JPH0142641Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a fluid pressure cylinder, and particularly includes an output member that is moved by an actuating member such as a piston or a ram fitted into a cylinder body, and that This invention relates to a hydraulic cylinder with a function of locking a member.

Background of the invention: A cylinder body and a ram fitted in a liquid-tight manner.
BACKGROUND OF THE INVENTION Hydraulic cylinders equipped with actuating members such as pistons are widely used in various fields. For example, in the process of welding automobile floor panels, such a hydraulic cylinder is used to advance or retreat a welding electrode toward or from the floor panel. Since the floor panel has many unevenness,
In order to avoid the electrode interfering with the floor panel when feeding it into or taking it out from the welding position, it is necessary to separate the electrode from the floor panel each time.

By the way, in this welding process, a large load is applied to the actuating member of the cylinder when pressurizing the welding part of the floor panel through the electrode, so a fluid pressure cylinder with a large driving force is used. However, in such a welding process, a large driving force is required only after the electrode contacts the floor panel, and during other steps, that is, the step of bringing the electrode closer to the floor panel, or the step of moving the electrode away from the floor panel. A large driving force is not required in the stroke. Therefore, if a fluid pressure cylinder with a large driving force is used, energy will be wasted accordingly, and at the same time, there will be a disadvantage that the device will become larger and the cost will increase.

This problem is not simply a problem unique to the fluid pressure cylinder used in the welding process, but is a problem common to many conventional fluid pressure cylinders used in various fields.

Solution The present invention was developed against the background of the above, and its gist is to (1) enable a fluid pressure cylinder to reciprocate in a direction parallel to the moving direction of the actuating member; (2) a lock surface formed on the cylinder body or a member fixed thereto in parallel with the moving direction of the actuating member; (3) a lock surface fixedly provided on the output member; ,
(4) a cam surface forming a wedge-shaped gap whose width changes in the direction of movement of the output member between the cam surface and the lock surface;
(5) a ball disposed so as to be able to fit into the wedge-shaped gap; and (5) fixedly disposed relative to the actuating member so as to move together with the actuating member, the ball being movable in a direction parallel to the direction of movement of the ball. (6) a ball retainer having a ball drive surface that drives the balls to be held in the wedge-shaped gap and to come into contact with the balls that are caught in the wedge-shaped gap to release the balls; (7) an elastic member provided between the output member and the actuating member, the actuating member moving in a first direction that results in the ball drive surface releasing the ball from biting; (8) the actuating member moves in a second direction opposite to the first direction; and (8) the actuating member moves in a second direction opposite to the first direction. and a second abutting portion that abuts against each other and moves the output member together with the actuating member in the second direction.

Effects of Action and Idea In this fluid pressure cylinder, when the actuating member is moved in the second direction, the second contact portion comes into contact with the actuating member and the output member is moved in the second direction together with the actuating member. When the output member reaches a certain position and a load is applied to the output member in the first direction opposite to the second direction, a lock surface formed on the cylinder body side and a lock surface formed on the output member side are applied. The ball is caught in the wedge-shaped gap between the output member and the cam surface, thereby preventing the output member from moving in the first direction. That is, the load is transmitted directly to the cylinder body and is not applied to the actuating member.

Meanwhile, the output member is returned to its original position by moving the actuating member in the first direction after the load on it in the first direction has been removed. When the actuating member is moved in the first direction, first, the ball drive surface of the ball retainer fixedly provided on the actuating member comes into contact with the balls caught in the wedge-shaped gap, causing the balls to become stuck. Drive in the direction of release,
The first abutment then abuts and moves the output member in the same first direction with further movement of the actuating member.

In this way, in the cylinder of the present invention, the ball is caught in the wedge-shaped gap between the locking surface on the cylinder body side and the cam surface on the output member side, so that the output member is locked and the actuating member is locked. is such that no load is applied to it. For this reason, it becomes possible to support a sufficiently large load with a cylinder with a small driving force, which saves energy that was previously wasted, and also reduces the size of the cylinder and reduces equipment costs. be.

Embodiments Next, embodiments of the present invention will be described in detail based on the drawings.

In FIGS. 1 and 2, 10 is a cylinder tube, which together with covers 12 and 14 which close openings at both ends constitutes a cylinder body 15. Inside the cylinder body 15, a piston 16 having a cylindrical shape with a bottom is slidably fitted into the cylinder body 15. It is divided into a second hydraulic pressure chamber 24 which communicates with the hydraulic pressure chamber 24. Two annular grooves are provided on the outer periphery of the piston 16, into which a sealing member 26 is fitted, thereby maintaining liquid tightness between the piston 16 and the cylinder body 15. .

In these figures, a ball retainer 28 having a cylindrical shape with a bottom is arranged on the left side of the piston 16. The retainer 28 is provided with a fitting shaft portion 30 at the rear, and this shaft portion 30 is connected to the fitting hole 30 of the piston 16.
is mated to. A female screw hole 34 is formed in the center of the shaft portion 30 in a direction parallel to the axis of the cylinder body 15, and through holes 36 and 38 are provided in the piston 16 and the cover 12, which are concentric with the female screw hole 34. There is. One end of the rod 40 penetrates through these through holes 36 and 38 and enters the inside of the cylinder body 15, and a male threaded portion 4 provided at the tip thereof is inserted into the cylinder body 15.
2 is screwed into the female threaded hole 34 of the retainer 28. The portion of the rod 40 adjacent to this male threaded portion 42 is formed in a stepped shape, and its shoulder surface is brought into contact with the shoulder surface of the through hole 36 of the piston 16, which is also formed in a stepped shape. . That is, the rod male threaded portion 42 and the retainer female threaded hole 34
The retainer 28, the piston 16, and the rod 40 are connected by screwing with the retainer 28 and move together. A stopper 44 is fixed to the other end of the rod 40, and when the piston 16 is moved forward in the left direction (this is the second direction) in FIGS.
4 comes into contact with the cover 12, thereby defining its forward end. Stoppa 44
is a cylindrical member with a bottom, and has a female threaded hole 46 formed at its bottom, into which the male threaded portion 48 of the rod 40 is screwed. The position of the stopper 44 in the front-rear direction (left-right direction in FIGS. 1 and 2) is adjusted by changing the screwing position thereof. A nut 50 arranged on the rear side of the stopper 44 is for locking the stopper 44 in the adjusted position.

An output rod 52 passes through a through hole 54 formed in the cover 14 and projects into the interior of the cylinder body 15 from the side opposite to the rod 40. A pin 56 is installed in the end of the output rod 52 on the entry side in the radial direction of the output rod 52.
This pin 56 is fitted into an elongated hole 58 formed in the cylindrical portion of the retainer 28. That is, when the retainer 28 is moved together with the piston 16 to the right in the figure (this is defined as the first direction), the output rod 52 is moved in the first direction together with the piston 16, and the inner wall surface 6 of the pin 56 and the elongated hole 58
0 constitutes the first contact portion. Note that when the retainer 28 is moved in the second direction (to the left in the figure) and its bottom surface 62 abuts the rear end surface 64 of the output rod 52, the elongated hole 58 has an inner wall surface 66 on the right side in the figure that is pinned. The length is such that it does not come into contact with 56. Therefore, when the piston 16 is moved in the second direction, the retainer bottom surface 62
The output rod 5 is brought into contact with the output rod 64.
2 will be moved together. In other words, the retainer bottom surface 62 and the output rod rear end surface 64 form a second contact portion.

At the rear end of the output rod 52, there is a cam surface 70 that slopes away from the inner wall surface (lock surface) 68 of the cylinder body 15 as it moves toward the right in the figure, that is, in the first direction, along the circumferential direction. Three are formed at intervals. At positions facing each of the cam surfaces 70, an elongated housing hole 72 is formed in the cylindrical portion of the retainer 28, and a ball 74 moves in the housing hole 72 in the direction of movement of the piston 16. accommodated as possible. ball 7
4 is located within a wedge-shaped gap 76 formed by the cam surface 70 of the output rod 52 and the locking surface 68 of the cylinder body 15, and the output rod 52 is moved relative to the retainer 28 in the first direction. When the cam surface 70 and the lock surface 6 of the cylinder body 15
8 and prevents the output rod 52 from moving in the first direction. In other words, the output rod 52 is locked. Note that the ball 74 is in a state where it is biased in the second direction by a coil spring 78 disposed inside the accommodation hole 72, so that the ball 74 is biased in the second direction.
As shown in the figure, it is normally in contact with the left inner wall surface (ball drive surface) 80 of the accommodation hole 72.
The ball drive surface 80 is connected to the cam surface 70 and the lock surface 68.
The ball 74 caught in the gap 76 between
This is for driving in the direction of releasing the biting, and when the retainer 28 moves in the first direction, the inner wall surface 6 of the elongated hole
The ball 74 is formed at a position where it can come into contact with the ball 74 which is in the biting position prior to the contact between the ball 74 and the pin 56 .

Next, the operation of this fluid pressure cylinder will be explained.
FIG. 1 shows a state in which the piston 16 is at the right end (retreat end), and in this state, the first contact portion, that is, the pin 56 implanted in the output rod 52 and the inner wall surface 60 of the retainer elongated hole 58 are connected. The ball 74 is in contact with the ball drive surface 80 of the retainer 28 at a position slightly apart from the cam surface 70 of the output rod 52. From this state, hydraulic pressure is supplied to the port 18 to move the piston 16 into the retainer 2.
8 and the rod 40 in the second direction, the elongated hole inner wall surface 60 is first separated from the pin 56, and then the ball 74 is brought into contact with the cam surface 70 of the output rod 52. Ball 7 in contact with cam surface 70
4 is blocked by the cam surface 70 and cannot move in the second direction. Therefore, when the piston 16 is further advanced, the ball 74 is relatively moved within the accommodation hole 72 while elastically deforming the spring 78, and is driven. spaced apart from surface 80. When the piston 16 is further advanced, the bottom surface 62 of the retainer 28 comes into contact with the rear end surface 64 of the output rod 52, and thereafter, as shown in FIG. 2, the output rod 52 moves forward together with the piston 16 in the second direction. I am made to do so. When the piston 16 advances to a certain position, the rod 40
The stopper 44 fixed to the cover 12 comes into contact with the rear end surface of the cover 12, and the piston 16
advance is stopped. This stop position is the position where a load is applied to the output rod 52,
The position of the stopper 44 is adjusted in advance so that the piston 16 stops at exactly this position.

When a load is applied to the output rod 52 in the first direction, the ball 74, which is in contact with the cam surface 70 and the locking surface 68 of the cylinder body 15, is bitten by those surfaces 70,68. ball 74
If the output rod 52 is jammed, the output rod 52 becomes immovable in the first direction, and the load applied to the output rod 52 is directly transmitted via the cylinder body 15 to the member supporting it. That is, no load is applied to the piston 16.

Next, after the load on the output rod 52 is removed, hydraulic pressure is supplied from the port 22 to pull the output rod 52 back so that the piston 16
When the ball 74 is moved in the first direction, the ball drive surface 80 of the retainer 28 first moves the ball 74 in the biting state.
and moves it together with the piston 16 in the first direction. In other words, it is moved in the direction of releasing the jamming. Subsequently, the elongated hole inner wall surface 60 of the retainer 28 comes into contact with the pin 56 of the output rod 52, and the output rod 52 is released from the movement-preventing state.
is moved together with the piston 16 in the first direction. When the rear end surface of the piston 16 comes into contact with the end surface of the cover 12, the movement of the piston 16 is stopped, and the piston 16 and the output rod 52 return to their original positions.

In the above device, no large driving force is required to move the piston 16 and the output rod 52, and moreover, the piston 16
It can support a large load at the stop position. That is, in such a device, energy is used efficiently and no waste occurs.
Further, in the device of this example, the ball 74 moves together while contacting the cam surface 70 of the output rod 52 and the lock surface 68 of the cylinder body 15, and when a load is applied to the output rod 52, the ball 74 is immediately moved between them. Since the load is supported by being caught in the gap 76, the position where the load should be supported can be arbitrarily determined, or the position can be changed continuously.

Next, another embodiment of the present invention will be described based on FIGS. 3 to 5. The cylinder shown in FIG. 3 is of a form in which the stopper of the previous embodiment is omitted, and the cover 84 has no through hole and only a port 86 is provided. Further, the piston 16 and the retainer 28 are connected by a bolt 82 with a head. Note that other parts in this example are the same as those in the previous embodiment, so only the reference numerals are shown and detailed explanations are omitted. The same applies to the following examples.

In the cylinder of this example, by keeping the driving force to the piston 16 small, the output rod 52 can be accurately stopped at a predetermined position.
It is possible to receive the load at that position. This is because the piston 16 can be stopped by the output rod 52 coming into contact with a workpiece or the like.

The above two embodiments show examples in which a locking mechanism for preventing the output rod, which is an output member, from moving in the first direction is provided inside the cylinder body, but such a locking mechanism may be provided outside the cylinder body. It is also possible to provide one, and FIG. 4 shows an example thereof. In this example, a retainer 92 is fixed to a piston rod 90 extending outward from the cylinder body 88, and the output rod 52 is connected to the retainer 92 by a pin 56 and an elongated hole 58. The retainer 92 is composed of a first member 94 and a second member 98 fitted thereto and fixed by a set screw 96. The retainer 92 is screwed into the male threaded portion 102 of the piston rod 90, and by changing the screwing position with respect to the male threaded portion 102, the retainer 92 can be screwed into the piston rod 90.
The position in the moving direction of 0 can be adjusted. Note that the nut 104 is for locking the retainer 92 in the adjusted position.

The retainer 92 is fitted into a sleeve 106 so that it can be slid on its inner surface, and the sleeve 106 is screwed to the cylinder body 88 at a cover 108 that closes an opening at one end, and an opening at the other end. In the cover 110 that closes the
is movably supported.

FIG. 5 shows an example of a cylinder in which the output rod 114 is locked in either the forward or backward direction of the piston 16.
In this cylinder, two cam surfaces 11 with opposite inclination directions are provided at the rear end of the output rod 114.
6,118 are formed, and each cam surface 116,1
Two wedge-shaped gaps 120, 122 are formed between the cylinder body 18 and the locking surface 68 of the cylinder body 15. Balls 124 and 126 are disposed within these two wedge-shaped gaps 120 and 122, respectively, and are movably held within a receiving hole 130 of a retainer 128. One ball (first ball) 124 is connected to the output rod 1 as in the previous embodiment.
When a load is applied to 14 in the right direction in the figure, the cam surface (first cam surface) 116 and the lock surface 68
The other ball (second ball) 126 prevents the output rod 114 from moving to the right by being caught in the gap (first gap) 120 between the two balls. When a load is applied to the rod 114 in the left direction, the output rod is caught in the gap (second gap) 122 between the cam surface (second cam surface) 118 and the lock surface 68. 114 from moving to the left. These first ball 124, second ball 1
The inner wall surface of the accommodation hole facing 26 serves as a first ball drive surface 132 and a second ball electrode drive surface 134 . The first ball drive surface 132 is connected to the piston 16
is moved to the right, the elongated hole inner wall surface 60
The second ball driving surface 134 is formed at a position where it can contact the first ball 124 before it contacts the pin 56, and the second ball driving surface 134 is formed in a position where it can contact the retainer bottom surface 62 when the piston 16 is moved leftward.
The second ball 126 is formed at a position where it can come into contact with the second ball 126 before it comes into contact with the rear end surface 64 of the output rod 114 . In addition, two balls 124,1
26 are urged away from each other by a coil spring 136, and the spring 136 is passed through a retaining hole provided in the output rod 114 to prevent it from coming off.

In such a cylinder, when the piston 16 is advanced leftward from the right end (retreat end) shown in FIG. Push in the opposite direction. Next, the retainer bottom surface 6
2 comes into contact with the rear end face 64 of the output rod and moves both of them to the left. At this time, the other first ball 124 is in contact with the other first cam surface 116 and the lock surface 68, so that if a load is subsequently applied to the output rod 114 in the right direction,
As in the previous embodiment, the ball 124 is located in the first gap 120.
is caught and prevents the output rod 114 from moving to the right. After the load is removed,
The action when pulling the output rod 114 back to the right is the same as in the previous embodiment. On the other hand, when a load is applied to the output rod 114 in the left direction, the second ball 126 is caught in the second gap 122 and prevents the output rod 114 from moving in the same direction. After the load is removed, when the piston 16 is moved to the left in the same direction as the load, the second ball drive surface 134 is moved to the second ball 12.
6 is released, the bottom surface 62 of the retainer comes into contact with the output rod rear end surface 64, and the output rod 114
move both to the left. That is, in this example, the output rod 114 is locked even if a load is applied to the output rod 114 in either the left or right direction, and the piston 16 as an operating member can be moved in either the left or right direction. The lock is released even when the lock is moved, and therefore the left direction in the figure is both the first direction and the second direction, and the right direction is both the second direction and the first direction. be. When the right direction in the figure is the first direction, the pin 56 and the inner wall surface of the elongated hole 60 become the first abutting part, and the retainer bottom face 62 and the output rod rear end face 64 become the second abutting part. On the other hand, when the left direction is the first direction,
The bottom surface 62 of the retainer and the rear end surface 64 of the output rod serve as a first contact portion, and the pin 56 and the inner wall surface 60 of the elongated hole serve as a second contact portion.

Note that a load is applied to the output rod 114 in the left direction, causing the second ball 126 to move into the second gap 12.
2, when the piston 16 is pulled back to the right after this load is removed,
The elongated hole inner wall surface 60 of the retainer 128 is the output rod 1
14 pins 56 and pull them back together. Since the direction of movement of the output rod 114 is the direction to release the second ball 126,
The second ball 126 does not prevent the output rod 114 from moving, and the first ball 124 is also driven by the first ball drive surface 132 in the direction of releasing the bit, thereby preventing the output rod 114 from moving. There's nothing wrong with that.

Next, another embodiment of the present invention will be described based on FIGS. 6 and 7. In this embodiment, a small diameter shaft portion 140 is formed at the rear end of the output rod 138, into which a cylindrical member 142 having two cam surfaces 144 is fitted and fixed. On the other hand, the retainer 146 is connected to the male threaded portion 10 of the piston rod 90.
2, a block-shaped first member 148 screwed together;
A cylindrical second member 152 is connected to the first member 148 by a pin 150.
A circular housing hole 154 is formed in the second member 152 at a position facing the cam surface 144, and the ball 74 is housed in the hole 154. In addition,
Cam surface 144, ball accommodation hole 154, ball 74
Although there are two pieces each, three or more pieces may be provided along the circumferential direction. The accommodation hole 154 has a larger diameter than the ball 74, allowing the ball 74 to move a short distance in the direction of movement of the retainer 146. Retainer 14
An annular groove 15 is provided on the inner peripheral side of the second member 152 of No. 6.
8 is provided, and a ring-shaped spring 160 is accommodated here. As shown in FIG. 7, the spring 160 is set in such a state that it is in contact with the ball 74, and in a state in which the contact portion is elastically deformed by a certain amount. That is, ball 7
4 is urged toward the ball drive surface 162. A contact portion 164 is formed at the distal end of the second member 152 and extends radially toward the output rod 138. It is inserted into a recess formed in between. The width of the recessed portion is made wider than the width of the abutting portion 164, so that the retainer 146 is connected to the output rod 138.
It is possible to move slightly relative to the

In such a cylinder, when the piston rod 90 is pushed out to the left in FIG.
The contact part 164 of the retainer 146 is connected to the output rod 13
The output rod 138 is brought into contact with the rear end surface of the main body part 166 of No. 8 and moved together with the output rod 138. Then output rod 1
When a load is applied to 38 in the right direction in the figure,
The ball 74 is caught in the gap 168 between the cam surface 144 and the lock surface 68, and the output rod 138
Prevent movement to the right.

When the piston rod 90 is retracted to the right in the figure after this load is removed, the ball drive surface 162 comes into contact with the ball 74 and releases the biting.
Thereafter, the contact portion 164 contacts the front end surface of the cylindrical member 142 and moves the output rod 138 together to the right. That is, in this example, the right direction in the figure is the first direction, and the left direction is the second direction, and the front end surface (the left end surface in FIG. 6) of the contact portion 164 of the retainer 146 Output rod main body 16
The rear end surface of 6 forms the second abutting part, and the same abutting part 1
The rear end surface of the cylindrical member 64 and the front end surface of the cylindrical member 142 constitute a first contact portion.

The cylinder of this example has the advantage of better machinability of the accommodation hole for accommodating the ball and better ease of assembling the spring than the cylinder of the previous example. This is because the housing hole is a circular hole instead of an elongated hole, and the spring is ring-shaped.

Several embodiments of the present invention have been described in detail above.
The invention can also be implemented in other ways.

For example, in the embodiment shown in FIG. 5, the first ball 124, the first ball drive surface 132, and the first cam surface 116 are omitted, and only when a load is applied to the output rod 114 in the left direction in the figure. It is also possible to prevent movement of the output rod 114. In this case, the left direction is the first direction,
The opposite rightward direction is the second direction, and the retainer bottom surface 62 and the output rod rear end surface 64
The first contact portion is connected to the pin 56 and the elongated hole inner wall surface 60.
constitutes the second contact portion. It is also possible to provide the cam surface forming the wedge-shaped gap on a member fixed to the output member. Furthermore, it is also possible to provide the locking surface formed on the inner wall surface of the cylinder body on a member fixed to the cylinder body.

Further, the present invention includes a ram as an operating member,
It can be applied to cylinders that generate operating force only in one direction, and can be applied not only to hydraulic cylinders but also to air cylinders, and also to general hydraulic cylinders used for various purposes.

In addition, the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a front cross-sectional view of a main part of a hydraulic cylinder according to an embodiment of the present invention, and FIG. 2 is a front cross-sectional view of a main part showing one operating state of the same cylinder. 3 to 5 are front sectional views of main parts of hydraulic cylinders according to other embodiments of the present invention. FIG. 6 is a front sectional view of a main part of a hydraulic cylinder according to another embodiment of the present invention, and FIG. 7 is a view taken in the direction of the arrow in FIG. 6. 15, 88: cylinder body, 16: piston,
28, 92, 128, 146: retainer, 52,
114, 138: Output rod, 56: Pin, 6
0: Inner wall surface, 62: Bottom surface, 64: Rear end surface, 68:
Lock surface, 70, 116, 118, 144: Cam surface, 72, 130, 154: Accommodation hole, 74, 12
4,126: Ball, 76,120,122,1
68: Gap, 80, 132, 134, 162: Ball drive surface, 90: Piston rod.

Claims (1)

[Claims for Utility Model Registration] A fluid pressure cylinder comprising a cylinder body and an actuating member such as a ram or piston that is fluid-tightly fitted into the cylinder body and moved in a linear direction by the pressure of fluid supplied to the cylinder body. an output member provided to be reciprocally movable in a direction parallel to the moving direction of the actuating member; a locking surface formed on the cylinder body or a member fixed thereto in parallel to the moving direction of the actuating member; a cam surface that is fixedly provided to the output member and forms a wedge-shaped gap with the lock surface that changes in width in the direction of movement of the output member; and a cam surface that is arranged to be able to bite into the wedge-shaped gap. a ball that is fixedly provided with respect to the actuating member and moves with it, holds the ball movably in a direction parallel to the direction of movement of the ball, and is caught in the wedge-shaped gap; a ball retainer including a ball drive surface that drives the balls to come into contact with the balls and release the balls; an elastic member that biases the balls in the direction of the balls; and between the output member and the actuating member. and when the actuating member moves in a first direction that results in the ball drive surface disengaging the ball, they abut each other after disengaging and move the output member together with the actuating member. a first abutting portion that contacts each other when the actuating member moves in a second direction opposite to the first direction, and a second abutting portion that causes the output member to move in the second direction together with the actuating member. When a load is applied to the output member in the first direction, a locking function based on the biting of the ball prevents the output member from moving in the first direction; When the actuating member moves in the first direction, the output member is moved in the first direction together with the actuating member by releasing the ball from the ball driving surface and contacting the first contact portion. Fluid pressure cylinder with functions.