JP3246323U - Cylinder Unit - Google Patents

Abstract

A cylinder device capable of reliably maintaining a locked state even if an external force that attempts to release the locked state acts on an output member.
[Solution] An output member 18 is inserted into an inner peripheral hole 24 of an annular piston 11 inserted into a housing 1. An engagement member 43 is provided between a large diameter portion 20 of the output member and the annular piston. The engagement member is guided by a guide mechanism 52 so as to be slidable relative to the large diameter portion. A wedge surface 12 of the annular piston is capable of surface contact with the engagement member. A receiving surface of a cylinder bore is capable of surface contact with the engagement member.
[Selected Figure] Figure 1

Description

The present invention relates to a cylinder device driven by a pressurized fluid, and to a technology for maintaining a locked state when an external force acts on an output member in a direction that releases the locked state of the cylinder device.

A conventional cylinder device of this type is described in Patent Document 1 (JP Patent Publication No. 2016-121788). This conventional technology is configured as follows.

An annular piston is inserted into the cylinder hole of the housing so that it can move up and down. An output member is inserted into the inner peripheral hole of the annular piston so that it can move up and down. An engagement ball is provided between the large diameter portion of the output member and the annular piston. The engagement ball is capable of point contact or line contact with a wedge surface formed on the annular piston and a receiving surface of the cylinder hole. When the cylinder device is in a locked state, the force of the pressurized fluid pushing the annular piston upward is amplified via the engagement ball and transmitted to the output member.

JP 2016-121788 A

The above-mentioned conventional techniques leave room for improvement in the following respects.
In the locked state of the cylinder device, even if an external force that retracts the output member downward acts on the output member for some reason, the locked state is mechanically maintained by the frictional force caused by point contact or line contact between the engagement ball and the wedge surface of the wedge member, and between the engagement ball and the receiving surface of the support member. However, it is desired that the locked state of the cylinder device be reliably maintained even if a force larger than that of the conventional device acts on the output member.

In order to achieve the above object, the present invention provides a cylinder device configured as follows, for example, as shown in Figs. 1 to 4B.
An annular piston 11 is inserted in a cylinder bore 10 of a housing 1 in a hermetically sealed manner so as to be movable in the axial direction. The annular piston 11 has an inner peripheral hole 24 formed in the axial direction. An output member 18 is inserted in the inner peripheral hole 24 of the annular piston 11 in a hermetically sealed manner so as to be movable in the axial direction. An engagement member 43 is provided between a large diameter portion 20 formed in the output member 18 and the annular piston 11. The engagement member 43 is guided slidably relative to the large diameter portion 20 or the engagement member 43 is guided slidably relative to the annular piston 11 by a guide mechanism 52 provided between the engagement member 43 and the large diameter portion 20 or between the engagement member 43 and the annular piston 11. A wedge surface 12 is formed on the annular piston 11 so as to be inclined with respect to the axial direction. The wedge surface 12 is capable of surface contact with a first sliding surface 48 of the engagement member 43. A receiving surface 50 is formed on an inner peripheral wall of the cylinder bore 10 so as to be inclined with respect to the axial direction. The receiving surface 50 is capable of surface contact with the second sliding surface 49 of the engaging member 43. The engaging member 43 is formed by the first sliding surface 48 and the second sliding surface 49 so as to taper toward the base end side in the axial direction. The inclination angle of the receiving surface 50 with respect to the axial direction is larger than the inclination angle of the wedge surface 12 with respect to the axial direction. The force pressing the annular piston 11 toward the tip side in the axial direction is increased to a force toward the tip side and transmitted to the output member 18.

When the cylinder device is in the locked state, an external force that tends to move the output member axially toward the base end may act on the output member for some reason. In this case, the wedge surface of the annular piston comes into surface contact with the engaging member, and the receiving surface 50 of the housing 1 comes into surface contact with the engaging member 43, generating a greater frictional force at the contact surfaces than in conventional point or line contact between the members. As a result, this greater frictional force acts on the output member against the external force, reliably maintaining the locked state of the cylinder device.

FIG. 1 is an elevational cross-sectional view showing an embodiment of the present invention, illustrating a cylinder device in a released state. FIG. 2 is a cross-sectional view similar to FIG. 1, showing the cylinder device in a locked state. Fig. 3A is a partially enlarged view showing part A in Fig. 1, which is a diagram showing a guide mechanism of the cylinder device, and Fig. 3B is a partially sectional view showing a modified example of the guide mechanism. Fig. 4A is a view taken along line 3A-3A in Fig. 3A, and Fig. 4B is a partial cross-sectional view showing a modified example of the guide mechanism in Fig. 4A.

Figures 1, 2, 3A, and 4A show one embodiment of the present invention. In this embodiment, a cylinder device used to fix a mold to a substrate is illustrated. First, the structure of the cylinder device is explained with reference to Figure 1, which shows the released state.

The housing 1 of the cylinder device has a base housing 2, a first annular member 3, a second annular member 4, an annular partition member 5, and a tip housing 6, which are arranged in this order from the lower end side (base end side) to the upper end side (tip side). These members from the base housing 2 to the partition member 5 are fixed to the tip housing 6 by a number of bolts 7.

A first cylinder hole 10 is formed in the first annular member 3. A ring-shaped first piston (annular piston) 11 is inserted into the first cylinder hole 10 in a hermetically sealed manner so as to be movable in the axial direction (up and down direction) of the first cylinder hole 10. A piston portion 11a is formed on the lower side (base end side) of the first piston 11. A wedge portion 11b is formed on the upper side (tip end side) of the piston portion 11a. A wedge surface 12 is formed on the outer peripheral wall of the wedge portion 11b in the circumferential direction so as to taper toward the tip end side. The wedge surface 12 is formed so as to be inclined at 35° to 50° with respect to the axial direction of the output member 18.

A second cylinder hole 14 is formed in the tip housing 6, and the axis of the second cylinder hole 14 is configured to coincide with (or be parallel to) the axis of the first cylinder hole 10. A ring-shaped second piston 15 is inserted into the second cylinder hole 14 so as to be movable in the axial direction. The second piston 15 has a large diameter portion 15a and a small diameter portion 15b formed in order from the top. The large diameter portion 15a is inserted into the second cylinder hole 14 so as to be movable in the axial direction and in a hermetically sealed state. The small diameter portion 15b is inserted into the communication hole 5a of the partition member 5 so as to be movable in the axial direction and in a hermetically sealed state. The axis of the second cylinder hole 14 and the axis of the communication hole 5a of the partition member 5 are formed so as to coincide with each other.

An output member 18 is inserted into the first cylinder bore 10 and the second cylinder bore 14 so as to be movable in the axial direction. The output member 18 has a base end rod 19, a large diameter portion 20, and a tip rod 21, which are formed in this order from the bottom. The base end rod 19 is inserted into the inner peripheral hole 24 of the first piston 11 so as to be movable in the axial direction and in a hermetically sealed state. The large diameter portion 20 is inserted between the first piston 11 and the partition member 5 in the first cylinder 10. The tip rod 21 is inserted into the inner peripheral hole 25 of the second piston 15 so as to be movable in the axial direction. An annular gap 26 is formed between the outer peripheral surface of the tip rod 21 and the inner peripheral hole 25 of the second piston 15. The first cylinder bore 10 and the second cylinder bore 14 are connected by the annular gap 26. The tip rod 21 is inserted into the insertion hole 27 formed in the tip housing 6 so as to be movable in the axial direction and in a hermetically sealed state. The tip rod 21 protrudes outward from the tip housing 6.

A nut 32 having a diameter larger than that of the base end rod 19 is screwed onto the male thread formed at the base end of the base end rod 19. The tip surface of the nut 32 faces and can engage with the base end surface of the first piston 11. The first piston 11 is movable between the base end surface of the large diameter portion 20 of the output member 18 and the tip surface of the nut 32.

The first cylinder bore 10 is partitioned into a base end chamber and a tip end chamber by the first piston 11 and the base end rod of the output member 18. The base end chamber constitutes the lock chamber 35, and the tip end chamber constitutes the first release chamber (release chamber) 36. A supply and discharge passage 37 for supplying and discharging pressure oil from a pressure oil source to the lock chamber 35 is formed in the base end housing 2. In addition, another supply and discharge passage 38 for supplying and discharging pressure oil from a pressure oil source to the first release chamber 36 is formed in the partition member 5.

The first release chamber 36 is connected to a second release chamber 39 formed on the upper side (tip side) of the second piston 15 through the annular space formed between the outer peripheral surface of the large diameter portion 20 of the output member 18 and the inner peripheral surface of the second annular member 4, and through the annular gap 26.

The chamber defined by the second piston 15, the second cylinder bore 14, and the partition member 5 is connected to the outside world through a breathing hole 40 formed in the tip housing 6.

The engagement member 43 is attached between the wedge portion 11b of the first piston 11 and the large diameter portion 20 of the output member 18 so as to be movable along the wedge portion 11b and along the base end surface of the large diameter portion 20.

3A and 4A, four guide grooves 44 (only one is shown in FIG. 3A and FIG. 4A) are formed in the radial direction at a predetermined angle in the base end wall of the large diameter portion 20 of the output member 18. The guide groove 44 is formed so that its cross section is T-shaped, and is a so-called T-groove. The guide groove 44 has a small groove 44a with a narrow groove width and a large groove 44b with a wide groove width, which are formed in sequence from the base end side. A T-leg 45 protruding from the tip wall of the engagement member 43 toward the tip side is inserted into each guide groove 44. The T-leg 45 has a small diameter portion 45a formed in a cylindrical shape and a large diameter portion 45b in a cylindrical shape, which are formed in sequence from the base end side. The large diameter portion 45b of the T-leg 45 is inserted into the large groove 44b of the guide groove 44, and the small diameter portion 45a of the T-leg 45 is inserted into the small groove 44a of the guide groove 44. The sliding portion 46 formed on the base end surface of the engagement member 43 is connected to the large diameter portion 20 so that it can slide on the guide surface 47 formed on the base end surface of the large diameter portion 20. The guide groove 44 and the T-shaped leg 45 form a guide mechanism 52.

A first sliding surface 48 is formed on the inner wall (the wall facing the output member 18) of the engagement member 43 so as to incline radially outwardly of the output member 18 as it moves downward (toward the base end in the axial direction). The inclination angle α (see FIG. 2) is set to 35° to 50° with respect to the axial direction of the output member 18. The first sliding surface 48 is capable of sliding on the wedge surface 12 of the first piston 11. The first sliding surface 48 and the wedge surface 12 are formed parallel to each other so as to be in surface contact with each other.

A second sliding surface 49 is formed on the outer wall of the engagement member 43 (the wall facing the inner peripheral surface of the second annular member 4) so as to be inclined radially inward of the output member 18 as it approaches the base end. The inclination angle β (see FIG. 2) is set to 40° to 55°. The inclination angle β of the second sliding surface 49 is set to be larger than the inclination angle α of the first sliding surface 48.

The second sliding surface 49 can engage with a receiving surface 50 formed on the inner peripheral wall of the second annular member 4. The receiving surface 50 is tapered so as to incline radially inward (taper) as it approaches the inner peripheral wall of the second annular member 4. The second sliding surface 49 and the receiving surface 50 are formed parallel to each other so as to be in surface contact. The receiving surface 50 constitutes a part of the first cylinder bore 10.

The sliding portion 51 formed on the upper side of the second sliding surface 49 of the engaging member 43 is slidably engaged with the inner circumferential surface of the first cylinder hole 10 below the receiving surface 50 of the second annular member 4.

A wedge member 54 is fixed to the tip of the output member 18. The wedge member 54 can be inserted into a support hole 56 of a support member 55 that protrudes leftward from a die (not shown) (object to be engaged). A wedge surface 57 is formed on the left wall of the wedge member 54 so as to be inclined with respect to the axial direction of the output member 18 and to taper upward (toward the tip). A receiving surface 58 is formed on the left wall of the support hole 56 of the support member 55. The receiving surface 58 is formed as a flat surface parallel to the wedge surface 57 of the wedge member 54. When the wedge member 54 is inserted into the support hole 56, the wedge surface 57 engages with the receiving surface 58.

The above-mentioned cylinder device, as shown in FIGS. 1 and 2, operates as follows.
1 , the pressure oil (pressurized fluid) in the lock chamber 35 is discharged, and pressure oil is supplied to the first release chamber 36 and the second release chamber 39. As a result, the pressure oil in the first release chamber 36 moves the first piston 11 downward, and the first piston 11 moves the output rod 18 downward to its lowest position. In addition, the pressure oil in the second release chamber 39 moves the second piston 15 to its lowest position, and the second piston 15 is received by the upper end surface of the partition member 5.

When the cylinder device is locked, in the release state of FIG. 1, pressurized oil is discharged from the first release chamber 36 and the second release chamber 39, and pressurized oil is supplied to the lock chamber 35. The pressurized oil in the lock chamber 35 moves the output member 18 upward, and also moves the output member 18 upward via the first piston 11 and the engagement member 43. Next, the tip surface of the large diameter portion 20 of the output member 18 engages with the lower end surface of the second piston 15, and then the output member 18 pushes up the second piston 15.

When the output member 18 rises by a predetermined stroke, the third sliding portion 49 of the engagement member 43 faces the receiving surface 50 of the second annular member 4. Then, the first piston 11 pushes the engagement member 43 toward the receiving surface 50 (radially outward). The reaction force of the force with which the engagement member 43 pushes the receiving surface 50 is amplified and transmitted to the large diameter portion 20 of the output member 18 via the engagement member 43 by the wedge effect. As a result, the first piston 11 strongly pushes up the large diameter portion 20 of the output member 18 via the engagement member 43.

As described above, when the first piston 11 and the output member 18 rise, the wedge member 54 attached to the upper end of the output member 18 is inserted into the support hole 56 of the support member 55. Then, the wedge surface 57 of the wedge member 54 strongly pushes the receiving surface 58 of the support member 55 to the left. As a result, the die (not shown) is pressed against the mounting surface of the substrate.

When switching from the locked state of FIG. 2 to the released state of FIG. 1, in the state of FIG. 2, pressure oil is discharged from the lock chamber 35 and pressure oil is supplied to the first release chamber 36 and the second release chamber 39. First, when the pressure oil in the first release chamber 36 pushes the first piston 11 downward, a gap (in this embodiment, a small gap that releases the wedge action) is generated between the engaging member 43 and the output member 18, allowing the engaging member 43 to move radially inward of the output member 18. Then, the pressure oil in the second release chamber 39 pushes the second piston 15 downward, and the second piston 15 pushes the large diameter portion 20 of the output member 18 downward. Next, the first piston 11 engages with the nut 32 of the output member 19, and then the first piston 11 and the second piston 15 push the output member 14 downward. The second piston 15 is received by the partition member 5, and the large diameter portion 20 of the output member 18 is separated from the second piston 15. Next, the first piston 11 is received by the base end housing 2 of the housing 1. This switches the cylinder device from the locked state of FIG. 2 to the released state of FIG. 1.

The first embodiment has the following advantages.
In the above-mentioned locked state, even if a force acting to move the support member 55 to the right is applied through the die for some reason, the locked state is mechanically maintained by the frictional force due to the surface contact between the wedge surface 57 of the wedge member 55 and the receiving surface 58 of the support member 54. In addition, the guide surface of the large diameter portion 20 and the first sliding portion 46 of the engaging member 43 are in surface contact. In addition, the wedge portion 11b of the first piston 11 and the first sliding portion 48 of the engaging member 43 are in surface contact. Furthermore, the receiving surface 50 of the second annular member 4 and the second sliding portion 49 of the engaging member 43 are in surface contact. As a result, the frictional force generated in these surface contact portions resists the force pushing the output member toward the base end, so that the locked state of the cylinder device is reliably maintained.

The above embodiments can be modified as follows.
The pressure fluid may be other liquids or gases such as compressed air instead of the pressure oil exemplified.
The housing 1 may be configured by the exemplary base end housing 2, first annular member 3, second annular member 4, partition member 5, tip housing 6, nut 32, etc., but some or all of these components may be formed integrally.
Instead of being reciprocatingly driven by pressurized oil supplied to and discharged from the lock chamber 35 and the first release chamber 36, the above-mentioned annular piston 11 may be locked by a lock spring attached to the lock chamber 35, or released by a release spring attached to the first release chamber 36.
The second cylinder hole 14, the second piston 15 and the breathing hole 40 may be omitted.
The guide groove 44 having a T-shaped cross section is not limited to four guide grooves 44 formed on the base end wall of the large diameter portion 20 of the output member 18, and may be one or more. The cross section of the guide groove 44 may be a dovetail groove (see FIG. 4B) having another shape instead of a T-shape. Also, instead of forming the guide groove 44 on the base end wall of the large diameter portion 20 of the output member 18, the guide groove 44 may be formed on the engaging member 43 side. In this case, a T-leg is provided on the base end wall of the large diameter portion 20 of the output member 18. Also, instead of providing the guide groove 44 on the base end wall of the large diameter portion 20 of the output member 18, the guide groove 44 may be provided on the wedge portion 11b of the first piston 11 (see FIG. 3B). In this case, the T-leg or the guide groove 44 may be provided on the engaging member.
Instead of providing the T-leg or the like on the engaging member 43, the T-leg or the like may be formed so as to extend radially on the large diameter portion 20 of the output member 18. In this case, a guide groove 44 is provided on the engaging member 43. Also, instead of providing the T-leg or the like on the engaging member 43, the T-leg or the like may be provided on the wedge portion 11b of the first piston 11. In this case, a guide groove 44 is provided on the engaging member 43.
Of course, various other modifications can be made within the scope of what a person skilled in the art can imagine.

1: Housing, 10: First cylinder bore (cylinder bore), 11: First piston (annular piston), 21: Output member, 24: Inner bore, 43: Engagement member, 48: First sliding surface, 49: Second sliding surface, 50: Receiving surface, 52: Guide mechanism.

Claims (1)

an annular piston (11) inserted in a cylinder bore (10) of a housing (1) in a hermetically sealed manner so as to be movable in an axial direction, the annular piston (11) having an inner peripheral bore (24) formed in the axial direction;
an output member (18) that is hermetically inserted into an inner peripheral hole (24) of the annular piston (11) so as to be movable in the axial direction;
an engagement member (43) provided between a large diameter portion (20) formed on the output member (18) and the annular piston (11);
a guide mechanism (52) provided between the engaging member (43) and the large diameter portion (20) or between the engaging member (43) and the annular piston (11), the guide mechanism (52) slidably guiding the engaging member (43) relative to the large diameter portion (20) or the engaging member (43) relative to the annular piston (11);
A wedge surface (12) formed on the annular piston (11) so as to be inclined with respect to the axial direction is capable of surface-contacting with a first sliding surface (48) of the engagement member (43),
a receiving surface (50) formed on an inner peripheral wall of the cylinder hole (10) so as to be inclined with respect to the axial direction is capable of surface-contacting with a second sliding surface (49) of the engaging member (43);
The engaging member (43) is formed by the first sliding surface (48) and the second sliding surface (49) so as to taper toward the base end side in the axial direction,
The inclination angle of the receiving surface (50) with respect to the axial direction is formed to be larger than the inclination angle of the wedge surface (12) with respect to the axial direction,
a force pushing the annular piston (11) toward the tip side in the axial direction is amplified into a force toward the tip side and transmitted to the output member (18);
A cylinder device with a boosting mechanism.

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