JP5476864B2 - Guide mechanism for the rotary joint of the spindle unit - Google Patents

Description

  The present invention relates to a guide mechanism for a rotary joint of a spindle device configured to supply coolant to a tool holder at the tip of a spindle.

  Conventionally, in a spindle device, a tool holder is mounted on the tip of a spindle (spindle) that is rotatably provided on the spindle head, and a draw bar that clamps and unclamps the tool holder by axial movement is provided on the spindle. A coolant supply hole is provided in the draw bar, a rotary joint capable of circulating coolant from the coolant supply device is connected to the coolant supply hole at the rear end of the draw bar, and a coolant supply device is connected to the rotary joint via a hose. A spindle device of a spindle oil supply (spindle through coolant) system is known. This is to cool the tool tip and the workpiece by spraying the coolant supplied from the coolant supply device to the tool holder through the rotary joint and coolant supply hole on the cutting tool or workpiece during workpiece machining. Chips are removed from the machined parts.

  As the main spindle device, one disclosed in Patent Document 1 is known. In the thing of patent document 1, it has the structure which provided the holding member which supports a rotary joint in the spindle head. In the rotary joint, a rotation-side support member that supports the rotation-side joint member and is slidably fitted to the draw bar is provided on the main shaft, and the fixed-side support member is supported from below by a holding member attached to the main shaft head. ing. Therefore, the rotary joint does not move in the axial direction even when the draw bar moves in the axial direction when changing the tool.

  Moreover, the thing of patent document 2 is known as said spindle apparatus. In the thing of patent document 2, it has a structure which does not provide the holding member which supports a rotary joint. In this structure, the rotary joint is connected to the rear end of the draw bar, and the rotary joint moves in the axial direction in accordance with the axial movement of the draw bar when the tool holder is replaced.

Japanese Patent No. 3687802 JP 2001-87910 A

  In recent years, due to the increased coolant discharge pressure from the coolant supply device, the load applied to the rotary joint due to the impact of the coolant discharge pressure on and off of the hose has increased, and the rotary joint and drawbar mounting part and the rotary joint and hose mounting There is an increased risk of breakage at parts. The hose is usually connected by slacking it into a U-shape in consideration of the movement of the main shaft, drawbar, or piping length, and when high pressure coolant is turned on and off, This is because the hose vibrates greatly (wave phenomenon) as it extends from the U-shape to the linear shape due to the discharge pressure. At this time, the load applied to the mounting portion is applied in a direction orthogonal to the axial direction.

  In the one described in Patent Document 1, when a load is applied to the rotary joint in a direction perpendicular to the axial direction due to vibration at the time of coolant discharge pressure on the hose, the downward load perpendicular to the axial direction is applied to the rotary joint. Although supported by the holding member from the lower side, this holding member does not support the entire circumference of the rotary joint, and loads in other directions are not supported. Since there is no telling whether vibrations will occur, there is a risk that the rotary joint will be damaged due to a large load applied to the mounting portion between the rotary joint and the hose. In addition, since the draw bar moves in the axial direction with respect to the rotary joint, a special rotary joint dedicated to the spindle device is used, and there is a problem that a commercial product cannot be used.

  In the thing of patent document 2, since the rotary joint moves to an axial direction, it is only connected to the drawbar rear end, and since it is not supported by the holding member, it is made into a rotary joint by vibration of the hose by coolant discharge pressure. When a load is applied in the direction orthogonal to the axial direction, a large load is applied to the mounting part of the rotary joint and the hose, and a large load is also applied to the mounting part of the rotary joint and the draw bar. There is a risk of damage.

  Accordingly, in view of the above problems, the present invention provides a rotary joint guide mechanism for a spindle device that supports a rotary joint with a small and simple structure, suppresses vibration of the hose, and prevents damage to the mounting portion due to impact from the hose. The purpose is to provide.

In order to achieve the above object, a first problem-solving means includes a tool holder mounted on the tip of a spindle that is rotatably provided, and a draw bar that clamps and unclamps the tool holder by axial movement is provided on the spindle. A coolant supply hole that can supply coolant to the tool holder is provided in the draw bar. The guide mechanism of the rotary joint of the main spindle device is configured to connect the coolant supply device to the rotary joint via a hose and supply the coolant from the coolant supply device to the tool holder via the rotary joint and the coolant supply hole. in, guide mechanism, main It consists of a plurality of pillars provided on the body and a holding member consisting of two clamping members attached to the pillars so as to be movable in the axial direction, and sandwiching the rotary joint. One end of a hose is connected, and the other end of the hose is linearly connected to the coolant supply device via a swingable swing joint so as to eliminate the looseness of the hose, and is supplied from the coolant supply device. This prevents the rotary joint from moving in the direction orthogonal to the axial direction due to the load and vibration from the hose .

In the invention of claim 1 of the present application, the guide mechanism includes a plurality of support columns provided on the main spindle body, and a holding member including two holding members that are attached to the support columns so as to be axially movable and sandwich the rotary joint. One end of the hose is connected to the rear end of the rotary joint supported by the guide mechanism, and the other end of the hose is configured to eliminate the looseness of the hose in the coolant supply device via the swingable swing joint. The rotary joint is prevented from moving in the direction orthogonal to the axial direction due to the load and vibration from the hose due to the pressure of the coolant that is linearly connected and supplied from the coolant supply device . According to this, while the holding member holds the rotary joint, the rotary joint can also move in the axial direction in accordance with the movement of the draw bar in the axial direction, and the load applied in the direction orthogonal to the axial direction of the rotary joint can be suppressed. It is possible to prevent damage to the rotary joint and draw bar due to vibration when the coolant discharge pressure enters and exits the hose.

It is sectional drawing of the main axis | shaft apparatus provided with the guide mechanism of the rotary joint of this invention. FIG. 2 is an II view of FIG. 1 and an enlarged view of a rotary joint and a guide mechanism. FIG. 3 is an enlarged view taken along the line III in FIG. 2. It is explanatory drawing which shows the connection of a flexible hose and a swivel joint. It is a figure which shows rocking | fluctuation of a swivel joint when a rotary joint retreats. It is a figure which shows rocking | fluctuation of a swivel joint when a rotary joint advances.

  Embodiments of the present invention will be described with reference to FIGS. The spindle device 1 shown in FIG. 1 is well-known, and the outline thereof will be described. A spindle 4 rotatably supported by a spindle head 2a and a plurality of bearings 3 provided in the spindle body 2b, and the spindle 4 A rotating spindle driving motor 5, a spindle bar 4 is provided so as to be movable in the axial direction, a tool bar 6 is clamped and unclamped to the spindle 4, and a rear end of the draw bar 7 is connected to a coolant supply device 8. It is composed of a rotary joint 9 through which coolant can flow to the draw bar 7 and an unclamp cylinder 10 that can release the clamped state of the tool holder 6 by pushing the draw bar 7 forward to replace the tool holder 6 from the main shaft 4. Yes.

  A through hole 11 is formed in the main shaft 4, and a large number of disc springs 12 are stacked in the through hole 11, and the draw bar 7 is attached axially rearward (clamping direction) by the spring force of the disc spring 12. As a result, the tool holder 6 is clamped to the main shaft 4 by the draw bar 7. The main shaft 4 is provided with a through hole 13 for supplying coolant to the tool holder 6. The draw bar 7 is provided with a coolant supply hole 14, and the draw bar 7 allows the through hole 13 and the coolant supply hole 14 to communicate with each other while the tool holder 6 is clamped to the main shaft 4. A rear end 7 a of the draw bar 7 passes through the unclamp cylinder 10 and protrudes rearward of the unclamp cylinder 10. A front end of the rotary joint 9 is connected to the rear end 7 a of the draw bar 7, and a flow path (not shown) provided in the rotary joint 9 communicates with the coolant supply hole 14.

  One end of a flexible hose 16 (hereinafter referred to as a hose) is connected to the rear end of the rotary joint 9. As shown in FIGS. 4 to 6, the other end of the hose 16 is connected to a pipe 18 connected to a terminal 2 c fixed to the main spindle body 2 b via a swingable swing joint 17. The coolant supply device 8 is connected. The swing joint 17 is, for example, a swivel joint, and is well known in Japanese Patent Application Laid-Open No. 2009-79636. The hose 16 is linearly connected between the rotary joint 9 and the swivel joint 17 so as to eliminate the looseness. Thereby, when the coolant is supplied from the coolant supply device 8, the hose 16 tends to extend linearly by the coolant discharge pressure as in the prior art, so that a load is applied to the rotary joint 9 in a direction orthogonal to the axial direction. Is to prevent. The hose 16 can swing when the rotary joint 9 moves in the axial direction together with the draw bar 7 when the tool holder 6 is unclamped (FIG. 6) and clamped (FIG. 5) by the swivel joint 17. , Can be connected linearly. In FIG. 6, the hose 16 at the time of unclamping is indicated by a solid line, and the hose 16 at the time of clamping is indicated by a two-dot chain line.

  As shown in FIG. 2, the rotary joint 9 is supported by a guide mechanism 19. The guide mechanism 19 includes a holding member 20 and a plurality of (two in the present embodiment) struts 21. The support column 21 is provided in parallel to the rear end in the axial direction via the plate 27 at the rear end of the unclamp cylinder 10 fixed to the main spindle body 2b. The holding member 20 is composed of left and right clamping members 22, and as shown in FIG. 3, the outer periphery 9 a of the rotary joint 9 is sandwiched and held by the left and right clamping members 22. The left and right clamping members 22 are connected by bolts 23 as shown in FIG. The holding member 20 sandwiches and holds the outer periphery 9a of the rotary joint 9, so that even if there is a variation in the outer dimension of the rotary joint 9, it can be held regardless of the variation in the dimension. As a result, it is possible to use general commercially available rotary joints whose outer dimensions vary. The left and right clamping members 22 are each provided with a linear bush 24, and the linear bush 24 is guided to each column 21 so as to be movable in the axial direction.

  When machining the workpiece, the coolant from the coolant supply device 8 passes through the pipe 18, the swivel joint 17, the hose 16, the flow path of the rotary joint 9, the coolant supply hole 14 of the draw bar 7, and the through hole 13 of the main shaft 4. Supply to the holder 6 is stopped. Conventionally, a load or vibration is generated in the hose 16 due to the coolant discharge pressure at this time, and an impact is applied to the hose 16 and the mounting portion 25 of the rotary joint 9 or the mounting portion 26 of the rotary joint 9 and the draw bar 7 due to the load or vibration. There was a risk of damage. However, at this time, since the rotary joint 9 is held by the main body 2b in the entire circumferential direction, that is, in the direction orthogonal to the axial direction by the guide mechanism 19, the rotary joint 9 is axially moved by the load and vibration from the hose 16. The mounting parts 25 and 26 are not damaged. Further, since the hose 16 is connected approximately linearly between the swivel joint 17 and the rotary joint 9, there is an effect of suppressing the vibration of the hose 16 as compared with the case where the hose 16 is loosely connected in a U shape as in the prior art. Can also prevent the attachment portions 25 and 26 from being damaged.

  Further, when the tool holder 6 is replaced, the draw bar 7 moves in the axial direction. However, since the rotary joint 9 is held by the column 21 and the holding member 20 so as to be movable in the axial direction, the rotary joint 9 is integrated with the draw bar 7. Therefore, it is possible to use a general commercial rotary joint, and it is not necessary to support it using a special rotary joint that allows the drawbar to move separately from the rotary joint as before. Can be implemented at low cost. The coolant may be supplied by connecting the coolant supply path 14 and the tool holder 6. Further, although the holding member 20 is provided with the linear bush 24 and can be moved to the support column 21, the holding member 20 may be provided to be directly movable to the support column 21.

DESCRIPTION OF SYMBOLS 1 Spindle device 2b Spindle body 4 Spindle 6 Tool holder 7 Draw bar 7a Draw bar rear end 8 Coolant supply device 9 Rotary joint 9a Rotary joint outer periphery 14 Coolant supply hole 16 Hose (flexible hose)
17 Swing joint (swivel joint)
19 Guide mechanism 20 Holding member 21 Strut

Claims (1)

A tool holder is attached to the tip of the main shaft that is rotatable, a draw bar that clamps and unclamps the tool holder by axial movement is provided in the main shaft, and a coolant supply hole that can supply coolant to the tool holder is provided in the draw bar. A rotary joint that can circulate the coolant from the coolant supply device is connected to the coolant supply hole at the rear end of the draw bar, a holding member that supports the rotary joint is provided on the spindle body, and the coolant supply device is connected to the rotary joint via a hose. In the guide mechanism of the rotary joint of the spindle device configured to supply the coolant from the coolant supply device to the tool holder via the rotary joint and the coolant supply hole, the guide mechanism includes a plurality of columns provided on the spindle body, Axial shift to the column The hose is configured to include a holding member composed of two holding members that sandwich the rotary joint. One end of the hose is connected to the rear end of the rotary joint supported by the guide mechanism, and the other end of the hose is swung. It is linearly connected to the coolant supply device through a swing joint that can eliminate the looseness of the hose, and the rotary joint is pivoted by the load and vibration from the hose due to the pressure of the coolant supplied from the coolant supply device. A guide mechanism for a rotary joint of a spindle device , wherein movement in a direction orthogonal to the direction is prevented.

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