JPH045595Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a hydraulic cylinder for clamping equipped with a pressure increasing function.

(Prior art and its problems) For example, as a drilling machine for drilling holes in the ground,
There is one that extrudes while rotating the drill and drives it into the ground by applying an impact to it. When drilling a long hole with this drilling machine, a drilling casing is attached to the drill by screw fitting.

After drilling a long hole of a predetermined length, the casing is pulled out and both casings, which are threaded together, are rotated in a direction opposite to the direction in which the threads are fitted, thereby releasing the threaded engagement. Needs to be disassembled.

Therefore, in the past, the screw fitting was released by grasping both screw-fitted casings with manual wrenches and turning both wrenches in opposite directions. Since the screws are extremely tightly fitted when tightened, the gripping force of the wrench is insufficient, and the casing easily slips inside the wrench, making it extremely difficult to unscrew the screws.

Therefore, it is conceivable to clamp one of the casings with a clamping device consisting of a fluid pressure cylinder, but if a strong clamping force is to be obtained using a normal fluid pressure cylinder, the fluid pressure cylinder will be large and heavy. Such a large and heavy clamp device has a problem in that it is difficult to transport to the drilling site.

(Purpose of the invention) In view of the above-mentioned problems, an object of the present invention is to provide a hydraulic cylinder for clamping that is small and lightweight, yet can obtain a powerful clamping force.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a partition wall 17 in the cylinder chamber and a first cylinder chamber 19 between the partition wall 17 and the head side cover 18. Further, a second cylinder chamber 21 is formed between the partition wall 17 and the rod side cover 20, and a first piston 22 is fitted into the first cylinder chamber 19 and a second cylinder chamber 22 is fitted into the second cylinder chamber 21. The first piston 22 is integrally or integrally connected with the piston 23.
An oil passage 24 communicating between the first cylinder chamber 19 and the second cylinder chamber 21 is provided in the first cylinder chamber 19 .
A first and second piston forward movement port 26 is provided on the side, and a first and second piston return movement port 28 is provided on the second cylinder chamber 21 side, and a clamp member 25 is provided on the piston rod 23A integrated with the second piston 23.
This system adopts a configuration in which the following is attached.

(Function) In the above configuration, when pressure oil is supplied to the first cylinder chamber 19, a part of the pressure oil is transferred to the first piston 2.
It enters the second cylinder chamber 21 through the second oil passage 24. Therefore, the first and second pistons 22 and 23 are simultaneously pressed together, and the clamp member 25
is strongly pressed against the clamped body 5.

In this embodiment, the second cylinder chamber 21
adopts a configuration in which the diameter is larger than that of the first cylinder chamber 19.

(Example) An example of the present invention will be described based on the drawings.
This embodiment relates to a screw unfitting device for releasing the screw fitting between excavation casings connected by screw fitting in a drilling machine for drilling a hole in the ground, for example. FIG. 5 is a partially cutaway front view thereof, and FIG. 6 is a longitudinal sectional view thereof. As is clear from these figures, this screw unfitting device is composed of a clamping device 2 provided on a machine frame 1 and a power wrench 3.

The clamp device 2 is constructed as follows. That is, a pair of foundation frames 4 are arranged parallel to each other on the machine frame 1, and the excavation casing 5 is placed from the top surface of each foundation frame 4 to near the bottom of the foundation frame 4.
A notch 6 is formed for inserting the base frame 4.
A tension bar 9 is provided at one end of the bearing 7 via a support shaft 8 so as to be movable up and down, and which closes the upper surface of the notch 6 when in a horizontal state. Tip engaging part 9A
A tension bolt with a handle that fixes the tension bar 9 to the base frame 4 by providing an engaging protrusion 10 that engages with the engagement protrusion 10 and screwing the tension bar 9 into the threaded hole of the engaging protrusion in the distal engagement portion 9A. 11, and arc-shaped guide plates 12 are bolted to the front and rear surfaces of the tension bar 9 and the outer surface of each base frame 4, respectively.

Furthermore, a pair of mounting plates 13 are disposed between both base frames 4 with a notch 6 in between, and a clamping hydraulic cylinder 14 is mounted on each mounting plate 13, respectively. The hydraulic cylinder 14 will be explained based on FIG. 1. The upper half of Figure 1 shows the operating state.
The lower half of the figure shows the non-operating state. That is, an intermediate cover (partition wall) 17 is provided in the cylinder chamber of the cylinder tube 16 bolted to the mounting plate 13 so as to abut the stepped portion 16a, and between the intermediate cover 17 and the head side cover 18, A first cylinder chamber 19 and a second cylinder chamber 21 are formed between the intermediate cover 17 and the rod side cover 20, respectively.
The piston rod 22A of the first piston 22, which is fitted to the
The first piston 22 is provided with an oil passage 24 that communicates the first cylinder chamber 19 and the second cylinder chamber 21, and is screwed into a screw hole of the second piston 23 that is fitted into the cylinder chamber 21. The piston rod 2 of the second piston 23 is inserted into the through hole of 20.
A clamp member 25 is bolted to 3A.
Further, the head side cover 18 is formed with first and second piston forward movement ports 26 that communicate with the first cylinder chamber 19 side, and the cylinder tube 16 is provided with a second piston forward movement port 26 that communicates with the first cylinder chamber 19 side.
First and second piston return movement ports 28 communicating with the cylinder chamber 21 side are formed. In Figure 1, 27 is the air vent port, 29 is the first and second port.
This is a set screw for preventing the pistons 22 and 23 from sagging when screwed together. Further, the casing-facing surface 25A of the clamp member 25 is formed into a substantially V-shape so that the casing 5 can be gripped reliably. Furthermore, the partition wall 17 in the second cylinder chamber 21 is only brought into contact with the stepped portion 16a, and even if it is not fixed to the cylinder chamber 21, the partition wall 17 is always loaded with hydraulic pressure in the direction of arrow P. Since it is supported by the oil pressure and the stepped portion 16a and does not move, and the inner diameter R of the second cylinder chamber 21 is larger than the inner diameter r of the first cylinder chamber 19, the pressure increasing ability can be improved.

The power wrench 3 will be explained based on FIGS. 2 to 4. Arc-shaped links 32A, 32 that can be opened from each other around the pivot pin 31 at one end
A tightening ring-shaped body 32 is formed by B, and the other ends of both links 32A and 32B are held together by a handle 33.
The upper link 3 is connected by a connecting pin 34 with
A set bolt 35 is provided on the machine frame 1 to prevent the connecting pin 34 from coming off by screwing into the screw hole at the other end of the bolt 2A and engaging the annular groove of the connecting pin 34 at its tip. , a pair of pedestals 36 for receiving the lower links 32B are provided, the link receiving surfaces 36A of the pedestals 36 are arcuate surfaces concentric with the ring-shaped body 32, and a gap formed in the lower links 32B is provided. An operating arm 39 is provided, the upper end of which is inserted into the interior of the machine frame 1
A piston rod of a hydraulic cylinder 41 rotatably supported via a rotation shaft 40 is connected to the lower end of the operating arm 39 by a pin 42, and the operating arm 39
A wrench tooth 43 that can be retracted into the ring-shaped body 32 is fixed to the upper end with bolts 44, and back-up plates 45 are provided at two locations 120 degrees apart from the wrench tooth 43 on the inner surface of the upper link 32A, as shown in FIG. It is fastened with 46 bolts.

In the above configuration, when releasing the screw fitting 5A between the casings 5, the upper link 32A is rotated upward as shown by the imaginary line in FIG. 2, and at the same time, as shown by the imaginary line in FIG. After rotating the tension bar 9 upward, screw fitting 5A
The casing 5 is inserted into the notch 6 and the lower link 3.
Insert it into 2B. Subsequently, the upper link 32A is rotated downward, and the other ends of the links 32A and 32B are connected to each other by the connecting pin 34, as shown by the solid line in FIG. The tension bar 9 is also rotated downward, and the tension bar 9 is fixed to the base frame 4 by the tension bolt 11, as shown by the solid line in FIG. At this time, the joint between both casings 5 is set to be located between the clamp device 2 and the power wrench 3 as shown in FIG.

Separately from the above procedure, the tension bar 9 is fixed to the reference frame 4 with bolts 11, and the upper and lower links 3
With pins 31 and 34 connected to 2A and 32B,
The casing 5 may be inserted into the notch 6 and the ring-shaped body 32 from the side.

Next, the first and second clamp hydraulic cylinders 14
From the piston forward movement port 26 to the first cylinder chamber 1
When pressure oil is supplied into the interior of the cylinder chamber 9, the first piston 22 is pressed from the state shown in the lower half of FIG. 23 is also pressed. In this case, pressure oil is applied to the pressure receiving surface 22B of the first piston 22 and the pressure receiving surface 23B of the second piston, and compared to a normal hydraulic cylinder with one piston, only the pressure receiving surface 23B of the second piston receives pressure. The area is increasing. Therefore, as shown in the upper half of FIG. 1, the casing 5 is clamped by the clamp member 25 with a strong pressing force.

Next, when the pressure oil cylinder 41 of the power wrench 3 shown in solid line in FIG. The casing 5 tries to protrude, and the casing 5 is held between the wrench teeth 43 and both backup plates 45. Then, when the piston rod of the hydraulic cylinder 41 is further pushed out as shown by the imaginary line in FIG. 5 is rotated, and the screw fitting 5A is loosened. In this case, the casing 5 is rotated in the pushing direction of the piston rod of the hydraulic cylinder 41, the screw fitting 5A is loosened, and the wrench tooth 43 is pressed against the casing 5. 5 is strongly held between the wrench teeth 43 and both backup plates 45, and the casing 5
There will be no slippage between the power wrench 3 and the power wrench 3. Note that the wrench teeth 43 may be pressed against the casing 5 in the direction in which the piston rod is pulled.

As described above, when the actuating arm 39 is rotated to rotate the casing 5, the wrench tooth 43 enters the ring-shaped body 32, so that the wrench tooth 43 can be held in a wide range. Therefore, even if the diameter of the casing 5 is much smaller than the inner diameter of the ring-shaped body 32 compared to the state shown in FIG. 2, the casing 5 can be reliably held. In that case, it is desirable to replace the backup plate 45 with a taller one.

In the clamping hydraulic cylinder 14 shown in FIG. 1, the first and second pistons 22, 23 are integrally formed by screw-fitting them, but both pistons 22, 23 are formed by cutting a single round bar. may be formed integrally.

(Effects of the invention) According to the hydraulic cylinder for clamping of the invention, the first and second pistons are provided integrally or integrally connected, and hydraulic pressure is simultaneously applied to the pressure receiving surfaces of both pistons. Since it has a pressure increasing function, it is possible to obtain a powerful clamping force while being small and lightweight.

Further, as shown in the embodiment, if a configuration is adopted in which the second cylinder chamber is formed to have a larger diameter than the first cylinder chamber, the pressure increasing function can be further improved.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a hydraulic cylinder for clamping which is an embodiment of the present invention, Fig. 2 is a front view of a power wrench, Fig. 3 is a side view of the same, and Fig. 4 is a - of Fig. 2.
5 is a partially cutaway front view of a screw disengagement device consisting of a hydraulic cylinder for clamping and a power wrench, and FIG. 6 is a longitudinal sectional view thereof. 2...Clamping device, 14...Hydraulic cylinder for clamping, 16a...Step part, 17...Intermediate cover (partition), 18...Head side cover, 19...First
Cylinder chamber, 20... Rod side cover, 21...
Second cylinder chamber, 22... First piston, 23...
...Second piston, 23A...Piston rod, 2
4... Oil passage, 25... Clamp member, 26... First and second piston forward movement ports, 28... First,
Port for second piston return motion.

Claims (1)

[Claims for Utility Model Registration] 1. A partition is provided in the cylinder chamber, and a first cylinder chamber is formed between the partition and the head side cover, and a second cylinder chamber is formed between the partition and the rod side cover. and integrally or integrally connect a first piston fitted in the first cylinder chamber and a second piston fitted in the second cylinder chamber,
The first piston is provided with an oil passage that communicates the first cylinder chamber and the second cylinder chamber, and the first and second piston forward movement ports are provided on the first cylinder chamber side, and the second
A hydraulic cylinder for clamping, in which ports for reciprocating the first and second pistons are respectively provided on the cylinder chamber side, and a clamping member is attached to a piston rod that is integrated with the second piston. 2. The second cylinder chamber is formed to have a larger diameter than the first cylinder chamber.Claim 1 for Utility Model Registration
Hydraulic cylinder for clamping as described in section.