JP2543531Y2 - Pressure control valve for pneumatic cylinder lift - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control valve for controlling a lifting operation of a pneumatic cylinder type lift.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open Publication No.
A pressure control valve disclosed in Japanese Patent No. 54873 is known. In the pressure regulating valve disclosed in JP-A-2-154873,
A supply valve for shutting off the communication between the input port and the output port and an exhaust valve for shutting off the communication between the output port and the exhaust port are opened and closed by the displacement of the first piston. The first piston constitutes a pressure regulating mechanism together with the second piston and a spring disposed between the two pistons.
A pressure regulation chamber is defined above the piston, and
A pressure receiving chamber is defined below the first piston. The pressure regulation chamber is switched to the air supply source and the atmospheric pressure region by a first electromagnetic switching valve installed outside, and the pressure receiving chamber is connected to the output pressure side and the first pressure switching chamber by a second electromagnetic switching valve. The switching communication is performed with the electromagnetic switching valve. The control pressure and the spring pressure introduced into the pressure adjustment chamber and the pressure receiving chamber oppose each other via the second and first pistons, and the first piston is displaced in accordance with a change in the pressure opposition relationship. The supply valve and the exhaust valve are opened and closed by the displacement of the piston, and the speed control at the time of raising and lowering the lift is performed.

[0003]

When the lift is decelerated and lowered, switching control is performed such that the pressure regulating chamber is communicated with the atmosphere and the pressure receiving chamber is communicated with the output pressure side which is an exhaust pressure region. By this switching control, the exhaust pressure becomes slightly lower than the balance pressure against the load, and the lift descends at a low speed.

However, when the load applied to the lift is suddenly reduced by placing the load at a predetermined position, the lift is lowered at a low speed by the balance between the load and the cylinder thrust (force by a pressure slightly lower than the balance pressure). However, a sudden change in the load causes the balance to be lost, and erroneous operations such as stop and reverse movement of the lift are inevitable.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a pressure control valve of a pneumatic cylinder type lift which does not malfunction even if the load fluctuates when the lift is decelerated and lowered. It is.

[0005]

According to one aspect of the present invention in order to achieve the above object, subjected to the connecting passage connecting the input port provided in the housing, an output port and an exhaust port each other
A pressure receiving body is connected to one end of the valve rod, a valve seat is provided at a position facing each valve body, and both valve bodies and valve seats facing them are housed. A valve rod is provided so as to be switchable between three positions: a neutral state in which the exhaust valve and an opposite valve seat abut, and a supply state in which the exhaust valve and the opposite valve seat abut. Pneumatic pressure with a displacement transmission relationship between both valve elements
A pressure control valve for a cylinder type lift, wherein the valve
It is arranged in series to be connectable to the rod and
Piston rod that presses the valve rod of
Provided so that it can move integrally with the ton rod and change the relative position
A piston mechanism composed of
Supply and discharge of fluid to and from the storage space in which the piston is stored
Press the valve rod with piston rod by a certain amount based on
Pressure causes a predetermined displacement of the valve rod
Fluid to control the placement of the exhaust valve in the open position.
An exhaust control means having a supply / discharge means is incorporated. Ma
The relative position between the piston and the piston rod
Includes an operating body operable from outside the housing.
It may be changed by the displacement adjusting mechanism.

[0006]

The output pressure and the exhaust pressure for controlling the speed of the lift during the high-speed rise, deceleration rise and high-speed fall of the lift are adjusted by appropriately adjusting the combination of the pressure opposing relationship via the pressure receiving member. This is performed by switching the valve and the supply valve. Exhaust control during deceleration descent of the lift is not only due to the pressure control via the pressure receiving member, Ru been made by an exhaust control means for controlling placement of the exhaust valve to the open position. here
Therefore, the exhaust control means of the present invention is a piston rod with a valve rod.
Pressure on the piston rod by pressing
The load on the lift.
Even if the balance of pressure opposition is lost due to
Ensure that the exhaust valve remains open without being affected.
Can be. At this time, the lift performs a predetermined operation.
Do it indeed. Therefore, rely only on pressure control via the pressure receiver
Malfunction is less likely to occur than in the conventional configuration. In addition,
According to the configuration of claim 2, the operating body is operated externally to operate the piston.
Changing the rod pressing amount may cause disassembly, etc.
The displacement can be easily adjusted.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 1 shown in FIG.
Reference numeral a denotes a valve housing. The valve housing 1a is provided with an input port 2, an output port 3, and an exhaust port 4 communicating with an air supply source 31, and these ports 2, 3, and 4 are connected by a connection passage T. ing. A muffler 14 is connected to the exhaust port 4. A valve rod 5 is slidably housed in the connection passage T, and a supply valve 6 and an exhaust valve 7 are fitted to the valve rod 5 so as to face each other. A valve seat 8 and a valve seat 9 are formed in the valve housing 1a. The supply valve 6 is urged by a spring 10 in a direction in which the supply valve 6 contacts the valve seat 8, and the exhaust valve 7 contacts the valve seat 9 by a spring 11. Biased in the direction. The input port 2 side and the output port 3 side are shut off by the contact between the supply valve 6 and the valve seat 8, and the exhaust port 4 side and the output port 3 side by the contact between the exhaust valve 7 and the valve seat 9. Is shut off.

The portion of the valve rod 5 between the supply valve 6 and the exhaust valve 7 is formed slightly larger in diameter than other portions, and the length of the large diameter portion is slightly smaller than the distance between the valve seats 8 and 9. It is set short. Therefore, as shown in FIG. 1, the supply valve 6 and the exhaust valve 7 can simultaneously contact the valve seats 8 and 9, respectively, and in this state, the input port 2 and the output port 3
And the exhaust port 4 are shut off from each other.

A first piston housing 1b is joined and fixed above the valve housing 1a, and a second piston housing 1c is joined and fixed below the valve housing 1a. A first piston 16 as a pressure receiving body is slidably housed in the first piston housing 1b, and an upper end portion of the valve rod 5 projects into the first piston housing 1b. Valve rod 5
A first piston 16 is screwed and fixed to an upper end of the first piston 16, and the first piston 16 and the valve rod 5 can move integrally. An upper cap 12 is screwed and fixed to the first piston housing 1b, and a pressure adjusting screw 30 is screwed into the upper cap 12. In the upper cap 12, an adjustment spring 28 is interposed between the spring retainer 29 and the first piston 16. Thereby, the first piston 1
6 is urged in the direction of the valve rod 5 by the adjusting spring 28, and the spring force F of the adjusting spring 28 is adjusted by the screwing position of the pressure adjusting screw 30. The inside of the upper cap 12 communicates with the atmosphere through a communication hole 13.

A second piston 18 is slidably accommodated in the accommodation space of the second piston housing 1c, and a piston rod 17 is slidably fitted to the second piston 18. ing. Therefore, both 17, 18
Integrally movable and one piston mechanism
Make up. In the valve housing 1a, the piston rod 17 is arranged in series with the lower end of the valve rod 5 so as to be able to contact and separate therefrom. This piston rod 17
The valve rod 5 is fixed upward when connected to the rub rod 5
By pressing the valve rod 5 by a predetermined amount,
, Thereby controlling the arrangement of the exhaust valve 7 in the open position.
Play a role. The second piston 18 is urged in a direction away from the valve rod 5 by a spring force of a return spring 19 provided in the second piston housing 1c.

A cylindrical screw portion 18a is formed integrally with the second piston 18, and projects outside from a lower cap of the second piston housing 1c. Piston rod 1
7 is fitted in the cylindrical screw portion 18a, and the cylindrical screw portion 18a
And project outside. On the outer peripheral surface of the cylindrical screw portion 18a, a displacement adjusting mechanism is provided together with the cylindrical screw portion 18a.
Regulatory knob 27 as an operation member for forming is screwed. Operation from the outside possible regulatory knob 27 is slidably engaged with the projecting end of the piston rod 17, piston rod 17 is adapted to be integrally moved control knob 27. Therefore, the relative position between the second piston 18 and the piston rod 17 can be changed by adjusting the screwing position of the adjustment knob 27 with respect to the second piston 18. That is, the external adjustment knob 27 is appropriately rotated and operated.
To change the amount of pressure on the piston rod 17
Therefore, adjust the displacement without disassembling the device
be able to.

A first control port 15 is provided in the first piston housing 1b. First control port 15
Communicates with the connection passage T. The valve housing 1a is provided with a second control port 20. The second control port 20 communicates with a control pressure chamber R1 defined by the first piston 16. The second piston housing 1c is provided with a third control port 21 and a fourth control port 22. The third control port 21 is an upper control pressure chamber R defined by the second piston 18.
The control pressure chamber R3 is in communication with the air supply source 31. The fourth control port 22 is connected to the second piston 1
The control pressure chamber R2 communicates with the air supply source 31 at all times.

A pneumatic cylinder 32 is connected to the output port 3, and a piston 33 in the cylinder 32 can move between a highest position h1 indicated by a solid line in FIG. 1 and a lowest position h2 indicated by a two-dot chain line. It has become. The load W placed on the lift L at the tip of the rod 34 rises and falls due to a change in the pressure in the cylinder 32. A first electromagnetic switching valve 23 and a second electromagnetic switching valve 24 are interposed on a connection passage 26 between the first control port 15 and the second control port 20, and
The third electromagnetic switching valve 25 is connected to the control port 21. First electromagnetic switching valve 23 and third electromagnetic switching valve 2
5 is connected to an air supply source 31, and the second electromagnetic switching valve 24 and the third electromagnetic switching valve 25 have silencers 24 a and 24.
5a is connected. These electromagnetic switching valves 23, 2
Each of the three-port two-position solenoid valves is used as each of the exhaust valves 7 and the supply valve 6 by appropriately changing the combination of excitation and demagnetization of each of the electromagnetic switching valves 23, 24, and 25.
Is performed.

In the state shown in FIG. 1, each of the electromagnetic switching valves 23, 24,
25 are in the demagnetized state, and are in the first switching arrangement position S1.
1, S21 and S31 are selected. Solenoid switching valve 23, 2
4 and 25 are excited, the second switching positions S12, S2
2, S32 is selected. When the first electromagnetic switching valve 23 is switched to the first switching arrangement position S11, the supply of pressure air from the air supply source 31 to the control pressure chamber R1 is cut off, and the control pressure chamber R1 is switched to the second pressure switching chamber R1. It is communicated with the electromagnetic switching valve 24.

When the second electromagnetic switching valve 24 is switched to the first switching position S21, the connection passage 26 communicates with the first electromagnetic switching valve 23. Second switching arrangement position S
When 22 is selected, the first control port 15 is closed, and the silencer 24 a is connected to the first switching solenoid valve 23. The third electromagnetic switching valve 25 is in the first switching position S
The control pressure chamber R3 communicates with the air supply source 31 in the state of being switched to the position 31. When the second switching arrangement position S32 is selected, the supply of the pressurized air from the air supply source 31 to the control pressure chamber R3 is shut off, and the control pressure chamber R3 communicates with the atmosphere.

FIGS. 2 to 5 schematically show the switching state of the supply valve 6 and the exhaust valve 7. FIG. As shown in FIG. 2, when the first and third electromagnetic switching valves 23 and 25 are in the demagnetized state and the second electromagnetic switching valve 24 is in the excited state, the first control port 15 and the second
And the first control port 15 communicates with the atmospheric pressure region via the first and second electromagnetic switching valves 23 and 24. In this state, the control pressure chamber R1 has the atmospheric pressure P
0, and the control pressure chamber R3 becomes the input pressure P.

As shown in FIG. 3, each electromagnetic switching valve 23, 2
When the magnets 4 and 25 are in the demagnetized state, the first control port 15 and the second control port 20 communicate with each other, and the control pressure chamber R3 communicates with the air supply source 31. In this state, the control pressure chamber R1 becomes the pressure of the connection passage T, and the control pressure chamber R2 becomes the input pressure P. As shown in FIG. 4, when the first electromagnetic switching valve 23 is in the excited state and the second and third electromagnetic switching valves 24 and 25 are in the demagnetized state, the first control port 15 and the second control port 20
Is closed. In this state, the control pressure chamber R1 and the control pressure chamber R2 have the input pressure P.

As shown in FIG. 5, when the third electromagnetic switching valve 25 is in the excited state and the first and second electromagnetic switching valves 23 and 24 are in the demagnetized state, the pressure in the control pressure chamber R1 becomes the pressure of the connection passage T, The pressure chambers R2 and R3 become the input pressure P. Piston 3
When the load W is increased from the state where the position 3 is at the lowermost movement position h2, the demagnetization of each of the solenoid-operated directional control valves 23, 24 and 25 is performed as shown in FIG.
Take the combination of

When the second electromagnetic switching valve 24 is in the excited state and the first
FIG. 2 in which the third electromagnetic switching valves 23 and 25 are in a demagnetized state.
In this case, the control pressure chamber R1 has the atmospheric pressure P0 (<P), and the control pressure chambers R2 and R3 have the input pressure P. Since the pressure opposition between the input pressures P via the second piston 18 cancels each other out, the piston rod 17 urged by the spring force of the return spring 19 separates from the variable region of the valve rod 5 in this state. Therefore, the first piston 16 is not affected by the pressures of the control pressure chambers R2 and R3, and the supply valve is provided by opposing the pressure of the control pressure chamber R1 via the first piston 16 and the spring pressure F of the adjusting spring 28. 6 and the exhaust valve 7 are opened and closed. At this time, the pressure opposing relationship via the first piston 16 is expressed by the following equation (1). The diameters of the pistons 16 and 18 are set to be the same, and the pressure receiving areas S1 and S2 of the first piston 16 and the pressure receiving areas S2 and S2 of the second piston 18 in the control pressure chambers R1, R2 and R3, respectively.
3 are substantially equal, and the pressure receiving area S0 on the back side of the first piston 16 is also the same.

[0020]

## EQU1 ## P0.S0 + F> P0.S1 (1) The second piston 18 moves downward due to the pressure opposition represented by the equation (1). The lowermost position of the second piston 18 is a position in contact with the inner bottom surface of the second piston housing 1b. However, even when the second piston 18 is at the lowermost position, the pressure expressed by the expression (1) is obtained. The opposing relationship is established, and the lower end of the valve rod 5 does not contact the upper end of the piston rod 17. When the second piston 18 moves to the lowermost position, the supply valve 6 and the valve seat 8 are largely separated from each other. At this time, the air having the pressure P introduced from the input port 2 is rapidly supplied into the cylinder 32 via the connection passage T and the output port 3. This rapid air supply moves the piston 33 upward at a high speed.

When the piston 33 in the cylinder 32 rises at a high speed to the height position shown in FIG.
Is demagnetized. When the second electromagnetic switching valve 24 is switched from the state of FIG. 2 to the demagnetized state as shown in FIG. 3, the cylinder 32 communicates with the control pressure chamber R1 via the second and first electromagnetic switching valves 24 and 23. I do. Accordingly, the control pressure chamber R1 has the output pressure A (P0 <A <P). Control pressure chambers R2 and R3
Is maintained at the input pressure P as before. The first at this time
The pressure opposing relationship via the piston 16 is expressed by the following equation (2).

[0022]

P0 · S0 + F = A · S1 (2) That is, the pressure in the control pressure chamber R1 rises from the atmospheric pressure P0 to the output pressure A. Since the pressure-to-pressure balance relationship represented by the equation (2) is obtained, the first piston 16 moves slightly upward, and the supply valve 6 approaches the valve seat 8. Since the distance between the supply valve 6 and the valve seat 8 is reduced, the supply speed of the compressed air supplied to the cylinder 32 is reduced. This slow air supply causes the piston 33 to move upward at a low speed. Therefore, the impact when the piston 33 reaches the uppermost position h1 is reduced.

When the load W is lowered from the state where the piston 33 is at the uppermost movement position h1, each of the electromagnetic switching valves 23, 2
4 and 25 take the combination shown in FIG. When only the first electromagnetic switching valve 23 is in the excited state shown in FIG. 4, the control pressure chambers R1, R2 and R3 are all at the input pressure P, and the valve rod 5 and the piston rod 17 are in contact. Never. At this time, the pressure opposing relationship via the first piston 16 is expressed by the following equation (3).

[0024]

## EQU3 ## The second piston 18 moves upward due to the pressure opposition represented by the equation (3). P0.S0 + F <P.S1 The pressure air in the cylinder 32 is discharged to the atmospheric pressure region via the output port 3, the connection passage T, and the exhaust port 4. Since the separation distance between the exhaust valve 7 and the valve seat 9 is large, the exhaust speed is high. Therefore, piston 3
3 moves downward at high speed due to the weight of the load W.

When the piston 33 in the cylinder 32 descends at a high speed to the height position shown in FIG.
3 is demagnetized, and the third electromagnetic switching valve 25 is excited. In the state of FIG. 5 in which the third electromagnetic switching valve 25 is excited from the state of FIG. 4 and the first electromagnetic switching valve 23 is demagnetized, the first control port 15 and the second control port 20 communicate with each other, A third control port 21 communicates with the atmospheric pressure region.
In this state, the control pressure chamber R1 has the exhaust pressure B and the control pressure chamber R2 has the atmospheric pressure P0, but the control pressure chamber R3 is maintained at the input pressure P. Thereby, the second piston 18 moves upward, and the piston rod 17 pushes up the valve rod 5.

The uppermost position of the second piston 18 is a position in contact with the inner bottom surface of the second piston housing 1c. When the second piston 18 is at the uppermost position, the exhaust valve 7
The valve rod 5 is pushed up by the piston rod 17 to a position slightly away from the valve seat 9. Assuming that the second piston 18 is moving downward in FIG. 5,
The pressure opposition relationship via the first piston 16 is given by the following equation (4).
It is represented by

[0027]

P0 · S0 + F = B · S1 (4) In the pressure opposing state represented by the equation (4), the separation between the exhaust valve 7 and the valve seat 9 is obtained so as to obtain this pressure opposing balance relationship. The distance becomes shorter, and the exhaust speed from the cylinder 32 decreases. This slow exhaust causes the piston 33 to move downward at a low speed, and the piston 33 moves to the lowermost movement position h2.
The impact when reaching is alleviated.

When the load W is placed at a predetermined position during the lowering, the operation is performed during the deceleration lowering. If a part of the load W is removed during the deceleration lowering, the pressure of the cylinder 32 is constant. By reducing only the load W, the cylinder 3
The balance between the thrust of No. 2 and the load W is lost. Since the descending speed of the load W is set by the difference between the load W and the thrust of the cylinder 32, the amount of decrease of the load W may prevent the piston 33 from lowering to the lowermost movement position, or may cause the piston 33 to move upward. A situation occurs. Such a malfunction in the cylinder 32 hinders reliable transfer of the load W to a predetermined position and subsequent lifting and lowering work.

In this embodiment, as shown in FIG. 5, the valve rod 5 is pushed up by the piston rod 17 at the time of the transition from the high speed descent to the deceleration descent, and the separation distance between the exhaust valve 7 and the valve seat 9 is the second piston. The distance is equal to or longer than the interval ρ when 18 is moved up. The spacing ρ is set by adjusting the screwing position of the adjustment knob 27. Therefore, in the state of FIG. 5, the cylinder 32 is lowered by the fixed throttle constituted by the interval ρ set by the adjustment knob 27. However, when the state shown in FIG. 4 changes to the state shown in FIG. 5, a rapid change in speed occurs, so that the exhaust pressure B is temporarily increased. However, the valve rod 5 is pushed up by the relation of the equation (4), and the height of the exhaust pressure B which is increased when the interval between the exhaust valve body 7 and the valve seat 9 becomes ρ or more is reduced, thereby suppressing the cylinder bouncing phenomenon.
At this time, the pressure opposing relationship between the pressure in each of the control pressure chambers R1, R2, R3 and the spring pressure F of the adjusting spring 28 is expressed by the following equation (5).

[0030]

## EQU00005 ## P0.S0 + F + P0.S3 <BS1 + PS2 (5) The valve rod 5 is pushed down even when the load W is removed due to the pressure relationship expressed by the equation (5). The interval between the exhaust valve 7 and the valve seat 9 shown in FIG. 4 is maintained at ρ. Therefore, even when the load W is removed during the deceleration lowering, the lift L does not stop on the way or operate in the opposite direction as in the related art, and the load W is reliably placed at the predetermined position.

The following Table (1) shows the combination of the demagnetization of the electromagnetic switching valves 23, 24, 25 and the control pressure chambers R1, R2,
It summarizes the pressure state at R3.

[0032]

[Table 1]

Second piston 18, piston rod 1
7. In the exhaust control means of this embodiment comprising the control pressure chambers R2, R3 and the electromagnetic switching valve 25, the relative position between the second piston 18 and the piston rod 17 is adjusted by the adjustment knob 27.
Is determined by the screw position. That is, the second piston 1
The push-up distance of the valve rod 5 by the piston rod 17 when the 8 moves to the uppermost position, that is, the separation distance ρ between the exhaust valve 7 and the valve seat 9 can be changed. The amount of exhaust from the cylinder 32 is adjusted by such an adjusting mechanism, and the change in the deceleration / lowering speed of the lift L can be easily changed.

The present invention is, of course, not limited to the embodiment described above, but may be, for example, the embodiments shown in FIGS. In the pressure control circuit of FIG.
Instead of 3, 24, 25, a pressure control valve and two 5-port 2-position electromagnetic switching valves 35, 36 are used. Connection path 2 between first control port 15 and second control port 20
A second electromagnetic switching valve 36 is interposed on 6, and an electromagnetic switching valve 35 is connected to the third control port 21.

The following table (2) shows the combination of the demagnetization of the electromagnetic switching valves 35, 36 and the control pressure chambers R1, R2 in the second embodiment.
3 summarizes the pressure conditions.

[0036]

[Table 2]

When the lift L is decelerated and lowered, switching control is performed such that the first electromagnetic switching valve 35 is excited and the second electromagnetic switching valve 36 is demagnetized as shown in FIG.
Accordingly, the same pressure control as in the first embodiment, in which the exhaust valve 7 is kept open even when the load W on the lift L changes, can be performed. According to the second embodiment, there is an advantage that the number of electromagnetic switching valves used in the pressure control circuit can be reduced.

In the third embodiment shown in FIG. 7, a pressure adjusting valve, a 5-port 2-position electromagnetic switching valve 37 and a 3-port 2-position electromagnetic switching valve 38 are used. In this embodiment, an electromagnetic switching valve 37 is interposed on the connection passage 26 between the first control port 15 and the second control port 20, and the fourth control port 2
An electromagnetic switching valve 38 is connected to 2 via an electromagnetic switching valve 37. The third control port 21 is always in communication with the atmospheric pressure region.

The following table (3) shows the combination of the demagnetization of the electromagnetic switching valves 37, 38 and the control pressure chambers R1, R2 in the third embodiment.
Is a summary of the pressure conditions at.

[0040]

[Table 3]

Except when the lift L is decelerated and lowered, the control pressure chamber R
Switching control is performed so that 2 and R3 become the atmospheric pressure P0. The second piston 18 returns by the spring force of the return spring 19. When the lift L is decelerated and lowered, the electromagnetic switching valves 37 and 38 are in a demagnetized state, the first control port 15 and the second control port 20 communicate with each other, and the input pressure P is applied to the fourth control port 22. be introduced. As a result, the second piston 18 moves upward, and the piston rod 17 comes into contact with the valve rod 5, whereby the open state of the exhaust valve 7 is maintained.
The same lifting control as in the second embodiment can be performed.

Further, in the present invention, it is possible to use a diaphragm in place of the first piston 16 as a pressure receiving body.

[0043]

As described above in detail, according to the pressure control valve of the pneumatic cylinder type lift of the present invention, it is assumed that the load fluctuates when the lift is decelerated and lowered, and the pressure counterbalance is lost.
Open the exhaust valve without being affected by
Can be maintained indeed. Therefore, the pressure through the pressure receiver
Unlike conventional arrangement relying only on the force control, an excellent effect that there is no causing erroneous operation.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a pressure control valve of a pneumatic cylinder type lift according to a first embodiment.

FIG. 2 is a conceptual diagram of a pressure control circuit showing a high-speed rising state of a lift L;

FIG. 3 is a conceptual diagram of a pressure control circuit showing a state in which a lift L is decelerated and raised.

FIG. 4 is a conceptual diagram of a pressure control circuit showing a state in which a lift L is rapidly lowered.

FIG. 5 is a conceptual diagram of a pressure control circuit showing a state in which a lift L is decelerated and lowered.

FIG. 6 is a conceptual diagram of a pressure control circuit showing a deceleration and lowering state of a lift L in a second embodiment.

FIG. 7 is a conceptual diagram of a pressure control circuit showing a deceleration and lowering state of a lift L in a third embodiment.

[Explanation of symbols]

1a (valve) housing, 1b (first piston)
Housing, 1c (second piston) housing, 2
Input port, 3 output port, 4 exhaust port, 5 valve rod, 6 supply valve, 7 exhaust valve, 8 valve seat, 9
Valve seat, 16 (first) piston as pressure receiver, 17
Piston rod constituting the exhaust control means 18 constitutes the exhaust control unit (second) piston, 18a constitute an exhaust quantity adjusting mechanism (cylindrical) screw portion, 25 that make up the exhaust control means fluid supply and exhaust means as (third) the electromagnetic switching valve, serving as an operation member that make up the 27 exhaust amount adjusting mechanism
Adjusting knob, T connecting passage, R2, R3 control pressure chamber to an exhaust control means.

Claims (2)

(57) [Scope of request for utility model registration] 1. A supply valve (6) in a connection passage (T) connecting an input port (2), an output port (3) and an exhaust port (4) provided in a housing (1a, 1b, 1c). , An exhaust valve (7) and a valve rod (5) are housed, a pressure receiving body (16) is connected to one end of the valve rod (5), and a valve seat is provided at a position facing each valve body (6, 7). (8,
9), a neutral state in which both the valve bodies (6, 7) and the valve seats (8, 9) opposed thereto are in contact with each other, and a supply valve (6).
And an exhaust state in which the valve seat (8) abuts against the valve seat,
Displacement transmission between the valve rod (5) and the two valve bodies (6, 7) so that the exhaust valve (7) and the valve seat (9) opposed thereto can be switched to three positions of a supply state where the exhaust valve (7) and the valve seat (9) abut thereon. Set Relationship
A pressure control valve for a pneumatic cylinder type lift, which is connected in series with said valve rod (5).
That presses the valve rod (5) when connected and connected
Ton rod (17) and its piston rod (17)
Fixie provided so that it can be moved integrally and the relative position can be changed
(18), and a housing space (R2) in which the piston (18) is housed.
, R3) based on the supply and discharge of fluid to the valve rod
(5) Pressing a certain amount with the piston rod (17)
As a result, a predetermined displacement is generated in the valve rod (5).
And thereby control the arrangement of the exhaust valve (7) to the open position.
Incorporating exhaust control means with fluid supply / discharge means (25)
Pressure control valve for the pneumatic cylinder lifting, characterized in that I. 2. The piston (18) and the piston lock ( 2 ).
Relative to the housing (1a, 1).
b, 1c) including an operation body (27) that can be operated from outside
The pressure control valve for a pneumatic cylinder type lift according to claim 1, wherein the pressure control valve is changed by a displacement adjusting mechanism .