JPS5837079B2 - Fun matsu hot yukusei keiki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a powder compression molding machine used as a tablet manufacturing machine or the like.

For example, tablet making in a tablet manufacturing machine is simply to say, powder is filled into a mortar installed on the periphery of a rotary disk into which a lower punch is inserted, an upper punch is inserted into this, and the upper and lower punches are After compressing the powder by pushing it through a compression roll, the upper punch is removed and the lower punch is pushed up to push the molded product out of the white.

By the way, the compression roll is generally installed so that its axis of rotation is tangential to the maximum compression point of the rotary disk, and the punch passes through the compression roll with some slipping relative to this roll.

This sliding phenomenon causes the contact surfaces of the punch and compression roll to wear out, which not only shortens their lifespan and becomes an obstacle to increasing tableting speed and compression force, but also causes the punch to spin, resulting in engraved tablets and irregularly shaped tablets. was unsuitable for manufacturing.

Therefore, even if you use a key etc. to stop the spin of the pestle,
The torsional force applied to the punch causes large lateral pressure to act on the key and keyway, which may cause unexpected damage to various parts of the drive mechanism.

However, the punch comes into contact with the compression roll in section XX in Fig. 1,
The amount of slippage So of the punch on the compression roll surface during this time can be determined from FIG. 1 by the following equation.

Here, in FIG. 1, Rr is the radius of the compression roll 1, and H is the radius of the punch 2.
The compression stroke, Rt, is the radius of the movement locus 3 of the center of the punch 2 attached to the rotary disk, and the center line connecting the center A of the rotary disk and the center B of the compression roll 1, and the distance between the punch 2 and the compression roll 1. The horizontal distance between the center line C and a parallel line passing through the point of first contact, Rt', is the horizontal distance between the pestle 2
The radius of the arc passing through the point where the first contact with the compression roll 1,
4 is the locus of the contact point of the punch 2 with the compression roll 1.

In other words, if we calculate the horizontal distance 2l from the compression roll 1 side,
According to Vitagoras' theorem, (2/)2=Rr2-(Rr-H)2, where H
The value of 2 is negligible, and rearranging the above equation results in (2l)2=2HRr.

If we calculate 2l from the rotary disk 3 side, then according to the Pythagorean theorem, (2l)2=Rt2-(Rt-So)2, where the value of So2 is negligible, and the above equation can be rearranged. Then, (2l)2÷2SoRt.

Therefore, from each of the above equations, S o = ”H.

Rt As can be seen from this equation, in order to reduce the slippage amount So, it is necessary to reduce the radius Rrt and the compression stroke H, or to increase the radius Rt.

However, if the radius Rr is made smaller, the compression speed of the punch 2 suddenly increases, which is undesirable. If Rt is increased, the machine becomes larger, which is not desirable.

For this reason, by using a conical roll having a conical surface and arranging the rotation axis at a predetermined angle,
There is a method that eliminates slippage by making the circular motion trajectory of the pestle due to the rotation of the rotary disk match the shape of the circular motion trajectory of the conical roll projected onto the rotary disk, but this method has the following drawbacks. There is.

That is, since the rotation axis of the conical roll is inclined, the forces acting on the roll bearings that support both ends of the conical roll are greatly different, making it difficult to keep the conical roll parallel to the rotary disk.

The compression force generated by the first compression force generates thrust on the rotating shaft, which may cause the rotating shaft to move, in which case the tablet (
Product) Dimensions change.

Furthermore, it is difficult to process the roll bearings, especially the bearings on the center side of the rotary disk, making it difficult to achieve precision and easily causing play.

These shortcomings are related to locking accuracy, machine maintenance management,
This had a major negative impact on lifespan and was not a practical countermeasure.

This invention was developed based on the above-mentioned circumstances, and its purpose is to move the compression roll in parallel so that its rotation axis is located on the rotation direction side of the rotary disk with respect to the radial direction of the rotary disk. It is an object of the present invention to provide a powder compression molding machine in which the amount of slippage of the punch can be significantly reduced without the disadvantages of using a conical roll.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 11 denotes a rotary disk, which is formed by integrally forming an upper punch holding disk 12 and a lower punch holding disk 13, and is adapted to rotate clockwise, for example.

A large number of discs are disposed along the periphery of the rotary disk 11 (only three are shown for the sake of explanation).

) are provided at equal intervals, and a mortar 14 is provided inside each of these holes.

On this day, the bottom of the 14 is shaped by the upper end of the lower pestle 16, which will be described later.

The upper punch holding board 12 has upper punches 15 facing the dies 14..., and the lower punch holding board 13 also has lower punches 16.
is provided.

The head of the upper punch 15 is suspended by an upper punch guide rail 17, so that the upper punch 15 moves together with the rotary disk 11 at a predetermined height.

Further, the lower punch 16 is moved together with the rotary disk 11 at a predetermined height by a lower punch guide rail 18.

1, 19 is a hopper containing powder, and this is the rotary plate 11
Powder is fed little by little into a feeder 20 placed on the top surface of the machine.

21 is a chute for taking out the tablet (product), and 2
Compression rolls 2 and 23 are used to press the upper punch 15 and the lower punch 16, and these rolls are made of normally used cylindrical bodies with extremely short widths, and are provided to rotate via rotating shafts 22a and 23a. .

As shown in FIG. 3, these rotating shafts 22a and 23a are moved in parallel to the radial direction of the rotary disk 11 by a predetermined amount in the direction of rotation of the rotary disk 11, preferably at a position in FIG. It is arranged at a position shifted by 1/2 of 2l.

Hereinafter, this amount of deviation will be referred to as an offset amount.

According to the powder compression molding machine having the above structure, the rotary disk 1
1, the feeder 20 is moved from the mill 1 at position a in Fig. 2.
The powder is supplied into the compression roll 2 at position b in Fig. 2.
2.23, the powder is compressed by the upper punch 15 and the lower punch 16, and at the position C in FIG. It is extruded from the mortar 14 and taken out from the chute 21.

The upper punch 15 and the lower punch 1 during such an in-operation compression process.
6 spin is sufficiently prevented.

In other words, the reason for this will be explained below.The state indicated by the broken line in FIG. 3 is the same as the explanatory diagram in FIG. Explain using things.

The amount of slippage SO in the state shown by the broken line in the figure (the state shown in FIG. 1) is determined by the following equation.

S cmot '-Rt' cos2 佽水t' (
1-cos2-(1) Here, Rt' is the point where the head of the upper punch 15 first hits the compression roll 22 and the center A of the rotary disk.
This is a straight line connecting these, which is approximately equal to Rt, and the angle 2θ in this state is also approximately equal to 2θI.

Therefore, the above equation (1) is becomes.

Therefore, when the compression rolls 22 and 23 are arranged parallel to the rotational direction by an offset l compared to the state shown in FIG. The amount of slippage Sa during this contact can be expressed as in the above equation (2).

Then, by expanding e08θ and substituting it for the above 0bu, we get the tailor becomes.

Therefore, from the above 3 wipes and equation (5), the slip amount Sa and S
Find the relationship with o.

As is clear from Equation 6), by shifting the position of the rotating shaft 22a by the offset amount l, the amount of slippage is reduced by a factor of 75 compared to the conventional system in which the position of the rotating shaft 22a is not shifted in this way.

However, it has been found that with the lever-forming machine that has achieved such a reduction in the amount of slippage, it does not apply to the pestle enough twisting force to cause almost any practical problems.

Furthermore, according to the above configuration, it is sufficient to simply change the position of the compression roll, and no mechanical change is required, so that there are no disadvantages that occur when using a conical roll.

Note that the value of the offset amount, l, is determined by the stroke H since the radius Rr is given.

However, in general, the value of the stroke H can be changed within a certain range, and therefore the value of the stroke H and the value of the offset amount l change depending on the product dimensions. Even if it is fixed according to the range, the reduction rate of the amount of slippage will only be small, which is bad for the rigidity of the machine.

Of course, the compression roll may be moved in response to changes in the value of the offset amount l, so that the amount of slippage is always minimized.

As explained above, the present invention moves the compression rolls that press the upper and lower punches that rotate together with the rotary disk during compression molding to a position where the rotation shaft thereof is moved parallel to the radial direction of the rotary disk in the direction of rotation of the rotary disk. It was placed in

Therefore, according to this invention, it is possible to reduce the amount of slippage by 1 to an extent that does not cause any practical problems without changing the mechanism, and it also has advantages such as not causing any of the disadvantages that occur when using conical rolls. It has a good effect.

[Brief explanation of drawings]

Figure 1 is a diagram for explaining the amount of slippage in a conventional molding machine, Figure 2 is an explanatory diagram showing the molding machine according to the present invention in cross section and developed, and Figure 3 is a diagram for explaining the amount of slippage in a conventional molding machine. It is a figure for explaining quantity. 11... Rotating disk, 14... Mortar, 15.
... Upper pestle, 16... Lower pestle, 22, 23.
... Compression roll, 22a, 23a ... Rotating shaft, l ... Offset amount.

Claims (1)

[Claims] 1. Compression rolls that press the upper and lower punches that rotate together with the rotary disk during compression molding are arranged at a position where the rotation axis is moved parallel to the radial direction of the rotary disk in the direction of rotation of the rotary disk. Features of powder compression molding machine.