Laser machining apparatus

A laser machining apparatus includes a chuck configured to hold a workpiece such that the workpiece is rotatable about a rotational axis, a first workpiece support provided on a first side with respect to the chuck in an axial direction along the rotational axis and configured to support a projected workpiece projecting from the chuck on the first side, and a parts catcher configured to receive a product when the projected workpiece is not supported by the first workpiece support and convey the product to a loading dock. The parts catcher includes a first catcher workpiece support configured to support the projected workpiece. In the axial direction, a first distance between the first catcher workpiece support and the chuck is shorter than a second distance between the first workpiece support and the chuck.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U. S. C. § 119 to Japanese Patent Application No. 2021-029401, filed Feb. 26, 2021. The contents of this application are incorporated herein by reference in its entirety.

BACKGROUND

Technical Field

The present specification relates to a laser machining apparatus.

Background Art

Japanese Patent No. 6,741,447 describes a laser machining apparatus including a workpiece shooter. The workpiece shooter is movable between a laser machining position and a standby position, and moves to the laser machining position to receive a short product to be laser-machined when a short workpiece is machined.

SUMMARY OF THE INVENTION

According to one aspect of the present disclosure, a laser machining apparatus includes a chuck, a first workpiece support, a laser machining head, and a parts catcher. The chuck is configured to hold a workpiece such that the workpiece is rotatable about a rotational axis. The first workpiece support is provided on a first side with respect to the chuck in an axial direction along the rotational axis, and is configured to support a projected workpiece which is a workpiece protruding from the chuck on the first side. The laser machining head is provided on the first side and is configured to machine the projected workpiece with laser beam to manufacture a product. The parts catcher is configured to receive the product when the projected workpiece is not supported by the first workpiece support and convey the product to the loading dock. The parts catcher includes a first catcher workpiece support configured to support the projected workpiece. In the axial direction, a first distance between the first catcher workpiece support and the chuck is shorter than a second distance between the first workpiece support and the chuck.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof. In the drawings, the same reference numerals denote corresponding or substantially identical components.

Embodiment

<Configuration of Laser Processing Machine1>

FIG. 1shows an external configuration diagram of a laser machining apparatus1according to an embodiment of the present invention. The laser machining apparatus1includes a bed10, a chuck12, a laser machining head14, a first workpiece support16, a second workpiece support17, an additional workpiece support19, a headstock20, a spindle22, an additional chuck24, a steady rest26, and a parts catcher30. The chuck12is configured to hold the workpiece W such that the workpiece W is rotatable about the rotational axis Ax. The workpiece W is also held by an additional chuck24provided on the spindle22. One end of the workpiece W is attached to the spindle22via the additional chuck24, and the spindle22is configured to rotate around the rotational axis Ax together with the workpiece W. That is, the additional chuck24is configured to rotate around the rotational axis Ax together with the spindle22. The headstock20supports a spindle22rotatably around a rotational axis Ax. The headstock20is provided at one end of the bed10. The headstock20is movable in the axial direction Dx along the rotational axis Ax by being guided by a rail (not shown) provided on the bed10. The spindle22and the additional chuck24are movable in the axial direction Dx together with the headstock20. The steady rest26is configured to rotatably support the workpiece W around the rotational axis Ax between the chuck12and the additional chuck24in the axial direction Dx. The headstock20, spindle22, additional chuck24and steady rest26are provided on a second side S2that is opposite to a first side S1shown with respect to the chuck12. The laser machining apparatus1may not include the steady rest26.

The workpiece W is held by the chuck12so as to pass through the chuck12. The workpiece W is pushed out from the chuck12in the forward direction Df by the headstock20moving in the forward direction Df from the headstock20toward the chuck12in the axial direction Dx. As the workpiece W is rotated by the spindle22, the machining surface of the projected workpiece PW projecting from the chuck12is directed toward the laser machining head14. The laser machining head14is provided on a first side S1with respect to the chuck12in the axial direction Dx, and is configured to machine a projected workpiece PW with laser beam to produce a product. As shown by dotted line inFIG. 1, the laser machining head14can be oriented to a direction inclined from the vertical direction Dv toward the axial direction Dx. Note that the vertical direction Dv refers to a direction of gravity or a bilateral direction opposite thereto. The vertical direction Dv substantially coincides with a height direction Dh along the height of the laser machining apparatus1.FIG. 1illustrates an example in which the laser machining head14is oriented to a direction inclined from the vertical direction Dv to the forward direction Df, but the laser machining head14may be oriented to a direction inclined from the vertical direction Dv to the rearward direction Dr opposite to the forward direction Df. The laser machining head14may be orientable to a direction inclined from the vertical direction Dv toward the width direction Dw perpendicular to both the axial direction Dx and the vertical direction Dv.

The first workpiece support16and the second workpiece support17are provided on the first side S1described above. The first workpiece support16is configured to support the projected workpiece PW in a case where the length L in the axial direction Dx of the projected workpiece PW projecting from the chuck12on the first side S1is longer than the distance (threshold distance DTH) in the axial direction Dx between the first workpiece support16and the chuck12. In the following embodiments, the threshold distance DTH may be referred to as a second distance D2. The second workpiece support17is provided between the first workpiece support16and the chuck12in the axial direction Dx. The second workpiece support17is configured to support the projected workpiece PW on the first side S1. The first workpiece support16and the second workpiece support17are preferably rollers. The first workpiece support16and the second workpiece support17can rotate counterclockwise inFIG. 1to discharge the product processed by the laser machining head14in the forward direction Df. The laser machining apparatus1may further include an additional workpiece support19for supporting the long projected workpiece PW. The additional workpiece support19is also preferably a roller for convenience of discharge of the projected workpiece PW. However, the first workpiece support16, the second workpiece support17, and the additional workpiece support19may be plate-shaped members.

The parts catcher30is configured to receive the product in a case where the projected workpiece PW is not supported by the first workpiece support16. The parts catcher30is movable to a standby position, a machining position, and a discharge position.FIGS. 2 to 4are a top view, a front view, and a right-side view of the parts catcher30when the parts catcher30is in the machining position, respectively.FIG. 1also shows the parts catcher30located at the machining position. InFIGS. 2 to 4, the projected workpiece PW and the chuck12are indicated by dotted lines.FIG. 4is a side view of the parts catcher30when viewed from the chuck12in the forward direction Df.

Referring toFIGS. 1 to 4, the parts catcher30includes a first catcher workpiece support41and a second catcher workpiece support42configured to support the projected workpiece PW. The second catcher workpiece support42is provided between the first catcher workpiece support41and the chuck12in the axial direction Dx. Further, the parts catcher30may include a third catcher workpiece support43configured to support the elongated projected workpiece PW. InFIGS. 2 to 4, the projected workpiece PW is supported by a first catcher workpiece support41, a second catcher workpiece support42, and a third catcher workpiece support43. Thus, when the parts catcher30moves to the machining position, the projected workpiece PW is supported by the first catcher workpiece support41.

As shown inFIG. 1, a first distance D1between the first catcher workpiece support41and the chuck12in the axial direction Dx is shorter than a second distance D2between the first workpiece support16and the chuck12in the axial direction Dx. Thus, a short member (a projected workpiece PW) that cannot be supported by the first workpiece support16can be supported by the first catcher workpiece support41. Referring toFIGS. 1 to 3, a third distance D3between the second catcher workpiece support42and the chuck12in the axial direction Dx is shorter than a fourth distance D4between the second workpiece support17and the chuck12in the axial direction Dx. Thus, a short member (the projected workpiece PW) that cannot be supported by the second workpiece support17can be supported by the second catcher workpiece support42. The first catcher workpiece support41, the second catcher workpiece support42, and the third catcher workpiece support43have the same configuration. The first catcher workpiece support41, the second catcher workpiece support42, and the third catcher workpiece support43are collectively referred to as a catcher workpiece support40.

Referring toFIGS. 2 to 4, the parts catcher30is connected to the catcher driving unit28. As shown inFIG. 4, the catcher driving unit28can drive the parts catcher30in a width direction Dw. By being driven by the catcher driving unit28, the parts catcher30moves to any one of the standby position, the machining position, and the discharge position. The catcher driving unit28drives the parts catcher30by an actuator such as a rack and pinion or a hydraulic cylinder. Since the configuration of the catcher driving unit28is well known, a detailed description thereof will be omitted. The parts catcher30further includes a catcher body32and a base34. The catcher body32has a pan-like shape and is configured to receive a product. The catcher body32is made of a plate material containing copper. Specifically, the surface of the catcher body32is made of a stainless steel material, and the inside of the catcher body32is made of a copper plate. Since copper is not easily melted by the laser, the durability of the catcher body32is maintained even when the catcher body32is brought close to the laser in order to support the projected workpiece PW.

The base34is provided on the catcher body32and stands upright from the catcher body32.FIG. 5is a perspective view of the parts catcher30. Referring toFIGS. 4 and 5, the base34includes a bottom wall35, a side wall36, a top wall37, and a bank38. The bottom wall35is connected to the catcher body32. The side wall36connects the bottom wall35and the top wall37. The top wall37faces the bottom wall35in the height direction Dh (vertical direction Dv). The bank38is provided on the top wall37on the side opposite to the portion connected to the side wall36. An angle α formed by the side wall36and the bottom wall35is substantially a right angle. An angle β formed by the side wall36and the top wall37is an obtuse angle. The shape of the base34when the base34is viewed in the axial direction Dx is described later with reference toFIG. 10.

The catcher workpiece support40includes a support component50and an attachment45. Referring toFIGS. 2, 4, and 5, the support component50is a replaceable plate-shaped member having a support surface SS corresponding to the side surface shape of the projected workpiece PW. The support component50is replaced with one that matches the shape of the workpiece W. InFIG. 5, a portion hidden by the support component50is indicated by a dotted line so that the shape of the attachment45can be understood. Referring toFIGS. 3 and 5, the attachment45is provided on the base34and the support component50can be attached to the attachment45. More specifically, the attachment45includes a mounting portion46, a guide47, and a support portion48. The mounting portion46of the attachment45is attached to the side wall36of the base34by a bolt BT1. Note that the attachment by a bolt BT1is an example, and the attachment45may be attached to the base34by other methods such as welding or the like. The guide47is formed by an L-shaped steel. When attaching the support component50to the attachment45, the support component50can be aligned by matching the corners of the support component50to the corners of the L-shaped steel. The support portion48is a plate-like member attached to the L-shaped steel, and has an attachment hole for attaching the support component50to the bolt BT2. A portion of the support component50that has the attachment hole and is in contact with the support portion48is referred to as an attaching part51. Note that the attachment by the bolt BT2is an example, and the attaching part51may be attached to the support portion48by other methods such as a hook. The support portion48supports the support component50when the support component50is attached to the attachment45. As shown inFIG. 3, the support component50is inclined so as to approach the catcher body32as the support component approaches the chuck12in the axial direction Dx. This makes it easier for the projected workpiece PW to run onto the support surface SS of the support component50.

When the projected workpiece PW is supported by the first workpiece support16, the parts catcher30moves to the standby position.FIG. 6is a top view of the parts catcher30when the parts catcher30is in the standby position.FIG. 7is a right-side view of the parts catcher30when the parts catcher30is at the standby position. As shown inFIGS. 6 and 7, when the parts catcher30moves to the standby position, the parts catcher30does not overlap the projected workpiece PW in a top view. Therefore, in a case where the projected workpiece PW is supported by the first workpiece support16, the parts catcher30does not interfere with the projected workpiece PW.

The parts catcher30is configured to convey the product PRO, which is the projected workpiece PW machined by the laser machining head14, to the loading dock29. The position of the parts catcher30when the product PRO is conveyed to the loading dock29is referred to as a discharge position.FIG. 8is a right-side view of the parts catcher30when the parts catcher30is at the discharge position. Here, the posture taken by the parts catcher30inFIG. 4 or 7, that is, the posture in which the parts catcher30is in a case where the projected workpiece PW is supported by the first catcher workpiece support41is referred to as a first posture. InFIG. 8, the posture in which the parts catcher30is, that is, the second posture in which the parts catcher30is when the product PRO is discharged at the loading dock29is referred to as a second posture. As shown inFIGS. 4, 7, and 8, a posture of the parts catcher30is changeable from the first posture to the second posture.

FIG. 9is a diagram illustrating a relationship between a first posture and a second posture.FIG. 9shows only the base34and the support component50of the parts catcher30, and the base34and the support component50in the first posture are shown by solid lines, and the base34and the support component50in the second posture are shown by dotted lines. Referring toFIG. 9, the second posture is a posture obtained by rotating the first attitude about an additional rotational axis Ax substantially parallel to the rotational axis Ax by a first acute angle θ.FIG. 10is a view illustrating the base34and the support component50when the parts catcher30ofFIG. 9takes the first posture. Referring toFIG. 10, when the parts catcher30is in the first posture and supports the projected workpiece PW, the support surface SS viewed in the axial direction Dx includes a bottom portion SS1, a first ridge portion SS2, and a second ridge portion SS3.

The bottom portion SS1intersects with a first reference plane RP1that includes a central axis Cx of the projected workpiece PW substantially coincident with the rotational axis Ax and extends in the vertical direction Dv when the projected workpiece PW is machined by the laser machining head14. The first ridge portion SS2is provided on a third side S3spreading from the first reference plane RP1in the discharge direction Ddis along the rotation direction Drot of the first acute angle θ, and bulges upward from the bottom portion SS1in the height direction Dh along the height of the laser machining apparatus1. The discharge direction Ddis is along a movement direction Dm in which the parts catcher30moves from the standby position toward the machining position. The second ridge portion SS3is provided on a fourth side S4opposite to the third side S3with respect to the first reference plane RP1, and bulges upward from the bottom portion SS1. When viewed in the axial direction Dx, the upper end UE1of the first ridge portion SS2in the height direction Dh is provided below the upper end UE2of the second ridge portion SS3in the height direction Dh. With such a configuration, not only is the projected workpiece PW correctly positioned in the width direction Dw by the first ridge portion SS2and the second ridge portion SS3, but the first ridge portion SS2does not interfere when the product PRO is discharged.

The upper end UE2of the second ridge portion SS3is located above the central axis Cx of the projected workpiece PW. Accordingly, when the product PRO is discharged, the second ridge portion SS3presses the product PRO in the discharge direction Ddis, and thus the catcher workpiece support40facilitates the discharge of the product PRO. The base34is provided on the catcher body32such that the base34is positioned on the fourth side S4when the parts catcher30is in the first posture and supports the projected workpiece PW. With this configuration, the catcher body32does not interfere with the discharge of the product PRO. As shown inFIGS. 6 and 7, since the standby position is located at the fourth side S4, the base34does not collide with the projected workpiece PW when the parts catcher30moves from the standby position toward the machining position.

The support surface SS has a first extending portion S S4extending from the first ridge portion SS2such that the first extending portion SS4is inclined to the movement direction Dm and to a downward direction of the height direction Dh. More specifically, the first extending portion SS4is formed such that the distal end DE1of the first extending portion SS4in the movement direction Dm is positioned further in the movement direction Dm than the distal end DE2of the guide47(attachment45) in the movement direction Dm and the distal end DE3of the attaching part51in the movement direction Dm. With such a configuration, when the parts catcher30moves from the standby position toward the machining position, the projected workpiece PW easily rides on the support surface SS. Note that the first extending portion SS4may be omitted.

When the support surface SS is viewed in the axial direction Dx, the curve representing the support surface SS includes an arc ARC passing through the bottom portion SS1. The curvature radius R of the arc ARC is greater than or equal to the distance D between the rotational axis Ax and the bottom portion SS1when the projected workpiece PW is machined by the laser machining head14. With such a configuration, the support surface SS can support the workpiece W having a round pipe shape. Even if the projected workpiece PW is the square bar PW′ as indicated by the two-dot chain line inFIG. 10, when the maximum distance between the square bar PW′ and the rotational axis Ax is the distance D, the square bar PW′ can be processed while being rotated.

FIG. 11is a view illustrating the base34and the support component50when the parts catcher30ofFIG. 9takes the second posture. Referring toFIG. 11, when the workpiece W is a round pipe material or a round bar material and the parts catcher30takes the second posture, the support surface SS is formed so as to satisfy the following conditions (1) to (3).

(1) The support surface SS contacts the projected workpiece PW (product PRO) at at least one connection point CP.

(2) When viewed in the axial direction Dx, all of the at least one connection point CP is located on a sixth side S6opposite to a fifth side S5with respect to the second reference plane RP2, the fifth side S5spreading from the second reference plane RP2in the discharge direction Ddis, the second reference plane RP2extending in the vertical direction Dv and includes the central axis Cx of the projected workpiece (product PRO).
(3) The support surface SS is inclined downward from the lowest point BCP of the at least one connection point CP as the support surface SS is separated from the lowest point BCP in the discharge direction Ddis. Since the support surface SS is formed as described above, the product PRO smoothly falls into the loading dock29when the parts catcher30is in the second posture.

Next, the planar shape of the support component50will be described. As described above with reference toFIG. 3, the support component50is inclined so as to approach the catcher body32toward the chuck12in the axial direction Dx.FIG. 12is a diagram schematically illustrating the support component50from the side.FIG. 13is a plan view of the support component50. As shown inFIG. 12, it is assumed that the support component50is inclined by an angle φ with respect to the vertical direction Dv. At this time, when viewed from a direction perpendicular to the support component50, the circular arc ARC having the radius of curvature R shown inFIG. 10is stretched into an elliptical arc ARC′ having a minor axis radius R and a major axis radius R (cos φ)−1as shown inFIG. 13.

<Effect of the Embodiment>

In the method described in Japanese Patent No. 6,741,447, since the short workpiece is supported in a cantilever state by the chuck, there is a problem in that the workpiece is bent by its own weight, and thus it is difficult to perform highly accurate machining. In particular, there has been a problem that accuracy is lowered due to the influence of deflection in oblique machining in which a workpiece is machined in a state where the laser machining head is obliquely inclined.

In the laser machining apparatus1of the present embodiment, the parts catcher30includes the first catcher workpiece support41(catcher workpiece support40) in addition to the first workpiece support16. Since the projected workpiece PW of the workpiece W, which is short, is supported by the first catcher workpiece support41(catcher workpiece support40), the projected workpiece PW can be accurately machined.

The catcher workpiece support40is not limited to the above-described con figuration.FIGS. 14 and 15show modifications of the catcher workpiece support40.

FIG. 14shows the catcher workpiece support40arealized by rollers. In the catcher workpiece support40a, the width Wf of the groove supporting the projected workpiece PW is uniform around the rotational axis Axr.FIG. 15shows the catcher work piece support40brealized by a special roller which changes the width Wv of the groove supporting the projected workpiece PW when rotated around the rotational axis Axr. The roller shown inFIG. 15can be adjusted to the width Wv of the groove corresponding to the shape of the projected workpiece PW to be supported. Both the catcher workpiece support40aand the catcher workpiece support40bprovide the same effects as those of the above embodiment.

In this application, “comprise” and its derivatives are open-ended terms that specify the presence of stated elements but do not preclude the presence of other unstated elements. This also applies to “having”, “including” and their derivatives.

The phrases “member”, “part”, “element”, “body” and ““structure” may have a plurality of meanings such as a single portion or a plurality of portions.

Ordinal numbers such as “first” and “second” are merely terms for identifying structures and do not have other meanings (e.g., a specific order). For example, the presence of a “first element” does not imply the presence of a “second element”, and the presence of a “second element” does not imply the presence of a “first element”.

Words such as “substantially,” “about,” and “approximately,” which represent degrees, can mean a reasonable amount of deviation such that the end result is not significantly changed, unless the embodiment is specifically described. All numerical values recited herein can be interpreted to include such terms as “substantially,” “about,” and “approximately.”

The phrase “at least one of A and B” in this application should be interpreted to include only A, only B, and both A and B.