JPH0618760B2 - Brush handle and its mold - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement of a brush handle for facilitating the operation of a brush bristle portion such as a toothbrush and a molding die for manufacturing the brush handle.

[Conventional technology]

Conventionally, a brush handle, especially a toothbrush, is generally composed of a synthetic resin, which is composed of a grip handle with a head of a flocked part at one end through the neck, and is generally made of a synthetic resin. Most of the gates are submarine gates, and the gate is usually located on the handle end face.

In addition, the handle that is a synthetic resin molded product must have a trace of the gate at the time of molding and a trace of the ejecting pin for mold release on the external surface of the molded product, and it is necessary to finish it by cutting or scraping it. Therefore, the improvement of the gate processing, which is costly, and the improvement of making the points that are bad after the processing and badly affecting the product value in appearance, unnoticeable, are being focused on.

For molding the brush handle, the side gate method is easily adopted because the molded product is thick and the marks of the protruding pins are relatively inconspicuous. That is, in order to reliably release a long and slender product such as a brush, it is common practice to project both ends of the product. That is, in the case of a brush mold using a side gate, a mold releasing device such as a pin is often provided on the runner portion that is continuous with the head (flocked portion or neck) of the mold and the end of the handle. And in order to enhance the commercial value of the product, the trace of the ejector pin should be about 1 mm in diameter between the flocked holes that are hidden by the hair after flocking and are invisible because the force that is not noticeable on the surface of the product is desirable. In many cases, a thin protruding pin is used, and the end of the handle avoids the product part, and the protrusion pin of the runner part also serves as the product protrusion.

As for the gate treatment, since the product after being released from the mold remains connected to the runner, it is necessary to cut the gate part and finish the cut surface. In this cutting step, since machining such as saw cutting or bending cutting is performed, the size of the cut surface at this time is φ4 to 6 mm.
The large amount of cutting chips generated from it adheres to the product,
It is desirable not to adopt the side gate method because finishing operations such as wiping of the cutting powder and removal of blade scratches on the cut surface do not result in cost reduction.

[Problems to be Solved by the Invention]

Therefore, the submarine gate method has the advantage that the gate is cut when it is released from the mold and the trace of cutting of the gate is extremely small, about φ1 mm, which is excellent in appearance, so even if this method is adopted, the mold release Sometimes it is necessary to project both ends of the product, which not only leaves the marks of the protruding pins remaining near the gate on the product, but also adversely affects the feel when gripping the handle.

In other words, regarding the protrusion of this handle, the flocked part can be hidden in the flocked hole, so when looking at the protrusion on the handle end side, it can be seen whether the gate is provided on the moving side mold or on the fixed side. For cutting and releasing, an ejector pin is required near the gate of the product. Therefore, even if a submarine gate is used, a trace of the ejector remains on a prominent portion of the product surface near the gate, which adversely affects the appearance.

Generally, the surface of the handle is not a flat surface but a curved surface.Therefore, when providing the ejector pin here, make sure that the product surface of the ejector pin matches the curvature so that it smoothly connects with the surroundings, and that there is no step. It is not easy to match the curvature and height of the surface of the protruding pin perfectly with the surroundings, and from the point of view of appearance and processing of the pin, the smaller the pin diameter, the better. When sticking out, there was a problem that a thin pin would sink into the product, leaving a concave surface on the product surface.

The present invention is intended to accurately eliminate these conventional drawbacks, and adopts a submarine gate method, and there is no trace at the time of molding on the exterior surface of the brush handle, and a finished product that is inconspicuous, The purpose of the present invention is to provide a brush handle and its molding die, which have a significantly improved printing finish, have a degree of freedom in design, can greatly enhance the product value, can significantly improve workability, and can reduce the production cost. It is what

[Means for Solving the Problems]

According to the present invention, a brush handle composed of a handle 3 having a head 1 of a hair-implanted portion A at one end via a neck 2 is injection-molded with a synthetic resin by a submarine method.
A gate 4 is provided on an end surface B of the handle 3, and a support hole 5 for suspending a handle is formed in the vicinity of the gate 4, and an abutment surface 6 for a protruding pin is provided in the support hole 5. It is a brush handle characterized by having.

In addition, as a molding die for manufacturing this brush handle, a pair of molds 8 and 8 forming the cavity 7 of the brush handle are provided with a submarine gate 9 at a position which becomes the handle end surface B, and Forming partitioning protrusions 10 for the support holes 5 are provided in the molds 8 and 8, and the protrusion pin 1 is provided.
It is a mold for forming a brush handle, characterized in that the partition projection 10 is provided with a surface forming the abutting surface 6 of No. 1 and a protruding pin 12 is provided on the flocked surface of the head 1 of the brush handle. This is one of the features.

[Action]

In this brush handle, a mold 8 with a cavity 7,
For example, when a fixed mold and a movable mold are joined to the parting surface, for example, a pair of 8's are joined to the partition projections 10 and 10 in the cavity 7 by the submarine line, and then the resin is press-fitted from the submarine gate 9 following the runner 14. Inject (Fig. 4A)
The head 1, the neck 2 and the handle 3 are integrally formed, and when one of the molds 8 is released, the submarine gate 9 is moved and the traces of the gate 4 are removed while part of the supporting hole 5 is pulled out. The end surface B is left to be cut (FIG. 4B), and the protruding pins 11, 12, and 15 on the other mold 8 are advanced to move the brush handle to both ends, that is, the head 1 having the hair-implanted part A. The brush handle is protruded from the mold 8 by the ejecting pins 11, 12, 15 at the position of the abutment surface portion 6 of the hole 5 and the runner 14, and the mold is released, so that the gate trace and the ejecting pin trace are not conspicuous. It is possible to easily produce products safely without disturbing the handle operation, the appearance of the handle outer surface is good, the print finish is improved without being limited to the design, and the product value can be greatly increased. It is a thing.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 to 4 as an example of a toothbrush. The head 1 of the hair-implanted portion A has a neck portion 2 at one end.
A brush handle composed of a handle 3 provided through the injection handle is injection-molded of a synthetic resin by a submarine method, and a gate 4 is provided on an end surface B of the handle 3 and in the vicinity of the gate 4. This is a brush handle in which a support hole 5 for suspending the handle is formed, and an abutment surface portion 6 for a protruding pin is provided in the support hole 5.

As the engagement hole 5, a contact surface portion 6 with which the tip of the product ejecting pin 11 is engaged at the time of molding at a position along the parting surface C of the molding die is provided in the engagement hole 5. Second
As shown in FIG. 3 and FIG. 3, it is preferable to leave the protruding wall of the tongue piece in the supporting hole 5 in a protruding state and form the contact surface portion 6 that is projected to the protruding position of the protruding pin 11.

In this case, when forming the contact surface portion 6, FIG.
Bottom may be as abutment face portion 6 as recesses 5 ₁ closes the engagement supporting hole 5 or a stepped portion 6 ₁ on the inner surface of the engaging support hole 5 of the through holes as shown in ~ (G), said protrusion It is also possible to form the engagement hole 5 by a tapered tapered through hole having a gap smaller than the diameter of the pin 11 and insert the protrusion pin 11 so that the protrusion pin 11 engages with the hook hole to protrude.

When manufacturing this brush handle, a pair of molds 8 for forming the cavity 7 of the brush handle,
8, for example, using a fixed mold and a moving mold, one mold 8
Is provided with a submarine gate 9 at a position to be a handle end surface B, and a molding partitioning projection 10 of a support hole 5 is provided on any one of the molds 8 and 8 and an abutting surface portion of a protruding pin 11 is provided. The surface portion forming 6 is provided with the partition projection 10
In addition, a brush pin head 1 of the brush handle is further provided with a protruding pin 12 for efficiently clamping the molds 8 and 8 and filling the resin, and releasing the protruding pins 11, 12 and 15 from the product and removing the runner. Can be produced well.

In this case, for example, the handle of the brush handle has a cross-sectional diameter of 9 to
Submarine gate 4 is provided on the side of the end face B of the handle, which is 13 mm in length, and has a width of 4 to 6 mm, 6 to 10 mm away from the end face B of the handle.
A locking hole 5 having an oval through hole having a length of 10 to 18 mm, preferably 15 to 16 mm, is provided perpendicularly to the parting surface. If a crescent-shaped planar contact surface portion 6 is formed in the semicircular portion of the locking hole 5 on the gate side, a protruding pin 11 having a diameter of about 4 mm is formed.
Therefore, it is possible to release the mold accurately and easily, and it is possible to make a product with good quality. Further, although the two protruding pins 12 and 12 are provided between the flocked holes 13 on the side of the flocked portion A, the protruding pins 12 may be provided on the mold 8 at the flocked portion or the neck portion as required.

The partition projection 10 provided in the cavity 7 forms a supporting hole 5 penetrating in a vertical direction in the parting surface of the mold, and the surface of the parting line is used as the contact surface part 6. The pin 11 is provided in the through hole and sticks out on the surface.
This eject pin 1
Although the diameter of 1 is smaller than the diameter of the locking hole 5, the partition projection 10 provided in the cavity 7 has an outer periphery that forms a hole having a diameter smaller than the diameter of the ejection pin 11. Which is at least the flocked hole 13 of the flocked part A
It is better to prepare for the side with.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY The present invention can utilize the advantages of the submarine gate and at the same time have the advantages of the sudgate method.The appearance of the protruding pin is not conspicuous on the appearance of the brush handle, there is no large cut surface caused by gate cutting, and there are design restrictions. Even when gripping the handle, the traces of the gate do not hit the touch feeling even when gripping the handle, and the traces of the molding gate are not conspicuous on the surface side of the brush handle, resulting in a smooth surface finish and a good print finish. The appearance is good, and the product design is flexible because it can be produced without being limited to the case design, and the product value is improved because a large protruding pin with a large cross-sectional area can be used at the time of mold release. It is difficult, and even if a small deformation occurs, it is inconspicuous and has little effect on the product value. Can the accuracy of product dimensions significantly products with reliable increase, the effect of the practical quality control is easy.

Further, in the molding die according to claim 4, since the ejection pin is not conspicuous in the handle hole, a thick ejection pin having a flat surface can be used, so that the releasing work can be stably performed and the ejection pin has a large diameter. In addition, the durability of the pin is increased, and the surface of the pin that abuts against the contact surface is flat, making it easy to process. In addition, even if there is a step with the surroundings of the pin, it is hard to stand out and mass-produces a brush handle with a good appearance. In addition to being possible, there is no need to adjust a cutting device for uniform gate cutting, which is required in the molding side gate method at the time of molding, and there is also no effect of cutting chips, which is an effect that the production cost can be significantly reduced.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a cut-away side view of a product, FIG. 2 is a partially enlarged vertical sectional view, FIG. 3 is a plan view thereof, and FIGS. Explanatory sectional view, FIG.
G is an enlarged vertical sectional view of the end portion of the brush handle. 1 ... Flocking part, B ... handle end face, C ... parting face, 1 ... head, 2 ... neck part, 3 ... grip handle part, 4 ...
... Gate, 5 ... Locking hole, 6 ... Abutting surface, 7 ... Cavity, 8 ... Mold, 9 ... Submarine gate, 10 ...
… Partitioning projections, 11, 12… Push-out pins.

Claims (5)

[Claims] 1. A brush handle comprising a handle (3) having a head (1) of a flocked portion (A) at one end through a neck (2), which is injection molded by a submarine method using a synthetic resin. Therefore, the gate (4) is provided on the end surface (B) of the handle (3), and a supporting hole (5) for suspending the handle is formed near the gate (4). A brush handle, characterized in that it has an abutment surface (6) for a protruding pin in the hole (5). 2. A contact surface portion (6) with which the tip end of a product ejecting pin engages at the time of molding at a position along the parting surface of the molding die, in the engaging hole. The brush handle according to claim 1, further comprising: 3. A pair of molds (8), (8) forming a cavity (7) of the brush handle, the handle end surface (B).
A submarine gate (9) is installed at the position where
Molding partition protrusions (1) of the support holes (5) in the molds (8) (8)
0) is provided, and the partition projection (10) is provided with a surface portion which forms the contact surface portion (6) of the protrusion pin (11), and the protrusion pin 12) is further provided on the flocked surface portion of the head (1) of the brush handle. A mold for forming a brush handle, which is characterized by being provided. 4. A partition projection (10) projecting in the cavity (7) forms a support hole (5) penetrating in a vertical direction on a parting surface of a mold, The brush handle according to claim 3, wherein a parting line surface is provided as an abutting surface portion (6) in the through hole, and a protruding pin (11) is attached to the abutting surface portion (6) so as to be able to come into contact with and separate from it. Mold for molding. 5. A partitioning projection (10) projectingly provided in the cavity (7) has an outer periphery forming a hole having a diameter smaller than the diameter of the ejecting pin (11), and at least a plant. The mold for brush handle molding according to claim 3 or 4, which is provided on the side where the pores (13) are present.