JP2005342829A - Deep hole machining device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten machining time when machining a deep hole on a machining surface of workpiece, and to improve accuracy of the deep hole. <P>SOLUTION: After making a bush 102 of a guide member 76 abut on the machining surface 122 for machining the deep hole of the workpiece 16, a drill 74 is inserted in the bush 102 made from super hard material. Thereby, a pair of guide portions 89a, 89b formed on an outer peripheral surface of the drill 74 holds the drill 74 in an axial direction by the bush 102. Therefore, the drill 74 rotating under driving action of a rotation driving source is displaced toward the workpiece 16, thereby forming the deep hole 17 with predetermined depth on the workpiece 16 through the guide member 76 abutting on the workpiece 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a deep hole machining apparatus capable of machining a deep hole in a workpiece by a drilling tool that is rotationally driven, such as a drill, and a machining method therefor.

  2. Description of the Related Art Conventionally, there is known a processing apparatus that performs drilling of a predetermined depth on a workpiece by a drilling tool that is rotationally driven, such as a drill. In recent years, in order to reduce the size of various products, it has been required to reduce the size of each component constituting the product. Therefore, the hole machining performed on these workpieces also reduces the size of the component. Along with this, there are many small diameters and deep holes, and high accuracy is required. For this reason, the tool of the processing apparatus which processes a deep hole to such a workpiece | work is formed in elongate along a small diameter and a longitudinal direction according to the desired hole shape processed into a workpiece | work.

  And, when processing a deep hole in the workpiece through the tool, if the surface of the workpiece is a material surface not subjected to the surface processing of the casting, or the surface of the workpiece is inclined by a predetermined angle, In some cases, the hole machining applied to the workpiece is an oblique hole. In such a case, when the rotationally driven tool is displaced toward the workpiece and brought into contact with the surface of the workpiece, the tip of the tool is displaced with respect to the workpiece, and the workpiece formed by the tool is moved. There exists a problem that the position of a deep hole will shift | deviate from a desired position.

  In order to solve such problems, conventionally, the material surface of the casting is removed by forming a counterbore hole having a plane perpendicular to the axis of the tool by a counterbore process or the like in advance on the surface of the workpiece, Next, a guide hole for guiding a long tool is formed to a predetermined depth with respect to the counterbore hole, and then a deep hole is formed with respect to the workpiece through the counterbore hole and the guide hole with the long tool. A processing apparatus and a processing method for processing are known. As a result, the tool is brought into contact with the surface of the work without being displaced, and deep hole machining is performed at a desired position of the work by the tool.

  However, in the above-described processing apparatus and processing method, when a deep hole processing is performed on a workpiece, a step of forming counterbore holes and guide holes on the surface of the workpiece is required, which increases the processing steps. The machining time of the workpiece becomes longer. At the same time, it is necessary to prepare separate tools according to each machining operation such as counterbore formation and guide hole formation, so that the cost required for each tool increases.

  In order to solve these problems, a guide means that is freely displaced toward the surface of the workpiece is provided, and after the guide means is brought into contact with the surface of the workpiece, a long tool is inserted through the guide means. Then, it is displaced toward the workpiece and brought into contact with the surface. A processing device is known that performs deep hole processing at a desired position of the workpiece by further displacing the tool that contacts the surface of the workpiece under the guide action of the guide means toward the workpiece (for example, patents). Reference 1 and 2).

  In such a processing apparatus, since the tool slip is prevented by the guide means when the tip of the tool comes into contact with the surface of the workpiece, a counterbore hole, a guide hole, etc. when performing deep hole machining on the workpiece This pre-processing step is unnecessary.

Japanese Utility Model Publication No. 60-37212 JP 2002-331401 A

  By the way, in the prior art which concerns on patent document 1 and 2, the tool for processing a deep hole in a workpiece | work is formed in elongate according to the depth of the deep hole formed in the said workpiece | work. For this reason, there is a problem that radial deflection occurs at the tip of the tool inserted through the guide means, and the deep hole position and deep hole shape of the workpiece formed by the tool are not stable.

  The present invention has been made in consideration of the above-described problems, and it is possible to improve the productivity by reducing the processing time when forming a deep hole in a workpiece and improve the accuracy of the deep hole. An object of the present invention is to provide a possible deep hole machining apparatus and a machining method thereof.

In order to achieve the above object, the present invention provides a deep hole machining apparatus for forming a deep hole in a workpiece via a drilling tool that is rotationally driven under a driving action by a drive source.
A groove portion extending along the axial direction is formed, and has a pair of guide portions extending in a radially outward direction from the outer peripheral surface of the shaft portion where the groove portion is formed, and with respect to the workpiece A drilling tool that can be freely approached and separated;
A hole portion through which the drilling tool is inserted is formed and a holding member made of a super hard material or a high hardness material is provided, and the drilling tool is held displaceably along the axial direction via the holding member. A guide mechanism;
A displacement mechanism for displacing the guide mechanism in a direction approaching / separating from the workpiece and bringing the holding member into contact with a processing surface of the workpiece;
With
When the drilling tool is inserted into the hole of the holding member, the guide portion of the drilling tool is guided in contact with the inner peripheral surface of the hole of the holding member in the axial direction. It is characterized by being displaced along.

  According to the present invention, when the deep hole is formed in the work surface of the workpiece, the guide mechanism having the holding member is displaced toward the workpiece, and the holding member made of a high hardness material or a super hard material is processed into the workpiece. After making contact with the surface, the drilling tool to be rotationally driven is displaced toward the workpiece and inserted into the hole of the holding member. At that time, a set of guide portions formed on the outer peripheral surface of the drilling tool comes into contact with the inner peripheral surface of the hole of the holding member, so that the drilling tool inserted through the holding member in the radial direction is inserted. Displacement (runout) is suppressed.

  Accordingly, when the drilling tool comes into contact with the machining surface of the workpiece via the holding member, the position accuracy of the drilling tool with respect to the machining surface can be improved, and the workpiece can be removed by the drilling tool penetrating the holding member. Even when deep hole drilling is performed, the drilling tool is held by the hole of the holding member so as to be displaceable in the axial direction, so that displacement of the drilling tool in the radial direction during deep hole drilling is suppressed. Is done.

  Therefore, when the drilling tool passes through the hole of the holding member, the straightness of the drilling tool with respect to the workpiece is preferably maintained, and the holding tool is maintained even when the drilling tool comes into contact with the workpiece. The drilling tool is not displaced with respect to the work surface of the workpiece under the guide action of the member and the guide portion, and the deep hole can always be reliably machined at a desired position with respect to the workpiece.

  In addition, since the holding member of the guide mechanism is brought into contact with the processing surface of the workpiece, and a deep hole can be machined into the workpiece by a drilling tool under the guide action of the holding member, As compared with the conventional machining process in which a deep hole is machined after a counterbore hole or the like is formed in advance, the machining process for machining the deep hole can be shortened.

  Further, the holding member may be formed of a cylindrical bush, and the inner peripheral diameter of the hole formed in the bush and the outer peripheral diameter of the guide part in the drilling tool may be formed substantially equal. Thus, when the drilling tool is inserted through the hole of the bush, the guide part of the drilling tool comes into contact with the inner peripheral surface of the hole of the bush and is securely held.

  Furthermore, the drilling tool may be a twist drill having a spiral groove.

  Still further, in the twist drill, the inclination angle of the groove with respect to the axis of the twist drill may be set within a range of 27 to 33 °. Thereby, when deep hole processing is performed on the workpiece by the twist drill, it is possible to improve the dischargeability of the chips discharged from the workpiece to the outside through the groove portion of the twist drill.

  Moreover, by setting the length along the axial direction of the twist drill to be 35 times or more the diameter of the twist drill, it is possible to achieve a workpiece that can be machined by a deep hole machining apparatus as compared with the conventional one. The depth of the deep hole can be increased.

Further, the drilling tool has a passage through which a lubricant and a pressure fluid circulate when performing deep hole machining on the workpiece,
An injection hole that communicates with the passage and opens at an end face facing the workpiece;
With
When deep hole machining is performed on the workpiece via the drilling tool, the lubricant supplied via the passage is mixed with the pressure fluid, and the workpiece and the drilling are performed via the injection hole. It is good to inject between the end surfaces of the tool.

  That is, the lubricant mixed with the pressure fluid is injected between the workpiece and the drilling tool from the injection hole through the passage in the drilling tool, thereby forming a deep hole in the workpiece by the drilling tool. Lubrication and cooling between the drilling tool and the workpiece can be performed.

  Thereby, when deep hole machining is performed on the workpiece, the lubricant used when machining the deep hole is compared with the case where the lubricant is always supplied from the outside of the drilling tool. The amount can be suppressed. For this reason, it is possible to reduce the cost of the lubricant required when processing the deep hole of the workpiece.

Furthermore, the present invention relates to a deep hole machining method in which a deep hole is formed in a workpiece through a drilling tool that is rotationally driven under a drive action by a drive source.
Bringing the holding member of the guide mechanism for guiding the drilling tool into contact with the work surface of the workpiece on which the deep hole is formed under the displacement action by the displacement mechanism;
A step of displacing the drilling tool provided so as to be able to approach / separate with respect to the workpiece toward the machining surface of the workpiece, and inserting the tool along the hole of the holding member;
A pair of guide portions formed so as to protrude radially outward from the outer peripheral surface of the drilling tool penetrates the hole portion while being in contact with and guided by the inner peripheral surface of the hole portion. Forming a deep hole in the machining surface of the workpiece by the drilling tool,
It is characterized by having.

  According to the present invention, after the holding member made of a high hardness material or a super hard material in the guide mechanism is brought into contact with the work surface of the workpiece via the displacement mechanism, the drilling tool to be rotated is moved to the work surface of the work. Is inserted through the hole of the holding member that is in contact with the. At that time, the drilling tool is displaced toward the workpiece in a state where a pair of guide portions formed on the outer peripheral surface of the drilling tool is in contact with the inner peripheral surface of the hole. Thereby, since the set of guide portions provided in the drilling tool is held by the inner peripheral surface of the hole in the holding member, the drilling tool is suitably guided along the axial direction. be able to.

  Therefore, after the holding member of the guide mechanism is brought into contact with the machining surface of the workpiece, the straightness of the drilling tool with respect to the workpiece is preferably maintained by inserting the drilling tool through the hole of the holding member. When the drilling tool comes into contact with the workpiece, the drilling tool penetrating through the hole of the holding member is displaced with respect to the work surface of the workpiece under the guide action by the hole of the holding member. However, the deep hole can always be reliably processed at a desired position with respect to the workpiece.

  Further, since the holding member of the guide mechanism is brought into contact with the processing surface of the workpiece, and a deep hole can be machined into the workpiece by a drilling tool under the guide action of the holding member, As compared with the conventional machining process in which a deep hole is machined after a counterbore hole or the like is formed in advance, the machining process for machining the deep hole can be shortened.

  According to the present invention, the following effects can be obtained.

  That is, after the holding member constituting the guide mechanism is displaced toward the workpiece, the holding member is brought into contact with the machining surface of the workpiece, and then a drilling tool having a pair of guide portions on the outer peripheral surface is inserted into the holding member. The guide part is held by the inner peripheral surface of the hole part by being inserted along the hole part. As a result, the deflection of the drilling tool in the radial direction is suppressed, the straightness of the drilling tool is suitably maintained, and the workpiece is processed when the drilling tool comes into contact with the workpiece by the holding member. Since the position does not shift with respect to the surface, the deep hole can always be processed at a desired position with respect to the workpiece.

  Further, since a deep hole can be machined in the workpiece through a drilling tool under the guide action of a holding member brought into contact with the workpiece machining surface, a counterbore hole or the like is previously formed on the workpiece. Compared with the conventional machining process in which the deep hole is machined after forming, the deep hole machining process can be shortened.

  A preferred embodiment of the deep hole machining method according to the present invention will be described below in detail with reference to the accompanying drawings, taking a preferred embodiment in relation to a deep hole machining apparatus for carrying out the machining method. Here, a case will be described in which a crankshaft employed in an engine of an automobile or the like is a workpiece, and a deep hole that functions as an oil hole is machined in the crankshaft.

  In FIG. 1, reference numeral 10 indicates a deep hole machining apparatus according to an embodiment of the present invention.

  The deep hole machining apparatus 10 (hereinafter simply referred to as the machining apparatus 10) is fixed to an upper portion of a base (not shown) installed on a floor surface (not shown) as shown in FIGS. Yes. And the processing apparatus 10 is provided in the upper part of the base (not shown), The 1st displacement mechanism 12 which reciprocates linearly with respect to the said base in the X-axis direction (arrow X direction), and said 1st A second displacement mechanism 14 is provided above the first displacement mechanism 12 and linearly reciprocates in the X-axis direction (arrow X direction) with respect to the first displacement mechanism 12, and above the second displacement mechanism 14. And a machining unit 20 having a machining portion 18 for machining the deep hole 17 in the workpiece 16.

  Further, between the upper surface of the base and the first displacement mechanism 12, the machining unit 20 reciprocates linearly in the Y-axis direction (see FIG. 3) substantially orthogonal to the axis (X-axis) of the machining unit 20. A Y-axis displacement mechanism 22 for displacement is provided. A workpiece holding mechanism (not shown) for holding the workpiece 16 (see FIG. 2) is provided at a position facing the processing portion 18 on the side of the base (not shown).

  The first displacement mechanism 12 is provided on the upper part of the Y-axis displacement mechanism 22, and a first drive source 24 that is rotationally driven by an electric current, and a guide that is formed on the upper part of the base under the drive action of the first drive source 24. The first slider 28 reciprocates along the rail 26 and a support member 30 provided on the lower surface side of the first slider 28 facing the guide rail 26. Then, when a current is supplied to the first drive source 24, the first slider 28 reciprocates linearly along the guide rail 26 via the support member 30 under the drive action of the first drive source 24. .

  The second displacement mechanism 14 includes an elongated base member 32, a second slider 34 that is displaceable along the axial direction (arrow X direction) of the base member 32, and one end of the base member 32. The second drive source 36 is mounted on the unit and is rotationally driven by an electric current to displace the second slider 34, and a conversion mechanism 38 that converts the rotational drive force of the second drive source 36 into a linear motion.

  The base member 32 is formed in a hollow shape and is fixed to the upper surface of the first slider 28 in the first displacement mechanism 12. The first slider 28 is integrally displaced along the X-axis direction (arrow X direction) under the displacement action of the first slider 28. In addition, a guide rail 40 that protrudes from the both side surfaces by a predetermined length extends along the axial direction (in the direction of the arrow X) on the upper portion of the base member 32, and the guide rail 40 extends from above the base member 32. The second slider 34 is engaged and freely displaced along the guide rail 40.

  The conversion mechanism 38 includes a screw shaft 44 connected to the drive shaft of the second drive source 36 attached to the base member 32, and a displacement member 46 screwed to the screw shaft 44. Screws are engraved on the outer peripheral surface of the screw shaft 44, and both ends thereof are rotatably supported by both side walls of the base member 32.

  The displacement member 46 is provided so as to be displaceable along the axial direction (arrow X direction) of the screw shaft 44 under the rotational action of the screw shaft 44, and the displacement in the rotational direction is restricted by a restriction means (not shown). . Therefore, even when the displacement member 46 is displaced along the axial direction (arrow X direction) under the rotational action of the screw shaft 44, the displacement member 46 is not rotationally displaced integrally with the screw shaft 44. Further, the displacement member 46 is formed with a flange whose diameter is increased outward in the radial direction, and is connected to the end surface of the second slider 34 via the flange.

  That is, when a current is supplied to the second drive source 36, the screw shaft 44 connected to the drive shaft rotates, and the displacement member 46 screwed to the screw shaft 44 guides integrally with the second slider 34. It is displaced along the direction of arrow X along the rail 40. In other words, the rotational driving force transmitted from the second drive source 36 to the screw shaft 44 is converted into a linear motion of the second slider 34 relative to the base member 32 via the displacement member 46.

  The processing unit 20 is displaced along the arrow X direction (X-axis direction) integrally with the second displacement mechanism 14 under the displacement action by the first displacement mechanism 12, and further under the displacement action by the second displacement mechanism 14. Further, the second displacement mechanism 14 is displaced integrally with the second slider 34 along the arrow X direction (X-axis direction). In addition, a Y-axis displacement mechanism 22 that can be displaced in a direction (arrow Y direction in FIG. 3) substantially orthogonal to the arrow X direction (X-axis direction) in which the first and second displacement mechanisms 12 and 14 are displaced. The processing unit 20 is displaced in the Y-axis direction (arrow Y direction).

  Therefore, the first and second displacement mechanisms 12, 14 and the Y-axis displacement mechanism 22 depend on the shape of the workpiece 16 held by the workpiece holding mechanism and the desired part where the deep hole 17 is to be processed in the workpiece 16. Thus, the processing unit 20 can be freely displaced along the XY plane.

  The machining unit 20 includes a main body 50 fixed to the upper surface of the second slider 34 of the second displacement mechanism 14 and a workpiece 16 (via a first shaft 52 rotatably held in the main body 50. 2), a processing unit 18 that processes the deep hole 17, a drive unit 56 that rotationally drives the processing unit 18 with an electric current, and a lubricant that supplies lubricant (for example, cutting oil) to the processing unit 18. A supply unit 58 and a chip box 60 that stores chips discharged when the workpiece 16 is processed into the deep hole 17 by the processing unit 18 are provided.

  The main body 50 is formed in a hollow shape, and a cylindrical first shaft 52 is rotatably held via a set of through holes (not shown) formed in the side wall thereof.

  A plate member 62 is mounted above the main body 50 so as to close the opened opening, and a rotational drive source 68 of the drive unit 56 is fixed to the upper surface of the plate member 62 via an adapter 64. ing. Since the main body 50 is fixed to the upper surface of the second slider 34 of the second displacement mechanism 14, the main body 50 is subjected to a displacement action in the X-axis direction along the guide rail 40 of the base member 32 of the second slider 34. It is displaced integrally.

  Further, an intrusion prevention cover 70 a is attached to one side surface of the main body 50 so as to be stretchable along the X-axis direction (arrow X direction) between the side surface of the chip box 60 and the other side of the main body portion 50. Similarly, an approach prevention cover 70b is mounted on the side surface so as to be extendable in the X-axis direction (arrow X direction) between the outer peripheral surface of the second drive source 36. The intrusion prevention covers 70a and 70b are formed such that a plurality of members are overlapped. When the main body 50 is displaced along the base member 32, the ingress prevention covers 70a and 70b are moved along with the displacement of the main body 50. 70b expands and contracts. That is, since the upper surface of the base member 32 is always covered by the intrusion prevention covers 70a and 70b, the chips generated from the workpiece 16 when the machining portion 18 processes the deep hole 17 to the workpiece 16, It is possible to prevent the second displacement mechanism 14 from entering the second slider 34, the guide rail 40, and the like.

  The processing unit 18 includes a long first shaft 52 that is rotatably held by the main body 50, a long second shaft 72 that is coupled to one end of the first shaft 52, and the second shaft 72. A drill (drilling tool) 74 that drills the deep hole 17 in the workpiece 16 and a guide member 76 that guides the displacement along the axial direction of the drill 74.

  As shown in FIG. 3, the first shaft 52 is formed in a hollow shape, and a first supply passage 78 passes through the substantially central portion along the axial direction. A hollow second shaft 72 is connected to one end of the first shaft 52 via a connection flange 80 by a bolt, and is formed along the axial direction at a substantially central portion of the second shaft 72. The second supply passage 82 communicates with the first supply passage 78 of the first shaft 52. Then, the lubricant is supplied to the second supply passage 82 of the second shaft 72 from the lubricant supply portion 58 attached to the other end portion of the first shaft 52 via the first supply passage 78.

  Further, the second shaft 72 is formed so that a mounting hole 84 in which a drill 74 is mounted is opened on the other end side opposite to the one end side connected to the first shaft 52, and the mounting hole 84 communicates with the second supply passage 82.

  The drill 74 is composed of, for example, a twist drill having a twist groove (groove portion) 85 (see FIG. 5) for discharging chips, and the drill 74 is fitted into the mounting hole 84 of the second shaft 72. A shaft portion 87 connected to the driver portion 86, having the twist groove 85 and extending in a straight line along the axial direction, and a processing surface of the workpiece 16 formed on the tip portion of the shaft portion 87. A cutting edge portion 90 for cutting 122 and two oil passages (passages) 92 (see FIG. 6) penetrating the shaft portion 87 and the inside of the driver portion 86 are included.

  The length L (see FIG. 4) along the axial direction of the shaft portion 87 is such that the ratio (L / D) to the outer peripheral diameter (diameter) D of the shaft portion 87 is 35 or more (L / D> 35). It is formed so as to be long. In other words, the length L of the shaft portion 87 is formed to be not less than 35 times the diameter D of the shaft portion 87 (L> 35D). Conventionally, a twist drill for processing a deep hole generally employs a ratio of the length L to the diameter D of 30 (L / D <30) or less.

  Further, as shown in FIGS. 4 and 5, the twisted groove 85 is formed in a spiral shape indented radially inward from the outer peripheral surface 87 a of the shaft portion 87, and along the twisted groove 85 in the outer peripheral surface 87 a. A pair of guide portions 89 a and 89 b are formed at the end portion so as to protrude slightly outward in the radial direction from the outer peripheral surface 87 a of the shaft portion 87. In other words, as shown in FIG. 4, since the outer peripheral surface 87a of the shaft portion 87 is formed in a spiral shape along the torsion groove 85, the guide portions 89a and 89b formed along the outer peripheral surface 87a. Is also formed in a spiral shape. The guide portions 89a and 89b are formed so that the outer diameters thereof are substantially constant, and the widths thereof are also substantially constant (see FIG. 5).

  Further, the two oil passages 92 communicate with the second supply passage 82 of the second shaft 72 through the mounting hole 84 in which the driver portion 86 is fitted, and the shaft portion 87 made of super hard material has a work piece. A cutting edge portion 90 is formed to face 16 (see FIG. 8). An oil hole (injection hole) 94 communicating with the oil passage 92 is formed in the cutting edge 90, and when forming the deep hole 17, lubricant and compressed air are passed from the oil hole 94 through the oil passage 92. Are sprayed to the outside in the state of being mixed. The compressed air is supplied to the oil passage 92 from an air supply source (not shown) communicating with the first and second supply passages 78 and 82.

  As shown in FIGS. 4 and 5, a chisel portion 91 that protrudes toward the workpiece 16 to be cut is formed at the substantially central portion of the cutting edge portion 90, and the chisel portion 91 faces the driver portion 86. It is formed so as to be inclined at a predetermined angle.

  As shown in FIG. 6, the drill 74 composed of the twist drill is set so that the twist angle θ representing the angle of the twist groove 85 with respect to the axis B is within a range of 27 ° to 33 °. Thereby, it becomes possible to improve the discharge property of the chips discharged from the twist groove 85 in the drill 74 to the outside. The twist angle θ is more preferably set to 30 °.

  The drill 74 is not limited to the above-described twist drill, and as shown in FIGS. 10 to 12, a gun drill in which a V-shaped groove 124 along the axial direction is formed on the outer peripheral surface as a drill 74a. May be adopted.

  The drill 74a made of this gun drill has a driver portion 86 fitted in the mounting hole 84 of the second shaft 72, and is respectively attached to the outer peripheral surface of the shank portion 88 connected to the driver portion 86 and the shaft portion 87b made of cemented carbide. This is different from the drill 74 in that the V-shaped groove 124 is formed to extend. Further, an oil hole 94a communicating with the oil passage 92a is formed in the cutting edge portion 90a formed at the tip of the shaft portion 87b and facing the workpiece 16, and is lubricated from the oil hole 94a when the deep hole 17 is formed. In a state where the agent and the compressed air are mixed, the mist is sprayed to the outside.

  On the other hand, the guide member 76 is formed in a cylindrical shape, and is connected to the end of the cover member 96 that is inserted into the insertion hole 114 b on the side wall of the chip box 60 via the flange portion 101.

  A guide hole 100 into which the shaft portion 87 of the drill 74 can be inserted is formed inside the guide member 76, and the guide hole 100 is gradually moved away from the cover member 96 (X1 direction in FIG. 3). It is formed so as to be reduced in diameter.

  Further, a cylindrical bush (holding member) 102 is fitted to one end of the guide member 76 facing the workpiece 16 through the guide hole 100. The bush 102 is fitted so as to protrude from the end face of the guide member 76 by a predetermined length (see FIG. 6). Thereby, when the guide member 76 is displaced toward the workpiece 16 and is brought into contact with the machining surface 122 of the workpiece 16, only the end surface of the bush 102 can be brought into contact with the machining surface 122. The guide member 76 including the bush 102 functions as a guide mechanism.

  The bush 102 is formed of a high hardness material or a super hard material having a hardness capable of cutting a non-worked material, and an inner peripheral diameter of a bush hole (hole portion) 102a (see FIG. 6) formed therein is as follows. It is formed to be slightly larger than the outer diameter (diameter) of the guide portions 89a and 89b formed on the shaft portion 87 of the drill 74, and a clearance 126 (see FIG. 5) is formed between the bush hole 102a and the guide portions 89a and 89b of the shaft portion 87. 5 and FIG. 6). The clearance 126 is formed to be about 20 to 30 μm in the radial direction, for example.

  As a result, when the shaft portion 87 constituting the drill 74 is swung in the radial direction while being inserted into the bush 102, the guide portions 89 a and 89 b of the shaft portion 87 are inserted into the bush hole 102 a in the bush 102. Contact with the peripheral surface via the clearance 126 prevents the deflection in the radial direction. In other words, as shown in FIG. 5, the guide portions 89 a and 89 b are formed so as to extend along the spiral outer peripheral surface 87 a of the drill 74, and thus the guide portions 89 a and 89 b and the bush 102 are formed. Are always in contact at four points spaced apart by a predetermined distance along the circumferential direction of the shaft portion 87.

  For this reason, when the shaft portion 87 of the drill 74 is inserted into the bush 102 and displaced along the axial direction, the displacement of the long drill 74 in the radial direction is changed via the guide portions 89a and 89b. It is suppressed by the bush 102, and the straightness of the drill 74 can be suitably maintained.

  At this time, since the bush 102 is formed of a high hardness material or a super hard material, it is possible to suppress wear under the contact action with the drills 74 and 74a and to prevent a decrease in durability of the bush 102. can do.

  Similarly, the inner peripheral diameter of the bush hole 102 a in the bush 102 is formed to be substantially equal to the inner peripheral diameter of a portion adjacent to the bush 102 in the guide hole 100. Thereby, when the drills 74 and 74a are inserted into the guide holes 100 of the guide member 76 under the displacement action along the axial direction (arrow X direction) of the processed portion 18, the distal ends of the long drills 74 and 74a are inserted. Even when the drill is bent in the radial direction, the tip ends of the drills 74 and 74a are guided to the substantially central portion of the guide hole 100 along the inner peripheral surface of the guide hole 100 that gradually decreases in diameter. The drills 74 and 74 a are reliably guided to the inside of the bush 102 by the guide hole 100 formed substantially equal to the inner peripheral diameter of the bush hole 102 a of 102.

  Further, as the length of the bush 102 along the axial direction (arrow X direction) becomes longer, the straightness of the drills 74 and 74a can be further stabilized, but the drills 74 and 74a are formed. When considering the dischargeability of the chips discharged from the workpiece 16 into the cover member 96 through the twisted groove 85 or the groove 124, the shorter length along the axial direction of the bush 102 is It excels in the dischargeability of the chips.

  For this reason, the length A along the axial direction (arrow X direction) of the bush 102 is such that the straightness in the axial direction of the drills 74 and 74a and the dischargeability of chips discharged through the drills 74 and 74a. Is set to a predetermined length based on the balance between

  The drive unit 56 includes a rotation drive source 68 composed of a motor or the like, and a power transmission belt 106 that transmits the drive force from the rotation drive source 68 to the first shaft 52 held by the main body unit 50. A disk-like drive pulley 108 is provided on the drive shaft of the rotation drive source 68, and a disk-like driven pulley 110 is similarly provided at one end of the first shaft 52. A power transmission belt 106 is suspended between the driving pulley 108 and the driven pulley 110, and the driving force of the rotational driving source 68 is transmitted from the driving pulley 108 to the driven pulley 110 via the power transmission belt 106. As a result, the second shaft 72 and the drill 74 are rotationally driven via the first shaft 52.

  The power transmission belt 106, the drive pulley 108, and the driven pulley 110 are disposed inside a box-shaped casing 112 fixed to the side wall of the main body 50.

  The chip box 60 is formed in a box shape, and is connected to the other end side of the base member 32 facing a workpiece holding mechanism (not shown). Further, insertion holes 114 a and 114 b are formed in the side wall of the chip box 60 facing the second shaft 72, respectively.

  A cylindrical holding member 116 is attached to one insertion hole 114 a formed on one side wall on the main body 50 side of the chip box 60, and the workpiece 16 is moved under the displacement action of the second displacement mechanism 14. When the second shaft 72 passes through the inside of the holding member 116, the second shaft 72 is held rotatably.

  A cylindrical cover member 96 is inserted in the other insertion hole 114b formed in the other side wall of the chip box 60 facing the workpiece 16 so as to be displaceable along the axial direction (arrow X direction). .

  The cover member 96 is formed in a substantially conical shape having a diameter gradually reduced from one end side attached to the chip box 60 toward the other end side, and a holding plate 118a is engaged with a substantially central portion thereof. The guide member 76 is connected to the distal end portion via a bolt 117.

  When the second shaft 72 is displaced in a direction (arrow X1 direction) approaching the workpiece 16 under the displacement action of the second displacement mechanism 14, the inside of the chip box 60 is inserted into the cover member 96. The second shaft 72 and the drill 74 are inserted.

  The holding plate 118a is connected to one end side of a plurality of connecting shafts 120 that pass through the inside of the chip box 60. The other end side of the connecting shaft 120 is provided on the other side wall side of the chip box. The holding plate 118b is connected.

  A driving mechanism (not shown) is provided inside the chip box 60 to integrally displace the cover member 96 along the axial direction (arrow X direction) via the holding plate 118a. Accordingly, the cover member 96 and the guide member 76 engaged with the holding plate 118 are integrally displaced along the X-axis direction (arrow X direction) under the displacement action by the drive mechanism.

  The deep hole machining apparatus 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and effects thereof will be described. In addition, the case where the crankshaft used as the workpiece | work 16 is previously hold | maintained at the side part of the processing apparatus 10 with the workpiece | work holding mechanism (not shown) is demonstrated. A case where a drill 74 made of a twist drill is employed in the machining unit 20 will be described.

  First, the first and second displacement mechanisms 12, 14 and the machining unit 20 are integrally displaced in the Y-axis direction (the arrow Y direction in FIG. 3) by the Y-axis displacement mechanism 22 provided on the upper surface of the base (not shown). The machining unit 18 in the machining unit 20 is displaced so as to face the position where the desired deep hole 17 is formed in the workpiece 16.

  Next, as shown in FIG. 1, the first slider 28 is displaced in the direction approaching the work 16 (see FIG. 2) (in the direction of the arrow X1) under the driving action of the first driving source 24. The second displacement mechanism 14 and the processing unit 20 are displaced integrally with the first slider 28. Then, a separation distance between the workpiece 16 and the machining unit 20 is detected by a detection means (not shown), and the current supplied to the first drive source 24 is stopped when the separation distance is set in advance.

  As a result, the displacement of the first slider 28 in the direction of the arrow X1 stops, and the processing unit 20 stops in a state of being separated from the workpiece 16 by a predetermined interval. That is, the guide member 76 in the machining unit 20 is in a state of facing the machining surface 122 of the workpiece 16 on which the deep hole 17 is machined with a predetermined distance.

  Next, the cover member 96 inserted into the insertion hole 114b of the chip box 60 is displaced in a direction approaching the workpiece 16 (arrow X1 direction) by a driving mechanism (not shown) provided in the chip box 60. The bush 102 of the guide member 76 connected to the cover member 96 is brought into contact with the machining surface 122 of the workpiece 16 (see FIG. 7). At this time, as shown in FIG. 7, the machining surface 122 of the workpiece 16 and the axis B of the machining unit 20 including the guide member 76 are set to be orthogonal to each other in advance. In other words, since the processing surface 122 of the workpiece 16 and the end surface of the bush 102 are set to be parallel, the entire end surface of the bush 102 is in contact with the processing surface 122 of the workpiece 16.

  Then, after the bush 102 of the guide member 76 is brought into contact with the machining surface 122 of the workpiece 16, as shown in FIGS. 1 and 2, a current from a power source (not shown) is supplied to the rotational drive source 68 of the drive unit 56. By being supplied, the rotational driving source 68 is rotationally driven, and the driving force is transmitted from the driven pulley 110 to the first shaft 52 via the driving pulley 108 and the power transmission belt 106.

  As a result, the first shaft 52 is rotationally driven while being held by the main body 50, and accordingly, the second shaft 72 and the drill 74 connected to the first shaft 52 are rotationally driven integrally.

  By supplying a current from a power source (not shown) to the second drive source 36, the screw shaft 44 rotates integrally under the driving action of the second drive source 36, and the displacement member is screwed to the screw shaft 44. 46 is displaced along the axial direction in a direction approaching the workpiece 16 (arrow X1 direction).

  Thereby, the processing unit 20 is displaced toward the workpiece 16 under the displacement action of the second slider 34 connected to the displacement member 46. At that time, the rotation speed of the drill 74 is set to about 4500 rpm, and the displacement speed when the drill 74 is displaced toward the workpiece 16 in the X-axis direction (arrow X direction) is 675 to 1350 mm / It is set to min.

  Next, after the second shaft 72 and the drill 74 are inserted through the inside of the holding member 116 attached to the chip box 60, the second shaft 72 and the drill 74 are inserted into the cover member 96 through the chip box 60, The second shaft 72 is rotatably supported by the inner peripheral surface of the holding member 116. The drill 74 inserted into the cover member 96 is displaced along the inner peripheral surface of the guide hole 100 of the guide member 76 and inserted into the bush hole 102 a of the bush 102.

  At that time, since the drill 74 is formed to be elongated along the axial direction and is driven to rotate, the vicinity of the distal end portion of the shaft portion 87 is bent by a predetermined amount radially outward with the driver portion 86 as a fulcrum. It is in a state of standing. Also in this case, the guide portions 89a and 89b formed on the outer peripheral surface 87a of the shaft portion 87 are in contact with the inner peripheral surface of the bush hole 102a of the bush 102 in contact with the machining surface 122 of the workpiece 16, The shaft part 87 can be guided so as to be substantially orthogonal to the machining surface 122 of the workpiece 16 by being supported at four points spaced apart by a predetermined distance along the circumferential direction inside the bush hole 102a.

  Next, the chisel portion 91 of the drill 74 is brought into contact with the machining surface 122 of the workpiece 16, and the drill 74 is displaced toward the workpiece 16 under the driving action of the second drive source 36. The machining surface 122 of the workpiece is cut by the cutting edge portion 90 from the base point, and a deep hole 17 having a predetermined depth is formed in the workpiece 16 (see FIGS. 2 and 9).

  At that time, an oil passage 92 of the drill 74 is supplied from a lubricant supply unit 58 (see FIG. 1) connected to the first shaft 52 and an air supply source (not shown) through first and second supply passages 78 and 82. Lubricant (for example, cutting oil) and compressed air are supplied to the surface, and the lubricant mixed with the compressed air passes from the oil passage 92 to the machining surface 122 of the workpiece 16 facing the drill 74 through the oil hole 94. It is jetted in the form of a mist. As a result, the gap between the drill 74 and the work surface 122 of the work 16 when the deep hole 17 is machined by the cutting edge 90 of the drill 74 is lubricated over a wide range and cooled. The lubricant injected from the oil hole 94 of the drill 74 toward the workpiece 16 is injected by an amount corresponding to the frictional resistance generated between the workpiece 16 and the drill 74.

  Further, chips formed when the workpiece 16 is cut when the deep hole 17 is formed in the workpiece 16 are formed on the second shaft 72 side via a torsion groove 85 formed on the outer peripheral surface of the drill 74 together with the lubricant. The chips fall into the chip box 60 along the inner peripheral surfaces of the guide hole 100 and the cover member 96 inclined downward toward the chip box 60 side, and are accommodated. That is, since the guide hole 100 of the guide member 76 and the inner peripheral surface of the cover member 96 are inclined at a predetermined angle toward the lower side of the chip box 60, the dischargeability of the chips to the chip box 60 is improved. Can be made.

  When the drill 74a made of a gun drill is employed in the processing portion 18, the chips are discharged together with the lubricant into the chip box 60 through the V-shaped groove 124 (see FIGS. 10 and 11). The Therefore, chips generated when the deep hole 17 is processed in the workpiece 16 are prevented from being discharged to the outside of the chip box 60.

  Finally, after the deep hole 17 having a desired depth is formed in the workpiece 16, the polarity of the current supplied from the power source to the second drive source 36 is reversed by a controller (not shown) to On the contrary, the machining unit 20 is displaced through the second slider 34 in the direction away from the workpiece 16 (the direction of the arrow X2), and the drill 74 is detached from the deep hole 17 formed in the workpiece 16 to Processing of the deep hole 17 for the workpiece 16 is completed.

  As described above, in the present embodiment, the processing unit 20 that processes the deep hole 17 in the workpiece 16 includes a guide member that includes the bush 102 that holds the displacement along the axial direction (arrow X direction) of the drill 74. Guide mechanism) 76 is provided. When processing the deep hole 17 in the workpiece 16, the bush 102 made of a high hardness material or a super hard material is brought into contact with the processing surface 122 where the deep hole 17 of the workpiece 16 is formed. A drill 74 is inserted along the hole 102a.

  Thereby, the deep hole 17 can be machined by the drill 74 on the machining surface 122 of the workpiece 16 under the guide action of the bush 102 constituting the guide member 76. Therefore, compared with the conventional machining process in which the deep hole 17 is machined after the counterbore hole and the guide hole are formed in advance on the work, the machining process when machining the deep hole 17 on the work 16 is shortened. can do. Thereby, the improvement of the productivity of the workpiece | work 16 in which the deep hole 17 is processed can be aimed at.

  In addition, it is not necessary to prepare a plurality of different tools such as a conventional counter boring tool, a tool for processing a guide hole, and a tool for processing a deep hole 17. The cost required for the tool can be reduced.

  Further, since the drill 74 is guided by the inner peripheral surface of the bush hole 102a through a pair of guide portions 89a and 89b formed on the outer peripheral surface 87a of the shaft portion 87, the tip of the drill 74 is moved to the workpiece. It is possible to position with high accuracy with respect to 16 desired positions.

  Furthermore, when a deep hole is drilled by the drill 74 that is in contact with the machining surface 122 of the workpiece 16 under the guide action of the bush 102, the shaft portion 87 of the drill 74 may be shaken in the radial direction. The guide portions 89 a and 89 b formed on the outer peripheral surface 87 a of the shaft portion 87 abut against the inner peripheral surface of the bush hole 102 a, thereby preventing the drill 74 from swinging in the radial direction and facing the workpiece 16. Thus, when the drill 74 is displaced, stable straightness is obtained.

  Therefore, since the long drill 74 is guided by the bush hole 102a of the bush 102 of the guide member 76, the drill 74 can be prevented from swinging in the radial direction, and the straightness of the drill 74 can be improved. The drill 74 can form the deep hole 17 surely and with high accuracy in the machining surface 122 of the workpiece 16.

  Furthermore, when the deep hole 17 is processed in the workpiece 16 by the processing unit 18 in which the drill 74a made of a gun drill is used, for example, as compared with the case where the deep hole processing is performed by the drill 74 using a twist drill. Since the gun drill has characteristics suitable for processing the small-diameter deep hole 17, it is possible to form the deep hole 17 with higher accuracy in the work 16, and the depth formed in the work 16 A good finished surface can be obtained in the hole 17.

  Furthermore, a necessary amount of the lubricant mixed in the compressed air from the oil hole 94 of the drill 74 through the first and second shafts 52 and 72 from the lubricant supply unit 58 and the air supply source (not shown). It sprays in the shape of a mist and lubricates and cools the workpiece 16 and the drill 74. Thereby, compared with the case where the deep hole 17 of the workpiece 16 is processed while always supplying only the lubricant from the outside of the drill 74 as in the prior art, it is used when the deep hole 17 is processed. The amount of lubricant to be reduced can be suppressed. Therefore, it is possible to reduce the cost of the lubricant required when processing the deep hole 17 of the workpiece 16, and to suppress the environmental impact that is a concern when the used lubricant is discarded. can do.

It is a partial omission longitudinal cross-sectional view of the deep hole processing apparatus which concerns on this invention, and the deep hole processing apparatus in the processing method. FIG. 2 is a partially omitted vertical cross-sectional view of a deep hole machining apparatus showing a state in which the machining unit of FIG. 1 is displaced toward a workpiece and a drill of the machining unit is inserted through a guide member and a deep hole is formed in the workpiece. . It is an expanded sectional view of the process part vicinity in the process unit of FIG. FIG. 4 is a partially omitted perspective view of the drill in the processing unit of FIG. 3. It is the front view which looked at the drill of FIG. 3 from the chisel part side. FIG. 6 is a partially sectional enlarged side view showing a state where the drill of FIG. 5 is inserted into a bush in the guide member. It is operation | movement explanatory drawing which shows the state which the guide member contact | abutted to the process surface of the workpiece | work which performs deep hole processing. It is operation | movement explanatory drawing which shows the state by which the drill was penetrated inside the bush of the guide member contact | abutted to the process surface of the workpiece | work of FIG. It is operation | movement explanatory drawing which shows the state which forms the deep hole in the said workpiece | work with the drill guided through the guide member contact | abutted to the process surface of the workpiece | work of FIG. FIG. 9 is a partially omitted enlarged longitudinal sectional view showing a state where a gun drill is employed in a drill inserted into the guide member in FIG. 8. It is the front view which looked at the gun drill of FIG. 10 from the chisel part side. It is a partial cross section enlarged side view of the guide member vicinity in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Deep hole processing apparatus 12 ... 1st displacement mechanism 14 ... 2nd displacement mechanism 16 ... Workpiece 17 ... Deep hole 18 ... Processing part 20 ... Processing unit 24 ... 1st drive source 28 ... 1st slider 32 ... Base member 34 ... 2nd slider 50 ... main body 52 ... 1st shaft 56 ... drive part 58 ... lubricant supply part 60 ... tip box 68 ... rotational drive source 72 ... 2nd shaft 74, 74a ... drill 76 ... guide members 87, 87b ... axis Part 89a, 89b ... Guide part 90, 90a ... Cutting edge part 96 ... Cover member 100 ... Guide hole 102 ... Bush 102a ... Bush hole 116 ... Holding member 122 ... Work surface

Claims (7)

In a deep hole machining apparatus that forms a deep hole in a workpiece via a drilling tool that is rotationally driven under the drive action of a drive source,
A groove portion extending along the axial direction is formed, and has a pair of guide portions extending in a radially outward direction from the outer peripheral surface of the shaft portion where the groove portion is formed, and with respect to the workpiece A drilling tool that can be freely approached and separated;
A hole portion through which the drilling tool is inserted is formed and a holding member made of a super hard material or a high hardness material is provided, and the drilling tool is held displaceably along the axial direction via the holding member. A guide mechanism;
A displacement mechanism for displacing the guide mechanism in a direction approaching / separating from the workpiece and bringing the holding member into contact with a processed surface of the workpiece;
With
When the drilling tool is inserted into the hole of the holding member, the guide portion of the drilling tool is guided in contact with the inner peripheral surface of the hole of the holding member in the axial direction. A deep hole drilling device characterized by being displaced along. The apparatus of claim 1.
The holding member is formed of a cylindrical bush, and an inner peripheral diameter of a hole formed inside the bush is formed substantially equal to an outer peripheral diameter of the guide part in the drilling tool. Deep hole processing equipment. The apparatus of claim 1.
The deep hole machining apparatus, wherein the drilling tool is a twist drill having a spiral groove. The apparatus of claim 3.
The deep drilling apparatus, wherein the twist drill has an inclination angle of the groove portion with respect to an axis of the twist drill set in a range of 27 to 33 °. The apparatus of claim 3.
The deep hole machining apparatus, wherein a length along the axial direction of the twist drill is set to be 35 times or more of a diameter of the twist drill. The apparatus of claim 1.
The drilling tool has a passage through which a lubricant and a pressure fluid circulate when performing deep hole machining on the workpiece,
An injection hole that communicates with the passage and opens at an end face facing the workpiece;
With
When deep hole machining is performed on the workpiece through the drilling tool, the lubricant supplied through the passage is mixed with the pressure fluid and the workpiece and the drilling through the injection hole. A deep hole machining apparatus characterized by being sprayed between an end face of a tool for use. In a deep hole machining method for forming a deep hole in a workpiece via a drilling tool that is rotationally driven under the drive action of a drive source,
Bringing the holding member of the guide mechanism for guiding the drilling tool into contact with the work surface of the workpiece on which the deep hole is formed under the displacement action by the displacement mechanism;
A step of displacing the drilling tool provided so as to be able to approach / separate with respect to the workpiece toward the machining surface of the workpiece, and inserting the tool along the hole of the holding member;
A pair of guide portions formed so as to protrude radially outward from the outer peripheral surface of the drilling tool penetrates the hole portion while being in contact with and guided by the inner peripheral surface of the hole portion. Forming a deep hole in the machining surface of the workpiece by the drilling tool,
A deep hole machining method characterized by comprising:

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