JP3524842B2 - Heater unit for melting and sealing the opening at the tip of the thermoplastic resin tube - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin which is used when an opening hole of a thermoplastic resin tube is melted and sealed, for example, when a liquid such as a chemical is stored in the tube and then the opening hole is closed. The present invention relates to a heater unit for melting and sealing a tip opening of a resin tube.

[0002]

2. Description of the Related Art When a drug is locally administered to a patient for medical treatment, the drug is enclosed in the tip of a thermoplastic resin tube (hereinafter referred to as "resin tube") and inserted into an organ through the skin. Alternatively, the drug may be administered by incising the tip of the resin tube after guiding the resin tube to the desired administration site via a blood vessel or the like.

In addition, as a medical procedure for diagnosing human organs, the internal organs and X
When a substance with a significantly different linear attenuation is injected, a contrast agent that can see the contour of an organ from the X-ray image of the injected substance may be used. For example, in the case of the gallbladder, iodine agent,
In the case of the digestive tract, barium sulfate is used. In that case, it is necessary to enclose the contrast agent at the tip of the resin tube and guide it to the desired projection location.

[0004] In particular, the iodine agent may cause a rejection reaction in some people, so that it is desirable to enclose it in a resin tube and insert it into the body as a safe medical procedure. When inserting the resin tube into the body, in order to reduce the pain to the patient, do not damage the tissue in the body, and process the shape of the tip so that it does not get caught in the tissue in the body, It is important to form so as to smoothly reach a local part in the body.

For that purpose, there should be no deformation, burrs, edges, etc. of the tip portion sealed in the resin tube. As a countermeasure, after the tip was sealed, it was cut and polished to a smooth surface with a cutter or file, but the resin tube is soft and the finish is thin. However, this method was not satisfactory in terms of quality.

As a method for solving the above problems, Japanese Patent Laid-Open No. 2-194925 discloses a method for processing the tip of a resin tube. The method is to wind an induction coil around a mold provided with an insertion portion of a resin tube so as to surround the insertion portion, insert the resin tube into the insertion portion of the die, and pass an alternating current through the induction coil. This is a method for processing the tip of a resin tube, in which the tip of the resin tube is formed along the inner surface shape of the insertion portion by inductively heating the mold.

However, this method has the following problems. That is, since the entire die is heated, the entire insertion portion becomes hot, and the portion other than the place where the resin tube is required to be heated is softened and the shape is deformed. For this reason, the tip of the resin tube can be molded into the desired shape, but in other parts the thickness becomes uneven and the surface smoothness is lost, so it is used as a resin tube to be inserted into the body. It may not be possible.

[0008]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention An object of the present invention is to form burrs, edges or irregularities around the tip of the thermoplastic resin tube at the time of sealing the opening of the tip, or to make a portion other than the tip. It is an object of the present invention to provide a heater unit for sealing a hole in a front end opening portion of a thermoplastic resin tube which is not deformed by heat of fusion.

[0009]

In order to achieve the above object, in the invention according to claim 1, a cylindrical resistance is provided in a heater unit for melting and sealing a tip opening of a thermoplastic resin tube. A bulging part consisting of concentric circles is formed at the tip of the heating element, and a tube insertion hole with a bottom is formed at the front side of this bulging part, and the bulging part has a smooth front surface. The outer diameter on the front side is the maximum
Is also large and has a small diameter toward the tip of the cylindrical resistance heating element.
There is a taper that changes to
It has a conical shape, a cooling air blowing pipe for blowing cooling air from the rear is inserted into the cylindrical resistance heating element, and a tip end portion of the cylindrical resistance heating element is connected to the cooling air blowing pipe. After the blowing cooling air cools the resistance heating element and the enormous part,
The present invention is characterized in that a slit for allowing the air to escape to the outside is formed, and a voltage applying wire is connected to the rear portion of the resistance heating element.

Further, in the invention according to claim 2,
The cylindrical resistance heating element according to claim 1 and the enlarging part are integrated or detached.
It is characterized by being separated from the country.

[0011]

According to the first aspect of the present invention, the resin tube is inserted by forming an insertion hole, which is slightly larger than the diameter of the resin tube, at the center of the shaft in the enlarged portion, which is one portion of the heater unit. In addition to the purpose as a guide when performing, the expansion of the resin tube is suppressed by the wall surface of the insertion hole even if the tip portion is heated, so that the deformation can be prevented.

On the other hand, in the other part of the heater unit, which is a heating element based on an electric resistor (hereinafter referred to as "resistance heating element"), a pipe for blowing cooling air to the back surface of the contact surface is insulated. Since it is attached via a pipe and slits are formed on both sides of the resistance heating element that face each other, the air that has cooled the abutting surface and the enlarged portion passes through the slits and is discharged to the outside during cooling. Therefore, as a result of efficient cooling, it is possible to instantaneously cool the relevant part. Further, electric wires are connected to both sides of the resistance heating element, which are divided by slits, and a rapid temperature rise can be obtained by applying a voltage from an external power supply device.

[0013] Then, the outer surface of the enlarged portion of the insertion hole is formed, the inclined surface of the conical becomes thicker toward the side with the entrance of the insertion hole from the vicinity of the contact portions are formed. Therefore, the resistance value decreases toward the insertion port, and the temperature distribution due to Joule heat shows that the contact part has the effect of gradually decreasing in the lateral direction while maintaining the temperature required for melting the resin. Due to this effect, a sharp temperature difference does not occur on the side surface of the resin tube. As a result, it is possible to prevent the occurrence of a step or deformation due to the temperature difference on the side surface of the resin tube.

According to a second aspect of the present invention, the resistance heating element has a cylindrical shape in the first aspect, and an enlarging member is provided as a separate member, and both are integrated by a detachable mounting mechanism. The shape and size of can be freely selected, and the optimum heat radiation effect can be selected with this enormous member according to the resin tube to be processed. The material used for the heater unit is typically stainless steel (SUS) or die steel (SKD).

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a heater unit for melting and sealing the tip opening of a thermoplastic resin tube according to the present invention will be described below with reference to the drawings.

[0016]

[Embodiment 1] This embodiment will be described for the embodiment of claim 1 based on the figures. 1 is a cross-sectional view (A) of a cylindrical resistance heating element 11 forming the center of the heater unit 10 of the present invention and a front view (B) seen from a side surface 12, and FIG.
4 to FIG. 4 are assembly perspective views of the heater unit 10. FIG. 5 is a cross-sectional view of the assembled heater unit 10.

The resistance heating element 11 will be described in more detail with reference to FIG. 1. The resistance heating element 11 is composed of an enlarged portion 13 and a resistance heating element body 14, and its branch point is an insertion hole 15 into which the resin tube 30 is inserted. This is the position of the contact surface portion 16. Die steel (SKD) was used as the material.

Explaining the enlarged portion 13, the outer surface 1
7 is formed with an inclined surface 18 that becomes thicker from the vicinity of the contact surface portion 16 toward the side surface 12. In the case of the present embodiment, the diameter at the contact surface portion 16 is 4 mm, and the thickness gradually increases toward the side surface 12, and the diameter at the side surface 12 is 14 mm.
mm. An insertion hole 15 having a diameter of 1.7 mm and a depth of 5 mm is provided at the center of the enlarged portion 13, and the contact surface 19 as the bottom of the insertion hole 15 has a radius of 0.85.
It is formed in a concave curved surface shape of mm. The outer diameter is cut so that the wall thickness around the contact surface portion 16 is equal to the wall thickness of the contact surface 19.

On the other hand, the resistance heating element body 14 has a two-stage structure. The reason why the two-stage structure is adopted is that it is easy to attach an insulating tube 24, which will be described later, at a predetermined position by providing the step 20, and the resistance heating element main body 14 has a uniform thickness. Therefore, if the insulating tube 24 is easily attached by some method and there is no problem in strength, the two-stage structure is not necessary.

A pair of electric wires 21 are electrically connected to the other end of the resistance heating element 11 away from the contact surface 19 by welding or the like (FIGS. 2 and 3). Further, a tip end of a pipe 22 for blowing cooling air into the resistance heating element 11 is inserted on the other end side of the resistance heating element 11, and is sprayed from the pipe 22 to cool the resistance heating element 11. After performing, the slits 23 for letting the cooling air escape to the outside are provided at two places so as to face the side surface of the resistance heating element 11.

The slits 23 are not limited to two positions, and the shape and the number thereof can be freely selected as required. The insulating tube 24 is the electric wire 21 and the pipe 2.
In addition to the role of fixing 2 to the resistance heating element 11 in a predetermined positional relationship, the external pressure applied to the resistance heating element 11 is blocked.

In the present embodiment, the cover 25 in FIG. 4 is made of, for example, heat-resistant synthetic resin, and covers a part of the exposed portion of each electric wire 21 in a hermetically sealed state. Figure 5
FIG. 3 is a sectional view of the completed heater unit 10. Although a power source for supplying a voltage to each electric wire 21 is not shown, a winding transformer of 80 VA is used and the secondary side is connected to the electric wire 21 of the heater unit 10 and the primary side is connected to the relay through A.
Each relay is connected to C100V, and the relay controls the opening / closing time with a timer or other control device.

Next, the operation of the above embodiment will be described with reference to FIGS. 6 to 10 which are sectional views of the heater unit 10. 7 to 10 are enlarged cross-sectional views of the main part of FIG. The resin tube 30 for terminal processing is made of a blend of low density polyethylene (LDPE) and high density polyethylene (HDPE), and has a wall thickness of 0.2 mm and an outer diameter of 4.0 mm.
It consists of

Further, a voltage application time, a current supply stop time, and a cooling time are set in advance in the power supply controller as follows. [Start] → [Primary energization (melting) 0.8 seconds] → [Energization stop 0.3 seconds] → [Secondary energization 0.7 seconds] → [Energization stop 4.0 seconds] → [Cooling air spray] 8.0 seconds] →
[End]

The reason why the power supply is divided into two is that the heater unit 10 used in this embodiment can heat rapidly, so that if the power supply time is long, the resistance heating element 11 is unnecessarily long.
There is a risk that the heat will be generated and the molecules of the material of the resin tube 30 will be destroyed.

Therefore, if the energization is momentarily stopped after the primary energization and the secondary heating is performed again, the temperature of the resistance heating element 11 can be surely controlled and the optimum heating temperature can be maintained. First, as shown in FIGS. 6 and 7, the resin tube 30 is inserted into the insertion hole 15 in the side surface 12 until the contact surface 19 is abutted. Further, the opening 31 of the resin tube 30 is set to 4.9N.
Is pressed against the contact surface 19 to hold it, and first, the power is first applied for 0.8 seconds.

The voltage applied to the pair of electric wires 21 is transmitted to the resistance heating element 11 and the temperature of the resistance heating element 11 rapidly rises due to Joule heat. It descends gently. However, it is possible to maintain the desired heating temperature with the residual heat by reheating at the next secondary energization and stopping energization for 4.0 seconds.

Further, in the temperature distribution of the contact surface 19, the temperature of the contact surface 19 can be made uniform because the thickness of the contact surface portion 16 is substantially uniform. The melting point of the high-density polyethylene that is the material of the resin tube 30 is 132 ° C., and the contact surface 1
When the temperature of 9 rises to around 128 ° C., it softens, and when it reaches the melting point, it melts. Pressing force of resin tube 30 and contact surface 19
Due to the effect of the spherical shape, the molten resin gathers toward the center, that is, the opening hole 31, and eventually closes the opening hole 31.

On the other hand, the resin tube 3 in the insertion hole 15
On the side of No. 0, the softening temperature of the low density polyethylene does not reach 84 ° C. due to the effect of the enlarged portion 13, so that abnormalities such as deformation do not occur (FIG. 8).

After the above melting time has passed, the pipe 2 is externally supplied.
The cooling air 40 is sent to the nozzle 2 and is blown from the nozzle 26 into the resistance heating element 11 to cool the resistance heating element 11. After the cooling air 40 is blown onto the resistance heating element 11, it escapes to the outside through the slit 23 formed in the resistance heating element 11, so that the forced cooling can be efficiently performed. (Figure 9)

As a result, the opening 31 of the resin tube 30
And the resin melted along the spherical contact surface 19 is cured to form the sealing portion 32. Cooling air 4
Stop spraying after a setting time of 0 seconds for 8.0 seconds,
When the resin tube 30 was pulled out from the heater unit 10, the opening 31 was closed by the sealing portion 32, and on the other hand, there was obtained the resin tube 30 having a smooth surface which was not affected by the sealing work (FIG. 10).

[0032]

[Embodiment 2] In Embodiment 2, the embodiment of Claim 2 is shown in FIG.
And FIG. 12 will be described. FIG. 11 shows a cylindrical resistance heating element 51, which is the main constituent member of the heater unit 50.
FIG. 6 is a cross-sectional view of an enlarged member 60 having a conical side surface.
The structure of the resistance heating element main body 52 in the resistance heating element 51 is the same as that of the first embodiment, but the other from the contact surface portion 53 is a cylindrical shape having a diameter of 4 mm, and the side surface 54 has a threaded portion for mounting the enlarging member 60. A61 was formed.

On the other hand, the enlarging member 60 has an inner diameter of 4
The mounting hole 62 of mm is penetrated, and the inner wall of the mounting hole 62 is formed with a screw portion B63 for screwing to the screw portion A61 of the enlarging member 60. The other dimensional relationships are the same as in Example 1.

FIG. 12 shows an enlarging member 60 for the resistance heating element 51.
FIG. 4 is a cross-sectional view in which is integrated as a screwed heater unit 50. By forming the resistance heating element 51 and the enlarging member 60 as separate members, it is possible to freely select the structure of the enlarging member 60 corresponding to the amount of heat generation related to the wall thickness of the resin tube 30. Since the method of sealing the hole of the resin tube 30 using the heater unit 50 is the same as that of the first embodiment, the description thereof will be omitted.

[0035]

As described above, the heater unit for sealing the hole of the thermoplastic resin tube of the present invention is composed of a resistance heating element capable of rapidly heating and cooling and an enormous portion for suppressing the temperature rise. Therefore, in the inventions of claims 1 and 2 , the following effects can be obtained.

A. Due to the effect of the enlarging portion, the temperature of the side surface of the resin tube does not reach the softening temperature except for the tip portion to be processed. Therefore, the resin tube can maintain a smooth surface without changing the shape of the side surface, except for the tip portion.

B. Since the molten resin in the resin tube can be instantaneously cooled and hardened by cooling air, the surface of the sealing part is transferred to the smooth contact surface of the resistance heating element and hardened to form a clean sealing part. Can be formed.

C. Further, in the invention of claim 2 , since the resistance heating element and the enlarging member are separately formed, an enlarging member having an optimum shape can be selected even when processing a plurality of types of resin tubes to be hole-sealed. The individualized resistance heating element and the enormous member can be easily integrated as a heater unit.

[Brief description of drawings]

FIG. 1 is a sectional view and a front view of a resistance heating element according to a first embodiment.

FIG. 2 is an assembled perspective view of the heater unit according to the first embodiment.

FIG. 3 is an assembled perspective view of the heater unit according to the first embodiment.

FIG. 4 is an assembled perspective view of the heater unit according to the first embodiment.

FIG. 5 is a sectional view of the heater unit according to the first embodiment, which is completed to be assembled.

FIG. 6 is a cross-sectional view showing a hole sealing operation for a resin tube using the heater unit according to the first embodiment.

FIG. 7 is an enlarged view of the vicinity of the contact surface portion in FIG. 6 (a state in which a resin tube is pressed against the contact surface).

FIG. 8 is an enlarged view of the vicinity of the contact surface portion in FIG. 6 (a state in which the resin tube is melted).

FIG. 9 is an enlarged view of the vicinity of the contact surface portion in FIG. 6 (a state in which a resistance heating element is blown with cooling air to cure the molten resin).

10 is an enlarged view of the vicinity of the contact surface portion in FIG. 6 (a state in which a sealing portion is formed in the resin tube and the resin tube is pulled out from the heater unit).

FIG. 11 is a sectional view of the resistance heating element and the enlarging member in the second embodiment.

FIG. 12 is a cross-sectional view in which the resistance heating element and the enlarging member according to the second embodiment are assembled and integrated.

[Explanation of symbols]

10 heater unit 11 Resistance heating element 13 Enormous section 14 Resistance heating element body 15 insertion holes 16 Contact surface 19 Contact surface 21 electric wire 22 pipes 23 slits 30 resin tube (thermoplastic resin tube) 40 cooling air 50 heater unit 60 enormous parts

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Claims (2)

(57) [Claims] 1. A front side of the expanded portion to form a large portion consisting of concentric circles on the tip portion of the cylindrical resistance heating element, the tube insertion hole having a bottom is formed in the center thereof, said The enlarged part has a smooth front surface and the outer diameter on the front side is the largest.
The diameter of the cylindrical resistance heating element decreases toward the tip.
Taper is formed and the overall shape is conical
It exhibits a and the cylindrical resistance heating body to the distal end portion of the cylindrical resistance heating element with the cooling air blowing pipe for blowing cooling air from the rear and is inserted blown from the cooling air blowing pipe After the cooling air cools the resistance heating element and the enormous part, a slit is formed to allow this air to escape to the outside, and a wire for voltage application is connected to the rear part of the resistance heating element. A heater unit for melting and sealing the tip opening of a thermoplastic resin tube. 2. The cylindrical resistance heating element and the enlarged portion according to claim 1,
Characterized by being integrally or detachably detached
Melt and seal the tip opening of the thermoplastic resin tube
Heater unit for.