JP4978650B2 - Half turn hook oiling mechanism and sewing machine - Google Patents

Description

  The present invention relates to an oil supply mechanism for a half-turn hook provided with an inner hook that reciprocates half-turns every time a stitch is formed, and a sewing machine provided with an oil supply mechanism for the half-turn hook.

  Conventionally, as a kind of hook mounted on a sewing machine, there is a half-turn hook provided with a middle hook that reciprocates half-turns every time a stitch is formed (for example, see Patent Document 1). According to the sewing machine using a half-turn hook, it is possible to satisfactorily sew even thick work cloths. In the half-turn hook, the timing for the upper thread loop caught by the sword to come out of the hook is earlier than in the case of the full-turn hook. The half-rotating hook has an early timing for pulling out the upper thread loop, so that the thread can be tightened well and is suitable for tack-fastening.

  The half-rotary hook is slid at a high speed with respect to the large hook fixed to the bed of the sewing machine. Therefore, it is necessary to supply lubricating oil to the sliding path to prevent the occurrence of seizure due to friction. Although there is a semi-rotary hook in which an oil-impregnated body is embedded in the sliding path (see, for example, Patent Document 1), it is difficult to appropriately supply lubricating oil to the embedded oil-containing body. There is also a device for supplying lubricating oil to the full rotary hook by inserting an oil guide pipe having an oil core inserted therein between the full rotary hook and the oil tank (for example, see Patent Document 2).

Japanese Utility Model Publication No. 51-141160 Japanese Patent Publication No.53-6581

  However, when connecting the oil guide pipe from the drive shaft side to the cauldron body of the semi-rotary hook, the oil guide pipe is deeply inserted into the cauldron because the members constituting the cauldron body are made thin in order to reduce the size of the cauldron body. Cannot be inserted into the body. Therefore, it arrange | positions so that the front end surface of an oil guide pipe may contact the end surface by the side of the drive shaft of a cauldron. Since the tip end face of the oil guide pipe is only in contact with the end face of the cauldron body, there may be a gap between the tip end part of the oil guide pipe and the cauldron body over time. In addition, if the cauldron is moved in the axial direction of the drive shaft for the purpose of adjusting the needle gap, which is the gap between the sword tip of the inner hook and the sewing needle, a gap will be created between the tip of the oil guide pipe and the cauldron. If the gap is left unattended, there is a problem that the amount of oil supply is not stable. This is because if dust, lint, etc. enters the oil guide pipe through the gap and comes into contact with the oil core, lint etc. absorbs the lubricating oil, so that the lubricating oil cannot be supplied to the half-turn hook.

  The present invention has been made in order to solve the above-described problems, and provides a half-rotary hook oil supply mechanism and a sewing machine in which no gap is generated between the tip of an oil guide pipe that guides lubricating oil and the cauldron body. With the goal.

In order to achieve the above object, an oil supply mechanism for a half-turn hook according to claim 1 of the present invention includes an inner hook that performs reciprocating half-rotation by driving a drive shaft, and an open annular shape that guides rotation of the inner hook. A cauldron body having a sliding path and through which the drive shaft is inserted, and an oil core that extends straight through the cylindrical outer peripheral wall of the cauldron body and guides lubricating oil by capillary action to the sliding path. A cylindrical oil guide hole to be inserted, and an oil guide pipe that protrudes outward from the end of the oil guide hole opposite to the sliding path side and extends through the oil core extending from the lubricating oil supply source side. A tubular joint to be fitted , and the joint is formed separately from the cauldron body and has a tapered portion whose outer shape is tapered, and the tapered portion is press-fitted into the oil guide hole. Fixed to the cauldron body, the oil guide hole is formed at the end opposite to the sliding path side, A joint fixing hole for fixing the joint, and a small-diameter portion located on the sliding path side of the joint fixing hole and having a smaller diameter than the joint fixing hole, and the center of the joint fixing hole is A portion of the cylindrical outer peripheral wall of the cauldron body that is located on the center side of the semi-rotary hook with respect to the central axis of the small-diameter portion that is cylindrical and that is outside the joint fixing hole and the small-diameter portion The thickness of is constant.

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the present invention, there are a plurality of the oil introduction holes, and at least one of the plurality of oil introduction holes is It is an oil drain hole for inserting a drain oil core that is the oil core for discharging the lubricating oil from the lower part of the sliding path.

The oil supply mechanism of the half rotary hook according to claim 3 of the present invention is the oil core that connects the lubricating oil supply source and the sliding path in addition to the configuration of the invention according to claim 1 or 2. Two oil guide holes for connecting a supply oil core to each of both ends of the open annular slide path are provided.

A sewing machine according to a fourth aspect of the present invention includes the oil supply mechanism for a half-turn hook according to any one of the first to third aspects.

In the oil supply mechanism of the semi-rotary hook according to claim 1 of the present invention, a cylindrical joint that fits into the oil guide pipe protrudes from the end of the oil guide hole formed in the cauldron body. By fitting the oil guide pipe and the joint portion, it is possible to prevent a gap from being generated between the tip portion of the oil guide pipe and the cauldron body. Even when the hook is moved in the axial direction of the drive shaft in order to adjust the distance between the sewing needle and the blade tip of the half-turn hook, no gap is generated between the oil guide pipe and the hook. Therefore, the amount of lubricating oil supplied to the sliding path can be stabilized. Since lint or the like does not enter from the gap, it is possible to prevent unstable oil supply and oil leakage. By forming the cauldron body and the joint part separately, the cauldron body can be manufactured more easily than when the joint part is formed integrally. Since the taper portion of the joint portion is pressed into the oil guide hole to fix the joint portion, the diameter of the oil guide hole can be reduced as compared with the case where the joint portion and the oil guide hole are fixed with threads. it can. Therefore, the downsizing of the shape of the cauldron body and the downsizing of the bed portion for fixing the cauldron body can be realized. Further, it is possible to prevent the occurrence of a gap between the joint portion and the oil guide hole by press-fitting and prevent oil leakage. Moreover, the thickness of the outer part of the cauldron body from the joint fixing hole can be reduced. Thereby, size reduction of the shape of a cauldron body and size reduction of the bed part which fixes a cauldron body are realizable.

The oil supply mechanism for the half-turn hook according to claim 2 of the present invention has an oil drain hole for discharging the lubricating oil from the lower part of the sliding path. In addition to the effect of the first aspect of the invention, the lubricating oil can be smoothly discharged to a predetermined location by the oil drain hole while preventing the oil core from being exposed and causing oil leakage by the joint portion.

According to the fuel supply mechanism of the oscillating shuttle according to claim 3 of the present invention, in addition to the effect of the invention according to claim 1 or 2, to supply lubricating oil to each of the opposite ends of the open circular slideways Can do. Thereby, lubricating oil can be reliably supplied to the both ends of an open annular sliding path.

Moreover, the sewing machine according to claim 4 of the present invention can achieve the same effects as the invention according to any one of claims 1 to 3 .

It is the perspective view which looked at the sewing machine 1 from the diagonally left front. 2 is an exploded perspective view of a half-turn hook 30. FIG. FIG. 3 is a perspective view of the cylinder bed 4 with the cover 6 removed as viewed from the right side of the sewing machine 1. It is a perspective view of the needle clearance adjusting shaft 66. It is the perspective view which looked at the half rotary hook 30 from diagonally right rear. It is sectional drawing which looked at the cylinder bed 4 from upper direction. 4 is a right side view of the half-turn hook 30. FIG. It is an enlarged view of the left joint part 74. FIG. 3 is an enlarged cross-sectional view showing a main part of an oil supply mechanism 70. FIG.

  Hereinafter, an oil supply mechanism 70 of a half-turn hook 30 and a sewing machine 1 including the oil supply mechanism 70 according to an embodiment of the present invention will be described with reference to the drawings. The drawings to be referred to are used for explaining the technical features that can be adopted by the present invention, and the described configuration and the like are not intended to be limited only to them but are merely illustrative examples.

  The overall structure of the sewing machine 1 will be schematically described with reference to FIG. In the following description, the lower right side in FIG. 1 is the front side of the sewing machine 1, and the upper left side in FIG. 1 is the rear side of the sewing machine 1. 1 is the right side of the sewing machine 1, and the lower left side of FIG.

  The sewing machine 1 includes a bed portion 2, a pedestal column portion 7, and an arm portion 8. The bed unit 2 includes a bed body 3 and a cylinder bed 4. The bed body 3 is placed on a work table (not shown) and serves as a base for the sewing machine 1. The cylinder bed 4 is formed in a cylindrical shape whose width in the left-right direction and the vertical direction is smaller than that of the bed main body 3, and extends forward from the front end portion of the bed main body 3. A semi-rotary shuttle 30 (see FIG. 2), which will be described later, is provided inside the tip of the cylinder bed 4. A cover 6 is detachably attached to the tip of the cylinder bed 4, and a part of the half-turn hook 30 can be exposed by removing the cover 6. The operator performs operations such as attachment / detachment of the bobbin case 55 (see FIG. 2), adjustment of the needle clearance, etc. with the half-turn hook 30 exposed, details of which will be described later. The cylinder bed 4 includes a drive shaft 39 (see FIGS. 2 and 6) that reciprocates and rotates halfway. The drive shaft 39 reciprocates and makes a half turn of the half hook 53 (see FIG. 2) of the half turn hook 30.

  The leg column portion 7 has a substantially prismatic shape, and is erected upward from the rear end portion of the bed portion 2. The arm portion 8 extends forward from the upper end portion of the pedestal portion 7 so as to face the cylinder bed 4. A head 9 protrudes downward from the tip of the arm 8, and the head 9 includes a needle bar 10 that reciprocates up and down. The needle bar 10 projects downward from the lower end of the head 9, and a sewing needle 11 is attached to the lower end of the needle bar 10. A thread spool (not shown) as an upper thread supply source supplies upper thread to the sewing needle 11. When a main shaft (not shown) rotatably provided inside the arm portion 8 is rotated by a sewing machine motor (not shown), the needle bar 10 moves up and down. The bed portion 2 includes a drive mechanism (not shown) that reciprocally drives the drive shaft 39 in conjunction with the rotation of the main shaft.

  On the upper surface of the cylinder bed 4, a feed base 12 that is movable in the horizontal direction and a cloth presser 13 that fixes the work cloth to the feed base 12 are provided. The cloth presser 13 includes a presser arm 14 that curves and extends forward from the rear of the feed base 12, and a presser foot 15 provided at the lower front end of the presser arm 14. The cloth presser 13 lowers the presser foot 15, presses the work cloth against the feed base 12, and fixes the work cloth to the feed base 12.

  Next, referring to FIG. 1, an outline of the configuration of the sewing machine 1 for supplying lubricating oil to the half-turn hook 30 and discharging the lubricant from the half-turn hook 30 will be described. On the left side of the bed main body 3 of the bed portion 2, an oil tank 20 that contains lubricating oil to be supplied to the half-turn hook 30 is provided. A window portion 21 is formed on the left side surface of the bed body 3 so that an operator can check the amount of lubricating oil stored in the oil tank 20. A substantially cylindrical lubricating oil supply pipe 22 for supplying lubricating oil to the oil tank 20 extends from the upper surface of the bed body 3 to the oil tank 20.

  Inside the bed portion 2, two oil guide pipes, a left oil guide pipe 24 and a right oil guide pipe 25, extend from the oil tank 20 to the half-turn hook 30. The left oil guide pipe 24 is connected to the upper left side of the back surface of the half-turn hook 30, and the right oil guide pipe 25 is connected to the upper right side of the back face of the half-turn hook 30. Further, a discharge oil guide pipe 26 for draining used lubricating oil from the half-turn hook 30 is connected to the lower part of the back surface of the half-turn hook 30. The discharge oil guide pipe 26 is bent downward inside the bed main body 3 and reaches a waste oil bottle 28 provided on a table (not shown) supporting the bed portion 2.

  Although details will be described later, the left oil guide pipe 24, the right oil guide pipe 25, and the discharge oil guide pipe 26 (hereinafter collectively referred to as "oil guide pipes 24-26") are oil cores that guide the lubricating oil by capillary action. Is inserted inside. Therefore, the lubricating oil stored in the oil tank 20 reaches the half-turn hook 30 through the left oil guiding pipe 24 and the right oil guiding pipe 25. The waste oil generated from the half-rotary hook 30 accumulates in the waste oil bottle 28 through the discharge oil guide pipe 26. In the present embodiment, vinyl tubes having appropriate flexibility are used for the left oil guide tube 24, the right oil guide tube 25, and the discharge oil guide tube 26. The oil tank 20 corresponds to the “lubricating oil supply source” of the present invention.

  Next, an outline of the structure of the half-turn hook 30 will be described with reference to FIG. In the following description, the diagonally lower left side in FIG. 2 is the front of the half-rotating hook 30, and the diagonally upper right side of FIG. The diagonally lower right side in FIG. 2 is the right side of the half-rotating hook 30, and the diagonally upper left side in FIG.

  As shown in FIG. 2, the half-turn hook 30 includes a large hook body 31, a middle hook 53 incorporated in the large hook body 31, a hook retainer 50 that holds the middle hook 53 on the large hook body 31, and the middle hook 53. A drive shaft 39 that reciprocates and a bobbin case 55 that can be attached to the inner hook 53 are provided. The cauldron 31 includes a trunk portion 32, a cylinder portion 34, and a flange portion 35. The trunk portion 32 has a cylindrical shape, and a shaft hole 33 (see FIGS. 5 and 6) that rotatably holds the drive shaft 39 is formed at a position that coincides with the central axis. The cauldron 31 is mounted on the cylinder bed 4 by inserting the body portion 32 into the cylinder bed 4 from the front side. The cylindrical portion 34 includes a bottomed cylindrical opening 341 (see FIG. 6) whose front side is open, and the inner hook 53 is mounted inside.

  The inner hook 53 holds the bobbin case 55 in a detachable manner, and the bobbin case 55 holds the bobbin inside. The front end of the drive shaft 39 protrudes into the cylindrical opening 341 and supports a driver (not shown). As is well known, the driver half-rotates integrally with the drive shaft 39 and half-rotates the inner hook 53.

  The diameter of the cylindrical portion 34 is larger than the diameter of the trunk portion 32. The cylindrical portion 34 is integrally formed at the front end portion of the barrel portion 32 so that the axial center of the cylindrical portion 34 and the axial center of the cylindrical barrel portion 32 coincide with each other. A flange portion 35 extending outward in the radial direction is formed at the front end portion of the cylindrical portion 34. At two locations on the left and right sides of the front surface of the flange portion 35, stoppers 36 that hold the hook presser 50 on the flange portion 35 are provided. A left oil guiding hole 71 and a right oil guiding hole 72 are formed above each stopper 36 of the collar portion 35, and details thereof will be described later. An inner surface of the flange portion 35 is a sliding path 37 on which the inner hook 53 slides. The sliding path 37 is an open ring with the upper end opened. As shown in FIGS. 2, 3, and 5, the thread guide plate 100 is attached to the collar portion 35 above the upper end open portion of the sliding path 37. The thread guide plate 100 is for guiding the upper thread loop when passing through the inner hook 53 while the upper thread loop expands.

  The inner hook 53 rotates halfway back and forth inside the flange 35 of the large hook body 31 by driving the drive shaft 39. A sword tip 54 that hooks a loop of an upper thread extending from the eye hole of the sewing needle 11 is formed at one end of the inner hook 53 that is substantially semicircular when viewed from the front. The intermediate hook 53 reciprocates half a turn while sliding the outer peripheral portion on the sliding path 37 of the large hook body 31, and catches the upper thread with the sword tip 54. The substantially annular hook presser 50 is attached to the large hook body 31 from the front side and is held by the hook 35 by the stopper 36.

  Next, with reference to FIGS. 3-5, the moving mechanism which moves the cauldron body 31 to the axial direction (front-back direction of the sewing machine 1) is demonstrated. In the sewing machine 1, the needle clearance that is the dimension of the clearance in the front-rear direction between the sword tip 54 of the inner hook 53 and the sewing needle 11 is adjusted by moving the large hook body 31.

  As shown in FIG. 3, the cylinder bed 4 includes a needle gap adjustment unit 61 at a predetermined position on the right side surface. The needle clearance adjusting unit 61 is a fixing screw for tightening a shaft hole 62 into which a needle clearance adjusting shaft 66 (see FIG. 4) described later is rotatably inserted and a screw (not shown) for fixing the position of the cauldron 31. It consists of holes 63. Both the shaft hole 62 and the fixing screw hole 63 penetrate to the inside of the cylinder bed 4.

  As shown in FIG. 4, the needle clearance adjusting shaft 66 includes a head 67, a body 68, and an eccentric shaft 69. The head 67 is formed with a groove for engaging the tool. The trunk | drum 68 is cylindrical, and the axial hole 62 of the cylinder bed 4 hold | maintains the trunk | drum 68 rotatably. The eccentric shaft 69 is provided at the end of the body 68 opposite to the end to which the head 67 is connected. The eccentric shaft 69 has a cylindrical shape whose diameter is smaller than that of the body portion 68, and the shaft center of the eccentric shaft 69 and the shaft center of the body portion 68 are eccentric. When the head 67 is rotated using a tool, the entire needle clearance adjusting shaft 66 rotates about the axis of the body 68. The eccentric shaft 69 connected in a state of being shifted from the axis of the body 68 moves while drawing an arc around the axis of the body 68. Therefore, the position of the eccentric shaft 69 can be moved by rotating the head 67.

  As shown in FIG. 5, an engagement groove 64 and a screw contact portion 65 are provided on the right side surface (the lower left side surface in FIG. 5) of the trunk portion 32 of the large hook body 31 of the half-turn hook 30. The engagement groove 64 extends in a vertical direction at a position corresponding to the shaft hole 62 of the cylinder bed 4. The width of the engaging groove 64 is substantially the same as the diameter of the eccentric shaft 69, and the eccentric shaft 69 of the needle clearance adjusting shaft 66 is engaged with the engaging groove 64. The screw contact portion 65 is a flat portion formed at a position corresponding to the fixing screw hole 63 of the cylinder bed 4.

  A method for moving the cauldron 31 will be described. When the cauldron body 31 is moved, the operator loosens the screw fastened to the fixing screw hole 63 to release the fixation of the cauldron body 31 to the cylinder bed 4. Next, the tool is engaged with the head 67 of the needle gap adjusting shaft 66 inserted into the shaft hole 62, and the needle gap adjusting shaft 66 is rotated. Then, since the eccentric shaft 69 moves while drawing an arc, the cauldron 31 engaged with the eccentric shaft 69 via the engagement groove 64 also moves in the front-rear direction of the sewing machine 1. The position of the sword tip 54 (see FIG. 2) of the inner hook 53 held by the cauldron 31 also moves, and the needle clearance changes. In a state where the cauldron 31 is moved to a desired position, the screw is fastened to the fixing screw hole 63 and the tip of the screw is brought into contact with the screw contact portion 65. Thereby, even a slight adjustment of the needle clearance can be easily executed.

  Next, the oil supply mechanism 70 of the half-turn hook 30 will be described with reference to FIGS. As shown in FIG. 5, a cylindrical left joint 74, a right joint 75, and a discharge are provided on the rear surface (the diagonally lower right surface in FIG. 5) of the cylindrical portion 34 of the half-rotary shuttle 30. The joint portions 76 (hereinafter collectively referred to as “joint portions 74 to 76”) are connected. The left joint portion 74 is connected to the upper left side of the back surface of the cauldron 31. The right joint 75 is connected to the upper right side of the back surface of the cauldron 31. The discharge joint 76 is connected to the lower center of the back surface of the cauldron 31. Further, the left oil guide pipe 24 extending from the oil tank 20 (see FIG. 1) has a left oil core 44 inserted therein. The right oil guide pipe 25 is inserted through the right oil core 45. A discharge oil guide pipe 26 extending to the waste oil bottle 28 (see FIG. 1) has a discharge oil core 46 inserted therethrough. The left oil core 44 and the right oil core 45 correspond to the “supply oil core” of the present invention.

  As shown in FIG. 6, a cylindrical left oil introduction hole 71 through which the left oil core 44 is inserted from the back side to the upper left end of the sliding path 37 is drilled on the left side (upper side in the figure) of the cauldron 31. is doing. The left oil introduction hole 71 extends straight from the upper left part of the back surface of the cylindrical portion 34 to the front side in parallel with the drive shaft 39 in the outer peripheral wall of the cylindrical portion 34 and penetrates to the front side of the flange portion 35. The left joint 74 is connected to the rear end of the left oil guide hole 71. The left oil core 44 passes through the inside of the left oil guide pipe 24, the inside of the left joint 74, and the left oil guide hole 71, from the oil tank 20 (see FIG. 1) to the upper left end of the sliding path 37 by capillary action. Guide lubricating oil. A knot is formed at the front end of the left oil core 44. A left large-diameter portion 81 having a large diameter is provided at the front end portion of the left oil introduction hole 71 to accommodate the knot of the left oil core 44. As a result, the left oil core 44 is prevented from falling out behind the cauldron 31.

  On the right side of the cauldron 31 (lower side in FIG. 6), a right oil introduction hole 72 is formed so as to be symmetrical with the left oil introduction hole 71. The right joint 75 is connected to the rear end of the right oil introduction hole 72. The right oil core 45 passes the right oil guide pipe 25, the right joint portion 75, and the right oil guide hole 72, and guides the lubricating oil to the upper right end portion of the sliding path 37. A knot is formed at the front end of the right oil core 45, and the knot is stored in the right large diameter portion 82.

  As shown in FIG. 7, in the lower part (lower side in the figure) of the cauldron body 31, a drain oil core 46 (see FIG. 5) is inserted from the lower end of the sliding path 37 (see FIG. 2) to the rear side. A cylindrical oil drain hole 73 is formed. The discharge joint portion 76 is connected to the rear end of the oil discharge hole 73.

  With the above configuration, the lubricating oil reaches the both ends of the sliding path 37 by the left oil core 44 and the right oil core 45, and smoothly slides between the sliding path 37 and the inner hook 53 (see FIG. 2). Let Waste oil generated at the lower end of the sliding path 37 moves to the waste oil bottle 28 (see FIG. 1) via the discharged oil core 46.

  As shown in FIGS. 6 and 7, the front end portion of the left oil guide pipe 24 that is a vinyl tube is closely fitted to the outer periphery of the left joint portion 74 by an elastic action. Similarly, the front end portion of the right oil guiding pipe 25 is closely fitted to the outer periphery of the right joint portion 75. The front end portion of the discharge oil guide pipe 26 is closely fitted to the outer periphery of the discharge joint portion 76. Therefore, there is no gap between the front end portions of the oil guide pipes 24 to 26 and the cauldron 31. In particular, even when the cauldron 31 is moved forward by adjusting the needle clearance, no gap is generated between the oil guide pipes 24 to 26 and the cauldron 31. The oil cores 44 to 46 inside the oil guide pipes 24 to 26 are not exposed to the outside. Even when the cauldron 31 is moved rearward, the possibility that the oil guide pipes 24 to 26 are bent is low. Therefore, it is possible to prevent occurrence of problems in supply and discharge of lubricating oil and occurrence of oil leakage. Here, the “close fitting” means fitting in which lubricating oil does not leak to the outside from between the outer periphery of the joint portions 74 to 76 and the oil guiding pipes 24 to 26. It is not limited that the entire fitting portion is in close contact with the outer periphery of the joint portions 74 to 76.

  Details of the oil supply mechanism 70 will be described. First, the shape of the left joint 74 will be described with reference to FIG. The shapes of the right joint 75 and the discharge joint 76 are the same as the shape of the left joint 74. As described above, the left joint 74 is cylindrical. The exposed portion 78, which is the rear portion of the left joint portion 74, is formed so that the outer diameter is constant. The exposed portion 78 protrudes rearward from the back surface of the cauldron 31 and is exposed to the outside, and fits with the left oil guiding pipe 24. The front portion of the left joint portion 74 is a tapered portion 79 whose outer diameter decreases toward the front.

  The shape of the left oil guiding hole 71 will be described in detail with reference to FIG. A rear end portion (right end portion in the figure) of the left oil introduction hole 71 is formed in a cylindrical joint fixing hole 84. The left joint 74 is press-fitted and fixed to the joint fixing hole 84 from the tapered portion 79 (see FIG. 8) side.

  The diameter L of the joint fixing hole 84 is larger than the diameter M of the small diameter portion 85 at the center in the front-rear direction (left-right direction in FIG. 9) of the left oil introduction hole 71. Furthermore, the position of the wall surface on the left side (upper side in FIG. 9) of the joint fixing hole 84 and the position of the wall surface on the left side of the small diameter portion 85 coincide. The center P of the joint fixing hole 84 is located closer to the center of the cauldron 31 than the center axis Q of the left oil guiding hole 71. Accordingly, the thickness D of the portion outside the joint fixing hole 84 in the cauldron 31 can be reduced. In addition, since the shape of the right oil introduction hole 72 and the oil discharge hole 73 is the same as the shape of the left oil introduction hole 71, description is abbreviate | omitted.

  As described above, in the sewing machine 1 of the present embodiment, the left oil guiding hole 71, the right oil guiding hole 72, and the oil draining hole 73 (hereinafter referred to as “oil guiding holes 71 to 71”) drilled in the cauldron 31. 73 ”), cylindrical joints 74 to 76 that closely fit with the oil guide pipes 24 to 26 protrude from the respective rear end portions. By closely fitting the oil guide pipes 24 to 26 to the outer peripheries of the joint parts 74 to 76, it is possible to prevent a gap from being generated between the tip of the oil guide pipes 24 to 26 and the back surface of the cauldron body 31 as in the past. be able to. Even when the cauldron 31 is moved in the axial direction of the drive shaft 39 in order to adjust the needle clearance which is the distance in the front-rear direction between the sewing needle 11 and the sword tip 54 of the half-turn hook 30, the oil guide pipes 24-26 and There is no gap between the cauldron 31 and the cauldron 31. Since there is no gap and lint, dust or the like does not enter the oil guide pipes 24 to 26, lint or the like does not come into contact with the oil core and suck the lubricating oil. Therefore, it is possible to prevent the problem of oil supply and the occurrence of oil leakage and stabilize the amount of oil supply.

  In the present embodiment, the cauldron 31 and the joint portions 74 to 76 are formed separately. Accordingly, the cauldron body 31 can be easily manufactured as compared with the case where they are integrally formed. Further, in order to press-fit the tapered portions of the joint portions 74 to 76 into the oil guide holes 71 to 73 and fix the joint portions 74 to 76, screw threads are formed in the joint portions 74 to 76 and the oil guide holes 71 to 73. Compared with the case where it fixes, the diameter of the oil guide holes 71-73 can be made small. Therefore, the downsizing of the cauldron 31 and the downsizing of the cylinder bed 4 for fixing the cauldron 31 can be realized. Furthermore, it is possible to prevent a gap from being generated between the joint portions 74 to 76 and the oil guide holes 71 to 73 by press-fitting, thereby preventing oil leakage.

  In the oil supply mechanism 70, the diameter of the rear end portion of the left oil introduction hole 71 is increased, and the joint fixing hole 84 that fixes the left joint 74 is formed. The center of the joint fixing hole 84 is located closer to the center of the half-turn hook 30 than the center axis of the small diameter portion 85 of the left oil guiding hole 71. Accordingly, the thickness D of the portion outside the joint fixing hole 84 in the cauldron 31 can be reduced. Thereby, size reduction of the shape of the cauldron body 31 and size reduction of the cylinder bed 4 which fixes the cauldron body 31 are realizable. Even if the left oil guiding hole 71 is formed obliquely with respect to the axial direction of the drive shaft 39, the thickness D on the back side of the cylindrical portion 34 can be reduced. However, in order to drill the left oil introduction hole 71 obliquely with respect to the axial direction, it is necessary to go through complicated and difficult processes. Further, the thickness D of the cylindrical portion 34 is not constant, and the strength is reduced. According to the present embodiment, it is possible to easily manufacture the cylindrical portion 34 having a thin and constant thickness D. The same applies to the shapes of the right oil introduction hole 72 and the oil discharge hole 73.

  According to the oil supply mechanism 70, the lubricating oil can be supplied to both end portions of the open annular sliding path 37, so that the lubricating oil can be reliably supplied to the sliding path 37. Further, an oil drain hole 73 for discharging the lubricating oil from the lower part of the sliding path 37 is formed. Therefore, it is possible to smoothly supply and discharge the lubricating oil to the sliding path 37 while preventing the oil core from being exposed and causing oil leakage by the joint portions 74 to 76.

  It should be noted that the configuration shown in the above embodiment is an exemplification, and it goes without saying that various changes can be made. For example, the structure of the joint portions 74 to 76 can be changed. As described above, in order to reduce the diameter of the oil guide holes 71 to 73 and prevent the gaps between the joint portions 74 to 76 and the oil guide holes 71 to 73, the joint portions 74 to It is desirable to press-fit 76 into the oil guide holes 71 to 73 and fix it. However, the joint portions 74 to 76 may be fixed by forming threads on the joint portions 74 to 76 and the oil guide holes 71 to 73 and tightening the joint portions 74 to 76. In this case, attachment and removal of the joint portions 74 to 76 can be easily performed. The joint portions 74 to 76 may be formed integrally with the cauldron body 31. In the above embodiment, the center of the joint fixing hole 84 of the left oil guiding hole 71 is located closer to the center of the half-turn hook 30 than the central axis of the small diameter portion 85 of the left oil guiding hole 71. However, the center axis of the small diameter portion 85 and the center of the joint fixing hole 84 may be matched. The same applies to the shapes of the right oil introduction hole 72 and the oil discharge hole 73.

DESCRIPTION OF SYMBOLS 1 Sewing machine 4 Cylinder bed 20 Oil tank 24 Left oil guide pipe 25 Right oil guide pipe 26 Oil guide pipe 30 for discharge Half-rotary shuttle 31 Cauldron body 34 Cylindrical part 37 Sliding path 39 Drive shaft 44 Left oil core 45 Right oil core 46 Drain oil core 53 Middle hook 70 Oil supply mechanism 71 Left oil introduction hole 72 Right oil introduction hole 73 Oil discharge hole 74 Left joint part 75 Right joint part 76 Discharge joint part 79 Taper part 84 Joint part fixing hole

Claims (4)

A hook that reciprocates half a turn by driving the drive shaft;
A cauldron body having an open annular sliding path for guiding rotation of the inner hook, and inserting the drive shaft into the interior;
A cylindrical oil introduction hole that extends straight through the cylindrical outer peripheral wall of the cauldron body and that inserts an oil core that guides lubricating oil by capillary action into the sliding path;
A cylindrical joint that protrudes outward from the end of the oil guide hole opposite to the sliding path side and fits into an oil guide pipe that extends through the oil core extending from the lubricating oil supply source side; Prepared ,
The joint portion is formed separately from the cauldron body, and includes a tapered portion whose outer shape is tapered, and the tapered portion is fixed to the cauldron body by being press-fitted into the oil guide hole,
The oil guide hole is
A joint fixing hole formed at an end opposite to the sliding path side, and fixing the joint;
A small-diameter portion that is located closer to the sliding path than the joint fixing hole and has a smaller diameter than the joint fixing hole;
The center of the joint fixing hole is located closer to the center of the half-turn hook than the central axis of the small-diameter portion that is cylindrical,
An oil supply mechanism for a semi-rotary hook in which a thickness of a portion outside the joint fixing hole and the small diameter portion is constant among the cylindrical outer peripheral wall of the large hook body . There are a plurality of oil guide holes,
2. The half according to claim 1, wherein at least one of the plurality of oil guide holes is an oil drain hole for inserting a drain oil core that is the oil core that drains the lubricating oil from a lower portion of the sliding path. Oiling mechanism for rotary hooks. The two oil guide holes for connecting a supply oil core, which is the oil core connecting the lubricating oil supply source and the sliding path, to each of both ends of the open annular sliding path. A refueling mechanism for a half-turn hook according to 1 or 2 . A sewing machine comprising the oil supply mechanism for a half-turn hook according to any one of claims 1 to 3 .

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