Patent Description:
Heretofore, a tube pump (a peristaltic pump) has been known that comprises a pair of roller parts rotating about an axis while being in contact with a tube through which a liquid flows (e.g., see Patent Literature <NUM>). In the tube pump disclosed in Patent Literature <NUM>, the pair of roller parts are rotated about the axis in the same direction, to discharge, to an outflow side, the liquid flowing from an inflow side into the tube.

[Patent Literature <NUM>] <CIT>
Furthermore, <CIT> discloses a pipe joint made of synthetics resin which allows a degree of tightening of a union nut to be appropriately controlled without increasing the number of components.

<CIT> discloses a flareless pipe coupling structure for a refrigerating device with a ferrule which is formed so as to be independent of a fitting body and joint member.

<CIT> discloses a diaphragm pump comprising a plurality of pumping sections, each pumping section comprising a rigid elongate tubular body having first and second opposite ends, a flexible diaphragm received in the interior of the tubular body and dividing the interior into a pressure chamber and a pumping chamber.

Document <CIT> discloses a joint unit according to the preamble of claim <NUM>.

A tube for use in a tube pump repeatedly comes in contact with a pair of roller parts, and is therefore required to have a durability to a pressing force from the roller parts. Consequently, it is necessary to set a tube thickness (a half of a difference between an outer diameter and an inner diameter of the tube) to a thickness sufficient to obtain a desired durability. The tube is formed of, for example, a resin material having a flexibility, but a rigidity of the tube having the sufficient thickness is comparatively high.

Furthermore, for example, in a use application to, for example, culture of cells for use in regenerative medicine, a flow rate of culture fluid or the like to be conveyed per unit time by a tube pump may be required to be an extremely micro flow rate (e.g., from about <NUM>/min to <NUM>/min). The tube for such an application use has an extremely small inner diameter of a channel (e.g., <NUM>). Furthermore, in a case of coupling the tube for use in the tube pump to another channel, a joint structure comprising a joint part to be partially inserted in the channel of the tube is required to couple these channels.

However, in a case where the inner diameter of the channel is smaller than the thickness of the tube, an operation of elastically deforming the channel of the tube having high rigidity and inserting the joint part in the channel is difficult. In particular, in a case where the inner diameter of the channel is extremely small, an operation of inserting the joint part while visually recognizing the channel is difficult.

The present invention has been developed in view of such situations, and an object of the present invention is to provide a joint structure, a joint unit, and an assembly method of the joint unit, in which an operator can easily perform an operation of inserting a protrusion in a liquid transferring channel without visually recognizing the liquid transferring channel formed in a resin-made tube.

To achieve the above object, the present invention employs the following solutions.

A joint unit according to an aspect of the present invention comprises a resin-made tube in which a liquid transferring channel extending along an axis is formed and a cross section orthogonal to the axis is round, and a joint structure attached to an end of a resin-made tube, the joint structure comprising a main body, a tubular part that is formed in a tubular shape to protrude from the main body along the axis and holds an outer peripheral surface of the resin-made tube, and a protrusion that is formed in a shaft shape to protrude from the main body along the axis and forms, between the protrusion and the tubular part, an insertion groove in which the resin-made tube is inserted, with the protrusion also being inserted into the liquid transferring channel of the resin-made tube, wherein the main body and the protrusion are formed with a coupling channel extending along the axis and coupling the liquid transferring channel and another channel, and a tip of the protrusion is disposed at a position closer to the main body than a tip of the tubular part. The protrusion includes a base having an outer diameter Dpo, and a tip portion having an outer diameter that gradually decreases towards the tip, wherein upon the insertion of the protrusion in the liquid transferring channel, the liquid transferring channel is elastically deformed so that the inner diameter of the liquid transferring channel increases up to a size of the outer diameter of the protrusion, wherein the outer diameter of the resin-made tube increases due to the increase in inner diameter of the liquid transferring channel and wherein the outer peripheral surface of the resin-made tube is held by the inner peripheral surface of the tubular part.

According to the aspect of the present invention, the joint structure comprises the protrusion that forms the insertion groove in which the resin-made tube is inserted, between the protrusion and the tubular part that holds the outer peripheral surface of the resin-made tube, and the tip of the protrusion is disposed at the position closer to the main body than the tip of the tubular part. Consequently, if the end of the resin-made tube is brought close to the joint structure, the outer peripheral surface of the resin-made tube is held by an inner peripheral surface of the tubular part before the end of the resin-made tube comes in contact with the tip of the protrusion. The outer peripheral surface of the resin-made tube is held by the inner peripheral surface of the tubular part, and the liquid transferring channel formed in the resin-made tube is accordingly disposed on the same axis as a center axis of the tubular part.

Since the protrusion is disposed on the same axis as the center axis of the tubular part, the liquid transferring channel formed in the resin-made tube and the protrusion are arranged on the same axis. In this state, when an operator presses the resin-made tube toward the main body of the joint structure, the protrusion disposed on the same axis is inserted in the liquid transferring channel. Thus, the operator can easily perform the operation of inserting the protrusion in the liquid transferring channel without visually recognizing the liquid transferring channel formed in the resin-made tube.

In the joint structure according to an aspect of the present invention, it is preferable that a length of the protrusion along the axis is three times or more as large as an outer diameter of the protrusion.

In the case where the length of the protrusion along the axis is three times or more as large as the outer diameter of the protrusion, the protrusion has a needle-like shape that protrudes from the main body. When the needle-like protrusion is inserted in the liquid transferring channel of the resin-made tube, a seal region having a sufficient length can be provided between an outer peripheral surface of the protrusion and the liquid transferring channel. Furthermore, it is a difficult operation for the operator to insert the needle-like protrusion in the liquid transferring channel while visually recognizing the protrusion. However, the protrusion is inserted in the liquid transferring channel in a state where the liquid transferring channel and the protrusion are arranged on the same axis, and hence the operator can easily perform the operation of inserting the protrusion in the liquid transferring channel.

In the joint structure according to an aspect of the present invention, it is preferable that a length from the tip of the protrusion to the tip of the tubular part is <NUM> times or more as large as an inner diameter of the tubular part.

Since the length from the tip of the protrusion to the tip of the tubular part is <NUM> times or more as large as the inner diameter of the tubular part, the end of the resin-made tube comes in contact with the tip of the protrusion in a state where the end of the resin-made tube is inserted as much as the sufficient length relative to the inner diameter of the tubular part. Consequently, the operation of inserting the protrusion in the liquid transferring channel can be performed in a state where the outer peripheral surface of the resin-made tube is securely held by the inner peripheral surface of the tubular part.

In the joint structure, an outer diameter of the protrusion is larger than an inner diameter of the liquid transferring channel, and an outer diameter of the resin-made tube is smaller than an inner diameter of the tubular part.

The outer diameter of the protrusion is larger than the inner diameter of the liquid transferring channel. Therefore, upon insertion of the protrusion in the liquid transferring channel, the liquid transferring channel is elastically deformed so that the inner diameter of the liquid transferring channel increases up to a size of the outer diameter of the protrusion. A seal region is formed between the resin-made tube and an outer peripheral surface of the protrusion by a contraction force due to the elastic deformation. Furthermore, the outer diameter of the resin-made tube is smaller than the inner diameter of the tubular part. Therefore, even if the outer diameter of the resin-made tube increases due to the increase in inner diameter of the liquid transferring channel, the resin-made tube can be inserted in the insertion groove.

In the joint unit according to an aspect of the present invention, it is preferable that the outer diameter of the resin-made tube is three times or more and <NUM> times or less as large as an inner diameter of the resin-made tube.

Since the outer diameter of the resin-made tube is sufficiently larger than the inner diameter thereof, the resin-made tube is provided with a sufficient thickness. Therefore, for example, also in a case where durability to a pressing force is required as in use in a tube pump, sufficient rigidity and corresponding durability can be exerted. Furthermore, in a case of using the resin-made tube having high rigidity, it is difficult to insert the protrusion for the elastic deformation. However, it is possible to perform an operation of inserting the protrusion in the liquid transferring channel in a state where the outer peripheral surface of the resin-made tube is held by the inner peripheral surface of the tubular part, and hence the protrusion can be easily inserted in the resin-made tube.

In the joint unit according to an aspect of the present invention, it is preferable that the inner diameter of the resin-made tube is <NUM> or more and <NUM> or less.

Since the inner diameter of the resin-made tube is an extremely small diameter of <NUM> or more and <NUM> or less, a flow rate of a liquid flowing through the channel formed in the resin-made tube per unit time can be maintained to be small. Furthermore, even if the inner diameter of the resin-made tube is the extremely small diameter of <NUM> or more and <NUM> or less, the operation of inserting the protrusion in the liquid transferring channel can be easily performed without visually recognizing the liquid transferring channel formed in the resin-made tube.

An assembly method of a joint unit according to an aspect of the present invention is an assembly method of a joint unit comprising a resin-made tube in which a liquid transferring channel extending along an axis is formed and a cross section orthogonal to the axis is round, and a joint structure attached to an end of the resin-made tube, the joint structure comprising a main body, a tubular part that is formed in a tubular shape to protrude from the main body along the axis and holds an outer peripheral surface of the resin-made tube, and a protrusion that is formed in a shaft shape to protrude from the main body along the axis and forms, between the protrusion and the tubular part, an insertion groove in which the resin-made tube is inserted, with the protrusion also being inserted into the liquid transferring channel of the resin-made tube, wherein an outer diameter of the protrusion is larger than an inner diameter of the liquid transferring channel, an outer diameter of the resin-made tube is smaller than an inner diameter of the tubular part, and a tip of the protrusion is disposed at a position closer to the main body than a tip of the tubular part, the method comprising an applying step of applying an adhesive to at least one of an outer peripheral surface of the end of the resin-made tube and an inner peripheral surface of the tubular part, an insertion step of inserting the protrusion in the liquid transferring channel of the resin-made tube to which the adhesive is applied in the applying step, , wherein upon the insertion of the protrusion in the liquid transferring channel, the liquid transferring channel is elastically deformed so that the inner diameter of the liquid transferring channel increases up to a size of the outer diameter of the protrusion, wherein the outer diameter of the resin-made tube increases due to the increase in inner diameter of the liquid transferring channel and wherein the outer peripheral surface of the resin-made tube is held by the inner peripheral surface of the tubular part, and a bonding step of curing the adhesive applied in the applying step, and bonding the outer peripheral surface of the resin-made tube in which the protrusion is inserted in the insertion step and the inner peripheral surface of the tubular part.

In the assembly method of the joint unit according to the aspect of the present invention, the protrusion is inserted in the liquid transferring channel of the resin-made tube in the insertion step, in a state where the adhesive is applied to at least one of the outer peripheral surface of the end of the resin-made tube and the inner peripheral surface of the tubular part in the applying step. When inserting the protrusion in the liquid transferring channel of the resin-made tube, the protrusion is disposed on the same axis as a center axis of the tubular part. Consequently, the operator can easily perform an operation of inserting the protrusion in the liquid transferring channel without visually recognizing the liquid transferring channel formed in the resin-made tube. Furthermore, in the bonding step, the adhesive is cured to bond the outer peripheral surface of the resin-made tube and the inner peripheral surface of the tubular part.

According to the present invention, there can be provided a joint structure, a joint unit, and an assembly method of the joint unit, in which an operator can easily perform an operation of inserting a protrusion in a liquid transferring channel without visually recognizing the liquid transferring channel formed in a resin-made tube.

Hereinafter, description will be made as to a joint unit <NUM> of a first embodiment of the present invention with reference to the drawings. <FIG> is a longitudinal cross-sectional view showing a joint unit <NUM> according to the present embodiment. <FIG> is a longitudinal cross-sectional view showing a state where an attaching nut <NUM> is removed from the joint unit <NUM> shown in <FIG>. <FIG> is a side view of a joint structure <NUM> shown in <FIG> and seen from a resin-made tube <NUM> side. <FIG> is a view taken along arrows A-A of the joint structure <NUM> shown in <FIG>, and shows a state prior to insertion of the resin-made tube <NUM>.

As shown in <FIG>, the joint unit <NUM> of the present embodiment comprises the joint structure <NUM>, the resin-made tube <NUM>, and a resin-made tube <NUM>. The joint structure <NUM> is a structure having one end side (a right side of <FIG>) to which an end of the resin-made tube <NUM> is attached, and the other end side (a left side of <FIG>) to which an end of the resin-made tube <NUM> is attached. The joint structure <NUM> couples a liquid transferring channel <NUM> of the resin-made tube <NUM> and a liquid transferring channel <NUM> of the resin-made tube <NUM> so that a liquid flows through these channels.

The joint structure <NUM> includes a main body <NUM>, a tubular part <NUM>, a protrusion <NUM>, an internal thread part <NUM>, the attaching nut <NUM>, and a ferrule <NUM>. The main body <NUM>, the protrusion <NUM> and the internal thread part <NUM> are formed with a coupling channel 100a extending along an axis X and coupling the liquid transferring channel <NUM> of the resin-made tube <NUM> and the liquid transferring channel <NUM> of the resin-made tube <NUM>.

The main body <NUM> is disposed between the tubular part <NUM> and the protrusion <NUM>, and the internal thread part <NUM>, and has an interior formed with the coupling channel 100a. The main body <NUM> is formed of a resin material (e.g., polyvinyl chloride (PVC), or polycarbonate) integrally with the tubular part <NUM>, the protrusion <NUM>, and the internal thread part <NUM>.

The tubular part <NUM> is formed in a tubular shape to protrude from the main body <NUM> along the axis X to the resin-made tube <NUM> side. As shown in <FIG> and <FIG>, the tubular part <NUM> includes a cylindrical inner peripheral surface <NUM> that holds an outer peripheral surface <NUM> of the resin-made tube <NUM>.

The protrusion <NUM> is formed in a shaft shape to protrude from the main body <NUM> along the axis X to the resin-made tube <NUM> side. As shown in <FIG>, the protrusion <NUM> includes a base <NUM> having an outer diameter Dpo, and a tip portion <NUM> having an outer diameter that gradually decreases toward a tip. As shown in <FIG> and <FIG>, the protrusion <NUM> forms, between the protrusion and the tubular part <NUM>, an insertion groove <NUM> in which the resin-made tube <NUM> is inserted. A bottom 133a of the insertion groove <NUM> corresponds to a boundary position between the main body <NUM> and the protrusion <NUM>.

As shown in <FIG>, a boundary position between the main body <NUM> and the protrusion <NUM> on the axis X is denoted with X1, a position of the protrusion <NUM> on the axis X is denoted with X2, and a position of the tubular part <NUM> on the axis X is denoted with X3. In this case, the position X2 of a tip of the protrusion <NUM> is disposed closer to the position X1 of an end of the main body <NUM> on a protrusion <NUM> side than the position X3 of a tip of the tubular part <NUM>.

As shown in <FIG>, a length L2 from the tip of the protrusion <NUM> to the tip of the tubular part <NUM> is the length L2 from X2 to X3 in an axis X direction. Furthermore, an inner diameter of the tubular part <NUM> is denoted with Dci. It is preferable that the length L2 from the tip of the protrusion <NUM> to the tip of the tubular part <NUM> is <NUM> times or more as large as the inner diameter Dci of the tubular part <NUM>.

Since the length L2 is <NUM> times or more as large as the inner diameter Dci, the end of the resin-made tube <NUM> comes in contact with the tip of the protrusion <NUM> in a state where the end of the resin-made tube <NUM> is inserted as much as the sufficient length L2 relative to the inner diameter Dci of the tubular part <NUM>. Consequently, the operation of inserting the protrusion <NUM> in the liquid transferring channel <NUM> can be performed in a state where the outer peripheral surface of the resin-made tube <NUM> is securely held by the inner peripheral surface of the tubular part <NUM>.

As shown in <FIG>, a length of the protrusion <NUM> along the axis X is a length L1 from X1 to X2 in the axis X direction. Furthermore, the outer diameter of the protrusion <NUM> is denoted with Dpo. It is preferable that the length L1 of the protrusion <NUM> is three times or more as large as the outer diameter Dpo of the protrusion <NUM>. In a case where the length L1 of the protrusion <NUM> is three times or more as large as the outer diameter Dpo of the protrusion <NUM>, the protrusion <NUM> has a needle-like shape that protrudes from the main body <NUM>. When the needle-like protrusion <NUM> is inserted in the liquid transferring channel <NUM> of the resin-made tube <NUM>, a seal region having a sufficient length can be provided between an outer peripheral surface of the protrusion <NUM> and the liquid transferring channel <NUM>.

The internal thread part <NUM> is a tubular member coupled to the main body <NUM> and extending along the axis X, and has an outer peripheral surface formed with an internal thread <NUM>. In a center portion of the internal thread part <NUM> along the axis X, an insertion hole <NUM> is formed in which the end of the resin-made tube <NUM> is inserted. An end of the insertion hole <NUM> on a main body <NUM> side is coupled to the coupling channel 100a.

As shown in <FIG>, in an end of the insertion hole <NUM> on a resin-made tube <NUM> side, a taper part 142a is provided in which a tip of the ferrule <NUM> is inserted. The taper part 142a is formed in a shape having an outer diameter around the axis X that gradually decreases from an end of the internal thread part <NUM> on the resin-made tube <NUM> side toward the coupling channel 100a with a constant gradient.

The attaching nut <NUM> is a member detachably attached to the internal thread part <NUM>, formed in a tubular shape along the axis X, and has an inner peripheral surface formed with an external thread <NUM>. The operator engages the external thread <NUM> with the internal thread <NUM> while rotating the attaching nut <NUM> about the axis X, to attach the attaching nut <NUM> to the internal thread part <NUM>.

In the attaching nut <NUM>, a through hole <NUM> is formed through which the resin-made tube <NUM> is passed. As shown in <FIG>, the operator inserts the resin-made tube <NUM> to pass the tube through the through hole <NUM>, and attaches the ferrule <NUM> to the resin-made tube <NUM> passed through the through hole <NUM>. Afterward, the operator inserts the resin-made tube <NUM> in the insertion hole <NUM> of the internal thread part <NUM>, and attaches the attaching nut <NUM> to the internal thread part <NUM>, to obtain an attached state shown in <FIG>.

The ferrule <NUM> is a member made of a resin (e.g., polytetrafluoroethylene (PTFE)) and formed in a cylindrical shape to be inserted between an outer peripheral surface of the resin-made tube <NUM> and the taper part 142a of the internal thread part <NUM>. As shown in <FIG>, in an end of the ferrule <NUM> on an internal thread part <NUM> side, a tapered tip portion <NUM> having an outer diameter that gradually decreases toward the insertion hole <NUM> is formed.

As shown in <FIG>, the ferrule <NUM> is movable in the axis X direction to the resin-made tube <NUM> in a state where the attaching nut <NUM> is not attached to the internal thread part <NUM>. In the ferrule <NUM>, when the attaching nut <NUM> is attached to the internal thread part <NUM>, the tip portion <NUM> comes in contact with the taper part 142a, and an inner diameter gradually decreases. The ferrule <NUM> firmly holds the outer peripheral surface of the resin-made tube <NUM> as the inner diameter decreases. In the attached state shown in <FIG>, the resin-made tube <NUM> is not movable in the axis X direction to the ferrule <NUM>.

The resin-made tube <NUM> is a tubular body in which the liquid transferring channel <NUM> extending along the axis X is formed, and a cross section orthogonal to the axis X is round. The resin-made tube <NUM> is made of a resin material such as polyvinyl chloride (PVC), silicone, or PharMed (registered trademark). The resin-made tube <NUM> is attached to the tubular part <NUM> and the protrusion <NUM> arranged in an end of the joint structure <NUM>.

As shown in <FIG>, the outer diameter Dpo of the protrusion <NUM> is larger than an inner diameter Dti of the liquid transferring channel <NUM> of the resin-made tube <NUM>, in a non-inserted state where the protrusion <NUM> of the joint structure <NUM> is not inserted in the liquid transferring channel <NUM> of the resin-made tube <NUM>. Furthermore, an outer diameter Dto of the resin-made tube <NUM> is smaller than the inner diameter Dci of the tubular part <NUM>.

A thickness T1 of the resin-made tube <NUM> is (Dto-Dti)/<NUM>. A distance L3 between an inner peripheral surface of the tubular part <NUM> and the outer peripheral surface of the protrusion <NUM> is (Dci-Dpo)/<NUM>. The thickness T1 of the resin-made tube <NUM> is equal to the distance L3, or slightly smaller than the distance L3. With such a relation, when the resin-made tube <NUM> is inserted in the protrusion <NUM>, an outer peripheral surface of the resin-made tube <NUM> is in contact with the inner peripheral surface of the tubular part <NUM> or close to the inner peripheral surface via a minute space.

In the non-inserted state, the outer diameter Dto of the resin-made tube <NUM> is three times or more and <NUM> times or less as large as the inner diameter Dti. Furthermore, it is preferable that the outer diameter Dto of the resin-made tube <NUM> is seven times or more and eight times or less as large as the inner diameter Dti. Since the outer diameter Dto of the resin-made tube <NUM> is sufficiently larger than the inner diameter Dti, the resin-made tube <NUM> is provided with the sufficient thickness T1.

The resin-made tube <NUM> of the present embodiment can be suitably used in, for example, a tube pump (a peristaltic pump). In the tube pump, the resin-made tube <NUM> is installed in a tube holding mechanism (not shown) having a cylindrical inner peripheral surface. The tube pump includes a roller member that rotates while being in contact with the resin-made tube <NUM>, and crushing of the resin-made tube <NUM> between the cylindrical inner peripheral surface and the roller member allows a fluid in the resin-made tube <NUM> to flow through the tube. Since the resin-made tube <NUM> of the present embodiment is provided with the sufficient thickness T1 as described above, sufficient rigidity and corresponding durability can be exerted also in a case where durability to a pressing force of the roller member is required.

The inner diameter Dti of the resin-made tube <NUM> is <NUM> or more and <NUM> or less. Since the inner diameter Dti of the resin-made tube <NUM> is an extremely small diameter of <NUM> or more and <NUM> or less, a flow rate of a liquid flowing through the liquid transferring channel <NUM> formed in the resin-made tube <NUM> per unit time can be maintained to be small.

The resin-made tube <NUM> is a tubular body in which the liquid transferring channel <NUM> extending along the axis X is formed, and a cross section orthogonal to the axis X is round. The resin-made tube <NUM> is made of, for example, a resin material such as polyvinyl chloride (PVC), silicone, or PharMed (registered trademark). The resin-made tube <NUM> is attached to the internal thread part <NUM> disposed in the end of the joint structure <NUM>.

Next, description will be made as to an assembly method of the joint unit <NUM> of the present embodiment with reference to the drawings. <FIG> are views taken along arrows A-A of the joint structure <NUM> shown in <FIG>, and <FIG> shows a state prior to the insertion of the resin-made tube <NUM>. <FIG> shows a state where a part of the resin-made tube <NUM> is inserted in the tubular part <NUM>. <FIG> shows a state where the tip of the protrusion <NUM> is inserted in the liquid transferring channel <NUM> of the resin-made tube <NUM>, and <FIG> shows a state where the insertion of the resin-made tube <NUM> is completed.

The assembly method of the joint unit <NUM> of the present embodiment includes attaching the end of the resin-made tube <NUM> to one end side (a right side of <FIG>) of the joint structure <NUM>, and attaching the end of the resin-made tube <NUM> to the other end side (a left side of <FIG>). First, description will be made as to a method of attaching the end of the resin-made tube <NUM> to the one end side (the right side of <FIG>) of the joint structure <NUM>.

As shown in <FIG>, in the state prior to the insertion of the resin-made tube <NUM> in the joint structure <NUM>, the operator applies an adhesive UA (e.g., an ultraviolet curable adhesive) to the outer peripheral surface of the end of the resin-made tube <NUM> (an applying step). Note that the adhesive UA may be applied to both the outer peripheral surface of the end of the resin-made tube <NUM> and the inner peripheral surface of the tubular part <NUM>. Alternatively, the adhesive UA does not have to be applied to the outer peripheral surface of the end of the resin-made tube <NUM>, and may be applied to the inner peripheral surface of the tubular part <NUM>.

Next, the operator grasps both the resin-made tube <NUM> and the joint structure <NUM>, and inserts the end of the resin-made tube <NUM>, to which the adhesive UA is applied, in the tubular part <NUM> of the joint structure <NUM> on an inner peripheral side. As shown in <FIG>, the end of the resin-made tube <NUM> comes in contact with the tip portion <NUM> of the protrusion <NUM> of the joint structure <NUM>. In a state shown in <FIG>, the outer peripheral surface of the resin-made tube <NUM> is held by the inner peripheral surface of the tubular part <NUM>. That is, even if the operator moves the resin-made tube <NUM> in a direction orthogonal to the axis X, the outer peripheral surface of the resin-made tube <NUM> comes in contact with the inner peripheral surface of the tubular part <NUM>, to maintain a state where the tube is disposed on the inner peripheral side of the tubular part <NUM>.

Next, the operator pushes the end of the resin-made tube <NUM> toward the bottom 133a of the insertion groove <NUM> while grasping both the resin-made tube <NUM> and the joint structure <NUM>. As shown in <FIG>, when pushing the end of the resin-made tube <NUM> toward the bottom 133a of the insertion groove <NUM>, the tip portion <NUM> of the protrusion <NUM> of the joint structure <NUM> is inserted in the liquid transferring channel <NUM> of the resin-made tube <NUM> (an insertion step).

In a case where the end of the resin-made tube <NUM> is pushed toward the bottom 133a of the insertion groove <NUM>, if the tubular part <NUM> is not present, a position of the tip portion <NUM> of the protrusion <NUM> may be shifted from a position of the liquid transferring channel <NUM> of the resin-made tube <NUM> by the operator's operation of pushing the resin-made tube <NUM> inward. In the present embodiment, since the outer peripheral surface of the resin-made tube <NUM> is held by the inner peripheral surface of the tubular part <NUM>, the position of the tip portion <NUM> of the protrusion <NUM> is prevented from being shifted from the position of the liquid transferring channel <NUM> of the resin-made tube <NUM>.

The operator further pushes the end of the resin-made tube <NUM> toward the bottom 133a of the insertion groove <NUM> from the state shown in <FIG>, to obtain a state shown in <FIG> where both the tip portion <NUM> and the base <NUM> of the protrusion <NUM> are inserted in the liquid transferring channel <NUM> of the resin-made tube <NUM> (the insertion step). In the state shown in <FIG>, the end of the resin-made tube <NUM> is in contact with the bottom 133a of the insertion groove <NUM>.

Next, in the joint unit <NUM> of the state shown in <FIG>, the operator cures the adhesive UA (not shown) that is present between the outer peripheral surface of the resin-made tube <NUM> and the inner peripheral surface of the tubular part <NUM>, to bond the outer peripheral surface of the resin-made tube <NUM> and the inner peripheral surface of the tubular part <NUM> (a bonding step). The operator irradiates a region where the adhesive UA is present with ultraviolet rays by use of an ultraviolet irradiator (not shown), to cure the adhesive UA.

Note that in a case of using a dry curing adhesive, the adhesive that is present between the outer peripheral surface of the resin-made tube <NUM> and the inner peripheral surface of the tubular part <NUM> is left to stand until dried and cured.

By the operation described above, the end of the resin-made tube <NUM> is attached to the one end side (the right side of <FIG>) of the joint structure <NUM>. Next, description will be made as to a method of attaching the end of the resin-made tube <NUM> to the other end side (the left side of <FIG>) of the joint structure <NUM>.

As shown in <FIG>, in a state where the attaching nut <NUM> is not attached to the internal thread part <NUM>, the operator inserts the resin-made tube <NUM> in the through hole <NUM>. Furthermore, the operator attaches the ferrule <NUM> to the resin-made tube <NUM> passed through the through hole <NUM>. Afterward, the operator inserts the end of the resin-made tube <NUM> in the insertion hole <NUM> of the internal thread part <NUM>, to obtain a state where the tip portion <NUM> of the ferrule <NUM> is in contact with the taper part 142a.

The operator engages the external thread <NUM> with the internal thread <NUM> while rotating the attaching nut <NUM> about the axis X, to attach the attaching nut <NUM> to the internal thread part <NUM>, thereby obtaining the attached state shown in <FIG>. In the attached state shown in <FIG>, the liquid transferring channel <NUM> of the resin-made tube <NUM> and the liquid transferring channel <NUM> of the resin-made tube <NUM> are coupled so that the liquid can flow through the coupling channel 100a of the joint structure <NUM>.

Operations and effects produced by the above described present embodiment will be described.

According to the present embodiment, the joint structure <NUM> comprises the protrusion <NUM> that forms the insertion groove <NUM> in which the resin-made tube <NUM> is inserted, between the protrusion and the tubular part <NUM> that holds the outer peripheral surface of the resin-made tube <NUM>, and the tip of the protrusion <NUM> is disposed at the position closer to the main body <NUM> than the tip of the tubular part <NUM>. Consequently, if the end of the resin-made tube <NUM> is brought close to the joint structure <NUM>, the outer peripheral surface of the resin-made tube <NUM> is held by the inner peripheral surface of the tubular part <NUM> before the end of the resin-made tube <NUM> comes in contact with the tip of the protrusion <NUM>. The outer peripheral surface of the resin-made tube <NUM> is held by the inner peripheral surface of the tubular part <NUM>, and the liquid transferring channel <NUM> formed in the resin-made tube <NUM> is accordingly disposed on the same axis X as the center axis of the tubular part <NUM>.

Since the protrusion <NUM> is disposed on the same axis X as the center axis of the tubular part <NUM>, the liquid transferring channel <NUM> formed in the resin-made tube <NUM> and the protrusion <NUM> are arranged on the same axis. In this state, when the operator presses the resin-made tube <NUM> toward the main body <NUM> of the joint structure <NUM>, the protrusion <NUM> disposed on the same axis is inserted in the liquid transferring channel <NUM>. Thus, the operator can easily perform the operation of inserting the protrusion <NUM> in the liquid transferring channel <NUM> without visually recognizing the liquid transferring channel <NUM> formed in the resin-made tube <NUM>.

In the joint structure <NUM> of the present embodiment, the length L1 of the protrusion <NUM> along the axis X is three times or more as large as the outer diameter Dpo of the protrusion <NUM>. Therefore, the protrusion <NUM> has the needle-like shape that protrudes from the main body <NUM>. When the needle-like protrusion <NUM> is inserted in the liquid transferring channel <NUM> of the resin-made tube <NUM>, the seal region having the sufficient length can be provided between the outer peripheral surface of the protrusion <NUM> and the liquid transferring channel <NUM>. Furthermore, it is the difficult operation for the operator to insert the needle-like protrusion <NUM> in the liquid transferring channel <NUM> while visually recognizing the protrusion. However, the protrusion <NUM> is inserted in the liquid transferring channel <NUM> in the state where the liquid transferring channel <NUM> and the protrusion <NUM> are arranged on the same axis, and hence the operator can easily perform the operation of inserting the protrusion <NUM> in the liquid transferring channel <NUM>.

In the joint unit <NUM> of the present embodiment, the outer diameter Dpo of the protrusion <NUM> is larger than the inner diameter Dti of the liquid transferring channel <NUM>. Therefore, upon the insertion of the protrusion <NUM> in the liquid transferring channel <NUM>, the liquid transferring channel is elastically deformed so that the inner diameter Dti of the liquid transferring channel <NUM> increases up to a size of the outer diameter Dpo of the protrusion <NUM>. The seal region is formed between the resin-made tube <NUM> and the outer peripheral surface of the protrusion <NUM> by a contraction force due to the elastic deformation. Furthermore, the outer diameter Dto of the resin-made tube <NUM> is smaller than the inner diameter Dci of the tubular part <NUM>. Therefore, even if the outer diameter Dto of the resin-made tube <NUM> increases due to the increase in inner diameter Dti of the liquid transferring channel <NUM>, the resin-made tube <NUM> can be inserted in the insertion groove <NUM>.

In the joint unit <NUM> of the present embodiment, the outer diameter Dto of the resin-made tube <NUM> is three times or more and <NUM> times or less as large as the inner diameter Dti of the resin-made tube <NUM>. Since the outer diameter Dto of the resin-made tube <NUM> is sufficiently larger than the inner diameter Dti, the resin-made tube <NUM> is provided with the sufficient thickness T1. Therefore, for example, also in a case where durability to a pressing force of a roller is required as in use in the tube pump, sufficient rigidity and corresponding durability can be exerted. Furthermore, in a case of using the resin-made tube <NUM> having high rigidity, it is difficult to insert the protrusion <NUM> for the elastic deformation. However, the protrusion <NUM> can be inserted in the liquid transferring channel <NUM> in a state where the outer peripheral surface of the resin-made tube <NUM> is held by the inner peripheral surface of the tubular part <NUM>.

In the joint unit <NUM> of the present embodiment, the inner diameter Dti of the resin-made tube <NUM> is <NUM> or more and <NUM> or less. Since the inner diameter Dti of the resin-made tube is an extremely small diameter, a flow rate of the liquid flowing through the channel formed in the resin-made tube <NUM> per unit time can be maintained to be small. Furthermore, even if the inner diameter Dti of the resin-made tube <NUM> is the extremely small diameter, the operation of inserting the protrusion <NUM> in the liquid transferring channel <NUM> can be easily performed without visually recognizing the liquid transferring channel <NUM> formed in the resin-made tube <NUM>.

According to the assembly method of the joint unit <NUM> of the present embodiment, the protrusion <NUM> is inserted in the liquid transferring channel <NUM> of the resin-made tube <NUM> in the insertion step, in a state where the adhesive is applied to at least one of the outer peripheral surface of the end of the resin-made tube <NUM> and the inner peripheral surface of the tubular part <NUM> in the applying step. When inserting the protrusion <NUM> in the liquid transferring channel <NUM> of the resin-made tube <NUM>, the protrusion <NUM> is disposed on the same axis X as the center axis of the tubular part <NUM>. Consequently, the operator can easily perform the operation of inserting the protrusion <NUM> in the liquid transferring channel <NUM> without visually recognizing the liquid transferring channel <NUM> formed in the resin-made tube <NUM>. Furthermore, in the bonding step, the adhesive is cured to bond the outer peripheral surface of the resin-made tube <NUM> to the inner peripheral surface of the tubular part <NUM>.

Next, description will be made as to a joint unit 400A according to a second embodiment of the present invention with reference to the drawings. <FIG> is a longitudinal cross-sectional view showing the joint unit 400A according to the second embodiment of the present invention. The present embodiment is a modification of the first embodiment, and in the following description, the modification is considered to be similar to the first embodiment, and is omitted unless otherwise mentioned.

The joint structure <NUM> of the joint unit <NUM> of the first embodiment comprises the internal thread part <NUM> and the attaching nut <NUM> to couple the resin-made tube <NUM>. On the other hand, the joint unit 400A of the present embodiment does not comprise a configuration corresponding to the internal thread part <NUM> and the attaching nut <NUM>, and comprises a tubular part <NUM> and a protrusion <NUM> in place of the configuration.

As shown in <FIG>, the joint unit 400A of the present embodiment comprises a joint structure 100A, a resin-made tube <NUM>, and a resin-made tube 300A. The joint structure 100A is a structure having one end side (a right side of <FIG>) to which an end of the resin-made tube <NUM> is attached, and the other end side (a left side of <FIG>) to which an end of the resin-made tube 300A is attached. The joint structure 100A couples a liquid transferring channel <NUM> of the resin-made tube <NUM> and a liquid transferring channel 310A of the resin-made tube 300A so that a liquid flows through these channels.

The joint structure 100A includes a main body <NUM>, a tubular part <NUM>, a protrusion <NUM>, the tubular part <NUM>, and the protrusion <NUM>. The main body <NUM>, the protrusion <NUM> and the protrusion <NUM> are formed with a coupling channel 100Aa extending along an axis X and coupling the liquid transferring channel <NUM> of the resin-made tube <NUM> and the liquid transferring channel 310A of the resin-made tube 300A. The main body <NUM>, the tubular part <NUM> and the protrusion <NUM> are similar to those of the first embodiment, and are therefore omitted from the following description.

The tubular part <NUM> is formed in a tubular shape to protrude from the main body <NUM> along the axis X to a resin-made tube 300A side. As shown in <FIG>, the tubular part <NUM> includes a cylindrical inner peripheral surface <NUM> that holds an outer peripheral surface 301A of the resin-made tube <NUM>.

The protrusion <NUM> is formed in a shaft shape to protrude from the main body <NUM> along the axis X to the resin-made tube 300A side. As shown in <FIG>, the protrusion <NUM> includes a base <NUM>, and a tip portion <NUM> having an outer diameter that gradually decreases toward a tip. As shown in <FIG>, the protrusion <NUM> forms, between the protrusion and the tubular part <NUM>, an insertion groove <NUM> in which the resin-made tube 300A is inserted. A bottom 183a of the insertion groove <NUM> corresponds to a boundary position between the main body <NUM> and the protrusion <NUM>. Note that a shape of the protrusion <NUM> is similar to the shape of the protrusion <NUM>, and is therefore omitted from the following description.

The resin-made tube 300A is a tubular body in which the liquid transferring channel 310A extending along the axis X is formed, and a cross section orthogonal to the axis X is round. The resin-made tube 300A is made of, for example, a resin material such as polyvinyl chloride (PVC), silicone, or PharMed (registered). The resin-made tube 300A is attached to the tubular part <NUM> and the protrusion <NUM> arranged in an end of the joint structure 100A. Note that a shape of the resin-made tube 300A is similar to the shape of the resin-made tube <NUM>, and is therefore omitted from the following description.

An assembly method of the joint unit 400A of the present embodiment includes attaching the end of the resin-made tube <NUM> to the one end side (the right side of <FIG>) of the joint structure 100A, and attaching the end of the resin-made tube 300A to the other end side (the left side of <FIG>). A method of attaching the end of the resin-made tube <NUM> to the one end side of the joint structure 100A is similar to the method of attaching the resin-made tube <NUM> to the one end side of the joint structure <NUM> of the first embodiment, and is therefore omitted from the following description. Furthermore, a method of attaching the end of the resin-made tube 300A to the other end side of the joint structure 100A is similar to the method of attaching the end of the resin-made tube <NUM> to the one end side of the joint structure 100A, and is therefore omitted from the following description.

According to the present embodiment, the one end side (the right side of <FIG>) and the other end side (the left side of <FIG>) of the joint structure 100A are formed as similar structures, and the end of the resin-made tube <NUM> can be attached to the one end side, while the end of the resin-made tube 300A can be attached to the other end side.

Next, description will be made as to a joint unit 400B according to a third embodiment of the present invention with reference to the drawings. The present embodiment is a modification of the first embodiment, and in the following description, the modification is considered to be similar to the first embodiment, and is omitted unless otherwise mentioned.

In the joint structure <NUM> of the joint unit <NUM> of the first embodiment, the main body <NUM>, the tubular part <NUM> that holds the outer peripheral surface of the resin-made tube <NUM> and the protrusion <NUM> are integrally formed of the resin material. On the other hand, in the joint unit 400B of the present embodiment, a main body 110B and a protrusion 130B are integrally formed, and a tubular ferrule 120B is formed as a component separate from the main body 110B and the protrusion 130B.

<FIG> are longitudinal cross-sectional views showing the joint unit 400B according to the present embodiment. <FIG> shows a state where the main body 110B, the ferrule 120B and an attaching nut 150B are disassembled. <FIG> shows a state prior to insertion of a resin-made tube <NUM>. <FIG> shows a state where the insertion of the resin-made tube <NUM> is completed. <FIG> shows a state where fastening of the attaching nut 150B is completed.

Note that <FIG> shows a structure of one end side (a right side of <FIG>) of the joint unit 400B of the present embodiment, and omits a structure of the other end side (a left side of <FIG>) of the joint unit 400B of the present embodiment. The structure of the other end side of the joint unit 400B is considered to be similar to the structure of the left side of <FIG> of the first embodiment, and is omitted from the following description.

As shown in <FIG>, a joint structure 100B of the joint unit 400B of the present embodiment comprises the main body 110B, the ferrule (a tubular part) 120B, the protrusion 130B, and the attaching nut 150B.

The main body 110B is formed integrally with the protrusion 130B, and in the main body, a coupling channel 100Ba is formed. An internal thread 111B is formed in an outer peripheral surface of the main body 110B. In the main body 110B, a taper part 112B having an inner diameter that gradually increases toward a tip side is formed on an outer peripheral side of the protrusion 130B.

The protrusion 130B is formed in a shaft shape to protrude from the main body 110B along an axis X to a resin-made tube <NUM> side. As shown in <FIG>, the protrusion 130B includes a base 131B, and a tip portion 132B having an outer diameter that gradually decreases toward a tip.

The ferrule 120B is a member made of a resin (e.g., PTFE) and formed in a cylindrical shape to be inserted between an outer peripheral surface of the resin-made tube <NUM> and the taper part 112B of the main body 110B. As shown in <FIG>, in an end of the ferrule 120B on a main body 110B side, a tapered tip portion 121B having an outer diameter that gradually decreases toward the tip is formed.

The attaching nut 150B is a member detachably attached to the internal thread 111B of the main body 110B, formed in a tubular shape along the axis X, and has an inner peripheral surface formed with an external thread 151B. An operator engages the external thread 151B with the internal thread 111B while rotating the attaching nut 150B about the axis X, to attach the attaching nut 150B to the main body 110B. The attaching nut 150B is formed with a through hole 152B through which the resin-made tube <NUM> is passed.

Next, description will be made as to an assembly method of the joint unit 400B of the present embodiment with reference to the drawings. The assembly method of the joint unit 400B of the present embodiment includes attaching an end of the resin-made tube <NUM> to the one end side (the right side of <FIG>) of the joint structure 100B, and attaching an end of another resin-made tube to the other end side (the left side of <FIG>). Hereinafter, description will be made as to a method of attaching the end of the resin-made tube <NUM> to the one end side (the right side of <FIG>) of the joint structure 100B.

Prior to the attaching of the resin-made tube <NUM>, the operator engages the external thread 151B with the internal thread 111B while rotating the attaching nut 150B about the axis X, to attach the attaching nut 150B to the main body 110B. Consequently, as shown in <FIG>, the ferrule 120B is interposed between the attaching nut 150B and the main body 110B.

In the state shown in <FIG>, the fastening of the attaching nut 150B to the main body 110B is not completed, and a gap GA is provided along the axis X between the attaching nut 150B and the main body 110B. Furthermore, in the state shown in <FIG>, an inner diameter Dfi of the ferrule 120B is larger than an outer diameter Dto of the resin-made tube <NUM>. Consequently, the operator can insert the resin-made tube <NUM> on an inner peripheral side of the ferrule 120B.

Next, the operator grasps both the resin-made tube <NUM> and the joint structure 100B, and inserts the end of the resin-made tube <NUM> in the ferrule 120B of the joint structure 100B on the inner peripheral side. In a state where the end of the resin-made tube <NUM> is in contact with the tip portion 132B of the protrusion 130B of the joint structure 100B, an outer peripheral surface of the resin-made tube <NUM> is held by an inner peripheral surface of the ferrule 120B. That is, even if the operator moves the resin-made tube <NUM> in a direction orthogonal to the axis X, the outer peripheral surface of the resin-made tube <NUM> comes in contact with the inner peripheral surface of the ferrule 120B, to maintain a state where the tube is disposed on the inner peripheral side of the ferrule 120B.

Next, the operator pushes the end of the resin-made tube <NUM> toward a space between the ferrule 120B and the protrusion 130B in the state where both the resin-made tube <NUM> and the joint structure 100B are grasped. As shown in <FIG>, when pushing the end of the resin-made tube <NUM> inward, the base 131B and the tip portion 132B of the protrusion 130B of the joint structure 100B are inserted in a liquid transferring channel <NUM> of the resin-made tube <NUM> (an insertion step).

In a case where the end of the resin-made tube <NUM> is pushed toward the protrusion 130B, if the ferrule 120B is not present, a position of the tip portion 132B of the protrusion 130B may be shifted from a position of the liquid transferring channel <NUM> of the resin-made tube <NUM> by the operator's operation of pushing the resin-made tube <NUM> inward. In the present embodiment, since the outer peripheral surface of the resin-made tube <NUM> is held by the inner peripheral surface of the ferrule 120B, the position of the tip portion 132B of the protrusion 130B is prevented from being shifted from the position of the liquid transferring channel <NUM> of the resin-made tube <NUM>.

Next, the operator rotates the attaching nut 150B about the axis X, to narrow the gap GA provided between the attaching nut 150B and the main body 110B. As the gap GA narrows, an inner diameter of the tip portion 121B of the ferrule 120B in contact with the taper part 112B of the main body 110B decreases. Consequently, the end of the resin-made tube <NUM> is interposed between the tip portion 121B of the ferrule 120B and the protrusion 130B. If the gap GA provided between the attaching nut 150B and the main body 110B is eliminated, the attaching nut 150B comes in contact with the main body 110B, and the fastening of the attaching nut 150B to the main body 110B is completed.

According to the joint unit 400B of the present embodiment described above, the operator can easily perform an operation of inserting the protrusion 130B in the liquid transferring channel <NUM> without visually recognizing the liquid transferring channel <NUM> formed in the resin-made tube <NUM>. Furthermore, without using any adhesive, the resin-made tube <NUM> can be held by the ferrule 120B so that the resin-made tube <NUM> does not fall out of the protrusion 130B.

Furthermore, according to the joint unit 400B of the present embodiment, when removing the resin-made tube <NUM>, the operator rotates the attaching nut 150B about the axis X in a direction opposite to a direction during the fastening, to widen the gap GA provided between the attaching nut 150B and the main body 110B. As the gap GA widens, the inner diameter of the tip portion 121B of the ferrule 120B in contact with the taper part 112B of the main body 110B increases.

Consequently, the state where the end of the resin-made tube <NUM> is interposed between the tip portion 121B of the ferrule 120B and the protrusion 130B is canceled. Upon the cancelation of the state where the end of the resin-made tube is interposed between the tip portion 121B of the ferrule 120B and the protrusion 130B, the operator pulls out the resin-made tube <NUM> along the axis X, so that the resin-made tube <NUM> can be removed from the joint unit 400B.

Claim 1:
A joint unit (<NUM>) comprising a resin-made tube (<NUM>) in which a liquid transferring channel (<NUM>) extending along an axis (X) is formed and a cross section orthogonal to the axis is round, and
a joint structure (<NUM>) attached to an end of the resin-made tube (<NUM>), the joint structure (<NUM>) including:
a main body (<NUM>);
a tubular part (<NUM>) that is formed in a tubular shape to protrude from the main body (<NUM>) along the axis (X) and holds an outer peripheral surface of the resin-made tube (<NUM>); and
a protrusion (<NUM>) that is formed in a shaft shape to protrude from the main body (<NUM>) along the axis (X) and forms, between the protrusion (<NUM>) and the tubular part (<NUM>), an insertion groove (<NUM>) in which the resin-made tube (<NUM>) is inserted, with the protrusion (<NUM>) also being inserted into the liquid transferring channel (<NUM>) of the resin-made tube (<NUM>), wherein
the main body (<NUM>) and the protrusion (<NUM>) are formed with a coupling channel (100a) extending along the axis (X) and coupling the liquid transferring channel (<NUM>) and another channel (<NUM>),
a tip of the protrusion (<NUM>) is disposed at a position closer to the main body (<NUM>) than a tip of the tubular part (<NUM>),
wherein the protrusion (<NUM>) includes a base (<NUM>) having an outer diameter Dpo, and a tip portion (<NUM>) having an outer diameter that gradually decreases towards the tip,
wherein the joint unit is configured so that upon the insertion of the protrusion (<NUM>) in the liquid transferring channel (<NUM>), the liquid transferring channel is elastically deformed so that the inner diameter (Dti) of the liquid transferring channel (<NUM>) increases up to a size of the outer diameter (Dpo) of the protrusion (<NUM>), wherein the outer diameter (Dto) of the resin-made tube (<NUM>) increases due to the increase in inner diameter (Dti) of the liquid transferring channel (<NUM>) characterized in that the outer peripheral surface of the resin-made tube (<NUM>) is held by the inner peripheral surface of the tubular part (<NUM>).