JP2020028968A - Work support - Google Patents

Abstract

To provide a work support that is able to remove a fixed state of a housing and a support rod of a work support, resulting from some cause.SOLUTION: A support rod (2), a forward spring (43) and an output member (24) are attached to a housing (1) in that order from an upper side. When the support rod (2) is being moved to a lower limit position, the support rod (2) may be fixed to the housing (1) due to some anomaly. An engaging part (70) of the output member (24) raised toward the support rod is made to collide with a locking part (71) of the support rod (2), thereby removing the foregoing fixed state.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a device that supports a work when the work is processed by a machine tool such as a milling machine or a grinding machine.

Conventionally, as this type of work support, there is a work support described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2003-307205). The prior art is configured as follows.
A cylindrical support rod inserted into the upper wall of the housing is movable vertically in the housing. The output member is inserted into the lower part of the housing so as to be movable in the vertical direction. A push bolt is screwed into the cylindrical hole of the support rod. An extension spring is mounted between the push bolt and the output member, and the extension spring urges the support rod and the output member to be separated from each other. When the output member is driven upward, the output member moves the support rod upward via the advance spring. Then, the upper end surface of the support block supports the lower surface of the work placed on the mounting table from below. The urging force of the advance spring is set so as to have a urging force of such a level as to resist the weight of the support rod, frictional resistance, or the like, but to a degree that the work is not lifted from the mounting table. Further, a sufficient gap is formed between the upper end of the output member and the lower end of the push bolt, and when the support rod is moved to the lower limit position and the output member is moved to the upper limit position, the push bolt is And the output member are not in contact with each other. Thus, the output member is configured to indirectly push the work support via the advance spring. As a result, by preventing the output member from lifting the work from the mounting table via the work support, the work accuracy of the work is prevented from deteriorating.

JP 2003-307205 A

When the work support is in the release state, the support rod may be in a fixed state in which the support rod is fixed to the upper wall of the housing due to some cause, for example, cutting chips and cutting oil that have accumulated. In this case, as described above, even if the output member pushes the support rod upward through the advance spring having a biasing force that does not lift the work, the above-described fixed state cannot be released.
An object of the present invention is to provide a work support in which a support rod and a housing of the work support can be released from a fixed state for some reason.

In order to achieve the above object, in the first invention, for example, as shown in FIGS. 1 to 3, FIG. 4, FIG. 5A and FIG. 5B, the work support is configured as follows.
A support rod 2 that is movable in the housing 1 toward the distal and proximal ends in the axial direction is inserted into the distal wall 1 a of the housing 1. An annular collet 5 is fitted around the outer periphery of the support rod 2. A piston 12 inserted into a cylinder hole formed in the housing 1 in the axial direction locks the support rod 2 via the collet 5 by driving the piston 12 in the axial direction. The output member 24 is inserted into the base end wall of the housing 1 so as to be movable in the axial direction. The support rod 2 and the output member 24 are urged to be separated by an urging means. When the support rod 2 at the limit position on the base end side is fixed to the housing 1 due to some abnormality, the output member 24 is moved from the base end side to the distal end side. Accordingly, the engaging portion 70 formed on the output member 24 pushes the locking portion 71 formed on the support rod 2 from the base end side to release the fixed state.

  In the work support according to the first aspect of the invention, in the release state where the support rod is moved to the limit position on the base end side, the support rod is moved to the distal end of the housing by some cause, for example, cutting chips and cutting oil deposited on the distal end of the housing. May be fixed to the wall. In this case, by moving the output member to the distal end side, the engaging portion of the output member abuts (collides) with the locking portion of the support rod. As a result, the fixed state between the support rod and the housing can be reliably released.

In the first aspect of the present invention, it is preferable to add the following configurations (1) to (3).
(1) For example, as shown in FIG. 1 to FIG. 3, FIG. 4, FIG. 5A and FIG. 5B, the distance S from the base end limit position of the output member 24 to the front end limit position is equal to the output S It is set so as to be longer than the distance H from the engaging portion 70 of the member 24 to the locking portion 71 of the support rod 2.
In this case, the engagement portion of the output member is reliably brought into contact with (collides with) the engagement portion of the support rod at the limit position on the base end side. Therefore, the fixed state between the support rod and the housing is reliably released by the impact of the collision.

(2) The urging means includes a working chamber 15 formed on the base end side of the support rod 2 and a working pressure fluid supplied to the working chamber 15.
In this case, the support rod is reliably raised by the urging means configured as described above.

(3) The urging means is constituted by an advance spring 43 mounted between the support rod 2 and the output member 24.
In this case, the support rod is reliably raised by the urging means configured as described above.

In order to achieve the above object, in the second invention, for example, as shown in FIGS. 6A and 6B, the work support is configured as follows.
A support rod 2 that is movable in the housing 1 toward the distal and proximal ends in the axial direction is inserted into the distal wall 1 a of the housing 1. An annular collet 5 is fitted around the outer periphery of the support rod 2. A piston 12 is inserted into a cylinder hole 11 formed in the housing 1 in the axial direction. When the piston 12 is driven, the piston locks the support rod 2 via the collet 5. The output member 24 is inserted into the base end wall 1b of the housing 1 so as to be movable in the axial direction. An advance spring 43 mounted between the support rod 2 and the output member 24 urges the support rod 2 and the output member 24 to separate from each other. When the advance spring 43 is most compressed, the adjacent windings of the advance spring 43 are in close contact with each other. When the support rod 2 at the limit position on the base end side is fixed to the housing 1 due to some abnormality, the output member 24 is moved from the base end side to the front end side. Accordingly, the output member 24 pushes the support rod 2 from the base end side via the advance spring 43 in the close contact state to release the fixed state.

FIG. 1 shows a first embodiment of the present invention and is a cross-sectional view in an elevation view showing a released state of a work support. FIG. 2 is an elevational sectional view showing the locked state of the work support, and is a view similar to FIG. FIG. 3 is an elevational sectional view showing a state where the second piston of the work support pushes up the support rod, and is a view similar to FIG. 1. FIG. 4 shows a second embodiment of the present invention and is similar to FIG. FIG. 5A and FIG. 5B are elevational sectional views showing a third embodiment of the present invention. FIG. 5A shows a release state of the work support, and is similar to FIG. 1. FIG. 5B is a view similar to FIG. 3 showing a state in which the second piston of the work support pushes up the support rod. 6A and 6B are elevational cross-sectional views showing a fourth embodiment of the present invention. FIG. 6A shows a release state of the work support, and is similar to FIG. 1. FIG. 6B is a view similar to FIG. 3, showing a state where the second piston of the work support pushes up the support rod.

  FIG. 1 shows a first embodiment of the present invention. In this embodiment, a case where the present invention is applied to a pneumatic work support is illustrated. First, the structure of the work support will be described.

  The housing 1 of the work support is screw-fixed to an accommodation hole formed in the table T as a fixing table. The housing 1 includes an upper wall (distal wall) 1a, a lower block 1b constituting a lower wall (base end wall), and a trunk portion 1c. A support rod 2 is inserted into the housing 1 so as to be movable in the vertical direction (the distal end and the proximal end in the axial direction). At an upper portion of the support rod 2, a push bolt 3 to be brought into contact with the work W is provided.

  A holding and fixing region R is provided in a lower half portion of the outer peripheral surface of the support rod 2, and a cylindrical collet 5 is externally fitted in the holding and fixing region R. The collet 5 is provided with a tapered outer peripheral surface 5a of an upper taper, and is elastically reduced in diameter by one slit 5b extending in the vertical direction. An annular transmission 6 is arranged on the outer peripheral side of the collet 5, and a tapered inner peripheral surface 6 a of the transmission 6 faces the tapered outer peripheral surface 5 a of the collet 5 from above. A large number of balls 8 are inserted into an annular tapered gap 7 formed between the tapered outer peripheral surface 5a and the tapered inner peripheral surface 6a.

  The first cylinder 10 for operation described above is inserted between a first cylinder hole (cylinder hole) 11 formed in the body portion 1c of the housing 1 and the first cylinder hole 11 and the transmission 6. An annular first piston (piston) 12, a working chamber 13 for lowering the first piston 12, and a first spring 14 for raising the first piston 12 are provided. The first spring 14 is mounted in a spring chamber 15 formed below the transmission 6.

  More specifically, the upper portion of the first piston 12 is hermetically guided by the sealing member 16 to the upper wall 1a, and the lower portion of the first piston 12 is hermetically sealed by another sealing member 17 to the lower block 1b. It is guided in the shape. By supplying compressed air to the working chamber 13, a downward force acts on a large-area annular pressure receiving surface formed on the upper end of the first piston 12, and a small area formed on the lower end of the first piston 12. An upward force acts on the annular pressure receiving surface, and the first piston 12 descends due to these upper and lower differential forces.

  Here, the first spring 14 is formed of a compression coil spring, and is mounted between an upper spring receiver 19 mounted on the lower surface of the transmission 6 and a lower spring receiver 20 mounted on the lower end of the collet 5. The upper spring receiver 19 receives many balls 8. Further, the urging force of the first spring 14 causes the lower end of the collet 5 to contact the lower block 1b via the lower spring receiver 20.

  A second cylinder 21 for reciprocation is provided in the lower block 1b. The second cylinder 21 is configured as follows. A large-diameter second cylinder hole 22 and a small-diameter rod hole 23 are connected in series to the lower block 1b in an upward direction. The second piston 25 of the output member 24 is hermetically inserted into the second cylinder hole 22 via the sealing member 25a, and the piston rod 26 of the output member 24 is inserted into the rod hole 23. In the present embodiment, both the second piston 25 and the piston rod 26 are configured separately, but they may be configured integrally.

  The lower wall 30 of the second cylinder hole 22 is formed by the bottom wall of the housing hole, and an inlet chamber 31 is formed between the lower wall 30 and the second piston 25. A supply / discharge port 32 for compressed air is communicated with the inlet chamber 31. An outlet chamber 35 is formed between the upper wall 34 of the second cylinder hole 22 and the second piston 25. A second spring 36 for retreating the second piston 25 downward is mounted between the upper wall of the rod hole 23 and the piston rod 26. In the present embodiment, the second spring 36 is configured by a compression coil spring. In the present embodiment, the driving means for moving the output member 24 upward includes the inlet chamber 31 and the compressed air supplied to the inlet chamber 31. The driving means for moving the output member 24 downward is constituted by the second spring 36.

  A flange portion 42 is formed at the tip of the piston rod 26, and the flange portion 42 is engaged with the operated portion 2a of the support rod 2 from above. An advance spring (biasing means) 43 for biasing the support rod 2 upward is mounted between the flange portion 42 of the piston rod 26 and the push bolt 3. In the present embodiment, the advance spring 43 is constituted by a compression coil spring.

  Further, a switching means 48 for communicating the working chamber 13 with one of the inlet chamber 31 and the outlet chamber 35 is provided. More specifically, a communication hole 49 is formed between the working chamber 13 and the upper part of the second cylinder hole 22. The opening of the communication hole 49 and the outer peripheral surface of the second piston 25 constitute a switching means 48.

The operation of the work support will be described with reference to FIGS. In the release state shown in FIG. 1, the diameter of the collet 5 is released by raising the first piston 12 and the transmission 6 by the first spring 14. Further, the second piston 25 and the piston rod 26 are lowered by the second spring 36. Thereby, the flange portion 42 of the piston rod 26 lowers the support rod 2 against the advance spring 43.
Here, the output member 24 of the present embodiment is movable from a lower limit position (a limit position on the proximal end side) shown in FIG. 1 to an upper limit position (a limit position on the distal end side) shown in FIG. 1 is shown in FIG. In the release state of the work support shown in FIG. 1, the support rod 2 at the lower limit position (the limit position on the proximal end) is moved from the engagement portion 70 of the output member 24 at the lower limit position (the limit position on the proximal end). The push bolt 3 (which is a part of the support rod 2) is spaced apart from the engaging portion 71 of the push bolt 3, and the distance is indicated by H in FIG. The movable stroke S of the output member 24 is set to be longer than the distance H from the engaging portion 70 to the locking portion 71.

In the release state, the work W is carried in a horizontal direction to a position above the push bolt 3.
When the work support is driven from the release state shown in FIG. 1 to the locked state shown in FIG. 2, compressed air is supplied from the supply / discharge port 32 to the inlet chamber 31. Then, first, the compressed air in the inlet chamber 31 raises the second piston 25 and the piston rod 26 against the second spring 36. Next, the flange portion 42 of the piston rod 26 raises the support rod 2 via the advance spring 43 and the push bolt 3. Then, the upper end surface of the push bolt 3 contacts the work W. In this state, a gap is formed in the vertical direction between the lower surface of the flange portion 42 of the piston rod 26 and the operated portion 2a of the support rod 2, and the upper end surface of the piston rod 26 and the push bolt 3 A contact gap is also formed between the lower end face and the lower end face.

  Next, the sealing member 25 a of the second piston 25 passes through the communication hole 49 due to the movement of the second piston 25 to the upper limit position. Then, the compressed air of the supply / discharge port 32 of the second piston 25 is supplied to the working chamber 13 through the inlet chamber 31 and the communication hole 49 in order. Then, when the pressure in the working chamber 13 exceeds a predetermined set pressure, a vertical differential force of the pneumatic pressure acting on the first piston 12 from the working chamber 13 acts on the transmission 6. When the downward differential force moves the transmission 6 downward, the tapered inner peripheral surface 6a of the transmission 6 smoothly engages with the tapered outer peripheral surface 5a of the collet 5 while rolling the ball 8, The collet 5 is reduced in diameter. As a result, the collet 5 whose diameter has been reduced presses the outer peripheral surface of the support rod 2 toward the axis, and locks the support rod 2 at the height position shown in FIG. The upper surface of the work W is machined in the locked state, and the pressing force during the working is strongly received from below by the support force of the support rod 2.

  After the above machining is completed, the compressed air in the inlet chamber 31 is discharged. Then, first, the second piston 25 and the piston rod 26 descend, and the flange portion 42 of the piston rod 26 comes into contact with the operated portion 2a of the support rod 2 in the locked state from above. Therefore, the flange portion 42 reliably prevents the support rod 2 from rising by the advance spring 43, and then the locked state of the support rod 2 is released. More specifically, it is as follows.

  Due to the discharge of the compressed air, first, the second piston 25 and the piston rod 26 are lowered by the second spring 36. Next, compressed air in the working chamber 13 is formed between the communication hole 49, the outlet chamber 35, the rod hole 23, the cylindrical hole of the support rod 2, the lower wall 1b, and the lower surface of the support rod 2. Through the communication groove 45, the spring chamber 15, and the vertical hole 46 formed in the lower wall in the up-down direction. When the pressure in the working chamber 13 falls below a predetermined set pressure, the first piston 12 and the transmission 6 are pressed upward by the first spring 14, and the tapered inner peripheral surface 6 a of the transmission 6 rolls the ball 8. It moves upward smoothly while moving, and releases the pressed state of the tapered outer peripheral surface 5a of the collet 5. Thereby, the collet 5 expands its diameter by its own elastic restoring force, and the locked state of the support rod 2 is released. Therefore, the second piston 25 and the piston rod 26 are further lowered, and the support rod 2 is returned to the lowered position in FIG.

The work support operates as follows in an abnormal state as described below.
In the above-mentioned released state, chips or cutting oil fall between the upper wall 1a of the work support and the support rod 2, or the sliding resistance of the support rod with respect to the housing 1 increases due to aging. The upper wall 1a and the outer peripheral wall of the support rod 2 may be fixed (abnormal state). In this abnormal state, in the conventional work support described above, even if the second piston 25 pushes the support rod 2 upward through the piston rod 26 and the advance spring 43, the support rod 2 cannot be lifted due to the above-described fixation.

  In the work support of the present embodiment, when the compressed air is supplied from the supply / discharge port 32 to the inlet chamber 31 when the lock drive is performed in the abnormal state, the compressed air in the inlet chamber 31 is applied to the urging force of the second spring 36. The second piston 25 is raised in opposition. At this time, the support rod 2 is fixed to the upper wall 1a of the housing 1, and the upward movement of the support rod 2 is restricted. Next, the engaging part 70 formed on the upper part of the piston rod 26 collides with the locking part 71 formed on the lower end of the push bolt 3. As a result, the impact force or pressing force of the collision is applied to the support rod 2 via the push bolt 3, and thereafter, the piston rod 26 pushes up the support rod 2. As a result, the fixed state between the support rod 2 and the upper wall 1 is released. Subsequently, the support rod 2 is raised by the spring biasing force of the advance spring 43, and the upper end surface of the push bolt 3 contacts the lower end surface of the work W. Thereafter, as described above, the first piston 12 locks (pinches and fixes) the support rod 2 at the predetermined height position via the collet 5.

The first embodiment has the following advantages.
When the work support is in the release state and the support rod 2 is fixed to the upper wall 1a of the housing 1, the output member 24 is moved upward, and the engaging portion 70 of the output member 24 is moved. By colliding with the locking portion 71 of the support rod 2, the fixed state between the support rod 2 and the housing 1 is reliably released. In the present embodiment, the output rod 24 can contact the support rod 2 at the lower limit position from the vicinity of the upper limit position slightly below the upper limit position to the upper limit position. The output rod 24 is configured so that it cannot be brought into contact when the support rod 2 is slightly moved upward from the release position (lower limit position) shown in FIG. For this reason, the advance spring 43 has an urging force enough to resist the own weight of the support rod, frictional resistance, and the like, but has an urging force enough not to lift the work from the mounting table, similarly to the conventional advance spring. 43 can be employed.

  FIGS. 4, 5A and 5B, 6A and 6B show the second to fourth embodiments of the present invention. In the second to fourth embodiments, members having the same configuration as in the first embodiment are given the same reference numerals in principle, and configurations different from those in the first embodiment will be described.

The differences between the second embodiment shown in FIG. 4 and the first embodiment are as follows.
A cylindrical collet 5 is externally fitted to the outer peripheral surface of the support rod 2 inserted into the housing 1. The collet 5 of the present embodiment is pressed against the lower block 1b by an elastic body 51 made of rubber. Further, the elastic body 51 may be constituted by a spring member such as a wave washer, a disc spring, and a coil spring instead of rubber.

A second cylinder 21 for advance and retreat is provided in a lower portion of the housing 1. The second cylinder 21 is configured as follows.
A second cylinder hole 22 is formed in the lower block 1 b of the housing 1, and a second piston 25 is inserted into the second cylinder hole 22 in a hermetically sealed manner. A piston rod 26 projects upward from the second piston 25, and the piston rod 26 is inserted into a cylindrical hole of the support rod 2. A second working chamber 52 formed below the second piston 25 can communicate with the first working chamber 13 via a communication passage 53. Further, an annular gap formed between the inner peripheral surface of the first cylinder hole 11 and the outer peripheral surface of the first piston 12 forms the throttle path 54.

  When the work support is in the release state, the pressure oil is discharged from the second working chamber 52. Therefore, the first piston 12 and the transmission 6 are lifted by the first spring 14 to release the diameter reduction of the collet 5. Further, the second piston 25 and the piston rod 26 are lowered by the second spring 36. Thus, the flange portion 42 lowers the support rod 2. Further, compressed air (operating pressure fluid) is supplied to the spring chamber (operating chamber) 15 through a supply passage 46 formed in the lower wall 1b of the housing 1. The compressed air in the spring chamber 15 urges the support rod 2 upward. In the present embodiment, the urging means for urging the support rod 2 upward with respect to the housing 1 is constituted by the spring chamber 15 and the compressed air supplied to the spring chamber 15.

  When operating the work support from the release state to the locked state, the work W is carried in a horizontal direction to a position above the push bolt 3. After that, the pressure oil of the pressure oil source is supplied to the second working chamber 52 through the supply / discharge port 32. The support rod 2 is lifted by the piston rod 26 via the advance spring 43. Then, when the second piston 25 and the piston rod 26 are raised against the second spring 36 by the pressurized oil in the second working chamber 52, the flange portion 42 of the piston rod 26 moves the operated portion 2 of the support rod 2. From the top. Next, the compressed air supplied to the spring chamber 15 moves the support rod 2 upward. Subsequently, the push bolt 3 contacts the work W. In this state, a contact gap is formed vertically between the flange portion 41 of the piston rod 26 and the operated portion 2a of the support rod 2.

  Next, the pressure oil in the second working chamber 52 is gently supplied to the first working chamber 13 through the throttle path 54. When the pressure in the first working chamber 13 is not sufficient (below a predetermined pressure), the upward biasing force of the first spring 14 holds the first piston 12 at the upper limit position. Thereafter, when the pressure in the first working chamber 13 exceeds a predetermined pressure, a vertical differential force of the pressure acting on the first piston 12 from the first working chamber 13 applies an upward force to the first spring 14. The transmission 6 is moved downward against the power. Then, the tapered inner peripheral surface 6a of the transmission 6 smoothly engages with the tapered outer peripheral surface 5a of the collet 5 while rolling the ball 8, thereby reducing the diameter of the collet 5. As a result, the collet 5 whose diameter has been reduced presses the outer peripheral surface of the support rod 2 inward in the radial direction, thereby holding and supporting the support rod 2 at a predetermined height. In the locked state, the upper surface of the workpiece W is machined, and the support rod 2 receives a strong external force acting in the vertical direction as a pressing force during the machining. In the present embodiment, the predetermined height position of the support rod is higher than the height position at which the engaging portion 70 of the output member 24 and the locking portion 71 of the support rod 2 can abut (on the distal end side). It is set as follows. That is, a gap is formed between the engaging portion 71 of the support rod 2 when supporting the work 2 and the engaging portion 70 of the output member 24. Accordingly, it is possible to prevent the output member 24 from lifting the work W from the mounting table via the support rod 2, and as a result, it is possible to prevent the processing accuracy of the work W from being deteriorated.

  When operating the work support from the locked state to the released state, after the machining is completed, the pressure oil in the second working chamber 52 is discharged to the outside. Then, first, the first spring 14 presses the first piston 12 and the transmission 6 upward, and the tapered inner peripheral surface 6 a of the transmission 6 smoothly moves upward while rolling the ball 8, and the collet 5 The pressed state of the tapered outer peripheral surface 5a is released. Thereby, the collet 5 expands its diameter by its own elastic restoring force, and the locked state of the support rod 2 is released. At substantially the same time, the second spring 36 lowers the second piston 25, and the flange 42 drives the support rod 2 to lower.

The work support operates as follows in the abnormal state shown in FIG.
In the above-described release state, chips or cutting oil may accumulate between the upper wall 1a of the work support and the support rod 2 to cause the upper wall 1a and the outer peripheral wall of the support rod 2 to adhere to each other (abnormal state). ).

  When the work support of the present embodiment is locked and driven in the above-described abnormal state, if pressure oil is supplied from the supply / discharge port 32 to the second working chamber 52, the pressure oil in the second working chamber 52 The second piston 25 is raised against the urging force. At this time, the support rod 2 is fixed to the upper wall 1a of the housing 1, and the movement in the vertical direction is restricted. Next, the engaging part 70 formed on the retaining ring of the piston rod 26 collides with the locking part 71 formed on the operated part 2 a of the support rod 2. Thus, the piston rod 26 directly and strongly pushes up the support rod 2. As a result, the fixed state between the support rod 2 and the upper wall 1a is released. Then, the support rod 2 is raised by the upward biasing force of the compressed air in the spring chamber 15, and the upper end surface of the push bolt 3 comes into contact with the lower end surface of the work W. Thereafter, as in the first embodiment described above, the first piston 12 clamps and fixes the support rod 2 at a predetermined height position via the collet 5.

The differences between the third embodiment shown in FIGS. 5A and 5B from the first embodiment are as follows.
A tubular central member 56 is provided upward at the center of the lower part of the housing 1 of the work support, and a lower flange 56a of the central member 56 is pressed and fixed to the housing 1 by the lower block 1b.

  A support rod 2 is supported by the housing 1 so as to be vertically movable. A cylindrical member 57 is screwed to the upper end of the support rod 2. The lower half of the support rod 2 is externally fitted to the central member 56 with a predetermined gap. The gap forms a part of an air flow path 58 described later.

The second piston 25 is hermetically inserted into the cylindrical hole of the central member 56.
A supply / discharge port 32 for supplying and discharging compressed air is formed in the table T, and the supply / discharge port 32 communicates with the working chamber 52 through a communication path 53. A flow path 73 branched in the middle of the communication path 53 is communicated with the first working chamber 13. A throttle 74 is provided in the flow path 73.

An air supply port 59 to which compressed air is supplied is provided at an upper right portion of the housing 2. Further, the valve member 61 is inserted into the cylindrical hole of the cylindrical member 57 so as to be movable in the vertical direction. An outlet path 60 is formed between the outer peripheral wall of the valve member 61 and the cylindrical hole and the upper end surface of the cylindrical member 57. A groove-shaped communication passage 62 that constitutes a part of the outlet passage 60 is formed vertically on the outer peripheral wall of the rod portion 61a of the valve member 61. The outer periphery of the enlarged diameter portion 61b provided on the upper portion of the valve member 61 projects downward, and a downward valve surface 63 is formed on the downward projection. Correspondingly, a valve seat 64 is provided at the upper end of the tubular member 57.
The valve member 61 is pressed downward by its own weight, and is switched to the upper open position against its own weight by the air pressure of the pressure chamber 65 below the enlarged diameter portion 61b. At the open position shown in FIG. 5B, an annular gap is formed between the valve surface 63 and the valve seat 64 in plan view. When the support rod 2 rises and the valve member 61 contacts the workpiece W, the valve surface 63 of the valve member 61 contacts the valve seat 64 of the cylindrical member 57, and the air flow path 58 is blocked. Is done. As a result, the pressure in the air flow path 58 is increased, and the increased pressure is detected by the pressure switch. As a result, it is confirmed that the valve member 61 has been raised to a position where it comes into contact with the lower surface of the work W.

  The air supply port 59 and the outlet path 60 are communicated by the air flow path 58. In this embodiment, the air flow path 58 includes an oblique path 66 at the upper right portion of the housing 1, the spring chamber 15, the slit 5 b of the collet 5, the outer peripheral space and the lower space of the lower end of the support rod 2, A gap 67 formed between the inner peripheral surface of the lower half of the support rod 2 and the outer peripheral surface of the central member 56, a vertical groove 68 provided in the operated portion 2 a of the support rod 2, and a cylindrical hole of the support rod 2 are formed. Prepare.

The work support shown in the third embodiment operates as follows in the following abnormal state.
In the release state shown in FIG. 5A, the upper wall 1a of the work support and the support rod 2 may be fixed by cutting chips, cutting oil, or the like (abnormal state). In this abnormal state, when the work support is locked and the compressed air is supplied from the supply / discharge port 32 to the working chamber 52, the compressed air in the working chamber 52 is pressed against the urging force of the second spring 36 to the second position. The piston 25 is raised. At this time, the support rod 2 is fixed to the upper wall 1a of the housing 1, and the movement in the vertical direction is restricted. Next, the engaging portion 70 of the piston rod 26 pushes up the locking portion 71 of the valve member 61. Then, the flange formed at the lower end of the valve member 61 collides with the lower end surface of the tubular member 57. The fixed state between the upper wall 1a and the support rod 2 is released by the impact or the pressing force of the collision. Subsequently, the support rod 2 is raised by the spring biasing force of the advance spring 43. At this time, the pressure of the pressure chamber 65 is increased by the compressed air supplied from the compressed air source to the outlet path 60 through the air flow path 58, and the air pressure of the pressure chamber 65 moves the valve member 61 upward from the cylindrical member 57. To open the valve. Next, the upper end surface of the valve member 61 contacts the lower end surface of the work W. Subsequently, the valve seat 64 of the cylindrical member 57 is brought into contact with the valve surface 63 of the valve member 61 and the valve is closed. At this time, the pressure in the flow path 58 is increased, and the increased pressure is detected by a pressure switch (not shown), so that the contact of the valve member 61 with the lower surface of the work W is reliably detected. Thereafter, the first piston 12 clamps and fixes the support rod 2 at a predetermined height position via the collet 5.

The differences between the fourth embodiment shown in FIGS. 6A and 6B and the first embodiment are as follows.
As shown in FIG. 6A, an advance spring (biasing means) 43 for biasing the support rod 2 upward is mounted between the flange portion 42 of the piston rod 26 and the push bolt 3. Here, the extension spring 43 is formed by a compression coil spring. Further, as shown in FIG. 6B, when the extension spring 43 is most compressed, the adjacent windings of the extension spring 43 are in a close contact state. When the support rod 2 is fixed to the housing 1 due to some abnormality at the lower limit position shown in FIG. 6A, the output member 24 moves from the lower side (base end side) to the upper side (distal end side). Then, the output member 24 pushes the support rod 2 from below through the advance spring 43 in the close contact state to release the fixed state. For this reason, in the present embodiment, the engaging portion 70 is formed on the upper surface of the advance spring 43 and is locked on the lower surface of the advance spring 43 so as to face the engaging portion.

The above embodiment can be modified as follows.
The driving means of the first embodiment is constituted by another pressure fluid supplied to the inlet chamber 31 instead of the inlet chamber 31 and the compressed air supplied to the inlet chamber 31. May be done. The driving means for moving the output member 24 downward may be an elastic body such as rubber instead of the illustrated second spring 36, and may be compressed air or the like.
Instead of the large number of balls 8 described above, a cylindrical member having a low friction function may be used.
The switching means 48 in the first embodiment and the fourth embodiment may be any as long as it switches the working chamber 13 between the inlet chamber 31 and the outlet chamber 35 to communicate therewith. Therefore, there may be a moment when the outer peripheral surface of the second piston 25 completely closes the opening of the communication hole 49, or there is a moment when the communication hole 49 communicates with both the inlet chamber 31 and the outlet chamber 35. No problem. Further, the switching means 48 is not limited to the combination of the opening of the communication hole 49 and the outer peripheral surface of the second piston 25.
Further, a throttle path may be provided in the communication hole 49 of the first embodiment, and instead of or in addition to the throttle path, an annular space between the first cylinder hole 11 and the first piston 12 is provided. It is preferable to set the gap to a small value. In this case, the flow resistance of the annular gap and the communication hole 49 increases, so that the time for raising and lowering the pressure of the working chamber 13 increases. Thereby, the lowering start and the uppering start of the first piston 12 are delayed. As described above, since the start of the lock and the release of the lock of the support rod 2 by the first piston 12 can be delayed, the support rod 2 can be reliably locked and unlocked after the piston rod 26 moves up and down.
Further, the present invention can be applied to a work support having another structure instead of being applied to a work support having the exemplified structure, and further, can be applied to a use different from the work support. For example, instead of the taper transmission mechanism using the collet 5, it is conceivable to form an annular gas working chamber on the outer periphery of the thin-walled sleeve and reduce the diameter of the thin-walled sleeve by the pressure gas to lock the support rod or the like. .
The outlet path 60 is only required to connect the internal space of the support rod 2 to the outside, and is not limited to the illustrated structure. Needless to say, the tubular member 57 may be omitted from the support rod 2. . In this case, the valve member 61 is directly supported by the support rod 2 of the support rod 2.
Further, the valve member 61 may be omitted from the support rod 2 and the outlet path 60 formed with a small diameter may be directly opened at the upper end surface of the support rod 2. In this case, when the upper end surface of the support rod 2 comes into contact with the work W, the opening of the outlet path 60 is closed and the outlet path 60 is closed.

1: Housing, 1a: Upper wall (tip wall), 1b: Lower wall (base wall), 2: Support rod, 5: Collet, 11: Cylinder hole, 12: First piston (piston), 15: Spring chamber (Operating chamber), 24: output member, 43: advance spring, 70: engaging portion, 71: locking portion.

Claims (5)

A support rod (2) inserted into the distal end wall (1a) of the housing (1) so as to be movable in the distal direction and the proximal direction in the axial direction within the housing (1);
An annular collet (5) fitted around the outer periphery of the support rod (2);
A piston (12) inserted into a cylinder hole (11) formed in the housing (1) in an axial direction, the piston (12) being driven by the support rod (5) via the collet (5). 2) a piston (12) for locking;
An output member (24) inserted into the base end wall (1b) of the housing (1) so as to be movable in the axial direction;
Biasing means for biasing the support rod (2) and the output member (24) so as to be separated from each other;
When the support rod (2) at the limit position on the proximal side is fixed to the housing (1) due to some abnormality, the output member (24) is moved from the proximal side to the output member (24). By being moved to the distal end side, the engaging portion (70) formed on the output member (24) pushes the locking portion (71) formed on the support rod (2) from the base end side. Release the fixed state,
Work support characterized by that. In the work support of claim 1,
The movable stroke (S) of the output member (24) from the proximal end limit position to the distal end limit position is equal to the engagement portion of the output member (24) at the proximal end limit position. It is set to be longer than the distance (H) from (70) to the locking portion (71) of the support rod (2) at the limit position on the base end side.
Work support characterized by that. In the work support according to claim 1 or 2,
The urging means includes an operating chamber (15) formed on the base end side of the support rod (2), and an operating pressure fluid supplied to the operating chamber (15).
Work support characterized by that. In the work support according to claim 1 or 2,
The biasing means is constituted by an advance spring (43) mounted between the support rod (2) and the output member (24).
Work support characterized by that. A support rod (2) inserted into the distal end wall (1a) of the housing (1) so as to be movable in the distal direction and the proximal direction in the axial direction within the housing (1);
An annular collet (5) fitted around the outer periphery of the support rod (2);
A piston (12) inserted into a cylinder hole (11) formed in the housing (1) in an axial direction, the piston (12) being driven by the support rod (5) via the collet (5). 2) a piston (12) for locking;
An output member (24) inserted into the base end wall (1b) of the housing (1) so as to be movable in the axial direction;
An extension spring (43) mounted between the support rod (2) and the output member (24), which biases the support rod (2) and the output member (24) apart. Advancing spring (43),
When the advance spring (43) is compressed most, adjacent windings of the advance spring (43) are in close contact with each other,
When the support rod (2) at the limit position on the proximal side is fixed to the housing (1) due to some abnormality, the output member (24) is moved from the proximal side. By being moved to the distal end side, the output member (24) pushes the support rod (2) from the base end side via the advance spring (43) in the close contact state to release the fixed state,
Work support characterized by that.