JP2011212770A - Workpiece clamping mechanism and machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a workpiece clamping mechanism capable of easily performing seating confirmation.SOLUTION: The workpiece clamping mechanism is provided, which includes: a body frame having a stage surface placed with a workpiece; a first mouthpiece part having a first mouthpiece, a first mouthpiece support part for slidably supporting the first mouthpiece in a direction perpendicular to the stage surface and a first mouthpiece pressing part for pressing the first mouthpiece supported on the first mouthpiece support part; a second mouthpiece part having a second mouthpiece, a second mouthpiece support part for slidably supporting the second mouthpiece in a direction crossing with the stage surface and a second mouthpiece pressing part for pressing the second mouthpiece; and a drive part for driving the second mouthpiece support part in a direction allowing the second mouthpiece support part to approach to the first mouthpiece part.

Description

  The present invention relates to a work holding mechanism such as a vise for fixing a workpiece (work) in between, and a machine tool having a work holding mechanism.

  Machine tools such as a milling machine, a drilling machine, and a planer that cut a workpiece generally move relative to the stage, the vice that fixes the workpiece on the stage, and the workpiece fixed to the vise. It is mainly equipped with cutting tools such as milling cutters, drills and cutting tools for cutting workpieces. For example, when cutting the upper surface of a rectangular parallelepiped workpiece, the workpiece is fixed to the stage by holding the side surface of the workpiece with a vice. And in the state which fixed the workpiece | work to the stage, it cuts into the upper surface of a workpiece | work using a suitable blade tool.

  Here, in order to machine the workpiece with high accuracy, it is necessary to prevent the position of the workpiece from being shifted with respect to the vise during the machining. As a factor that causes the displacement of the workpiece, for example, the force (clamping force) with which the vice clamps the workpiece is insufficient. If the force with which the vice clamps the workpiece is insufficient, the force applied to the workpiece during machining cannot be withstood, and the position of the workpiece is shifted. However, if the tightening force is increased more than necessary, the workpiece may be excessively elastically deformed or plastically deformed. When machining is performed in a state where excessive elastic deformation has occurred in the workpiece, the machining accuracy is impaired when the workpiece returns to its original state even after the elastic deformation has been eliminated. Further, when plastic deformation occurs in the workpiece, the quality of the product is impaired.

  Patent Document 1 discloses a main body frame, a movable jaw that is restricted in rotation by the main body frame and moves in the axial direction of an engaging screw shaft, a fixed jaw fixed at a position facing the movable jaw, and a movable There is disclosed a vise including a force-intensifying device that presses a jaw along a screw shaft, and a tightening force adjusting device that adjusts a tightening force of a work held between a fixed jaw and a movable jaw. Here, the intensifier can generate a large tightening force using the wedge action, but the tightening force adjustment device ensures that the tightening force is appropriate so that excessive tightening force is not applied to the workpiece. It is adjusted so as to be a large size.

JP 2007-185759 A

  As described above, when the force with which the vice sandwiches the workpiece is insufficient, the force applied to the workpiece during machining cannot be withstood, and the position of the workpiece is shifted. In order to avoid this, it is necessary to sandwich the workpiece with a sufficiently large force. At this time, even when an excessive fastening force is applied to the workpiece, as well as a case where adjustment is made so that an excessive clamping force is not applied to the workpiece, as in the case of using the vise disclosed in Patent Document 1. As will be described later, it is known that the bottom surface of the workpiece floats up from the stage surface of the main body frame of the vice, which will be described later, in the process of gradually applying the tightening force from the state in which the movable jaw is in contact with the workpiece. Such a state where the bottom surface of the workpiece and the stage surface of the main body frame of the vice are not in close contact with each other and a gap is formed between them is generally expressed as “the workpiece is not seated”. When machining is performed in a state where the workpiece is not seated in this manner, the possibility that the position of the workpiece is shifted during machining is increased. Furthermore, when a plurality of workpieces are sequentially processed while exchanging the workpieces, the amount of lift of each workpiece in the plurality of workpieces is not constant, which causes a problem of unevenness in the machining accuracy of each workpiece. Therefore, conventionally, after the work is sandwiched between the vices, it is necessary for the worker to check whether each work is seated or not. In addition, when the workpiece is not seated, it is necessary for the worker to manually seat the workpiece. The amount of workpiece lifting is generally about 10 μm to several tens of μm and cannot be easily confirmed visually. Therefore, conventionally, an operator tries to tap the work with a wooden mallet or a hammer, and confirms whether the work is seated by the impact sound at that time, and if the work is lifted, tap it. The work of seating is being done. In order to make sure that the workpiece is seated by listening to the sound in this way, and to properly seat the workpiece that has not been seated manually by hitting it with a wooden mallet etc. High skill is required. Therefore, there is a problem in that not all workers including beginners can work in the same manner. In addition, if the step of confirming the seating of the workpiece and / or the step of properly seating the workpiece must be performed by a skilled worker, a series of steps including a step of clamping the workpiece between the vice and a step of processing the workpiece It is also a problem when trying to automate.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a work holding mechanism such as a vise and a machine tool having the same, which is capable of holding a work with sufficient strength during processing and has a mechanism for preventing the work from lifting. Is to provide.

  According to the first aspect of the present invention, there is provided a workpiece holding mechanism for holding a workpiece, the main body frame having a stage on which a stage surface on which the workpiece is placed is formed, and the stage surface of the stage. A first base part that protrudes and has a first base formed with a first contact surface that comes into contact with the workpiece, and a first base that supports the first base so as to be slidable in a direction perpendicular to the stage surface. A first base part having a first base pressing part that presses the support part and the first base supported by the first base support part in a direction perpendicular to the stage surface in a direction approaching the stage surface; A second base part that protrudes from the stage surface of the stage and moves in a direction of separating from and contacting the first base part in the surface direction of the stage surface, and is in contact with the workpiece and the first contact surface; A second base formed with a second contact surface facing the second base, a second base supporting part that slidably supports the second base in an intersecting direction intersecting the stage surface, and supported by the second base supporting part A second base part having a second base pressing part for pressing the second base in the direction intersecting with the second base, and a second base support part of the second base part as the first base part. A workpiece holding mechanism is provided that includes a drive unit that drives in the approaching direction.

  According to the work clamping mechanism of the present invention, the second base part can be driven in a direction close to the first base part, so that the work is held between the first base part and the second base part. be able to. Here, as the fastening force between the first base part and the second base part increases, the workpiece floats from the stage surface. At this time, since the first base of the first base part and the second base of the second base part can move in a direction approaching the stage surface, the work floating from the stage surface can be appropriately seated. . Here, since the first base of the first base part is movable in a direction perpendicular to the stage surface, the position of the surface where the first mouth of the work comes into contact with the sheet is shifted when the work is seated. There is no fear. In addition, in this application, when the expression that the workpiece is placed on the stage surface is used, the case where the workpiece is placed directly on the stage surface and the case where the appropriate height is placed on the stage surface. This includes the case where a workpiece is placed after the height is adjusted by placing a table.

  In the workpiece clamping mechanism of the present invention, a groove extending in a first direction from the first base part toward the second base part may be formed in the stage of the main body stage, and the driving unit may A shaft disposed inside the groove, a second base support member that moves in the first direction along the shaft, and has a second base support portion of the second base portion fixed thereto; and a second base support member. You may have a drive mechanism which drives in the direction which approaches the 1st nozzle | cap | die part along the said shaft. In this case, since the second base support member and the shaft to which the second base support portion of the second base portion is fixed are disposed inside the groove formed in the stage, the member is disposed on the upper surface of the stage. For example, it is possible to avoid interference with the cutting tool when processing a workpiece.

  In the workpiece clamping mechanism of the present invention, a screw groove may be formed on the outer peripheral surface of the shaft, and the shaft is inserted into the base support member and fitted into the screw groove formed in the shaft. A screw hole in which a thread groove is formed may be formed, and the drive mechanism may be a motor or a handle for rotating the shaft. In this case, the second base part can be easily moved toward the first base part by rotating the shaft with a motor or a handle.

  In the workpiece clamping mechanism according to the present invention, the first and second base pressing portions may be first and second fixing screws having neck portions partially reduced in diameter. A semi-cylindrical groove in which the first and second fixing screws are arranged is formed on the surface of the base opposite to the first and second contact surfaces, respectively, and the neck is formed inside the groove. The first and second base support portions may each have a hole for disposing the first and second fixing screws in cooperation with the semi-cylindrical groove. A semi-cylindrical groove formed and a female screw portion that fits into the first and second fixing screws may be formed. In this case, since the necks of the first and second fixing screws are engaged with the protrusions formed in the grooves of the first and second caps, the first and second fixing screws are tightened. By a simple operation, the first and second caps can be moved toward the stage surface, and the seating confirmation of the workpiece can be easily performed.

  In the work clamping mechanism of the present invention, the first base support part of the first base part may be fixed to the main body frame. In this case, since the first base support part of the first base part is fixed to the main body frame, the position of the first contact surface of the first base in the surface direction of the stage surface is fixed. Therefore, for example, in order to process a plurality of workpieces in order, even if the operation of attaching the workpiece to the workpiece clamping mechanism or removing it from the workpiece clamping mechanism is repeated, the first contact surface of the first die There is no possibility that the position is shifted in the surface direction of the stage surface. Therefore, the position of the first contact surface of the first base can be used as a coordinate origin fixed through processing.

  In the workpiece holding mechanism of the present invention, the intersecting direction may be inclined in a direction closer to the first cap portion as the stage surface is approached, not parallel to a direction perpendicular to the stage surface. In this case, when the second base is moved close to the stage surface in order to seat the work, the second contact surface moves in a direction approaching the fixed base, so that the fastening force applied to the work is further increased. Work can be seated while strengthening.

  According to the second aspect of the present invention, there is provided a machine tool for processing a workpiece, the surface having the surface to which the workpiece is fixed provided integrally with the workpiece clamping mechanism according to the first aspect of the present invention. A pallet, a cutting tool for processing a workpiece, a spindle to which the cutting tool is attached, a spindle for rotating the cutting tool, and a pallet moving mechanism for moving the pallet relative to the spindle to which the cutting tool is attached. A machine is provided. The cutting tool may be a plurality of cutting tools, and the machine tool may be a machining center including a tool magazine that accommodates the plurality of cutting tools.

  By utilizing the base according to the workpiece clamping mechanism of the present invention, the workpiece can be clamped with sufficient strength and the workpiece can be easily seated. For this reason, it is not necessary to perform the work seating confirmation process and the work seating process, which are difficult, after the work is held.

FIG. 1 is a schematic view of a machine vice according to the present invention. FIG. 2 is a schematic view of the first base and the second base. FIG. 3 is a schematic view showing a state in which the workpiece is held by the machine vice according to the present invention. FIG. 4 is a schematic view showing a state in which the workpiece is not seated. FIG. 5 is a schematic view showing a state in which the first and second caps are lowered and the workpiece is seated. FIG. 6 is a schematic view showing a state in which the lifting of the workpiece held by the machine vice according to the present invention is measured. FIG. 7 is another example of the first base. FIG. 8A is a schematic view showing a state in which a workpiece is not seated in a machine vise having a seating confirmation mechanism, and FIG. 8B is a diagram showing a state in which a workpiece is seated in a machine vise having a seating confirmation mechanism. It is the schematic which shows the state which is. FIG. 9 is a schematic view of a machining center as an example of a machine tool including a machine vice according to the present invention.

  Hereinafter, as an example of a vice as a workpiece clamping mechanism of the present invention, a single-clamp machine vise will be described with reference to the drawings. In the following description, each member of the machine vise is assumed to be made of a metal material unless otherwise specified. For example, chromium molybdenum steel such as SCN435 or SCN440, steel, nickel alloy, or the like may be used, and the surface may be quenched. Further, the description will be made assuming that the workpiece (work) to be machined while being fixed to the machine vise has a rectangular parallelepiped shape. As shown in FIG. 1, FIG. 3, etc., the machine vise 100 includes a main body frame 10 on which a stage surface 10 a for placing a workpiece 200 to be processed is formed, and a fixing fixed to one end of the main body frame 10. A base part 20, a movable base part 30 that is arranged opposite to the fixed base part 20 and moves in a direction approaching and moving away from the fixed base part 20 (fastening direction), and a fastening direction of the movable base part 30 And a driving unit 40 for driving the main body.

  First, each component of the machine vice 100 will be described. The main body frame 10 has a substantially rectangular parallelepiped base portion 11 having a predetermined longitudinal direction, an attachment portion 12 provided on the lower side of the base portion 11 for attaching to a processing stage of a machine tool such as a machining center described later, It has a guide groove 13 that is formed along the longitudinal direction on the upper surface of the base 11 and guides the movement of the movable base 30. As described above, the upper surface of the base 11 defines the stage surface 10a on which the workpiece 200 is placed. That is, the stage surface 10a as a flat surface without unevenness is formed on the upper surface of the base 11 except for the guide groove 13. A fixed base portion 20 is fixed to one end of the stage surface 10a of the base 11 in the longitudinal direction, and a movable base portion 30 is slidably provided on the stage surface 10a at a position facing the fixed base portion 20. It has been. As will be described later, the movable base portion 30 is fixed to the movable base portion support member 41 of the drive unit 40 that moves along the guide groove 13. Here, when the movable base support member 41 moves along the guide groove 13, the movable base portion 30 also slides on the stage surface 10 a along the guide groove 13.

  The fixed base portion 20 is disposed so as to protrude from the stage surface 10 a of the base portion 11, and can be moved up and down by the first base support portion 21 fixed to the stage surface 10 a of the base portion 11 and the first base support portion 21. And a first fixing screw 23 that fastens the first base 22 to the first base support portion 21. The first base support portion 21 is fixed to one end portion in the longitudinal direction of the base portion 11 of the main body frame 10. The first base support portion 21 has a side surface 21a (a surface facing the movable base portion 30) on one side in the longitudinal direction extending in the vertical direction (normal direction of the stage surface 10a of the base 11). A single base guide groove 24 is formed to guide the first base 22 in the vertical direction. A semi-cylindrical hole 25 for inserting the first fixing screw 23 is formed in the side surface portion 21 a of the first base support portion 21, and a first fixing screw 23 is formed in the lower portion of the hole 25. A female screw portion 26 in which a female screw to be fitted is cut is formed.

  As shown in FIGS. 1 and 2, the first base 22 is a plate-like member, and a guide portion 22 b that fits into the first base guide groove 24 is formed on the side surface portion 22 a. The surface of the first base 22 that faces the movable base 30 is a holding surface (first contact surface) 22 c that comes into contact with the work 200 when the machine vise 100 holds the work 200. The holding surface 22c is formed to be accurately orthogonal to the stage surface 10a of the base 11 when the first base 22 and the first base support portion 21 are combined. Further, a semi-cylindrical hole 22d is formed in a portion of the surface of the first base 22 opposite to the gripping surface 22c and facing the hole 25 of the first base support portion 21. The upper portion of the hole 22d is substantially the same size as the hole 25, and an insertion hole for inserting the first fixing screw 23 is defined by combining the upper portion of the hole 22d and the hole 25 so as to face each other. Is done. The lower portion of the hole 22d has a diameter that can avoid the female screw portion 26, and the first base 22 moves downward as the first fixing screw 23 is tightened as described later. At this time, the first base 22 does not interfere with the female screw portion 26. Further, an upper portion of the hole 22d is a semicircular fan-shaped wall portion protruding from the wall surface defining the hole 22d, and an engagement portion 22e that engages with a neck portion 23c of the first fixing screw 23 described later. Is formed.

  The first fixing screw 23 includes a male screw portion 23a in which a male screw fitted to the female screw portion 26 is cut, and a hexagon hole for a hexagon wrench, a plus hole for a plus driver, and a minus hole for a minus driver at the top. And a neck portion 23c that is formed between the head portion 23b and the female screw portion 23a and is thinner than the head portion 23b and the female screw portion 23a. The length of the engagement portion 22e in the depth direction of the hole 22d is substantially the same as the length of the neck portion 23c of the first fixing screw 21. Further, when the neck portion 23c of the first fixing screw 21 and the engaging portion 22e are engaged as described later, the radial tip of the hole 22d of the engaging portion 22e is the neck portion 23c of the first fixing screw 21. The diameter of the neck portion 23c of the first fixing screw 21 and the height of the engaging portion 22e are adjusted so as to substantially contact the surface of the first fixing screw 21. Therefore, the engaging portion 22e engages with the neck portion 23c of the first fixing screw 23 with almost no gap.

  Here, both the insertion hole for inserting the first fixing screw 23 and the female screw portion 26 formed by combining the upper portion of the hole 22d and the hole 25 are formed on the stage surface 10a of the base 11. The first base guide groove 24 is formed so as to be accurately perpendicular to the stage surface 10 a of the base 11. Therefore, as described later, the first base 22 can be moved in the vertical direction relative to the first base support portion 21 while keeping the holding surface 22c and the stage surface 10a of the base portion 11 vertical.

  The movable base portion 30 is fixed to a movable base portion support member 41 of the drive unit 40 described later, and is formed to be slidable with respect to the stage surface 10a of the base portion 11 as the movable base support member 41 moves. The second base support portion 31, the second base 32 supported by the second base support portion 31 so as to be movable up and down, and the second fixing screw 33 for fastening the second base 32 to the second base support portion 31. .

  The second base support part 31 extends in the vertical direction (normal direction of the stage surface 10a of the base 11) on the side surface part 31a (the surface facing the fixed base part 20) on one side of the base 11 in the longitudinal direction. A second base guide groove 34 is formed to guide the second base 32 in the vertical direction. In addition, a side surface portion 31a of the second base support portion 31 is formed with a semi-cylindrical hole 35 for inserting the second fixing screw 33 in cooperation with a hole 32d of the second base 32 described later. In the lower portion of the hole 35, a female screw portion 36 in which a female screw into which the second fixing screw 33 is fitted is formed.

  The second base support portion 31 is fixed to the movable base portion support member 41 of the drive unit 40 by screws (not shown). In a state where the second base support portion 31 is fixed to the movable base support portion 41 of the drive unit 40, the lower surface of the second base support portion 31 is substantially flush with the stage surface 10a of the base portion 11, and the movable base Along with the movement of the support portion 41, the second base support portion 31 slides in a state where the lower surface thereof is in contact with the stage surface 10 a of the base portion 11.

  As shown in FIGS. 1 and 2, the second base 32 is a plate-like member, and a guide portion 32 b that fits into the second base guide groove 34 is formed on the side surface portion 32 a. The surface of the second base 32 that faces the fixed base portion 20 is a holding surface (second contact surface) 32 c that comes into contact with the work 200 when the machine vise 100 holds the work 200. The holding surface 32 c is formed to be accurately orthogonal to the stage surface 10 a of the base 11 when the second base 32 and the second base support portion 31 are combined. A semi-cylindrical hole 32d is formed in a portion of the surface of the second base 32 opposite to the gripping surface 32c and facing the hole 35 of the second base support portion 31. The upper portion of the hole 32d is substantially the same size as the hole 35, and the insertion hole for inserting the second fixing screw 33 is formed by combining the upper portion of the hole 32d and the hole 35. The lower portion of the hole 32d has a diameter that can avoid the female screw portion 36, and the second base 32 moves downward as the second fixing screw 33 is tightened as will be described later. At this time, the second base 32 does not interfere with the female screw portion 36. Further, an upper portion of the hole 32d is a semicircular fan-shaped wall portion protruding from the wall surface defining the hole 32d, and an engaging portion 32e that engages with a neck portion 33c of the second fixing screw 33 described later. Is formed.

  The second fixing screw 33 is formed with a male screw portion 33a in which a male screw fitted to the female screw portion 36 is cut, a hexagon hole for a hexagon wrench, a plus hole for a plus driver, a minus hole for a minus driver, and the like. And a neck portion 33c that is formed between the head portion 33b and the female screw portion 33a and is narrower than the head portion 33b and the female screw portion 33a. The length of the engagement portion 32e in the depth direction of the hole 32d is substantially the same as the length of the neck portion 33c of the second fixing screw 31. Further, when the neck portion 33c of the second fixing screw 31 and the engaging portion 32e are engaged as described later, the radial tip of the hole 32d of the engaging portion 32e is the neck portion 33c of the second fixing screw 31. The diameter of the neck portion 33c of the second fixing screw 31 and the height of the engaging portion 32e are adjusted so as to substantially contact the surface of the second fixing screw 31. Therefore, the engaging portion 32e engages with the neck portion 33c of the first fixing screw 33 with almost no gap.

  Here, both the insertion hole for inserting the second fixing screw 33 and the female screw portion 36 formed by combining the upper portion of the hole 32d and the hole 35 are formed on the stage surface 10a of the base 11. The second base guide groove 34 is also formed to be inclined at the same angle from the vertical with respect to the stage surface 10 a of the base 11. Specifically, both the insertion hole for inserting the second fixing screw 33 and the female screw portion 36 are close to the stage surface 10a of the base portion 11 from a direction perpendicular to the stage surface 10a of the base portion 11. It is formed so as to be inclined by about 5 ° in the direction approaching the fixed base portion 20. Here, the insertion hole for inserting the second fixing screw 33 and the female screw portion 36 are not formed in parallel to the surface direction of the holding surface 32c, and are the same angle (about 5 °) as the above angle. It is formed to tilt only. Therefore, as described later, when the second base 32 is moved relative to the second base support portion 31, the holding surface 32 c and the stage surface 10 a of the base portion 11 can be kept vertical.

  The drive unit 40 is connected to a motor 42 fixed to an end of the base 11 of the main body frame 10 opposite to the end to which the fixed base unit 20 is attached, a rotation shaft of the motor 42, and A shaft 43 having a spiral thread groove on the outer periphery, and a movable base support member 41 in which the shaft 43 is inserted and a screw hole having a thread groove fitted to the thread groove of the shaft 43 is formed. And have. The shaft 43 and the movable base support member 41 are disposed inside the guide groove 13 formed in the base portion 11 of the main body frame 10. The movable base support member 41 has a substantially rectangular parallelepiped shape, and is disposed so as to fit in the guide groove 13 with almost no gap. Further, as described above, the second base support portion 31 of the movable base portion 30 is fixed to the upper surface of the movable base support member 41.

  Next, a procedure for pinching the workpiece 200 using the machine vice 100 will be described with reference to FIGS. Note that the following procedure is merely an example, and the work does not necessarily have to be performed in this order, and can be changed as necessary.

  First, the second base support portion 31 of the movable base portion 30 is fixed to the upper surface of the movable base support member 41 by screwing or the like. Here, as described above, the movable base support member 41 having a substantially rectangular parallelepiped shape is disposed inside the guide groove 13 formed in the base portion 11 of the main body frame 10, and the guide groove is provided in the movable base support member 41. A shaft 43 extending along the line 13 is inserted. Here, a spiral thread groove is cut on the surface of the shaft 43, and the thread groove formed on the surface of the shaft 43 is inserted into the screw hole through which the shaft 43 of the movable base support member 41 is inserted. The thread groove to be fitted is cut. Here, when the motor 42 is driven to rotate the shaft 43, the rotational force is transmitted to the movable base support member 41. Here, the movable base support member 41 is arranged in the guide groove 13 with almost no gap. In other words, both side surfaces of the movable base support member 41 are in close contact with the inner surface of the guide groove 13. Therefore, the movable base support member 41 cannot rotate around the shaft 43 as the shaft 43 rotates. Here, since the screw groove formed in the screw hole of the movable base support member 41 and the screw groove formed on the surface of the shaft 43 are fitted, the movable base support member is rotated with the rotation of the shaft 43. 41 moves in the extending direction of the shaft 43. Thus, by driving the motor 42 and rotating the shaft 43, the movable base support member 41 can be moved in the extending direction of the shaft 43, that is, in the extending direction of the guide groove 13.

  Note that, as described above, the fixed base portion 20 is disposed on one end of the stage surface 10 a of the base portion 11 in the longitudinal direction of the base portion 11. Since the second base support portion 31 of the movable base portion 30 is fixed to the movable base support member 41, the movable base portion 30 (second portion) fixed to the movable base support member 41 as the shaft 43 rotates. By moving the base support portion 31) along the longitudinal direction of the base 11 that is the extending direction of the guide groove 13, the interval between the fixed base portion 20 and the movable base portion 30 is narrowed or widened. Can do.

  Next, with the neck portion 23 c of the first fixing screw 23 and the engaging portion 22 e of the first base 22 engaged, the first fixing screw 23 and the first base 22 are connected to the first base supporting portion 21. It fixes to the side part 21a. Specifically, the first fixing screw 23 is disposed in the hole 22 d of the first base 22 in a state where the neck portion 23 c of the first fixing screw 23 and the engaging portion 22 e of the first base 22 are engaged. Then, the guide portion 22 b of the first base 22 is inserted into the first base guide groove 24 of the first base support portion 21 with the first fixing screw 23 disposed in the hole 22 d of the first base 22. In this way, the first base 22 is attached to the first base support portion 21, and the first fixing screw 23 is screwed to the female screw portion 26. At this time, since the guide portion 22 b of the first base 22 is engaged with the first base guide groove 24, the first base 22 is supported so as to be movable only in the vertical direction with respect to the first base support portion 21. . Here, when the first fixing screw 23 is screwed to the female screw portion 26, the vertical position of the first base 22 with respect to the first base support portion 21 is fixed. That is, the neck portion 23 c of the first fixing screw 23 and the engaging portion 22 e of the first base 22 are engaged, and the first base 22 is connected to the first fixing screw 23 in the extending direction of the first fixing screw 23. Therefore, when the first fixing screw 23 is screwed to the female screw portion 26, the vertical position of the first base 22 relative to the first base support portion 21 is also fixed. In addition, since there is a slight gap between the lower end of the first base 22 and the portion of the first base support portion 21 that faces the lower end of the first base 22, as described later, the first base 22 After the 22 is fixed to the first base support 21, the first base 22 can be moved further downward relative to the first base support 21 by further tightening the first fixing screw 23. it can.

  Next, in the same manner as the first base 22 is fixed to the first base support portion 21 using the first fixing screw 23, the second base 33 is connected to the second base 33 using the second fixing screw 33. Fix to the base support 31.

  Next, the motor 42 is driven to sufficiently widen the interval between the fixed base part 20 and the movable base part 30, and the work 200 is placed on the stage surface 10 a of the base part 11 of the main body frame 10. At this time, one of the side surfaces of the workpiece 200 (first workpiece contact surface 200a) is disposed so as to be in close contact with the holding surface 22c of the first cap 22 of the fixed cap portion 20. In this state, the motor 42 is driven to move the movable base portion 30 so as to approach the fixed base portion 20, so that the surface of the workpiece 200 opposite to the first workpiece contact surface 200 a (second workpiece contact surface 200 b). And the holding surface 32c of the second base 32 of the movable base part 30 are brought into contact with each other.

  Here, as shown in FIG. 3, when the holding surface 32 c of the second base 32 of the movable base portion 30 and the second work contact surface 200 b of the work 200 are merely in light contact, the lower surface of the work 200 is used. And the stage surface 10a of the main body frame 10 are completely in close contact with each other. That is, in this case, the workpiece 200 is seated on the stage surface 10 a of the main body frame 100. However, since the machine vise 100 does not fasten the workpiece 200 with a sufficiently large fastening force as it is, the workpiece 200 is detached from the machine vise 100 when the workpiece 200 is cut. Therefore, after the holding surface 32c of the second base 32 of the movable base portion 30 comes into contact with the second work contact surface 200b of the work 200, the motor 42 is further driven to give a sufficiently large fastening force to the work 200. Specifically, the motor 42 is driven so that the movable base 30 moves in a direction approaching the fixed base 20, and the holding surface 32 c of the second base 32 of the movable base 30 is the second workpiece contact of the workpiece 200. The contact surface 200b is pushed with a sufficiently large force.

  At this time, the first base 22 that contacts the first workpiece contact surface 200a of the workpiece 200 is fixed so that it cannot move in the longitudinal direction (fastening direction) of the main body frame 10. Therefore, the first and second workpiece contact surfaces 200a and 200b of the workpiece 200 are pressed from the holding surfaces 22c and 32c of the first and second caps 22 and 32, respectively. In other words, the workpiece 200 is subjected to a large force in the direction of compressing the workpiece 200 in the longitudinal direction of the main body frame 10. At this time, since the lower surface side of the workpiece 200 is defined by the stage surface 10a of the base portion 11, the workpiece 200 cannot escape downward but tries to escape upward. As a result, as shown in FIG. 4, a slight gap is formed between the bottom surface of the workpiece 200 and the stage surface 10a. In other words, the lower part of the fixed base part 20 and the lower part of the movable base part 30 are fixed to the main body frame 10 and the movable base support member 41, respectively, but the upper part of the fixed base part 20 and the movable base part 30. None of the tops of are fixed. Therefore, when the movable base 30 is moved toward the fixed base 20 and a large force is applied to the holding surfaces 22c and 32c of the first and second bases 22 and 32, the first and second bases 22 are applied. , 32 does not have a uniform force distribution on the holding surfaces 22c, 32c, and is fixed to the main body frame 10 and the movable base support member 41, respectively, and below the fixed base portion 20 and the movable base portion 30. The force applied to the lower part is greater than the force applied to the upper part of the fixed base part 20 that is not fixed and the upper part of the movable base part 30. That is, when the movable base part 30 is moved in a direction approaching the fixed base part 20, the force is distributed so that the upper part of the movable base part 30 and the upper part of the fixed base part 20 are opened. Due to such a force distribution, the workpiece 200 moves so as to escape upward, so that a slight gap is formed between the bottom surface of the workpiece 200 and the stage surface 10a.

  Here, in the machine vise 100 according to the present invention, both the first base 22 of the fixed base portion 20 and the second base 32 of the movable base portion 30 are in contact with the stage surface 10 a of the base portion 11 of the main body frame 10. It can move in the direction. Specifically, the first fixing screw 23 can be moved downward by tightening the first fixing screw 23 so that the first fixing screw 23 is further inserted into the female screw portion 26. As described above, the neck portion 23 c of the first fixing screw 23 is engaged with the engaging portion 22 e of the first base 22. Therefore, as the first fixing screw 23 is moved downward, the first base 22 can also be moved downward (in a direction approaching the stage surface 10a). Similarly, the second fixing screw 33 is further tightened so that the second fixing screw 33 is further inserted into the female screw portion 36, whereby the second fixing screw 33 is moved downward and the second base screw 33 is moved downward. 32 can be moved downward (toward the stage surface 10a).

  As described above, when a strong fastening force is applied to the workpiece 200 by driving the motor 42 so that the movable cap portion 30 moves toward the fixed cap portion 20, the workpiece 200 escapes upward. Thus, a slight gap is formed between the bottom surface of the workpiece 200 and the stage surface 10a. At this time, by tightening the first fixing screw 23 and the second fixing screw 33, as shown in FIG. 5, the first base 22 and the second base 32 can be moved in a direction approaching the stage surface 10a. The workpiece 200 can be easily seated on the stage surface 10a. Here, generally, when the workpiece 200 is fastened with a strong force, a slight gap generated between the bottom surface of the workpiece 200 and the stage surface 10a is about 10 μm to several tens of μm. In order to eliminate this gap and seat the workpiece 200, the first fixing screw 23 and the second fixing screw 33 may be rotated by about 30 ° to 360 ° and tightened.

  When the work 200 is seated according to the above-described procedure, as shown in FIG. 6, when the inventor measures the lifting of the work 200 using the displacement sensor 210, the lifting of the work 200 may be detected. could not. From this, it was found that when the workpiece 200 is seated according to the above-described procedure, the lift of the workpiece 200 from the stage surface 10a is at least 5 μm or less.

  As described above, in the fixed base portion 20, the insertion hole for inserting the first fixing screw 23 and the female screw portion 26, which are formed by combining the upper portion of the hole 22d and the hole 25, Both are formed so as to be accurately perpendicular to the stage surface 10 a of the base 11, and are formed so that the first base guide groove 24 is accurately perpendicular to the stage surface 10 a of the base 11. Has been. Accordingly, the holding surface 22c of the first base 22 and the stage surface 10a of the base 11 are kept vertical, and the position of the holding surface 22c of the first base 22 in the longitudinal direction of the base 11 is not changed. The first base 22 can be moved toward the stage surface 10 a of the base 11. Thereby, the workpiece | work 200 can be seated, keeping the position regarding the longitudinal direction of the base 11 of the 1st workpiece | work contact surface 200a of the workpiece | work 200 constant. As described above, even when the workpiece 200 is seated, the position of the first workpiece contact surface 200a of the workpiece 200 in the longitudinal direction of the base portion 11 is not changed, so that this position is used as the origin in the subsequent processing. can do.

  Furthermore, as described above, the insertion hole for inserting the second fixing screw 33 and the female screw portion 36 formed by combining the upper portion of the hole 32d and the hole 35 are both of the base portion 11. The second base guide groove 34 is formed so as to be inclined at the same angle from the vertical with respect to the stage surface 10 a of the base 11. Further, the insertion hole for inserting the second fixing screw 33 and the female screw portion 36 are not formed in parallel to the surface direction of the holding surface 32c, and are only the same angle (about 5 °) as the above angle. It is formed to tilt. Accordingly, the second base 32 can be moved toward the stage surface 10 a of the base 11 while keeping the holding surface 32 c of the second base 32 and the stage surface 10 a of the base 11 vertical. At this time, the holding surface 32c of the second base 32 moves in a direction approaching the fixed base 20 with respect to the longitudinal direction of the base 11, so that the work 200 is seated while further tightening the fastening force applied to the work 200. Can do. Incidentally, the insertion hole for inserting the first fixing screw 23, the female screw portion 26, and the first base guide groove 24 of the fixed base portion 20 are the stage surface of the base portion 11, similarly to the movable base portion 30. When it is formed to be inclined with respect to 10a, even when the first fixing screw 23 is tightened in order to move the first base 22 toward the stage surface 10a, a stronger fastening force is applied to the workpiece 200. Will be given. According to the knowledge of the present inventor, in such a case, the fastening force applied to the work 200 becomes too strong, and the first base 22 and / or the second base 32 until the work 200 is seated on the stage surface 10a. It has been found that it may not be possible to move down. Therefore, at least one of the first and second caps is formed so as to accurately move vertically with respect to the stage surface.

  In this way, a simple operation of turning the first and second fixing screws 23 and 33 by a predetermined angle after applying a strong fastening force with the workpiece 200 sandwiched between the fixed base part 20 and the movable base part 30. Therefore, since the workpiece 200 can be easily seated, a high skill of a skilled worker as in the prior art is not required in the workpiece seating confirmation step and the workpiece seating step. Therefore, even a person who does not have sufficient skills, such as an apprentice or a part-time worker, can easily seat the work appropriately. Previously, the work to be processed was placed on the vise and the work was automated until the work was fastened to the vise. At that time, the process of removing the work lift and seating the work It was not possible to automate the process, and a process was required in which a skilled worker hits and sits the workpiece. On the other hand, when the machine vice 100 according to the present invention is used, the operation of turning the first and second fixing screws 23 and 33 by a predetermined angle can be easily automated. There is an advantage that a series of steps of placing the workpiece, fastening the workpiece to the vise, seating the workpiece, and then processing the workpiece can be automated.

  The vise as the workpiece clamping mechanism according to the present invention is not limited to the above-described single-clamp machine vise 100, and for example, the following modifications can be added. The vice of the present invention is not limited to a single-clamp type vise, and may be a double-clamp type vise. In this case, it may replace with the above-mentioned fixed base part, and the two movable base parts arrange | positioned facing may be provided. Furthermore, three or more movable base parts may be provided. For example, three movable base parts may be provided every 120 °, and four movable base parts may be provided every 90 °.

  Further, in the movable base part 30 of the machine vise 100 described above, the insertion hole for inserting the second fixing screw 33 and the female screw part 36 formed by combining the upper part of the hole 32d and the hole 35 are: Both are formed so as to be inclined by about 5 ° from the vertical with respect to the stage surface 10a of the base 11, and the second cap guide groove 34 is also inclined by the same angle from the vertical with respect to the stage surface 10a of the base 11. Was formed. These inclination angles are not limited to 5 °, and may be, for example, 0 ° to 15 °, and more preferably about 3 ° to 7 °. When the angle of inclination is 0 °, the holding surface 32c of the second base 32 is moved in the direction approaching the fixed base portion 20 with respect to the longitudinal direction of the base portion 11 as described above, and the workpiece 200 is moved. Although the applied fastening force cannot be further increased, the effect that the workpiece 200 can be properly seated can be obtained.

  In the above description, the holding surface 22c of the first base 22 and the holding surface 32c of the second base 32 are both formed as flat surfaces without irregularities. This is effective, for example, when sandwiching the rectangular parallelepiped workpiece 200 because the area that contacts the side surface of the workpiece 200 becomes wide. However, the holding surfaces 22c and 32c do not necessarily have to be flat. For example, the holding surfaces 22c and 32c may be provided with irregularities such as grooves for preventing slipping. Furthermore, the shapes of the holding surfaces 22c and 32c of the first and second caps 22 and 32 can be arbitrarily changed according to the shape of the workpiece. For example, when sandwiching a cylindrical workpiece, as shown in FIG. 7, instead of the first base 22 described above, a first base 122 whose holding surface 122c has a substantially V-shaped shape is used. It may be used. The same applies to the second base 32.

  In the above description, the guide groove 13 in which the shaft 43 of the drive unit 40 is disposed is formed in the main body frame 10, and the hole through which the shaft 43 is inserted is formed in the movable base 30. The movable base portion 30 has moved along the shaft 43 inside the guide groove 13, but the present invention is not limited to this. As long as the movable base 30 is formed to be slidable on the stage surface 10a of the frame 10, any configuration can be adopted.

  In the above description, the lower surface or lower end of the workpiece 200 is in contact with the stage surface 10a of the base 11 of the main body frame 10. However, the present invention is not limited to this, for example, in the case of holding a workpiece having a low height. Alternatively, a stage with an appropriate height may be placed on the stage surface 10a, and the workpiece may be placed on the stage.

  In the above description, the workpiece 200 is seated by turning the first and second fixing screws 23 and 33 by a predetermined angle, but the present invention is not limited to this. For example, the workpiece holding mechanism according to the present invention includes a seating confirmation mechanism for confirming whether the workpiece 200 is seated, thereby confirming that the workpiece 200 is seated while monitoring whether the workpiece 200 is seated. The first and second fixing screws 22 and 23 may be turned until it is done. As an example of the seating confirmation mechanism, for example, a gas injection unit 303 including a gas flow path including the nozzle 301 for injecting the gas 302 from the stage surface 10a toward the lower surface of the workpiece 200, and a change in the flow rate of the gas 302 Or a seating confirmation mechanism 310 including a detector 304 that detects a change in gas pressure. Here, as shown in FIG. 8A, a nozzle 301 is formed at a position on the stage surface 10 a of the base 11 where the workpiece 200 is placed, and a gas 302 such as air is ejected from the nozzle 301. Is done. Here, when the workpiece 200 is seated, the nozzle 301 is blocked by the workpiece 200, so that the gas 302 is not injected from the nozzle 301. On the other hand, when the workpiece 200 is not seated and a gap is formed between the lower surface of the workpiece 200 and the stage surface 10a, the nozzle 301 is moved by the workpiece 200 as shown in FIG. Since it is not blocked, the gas 302 is injected from the nozzle 301. At this time, it is confirmed whether or not the workpiece 200 is seated on the stage surface 10a by detecting a change in the flow rate of the gas 302 ejected from the nozzle 301 or a change in the gas pressure using an appropriate detector 304. can do. As described above, the gas injection unit 303 including the gas flow path including the nozzle 301 for injecting the gas 302 from the stage surface 10a toward the lower surface of the workpiece 200, the change in the flow rate of the gas 302, or the gas pressure. Confirming whether or not the workpiece 200 is seated on the stage surface 10a using the seating confirmation mechanism 310 provided with the detector 304 that detects a change in the position of the workpiece 200 is performed as described above. It is very effective when automating.

  In the above-described machine vise 100, the movable base part 30 is driven by the motor 42 provided in the drive part 40. However, the present invention is not limited to this, and for example, a handle for hand turning is provided instead of the motor 42. It is provided and the shaft 43 may be rotated manually. Alternatively, instead of moving the movable base 30 by the rotational force applied to the shaft 43, for example, the movable base 30 is directed to the fixed base using a hydraulic drive mechanism or a gas pressure drive mechanism (for example, a cylinder). May be moved. Further, in the machine vise 100 described above, the first base 22 and the second base 32 are moved in a direction approaching the stage surface 10a of the main body frame 10 by the first fixing screw 23 and the second fixing screw 33, respectively. However, the present invention is not limited to this, and the first base 22 and the second base 32 may be moved using, for example, a hydraulic drive mechanism or a gas pressure drive mechanism (for example, a cylinder).

  In the above description, the base portion 11 of the main body frame 10 is provided with the attachment portion 12 for attachment to a machining stage of a machine tool such as a machining center, but the present invention is not limited to this. For example, as shown in FIG. 9, an operation panel 401, a tool magazine 402 on which a plurality of cutting tools for processing a workpiece are mounted, a cutting tool included in the tool magazine 402 is attached, and the workpiece is moved by rotating the cutting tool. In a machining center 400 provided with a spindle 403 for processing and a pallet 404 as a processing stage on which a work is fixed, the work holding apparatus according to the present invention may be integrated into the pallet 404. Specifically, as shown in FIG. 9, the upper surface 404 a of the pallet 404 is a stage surface on which a workpiece is placed, and the same configuration as described above is provided at one end of the groove 404 b formed in the pallet 404. The fixed base part 20 having the same configuration as that described above is disposed on the other end side, and the movable base part 30 is disposed on the movable base support member 41 of the drive part 40. Good.

  In addition, the machine tool incorporating the workpiece holding apparatus according to the present invention is not limited to the machining center, and may be a milling machine, a drilling machine, a planer, or the like.

  By using the workpiece clamping device of the present invention, it is not necessary for a skilled worker having a high skill to strike a workpiece and perform seating confirmation, so that the workpiece seating confirmation process can be easily automated. As a result, it is possible to automate all the series of steps of fixing and fastening the workpiece on the work stage, confirming the seating of the workpiece, and then processing the workpiece.

DESCRIPTION OF SYMBOLS 10 Main body frame 10a Stage surface 11 Base 13 Guide groove 20 Fixed base part 21 1st base support part 22 1st base 23 First fixing screw 30 Movable base part 31 2nd base support part 32 2nd base 33 Second fixed screw 40 Drive unit 100 Machine vice 200 Workpiece

Claims (8)

A workpiece clamping mechanism for clamping a workpiece,
A body frame having a stage on which a stage surface on which the workpiece is placed is formed;
A first base part protruding from the stage surface of the stage, the first base having a first contact surface that contacts the workpiece, and the first base is slid in a direction perpendicular to the stage surface A first base supporting portion that supports the first base, and a first base pressing portion that presses the first base supported by the first base supporting portion in a direction perpendicular to the stage surface in a direction approaching the stage surface. A first base part having,
A second base part that protrudes from the stage surface of the stage and moves in a direction of separating from and coming into contact with the first base part in the surface direction of the stage surface, is in contact with the workpiece and is opposed to the first contact surface A second base having a second abutting surface formed thereon, a second base supporting portion that supports the second base slidably in an intersecting direction intersecting the stage surface, and a second base supporting portion. A second base part having a second base pressing part that presses the second base in the crossing direction so as to approach the stage surface;
A workpiece holding mechanism including a drive unit that drives the second base support part of the second base part in a direction to approach the first base part. The stage of the main body stage is formed with a groove extending in a first direction from the first base part toward the second base part,
The drive unit includes a shaft disposed in the groove, a second base support member that moves in the first direction along the shaft, and the second base support part of the second base part is fixed; The work clamping mechanism according to claim 1, further comprising a drive mechanism that drives the second base support member in a direction to approach the first base portion along the shaft. A thread groove is formed on the outer peripheral surface of the shaft,
The base support member is formed with a screw hole in which a screw groove is formed to be fitted into a screw groove formed in the shaft while the shaft is inserted therethrough,
The workpiece holding mechanism according to claim 2, wherein the drive mechanism is a motor or a handle that rotates the shaft. The first and second cap pressing portions are first and second fixing screws having neck portions that are partially reduced in diameter,
Semi-cylindrical grooves on which the first and second fixing screws are disposed are formed on the surfaces of the first and second caps on the opposite sides of the first and second contact surfaces, respectively. A projection that engages with the neck is formed inside,
Each of the first and second base support portions cooperates with the semi-cylindrical groove to form a semi-cylindrical groove that defines a hole for arranging the first and second fixing screws, and the first and second The workpiece clamping mechanism according to any one of claims 1 to 3, wherein a female screw portion to be fitted to the two fixing screws is formed.   The work clamping mechanism according to any one of claims 1 to 4, wherein the first base support portion of the first base portion is fixed to the main body frame.   The workpiece according to any one of claims 1 to 5, wherein the intersecting direction is inclined with respect to a direction perpendicular to the stage surface so as to approach the first base portion as the stage surface is approached. Nipping mechanism. A machine tool for machining a workpiece,
A pallet having a surface to which the workpiece is fixed, which is provided integrally with the workpiece clamping mechanism according to claim 1;
A cutting tool for machining a workpiece;
A spindle for attaching the cutting tool to the tip, and a spindle for rotating the cutting tool;
A machine tool comprising a pallet moving mechanism for moving the pallet relative to the spindle to which the blade is attached. The cutting tool is a plurality of cutting tools,
The machine tool according to claim 7, wherein the machine tool is a machining center including a tool magazine that accommodates the plurality of cutting tools.

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