JP5411686B2 - Machining tool holder - Google Patents

Description

  The present invention relates to a processing tool holder for holding a processing tool.

  Some machining tool holders are attached to a machine tool including a spindle and a spindle head that rotatably holds the spindle to hold a machining tool. There are various types of machining tools, but machining resistance acts when machining with any machining tool, so if the machining tool holder lacks rigidity, the machining tool will be displaced and vibrated, resulting in reduced machining accuracy. .

  For this reason, in the machining tool holder described in Patent Document 1 below, three support members protrude from the guide member that rotatably supports the machining tool holder toward the spindle head, and abut against the spindle head positioning block. The machining tool holder is supported. These support members have male threaded portions and are screwed into the guide member, and the protruding length of the support member from the guide member is adjusted by adjusting the screwing amount. As a result, in a state where the machining tool holder is held by the main shaft, the three support members abut on the positioning block, and the machining tool holder is supported, thereby improving the rigidity of the machining tool holder and machining accuracy. Is suppressed.

JP 2001-293624 A

However, this machining tool holder still has room for improvement. For example, every time the machine tool to which the processing tool holder is attached is changed, it is necessary for the operator to adjust the protruding length of the support member from the guide member, which is inconvenient.
In view of such circumstances, the present invention has been made to obtain a more practical working tool holder.

  The above problem is that a machining tool holder that holds a machining tool and is attached to a machine tool that includes a spindle that rotates about the spindle axis and a spindle head that rotatably holds the spindle, A rotating shaft that is fixed and rotated by the main shaft, (b) a holder body that is fitted so as to be relatively rotatable with the rotating shaft, and (c) three or more locations around the rotating shaft of the holder body, Three or more support members held so as to be able to advance and retreat including a component in a direction parallel to the spindle axis, abutting on the spindle head in a forward position, and spaced from the spindle head in a retracted position; and (d) them Each of the support members has a second engagement surface that engages with a first engagement surface that is an engagement surface, and is held by the holder body so as to be relatively movable. The second engagement surface and the first engagement surface Each of the support members is advanced and retracted by engagement with the engagement surface. A force in the backward direction applied to the support member in a state including at least three drive members and (e) a drive device for driving the drive members, and at least the support member is in contact with the spindle head Based on the above, the force to move the drive member in a direction allowing the support member to retract is smaller than the frictional force acting between the first engagement surface and the second engagement surface. This is solved by configuring as described above.

Examples of the processing tool include a rotary processing tool and a slotting processing tool. Further, the rotary machining tools include cutting tools and grinding tools.
The support member can be moved back and forth in a direction parallel to the main shaft axis, or can be moved back and forth in a direction inclined with respect to the main shaft axis, for example, a direction parallel to the generatrix of the conical surface with the main shaft axis as the center line. Is also possible.
The first engagement surface and the second engagement surface are, for example, engagement surfaces that engage in such a manner that force in both forward and reverse directions can be transmitted, such as engagement between a T groove and a T-shaped engagement convex portion. However, it is also possible to use an engaging surface that simply abuts. In the latter case, it is desirable to provide a biasing device that biases the support member in the backward direction in order to facilitate handling.

In this machining tool holder, three or more support members abut on the spindle head and support the holder body, but the support member is held by the holder body so as to be able to advance and retreat, and the advance position where it abuts on the spindle head Is automatically determined according to the distance between the holder body and the spindle head in a state where the rotation shaft is fixed to the spindle, and can support the holder body. In the state where the support member is in contact with the spindle head, the support member and the drive member have the first engagement surface and the second engagement surface even if a force in the direction of retracting the support member from the spindle head acts. Is in a deadlock state due to the frictional force between the support member and the support member, the support member will not be retracted no matter how large the force to retract the support member is, and the support member is maintained in a state of supporting the holder body. .
Thus, in the processing tool holder according to the present invention, it is not necessary to adjust the position of the support member, and it is possible to obtain a user-friendly processing tool holder while improving the support rigidity of the rotating shaft by the holder body.
The effect of increasing the rigidity by supporting the holder main body on the support member is that the holder main body is rotatable around an axis extending in a direction intersecting with the axis of the first rotation axis in addition to the rotation axis as the first rotation axis. Can be enjoyed particularly effectively in a processing tool holder (hereinafter referred to as an angle head) including a second rotating shaft held by the shaft and a rotation transmitting device that transmits the rotation of the first rotating shaft to the second rotating shaft. However, even when rotary cutting tools such as face mills, side cutters, and end mills are attached coaxially to the rotary shaft, a large lateral load is applied to the main shaft when heavy cutting is performed. You can enjoy the effect. According to the processing tool holder according to the present invention, it is not necessary to reduce the cutting and feeding of the processing tool to the workpiece in order to suppress the cutting resistance, and it is possible to suppress a decrease in processing efficiency, or These cutting processes can be performed with high accuracy.
When a grinding tool is used as a processing tool, the machining resistance is often smaller than when a cutting tool is used, but grinding may be performed in a state where a considerable grinding resistance acts. In that case, an effect similar to that in the cutting tool can be obtained. Further, in grinding, since high accuracy is usually required, the effect of improving the processing accuracy is great.
In addition, since the frictional force may be reduced by vibration, the drive device is in the direction in which the drive member drives the support member in the forward direction while the support member is in contact with the spindle head. It is desirable to continue to apply the driving force.
Further, the greater the number of support members, the higher the rigidity of the holder body. However, the arrangement of the support members around the rotation axis may be equiangular intervals or unequal angular intervals. For example, the arrangement interval of the support members in the portion opposite to the processing tool holding portion with respect to the rotation axis of the rotation axis (first rotation axis) is made narrower than the equiangular interval. Thereby, the moment which acts on a processing tool holder based on processing resistance can be received firmly.

Aspects of the Invention

  In the following, the invention that is claimed to be claimable in the present application (hereinafter referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, or inventions of different concepts) will be illustrated and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiment, the prior art, and the like. The added aspect and the aspect in which the constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In each of the following items, (1) corresponds to claim 1, (2) corresponds to claim 2, (3) corresponds to claim 3, (6) corresponds to claim 4, (7) corresponds to claim 5 and (9) corresponds to claim 6.

(1) A machining tool holder that is attached to a machine tool having a spindle that rotates about a spindle axis and a spindle head that rotatably holds the spindle, and holds a processing tool,
A rotating shaft fixed to the main shaft and rotated by the main shaft;
A holder body which is fitted so as to be rotatable relative to the rotation shaft;
The holder main body is held at three or more positions around the rotation axis so as to be able to advance and retreat in a forward and backward direction including a component parallel to the spindle axis, abuts on the spindle head in a forward position, and the spindle in a retracted position. Three or more support members spaced from the head;
Each of the support members has a second engagement surface that engages with a first engagement surface that is an engagement surface of each of the support members, and is held by the holder body so as to be relatively movable. Three or more drive members for advancing and retracting each of the support members by engagement with one engagement surface;
A drive device that drives the drive member, and at least the support member is in contact with the spindle head, and the drive member is moved to the support member based on a backward force applied to the support member. The processing is characterized in that the force to move in a direction allowing the retraction of the motor is smaller than the frictional force acting between the first engagement surface and the second engagement surface. Tool holder.
(2) The driving member is a rotating member that can rotate around a rotation axis, the driving device rotates the rotating member, and the support member is in contact with the spindle head. In a state, a plane perpendicular to a straight line connecting the portion of the second engagement surface of the rotation member that contacts the first engagement surface and the rotation axis, the first engagement surface, and the first engagement surface 2. The processing tool holder according to item (1), wherein an angle formed by a tangential plane with respect to a portion that contacts each other with the two engaging surfaces is equal to or less than a friction angle.
If the drive member is a rotating member, the space required for driving the support member can be reduced compared to the case where the drive member is a linear moving member, and the processing tool holder can be configured compactly.
(3) The rotating member is an L-shaped lever having two arms, one arm is engaged with the rear end surface of the support member at the tip, and the other arm is used to drive the driving force of the driving device. The processing tool holder according to item (2).
According to the feature described in this section, the support member and the driving device can be provided in parallel, and it is easy to configure the processing tool holder in a compact manner.
(4) The processing tool holder according to any one of (1) to (3), wherein the driving device includes an actuator that operates by receiving supply of driving energy.
(5) Further, as the rotating shaft is fixed to the main shaft, the first connecting portion which is the connecting portion on the main shaft head side is connected, and the driving energy can be supplied. The machining tool holder according to (4), including two connecting portions.
(6) Furthermore,
The holder main body is held so as to be movable in a direction parallel to the main shaft axis, and as the rotary shaft is fixed to the main shaft, the main shaft of the holder main body is inserted into the positioning recess on the main shaft head side. A positioning pin that determines the relative rotational position with respect to the head;
A biasing device that biases the positioning pin in a forward direction toward the spindle head;
It moves together with the positioning pin, and when the positioning pin is in the forward position, it engages with the rotating shaft side engaging portion that is the engaging portion of the rotating shaft to prevent relative rotation between the rotating shaft and the holder body, After the positioning pin is inserted into the positioning recess, it is separated from the rotating shaft side engaging portion as it is retracted against the biasing force of the biasing device, and the rotating shaft and the holder main body (5) The positioning pin side engaging portion that is in a state allowing relative rotation, and the positioning pin and the spindle head side positioning recess serve as the second connection portion and the first connection portion, respectively. Machining tool holder.
The drive energy may be supplied in the form of an electric current or in the form of a pressure fluid. In the former case, the first and second connection portions are electrical connectors, and in the latter case, fluid connectors are used. In the vicinity of the main shaft and the head of the main shaft, since it is often easy to obtain drive energy in the form of pressure fluid, a fluid connector is generally desirable. The fluid may be liquid or gas.
By preventing relative rotation between the rotating shaft and the holder main body, the phase between the rotating shaft and the holder main body is uniquely determined in a state where the processing tool holder is detached from the machine tool. Thereby, when attaching the processing tool holder to the machine tool, the phases of the rotating shaft and the main shaft, and the holder main body and the main shaft head can be adjusted simultaneously, and the attachment is easy.
The positioning pin, the spindle head side positioning recess, and the first and second connecting portions may be provided separately. If the former also serves as the latter, the machining tool holder can be configured easily and the apparatus cost can be reduced.
(7) The driving device includes an urging device that urges the driving member in a direction to drive the support member in the forward direction, and the actuator is actuated by receiving supply of driving energy. The processing tool holder according to any one of (4) to (6), which is operated against a biasing force of the biasing device.
The support member may be kept in contact with the spindle head by driving the drive member by an actuator, but if an abnormality occurs in the supply of drive energy during machining and the supply is interrupted, the support member There is a risk that the rigidity of the holder main body is lowered away from the spindle head. On the other hand, if the support member is kept in contact with the spindle head based on the urging force of the urging device, it is not necessary to supply driving energy during processing, and the holder is in the event of abnormal driving energy supply. A reduction in rigidity of the main body is avoided.
(8) The actuator according to any one of (4) to (7), wherein the actuator is a fluid pressure cylinder including a linearly moving piston and a cylinder housing in which the piston is slidably accommodated. The described processing tool holder.
(9) Further, according to any one of (1) to (8), further including a machining tool holding unit that holds the machining tool in a state in which a machining resistance in a direction intersecting the spindle axis is applied to the holder body. The described processing tool holder.
When the workpiece is machined by the machining tool held by the machining tool holder, a bending moment acts on the rotating shaft based on the machining resistance, but the holder body supported by the support member is more rigid. Highly supported and processed with high accuracy.
(10) The machining tool holder according to (9), wherein the machining tool holding portion is fixedly provided on the rotating shaft.
The processing tool holding part may be provided integrally with the rotating shaft, or a separate processing tool holding part may be fixed to the rotating shaft.
(11) Furthermore, a second rotating shaft held by the holder body so as to be rotatable around a second rotating shaft axis that intersects the first rotating shaft axis of the rotating shaft as the first rotating shaft;
A rotation transmission device that transmits the rotation of the first rotation shaft to the second rotation shaft, and the processing tool holding portion is fixedly provided on the second rotation shaft. holder.
(12) The rotating shaft includes a connecting portion connected to a draw bar provided in the main shaft and a bottleneck portion held by a tool changing arm, and is automatically attached to the machine tool. Or the processing tool holder in any one of (11) term.
A machining center is an example of the machine tool described in this section.
In a machining center, various machining tools are selectively attached to the spindle, and multiple types of machining are performed. Generally, cutting such as machining using a drill, reamer, tap, etc. is planned. This is a process that has a relatively small resistance and acts symmetrically with the rotation axis of the rotating shaft. A large lateral force (bending moment) is applied to the main shaft as in heavy cutting or cutting with an angle head. In many cases, the supporting rigidity is not given to withstand the machining that is applied or a machining in which a large load in the axial direction of the spindle is applied to the spindle, such as slotting. Therefore, if the machining is performed, the machining accuracy is lowered and the spindle and the spindle bearing may be damaged. Can be performed accurately and without damaging the spindle, etc., so that versatility is improved and the equipment cost can be reduced as compared with the case where a dedicated machine is provided. In particular, since the machining tool holder is easy to use, heavy cutting by a machining center can be easily performed.

It is front sectional drawing which shows the state in which the processing tool holder which is one Embodiment was attached to the machining center. It is a right view which shows the said processing tool holder. It is side surface sectional drawing which shows the support unit of the said processing tool holder. It is a figure explaining the contact angle of the support rod of the said support unit, and an L-shaped lever. It is front sectional drawing which shows the state at the time of the attachment start to the machining center of the said processing tool holder. It is front sectional drawing which shows the state by which the positioning pin of the said processing tool holder was fitted by the positioning recessed part of the spindle head.

  Embodiments of the claimable invention will be described in detail below with reference to the drawings. In addition to the following embodiments, the claimable invention can be implemented in various modifications based on the knowledge of those skilled in the art, including the aspects described in the above [Aspect of the Invention] section. .

  FIG. 1 shows a processing tool holder as one embodiment. The machining tool holder is attached to the machining center and holds the rotary machining tool. The machining center includes a spindle 10 and a spindle head 12. The main shaft 10 is rotatably held by a main shaft head 12 through a bearing 13 in a posture in which the axis thereof is horizontal, and is rotated around a horizontal main shaft axis by a main shaft rotation driving device (not shown). A tapered hole portion 18 whose diameter increases linearly toward the distal end surface 16 side of the main shaft 10 is provided at the distal end portion of the center hole 14 formed in the main shaft 10.

  As shown in FIG. 1, the processing tool holder includes a holder body 20. In the present embodiment, the holder main body 20 is formed by assembling a plurality of members, and functions as an integral holder main body after the assembly. The first main body member 22 and the second main body member 24 are provided. including. The main body members 22 and 24 are positioned by fitting and fixed by a plurality of bolts (not shown). The bolt is a kind of fixing means, and a plurality of members fastened by the bolt can be attached to and detached from each other. The same applies to other bolts described in the following description. The holder body may be composed of a single member.

  As shown in FIG. 1, the main body member 22 is formed with a through hole 28 penetrating parallel to the assembly direction of the main body members 22 and 24 and having a circular cross-sectional shape, and is rotated as a first rotation axis. The shaft 30 is rotatably held via a pair of bearings 32. The rotary shaft 30 is supported by the main body member 22 at one end portion in the axial direction, and the other end portion protrudes from the holder main body 20 to the front side (the side opposite to the main body member 24 side) and the outward flange portion 34. The bottleneck part 36 and the connecting part 38 are provided concentrically. The outward flange portion 34 extends radially outward from a portion adjacent to the portion of the rotating shaft 30 supported by the main body member 22, and is opposed to the front end surface of the main body member 22 with a slight gap. ing. The bottle neck portion 36 is provided on the front side of the outward flange portion 34 and has a smaller diameter than the outward flange portion 34. The connecting portion 38 protrudes from the front end surface 39 of the bottle neck portion 36 and has a smaller diameter than the bottle neck portion 36, and the outer peripheral surface thereof is a tapered outer peripheral surface 40 corresponding to the tapered hole portion 18 of the main shaft 10. Has been.

  As shown in FIG. 1, a through hole 48 orthogonal to the through hole 28 is formed in the main body member 24, and a rotary shaft 50 as a second rotary shaft is connected to the rotary shaft via a pair of bearings 52. It is held so as to be rotatable around an axis perpendicular to the 30 axis. The rotation of the rotation shaft 30 is transmitted to the rotation shaft 50 by the rotation transmission device 56. The rotation transmission device 56 includes bevel gears 58 and 60 which are rotation transmission members attached to the rotation shafts 30 and 50 so as not to rotate relative to each other and not to move relative to each other in the axial direction. The bevel gears 58 and 60 are meshed with each other, and the rotation of the rotary shaft 30 is changed by 90 degrees and transmitted to the rotary shaft 50.

  One end of the rotating shaft 50 is protruded from the main body member 24, and a working tool holding portion 70 is provided at the protruding end as shown in FIG. The processing tool holding unit 70 has a circular cross-sectional shape, a pedestal portion 72 provided integrally with the rotary shaft 50, and a cross-sectional shape of the horizontal step is circular, and protrudes from the center of the pedestal portion 72. The positioning unit 74 and a plurality of, for example, two rotation transmission units 76 provided on the outer periphery of the pedestal unit 72 are included. The machining tool holding unit 70 holds a rotary machining tool, for example, a front milling cutter 78. The front milling cutter 78 is fitted to the positioning portion 74 and the rotation transmitting portion 76, and the bolt 80 is screwed to the positioning portion 74, thereby being fixed to the processing tool holding portion 70 so as to be able to transmit the rotation.

  As shown in FIG. 1, a positioning block 90 is fixed to the main body member 22 of the holder main body 20, and a positioning pin 92 is fitted so as to be movable in a direction parallel to the rotation axis of the rotation shaft 30. The positioning block 90 is fixed to the holder main body 20 by a plurality of bolts 94 (see FIG. 2), and can be attached to and detached from the holder main body 20, but functions as a part of the holder main body 20 after fixing. The positioning block may be provided integrally with the holder body.

  As shown in FIG. 1, a bottomed fitting hole 100 is formed in the positioning block 90 so as to open to the front end surface (end surface on the spindle head 12 side) and extend in parallel with the rotation axis of the rotation shaft 30. ing. The positioning pin 92 has a circular cross-sectional shape, is fitted in the fitting hole 100 so as to be airtight and movable in the axial direction, and is a compression coil spring disposed between the bottom surface of the fitting hole 100. 102 is biased in the forward direction toward the spindle head 12. The limit of movement of the positioning pin 92 due to the urging of the spring 102 is defined by the engagement of the engaging pin 104, which is an engaging member provided in a state orthogonal to the axis of the positioning pin 92, with the positioning block 90. The The compression coil spring 102 is a spring as an elastic member which is a kind of urging device. The same applies to the compression coil spring described in the following description.

  In the positioning block 90, as shown in FIG. 1, elongated holes 106 extending in parallel to the center line of the fitting hole 100 are formed at two locations separated in the diameter direction of the peripheral wall of the fitting hole 100, respectively. The protruding portions of the engaging pin 104 that protrude to both sides in the diameter direction of the positioning pin 92 are fitted so as to be movable in the longitudinal direction of the long hole 106. Thereby, the relative rotation of the positioning pin 92 with respect to the positioning block 90 is prevented, the phase is determined, and the engaging pin 104 that moves together with the positioning pin 92 is engaged with the front end surface of the elongated hole 106, whereby the spring 102. The movement limit of the positioning pin 92 due to the urging is defined, and the positioning pin 92 is positioned at the forward movement position (see FIG. 5). The engaging pin 104 constitutes an engaging protrusion as an engaging portion, and the long hole 106 constitutes an engaging recess as an engaging portion, and these constitute a relative rotation preventing device.

  As shown in FIG. 1, one of the two long holes 106 is formed in a portion facing the main body member 22, and one end of the engagement pin 104 extends to the main body member 22 side, and the holder main body 20 and the rotary shaft 30 are alternatively engaged. The front end portion of the main body member 22 is formed with an outer peripheral surface and a concave portion 110 that opens to the front end surface. At least one outward flange portion 34 of the rotating shaft 30, a plurality of, for example, 2 in the present processing tool holder. Two engaging recesses 112 are formed. These engaging recesses 112 are formed at two positions separated in the diameter direction of the outward flange portion 34 so as to open to the outer peripheral surface and the rear end surface, respectively.

  In the state where the positioning pin 92 is located at the forward movement position, the engaging pin 104 is fitted into the engaging recess 112 of the outward flange portion 34 as shown in FIG. 5, and the engaging pin 104, the positioning pin 92, and the positioning pin are positioned. Relative rotation between the rotary shaft 30 and the holder body 20 is prevented via the block 90. As shown in FIG. 1, as the positioning pin 92 is retracted against the positioning block 90 against the biasing force of the spring 102, the engaging pin 104 is removed from the engaging recess 112 and the recess 110. The rotating shaft 30 and the holder body 20 are allowed to rotate relative to each other.

  At the front end portion of the positioning pin 92, a fitting portion 118 whose diameter is linearly reduced toward the front is provided. As shown in FIG. 1, the spindle head 12 is formed with a positioning recess 120 having a shape corresponding to the fitting portion 118, which opens to the front end surface of the spindle head 12. The relative rotational position of the holder body 20 with respect to the spindle head 20 is determined by the insertion. In this machining tool holder, the position of the positioning pin 92 around the rotation axis 30 is set in advance with respect to the spindle 10 with the machining tool holding unit 70 in a state where the relative rotation position of the holder body 20 with respect to the spindle head 12 is determined. It is set to a position that extends in the opposite direction.

  Further, as shown in FIG. 1, a passage 122 is formed in the positioning pin 92 so as to open in the front end surface thereof and extend in the axial direction. A passage 124 opening in the bottom surface of the positioning recess 120 is formed in the spindle head 12. The passages 122 and 124 are connected by fitting the fitting portion 118 to the positioning recess 120. As a result, the pressurized air supplied from the pressurized air source (not shown) can enter the passage 122 through the passage 124. In this machining tool holder, the engagement pin 104 constituting the engagement protrusion constitutes the positioning pin side engagement portion, the engagement recess 112 constitutes the rotating shaft side engagement portion, and the positioning pin 92 and the spindle head The positioning recess 120 on the 12 side serves as the second connection portion and the first connection portion, respectively. The positioning pin side engaging portion may be an engaging recess, and the rotating shaft side engaging portion may be an engaging protrusion.

  As shown in FIGS. 1 and 2, the holder body 20 is also provided with three or more support units 140 in the present embodiment. As shown in FIG. 2, these support units 140 are provided at equal angular intervals around the axis of the rotary shaft 30 in the present embodiment. The configuration of the three support units 140 is the same, and one will be described as a representative.

  In this embodiment, the unit main body 142 of the support unit 140 is separated from the holder main body 20, and as shown in FIGS. 1 and 2, the outer peripheral surface of the main body member 22 is parallel to the rotation axis of the rotation shaft 30. A plurality of bolts 146 are fixed to a flat mounting seat 144 formed on the holder body 20 and are detachably attached to the holder body 20. The unit main body 142 functions as a part of the holder main body 20 after being fixed.

  As shown in FIGS. 1 and 3A, the unit main body 142 is formed with a fitting hole 150 that opens in the front end surface thereof and extends in parallel with the rotation axis of the rotation shaft 30. One end of the sleeve 152 is fitted into the opening 150 and is fixed by a bolt (not shown). The sleeve 152 is protruded forward from the unit main body 142, and is fitted into the unit main body 142 by the fitting hole 150 and the through hole 153 having a smaller diameter than the fitting hole 150 in the sleeve 152. It can also be considered that stepped holes extending in parallel are formed.

  A support rod 154 as a support member is fitted in the through-hole 153 of the sleeve 152 so as to be movable in a direction parallel to the rotation axis of the rotary shaft 30 and to be able to advance and retreat. The support rod 154 has a circular cross-sectional shape, and a rear end portion which is one end portion in the axial direction is provided with a head portion 156 having a larger diameter than a portion fitted to the sleeve 152 and a fitting hole 150. Are fitted so as to be movable in the axial direction. The support rod 154 is biased in a backward direction away from the spindle head 12 by a compression coil spring 158 disposed between the head 156 and the sleeve 152.

  A space 160 is also formed in the unit main body 142 as shown in FIG. The space 160 includes a portion following the fitting hole 150 and a portion extending in a direction perpendicular to the plane including the center line of the fitting hole 150 and the axis of the rotation shaft 30 with respect to the fitting hole 150. The shape viewed from the direction perpendicular to the plane is L-shaped. In the space 160, an L-shaped lever 170 as a rotating member is accommodated, and supported by a support shaft 172 fixed to the unit main body 142 so as to be rotatable about an axis that intersects the axis of the support rod 154 at a right angle. Has been.

  As shown in FIG. 3A, the support shaft 172 is disposed at a portion corresponding to the fitting hole 150 in the space 160, and as shown in FIG. 1, the L-shaped lever 170 is rotated around the support shaft 172. A central position in a direction parallel to the movement axis is attached at a position that coincides with the axis of the support rod 154, and one arm 174 extends from the support shaft 172 to the support rod 154 side. As shown in FIG. 3A, the distal end of the arm 174 has a shape viewed from a direction parallel to the rotation axis, and the width of the distal end is narrower toward the support rod 154 side. It is a surface that forms part of a cylindrical surface with a straight line parallel to the rotation axis of the lever 170 as a center line, and constitutes an engagement surface 176 that is a second engagement surface. The support rod 154 is biased by a spring 158 so that the rear end surface 178 of the head 156 is brought into contact with the engagement surface 176, and is advanced and retracted following the rotation of the L-shaped lever 170. The rear end surface 178 of the support rod 154 constitutes a first engagement surface, and this rear end surface 178 is perpendicular to the axis of the support rod 154, that is, perpendicular to the line of action of the backward force applied to the support rod 154. It is assumed to be a plane.

  As shown in FIG. 3, the other arm 184 of the L-shaped lever 170 extends in a direction perpendicular to the axis of the support rod 154, and is a compression coil spring disposed between the unit main body 142. By 186, the arm 174 is biased in a direction to move the support rod 154 in the forward direction.

  Further, as shown in FIG. 3, an air cylinder 200 as a fluid pressure cylinder, which is a kind of actuator, is provided in the unit main body 142. A bottomed hole 202 is formed in the unit main body 142 so as to extend in parallel with the fitting hole 150 and open to a portion of the space 160 in which the arm 184 is accommodated, thereby constituting a cylinder bore. The bottomed hole 202 is fitted with a piston 204 that is airtight and linearly movable in the axial direction, and an air chamber 206 is formed behind the piston 204 (on the bottom side of the bottomed hole 202). . A portion of the unit main body 142 where the bottomed hole 202 is formed constitutes a cylinder housing.

  Pressurized air is supplied to the air chamber 206 from the spindle head 12 side through the passage 122 formed in the positioning pin 92. As shown in FIG. 1, the positioning pin 92 is formed with a passage 210 different from the passage 122, and passages 212, 214, and 216 are formed in the positioning block 90, the holder body 20, and the unit body 142, respectively. Has been. The passage 210 is formed at a right angle with respect to the passage 122, opened on the outer peripheral surface of the positioning pin 92, and communicated with the passage 212 formed in the positioning block 90. The opening of the passage 210 that is communicated with the passage 212 is elongated in the axial direction of the positioning pin 92, and is always kept in communication with the passage 212 even when the positioning pin 92 is moved relative to the positioning block 90. Has been. The passage 214 formed in the holder main body 20 communicates with the passage 212 and the passage 216 formed in the unit main body 142, and the passage 216 communicates with the air chamber 206.

  As shown in FIG. 3A, the air cylinder 200 is provided so as to face the arm 184 of the L-shaped lever 170, and the arm 184 is urged by and abutted against the piston 204 by a spring 186. Therefore, in a state where the air chamber 206 is opened to the atmosphere, the L-shaped lever 170 is rotated by the biasing force of the spring 186, and the support rod 154 is advanced against the biasing force of the spring 158. At this time, the piston 204 is retracted to allow the L-shaped lever 170 to rotate. As shown in FIG. 3B, the rotation limit of the L-shaped lever 170 is that the protrusion 220 as a stopper protruding from the rear end surface of the piston 204 comes into contact with the bottom surface of the bottomed hole 202 as a stopper. It is prescribed by.

  In this embodiment, the L-shaped lever 170 is positioned so that the contact portion with the rear end surface 178 of the engagement surface 176 does not exceed the top dead center position in a state where the L-shaped lever 170 is positioned at the rotation limit position by the bias of the spring 186. A plane P perpendicular to a straight line L (see FIG. 4) connecting the contact portion with the rear end surface 178 of the engagement surface 176 and the rotation axis A of the L-shaped lever 170, and the engagement surface 176 and the rear end surface 178 Are formed so as not to exceed a position where an angle θ formed with a tangential plane (in the present embodiment, the rear end face 178) with respect to the portions in contact with each other is 0 degree. In a state where the L-shaped lever 170 is located at the rotation limit position by the bias of the spring 186, the support rod 154 is most advanced and is located at the advance end position. The L-shaped lever 170 is in a state where the support rod 154 is located between the forward end position and a position behind the forward end position by a set distance, and within a range in which contact with the spindle head 12 is expected. 4, the angle θ is set to be equal to or less than the friction angle, and in this embodiment, equal to or less than 10 degrees.

  When pressurized air is supplied to the air chamber 206, the piston 204 is advanced against the urging force of the spring 186, and the L-shaped lever 170 is rotated in a direction in which the engagement surface 176 is separated from the support rod 154. . In this case, the rotation limit of the L-shaped lever 170 is defined by the end 224 of the arm 184 serving as a stopper contacting the inner surface of the unit main body 142 serving as a stopper, as shown in FIG. The When the L-shaped lever 170 is rotated, the support rod 154 is retracted following the arm 174 by the bias of the spring 158, and in the state where the L-shaped lever 170 is rotated to the rotation limit position, the retracted end. To be positioned. In the present embodiment, the retracted end position is the retracted position, and a state in which the support rod 154 is separated from the spindle head 12 is obtained. In the present embodiment, the air cylinder 200 and the spring 186 constitute the drive device 226.

  As shown in FIG. 1, the spindle head 12 is provided with three abutting blocks 230 to which the support rods 154 of the three support units 140 are applied to form a contact portion (see FIG. 1). Is a single abutment block 230). The abutting block 230 and the positioning recess 120 are provided in a phase corresponding to the phases of the positioning pin 92 and the three support rods 154. The abutting surface 232, which is the tip surface of the abutting block 230, has a planar shape perpendicular to the axis of the main shaft 10.

  As shown in FIG. 1, a passage 234 is formed in the abutting block 230 so as to open to the abutting surface 232, and pressurized air is supplied from a pressurized air source to be ejected from the abutting surface 232. ing. Therefore, when the support rod 154 is brought into contact with the abutting block 230, the opening of the passage 234 is blocked by the support rod 154, and the pressure in the passage 234 is increased by preventing the injection of pressurized air. The contact of the support rod 154 is detected. The pressure in the passage 234 is detected by the pressure sensor 236, and different signals are output depending on whether the pressure exceeds the set pressure or not. In the present embodiment, the passage 234 and the pressure sensor 236 constitute a contact detection device.

  The machining tool holder configured as described above is attached to the machining center in a state where the face mill 78 is attached to the machining tool holding unit 70. When the machining tool holder is detached from the machining center, as shown in FIG. 5, the positioning pin 92 is located at the forward movement position, and relative rotation between the rotary shaft 30 and the holder body 20 is prevented. Further, the air chamber 206 is opened to the atmosphere, and the support rod 154 is positioned at the forward end position as shown in FIG.

  At the time of attachment, the processing tool holder is such that the bottle neck 36 is held by an exchange arm (not shown), the axis of the rotary shaft 30 is concentric with the axis of the main shaft 10, the positioning pin 92, the three support rods 154, and the positioning recess The spindle 10 and the spindle head 12 are brought close to each other in a state where the phases of the 120 and the three abutting blocks 230 coincide with each other. First, the connecting portion 38 begins to fit into the tapered hole portion 18, and then the fitting portion 118 of the positioning pin 92 begins to fit into the positioning recess 120. Before the front end surface 39 of the bottle neck portion 36 of the rotating shaft 30 comes into contact with the front end surface 16 of the main shaft 10, the fitting portion 118 is fitted into the positioning recess 120, and the passage 122 is connected to the passage 124. When the machining tool holder is attached, pressurized air is supplied to the passage 124. Simultaneously with the connection, the pressurized air flows from the passage 124 into the passage 122 and is supplied to the air chamber 206 through the passages 210 to 216.

  Accordingly, the piston 204 is advanced, the L-shaped lever 170 is rotated in a direction in which the arm 174 is separated from the support rod 154, and the support rod 154 is retracted to the retracted end position. The processing tool holder is further advanced from the state in which the positioning pin 92 is fitted in the positioning recess 120. However, since the positioning pin 92 is fitted in the positioning recess 120 and does not move, the holder main body 20 moves relative to the positioning pin 92. As shown in FIG. 6, the front end surface 39 is brought into contact with the front end surface 16, and the connecting portion 38 is fitted into the tapered hole portion 18.

  At this time, since the support rod 154 is retracted to the retracted end position, as shown in FIG. 6, the support rod 154 does not hit the abutting block 230 and allows the coupling portion 38 to be fitted into the tapered hole portion 18. In FIG. 6, the gap between the support rod 154 and the abutting block 230 is exaggerated for easy understanding. Further, the advancement of the holder body 20 with respect to the positioning pin 92 causes the positioning pin 92 to be retracted against the urging force of the spring 102, so that the engagement pin 104 is detached from the engagement recess 112 and fitted into the recess 110 to rotate. The shaft 30 can rotate with respect to the holder body 20. The support rod 154 held by the unit main body 142 in parallel to the rotation axis of the rotation shaft 30 is also parallel to the main axis.

  After the connecting portion 38 is fitted into the tapered hole portion 18 until the front end surface 39 is brought into contact with the front end surface 16, a draw bar (not shown) disposed in the main shaft 10 is connected to the connecting portion 38, and the draw bar Is pulled into the main shaft 10 by the movement of. As a result, the connecting portion 38 is tightly fitted into the tapered hole portion 18, the bottle neck portion 36 is pressed against the distal end surface 16, and the rotating shaft 30 is firmly and concentrically fixed to the main shaft 10. As a result, the holder body 20 is held by the rotary shaft 30 so as to be relatively rotatable.

  Thus, after the front end surface 39 is pressed against the front end surface 16 and the connecting portion 38 is tightly fitted in the tapered hole portion 18, the air chamber 206 is opened to the atmosphere, and the supply of pressurized air is shut off. The tight fitting of the connecting portion 38 to the tapered hole portion 18 can be seen from the progress of the draw bar operation. When the air chamber 206 is released to the atmosphere, the L-shaped lever 170 is rotated by the bias of the spring 186, and the arm 174 advances the support rod 154 against the biasing force of the spring 158. The arm 174 pushes the central portion of the support rod 154 in a direction parallel to the rotation axis of the L-shaped lever 170, and an eccentric load is prevented from being applied to the support rod 154 as much as possible.

  The advancement of the support rod 154 is stopped by contacting the abutting block 230. The distance between the holder main body 20 and the abutting block 230 in a state where the front end surface 39 is pressed against the front end surface 16 may vary depending on manufacturing errors of the processing tool holder or the spindle head 12, but the support rod 154 Then, it is advanced to a position corresponding to the distance, and abuts against the abutting block 230. In this state, the engagement surface 176 of the arm 174 has an angle between the moving direction of the engagement surface 176 accompanying the rotation of the L-shaped lever 170 and the tangential plane as shown in FIG. Engage with the rear end face 178 in a state of greater than 10 degrees and less than 10 degrees. Therefore, the arm 174 and the support rod 154 enter a deadlock state due to the frictional force between the engagement surface 176 and the retraction surface 178, and retreat even when a force in the retraction direction is applied from the spindle head 12 to the support rod 154. There is nothing. The arm 174 is maintained in a state where the support rod 154 is pressed against the abutting block 230 by the urging force of the spring 186, and the three support rods 154 are maintained in a state of supporting the holder body 20. As long as the support rod 154 abuts against the abutting block 230 at a position within the predetermined range in the above-described advance / retreat direction, a deadlock state is obtained between the support rod 154 and the holder body 20 while accommodating the variation in the distance. Can be supported rigidly. Based on the output signal of the pressure sensor 236, the contact of the support rod 154 with the abutting block 230 is confirmed.

  At the time of machining, the main shaft 10 is rotated in the counterclockwise direction indicated by the arrow A in FIG. 1, the rotary shafts 30 and 50 are rotated, and the face mill 78 is rotated in the clockwise direction indicated by the arrow B, while the workpiece W is rotated. And is moved relative to each other for cutting. As is well known, a cutting resistance force having components in three directions acts on the face mill 78 and is held at the tip of the rotary shaft 50 provided orthogonal to the main shaft axis of the main shaft 10. Furthermore, since the separation distance from the front end surface 16 of the main shaft 10 is large, a large force in a direction intersecting the main shaft axis of the main shaft 10 acts on the holder body 20. That is, a large rotational moment acts on the holder body 20, but in the present processing tool holder, the holder body 20 is firmly supported by the spindle head 12 via the three support rods 154. A large bending moment does not act, the bearing 13 of the main shaft 10 and the like are protected, and the cutting edge position of the front milling cutter 78 is well suppressed, and heavy cutting is possible. Moreover, even if it is not heavy cutting, the effect that a processing precision improves is acquired.

  When the processing tool holder is removed from the main shaft 10, the connection with the connecting portion 38 of the draw bar is released. Then, the bottleneck portion 36 is gripped by the replacement arm and moved in a direction away from the main shaft 10. Thereby, first, the connecting portion 38 is pulled out from the tapered hole portion 18, the bottle neck portion 36 is separated from the main shaft 10, the holder body 20 is retracted with respect to the positioning pin 92, and the engaging pin 104 is moved. The main body member 22 is pulled out of the concave portion 110 and fitted into the engaging concave portion 112 of the outward flange portion 34, and the rotation of the rotary shaft 30 relative to the holder main body 20 is prevented. Therefore, at the end of machining, the main shaft 10 is stopped at a rotational position where one of the two engaging recesses 112 is in phase with the recess 110 of the main body member 22.

  After the holder body 20 is retracted to a position where the front end surface of the elongated hole 106 engages with the engagement pin 104, the positioning pin 92 is retracted together with the holder body 20, and the fitting portion 118 comes out of the positioning recess 120. Be made. When the processing tool holder is removed, the air chamber 206 of the air cylinder 200 is opened to the atmosphere, the supply of pressurized air is shut off, and the holder body 20 is in a state in which the support rod 154 remains in contact with the abutting block 230. It is made to retreat with. As the holder body 20 moves backward, the L-shaped lever 170 is rotated by the bias of the spring 186 until the projecting portion 220 of the piston 204 comes into contact with the bottom surface of the bottomed hole 202, and the support rod 154 is moved forward. It will be in the position located. Thereafter, the support rod 154 is retracted together with the holder body 20 and separated from the abutting block 230.

  When removing the machining tool holder from the spindle 10, first, pressurized air is supplied from the pressurized air source to the passage 124, supplied to the air chamber 206 of the air cylinder 200 through the passage 122, etc. As shown, the support rod 154 may be retracted to the retracted end position and separated from the abutting block 230, and the holder body 20 may be moved away from the main shaft 10 by the gripping arm in this state. In this case, if the positioning pin 92 is retracted, the connection between the passages 122 and 124 is disconnected, the air chamber 206 is opened to the atmosphere, and the support rod 154 is advanced. The support rod 154 is separated from the abutting block 230 and does not contact the abutting block 230 even if it is moved to the forward end position.

  If the support unit is provided separately from the holder main body, it can be easily processed and manufactured, and can be replaced when a failure occurs. However, the support unit may be provided integrally with the holder main body. In this case, it can be considered that three or more support portions including a support member, a drive member, and a drive device are provided around the rotation axis of the holder body. It can be considered that the separate support unit also constitutes the support part after being attached to the holder body.

  Moreover, in the said embodiment, although the attachment to the machine tool of the processing tool holder was performed continuously without being stopped on the way, the approach speed with respect to the spindle 10 and the spindle head 12 of the processing tool holder is high. When the speed is high, the positioning pin 92 is fitted in the positioning recess 120, the passages 122 and 124 are connected, and the pressurized air is supplied to the air chamber 206. The attachment may be resumed after the passage of time during which it is ensured that pressurized air is supplied and the support rod 154 is retracted to the retracted end position.

  DESCRIPTION OF SYMBOLS 10: Main shaft 12: Main shaft head 20: Holder main body 30: Rotating shaft 36: Bottle neck part 38: Connection part 50: Rotating shaft 56: Rotation transmission device 70: Processing tool holding part 78: Front milling cutter 92: Positioning pin 104: Engagement Joint pin 112: Engagement recess 120: Positioning recess 154: Support rod 158: Compression coil spring 170: L-shaped lever 174: Arm 176: Engagement surface 178: Rear end surface 184: Arm 186: Compression coil spring 200: Air cylinder 204 : Piston 226: Drive device

Claims (6)

A machining tool holder for holding a machining tool, which is attached to a machine tool having a spindle that rotates around a spindle axis and a spindle head that rotatably holds the spindle,
A rotating shaft fixed to the main shaft and rotated by the main shaft;
A holder body which is fitted so as to be rotatable relative to the rotation shaft;
The holder main body is held at three or more positions around the rotation axis so as to be able to advance and retreat in a forward and backward direction including a component parallel to the spindle axis, abuts on the spindle head in a forward position, and the spindle in a retracted position. Three or more support members spaced from the head;
Each of the support members has a second engagement surface that engages with a first engagement surface that is an engagement surface of each of the support members, and is held by the holder body so as to be relatively movable. Three or more drive members for advancing and retracting each of the support members by engagement with one engagement surface;
A drive device that drives the drive member, and at least the support member is in contact with the spindle head, and the drive member is moved to the support member based on a backward force applied to the support member. The processing is characterized in that the force to move in a direction allowing the retraction of the motor is smaller than the frictional force acting between the first engagement surface and the second engagement surface. Tool holder. In the state where the drive member is a rotation member that can rotate around a rotation axis, the drive device rotates the rotation member, and the support member is in contact with the spindle head. A plane perpendicular to a straight line connecting the portion of the second engagement surface of the rotation member that contacts the first engagement surface and the rotation axis, the first engagement surface, and the second engagement machining tool holder according to claim 1 the angle formed between the plane tangent portion in contact with each other with the surface is less than the friction angle.
  The rotation member is an L-shaped lever having two arms, one arm is engaged with a rear end surface of the support member at a tip portion, and the other arm receives a driving force of the driving device. 2. The processing tool holder according to 2. The drive device includes an actuator that operates in response to a supply of drive energy;
The machining tool holder further includes
As the rotating shaft is fixed to the main shaft, the second connecting portion is connected to the first connecting portion, which is the connecting portion on the main shaft head side, and can receive supply of the driving energy;
The holder main body is held so as to be movable in a direction parallel to the main shaft axis, and as the rotary shaft is fixed to the main shaft, the main shaft of the holder main body is inserted into the positioning recess on the main shaft head side. A positioning pin that determines the relative rotational position with respect to the head;
A biasing device that biases the positioning pin in a forward direction toward the spindle head;
It moves together with the positioning pin, and when the positioning pin is in the forward position, it engages with the rotating shaft side engaging portion that is the engaging portion of the rotating shaft to prevent relative rotation between the rotating shaft and the holder body, After the positioning pin is inserted into the positioning recess, it is separated from the rotating shaft side engaging portion as it is retracted against the biasing force of the biasing device, and the rotating shaft and the holder main body The positioning pin side engaging part which will be in the state which accept | permits relative rotation, The said positioning pin and the said spindle head side positioning recessed part serve as said 2nd connection part and said 1st connection part, respectively. The processing tool holder in any one.   The drive device includes an urging device that urges the drive member in a direction to drive the support member in the forward direction, and the actuator is actuated upon supply of drive energy to urge the drive member. The processing tool holder according to claim 4, which is operated against an urging force of the apparatus.   The machining tool holder according to any one of claims 1 to 5, further comprising a machining tool holding unit that holds the machining tool in a state in which a cutting resistance in a direction intersecting with the spindle axis is applied to the holder body.

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