JP2012075478A - Sewing machine under-cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sewing machine under-cover capable of improving workability of an operator by reducing a vertical direction dimension of a circuit board arranged under a sewing machine table.SOLUTION: An under-cover 200 comprises a first cover part 210 and a second cover part 220, in which a lower surface of the under-cover 200 is located higher in the second cover part 220 than in the first cover part 210 when the under-cover 200 is attached to a sewing machine table 20. A bearing 52 of a switch lever 50 is arranged inside the second cover part 220, thereby allowing a maintenance operator to work in a space greater than a space below the first cover part 210.

Description

  The present invention relates to an under cover of a sewing machine that covers a lower part of a sewing machine having a switch lever for operating a presser foot.

  2. Description of the Related Art Conventionally, a cloth presser lifting / lowering device that lifts and lowers a cloth presser of a sewing machine is known (see, for example, Patent Document 1).

  A sewing machine equipped with a cloth presser lifting / lowering device has a presser bar supported at the tip of an arm portion of a sewing machine frame so that the presser bar can be lifted / lowered, and a presser foot that presses a work cloth against a needle plate. The presser bar is moved up and down by a link mechanism stored in the sewing machine frame. The sewing machine can be rotated to an oil pan (corresponding to the under cover of the present invention) provided with a manual operating body (corresponding to the switch lever of the present invention) for operating the link mechanism by the operator at the lower part of the machine frame. I support it.

  The manual operation body is connected to a rotation shaft that is rotatably supported by a pair of support legs (corresponding to the bearing of the present invention) provided on the lower surface of the oil pan.

Japanese Patent Laid-Open No. 62-101287

  In the conventional sewing machine, since the pair of support legs and the rotation shaft are exposed on the lower surface of the oil pan, it has become an obstacle to the operator when performing maintenance work from below the oil pan.

  Further, in the sewing machine, since the rotation shaft is below the oil pan, when the tall operator operates the manual operating body, the manual operating body abuts below the operator's knee, There was also a problem that it was difficult to operate.

  The purpose of the present invention is to arrange a bearing that rotatably supports the switch lever inside the under cover to improve the workability of the maintenance worker and to operate the sewing machine comfortably even for a tall operator. It is to provide an under cover for the sewing machine.

  In order to achieve the above object, the under cover of the sewing machine according to the first aspect of the present invention is provided with a leg pillar portion installed at an opening portion of the sewing machine table and standing from the sewing table, and the sewing machine table from above the leg pillar portion A lower cover of the sewing machine main body provided with an arm portion extending in parallel with the arm portion, and the under cover includes a first cover portion located below the arm portion and a second cover portion located below the pedestal portion. And the lower surface of the first cover portion is positioned lower than the lower surface of the second cover portion when attached to the sewing machine table, and the sewing machine main body is disposed inside the second cover portion. A bearing for supporting the rotating shaft of the switch lever for switching the vertical position of the cloth presser provided on the shaft is provided, and a hole through which the rotating shaft can pass is provided in a side wall of the second cover portion. That.

Thereby, when the under cover is attached to the sewing machine table, the bearing is disposed inside the second cover where the lower surface of the under cover is higher than the first cover portion. You can work in a larger space than the space. Further, the maintenance worker is not disturbed by the bearing. The rotating shaft has a height difference between the first cover portion and the second cover portion as compared with the conventional under cover, and a height difference and a high position due to the bearings disposed from the bottom of the under cover. Therefore, the undercover allows a tall operator of the sewing machine to place the switch lever at an appropriate position and operate the sewing machine comfortably.

  According to the present invention, since the bearing is disposed inside the second cover where the lower surface of the under cover is positioned higher than the first cover portion, the maintenance worker can use a space wider than the space below the first cover portion. Can work.

It is a front view showing the schematic structure of a sewing machine. It is the perspective view which looked at the sewing machine table, the under cover, and the circuit board from the front side diagonally downward. It is a front view of an undercover and a circuit board. It is a bottom view of the under cover showing the arrangement configuration of a circuit board. It is the perspective view seen from the diagonally upper direction showing the internal structure of an undercover. It is the perspective view seen from the diagonally downward direction showing the lower surface structure of an undercover. FIG. 4 is a cross-sectional view in the direction of the arrows along the line VII-VII in FIG. 3. It is arrow direction sectional drawing in the VIII-VIII line of FIG. It is a side view from the left direction showing the state which the board | substrate cover accommodated the circuit board. It is a side view from the left direction showing the state which the board | substrate cover opened. It is the perspective view seen from the diagonally upper direction showing the bearing structure of a switch lever. It is a side view from the left direction showing the fixation structure of the link mechanism which concerns on a pedal. It is a figure equivalent to FIG. 7 in the modification which provided the uneven | corrugated part for heat dissipation in the side surface of the undercover.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the front side of the sheet of FIG. 1 is the front of the sewing machine 1 that faces the operator.

  A schematic structure of the sewing machine 1 will be described with reference to FIG.

  As shown in FIG. 1, the sewing machine 1 is provided with a sewing table 20 having an opening 10, a sewing machine main body 100 installed in the opening 10 of the sewing table 20 from above, and an opening 10 in the sewing table 20 from below. A metal under cover 200 that covers the lower part of the sewing machine main body 100 and a circuit board 300 (see FIG. 2) provided on the under cover 200 and used for driving control of the sewing machine main body 100 are included. FIG. 1 shows a state where the circuit board 300 is covered with the board cover 400.

The sewing machine main body 100 includes a bed 101, a pedestal column portion 102 erected on the right side of the bed 101, and an arm portion 103 extending leftward from the upper portion of the pedestal column portion 102. The sewing machine body 100 incorporates a sewing machine motor (not shown). The arm portion 103 includes a needle bar 105 that reciprocates up and down based on driving of the sewing machine motor on the left side. The needle bar 105 has a sewing needle 106 attached to the lower end thereof. A thread spool (not shown) which is an upper thread supply source supplies an upper thread to the sewing needle 106. The sewing machine main body 100 is provided with a thread tension device 107 that adjusts the tension of the upper thread on the left front surface of the arm portion 103. The sewing machine main body 100 includes a cover 108 that covers the sewing machine motor on the right side surface of the pedestal 102. The bed 101 includes a thread trimming mechanism (not shown), a rotary hook (not shown), and the like, and a bobbin around which a lower thread is wound is detachably mounted on the rotary hook.

  Below the sewing machine table 20, a pedal 30 is provided for changing the rotational speed of the sewing machine motor built in the sewing machine body 100 in accordance with the amount of depression. When the pedal 30 is operated, the connecting rod 31 connected to the pedal 30 moves up and down, and the up and down movement of the connecting rod 31 is performed via a link mechanism 40 (see FIG. 12 to be described later). 12).

  A switch lever 50 for switching the vertical position of a cloth presser (not shown) provided in the sewing machine body 100 is provided below the sewing machine table 20. The switch lever 50 is rotatable around a rotation shaft 51 provided through the front side surface 252 of the under cover 200, and the operator rotates the switch lever 50 with a knee. It is possible to switch the vertical position of the cloth presser.

  Next, the circuit board 300 will be described with reference to FIGS. In all the drawings, the sewing machine main body 100, the substrate cover 400, and the switch lever 50 are not shown.

  As shown in FIGS. 2 to 4, a circuit board 300 is disposed on the lower surface of the under cover 200. Specifically, the lower surface of the under cover 200 includes a first lower surface 201 that is in a low position when attached to the sewing machine table 20, and a second lower surface 202 that is in a higher position than the first lower surface, The circuit board 300 is horizontally disposed on the second lower surface 202. The term “horizontal” means that a substrate surface on which control elements 312 and 322 of substrates 311 and 321 described later are disposed is substantially parallel to the second lower surface 202.

  As the circuit board 300, a control circuit board 310 and a power circuit board 320 are provided. The circuit boards 310 and 320 are printed wiring boards, and are configured by mounting a plurality of control elements 312 and 322 such as integrated circuits, resistors, and capacitors on the boards 311 and 321 on which wiring patterns are formed by printing. A large number of control elements 322 having a thickness (a thickness in the vertical direction; the same applies hereinafter) larger than that of the control circuit board 310 are mounted on the power supply circuit board 320. Therefore, the power supply circuit board 320 is thicker than the control circuit board 310 as a whole. The control circuit board 310 is arranged on the left side (one side in the left-right direction) which is the operator side on the second lower surface 202. The power supply circuit board 320 is arranged on the right side (the other side in the left-right direction) opposite to the worker side on the second lower surface 202.

  As shown in FIG. 3, the control element 312 mounted on the substrate 311 of the control circuit board 310 includes a plurality of first control elements 313 having a thickness from the substrate 311 smaller than a predetermined thickness To, and a predetermined thickness To. A plurality of second control elements 314 that are larger than the second control element 314 are included. In the control circuit board 310, the first control elements 313 are intensively arranged on the left side (one side in the left-right direction) which is the worker side. The control circuit board 310 is intensively arranged on the right side (the other side in the left-right direction) where the second control element 314 is opposite to the worker side.

  In the present embodiment, the circuit board 300 is composed of two boards, that is, the control circuit board 310 and the power circuit board 320. However, the circuit board 300 may be composed of one board having these functions as one, or three or more. You may comprise with the board | substrate of. In the control circuit board 310, the first control element 313 having a small thickness and the second control element 314 having a large thickness are arranged on one side and the other side in the left-right direction, but the first control element is similarly applied to the power circuit board 320. And the second control element may be arranged on one side and the other side in the left-right direction.

As shown in FIGS. 3 and 4, the control circuit board 310 is on the back side of the board 311 (upper side in FIG. 3).
A heating element 315 is provided at a substantially central position in the left-right direction. As an example of the heat generating element 315, there is an IPM (intelligent power module), for example.

  The control circuit board 310 and the power circuit board 320 are spaced from the second lower surface 202 by a predetermined gap via a plurality of ribs 203 (see FIG. 3 or FIG. 6 described later) formed on the second lower surface 202 of the under cover 200. And arranged opposite to each other.

  On the other hand, a heat generating component 330 used for drive control of the sewing machine main body 100 is provided on the right end side (one end side) of the second lower surface 202 of the under cover 200. The heat generating component 330 is provided so as to be in direct contact with the second lower surface 202 of the under cover 200 by, for example, an adhesive. An example of the heat generating component 330 is a regenerative resistor for consuming electric power generated when the sewing machine motor is regeneratively operated and brakes are applied. The regenerative resistor is a heat generating component having the largest heat generating action among components used for drive control of the sewing machine main body 100.

  Next, the notch structure in the opening 10 of the sewing machine table 20 will be described with reference to FIGS. 1 and 2 described above.

  As shown in FIGS. 1 and 2, the opening 10 of the sewing machine table 20 is notched in one end side corresponding to the position where the heat generating component 330 is disposed in the under cover 200, that is, the inner peripheral surface 11 r on the right end side. Part 12 is formed. The notch 12 is formed in a concave shape toward the right at a substantially central position in the front-rear direction of the inner peripheral surface 11r. The notch 12 has the following functions.

  The sewing machine table 20 is provided with the sewing machine main body 100 in the opening 10 from the upper side and an under cover 200 for covering the lower part of the sewing machine main body 100 from the lower side. Thereby, the opening 10 of the sewing machine table 20 is closed by the sewing machine body 100 and the under cover 200. As shown in FIG. 2, the notch 12 can form a heat radiation hole H that is not blocked by the sewing machine body 100 and the under cover 200. As shown in FIG. 1, the cover 108 of the sewing machine main body 100 has a shape protruding above the heat radiation hole H, but a gap S is secured at the lower portion so that the heat radiation hole H is not blocked. ing. Therefore, the notch 12 can sufficiently generate natural convection from the lower side to the upper side due to heat generation through the sewing machine table 20 on the heat generating component 330 side of the under cover 200. Cooling can be promoted.

  The notch 12 is not necessarily provided on the right end side of the opening 10. For example, when the heat generating component 330 is provided on the rear end side of the under cover 200, the notch may be provided on the rear end side of the opening 10, and on the side corresponding to the arrangement position of the heat generating component 330 in the under cover 200. I just need it. The position on the right end side is preferable for the following reason. That is, in the sewing work, the work cloth is moved back and forth in the area below the arm portion 103 on the sewing machine table 20 (hereinafter referred to as “work area”). When the notch 12 that is not blocked by the sewing machine main body 100 is located in the work area, the work cloth is caught. In contrast, when the notch 12 is provided on the right end side of the opening 10, that is, on the side of the leg column 102 in the sewing machine main body 100 as described above, the notch 12 is sandwiched from the work area to the leg column 102. And can be provided at positions separated from each other. Therefore, the cutout portion 12 does not catch the work cloth. Further, since the worker is located on the work area side, the heat generating component 330 can be disposed on the right end side of the under cover 200 opposite to the worker side, and the heat generating component contacts the operator's leg or the like. It is possible to improve the safety of workers.

  Note that the shape and size of the notch 12 are not limited to those shown in FIG. 2, and may be appropriately set according to, for example, the shape, size, and heat generation amount of the heat generating component 330.

  Next, the structure of the undercover 200 will be described with reference to FIGS.

  As shown in FIGS. 5 and 6, the under cover 200 has a box-like shape with an upper portion opened in a substantially rectangular shape. Hereinafter, the upper opening of the under cover 200 is referred to as a cover opening 205. As shown in FIGS. 1, 5, and 6, the under cover 200 includes a first cover part 210 that is located on the lower left side of the arm part 103, and a first cover part 210 that is connected to the first cover part 210 and reaches the lower part of the leg pillar part 102. 2 cover portion 220. The first cover part 210 has a deeper structure than the second cover part 220 in order to accommodate a drive mechanism such as a rotary hook. Therefore, when the under cover 200 is attached to the sewing machine table 20, the first lower surface 201 of the first cover portion 210 is positioned lower than the second lower surface 202 of the second cover portion 220.

  The under cover 200 functions as a cover that covers the lower part of the sewing machine body 100 through the opening 10 of the sewing machine table 20. The 1st cover part 210 also functions as an oil pan which receives the oil which is supplied to a rotary hook and is scattered by rotation of a rotary hook. Therefore, a partition wall 230 that prevents oil received by the first cover part 210 from entering the second cover part 220 side is provided inside the under cover 200. The first cover part 210 has an opening 211 required for maintenance work such as replacement of a bobbin in which a lower thread is wound around a rotary hook from the left end side surface 253 to the first lower surface 201.

  The height relationship between the first lower surface 201 and the second lower surface 202 is set as follows. As shown in FIG. 3, when the control circuit board 310 and the power circuit board 320 are arranged on the second lower surface 202 via the rib 203, the height of the substrates 311 and 321 is higher than the first lower surface 201 by the height h. It is set to be a position. The height of the rib 203 is set to be lower than the height difference between the first lower surface 201 and the second lower surface 202. Since the height of the substrates 311 and 321 is higher than that of the first lower surface 201, it is possible to prevent oil that hangs downward from the opening 211 from entering the first lower surface 201 and adhering to the control circuit substrate 310.

  As shown in FIG. 6, the second lower surface 202 is provided with a projecting wall 204 projecting downward so as to surround the periphery of the control circuit board 310 and the power supply circuit board 320 arranged horizontally. The protruding wall 204 has the following functions. For example, when an operator spills liquid such as drinking water on the upper surface of the sewing machine table 20, the liquid is transmitted from the inner peripheral surface 11 (see FIGS. 7 and 8) of the opening 10 of the sewing machine table 20 to the side surface of the under cover 200. , May hang down. In this case, when the liquid goes around the second lower surface 202 of the under cover 200 and adheres to the control circuit board 310 and the power supply circuit board 320, the circuit formed on the boards 311 and 321 and the control elements 312 and 322 are corroded. The protruding wall 204 prevents the liquid dripping from the side surface of the under cover 200 from flowing into the second lower surface 202, and prevents the liquid from adhering to the control circuit board 310 and the power supply circuit board 320.

As shown in FIG. 6, the protruding wall 204 is provided so as to surround the periphery of the circuit board 300 except for the first lower surface 201 side. The protruding walls 204 are not provided at both ends in the left-right direction on the front side of the second lower surface 202. About the both ends of the left-right direction of the front side of the 2nd lower surface 202, it prevents that a liquid wraps around the 2nd lower surface 202 by the bearing part 207 and the axial part 402 (refer FIG. 9) of the board | substrate cover 400 mentioned later. On the first lower surface 201 side, the height of the substrates 311 and 321 is higher than that of the first lower surface 201, so that the liquid that has entered the first lower surface 201 can be prevented from adhering to the control circuit substrate 310. Liquid that hangs down the front side surface 252, the right side surface 255, and the rear side surface 251 of the undercover 200 by the protruding walls 204 provided in the three directions of the front side, the right side, and the rear side of the control circuit board 310 and the power circuit board 320. Can be prevented from entering the second lower surface 202.

  As shown in FIGS. 7 and 8, the protruding wall 204 has the shape of the upper edge portion 401 of the substrate cover 400 so as to be close to the periphery of the upper edge portion 401 of the substrate cover 400 when the substrate cover 400 is closed. It is provided along. As shown in enlarged views in FIGS. 7 and 8, when the substrate cover 400 is closed, a labyrinth structure LS is formed between the protruding wall 204 provided on the second lower surface 202 and the upper edge 401 of the substrate cover 400. . Therefore, the liquid outside the substrate cover (for example, the liquid that hangs down the front side surface 252, the right side surface 255, and the rear side surface 251 of the under cover 200) does not flow to the circuit board 300 side.

  The cover opening 205 of the under cover 200 has an area (opening area; the same applies hereinafter) larger than the area of the opening 10 of the sewing machine table 20. The opening 10 of the sewing table 20 and the cover opening 205 of the under cover 200 both have a substantially rectangular shape, and the long side Lc2 (length in the left-right direction) of the cover opening 205 is the long side Lh2 of the opening 10 of the sewing table 20. Longer than (horizontal length). The length Lc1 of the short side (length in the front-rear direction) of the cover opening 205 is longer than the length Lh1 of the short side (length in the front-rear direction) of the opening 10 of the sewing machine table 20. Therefore, the edge portion 206 of the cover opening 205 is located on the outer peripheral side of the edge portion 13 d of the sewing table 20 below the opening 10.

  As shown in FIGS. 5 and 6, the under cover 200 includes bolt mounting portions 256 formed in a concave shape so as to allow a fixing bolt (not shown) to pass therethrough at four corners. As shown in FIGS. 7 and 8, a recess 22 is formed on the lower surface 21 of the sewing machine table 20 in a substantially rectangular frame shape along the lower edge 13 d of the opening 10. Bolt holes (not shown) are formed in the recesses 22 at positions corresponding to the bolt mounting portions 256. The under cover 200 is attached to the sewing machine table 20 by fastening the fixing bolts inserted through the respective bolt mounting portions 256 to the bolt holes of the concave portions 22 with the edge portions 206 of the cover openings 205 in contact with the concave portions 22. It is attached.

  As shown in FIGS. 3 and 6, the second lower surface 202 of the under cover 200 is provided with a heating element contact portion 240 protruding downward at a position corresponding to the heating element 315 of the control circuit board 310 described above. Yes. The heating element contact portion 240 includes a flat surface 241 that contacts the heating element 315 provided on the back side (upper side in FIG. 3) of the control circuit board 310 at the lower end. The flat surface 241 of the heating element contact portion 240 is formed by, for example, slightly thickening the undercover 200 when casting, and then polishing the end surface. The heating element contact portion 240 is made of the same metal material (aluminum or the like) having the same thermal conductivity as the under cover 200. Therefore, the heating element contact portion 240 secures a heat transfer area with the heating element 315 of the control circuit board 310 by the flat surface 241 and efficiently transfers the heat generated by the heating element 315 to the under cover 200 to radiate heat. be able to.

  Next, the structure of the substrate cover 400 will be described with reference to FIGS.

  The substrate cover 400 is a cover that protects the control circuit board 310 and the power supply circuit board 320 that are horizontally arranged on the second lower surface 202. The substrate cover 400 includes two shaft portions 402 projecting outward in the left-right direction at the front end (right side in FIGS. 9 and 10). As shown in FIG. 6, the under cover 200 is provided with two bearing portions 207 that rotatably support the shaft portion 402 at the front side end portion of the second lower surface 202. The substrate cover 400 is rotatable about the shaft portion 402 with respect to the second lower surface 202 of the under cover 200.

As shown in FIG. 9, in the normal state, the substrate cover 400 has its upper edge 401 (see FIG. 10) brought into contact with the second lower surface 202 within the enclosure of the protruding wall 204 of the under cover 200, thereby cover. Therefore, the board cover 400 prevents foreign matter such as dust from adhering to the circuit board 300 and contact of the operator's legs. As shown in FIG. 1, the first lower surface 201 of the under cover 200 is not covered by the substrate cover 400. As shown in FIG. 10, when performing maintenance work such as replacement of the circuit board 300, the board cover 400 rotates about the shaft portion 402, and the rear side (the left side in FIG. 10) of the circuit board 300 is exposed. The substrate cover 400 rotates so as to close the front side (right side in FIG. 10) which is the worker side.

  Next, the bearing structure of the switch lever 50 will be described with reference to FIG.

  As shown in FIG. 11, two bearings 52, 52 that support the rotary shaft 51 of the switch lever 50 described above are provided inside the second cover portion 220 of the under cover 200 (see also FIG. 5). The rotating shaft 51 that is pivotally supported by the bearings 52, 52 passes through a shaft hole 254 (see FIGS. 3, 5, and 6) provided in the front side surface 252 of the undercover 200, and is switched on the front side of the undercover 200. The lever 50 is connected to the arm member 53 via a connector 54. The rotating shaft 51 is connected to a cloth pressing drive mechanism (not shown) via a connecting member 55 and a connecting mechanism (not shown), and the rotation operation of the rotating shaft 51 is transmitted to the cloth pressing drive mechanism. Therefore, the operator can perform the switching operation of the vertical position of the cloth presser by rotating the switch lever 50 with the knee.

  Next, the link mechanism 40 of the pedal 30 will be described with reference to FIG.

  Below the sewing machine table 20, a pedal 30 (see FIG. 1) is provided for changing the rotation speed of the sewing machine motor built in the sewing machine body 100 in accordance with the amount of depression. The vertical movement of the pedal 30 is input to the pedal sensor 32 via the connecting rod 31 and a link mechanism 40 including a plurality of link members. The pedal sensor 32 is provided on the rear side surface 251 of the under cover 200. The link mechanism 40 is provided on the rear side surface 251 of the under cover 200 via the pedal sensor 32.

  The under cover 200 according to the embodiment described above has the bearing 52 in the second cover portion 220 where the lower surface of the under cover 200 is higher than the first cover portion 210 when the under cover 200 is attached to the sewing machine table 20. Therefore, the maintenance worker can work in a space wider than the space below the first cover part 210. Further, the maintenance worker is not obstructed by the bearing 52. The rotary shaft 51 has a height difference between the first cover part 210 and the second cover part 220 as compared with a conventional under cover, and a height difference and a high position due to the bearing 52 being arranged from the bottom of the under cover. Therefore, the under cover 200 can arrange the switch lever 50 at an appropriate position even for a tall sewing machine operator, and can operate the sewing machine comfortably.

  The under cover 200 has circuit boards 310 and 320 constituting the circuit board 300 used for driving control of the sewing machine main body 100 mounted on the second lower surface 202 thereof, and control elements 312 and 322 are mounted on the boards 311 and 321. These surfaces are arranged so as to be parallel to the second lower surface 202. Therefore, the under cover 200 can reduce the vertical dimension of the circuit board 300. As a result, when the operator operates the pedal 30 for changing the rotational speed of the sewing machine motor according to the amount of depression, the switch lever 50 for switching the vertical position of the cloth presser, etc. with the legs, the circuit board 300 Interference with the operator's legs can be suppressed, and the operator's workability can be improved.

Since the control circuit board 310 includes a heat generating element 315 such as an IPM, it is necessary to dissipate heat. According to the present embodiment, the heat transfer area between the control circuit board 310 and the metal undercover 200 can be increased by horizontally arranging the control circuit board 310 on the second lower surface 202 of the undercover 200. Therefore, the under cover 200 can efficiently dissipate heat from the control circuit board 310.

  Particularly in the present embodiment, the circuit board 300 has a control circuit board 310 having a small thickness arranged on the left side which is the worker side, and a power circuit board 320 having a large thickness arranged on the right side which is the opposite side to the worker side. Yes. Therefore, the under cover 200 can further reduce the vertical dimension of the circuit board 300 on the operator side, so that the circuit board 300 can be further prevented from interfering with the operator's legs, and the workability of the operator can be improved. Further improvement can be achieved.

  Particularly in the present embodiment, in the control circuit board 310, the first control elements 313 smaller than the predetermined thickness To are intensively arranged on the left side which is the operator side, and the second control larger than the predetermined thickness To. Elements 314 are intensively arranged on the right side opposite to the worker side. Therefore, the under cover 200 can further reduce the vertical dimension of the circuit board 300 on the operator side, so that the circuit board 300 can be further prevented from interfering with the operator's legs, and the workability of the operator can be improved. Further improvement can be achieved.

  Particularly in the present embodiment, the under cover 200 includes a first cover part 210 and a second cover part 220. In the under cover 200, when the under cover 200 is attached to the sewing machine table 20, the first lower surface 201 of the first cover portion 210 is positioned lower than the second lower surface 202 of the second cover portion 220. The circuit board 300 is disposed on the second lower surface 202. Therefore, by arranging the circuit board 300 on the second lower surface 202 which is a high position among the lower surfaces of the under cover 200, it is possible to suppress the downward projection and further suppress the interference with the operator's leg. .

  Particularly in the present embodiment, the control circuit board 310 and the power circuit board 320 are arranged such that the heights of the boards 311 and 321 are higher than those of the first lower surface 201. Therefore, the under cover 200 can prevent the liquid such as oil leaked to the outside from the first cover part 210 from adhering to the circuit board 300 even if it hangs down and wraps around the first lower surface 201. The under cover 200 can prevent corrosion of circuits and elements due to liquid such as oil adhering to the circuit board 300.

  Particularly in the present embodiment, the under cover 200 is provided with a protruding wall 204 that protrudes downward on the second lower surface 202 so as to surround the periphery of the circuit board 300 except for the first lower surface 201 side. For example, the operator spills liquid such as drinking water on the upper surface of the sewing machine table 20, and the protruding wall 204 is transferred downward from the edge of the opening 10 of the sewing machine table 20 to the side surfaces 251, 252, and 255 of the undercover 200. Even in this case, the liquid is prevented from entering the second lower surface 202. The protruding wall 204 can prevent the liquid from adhering to the circuit board 300.

  Particularly in the present embodiment, the under cover 200 is provided with a substrate cover 400 on the second lower surface 202 so as to be rotatable. The substrate cover 400 is configured to be opened so that the rear side of the circuit substrate 300 is exposed. For example, even when the maintenance worker forgets to close the substrate cover 400 or when the substrate cover 400 is opened due to vibration or the like at normal times, the substrate cover 400 is opened so as to block the front side which is the operator side of the circuit board 300. Therefore, it is possible to reliably prevent the operator's leg from contacting the circuit board 300.

When the substrate cover 400 is closed, the upper edge 401 is brought into contact with the second lower surface 202 within the enclosure of the protruding wall 204. This prevents the liquid that hangs down from the side surface by the protruding wall 204 of the under cover 200 from entering the second lower surface 202, and further prevents the liquid from entering by the substrate cover 400 in the enclosure. The function of preventing intrusion to the 300 side can be further enhanced.

  Particularly in the present embodiment, the under cover 200 forms a heating element contact portion 240 protruding downward at a position corresponding to the heating element 315 of the second lower surface 202. The under cover 200 arranges the control circuit board 310 via ribs 203 provided at a plurality of locations on the second lower surface 202 of the under cover 200. Therefore, the second lower surface 202 of the under cover 200 and the control circuit board 310 are disposed to face each other with a predetermined distance and do not directly contact each other. However, since the heating element contact portion 240 has a flat surface 241 that contacts the heating element 315 at the lower end, the heating element contact portion 240 can reliably contact the heating element 315 and secure a heat transfer area. As a result, the undercover 200 can efficiently dissipate the heat generated in the heating element 315 via the heating element contact portion 240.

  In this embodiment, in particular, the link mechanism 40 that transmits the vertical movement of the connecting rod 31 connected to the pedal 30 to the pedal sensor is provided on the side surface 251 on the rear side of the under cover 200. Thereby, for example, the link mechanism can be arranged more upward than the structure in which the link mechanism 40 is provided in a control box provided in the lower part of the under cover 200. Therefore, the under cover 200 can suppress the link mechanism 40 from interfering with the operator's leg, and can further improve the operator's workability. Although the load due to the depression of the pedal 30 acts on the link mechanism 40, since the under cover 200 is made of metal, the link mechanism 40 can be supported stably in terms of strength.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and technical idea of the present invention.

  For example, as shown in FIG. 13, a heat radiation uneven portion 257 for radiating heat from the circuit board 300 may be provided on the side surface of the undercover 200 (the rear side surface 251 in the illustrated example). As described above, the heat generated in the heat generating element 315 of the control circuit board 310 and the heat generated in the heat generating component 330 are transferred to the under cover 200. Since the heat radiation uneven portion 257 is provided on the side surface, the heat radiation area is increased and heat can be efficiently radiated. In addition, the uneven | corrugated | grooved part 257 for heat radiation may be provided in all the side surfaces 251,252,253,255 of the undercover 200, and may be provided only in any one side surface. The heat radiating uneven portion 257 may be provided only in a partial region rather than all of the side surfaces.

  In addition to those already described above, the methods according to the above-described embodiments and modifications may be used in appropriate combination.

DESCRIPTION OF SYMBOLS 1 Sewing machine 10 Opening 20 Sewing machine table 30 Pedal 31 Connecting rod 40 Link mechanism 50 Switch lever 51 Rotating shaft 52 Bearing 100 Sewing machine main body 102 Leg column part 103 Arm part 200 Under cover 201 1st lower surface 202 2nd lower surface (lower surface)
204 Projection Wall 210 First Cover Part 220 Second Cover Part 240 Heating Element Contact Part 241 Flat Surface 251 Side 252 Side 253 Side 255 Side 257 Heat Dissipation Convex Section 300 Circuit Board 310 Control Circuit Board (Circuit Board)
311 Substrate 313 First control element 314 Second control element 315 Heating element 320 Power supply circuit board (circuit board)
400 Substrate cover 401 Upper edge 402 Shaft

Claims (1)

A sewing machine that covers a lower portion of the sewing machine main body provided with a pedestal that is installed at an opening of the sewing machine table and is erected from the sewing machine table, and an arm that extends in parallel with the sewing machine table from the upper part of the pedestal. In the under cover of
The under cover includes a first cover portion located below the arm portion and a second cover portion located below the pedestal portion, and when the under cover is attached to the sewing machine table, the first cover portion The lower surface of the second cover portion is configured to be lower than the lower surface of the second cover portion,
Provided inside the second cover part is a bearing that pivotally supports a rotating shaft of a switch lever for switching the vertical position of the cloth presser provided in the sewing machine body,
An under cover for a sewing machine having a hole through which the rotating shaft can penetrate in a side wall of the second cover portion.

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