JPH0352261Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Purpose of the invention (1) Industrial application field The present invention relates to a pile press-in machine, and particularly to a press-fit cylinder with a chucking mechanism that chucks and press-fits piles.
This relates to a pile press-in machine with a fixed differential circuit block.

(2) Conventional technology Conventionally, in a hydraulic pile press-in machine, an upper frame is erected on the machine base, and a press-fit cylinder is fixed to the upper frame via a support with the rod side facing downward. A chucking mechanism is attached to the rod-side end edge of the press-fit cylinder tube, and the chucking mechanism moves up and down by the operation of the press-fit cylinder along a guide rail formed on the side wall of the upper frame. The pile is press-fitted into the ground by chucking the pile with the chucking mechanism and contracting the piston rod, and one stroke of the press-fitting is determined by the length of the press-fitting cylinder. Therefore, in order to press-fit a long pile, the press-fitting capacity can be increased by repeating the expansion and contraction operations of the press-fitting cylinder, and in particular by speeding up the lifting operation of the chucking mechanism after the pile is press-fitted. For this purpose, a so-called differential circuit is built into the upper frame, and when the vertical switching valve is switched to the upward (withdrawal) position, the oil discharged from the hydraulic pump and the return oil from the rod side of the press-fit cylinder are force-fed to the head side at an extremely high speed. Some models have a structure in which the piston rod is pushed out and the chucking mechanism can be raised more quickly.

(3) Problems to be solved by the invention However, in the above conventional method, a large amount of hydraulic oil flows at high speed between the differential circuit in the frame and the external press-fit cylinder, so a large diameter hydraulic pressure is required. A hose must be attached, which increases costs, and the need for a long hydraulic hose causes pressure loss and poses problems such as getting in the way of the device configuration.

(4) Purpose The present invention solves these problems and provides a pile that can increase the lifting speed of the chucking mechanism of a press-fit cylinder by simply attaching a thin hydraulic hose through which hydraulic oil from a hydraulic pump passes to the press-fit cylinder. The purpose is to provide press-in machines.

B. Structure of the invention The invention uses a chucking mechanism that slides up and down along a guide rail formed on the side wall of the upper frame by the operation of a hydraulic press-fit cylinder supported by the upper frame and controlled by a differential circuit. The present invention relates to a pile press-in machine, characterized in that a differential circuit block is directly connected and integrally attached to the press-fit cylinder.

(1) Measures to solve the problem In the conventional pile press-in machine, since a hydraulic differential circuit is built into the upper frame, there is a gap between the differential circuit and the press-fit cylinder outside the upper frame. Since it was necessary to attach a large-diameter hydraulic hose to the press-fit cylinder, in the present invention, a block having a differential circuit was directly connected and integrally attached to the press-fit cylinder.

Therefore, only a vertical switching valve connected to a hydraulic power source is installed in the upper frame, and a narrow hydraulic pressure line sufficient to send hydraulic fluid from the hydraulic power source is required from the vertical switching valve to the differential circuit block. A total of three hoses were attached, two hoses and one thinner hydraulic hose for the pilot. Further, from the differential circuit block, one thick metal transfer pipe was installed on the rod-side end side wall of the press-fit cylinder, and one extremely short metal connecting pipe was installed on the head-side end side wall. Furthermore, the length of the piping was shortened by installing a vertical switching valve inside the upper frame, which switches when supplying the discharged oil from the hydraulic power source to the press-fit cylinder.

(2) Effect When the vertical switching valve in the upper frame is switched downward, hydraulic oil enters the rod side of the press-fit cylinder and lowers the press-fit cylinder, and the chucking mechanism fixed to the press-fit cylinder moves the chucked pile into the ground. Press fit into. After pile press-fitting is completed, when the chuck is opened and the valve is switched upward, the oil discharged from the hydraulic source is sent to both the head side and rod side of the press-fit cylinder via the differential circuit block, and the piston is pushed from both sides. Since the piston area on the rod side is smaller than the area on the head side, the piston is pushed toward the rod side due to the pressure difference, and the hydraulic fluid pushed out from the rod side is transferred to the head side of the press-fit cylinder via the differential circuit block. The oil flows back in together with the oil discharged from the hydraulic source and pushes the piston at a speed several times higher than usual, so the press-fit cylinder and the chucking mechanism fixed thereto move up at high speed. At this time, a large amount of hydraulic oil flowing back at high speed from the rod side to the head side enters the differential circuit block through the above-mentioned return pipe.
This delivery pipe can be installed over the shortest distance and can be installed securely. A thin hydraulic hose is sufficient between the differential circuit block and the upper/lower switching valve because it only sends discharged oil from the hydraulic source.

(3) Embodiments Next, embodiments of the present invention will be described based on the drawings. Fig. 1 is a front view of the main parts of the pile press-in machine, Fig. 2 is a side view of Fig. 1, and Fig. 3 is a hydraulic circuit.

The pile press-in machine 1 has an upper frame 3 erected on a machine stand 2. The machine base 2 has a front and rear slide frame 2b disposed on a reaction frame 2a, a left and right slide frame 2c on the front and rear slide frame 2b, and a rotation frame 2d on the left and right slide frame 2c. An upper frame 3 is provided upright on the rotating frame 2d.

The upper frame 3 is approximately rectangular in plan, and a guide rail 3a is attached vertically to the end edge of a side wall in contact with one side thereof, and a chucking mechanism 4 is vertically slidable along the guide rail 3a. It is fitted. Further, the chucking mechanism 4 is attached in such a manner that it is fixed to the tube of the press-fit cylinder 5, and connects the end of the piston rod 5a of the press-fit cylinder 5 to the machine base 2.
(not shown), press-fit cylinder 5
When the piston rod 5a expands and contracts, the tube of the press-fit cylinder 5 moves into the guide rail 3 of the upper frame 3.
The chucking mechanism 4, which is fixed to the tube, moves up and down along the upper frame 3. The chucking mechanism 4 opens and closes a chucking portion by a hydraulic mechanism (not shown) to chuck or release the pile.

A differential circuit block 6 for accommodating a differential circuit is fixedly and directly connected to the head side of the tube of the press-fit cylinder 5. The differential circuit block 6 has a rising oil passage 6a and a descending oil passage 6b extending therethrough, and the base end of the rising oil passage 6a is connected to the head side cylinder chamber of the press-fit cylinder 5 via an extremely short connecting pipe 7. 5b, and a lifting hydraulic hose 9 is attached to the tip. A large-diameter feeding pipe 8 is attached to the base end of the descending oil passage 6b, and the tip of the feeding pipe 8 is fixed in communication with the rod-side cylinder chamber 5c of the press-fit cylinder, and the tip of the descending oil passage 6b is fixed to the rod-side cylinder chamber 5c of the press-fit cylinder. is equipped with a lowering hydraulic hose 10. Further, within the differential circuit block 6, the lowering oil passage 6b and the rising oil passage 6a are connected by a differential circuit 12 with a cylinder type pilot type control valve 11 interposed therebetween. Code 13 in the drawing
is a hydraulic hose for pilots. Since the differential circuit block 6 is fixed to the press-fit cylinder 5, the connecting pipe 7 and the feed pipe 8 are made of metal to prevent bending, and it is possible to eliminate extra space provided to absorb bending.

A vertical switching valve 15 connected to a hydraulic power source 14 is installed inside the upper frame 3. The vertical switching valve 15 is provided with a rising oil passage 16 connected to the rising hydraulic hose 9 and a lowering oil passage 17 connected to the lowering hydraulic hose 10 so as to be connected to the hydraulic power source 14. The oil passage 16 has an ascending control valve 16a, and the descending oil passage 17 has a descending control valve 17a.
are arranged respectively.

In the above configuration, when the vertical switching valve 15 is switched to the ascending side, the oil discharged from the hydraulic source 14 is sent to the ascending hydraulic hose 9 toward the press-fit cylinder head side. At the same time, the control valve 11 is also opened, passing through the differential circuit 12 and the transfer pipe 8, and leading to the rod side cylinder chamber 5c. The head side cylinder chamber 5b and the rod side cylinder chamber 5c have the same pressure and push the pistons together, but since the rod side cylinder chamber 5c has a smaller area, the force balance is lost and the piston is pushed toward the rod 5a. The hydraulic fluid in the rod-side cylinder chamber 5c pushed out at this time does not return to the tank, but enters the head-side cylinder chamber 5b via the transfer pipe 8, differential circuit 12, and control valve 11 together with the discharge oil from the hydraulic power source 14. Raise the press-fit cylinder and the chucking mechanism fixed to it at high speed. The force trying to push the piston out at this time is equal to the cross-sectional area of the rod multiplied by the hydraulic pressure. Furthermore, if the piston cylinder to rod area ratio is 4:1, the extrusion speed will be four times faster than that of the direct-acting circuit.

Note that the present invention is not limited to the above configuration, and the design can be modified as appropriate.

C. Effects of the Invention As described above, the present invention has a differential circuit block directly connected to the press-fit cylinder, and therefore has many excellent effects as described below.

(1) In the conventional model, the differential circuit was housed inside the upper frame, so two long, large-diameter hydraulic hoses were required between the differential circuit and the press-fit cylinder. In the design, the differential circuit block was attached directly to the press-fit cylinder, so a thin hydraulic hose was sufficient to transport oil discharged from the hydraulic source from the upper frame to the press-fit cylinder. In addition to cost reduction, this
This has the effect of eliminating pressure loss, etc.

(2) When the press-fit cylinder is raised, the hydraulic fluid that is discharged from the cylinder chamber on the rod side at high speed and in large quantities is sent to the head side by the thick and short delivery pipe 8 installed between the differential circuit block and the press-fit cylinder. Since the differential circuit block is fixed to the press-fit cylinder, a metal pipe can be used as the feed pipe 8, which can be firmly fixed and is less prone to failure. Furthermore, since it can be transported over short distances, it has the effect of minimizing pressure loss.

[Brief explanation of drawings]

Figure 1 is a front view of the main parts of the pile press-in machine, and Figure 2 is the front view of the main parts of the pile press-in machine.
3 is a hydraulic circuit diagram, and FIG. 4 is a hydraulic circuit diagram showing the flow of hydraulic oil in a differential circuit. DESCRIPTION OF SYMBOLS 1... Pile press-in machine, 2... Machine base, 3... Upper frame, 4... Chucking mechanism, 5... Press-fit cylinder, 5a... Rod, 5b... Head side cylinder chamber, 5c... Rod side cylinder Chamber, 6... Differential circuit block, 6a... Ascending oil passage, 6b... Descending oil passage, 7... Connecting pipe, 8... Transfer pipe, 9
... Hydraulic pipe for ascending, 10... Hydraulic pipe for descending, 11... Control valve, 12... Differential circuit, 13...
...Pilot hydraulic hose, 14...Hydraulic power source, 1
5... Up/down switching valve, 16... Ascending oil path,
16a... Ascent control valve, 17... Descending oil path,
17a...Descent control valve, A...Pressure oil pump discharge oil flow, B...Rod side cylinder chamber discharge oil flow, C...
...The combined oil flow of A and B.

Claims (1)

[Claims for Utility Model Registration] (1) A hydraulic press-fit cylinder supported by the upper frame and controlled by a differential circuit is operated to vertically slide along a guide rail formed on the side wall of the upper frame. 1. A pile press-in machine having a chuck mechanism, characterized in that a differential circuit block is attached directly and integrally to the press-fit cylinder. (2) The pile press-in machine according to claim 1 of the utility model registration claim, characterized in that a vertical switching valve is installed in the upper frame to perform a switching operation when supplying oil discharged from a hydraulic power source to the press-fit cylinder.