JPS6116411Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fluid pressure cylinder used in an industrial machine that utilizes fluid pressure, and more particularly to a fluid pressure cylinder having a piston locking device.

BACKGROUND ART Conventionally, a fluid pressure cylinder with a locking device for locking a piston at the end of its stroke has been disclosed, for example, in Japanese Patent Laid-Open No. 48-58272 and Japanese Patent Laid-Open No. 49-1989.
This is already known from Publication No. 116472.

These locking devices have a configuration in which a sphere provided on the cover side of the end of the cylinder tube is engaged with a recess provided on the piston side at the end of the stroke. The disadvantage is that the structure is complicated because it is provided in a.

To explain this point more specifically, the above-mentioned locking device essentially requires at least the following components to be provided on the piston or cylinder side.

(a) A sphere fitted into a sleeve and a radial hole in it.

(b) A member provided with a recess into which the sphere engages when the piston is locked.

(c) A member for holding the sphere in engagement with the recess (this member is biased by a spring into a position where the sphere engages with the recess and is moved by fluid pressure into a position where it is disengaged); must be movable).

However, in the case of the above-mentioned known lock device in which the above-mentioned member (a) is provided on the cylinder side, (b) and (c)
These members will be installed on the piston side, which will make the structure of the piston very complicated, and the piston side will become larger overall, resulting in a shorter stroke compared to the cylinder length, making repairs and repairs more difficult. It has drawbacks such as the need to completely disassemble it when replacing parts.

Although it is possible to provide the member (c) above on the cylinder side, in that case the structure becomes even more complicated.

Problems to be Solved by the Invention This invention requires that, when the member (a) above is provided on the piston side, the members (b) and (c) above, especially the springs, must be provided to make them slidable. Focusing on the fact that it is now possible to install a certain member on the cylinder side, and it also makes it easier to repair the lock device and replace parts,
The problem to be solved is to simplify the structure of the locking device and reduce the number of parts.

Means for Solving the Problems The present invention connects an auxiliary cylinder tube in which an auxiliary piston is slidably inserted in the axial direction to a cylinder tube in which the piston is slidably inserted in the axial direction. A pressure chamber formed between the piston rod and the auxiliary piston is communicated with the cylinder port, and a plurality of through holes are bored in the sleeve at the tip of the piston rod to which the piston is fixed, and a pressure chamber formed between the piston rod and the auxiliary piston is made to communicate with the cylinder port. A large diameter sphere is disposed so as to be displaceable in the wall thickness direction within a range that does not fall out of the sleeve, and a protrusion that presses the sphere from the outside of the sleeve to protrude inward, and a protrusion that pushes the sphere from the outside of the sleeve to the outside of the sphere. an insertion portion that engages a sphere that fits into the sleeve and protrudes inward, and that causes the sphere to protrude outward and restrict inward displacement of the auxiliary piston; established,
The above-mentioned problem is solved by employing a means of urging the auxiliary piston toward the piston by a spring.

Operation When the sphere hits the protrusion of the auxiliary cylinder tube near the stroke end of the piston, it is pressed by the protrusion and the sphere protrudes inside the sleeve, so the auxiliary piston is pressed by this and strokes in the same direction as the piston.

When the piston reaches the stroke end, the sphere passes the protrusion of the auxiliary cylinder and reaches the groove, allowing for outward displacement.The auxiliary piston returns with the biasing force of the spring, causing the sphere to be displaced inward. Since the piston is regulated, the piston is locked.

To drive the piston in the opposite direction, when pressurized fluid is supplied to the pressure chamber, the fluid pressure causes the auxiliary piston to move back and move the sphere inward, releasing the lock and causing the piston to move in the opposite direction. Stroke.

In this case, since the piston side is simply provided with a sleeve into which a sphere is inserted, the stroke is longer compared to the cylinder length than in the conventional example.
Repairs and parts replacement of the locking device can be easily carried out by removing the cover provided at the end of the cylinder tube.In particular, since there is only a sleeve fitted with a sphere on the piston side,
The work is easy.

Effects of the invention In this invention, the sleeve into which the sphere is inserted is provided on the piston side, and the other members necessary for locking the piston are provided on the cylinder side, so the structure of the locking device is simple and the number of parts can be reduced. It is possible to make the stroke longer than the cylinder length.

Furthermore, maintenance is easy because the auxiliary cylinder and the auxiliary piston are additionally attached to the end of the cylinder tube, and a sleeve into which a sphere is inserted is provided on the piston side.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings. In FIG. 1, 1 is a double-acting air cylinder device, 2 is an auxiliary cylinder device connected thereto, and 3 is a connection between them. The head cover 3 is fixed to the cylinder device 1 with tie rods 4 and nuts 5, and the auxiliary cylinder device 2 is screwed onto the head cover 3 to integrate the whole.

In the cylinder device 1, the piston 6
is fitted and fixed to the piston rod 9 with its both ends sandwiching the cushion rings 7, 8, and the piston 6 is fitted into the cylinder tube 10 so as to be slidable in the axial direction. A sleeve 12 is screwed onto the tip of the piston rod 9 to solidify the piston 6 via a cushion ring 8 and to be inserted into the pressure chamber 11 at the end of the stroke. , 12a, . . . are bored at 90° intervals, and a steel sphere 13 having a diameter larger than the wall thickness of the sleeve 12 is disposed in the through hole 12a so as to be displaceable in the thickness direction. A flange portion 12b and a caulking portion 12c are formed on the inner opening edge and the outer opening edge of the sleeve 12, respectively, thereby preventing the sphere 13 from falling out of the through hole 12a.
It is configured so that it can take either an outwardly protruding position (see FIG. 3) or an inwardly protruding position (see FIG. 2).

On the other hand, in the auxiliary cylinder device 2, an auxiliary piston 16 having an insertion portion 16a inserted into the sleeve 12 is inserted into the auxiliary cylinder tube 15 so as to be slidable in the axial direction. The end of the tube 15 is closed by fixing a retaining plate 19 provided with a spring seat 17 and a damper 18 with a retaining ring 21. Thus, the piston 6 is moved by the spring 22 compressed between the auxiliary piston 16 and the spring seat 17.
The auxiliary piston 16
A lock means release screw 23 which freely passes through the presser foot 19 is screwed into the auxiliary piston 16 so that the auxiliary piston 16 can be freely displaced by manual operation against the biasing force of the spring 22. Further, as the sleeve 12 is inserted into the auxiliary cylinder tube 15, a sphere 13 is pressed from the outside of the sleeve 12 to protrude inward from the inner peripheral surface of the auxiliary cylinder tube 15. Grooves 15b are provided around the protrusion 15a and the insertion portion 16a of the auxiliary piston 16 to allow the sphere 13 (see FIG. 3) pressed from inside to protrude outward. The insertion portion 16a of the auxiliary piston 16 is inserted into the sleeve 1.
It engages a sphere 13 that is fitted into the inside of 2 and protrudes inward, and also causes the sphere 13 to protrude outward to restrict inward displacement.

The pressure chamber 11 provided between the piston 6 and the auxiliary piston 16 in the head cover 3 directly communicates with the cylinder port 3a on the head side.
Further, this pressure chamber 11 is communicated with a head side pressure chamber 24 in the cylinder device 1.

In addition, 25 in the figure is a rod side pressure chamber of the cylinder device 1.

Next, the operation of the locking mechanism in the hydraulic cylinder with locking device configured as described above will be explained.

As shown in Fig. 1, first, the piston rod 9
When the cylinder approaches the stroke end while discharging the air in the head side pressure chamber 24 from the cylinder port 3a, the sleeve 12 is inserted between the auxiliary cylinder tube 15 and the insertion part 16a of the auxiliary piston 16, and the spherical 13 is pressed from the outside of the sleeve 12 by the protrusion 15a of the auxiliary cylinder tube 15 and protrudes inward, and this protrusion engages with the insertion portion 16a. If the sleeve 12 further strokes in this state, the second
As shown in the figure, the auxiliary piston 16 is connected to the spring 2
When the ball 13 is pushed into the auxiliary cylinder tube 15 against the urging force of 2 and the stroke progresses further, the sphere 13 passes the protrusion 15a of the auxiliary cylinder tube 15 and reaches the groove 15b as shown in FIG. Therefore, the spherical body 13 is pressed by the tip of the insertion portion 16a and is displaced to the outside of the sleeve 12, whereby the engagement between the spherical body 13 and the insertion portion 16a is released, and the insertion portion 16a is pushed by the biasing force of the spring 22. It is then inserted into the sleeve 12 and returned to its original position. Therefore, in this state, the sphere 13
is in contact with the circumferential surface of the insertion portion 16a and the inward displacement of the sleeve 12 is restricted, so that the spherical body 1
3 engages with the protrusion 15a of the auxiliary cylinder tube 15, and the piston rod 9 is locked.

After this, in order to release the locked state of the piston rod 9 and make it stroke in the opposite direction, there is no need to perform any special operation. Just by applying fluid pressure to the cylinder port 3a, the locked state will be automatically released and the piston rod will move. 9 strokes in the opposite direction. That is, if fluid pressure is applied to the cylinder port 3a, the fluid pressure also acts on the auxiliary piston 16,
The auxiliary piston 16 is stroked against the urging force of the spring 22. As a result, the insertion portion 16a of the auxiliary piston 16 comes out of the sleeve 12, allowing the sphere 13 to move inside the sleeve 12, and the sphere 13 and the auxiliary cylinder tube 15
The piston rod 9 is disengaged from the protrusion 15a, and the locked state of the piston rod 9 is released, and at the same time, the piston 6 and the piston rod 9 stroke in opposite directions due to the action of the fluid pressure.

The locked state can also be manually released by pulling the threaded rod 23 screwed onto the auxiliary piston 1 against the biasing force of the spring 22.

Alternatively, the screw rod 23 may be omitted and the dustproof body 26 may be fitted into a breathing hole 19a protruding from the holding plate 19, as shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of the main part of the present invention, FIGS. 2 and 3 are partial sectional views of the upper half of the device in different operating states, and FIG. 4 is a sectional view of the main part of another embodiment. 3a...Cylinder port, 6...Piston, 9
...Piston rod, 10...Cylinder tube, 11...Pressure chamber, 12...Sleeve, 12a
...Through hole, 13...Sphere, 15...Auxiliary cylinder tube, 15a...Auxiliary piston, 22...Spring.

Claims (1)

[Scope of utility model registration request] A pressure chamber is formed between the piston and the auxiliary piston by connecting an auxiliary cylinder tube in which the auxiliary piston is slidably inserted in the axial direction to a cylinder tube in which the piston is slidably inserted in the axial direction. is connected to the cylinder port, and a plurality of through holes are bored in the sleeve at the tip of the piston rod to which the piston is fixed, and a sphere with a diameter larger than the wall thickness of the sleeve is inserted into the through holes within a range that does not fall out from the sleeve. The auxiliary cylinder tube is disposed so as to be displaceable in the wall thickness direction, and a protrusion that presses the sphere from the outside of the sleeve to protrude inward, and a groove that allows the sphere to protrude outward are provided around the auxiliary cylinder tube, respectively; The auxiliary piston is provided with an insertion portion that fits into the sleeve and engages the sphere protruding inward, and also causes the sphere to protrude outward to restrict inward displacement, and the auxiliary piston is moved toward the piston side by a spring. A fluid pressure cylinder with a locking device, characterized in that it is biased toward.