JPH11230111A - Fluid pressure actuator jump-out prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pop-out prevention device for a hydraulic actuator having a wide selection range of a main switching valve despite its relatively simple structure. SOLUTION: A pop-out prevention device 1 is installed between a fluid pressure actuator 2 and a main switching valve 17. The first valve portion 31 is provided with two passages 5 branching from the main flow passages 8 and 10.
The high pressure side is communicated with the pressure fluid 2 and 53, and the pressure fluid flowing therethrough is constantly output to the output side. The second valve portion 32 switches between the pop-out prevention state and the normal use state. In the former state, the secondary areas of both the main flow paths 8 and 10 and the output side of the first valve portion 31 communicate with each other, and both the primary and secondary areas of both the main flow paths 8 and 10 are shut off. . In the latter state, the connection between the secondary area of both main flow paths 8 and 10 and the output side of the first valve portion 31 is cut off, and the primary and secondary areas of both main flow paths 8 and 10 are communicated with each other. . The on-ready timer section 33 is turned on after a lapse of a predetermined time from the start of fluid supply, and switches the second valve section 32 from the pop-out prevention state to the normal use state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus which is installed between a fluid pressure actuator and a main switching valve to prevent a moving body from jumping out at the start of driving.

[0002]

2. Description of the Related Art It has been known that, in a fluid pressure actuator such as an air cylinder, if there is no air in a pressure action chamber defined in a cylinder tube, a piston may jump out at the start of driving. FIG. 8 illustrates a conventional technique for preventing such a protrusion of the piston. A similar technique is described in Jpn.
This is also disclosed in the official gazette.

FIG. 8 shows a cylinder drive system including an air cylinder 121, a main switching valve 122, a main valve 123, a pressurized air supply source 124, and a spill-out prevention device (safety control valve) 125. A piston 127 is accommodated in a cylinder tube 126 that constitutes the air cylinder 121, and the piston 127
A pair of pressure action chambers 128 and 129 are defined therein. The main switching valve 122 is a 3-position 5-port center-closed solenoid valve. The main valve 123 is a two-position, three-port solenoid valve (so-called three-way valve). Original valve 12
3 is connected to the pressurized air supply source 124,
The 0 port is connected to the P1 port of the main switching valve 122. The A1 port of the main switching valve 122 is connected to the first main flow path 130
Through one of the pressure action chambers 128 through the main switching valve 1
The B1 port 22 communicates with the other pressure action chamber 129 via the second main flow path 131. Projection prevention device 1
Reference numeral 25 includes a first control valve 132, a logic valve 133, and a speed controller 134 serving as an off-ready timer. The logic valve 133 is a two-position three-port spool valve, and its P2 port is connected to the P1 port of the main switching valve 122. The first control valve 132 is a 2-position 5-port spool valve, and its P3 port and P4 port are connected to the P3 port and P4 port of the logic valve 133, respectively. First control valve 132
A3 port is connected to the first main flow path 130, and B3 port is connected to the second main flow path 131. The first control valve 132 has a pilot pressure of P2
Pressurized air supplied to the port is speed controller 1
34. Pressurized air flowing through both main flow paths 130 and 131 is similarly applied to the logic valve 133 as pilot pressure.

In the prior art configured as described above, when pressurized air is supplied to the P2 port of the logic valve 133, the first control valve 132 switches from the residual pressure removing position to the pop-out preventing position, and the piston 127 is prevented from jumping out. When one of the A1 port and the B1 port reaches the predetermined pressure value, the logic valve 133 switches from the communicating position to the shut-off position. Thereafter, the main switching valve 122
Is switched to the operating position, the logic valve 133 is held at the shut-off position, so that the air cylinder 121 can be used normally.

[0005]

However, with the configuration of the prior art described above, the solenoid valve that can be used as the main switching valve 122 is practically limited to only the center-closed type. There was a disadvantage that the width was extremely small. Further, if a center-open type solenoid valve is used, the exhaust from the R1 and R2 ports via the main flow paths 130 and 131 is performed, so that it is necessary to provide another device (such as a solenoid valve). Inevitably, the entire circuit becomes complicated.

[0006] Further, such a projection prevention device 12
In the fifth example, in addition to the first control valve 132, a logic valve 133 having a special structure was required to operate the first control valve 132. This has caused the structure and size of the device 132 to be complicated.

Further, in the prior art, the number of external pipes provided for connecting each device is large, which also causes the whole circuit to be complicated. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a device for preventing a hydraulic actuator from popping out with a wide selection range of a main switching valve despite its relatively simple structure. It is in.

[0008]

According to a first aspect of the present invention, there is provided a moving body driven by a pressure fluid and a pair of pressure action chambers defined by the moving body. An apparatus that is installed on a pair of main flow paths that connect a fluid pressure actuator and a main switching valve that alternately supplies the pressure fluid into the pair of pressure action chambers, and that prevents the moving body from jumping out at the start of driving. ,
A first valve portion which communicates a side of the two passages branched from the both main flow paths with a relatively high pressure side and constantly outputs a pressure fluid flowing through the high pressure side passage to an output side; A pop-out prevention state in which the secondary region of the two main flow paths connected to the output side of the first valve portion and the primary region and the secondary region of the two main flow paths are both shut off, It cuts off between the secondary area of the two main flow paths and the output side of the first valve portion, and switches to a normal use state in which the primary area and the secondary area of the both main flow paths are communicated with each other. A second valve portion which is switched on and which is turned on after a lapse of a predetermined time from the fluid supply start time, thereby switching the second valve portion from the pop-out prevention state to the normal use state, and holding the state thereafter. And a timer section. The prevention device jumping out of the fluid pressure actuator and its gist that.

According to a second aspect of the present invention, in the first aspect, the second valve portion is a two-position five-port valve in which a spool is movably housed in a main body. According to a third aspect of the present invention, in the first aspect, the second valve portion is a pilot-pressure single-drive type two-position five-port valve in which a spool is movably accommodated in a main body, and The timer unit is connected to a pilot port of the 2-position 5-port valve, and is turned on when the pressure on the output side of the first valve unit reaches a constant value to drive the spool. It is assumed that it is an on-ready timer section.

According to a fourth aspect of the present invention, in the third aspect, the fluid pressure type on-ready timer unit includes a speed controller including a check valve and a throttle valve connected in parallel, and a fluid reservoir in series. It was connected.

[0011] The invention according to claim 5 is the invention according to claims 2 to 4.
In any one of the above, the second valve portion is provided with an urging means for returning the spool to a normal side position in the pop-out prevention state, and an adjustment for adjusting the urging force of the urging means. Means.

[0012] The invention according to claim 6 is the invention according to claims 1 to 5.
In any one of the above, the first valve portion is a pair of valve seats formed facing each other, and a valve body which is arranged to be able to reciprocate between the two valve seats so as to contact and separate from the two valve seats. And a shuttle valve consisting of

According to a seventh aspect of the present invention, in the sixth aspect, the shuttle valve is formed in a passage in the main body. According to an eighth aspect of the present invention, in any one of the fourth to seventh aspects, the fluid reservoir is formed at an end of a spool accommodation space in the main body,
The speed controller is provided on a wall located between the fluid reservoir and the shuttle valve forming portion.

The invention according to claim 9 is the invention according to claims 3 to 8
In any one of the above, at least one end of the spool is provided with a detent mechanism for holding the spool at a normal position in the pop-out preventing state until the pilot pressure reaches a predetermined value. did.

According to a tenth aspect of the present invention, in the ninth aspect, the detent mechanism includes a concave portion formed on an outer peripheral surface of an end of the spool, a sphere that can be disengaged from the concave portion, and the sphere. Urging means for urging the spherical body in the radial direction of the spool to engage with the concave portion.

Hereinafter, the "action" of the present invention will be described. According to the first aspect of the present invention, before the supply of the fluid is started, the on-ready timer section is still in the off state, so that the second valve section is in the pop-out prevention state. When the supply of the pressure fluid is started, the output side of the first valve section and both the pressure action chambers are communicated, and the pressure fluid flowing through the main flow path on the high pressure side flows through the first valve section and the second valve section. It flows into the pressure chamber almost simultaneously. As a result, a difference between the pressures in the two pressure action chambers hardly occurs, and the moving body is prevented from jumping out. When a predetermined time elapses from the fluid supply start time, the on-ready timer section is turned on, so that the second valve section is switched to the normal use state, and that state is maintained thereafter. At this time, the secondary area of both main flow paths and the output side of the first valve portion are shut off, but the primary area and the secondary area of both main flow paths are communicated with each other. Therefore, the moving body starts a normal reciprocating operation by alternately supplying the pressure fluid into the pair of pressure action chambers through the pair of main flow paths.

According to the configuration of the present invention, since the second valve section performs a predetermined operation using the first valve section and the on-ready timer section, a logic valve having a special structure as in the prior art is used. do not need. Therefore, a pop-out prevention device having a relatively simple structure can be provided. Further, the solenoid valve that can be used as the main switching valve is not limited to the center closed type, and the range of choice of the main switching valve is increased.

According to the second aspect of the present invention, when the spool accommodated in the main body moves to one side, it is switched to the pop-out prevention state, and when it is moved to the other side, it is switched to the normal use state.

According to the third aspect of the present invention, the on-ready timer is in the off state until the pressure on the output side of the first valve reaches a constant value. The specified pilot pressure is not applied to the port. The spool remains at the normal position at this time. When the pressure on the output side of the first valve unit reaches a constant value, the on-ready timer unit is turned on, and as a result, a predetermined pilot pressure is applied to the pilot port of the second valve unit. Then, the spool moves from the normal position to the pilot pressure side position, and the second valve portion switches from the pop-out prevention state to the normal use state.
Such a fluid-type on-ready timer unit does not require a control program or the like by a sequencer, unlike the case of using an electric type, so that it is suitable for cost reduction.

According to the fourth aspect of the present invention, the pressure fluid flows into the fluid reservoir from the output side of the first valve portion via the speed controller connected in series with the fluid reservoir. Since the flow rate of the pressure fluid is regulated by the throttle valve, the pressure in the fluid reservoir rises gradually, not suddenly. The amount of pressurized fluid flowing into the fluid reservoir can be adjusted by changing the opening of the throttle valve. When the pressure in the fluid reservoir reaches a predetermined value after a certain period of time, the spool moves from the normal position to the pilot pressurized position by the action of the pilot pressure. As a result, the second valve portion switches from the pop-out prevention state to the normal use state.
Since the check valve is connected to the throttle valve in parallel, the time required for the fluid to be discharged from the fluid reservoir is relatively short, and the responsiveness of the second valve portion is excellent.

According to the fifth aspect of the present invention, since the urging force of the urging means is working, when the pilot pressure is lost, the spool is pushed back from the pilot pressure side position to the normal side position. In this case, since the urging force can be adjusted by the adjusting means, an appropriate urging force corresponding to the pilot pressure can be applied to the spool. As described above, the spool can be quickly and reliably returned, and the responsiveness and reliability are improved.

The operation of the present invention will be described.
If the one located on the main flow path side which is relatively high pressure side is the first valve seat and the one located on the main flow path side which is relatively low pressure side is the second valve seat, the valve element is moved to the second valve seat by fluid pressure. Move from one valve seat to a second valve seat. As a result, the valve element abuts on the second valve seat to shut off the main flow path on the relatively low pressure side, and allows only the main flow path on the relatively high pressure side to communicate. Therefore, the pressure fluid flowing through the main flow path is constantly output to the output side. In addition, with a shuttle valve having such a structure,
It has the advantage that it can be realized with an extremely simple structure, and is suitable for cost reduction.

According to the seventh aspect of the present invention, since the shuttle valve is formed in the passage in the main body of the second valve portion, the external piping can be reduced as compared with a case where the shuttle valve is separately provided. Therefore, the pop-out prevention device itself becomes compact, and the circuit is simplified as a whole.

According to the eighth aspect of the present invention, the number of external piping can be reduced as compared with the case where the fluid reservoir and the speed controller are provided separately from the second valve portion. Therefore, the pop-out prevention device itself becomes compact, and the circuit is simplified as a whole.

According to the ninth aspect, the spool is held at the normal position by the operation of the detent mechanism until the pilot pressure reaches the predetermined value.
The spool is not displaced therefrom. Therefore,
Until a predetermined time elapses from the start of the fluid supply, the pressurized fluid is simultaneously supplied to both the pressure action chambers, so that the projection is surely prevented.

According to the tenth aspect of the present invention, the sphere is engaged with the concave portion by the urging force of the urging means until the pilot pressure reaches the predetermined value. Can not move along.
Therefore, the spool is still held at the normal position. When the pilot pressure reaches a predetermined value, the effect becomes relatively larger than the effect of the urging force. Then, the sphere comes off from the concave portion, and the spool can move along its own axial direction. Therefore, the spool moves from the normal side position to the pilot pressure side position. In addition, since the detent mechanism including the recess, the sphere, and the urging means has a simple structure, it can be easily assembled in the main body of the second valve portion.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] Hereinafter, a protrusion prevention device according to a first embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 is a circuit diagram showing the entire cylinder drive system S1 of the present embodiment. FIG. 2 is a cross-sectional view showing the pop-out prevention device 1 used in the system S1. The fluid pressure actuator used here is a rodless air cylinder 2 (hereinafter simply referred to as a rodless cylinder 1) driven by using pressurized air as a fluid.
Call. ). A piston 4 as a moving body is housed in a cylinder tube 3 constituting the rodless cylinder 2 so as to be able to reciprocate. The piston 4 partitions the internal space of the cylinder tube 3 into a pair of pressure action chambers 5 and 6. In FIG. 1, the one located on the left end side of the piston 4 is called a first pressure action chamber 5, and the one located on the right end side of the piston 4 is called a second pressure action chamber 6. The second port region of the first main flow path 8 is connected to the first port 7 communicating with the first pressure action chamber 5. The second port 9 communicating with the second pressure action chamber 6 has a second port 9.
Of the main flow path 10 are connected. A slider 1 as a follower is provided on the upper surface of the cylinder tube 3.
1 is provided movably. The slider 11 and the piston 4 are connected to each other via a slit (not shown) formed on the upper surface of the cylinder tube 3. Therefore, when pressurized air is supplied from the first main flow path 8 side,
The pressure in the first pressure action chamber 5 increases, and the piston 4 and the slider 11 move integrally in the rightward direction in FIG. Conversely, when the pressurized air is supplied from the second main flow path 10 side, the pressure in the second pressure action chamber 6 increases, and the piston 4 and the slider 11 move integrally in the leftward direction in FIG. .

The system S1 includes a pressurized air supply source 16 and a main switching valve 17 in addition to the rodless cylinder 2. In FIG. 1, a 3-position 5-port center open type switching solenoid valve is used as the main switching valve 17. The main switching valve 17 has five ports, A1 port, B1 port, P port, R1 port and R2 port. The main switching valve 17 includes two solenoids 18A and 18B and two return springs 19.
A, 19B are provided at both ends, and are of a double solenoid type. The P port is connected to a pressurized air supply 16. The A1 port is connected to the primary area of the first main flow path 8, and the B1 port is connected to the primary area of the second main flow path 10. The R1 port and the R2 port are both free and are connected to the atmospheric pressure region.

The main switching valve 17 can switch between three states: a neutral state, a first switching state, and a second switching state. When both of the solenoids 18A and 18B are demagnetized, the biasing forces of the pair of return springs 19A and 19B are balanced, so that the main switching valve 17 does not move in either the left or right direction in FIG. Therefore, at this time, the main switching valve 17 is in the neutral state. The A1 port communicates with the R1 port, and the B1 port communicates with the R2 port, but the P port does not communicate with any port. Therefore,
In this state, the two main flow paths 8, 10 are supplied from the pressurized air supply source 16.
No pressurized air is supplied.

When only the solenoid 18A located on the left side of FIG. 1 is excited, the main switching valve 17 is pressed to the right side of FIG. 1 and moves in that direction, so that the first switching state is established. At this time, A1 port communicates with P port and B port
One port communicates with the R2 port, but the R1 port no longer communicates with any port. Accordingly, the pressurized air coming from the pressurized air supply source 16 is supplied to the first main flow passage 8 and the pressurized air coming from the second main flow passage 10 is discharged to the outside from the R2 port. .

When only the solenoid 18B located on the right side of FIG. 1 is excited, the main switching valve 17 is pressed to the left side of FIG. 1 and moves in that direction, so that the second switching state is established. At this time, the A1 port communicates with the R1 port and the B1 port communicates with the P port, but the R2 port does not communicate with any port. Accordingly, the pressurized air coming from the pressurized air supply source 16 side is supplied to the second main flow path 10 and the pressurized air coming from the first main flow path 8 side is discharged to the outside from the R1 port. .

In other words, the main switching valve 17 serves to alternately supply compressed air to the pair of pressure chambers 5 and 6 of the rodless cylinder 2 through the pair of main flow paths 8 and 10. The pair of solenoids 18A, 18
B is driven based on a predetermined drive signal from a sequencer (not shown) that exists separately from the system S1.

As shown in FIG. 1, a first speed controller 20 is provided in a secondary area of the first main flow path 8, and a first speed controller 20 is provided in a secondary area of the second main flow path 10. Two speed controllers 21 are provided. Each of these speed controllers 20 and 21 comprises a check valve 22 and a throttle valve 23 connected in parallel. The check valve 22 allows pressurized air to pass only in the direction of flowing into the rodless cylinder 2. Therefore, the pressurized air flowing out of the rodless cylinder 2 cannot pass through the check valve 22 but passes through the throttle valve 23. At that time, the flow rate is regulated according to the opening degree of the throttle valve 23. The pressurized air flowing into the rodless cylinder 2 can pass through the check valve 22, so that the flow rate is not restricted by the throttle valve 23 at that time. That is, when the opening degree of the speed controllers 20 and 21 is increased, the moving speed of the piston 4 increases, and when the opening degree is reduced, the moving speed of the piston 4 decreases.

Further, the pop-out prevention device 1, which is a component of the system S1, is installed on the pair of main flow paths 8, 10 connecting the rodless cylinder 2 and the main switching valve 17. The pop-out prevention device 1 of the present embodiment includes a first
The shuttle valve 31 includes a shuttle valve 31 serving as a valve unit, a pilot-pressure single-drive two-position 5-port valve 32 serving as a second valve unit, and an on-ready timer unit 33. The shuttle valve 31 and the on-ready timer section 33 are both provided in a part of the main body 34 of the 2-position 5-port valve 32.

As shown in FIG. 2, a spool housing space 35 is formed in the center of the main body 34. A first external connection port 36, a second external connection port 37, a third external connection port 38, and a fourth external connection port 39 are provided on the outer peripheral surface of the main body 34. The first external connection port 36 and the third external connection port 38 form a part of the first main flow path 8, and the second external connection port 37 and the fourth external connection port 39 are connected to the second main flow path 10. Is part of. Note that these four external connection ports 36 to 39 are schematically shown by white circles in FIG. The two-position five-port valve 32 as the main switching valve is schematically shown in FIG. 1 as having a pilot port Pt in addition to the five ports A2, A3, B2, B3, and P. ing.

In FIG. 2, the spool accommodation space 35
The four external connection ports 36 to 39 communicate with each other at different positions. The spool 40 is accommodated in the spool accommodation space 35 so as to be slidable along its own axis. The spool 40 moves between two positions: a normal position (a left position in FIG. 1) and a pilot pressure side position (a right position in FIG. 1). In FIG. 2, the spool 40 is illustrated as being in the normal position.

The spool 40 has pistons 42 and 43 at both ends of a shaft 41. The shaft portion 41 has first to fifth lands (that is, large-diameter portions that are in sliding contact with the inner wall surface of the spool housing space 35) in order from the left side in FIG. An annular packing for improving the sealing property is mounted on the outer peripheral surface of each land.

The first piston portion 42 located on the left side of FIG.
An annular packing 44 having a substantially Dharma-shaped cross section is mounted on the outer peripheral surface near the right end of the. An urging means accommodating recess 45 is formed at the center of the left end surface of the first piston portion 42. A coil spring 46 as an urging means is accommodated in the urging means accommodating recess 45. One end of the coil spring 46 is in contact with the inner bottom surface of the urging means accommodating recess 45, and the other end is in contact with the inner surface of the left side wall partitioning the spool accommodation space 35. The spring force of the coil spring 46 always acts to urge the spool 40 rightward in FIG. Therefore, the coil spring 46 plays a role of returning the spool 40 to the normal position. In addition, the spool accommodation space 35
A first passage 50 is provided in a left wall partitioning the first piston portion 42, whereby a space on the left end side of the first piston portion 42 is communicated with the atmospheric pressure region.

The second piston portion 43 located on the right side of FIG.
An annular packing 44 having a substantially Dharma-shaped cross section is mounted on the outer peripheral surface near the left end, and an annular packing 47 having a substantially V-shaped cross section is mounted on the outer peripheral surface near the right end. A concave portion 48 is formed on the right end surface of the second piston portion 43. The right end area of the spool housing space 35 where the right end surface of the second piston portion 43 exists is formed slightly larger than the other area in the spool housing space 35. In the right end region of the second piston portion 43, an air reservoir 49 is defined as a fluid reservoir.

As shown in FIG. 2, the main body 34 further includes a second passage 51, a third passage 52, and a fourth passage 5.
3 are formed. A second part of the first main channel 8
The passage 51 communicates the first external connection port 36 with the lower end of the shuttle valve forming space 54. The third passage 52 that forms a part of the second main flow path 10 connects the second external connection port 37 to the upper end of the shuttle valve forming space 54. The fourth passage 53 communicates a portion substantially serving as a P port with an output side (that is, a central portion) of the shuttle valve forming space 54.

The shuttle valve 31, which is the first valve portion, includes a pair of valve seats 55 and 56 and a valve body 57. One valve seat 55
Is formed at the lower end side entrance of the shuttle valve formation space 54, and the other valve seat 56 is formed at the upper end side entrance of the shuttle valve formation space 54. These valve seats 55 and 56 are arranged facing each other at a predetermined distance. A substantially cylindrical valve body 57 made of rubber is arranged between both valve seats 55 and 56 so as to be able to reciprocate. When the valve body 57 is at the lowermost position, the valve body 57 is separated from the upper end side valve seat 56, while
It abuts on the lower end side valve seat 55 to shut off the space between the second passage 51 and the shuttle valve forming space 54. At this time, the third passage 52
And the shuttle valve forming space 54 and the fourth passage 53 and the shuttle valve forming space 54 are in communication with each other. Conversely, when the valve body 57 is at the uppermost position,
7 is separated from the lower end valve seat 55, while the upper end valve seat 56
To shut off the space between the third passage 52 and the shuttle valve forming space 54. At this time, the second passage 51 and the shuttle valve formation space 54 and the fourth passage 53 and the shuttle valve formation space 54 communicate with each other. It should be noted that such a valve body 57 moves in any of the upper and lower directions due to the pressure difference of the pressurized air acting on both end surfaces of the valve body 57. If the pressure acting on the lower end surface side is relatively large, the valve body 57 moves upward, and if the pressure acting on the upper end surface side is relatively large, the valve body 57 moves downward. In other words, the shuttle valve 31 communicates the relatively high pressure side of the two main flow paths 8 and 10 and outputs the pressure air flowing through the main flow paths 8 and 10 to the output side (that is, the connection portion with the fourth passage 53). ) Always plays a role.

The on-ready timer section 33 used in this embodiment is of a hydraulic type and is constituted by connecting a speed controller 61 and an air reservoir 49 in series. The on-ready timer section 33 is connected to the pilot port (see Pt in FIG. 1) of the 2-position 5-port valve 32 and is turned on when the pressure on the output side of the shuttle valve 31 reaches a constant value. It plays the role of driving the 40.

The speed controller 61 is provided on the right side wall 62 located between the air reservoir 49 and the shuttle valve forming portion 54. The speed controller 61
It comprises a check valve 63 and a needle valve 64 as a throttle valve. A through hole is formed in the right side wall 62 to allow the fourth passage 53 side to communicate with the air reservoir 49 side.

A needle valve 64 is provided at the right opening of one of the through holes.
Are disposed so as to be able to come and go. A thread groove is formed on the outer peripheral surface of the needle valve 64. The proximal end of the needle valve 64 protrudes out of the apparatus via a screw hole 67 formed in the main body 34 so that the needle valve 64 can be turned. When the needle valve 64 is rotated in the immersion direction, the valve opening decreases, and when the needle valve 64 is rotated in the protruding direction, the valve opening increases.

A check valve 63 constituted by a valve body and a coil spring is provided in the other through hole.
The check valve 63 allows the passage of pressurized air only in a direction in which the air flows into the air reservoir 49 from the fourth passage 53 side. Therefore, the pressurized air that is going to flow into the air reservoir 49 from the fourth passage 53 cannot pass through the check valve 63 but passes through the needle valve 64. At this time, the flow rate is regulated according to the opening degree of the needle valve 64, and the pressure in the air reservoir 49 gradually increases, not suddenly.
When the valve opening of the needle valve 64 is increased, the pressure in the air reservoir 49 (that is, the pilot pressure) becomes a constant value from the time when the supply of the pressurized air is started, that is, the value required for moving the spool 40. Takes longer to reach. In other words, the time required for the on-ready timer unit 33 to change from the off state to the on state becomes longer. On the other hand, when the valve opening of the needle valve 64 is reduced, the time required from the start of the supply of the pressurized air until the pilot pressure reaches a certain value is shortened. In other words, the time required for the on-ready timer unit 33 to change from the off state to the on state is shortened.

The fourth passage 53 from the air reservoir 49 side
The pressurized air flowing to the side can pass through the check valve 63, so that the flow rate is not regulated by the needle valve 64 at that time.

When the on-ready timer section 33 is in the off state, the pressure in the air reservoir 49 is still small, and the force for pressing the right end face of the second piston section 43 leftward in FIG. 2 is still small. Therefore, the spool 40 is provided in the spool accommodation space 3
5 cannot move to the left side against the sliding resistance received by the sliding contact with the inner wall surface and the spring force of the coil spring 46. Therefore, the spool 40 remains at the normal position.

When the spool 40 is at the normal position, the two-position five-port valve 32 is in a state in which it does not pop out.
In this state, the P port, the A3 port, and the B3 port communicate with each other. Therefore, the shuttle valve 31
The pressurized air flowing through the fourth passage 53 connected to the output side of the third port can reach the third and fourth external connection ports 38 and 39 via a portion that is a P port. Therefore, the first
The secondary side region of the first main flow path 8 connected to the pressure action chamber 5 and the output side of the shuttle valve 31 communicate with each other. The secondary side area of the second main flow path 10 connected to the second pressure action chamber 6 is similarly connected to the output side of the shuttle valve 31.

On the other hand, at this time, both the A2 port and the B3 port do not communicate with other ports. Therefore, between the primary side area and the secondary side area of the first main flow path 8 and between the primary side area and the secondary side area of the second main flow path 10 are all shut off.

When the on-ready timer section 33 is turned on, the pressure in the air reservoir 49 becomes sufficiently large, and the force for pressing the right end face of the second piston section 43 leftward in FIG. 2 increases. Therefore, the spool 40 located at the normal position moves against the above-described sliding resistance and spring force, and reaches the pilot pressure position. As a result, the 2-position 5-port valve 32 switches from the pop-out prevention state to the normal use state. In this state, the communication between the A2 port and the A3 port and the communication between the B2 port and the B3 port are performed.

On the other hand, at this time, the P port stops communicating with other ports. Therefore, the pressurized air flowing through the fourth passage 53 connected to the output side of the shuttle valve 31 is P
The third and fourth external connection ports 38 and 39 cannot be reached via the port.

After the on-ready timer section 33 is switched from the off state to the on state, the on state is maintained as long as the pilot pressure of a predetermined value or more is applied.
Therefore, even after switching from the pop-out prevention state to the normal use state, the normal use state is maintained throughout the supply of pressurized air.

Next, the operation of the system S1 of this embodiment will be described. In an initial state before the supply of pressurized air is started, the main switching valve 17 is still in a neutral state. The on-ready timer section 33 is in the off state and the spool 40
Is located at the normal side position, the 2-position 5-port valve 32 is still in the pop-out preventing state. At this time, the pressurized air is not supplied from the pressurized air supply source 16 to both the main flow paths 8 and 10, and the piston 4 is not driven.

When the main switching valve 17 is set to the first switching state, A
As a result of communication between the 1 port and the P port, pressurized air is supplied to the primary region of the first main flow path 8 via these ports. At this time, pressurized air is not supplied to the primary region of the second main flow path 10. Since the A2 port of the 2-position 5-port valve 32 is in the shut-off state, the pressurized air supplied to the primary area of the first main flow path 8 is supplied to the shuttle valve 31 via the second passage 51 branched from the area. Flows into the side.

At this time, since the pressurized air is not supplied to the third passage 52 branching from the primary region of the second main flow passage 10, the side where the lower end valve seat 55 is located is relatively high pressure side. On the other hand, the side with the upper end valve seat 56 is a relatively low pressure side. Therefore, the pressurized air that has flowed in from the second passage 51 presses the valve body 57 to separate it from the lower valve seat 55 and flows out from the fourth passage 54 on the output side.

Since the 2-position 5-port valve 32 is in the pop-out preventing state, the P port, the A3 port and the B3 port communicate with each other. Therefore, the pressurized air reaching the fourth passage 53 can flow to both the third and fourth external connection ports 38 and 39. Then, the pressurized air that has reached the third external connection port 38 flows into the first pressure action chamber 5 via the secondary area of the first main flow path 8. 4th
The pressurized air that has reached the external connection port 39 flows into the second pressure action chamber 6 via the secondary region of the second main flow path 10. As described above, as a result of the pressurized air flowing into the two pressure action chambers 5 and 6 almost simultaneously, there is almost no difference between the pressures in the two pressure action chambers 5 and 6. Accordingly, the pressing forces of the pressurized air acting on both end surfaces of the piston 4 at the start of driving are offset. Therefore, even if the supply of the pressurized air is started, the piston 4 does not accidentally jump out.

Since the on-ready timer section 33 is turned off until a predetermined time elapses from the start of the supply of the pressurized air, the pilot port P of the 2-position 5-port valve 32 is turned off.
No predetermined pilot pressure is applied to t. Spool 40
At this time, stays at the normal side position and maintains the pop-out prevention state. Therefore, the supply of the pressurized air to both pressure action chambers 5 and 6 is continued.

When a predetermined time has elapsed from the start of the supply of the pressurized air, the on-ready timer section 33 is turned on, so that a predetermined pilot pressure is applied to the pilot port Pt of the 2-position 5-port valve 32. Then, the spool 40 moves from the normal side position to the pilot pressurizing side position, and the 2-position 5-port valve switches from the pop-out prevention state to the normal use state, and thereafter the state is maintained.

Accordingly, the pressurized air reaching the primary region of the first main flow path 8 is supplied to the first and third external connection ports 36,
It can flow into the secondary side region of the same main flow path 8 and further into the first pressure action chamber 5 through the passage 38. Therefore, the piston 4 and the slider 11 start to move rightward in FIG. The air in the second pressure action chamber 6 is supplied to the secondary area of the second main flow path 10, the fourth and second external connection ports 39 and 37, the primary area of the main flow path 10, the main switching valve. 17
The air is smoothly discharged from the R2 port to the atmospheric pressure region via the A2 port. When the main switching valve 17 is switched from the first switching state to the second switching state after the piston 4 and the slider 11 reach the right stroke end, pressurized air is supplied to the primary region of the second main flow path 10 this time. Will be done. Therefore, the pressurized air reaching the primary side region of the second main flow path 10 is subjected to the second and fourth external connection ports 37,
Through the passage 39, it can flow into the secondary side area of the main flow path 10 and further into the second pressure action chamber 6. Therefore,
The piston 4 and the slider 11 start moving to the left in FIG. The air in the first pressure action chamber 5 is supplied to the secondary area of the first main flow path 8, the third and first external connection ports 38 and 36, the primary area of the main flow path 8, the main switching valve Through the A1 port of No. 17, the gas is smoothly discharged from the R1 port to the atmospheric pressure region. When the piston 4 and the slider 11 reach the left stroke end, the main switching valve 17 is switched from the second switching state to the first switching state again.

As described above, the compressed air is alternately supplied to the pair of pressure action chambers 5 and 6 through the pair of main flow paths 8 and 10, so that the piston 4 and the slider 11 perform a normal reciprocating operation.

Now, the characteristic effects of the present embodiment will be enumerated below. (A) In the system S1 provided with the above-mentioned pop-out prevention device 1, the 2-position 5-port valve 32 performs a predetermined operation using the shuttle valve 31 and the on-ready timer unit 33. Therefore, the pop-out prevention device 1 having a relatively simple structure can be provided without requiring a logic valve having a special structure as in the prior art shown in FIG. Further, according to the configuration of the present embodiment, the solenoid valve that can be used as the main switching valve 17 is not limited to the center-closed type alone, and the range of choice of the main switching valve 17 is surely increased. The reason is as follows. That is, the conventional apparatus of FIG. 8 is provided in parallel with both main flow paths, and each main flow path directly communicates with each pressure action chamber. Therefore, unless the main switching valve is a center-closed type, pressurized air is always supplied directly to each pressure action chamber via each main flow path. On the other hand, in this embodiment, the two main flow paths 8 and 10 are provided in series, so to speak, and each main flow path does not directly communicate with each pressure action chamber, so that such a problem does not occur. . Therefore, it is possible to select a center open type as shown in FIG. 1 as the main switching valve 17.

(B) Fluid pressure type on-ready timer section 33
According to the present embodiment, the control program by the sequencer becomes unnecessary unlike the case of using an electric on-ready timer unit, for example. Therefore, it is suitable for cost reduction.

(C) In this embodiment, the air pool 49
The amount of pressurized air flowing into the needle valve 64 can be adjusted by changing the valve opening of the needle valve 64, so that the time for preventing pop-out can be set arbitrarily. Since the check valve 63 is connected in parallel to the needle valve 64, air is discharged from the air reservoir 49 in a short time. Therefore, when the main switching valve 17 is switched to the neutral state, the spool 40 quickly returns to the normal position by the spring force of the coil spring 46. Therefore, 2 with excellent responsiveness
Position 5 port valve 32 can be used.

(D) In this embodiment, the shuttle valve 31 is employed as the first valve body. Therefore, there is an advantage that the first valve body can be realized with an extremely simple structure, which contributes to the cost reduction of the pop-out prevention device 1.

(E) In this embodiment, the shuttle valve 31
In addition to the air reservoir 49 and the speed controller 61
Is formed in the main body 34 of the two-position five-port valve 32. Therefore, as compared with the case where these components 31, 49 and 61 are provided separately from the two-position five-port valve 32, the number of external pipes can be reliably reduced. Therefore, the pop-out prevention device 1 itself becomes compact and the circuit becomes simple as a whole. [Second Embodiment] Next, a cylinder drive system S1 using a pop-out prevention device 71 of a second embodiment will be described with reference to FIG. Here, differences from the first embodiment will be mainly described, and the common points will be denoted by the same member numbers, and description thereof will be omitted.

As schematically shown in FIG. 3B,
The pop-out prevention device 71 includes a so-called detent mechanism 7.
2 is provided on one side of the spool 40. As shown in FIG. 3A, concave portions 73 are formed at a plurality of locations on the outer peripheral surface of the second piston portion 43 of the spool 40. On the other hand, a sphere 74 and a coil spring 75 as urging means are arranged near the position where the concave portion 73 is located. The sphere 74 and the coil spring 75 can be held by a holding member 76 located on the outer peripheral portion of the second piston portion 43 so as not to fall off at a predetermined position. The coil spring 75 constantly presses the sphere 74 in the radial direction of the spool 40. Therefore, the sphere 7
When the concave portion 73 of the spool 40 moves to the position where the 4 exists, about half of the sphere 74 engages with the concave portion 73, and the spool 40 is held immovable along its own axial direction. It is designed to be. In the present embodiment, when the spool 40 is at the normal position, the sphere 74 is engaged with the concave portion 73, and at other times, the sphere 74 comes off the concave portion 73.

When the spool 40 is at the normal position, the spool 40 is still held at that position by the action of the detent mechanism 72 until the pilot pressure reaches a predetermined value. When the pilot pressure reaches a predetermined value, the effect becomes relatively larger than the effect of the spring force of the coil spring 75. Then, the sphere 74 comes off the concave portion 73, and the spool 40 can move along its own axial direction. Therefore, spool 4
0 moves from the normal side position to the pilot pressure side position, and switches from the pop-out prevention state to the normal use state.

Of course, since the spring force of the coil spring 46 always works, when the pilot pressure is lost, the spool 40 is quickly pushed back from the pilot pressurized position to the normal position.

In the pop-out prevention device 71, a fifth passage 77 is formed instead of the first passage 50. The fifth passage 77 communicates the region where the first piston portion 42 is accommodated with the fourth passage 53.

Now, the characteristic effects of the present embodiment will be enumerated below. (A) Since the present embodiment also has the basic configuration of the first embodiment, the functions and effects A to E listed in the first embodiment are achieved.

(B) Since the pop-out prevention device 71 is provided with the above-described detent mechanism 72, the spool 4 is not supplied until a predetermined time elapses from the start of supply of pressurized air.
0 is not inadvertently displaced from the normal position. Therefore, the pressurized air is simultaneously supplied to both of the pressure action chambers 5 and 6 for a certain period of time, so that it is possible to reliably prevent the pressure from coming out.

(C) In the present embodiment, the concave portion 73 and the sphere 7
4. A detent mechanism 72 including a coil spring 75 and the like is used. Therefore, a relatively simple structure is sufficient,
It can be easily assembled in the main body 34.

(D) The detent mechanism 72 is provided at both ends of the spool 40 as in the pop-out prevention device 71A of the modification of the present embodiment schematically shown in FIG. Can also be adopted. By doing so, the structure is slightly complicated, but it is possible to more reliably prevent the protrusion. [Third Embodiment] Next, a cylinder drive system S1 using the pop-out prevention device 81 of the third embodiment will be described with reference to FIG. Here, the differences from the first embodiment will be mainly described, and the common points will be denoted by the same reference numerals, and description thereof will be omitted.

As schematically shown in FIG. 4B,
The pop-out prevention device 81 of this embodiment includes an adjusting screw 82 as an adjusting means for adjusting the spring force of the coil spring 46 as an urging means.

As shown in FIG. 4A, the adjusting screw 82 is inserted into a screw hole 83 formed in the left end face of the main body 34. A seal packing 86 is provided on the inner wall surface of the screw hole 83. This adjustment screw 82
The operating portion 84 is provided on the outer end side of the shaft portion having a thread groove formed on the outer peripheral surface, and the spring contact portion 85 is provided on the inner end side of the shaft portion. The shaft portion is rotatably inserted into the screw hole 83. Since the operating portion 84 of the adjusting screw 82 is provided to protrude from one end of the main body 34,
External operation is possible.

When the spring contact portion 85 is moved rightward in FIG. 4A by turning the adjustment screw 82, the degree of compression of the coil spring 46 increases, and as a result, the spring force increases. Conversely, when the spring contact portion 85 is moved to the left in FIG. 4A, the degree of compression of the coil spring 46 decreases, and as a result, the spring force decreases.

Now, the characteristic effects of the present embodiment will be enumerated below. (A) Since the present embodiment also has the basic configuration of the first embodiment, the functions and effects A to E listed in the first embodiment are achieved.

(B) Projection prevention device 81 of this embodiment
Thus, when no pilot pressure is applied, the spool 40 is pushed back from the pilot pressure side position to the normal side position by the spring force of the coil spring 46. In this case, since the spring force can be adjusted by the adjusting screw 82, an appropriate spring force corresponding to the pilot pressure can be applied to the spool 40. As described above, the spool 40 can be promptly and reliably returned, and the responsiveness and reliability are surely improved.

The present invention is not limited to the above embodiment, but can be modified to another form as follows, for example. A different example of the pop-out prevention device 91 as shown in another example of FIG. This device 91 does not have the on-ready timer section 33, but has a throttle valve 92. The throttle valve 92 is provided between the output side of the shuttle valve 31 and the P port of the 2-position 5-port valve 32, specifically, the fourth passage 53.
And adjusts the flow rate of the pressurized air passing through the portion there. Throttle valve 9
The air pressure obtained from the passage connecting the two-position five-port valve 32 to the pilot port Pt of the two-position five-port valve 32
Has been granted. Therefore, after a predetermined period of time has elapsed from the start of the air supply, the two-position five-port valve 32 is switched from the pop-out prevention state to the normal use state, and the state is maintained thereafter. In addition,
The time until the ON state can be adjusted by appropriately changing the opening of the throttle valve 92.

A different example of the pop-out prevention device 101 as shown in another example of FIG. 6 may be used. This device 101
Does not have the on-ready timer section 33, but has the throttle valve 9
2 and a shuttle valve 104. The throttle valve 92 is provided between the output side of the shuttle valve 31 and the 2-position 5-port valve 32. From the third external connection port 38, the sixth
The passage 102 branches, and a seventh passage 103 branches from the fourth external connection port 39. One end on the input side of the shuttle valve 104 is connected to the sixth passage 102, and the other end on the input side is connected to the seventh passage 103. Shuttle valve 1
The output side of 04 is connected to one pilot port Pt of the 2-position 5-port valve 32 via the eighth passage 105. That is, in each of the embodiments, the pilot pressure supply source is located before the passage of the 2-position 5-port valve 32A, whereas in this alternative example, the pilot pressure supply source is located after the 2-position 5-port valve 32A. The points are different. The shuttle valve 3 is connected to the other pilot port Pt via the ninth passage 106.
1 is applied. With such a configuration, since the throttle valve 92 is provided, the pressure of the pressurized air flowing through the third and fourth external connection ports 38 and 39 gradually increases instead of suddenly increasing. Therefore, the air pressure in the sixth and seventh passages 102 and 103 is still small during the predetermined period, and the pilot port Pt
No force is applied to move 0. After a lapse of a predetermined period, the air pressure in the sixth and seventh passages 102 and 103 becomes sufficiently high, and the spool 40 moves from the normal side position to the pilot pressurizing side position.

◎ It may be configured as another example of the pop-out prevention device 111 as shown in another example of FIG. Here, by using a pair of two-position three-port valves 112 and 113 in place of the two-position five-port valve 32, the same switching operation is performed by the two 112-113.
The on-ready timer unit 33A stores two air reservoirs 49 so as to correspond to the pair of two-position three-port valves 112 and 113.
I have one.

When the load is in one direction and the installation direction of the air cylinder is predetermined (for example, in the case of a lifter), one of the two-position three-port valve 112 is connected to, for example, a normally closed two-port valve. It is also possible to change to a position 2-port valve (so-called 2-way valve).

The fluid pressure type on-ready timer unit 33
It is also possible to employ another type (for example, an electric type) on-ready timer unit instead of the 33A. A specific description will be given of the case of the electric type.
A solenoid valve for a timer is provided in a passage connecting the output side of the valve and the pilot port Pt, and the solenoid of the solenoid valve is initially turned off to shut off the passage. The solenoid of the timer solenoid valve is turned on and off based on a drive signal from the sequencer. The solenoids 18A, 18 of the main switching valve 17
The sequencer is provided in advance with a control program for issuing a drive signal to the timer solenoid valve a predetermined period after the issuance of the drive signal for driving B.

The fluid pressure type on-ready timer 33,
As 33A, a valve formed by connecting a throttle valve 64 and an air reservoir 49 in series, that is, a valve without the check valve 63 may be employed.

It is also possible to use something other than the shuttle valve 31 as the first valve portion. ◎ The main switching valve 17 can be changed to a type other than the 3 position 5-port center open type switching solenoid valve. For example, a normally open or normally closed 2-position 5-port valve, a center-closed 3-position 5-port valve, a normally open or normally-closed 4-position 5-port valve, a 2-position 3-port valve, or the like may be used. Can be

The shuttle valve 31 and the on-ready timer units 33 and 33A, which are the first valve unit, are just constructed inside the main body 34 such as the two-position 5-port valves 32, 32A, 71 which are the second valve units. Instead, it may be configured separately from the main body 34.

The fluid pressure actuator is not limited to the rodless cylinder 2, but may be an air cylinder having a rod. Further, the present invention is not limited to an actuator that performs a linear motion, and may be, for example, a swing actuator.

Here, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments are listed below together with their effects. (1) In the first aspect, the second valve portion is a combination of two two-position three-port valves each of which has a spool movably housed in a main body. apparatus. Even with this configuration, it is possible to provide a pop-out prevention device for a fluid pressure actuator having a wide selection range of the main switching valve despite its relatively simple structure.

(2) An apparatus for preventing a hydraulic actuator from jumping out according to claim 1 or 2, wherein said on-ready timer section is an electric on-ready timer section.

(3) A device according to any one of claims 5 to 10, wherein said adjusting means projects from one end of said main body so as to be operable externally. . With this configuration, the urging force of the urging means can be adjusted without disassembling and assembling the device.

(4) An apparatus for preventing a hydraulic actuator from jumping out according to any one of claims 1 to 10, wherein said main switching valve is a three-position five-port center-open type switching solenoid valve.

(5) A fluid pressure actuator, a three-position five-port center-open type switching solenoid valve serving as a main switching valve, and the pop-out prevention device according to any one of claims 1 to 11 Hydraulic actuator drive system. With such a configuration, it is possible to provide a system having a relatively simple structure, a wide range of selection of the main switching valve, and capable of reliably preventing the hydraulic actuator from jumping out.

(6) In claim 2, instead of omitting the on-ready timer section, a throttle valve is provided between the output side of the first valve section and the 2-position 5-port valve, and the throttle valve is provided. By applying a fluid pressure obtained from a passage connecting the valve and the two-position five-port valve to a pilot port of the two-position five-port valve, the fluid pressure is turned on after a lapse of a predetermined time from the fluid supply start time. A pop-out prevention device for a fluid pressure actuator, wherein a 2-position 5-port valve is switched from the pop-out prevention state to the normal use state, and is maintained thereafter.

[0095]

As described in detail above, according to the first to tenth aspects of the present invention, the pop-out of the fluid pressure actuator having a wide selection range of the main switching valve despite its relatively simple structure. A prevention device can be provided.

According to the third aspect of the present invention, the cost can be reduced as compared with, for example, an electric type. According to the fourth aspect of the invention, it is possible to arbitrarily set the time for preventing the pop-out, and to make the second valve portion excellent in responsiveness.

According to the fifth aspect of the present invention, the spool can be quickly and reliably returned, and responsiveness and reliability can be improved. According to the sixth aspect of the present invention, the shuttle valve can be realized with an extremely simple structure, so that the cost can be reduced.

According to the seventh and eighth aspects of the present invention, the pop-out prevention device itself becomes compact and the circuit becomes simple as a whole. According to the ninth aspect of the present invention, it is possible to reliably prevent the protrusion.

According to the tenth aspect of the present invention, since the detent mechanism has a simple structure, it can be easily assembled in the main body of the second valve portion.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a system using a rodless cylinder pop-out prevention device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the projection prevention device according to the first embodiment.

FIG. 3A is a cross-sectional view of a projection prevention device according to a second embodiment, FIG. 3B is a symbol representing the device, and FIG. 3C is a symbol representing a modification of the device having a detent mechanism at both ends of a spool. .

4A is a cross-sectional view of a projection prevention device according to a third embodiment, and FIG. 4B is a symbol representing the device.

FIG. 5 is a circuit diagram of a system using another example of the pop-out prevention device.

FIG. 6 is a circuit diagram for explaining another example of the pop-out preventing device.

FIG. 7 is a circuit diagram for explaining another example of the pop-out preventing device.

FIG. 8 is a circuit diagram of a system using a conventional air cylinder pop-out prevention device.

[Explanation of symbols]

Reference numerals 1, 71, 71A, 81, 91, 101, 111: anti-protrusion device, 2: rodless air cylinder as fluid pressure actuator, 4: piston as moving body, 5, 6: pressure action chamber, 8, 10 ... main flow path, 17 ...
Main switching valve, 31 ... shuttle valve as the first valve portion, 32,
32A: 2-position 5-port valve as second valve portion, 33, 3
3A: On-ready timer section, 34: Main body, 35:
Spool accommodation space, 40: spool, 46: spring as urging means, 49: air pool as fluid pool, 55, 56: valve seat, 57: valve body, 61: speed controller, 62: wall, 63: check Valve: 64: Needle valve as a throttle valve; 72: Detent mechanism; 73: Depression constituting a detent mechanism; 74: Spherical body constituting a detent mechanism; 75: Coil spring as urging means constituting a detent mechanism; ... Adjustment screw as adjustment means, Pt ... Pilot port.

Claims (10)

[Claims] 1. A moving body driven by a pressure fluid, a fluid pressure actuator having a pair of pressure action chambers defined by the moving body, and a main switch for alternately supplying the pressure fluid into the pair of pressure action chambers. A device that is installed on a pair of main flow paths connecting a valve and that prevents the movable body from jumping out at the start of driving, wherein a side having a relatively high pressure among two passages branched from the two main flow paths, respectively. A first valve portion that constantly communicates a pressure fluid flowing through the high-pressure side passage to an output side, a secondary region of the two main flow paths connected to the two pressure action chambers, and an output side of the first valve portion. Between the primary side area and the secondary side area of both main flow paths, and between the secondary side area of both main flow paths and the output side of the first valve section. And shut off both mainstream A second valve portion that switches to a normal use state in which the primary region and the secondary region communicate with each other, and that the second valve portion pops out by being turned on after a predetermined time has elapsed from the start of fluid supply. A jump-out prevention device for a fluid pressure actuator, comprising: an on-ready timer section that switches from a prevention state to the normal use state and holds the state thereafter. 2. The apparatus according to claim 1, wherein the second valve portion is a two-position five-port valve in which a spool is movably housed in a main body. 3. The two-position five-port valve of a pilot pressure single drive type in which a spool is movably housed in a body of the main body, and the on-ready timer part is the two-position five-port valve. A fluid-type on-ready timer unit that is connected to a pilot port of a valve and that is turned on when the pressure on the output side of the first valve unit reaches a constant value to drive the spool. The device for preventing a hydraulic actuator from jumping out according to claim 1. 4. The fluid pressure type on-ready timer section comprises a speed controller comprising a check valve and a throttle valve connected in parallel, and a fluid reservoir connected in series. 3. The pop-out prevention device for a fluid pressure actuator according to claim 1. 5. The urging means for returning the spool to a normal position in the pop-out preventing state, and an adjusting means for adjusting the urging force of the urging means. The device for preventing a hydraulic actuator from jumping out according to any one of claims 2 to 4, further comprising: 6. The first valve portion comprises: a pair of valve seats formed to face each other; and a valve element which is disposed between the two valve seats so as to be able to reciprocate and which comes into contact with and separates from the two valve seats. The pop-up prevention device for a fluid pressure actuator according to any one of claims 1 to 5, wherein the device is a shuttle valve. 7. The device according to claim 6, wherein the shuttle valve is formed in a passage in the main body. 8. The apparatus according to claim 8, wherein the fluid reservoir is formed at an end of a spool accommodating space in the main body, and the speed controller is provided on a wall located between the fluid reservoir and the shuttle valve forming portion. The pop-out prevention device for a fluid pressure actuator according to any one of claims 4 to 7, wherein 9. A detent mechanism is provided at at least one end of the spool for holding the spool at a normal position in the pop-out prevention state until the pilot pressure reaches a predetermined value. The pop-out prevention device for a fluid pressure actuator according to any one of claims 3 to 8. 10. A detent mechanism comprising: a concave portion formed on an outer peripheral surface of an end portion of the spool; a sphere that can be disengaged from the concave portion; 10. The pop-out prevention device for a fluid pressure actuator according to claim 9, further comprising: urging means for urging in a radial direction.