JPH05154788A - Large-stroke cylinder device - Google Patents

Abstract

PURPOSE:To prevent the relative rotation between a cylinder and a piston without separately requiring a guide on a cylinder device having no piston returning pipe and no tool driving pipe in a double-acting cylinder piston system allowing full-stroke actions via fluid pressure for both the forward motion and return motion. CONSTITUTION:A stem 5 is provided on a cylinder 3 side, and the stem 5 is slidably arranged in a piston 4 in a double-acting cylinder piston system. A piston returning fluid passage and a tool driving fluid passage are provided on the stem 5, and the tool driving fluid passage is communicated to a tool fitted at the front end of the piston 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder device used as a telescopic arm of a transfer machine.

[0002]

2. Description of the Related Art In a transfer machine, a long arm is required to mount a component inside a housing or to remove a component from a deep tray, and a chuck cylinder that is operated by air pressure is mostly used. Such a cylinder also opens and closes the chuck as a tool attached to the tip by fluid pressure, for example, air pressure, so when the cylinder is a double-acting type, it is necessary to open and close the chuck in the forward and backward air pipes. Requires air piping. In such a case, the three pipes may be complicated and hinder the work. Further, when piping is provided in a movable part such as a piston, the piping is swayed each time it is operated, and a specific portion of the piping is prematurely fatigued, or the piping comes into contact with other members.

In order to solve such a point, an axial through hole is formed in the piston to form an air passage for driving the chuck, and a coil spring for return movement is inserted between the piston and the outer tube to extend. A single-acting cylinder that returns the piston to the original position has been proposed. In such a single-acting cylinder, the pipe can be used only for the forward movement of the piston, so that the above inconvenience can be solved. However, in coil springs, the force required for compression during forward movement and the force required for rebounding due to spring characteristics are not uniform in the process, and fatigue tends to occur over time. Lacks stability when you need. Further, even if the piston is extended from the size of the cylinder to the allowable full stroke, the coil spring has a length at the time of critical compression and cannot be extended to the full stroke.

Further, since the cylinder and the piston usually have a circular cross section, a relative rotation occurs between the cylinder and the piston at the time of operation. Therefore, a guide is separately provided to prevent the rotation of the piston to which the tool is attached. ing.

[0005]

SUMMARY OF THE INVENTION The present invention is a double-acting cylinder / piston mechanism capable of full stroke operation with fluid pressure in both forward and backward movements. Piping for backward movement of a piston and tool driving pipe. An object of the present invention is to provide a cylinder device that does not have a cylinder, and a cylinder device that does not require a separate guide and that prevents relative rotation between the cylinder and the piston.

[0006]

A double-acting cylinder / piston mechanism is provided in which a stem is provided on the cylinder side and the stem is slidably arranged inside the piston. The stem has a piston return fluid passage and a tool driving fluid passage, and the tool driving fluid passage communicates with a tool attached to the front end of the piston.

[0007]

With the structure in which the piston return fluid passage and the tool drive fluid passage are provided in the stem, the conventional piston return fluid piping and tool drive fluid piping are provided in the cylinder device equipped with the tool at the piston tip. Eliminate the need for piping for moving parts.

[0008]

FIG. 1 shows a chuck cylinder 1 driven by air pressure as an example of a large stroke cylinder device, and a chuck 2 also driven by air pressure is attached to the front end. The chuck cylinder 1 is shown in FIG.
As in (b) and (c), a cylinder-piston mechanism including a cylinder 3, a piston 4 and a stem 5 is provided.
In this embodiment, the main cross section of the cylinder 3, piston 4 and stem 5 are all circular and are arranged coaxially with the central axis aa of the cylinder 3.

The cylinder 3 (FIG. 2A) comprises an outer end cap 6, a first tube 7 and a sleeve 8,
The outer end cap 6 is fixed to the rear end of the first tube 7 by screwing, and the sleeve 8 is fixed to the front end with bolts 9 (FIG. 8). The outer end cap 6 has first and second ports 10 and 11 formed on the rear end surface thereof, and a core 31 to be described later is attached to the through hole 12 between them to form a third port 13.
Is configured. Reference numeral 14 is a sealing material, which is attached to the inner peripheral surface of the through hole 12 at two positions in the front and rear.

The flow rate of each of the first and second ports 10 and 11 can be adjusted by a needle valve 15 and communicates with fluid passages 16 and 17 formed in the outer end cap 6. The fluid passage 16 of the first port 10 opens to the front end surface of the outer end cap 6 and communicates with the inside of the cylinder 3, and the fluid passage 17 of the second port 11 opens to the front portion of the through hole 12. Further, slits 18 (FIG. 3) in the axial direction are provided at the front end of the first tube 7 at equal intervals in the circumferential direction, and a needle guide 19 is fitted in that position. In FIG. 2, reference numeral 20 is a contraction position sensor of the piston 4, and reference numeral 21 is an extension position sensor thereof, which is a magnetic sensor using a Hall element.

The piston 4 (FIG. 2C) is located inside the inner end cap 22, the second tube 23, the tool head 24 and the second tube 23 coaxially with the tube, and the front end is in the center of the tool head 24. It is composed of a fixed sliding pipe 25. The inner end cap 22 is annular and fixed to the rear end of the second tube 23 with a screw, and the tool head 24 is fixed to the front end of the second tube 23 with a set screw. Reference numeral 46 is a screw hole therefor. Thus, the piston 4 has a hollow main body.

Axial grooves 26 (FIG. 2C, FIG. 3) are formed on the outer surface of the second tube 23 at equal intervals in the circumferential direction over the entire length of the tube 23, corresponding to the slits 18. .. Seal rings 27 and 28 are attached to the outer peripheral surface and the inner peripheral surface of the inner end cap 22, respectively.
1 is provided with a magnet 29 (FIG. 6).

The stem 5 (FIG. 2B) is the third tube 3
0 and the core 31, and the core 31 is fitted and inserted into the third tube 30 during assembly. At this time, a flow path gap 32 serving as a fluid path is formed between the inner surface of the third tube 30 and the outer surface of the core 31, as shown in the figure. The third tube 30 has an annular centering guide 33 at the front end, and the core 31 is formed with a tool driving fluid passage 34 that axially penetrates and communicates with the third port 13 at the rear end. The front end of the tool driving fluid passage 34 has an enlarged diameter to form a head 35 having the same diameter as the centering guide 33, and seal rings 36 and 37 are attached to the outer peripheral surface and the inner peripheral surface thereof.

In the centering guide 33, there is formed a connecting gap 38 (FIG. 2B) consisting of an annular recess formed in the front end surface and a groove communicating with this and penetrating the outer peripheral surface of this guide 33 in the axial direction. In addition, the head 35 of the core 31 has
As shown in FIGS. 4 and 5, a passage recess 39 (FIGS. 4 and 5) is formed by cutting off a part of the shaft of the core 31 and the rear end surface of the head 35 by cylindrical cutting. Has been done. The diameter of the front portion of the tool driving fluid passage 34 is slightly enlarged so that the sliding pipe 25 can be fitted therein.

The cylinder 3, piston 4 and stem 5 are assembled as follows. Third tube 3
The core 31 is fitted and inserted into the stem 0 to form the stem 5, which is attached to the outer end cap 6 by the first and second end caps 6.
The core 31 is fixed to the through hole 12 between the ports 10 and 11 by projecting the rear end portion of the core 31 which becomes the third port 13.
As shown in FIG. 7, the fixing is performed by the engaging notch 43 of the protruding portion.
The locking piece 44 is engaged with and is fixed to the rear surface of the outer end cap 6 with the bolt 45. The space between the outer peripheral surface of the core 31 and the outer end cap 6 and the space between the outer peripheral surface of the third tube 30 and the outer end cap 6 are kept airtight by the sealing material 14 mounted on the inner peripheral surface of the through hole. Also, the third tube 30 has an outer end cap 6
And is fixed by being sandwiched by the head 35 of the core 31. The sliding pipe 25 of the piston 4 is slidable to the enlarged portion of the tool driving fluid passage 34 of the core 31, and the head 35
The airtightness is maintained by the seal ring 37 on the inner peripheral surface side, and the insertion is performed.

At the same time, the inner end cap 22 of the piston 4
Between the inner surface of the first tube 7 and the outer surface of the third tube 30 (that is, the outer surface of the stem 5), and the seal ring 27 on the outer peripheral surface and the seal ring 28 on the inner peripheral surface both the tubes 7, The inner end cap 22
To be airtight and slidable. Further, at the same time, the centering guide 33 at the front end of the third tube 30 in the stem 5 and the head 35 of the core 31 are connected to the second tube 23.
Insert into. The head 35 is in contact with the inner surface of the second tube 23 via a seal ring 36, and is fitted in an airtight and slidable manner. At this time, the needle guide 19 is interposed between the inner surface of the sleeve 8 and the axial groove 26 of the second tube 23. In addition, the needle guide 1 is provided on the inner surface of the sleeve 8.
A similar groove 26 'is provided at position 9 corresponding to the axial groove 26 of the second tube 23 (FIG. 3). The piston 4 is attached to the cylinder 3 as described above.

As a result, the forward fluid chamber 40 (FIG. 6) is provided between the front end surface of the outer end cap 6 and the rear end surface of the inner end cap 22, and the second tube 23 and the third tube 30 are provided.
A return fluid chamber 41 is formed between the front end surface of the inner end cap 22 and the rear end surface of the centering guide 33 in the gap.
Further, a communication passage 42 (FIG. 8) is formed between the centering guide 33 and the outer surface of the core 31 and the inner surface of the second tube 23 by the passage recess 39 (core side) and the communication gap 38 (centering guide side). The flow path gap 32 and the return fluid chamber 41 are connected to each other.

Further, the first port 10 is communicated with the forward fluid chamber 40 via the fluid passage 16, and the second port 11 is connected.
Is communicated with the return fluid chamber 41 via the flow path gap 32 between the third tube 30 and the core 31. In addition, the third port 1
3 is integrally formed with the core 31, and communicates with the chuck 2 attached to the tip of the piston 4 via the tool driving fluid passage 34, the sliding pipe 25 and the fluid passage inside the tool head 24.

Therefore, in FIG. 1, the first port 1
When air is supplied from 0 and the second port 11 is opened, the air enters the forward movement fluid chamber 40 through the fluid passage 16.
The piston 4 is pushed forward. The stroke during extension is until the inner end cap 22 of the piston 4 contacts the centering guide 33 of the stem 5, and this position is detected by the extension position sensor 21. Then, the first port 1
When 0 is opened and air is supplied from the second port 11, the air passes through the fluid passage 17 into the passage gap 32, further passes through the communication passage 42 at the front end into the return fluid chamber 41, and the piston 4 is moved. Pull back. The contraction stroke is until the inner end cap 22 comes into contact with the front end surface of the outer end cap 6, and this position is detected by the contraction position sensor 20. The flow path gap 32 is a return fluid passage formed in the stem 5.

During this time, the sliding pipe 25, one end of which is fixed to the tool head 24 of the piston 4, slides on the enlarged portion of the tool driving fluid passage 34 in the core 31 to remove air from the third port 13. Communicate with the chuck 2. Further, since the piston 4 is smoothly moved in the axial direction by the needle guide 19 and is prevented from rotating with respect to the cylinder 3, accurate chuck operation can be performed.

The above is an embodiment. Instead of air pressure, generally fluid pressure such as hydraulic pressure can be used as the drive source. The cross section of the cylinder is usually circular, but is not limited to a circular shape in terms of function. If the cross section is not circular, a sleeve may be provided and a needle guide or the like to prevent rotation may not be needed between the sleeve and the piston. In the stem, the third tube and the core are integrally formed, and the returning fluid passage is formed in the form of a through hole like the tool driving fluid passage, and the stem opens from the side surface to the returning fluid chamber. good.

Further, the chuck as a tool is an example, and the designations of front and rear used in this specification are for clarifying the position of the member, and the posture of the cylinder is arbitrary. The technical idea of the present invention can be applied to a general telescopic cylinder.

[0023]

Since the stem for inserting into the hollow portion of the piston is provided with the return fluid passage and the tool drive fluid passage, it is not necessary to provide piping for the return movement and the tool drive. Therefore, it is possible to prevent an accident due to the piping being obstructed or fatigue of the piping during the operation of the cylinder device. With the above configuration, ports can be centrally provided at the rear end of the cylinder, and there is no need for piping for moving parts, so the equipment for incorporating the cylinder device can be easily designed. Since it is a double-acting cylinder mechanism, the operation is stable, and the piston can be operated in full stroke without waste for the size of the cylinder.

[Brief description of drawings]

FIG. 1 is a plan view showing a vertical cross section along a central axis aa.

FIG. 2 is a plan view showing a vertical cross section, (a) a cylinder,
(B) Stem, (c) Piston

FIG. 3 is a cross-sectional view taken along the line bb in FIG.

FIG. 4 is a front view of the front end portion of the core.

FIG. 5 is a plan view showing a front end portion of the core in a vertical cross section.

FIG. 6 is a plan view (front part) of a longitudinal section showing an enlarged main part.

FIG. 7 is a front view with a vertical cross section showing an enlarged main part.

FIG. 8 is a plan view (rear portion) with a longitudinal section showing an enlarged main part.

[Explanation of symbols]

1 Large Stroke Cylinder Device 2 Chuck 3 Cylinder 4 Piston 5 Stem 6 Outer End Cap 7 1st Tube 8 Sleeve 10 1st Port 11 2nd Port 13 3rd Port 22 Inner End Cap 23 2nd Tube 24 Tool Head 25 Sliding Pipe 30 3rd tube 31 Core 32 Flow path gap 33 Centering guide 34 Tool driving fluid passage 35 Head 40 Forward fluid chamber 41 Return fluid chamber 42 Communication passage

Claims (7)

[Claims] 1. A double-acting cylinder / piston mechanism, wherein a piston having a tool head has a hollow structure of a tube, and a stem fixed to the cylinder side is inserted into the inside of the tube, and the stem is returned to the stem. A large stroke cylinder device characterized in that a moving fluid passage and a tool driving fluid passage are formed, and the returning fluid passage communicates with the returning fluid chamber of the cylinder-piston mechanism. 2. The large stroke cylinder device according to claim 1, wherein the stem has a tube and a core fitted inside the tube with a gap formed therein, and the gap serves as a return fluid passage. 3. A front end of a sliding pipe communicating with the fluid passage of the head is fixed to the tool head, and a rear portion of the pipe is fitted in a tool driving fluid passage of the stem so as to be airtight and slidable back and forth. The large stroke cylinder device according to claim 1 or 2 characterized by the above. 4. A guide in which a sleeve through which a piston penetrates is attached to a front portion of a cylinder, and a relative rotation between the piston and the cylinder is prevented between an inner surface of the sleeve and an outer surface of the piston, and only relative movement in the front-rear direction is allowed. The large stroke cylinder device according to any one of claims 1 to 3, wherein a member is attached. 5. A first port communicating with the forward fluid chamber,
The second port communicating with the return fluid passage and the third port communicating with the tool driving fluid passage are provided in the end cap of the cylinder. Large stroke cylinder device described. 6. A cylinder, a piston and a stem are provided, wherein the cylinder has an outer end cap having first and second ports fixed to the rear end of the first tube, and the piston has an inner part inside the first tube. An annular inner end cap is fixed to the rear end of the second tube to be fitted in, and a tool holder is fixed to the front end, and the front end of the sliding pipe is fixed to the fluid passage formed in the holder. A centering guide is provided at the front end of a third tube that fits inside the second tube, a head is provided at the front end, and a third port is provided at the rear end inside the tube, and the tool is driven in the axial direction. A fluid passage and a second
A core that forms a flow path gap that serves as a return fluid passage is inserted between the inner surface of the second tube and the inner surface of the second tube when the tube is inserted into the tube. And slidingly and slidingly fit the sliding tube into the tool drive fluid passage of the core, and the inner end cap of the piston can be slid airtightly on the inner surface of the first tube and the outer surface of the third tube. And the tube is fitted between both tubes, and the centering guide of the third tube front end of the stem and the head of the core are brought into airtight and slidable contact with the inner surface of the second tube to fit the piston into the cylinder. A forward fluid chamber between the front end surface of the outer end cap and the rear end surface of the inner end cap, and the front end surface of the inner end cap and the rear end surface of the centering guide in the gap between the second tube and the third tube. A return fluid chamber is formed between the centering guide and the outer surface of the core and the inner surface of the second tube to form a communication passage that connects the flow path gap and the return fluid chamber, and the first port is used as the forward fluid. That the second port is in communication with the return fluid chamber through the flow path gap between the second tube and the core, and the third port is in communication with the tool driving fluid passage of the core. Characterized large stroke cylinder device. 7. The first tube and the second tube are cylindrical in cross section, and a sleeve is attached to the front end of the first tube to allow mutual rotation of both tubes between an inner surface of the sleeve and an outer surface of the second tube. 7. The large stroke cylinder device according to claim 6, further comprising a guide member for blocking and allowing only mutual axial movement of both tubes.