JP6353782B2 - Cylinder device with booster mechanism - Google Patents

Description

  The present invention relates to a cylinder device with a booster mechanism.

Conventionally, this type of cylinder device with a booster mechanism is described in Patent Document 1 (Japan, JP 2013-044436 A). The prior art is configured as follows.
An annular piston for boosting is inserted into the housing, and an output rod is inserted into the through hole of the annular piston. Between the through hole of the annular piston and the outer periphery of the output rod, the engagement balls of the booster mechanism are arranged at a predetermined interval in the circumferential direction.

JP 2013-044436 A

The above prior art has room for improvement in the following points.
Since a plurality of engagement balls are disposed between the through hole of the annular piston and the outer peripheral portion of the output rod, the number of engagement balls is limited by the inner peripheral dimension of the through hole of the annular piston. When an unexpected overload acts on the engaging ball, the load acting on each engaging ball increases, and the engaging ball, the through hole of the annular piston, and the outer periphery of the output rod are worn. There is a risk of damage. As a result, the durability of the cylinder device with a booster mechanism is reduced.
An object of the present invention is to improve the durability of a cylinder device with a booster mechanism.

In order to achieve the above object, according to the present invention, for example, as shown in FIGS. 1 to 4, a cylinder device with a booster mechanism is configured as follows.
An annular piston 10 is inserted into a cylinder hole 9 configured as a part of the cylindrical hole 6 of the housing 1 so as to be movable in the axial direction. The output rod 21 of the output member 20 is inserted into the through hole 11 of the annular piston 10 so as to be able to move in the axial direction. A force that pushes the annular piston 10 toward one end in the axial direction is boosted and converted to a force toward the one end by the booster mechanism 40 and transmitted to the output member 20. The booster mechanism 40 includes a plurality of engagement balls 50 disposed between the cylindrical hole 6 and the annular piston 10 at a predetermined interval in the circumferential direction. The engagement ball 50 is in a state of restricting the relative movement of the annular piston 10 toward the one end side with respect to the output member 20 and a state of being driven by a boost while allowing relative movement toward the one end side. It is configured to be switchable. Further, a guide surface 41 configured as a part of the cylindrical hole 6 of the housing 1 is continued from the cylinder hole 9 to the one end side. The guide surface 41 receives the engaging ball 50 from the outside in the radial direction during a low load stroke before the boost driving is started.

The present invention has the following effects.
A plurality of engagement balls are arranged at predetermined intervals in the circumferential direction between the cylindrical hole of the housing and the annular piston. Thereby, compared with the case where a plurality of engagement balls are arranged between the through hole of the annular piston and the output rod as in the prior art, the number of engagement balls can be increased, and the increase number Accordingly, it is possible to reduce the load applied to each engagement ball. For this reason, it can prevent that an engagement ball | bowl, the cylindrical hole of a housing, or a cyclic | annular piston are worn out or damaged. As a result, the durability of the cylinder device with a booster mechanism is improved.
Furthermore, since the guide surface and the cylinder hole are configured as a part of the cylindrical hole of the housing and the guide surface is continuous from the cylinder hole, the guide surface and the cylinder hole can be used together. The size can be reduced. As a result, the cylinder device with a booster mechanism can be reduced in size.

In the present invention, the following configurations (1) to (6) are preferably added.
(1) For example, as shown in FIGS. 1 to 4, a lock chamber 30 and a release chamber 31 are defined in the cylindrical hole 6 of the housing 1 by the annular piston 10 and the output rod 21. The lock chamber 30 is configured to supply and discharge pressure fluid, and the release chamber 31 is configured to supply and discharge pressure fluid.
In this case, at the time of lock driving, the cylinder device can be surely boosted by the pressure fluid supplied to the lock chamber by causing the annular piston to move forward toward the one end side.

(2) It is preferable to provide an auxiliary piston 65 that pushes the output member 20 to the other end side during release driving for moving the output member 20 to the other end side. Furthermore, a small-diameter hole 62 and a large-diameter hole 61 are formed in the housing 1 in order from the cylindrical hole 6 to the one end side. The small diameter portion 65b of the auxiliary piston 65 is movable and tightly inserted into the small diameter hole 62, and the large diameter portion 65a of the auxiliary piston 65 is movable and tightly inserted into the large diameter hole 61. . An auxiliary release chamber 67 formed on the one end side of the large-diameter portion 65 a is configured to communicate with a release chamber 31 formed in the cylindrical hole 6 of the housing 1.
In this case, the auxiliary piston can strongly release the output member.

(3) The booster mechanism 40 has a cam surface 42a formed in the cylindrical hole 6 so as to move away from the axial center toward the one end side in the axial direction. A boosting surface 45 is formed on the outer peripheral portion of the annular piston 10 so as to approach the axial center toward the one end side. An input surface 47 is formed on the input ring 22 of the output member 20. When the booster mechanism 40 is driven with a booster, it is preferable that the engagement ball 50 is engaged with the cam surface 42 a, the booster surface 45, and the input surface 47. Furthermore, at the start of the boost drive of the boost mechanism 40, the pushing portion 44 provided on the annular piston 10 pushes the engagement ball 50 outward in the radial direction. During a low load stroke before the boost drive is started, the push portion 44 pushes the engagement ball 50 toward the input surface 47.
In this case, it is possible to prevent the engagement ball, the cam surface, the boost surface, and the pressing portion from being worn or damaged by a simple structure booster. As a result, the durability of the cylinder device with a booster mechanism is improved.

(4) At the time of the low load stroke, the annular piston 10, the engagement ball 50, and the input ring 22 of the output member 20 are integrated to be movable toward the one end side.
In this case, at the time of a low load stroke, the annular piston, the engagement ball, and the input ring of the output member are quickly moved to the one end side.

(5) The cam surface 42 a is formed continuously in the circumferential direction of the cylindrical hole 6. In this case, the cam surface can be easily processed.

(6) The boosting surface 45 is formed at the bottom of the first groove 43 formed on the outer periphery of the annular piston 10. The input surface 47 is formed at the bottom of the second groove 46 formed in the input ring 22 of the output member 20. The engagement ball 50 is accommodated in the first groove 43 or the second groove 46.
In this case, the engagement ball can be prevented from falling off from the annular piston or the input ring, so that the cylinder device can be surely driven with a boost. As a result, the cylinder device can be used well over a long period of time.

FIG. 1 is a sectional view as seen from an elevation showing a cylinder device with a booster mechanism in a released state. FIG. 2 is a sectional view as seen from an elevation showing the cylinder device in the middle of switching. FIG. 3 is a sectional view as seen from an elevation showing the cylinder device in the locked state. FIG. 4 is an elevational sectional view showing a state in which the output member is left in the locked position by the resistance force applied to the output member of the cylinder device, and only the annular piston is lowered.

1 to 4 show an embodiment of the present invention. In this embodiment, a cylinder device with a booster mechanism used for holding and extracting a core (not shown) fitted in a mold is illustrated. First, the structure of the cylinder device with a booster mechanism will be described with reference to FIG.
The housing 1 includes an upper end wall 1a, a first cylindrical portion 1c, a second cylindrical portion 1d, and a lower end wall 1b provided in this order from the upper side (one end side) to the lower side (the other end side). A cylindrical hole 6 of the housing 1 is configured by the inner peripheral hole of the second cylindrical portion 1d.

  A cylinder hole 9 is formed by the lower portion of the cylindrical hole 6, and the annular piston 10 is inserted into the cylinder hole 9 in a constricted manner so as to be movable in the vertical direction. The annular piston 10 has a large-diameter portion 12 that is inserted into the cylinder hole 9 and a small-diameter portion 13 that protrudes upward from the large-diameter portion 12.

  The output rod 21 of the output member 20 is inserted into the through-hole 11 of the annular piston 10 so as to be movable up and down in a tight manner. Between the annular piston 10 and the output rod 21, a rectilinear guide means 21g is provided. The rectilinear guide means 21g guides the annular piston 10 straight in the vertical direction with respect to the output rod 21, and prevents the annular piston 10 from rotating about the axis with respect to the output rod 21. The output rod 21 is inserted into the through hole of the upper end wall 1a of the housing 1 in a close-packed manner and protrudes upward from the upper end wall 1a. An annular input ring 22 protrudes outward in the radial direction at an intermediate height portion of the output rod 21. A locking member 23 having a diameter larger than that of the lower end portion is provided at the lower end portion of the output rod 21, and a locking portion 25 is formed above the locking member 23. The output member 20 includes the output rod 21, the input ring 22, and the locking member 23.

  The annular piston 10 and the output member 20 define the internal space of the housing 1 into a lower lock chamber 30 and an upper release chamber 31. A lock port 35 communicating with the lock chamber 30 is formed in the lower end wall 1b. The release chamber 31 includes a first release chamber 31a formed below the input ring 22, a second release chamber 31b formed above the input ring 22, and the first release chamber 31a and the second release chamber. And a communication path 31d communicating with 31b. The communication path 31 d is formed in a gap between the cylindrical hole 6 and the outer peripheral portion of the input ring 22. A release port 36 communicating with the second release chamber 31b is formed across the first cylindrical portion 1c and the second cylindrical portion 1d of the housing 1.

  In the cylindrical hole 6, the guide surface 41 and the cylinder hole 9 are formed in a straight line continuously in the vertical direction. The guide surface 41 and the cylinder hole 9 have the same inner diameter, and both are configured as a part of the cylindrical hole 6. A part of the guide surface 41 is also a part of the cylinder hole 9.

A booster mechanism 40 is disposed in the internal space of the housing 1. The booster mechanism 40 is configured as follows.
A cam surface 42a is formed in the cylindrical hole 6 on the upper side of the guide surface 41 so as to move away from the axis as it goes upward. The cam surface 42a is configured by a tapered surface or a curved surface formed to be continuous with the cylindrical hole 6 in the circumferential direction. The cam surface 42a is formed integrally with the second cylindrical portion 1d other than the cam surface 42a. The cylinder hole 6 includes a cylinder hole 9, a guide surface 41, a cam surface 42a, and a large diameter portion that are formed in order from the bottom to the top.
A plurality of grooves (first grooves) 43 are formed on the outer peripheral portion of the small-diameter portion 13 of the annular piston 10 at predetermined intervals in the circumferential direction, and are formed so as to approach the axial center as going upward. At the bottom of each groove 43, a pressing portion 44 and a boosting surface 45 are sequentially formed downward. In the present embodiment, the inclination angle of the pressing portion 44 with respect to the axis is set to be larger than the inclination angle of the booster surface 45.
A plurality of grooves (second grooves) 46 are formed at predetermined intervals in the circumferential direction below the input ring 22 of the output member 20 so as to correspond to the grooves 43, and the input surface 47 is formed at the bottom of each groove 46. Is formed.
The engaging ball 50 is accommodated in the groove 43 or the groove 46 described above. As a result, the engagement ball 50 is prevented from falling off the annular piston 10. As a result, the above clamping device can be used satisfactorily for a long time.

A large-diameter hole 61 is formed in the upper end wall 1 a of the housing 1, and a small-diameter hole 62 is formed in the first cylindrical portion 1 c of the housing 1.
The auxiliary piston 65 is inserted into the large diameter hole 61 and the small diameter hole 62 so as to be movable in the vertical direction. The auxiliary piston 65 includes a large-diameter portion 65a that is inserted into the large-diameter hole 61 in a close-tight manner, and a small-diameter portion 65b that protrudes downward from the large-diameter portion 65a and is inserted into the small-diameter hole 62 in a close-contained manner. Have. The output rod 21 of the output member 20 is inserted into the through hole of the auxiliary piston 65.
A third release chamber 67 as an auxiliary release chamber is formed in the large-diameter hole 61 above the large-diameter portion 65a. Note that a breathing hole 66 communicating with the outside air is communicated with a chamber formed between the large diameter portion 65a and the small diameter portion 65b. A communication path 68 that allows the third release chamber 67 and the second release chamber 31 b to communicate with each other is formed between the through hole of the auxiliary piston 65 and the outer periphery of the output rod 21 and at the lower end of the auxiliary piston 65.

The cylinder device operates as follows, as shown in FIGS.
In the release state of FIG. 1, the pressure oil (pressure fluid) in the lock chamber 30 is discharged and the pressure oil is supplied to the release chamber 31. As a result, the pressure oil in the release chamber 31 lowers the annular piston 10, lowers the output rod 21 via the annular piston 10, and lowers the auxiliary piston 65. Further, the engaging ball 50 is received from the outside in the radial direction by the guide surface 41 of the cylindrical hole 6.

  When the cylinder device is locked, the pressure oil in the release chamber 31 is discharged and the pressure oil is supplied to the lock chamber 30 in the release state of FIG. Then, the pressure in the lock chamber 30 moves the annular piston 10 and the output rod 21 upward, and the pushing portion 44 of the annular piston 10 raises the engagement ball 50 along the guide surface 41 of the cylindrical hole 6. The engagement ball 50 raises the output rod 21 through the input ring 22. Thus, the low load stroke of the cylinder device is performed. At the end of the low load stroke shown in FIG. 2, the upper surface of the input ring 22 comes into contact with the lower surface of the auxiliary piston 65, and the output rod 21 raises the auxiliary piston 65 via the input ring 22.

  When the output rod 21 is raised by a predetermined stroke, the pushing portion 44 of the annular piston 10 pushes the engagement ball 50 toward the cam surface 42a (outward in the radial direction). Thereafter, the boosting surface 45 of the annular piston 10 raises the output rod 21 via the cam surface 42a, the engagement ball 50, and the input surface 47 of the input ring 22, and the boosting drive of the cylinder device is started.

  Subsequently, when the annular piston 10 and the output rod 21 are raised, the upper end of the auxiliary piston 65 is received by the upper end wall 1a, and the cylinder device is in the locked state shown in FIG. Thereby, the core (not shown) fixed to the upper end of the output rod 21 is held in the mold.

  In the locked state of FIG. 3 described above, when an external force is applied downward to the output rod 21 via the core, the oil pressure in the lock chamber 30 and when the output rod 21 in the locked state receives a downward force. It is possible to prevent the output rod 21 from being pushed back downward by the frictional force generated between the engagement ball 50, which is a constituent member of the wedge type booster mechanism 40, the cam surface 42a, and the booster surface 45.

  When switching from the locked state of FIG. 3 to the released state of FIG. 1, when the metal solidified by cooling in the mold and the core are fixed and a resistance force acts on the output rod 21, In the state, the pressure oil is discharged from the lock chamber 30 and the pressure oil is supplied to the release chamber 31. Then, the annular piston 10 is lowered until it comes into contact with the locking member 23, but the output rod 21 is not lowered due to the resistance force (see FIG. 4). Subsequently, the annular piston 10 lowers the output rod 21 via the locking member 23, and the auxiliary piston 65 strongly lowers the output rod 21 via the input ring 22. Thereby, the core fixed to the upper end part of the output rod 21 is pulled out from the solidified metal. Thereafter, as shown in FIG. 1, the annular piston 10 is received by the lower end wall 1 b of the housing 1.

  On the other hand, when the resistance force is not applied to the output rod 21, the pressure oil is discharged from the lock chamber 30 and supplied to the release chamber 31 in the locked state of FIG. 3. Then, the pressure oil in the release chamber 31 lowers the annular piston 10. Accordingly, the engagement ball 50 is allowed to move inward in the radial direction along the cam surface 42a, and the pressure oil in the release chamber 31 lowers the auxiliary piston 65. Subsequently, as shown in FIG. 2, the lower portion of the annular piston 10 abuts on the locking portion 25 of the output rod 21 to lower the output rod 21, and the input ring 22 of the output rod 21 is engaged. The ball 50 is moved downward along the guide surface 41 of the tube hole 6. Thereafter, as shown in FIG. 1, the annular piston 10 is received by the lower end wall 1 b of the housing 1.

The above embodiment has the following advantages.
The engagement balls 50 are arranged at a predetermined interval in the circumferential direction between the cam surface 42 a of the cylindrical hole 6 and the boosting surface 45 of the annular piston 10. Thereby, compared with the case where an engagement ball is arrange | positioned between the through-hole of an annular piston and the outer peripheral part of an output rod like the prior art, the arrangement | positioning quantity of the engagement ball 50 can be increased. The load acting on the engagement balls 50 (per one) can be reduced according to the increased number. Thereby, it can prevent that the engagement ball | bowl 50, the cam surface 42a, and the booster surface 45 are worn out or damaged. As a result, the durability of the cylinder device is improved.

As shown in FIG. 1 (release state) to FIG. 2 (switching halfway state), the push portion 44 of the annular piston 10 raises the engagement ball 50 along the guide surface 41 of the cylindrical hole 6.
Thereby, compared with the case where the boosting surface 45 raises the engagement ball 50 along the guide surface 41, the force with which the engagement ball 50 is pressed against the guide surface 41 can be suppressed. Can be prevented from being worn or damaged. As a result, the durability of the cylinder device is improved.

The engagement ball 50 is accommodated in a groove 43 formed in the annular piston 10 or a groove 46 formed in the input ring 22, and the cam surface 42 a is formed continuously in the circumferential direction of the cylindrical hole 6.
This eliminates the need to match the circumferential position (phase) of the cam surface 42a with respect to the groove 43 or 46. Therefore, it is not necessary to provide a straight guide means for restricting the rotation of the cylindrical hole 6 relative to the annular piston 10 or the input ring 22 between the annular piston 10 and the cylindrical hole 6 or between the input ring 22 and the cylindrical hole 6. Therefore, the cylinder device can be reduced in size.

The above embodiment can be modified as follows.
The pressure fluid may be another liquid or a gas such as compressed air instead of the exemplified pressure oil.
The housing 1 may be integrally formed instead of the illustrated upper end wall 1a, first cylinder portion 1c, second cylinder portion 1d, and lower end wall 1b.
The annular piston 10 is driven to lock by a lock spring mounted on the lock chamber 30 instead of being configured to reciprocate by the pressure fluid supplied to and discharged from the lock chamber 30 and the release chamber 31, and the release chamber 31. It may be configured to be driven to release by the pressure fluid supplied to and discharged from.
The guide surface 41 and the cylinder hole 9 are connected to each other in the cylinder hole 6 so as to be straight and formed. However, the guide surface 41 and the cylinder hole 9 are substantially the same (substantially the same). It is good also as composition which is. The configuration that is substantially the same may include, for example, a configuration in which the guide surface 41 continues to the cylinder hole 9 via a gently inclined surface.
The cam surface 42a, instead of being configured by a tapered surface or a curved surface formed so as to be continuous with the cylindrical hole 6 in the circumferential direction, a plurality of cam surfaces 42a formed at predetermined intervals in the circumferential direction. It may be formed at the bottom of the groove.
The cam surface 42a may be formed separately from the second cylindrical portion 1d other than the cam surface 42a. In this case, the strength of the cam surface 42a that receives a large force from the engagement ball 50 may be higher than that of the second cylindrical portion 1d other than the cam surface 42a, and the cam surface 42a may be made of a material such as special steel. Also good.
Even if the output rod 21 of the output member 20 is inserted into a through hole (not shown) formed in the lower end wall 1b of the housing 1 so as to be vertically movable and tightly fitted, and protrudes downward from the lower end wall 1b. Good.
The fixed state shown in FIG. 4 is not only when the core is fixed, but also when the product is shipped, when the resistance of the output rod 21 is large, or when a hydraulic failure occurs.
The cylinder device may be disposed in an upside down posture, a horizontal posture, or an oblique posture, instead of being disposed in the illustrated vertical posture.
In addition, it is needless to say that various modifications can be made within a range that can be assumed by those skilled in the art.

1: housing, 6: cylinder hole, 9: cylinder hole, 10: annular piston, 11: through hole, 20: output member, 21: output rod, 22: input ring, 30: lock chamber, 31: release chamber, 40 : Boosting mechanism, 41: Guide surface, 42a: Cam surface, 43: Groove (first groove), 44: Pushing portion, 45: Boost surface, 46: Groove (second groove), 47: Input surface, 50 : Engagement ball, 61: large diameter hole, 62: small diameter hole, 65: auxiliary piston, 67: third release chamber (auxiliary release chamber).

Claims (9)

An annular piston (10) inserted in a cylinder hole (9) configured as a part of a cylindrical hole (6) of the housing (1) so as to be able to move in a concentric manner in the axial direction, and extending through the axial direction An annular piston (10) having a hole (11);
An output member (20) having an output rod (21) inserted into the through hole (11) so as to be able to move in a concentric manner in the axial direction;
A booster mechanism (40) for converting a force pushing the annular piston (10) toward one end side in the axial direction into a force toward the one end side and transmitting it to the output member (20), A booster mechanism (40) having a plurality of engagement balls (50) disposed at predetermined intervals in the circumferential direction between the cylindrical hole (6) and the annular piston (10),
The engagement ball (50) is doubled while allowing the annular piston (10) to move relative to the one end side relative to the output member (20) and allowing relative movement toward the one end side. It is configured to be switchable to a force driven state,
And a guide surface (41) configured as a part of the cylindrical hole (6) of the housing (1) and continuous from the cylinder hole (9) to the one end side. A guide surface (41) for receiving the engagement ball (50) from the outside in a radial direction during a low-load stroke before starting
A cylinder device with a booster mechanism. The cylinder device with a booster mechanism according to claim 1,
A lock chamber (30) and a release chamber (31) are defined by the annular piston (10) and the output rod (21) in the cylindrical hole (6) of the housing (1), and the lock chamber (30 The pressure fluid can be supplied and discharged to the release chamber (31), and the pressure fluid can be supplied and discharged to the release chamber (31).
A cylinder device with a booster mechanism. The cylinder device with a booster mechanism according to claim 1,
An auxiliary piston (65) for pushing the output member (20) to the other end side during release driving for moving the output member (20) to the other end side;
A cylinder device with a booster mechanism. The cylinder device with a booster mechanism according to claim 3,
A small-diameter hole (62) and a large-diameter hole (61) are formed in the housing (1) in order from the cylindrical hole (6) to the one end side.
The small-diameter portion (65b) of the auxiliary piston (65) is movable and tightly inserted into the small-diameter hole (62), and the large-diameter portion (65) of the auxiliary piston (65) is inserted into the large-diameter hole (61). 65a) is movable and inserted tightly,
An auxiliary release chamber (67) formed on the one end side of the large-diameter portion (65a) communicates with a release chamber (31) formed in the cylindrical hole (6) of the housing (1). ,
A cylinder device with a booster mechanism. In the cylinder device with a booster mechanism according to any one of claims 1 to 4,
The booster mechanism (40) includes a cam surface (42a) formed in the cylindrical hole (6) so as to move away from the axial center toward the one end side in the axial direction and the cam surface (42a) formed toward the one end side. A boost surface (45) formed on the outer peripheral portion of the annular piston (10) so as to approach the axis, and an input surface (47) formed on the input ring (22) of the output member (20), Further comprising
At the time of the boost drive of the booster mechanism (40), the engagement ball (50) is engaged with the cam surface (42a), the booster surface (45), and the input surface (47). ,
A cylinder device with a booster mechanism. In the cylinder device with a booster mechanism according to claim 5,
A push portion (44) for pushing out the engagement ball (50) radially outward at the start of the boost drive of the boost mechanism (40), before the boost drive is started. The annular piston (10) is provided with a pressing portion (44) that pushes the engagement ball (50) toward the input surface (47) during a low load stroke.
A cylinder device with a booster mechanism. In the cylinder device with a booster mechanism according to claim 5,
At the time of the low load stroke, the annular piston (10), the engagement ball (50), and the input ring (22) of the output member (20) are integrated to be movable toward the one end side.
A cylinder device with a booster mechanism. In the cylinder device with a booster mechanism according to claim 5,
The cam surface (42a) is continuously formed in the circumferential direction of the cylindrical hole (6).
A cylinder device with a booster mechanism. In the cylinder device with a booster mechanism according to claim 5,
The boost surface (45) is formed at the bottom of a first groove (43) formed in the outer periphery of the annular piston (10),
The input surface (47) is formed at the bottom of a second groove (46) formed in the input ring (22) of the output member (20),
The engagement ball (50) is accommodated in the first groove (43) or the second groove (46).
A cylinder device with a booster mechanism.

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