JP2017159383A - Clamp device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clamp device capable of accurately checking the seating of a tool holder.SOLUTION: On a seating surface 21 of a spindle 20, an arc-shaped air blowout groove 27 continuing to an air supply passage 26 is formed. Air supplied from a compressor 41 passes through air piping 40 and an air flow path 15 of the casing 11, then circulates in a recessed groove 26a of the spindle 20, the air supply passage 26 and the air blowout groove 27 toward the seating surface 21 side, and is blown out to a holder body portion 31 of the tool holder 30. The pressure of air at that time is detected by a pressure detection sensor 42.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a clamping device.

  Conventionally, after the tool holder is mounted on the spindle, the contact confirmation air is jetted from the contact confirmation air injection hole that opens at the front end surface of the spindle, and this contact confirmation air cannot be blown out. A spindle device of a machine tool is known in which it is confirmed that the rear end surface of a tool holder and the front end surface of a spindle are in close contact with each other when air pressure is detected (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-225845

  However, in the conventional spindle device, there is a problem that air cannot be sufficiently supplied to the tip end surface of the spindle, and the tool holder may not be confirmed accurately.

  Specifically, an air blow passage is provided on the spindle head side, and an adhesion confirmation air passage communicating with the air blow passage on the spindle head side is provided on the spindle side. The adhesion confirmation air passage is formed over the entire circumference of the main shaft so as to communicate with the air blow flow passage on the main shaft head side during high-speed rotation of the main shaft.

  Here, a predetermined gap is provided between the spindle and the spindle head to prevent seizure. For this reason, when the hole diameter of the close-contact confirmation air injection hole is small, the air flowing through the air blow channel is unlikely to flow toward the close-contact confirmation air passage, and the air easily leaks out from the gap between the spindle and the spindle head. The air blown out from the tip surface of the main shaft is reduced.

  This invention is made | formed in view of this point, The objective is to provide the clamp apparatus which can perform the seating confirmation of a tool holder correctly.

  The present invention is directed to a clamping device including a spindle having a mounting hole in which a tool holder is mounted and a casing that rotatably supports the spindle, and has taken the following solutions.

That is, according to the first aspect of the present invention, the spindle is provided with an air supply passage that opens in a seating surface to which the tool holder is in close contact, and a long hole-shaped air blowout formed in the seating surface continuously to the air supply passage. A groove is provided,
An air supply section for supplying air to the seating surface side through the air supply passage and the air blowing groove;
And a pressure detection unit that detects an air pressure of the air supplied to the seating surface side.

  In the first aspect of the invention, an elongated air blowing groove that is continuous with the air supply passage is formed on the seating surface of the spindle. The air supplied from the air supply unit flows through the air supply passage and the air blowing groove toward the seating surface, and the air pressure at this time is detected by the pressure detection unit.

  Thus, by providing a long hole-like air blowing groove on the seating surface of the spindle, it is possible to secure a sufficient air flow area on the seating surface as compared with the case where only the air supply passage is opened on the seating surface. Can do. As a result, air can be smoothly blown out toward the seating surface, making it difficult for air to leak from the gap between the spindle and casing, and supplying the seating surface with the air necessary to check the seating of the tool holder. can do.

  In addition, since the air flow area on the seating surface is increased, the clearance can be detected even if the clearance between the tool holder and the seating surface is very small. For example, it is possible to detect that the tool holder is held on the spindle in a tilted posture by cutting chips between the tool holder and the seating surface.

According to a second invention, in the first invention,
The air blowing groove is formed in an arc shape extending along a peripheral edge of the mounting hole.

  In 2nd invention, air can be supplied with sufficient balance along the periphery of a mounting hole by forming an air blowing groove in circular arc shape along a mounting hole.

  A third invention is directed to a clamping device including a spindle having a mounting hole in which a tool holder is mounted, and a casing that rotatably supports the spindle.

The spindle has an air supply passage that opens to a seating surface to which the tool holder is in close contact, and an annular air outlet formed in the seating surface continuously to the air supply passage and substantially concentric with the mounting hole. A groove is provided,
An air supply section for supplying air to the seating surface side through the air supply passage and the air blowing groove;
And a pressure detection unit that detects an air pressure of the air supplied to the seating surface side.

  In the third invention, an annular air blowing groove substantially concentric with the mounting hole is formed on the seating surface of the spindle. Thereby, air can be supplied in a well-balanced manner along the entire periphery of the mounting hole.

  According to the present invention, by providing a long hole-like air blowing groove on the seating surface of the spindle, the air flow area on the seating surface can be sufficiently increased as compared with the case where only the air supply passage is opened on the seating surface. Can be secured.

It is side surface sectional drawing which shows the structure of the clamp apparatus which concerns on this Embodiment 1. FIG. It is a top view which shows the structure of a clamp apparatus. It is a top view which shows the structure of the clamp apparatus which concerns on this Embodiment 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

Embodiment 1
As shown in FIGS. 1 and 2, the clamping device 10 includes a substantially cylindrical casing 11, and a hollow spindle 20 disposed in the casing 11 and rotatably supported via a plurality of bearings 12. And a draw bar 35 disposed in the through hole 23 of the spindle 20 and movable in the axial direction.

  The casing 11 is disposed with its axis extending in the vertical direction. The outer ring portions of the plurality of bearings 12 are fitted inside the cylinder of the casing 11. The outer periphery of the spindle 20 is fitted into the inner ring portion of the bearing 12. The bearings 12 are provided on the upper side and the lower side of the spindle 20, respectively. The spindle 20 is rotationally driven by a motor (not shown).

  The lower end surface of the spindle 20 is a seating surface 21 to which the holder main body 31 of the tool holder 30 is in close contact. The seating surface 21 of the spindle 20 has a tapered hole 22 (mounting hole) in which the tool holder 30 is mounted. The tapered hole 22 is formed in a tapered shape that expands downward. The spindle 20 is formed with a through hole 23 continuous with the tapered hole 22.

  The draw bar 35 is disposed in the through hole 23 of the spindle 20 and is urged upward by a disc spring (not shown). The draw bar 35 can be moved up and down in the through hole 23 of the spindle 20 by a hydraulic cylinder (not shown). A clamp claw 36 is attached to the lower end of the draw bar 35. The clamp pawl 36 will be described later.

  The tool holder 30 holds a tool such as a drill (not shown), and includes a holder main body portion 31, a tapered portion 32 that tapers upward from the upper end surface of the holder main body portion 31, and an upper end portion of the tapered portion 32. And a gripping portion 33 that extends upward from the gripping portion and is gripped by the clamp claw 36.

  The holder main body 31 protrudes outward in the radial direction from the tapered portion 32. The tapered portion 32 is formed in a shape that can be fitted into the tapered hole 22 of the spindle 20. As a result, when the tool holder 30 is mounted on the spindle 20, the tapered portion 32 comes into close contact with the tapered hole 22, and the upper end surface of the holder main body portion 31 and the seating surface 21 of the spindle 20 come into close contact and are constrained on two sides.

  Here, two drive keys 24 are attached to the seating surface 21 of the spindle 20 so as to be spaced apart from each other. Further, the holder main body 31 is formed with a key groove 34 into which the drive key 24 can be fitted. Thereby, it is possible to restrict the rotation of the tool holder 30 in the circumferential direction by fitting the drive key 24 into the key groove 34 of the holder main body 31.

  The clamp pawl 36 is an elastic body formed in a substantially cylindrical shape, and constitutes a clamp mechanism for gripping the grip portion 33 of the tool holder 30. Specifically, when the draw bar 35 is moved upward and the clamp pawl 36 is pulled upward, the clamp pawl 36 is pressed by the cam portion 25 provided in the through hole 23 of the spindle 20 and the clamp pawl 36 is contracted in the radial direction. . As a result, the grip portion 33 of the tool holder 30 is gripped by the clamp pawl 36 and is in a clamped state.

  On the other hand, when the draw bar 35 is moved downward and the clamp pawl 36 is moved downward, the pressing state of the cam portion 25 against the clamp pawl 36 is released, and the clamp pawl 36 expands in the radial direction. As a result, the grip portion 33 of the tool holder 30 is released to enter an unclamped state.

-Confirmation of seating of tool holder-
In the present embodiment, in order to confirm the seating of the tool holder 30, air is supplied to the seating surface 21 side to detect the air pressure. Hereinafter, a specific configuration will be described.

  In the casing 11, an air flow path 15 extending in the up-down direction in the casing 11 is formed. The upstream end of the air flow path 15 extends outward in the radial direction of the casing 11 and opens to the outer peripheral surface of the casing 11. The downstream end of the air flow path 15 extends inward in the radial direction of the casing 11 and opens on the inner peripheral surface of the casing 11. Two air flow paths 15 are provided at intervals in the circumferential direction of the casing 11.

  An air pipe 40 is connected to the upstream end of the air flow path 15. A compressor 41 (air supply unit) is connected to the air pipe 40. The compressor 41 sends air into the air flow path 15 via the air pipe 40. A pressure detection sensor 42 (pressure detection unit) is connected in the middle of the air pipe 40. The pressure detection sensor 42 detects the air pressure of the air sent from the compressor 41.

  On the outer peripheral surface near the lower end portion of the spindle 20, a concave groove 26a is formed which is depressed over the entire periphery. The concave groove 26 a is formed at a position communicating with the downstream end of the air flow path 15 that opens on the inner peripheral surface of the casing 11. Thereby, air can be always circulated from the air flow path 15 to the concave groove 26a while the spindle 20 is rotating.

  An air supply passage 26 is formed at the lower end of the spindle 20. The upstream end of the air supply passage 26 communicates with the concave groove 26a. The downstream end of the air supply passage 26 opens in the seating surface 21 of the spindle 20. On the seating surface 21 of the spindle 20, two air blowing grooves 27 are formed corresponding to the two air supply passages 26.

  The air blowing groove 27 is formed in a long hole shape extending in the circumferential direction continuously to the air supply passage 26. More precisely, the air blowing groove 27 is formed in an arc shape extending along the peripheral edge of the tapered hole 22 between the two drive keys 24.

  Thus, by providing the arc-shaped air blowing groove 27 on the seating surface 21 of the spindle 20, compared with the case where only the air supply passage 26 is opened on the seating surface 21, the air flow area on the seating surface 21 is increased. It can be secured sufficiently.

  The air sent from the compressor 41 to the air flow path 15 through the air pipe 40 passes through the concave groove 26a and the air supply passage 26 of the spindle 20 and then flows through the air blowing groove 27 and the holder main body 31. It is blown out to the upper end surface. Thus, the air fed from the compressor 41 is supplied between the seating surface 21 of the spindle 20 and the upper end surface of the holder main body 31.

  Here, when the tool holder 30 is in close contact with the seating surface 21 of the spindle 20, air does not leak from between the tool holder 30 and the spindle 20, and the air pressure of the air rises. That is, when the air pressure detected by the pressure detection sensor 42 is equal to or higher than a predetermined pressure, it can be determined that the tool holder 30 is in close contact with the seating surface 21 of the spindle 20.

  On the other hand, when foreign matter such as chips is caught between the holder main body 31 of the tool holder 30 and the seating surface 21 of the spindle 20, air leaks from the gap between the tool holder 30 and the spindle 20. Even though air is supplied from the compressor 41, the air pressure detected by the pressure detection sensor 42 does not exceed a predetermined pressure.

  In this state, since it can be determined that the holder body 31 is not in close contact with the seating surface 21 of the spindle 20, for example, an alarm operation such as sounding an alarm sound or lighting an alarm lamp is performed. You can do it.

<< Embodiment 2 >>
FIG. 3 is a plan view showing the configuration of the clamping device according to the second embodiment. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and only differences will be described.

  As shown in FIG. 3, the casing 11 is provided with one air flow path 15. One air supply passage 26 is formed at the lower end of the spindle 20. The downstream end of the air supply passage 26 opens in the seating surface 21 of the spindle 20. On the seating surface 21 of the spindle 20, an air blowing groove 27 is formed continuously with the air supply passage 26.

  The air blowing groove 27 is formed in an annular shape substantially concentric with the tapered hole 22. Thereby, air can be supplied in a well-balanced manner along the entire periphery of the tapered hole 22.

  As described above, the present invention provides a highly practical effect that the seating confirmation of the tool can be accurately performed, and thus is extremely useful and has high industrial applicability.

10 Clamping Device 11 Casing 20 Spindle 21 Seating Surface 22 Tapered Hole (Mounting Hole)
26 Air supply passage 27 Air blowout groove 30 Tool holder 41 Compressor (air supply part)
42 Pressure sensor (pressure detector)

Claims (3)

A clamping device comprising a spindle having a mounting hole in which a tool holder is mounted, and a casing for rotatably supporting the spindle,
The spindle is provided with an air supply passage that opens in a seating surface to which the tool holder is in close contact, and an elongated air blowout groove that is formed in the seating surface continuously to the air supply passage,
An air supply section for supplying air to the seating surface side through the air supply passage and the air blowing groove;
A clamp device comprising: a pressure detection unit that detects an air pressure of the air supplied to the seating surface side. In claim 1,
The said air blowing groove is formed in the circular arc shape extended along the periphery of the said mounting hole, The clamp apparatus characterized by the above-mentioned. A clamping device comprising a spindle having a mounting hole in which a tool holder is mounted, and a casing for rotatably supporting the spindle,
The spindle includes an air supply passage that opens in a seating surface to which the tool holder is in close contact, and an annular air blowout groove that is formed in the seating surface continuously to the air supply passage and is substantially concentric with the mounting hole. Is provided,
An air supply section for supplying air to the seating surface side through the air supply passage and the air blowing groove;
A clamp device comprising: a pressure detection unit that detects an air pressure of the air supplied to the seating surface side.

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