JP3065531B2 - Cylinder device for pneumatic work transfer device with rapid rise prevention mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a mechanism for preventing a sudden rise of a support portion of a work due to a sudden movement of a piston when a supported work is released.
The present invention relates to a cylinder device for a pneumatic work transfer device.

[0002]

2. Description of the Related Art In a conventional pneumatic work transfer apparatus, as shown in FIG. 3, a piston 21 is slidably fitted in a cylinder 20, and a lower end of a piston rod 22 of the piston 21 is provided. The work W is suspended and held. A piston valve 24 having an orifice 24A formed near the value surface of a cylinder head 23 is slidably fitted in the cylinder 20.
3 is urged away from the inner surface.

[0003] An oil passage 28 is formed in the cylinder head 23 through an oil pipe 26 to communicate with an external oil tank 27, and the oil stored in the oil tank 27 is supplied to the head of the cylinder 20. It is introduced on the room side. Pressurized air is introduced from the booster A to the piston rod chamber side of the cylinder 20.

The booster A has an air introduction chamber B connected to a compressed air source (not shown). The air introduction chamber B is connected to the air supply passage D through an air introduction hole C. It communicates with the connected air passage E. An exhaust valve F is provided in the air introduction hole C, and the exhaust valve F is constantly urged by a spring G in a direction to close the air introduction hole C. The exhaust valve F is
An exhaust hole H is formed at the center, one end of which is in contact with the end face of a diaphragm valve J provided at the center of the diaphragm I, and the other end of which the exhaust hole H is open to the outside. ing.

[0005] The diaphragm valve J is pressed against the end face of the exhaust valve F by a spring K, and the space between the air passage E and the exhaust hole H is always closed. The biasing force of the spring K is set smaller than the biasing force of the spring G, and the biasing force of the spring G does not cause the air introduction hole C to open.

[0006] In the booster A, the diaphragm I
A diaphragm chamber L defined by the air passage E side is provided. One end of a control air passage M is connected to the diaphragm chamber L, and a balance valve N and a descending valve are connected to the other end. O and the ascending valve P are connected in order.

The rising valve P is connected to the air introduction chamber B
Is connected to one of the ascending air introduction passage Q communicating with the air supply passage D and the bypass passage R connected to the air supply passage D.

In the pneumatic workpiece transfer device constructed as described above, in the state shown in FIG. 3, the air passage E and the diaphragm chamber L are connected to the air supply passage D, the bypass passage R, and the ascending valve P. , The lowering valve O, the balancing valve N, and the control air passage M, and the air pressure in the diaphragm chamber L and the air pressure in the air passage E are always equal.

In the above state, the exhaust valve F closes the air introduction hole C, and the end face of the diaphragm valve J is
Since the exhaust hole H of the exhaust valve F is closed, air does not flow in and out through the air supply path D, the piston 21 and the piston rod 22 are held at a fixed position, and a downward load is applied to the piston rod 22 and the workpiece W. Is added, the piston rod 22 does not descend.

When the work W is lifted from the state shown in FIG. 1, when the operating lever of the lift valve P is depressed as shown in FIG. 4A, the high-pressure air in the air introduction chamber B rises. Control air passage M from the air introduction passage Q through the ascending valve P, the descending valve O, and the balancing valve N.
From the diaphragm chamber L. As a result, the pressure in the diaphragm chamber L becomes higher than that in the air passage E side, and the differential pressure causes the diaphragm I to be displaced to the right in the figure, and the diaphragm valve J provided integrally with the diaphragm I changes the exhaust valve. The air introduction hole C is opened by pressing the end face of F.

As a result, high-pressure air in the air introduction chamber B flows into the air passage E, flows into the piston rod chamber side of the cylinder 20 via the air supply path D, pushes up the piston 21, and pushes the piston rod 22. The connected work W rises.

When the balance valve N is depressed to switch to the shut-off position as shown in FIG. 1B, the air in the diaphragm chamber L cannot flow through the control air passage M. The air pressure is balanced on both sides of the diaphragm chamber L and the air passage E, which are confined in the diaphragm chamber L and separated by the diaphragm I, and the work W is stationary.

When the work W or the lower part of the piston rod 22 is pushed upward by hand from the above state, the downward load applied to the piston 21 is slightly reduced, and the air pressure in the piston rod chamber is reduced. As a result, the diaphragm chamber is lowered. The balance of the air pressure between the L side and the air passage E side is broken, the diaphragm I is displaced rightward, and the air introduction hole C is opened.

Then, the high-pressure air in the air introduction chamber B flows through the air passage E and the air supply passage D to the cylinder 20.
, And the piston 21 is raised. Here, when the hand is released from the work W, the pressure in the piston rod chamber rises, the diaphragm I returns to the original position, the work W stops, and the balance state is maintained again at that position.

When the work W or the piston rod 22 is pushed downward by hand, the downward load applied to the piston 21 slightly increases, the air pressure in the piston rod chamber increases, and the diaphragm I is moved to the position shown in FIG. , The end face of the diaphragm valve J is separated from the end face of the exhaust valve F.

As a result, the air in the piston rod chamber of the cylinder 20 flows from the air supply passage D to the air passage E and the exhaust hole H.
The work W connected to the piston rod 22 together with the piston 21 descends to the atmosphere via the airbag. Then, when the user releases his / her hand from the work W at the desired position, the diaphragm I returns to the original position, and the work W stops again in a balanced state.

When the work W is lowered, as shown in FIG. 3C, when the operating lever of the lowering valve O is depressed, the air in the diaphragm chamber L flows from the control air passage M to the balancing valve N. The air is discharged from the descending valve O into the atmosphere via the lowering valve O. Then, the diaphragm chamber L
Since the internal pressure is lower than the pressure on the air passage E side, the diaphragm I is displaced to the left in the figure, the end face of the diaphragm valve J is separated from the end face of the exhaust valve F, and the air in the piston rod chamber of the cylinder 20 is Then, the workpiece W is discharged into the atmosphere from the air supply path D through the air path E and the exhaust hole H, and the work W descends.

The conventional pneumatic work transfer device having the above-described structure can be used when the work W is lifted.
If the work W comes off the lower end of the piston rod 22 for some reason, the pressure balance between the piston rod chamber side and the head chamber side of the cylinder 20 is lost, and the piston 21 starts to rise rapidly together with the piston rod 22. The oil filled between the piston 24 and the piston 21 moves toward the cylinder head 23 through the orifice 24A of the piston valve 24. At this time, since the speed of the oil passing through the orifice 24A increases rapidly, a large pressure difference is generated on both sides of the orifice 24A, and the pressure difference opposes the urging force of the spring 25 to move the piston valve 24 to the cylinder head 23A. Move to the side. When the gap between the piston valve 24 and the cylinder head 23 decreases,
When the amount of oil passing decreases, the piston 21 and the integral piston rod 22 are decelerated, and when the piston valve 24 abuts against the cylinder head 23 to eliminate the gap, the orifice 24A is completely closed, and the piston 2
1 and the lifting of the piston rod 22 stop.

[0019]

In the above-described pneumatic work transfer device having the above-mentioned conventional rapid rise prevention mechanism, if the gap between the cylinder head and the piston valve is made narrow, the operation sensitivity of the piston valve increases, and the work comes off. Although the safety can be improved when the piston rod rises even when the workpiece does not come off, the piston valve operates when the piston rod rises. While it can be enhanced,
When the work comes off, the operation sensitivity of the piston valve becomes weak. Therefore, the gap is designed in a range where both conditions are satisfied.

However, when the type of work to be handled is light, even if the sensitivity of the piston valve is slightly reduced, there is no fear that the piston rod will suddenly rise when the work falls off, and the workability can be increased by increasing the work lifting speed. In addition, when the weight of the workpiece is large, safety may be required over operability.In the above-described conventional device, the operation sensitivity of the piston valve is adjusted according to the working conditions. There was a problem that could not be done.

Further, since an oil tank for supplying oil to the cylinder is used separately from the cylinder device, there is a problem that a space for installing the oil tank and an oil pipe for connecting the cylinder and the oil tank are required. there were.

Therefore, the present invention solves the above-mentioned problems in the prior art, and can easily adjust the operation sensitivity of the piston valve constituting the sudden rise prevention mechanism, and install a separate oil tank. It is an object of the present invention to provide a cylinder device for a pneumatic work transfer device which does not need to be performed.

[0023]

In order to achieve the above object, the present invention provides a pneumatic work transfer cylinder device having a sudden rise preventing mechanism, which has a cylinder head having an oil passage formed therein, and which is provided on a piston rod chamber side. A cylinder having an air supply / discharge hole, a piston slidably fitted into the cylinder, and an oil having an opening sealed on the outer surface of the cylinder head and removably mounted on the cylinder head. A piston valve receiving recess in which a piston valve having an orifice is slidably fitted on the outer surface of the cylinder head, and the oil is contained in the piston valve receiving recess. A passage is opened, and the head chamber side of the cylinder communicates with the inside of the oil tank via the orifice, and the inside of the oil tank is In the meantime, a plurality of studs are erected around the piston valve accommodating recess, and a closing plug facing the piston valve is fixedly supported on these studs so as to be adjustable in position in the sliding direction of the piston valve. A spring is provided between the piston valve and the closing plug to bias the piston valve away from the closing plug, and when the piston is rapidly moved to the cylinder head side, the piston valve is closed. The orifice slides against the urging force of the spring due to a pressure difference between the oils generated on both sides, and the orifice is closed by a closing plug, so that oil is prevented from flowing from the head chamber side to the oil tank side. ing.

[0024]

In the above construction, pressurized air is supplied from the air supply source to the piston rod chamber side of the cylinder.
The load of the work applied to the piston by the pressure of the air is supported in an equilibrium state. On the other hand, the head chamber side of the cylinder is always filled with oil.

In the above state, when the piston is moved to the cylinder head side, the oil pushed by the piston moves from the oil passage into the piston valve accommodating recess, and then returns to the oil tank through the orifice of the piston valve. It is. When the piston is moved to the opposite side, the oil in the oil tank passes through the orifice and flows into the head chamber side of the cylinder.

If the load applied to the piston in the equilibrium state is removed for some reason due to the work coming off, the equilibrium state between the load and the air pressure is broken, and the piston moves to the piston rod. At the same time, movement to the cylinder head side is started rapidly.

Then, the speed of the oil passing through the orifice of the piston valve rapidly increases, and a large pressure difference is generated on both sides of the orifice. The pressure difference pushes the piston valve toward the closing plug against the urging force of the spring. Move. And
When the piston valve approaches the closing plug, the orifice is closed by the closing plug, and the flow of oil from the head chamber side of the cylinder to the oil tank is prevented, so that rapid movement of the piston rod is prevented.

The operating sensitivity of the piston valve can be adjusted by changing the gap between the piston valve and the plug. The adjustment is performed by removing the oil from the oil tank and then removing the oil tank from the outer surface of the cylinder head. Do it.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a cylinder device for a pneumatic work transfer device having a rapid rise prevention mechanism according to the present invention. The cylinder device 1 is slidably fitted inside a cylinder 2. And a piston rod 4 integral with the piston 3.

The lower part of the piston rod 4 projects below the cylinder 2 so that the work W is held at the lower end thereof. An air supply / discharge hole 6 communicating with the piston rod chamber 5 is formed in a lower portion of the cylinder 2. The air supply / discharge hole 6 has an air supply passage of a booster A having the same structure as the booster shown in FIG. D is connected,
Pressurized air is introduced into the piston rod chamber 5.

On the other hand, the head chamber 7 side of the cylinder 2 is filled with oil. The oil is supplied from an oil tank 10 mounted on the upper part of the cylinder head 8 through an oil passage 9 formed in a cylinder head 8 mounted on the upper end of the cylinder 2.

The oil tank 10 has an opening 10 at the bottom.
A, and a peripheral portion of the opening 10A is detachably fixed to an upper surface of a flange portion 8A formed around the cylinder head 8 by a plurality of fastening members 11. Are sealed by the cylinder head 8. Further, an air vent hole and an oil supply hole are formed at positions not shown in the upper part of the oil tank 10.

On the upper surface of the central portion of the cylinder head 8 which enters the oil tank 10 from the opening 10A, there is formed a circular piston valve accommodating recess 12 in which the oil passage 9 passes through the central portion of the bottom surface. ing.

A piston valve 13 having an outer diameter that matches the inner diameter of the piston valve housing 12 is slidably inserted into the piston valve housing recess 12 up and down. A flowing orifice 13A is formed penetrating vertically.

A plurality of spring guides 14 are provided upright on the upper surface of the piston valve 13 so as to surround the orifice 13A, and the lower ends of springs 15 are guided and supported by the respective spring guides 14.

On the other hand, the upper end of each of the springs 15
The plug 15 is in contact with the lower surface of the ear 17A of the plug 17 supported by a plurality of studs 16 concentrically provided around the piston valve accommodating concave portion 12, and the spring 15 causes the piston valve 13 to be always in contact with the piston valve. It is urged downward so as to be immersed in the accommodation recess 12.

The ear 17A of the plug 17 has
A through hole 17B through which each stud 16 passes is formed, and a nut 18 is screwed onto the upper end of the stud 16 in a state where the stud 16 passes through the through hole 17B.
The plug 17 pressed upward by the repulsive force of the spring 15
Is prevented.

The lower end face 17C at the center of the plug 17
Is opposed to the upper end surface of the piston valve 13 with a space S therebetween. The distance S can be adjusted by rotating the nut 18 to change the vertical position of the plug 17.

The cylinder device 1 constructed as described above is suspended from the ceiling of a building or the like by a suspension portion 19 provided at the upper end of the oil tank 10, and the lower end of the piston rod 4 is not shown. The work W is held via a hanging tool or the like. FIG. 1 shows that the ascending valve P is depressed and the piston rod chamber 5 of the cylinder 2 is moved from the air supply path D.
This shows a state in which pressurized air is being supplied to the side, the work W is in the process of rising, and the oil filled in the head chamber 7 is moved from the oil passage 9 to the piston valve 13 by the rise of the piston 3. It moves into the oil tank 10 through the orifice 13A.

At this time, the oil pressure acting on the upper end face and the lower end face of the piston valve 13 is determined by the oil
Due to the flow resistance at the time of passing through A, the lower end surface side becomes higher and a force for moving the piston valve 13 upward acts, but the upper end of the piston valve 13 is urged downward by a plurality of springs 15. Therefore, it is stopped in the piston valve housing recess 12.

Here, as shown in FIG. 2, when the work W comes off the lower end of the piston rod 4 for some reason, high-pressure air, which has supported the weight of the work W, enters into the piston rod chamber 5. On the other hand, since the pressure of the oil on the side of the head chamber 7 communicating with the oil in the oil tank 10 which is substantially equal to the atmospheric pressure is low, the piston 3 has a large difference in pressure acting on the upper and lower end surfaces thereof. Start the soar.

As a result, the oil filled in the head chamber 7 is rapidly discharged to the oil tank 10 through the orifice 13A of the piston valve 13, and at this time, the flow resistance of the oil rapidly passing through the orifice 13A is reduced. By
The pressure difference between the upper and lower end surfaces of the piston valve 13 increases,
The piston valve 13 moves upward against the urging force of the spring 15, and the orifice 13A of the piston valve 13 is closed by the lower end face 17C of the closing plug 17. When the flow of the oil stops, the piston valve 13 is pressed against the plug 17 by the pressure of the oil acting on the lower end surface of the piston valve 13, and the piston 3 and the piston rod 4 are stopped from rising.

The piston valve 13 when the orifice 13A is closed by moving the piston valve 13 to the closing plug 17 side
Can be adjusted by changing the gap S between the piston valve 13 and the closing plug 17, and the adjustment is performed by loosening the fastening member 11 with the oil in the oil tank 10 empty. Remove the oil tank 10 from the cylinder head 8
8 can be easily rotated.

That is, when the gap S is narrowed, the piston valve 13 immediately abuts against the end face 17C of the closing plug 17 when the pressure difference is generated on both sides of the piston valve 13 to cut off the oil flow and to stop the piston rod 4. The movement is immediately stopped, and the operation sensitivity is increased. However, if the speed of the piston rod 4 is increased during normal use, the piston valve 13
Since it moves only slightly, the speed at which the workpiece is lifted cannot be increased.

On the other hand, when the gap S is increased, the piston valve 13
The distance of movement of the piston rod 4 against the urging force of the spring 15 until it comes into contact with the end face 17C becomes longer, and the operating sensitivity is reduced. Does not operate, so that operability can be improved.

Also, by removing the oil tank 10, the spring 15 can be replaced with one having a different strength.
The plug 17 is replaced with a plug having a different length in the vertical direction, or the piston valve 13 is replaced with an orifice 13A.
It is also possible to adjust the ascending speed of the piston rod 4 when the piston valve 13 operates by exchanging the piston valve 13 with one having a different diameter or length.

In the above-described embodiment, the case where the workpiece W comes off from the lower end of the piston rod 4 while ascending is described.
When the workpiece W falls off from the lower end of the piston rod 4 while the
Operates in a similar manner to prevent the piston rod 4 from rising rapidly.

Further, the cylinder device having the above-mentioned structure can be used for a work transfer device of a balance arm type. That is, in this case, the cylinder device is arranged upside down from the above embodiment, the work is hung on the tip of the balance arm, and the work is suspended upward at the tip of the piston rod on the opposite side of the rotation fulcrum of the balance arm. May be supported. In this case, since the oil tank is located below the cylinder, it is necessary to appropriately change the positions of the air vent holes and the oil supply holes of the oil tank.

[0049]

As described above, according to the cylinder device for the pneumatic work transfer device having the rapid rise prevention mechanism of the present invention, the oil tank is removed from the cylinder head, and the lower end surface of the closing plug and the piston valve are removed. The gap between the end face where the orifice is opened can be adjusted, so the sensitivity of the piston valve that constitutes the sudden rise stop mechanism is set to the optimum sensitivity according to the difference in work conditions such as the weight of the work to be handled. be able to.

Further, since the oil tank is directly connected to the cylinder head, the flow of oil between the head chamber of the cylinder and the oil tank is smooth, and
Compared with a conventional cylinder device in which an oil tank is installed independently of a cylinder, piping between the cylinder and the oil tank can be omitted and installation space can be saved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a work of a pneumatic work transfer cylinder device of the present invention is being lifted.

FIG. 2 is a cross-sectional view showing a state at the moment when a work of the pneumatic work transfer cylinder device of the present invention comes off.

FIG. 3 is a sectional view of a conventional cylinder device for a pneumatic work transfer device.

FIG. 4 is an explanatory view of the operation of a conventional cylinder device for a pneumatic work transfer device. FIG.
(B) shows a balance state, and (c) shows a state at the time of lowering.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cylinder device 2 Cylinder 3 Piston 4 Piston rod 5 Piston rod chamber 6 Air supply / discharge hole 7 Head chamber 8 Cylinder head 8A Flange part 9 Oil passage 10 Oil tank 10A Opening 11 Fastening member 12 Piston valve accommodating recess 13 Piston valve 13A Orifice 14 Spring Guide 15 Spring 16 Stud 17 Closure Plug 17A Ear 18 Nut 19 Suspension

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-147892 (JP, A) JP-A-4-202000 (JP, A) JP-A-5-81200 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) B66F 13 / 24,3 / 26,19 / 00

Claims (1)

(57) [Claims] 1. A cylinder having an oil passage formed in a cylinder head having an air supply / discharge hole formed in a piston rod chamber side, a piston slidably fitted in the cylinder, and the cylinder head. An oil tank having an opening sealed on the outer surface and detachably mounted on the cylinder head, and a piston valve receiving recess in which a piston valve having an orifice is slidably fitted on the outer surface of the cylinder head. Is formed, the oil passage is opened in the piston valve accommodating recess, and the head chamber side of the cylinder is communicated with the inside of the oil tank via the orifice, and the piston valve accommodating recess is provided inside the oil tank. A plurality of studs are erected around the periphery of these studs. A lug is fixedly supported so that the position can be adjusted in the sliding direction of the piston valve, and a spring is provided between the piston valve and the closing plug to bias the piston valve away from the closing plug, When the piston rapidly moves to the cylinder head side, the piston valve slides against the urging force of the spring due to the pressure difference of the oil generated on both sides thereof so that the orifice is closed by the closing plug. A cylinder device for a pneumatic work transfer device having a sudden rise prevention mechanism, characterized by being constituted.