JPH02172430A - Manufacture of shaft body of rotary brush - Google Patents

Abstract

PURPOSE:To integrally mold a brush shaft and to eliminate after-treatment by a method wherein a columnar body provided at its periphery with a helical groove or a line of helical protrusion is formed, plating is applied on the surface of a master manufactured by polishing a surface, and the master on the surface of which a plating layer is formed is manufactured, and only the master is dissolved by means of a chemical. CONSTITUTION:A master 10 is manufactured by a cutting work by means of a metallic material being dissoluble by means of a chemical. A helical member 11 made of a metallic material formed in a T-shape in cross section and being not eroded by a chemical is manufacture by cutting. After the helical member 11 is inserted in the master 10 and a plating layer 12 of a material being not eroded by a chemical is formed for a long time, the outer periphery thereof is finish-molded. Finally, only the master is dissolved by a chemical for removable to manufacture a mold.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a shaft body of a rotating brush used in a vacuum cleaner, a manual vacuum cleaner, or the like.

As a rotary brush conventionally used in a mud remover, there is one shown in FIG. This rotating brush has bristles 2 spirally implanted on a round bar l with a circular cross section, and furthermore, a protrusion 3 is also formed in a spiral shape on the outer periphery of the round bar 1. .

Prinsle 2 works by sweeping up dust on the floor.
On the other hand, the raised part 3 has the function of hitting the pile of a rug, carpet, etc. to lift up the dust at the bottom of the pile and make it easier to collect the dust. In addition, the reason why the prinsle 2 and the protrusion 3 are arranged in a spiral is that the rotating brush
This is because consideration has been given to ensuring that the floor surface can be rubbed smoothly.

When manufacturing the shaft of such a rotating brush, it is preferable to integrally mold the round bar 1 part and the protrusion 3 part by plastic injection molding. This requires a very complex divided mold. Furthermore, since the parting line a of the mold appears in the form of a protrusion in the product, although it has a very small height, thread waste, cotton waste, etc. tend to adhere there, which is unhygienic.

Although not shown, there are cases where the protrusion 3 is manufactured separately and attached to the round bar 1 by post-processing, but this method is disadvantageous in terms of cost.

In order to manufacture a product as shown in Fig. 3 without the above-mentioned parting line a by injection molding, the part of the mold corresponding to the length must be
For example, as shown in FIG. 4, electrical discharge machining may be performed to obtain a spiral hollow body with a predetermined cross section. In this case, since the length of the brush shaft is usually about 250 m or more, the surface of the mold needs to be mirror-polished and have a draft angle to reduce mold release resistance. However, since the basic outside diameter of the brush shaft is generally in the range of about 15m5 to about 35mm, it is impossible to polish the inner surface of the hollow body with such a small diameter, and insufficient polishing may result. In order to deal with this, it was necessary to set the draft angle to a value greater than the normally set value. In injection molding, the ideal draft angle is generally considered to be 2" to 3 degrees, but it is generally reduced to a minimum of 0. In some cases, it is implemented at around 5@.

However, the draft angle of the shaft of such a rotating brush is an important issue. This is because, in Fig. 3, if L=250(mal,
If the slope is 0.5', the difference in height between points C and d is 25
0 nX tan O, 5° = 2.18 cranes. Therefore, the effect of hitting the carpet surface differs between the left and right sides of the brush, making it impossible to obtain a sufficient cleaning effect.

Furthermore, when electrical discharge machining is performed, the electrode is supported in a cantilevered manner, and in such a state, a narrow and long cavity must be formed, but the accuracy of the electrical discharge machining itself becomes a problem. For this reason, a beryllium steel casting method is also considered as a separate method. This is a manufacturing method in which a master is manufactured separately, molten beryllium copper alloy is poured around it, and then the master is extracted to obtain a hollow body. However, in this case, the surface roughness of the master itself is relatively easy to polish, so there is no problem with the surface roughness, but as mentioned above, the draft angle for removing the master is 0.5" to 1".
This would result in a large difference in the shaft diameter of the rotary brush and the thickness of the protrusion at both ends, making this manufacturing method unsuitable for manufacturing rotary brushes.

Therefore, in the above method, if the necessary draft angle is created, the difference in diameter between the product ends becomes large (and for the same reason, the amount of contact of the top of the protrusion with the carpet surface is reduced at both ends of the brush shaft. The disadvantage was that there were differences.

Furthermore, in the case of the conventional injection molding method, a large space 1 (Fig. 5) is required to take out the molding shaft, and a large molding machine with a large mold opening dimension is required, which increases manufacturing costs. It also had the disadvantage of leading to an increase in Due to the above-mentioned background, a manufacturing method based on profile extrusion molding was developed in JP-A No. 5.
8-175530. FIG. 6 shows a brush shaft manufactured by the profile extrusion method. The profile extrusion method is a method in which a product material having a predetermined cross section is continuously extruded while being twisted. According to this method, the cross-sectional shape can be set relatively freely, there is no parting line seen in the injection molding method described above, and there is no need for a draft angle, which is an improvement in these respects.

However, this method has the following drawbacks when compared with injection molding method.

That is, there is a lot of post-processing after fi+ molding, as described below, and therefore, the manufacturing cost increases.

■ Cut to the specified length and finish the end face.

■ Machining the drive pulley insertion part 5 into a cylindrical shape.

■ Separately manufacture and install the drive pulley 4.

■ Machining the hole 6 for mounting the rotation support shaft.

■ Press-fit the rotating support shaft 7.

(2) There are many factors that impede the smooth rotation of the rotating brush. That is, when this rotation plan is installed in a vacuum cleaner, it is generally used at a rotation speed in the range of 3000 to 6000 rpm in many cases. Therefore, the rotating support shaft 7 may be bent and driven into the
If there is misalignment, rotational imbalance will occur,
Since this becomes a source of noise and increases power consumption, the attachment of the rotating support shaft 7 requires the most careful work during the manufacturing process. However, this method requires a lot of post-processing as mentioned above, and there are individual opportunities for misalignment or bending of the rotating support shaft 7 during the post-processing process, so there is a high probability that defective products will occur. There is a problem of becoming high.

The present invention has been made in order to solve the drawbacks of each of the above-mentioned conventional techniques.

That is, the present invention provides a method for manufacturing a rotating brush shaft that satisfies the following requirements.

(1) By molding not only the protrusion but also other necessary parts integrally with the power rotation axis, post-processing is made as unnecessary as possible, and therefore a good rotational balance can be obtained and costs can be reduced.

(2) The base surface has a smooth finish.

(3) Can be molded with a small molding machine.

(4) The amount of contact between the protrusions and the carpet is as uniform as possible over the entire length of the rotating brush.

The present invention employs (1) an injection molding method in order to manufacture a rotating brush shaft having the above requirements.

This allows the protrusion and other necessary parts to be integrally molded with the rotating shaft, thereby reducing costs. Furthermore, the rotational support shaft can also be integrally insert-molded, making it possible to obtain ideal rotational balance.

(2) What about the brush mold? j! Instead of the conventional method requiring rough division, the mold structure, which will be detailed later, prevents the formation of parting lines.

(3) By installing the mold so that the mold opening direction of the molding machine is perpendicular to the product axis direction and providing a separate product protrusion mechanism (ejector device), molding can be performed even with a small molding machine with a small mold opening amount. Get used to it.

(4) By setting the slope of product removal to a minimum using the mold structure described below, the amount of contact between the protrusions and the droop can be made uniform over the entire length of the rotating brush.

The solution has been generally explained above, but the important point of the present invention, the mold structure, will be explained in detail.

First, make a master with the same shape as the mold cavity, and thoroughly polish the surface. Next, the outer peripheral surface of this master is plated over a long period of time to form a thick plating layer, and then the master is dissolved and removed using a chemical solution that dissolves only the material of the master, resulting in a hollow body with a thick plating layer. The surface of the hollow part is a copy of the well-polished master surface, so it has a smooth finish and can be used as a mold as is.

In addition, in recent years, a type of rotating brush in which a blade 8 made of a flexible material such as rubber is erected on a rotating shaft has been introduced in place of the conventional Buri/Nosuru flocked type brush, and its shape is It is shown in FIG. In this case, a helical shaft 9 as shown in FIG. 8(a) having a cross section as shown in FIG. 8(b) is required. According to the present invention, the above requirements can also be achieved.

In this case, it is not possible to create a master cross-section as shown in FIG. 8(b) and perform plating. This is because the spiral groove 9 for attaching the flexible blade is not plated.

Therefore, it will be manufactured using the following process.

■ Due to metal materials that can be dissolved by chemical solutions,
The master lO shown in b) is manufactured by cutting.

(2) A spiral member 11 with a T-shaped cross section is manufactured by cutting from a metal material that is not corroded by the chemical solution.

This can be obtained by processing a pipe material as shown by the broken line in FIG. 9(b).

(2) FIG. 9(C) shows the spiral member 11 being inserted into the master 10.

(2) A plating layer 12 made of a material that is not attacked by the chemical solution is applied over a long period of time to the member obtained in the above step (2), and then the outer periphery is finished and formed into the shape shown in FIG. 9(d).

■Finally, only the master is melted and removed with 'J liquid, and manufactured using a mold having the shape shown in Fig. 9 (E).

As mentioned above, by applying electroforming technology, there is no restriction on draft angle due to the manufacturing method itself such as beryllium steel casting method, it is possible to set a free gradient, and it is possible to create a metal with a smooth surface. You can get the mold.

Using the above method, we were able to manufacture a mold with a smooth surface and a predetermined draft angle.However, although the above method can be used for brush shafts with a length of about 1,500 mm, When the body becomes longer than 200-1, the effect of the draft becomes large due to the spiral shape of the protrusion, which is not satisfactory. 10 and 11, a method of making the draft angle as close to 0 as possible by using a structure that further improves the mold releasability will be explained in detail. This is an example of a shaft body for a Prinsle flocked brush.The mold manufactured as described above is divided into two parts in the axial direction in a spiral shape as shown in Fig. 1θ, and these parts are combined as shown in Fig. 11. As shown, a mold clamping piece 13b for an injection molding machine consists of a mold clamping piece 13a on the movable side of the injection molding machine and a single shaft piece 13b on the fixed side of the injection molding machine.
It is arranged on a mold clamping piece for an injection molding machine.

As is clear from Figures 10 and 11, if the spiral lead extends over a circumference of 180 @ or more, the two divided molds cannot theoretically separate from each other in the radial direction. However, when the mold clamping force is released after molding, a minute gap is created in the parting part of the separation mold during mold release, which is advantageous for mold release. With this method, smooth mold release is possible even if the draft angle is extremely small.

Also, regarding this two-division method, T in Figure 8 (a) and (b)
It can also be applied to products having a shape of a spiral groove 9.

With the mold manufacturing method and structure according to the invention as described above,
Even long brush shafts with a spiral cross section that are difficult to release from the mold can be easily injection molded, and the drawbacks of conventional injection molding and profile extrusion molding can be solved. can.

Next, as shown in FIG. 1, the mold formed as described above is arranged perpendicular to the mold opening direction of the injection molding machine, and the ejector device 20 is separately arranged. The ejector turbine 21 of the ejector device 20 is designed to rotate as the molded product is extruded while rotating along the spiral groove of the mold, as shown in FIGS. 12(a) and 12(b). The ejector device 20 is connected to the ejector device 20 via a rotatable jet pin 22.

Since the present invention is configured as described above, it produces the effects described below.

(1) The brush shaft can be integrally molded, no post-processing is required, and the mold is placed horizontally on the injection molding machine, so a small injection molding machine with a small clamping stroke is used. Therefore, manufacturing cost 1- can be reduced.

(2) The surface of the brush shaft has a smooth finish.

(3) Even in the case of long products, the draft angle can be made small, and the amount of contact between the protrusions and the carpet is uniform over the entire length of the rotating brush, so a sufficient cleaning effect can be obtained.

(4) Since there is no shaft imbalance caused by errors in the shaft hole or bending of the shaft rod, noise generation is eliminated and quality can be stabilized.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an injection molding machine according to the present invention, FIG. 2 is a perspective view showing a conventional rotating brush, FIG. 3 is a perspective view of a rotating brush shaft without parting line a, and FIG. A mold for manufacturing what is shown in the figure, Figure 5 is a front view of a conventional injection molding machine, Figure 6 is the shaft of a rotating brush manufactured by profile extrusion molding, and Figure 7 is a blade type rotating brush. A perspective view of
Figure 8 (A) is a perspective view of the brush shaft of the one in Figure 7, Figure 8 (B) is a sectional view of Figure 8 (A), and Figures 9 (A) to (E) are according to the present invention. An explanatory diagram showing a method of manufacturing a mold by
Fig. 1O is a perspective view showing the mold and the spiral cut into two parts along line h, Fig. 11 is an explanatory view showing the state in which the mold is attached to the mold clamping piece for an injection molding machine, and Fig. 12 (A) and (B) are explanatory diagrams showing the operating state of the injection molding machine shown in FIG. 1. Explanation of symbols l...Round bar 2...Bristle 3...
・Protrusion 4... Drive pulley 5...
Drive pulley insertion part 6...Rotation spindle mounting hole 7...Rotation spindle 8...Blade 9...
Spiral groove 10... Master 11... Spiral member 12... Plating layer 20... Ejector device 21... Ejector turbine 22... Joint (a) (b) Figure 9 (d) Procedure Written amendment (spontaneous) 1. Indication of the case Patent Application No. 327180 filed in 1988 2. Name of the invention Method for manufacturing a rotating brush shaft 3. Person making the amendment Relationship with the case Name of patent applicant Honi Toy Co., Ltd. 4. Agent (102) Address: 5° Ichibancho Central Building, 22-1 Ichibancho, Chiyoda-ku, Tokyo Engraving of the drawing dated the date of the amendment order (no changes to the contents)

Claims (1)

[Scope of Claims] 1(1) A cylindrical body having a spiral groove or a spiral protrusion on the outer periphery is formed by cutting a metal material that can be dissolved by a predetermined chemical solution, and the cylindrical body with the spiral groove formed therein has In the spiral groove,
A first step of manufacturing a master by inserting a protrusion member made of a material that is not eroded by the chemical and further polishing the surface; (2) plating the surface of the master with a material that is not erodible by the chemical; (3) a third step of dissolving only the master on which the plating layer is formed with the chemical solution; A method for manufacturing a mold for a rotating brush shaft having an unusual spiral shape. 2. In a mold having a spiral groove or spiral protrusion extending in the axial direction on the inner wall of the hollow part, the mold is spirally axially extended in the axial direction.
2. A method for manufacturing a mold for a shaft of a rotary brush having an irregular spiral according to claim 1, wherein the mold is divided into parts. 3. In an injection molding method that uses a mold that extends in the axial direction, the mold is arranged so that the axial direction of the mold is orthogonal to the opening direction of the mold of the injection molding machine. An injection molding method characterized by: