JP2003275944A - Work supporting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a work supporting device offering simplified inexpensive construction permitting a work to be surely supported while keeping contact between the work being machined and a supporting pin in a proper condition. <P>SOLUTION: An air pilot valve 37 for controlling the supply of a driving pressure oil to supporting pin constraining means is driven directly by the back pressure of air supply means for supplying air to an air jet nozzle 24 at the end of the supporting pin 3. Thus, the work supporting device 1 offers simplified inexpensive construction permitting the work to be surely supported while keeping the contact between the work being machined and the supporting pin in a proper condition after constraining or releasing the supporting pin 3 depending on the contacting condition between the work 2 and the supporting pin 3, namely, the back pressure of the air supply means. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work support device, and more particularly to a work support device provided on a machining jig of a machining center or the like based on an air leakage amount from an air ejection port provided at an end portion of a support pin. The present invention relates to a work support device that detects a contact state between a support pin and a support pin.

[0002]

2. Description of the Related Art For example, in machining by a machining center or the like, particularly in milling and end milling, vibration (chattering) is likely to occur in a portion having a small wall thickness and low rigidity. Since the vibration of the work during the machining leads to the deterioration of the accuracy of the machining surface and the life of the tool and the deterioration of the working environment due to noise, it is required to be suppressed as much as possible. Therefore, conventionally, a work support device is known in which a support pin is brought into contact with a work to reinforce and support a portion of the work having insufficient rigidity. With such a work support device,
By efficiently disposing the work support device on the jig, the vibration generated in the work during processing is effectively suppressed. However, even when the support pins of each work support device placed on the jig are brought into contact with the work piece in an appropriate state to start the work, the work pressure applied to the work, vibration during the work, etc. May move with respect to the support pin, resulting in a gap between the work and the support pin. In the conventional work support device, since the support pin is held fixed to the work support main body when the processing is started, there is a possibility that the accuracy of the product may deteriorate if the processing is continued in this state. However, since this processing defect is detected in the inspection process after the processing is finished, a great loss of processing time and waste of material are caused, and even if it can be corrected, much labor and time are required for the additional processing. I need
This will increase the manufacturing cost.

Therefore, in Japanese Utility Model Laid-Open No. 3-37553, there is provided a contactor which can freely project and retract on the seating surface of the work mounting table.
There is disclosed a work seating detection device provided with a detector for detecting that the contactor is within a predetermined immersion depth range. In the work seating detection device, when the work piece is seated, the contactor comes into contact with the work piece in a retracted state, and at this time, when the detector detects that the contactor is within a predetermined immersion depth range, it is appropriate. It is determined that the user is seated. Since the surface of the work is rough due to the given detection width, even if the contact is slightly protruding from the seating surface and is in contact with the work, the detector detects the proper seating condition. Therefore, even if the seating surface is a rough surface such as a casting surface, it is possible to properly detect the seating.

However, the conventional work seating detection device described above only detects the contact state between the work piece and the contact piece during machining of the work piece, and the work piece and the contact piece are not in proper contact with each other. When it is detected, the machining is interrupted and the contact is manually brought into contact with the work to correct the contact between the work and the contact, and then the machining is restarted. Therefore, it is difficult to ensure safety because the machining time is significantly lost and the work of correcting the contact state by the operator's manual work may be performed on a slippery machine table on which cutting fluid is scattered. It is also possible to correct the contact state between the work being processed and the support pin (contactor) by using electrical control, but this increases the production cost of the jig and causes an increase in the production cost. It was difficult to realize. Furthermore, in order to add a mechanism for correcting the contact state between the work and the support pin using electric control to the work support device of the existing jig, it is necessary to change the electric circuit, which requires a lot of time and effort. .

[0005]

Therefore, the present invention has been made in view of the above circumstances, and it is possible to maintain a proper contact between a work being processed and a support pin to reliably support the work. It is an object of the present invention to provide a work support device that can be configured at a low cost with a simple structure.

[0006]

In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention is a support pin which is provided in a work support body so as to be strokeable and which supports a work at an end thereof, Support pin pressing means for pressing the support pin toward the work, air supply means for supplying air to the air ejection port provided at the end of the support pin, and pressure fluid supplied via a predetermined fluid pressure circuit. And a support pin restraining means for releasably restraining the support pin, and a directional control valve driven by the back pressure of the air supplying means is provided in the fluid pressure circuit, and the directional control valve is the air supplying means. When the back pressure rises and reaches a predetermined pressure, the back pressure is directly driven to communicate the pressure fluid supply port with the pressure fluid supply / discharge port of the support pin restraining means, and Pressure and wherein the communicating the fluid supply and discharge port of the support pin restraining means drain port and a self-reset when the predetermined pressure or less.

According to a second aspect of the present invention, in the invention according to the first aspect, the support pin restraining means is provided in the work support main body and a cylinder in which the support pins are coaxially arranged, and the cylinder is provided in the cylinder. A piston driven by the pressure fluid supplied to the pressure fluid supply / discharge port, a collet sleeve that is provided inside the cylinder and whose inner peripheral surface can restrain the support pin, and a collet sleeve that is provided on the piston and is driven by the piston. Collet tightening hole for tightening
It is characterized by including.

The invention described in claim 3 is the invention according to claim 1 or 2.
In the invention described in (3), the directional control valve is directly driven by the pressurized fluid supplied through a branch of the air supply path communicating with the air ejection port.

The invention according to a fourth aspect is the first to the third aspects.
In the invention described in any one of above, the directional control valve is an air pilot valve in which the spool is directly driven by the back pressure of the air supply means.

The invention according to claim 5 is the same as claims 1 to 3.
In any one of the inventions described above, the directional control valve is a sequence type directional control valve whose drive pressure can be arbitrarily set.

Therefore, according to the first aspect of the invention, when the work floats from the support pin during the work processing and a gap is formed between the work and the support pin, air leaks from the end of the support pin. As a result, the back pressure of the air supply means decreases. When the back pressure of the air supply means falls below a predetermined pressure, the directional control valve that controls the supply / discharge of the pressure fluid to / from the pressure fluid supply / discharge port of the support pin restraining means self-returns, and the directional control valve supports the drain port. The pin restraining means is communicated with the pressure fluid supply / discharge port. As a result, the restraint of the support pin by the support pin restraining means is released, and the support pin is pushed toward the work by the support pin pushing means. Then, when the end of the support pin comes into contact with the work again and the air ejection port is closed by the work, leakage of air from the end of the support pin is prevented and the back pressure of the air supply means rises. When the back pressure of the air supply means reaches a predetermined pressure, the directional control valve is directly driven by the back pressure to communicate the pressure fluid supply port with the pressure fluid supply / discharge port of the support pin restraining means. As a result, the pressure fluid for restraint driving is supplied to the support pin restraining means, and the support pin is restrained in a state where the end portion of the support pin appropriately contacts the work.

According to the second aspect of the invention, in the support pin restraining means, the piston is driven when the pressure fluid is supplied to the pressure fluid supply / discharge port via the directional control valve, whereby the collet tightening hole causes the collet to tighten. The sleeve is tightened to restrain the support pin.

According to the third aspect of the present invention, since the directional control valve is directly driven by the pressure fluid supplied through the branch of the air supply passage communicating with the air ejection port, the fluid pressure circuit and the work support device. It can be simply configured.

In the invention according to claim 4, since the air pilot valve which is directly driven by the back pressure of the air supply means is used as the directional control valve, the supply and discharge control of the pressure fluid to the support pin restraining means is performed electrically. It is possible to configure with a simple fluid pressure circuit without using physical control.

According to the fifth aspect of the invention, since the sequence type directional control valve whose operating pressure can be arbitrarily set by the back pressure of the air supply means is used as the directional control valve, the pressure fluid to the support pin restraining means is The supply / discharge control can be configured by a simple fluid pressure circuit without using electrical control.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a view showing a cross section of the main body portion of the work support device 1. The work support device 1 includes a support pin 3 for supporting a work 2 by abutting ends formed in a substantially spherical shape, and a work support case 4 (work support main body) for slidably holding the support pin 3. ), And are provided. The work support case 4 has a first inner wall with a predetermined inner diameter.
Cylinder 5 is formed, and the base of the support pin 3 is coaxially housed in the first cylinder 5. Further, the first cylinder 5 is provided with support pin restraining means for restraining the support pin 3 in a releasable manner. As shown in FIG. 2, the support pin restraining means includes a collet sleeve 7 formed in a tapered shape in which the inner peripheral surface is engageable with the base portion of the support pin 3 in a constrainable manner and the outer peripheral surface becomes narrower toward the work 2. Provided with the collet sleeve 7
Is the axial direction of the support pin 3 (vertical direction in FIG. 2)
It is provided in a state where movement to is restricted. further,
The support pin restraining means includes a first piston 6 that can be stroked in the axial direction.
Is provided with a collet tightening hole 9 which is engaged with the outer peripheral surface of the collet sleeve 7 through a plurality of steel balls 8.

Further, in the work support device 1, the first cylinder 5 and the support pin restraining pressure oil supply / discharge port 10 arranged in the work support case 4 are communicated with each other through the pressure oil supply passage 11a. The support pin restraining means presses the first piston 6 in a direction away from the work 2 by supplying pressure oil as pressure fluid to the first cylinder 5, and the outer peripheral surface of the collet sleeve 7 is pressed. Is pressed by the collet tightening hole 9. Thereby, the support pin 3 is restrained by the collet sleeve 7, and the support pin 3 can be fixed at an arbitrary position with respect to the work support case 4. As shown in FIG. 2, the support pin restraining means is such that the first piston 6 is biased in the direction in which it approaches the work by the elastic force of the compression coil spring 12 for releasing the restraint, and the first cylinder 5 When the pressure oil is not supplied to the compression coil spring 12
Thus, the first piston 6 is pressed in the direction approaching the work 2 to release the restraint of the support pin 3.

As shown in FIG. 2, the outer peripheral surface of the first cylinder 5 is slid on the second cylinder 13 formed on the bottom surface 5a of the first cylinder 5 and on the bottom surface of the support pin 3. The pillars 14 are erected so as to be engaged with each other. Further, on the bottom surface 5a of the first cylinder 5, the support pin 3
A third cylinder 15 is formed coaxially with the column 14 and is continuous with the inner peripheral surface of the column 14. The third cylinder 15 is provided with a second piston 16 which can be stroked in the axial direction, and the second piston 16 has a work 2
A piston rod 18 having a stopper 17 is provided upright at the end extending toward the. Also, as shown in FIG.
The support pin 3 is provided above the second cylinder 13 (workpiece side) via an inner flange 19 capable of locking the stopper 17, and a stopper accommodating portion 20 through which the stopper 17 can be inserted is formed. There is.

Further, in the second cylinder 13, a compression coil spring 21 for a work support, one end of which abuts on the inner flange 19 and the other end of which abuts on the second piston 16, and the work support. Compression coil spring 21
And a compression coil spring 22 for returning the support pin, one end of which is in contact with the upper end of the inner peripheral surface of the column 14 and the other end of which is in contact with the second piston 16, are provided. Further, as shown in FIG. 2, the third cylinder 15 and the support pin pressing pressure oil supply / discharge port 23 provided in the work support case 4 are communicated with each other through a pressure oil supply passage 11b. In the work support device 1, pressure oil is supplied to the pressure oil supply / discharge port 23 for pressing the support pin to thereby compress the work support compression coil spring 21 and the support pin return compression coil spring 22.
The second piston 16 is pressed and biased toward the work 2 against the spring force.

Further, as shown in FIG. 2, the support pin 3 is provided with a support pin side air supply passage 26 which communicates the air ejection port 24 provided at the end portion with the outer peripheral surface. Further, the work support case 4 is provided with a case-side air supply passage 29 that communicates the air supply port 27 provided in the work support case 4 with the support pin guide hole 28. In addition, a gap 30 is provided between the support pin guide hole 28 and the outer peripheral surface of the support pin 3 to connect the support pin side air supply 26 and the case side air supply passage 29, and the gap 30 is a support pin guide hole. Two
A pair of O-rings 31 arranged in the axial direction 8 isolates it from the atmosphere. The pair of O-rings 31 are
Even when the support pin 3 is stroked in the axial direction, each of the support pin side air supply passages 26 has an opening on the outer peripheral surface of the support pin 3 that moves within a gap 30 separated from the atmosphere. It is arranged.

The fluid pressure circuit shown in FIG. 1 will be described. The air ejected from the air ejection port 24 is supplied from the air supply source 32 to the air regulator 25 and the first solenoid valve 3.
3 is supplied. The air regulator 25
Indicates that the pressure of the air supplied from the air supply source 32 is 0.2
The pressure is adjusted to 0 to 0.44 MPa and is supplied to the first solenoid valve 33. The first solenoid valve 33 is a 3-port / 2-position switching solenoid valve 33.
Has a structure in which the discharge side port (not shown) of the air regulator 25 and the air supply port 27 of the work support case 4 communicate with each other when the solenoid is turned on (the state shown in FIG. 1). Further, the pressure oil for driving the second piston 16 is supplied to the third pressure oil from the oil pump 34 via the oil regulator 35 and the second solenoid valve 36.
Is supplied to the cylinder 15. In the oil regulator 35, the pressure oil of the oil pumped from the oil pump 34 is adjusted to 5 to 7 MPa and is supplied to the second solenoid valve 36. The second solenoid valve 36 is a 3-port, 2-position switching solenoid valve 36.
Has a structure in which the discharge side port (not shown) of the oil regulator 35 and the support pin pressing pressure oil supply / discharge port 23 of the work support case 4 communicate with each other when the solenoid is turned on (the state shown in FIG. 1). ing.

Further, as shown in FIG. 1, the pressure oil for driving the first piston 6 is supplied to the discharge side port of the second solenoid valve 36 and the pressure oil supply / discharge port 23 for pressing the support pin. Is supplied to the first piston 6 through a pressure oil supply passage 11d that is a branch of the pressure oil supply passage 11c that connects to the pressure oil supply passage 11c. The air pilot valve 37 is provided in a spool driving port (not shown), and a discharge side port (not shown) of the first solenoid valve 33.
And one of the air supply passages 38 connecting the air supply port 27 of the work support case 4 and the one air supply passage 3
8 is connected. And this work support device 1
Then, the work 2 and the support pin 3 are in proper states (see FIG. 4).
Contact), the back pressure in the air supply passage 38 rises, the back pressure drives a spool (not shown) of the air pilot valve 37, and the support pin restraining pressure oil supply / discharge port 10 and the first The second solenoid valve 36 communicates with the pressure oil discharge port (not shown). Thereby, the pressure oil is supplied to the first cylinder 5, the first piston 6 is driven, and the collet tightening hole 9 presses the outer peripheral surface of the collet sleeve 7 so that the support pin 3 is constrained. Has become.

On the other hand, when the work 2 and the support pin 3 are not in proper contact with each other, air leaks from the air ejection port 24 of the support pin 3 and the back pressure in the air supply passage 38 falls. As a result, the spool of the air pilot valve 37 self-returns, and as shown in FIG. 6, the first cylinder 5 and the drain port (not shown) of the air pilot valve 37 communicate with each other. Then, the first piston 6 is pushed back by the spring force of the compression coil spring 12 in the direction approaching the work 2, and the constraint of the support pin 3 by the collet sleeve 7 is released. In addition, as shown in FIGS. 4 and 5, when the workpiece is processed, the third cylinder 1
5, the second piston 16 is driven to move to the stroke end position, and the support pin 3 is interposed between the second piston 16 and the inner flange 19 and is a compression coil for work support. It is biased toward the work 2 via the spring 21. In addition, the second cylinder 13
The atmospheric pressure is transmitted to the atmosphere through the O-ring 31, and the support pin 3 can be stroked in the axial direction.

Next, a work support method by the work support device 1 will be described. First, in a state before the work 2 is attached to a jig (not shown) and the work support device 1 is operated, as shown in FIG. 7, the first solenoid valve 33 is turned off and is in a self-reset state. Thus, both the air supply port 27 and the spool driving port (not shown) of the air pilot valve 37 are connected to the drain port (not shown) of the first solenoid valve 33. Further, the air pilot valve 37 is turned off and is in a self-restoring state, the support pin restraining pressure oil port 10 of the work support case 4 and the drain port of the air pilot valve 37 are communicated with each other, and the support pin restraining means supports the support pin. The constraint of 3 has been released. Further, the second solenoid valve 36 is in the OFF state and is in the self-recovery state, and the support pin pressing pressure oil supply / discharge port 23 of the work support case 4 and the drain port of the second solenoid valve 36 are communicated with each other. . This allows
The support pin 3 is positioned at the stroke end by being pressed in the direction in which the second piston 16 separates from the work 2 by the spring force of the compression coil spring 22 for returning the support pin.

Then, as shown in FIG. 6, when the first solenoid valve 33 and the second solenoid valve 36 are turned on from the above state, air is supplied to the air supply port 27 of the work support case 4 and the support pin is supplied. 3, air is ejected from the air ejection port 24 of the pressure roller 3 and pressure oil is supplied to the pressure oil supply / discharge port 23 for pressing the support pin so that the support pin 3 becomes the compression coil spring 21 for the work support. It is pressed by the second piston 16 via the and starts moving in the direction approaching the work 2. Then, the second piston 16 reaches the stroke end toward the work 2, and the support pin 3 is pressed toward the work 2 by the spring force of the compression coil spring 21 for work support, as shown in FIG. The end of the support pin 3 is the work 2.
If the contact is made in an appropriate state, the leakage of air from the air ejection port 24 falls within a predetermined allowable range, which increases the back pressure in the air supply passage 38. Then, when the back pressure reaches a predetermined pressure, the air pilot valve 37 is turned on as shown in FIG. 1, and the pressure oil is supplied to the support pin restraining pressure oil supply / discharge port 10 as shown in FIG. Supplied. As a result, the outer peripheral surface of the collet sleeve 7 is pressed by the collet tightening hole 9 of the first piston 6, the support pin 3 is constrained in a state where the end portion of the collet sleeve 7 is in contact with the work 2, and the axial movement thereof is restricted. It Therefore, the work support device 1 maintains the state in which the support pins 3 are in contact with the work 2.

If the work 2 floats from the support pin 3 for some reason during processing, the amount of air leaking from the air ejection port 24 of the support pin 3 increases and the back pressure in the air supply passage 38 decreases. . As the back pressure decreases, the pressure of the air supplied to the spool drive port of the air pilot valve 37 decreases, and the air supplied to the spool drive port falls below a predetermined pressure. Thus, the air pilot valve 37 is turned off and self-recovers. As a result, the support pin restraining pressure oil supply / discharge port 10 of the work support case 4 and the drain port of the air pilot valve 37 are communicated with each other, and the first piston 6 is pressed by the compression coil spring 12 toward the work 2. Then, the restraint of the support pin 3 by the support pin restraining means is released. When the support pin 3 is released from the restraint by the support pin restraining means, the support pin 3 is pressed in the direction of approaching the work 2 by the spring force of the work support compression coil spring 21 to bring the end portion into contact with the work 2 again. You can

When the contact between the work 2 and the support pin 3 becomes proper, the back pressure in the air supply passage 38 increases again and the spool of the air pilot valve 37 is driven. As a result, pressure oil is supplied to the support pin restraining pressure oil supply / discharge port 10, the support pin 3 is restrained by the support pin restraining means, and the support pin 3 is fixed again in a state of properly contacting the work 2. Then, in the work support device 1, it is possible to correct the contact between the work 2 and the support pin 3 and maintain the proper state by repeating the above-described operation as appropriate.

This embodiment has the following effects.
When a gap is generated between the work 2 and the support pin 3 during the machining of the work, the constraint of the support pin 3 by the support pin restraint means is released, and the support pin 3 is pushed by the work support compression coil spring 21 (work support pressing means). It is pressed toward 2, and the end of the support pin 3 comes into contact with the work 2 to correct the contact between the work 2 and the support pin 3. Then, when the contact state between the work 2 and the support pin 3 is properly corrected, the support pin 3 is restrained by the support pin restraining means and this state is maintained. Therefore, in the work support device 1 according to the present embodiment, the contact state between the work 2 and the support pin 3 during the work processing can be appropriately maintained, the quality of the product can be improved, and the accuracy defect can be caused. It is possible to significantly reduce the manufacturing cost. Further, the support pin restraining pressure oil supply / discharge port 1 is provided by the air pilot valve 37 whose spool is directly driven by the back pressure of the air supply means.
Since the supply and discharge of pressure oil to 0 is controlled, the device can be configured easily and inexpensively by controlling the restraint and release of the support pin 3 by the support pin restraining means without using electrical control. The manufacturing cost can be suppressed. Also,
When the work support device 1 of the present embodiment is applied to a processing jig or the like equipped with an existing work support device, it is easy to add an air pilot valve and change a fluid pressure circuit without changing the electric circuit. It can be added cheaply.

The embodiment is not limited to the above, but may be configured as follows, for example. In the above-described embodiment, the directional control valve for controlling the supply / discharge of the pressure oil to / from the support pin restraining pressure oil supply / discharge port 10 of the support pin restraining means is constituted by the air pilot valve 37. Alternatively, a sequence type directional control valve whose operating pressure can be set to an arbitrary pressure may be used.
In this case, the fluid pressure circuit can be configured more simply and the work support device 1 itself can be easily adjusted.

As described in detail above, according to the present invention,
(EN) A work support device capable of maintaining a proper contact between a work being processed and a support pin to reliably support the work, and having a simple structure and inexpensive structure.

[Brief description of drawings]

FIG. 1 is a schematic view of a fluid pressure circuit of a work support device according to the present embodiment, and particularly a view showing a state in which a support pin appropriately contacts a work and an air pilot valve is operated.

FIG. 2 is a cross-sectional view of the work support device of the present embodiment, and in particular, the first solenoid valve and the second solenoid valve are O-shaped before the support pins are brought into contact with the work.
It is a figure which shows the state which carried out FF.

FIG. 3 is a cross-sectional view of the work support device of the present embodiment, and in particular, from the state in FIG. 2, the first solenoid valve and the second solenoid valve are turned on to supply pressure oil to the third cylinder, It is a figure showing the state where the 2nd piston is driven.

FIG. 4 is a cross-sectional view of the work support device of the present embodiment, particularly showing the state in which the second piston is driven from the state in FIG. 3 to the stroke end and the support pin is in contact with the work.

5 is a cross-sectional view of the work support device according to the present embodiment, particularly showing the state in which the air pilot valve is turned on and the support pin is restrained by the support pin restraining means in the state shown in FIG.

FIG. 6 is a schematic view of a fluid pressure circuit of the work support device according to the present embodiment. In particular, a gap is created between the work and the support pin, the back pressure in the air supply path is reduced, and the air pilot valve self-recovers. It is a figure showing the state where restraint by a support pin restraint means of a support pin was released.

FIG. 7 is a schematic view of a fluid pressure circuit of the work support device according to the present embodiment, and particularly shows a state in which the first solenoid valve and the second solenoid valve are turned off before the support pin is brought into contact with the work. It is a figure. .

[Explanation of symbols]

1 Work Support Device 2 Work 3 Support Pin 4 Work Support Case (Work Support Body) 5 First Cylinder (Cylinder) 7 Collet Sleeve 9 Collet Tightening Hole 24 Air Jet 27 Air Pilot Valve (Directional Control Valve)

Claims (5)

[Claims] 1. A support pin movably provided on a work support body for supporting a work at an end, support pin pressing means for pressing the support pin toward the work, and a support pin provided at an end of the support pin. And an air supply means for supplying air to the air ejection port, and a support pin restraining means for releasably restraining the support pin driven by a pressure fluid supplied through a predetermined fluid pressure circuit, and The fluid pressure circuit is provided with a directional control valve driven by the back pressure of the air supply means, and the directional control valve operates by the back pressure when the back pressure of the air supply means rises and reaches a predetermined pressure. It is directly driven to communicate the pressure fluid supply port with the pressure fluid supply / discharge port of the support pin restraining means, and self-recovers when the back pressure of the air supply means is below a predetermined pressure. A work support device, wherein a drain port is communicated with a pressure fluid supply / discharge port of the support pin restraining means. 2. The support pin restraining means includes a cylinder provided in the work support body and coaxially arranging the support pin, and a pressure fluid provided in the cylinder and supplied to the pressure fluid supply / discharge port. A driven piston, a collet sleeve which is provided in the cylinder and whose inner peripheral surface can restrain the support pin, and a collet tightening which is provided on the piston and tightens the collet sleeve by driving the piston. The work support device according to claim 1, further comprising: a hole. 3. The directional control valve is directly driven by a pressure fluid supplied through a branch of an air supply path communicating with the air ejection port. Work support device described in. 4. The work support device according to claim 1, wherein the directional control valve is an air pilot valve in which a spool is directly driven by a back pressure of the air supply means. 5. The work support device according to claim 1, wherein the directional control valve is a sequence type directional control valve whose drive pressure can be arbitrarily set.