JPH0136402B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gypsum mold holder that prevents damage during molding of a gypsum mold in a roller-type potter's wheel molding machine or water trowel potter's wheel molding machine used for molding ceramics and the like.

Conventionally, various types of holder for holding this plaster mold have been known, but the one shown in Figs. 1 and 2 described in Publication of Utility Model Publication No. 53-42601 is the one with the simplest structure. There are ingredients.

To explain what is shown in FIGS. 1 and 2, the holder D attached to the upper end of the rotating shaft S is
The plaster mold P is suspended and held by a dowel rubber R interposed between the outer peripheral surface P' of the plaster mold P and the inner peripheral surface D' of the upper part of the holder D. B and receiver D
An escape gap K is provided between the inner bottom surface B' of the
The structure is such that the support D does not support the plaster mold P at the bottom. This gap K has variations in the dimensions of each plaster mold P placed on the holder D, and the dimensions of the outer circumferential surface P' which is suspended and held at the top and the dimension from the position where it is held to the bottom outer surface B. Because the plaster mold is not always constant due to wear caused by its use, it is difficult to securely hold the plaster mold P in the holder D at both the top and bottom, and it is extremely difficult to rotate the plaster mold D to form the mold. Since this is inconvenient, the plaster mold P is always fitted only on the upper outer circumferential surface P' (the fitting part of the plaster mold is tapered even if it wears out, so it lowers a little and can be tightly fitted). ) The bottom part is a gap provided for the purpose of being held in a suspended position apart from the support D. In this type of product, as shown in Fig. 2, clay H is put into a plaster mold P placed in a receiver D, and the clay H is pressed and rolled using a roller trowel or water trowel T. When doing this, not only is the weight of the plaster mold P and clay H applied, but also a large molding pressure is applied especially in the downward direction, making the lower corner C of the plaster mold P prone to cracks and breakage. . Therefore, in order to prevent this, the wall thickness of the plaster mold P must be made sufficiently thick, or a reinforcing frame must be inserted to make it strong enough to withstand this, or it cannot be used.

This invention solves these problems and allows safe use of thin, low-strength plaster molds without the need for metal reinforcing frames, etc., without damaging them during molding, thereby maintaining smooth production. The purpose is to

The basic structure of this invention is that a compression spring and a rolling body are interposed in an outer frame that is attached to the upper part of a rotating shaft, has an outer circumferential support part at the upper part, and has a hollow protruding ring part in the center. An inner frame having a flange at its upper end is fitted, and the inner frame supports the outer bottom surface of the plaster mold below during rotational molding.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In this embodiment, as shown in FIG.
A support part 3 is formed by pasting dowel rubber R on the outward-opening inclined surface of the upper inner peripheral surface of the outer frame 2 in the shape of a saucer. An annular inclined surface 5 having an upward slope in the direction is formed, and the bottom part 6 of the outer frame 2 is fixed concentrically to the upper end of the rotating shaft S by a plurality of bolts 7.

The saucer shape of the outer frame 2 is open at the top, has a protruding ring part 4 in the center with a hollow part inside, and has a main body part with a U-shaped cross section below the protruding ring part 4. It is a matter of form.

Inside the outer frame 2, a cylindrical inner frame 8 in the shape of a saucer with a flange 13 at the upper end is fitted so as to be movable up and down. A compression spring 12 is interposed in the gap 11 between the inner frame 8 and the inner frame 8 to elastically push it up.

The magnitude of the elastic force of the compression spring 12 is such that in an empty state before the plaster mold P is placed on the inner frame 8, the inner frame 8 is pushed upward, and the plaster mold P is placed on the inner frame and the plaster mold P is The size is such that the inner frame 8 descends to follow the descent of the plaster mold P against the elastic force when weight is applied. That is, the upper outer peripheral surface of the plaster mold P is held by the outer frame 2, and the inner frame 8 is kept applied to the bottom from below.

A deaeration hole 10' is bored in the bottom 9 of the inner frame 8, which communicates the deaeration hole 10 provided at the center of the outer frame 2 and the rotating shaft S through a gap 11.

The flange 13 of the inner frame 2 is inserted into the protruding ring 4 of the outer frame 2, and a plurality of spheres 16 are interposed in the space 15 between the lower surface 14 of the flange 13 and the inclined surface 5. There is. Note that a rod-shaped body may be used instead of the sphere 16.

The operation of the present invention will be explained based on the drawings of the embodiment. As shown in FIG. 4, when the plaster mold P is placed on the inner frame 8 while the rotating shaft S has stopped rotating,
The weight of the plaster mold P is added, and the inner frame 8 descends against the elastic force of the compression spring 12 interposed below.
The tapered outer circumferential surface of the plaster mold P fits into the inner circumferential surface of the dowel rubber R of the outer frame 2 and stops at a position where it is held. At this time, the flange 13 of the inner frame 8
is located at a vertically intermediate position within the space 15 of the protruding ring portion 4 of the outer frame 2, and is away from the sphere 16. When the inner frame 8 is lowered, the air trapped within the outer frame 2 is discharged to the outside through the degassing holes 10.

Next, as shown in FIG. 5, when the rotating shaft S is rotated, the plurality of spheres 16 interposed in the protruding ring part 4 of the outer frame 2 are moved by centrifugal force to the inclined surface of the protruding ring part 4. 5 is moved upward in the direction of arrow Q, and the sphere 16 abuts against the lower surface 14 and moves outward within the space 15 having a wedge-shaped cross section formed between the inclined surface 5 and the lower surface 14 of the flange 13 of the inner frame 8. It stops when it moves to a position where it is prevented from moving. Due to the action of the spheres 16, the inner frame 8 is fixed in its position within the outer frame 2 during rotation, and is stabilized in the vertical direction.

Next, as shown in FIG. 6, the clay H is put into the rotating plaster mold P, and molding is performed by lowering the molding iron T while rotating it. During molding, the weight of the plaster mold P, the weight of the clay H, and the downward molding pressure from the molding iron T overlap and are applied to the plaster mold P, but these weights and pressures are transferred to the upper outer peripheral surface of the plaster mold P. By holding the outer bottom surface B in close contact with the upper surface of the bottom portion 9 of the inner frame 8, the weight and pressure are dispersed and held, and in particular, the bottom portion of the plaster mold P is stably supported from below. , damage to the plaster mold P during molding can be prevented.

When the molding is completed, the rotation of the rotating shaft S is stopped, and the plaster mold P is taken down, the inner frame 8 is pushed up by the elastic force of the compression spring 12, and the space 15 in the protruding ring part 4 is vertically moved. Since the spheres 16 each roll inward on the inclined surface 5, the empty inner frame 8 on which the plaster mold P is not placed has a compression spring. The weight of the inner frame 8 is not supported by the sphere 16 only. In this state, continuous molding is performed by waiting for the next new plaster mold P to be placed and repeating the above steps one after another.

Since the present invention has the above configuration, it has the following advantages.

(1) Since the plaster mold being molded is supported by both the top outer circumferential surface and the bottom outer surface, it is possible to safely mold the plaster mold without damaging it even when large molding pressure is applied. It has become possible to use even weaker plaster molds whose wall thickness has been reduced to about one-half of that of conventional plaster molds. By making this thin plaster mold usable, we can expect the following ripple effects.

In other words, a. Normally, 500 or 600 plaster molds are manufactured in order to mold one type of product, so 1
Even by reducing the wall thickness slightly per mold, a large amount of mold material can be saved overall.

b) Since the plaster mold is lightweight, it is easy to handle and transport, and the molding process
This helps reduce the weight of each machine in the drying process.

C. Because the wall is thin, the time required to dry the plaster mold to remove moisture absorbed by it can be significantly reduced, which improves production efficiency, especially in mass production.

D. It is now possible to use molds made of materials that previously could not be used because they have excellent water absorption but low strength, so the time from molding to demolding of the product can be significantly shortened.

(2) Even if the external dimensions of a large number of plaster molds used to mold one type of product vary, the outer peripheral surface of the upper part of the plaster mold is first held securely by the outer frame and then rotated at high speed. The bottom of the plaster mold is then supported by an inner frame that is raised by the necessary amount using centrifugal force, so that it can be stabilized to withstand any fluctuations. This enabled us to ensure safe molding at all times.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a conventional receiver, Fig. 2 is a longitudinal cross-sectional view of the conventional receiver, Fig. 3 is a longitudinal cross-sectional view of an embodiment of the present invention, and Figs. It is a diagram. (Explanation of symbols of main parts), 1... Receiver, 2...
... Outer frame, 3... Support part (of the upper part), 4... Protruding ring part, 5... Inclined surface, 6... Bottom part (of the outer frame), 8...
...Inner frame, 9...Bottom (of the inner frame), 12...Compression spring, 13...Brim part, 16...Sphere, P...
plaster mold.

Claims (1)

[Scope of Claims] 1. A plaster mold holder that is fixed to the tip of a rotating shaft S of a potter's wheel molding machine that performs molding during high-speed rotation and that accommodates and holds a plaster mold, the upper end of which holds the outer surface of the plaster mold. A saucer-shaped outer frame 2 having a hollow protruding ring part 4 in the center thereof, and a collar part 1 having a substantially horizontal lower surface at the upper end.
A saucer-shaped inner frame 8 having 3 is provided separately, and the flange 13 of this inner frame 8 is directed outward from the inner bottom of the protruding ring part 4 of the outer frame 2 to form a plurality of holes on the upwardly sloped slope 5. A rolling body 16 is interposed and fitted into the protruding ring portion 4 of the outer frame 2, and a compression spring 12 is interposed between the bottom outer surface of the inner frame 8 and the bottom inner surface of the outer frame 2. Features a plaster mold holder for the potter's wheel molding machine.