JPS6123080Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drop hammer device having a pressure fluid as the working medium and to a control mechanism for such a device.

In a utility model application (corresponding to UK Patent Application No. 25751/75) filed on the same day as the present application, a control having both an automatic and manual control switching mechanism for initiating the movement cycle of the reciprocating ram driving the hammer weight is disclosed. A device with a mechanism is described.

The invention particularly relates to a control mechanism for this purpose, according to which the control mechanism is actuated moments before the impact of the hammer weight to switch the flow of pressure fluid to the ram for the return stroke of the weight. a limit switch configured to: and an impact switch adapted to sense hammer weight impact to switch the flow of the pressure fluid;
manual selection means for incorporating the switch into a circuit so that the shock switch acts as a backup for the limit switch or disables the limit switch to delay switching of the flow until a shock occurs; , the limit switch and the shock switch preferably use switch mechanisms of similar nature, with time delay means for determining the upper limit of the return stroke and separate manual selection means for varying the stroke of the hammer weight movement. It has the means to be adjusted.

By controlling the reversal from the impact stroke of the hammer weight, it can be avoided that when driving in soft ground, the drop of the guide with each impact can be significant and switching of the ram before impact can cause undesirable shock forces. When the shock detector is used, it is ensured that the shock detector only switches after the shock. On the other hand,
On harder ground where these problems do not occur, the limit switch can be used with a trip, thereby increasing the speed of hammer operation. In addition, the provision of a manually controlled variable delay means, such as a dial knob, allows the operator to consistently adjust the stroke of the ram and thereby the impact force and drive speed of the hammer weight. possible. This is an important feature when driving piles into soft ground, if always with maximum force there is a risk that the pile will run away, i.e. the pile will move too much on each stroke and the pile driving machine will become unstable. Become.

The invention will be explained in more detail by way of an example of implementation with reference to the accompanying drawings.

The control mechanism is a utility model registration application filed on the same day as the main application (1)
arranged similarly to that described in , and comprising a power source unit, the power source generating pressurized fluid flow for the hydraulic servos of the hammer ram and ram control valves, respectively, and an output directed through the control panel. The control panel is typically separate from the hammer frame and the hydraulic elements on the frame, such as the ram control valve, and the control panel may also be adjacent to or remote from the power source unit.

The fluid hydraulic circuit of the control panel of FIG.
and a pressure line 74 for supplementary pressure fluid supply to the pilot valve 60 for the ram control valve. Return lines 76, 78 are provided for the main and pilot fluid flows, pressure relief valves 80, 82 are provided for each flow pressure line, and an accumulator 84 is provided for the pilot pressure flow. Also shown in FIG. 1 is a dump valve 86 that relieves pressure in the ram's main circuit, and an irreversible valve 88 and filter 90 in the pressure supply line.

The fluid hydraulic circuit on the hammer frame is necessarily of the type shown in the utility model registration application (1) filed on the same day as the present application, in which a pilot circuit is used to control the fluid flow toward and out of the ram cylinder. a ram control valve actuated by valve 60 and a high pressure accumulator configured to be filled with pressure fluid during the fall of the hammer weight and for low pressure flow to the upper end of the ram cylinder during the fall of the hammer weight. low-pressure accumulator and replenishment tank.

Pilot valve 60 has three positions, with the central position shown allowing pressure fluid to flow through both lines 64, 66.
through the servo cylinders at both ends of the ram control valve to hold the ram control valve in a central position to allow the hammer weight to fall, as shown in the above-mentioned other same-day application (1). By energizing the valve actuating solenoid 60a, the ram control valve is switched to admit pressure fluid to the underside of the ram piston, thereby raising the hammer weight. On the other hand, energizing the dump solenoid 60b switches the ram control valve to admit pressure fluid to the top side of the ram piston, thus forcing the ram piston to the bottom position.

In the schematic diagram of FIG. 2, a dotted box 102 indicates the hammer frame, and a limit switch provided for controlling the operation of the hammer is shown. Among these are a ferrite rod inductive switch 110 configured as a shock detector and a switch 11 for the upper and lower limits of the hammer weight, respectively.
0, the same ferrite rod induction type trip actuation switches 112, 114, and the switches 112, 1.
Mechanically tripped bi-stable electromechanical upper and lower limit switches 1 located at positions on the hammer frame corresponding to positions 14;
16,118 are included. Delay timer 12 operating as an adjustable upper limit switch
0 is also provided, but this is, for example, the dotted line box 1
It can be provided separately from the hammer frame in a control panel designated by 04.

Also shown in FIG. 2 is a control pendant, indicated by a dotted box 106, which connects the control panel and flexible cables to allow freedom of movement to the operator during hammer operation. (not shown) so that the operator can more easily control the driving process. The control attachment 106 includes an on/off dump switch 122, a control potentiometer 124 for a timer 120, and a "manual" contact 1.
26a, three position selection switch 1 with "autooperate" contact 126b and "off" contact 126c
26 and adjustable stroke (contact 128a) or maximum stroke (contact 128a) for reciprocating motion of the hammer weight when switch 126 is in the "autooperate" position.
8b) and a manually operated push button switch 130 are provided.

Dump switch 122 is in the “on” position (contact 1
At 22a), a power source 132 is connected to the dump solenoid 60b to maintain the pilot valve 60 in such a manner that no pressurized fluid can enter the hammer ram to lift the hammer weight. When the dump switch 122 is in the "off" position (contact 122b), the selection switch 126 is connected to the power source and is activated. If the selection switch 126 is in the "manual" position 126a, the hammer is operated by a push button switch 130 which is normally spring biased in the open position. If switch 126 is in the "auto-operate" position 126b, the operator can use switch 128 to achieve maximum travel (contact 128b) or variable travel (contact 128b).
The operation of the ram in a) can be selected, the length of the stroke in the latter case being determined by the setting of the potentiometer 124, which can be adjusted continuously during operation of the hammer.

Considering first the automatic operation of the hammer with an adjustable stroke, this type of selection is made by the induction switch 110,
112 and 114 are activated. The bottom limit switch 1 is activated by the hammer initially in the bottom position.
14 energizes the operating solenoid 60a, thereby switching the control valve on the hammer frame to lift the hammer weight so that pressure fluid enters the underside of the ram piston. The delay timer 120 is
Depending on the setting of potentiometer 124, the upper limit of hammer weight movement is determined, with the maximum upper limit provided by upper limit switch 112 on the hammer frame.

When the weight rises a sufficient distance to actuate the trip mechanism of upper limit switch 112, the output generated discharges the timer via amplifier 112a and de-energizes solenoid 60a. In response, the ram pilot valve 60 is switched to isolate the ram control valve from the pressure source and the hammer weight is allowed to fall, directing some of the fluid directly from the underside of the ram piston and some of it to the low pressure accumulator. It flows into the upper side of the cylinder from the replenishment tank on the hammer frame.

Induction switches 110 and 114 act to activate the return of the hammer after it has fallen. These switches 110 and 114 are provided in the circuit in combination with switches 136 and 134, respectively, which are controlled by relays 150 on control attachment 106. By turning off relay solenoid 150, normally closed switch 136 puts shock detection switch 110 into circuit with amplifier 110a, and when solenoid 150 is energized, switch 136 is opened but normally closed switch 134 is closed and pulled into position. Remove switch 114 from amplifier 1
14a into the circuit. Thus, if the user operates the control relay 150 on the control attachment 106, when the hammer weight approaches the or other impact surface to be struck,
The hammer is connected to the solenoid 60 via the amplifier 114a.
Bottom limit switch 11 to reenergize a.
4 activates the trip mechanism, switches the pressure supply to the underside of the ram piston to lift the hammer weight, and activates the delay timer 120.

Alternatively, if control relay 150 is de-energized, switch 136 is closed in place of switch 134 so that valve solenoid 60a and amplifier 110a switch only upon impact of the hammer weight.
Activation of timer 120 starts via .

A bypass switch 134a on control board 104 is shown in FIG. 2, which switch 134a can be closed to incorporate position on/off switch 114 into circuit with the amplifier. Although this is not a necessary feature, both switches can be closed simultaneously allowing one switch to act as a backup for the other switch.

In other configurations, the inductive switch 110,1
14 can be incorporated into the circuit, in which case a single amplifier can be provided instead of each amplifier, and the signal of the bottom limit induction switch acts through that amplifier. do. In either case,
Since shock detectors and limit switches use switch mechanisms of similar nature, such as ferrite rod induction mechanisms, similar signals are generated in the control circuitry regardless of which switch is activated. A considerable simplification of the circuit is thus obtained.

A dial potentiometer 124 in the control attachment 106 is adjustable by the operator at will during hammer operation and if a timer is set to time out before reaching the upper limit switch release mechanism. The stroke of the hammer is correspondingly shorter.

While operating the hammer at maximum stroke with the adjustable control, a separate circuit is provided with a more robust electromechanical switch for this mode of operation and the changeover switch 128 is placed in the other position 1.
Advantageously, the upper and lower switches 116 and 118, which are latch-activated by movement to 28b, are activated.

Considering again the condition where the hammer is at the bottom of its stroke, in this condition the two-stable switch 116,
118 are closed and such operating solenoid 60a is energized to lift the hammer weight, and the circuit to that solenoid 60a is connected to relay 1.
40, the relay 140 also includes a switch 142
is biased to close. During the first part of the upward movement the lower limit switch latch mechanism is moved by the hammer weight and the switch 118
Switch 1 is opened but its circuit is closed
42 so that the circuit is not affected. When the upper limit switch trip member is actuated and switch 116 is also opened, the circuit to both operating solenoid 60a and relay 140 is broken and the ram control valve is switched to allow the hammer weight member to fall. Upper limit switch 116 is closed again as soon as descent begins, but does not affect the operating solenoid circuit since switch 140 is already open. Only when lower limit switch 118 is tripped and reclosed and bypasses relay 140 will both switches 11
A circuit is formed through solenoid 6 and 118.
0a and relay 140 are reenergized and the cycle begins again.

When the transfer switch 126 is at contact 126a using manual pushbutton control, the stroke of the hammer weight is simply determined by the length of time the pushbutton is depressed. For safety reasons, it is preferable to provide an upper limit switch that limits the maximum increase in weight. For this purpose, the circuit of the pushbutton switch 130 can be configured, for example, by the limit switch 11.
By connecting the switch 130 to the operating solenoid 60a via the controller 128b, the valve solenoid 60a can be deenergized when the limit switch 116 opens.

Figure 3 shows utility model registration application (1) filed on the same day as the main application.
The hammer frame described in the above application is shown with the same numerals in the figure. However, the upper limit switch 11
2,116 and lower limit switch 114,
The position of the limit switch pull member for 118 is shown. The apparent relatively close setting of these members is due to some overshoot of the hammer weight rising when the upper limit switch is tripped, as well as the pressure fluid connection with the ram cylinder. There is also a hydraulic inertial effect during connection switching, which requires the electrical switching to proceed for a certain amount of time.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a fluid hydraulic circuit in a control panel of a control mechanism according to the present invention. FIG. 2 is a schematic diagram of the electrical circuitry in the control mechanism. FIG. 3 is a schematic side view of the stake hammer showing the position of the limit switch of the control mechanism. Explanation of symbols, 60...Pilot valve, 102...
...Hammer frame, 110, 112, 114, 1
16, 118...switch, 120...delay timer, 124...potentiometer.

Claims (1)

[Claims for Utility Model Registration] A control mechanism for a drop hammer device in which a hammer weight is reciprocated by a fluid pressure ram to generate a series of impacts, the hammer weight being moved back and forth to the ram 4 for the return stroke of the hammer weight 10. a limit switch 114 configured to operate an instant before the impact of the hammer weight 10 in order to switch the flow of the pressure fluid; and a limit switch 114 configured to switch the flow of the pressure fluid upon sensing the impact of the hammer weight. The shock switch 110 is inserted to operate in conjunction with the limit switch 114. Either one of these switches is selectively turned on, or the shock is generated and the shock switch is turned on. Manual actuation means for deactivating the limit switch 114 and manual actuation means 124 are provided to delay switching of the flow of pressure fluid until the limit switch 114 is actuated; and variable time delay means for determining the length of time for the outflow of the pressure fluid to said ram 4 to determine.