JPH0116508B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a medical device used for sterilization, blood filtration, drug purification, etc.

Conventionally, this kind of fine pore size filter has been widely used for sterilizing infusions, blood samples, purifying drug solutions, and the like. Such filters mainly consist of two housing parts and a filter element, and are manufactured by mounting the filter element between the two housing parts in a liquid-tight manner.The following two methods are typical. There is.

In the first method, a filter element is set in a lower housing, the two are welded together using a heat sealer, and then the upper and lower housings are ultrasonically sealed at their outer peripheries. In the second method, the filter element is sandwiched between the outer peripheral edges of the upper and lower housings to be welded, and two ultrasonic welders are used to simultaneously weld both housing parts and the filter element from above and below.

The disadvantage of the first method is that it requires two assembly steps: heat-sealing the filter element to the lower housing and then ultrasonically sealing the upper and lower housings, the sealing methods are different, and the process is complicated. The disadvantage of the second method is that the filter element is sandwiched between the upper and lower housings and ultrasonically welded all at once, reducing assembly steps, but the welding conditions for the filter housing and the welding conditions for the housings must be the same. It won't happen. However, filter elements are generally made from cellulose-based resins such as cellulose acetate (with a melting temperature of approx.
200℃), and the housing is made of MBS resin with a considerably lower melting temperature (melting temperature approximately 80℃).
etc., the welding results in significant unnecessary loading of the filter element or housing and tends to weaken the sealing portion of the filter element. In addition, in either method, the filter element is welded to the housing, and since the seal part of the filter element is molten, the material of the filter is considerably limited and its pressure resistance is poor. There's a problem. Furthermore, the oversized device manufactured by either method has the disadvantage that it significantly hinders the provision of inexpensive and safe oversized devices to users.

Therefore, an object of the present invention is to fix the filter element and assemble the housing at the same time, and to install the filter element in a simple process without melting the filter element or causing liquid leakage between the housing parts. Our goal is to provide the safest and cheapest medical devices possible.

According to the present invention, in a medical device in which a filter element is installed between two housing parts, a welding rib is provided on the outside and the welding rib is provided on the inside around the entire circumference of the open end of one housing part. A caulking rib for filter pressing that is longer and wider than the rib is formed in parallel, and a first step portion and a first step portion are formed on the entire periphery of the opening end of the other housing portion at locations corresponding to the welding rib and the caulking rib. , forming a second step part deeper and wider than the first step part, and forming the tip of the welding rib to be tapered, and setting the angle of the proximal end of the tapered tip welding part to 40° to 120°. ,
The width of the proximal end is set to be in the range of 1/2 to 1/5 of the width of the caulking rib, and the unfused part of the welded rib is pressed against the first step by melting the welded part at the tip of the welded rib. Accordingly, the caulking rib liquid-tightly seals the second step through the filter element, and at the same time, the caulking rib presses and fixes the filter element within a range of 3/4 to 1/4 of its thickness. Provided is a medical device characterized by the following configurations.

Here, it is preferable to provide means for preventing the first step outer periphery burr of the other housing part, which is welded by the welding rib of the housing part, from protruding to the outside of the container.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The medical device of the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings.

As shown in FIG. 1, a filter element 1 according to the invention preferably has a filter element 4 inserted and fixed between a first housing part 2, which is preferably circular, and a second housing part 3, which is also circular, as shown in dotted lines. This is what happens. In particular, the invention relates to a filter that can be fixed by pressing the filter element 4 in the housing part when sealing the two housing parts 2 and 3, which will be described in detail below. The inlet 5 is connected to the liquid to be filtered, such as infusion, blood, or medicinal solution, through a suitable tube, and foreign matter larger than a predetermined size, such as bacteria, is removed by the filter element 4. 6, which is used for a wide range of applications such as sterilization filters, blood filters, and drug solution purification filters.
Therefore, the filter element 4 is a special one with a fine pore size, and is mounted in such a way that there is no leakage of liquid between the housing parts 2 and 3, which are preferably transparent, and has sufficient pressure resistance. This is an important issue. However, as described above, various problems have arisen because the pore size element 4 has conventionally been fixedly attached to the housing parts 2 and 3 by welding. Therefore, the overpass device of the present invention attempts to solve the above-mentioned problems as described below. Note that any method for sealing the housing parts in a liquid-tight state may be used, such as gluing, crimping, or welding, as long as the filter element can be press-fixed, but here we will specifically explain a sealing method using ultrasonic waves. .

FIG. 2 shows a cross section taken along the - line in FIG. 1, and shows the state before both housing parts are welded together.
In FIG. 2, the upper first housing part 2 has an outer circumferential welding rib 7 and a filter element pressing circumferential rib 8 slightly inside the outer circumferential welding rib 7 extending downward from the housing part 2, as will be described in detail later. Protrude at an appropriate length. These ribs 7 and 8
are preferably provided upright at an angle of approximately 90° to the housing part 2, but the ribs 7 may also be provided at a considerable angle and the ribs 8 at a slight angle to the housing part 2. . In FIG. 2, the second housing 3 located on the lower side has a third step 9 for preventing burr generation during welding, and a first step that is welded by contacting the welding rib 7 of the first housing portion 2. Part 10
A second step portion 11 for placing the filter element 4 and pressingly supporting it between it and the caulking rib 8 of the first housing portion 2 is sequentially provided in a circumferential manner on the periphery. It is preferable to provide a large number of reinforcing ribs 12 in order to withstand the pressure of liquid or the like that comes into contact with the lower surface of the container 4. At this time, each space between the reinforcing ribs 12 is
It forms a passage for the evaporated liquid, etc., and communicates with the outlet 6.

To weld both housing parts 2 and 3 and to fix the filter element 4, as shown in FIG. , the first housing portion 2 is aligned and positioned over these, and the ultrasonic horn 14 is applied to simultaneously apply an appropriate pressure and apply ultrasonic waves of an appropriate frequency for an appropriate time as shown by the arrows.

When ultrasonic energy is applied by the ultrasonic welder in this way, the welding rib 7 of the first housing part 2 melts and welds both housing parts, and at the same time the melted rib 7 loses its length due to the pressing force. The first housing part 2 is pushed down towards the second housing part 3, and the caulking rib 8 of the first housing part 2 presses the filter element 4 between it and the third step 11 of the second housing part 3. Can be crimped to prevent liquid from leaking. It has been found that in order to perform such welding and caulking at the same time using ultrasonic sealing, there are several conditions regarding the dimensions and shapes of the components of the overcoat shown in FIG. These conditions will be explained in detail with reference to FIG.

Generally, when welding using an ultrasonic welder, the smaller the area of the contact area is, the more advantageous it is for exothermic welding. Therefore, it is preferable that the tip of the welding rib 7 be tapered as shown in FIGS. 2 and 3. Moreover, when there are two simultaneous contact points, that is, in this example, the welding rib 7 of the first housing part 2 and the first step part 10 of the second housing part 3, and the caulking rib 8 of the first housing part 2 and the filter element. 4, and in such a case, there is a possibility of welding at both the contact areas of 7 and 10 and 8 and 4. However, it is impossible to weld both contact areas uniformly and at the same time due to differences in materials and distortion of the molded product.Also, welding with a filter element sandwiched between the housing parts may be made of different materials. many,
As mentioned above, even if the filter element is welded, it is not preferable because it weakens the filter element and tends to cause incomplete welding of the housing.

Therefore, in the present invention, only the welding ribs 7 are heated and melted, and the kashimeri ribs are not melted even though they generate some heat. For this purpose, it is necessary to make the width Z of the welding rib 7 smaller than the width Y of the caulking rib 8. Further, it is preferable that the welded portion 15 at the tip of the welded rib 7 is tapered as described above, and the width X of the base portion thereof is preferably equal to or smaller than the width Z of the welded rib. confirmed. In particular, it has been confirmed that a suitable range is Y/2≧X≧Y/5. This is because if X is larger than Y/2, the heat generation of the caulking rib 8 will be considerable, and if X is smaller than Y/5, the welding force due to melting of the melted portion 15 will not be sufficient. Further, it was confirmed that the angle R of the tip of the melting part 15 is preferably in the range of 40° to 120°, and 90° is optimal. If R is larger than 120°, it will take time to melt and it will be difficult to control the welding. If R is smaller than 40°, sufficient welding force will not be obtained, and conversely, if you try to obtain sufficient welding force, the length to be melted will increase. This is because the distance becomes too large than the caulking distance of the filter element, which will be described later.

Another important condition is that when the welded part 15 at the tip of the welded rib 7 is melted by the ultrasonic welder and seals the outer peripheral edges of both housing parts, the welded rib 7 is shortened by the length L of the welded part 15. The first housing part 2 is thus pushed down by L, but
At this time, the caulking rib 8 formed on the first housing portion 2 is also pushed down by an amount L, thereby making it possible to apply a pressing force to fix the filter element 4. The caulking distance (strength) of the filter element 4 by the caulking rib 8 is preferably such that the thickness when caulked is in the range of 3/4 to 1/4 of the original thickness U of the filter element 4. . If the pressing distance (strength) of the filter element 4 is out of this range, the liquid that should be leaked will leak from this caulked part.
It was confirmed that the intended purpose could not be achieved.

In order to keep the caulking strength of the filter element 4 by the caulking rib 8 within a certain range, as shown in FIG.
It has also been confirmed that it is preferable that the welded part 15 at the tip of the welded part 15 has a vertical part 16 and then a horizontal stepped part 17. It is preferable that the melting length L is the distance from the tip of the melting rib 7 to the vicinity of the horizontal step portion 17. At this time, the ribs 7 and 8 of the first and second housing parts, the step portions 10 and 11, and the thickness of the filter element 4 should be designed so that the crimping rib 8 crimps the filter element 4 within the above range.

In such a configuration, both housing parts 2
It has also been found that when 3 and 3 are sealed, the water part of the molten part 15 enters the space 18 between both housing parts, and a part of it enters the space 19 between the filter element 4, so that no burrs are formed on the outside. . but,
As shown in Figure 5, the second
Circumferential groove 2 corresponding to the melting rib on the housing part
0, the third step 9 of the second housing portion 3 does not necessarily need to be formed, and the generated burrs can be finished later, so the structure shown in the figure is not necessary. is not necessarily the case. In short, it is sufficient that the two housing parts are reliably welded by melting the welding ribs, and that the filter element 4 is caulked without leaking at this time.

A filter membrane plan made of acetyl cellulose with a thickness of 150μ is set between the housing parts made of MBS resin as shown in Figure 3, and an ultrasonic welder (Mode 18600 manufactured by Bronson) is used to generate a 20KHz signal.
Ultrasonic sealing was performed using ultrasonic waves with a frequency of , a pressing pressure of 70 psi, and a welding time of 0.2 seconds. As a result of tests, the filter membrane thus obtained and the housing showed no leakage at a pressure of 1 kg/cm ² , and the housing had a withstand pressure of 4 kg/cm ² or more.

As is clear from the above explanation, the medical device of the present invention provides many advantages as follows.

(1) Sealing of the housing and fixing of the filter element can be performed in one assembly process using a single ultrasonic welder, the sealing and fixing are highly reliable, and the filter element can be manufactured at low cost. .

(2) In order to fix the filter element by caulking instead of welding as in the past,
A wide variety of filter elements can be selected, the filter element will not be damaged, there will be no variation in pressure resistance, and it will be strong against positive pressure and reverse pressure.

The above description only shows preferred examples of the present invention,
Various modifications can be made within the scope of the invention, for example, instead of welding the housing parts 2 and 3 together, the two housing parts are snap-fitted together, and the snap-fit allows for a snap fit between the two housing parts. It is possible to configure the filter element so that the filter element is sealed in a liquid-tight state and at the same time the caulking rib presses the filter element to a required thickness.

[Brief explanation of drawings]

FIG. 1 is a side view of the over-container of the present invention, FIG. 2 is a cross-sectional view of the over-container along the - line in FIG. 1, showing the state before welding, and FIG. 3 is a welded housing part. FIG. 4 is a cross-sectional view showing the shape of the welding rib of the first housing portion, and FIG. 5 is a cross-sectional view of another example of the structure of the welded portion. Explanation of symbols 1... Filter element, 2, 3... Housing portion, 4... Filter element, 7... Welding rib, 8... Crimping rib, 9, 10, 11...
Stepped portion, 13... Receiving jig, 14... Ultrasonic horn,
15... Welded part, 20... Groove.

Claims (1)

[Claims] 1. In a medical device in which a filter element is installed between two housing parts, one housing part has a welding rib on the outside and a welding rib on the inside around the entire circumference of the opening end. A caulking rib for filter pressing that is longer and wider than the welding rib is formed in parallel, and a first stepped portion is formed around the entire circumference of the opening end of the other housing portion at a location corresponding to the welding rib and the caulking rib. and forming a second step portion deeper and wider than the first step portion, and forming the tip of the welding rib to be tapered,
The angle of the proximal end of the tapered tip welded part is 40° to 120°, and the width of the proximal end is in the range of 1/2 to 1/5 of the width of the caustic rib. As the unfused portion of the welding rib is pressed against the first step, the caulking rib liquid-tightly seals the second step through the filter element, and at the same time, the caulking rib seals the filter element by its thickness. A medical device characterized by being configured to be fixed by pressing within a range of 3/4 to 1/4 of the diameter. 2. Claim 1, characterized in that means is provided for preventing the first step outer periphery burr of the other housing part, which is welded by the welding rib of the one housing part, from protruding to the outside of the filter. Medical devices listed in .