MXPA96001442A - A hueca medical needle and a method for suproducc - Google Patents

Abstract

The present invention relates to a hollow medical needle which comprises: a cylindrical member having a flow path capable of passing a fluid therein, along a central axis direction; a first beveled, bevelled face formed in an upper end portion of the cylindrical member, such that the flow path opens in an oblique direction, having a first angle inclined with respect to the central axis; a second bevelled face formed by rotating a first rotation angle in a positive direction with respect to the first face bevelled in bevel, with the central axis as its center, having a second angle inclined with respect to the central axis, and a third face bevelled in bevel formed by the rotation of a second angle of rotation in a opposite direction with respect to the first face bevelled in bevel with the central axis as its center, which has a slanted third angle co n with respect to the central axis, both formed in the upper edge portion of the cylindrical member, a fourth face beveled in a planar shape, ground and formed in a position opposite to the first beveled face in the upper edge bevel of the cylindrical member in an oblique direction with respect to the direction of the central axis of the cylindrical member so that a thickness of the cylindrical member is thinned, and a sharp edge portion comprised of at least three ground faces, i.e. the second, third and fourth frosted faces in bis

Description

A HUECA MEDICAL NEEDLE AND A METHOD FOR ITS PRODUCTION TECHNICAL FIELD The present invention relates to a hollow medical needle suitable for use as a hollow medical needle, such as an injection needle, cannular needle, or the like, for hypodermic injection, dialysis, intravenous drip, or blood collection, is say, the needle has a flow path in which a fluid such as liquid injection drug, blood, or the like can flow and also refers to a method for its production. BACKGROUND OF THE INVENTION In a conventional method, a hollow medical needle such as a hypodermic injection needle, or a cannulated needle, has been produced by grinding a cylindrical member having a thin diameter. That is, the upper end portion of the cylindrical member is ground in an oblique direction with respect to the direction of the central axis of the cylindrical member to form an open bevel end face in an oblique direction with respect to the direction of the central axis of the cylindrical member. cylindrical member, and in this way the hollow medical needle has been produced. It is known that the thinner the wall thickness of an upper edge portion of the cylindrical member is, that is, the thinner the sharp edge portion of a hollow medical needle, the less blood vessels are injured in the part of the hollow needle. injection of a patient or similar, and less pain the patient feels in the part of the injection, at the time of injection or similar. In a conventional hollow medical needle, in order to make an extremely thin sharpened edge portion, an idea can be proposed such that, when grinding and forming an open bevel end face, the grinding is performed in such a way that the inclined angle of the bevel end face open to the direction of the central axis of the cylindrical member becomes extremely small. However, in order to excessively grind by making the inclined angle of the open bevel end face small, the area to form the open bevel end face in the direction of the central axis of the hollow medical needle, i.e. area to grind the cylindrical member, it gets wider. As a result, the strength of the hollow medical needle decreases, since the cylindrical member becomes thin within its wide area. That is, it was difficult to make the sharp edge portion extremely thin without decreasing the strength of the hollow medical needle. It is an object of the present invention to provide a hollow medical needle and a method for its production capable of making an extremely thin sharpened edge portion without damaging the strength of a hollow medical needle, taking into consideration the aforementioned circumstances. SUMMARY OF THE INVENTION Of the present invention, the invention comprises a hollow medical needle comprising: a cylindrical member having a flow path capable of passing a fluid therein, in the direction of its central axis, which has a face cylindrical outer peripheral on an external peripheral side; a first beveled face bevelled into an upper end portion of the cylindrical member, such that the flow path opens in an oblique direction, having a first angle inclined with respect to the central axis; the first bevelled face being located in such a manner that a grinding boundary on a side opposite a direction of the upper end of the cylindrical member of the first beveled face is connected to the outer cylindrical peripheral face; a second chamfered ground face formed by rotating a first angle of rotation in a positive direction with respect to the first beveled face, with the central axis as its center, having a second angle inclined with respect to the central axis, and a third chamfered ground face formed by rotating a second angle of rotation in an opposite direction with respect to the first chamfered ground face with the central axis as its center, having a third angle inclined with respect to the central axis, both formed in the upper edge portion of the cylindrical member, respectively; a fourth face bevelled, bevelled and formed in a position opposite to the first bevelled face of the upper edge portion of the cylindrical member in a direction oblique with respect to the direction of the central axis of the cylindrical member, thinning the thickness of the wall of the cylindrical member; and a sharp edge portion comprised of at least three frosted faces, ie, the second, third, and fourth beveled faces. In the hollow medical needle according to the present invention, the fourth beveled face is provided in addition to the ground faces, such as the second and third beveled faces, whereby the sharp edge portion is extremely thin. Accordingly, when the hollow medical needle according to the present invention is used, which has the sharpened edge portion, where the thickness of the wall of the upper edge portion is thinned, a patient or the like hardly injures itself. blood vessel in the part of the injection at the moment of the injection (ie, since the sharp edge portion is thin and sharp, the blood vessel or similar lesion is kept to a minimum together with an action of itching), and you can hardly feel the pain in the injection part. In addition, since in the hollow medical needle according to the invention, the sharp edge portion is comprised of at least three ground faces, that is, the second, third, and fourth beveled faces, the sharp edge portion. it is located out of phase on the side of the central axis of the cylindrical member for the fourth face bevelled in bevel, in comparison with a conventional hollow medical needle. Then, when the hollow medical needle according to the present invention is inserted into a blood vessel, the sharp edge portion is located exiting from the inner wall of the blood vessel. As a result, the sharp edge portion is prevented from biting the inner wall of a blood vessel, and pain is reduced due to injury to the inner wall of a blood vessel and injury to a blood vessel. In particular, the pain felt in the portion where a needle stings was a great difficulty in dialysis, where actions are often made to prick with a needle. However, when the hollow medical needle according to the present invention is used as a dialysis needle, the pain felt in the portion where the needle stings becomes small, and in this way the difficulty can be greatly alleviated. at the time of dialysis.

Further, since the sharp edge portion is extremely thin, as the thickness of the wall in the upper edge portion of the cylindrical member decreases to provide the fourth beveled face, even if the inclined angle of the second and third faces is ground in Bevel to the direction of the central axis is not made extremely small, the sharp edge portion can be made thin, without widening the area to form each face bevelled bevelled in the direction of the central axis of the hollow medical needle (for example, the second length L2 and similar), that is, the area for grinding the cylindrical member. Then, the cylindrical member is not thin over its wide area, so that the strength of the hollow medical needle does not decrease. That is, the hollow medical needle of the present invention is one that has the sharp edge portion that becomes extremely thin, and does not decrease its strength. In addition, the fourth beveled face is provided in the opposite position to the first beveled face. Of the first bevelled ground face, the grounding edge on the side opposite the direction of the upper edge of the cylindrical member is connected to the outer cylindrical peripheral face. That is, the present invention provides such a structure that the first beveled face is not adjacent to, and does not connect to, the fourth beveled face on the side opposite the direction of the top edge of the cylindrical member. Accordingly, for example, the first face bevelled in bevel and the fourth face bevelled in bevel are adjacent to, and are connected with each other in the direction of the upper edge of the cylindrical member, so that it can be largely resolved the inconvenience such as the stepped portion which inadvertently hurts blood tissue or the like at the time of injection, which is formed between the first beveled face and the fourth beveled face. When the hollow medical needle according to the invention is used as a metallic needle for a remaining needle, the following effects occur. That is, a remaining needle is assembled in such a way that a metallic needle and a tube needle made of synthetic resins, such as fluorine-containing resin, are produced in advance from the outside in an independent manner, and in the last routine the Metallic needle is inserted into the tube needle. However, the problem arises that, in a conventional metal needle, when the metal needle is inserted into the tube needle, the sharp edge portion (ie, the cutting edge) of the metal needle sticks to the wall. inner tube needle for the reason that the inner diameter of the tube needle is extremely small, and then the tube needle is damaged. However, in the metallic needle of the hollow medical needle according to the present invention, the sharp edge portion is comprised of at least three ground faces, ie, the second, third, and fourth beveled faces, so that the sharp edge portion is located offset on the side of the central axis of the cylindrical member for the formation of the fourth face bevelled in bevel, in comparison with a conventional metallic needle. Accordingly, when the metal needle is inserted into the tube needle, the sharp edge portion of the metal needle is prevented from sticking to the inner wall of the tube needle, since the sharpened edge portion is located leaving the inner wall of the tube needle, and then the damage of the tube needle is reduced. Of the present invention, the second invention comprises the hollow medical needle of the invention, wherein the sharp edge portion is comprised of four ground faces, that is, the first, second, third and fourth beveled faces. In addition to the effects according to the invention, the present invention can also be applied to the needle, such as preferably the so-called backward cutting needle. Of the present invention, the third invention comprises the hollow medical needle of the invention, wherein the fourth face bevelled in bevel is a part of a frosted face thinned with the central axis at its center. With this invention, in the portion formed by the fourth beveled face, near the sharp edge portion, in particular in the peripheral direction of the cylindrical member, the cylindrical and similar outer peripheral face of the cylindrical member is not left adjacent to the cylindrical member. fourth face ground in bevel and similar. Therefore, in addition to the effects of the invention, since a stepped portion or the like is not formed in a state such that the fourth beveled face is joined to the cylindrical outer peripheral face in the peripheral direction, it can be reduced also the pain at the time of injection in a considerable way. Of the present invention, the fourth invention comprises the hollow medical needle of the invention, wherein the fourth beveled face is in the form of a plane. That is to say, the member in the shape of a cylinder is ground on a plane, and then, in the part formed by the fourth face bevelled in bevel, there remains the portion whose wall thickness is relatively large, and the portion whose wall thickness It is relatively small. That is, in addition to the effects according to the invention, the portion whose wall thickness is relatively large is formed. For this reason, the strength of the hollow medical needle is greatly increased.

In addition, the portion whose wall thickness is relatively small is located near the upper edge portion, whereby it is possible to increase the strength of the hollow medical needle and further to make the edge portion sharp. Of the present invention, the fifth invention comprises the hollow medical needle of the fourth invention, wherein the fourth bevelled face extends from the side of the sharpened edge portion to a side opposite the direction of the upper end of the cylindrical member. . That is, the fourth beveled face is formed along the direction in which a needle is locked at the time of injection with the hollow medical needle, so that the sting operation can be performed in an extremely manner soft without adding an inadvertent shock to the chopped blood tissue in addition to the effects of the fourth invention. Accordingly, the pain at the time of injection can be further reduced in a considerable manner. Of the present invention, the sixth invention comprises the hollow medical needle of the fifth invention, wherein the fourth beveled-in-bevel is provided in such a way that the positions corresponding to an apical portion of one side of the outer cylindrical peripheral face of the member cylindrical of a first intersecting portion formed by crossing the first beveled face and the second beveled face, and an apical portion of one side of the cylindrical outer peripheral face of the cylindrical member of a second intersecting portion formed by the crossing of the first face bevelled in bevel and the third face bevelled in bevel, are crossed by the fourth face beveled in bevel in a direction opposite to the direction of the upper end of the cylindrical member. Then, when the injection is performed with the hollow medical needle, the apical end portion of the first intersecting portion, or the apical end portion of the second intersecting portion, could add an inadvertent shock to the blood tissue as it passes through. of chopped blood tissue. However, the fourth beveled face is provided in such a way that the portions corresponding to these apical end portions extend in the direction opposite the direction of the upper end of the cylindrical member, i.e. the effective diameter of the cylindrical member. same is small by the fourth face bevelled in bevel in the position corresponding to these apical portions, so that the inadvertent shock to the aforementioned blood tissue is greatly softened. Accordingly, in addition to the effects of the fifth invention, the pain at the time of injection can be further reduced in a considerable manner. Of the present invention, the 7th invention comprises the hollow medical needle of the fifth invention, wherein the fourth face bevelled in bevel is provided in such a way that a position corresponding to the apical portion of the side opposite the direction of the upper end of the Cylindrical member, at the grinding limit of the first beveled face, is crossed by the fourth face bevelled in a direction opposite to the direction of the upper end of the cylindrical member. Then, when the injection is performed with the hollow medical needle, the apical end portion of the grinding cap could add an inadvertent shock to the blood tissue as it passes through the chopped blood tissue. However, the fourth beveled face is provided in such a way that the portion corresponding to this apical end portion extends in the direction opposite to the direction of the upper end of the cylindrical member, ie the effective diameter of the cylindrical member. same is small by the fourth face bevelled in bevel in the position corresponding to this apical portion, so that the inadvertent shock to the aforementioned blood tissue is greatly softened. Therefore, in addition to the effects of the 5th invention, the pain at the time of injection can be further reduced in a considerable manner. Of the present invention, the 8th invention comprises the hollow medical needle of the 4th or the 5th invention, wherein the fourth beveled face is provided in such a manner that there is a cylindrical outer peripheral face of the cylindrical member between the fourth ground face in bevel and the second bevelled face in bevel, and between the fourth face bevelled in bevel and the third face bevelled in bevel, in a peripheral direction of the cylindrical member. That is, the cylindrical outer peripheral face of the cylindrical member is left without grinding between the fourth chamfered ground face and the second and third chamfered ground faces. That is, in addition to the effects of the 4th or the 5th invention, the outer cylindrical peripheral face of the cylindrical member is left unblended near the sharp edge portion, whereby the strength of the hollow medical needle is extremely increased. in the portion near the sharp edge portion. In addition, the strength of the portion near the sharp edge portion is not impaired, so it is possible to thin the sharpened edge portion by making the inclined angle K4 with the central axis of the fourth face bevelled extremely bevelled small (then, the forming area of the fourth beveled face is made wider in the direction of the central axis). Of the present invention, the 9th invention comprises the hollow medical needle of the invention, wherein the sharp edge portion is formed by placing it on an internal wall forming the flow path of the cylindrical member. With this invention, the edge line portion 16 or the like is prevented from forming by the second and third beveled faces, it is prevented from forming in the wall thickness portion of the cylindrical member of the edge edge portion, and then the sharply sharpened edge portion is formed. Therefore, in addition to the effects of the invention, the sharp edge portion is formed extremely sharp, so that the pain can be further reduced at the time of injection in a considerable manner. Of the present invention, the 10th invention comprises the hollow medical needle of the invention, wherein the fourth beveled face is formed at an inclined angle of 2 to 15 degrees with respect to the direction of the central axis of the cylindrical member. With this invention, in addition to the effects of the first invention, the sharp edge portion is formed in an appropriate state on its edge and strength, in a convenient manner. Of the present invention, the 11th invention comprises the hollow medical needle of the invention, wherein the second and third inclined angles are equal to each other. With this invention, in addition to the effects of the invention, the shape of the sharp edge portion is equal to the right and left, in a convenient manner.

Of the present invention, the 12th invention comprises the hollow medical needle of the invention wherein the first and second angles of rotation are equal to each other. With this invention, in addition to the effects of the invention, the shape of the portion of the sharp edge is equal to the right and left, in a convenient manner. Of the present invention, the 13th invention comprises a method for producing a hollow medical needle, this method comprising: performing a grinding machining on top edge portion of a cylindrical member that forms a flow path capable of passing a fluid therein. in the direction of its central axis, to form a first thinned ground face whose outer diameter is reduced towards a direction of the upper edge of the cylindrical member, by thinning a wall thickness of the cylindrical member; performing a grinding machining on the portion of the upper edge of the cylindrical member, forming the first face ground in an oblique direction, having a first angle inclined with respect to the central axis to form a first face beveled in bevel, where the trajectory of flow is open in an oblique direction, and perform a grinding machining on the upper edge portion of the cylindrical member by rotating a first angle of rotation in a positive direction with respect to the first beveled face with the central axis at its center, which has a second angle inclined with respect to the central axis, to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the first face beveled in bevel with the central axis at its center, which has a third angle inclined with respect to the central axis to form a third bevel ground face, respectively; and forming a sharp edge portion comprised of at least three ground faces, that is, the second and third beveled faces, and a fourth beveled face which is left unbleached by the grounding machining of the first, second, and third faces frosted in bevel, from the first ground face. With this invention, the fourth beveled face is formed, as well as the second and third beveled faces, and the like, different from a conventional hollow medical needle, and the sharp edge portion is comprised of at least three ground faces, so the portion of sharp edge becomes extremely thin. That is to say, the sharp edge portion becomes extremely thin by the fourth bevelled face that remains unbleached from the first ground face, by forming the first ground face even if the grinding machining is performed so as not to cause the inclined angle of the second and third bevelled faces to the direction of the central axis is small. Accordingly, the sharp edge portion can be made thin without widening the area to form the first, second, third, and fourth faces bevelled in the direction of the central axis of the hollow medical needle, i.e., the grinding area the cylindrical member. Then, the cylindrical member does not become thin at its widest area, and the strength of the hollow medical needle is not decreased. That is, in the production method of the present invention, the sharp edge portion can be made extremely thin without decreasing the strength of the hollow medical needle. In addition, since the fourth face bevelled in bevel is a part of the first frosted face thinned with the central axis as its center, the face not frosted (the outer peripheral face of the cylindrical member which is not the first, second, third, or fourth frosted faces in bevel, and similar) is not left adjacent to the fourth face bevelled in bevel and similar, in the portion forming the fourth face bevelled in bevel, near the sharp edge portion, in particular, in the peripheral direction of the cylindrical member. Then, a stepped portion or the like is not formed in such a state that the fourth face bevelled in bevel meets the non-ground face, and consequently, the pain at the time of injection can be further reduced in a considerable manner. When grinding is performed on the first, second, and third beveled faces, and the like, the upper end portion, which is a ground portion, receives a lot of heat if the amount of grinding is increased at one time, so that The material of the upper end portion is softened. When the material of the upper end portion is softened, the inconvenience arises that the upper end portion is separated at the time of removing the flash after grinding, and then the strength is increased at the moment when the insert is inserted. needle and the pain increases. However, in the production method according to the present invention, the upper end portion is ground to form the first ground face, and subsequently the ground is performed on the first, second, and third faces bevelled. Then, when the first, second, and third bevelled faces are ground, the amount of grinding is reduced, since the first ground face has already been ground. Accordingly, the upper end portion is prevented from receiving much heat and is softened by the reduced amount of grinding. Then, the inconvenience of the upper end portion separating at the time of removing the burr after grinding is eliminated. Of the present invention, the 14th invention comprises a method for producing a hollow medical needle, this method comprising: grinding an upper edge portion of a cylindrical member that forms a flow path capable of passing a fluid therein in the direction of its central axis, in an oblique direction with respect to the direction of the central axis of the cylindrical member, thinning the thickness of the wall of this cylindrical member, to form a fourth face beveled in bevel in the form of a plane, - performing a machination of grinding on a portion opposite the fourth beveled face of the upper edge portion of the cylindrical member, which forms the fourth face bevelled in bevel, in an oblique direction, having a first angle inclined with respect to the central axis for form a first face bevelled in bevel, where the flow path is open in an oblique direction, and perform a machination of grinding on the upper edge portion of the cylindrical member by rotating a first angle of rotation in a positive direction with respect to the first face bevelled with the center axis at its center, having a second angle inclined with respect to the central axis, to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the first beveled face with the central axis at its center, having a third inclined angle with with respect to the central axis to form a third beveled face, respectively; and forming a portion of sharp edge comprised of at least the second, third, and fourth beveled faces. With this invention, the sharp edge portion becomes extremely thin, since the fourth beveled face is formed, as well as the second and third beveled faces, and the like, different from a conventional hollow medical needle, and the The sharp edge portion is comprised of at least these three ground faces. That is, the sharp edge portion becomes extremely thin by the fourth beveled face, by forming the fourth beveled face, even when the grinding machining is performed so as not to make the inclined angle of the second face. and third bevelled faces facing the direction of the central axis of the cylindrical member is small. Accordingly, the sharp edge portion can be made thin without widening the ground area of the hollow medical needle in the direction of the central axis, i.e., the area for grinding the cylindrical member. Then, since the cylindrical member does not become thin because of its wider area, the strength of the hollow medical needle does not decrease. That is, in the production method of the present invention, the sharp edge portion can be made extremely thin without decreasing the strength of the hollow medical needle. Furthermore, since in the production method of the present invention, the first, second, third and fourth beveled faces are ground in an oblique direction with respect to the direction of the central axis of the cylindrical member, for example, not It is necessary to perform a cylindrical grinding or similar. Accordingly, in the production method of the present invention, a grinding machining can be performed with only one grinding machine, such as the grinding machine to form the grinding of the bevel face (known) that is used when a grinding occurs. conventional hollow medical needle, where the grinding is done by turning a grinding stone in the shape of a disc, without using the other machines, such as a cylindrical grinder, in a convenient manner. In addition, since the fourth beveled face is formed in the configuration of a plane, the face is not ground (the outer peripheral face of the cylindrical member which is not the first, second, third, or fourth face bevelled in bevel, and similar ) is left adjacent to the fourth beveled face in the portion forming the fourth beveled face, near the sharp edge portion, in particular in the peripheral direction of the cylindrical member. Accordingly, the strength near the sharp edge portion of the hollow medical needle is greatly increased. In addition, since the non-frosted face is left near the sharp edge portion, and the strength near the sharp edge portion does not decrease, the inclined angle K4 of the fourth face bevelled to the center axis can be made extremely small (ie, the area forming the fourth beveled face in the direction of the central axis can be made wider), to thin the portion of sharp edge. Of the present invention, the 15th invention comprises a method for producing a hollow medical needle, this method comprising: performing a grinding machining on an upper edge portion of a cylindrical member that forms a flow path capable of passing a fluid in the same in the direction of its central axis, in an oblique direction having a first angle inclined with respect to the central axis, to form a first beveled face in which the flow path is open in an oblique direction; performing a grinding machining on the upper edge portion of the cylindrical member by rotating a first angle of rotation in a positive direction with respect to the first beveled face with the center axis at its center, having a second inclined angle with respect to the central axis, to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the first beveled face with the central axis at its center, which has a third angle inclined with respect to the central axis to form a third beveled face, respectively; and grinding a position opposite the first bevelled face of the upper edge portion of the cylindrical member in a direction oblique with respect to the central axis, the thickness of the wall of the cylindrical member being thinned to form a fourth beveled face in the shape of a plane; and forming a portion of sharp edge comprised of at least the second, third, and fourth beveled faces. With this invention, in addition to the effects of the 14th invention, the working steps until the first, second, and third beveled faces are formed, are similar to the steps of producing a conventional hollow medical needle, so that a production line of a conventional hollow medical needle can be easily applied in a convenient manner. Of the present invention, the 16a comprises a method for producing a hollow medical needle, this method comprising: performing a grinding machining on an upper edge portion of a cylindrical member that forms a flow path capable of passing a fluid therein. in the direction of its central axis, in an oblique direction having a first angle inclined with respect to the central axis, to form a first bevelled ground face wherein the flow path is open in an oblique direction; grinding a position opposite the first bevelled face of the upper edge portion of the cylindrical member in a direction oblique with respect to the direction of the central axis, thinning the thickness of the wall of the cylindrical member to form a fourth face bevelled in bevel in the form of a plane, - performing a grinding machining on the upper edge portion of the cylindrical member by rotating a first angle of rotation in a positive direction with respect to the first face bevelled in bevel with the central axis in its center, which has a second angle inclined with respect to the central axis, to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the first face beveled in bevel with the central axis at its center, which has a third angle inclined with respect to the central axis to form a third face frosted in bis the, respectively; and forming a portion of sharp edge comprised of at least the second, third, and fourth beveled faces. With this invention, in addition to the effects of the 14th invention, the working steps until the first beveled face is formed, are similar to the steps of producing a conventional hollow medical needle, so it can be easily applied a production line of a conventional hollow medical needle in a convenient manner. Of the present invention, the 17th invention comprises a method for producing a hollow medical needle, this method comprising: performing a grinding machining on an upper edge portion of a cylindrical member that forms a flow path capable of passing a fluid in the same in the direction of its central axis, by rotating a first angle of rotation in a positive direction with respect to a previously determined standard position with the central axis as its center, having a second angle inclined with respect to this central axis to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the standard position with the central axis as its center having a third angle inclined with respect to the central axis to form a third face bevelled in bevel, respectively; grinding a position opposite to the standard position of the upper edge portion of the cylindrical member in an oblique direction with respect to the direction of the central axis, thinning the thickness of the wall of the cylindrical member to form a fourth beveled face in the shape of a plane perform a grinding machining on the upper edge portion of the cylindrical member in the standard position in an oblique direction having a first angle inclined with respect to the central axis, to form a first face beveled in bevel where the path of flow is open in an oblique direction; and forming a portion of sharp edge comprised of at least the second, third, and fourth beveled faces.

With this invention, in addition to the effects of the 14th invention, the working steps until the second and third beveled faces are formed are similar to the steps of producing a conventional hollow medical needle, so it can be applied easily a production line of a conventional hollow medical needle in a convenient manner. Of the present invention, the 18th invention comprises a method for producing a hollow medical needle, this method comprising: performing a grinding machining on an upper edge portion of a cylindrical member that forms a flow path capable of passing a fluid in the same in the direction of its central axis, by rotating a first angle of rotation in a positive direction with respect to a previously determined standard position with the central axis as its center, having a second angle inclined with respect to this central axis to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the standard position with the central axis as its center having a third angle inclined with respect to the central axis to form a third face bevelled in bevel, respectively, - perform a grinding machining on the portion of o upper rim of the cylindrical member in the standard position in an oblique direction having a first angle inclined with respect to the central axis, to form a first bevelled face in bevel where the flow path is open in an oblique direction, - to ground a position opposite to the first bevelled face of the upper edge portion of the cylindrical member in a direction oblique with respect to the direction of the central axis, the thickness of the wall of the cylindrical member being thinned to form a fourth beveled face in the shape of a plane; and forming a portion of sharp edge comprised of at least the second, third, and fourth beveled faces. With this invention, in addition to the effects of 14th invention, the working steps until the first, second, and third beveled faces are formed, are similar to the steps of production of a conventional hollow medical needle, so that a production line of one can be easily applied. Conventional hollow medical needle in a convenient way. Of the present invention, the 19th invention comprises the method for producing the hollow medical needle of the 13th, 14th, 15th, 16th, 17th or 18th invention, and wherein the sharp edge portion is formed by placing it on an internal wall forming the flow path of the cylindrical member. Then, the flange line portion 16 or the like is prevented from forming by the second and third beveled faces, in the wall thickness portion of the cylindrical member of the sharpened edge portion, and then the very sharp edge is formed. portion of sharp edge. Accordingly, in addition to the effects of the 13th, 14th, 15th, 16th, 17th, or 18th invention, the sharp edge portion is formed extremely sharp, so that the pain at the time of injection can also be reduced. in a considerable way. Of the present invention, the 20th invention comprises the method for producing the hollow medical needle of the 13th, 14th, 15th, 16th, 17th or 18th invention, wherein the fourth beveled face is ground at an inclined angle of 2 to 15 degrees with respect to the direction of the central axis of the cylindrical member. With this invention, in addition to the effects of the 13th, 14th, 15th, 16th, 17th or 18th invention, the sharp edge portion is formed in an appropriate state in edge and strength, conveniently. Of the present invention, the 21st invention comprises the method for producing the hollow medical needle of the 13th, 14th, 15th, 16th, 17th, or 18th invention, wherein the second and third inclined angles are equal to one another. With this invention, in addition to the effects of the 13th, 14th, 15th, 16th, 17th or 18th invention, the shape of the sharp edge portion is likewise formed to the right and to the left, in a convenient manner. Of the present invention, the 22nd invention comprises the method for producing the hollow medical needle of the 13a, 14a, 15a, 16a, 17a, or 18a invention, wherein the first and second angles of rotation are equal to one another. With this invention, in addition to the effects of the 13th, 14th, 15th, 16th, 17th or 18th inventions, the shape of the sharp edge portion is likewise formed to the right and to the left, in a convenient manner. Of the present invention, the 23rd invention comprises the hollow medical needle of the first invention, wherein a fifth beveled face is provided in an apical portion of one side of the cylindrical outer peripheral face of the cylindrical member in a first intersecting portion. formed by crossing the first bevelled ground face and the second bevelled face by removal of the apical portion, and a sixth beveled face is provided in an apical portion of one side of the cylindrical outer peripheral side of the face. cylindrical member in a second intersecting portion formed by crossing the first face beveled in bevel and the third face beveled in bevel, by removing this apical portion. Then, in addition to the effects of the first invention, since the fifth and sixth faces bevelled in bevel are provided by respectively removing both sides of the apical portions in the hollow medical needle according to the aforementioned 23rd invention, the resistance to the insertion with the hollow medical needle is lower than one where both sides of the apical portions are not removed. That is, when the hollow medical needle according to the 23rd invention is introduced into a human body or the like, at the time of performing an injection, the resistance of a tissue of the skin or of a blood vessel is small because it does not provide both. sides of the apical portions, so that damage to the skin and blood vessel tissue is hardly caused, and then a patient hardly feels pain in the part of the injection. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side view showing an example of a hollow medical needle in accordance with the present invention. Figure 2 is a view from the top of Figure 1. Figure 3 is a view from the bottom of Figure 1. Figure 4 is a sectional view of line XI-Yl of Figure 2. Figure 5 is a side view showing another example of the hollow medical needle in accordance with the present invention. Figure 6 is a view from the bottom of Figure 5. Figure 7 is a sectional view of line X2-Y2 of Figure 5. Figure 8 is a side view showing another example of the hollow medical needle in accordance with the present invention. Figure 9 is a view from the top of Figure 8. Figure 10 is a view from the bottom of Figure 8. • Figure 11 is a side view showing another example of the hollow medical needle in accordance with the present invention. Figure 12 is a view from the bottom of Figure 11. Figure 13 is a side view showing another example of the hollow medical needle in accordance with the present invention. Figure 14 is a view from the top of Figure 13. Figure 15 is a view from the bottom of Figure 13.

Figure 16 is a side view showing another example of the hollow medical needle in accordance with the present invention. Figure 17 is a view from the top of Figure 16. Figure 18 is a sectional view of line X3-Y3 of Figure 17. Figure 19 is a side view showing another example of the hollow medical needle in accordance with the present invention. Figure 20 is a view from the bottom of Figure 19. Figure 21 is a side view showing another example of the hollow medical needle in accordance with the present invention. Figure 22 is a view from the bottom of Figure 21. DESCRIPTION OF THE PREFERRED MODALITY A medical needle 1, or an example of a hollow medical needle in accordance with the present invention, is produced, as shown in Figures 1 to 4, grinding a cylindrical member 2 (shown by a chain line of two points in a part) which is a cylindrical rod-shaped member, whose diameter is extremely small, extending in the directions shown by the arrows A and B in the respective Figures (On this occasion, the direction as shown by the arrow B is a direction of an upper end of the cylindrical member 2). Within the cylindrical member 2, a medical fluid flow orifice 25 is formed in which a fluid, such as a medical injection liquid, can pass in the direction of a central axis Ql of the cylindrical member 2 (or in the directions shown by arrows A and B). On the outer peripheral side of the cylindrical member 2, a cylindrical outer peripheral face 2c is basically formed. A sub-beveled face 12 is provided with an upper end portion 10 of the cylindrical member 2, placed on the underside of the paper of Figure 1 and Figure 4. The sub-beveled face 12 comprises a part of a first face frosted 20 formed by the thinning grinding of a first section Ll (i.e., the area in the directions shown by arrows A and B) on one side of the upper edge 2a of the cylindrical member 2 (i.e., the side of the edge portion of the arrow side B of Figure), reduce the outer diameter of the cylindrical member 2 in the direction shown by the arrow B, coaxially with the cylindrical member 2 (ie, forming the configuration of a circular truncated cone) , and then thinning a wall thickness NA of the cylindrical member 2 in the direction shown by the arrow B. That is, the sub-beveled face 12 is positioned along the direction shown by the arrow D in the Figure, which it is a direction Oblique with respect to the direction shown by the arrow B, or the direction of the central axis Ql of the cylindrical member 2 (ie, in the direction of a generatrix of a circular truncated cone by the first ground face 20). In the upper edge portion 10 of the cylindrical member 2, a first beveled face 3 is formed, the first beveled face 3 being the portion placed on the left side of the paper of Figure 1, of a second ground face 21 made by cutting of the upper end portion 10 of the cylindrical member 2 in a state such that the first ground face 20 is produced, by a ground plane SI where the central axis Ql of the cylindrical member 2 and a first inclined angle Kl (acute angle) intersect each other, leaning towards the upper left of Figure 1 (in fact, the ground plane SI is a curved face close to a plane, but this SI plane is explained as a plane in the present modality for greater convenience ), by removing the side of the arrow B. Accordingly, a grinding limit 65 on the side of the arrow A of the first beveled face 3 is connected to the outer cylindrical peripheral face 2c. The grinding limit 65 is the linear portion in the C-shape that connects the API, AP2, and AP3 points, with each other, as shown in Figure 2 and Figure 4.

The second ground face 21 is formed in a second section L2 on the side of the upper edge 2a of the cylindrical member 2 (ie, the area in the directions shown by the arrows A and B), the second section L2 is wider than the first section Ll, and a central position CS showing the position of the first beveled face 3 for greater convenience (ie, the position of the upper part of the central axis Ql in the paper of Figure 1 and of Figure 4) is opposite the sub-beveled face 12. The first beveled face 3 is formed, so the orifice of medical liquid flow 25, is open in an oblique direction in the first beveled face 3. In the upper edge portion 10 of the cylindrical member 2, the first ground face 20 is formed. In addition, a second beveled face 5 is formed, formed by cutting the side of the upper edge 2a of the cylindrical member 2, in a state such that the second ground face 21 is formed when grinding the planes S2a and S2b of the Figure (these are in fact facing curves related to a plane, similar to the grinding plane SI, but in the present embodiment, each is explained as a plane for greater convenience), in a third section L3 on the side of the upper edge 2a of the cylindrical member 2 (ie, the area in the directions shown by arrows A and B). The third section L3 is wider than the first section Ll, and is narrower than the second section L2.

The plane of grinding S2a is a plane that rotates to a plane S2, where the central axis Ql of the cylindrical member 2 and a second inclined angle K2 (is an acute angle and is larger than the first inclined angle Kl) intersect one the other, capable of having a normal vector N2 that exists on the TI plane (the plane along the paper in Figure 1) equal to a normal vector NI of the ground plane SI (in addition, the plane S2 is a plane that slopes towards the upper left in Figure 1), a first predetermined rotation angle MI in the direction shown by the arrow J in Figure 1 and Figure 4, with the central axis Ql as its center. And, the grinding plane S2b is a plane that rotates to a plane S4, where the central axis Ql and a third inclined angle K3 (is an acute angle and is larger than the first inclined angle Kl) intersect each other , capable of having a normal vector N3 that exists on the TI plane equal to the normal vector NI (in addition, the plane S4 is a plane that slopes towards the upper left in Figure 1), a second angle of rotation previously determined M2 in the direction shown by arrow H of the Figure 4, opposite the direction shown by the arrow J with the central axis Ql as its center. In the mode, the second inclined angle K2 is equal to the third inclined angle K3 (then, the plane S2 and the plane S4 are the same plane, and the first rotation angle MI and the second rotation angle M2 are equal to each other) (but, the hollow medical needle according to the present invention is not limited only to the present embodiment, for example, the second inclined angle K2 and the third inclined angle K3 may be different from each other, or the first rotation angle MI and the second rotation angle M2 may be different from one another). The face is made by cutting the side of the upper edge 2a of the cylindrical member 2, in a state such that the first ground face 20 is made, and in addition, the second ground face 21 is made, by the plane of grinding S2a that is a right beveled face 6, and the face is cut by the ground plane S2b which is a left beveled face 7. That is, the second beveled face 5 is comprised of the right beveled face 6 and the left beveled face 7. In other words, in the upper edge portion 10 of the cylindrical member 2, the right bevel face 6 is formed, rotating it by the first rotation angle MI in a positive direction (i.e., the direction shown by the arrow J) to the first beveled face 3 (that is, to the central position CS) with the central axis Ql as its center, which has the second inclined angle K2 to the central axis, and the face is formed beveled left 7, rotating it by the second rotation angle M2 in the opposite direction (ie, the direction shown by the arrow H) to the first beveled face 3 (ie, to the central position CS) with the central axis Ql as its center, which has the third inclined angle K3 to the central axis Ql. As described hereinabove, in the upper edge portion 10 of the cylindrical member 2, the first beveled face 3 and the second beveled face 5 are successively formed in the second section L2 in the direction shown by the arrow B, and a open bevel end face 11 is comprised of the first beveled face 3 and the second beveled face 5. The open bevel end face 11 is also the edge portion of the medical liquid flow orifice 25 inside the cylindrical member 2, and consequently, the medical liquid flow orifice 25 is open outwardly. This open direction is the direction shown by the arrows Cl in the figure, which is the direction of the normal vector NI of the grinding plane SI that forms the first beveled face 3, and the direction shown by the arrow C2 in the figure, which is the direction of the vector that averages the normal vectors of the grinding planes S2a, S2b, which form the second beveled face 5 (that is, the normal vector N2 of the plane S2). Then, the open bevel end face 11 is open in a direction oblique to the direction shown by the arrow B, which is the direction extending from the upper edge of the cylindrical member 2. The open bevel end face 11 is provided on the upper side of the paper of Figure 1, as shown in Figure 1, and then the sub-beveled face 12 (the underside of the paper of Figure 1) is provided on the opposite position to the end face open bevel 11. Further, the open bevel end face 11 and sub-beveled face 12 are adjacent to each other on the side of the upper edge 2a of the cylindrical member 2, and then a sharp edge portion is formed 13, which is sharpened in the direction shown by the arrow B, between the open bevel end face 11 and the sub-beveled face 12. That is, the sharp edge portion 13 is formed by the three ground faces, the face bevel right 6, face b left side 7, and the sub-beveled face 12. Then, on medical needle 1, the sub-beveled face 12 is provided (in a conventional hollow medical needle, only the open bevel end face), as well as the face end of open bevel 11, whereby the sharp edge portion 13 is extremely thin. The medical needle 1 according to the present invention is comprised as described hereinabove. The medical needle 1 is produced as follows. At the beginning, a grinding machining is performed on the first section Ll of the upper edge portion 10 of the cylindrical member 2 with an appropriate (known) cylindrical grinder, as shown in Figures 1 to 3, coaxially to the cylindrical member 2, reducing the external diameter of the cylindrical member 2 in the direction shown by the arrow B, that is, thinning the wall thickness NA of the cylindrical member 2 in the direction shown by the arrow B, to form the first thinned ground face 20 (shown for a complete line in part, and for a line in chain of two points in the other part). Next, a grinding machining is performed on the upper edge portion 10 of the cylindrical member 2, in such a state that the first ground face 20 is formed, with an appropriate grinding machine, such as the grinding machine capable of grinding by rotating a grinding stone in the shape of a disc (known) in an oblique direction to the direction shown by arrow B in the figure (ie, the direction having the first inclined angle Kl to the central axis Ql), that is, in the direction shown by the arrow El of the figure, which is the direction along the plane of grinding SI, to form the second ground face 21 in the second section L2 (then, the first beveled face 3 is made which is a part of the second ground face 21). In addition, the upper edge portion 10 of the cylindrical member 2, in such a state as to make the first ground face 20 and the second ground face 21, is ground with the grinding machine in a direction oblique to the direction shown by the arrow B in the figure, that is, in the direction shown by the arrow E2 in the figure, which is the direction along the grinding plane S2a or the grinding plane S2b to form the right bevel face 6 and the left bevel face 7 in the third section L3, that is, to form the second beveled face 5. The second beveled face 5 is formed by grinding, where a part of the second ground face 21 is grinded and removed (the right side of the paper of the Figure 1, that is, the portion of the third section L3), and the first beveled face 3 is formed, which is a part of the second ground face 21 (the left side of the paper of Figure 1), which remains without grinding. That is, the open bevel end face 11 comprised of the first beveled face 3 and the second beveled face 5 is formed. This open bevel end face 11 (i.e. the second ground face 21 and the second bevel face 5) ) is ground and formed, so that a part of the first ground face 20 (the portion on the upper side of the paper of Figure 1) is ground and removed, and the sub-bevelled face 12 is formed which is a part of the first ground face 20 (the underside of the paper of Figure 1), which is not ground. And the sharp edge portion 13 is formed between the open bevel end face 11 and the sub-beveled face 12, and then the production of the medical needle 1 is completed.

As described above, in the present embodiment, the medical needle 1 can be produced to make the sharp edge portion 13 extremely thin, thinning the wall thickness NA of the cylindrical member 2, leaving the sub-bevelled face 12 the first ground face 20 without grinding, since the first ground face 20 is formed, unless the grinding machining is done to make small inclined angles Kl, K2, K3 of the open bevel end face 11 to the direction shown by the arrow B. That is to say, the medical needle 1, having the thin upper edge portion, can be produced without widening the second section L2 forming the open bevel end face 11, that is, the area where the cylindrical member 2 is grinded along the entire length in the direction of the central axis Ql of the medical needle 1. Accordingly, it can be prevented that the cylindrical member 2 becomes thin in its wide area, and then no the resistance of the medical needle 1 can be impaired. The hollow medical needle according to the present invention can be a needle different from the medical needle 1 described hereinabove. For example, the hollow medical needle according to the present invention may be a medical needle 1P as shown in Figures 5 to 7. The different portion of the medical needle 1 described above, of the medical needle 1P, is the face sub-beveled 12, and this sub-bevelled face 12 of the medical needle 1P is in the form of a plane. The medical needle 1P is produced as follows. At the beginning, a grinding machining is performed with an appropriate grinding machine, such as the grinding machine capable of grinding by rotating a grinding stone in the shape of a (known) disk on the upper edge portion 10 of the cylindrical member 2, as is shown in Figure 5, in an oblique direction to the direction shown by arrow B in the figure, which is the direction of the central axis Ql of the cylindrical member 2, ie, in the direction shown by arrow D of the Figures 5 and 6, thinning the wall thickness NA of the cylindrical member 2 in the direction shown by the arrow B, to form the sub-beveled face 12 in the form of a plane made by cutting the upper edge portion 10 of the cylindrical member 2, by a plane of grinding S3 along the direction shown by the arrow D (in fact, the sub-beveled face 12 is a curved face close to a plane, for greater convenience of grinding, but the face 12 can be treated substantially as a plane). Between the sub-beveled face 12 and the right beveled face 6, and between the sub-beveled face 12 and the left beveled face 7, that is, in the areas between the bevel faces 66, 66, as shown in the Figures 5 to 7, there is a cylindrical outer peripheral face 2c of the cylindrical member 2 in the peripheral direction of the cylindrical member 2. Subsequently, in a manner similar to the case of the medical needle 1 described above, with the aforementioned grinding machine, the ground machining on the upper edge portion 10 of the cylindrical member 2 forming the sub-beveled face 12 in an oblique direction having the first inclined angle Kl with respect to the central axis Ql in the opposite position to the sub-beveled face 12 (ie, the central position CS of Figure 5), that is, the grinding machining is performed in the direction shown by the arrow El of Figure 5, which is the direction along the grinding plane. SI side, to form the second ground face 21 in the second leg L2 (then, the first beveled face 3 is formed, wherein the medical liquid flow port 25 is open in an oblique direction, as a part of the second side frosted 21). In addition, the upper edge portion 10 is ground in an oblique direction with respect to the direction shown by arrow B in the figure, that is, in the direction shown by the arrow E2 of the figure, which is the direction along the plane of grinding S2a or S2b, to form the right bevel face 6 and the left bevel face 7 in the third section L3, that is, to form the second beveled face 5, and then the open bevel end face 11 is formed. This open bevel end face 11 is ground and formed, thereby forming the sharpened edge portion 13 between the bevel. open bevel end face 11 and the sub-beveled face 12, and then the production of the medical needle 1P ends. The medical needle 1P can be produced by other kinds of steps than those mentioned above. For example, the upper edge portion 10 of the cylindrical member 2 is ground with the aforementioned grinding machine in an oblique direction having the first inclined angle Kl with respect to the central axis Ql in the central position CS to form the second ground face 21 in the second section L2 (that is, the first beveled face 3 is formed as a part of the second ground face 21). Subsequently, the upper edge portion 10 of the cylindrical member 2 is ground in an oblique direction with respect to the central axis Q 1, ie, in the direction shown by the arrow E 2 of the figure, which is the direction along the plane of frosted S2a or grinding plane S2b, to form the right bevel face 6 and the left bevel face 7 in the third section L3, that is, to form the second beveled face 5, and then the open bevel end face is formed 11. Subsequently, the upper edge portion 10 is grinded in the opposite position to the first beveled face 3 in an oblique direction with respect to the central axis Ql in the first section Ll, to form the sub-beveled face 12 in the form of a plane made by cutting the upper edge portion 10 of the cylindrical member 2 by the grinding plane S3 along the direction shown by the arrow D. In this manner, the sharp edge portion 13 between the liner is formed. to the open bevel end face 11 and the sub-beveled face 12, and then the production of the medical needle 1P ends. The medical needle 1P can also be produced by another kind of steps. For example, the upper edge portion 10 of the cylindrical member 2 is ground with the aforementioned grinding machine in an oblique direction having the first inclined angle Kl with respect to the central axis Ql in the central position CS, to form the second ground face 21 in the second section L2 (then, the first beveled face 3 is formed as a part of the second ground face 21). Subsequently, the upper edge portion 10 in the first section Ll is ground in an oblique direction with respect to the central axis Ql in the opposite position to the first beveled face 3 (then, the opposite position to the central position CS), to form the sub-beveled face 12 in the form of a plane made by cutting the upper edge portion 10 of the cylindrical member 2 by the grinding plane S3 along the direction shown by the arrow D. Subsequently, the upper edge portion 10 of the cylindrical member 2 in an oblique direction with respect to the central axis Q1, that is, in the direction shown by the arrow E2 of the figure, which is the direction along the plane of grinding S2a or the plane of grinding S2b, to form the right bevel face 6 and the left bevel face 7 in the third section L3, that is, to form the second beveled face 5, and then the open bevel end face 11 is formed. nera, the sharp edge portion 13 is formed between the open bevel end face 11 and the sub-beveled face 12, and then the production of the medical needle 1P ends. Now another kind of step will be explained to produce the 1P medical needle. For example, the upper edge portion 10 of the cylindrical member 2 is ground in the direction along the grinding plane S2a or the grinding plane S2b, to form the right beveled face 6 and the left beveled face 7 in the third section L3, that is, to form the second beveled face 5. Subsequently, the upper edge portion 10 is ground in an oblique direction having the first angle inclined Kl with respect to the central axis Ql in the central position CS, to form the first beveled face 3. Subsequently, the upper edge portion 10 is ground in the opposite position to the first beveled face 3 (then, the opposite position to the central position CS) in the first section Ll, to form the sub-beveled face 12 in the form of a plane made by cutting the upper edge portion 10 of the cylindrical member 2 by the grinding plane S3. In this way, the sharp edge portion 13 is formed between the open bevel end face 11 and the sub-beveled face 12, and then the production of the medical needle 1P is terminated. The hollow medical needle according to the present invention may have another shape, except for the medical needles 1, 1P shown in the respective embodiments mentioned above. For example, as shown in Figures 8 to 10, a medical needle IX has the cylindrical member 2 inside which the medical liquid flow orifice 25 is formed in the direction of the central axis Q1, basically similar to the medical needle 1 previously mentioned. In the upper edge portion 10 of the cylindrical member 2, the first beveled face 3, wherein the medical liquid flow orifice 25 is open in an oblique direction, formed with the first inclined angle K 1 with respect to the central axis Q 1, is provides on the central position CS. In addition, in the upper edge portion 10 of the cylindrical member 2, the right beveled face 6 is provided, formed by rotating at the first rotation angle MI in the positive direction with respect to the first beveled face 3 with the central axis Ql as its center, and formed with the second inclined angle K2 with respect to the central axis Q1, and the left bevelled face 7 is provided, formed by rotating at the second rotation angle M2 in the opposite direction to the first beveled face 3, with the central axis Ql as its center, and formed with the third inclined angle K3 with respect to the central axis Ql. In the opposite position to the first beveled face 3 of the upper edge portion 10, the sub-beveled face 12 is provided which is ground and formed in the oblique direction with respect to the central axis Ql of the cylindrical member 2, thinning the thickness of the wall NA of the cylindrical member 2. The sharp edge portion 13 is comprised of the three ground faces, or the right bevel face 6, the left beveled face 7, and the sub-beveled face 12. In a manner similar to the medical needle 1 aforementioned, the sub-bevelled face 12 is a part of the first ground ground face 20 with the central axis Ql as its center. However, since in the medical needle IX, as shown in Figures 8 and 9, the sharpened edge portion 13 is formed by placing it on an inner wall 2b which forms the medical liquid flow orifice 25 of the cylindrical member 2, a portion of bead line 16 (as shown in Figures 1 and 2) is not formed which would occur by crossing the right bevel face 6 and the left bevel face 7 near the sharp edge portion 13 and then the 13 sharp edge portion is formed in an extremely sharp manner. Since the sub-beveled face 12 of the medical needles 1 and IX is a part of the first ground ground face 20 with the central axis Ql as its center, in the portion formed by the sub-beveled face 12, or the near portion to the sharp edge portion 13, especially in the peripheral direction of the cylindrical member 2, as shown in Figure 10 (see Figure 3 with respect to the medical needle 1), the outer cylindrical peripheral face 2c of the member is not left cylindrical 2 that remains adjacent to the sub-beveled face 12. Therefore, a stepped or similar portion is not formed where the sub-bevelled face 12 and the outer cylindrical peripheral face 2c would join, and then the pain can be conveniently further prevented at the time of injection. In addition, the hollow medical needle according to the present invention may have another form, except for medical needles 1, 1P, and IX shown in the respective embodiments mentioned above. For example, as shown in Figure 11 and Figure 12, a medical needle 1Y has the cylindrical member 2 inside which the flow orifice of the medical liquid 25 is formed in the direction of the central axis Q1, basically similar to the 1P medical needle mentioned above. In the upper edge portion 10 of the cylindrical member 2, the first beveled face 3 is provided, wherein the medical liquid flow orifice 25 is open in an oblique direction, formed with the first inclined angle Kl with respect to the central axis Ql. . Further, in the upper edge portion 10 of the cylindrical member 2, the right beveled face 6, formed by rotating the first rotation angle MI in the positive direction with respect to the first beveled face 3 with the central axis Ql is provided as its center, and formed with the second inclined angle K2 with respect to the central axis Ql, and the left bevelled face 7 is provided, formed by rotating the second rotation angle M2 in the opposite direction to the first beveled face 3 with the axis central Ql as its center, and formed with the third inclined angle K3 with respect to the central axis Ql. In the opposite position to the first beveled face 3 of the upper edge portion 10, the sub-beveled face 12 is provided which is ground and formed in the direction oblique to the direction of the central axis Ql of the cylindrical member 2, the thickness of the NA wall of the cylindrical member 2. The sharp edge portion 13 is comprised of the three ground faces, or the right bevel face 6, the left beveled face 7, and the sub-beveled face 12. The sub-bevel face 12 is in the shape of a plane, similar to the aforementioned 1P medical needle.

However, since in the medical needle 1Y, as shown in Figure 11, the sharpened edge portion 13 is formed by placing it on an inner wall 2b forming the medical liquid flow orifice 25 of the cylindrical member 2, it is not forms a portion of bead line 16 (as shown in Figure 5) that would be produced by crossing the right bevel face 6 and the left bevel face 7 near the sharp edge portion 13, and then the portion is formed of sharp edge 13 in an extremely sharp way. The sub-bevelled face 12 of the medical needle 1Y is in the shape of a plane, in a manner similar to the medical needle 1P, and in the portion forming the sub-beveled face 12, or the portion near the portion of sharp edge 13, especially in the peripheral direction of the cylindrical member 2, as shown in Figures 11 and 12, the outer peripheral cylindrical face 26 of the cylindrical member 2 is left in the areas between the beveled faces, between the sub-beveled face 12 and the right bevel face 6, and between the sub-beveled face 12 and the left beveled face 7. That is, the outer cylindrical peripheral face 2c is left near the sharp edge portion 13 without grinding, so it is increased much the resistance of the medical needle 1Y in the portion near the sharp edge portion 13 (is in a similar manner to the medical needle 1P mentioned above, of course). Further, since the cylindrical outer peripheral face 2c is left near the sharpened edge portion 13 without grinding, and does not decrease the strength near the sharp edge portion 13, a sub-chamfered inclined angle K4 with respect to the central axis Ql of the sub-beveled face 12 can be made extremely small (consequently, the area forming the sub-beveled face 12 in the directions shown by the arrows A and B, can be made wider), to make the edge portion sharp 13 thinner. There are results of an insertion resistance measurement experiment, when a concrete example of the above-mentioned medical needle 1Y is used. That is, an experiment measuring the resistance to insertion with hollow medical needles has been executed, wherein the fourth beveled face is formed, such as the sub-beveled face 12 (ie, the medical needle 1Y), and another where the fourth beveled face is not formed, such as the sub-beveled face 12 (ie, the conventional hollow medical needle), and with respect to each of these hollow medical needles (the proportion of silicone to flutter) is 6 percent), the length of the face of one cut edge (ie, the second leg L2) is 5.5 millimeters, the second beveled angle (ie, the second and third angles inclined K2, K3) is from 25.5 to 26 degrees, the length of the lancet (i.e., the ratio of the third leg L3 to the second leg L2) is 40 to 43 percent, the angle of rotation (ie, the first and second rotation angles MI , M2) is 27.5 degrees, under ambient temperature conditions of 25 degrees. As the results of the experiment, the values of the resistance to insertion in the needle where the fourth beveled face is formed, are 150.5 grams, 156.8 grams, 136.2 grams, 149.0 grams, 137.3 grams, 151.0 grams, 137.8 grams (the value of resistance to the average insertion is 145.5 grams), and the values of resistance to insertion in the needle where the fourth beveled face is not formed in bevel are 261.2 grams, 235.6 grams, 201.3 grams, 200.7 grams , and 217.1 grams (the average insertion resistance value is 223.18 grams). From the results, it is found that the resistance to insertion in the hollow medical needle where the fourth beveled face is formed in bevel, is smaller than that found in the conventional hollow medical needle, where it is not formed the fourth face frosted in bevel. In the last experiments, it was found that the value of resistance to insertion decreases approximately 40 percent. Accordingly, the resistance to insertion into the hollow medical needle according to the present invention is small, so that at the time of execution of the injection or the like, a patient or the like becomes less injured blood vessels and the like in the part of the injection, and feel less pain in the part of the injection. In the aforementioned embodiment, the medical needle of the so-called lancet type is shown as the specific example of the hollow medical needle in accordance with the present invention, but the hollow medical needle according to the present invention can be one except the type of lancet. For example, the hollow medical needle according to the present invention may be the medical needle of the so-called type K3, type K3 ', a needle having a side hole, and a type of posterior cut. A medical needle 1Z of the posterior cutting type of the hollow medical needles in accordance with the present invention will now be explained. As shown in Figures 13 to 15, the medical needle 1Z has the cylindrical member 2 inside which the medical liquid flow orifice 25 is formed in the direction of the central axis Ql. In the upper edge portion 10 of the cylindrical member 2, the first beveled face 3 is provided, wherein the medical liquid flow orifice 25 is open in an oblique direction, formed with the first inclined angle Kl with respect to the central axis Ql. , on the central position CS. On this occasion, the grinding limit 65 on the side of the arrow A of the first beveled face 3 is connected to the cylindrical outer peripheral face 2c of the cylindrical member 2, in a manner similar to the aforementioned medical needles 1, 1P, IX , and 1Z. In addition, in the upper edge portion 10 of the cylindrical member 2, the right beveled face 6, formed by rotating the first rotation angle MI (90 degrees or more than 90 grams) in the positive direction with respect to the first beveled face 3 with the central axis Ql as its center (then, to the central position CS), and formed with the second inclined angle K2 with respect to the central axis Ql, and the left bevelled face 7, formed by the rotation of the second rotation angle M2 (90 degrees or more than 90 degrees, - in the present embodiment, it is shown that the first rotation angle MI and the second rotation angle M2 are equal to each other, but the first rotation angle MI and the second rotation angle M2 may be different from each other), in the opposite direction to the first beveled face 3 (then, to the central position CS) with the central axis Ql as its center, and formed with the third inclined angle K3 with respect to the central axis Ql (in the present embodiment, the second inclined angle K2 and the third inclined angle K3 are equal to each other, but both angles K2 and K3 may be different from one another). Then, the second beveled face 5 comprised of the right bevel face 6 and the left bevel face 7 is located in the opposite position to the first beveled face 3, and consequently, the open bevel end face 11 is formed by only the first bevelled face 3. In the opposite position to the first beveled face 3 the upper edge portion 10, the sub-beveled face 12 in the shape of a plane, ground and formed in the oblique direction with respect to the central axis Ql of the member cylindrical 2, thinning the thickness of the wall NA of the cylindrical member 2, is provided by joining respectively the right beveled face 6 and the left beveled face 7 on both sides, as shown in Figure 15. The sharp edge portion 13 is comprised of of the four frosted faces, or the first beveled face 3, the right beveled face 6, the left beveled face 7, and the sub-beveled face 12. In the case where the medical hollow needle of conformity d with the present invention is the medical needle of the so-called lancet type, such as the medical needles 1, 1P, IX and 1Y shown in the aforementioned embodiments, the medical needle may be comprised of an IR medical needle, for example, as shown in Figures 16 to 18, except medical needles 1 , 1P, IX, and 1Y. That is, the IR medical needle of the lancet type has the cylindrical member 2 inside which the orifice of the medical liquid flow 25 is formed in the direction of the central axis Q1, basically similar to the aforementioned medical needle IX, as shown in Figures 16 to 18. In the upper edge portion 10 of the cylindrical member 2, the first beveled face 3 is provided, wherein the medical liquid flow orifice 25 is open in an oblique direction, formed with the first inclined angle Kl. with respect to the central axis Ql, on the central position CS. Further, in the upper edge portion 10 of the cylindrical member 2, the right beveled face 6, formed by rotating the first rotation angle MI in the positive direction with respect to the first beveled face 3 with the central axis Ql is provided as its center, and formed with the second inclined angle K2 with respect to the central axis Ql, and the left bevelled face 7 is provided, formed by rotating the second rotation angle M2 in the opposite direction to the first beveled face 3 with the axis central Ql as its center, and formed with the third inclined angle K3 with respect to the central axis Ql. In the opposite position to the first beveled face 3 of the upper edge portion 10, the sub-beveled face 12 is provided which is ground and formed in the oblique direction with respect to the central axis Ql of the cylindrical member 2, thinning the thickness of the wall NA of the cylindrical member 2. The sharp edge portion 13 is comprised of the three ground faces, or the right bevel face 6, the left beveled face 7, and the sub-beveled face 12. The sub-beveled face 12 is a part of the first ground ground face 20 with the central axis Ql as its center, similar to the aforementioned medical needle IX, and the sharp edge portion 13 is formed by placing it on the inner wall 2b forming the medical fluid flow orifice. of the cylindrical member 2. The medical needle IR has the following structure in addition to the aforementioned structure. That is, in the upper edge portion 10 of the cylindrical member 2, a right auxiliary ground face 90 and a left auxiliary ground face 91 are provided. The right side ground face 90 and the left side ground face 91 are ground and then formed the first beveled face 3, the right beveled face 6, and the left beveled face 7, and the sub-beveled face 12 (hence, after the needle reaches this in a condition similar to that of the medical needle IX mentioned above). (This order of grinding is not important in the present invention.) Any order is applicable). That is, the right auxiliary ground face 90 is provided by removing a right apical portion 98 (shown in Figure 8 or Figure 9) on the side of the cylindrical outer peripheral face 2c of the cylindrical member 2 of a right intersecting portion 92 formed by crossing the first beveled face 3 and the right beveled face 6, and the left auxiliary ground face 91 is provided by the removal of a left apical portion 96 (shown in Figure 9) on the side of the outer cylindrical peripheral face 2c of the cylindrical member 2 of a left intersecting portion 97 formed by crossing the first beveled face 3 and the left beveled face 7. Furthermore, the right auxiliary ground face 90 is formed by rotating the third rotation angle M3 in the direction positive with respect to the first beveled face 3 with the central axis Ql as its center, which has a fifth inclined angle K5 which is an almost in angle between the first inclined angle Kl and the second inclined angle K2 with respect to the central axis Ql. The left auxiliary ground face 91 is formed by rotating a fourth rotation angle M4 in the opposite direction to the first beveled face 3 with the central axis Ql as its center, having a sixth inclined angle K6 which is an almost intermediate angle between the first inclined angle Kl and the third inclined angle K3 with respect to the central axis Ql. Since the right auxiliary ground face 90 and the left auxiliary ground face 91 are formed in the medical IR needle by respectively removing the right apical portion 98 and the left apical portion 96, as described hereinabove, the insertion resistance with the medical needle IR is lower than with the needle such as the medical needle IX having the right apical portion 98 and the left apical portion 96. That is, when the medical IR needle is inserted into a human body or the like, in the At the moment of the execution of the injection or the like, the resistance of the skin tissue or blood tissue is lowered by not providing the right apical portion 98 and the left apical portion 96, so that a patient becomes slightly injured in the skin and in the blood tissue, and then little pain is felt in the part of the injection. In addition, the hollow medical needle having the fifth beveled face, such as the right auxiliary ground face 90 and the sixth beveled face, such as the left auxiliary ground face 91, can be applied to any shape of a needle that have the apical portions 96 and 98 of the outer peripheral side of the intersecting portions 92, 97 formed by the first beveled face and the second beveled face (i.e., the right beveled face 6 and the left beveled face 7), such as the of the type of posterior cut in addition to the aforementioned type of lancet. Of course, it is also applicable to medical needles 1P and 1Y which are of the lancet type, and whose sub-beveled faces 12 are in the form of a plane, and medical needles 1 and 1P in each of which the portion of sharp edge 13 is not on the inner wall 2b and the flange line portion 16 is formed. For example, in the medical needle 1Z of the posterior cut type, as shown in Figures 13 to 15, the right apical portion 98 on the side of the cylindrical outer peripheral face 2c of the cylindrical member 2 of the right intersecting portion 92 formed by crossing the first beveled face 3 and the right beveled face 6, is ground and removed to provide the fifth face frosted in bevel, and the left apical portion 96 on the side of the cylindrical outer peripheral face 2c of the cylindrical member 2 of the left intersecting portion 97 formed by crossing the first beveled face 3 and the left beveled face 7, grind and stir, to provide the sixth face bevelled in bevel. The fifth and sixth bevelled faces are provided with the hollow medical needle of the posterior cut type, so that effects similar to those of the aforementioned medical needle IR are exerted. In the above-mentioned medical needle 1P and the like, the sub-beveled face 12 is formed in the form of a plane. However, the shape of the sub-beveled face 12 may have the shape extending from the side of the sharpened edge portion 13 to the side of the arrow A, as shown in Figures 19 to 22. In this case , as shown in Figures 19 and 20, on the sub-beveled face 12, the positions corresponding to the right apical portion 98 on the side of the cylindrical outer peripheral face 2c of the cylindrical member 2 of the right intersecting portion 92 formed by crossing the first beveled face 3 and the right beveled face 6, and the left apical portion 96 of the side of the cylindrical outer peripheral face 2c of the cylindrical member 2 of a left intersecting portion 97 formed by crossing the first face beveled 3 and the left beveled face 7, may be crossed in the opposite direction to the direction of the upper end of the cylindrical member 2, ie, in the direction shown by the arrow A. Also, as shown in FIGS. Figures 21 and 22, on the sub-beveled face 12, the position corresponding to an apical portion 65a (shown in Figure 5 and in Figure 7 as well), on the side opposite the direction of the upper end of the cylindrical member 2 of the grinding boundary 65 of the first beveled face 3, that is, on the side of the arrow A, can cross in the opposite direction to the direction of the upper end of the cylindrical member 2, that is, in the direction shown by the arrow A. The hollow medical needle according to the present invention can be applied to different needles, such as a needle to collect blood, a dental needle, and a metal needle of a remaining needle used for blood transfusion or dialysis, in addition to the needle for hypodermic injection. In the medical needles 1, 1P, IX, 1Y, 1Z, and IR, as shown in the respective embodiments mentioned above, the sub-bevelled inclined angle K4 of the sub-beveled face 12 to the direction of the central axis Ql of the member cylindrical 2 is set from 2 to 15 degrees, whereby the sharp edge portion 13 can be formed with an appropriate state of edge and strength. The present invention has been explained based on the modalities presented herein. However, the modalities described in this specification are illustrative and not limiting. The scope of the invention is designated by the appended claims, and is not restricted by the descriptions of the specific embodiments. In accordance with the foregoing, all transformations and changes pertaining to the claims are included in the scope of the present invention.

Claims (23)

1. NOVELTY OF THE INVENTION Having described the foregoing invention, it is considered as a novelty, and therefore, property is claimed as contained in the following: CLAIMS 1. A hollow medical needle which comprises: a cylindrical member having a trajectory of flow capable of passing a fluid therein, in the direction of its central axis, having a cylindrical outer peripheral face on an outer peripheral side; a first beveled face bevelled into an upper end portion of the cylindrical member, such that the flow path opens in an oblique direction, having a first angle inclined with respect to the central axis; the first bevelled face being located in such a manner that a grinding boundary on a side opposite a direction of the upper end of the cylindrical member of the first beveled face is connected to the outer cylindrical peripheral face; a second chamfered ground face formed by rotating a first angle of rotation in a positive direction with respect to the first beveled face, with the central axis as its center, having a second angle inclined with respect to the central axis, and a third chamfered ground face formed by rotating a second angle of rotation in an opposite direction with respect to the first chamfered ground face with the central axis as its center, having a third angle inclined with respect to the central axis, both formed in the upper edge portion of the cylindrical member, respectively; a fourth face bevelled, bevelled and formed in a position opposite to the first bevelled face of the upper edge portion of the cylindrical member in a direction oblique with respect to the direction of the central axis of the cylindrical member, thinning the thickness of the wall of the cylindrical member, - and a sharp edge portion comprised of at least three ground faces, that is, the second, third, and fourth beveled faces.
2. 2. The hollow medical needle according to claim 1, characterized in that the sharp edge portion is comprised of four ground faces, that is, the first, second, third, and fourth face ground bevel.
3. 3. The hollow medical needle according to claim 1, characterized in that the fourth chamfered face is a part of a ground face that is thinned with the central axis as its center.
4. 4. The hollow medical needle according to claim 1, characterized in that the fourth beveled face is in the form of a plane.
5. 5. The hollow medical needle according to claim 4, characterized in that the fourth beveled face extends from the side of the sharpened edge portion to a side opposite the direction of the upper end of the cylindrical member.
6. The hollow medical needle according to claim 5, characterized in that the fourth beveled face is provided in such a way that the positions corresponding to an apical portion of one side of the cylindrical outer peripheral face of the cylindrical member of a first intersecting portion formed by the intersection of the first beveled face and the second beveled face, and an apical portion of one side of the cylindrical outer peripheral face of the cylindrical member of a second intersecting portion formed by the crossing the first bevelled ground face and the third face bevelled in bevel are crossed by the fourth beveled face in a direction opposite to the direction of the upper end of the cylindrical member.
7. The hollow medical needle according to claim 5, characterized in that the fourth beveled face is provided in such a way that a position corresponding to the apical portion of the side opposite the direction of the upper end of the cylindrical member, at the grinding limit of the first beveled face, it is crossed by the fourth beveled face in a direction opposite to the direction of the upper end of the cylindrical member.
8. 8. The hollow medical needle according to claim 4 or 5, characterized in that the fourth beveled face is provided in such a way that there is a cylindrical outer peripheral face of the cylindrical member between the fourth beveled face and the second face bevelled in bevel, and between the fourth beveled face in bevel and the third face beveled in bevel, in a peripheral direction of the cylindrical member.
9. 9. The hollow medical needle according to claim 1, characterized in that the sharp edge portion is formed by placing it on an internal wall forming the flow path of the cylindrical member.
10. 10. The hollow medical needle according to claim 1, characterized in that the fourth beveled face is formed at an inclined angle of 2 to 15 degrees with respect to the direction of the central axis of the cylindrical member.
11. 11. The hollow medical needle according to claim 1, characterized in that the second and third inclined angles are equal to each other.
12. 12. The hollow medical needle according to claim 1, characterized in that the first and second angles of rotation are equal to each other.
13. A method for producing a hollow medical needle, this method comprising: performing a grinding machining on top edge portion of a cylindrical member that forms a flow path capable of passing a fluid therein in the direction of its central axis , to form a first thinned ground face whose outer diameter is reduced towards a direction of the upper edge of the cylindrical member, by thinning a wall thickness of the cylindrical member; performing a grinding machining on the portion of the upper edge of the cylindrical member, forming the first face ground in an oblique direction, having a first angle inclined with respect to the central axis to form a first face beveled in bevel, where the trajectory of flow is open in an oblique direction, and perform a grinding machining on the upper edge portion of the cylindrical member by rotating a first angle of rotation in a positive direction with respect to the first beveled face with the central axis at its center, which has a second angle inclined with respect to the central axis, to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the first face beveled in bevel with the central axis at its center, which has a third angle inclined with respect to the central axis to form a third bevel ground face, respectively; and forming a sharp edge portion comprised of at least three ground faces, ie, the second and third beveled faces, and a fourth beveled face which is left unbleached by the grounding machining of the first, second, and third faces frosted in bevel, from the first ground face.
14. A method for producing a hollow medical needle, this method comprising: grinding an upper edge portion of a cylindrical member that forms a flow path capable of passing a fluid therein in the direction of its central axis, in one direction oblique with respect to the direction of the central axis of the cylindrical member, the thickness of the wall of this cylindrical member being thinned, to form a fourth face bevelled in bevel in the form of a plane, - performing a grinding machining on a portion opposite to the fourth bevelled face of the upper edge portion of the cylindrical member, which forms the fourth face bevelled in bevel, in an oblique direction, having a first angle inclined with respect to the central axis to form a first face bevelled in bevel , where the flow path is open in an oblique direction, and perform a grinding machining on the upper edge portion the cylindrical member by rotating a first angle of rotation in a positive direction with respect to the first beveled face with the central axis at its center, having a second angle inclined with respect to the central axis, to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the first beveled face with the central axis at its center, having a third angle inclined with respect to the central axis to form a third face bevelled in bevel, respectively; and forming a sharp edge portion comprised of at least the second, third, and fourth beveled faces
15. 15. A method for producing a hollow medical needle, this method comprising: performing a grinding machining on an upper edge portion of a cylindrical member forming a flow path capable of passing a fluid therein in the direction of its central axis, in an oblique direction having a first angle inclined with respect to the central axis, to form a first face beveled in bevel where the flow path is open in an oblique direction; performing a grinding machining on the upper edge portion of the cylindrical member by rotating a first angle of rotation in a positive direction with respect to the first beveled face with the center axis at its center, having a second inclined angle with respect to the central axis, to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the first beveled face with the central axis at its center, which has a third angle inclined with respect to the central axis to form a third beveled face, respectively; grinding a position opposite the first beveled face of the upper edge portion of the cylindrical member in a direction oblique with respect to the central axis, thinning the thickness of the wall of the cylindrical member to form a fourth beveled face in the shape of a plane, - and forming a portion of sharp edge comprised of at least the second, third, and fourth faces frosted in bevel.
16. 16. A method for producing a hollow medical needle, this method comprising: performing a grinding machining on an upper edge portion of a cylindrical member that forms a flow path capable of passing a fluid therein in the direction of its axis central, in an oblique direction having a first angle inclined with respect to the central axis, to form a first beveled face in which the flow path is open in an oblique direction, - to ground a position opposite to the first face ground in bevel of the upper edge portion of the cylindrical member in an oblique direction with respect to the central axis, the thickness of the wall of the cylindrical member being thinned to form a fourth beveled face in the form of a plane; performing a grinding machining on the upper edge portion of the cylindrical member by rotating a first angle of rotation in a positive direction with respect to the first beveled face with the center axis at its center, having a second inclined angle with respect to the central axis, to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the first beveled face with the central axis at its center, which has a third angle inclined with respect to the central axis to form a third beveled face, respectively; and forming a portion of sharp edge comprised of at least the second, third, and fourth beveled faces.
17. A method for producing a hollow medical needle, this method comprising: performing a grinding machining on an upper edge portion of a cylindrical member that forms a flow path capable of passing a fluid therein in the direction of its axis central, by rotating a first angle of rotation in a positive direction with respect to a previously determined standard position with the central axis as its center, having a second angle inclined with respect to this central axis to form a second face ground in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the standard position with the central axis as its center having a third angle inclined with respect to the central axis to form a third beveled face, respectively; grinding a position opposite to the standard position of the upper edge portion of the cylindrical member in an oblique direction with respect to the direction of the central axis, thinning the thickness of the wall of the cylindrical member to form a fourth beveled face in the shape of a plane; performing a grinding machining on the upper edge portion of the cylindrical member in the standard position in an oblique direction having a first angle inclined with respect to the central axis, to form a first face beveled in bevel where the flow path is open in an oblique direction, - and forming a portion of sharp edge comprised of at least the second, third, and fourth beveled faces.
18. 18. A method for producing a hollow medical needle, this method comprising: performing a grinding machining on an upper edge portion of a cylindrical member that forms a flow path capable of passing a fluid therein in the direction of its axis central, by rotating a first angle of rotation in a positive direction with respect to a predetermined standard position with the central axis as its center, having a second angle inclined with respect to this central axis to form a second face bevelled in bevel, and by rotating a second angle of rotation in an opposite direction with respect to the standard position with the central axis as its center that has a third angle inclined with respect to the central axis to form a third beveled face, respectively; performing a grinding machining on the upper edge portion of the cylindrical member in the standard position in an oblique direction having a first angle inclined with respect to the central axis, to form a first face beveled in bevel where the flow path is open in an oblique direction; grinding a position opposite the first bevelled face of the upper edge portion of the cylindrical member in a direction oblique with respect to the direction of the central axis, thinning the thickness of the wall of the cylindrical member to form a fourth face bevelled in bevel in the form of a plane; and forming a portion of sharpened edge comprised of at least the second, third, and fourth beveled faces.
19. 19. The method for producing the hollow medical needle according to claim 13, 14, 15, 16, 17, or 18, characterized in that the sharp edge portion is formed by placing it on an internal wall forming the path of flow of the cylindrical member.
20. The method for producing the hollow medical needle according to claim 13, 14, 15, 16, 17, or 18, characterized in that the fourth beveled face is ground at an inclined angle of 2 to 15 degrees with respect to the direction of the central axis of the cylindrical member.
21. 21. The method for producing the hollow medical needle according to claim 13, 14, 15, 16, 17, or 18, characterized in that the second and third inclined angles are equal to one another.
22. 22. The method for producing the hollow medical needle according to claim 13, 14, 15, 16, 17, or 18, characterized in that the first and second angles of rotation are equal to one another.
23. 23. The hollow medical needle according to claim 1, characterized in that a fifth beveled face is provided in an apical portion of one side of the cylindrical outer peripheral face of the cylindrical member in a first intersection portion formed by the crossing of the first face bevelled in bevel and the second face bevelled in bevel, by removing the apical portion, and a sixth beveled face is provided in bevel in an apical portion of one side of the cylindrical outer peripheral face of the cylindrical member in a second intersecting portion formed by crossing the first face bevelled in bevel and the third face bevelled in bevel, by removing this apical portion.