetting polyurethane is difficult to form into a belt-like belt by injection molding, etc., so the inventors of the present invention first developed a method of forming thermosetting polyurethane from bulk thermosetting polyurethane. It has been proposed to obtain a band-shaped belt by cutting or other means (see Japanese Patent Application No. 1983-90497).

(Problem to be Solved by the Invention) By the way, even with the belt-shaped belt obtained in this way, when used for practical purposes such as tooth alignment correction or timing belts, it is difficult to form a predetermined hole depending on the purpose. It is necessary to perform machining and contour processing.

This invention was made based on the above circumstances, and its purpose is to continuously perform hole drilling and contour processing at a constant pitch on a belt intermediate product formed in the shape of a long belt. be.

(Means for Solving the Problems) In order to achieve this object, the present invention manufactures a belt by punching out the outer shape of a belt intermediate product made of thermosetting polyurethane and formed as a belt-like elongated body with a constant width. A manufacturing device comprising a press device having a punch and a die for punching, and forming a processing section having a cutting edge for contour processing in the center of the die, and forming a processing section linearly from both sides of the processing section. A series of concave grooves are formed, and an unprocessed belt intermediate product is supplied as a belt-like elongated body with a constant width through the concave grooves on one side, and the belt is processed at the processing section from the concave grooves on the other side. The belt is discharged, and the width of the groove on the other side is set smaller than the width of the groove on the one side, and the outer shape is processed in the processing section on the belt intermediate product. A step-shaped cut edge is formed at the end of the concave groove side on the one side in the cut portion, and a pulling force is applied to the belt intermediate product from the concave groove side on the other side, With this pulling force, each time the processing is performed in the processing section, the processed part is moved toward the groove on the other side, and the cut edge is moved to the end of the groove on the other side. The punch is abutted against an abutting wall portion formed in the punch, and a predetermined unprocessed length corresponding to the length of the processed portion is positioned between the punch and the die.

(Function) According to the present invention, the cut edge formed on the belt intermediate product is positioned by abutting against the abutment wall formed on the die, so that the belt made of flexible thermosetting polyurethane is positioned at the processing section. Deformation of the intermediate product due to pulling force is reduced, and the belt intermediate product made of flexible thermosetting polyurethane can be accurately supplied to the processing section.

Therefore, a belt intermediate product made of thermosetting polyurethane is punched at a constant pitch using a punch and a die, thereby making it possible to obtain a long belt-shaped thermosetting polyurethane belt.

(Example) The present invention will be explained below with reference to an example shown in the drawings. In this example, an orthodontic belt shown in FIG. 5 is manufactured. Next, the manufacturing apparatus and manufacturing method will be explained.

Reference numeral 1 denotes a press device constituting the manufacturing apparatus, which has a slide 2 configured to be movable up and down and a bed 3 fixed below the slide 2.

A punch 5 is attached to the lower end of the slide 2 via a punch holder 4, and a die 7 is attached via a die plate 6 to the bed 3 corresponding to the lowered position of the punch 5.

Reference numeral 8 indicates a knockout plate installed on the punch 5, and a second knockout plate is provided between the punch 5 and the die 3.
As shown in the figure, the belt intermediate product 10 is supplied from the left side of the figure by pulling it out to the right (arrow P).

The belt intermediate product 4 is a flexible long belt-shaped body formed into a fixed width and thickness using a lathe or the like from thermosetting polyurethane formed into a lump. It is.

As shown in a perspective view in FIG. 3, the punch 5 has a cutting edge 11 for contour processing and a cutting edge 12 for hole drilling. It is formed in a groove 13 formed in the direction, and the width of this groove 13 is approximately equal to the width W1 of an intermediate belt product 10, which will be described later, as shown in FIG.

The die 7, as shown in FIG. A through-hole 18 is formed to accommodate the cutting blade 21 and the hole-machining cutting blade 21 on the die 7 side at the center of the through-hole 18 at a position corresponding to the cutting blades 11 and 12 of the punch 5. A portion 22 is formed.

Grooves 16a and 16b extending to both ends of each side are formed on both sides of the processing section 17, and the belt intermediate product 10 is supplied to the processing section 17 through these grooves 16a and 16b. Evacuation takes place.

The width dimension of the groove 16a is formed to be equal to the width dimension W1 of the belt intermediate product 10, and the width dimension of the groove 16b on the side discharged from the processing section 17 is equal to the belt width dimension W2 as a product after processing. An abutment wall portion 23 is formed to be equally narrow and is formed at the entrance portion from the processed portion 17 to the groove 16b.

This abutting wall portion 23 maintains a constant supply of the belt intermediate product 10, as will be described later.

By the way, in this embodiment, the punch 5 and the die 7 are combined to punch out the belt intermediate product 10 at one time, thereby punching out four locations A, B, C, and D shown in FIG. The cutting edges 11, 12, 21, 22 for forming each of these parts A, B, C, and D are formed in the same shape at a constant pitch. ing.

In addition, among these parts A, B, C, and D,
Parts B and C are both punched into a perfect shape, but part A is used to form a hole in the belt intermediate product 10, as well as to form the right half of the outer shape and the cut edge 25 in the direction perpendicular to the belt length. In section D, only the outer shape of the left half of the belt intermediate product 10 that was not formed in section A is punched out.

Therefore, in the next punching process, the part processed in part A is punched again in part D, so that it is formed into the same shape as the parts punched in other parts B and C. It is something.

Next, a method for manufacturing a thermosetting polyurethane belt for orthodontics using the manufacturing apparatus 1 configured as described above will be described.

First, grooves 16a and 16b formed in the die 7
A predetermined intermediate belt product 10 is attached to the inside, a predetermined weight (not shown) is applied to the end of the intermediate belt product 10 that is to be discharged, and the intermediate belt product 10 is discharged as shown by arrow P with appropriate tension. Let it be pulled to the side.

Thereafter, by lowering the punch 5, the belt intermediate product 10 undergoes a predetermined punching process with the die 7.

Due to this punching process, there is a risk that the punched intermediate belt product 10 may adhere to the area around the hole cutting edge 12 of the punch 5, but after this process, the knockout plate 8 is moved and the belt product is removed. The punch 5 is prevented from escaping from the concave groove 16 of the die 7 as it rises.

The punch 5 rises and the belt intermediate product 10 hits the die 7.
When the intermediate belt product 10 is left in the groove 16 of the belt, the intermediate belt product 10 moves in the direction of the arrow P due to the load of the weight.
The cut edge 25 formed on the intermediate belt product 10 abuts against the abutting wall portion 23 formed on the die 7 to position the intermediate belt product 10. Other processing department 17
The belt intermediate product 10 located at is an unprocessed portion.

If the belt intermediate product 10 is pulled out from the groove 16b with a constant force in the direction of the arrow P and supplied in this way,
A belt intermediate product 10 made of flexible thermosetting polyurethane is always processed at a constant length in a processing section 17.
It can be sent inside.

On the other hand, as the punch 5 moves downward in the same manner as described above, the part that was previously partially machined at section A is partially machined at section D, and the remaining part is left in an unprocessed state. The intermediate belt product 10 is subjected to the same processing as described above.

Thereafter, by repeating the punching operation and the pulling out of the belt intermediate product 10 from the processing section 17, the belt intermediate product 10 formed into a long length is continuously punched to form a predetermined shape. A thermosetting polyurethane belt for orthodontics can be produced.

In addition, in this example, the belt intermediate product 10
Although the drawing from the processing section 17 is carried out using a weight, it goes without saying that a known take-up reel or the like that can apply a constant tension may also be used.

Orthodontic belt 2 formed in this way
0 is cut to an appropriate length, and as shown in FIG.
The alignment of the teeth is corrected by applying a and applying tension so that an appropriate tension is applied between them.

That is, a belt intermediate product 10 made of a long thermosetting polyurethane formed into a predetermined shape,
In the same manner as described above, holes 45 are continuously formed at a constant pitch using the punch 5 and die 7 to form a hole-machined timing belt intermediate product 42, and from this timing belt intermediate product 42, a required length is formed. An annular timing belt 41 is made by cutting out the belt and connecting both ends in a known manner.

A pin 44 installed on a sprocket 43 is fitted into the hole 45 of the timing belt 41 to transmit driving force.
Timing belt 41 shown in FIGS. 7 and 8
In this case, both the pin 44 and the hole 45 are formed in a circular shape, and an appropriate clearance is set.

When forming the timing belt 41, the shape of the hole to be formed in the timing belt intermediate product 42 may be a square hole 46 as shown in FIG. 9 or any other suitable shape, in addition to the circular shape described above. I can do it.

(Effects of the Invention) Since the present invention is configured as described above, the cut edge formed on the belt intermediate product is positioned by abutting against the abutment wall formed on the die, so that
This reduces deformation of the belt intermediate product made of flexible thermosetting polyurethane due to pulling force in the processing section, and allows the belt intermediate product made of flexible thermosetting polyurethane to be accurately fed to the processing section. can.

Therefore, a belt intermediate product made of thermosetting polyurethane is punched at a constant pitch using a punch and a die, thereby making it possible to obtain a long belt-shaped thermosetting polyurethane belt.

[Brief explanation of the drawing]

Figures 1 to 4 show the manufacturing equipment, Figure 1 is a sectional view taken along the - line in Figure 4 with the punch and die fitted together, and Figure 2 is a front view showing an outline of the manufacturing equipment. Figure 3 is a perspective view of the punch,
FIG. 4 is a top view of the die, FIG. 5 is a plan view of a thermosetting polyurethane belt for orthodontics manufactured by the manufacturing method of the present invention, and FIG. 6 is a thermosetting orthodontic polyurethane belt shown in FIG. FIG. 3 is an explanatory diagram of the state in which the polyurethane belt is used. DESCRIPTION OF SYMBOLS 1...Press device, 5...Punch, 7...Die, 10...Belt intermediate product, 11, 21...Outline processing cutting blade, 12, 22... Hole processing cutting blade.

Claims (1)

[Scope of Claims] 1. A manufacturing device for manufacturing a belt by punching out the outer shape of a belt intermediate product made of thermosetting polyurethane formed as a belt-like elongated body with a constant width, comprising: a punch and a die for the punching process; forming a processing section having a cutting edge for contour processing in the center of the die, forming grooves extending linearly from both sides in the processing section, and forming grooves on one side of the processing section; At the same time, the unprocessed belt intermediate product is supplied as a belt-like elongated body with a constant width through the process, and the belt processed at the processing section is discharged from the groove on the other side. The width of the concave groove is set to be smaller than the width of the concave groove on the one side, and the end of the concave groove on the one side is set on the belt intermediate product at a portion where the external shape has been processed in the processing section. A step-like cutting edge is formed in the processing section, and a pulling force is applied to the belt intermediate product from the concave groove side on the other side, and with this pulling force, each time the processing is performed in the processing section. Then, move the processed part toward the groove on the other side, abut the cut edge against the abutment wall formed at the end of the groove on the other side, and finish the process. A method for manufacturing a thermosetting polyurethane belt, characterized in that a predetermined unprocessed length corresponding to the length of the portion where the polyurethane is formed is positioned between the punch and the die. 2. The thermosetting method according to claim 1, wherein the punch and the die for punching are formed with a cutting edge for hole processing and a cutting edge for contour processing, respectively, and the orthodontic material is obtained from the belt intermediate product. A method for manufacturing polyurethane belts.