JPH0116587Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a urea resin pattern molding mold, and more specifically, to a urea resin pattern molding mold having an undercut-shaped portion in precision casting using urea resin.

Conventionally, as a mold for molding a urea resin pattern having an undercut-shaped portion, a mold using a cylinder mechanism, a mold using a link mechanism, etc. have been employed.

For example, FIG. 1 shows a cross-sectional view of a urea resin pattern molding mold having an undercut feature using a conventional linkage mechanism.

In FIG. 1, the slide insert 4 is connected to the support 11
A connecting plate 7 is rotatably attached to a lever 9 attached to a shaft 10 that is held by a bearing provided in the holder, and furthermore, a slide insert 4 and the connecting plate 7 are in contact with the connecting plate 7. Fixing member 6 that fixes
The slide insert 4 can be removed and inserted by a link mechanism via the link mechanism.

After forming the outer shape of the product cavity 5 by clamping the movable mold 1 and the fixed mold 2, the slide insert 4 is inserted using the link mechanism described above, and the undercut at the tip of the slide insert 4 is inserted. By bringing the shaped portion 4a into contact with the movable input 3,
Product cavity 5 with undercut shaped part
The urea resin is injected and molded from an injection port (not shown), and then the slide insert 4 is extracted from the product cavity 5 using the link mechanism described above, and the mold is opened to take out the product urea resin pattern. It is something.

The above example shows an example of a urea resin pattern molding mold that has an undercut shaped part using a link mechanism, but even when a cylinder mechanism is used, a slide insert that forms an undercut shaped part by a hydraulic cylinder can be used. Since it is necessary to insert and extract the link mechanism, the mold structure becomes complicated, similar to when a link mechanism is used.

In this way, urea resin pattern molding molds with undercut shaped parts using conventional cylinder mechanisms or link mechanisms have complicated mold structures, resulting in high mold costs and long mold manufacturing processes. As a result, mold delivery time will be delayed.

Failures occur frequently and maintenance costs are high.

There are drawbacks such as.

This invention provides an eccentric cam mechanism in the mold that operates in conjunction with the opening and closing of the mold, and by molding a urea resin pattern with an undercut shape,
The purpose of the present invention is to simplify the mold structure, reduce mold costs, shorten mold manufacturing delivery time, and provide a urea resin pattern molding mold with fewer failures.

According to the present invention, a fixed type and a support are installed, and one side of the support forms an eccentric cam on the shaft held by the bearing part of the support, and a protrusion is provided at the end of the cam shape. On the other hand, there is a fixed base on which a square rod-shaped lever is rotatably provided via the shaft, a movable mold and a push rod, and the push rod is slanted downward toward the square rod of the lever. The movable base is provided with a fulcrum at its tip for pressing the square bar of the lever, and the movable base is shaped like a flanged bar and is arranged to be able to slide through the fixed die, with one end attached to the base. The product has the shape of an undercut part of the urea resin pattern, the flange part at the other end is in contact with the eccentric cam part, and further, by the spring placed in the counterbore part recessed in the fixed mold,
A product urea resin pattern molding mold having an undercut-shaped part, which is composed of a slide insert biased in the extraction direction, and when the mold is closed, the fulcrum of the tip of the push rod is the square bar part of the lever. As a result, the eccentric cam part of the lever pushes the slide insert against the spring force, and the tip of the slide insert becomes the undercut part of the product urea resin pattern to form the product cavity. When the mold is opened, the push rod moves up together with the movable mold base, and the slide insert slides in the ejection direction due to the spring force, so that the flange surface of the slide insert moves on the eccentric cam part. This is achieved by using a urea resin pattern molding die that stops when it reaches the protrusion.

Embodiments of the present invention will be described below based on the accompanying drawings.

Fig. 2 is a diagram showing the state of the urea resin pattern molding mold according to the present invention after the mold is closed (state at the time of urea resin injection), and Fig. 3 is a diagram showing the open state of the urea resin pattern molding mold according to the present invention. FIG.

In the description of this embodiment, the same or equivalent parts as in the conventional example shown in FIG. 1 will be designated by the same reference numerals as in FIG. 1, and the description will be omitted.

As is clear from FIG. 1, the fixed base 13
A fixed mold 2 and a support 14 are installed, and on a shaft 15 held by a bearing part of the support 14, one forms an eccentric cam and has a protrusion 16a at the end of the cam shape, and the other has a protrusion 16a at the end of the cam shape. A square rod-shaped lever 16 is rotatably provided via the shaft 15.

Furthermore, the movable die 1 and the push rod 17 are installed on the movable die base 12, and the push rod 17 is provided with a lever 16.
A fulcrum 18 for pressing the square bar of the lever 16 is provided at its tip.

On the other hand, a flanged rod-shaped slide insert 4 is slidably arranged to pass through the fixed mold 2, and one end has the shape of an undercut part of the product urea resin pattern, and the other end has a flange part and the eccentric cam A spring disposed in a counterbore recessed in the stationary die 2 is biased in the extraction direction.

With this configuration, when the mold is clamped, the fulcrum 18 at the tip of the push rod 17 vertically installed on the movable mold base 12 pushes the square rod part of the lever 16, and the slide insert 4
By pushing up against the force of the spring 19, the product cavity 5 is formed by contacting the movable mold insert 3 provided in the movable mold 1, and urea resin is injected from an injection port (not shown).

When the mold is opened, as the movable mold base 12 rises, the spring 19 provided between the slide insert 4 and the counterbore recessed in the fixed mold 2 causes the slide insert 4 to slide downward on the eccentric cam. The lever 3 comes into contact with a protrusion 16a provided on the lever 3 and stops.

In this way, the protrusion 16a serves as a kind of automatic stop device, and there is an advantage that parts such as a stopper can be omitted.

The pattern forming process is completed by taking out the molded urea resin pattern 20 from the mold.

As is clear from the above, according to the urea resin pattern molding mold according to the present invention, an eccentric cam mechanism that operates in conjunction with the opening and closing of the mold is provided in the mold, and by performing undercut shape molding, It has the advantage of simplifying the structure, lower mold cost, faster mold production delivery time, and fewer mold failures.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a urea resin pattern molding mold using a conventional link mechanism, and Fig. 2 is a longitudinal cross-section of a urea resin pattern molding mold incorporating an eccentric cam mechanism according to the present invention when the mold is closed. FIG. 3 is a longitudinal cross-sectional view of a urea resin pattern forming mold incorporating the eccentric cam mechanism according to the present invention when the mold is opened. DESCRIPTION OF SYMBOLS 1... Movable type, 2... Fixed type, 3... Movable insert, 4... Slide insert, 4a... Undercut shaped part, 5... Product cavity, 6... Slide insert fixing member, 7 ... Connecting plate, 8 ... Rotating shaft, 9
... Lever, 10 ... Rotating shaft, 11 ... Support column, 1
2...Movable base, 13...Fixed base, 1
4... Prop, 15... Shaft, 16... Lever, 16a
... Protrusion, 17 ... Push rod, 18 ... Fulcrum, 1
9...Spring, 20...Uria pattern.

Claims (1)

[Scope of utility model registration request] A fixed mold and a support are installed, and a lever having an eccentric cam on one side and a protrusion at the end of the cam shape, and a square bar shape on the other side is attached to the shaft held by the bearing of the support. A fixed base that is rotatable via a shaft, a movable mold, and a push rod are installed, and the push rod is vertically installed toward the square rod of the lever, and the tip of the push rod is attached to the lever. A movable base is provided with a fulcrum that presses the square bar of the base, and a flanged bar is arranged so as to be able to slide through the fixed die, and one end is in the shape of an undercut part of the product urea resin pattern. The flange portion at the other end is in contact with the eccentric cam portion, and is further comprised of a slide insert biased in the extraction direction by a spring disposed in a counterbore portion recessed in the fixed mold. This is a product urea resin pattern molding mold having an undercut shaped part, and when the mold is closed, the fulcrum of the tip of the push rod pushes the square bar part of the lever, whereby the eccentric cam part of the lever applies a spring force. Pushing the slide insert against the pressure, the tip of the slide insert becomes an undercut part of the product urea resin pattern to form a product cavity, and when the mold is opened, the push rod rises together with the movable mold base, A urea resin characterized in that when the slide insert slides in the extraction direction due to spring force, the flange surface of the slide insert moves on the eccentric cam section and stops when it reaches the protrusion. Pattern molding mold.