JPS59170322A - Weight controller for oil-pressure hammer - Google Patents

Abstract

PURPOSE:To strike a weight by an oil-pressure hammer with good efficiency by directly proportioning both the setting times of a stroke timer to set up the rising height of a weight and an interval timer to set up the time from the beginning of dropping the weight to the beginning of the next rising. CONSTITUTION:An oil-pressure hammer 2 is provided with an oil-pressure cylinder 4 for rising a weight 7, a direction switch valve 11 to supply pressure oil to the cylinder 4 and discharge the pressure oil from the cylinder 4, a solenoid 11a for switching the direction switch valve 11, and a timer T for setting up ON- OFF time of the solenoid 11a. The timer T consists of a stroke timer T2 to set up the rising height of the weight 7 and an interval timer T1 to set up the time from the beginning of dropping the weight 7 to the beginning of the next rising. Since the timers T2 and T1 are in directly proportional relation to each other with respect to setting times, the setting time of the timer T1 can be varied according to the stroke of the weight 7, and the striking of the weight 7 can be made with good efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention raises a weight by supplying pressure oil to a hydraulic cylinder for lifting a weight through a directional control valve, and when the directional control valve is switched ( The hydraulic hammer has a configuration in which the pile is driven by dropping a weight from two directions, and the on/off time of the solenoid for controlling the switching of the directional control valve is set by a timer. Regarding a control device.

Conventional weight control devices for hydraulic hammers of this type include a stroke timer that sets the rising height and stroke of the weight, as disclosed in Japanese Unexamined Patent Publication No. 56-34825. , Set the time from when the weight starts falling until the next start of ascent (this time varies depending on the rising height of the C double weight, since the falling time differs depending on the rising height of the weight). Two interval timers are installed separately, and the set time sounds of these two timers are manually adjusted separately.

However, in this conventional device (2), if the stroke is changed by changing the setting time of the stroke timer, the interval timer must also be adjusted accordingly in order to fully operate the weight without wasting time. Narai-
, adjustment operations are cumbersome. Also, if you temporarily set the no-stroke timer to a short time, that is, to a low stroke, and shorten the interval timer accordingly, then the next time you change to a high stroke, it will operate without adjusting the interval timer. If this happens, the solenoid is activated while the weight is falling, and a large force due to the falling weight acts on the weight lifting hydraulic cylinder, causing high pressure to occur in the hydraulic cylinder and potentially damaging various parts. Furthermore, in order to prevent the occurrence of such troubles, if the set time of the interval timer is set too long and the work is carried out, the work efficiency will decrease during low strokes.

SUMMARY OF THE INVENTION An object of the present invention is to provide a weight control device for a hydraulic hammer that eliminates the drawbacks of the prior art described above and allows pile driving work to be carried out efficiently and safely.

In order to achieve this object, the hydraulic weight control device of the present invention includes a stroke timer that sets the entire height of the weight to be lifted, and a time period from the start of the fall of the weight to the start of the next rise. The present invention is characterized in that it is equipped with an interval timer for setting the time, and these timers are configured so that the set time is adjusted in conjunction with the same tendency.

An embodiment fi' of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram showing an example of a hydraulic hammer to which the present invention is applied, in which 1 is a pile, 2 is a hydraulic hammer for driving the pile 1, and is attached to a leader (not shown) so as to be movable up and down. It will be installed. The hydraulic hammer 2 includes a cylindrical frame 3 and a cylindrical frame 3.
(A hydraulic cylinder 4 housed in the multi-frame 3 and a rod 6 connected to the piston 8 of the hydraulic cylinder 4.)
A cap 1 is connected to the lower end of the frame 3 and is housed in the frame 3 so as to be movable up and down;
6. Reference numeral 11 is a directional switching valve for supplying and discharging pressure oil to the hydraulic cylinder 4, and in this example, it is a pesoslenoid lla' (
The case of an electromagnetic valve having z is shown below. The directional valve 110 and the two secondary boats A+B each have a conduit 9.10.
'i through the lower chamber Y of the piston 8 of the hydraulic cylinder 4
1 is connected to the upper chamber X, and the next side is a hydraulic pump 13 (=the connected pump boat P and the tank port connected to the oil tank) T. 12° is an operating device for the directional control valve 11, which has a built-in timer T described later, and an output signal line 1.
Reference numeral 9 is connected to the solenoid lla, and reference numeral 017 is an accumulator connected to the upper chamber X of the hydraulic cylinder 4 through a conduit 18 in order to speed up the fall of the weight.

FIG. 2 shows the configuration of the operating device 12.
is the power supply, FU is the fuse, sw is the power switch f, Tij
: Tie, Ma, Tla, and T2b, which are composed of the interval timer T1 and the stroke timer T2, are respectively the a contact of the interval timer T1 and the b contact of the stroke timer T2, R1 is the auxiliary relay, Rlaz and Rlaz are the a contacts of the auxiliary relay R1, Rlb is a b contact. The interval timer T1 and stroke timer T2 each have a set time of
As shown in FIG.
When the setting time of stroke timer T1 is short as 21, the setting time of interval timer T1 is short as Tll, and on the other hand, when the setting time of stroke timer 2 is long as T22, the setting time of interval timer T1 is also short as T, 12. It is structured so that it is related to each other so that it becomes longer.

Next, the operation of the apparatus and circuit shown in FIGS. 1 and 2 will be explained. When the power switch SW of the operating device 12 is turned on, a closed circuit consisting of the power supply section [Co., Ltd.] Gen E1 fuse FU', the power switch SW), the contact R1b and the interval timer T1 is formed, and the ink-pulse timer T1 is started. If the set time of the interval timer T1 is T12 in FIG. 3, the interval timer T1 closes its contact Tla when the time T12 has elapsed since it was started, so that the power supply section and the contacts T2. b, the coil of relay R1, and contact Tla form a closed circuit, and the coil of relay R1 is energized twice to close contact R1a1.
2 closes and maintains itself, and the contact R1a□ closes (Secondly, the power supply section, the contact T2b, and the contact R1a□
A closed circuit consisting of the stroke timer T2 is formed, the stroke timer T2 is started, and the solenoid Ila of the directional control valve 11 is energized via the output signal line 19, and the directional control valve 11t- is activated. Against the force of D
The operation of the interval timer T1 is stopped by switching from the position to the position a (2) and the contact R1b is opened.The coil of the relay R1 is energized through the contact T2 b s, the coil of the relay R1, and the contact R1a2'i. Therefore, while the contact T2b of the stroke timer T2 is closed (that is, the third
The current supply to the coil is continued until the time T22 in the figure has elapsed. In this state, directional control valve 1
1 is switched to position C2, the pressure oil discharged from the hydraulic pump 13 in FIG. The pressure oil in the upper chamber X enters the accumulator 17 via the conduit 18, and the remaining oil returns to the oil tank 20 via the conduit 21. Due to this flow of pressure oil, the piston 8 is pushed up,
As a result, the weight 7 is pushed up via Shirondro f:. The height to which the weight 7 is pushed up, ie, the stroke, is proportional to the time during which the directional control valve 11 is switched to the a position, ie, the set time of the stroke timer T2. Curve a in FIG. 4 shows the relationship between elapsed time and stroke in this case.

When the set time T22 of the stroke timer T2 has elapsed,
Since contact T2b opens, the coil of relay R1 is no longer energized, contacts R1a□y and R1a2 open, stroke timer T2 stops operating, and solenoid 11.
The directional control valve 11 returns to the 5b position (2) due to the force of the spring D, and the interval timer T1 is started again by closing the contact R1b. By returning to position b, the pressure oil in the lower chamber Y of the hydraulic cylinder 4 enters the upper chamber , accumulator 1
The pressure oil stored in 7 is also transferred to the upper chamber X via conduit 1-8.
Then, the weight 7 falls. Then, the stake 1 is driven through the cap 16. That is, as shown in FIG. 4, the weight reaches the stroke s2 (highest position) when the set time T22 of the stroke timer T2 is reached, and then falls as shown by a□. When the interval timer Tl2O time has elapsed from the time when the weight started falling, the weight is lifted again. Naturally, this setting time T
12 is the sum of the time t required for the weight 7 to fall as shown by the curve a □ during the stroke s2, and the time t2 during which the weight remains stationary as shown in the straight line a 2 (T12
= t□ + t2), falling [2 The required time t□ is t1 = (2・S2/'g)'' However, g = acceleration of gravity, and the resting time t2 is a margin considering safety. Therefore, the set time of the interval timer T1 is the time determined by the stroke.On the other hand, the set time of the stroke timer T2 is T2 in FIG.
When C2 is short, such as 1, the set time of the interval timer T1 is also shortened by 12, such as Tll, and in this case, it becomes one cycle short, as shown by the curve in FIG. In other words, the set time Tl1(
<T12), the weight is pushed up again, resulting in a repeated operation with a short cycle time. in this way,
By changing the set time of the interval timer according to the stroke, the weight can be driven in efficiently.

In addition, since the interval timer setting time is set in advance with safety in mind, when the weight is falling, the directional switching valve 11
The weight is pushed up to position C: There is no danger of switching. In addition, as in this embodiment (as long as the dual power switch sw'1 is turned on, the vertical movement of the weight can be performed automatically), thereby eliminating the complexity of the operation. There is no wasted time and efficiency is improved.

Note that the timer T can be realized by a circuit that changes the set time by adjusting the time constant of an OR circuit, as shown in FIG. 5, for example. In the figure, 22 and 23 are the contact points T1a, respectively.
, T2b'tl-, 24 and 25 are switching transistors of each relay, variable resistor 26, fixed resistor 27 and variable capacitor 28 constitute a time constant circuit of interval timer T1, fixed resistor 29 and variable capacitor 30 constitutes a time constant circuit of the stroke timer T2, and the capacitors 28 and 30 are, for example, one knob (2), so that the capacitance can be changed in conjunction with each other. When the voltage of charging C2 exceeds the set voltage of these diodes, the base current flows through the transistor 24.25,
This turns on transistors 24 and 25. 33
．． 34 are transistors for discharging the charge of the capacitors 28 and 30, respectively. When an input voltage is applied to the base and a base current flows, the charge is discharged and the next charging operation (
- be prepared.

In this circuit (2), the capacitances of the variable capacitors 28 and 30 are increased and decreased in conjunction with each other, so that charging of these capacitors 28 and 300 is started, and the constant voltage diodes 31 and 30 are charged.
The time until the set voltage of 32 is exceeded, that is, the time from when the voltage is applied to each timer until the current flows to the relay coils 22 and 23, that is, the set time of each timer can be adjusted in conjunction with each other. Two resistors 26 are provided in order to adjust the set time of the interval timer TI within a narrow range.

Note that instead of using such an OR circuit, a microcomputer may be used to control the switching of the directional switching valve 11 through program control.
The setting time may also be set in stages. Further, the directional control valve 11 is not an electromagnetically operated valve as in the embodiment, but may be a hydraulically operated valve with a solenoid (electromagnetic valve) controlled by a timer T (2) in its pilot circuit.

As described above, according to the present invention, the set times of the stroke timer and interval timer are adjusted in tandem, so that the time from the start of the weight falling until it rises again is set to the optimal time corresponding to the stroke. It can be set automatically, improving work efficiency, and eliminating the need to adjust the setting time of the interval timer in response to stroke adjustment. In addition, it is possible to prevent failures caused by incorrect adjustment of the interval timer.
Improves safety.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an example of a hydraulic hammer to which the present invention is applied, Fig. 2 is a circuit diagram showing an embodiment of a control device using the present invention, and Fig. 3 is a diagram showing a stroke timer set in the present invention. A diagram showing an example of the relationship between each set time of the interval timer, FIG. 4 is a diagram showing the relationship between the set time and the weight stroke in the present invention, and FIG. 5 is a circuit showing a specific example of the timer in the present invention. It is a diagram. DESCRIPTION OF SYMBOLS 1... Pile, 2... Hydraulic hammer, 4... Hydraulic cylinder, 7... Weight, 11... Directional switching valve, 11a...
・Solenoid, 12... Operating device, T... Timer,
TI...Interval timer, T2...Stroke timer Patent applicant Hitachi Construction Machinery Co., Ltd.

Claims (1)

[Scope of Claims] 1. A hydraulic cylinder for raising a weight, and a pressure oil supply/discharge path to the hydraulic cylinder, and the hydraulic pressure is controlled by a switching operation.
% A directional control valve that supplies and discharges pressure oil to the IJ cylinder,
A hydraulic valve equipped with a solenoid that switches the directional control valve and a timer that sets the on/off time of the solenoid.
(ii) a stroke timer for setting the rising height of the weight as the timer; and an interval timer for setting the time from the start of falling of the weight to the start of the next rise; A weight control device for a hydraulic hammer, characterized in that the stroke timer and the interval timer are adjusted so that their set times tend to be the same (long and short). 2. The stroke timer and the interval timer Claims characterized in that the power supply section is provided with a power switch that is shared by these, and that the stroke timer and the interval timer are configured to repeat on/off operations as long as the power switch is on. A weight control device for a hydraulic hammer according to item 1.